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Fruit Notes 

Prepared by the Depeirtment of Plant & Soil Sciences. 

University of Massachusetts Cooperative Extension System. 

United States Department of Agriculture, and Massachusetts Counties Cooperating. 

Editors: Wesley R. Autio and William J. Bramlage 



ISSN 0427-6906 




Volume 58, Number 1 
WINTER ISSUE, 1993 

Table of Contents 

Peach Pests III: Diseases of Fruit and Foliage 

Peach Pests IV: Diseases of Peach Wood 

Apple Maggot Fly Behavior: Probability of Fly Capture 
on Red Sticky Spheres in Relation to Fly Age and Maturity 

Evaluation of Four Rootstocks and Two Mcintosh Strains 

Do Overwintering Red Mite Eggs Portend Summer Mite Troubles? 

Evaluation of Red Coloring Strains of Gala Apple 

Spiders in Second-level and First-level Apple IPM Blocks 

Apple Integrated Pest Management in 1992: 
Insects and Mites in Second-level Orchard Blocks 



Fruit Notes 



Publication Information: 

Fruit Notes (ISSN 0427-6906) is published the first day of January, April, 
July, and October by the Department of Plant & Soil Sciences, University 
of Massachusetts. 



The costs of subscriptions to Fruit Notes are $7.00 for United States 
addresses and $9.00 for foreign addresses. Each one-year subscription 
begins January 1 and ends December 3 1 . Some back issues are available 
for $2.00 (United States addresses) and $2.50 (foreign addresses). 
Payments must be in United States currency and should be made to the 
University of Massachusetts. 



Correspondence should be sent to: 

Fruit Notes 

Department of Plant & Soil Sciences 

205 Bowditch Hall 

University of Massachusetts 

Amherst, MA 01003 



COOPERATIVE EXTENSION SYSTEM POLICY: 

All chemical uses suggested in this publication are contiDgcnt upon continued registration. These chemicals should 
be used in accordance with federal and state laws and regulations. Growers are urged to be familiar with all current 
stale regulations. Where trade names are used for identification, no company endorsement or product discrimination 
is intended. The University of Massachusetts makes no warranty or guarantee of any kind, expressed or implied, 
conctTning the use of these products. USER ASSUMES ALL RISKS FOR PERSONAL INJURY OR PROPERTY 
DAMAGE. 



Issued by the University cf Massachusetts Cooperative Extension System, Robert G. Helgesen, Director, in 
furtherance cf the acts of May 8 and June 30, 1914. The University of Massachusetts Cooperative Extension System 
t^ers equal opportunity in programs and employment. 



Peach Pests III: Diseases of Fruit 
and Foliage 

Karen I. Hauschild 

University of Massachusetts Cooperative Extension System 



In "Peach Pests I" and "II," I discussed insect 
and mite pests of peach finiit, foUage, and wood. 
In this article I will focus on the diseases of peach 
fiiiit and foUage. 

There are several frequently observed dis- 
ease problems of peach fruit in Massachusetts. 
The most common of these is brown rot; how- 
ever, peach scab and bacterial spot also can be 
troublesome. X-disease and peach leaf curl are 
the most frequently encountered foliar disease 
problems. 

Below is a brief description of each of these 
problems and basic information on non-chemi- 
cal control measures. 

Brown Rot 

Brown rot of peaches is caused primarily by 
Monilia fructicola (Wint. ) [There is another spe- 
cies oiMonilia, M. laxa (Aderh. & Rhul.) which 
normally is associated with almond, apricot, or 
tart cherry.] M. fructicola is a fungus that over- 
winters in mummified fruit, or in infected flow- 
ers or twigs. As frviit buds open in the spring, 
smaU apothecia (cup-shaped mushroom-like 
fruiting bodies) develop from mummied fruit. 
Development is favored by adequate moistin*e 
and temperatures between 63 and 68°F. Within 
each apothecium, asci bearing 8 ascospores each 
are produced. When moisture hits these asci, the 
ascospores are ejected and carried by wind to 
peach blossoms where they cause infections. 
The most susceptible flower part is the pistil. 

Brown rot infections also can occur when 
conidia arise either from cankers on the tree or 
from the surface of fruit mummies. Spores from 
these conidia are carried by wind or rain to 
susceptible peach flowers. (For conidia to form, 
relative humidity must be 85% or higher.) In- 
fected blossoms brown and wither but remain 



attached to twigs. 

During summer months, brown rot activity 
decreases, but increases again as fruit begins to 
mature. Conidia produced on infected blossoms 
or on green fruit usually are the source of infec- 
tion for fruit at harvest. Fruit infection can occvir 
directly through the fruit cuticle, through natu- 
ral openings on the fruit, or, most readily, 
through wounds. Warm, wet weather favors 
brown rot infections. Under optimum conditions 
for the fungus, mature fruit can decay in a 
matter of hours. Initial infections on fruit ap- 
pear as brown, dry blotches that spread rapidly 
over the finiit. Spores are produced 6x)m these 
blotches, resulting in grey fiizz. Handling in- 
fected fruit also can spread the disease to 
uninfected fruits. 

Removing infected and mummified firuits 
can reduce disease inoculum levels. Mowing in 
late fall also helps reduce inoculum. Removal of 
twigs infected with blossom blight helps control 
future brown rot infections. Fungicides apphed 
at bloom and before moistiire forms on the 
surface of maturing fruits help prevent brown 
rot infections. 

Peach Scab 

Peach scab is an occasional problem locally, 
but is more prevalent in warmer peach growing 
areas than here. Peach scab is caused by a 
fungus, Cladosporium carpophilum, that over- 
winters on twig lesions. Conidia are produced 
from these lesions in the spring and they infect 
peach fi-uit a few weeks after petal fall. Forty to 
70 days after an infection has occurred small, 
greenish circular spots appear on fruit surfaces, 
especially near the stem end. As lesions age, 
they become velvety (like apple scab) and black. 
If infections are severe, the lesions coalesce. 



Fruit Notes, Winter, 1993 



resulting in abnormal finiit growth and fixiit 
cracking. 

Pruning to facilitate good air circulation 
within trees helps to control peach scab. Fungi- 
cides applied to control brown rot usually also 
are efifective against peach scab. Peach scab 
generally is more prevalent when warm, wet 
weather occurs just after shuck split. 

Bacterial Spot 

Bacterial spot, caused by the bacterium 
Xanthomonas pruni, can infect leaves, shoots, 
and fruit of peaches, apricots, and nectarines. In 
the spring, bacteria oozing out of overwintering 
cankers are carried by water droplets to young 
fruit leaves or shoots. Moisture in fog or dew is 
sufficient to spread the bacteria. Heavy rain 
spreads the disease even further. Frequent 
rains accompanied by moderate temperatures 
and high winds also encourage infections, espe- 
cially during the months of June and July. 

Leaf lesions are small and angular, appear- 
ing first as water-soaked spots and then turning 
brown to black. Centers of these spots often fall 
out, leaving reddish colored margins. Lesions 
generally are more severe at the tips of leaves. 
Leaves that are severely infected turn yellow 
and drop. Early season infections on fruit de- 
velop into cracks. Lesions are not confined to the 
friait surface, but rather go deep into the frijit 
flesh. 

Non-chemical controls for bacterial spot in- 
clude the use of resistant cultivars such as 
Redhaven, Loring, Sunhaven, Jefferson, and 
Madison. Excessive use of nitrogen may aggra- 
vate bacterial spot problems. 



to leaf tissue and infection then can occur. Leaf 
curl is most severe during cool, wet weather, 
particularly at temperatures between 50 and 
70°F. Peach trees are susceptible only during 
the short period of bud swell to bud opening. 
Symptoms appear about two weeks after leaf 
emergence. Small, reddish areas develop on 
small leaves. As the disease infection 
progresses, the leaf wrinkles and puckers in 
small areas or along the entire leaf. The m^'or- 
ity of infected leaves drop. The fungus produces 
ascospores which spend the summer on the 
peach tree, but then produce overwintering bud 
conidia. 

Where leaf curl is severe, maintain tree vigor 
by: 1) thinning fruit, 2) irrigating during periods 
of drought, and 3) fertilizing by mid-June. A 
dormant spray of a copper-containing fungicide 
after leaf drop or before bud swell usually will 
control leaf curl. 

A recent study conducted by L. Burkham 
("Alternatives for ControlHng Peach Leaf Curl" 
appearing in Common Sense Pest Control Quar- 
terly) found that organic growers in California 
were able to control peach leaf curl by sprajdng 
a seaweed fertiUzer once a month. Speculation 
is that susceptibility to leaf curl may be related 
to magnesium deficiency. Seaweed contains a 
high level of this element. 

Also, numerous nectarine and peach culti- 
vars have been evaluated for susceptibility to 
leaf cin-1. (Scorza, R. 1992. Evaluation of foreign 
peach and nectarine introductions. Fruit Variet- 
ies Journal 46: 141-144). All of the North Ameri- 
can cultivars mentioned in this study (Harbelle, 
Elberta, Redhaven, ReUance, Loring, and Sun- 
Ught) showed varying degrees of susceptibility. 



Peach Leaf Curl 

Peach leaf curl is caused by the fungus 
Taphrina deformans. Spores of the leaf curl 
fungus are very resistant to adverse weather 
and can remain dormant on twig surfaces for 
two years or longer. Overwintering spores are 
washed to the surfaces of leaf buds by spring 
rains. These spores then multiply during wet 
weather until leaf bud scales open. Once bud 
scales become loose, spores are carried by water 



X-disease 

X-disease is caused by a virus-like organism 
known as a mycoplasma. Leafhoppers carry the 
disease from infected chokecherries or peaches 
to other peach, nectarine, or cherry trees. Once 
in the trees, mycoplasmas live in phloem cells, a 
type of vascular conducting cell. 

Symptoms of x-disease are leaf yellowing or 
reddening with shot-holing appearing during 
July and August. Affected leaves drop, leaving 



Fruit Notes, Winter, 1993 



"tufts" of green leaves at ends of twigs. As the 
disease progresses through the tree, Umbs die 
back and each year more of the tree becomes 
infected. Fruit on infected trees at first appear 
normal, but they most often drop prematurely. 

Young trees infected with x-disease should 
be removed and destroyed. In older trees, re- 
moving infected Umbs may slow the spread of 
the mycoplasmas; but once x-disease has 
started, it is difficult to control. Antibiotic 
therapy may help also. 

Removing chokecherries near peach or- 
chards is essential. 



For additional information on any of these 
pests, please refer to: 

Jones, A.L. 1976. Diseases of Tree Fruits. (Cooperative 
Extension Services of the Northeast States. NE 96. 

LaRue, J.H. and RS. Johnson (eds.). 1989. Peaches, 
Plums, and Nectarines: Growing and Handling for 
Fresh Market. Cooperative Extension, University of 
California. No. 331. 

Prokopy, R.J., P.J. Powers, D.R. Cooley, and J.W. 
Gamble. 1991. Peaches, Pears, Plums - Pest Control 
Guide for Commercial Growers in Southern New En- 
gland. University of Massachusetts Cooperative Ex- 
tension System Circular C-159 R 1991-2. 



^% •10 •i^ ^L0 ^|V 

#J% rfi rf» •Y* •?• 

Peach Pests IV: Diseases of 
Peach Wood 



Karen I. Hauschild 

University of Massachusetts Cooperative Extension System 



This is the last in a series of four articles 
describing major insect and disease pests of 
peaches in Massachusetts. In this article I wiU 
describe diseases that attack peach wood, pri- 
marily canker diseases. 

In general canker diseases occur where 
peach trees are stressed due to drought, poor 
growing conditions, cold temperature, or poor 
pruning. Healthy, vigorous trees are less sus- 
ceptible to attack by canker diseases. Several 
disease organisms cause canker formation on 
peaches. Following are brief descriptions of the 
major causal agents of perennial cankers found 
on peaches and nectarines in Massachusetts 
orchards. 

Cytospora (Valsa) Canker 

Two species oiCytospora are associated with 
peach canker - C. leucostomia Saac. and C. 



cincta Saac. Cytospora overwinter in cankers or 
on dead peach wood. Bumps containing pyc- 
nidia with small conidia are produced under 
bark. These pycnidia grow through the bark and 
expose spores to rain. Splashing rain or rain 
driven by heavy winds spread conidia to other 
infection sites on damaged or injured bark. 
Canker growth is related to temperature and 
growth habit of the peach tree itself C. cincta is 
most active during spring and fall at tempera- 
tures between 60 and 75°F. C. leucostomia is 
more active at temperatures between 86 and 
91°F, that is, during the summer months. Can- 
ker development can occur in one of three ways. 
First, cankers may extend down limbs toward 
tree trunks, with Umb death occiirring at the 
rate of one or two Umbs per year over a period of 
several years until the entire tree eventually is 
killed. This pattern is the classic "perennial 



Fruit Notes, Winter, 1993 



canker syndrome." Second, cankers may de- 
velop in twigs, small branches, or around prun- 
ing cuts but remain localized. This type of 
canker generally results in only minor damage 
to the tree. Third, trees may leaf out normally, 
followed by sudden wilting and total tree death. 
In cases like this the tree usually is severely 
damaged by cold temperatures and the trunk 
and lower scaffold Umbs quickly are colonized by 
Cytospora. Again, tree health and environmen- 
tal factors play a major role in the severity of 
Cytospora. 

Since both species of Cytospora reqmre a 
wound or natural opening to infect peach trees, 
proper priming and pest management practices 
help prevent serious infections. Pruning in fall 
or early winter can contribute to Cytospora 
infections because pruning cuts made at these 
times do not heal as quickly as those made in the 
spring. 

For injured or weak trees, there are no 
chemical control measures for Cytospora that 
have proven completely successful, partly be- 
cause spores can be released throughout the 
year. If only a few cankers are present, remov- 
ing and destroying infected branches below any 
sign of disease can be helpful. Do not plant new 
pe ach orchards on poor si tes . Do not prune in the 
fall or early winter. Additional measures that 
will help prevent Cytospora canker infections 
include the following: 

1. fertiUze trees early in the spring to avoid late 
growth spurts; 

2. avoid mechanical injury to trees; 

3. apply a fungicide spray after pruning, but 
before a rain; 

4. avoid weak crotch angles; and 

5. whitewash southwest sides of trees and 
lower limbs (this practice can help prevent 
injury due to cold temperatures). 

Brown Rot 

As mentioned in "Peach Pest III," brown rot, 
Monilia fructicola, can infect twigs. When the 
fungus moves into woody tissues it causes the 
development of small CEinkers. Cankers, as they 
grow, can girdle twigs eventually, resulting in 
withering and death of terminal growth. Gum- 



mosis often accompanies spur blight and canker 
formation. 

Cankers caused by brown rot may develop as 
a result of blossom blight or may move down 
from the finiit pedicel into a twig or larger 
branch. On twigs or small branches, brown rot 
cankers normally are eUiptical, well-defined, 
and brown. During wet weather, gummosis 
appears, followed or accompanied by tufts of 
grey spores. Cankers on larger branches caused 
by rotted fruit appear (similar to those described 
above, but likely to be much more severe and 
eventually kill the infected branch). In the year 
following severe canker development, leaves 
above the girdling cankers first appear normal 
then later turn yellow, wilt, and eventually die. 

Phytophthora Root and Crown Rot 

Crown rot does not appear to be a serious 
problem in Massachusetts peach orchards, but a 
brief description is given below. 

Waterlogged soil, air temperature, plant 
nutrient status, species of Phytophthora in- 
volved, and susceptibility of host tissue all play 
roles in the occurrence and severity of 
Phytophthora infections. Most infections occur 
during the spring, summer and fall months and 
are spread by infected plants, soil, or water. 
Infections that occur in crowns or larger roots 
(especially of yoimg trees) spread rapidly, oft^n 
killing trees in one or two seasons. Infected trees 
may appear healthy in the fall, leaf out normally 
in the spring, but then collapse when warmer 
temperatures occur. Symptoms of infection 
vary fi-om withered, bright rust-colored leaves 
on severely infected trees to decreased overall 
growth and smaller, yellow leaves on trees that 
show slower decline. Infected roots or crowns 
show reddish-brown necrosis of bark and outer 
wood with a distinct, layered margin; however, 
after some time roots decay and turn grey-black. 

Avoiding waterlogged soils, proper schedul- 
ing of irrigation, and proper planting practices 
help prevent Phytophthora infections from oc- 
curring and becoming severe. 

Bacterial Canker 

Bacterial canker, caused by either Pseudo- 



Fruit Notes, Winter, 1993 



monas syrincae or P. morsprunorium, is thought 
to be an increasing problem in Massachusetts 
peach orchards. Damage by Pseudomonas var- 
ies among types of host fruit. On peaches, leaf 
and flower buds fail to open in the spring and are 
thought to have been infected during winter 
months. Or, in other instances, infected spurs 
show normal growth in the spring but collapse 
during sunmier months, turning into wilted 
leaves and dried-up fruit. If infection occurs 
annually, trees lose bearing surface. 

Bacteria overwinter in infected buds or can- 



kers. Spring rains wash bacteria to unfolding 
plant tissue. Frost-injvired leaves and blossoms 
are thought to be more susceptible to Pseudo- 
monas infection. Periods of cool, rainy weather 
foster early-season infections and disease 
spread. Disease spread also occurs under simi- 
lar weather conditions in the fall. 

Canker removal is the only known cultural 
control practice 

For additional information on any of these 
diseases, please refer to references listed in 
"Peach Pests III." 



%% ^% %% %% %% 

rj% •^ rj% rj* rj% 



Apple Maggot Fly Behavior: 
Probability of Fly Capture on 
Red Sticky Spheres in Relation to 
Fly Age and Fruit Maturity 

Max P. Prokopy, Jian Jun Duan, Gabriela G. Galarza, and Ronald J. 

Prokopy 

Department of Entomology^ University of Massachusetts 



To augment our current program of second- 
level apple IPM involving the use of baited 
sticky red spheres to intercept and capture apple 
maggot flies (AMF), we have been tracking 
foraging behavior patterns of female AMF. We 
want to know if the probability of a fly being 
captured on a sphere or of laying eggs in apples 
changes as flies age or apples mature. 

Methods Used 

In 1991, two potted apple trees were placed 
in screen cages on the campus of the University 
of Massachusetts. Each tree had approximately 
the same canopy size as a normal four-year-old 
dwarf (M.9) fruit-bearing tree. We placed either 



50 green or 50 red evenly-spaced Gravenstein 
apples on a tree. The leaf-to-fruit ratio was 
about 20: 1 . The green fruit were picked on June 
19 and had a diameter of about 3 cm. The red 
fruit were picked on August 1 and had a diam- 
eterofabout4.5cm. In all, 36 AMF of each of five 
ages were tested in the presence of only green 
finiit, and 30 of each of five ages in the presence 
of only red fruit. The flies were collected fix)m 
naturally infested fruit and were 3, 7, 11, 15, or 
19 days old when tested. FUes seven days old or 
younger usually are not capable of lajdng eggs in 
fruit. 

A single fly was released onto a leaf at the 
lower center of the tree. A sticky red sphere, 
baited with one vial of the synthetic apple odor 



Fruit Notes, Winter, 1993 



Table 1. Behavior of apple maggot females of different ages when 
released individually on a caged apple tree containing a sticky red 
sphere baited with butyl hexanoate and 50 green or 50 red 
Gravenstein apples.* 









Flies that 




Flies 


Number of 


laid one 


Fruit that 


captured 


fVuit visited 


or more 


eggs 


received an 


(%) 


Â¥* 


per fly*** 


(%)*** 


egg(%) 


Fly 












age 












(days) Green 


Red 


Green Red 


Green 


Red 


Green Red 


3 25 b 


27 b 


1.9 a 2.8 b 


b 


b 


Ob Ob 


7 68 a 


47 a 


2.7 a 3.9 a 


6 b 


b 


2 b lb 


11 61 a 


57 a 


1.8 a 3.8 a 


22 a 


10 a 


12 a 6 b 


15 71 a 


57 a 


1.7 a 4.3 a 


26 a 


13 a 


10 a 5 b 


19 64 a 


57 a 


1.6 a 2.7 b 


19 a 


30 a 


8 a 19 a 



** 



Values in each column not followed by the same letter are 
significantly different at an odds ratio of 19:1. 
Represents flies captured on a sphere before leaving tree or 
before one hour had elapsed. 
*** Visits and egg laying before being captured on a sphere, before 
leaving the tree, or before one hour had elapsed. 



butyl hexanoate, was placed in the upper part of 
the tree canopy. After the fly was released, its 
movement was tracked during one hour of forag- 
ing within the tree. Tracking involved recording 
all leaves and fruit visited, all oviposition at- 
tempts and ovi}X)sitions, and whether or not the 
fly was captured on the sticky sphere. Any finiit 
iQ which the fly made an oviposition, or an 
attempt at it, was removed from the tree and 
dissected to see if eggs had been laid. 

Results 

Fly captures when either green or red fruit 
were on the tree increased significantly when 
the flies were more than three days old (Table 1 ). 
For flies seven or more days old, consistently 
more were captured when fruit were green than 
when they were red. Sixty-six percent of flies 
seven or more days old were captured when fruit 
were green; whereas, 55 percent were captured 



when finiit were red. 

Regardless of fly age, red fruit received more 
visits than green fruit (Table 1). Flies 1 1 or more 
days old were more hkely to oviposit in a frtiit 
than were younger ones. Interestingly, except 
for the oldest flies tested, a greater percentage of 
green fruit than red fruit received eggs. 

Conclusions 

Our results demonstrate that the age or 
maturity of a female AMF can strongly affect its 
fruit foraging and egg laying behavior and the 
probabihty of capture on a baited sticky red 
sphere. Once a female reached seven days of 
age, the chance that it would be captured on a 
sticky red sphere baited with butyl hexanoate 
hung in our test trees was 50% or better. As fly 
age increased above seven days, the probability 
of capture on a sphere did not increase, but the 
probabihty that it would lay eggs before being 



Fruit Notes, Winter, 1993 



captured on a sphere did increase. This result 
indicates that for greatest effectiveness in con- 
troUing AMF, baited sticky red spheres should 
be hung very early in the fly season, before 
immigrating AMF have reached maturity. In 
addition, our findings suggest that while green 
apples may receive fewer visits by AMF than red 
apples, green apples may be more susceptible to 
oviposition by arriving AMF. This result again 
affirms the need to hang baited sticky red 



spheres early in the fly season for greatest 
effectiveness in avoiding finiit injury by immi- 
grating AMF. 

Acknowledgements 

This work was supported by the Science and 
Education Administration of the U.S.D.A, im- 
der grant 8900901 from the Cooperative Re- 
search Grants OfBce and by a USDA grant 
under the NE-156 Apple IPM project. 



^% %% %% ^10 «^ 

rf* •^ rf% #J% rj% 



Evaluation of Four Rootstocks and 
Two Mcintosh Strains 



Wesley R. Autio and Franklin W. Southwick 

Department of Plant & Soil Sciences, University of Massachusetts 



Through the 1960's and 1970's, the trend 
in the New England apple industry was from 
seedling-rooted trees to trees on M.7 or similar 
sized rootstocks. In the latter part of the 1980's, 
the trend shifted toward smaller trees. In the 
1990's, growers are planting significant num- 
bers of dwarf trees, mostly on M.9 and Mark 
rootstocks. In 1979, a planting was established 
at the University of Massachusetts Horticul- 
tural Research Center to assess rootstocks in 
the size range from M.7 to M.9. 

The planting included Rogers Red Mcin- 
tosh and Macspur Mcintosh on M.7A, M.26, M.9 
(trained either to a post or on a 4- wire vertical 
trelhs, seven-feet tall), andM.9/MM. 111. Seven 
replications were planted, and each replication 
had four trees of each cultivar/rootstock combi- 
nation. Two trees of each group were used for 
data collection, and any Macspur that reverted 
to a nonspur habit was eliminated from the 
experiment. Normal fertilization and pest man- 



agement practices were used. All trees were 
maintained as central leaders. With the excep- 
tion of tjdng branches to the wires in the trellis 
treatment, very Uttle limb positioning was per- 
formed in the planting. 

After 10 growing seasons, trees on M.7A 
were the tallest, regardless of Mcintosh strain 
(Table 1). Trees on M.26 and M.9/MM.1 1 1 were 
similar in size and intermediate. Trees on M.9 
were the shortest. Rogers trees were signifi- 
cantly taUer than Macspur trees. Tree spread 
followed a similar trend (Table 1); however, 
trees on M.9 trained to a trellis had a greater 
tree spread after 10 seasons than those trained 
to a post. Clearly, this difference related to the 
support provided to lateral branches by the 
trelhs wires. 

Tree spread was used to calculate poten- 
tial tree density (Table 1). It was assumed that 
trees could be planted 1 percent closer than the 
spread measured after 10 seasons. Seven feet 



Fruit Notes, Winter, 1993 



Table 1. Tree size after 10 growing seasons and projected tree densities of Rogers Red 
Mcintosh and Macspur Mcintosh on different rootstocks. 





Tree height 


Tree spread 


Tree density 






(fl) 




(ft) 


(trees/acre)* 


Treatment 


Rogers 


Macspur 


Rogers 


Macspur 


Rogers 


Macspur 


M.7A 


14.8 


a* 14.9 


15.8 


a 14.5 


145 


c 172 


M.26 


12.0 


b 9.9 


13.2 


be 11.5 


202 


b 254 


M.9 (post) 


8.8 


c 8.4 


10.2 


d 9.3 


297 


a 363 


M.9 (trellis) 


9.3 


c 9.0 


12.9 


c 10.6 


295 


a 363 


M.9/MM.111 


11.5 


b 10.0 


14.3 


b 12.0 


172 


b 239 


Average 


11.3 


••• 10.4 


13.3 


- 11.5 


222 


- 278 



Distance between trees within rows was projected to be 10% less than the natural tree 

spread, allowing for overlap of trees. The distance between rows was the distance 

between trees plus seven feet, with the exception of the trelhs, which was assumed to be 

spaced 13 feet between rows. 

For the three characteristics in this table, the relative differences between rootstock 

treatments were statistically similar for each strain. The letter presented between the 

Rogers and Macspur columns represents the differences among rootstock treatments only. 

For a particular characteristic, if not represented by the same letter, rootstock treatments 

are significantly different at odds of 19:1. 

Rogers and Macspur averages are different at odds of 999:1. 



were added to the distance between trees in a 
row to determine between-row spacing, with the 
exception of the trellis. Because of the shape of 
the trelUs, it was assixmed that all trellis combi- 
nations could be maintained at 13 feet. (This 
assumption is conservative, and it depends on 
the final width of the trellis rows.) Potential tree 
density ranged from over 360 trees per acre of 
Macspur/M.9 to 145 trees per acre for Rogers/ 
M.7A, Because of the difference in spread, 
Macspur could be planted at approximately a 20 
percent higher density than Rogers, assuming 
no reversion. 

Figures 1 and 2 show the cumulative 
yield per tree for the rootstock treatments and 



the Mcintosh strains, respectively. (jeneraUy, 
larger trees )delded more per tree than smaller 
trees, that is, trees on M.7A yielded more than 
those on M.26, which yielded more than those on 
M.9. The exception is M.9/MM. 111. Trees on 
M.9/MM.111 yielded significantly less than the 
trees on M.26, which were of similar size. Trees 
on M.9 trained to a treUis yielded more than 
those trained to a post. This result may have 
occurred because the trellis maintains wood at 
a more desirable angle for continued Smiting 
and allows for upper branches to fill a larger 
portion of the canopy than when no additional 
support is provided. Additionally, the larger 
Rogers trees yielded more than the Macspur 



8 



Fruit Notes, Winter, 1993 



20 














Rootstocks: 


a 




_ 


-»-M.7A 




> 


^15 


-°-M.26 






o> 


-^ M.9 (post) 


/ b 


1 


i» 


^ M.9 (trellis) 






Q. 

|io 

>> 


-•-M.9/MM.111 




1 




y Ztf:=C^ 


Cumulative 


...>^^' 




1982 1983 1984 1985 1986 1987 1988 


Figiire 1. Cumulative yield per tree through the tenth 


growing season for each rootstock treatment (average of the 


two Mcintosh strains). 



20 



— 15 



o> 

Q. 

•55 10 



> 
E 

3 

o 



Strains: 
^*" Rogers 
^ Macspur 






/L^^^^'o 



1982 1983 



1984 1985 



1986 



1987 



1988 



Figure 2. Cumulative jdeld per tree through the tenth 
growing season for each Mcintosh strain (average of the five 
rootstock treatments). 



Truit Notes, Winter, 1993 



4 












o 

o 
o 


Rootstocks: 
-•-M.7A 


a. 


k 


33 


-^M.26 

-^ M.9 (post) 


0C ^ 


r 

1 

• 


2 



^M.9 (trellis) 


/ X^y^° 




1.2 


♦M.9/MM.111 


y ///^ ^ 


> 


« 

>> 


y1^^^^:^y^ 




? 

3 

E 

3 

u 


.^^'^ 




1982 1983 1984 1985 1986 1987 1988 


Figure 3. Cumulative yield per acre through the tenth 


growing season for each roots tock treatment (average of the 


two Mcintosh strains). 



4 














Strains: 











^ Rogers 






^3 


"H- Macspur 


a 


1 




y^ ^ 


£ 

u 


y^^^b 






// 




•0 
» 

>> 


^^^:^ 





> 

3 
E 
3 


1 


^^---^ 




1982 1983 1984 1985 1986 1987 1988 


Figure 4. Cumulative yield per acre through the tenth 


growing season for each Mcintosh strain (average of the five 


rootstock treatments). 



10 



Fruit Notes, Winter, 1993 



Table 2. Economic comparison of the five rootstock treatments (average of both strains of 
Mcintosh). Establishment costs were modified fi-om those presented in Fruit Notes 55(4): 1-5. 
Growing and harvesting costs were modified from those presented in Fruit Notes 53(l):4-7. 


Item 


M.7A 


M.26 


M.9 
(post) 


M.9 
(treUis) 


M.9/ 
MM.lll 


Costs: 

Establishment 

Growing 

Harvesting 


$920 
$6,660 
$4,780 


$2,030 
$6,540 
$5,040 


$2,980 
$7,010 
$5,170 


$3,900 
$7,190 
$6,170 


$1,730 
$6,540 
$3,730 


Total yield (bu)* 


2780 b 


2930 b 


3010 b 


3590 a 


2170 c 


U.S. Extra Fancy, 
1987 + 1988 (%)• 


37 d 


62 be 


64 b 


51 c 


80 a 


Fruit count per 
42 lbs, 1988* 


140 a 


125 b 


120 c 


119 c 


144 a 


Estimated crop 
value 


$25,890 


$36,210 


$39,310 


$42,650 


$25,370 


Net returns 


$13,530 


$22,610 


$24,150 


$25,390 


$13,370 


Within a row, means 
19:1. 


not followed by the same 


letter are significantly different at odds of 



trees. 

Obviously, the amount of fi*\iit obtained 
fix)m individual trees is of little importance 
when the trees are at different densities. Fig- 
ures 3 and 4 show the cumulative yield per acre 
for the rootstock treatments and the Mcintosh 
strains, respectively. M.9 trained to a trelHs 
resulted in the highest jdelds per acre. M.9 
trained to a post, M.26, and M.7 were statisti- 
cally similar in cumulative yield, and M.9/ 
MM.lll resulted in the poorest yield per acre, 
yielding only 60 percent of trees on M.9 trained 
to a trelUs. Macspur trees outyielded Rogers 
trees on a per-acre basis. 

Factors other than yield must be consid- 
ered before selecting the most desirable root- 



stock or training system. Establishment, grow- 
ing, and harvesting costs vary fi-om treatment to 
treatment. Estimates of these differences are 
presented in Table 2. Also, packout is an impor- 
tant consideration. Table 2 presents the percent 
of a whole-canopy random sample which made 
the U.S. Extra Fancy grade in 1987 and 1988. 
Trees on M.9/MM.111 produced the most high 
grade fruit; whereas, trees on M.7A produced 
the least. Of the M.9-rooted trees, those on posts 
produced more U.S. Extra Fancy finiit than 
those on trellises. These numbers were used to 
approximate the grade distribution of fi-uit. It 
was assimaed that one half of the fi-uit not 
making U.S. Extra Fancy were Number 1 and 
the other half were used for cider. These esti- 



Fruit Notes, Winter, 1993 



11 



$30 












o" 


Rootstocks: 






1 $25 


-fr^M.TA 


A 


f 


x^ 

2^ $20 
u 

10 


-0-M.26 

-^ M.9 (post) 


0/ 


] 


|$15 

M 


-A-M.9 (trellis) 
♦ M.9/MM.111 


1/ y 


> 


1 $10 




yi'/ -^ 






^Z 


c 


ji^ 




Cumulative 

U1 o 


y^^^6^ 






^^ 




-$10 
19 






79 1980 1982 1982 1983 1984 1985 1986 1987 1988 


Figure 5. Cumulative net returns per acre for the ten years 


1979 through 1988. 



mates are conservative, since the sample for 
grading was random. Multiple pickings would 
have resulted in greater percents in the highest 
grade. Additionally, no summer pruning was 
performed in our trellis treatment, and fruit 
quahty clearly would have benefitted greatly 
fi*om summer pruning. 

Fruit size also varied significantly 
among the treatments (Table 2). The average 
fruit from trees on M.7 or M.9/MM.111 were 
140-count or smaller. Fruit from trees on M.9 
averaged nearly 120-count in size, and those 
from trees on M.26 were somewhat smaller than 
120-count. 

When size and grade are considered, 
along with yield, crop value can be estimated 
(Table 2). Accomiting for crop value and costs, 
Table 2 presents the net returns possible from 
these treatments. The two M.9 and the M.26 
treatments produced similar returns, with the 



M.9 trellis treatment giving approximately five 
percent more, and the M.26 treatment giving 
approximately six percent less than the M.9 
post. The M.7A treatment netted only 53 per- 
cent of what the M. 9 trellis netted. M. 9/MM. Ill 
was slightly less profitable than M.7A. 

When evaluating different rootstocks 
and training systems, it is necessary to assess 
many different characteristics. Costs of estab- 
hshment, training characteristics, jrield poten- 
tial, fruit grade, fruit size, and costs of manage- 
ment must all be considered before selecting an 
appropriate combination. The best system is 
the one that can be managed within the con- 
straints of a particular grower and that provides 
the best net returns to the orchard. In this 
study, trees on M.9 and on M.26 were the most 
profitable over the first ten years, and clearly 
would be better choices than trees on either 
M.7AorM.9/MM.lll. 



^f^ %f^ %{« «£# %t« 
0^ rj% rj% •Y* •Y* 



12 



Fruit Notes, Winter, 1993 



Do Overwintering Red Mite Eggs 
Portend Summer Mite Troubles? 



Jennifer Mason, Margaret Christie, and Ronald Prokopy 
Department of Entomology^ University of Massachusetts 



Among foliar pests, European red mites 
(ERM) remain a major problem for apple trees. 
They can be particvdarly difGcvdt in second- level 
IPM blocks, where growers are dependent on 
predator mites to control summer ERM popula- 
tions. In these blocks, current non-biological 
control measures consist of one or two dormant 
oil sprays in the spring prior to egg hatch. To 
maintain control of ERM, predators build up to 
levels capable of controlling the mites that 
hatch. Unfortunately, it is difiicult to balance 
spring oil control of ERM and encouragement of 
a healthy population of predator mites. This 
leads to the question: Can prebloom oil alone 
effectively control summer ERM populations? 

During January of 1992, we collected 200 
buds per orchard from 11 orchards that partici- 
pate in the second-level IPM project. Six of these 
were full second-level IPM blocks, and five were 
transitional second-level blocks. The percentage 
of buds with ERM eggs present was recorded for 
each block, and orchards were placed into three 
categories: low (0-33%), medium (34-66%), and 
high (67-100% of buds with mite eggs). 

During late spring and summer months, 
mite populations in each block were recorded as 
part of normal IPM scouting procedures. ERM 
presence or absence was counted on 200 fruit 
cluster leaves beginning in May and continuing 
through September. Examination of peak ERM 
populations in the second-level IPM blocks in 
May showed little or no apparent relationship 
between winter ERM egg percentages and 
spring mite numbers. Peak ERM populations in 
June, however, were related to winter egg per- 
centages (Table 1). The low and medium ERM 
egg groups both had very low June ERM popula- 



tions, but all orchards in the high ERM egg 
group had substantial numbers of Jxine mites. 
In first-level blocks there appeared to be no 
consistent relationship between overwintering 
egg numbers and June mites, which were low in 
all of these orchard blocks (Table 1). 

Of the second-level blocks, all received at 
least one dormant oil spray prior to egg hatch in 
the spring (Table 1). In the high group, two 
blocks had received two sprays. In the low and 
medium orchards, it appears that dormant oil 
sprays were sufficient to control mite popula- 
tions through June. In the orchards in the high 
group, however, even those receiving two appli- 
cations had thriving ERM populations by the 
endof Jvme. 

Further work needs to be done on the rela- 
tionship between dormant oil sprays, overwin- 
tering ERM eggs and resulting early summer 
ERM populations before any firm conclusions 
can be drawn. If these results are estabhshed as 
fact, then oil spray recommendations may need 
to be revised for blocks where high numbers of 
overwintering ERM eggs are foxuid in winter 
coimts. Without a strong predator population, 
these orchards may be subjected to large sum- 
mer ERM populations if they depend on normal 
amoimts of prebloom oil to be effective. Higher 
rates of oil (e.g., three gallons of oil per 100 
gallons of water) at green tip or half -inch green 
may be necessary, with a second oil treatment at 
a lower rate at tight cluster. It is p>ossible, 
however, that the higher mite numbers in the 
high blocks may be "attractive" to predator 
populations, and that these orchards may even- 
tually become areas of good biological control. 



Fruit Notes, Winter, 1993 



13 



Table 1. 


Overwintering egg 


and peak mite levels in eleven second-level and 


eleven first-level IPM blocks. 












Number of 








Number of 


dosage 


Twigs with 


Leaves with 




prebloom oil 


equivalents 


overwintering 


ERMin 


Orchard 


sprays 


of oil 


eggs (%) 


June (peak %) 


Second-level IPM blocks 








A 


3 


1.8 


4.5 


2.5 


B 


2 


0.9 


8.5 


0.0 


C 


1 


1.0 


16.0 


0.5 


D 


2 


1.5 


35.0 


0.0 


E 


2 




44.5 


0.0 


F 


2 


1.3 


56.0 


0.5 


G 


2 


1.5 


58.0 


1.5 


H 


1 


0.8 


81.0 


13.0 


I 


1 


0.3 


90.0 


19.5 


J 


2 


1.0 


90.0 


13.0 


K 


2 


1.5 


92.0 


19.5 


First-level IPM blocks 








A 


3 


1.8 


4.5 


2.5 


B 


2 


1.3 


31.0 


1.5 


E 


2 




37.5 


2.0 


F 


2 


1.3 


40.0 


2.5 


G 


2 


1.5 


44.0 


0.5 


C 


1 


1.0 


63.0 


0.5 


J 


2 


0.8 


75.5 


6.5 


I 


2 


0.8 


78.5 


0.0 


D 


2 


1.5 


81.0 


0.0 


K 


2 


1.5 


81.5 


0.0 


H 


1 


1.0 


87.0 


4.0 


1 



Acknowledgements 

We are grateful to the Massachusetts Soci- 
ety for Promoting Agriculture, the USDA North- 



east Regional IPM Competitive Grant Program, 
and State/Federal IPM fimds for funding this 
project. 



%% %% ^t^ %% %f^ 

ry% •^ ry% ry% rj% 



14 



Fruit Notes, Winter, 1993 



Evaluation of Red Coloring Strains of 
Gala Apple 

Duane W. Greene And Wesley R. Autio 

Department of Plant & Soil Sciences, University of Massachusetts 



Gala is an apple that has experienced a 
recent and rapid rise in popularity throughout 
the world. It is being planted heavily in Europe, 
South America, New Zealand, and the United 
States. Gala represented 25% of all apple trees 
sold by Washington State nurseries in 1990. 

Gala has many desirable characteristics, 
including very high flesh quahty, attractive 
appearance, precocity, and high productivity. 
The original strain of Gala is not a red apple, but 
rather, a cream-yellow one with an orange-red 
cheek. Mutations in fruit skin coloring occur 
readily. There is a general preference among 
nurserymen and growers for red coloring strains 
of a cultivar because there is the perception that 
these strEuns are preferred by the consumer. It 
is commonly accepted that the red coloring 
strains of Delicious that are being sold today, 
although very attractive, have decidedly infe- 
rior quality compared 
with the original Deli- 
cious strain. Further, 
production from some 
strains of Delicious may 
be only one third of more 
productive strains. 

There has been no 
comprehensive evalua- 
tion of the commonly- 
available strains of Gala. 
A Gala strain trial con- 
taining Kidd's D-8 (stan- 
dard). Royal, Regal 
(Fulford), Imperial, and 
Scarlet Gala was planted 
at the University of Mas- 
sachusetts Horticultural 
Research Center in 
Belchertown in 1988. 
This report summarizes 



growth, flowering, fruit characteristics, and 
fi*uit quahty of these five strains of Gala. 

lyees 

Kidd's D-8 and Royal Gala were obtained 
fi-om Stark Bros. Nursery, Louisiana, Missouri, 
and Imperial and Regal Gala were obtained 
fi-om Newark Nursery, Hartford, Michigan. All 
trees were on M.26 roots tock and were similar in 
caHper at planting. Propagating wood of Scarlet 
Gala was obtained fix)m Txu-key Hollow Nursery 
(Cumberland, Kentucky) in the spring of 1987, 
bench grafted on M.26 rootstock and then lined 
out in the nxirsery. In the spring of 1988, trees 
were planted in a randomized complete block 
design with eight rephcations. Each tree was 
supported by a one-inch x 10-foot metal conduit 
post set three feet in the ground. The first data 
on these trees were collected in 1990. 



Table 1. Growth in 1990 of five strains of Gala planted in 1988. 



Strain 



Kidd's 

Royal 

Scarlet 

Imperial 

Regal 







Trunk cross- 


Final 






sectional 


trunk 






area 


cross- 


Tree 


Tree 


increase in 


sectional 


height (ft) 


spread (ft) 


1990 (in=^ 


area (in^) 


9.6 a 


7.9 a 


1.4 a 


5.3 a 


9.9 a 


7.6 a 


1.5 a 


5.6 a 


8.9 a 


5.0 b 


1.4 a 


4.0 b 


10.2 a 


7.6 a 


1.7 a 


5.2 a 


9.2 a 


6.9 a 


1.6 a 


4.9 a 



Means within columns not followed by the same letter are 
significantly diff'erent at odds of 19:1. 



Fruit Notes, Winter, 1993 



15 



Growth 

Prior to bud break in 1990, a line was 
painted 20 inches above the soil surface and the 
trunk circumference was measured. After leaf 
fall, height, spread, and trunk circumference 
were measured. 

At the end of the third leaf. Gala strains 
differed little in vegetative growth. The height 
of all Gala strains was comparable, while the 
spread of Scarlet was smaller than that of the 
others (Table 1). The trunk circumference in- 
crease of all Gala strains in 1990 was similar, 
but the total cross-sectional area of Scarlet was 
less. Scarlet Gala trees were smaller at planting 
because they were bench grailed and grown for 
only one year; the other strains were budded on 
roots that were in the ground for one growing 
season and grew an additional year after bud- 



ding. Therefore, the small spread and trunk 
cross-sectional area of Scarlet Gala trees is 
probably a reflection of the tree size at planting 
rather than inherent vigor of the strain. 

Bloom, and Fruit Set 

Two limbs per tree were selected at the pink 
stage of flower development and the circumfer- 
ences were measured. The numbers of blossom 
clusters on one-year-old and two-year-old wood 
were counted. In 1991, fi-uit set also was as- 
sessed on these two hmbs in July by determining 
separately the fruit persisting on one-year-old 
and on older wood. 

Spur bloom density was lowest on Scarlet 
Gala and highest on Royal Gala in 1990, but 
there were no differences in 1991 (Table 2). 
Fruit set on all strains of Gala was comparable 



Table 2. 


Flower bud formation and fruit set of five strains of (Jala.* 






Bloom density 






Fruit set 






(blossom clusters/in 


Mimb 


(firuit/in" limb 




Strain 


cross 


.-sectional ar 


ea) 


cross-sectional area) 


Spur 


One-yr-old 


Total 


Spur 


One-yr-old 


Total 








1990 








Kidd's 


52 ab 


124 a 


176 ab 








.. 


Royal 


63 a 


123 a 


186 a 


~ 


~ 


~ 


Scarlet 


16 c 


128 a 


144 be 


— 


~ 


~ 


Imperial 


34 be 


103 a 


137 c 


~ 


~ 


~ 


Regal 


46 ab 


102 a 


148 be 
1991 








Kidd's 


67 a 


147 a 


214 a 


35 a 


85 a 


121 a 


Royal 


66 a 


127 a 


193 ab 


44 a 


77 a 


121 a 


Scarlet 


61 a 


132 a 


192 ab 


30 a 


77 a 


108 a 


Imperial 


48 a 


117 a 


164 b 


25 a 


67 a 


92 a 


Regal 


52 a 


134 a 


185 ab 


23 a 


68 a 


92 a 


* Means 


within columns and years not followed by 


the same letter are 


significantly different at odds of 19:1. 









16 



Fruit Notes, Winter, 1993 



and very heavy. In general, the bloom density of 
Imperial Gala was lower than that of the other 
strains. Bloom on all trees was considered 
'snowball* and excessive when compared to most 
other cultivars. Although the lower bloom den- 
sity of Imperial may have been real, it is of Uttle 
practical significance because of the excessive 
bloom that occurred on all strains in this trial. 
All strains of Gala bloomed extensively and 
comparably on one-year-old wood, accounting 
for over two-thirds of the bloom. Following 
June-drop, over two- thirds of the fruit that per- 
sisted originated from one-year-old wood. Fruit 
produced from bloom on one-year-old wood gen- 
erally was small and the quality was inferior. 
Since fruit size of Gala is normally small, and 



lateral fi^dt are even smaller, it is important to 
develop a thinning strategy for all strains of 
Gala to remove fiiiit developing from lateral 
bloom selectively. 

Fruit Characteristics and Quality 

At normal harvest, 15 fruit per tree were 
sampled. Fruit were weighed, flesh firmness 
and soluble soUds measured, ground color and 
starch pattern were rated, and p>ercent red color 
on each fi-uit was estimated to the nearest 10%. 
In 1991, finit were harvested September 3, 12, 
and 19. Additionally, stem-end cracking was 
evaluated and the length-to-diameter ratio was 
determined. 



Table 3. 


Fruit characteristics of five strains of Gala at harvest.* 








Fruit 
















size 


Flesh Soluble Red 


Ground 




1 


i'edicel-end 




(count/ firiimess 


solids color 


color 


Starch 


L/D 


cracking 


Strain 


42-lb box) 


(lbs) 


(%) (%) 


index** 


index*** 


ratio 


(%)**** 








1990 










Kidd's 


111 a 


19.2 ab 


14.2 b 74 b 


7.1 b 


5.6 a 


__ 


__ 


Royal 


114 a 


19.9 a 


14.6 b 88 a 


7.1 b 


5.0 a 


~ 


~ 


Scarlet 


119 a 


19.7 a 


15.0 ab 80 ab 


7.2 b 


5.4 a 


— 


— 


Imperial 


110 a 


20.0 a 


14.5 b 86 a 


7.2 b 


4.7 a 


— 


— 


Regal 


107 a 


18.3 b 


15.7 a 84 ab 
1991 


8.1 a 


6.8 a 






Kidd's 


135 b 


18.3 b 


13.0 c 70 c 


6.7 b 


5.4 a 


0.86 


a 2.2 b 


Royal 


131 b 


18.0 ab 


13.2 b 77 b 


6.8 b 


5.2 a 


0.87 


a 1.1 b 


Scarlet 


126 b 


19.6 a 


14.2 a 78 b 


6.9 b 


5.1 a 


0.86 


a 4.6 b 


Imperial 


126 b 


18.6 b 


13.3 b 87 a 


6.9 b 


5.3 a 


0.87 


a 6.7 b 


Regal 


112 a 


18.7 ab 


14.4 a 89 a 


7.5 a 


5.9 a 


0.86 


a 21.1 a 


* Means within col 


umns and 


years not followed by the same letter are significantly 


different at odds of 19:1. 












** Adapted from a 


New Zealand Gala ground color 


chart provided 


by Dr. Ian 


Warrington, 1 = 


green; 10 


= orange. 










*** Starch chart developed by W. R. Autio, 1 = 


immature; 9 = oveiinature. 1 


*♦** Cracking on the third harvest, September 19, 1991. 









Fruit Notes, Winter, 1993 



17 



There were no differences in fi-uit weight 
among strains in 1990, but in 1991, Regal Gala 
stood alone as the strain with the largest finiit 
(Table 3). Strains differed in flesh firmness and 
soluble solids but the differences were not con- 
sistent in the two years evaluated. All strains of 
Gala colored well, although red coloring selec- 
tions generally had more red color. Quantitative 
differences in red color among red coloring 
sports were not consistent. Regal had the high- 
est ground color rating, indicating a greater loss 
of chlorophyll. Strains did not differ in either 
starch index or length-to-diameter ratio. Sig- 
nificant stem-end cracking did not occur vmtil 
the last harvest in 1991 and then it occurred 
only on Regal Gala. 

There were clear indications that Regal Gala 
was an early maturing strain. As Gala ripen, 
ground color index, starch index, red color, 
soluble sohds and finiit cracking increase. Regal 
Gala differed consistently from the other strains 
in each of these characteristics in a way that 
indicated advanced ripening. 

Cracking at harvest has been cited as a 
problem with Gala in some areas, and that 



problem may be associated with uneven ripen- 
ing. If trees are thinned properly and pruned to 
allow good light penetration, we have observed 
that Gala can be picked injust two harvests. No 
significant cracking occurred until the last har- 
vest, and even then, it was restricted to Regal 
Gala. All strains could have been harvested 
before September 19, 1991, and Regal Gala a 
week earlier, when cracking was minimal. 
Therefore, we feel that cracking is not a problem 
with Gala if finiit are harvested at the proper 
time. When cracking does become a problem, 
fi-uit maturity has advanced to a point where 
fi-uit feel 'greasy*, and the postharvest life has 
been diminished significantly. 

Sensory and Visual Evaluation 

In 1991, sensory and visued evaluation of 
strains (Table 4) was done by 17 judges includ- 
ing pomology faculty, pomology graduate stu- 
dents, technical assistants, and students in an 
orchard management class. Each panelist 
evaluated three repUcations. A replication in- 
cluded one fi-uit of each of the five strains and one 



Table 4. 


Visual and sensory evaluation of five strains of Gala at harvest* 










Skin Flesh 












Strain 


Aroma 


toughness crispness 


Juiciness ! 


Sweetness 


Acidity 


Starchiness Flavor 


Kidd'8 


-0.1 a 


0.2 a 0.1 


b 


0.2 a 


0.2 a 


-0.3 


c 


0.0 a 0.1c 


Royal 


-0.3 a 


0.5 a 0.8 


a 


0.4 a 


0.5 a 


0.6 


ab 


-0.2 a 0.9 a 


Scarlet 


0.0 a 


0.5 a 0.8 


a 


0.3 a 


0.4 a 


0.8 


a 


-0.1 a 0.7 ab 


Imperial 


-0.6 a 


0.5 a 0.2 


b 


0.3 a 


0.1 a 


0.3 


b 


-0.2 a 0.4 be 


Regal 


-0.1 a 
Color 


0.6 a 0.4 
Color 


b 


0.4 a 


0.7 a 
Overall 


0.5 


ab 


0.0 a 1.1 a 


Kidd'8 


brightness 


uniformity 


Attractiveness 


desirability 








0.1c 


-0.1 c 




0.1 b 


0.2 b 


Royal 


0.8 b 


0.9 b 




0.7 b 


0.8 a 








Scarlet 


0.7 b 


0.6 be 




0.5 b 


0.7 a 








Imperial 


0.7 b 


0.8 b 




0.8 b 


0.5 ab 






Regal 


1.7 a 


1.7 a 




1.6 a 


1.0 a 








•Means within columns not followed by the 


same letter 


are significantly different at odds of 19:1. 



18 



Fruit Notes, Winter, 1993 



reference fruit to which all of the strains were 
compared. The reference fruit was Kidd's D-8, 
and this fact was not divulged to the panehsts. 
Judges scored each fi*uit on a horizontal scale 
with opposite descriptive terms at each end of 
the line and the center represented by the refer- 
ence fruit. The intensity of the deviation of each 
fi-uit from the reference fruit was recorded by a 
pencil mark either to the right or left of the 
reference fruit. 

Taste pgmeUsts were able to distinguish dif- 
ferences in quality and appearance among the 
Gala strains. Royal, Scarlet, and Regal Gala all 
were judged to have better flavor than Kidd's D- 
8. Royal and Scarlet had the crispiest flesh. The 
flesh of £dl red-coloring strains was more acid 
than Kidd's D-8. There were no differences 
eunong strains in aroma, skin toughness, juici- 
ness, sweetness, or starchiness. Regal Gala was 
judged to be the most attractive Gala strain. It 
also had the brightest red color and the most 
uniform color. 



There are legitimate concerns that the Gala 
strains selected solely on the basis of red skin 
color may not have the same high quality char- 
acteristics of the original Kidd's D-8 strain. Not 
only were all strains judged to be equal to Kidd's 
D-8, but when panelists considered all factors 
and rated overall desirability, Royal, Scarlet, 
and Regal Gala were selected as being better 
than Kidd's D-8. 

Conclusions 

Growth Emd bloom characteristics of Gala 
strains appeared to be similar; however, all 
strains bloomed heavily on one-year-old wood. 
Because of the lower value of fruit borne on this 
wood, thinning strategies should target these 
fruit. 

Regal is an early maturing strain of Gala, 
and was selected by paneUsts as the most attrac- 
tive strain. Royal, Scarlet, and Regal were 
judged to have better flavor and to be, overall, 
more desirable than Kidd's D-8 Gala. 



%|# %% %% ^f^ ^% 

rj* #1% rj% #1% •Y* 



Fruit Notes, Winter, 1993 



19 



Spiders in Second-level and First-level 
Apple IPM Blocks 

Joanna Wlsniewska, Yanghe Yang, and Ronald Prokopy 
Department of Entomology^ University of Massachusetts 



One of the principal practices of full second- 
level IPM is to control key summer fruit pests by 
a combination of behavioral and ecological tech- 
niques, thus allowing beneficial predators and 
parasitoids to increase enough to control sum- 
mer foUar pests. Spiders may be an important 
group of such predators. Insecticides can reduce 
numbers and diversity of spiders in apple or- 
chards. Therefore, full second-level IPM, which 
eliminates insecticide use Eifter early June, may 
allow spiders to prohferate in apple orchards. 

In 1992, we assessed spider populations in 
blocks of apple trees under full second- level IPM 
compared with first-level IPM practices. Addi- 
tionally, we conducted a laboratory test of the 
effects of Guthionâ„¢, Thiodanâ„¢, and Omiteâ„¢ on 
the most common spider species found in second- 
level IPM blocks. 

Besides these evaluations, we also were in- 
terested in the effects of herbicides on spider 
populations in these orchards. Frequently, veg- 
etation growing under apple trees is controlled 
in commercial orchards with herbicides applied 
early in the growing season, v/hile vegetation 
between the tree rows is mowed throughout the 
season. These practices reduce competition for 
nutrients, lower humidity (which may contrib- 
ute to higher disease pressure), and eliminate 
alternative sources of food and shelter for many 
orchard pests. Herbicides can decrease spider 
numbers in vegetable production systems 
(Riechert and Bishop, 1990), but their effects 
have not been examined in an orchard system. 
Hence, in 1992, we examined the effects of 
herbicide treatments on the number of spiders 
on apple trees in second-level IPM blocks. 

Spider Numbers in Full Second-level 
and First-level IPM Blocks 

Spiders were sampled in six apple orchards. 



Each orchard contained a six- to nine-acre block 
imder full second-level IPM and a nearby six- to 
nine-acre block under grower-supervised first- 
level IPM. Guthion and Thiodan were used in 
both types of blocks through early or mid-June 
to control early-season insect pests. After mid- 
June, second-level blocks received no insecti- 
cides while first-level blocks received an average 
of 2 sprays of Guthion or Imidan (once in July 
and once in August). All blocks were sprayed 
with carbaryl in early June to thin finiit. 

Beginning in early July, spiders were 
sampled on twenty randomly chosen trees every 
two to three weeks in both tjT)es of blocks in each 
orchard by tapping tree branches with a rubber 
mallet over a two-by-two-foot tray. Spiders were 
preserved in 70% alcohol and returned to the 
laboratory for identification, a process not yet 
complete. 

Figure 1 summarizes the results obtained 
over the entire season. The mean number of 
spiders collected per tree at the beginning of the 
sampUng period (July 2) was very low and W£is 
the same in both second-level and first-level 
IPM blocks. As the season progressed, however, 
these numbers increased to 1.5 spiders per tree 
by late September in the second-level blocks 
compared with 1.0 spiders per tree in the first- 
level blocks. Data trends were similar for each 
orchard considered, except for one orchard 
where there seemed to be no difference between 
the two types of blocks. 

The low numbers of spiders per tree in early 
July in all blocks may have been due to spraying 
for plum curculio, which extended through early 
to mid-June in all blocks. Beyond mid-June, 
growers continued to use insecticides in the first- 
level blocks but not in the second-level blocks. 
This difference probably accounted for the 
greater abundance of spiders in the second-level 



20 



Fruit Notes, Winter, 1993 





1.8 


























1.6 


- 


O 2nd level IPM 
• 1st level IPM 




a 
P 




1) 
t) 

V 

a. 


1.4 
1.2 


- 




/ 


/ - 




V 

•g 
'q. 
in 

o 


1.0 
0.8 


_ 




/ / 


/•: 




c 
o 
l> 

2 


0.6 
0.4 


- 


c 


/ / 

V / b 








0.2 


_a 


-4==^::^ 


» 
b 







0.0 



7/2 7/17 7/30 B/23 9/10 

Collection period 



9/24 



Figure 1. Numbers of spiders collected per tree ia full second- 
level and first-level IPM blocks during 1992. Means within 
each date accompanied by a different letter are significantly 
different at odds of 19:1. 



blocks during August and September, a conclu- 
sion reinforced by laboratory findings (next sec- 
tion). 

Insecticide and Miticide Effects 
on Spiders 

To test the effects of insecticides and miti- 
cides on spiders directly, a laboratory test was 
conducted on the most common spider species 
found in all six orchards: Araniella displicatta 
(Araneidae). All individuals tested were imma- 
ture, averaging 2 mm in size (the size found in 
early September in the field). All were collected 
at the same time in the same orchard. Spiders 



ity to pesticides. 



cation). Ten additional 
jars were coated with 
water as controls. 

After 9 hours all 10 
spiders in the Thiodan 
jars were dead, as were 9 
of the 10 in Guthion jars. 
None died in the Omite or 
control jars, although one 
spider died in the Omite 
jar after 45 hours. 

These results indi- 
cate that these insecti- 
cides were highly toxic to 
spiders, or at least to this 
particular found species. 
Omite, on the other hand, 
was not very toxic to this 
species of spider. It would 
be inappropriate, how- 
ever, to apply these find- 
ings to all orchard pesti- 
cide-use situations, in 
that pesticide effects may 
not be confined to pure 
contact toxicity. Also, 
many different spider 
species exist and some 
may differ from A. 
displicatta in susceptibil- 



Effects of Herbicides on Spiders 
on Apple Trees 

To determine if herbicide treatment of 
ground cover affects the number of spiders on 
trees, some trees in five second-level IPM blocks 
were not treated with herbicide while a herbi- 
cide treatment was apphed in May beneath 
other trees. Two additional blocks (likewise 
under full second-level IPM) at the University of 
Massachusetts Horticultural Research Center 
(HRC) in Belchertown also were employed in 
this experiment. Herbicides vised included para- 



were placed individually in glass jars coated quat and simizine in the HRC blocks, and these 

with the substance to be tested. Ten jars were herbicides as well as Postâ„¢, amate, and 

coated with Guthion, 10 with Thiodan, and 10 Fusiladeâ„¢ in the five second-level IPM blocks, 

with Omite (each at standard field rate of appli- The two HRC blocks consisted of dwarf trees 



Fruit Notes, Winter, 1993 



21 



3.5 



3.0 



" 2.5 



« 
a 

m 

\- 
«) 
â– o 
â– q. 



2.0 



-s 1-5 



o 

u 
2 



1.0 



0.5 - 



0.0 



O herbicides 
• no herbicides 




7/16 8/19 

Collection period 



8/31 9/15 



Figure 2. Effects of herbicide treatment of ground cover on the 
mean number of spiders per tree at different times of the 
season. This portion of the study was conducted in two blocks 
at the University of Massachusetts Horticultural Research 
Center which were under second-level IPM. Means within 
each date accompanied by a different letter are significantly 
different at odds of 19:1. 



(seven feet tall). On each sampling occasion (five 
in all, starting Jvdy 1), spiders were collected 
from 40 trees of each treatment. The five sec- 
ond-level IPM blocks contained larger trees (10 
to 13 feet tall). Forty to 65 of these in each 
treatment were sampled on four different occa- 
sions from each orchard. Sampling was carried 
out by tapping the branches as described above. 
In the five full second- level IPM blocks, her- 
bicide treatments did not have any effect on the 
number of spiders on trees. Mean numbers of 
spiders per tree show the same seasonal trend 
for herbicide as well as non-herbicide treat- 
ments. In the two HRC blocks (Figure 2), 
herbicide-treated trees contained significantly 



more spiders in August 
than non-herbicide- 
treated trees. There were 
no significant differences 
earlier and later in the 
season. 

Lack of any difference 
between herbicide- and 
non-herbicide-treated 
trees in the five second- 
level IPM blocks might 
have been due to the fact 
that trees in these blocks 
werematiire. Their cano- 
pies reached well into the 
vegetative region between 
rows, diminishing the con- 
trast between herbicide 
and non-herbicide treat- 
ments. 

In general, it can be 
concluded that no nega- 
tive effect of herbicide 
treatment on numbers of 
spiders per tree has been 
demonstrated by these 
data. Among smaller 
trees there may be a slight 
positive effect. Perhaps 
when an understory cover 
exists directly beneath the 
trees, spiders may forage 
there for prey and be di- 
verted away from the 
trees. They may move back into the tree cano- 
pies when there are more insect prey to be foimd 
there than in the ground cover. 

Conclusions 

Spiders were found to be significantly more 
abundant in second-level than in first-level IPM 
blocks. This result suggests that elimination of 
insecticide use after early or mid-June allows an 
increase in population of at least one group of 
natural enemies. High toxicity of broad-spec- 
trum insecticides to spiders, as revealed in our 
laboratory tests, supports this suggestion, £is do 
findings of Mansour et al. (1980), Madsen and 



22 



Fruit Notes, Winter, 1993 



Madsen (1982), and Bostonian et al. (1984) and 
other authors. 

The decreased number of spiders in first- 
level IPM blocks may have been due not only to 
direct contact toxicity of insecticide but also to 
insecticide acting as a repellant to spiders, tox- 
icity to spiders of prey feeding on insecticide- 
treated plant material, lack of prey insects (as a 
result of prey being killed or driven away by 
pesticide), destruction of webs by turbulence 
created by spraying, or a combination of these 
and other factors. 

Several questions stiU remain to be an- 
swered. One of them is whether or not the 
increased number of spiders in second-level IPM 
blocks is great enough to contribute signifi- 
cantly to the control of foliar pests. Can spiders 
prey effectively on leafminers, leafhoppers, and 
mites? Will they eat enough of such pests to 
make a difference? We plan to address these 
questions in the near futiu-e. 

Acknowledgements 

This project was funded by the Massachu- 
setts Society for Promoting Agriculture, the 
USDA Northeast Regional IPM Competitive 
Grants Program, and State/Federal IPM funds. 



We gratefully acknowledge this funding. We are 
grateful to the following growers for their par- 
ticipation and support: Dana Clark, Dave Chan- 
dler, Dick Gilmore, Tony Lincoln, Wayne Rice, 
and Joe Sincuk. 

Literature Cited 

Bostonian, N.J., CD. Dondale, M.R. Binns, D. 
Pitre. 1984. Effects of pesticide use on spiders 
(Araneae) in Quebec apple orchards. Canadian 
Entomologist 116:663-675. 

Madsen, H.F. and B.J. Madsen. 1982. Popula- 
tions of beneficial and pest arthropods in an 
organic and a pesticide treated apple orchard in 
British Columbia. Canadian Entomologist 
114:1083-1088. 

Mansour, F., D. Rosen, and A. Sulov. 1980. A 
survey of spider populations (Araneae) in 
sprayed and unsprayed apple orchards in Israel 
and their ability to feed on larvae of Spodoptera 
littoralis (Boisd.). Acta Oecologica: Oecol. 
Applic. 1:189-197. 

Riechert,S.E. and L. Bishop. 1990. Prey control 
by an assemblage of generalist predators: spi- 
ders in garden test systems. Ecology 71:1441- 
1450. 



•^ ^JV •t» ^JV ^{f 

^ ^ rfi rf» #Y* 



Fruit Notes, Winter, 1993 



23 



Apple Integrated Pest Management 
in 1992: Insects and Mites in 
Second-level Orchard Blocks 

Margaret Christie, Ronald Prokopy, Kathleen Leahy, Jennifer Mason, 

Andrea Pelosi, and L. Kate White 

Department of Entomology, University of Massachusetts 



Last spring, in Fruit Notes [57(2):5-13], we 
reported results of oiir first year of second-level 
IPM trials in Massachusetts apple orchards. 
Under second-level IPM, orchard management 
is integrated across all classes of pests: insects, 
mites, diseases, weeds, and vertebrates, rather 
than focusing on a single type of pest. Here, we 
report results of the second year of second- level 
IPM trials on insects and mites in commercial 
Massachusetts orchards. 

Insect and mite management under second- 
level IPM practices requires appUcation of three 
to four selective insecticide sprays fi-om April to 
early June to manage tarnished plant bug 
(TPB), European apple sawfly (EAS), plum 



curculio (PC), green fruitworm (GFW), the first 
generations of codling moth (CM), lesser 
appleworm (LAW), leafminer (LM), and leaf- 
hopper (LH). Insecticide application to the inte- 
rior of the block ceases after the final plum 
ctu"cuho spray in early June, allowing natural 
populations of predatory insects and parasitoids 
to increase to levels we hope will be sufficient to 
provide control of summer populations of foliar 
pests. In full second-level IPM blocks, apple 
maggot flies (AMF) are controlled by perimeter 
interception traps. In transitional second-level 
blocks, use of AMF interception traps is replaced 
by perimeter row spraying with Guthion"â„¢ or 
Imidan"â„¢ every three weeks beginning in early 



Table 1. Average percent injury by early-season insect pests in second-level eind 
first-level IPM blocks in 1992.* 



Type of block 



TPB 



PC 



EAS 



GFW 



Total 



Full second-level 1.5 a 0.1 a 0.1a 0.0 a 1.7 a 

First-level 2.3 a 0.1 a 0.1 a <0.1 a 2.5 a 

Transitional second-level 1.1 a 0.5 a 0.1 a 0.2 a 1.9 a 

First-level 0.7 a 0.1 a 0.1 a 0.1 a 1.0 a 



* Means in each couplet in each column followed by a different letter are 
significantly different at odds of 19:1. Two hundred fruit of each of three cultivars 
(Mcintosh, Cortland, and Delicious) were sampled at harvest. TPB = tarnished 
plant bug; PC = plum curculio; EAS = European apple sawfly; GFW = green 
fruitworm. 



24 



Fruit Notes, Winter, 1993 



July. In both typ>es of blocks, removal of 
unmanaged apple and pear trees within 100 
yards of each block reduces immigration of CM 
and LAW. Removal of drops after harvest dis- 
courages buildup of within-orchard populations 
ofAMF, CM, andLAW. 

In early April of 1 99 1 , we selected six full and 
six transitional second-level IPM test blocks of 
six to nine acres each. In 1992, we replaced one 
of the transitional blocks (which had been sold 
and was no longer available to us) with a new 
block on another farm. Each second-level block 
was matched with a nearby control block which 
weis managed by the grower, using first-level 
IPM methods. 

Early-season Fruit-injuring Pests 

For control of arthropod pests active up to 
early June, second-level IPM reUes on early- 
season pesticide treatment based on monitor- 
ing. We monitored each orchard weekly begin- 



ning in mid-April, then biweekly from mid-Jime 
through September. Five each of four types of 
sticky traps were hung in each block to monitor 
for TPB, LM, and EAS. We examined 100 or 200 
leaves or terminals per block for LM, LH, 
aphids, mites, and mite predators. Fruit were 
examined both by IPM scouts and growers for 
fresh PC injury. Based on this monitoring, 
recommendations were made to the grower for 
treatment of the experimental block. 

In second-level IPM blocks (both fiill and 
transitional) in 1992, combined injuries from 
early-season fruit pests were simUsu" to those in 
nearby first-level IPM (grower control) blocks. 
In both first- and second-level IPM blocks, TPB 
caused the greatest amount of injiuy, followed 
by PC, EAS, and GFW (Table 1). Early season 
insecticide use was similar in both types of 
blocks, probably because both types were man- 
aged through identical first-level IPM tech- 
niques (Table 2). Injury by these early-season 
pests was lower in 1992 than in 1991. 



Table 2. Dosage equivalent 


s (spray 


events 


in parentheses) of 


insecticides and acaricides 


used in second-level and first-level IPM blocks in 1992.* 










Fruit pests 




















Mites 








Before 


After 








mid- 


mid- 




Other 








Type of block 


June 


June 


Oil 


miticides 


LH 


ABLM 


Total 


Full 
















second-level 


2.4 


0.0 


0.9 


0.0 


0.2 


1.1 


4.6 




(4.0) 


(0.0) 


(1.8) 


(0.0) 


(0.2) 


(1.0) 


(7.0) 


First-level 


2.8 


2.0 


1.1 


0.1 


0.0 


0.4 


6.4 




(3.8) 


(2.2) 


(1.8) 


(0.2) 


(0.0) 


(0.5) 


(8.5) 


Transitional 
















second-level 


2.7 


0.7 


1.2 


0.3 


0.0 


1.0 


5.9 




(3.4) 


(2.6) 


(2.0) 


(0.2) 


(0.0) 


(1.0) 


(9.2) 


First-level 


3.3 


3.1 


1.3 


1.1 


0.0 


0.5 


9.3 




(3.6) 


(3.2) 


(2.0) 


(1.0) 


(0.0) 


(0.6) 


(10.4) 


* LH = leafhopper; ABLM 


= apple 


blotch leafminer. 









Fruit Notes, Winter, 1993 



25 



Table 3. Season-long apple maggot fly (AMF) injury and trap captures in second-level 
IPM blocks and first-level IPM blocks in 1992.* 







Interior 


Perimeter 






% AMF 


monitoring 


monitoring 


Interception 




injury 


trap 


trap 


trap 




to finiit 


captures 


captures 


captures 


Type of block 


at harvest 


per trap 


per trap 


per block 


Full second-level 


0.4 a 


9.0 a 


16.2 a 


2430 


First-level 


0.1 a 


6.9 a 


14.4 a 


- 


Transitional second-level 


0.2 a 


3.5 a 


5.9 a 


„ 


First-level 


0.1 a 


3.7 a 


5.6 a 


— 



* Means in each couplet in each column followed by a different letter are significantly 
different at odds of 19:1. Two hundred finiit of each of three cultivars (Mcintosh, 
Cortland, and Delicious) and two hundred border row fruit of mixed cultivars were 
sampled at harvest. 



Table 4. Fruit injury by codling moth (CM), leafrollers (LR), lesser 
appleworms (LAW), and San Jose scale (SJS) in second-level and first- 
level IPM blocks in 1992.* 



Type of block 



CM 



LR 



LAW 



SJS 



Full second-level 
First-level 

Transitional second-level 
First-level 



<0.1 a 


0.2 


a 


0.0 


a 


0.0 


a 


<0.1 a 


0.1 


a 


0.0 


a 


0.0 


a 


0.0 a 


0.2 


a 


0.0 


a 


0.0 


a 


0.0 a 


<0.1 


a 


0.0 


a 


0.0 


a 



* Means in each couplet in each column followed by a different letter 
are significantly different at odds of 19:1. Two hundred fniit of each 
of three cultivars (Mcintosh, Cortland, and Delicious) were sampled 
at harvest, and for CM and LR and additional two hundred border- 
row fruit of mixed cultivars were sampled at harvest. 



26 



Fruit Notes, Winter, 1993 



Summer Fruit-injuring Pests: 
Full Second-level IPM 

Odor-baited sticky red spheres were hung 
every five yards on perimeter apple trees of each 
full second-level experimental block to intercept 
immigrating AMF. These were baited with both 
butyl hexanoate, a synthetic fi-uit odor deployed 
in polyethylene vials, and ammonivun acetate, a 
sjTithetic food odor released through a Consepâ„¢ 
membrane. 

Interception trap captures averaged 2430 in 
the six full second-level blocks, indicating that 
AMF pressure was moderate in 1992. In 1991, 
trap captures averaged 3562 in three blocks in 
which traps were baited with both food and firuit 
odor. Captures ofAMF on four interior unbEii ted 
monitoring traps (indicative of AMF penetra- 
tion into the block interior) were statistically 
similar in second-level blocks and in nearby 
first-level blocks. AMF injury to firuit at harvest 
in second-level blocks was similar to that in 
nearby first-level blocks (Table 3). One second- 
level block, however, had 8% injury to Cortlands 
in mid-September. The nearby first-level block 
had no Cortlands , and all the Mcintosh had been 
picked, so no comparison was available. 

The second year of use of both butyl 
hexanoate and ammonivim acetate (or carbon- 
ate) to bait the AMF interception traps indicates 
that this double-odor strategy may be very effec- 
tive in large blocks. We ehminated the problem 
of quick loss of ammonia by replacing polyethyl- 
ene vials with slow release membranes. Tests 
performed in our laboratory showed that flies 
continue to be attracted to these membranes 
even afler they have been in the field for several 
months. Tests also indicated, however, that 
fewer flies approached the trap if the membrane 
flapped loosely in the wind. In addition, traps 
may require more fi-equent cleaning than we 
had previously thought, especially if the double- 
odor trapping procedure results in the capture of 
additional non-target insects. In 1992, we 
cleaned our traps once a month, but in one 
orchard, trap captures during a one-month pe- 
riod were 271% higher on traps which were 
cleaned of all insects than on those which were 
not cleaned thoroughly, indicating that as in- 



sects build up on the traps, trap captures de- 
crease. In high-pressure situations, more fre- 
quent trap cleaning may be necessary if AMF 
are to be captured effectively. 

Fruit injury by CM averaged less than 0.1% 
in both block types for the second year. 
LeafroUer (LR) injury averaged 0.2% in fuU 
second-level blocks for the second year, and was 
0.1% in nearby first-level blocks (Table 4). We 
will continue to monitor carefiilly for leafrollers 
because of concern that leafi-oller populations 
may grow in blocks in which the interior is not 
sprayed afler early or mid-June. No LAW or San 
Jose scale (SJS) injury was found (Table 4). 

No insecticides were apphed in second-level 
blocks after mid-Jime. In the companion first- 
level blocks, growers applied an average of 2.0 
dosage equivalents of pesticide after mid-June, 
and sprayed the block an average of 2.2 times 
(Table 2). 

Summer Fruit-injuring Pests: 
Transitional Second-level IPM 

Every three weeks after early June, i)erim- 
eter row apple trees in transitional second-level 
blocks were treated with insecticide to control 
AMF. The block interior remained firee of insec- 
ticide after early June. AMF injury averaged 
0.2% in transitional second-level blocks and 
0.1% in the nearby first-level blocks, slightly 
lower in both cases than in 1991. On average, 
3.5 AMF were captured on unbaited interior 
monitoring traps in transitional second-level 
blocks and 3.7 in first-level blocks, indicating 
that in most cases relatively few AMF pen- 
etrated into the orchard interior (Table 3). In- 
secticide use after mid- June was reduced signifi- 
cantly in transitional second-level blocks com- 
pared to first-level blocks because apphcations 
were made only to the block perimeter. Total 
dosage equivalents of insecticide applied 
against fi-uit pests afler mid-June averaged 0.7 
in transitional second-level blocks and 3.1 in 
first-level blocks. Growers also sprayed transi- 
tional second-level blocks slightly less fre- 
quently (Table 2). 

Unmanaged apple and pear trees were re- 
moved fi"om within 100 yards of the six transi- 



Fruit Notes, Winter, 1993 



27 



Table 5. Peak levels of mites and mite predators in second-level and first- 
level IPM blocks in 1992.* 





Mite presence (% of leaves) 




Type of block 


ERM+TSM 


Af 


YM 


Ratio of 
ERM+TSM to Af 


Full second-level 43.2 a 
First-level 42.5 a 

Transitional second-level 25.7 a 
First-level 20.3 a 


1.5 a 
2.7 a 

0.5 a 
1.0 a 


3.7 a 
0.9 a 

0.4 a 
0.7 a 


29:1 
16:1 

51:1 
20:1 



* Means in each couplet in each column followed by a different letter are 
significantly different at odds of 19:1. ERM = European red mite; TSM 
= two-spotted mite; Af = Amblysieus fallacis; YM = yellow mite. 



Table 6. Foliar insect pest peak population and injury levels in second-level and first-level 
blocks in 1992.* 



Type of 




PLH 




WALK 










block 


PLH 


injury 


WALK 


injury 


ABLM 


GAA 


GAAP 


WAA 


Full 


















second-level 


11.2 a 


15.0 a 


13.8 a 


0.3 a 


10.8 a 


68.7 a 


54.5 a 


6.2 a 


First-level 


2.3 b 


6.3 a 


10.6 a 


3.4 a 


13.6 a 


69.5 a 


44.3 a 


3.3 a 


Transitional 


















second-level 


7.2 a 


4.5 a 


6.1 a 


9.3 a 


10.8 a 


77.3 a 


55.3 a 


8.2 a 


First-level 


0.5 b 


0.5 a 


1.1 a 


0.4 a 


11.8 a 


65.3 a 


57.0 a 


11.0 a 



* Means in each couplet in each column followed by a different letter are significantly 
different at odds of 19:1. PLH = potato leafhopper, WALH = white apple leaftiopper; 
ABLM = apple blotch leafminer; WAA = wooly apple aphid; GAA = green apple aphid; 
GAAP = green apple aphid predators: cecidomyiids and syrphids. Data for PLH, PLH 
injury, and WALH is in terms of percent of terminals examined. Data for WALH is in 
terms of percent of fruit examined at harvest. Data for ABLM is in terms of the average 
number of mines per 100 leaves. Data for GAA, GAAP, and WAA is in terms of the 
percent of watersprouts examined. 



28 



Fruit Notes, Winter, 1993 



tional second-level blocks. No CM injury was 
seen in the transitional second-level blocks or 
their companion first-level blocks. LR injury 
was sUghtly, but not significantly higher in the 
transitional second-level blocks than in the first- 
level blocks. LR injury in transitional second- 
level blocks was no higher in 1992 than in 1991. 
No sampled fi-uit in either block were damaged 
by SJS or LAW (Table 4). 

Foliar Pests and Predators: 
Full Second-level IPM 

In 1991, we reported season-long average 
population levels of fohar pests; this year we 
noted their p>eak populations in an efifort to 
reflect damage more accurately. Cool and wet 
summer weather helped to maintain low popu- 
lations of fohar pests in most cases. 

Mite popxilations remained low in most 
cases, as were populations ofAmblysieusfallacis 
predators, which were not seen in full second- 
level blocks until late August, £md were never 
present in numbers thought to be sufficient to 
achieve biocontrol. Yellow mite predator popu- 
lations were slightly higher in second-level than 
in first-level blocks throughout the summer, but 
their abiUty to control any but the lowest mite 
populations is questionable (Table 5). 

Another predator, Typhlodemus pyri, which 
is present in orchards in Western New York, was 
released in two second-level IPM blocks. Sam- 
pling one month after release revealed high 
numbers of these mite predators on release 
trees. We wiU not know until 1993 whether or 
not they survived the winter and spring and 
successfully colonized the blocks. 

Both full second-level and nearby first-level 
blocks were treated with about one dosage 
equivadent of oil (Table 2). No other miticide was 
used in full second-level blocks, and only one 
grower apphed miticide to a first-level block. 

Potato leafhopper peak population levels on 
terminals were higher in full second-level than 
in first-level blocks. Potato leafhoppers infested 
11% of sampled terminals in full second-level 
blocks and 2% in nearby first-level blocks. Peak 
potato leafhopper injury to terminals was 15% 
in second-level and 6% in first-level blocks. 



White apple leafhoppers infested 14% of 
sampled terminals in second-level blocks and 
11% in first-level blocks; however, injury to fi-uit 
averaged only 0.3% in second-level blocks, ver- 
sus 3.4% in first-level blocks (Table 6). Injury in 
first-level blocks, however, was confined prima- 
rily to one orchard. In August, we identified rose 
leafhoppers in all t)T)es of orchard blocks, but 
further study is needed to determine their im- 
portance in Massachusetts orchards. Pesticide 
was applied against leafhoppers in early June in 
only one second-level block, which had a signifi- 
cant late-season infestation in 1991 (Table 2). 

Average peak leafininer population levels 
were similar in the second-level blocks and first- 
level blocks (Table 6). All of the six fiill second- 
level blocks were treated with DimUinâ„¢ against 
leafminers (Table 2). Leafininer population 
levels throughout the summer confirmed our 
previous conclusion that apphcation of DimUin 
against the overwintering generation of 
leafininer adults, when indicated by trap cap- 
tures, is the most effective and least invasive 
technique for their control. Treatment with 
Dimihn is preferable to use of other materials 
which are harsher on beneficial insects and 
mites. Dimilin was not available for vise in first- 
level blocks, and few growers chose to treat 
leafminers in those blocks. If registered, Dimilin 
will be a good option for control of leafminers 
without serious disruption of beneficials. We 
chose to apply it before bloom so that it did not 
affect leafi:x)ller and codling moth populations, 
which we are trjdng to study in the absence of 
insecticide use after mid-June. If registered, 
Dimilin could be used later in the season after 
first-generation mines have appeared, allowing 
growers to avoid its use in years in which it may 
not be needed. 

In other articles, we provide data indicating 
that predacious spiders are significantly more 
abundant late in the growing season in second- 
level blocks than in first-level IPM blocks, and 
that some of these spiders feed on leafininer 
larvae inside mines as well as on leafhopper 
nymphs. 

Green apple aphid (GAA) populations were 
almost the same in the two types of blocks. At 
their peak, aphids infested 69% of sampled 



Fruit Notes, Winter, 1993 



29 



terminals in full second-level blocks and 70% in 
nearby first-level blocks. Two aphid predators, 
sjrrphid and cecidomyiid flies, were slightly 
more prevalent in second-level blocks than in 
first-level blocks. These high levels indicate 
that predators achieved control of GAA in both 
second-level and first- level IPM blocks. Infesta- 
tion of terminals by wooly apple aphid (WAA) 
was similar in second-level and first-level 
blocks, but in both types of blocks WAA popula- 
tions were lower in 1992 than in 1991 (Table 6). 

Foliar Pests and Predators: 
Transitional Second-level IPM 

Very few Amblysieus fallacis predatory 
mites were seen in transitional second-level or 
nearby first-level blocks luitU September (Table 
5). Mite levels in most cases remained low, 
although one grower had European red mite 
populations in his transitional second-level 
block sufficient to warrant treatment with a 
miticide in mid-summer (Table 2). Mid-season 
miticides were applied in four of the six first- 
level blocks, with an average of 1.1 dosage 
equivalents of miticide per block (Table 2). 

Potato leafhopper infestation levels on ter- 
minals averaged higher in transitional second- 
level blocks than in nearby first-level blocks. In 
transitional second-level blocks, white apple 
leafhoppers infested 6% and potato leaflioppers 
7% of terminals at their peak, while in nearby 
first-level blocks, both white apple leafhopper 
and potato leafhopper populations peaked at 
about 1% of terminals infested. White apple 
leafhopper injury to frmt at harvest was statis- 
tically simUar in transitioned second-level and 
first-level blocks, and potato leaQiopper injury 
also was statistically similar in transitioned 
second-level and first-level blocks (Table 6). In 
no case did these insects cause serious problems 
for growers. 

All six transitional second-level blocks were 
treated with DimiUn against first generation 
leafminers. Only two growers treated their 
first-level blocks for leafminers (Table 2). Peak 
numbers of mines on 100 leaves averaged 10.8 
in transitional second-level blocks and 11.8 in 
first-level blocks, considerably lower in both 



blocks than in 1991 (Table 6). 

GAA populations were higher in 1992 than 
in 1991. At their peak, they infested an average 
of 77% of terminals in transitional second-level 
blocks and 65% of terminals in nearby first-level 
blocks. Predator populations were higher this 
year as well; their populations peaked at an 
average of 55% of terminals infested in transi- 
tional second-level blocks and 57% of terminals 
in first-level blocks. In both cases predators 
were adequate to provide control of aphid pests. 
Similar numbers of terminals in the transitional 
second-level blocks and in first-level blocks were 
infested with wooly apple aphids (Table 6). 

Conclusions 

We continue to be pleased with the success of 
implementation of second-level IPM for apple 
insects and mites in six- to nine-acre blocks in 
commercial orchards. In 1992, full second-level 
IPM blocks received 28% less total dosage 
equivalents of insecticide and miticide and 18% 
fewer total spray events for insects and mites 
than first-level IPM blocks. Excluding pre- 
bloom sprays of oil (non-toxic in the environ- 
ment), dosage equivalents were reduced 30% 
and spray events were reduced 22%. Despite 
this difference, total firut injury by insects was 
similar in full second-level and first-level IPM 
blocks, and peak populations of foUar pests were 
not different, except for leafhoppers. 

Early season fruit injury from PC, TPB, 
EAS, and GFW was low in all cases, as was finiit 
injury by CM, LR, LAW, and SJS. GAA were 
controlled by predators in both second-level and 
first-level blocks. We continue to work toward 
gaining registration of Dimilin, which provides 
good control of leafminers without disrupting 
beneficial parasites and predators. 

Transitional second-level IPM appears to be 
an effective reduced-spray management pro- 
gram for insect and mite pests in commercial 
orchards. In 1992, transitional second-level 
IPM blocks received 37% less total dosage 
equivalents of insecticide and miticide and 12% 
fewer total spray events for insects and mites 
than first-level IPM blocks. Total fruit injury by 
insects did, however, average sUghtly but not 



30 



Fruit Notes, Winter, 1993 



significantly higher in transitional second-level 
blocks than in first-level blocks. Peak popula- 
tions of foUar pests were Uttle different, except 
for leaflioppers, which were somewhat more 
abundant in the transitional second-level 
blocks. 

For 1991 and 1992, combined, transitional 
second-level IPM blocks received about 17% 
more insecticide and miticide and 23% more 
spray events than full second-level IPM blocks. 
Insect-caused fi*uit injury averaged over both 
years was virtually identical in full and transi- 
tional second-level blocks. 

Our main concern with the benefits of tran- 
sitional second-level IPM over the long-term Ues 
with the potential buildup of AMF from infested 
fallen drops not removed at harvest. The odor 
baits employed with the interception traps im- 
der full second-level IPM can attract these AMF. 
A second concern with the long-term benefits of 
transitional second- level IPM Hes with potential 
negative effects of perimeter-row sprays on im- 
migration of beneficial predators and parasites. 
Two more years of planned comparison of full 
second-level IPM vs. transitional second-level 
IPM vs. first-level IPM orchard practices should 
provide more insight into the benefits and costs 
of each practice. 

A second year of trials has not answered all 
of our questions about two foUar pests, mites 
and leafhoppers. Although mites were rarely a 
problem in this wet, cool summer, predator 
populations were low even where pest mites 
existed in numbers sufficient to support them. 
We need to learn more about overwintering 
locations of mite predators and about the exact 
identity of predators in Massachusetts or- 
chgirds. Further monitoring of the newly-re- 
leased predator, Typhlodemus pyri, will help us 
to determine if release of this pesticide-resistant 
predator could help to control pest mites in 
Massachusetts orchards. We will continue to 
study the role of spiders in pre3dng on leafinLners 
in mines and on leafhopper njrmphs. 

In our judgement, the key to grower adop- 
tion of second- level IPM practices for insects and 
mites hes in availabihty of a low-cost approach 
to interception trapping of AMF. At present, 
costs of labor and materials to employ odor- 



baited sticky red spheres exceeds by nearly 
twofold the cost of applying insecticide sprays 
against AMF and other summer finiit-injuring 
insects. The fi:^quent cleaning of sticky traps 
necessary to provide an effective capturing sur- 
face is a major component of the cost of this 
system. We believe that development of pesti- 
cide-treated spheres (now in progress) as a sub- 
stitute for sticky spheres will provide a cost- 
effective approach to using interception traps 
for this insect. 

Even if we assume that a pesticide-treated 
sphere interception trap system for AMF will be 
no more costly than applying insecticide after 
mid-Jime, why should a grower want to switch 
from an insecticide-based first-level IPM ap- 
proach? We believe there are at least four 
reasons for doing so: ( 1) saving money on sprays 
against foliar pests by allowing beneficial natu- 
ral enemies to build up and provide control in the 
absence of pesticide use; (2) reducing the UkeU- 
hood that foHar pests will develop resistance to 
pesticides, thereby preserving the long-term ef- 
fectiveness of these pesticides; (3) reducing pes- 
ticide intrusions on neighbors or the environ- 
ment adjacent to orchards; and (4) greatly re- 
ducing or eliminating pesticide residues on finait 
at harvest. For some growers, these potential 
advantages could be large. 



Acknowledgements 

This project was funded by the Massachu- 
setts Society for Promoting Agriculture, the 
USDA Northeast Regional IPM Competitive 
IPM Grants Program, State/Federal IPM funds, 
and the Northeast Region Sustainable Agricul- 
ture Research and Education Program (for- 
merly LISA). We gratefully acknowledge this 
funding. We are also grateful for the participa- 
tion and support of the following growers: Bill 
Broderick, Dave Chandler, Dana Clark, Dick, 
Greg, and Kevin Gilmore, Tony Lincoln, Jesse 
and Wayne Rice, Joe Sincuk, Dave Shearer, Tim 
Smith, £md Barry and Bud Wiles, and for the 
scouting assistance of Ryan Elliott, Kathy 
Hickey, James Gamble, £md Peter Winnick of 
the Department of Plant Pathology. 



Fruit Notes, Winter, 1993 



31 




Fruit Notes 



University of Massachusetts 

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Fruit Notes 

Prepared by the Department of Plant & Soil Sciences. j zsi j y Q F M A S S 

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Eklitors: Wesley R. Autio and William J. Bramlage 



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Volume 58. Number 2 
SPRING ISSUE, 1993 

Table of Contents 



Spiders That Feed on Leafhoppers 
and Leafminer Larvae 



Apple Growing in China 

Evaluation of New Apple Cultivars 

Implementation of the MARYBLYT Model for Fire Blight Control 

Fish Hydrolysate Fertilizer Should Not Be Applied Foliarly to Apple 

Comparative Effects of Margosan-O (Neem Extract) 
and Imidan on Plum Curculio and Apple Maggot 

Orchard Mineral Nutrition: Ground-applied vs. Foliar-applied Fertilizers 



^ 



Fruit Notes 

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July, and October by the Department of Plant & Soil Sciences, University 
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J 



Spiders That Feed on Leafhoppers 
and Leafminer Larvae 



Joanna \^sniewska and Ronald Prokopy 

Department of Entomology, University of Massachusetts 



Recently in Fruit Notes [58(1): 20-23], we 
showed that spiders were signiRcantly more abun- 
dant in second-level than in first-level IPM blocks. 
We concluded by asking whether or not increased 
numbers of spiders in second-level blocks were great 
enough to contribute to the control of foliar pests. 
Here, we describe 1992 laboratory studies in which 
some of the most abundant types of spiders collected 
in second-level blocks were offered white apple leaf- 
hopper nymphs and adults and apple blotch 
leafminer larvae as potential prey. 

Each spider was placed in a waxed paper cup 
(four inches tall by three inches in diameter) with a 
plastic lid. Into each cup we introduced an apple leaf 
kept turgid by placing its stem in water. The leaf 
harbored one tissue-feeding (late instar) leafminer 
larva and two 
leafhopper 
nymphs (or 
one nymph 
and one 

adult). The 
test lasted for 
24 hours. Re- 
sults 



are 
in 



Table 1. Laboratory tests of orchard-collected spiders feeding on 
potential prey. 



Family 
of spiders 



Number 
tested 



a cat stalks a mouse before the final pounce. They 
may even capture it in mid air and then climb back 
to the leaf fVom which they have jumped using a 
piece of silk previously attached to that leaf. Salticid 
spiders are successful nine times out often. They are 
active only during the day. 

Of the Araneid spiders, 28% fed on leafhoppers. 
Most of these spiders were smaU immature individu- 
als otAraniella displicatta, which are found com- 
monly on terminals of apple tree branches. They 
build tiny orb webs stretching across dorsal surfaces 
of leaves. Their webs are found at night and during 
the day. These spiders prayed mostly on the adult 
leafhoppers which got caught in their webs. 

Only members of the Anyphaenid family fed on 
leafminers. Predation on leafminer larvae took 

place by 90% 
of the 

Anyphaenid 
spiders 
tested. In all 
the 



Spiders that 

fed on 

leafhoppers (%) 



Spiders that fed 

on leafminer 

larvae (%) 



Philodromidae 

Araneidae 

Salticidae 

Anyphaenidae 

Thomisidae 



27 
22 
11 
10 

7 



given 
Table 1. 

Of the 
five families 
of spiders ex- 

a m i n e d , _^^^^^^___^^^^^^_^^^^^_ 
members of 

three families fed on leafhoppers: Anyphaenidae 
(hunting spiders), Salticidae (jumping spiders), and 
Araneidae (orb web spiders). The Anaphyenid spi- 
ders were the most voracious, as 100% of the tested 
individuals fed on leafhopper nymphs and adults 
(their behavior will be described later in conjunction 
with predation on leafminers). 

Of the Salticid spiders, 36% fed on leafhoppers. 
These visually oriented spiders are often observed 
running around on leaves and branches moving 
their heads from side to side as they search for prey. 
Once they locate a prey insect, they stalk it much as 



4 

28 

36 

100 








90 




cases 

mines were 
opened from 
the underside 
of the leaf and 
the larvae 
were missing. 
It was not 
possible to 
identify the 
specific spe- 
cies, because they all were immature. But our best 
guess is that 9 of the 10 individuals tested were 
Aysha gracillis. These hunting spiders are common 
on foliage. They forage for prey mostly by sensing 
vibrations on leaves and (possibly) branches. They 
were often found foraging at night but they may also 
be active during the day. 

The type of leafminer predation observed in this 
experiment is characterized by a very specific mark 
left on the leaves. For this reason it may be possible 
to quantify predation by Anyphaenid spiders in the 
field by counting the leaves which have the signs of 



Fruit Notes, Spring, 1993 



predation and those which do not, provided that 
observations are made soon after predation. We 
conducted a preliminary study to quantify predation 
in this way. 

In one of the three orchards where spiders were 
collected for use in the feeding test (University of 
Massachusetts Horticultural Research Center, 
Belchertown), we inspected 600 randomly selected 
leaves from 60 different apple trees on October 7. Of 
these leaves, 228 had leafrniner mines, 20% of which 
appeared damaged due to spider predation. In other 
words, 20% of the leafrniner larvae in the orchard in 
late September may have been prayed upon by 
Anyphaenid spiders. To compare this finding with 
what may be taking place in an orchard that has 
more spiders, on November 5, we inspected 169 
randomly selected leaves containing leafrniner lar- 
vae on four apple trees in an abandoned apple 
orchard (Orchard Hill area at the University of 
Massachusetts at Amherst). Of these mines, 37% 
appeared damaged due to predation of Anyphaenid 
spiders. 

Even though these findings are very prelimi- 
nary, they suggest that spiders of at least three 
families exhibiting different foragingstrategies may 
be able to prey upon some of the most troublesome 
foliar pests of apple orchards. Aysha species of the 
family Anyphaenidae, in particular, may play a 



beneficial role in leafhopper and leafrniner control. 
In 1993, we plan to conduct feeding tests on more 
spider species commonly found in second-level or- 
chard blocks and more individuals of each species. 
We also plan to conduct these tests under more 
natural conditions than the highly confining condi- 
tions of the laboratory used in 1992. We also hope to 
investigate the relationship between spiders feeding 
on leafminers and beneficial parasitoids feeding on 
leafminers. For example, it would be important to 
know if (and how much) spiders are likely to prey 
upon parasitized leafminers. Are spiders beneficial 
if they selectively extract parasitized leafrniner lar- 
vae but leave unparasitized larvae alone? HopefuUy 
our planned 1993 research wUI provide greater 
insight into the value of spiders as biological control 
agents of foliar apple pests. 

Acknowledgments 

This project was funded by the Massachusetts 
Society for Promoting Agriculture, the USDA 
Northeast Regional IPM Competitive Grant Pro- 
gram, and State/Federal IPM funds. We gratefiilly 
acknowledge this funding. We are grateful to the 
following growers for their participation and sup- 
port: Dana Clark, Dave Chandler, Dick Gilmore, 
Tony Lincoln, Wayne Rice, and Joe Sincuk. 



%f^ •S^ mS^ ^# •S^ 

0^ rj% w^ r{% 0^ 

Apple Growing in China 

Ronald J. Prokopy, M^lliam M. Coli, and Jian Jun Duan 
Department of Entomology, University of Massachusetts 



In Jiine of 1992, we had the wonderful oppor- 
tunity of visiting several apple orchards in vari- 
ous parts of east-central China in combination 
with a trip to the International Congress of 
Entomology in Bejing. We thought it might be 
interesting to convey some of the things that 
impressed us. 

First of all, a bit of history. According to our 
Chinese colleagues, apples have been grown in 
China for at least 2000 years. Apples are planted 
on nearly four million acres in China, equal to 



about one-third of all acreage devoted to horti- 
cultural crops. China is roughly the size and 
shape of the continental United State. This 
means that a greater percent of the land area of 
China is devoted to apples than in the United 
States (which has about 500,000 acres in 
apples). Although production per acre is not 
nearly as great in China as in the United States, 
total production is about the same: 230 million 
bushels a year. Many Chinese orchards are 
newly planted, thus partly accoiinting for low 



Fruit Notes, Spring, 1993 



average yield. In the United States, we produce 
about one bushel for every person. In China, 
production is about one bushel for every five 
people. Because living standards are improving 
very rapidly in China, there is a potential mar- 
ket for firuit appearing from either a major 
increase in Chinese apple production or mcgor 
importation of apples fi:t)m abroad. The most 
popular cxiltivars in China are DeUdous and 
Golden Delicious and more recently Fuji and 
"Red Snake." 

Presently, most orchards are owned by com- 
mimes. Each family in the commune is entitled 
to lease about three acres of land firom the 
commime and farm it in any way the family sees 
fit. The family can keep whatever it earns. All 
the trees that we saw were dwarf or semi-dwarf. 
One of the fascinating things to us was that 
every 20 rows or so were managed by a different 
family and often in a different way. So your 
immediate neighbor's horticultural practices 
could have a very strong influence on your crop, 
for better or for worse. 

Another fascinating thing was the absence 
of £my vegetation whatsoever beneath the trees 
but the lush vegetation of other crops grown in 
the allesrways between rows. These crops in- 
cluded peanuts, cotton, strawberries, melons, 
com, and several others. All vegetation beneath 
trees was removed by stout Chinese hoes in 
order to reduce the drain of vegetation on water 
and nutrients. We wondered how it was fmssible 
to run tractors and sprayers down the allejrways 
without crushing the other crops. The answer 
was: tractors and motorized sprayers are few 
and far between. Nearly all the sprajdng is done 
by attaching a hose 30 yards or so in length to an 
outlet fi*om an imderground pipe that supplies 
the spray mixtvire fi-om a central mixing point. 
The farmer simply sprays all trees within reach 
of the hose before picking up and moving on to 
the next attachment site. Some sprajdng is also 
done with backpack sprayers and "bucket- 
pumps." In this way there is no harm to crops in 
the alleyways (other than pesticide drift). Most 
applicators did not seem concerned about poten- 
tial dangers fi*om pesticide. They wore no gloves, 
masks or other protection, much the way it was 
in the United States in the 1940's! 

Nearly all of the 20 or so orchards that we 



saw were maintained in excellent condition. 
Tree structure was particularly good, generally 
better than the average Massachusetts block of 
dwarf trees. It w£is mainly based on a three- 
tiered, central-leader tree pruning and Umb 
training system. Advice on tree planting, tree 
training, fertiUzation, and pest control is given 
to all apple-growing members of a commune at 
least four times a year through visits by exten- 
sion pomologists from the Division of Fruit and 
Forestry. We were told that the average family 
sprays about eight times a year, mainly against 
mites, aphids, moth larvae, powdery mildew, 
scab, and canker. From our perspective, tree 
foUar growth was very lush (probably too lush). 
So it was not siuprising that mites and aphids 
took a strong liking to it. Maybe the lack of 
competition for nutrients in the absence of 
understory plants was too much of a good thing. 
The high upright growth of many trees was at 
least partly due to the common practice of t)dng 
branches down to horizontal or below horizontal 
positions, which then results in unnecessary 
uprights. There was a great deal of interest in 
biological control of mites and aphids but less 
progress on this area than we ex{)ected. 

We wondered how apples were stored and 
sold aRer harvest. It turns out that cold storage 
does not exist to any appreciable extent. The 
fi-uit are trucked by the buyer to the local mar- 
kets for immediate consumption. The storages 
that do exist are mostly in undergroimd cellars 
or in above-ground clay structures that are 
periodicedly hosed with water for cooling. 

Of all the many surprising things we encoun- 
tered, perhaps the most siurprising of all was the 
intent interest by the governor of a coimty of 
about two million people in the possibility of 
making applejuiceorcider. She questioned us at 
length about how cider was made in the United 
States. It seems that apples have never been 
iised in this way in China. She said that her 
people would love to have apple cider if they 
knew a good way to make it. What an opportu- 
nity for marketing low cost hand-operated cider 
presses. 

We were treated royally with unexcelled 
hospitality (including 35-course Ivmches) wher- 
ever we went. It was indeed an eye-opening, 
unforgettable experience. 



Fruit Notes, Spring, 1993 



Evaluation of New Apple Cultivars 



Duane W. Greene and Wesley R. Autio 

Department of Plant & Soil Sciences, University of Massachusetts 



In recent years, apple cultivars originating pri- 
marily from New Zealand, Australia, or Japan have 
gained considerable consumer acceptance in the 
market place. Prices received for these new culti- 
vars have exceeded those for the traditionally-grown 
apples. This differential has led to a new awareness 
and a hei^tened interest in planting new apple 
cultivars. Many new apples are under test but there 
is a dilemma about which of these to plant. The 
decisions are made somewhat easier now since there 
are a number of good and legitimate choices avail- 
able to growers. 

About iive years ago we started planting some of 
the most promising new cultivars and numbered 
selections. Scion wood was obtained for propagating 
trees from several countries and from various breed- 
ing programs. During the 1992 season many of these 
cultivars fruited. This report presents evaluations 
of some of these new cultivars. 

Fruit evaluation started the first week in August 
and continued weekly through the third week in 
October. Where sufficient fruit were available, mul- 
tiple harvests were made. Fruit on each harvest date 
were evaluated in two ways. First, fruit were 
weighed, counted, the diameter measured, and then 
red color was estimated to the nearest 10% on red 
coloring cultivars or on those yellow cultivars that 
had a prominent red cheek. Flesh firmness and 
soluble solids were measured. Fruit then were 
evaluated visually and sensory characteristics were 
judged on a specially prepared evaluation sheet 
(Figure 1). Lines approximately 10 cm in length 
were anchored at either end with descriptive terms. 
In each category a line was drawn through the line 
at a point that was judged to be appropriate for the 
apple. For example, if the color was judged to be 
neither dull nor bright a pencil mark was drawn half 
way between the terms. The length of this was 
measured from the zero point on the left and then 
recorded in the blank. The numerical value given in 
this instance would be 5.0. All other parameters 
were eveiluated similarly and measured. A value of 
6.5 is considered to be very good and a score of 7.5 or 
greater is excellent. A summary of the taste, visual, 
and laboratory evaluations of selected parameters 
are presented in Tables 1 and 2. Cultivars are listed 
in order of the harvest date at which they were 



considered best. 

A log was kept and notes were taken for each 
cultivar at each harvest date. Below, listed by 
alphabetical order, are summaries of observation 
made on many of the cultivars evaluated. The star 
rating system recommended by the Pacific North- 
west Fruit Tester's Association was used. 



*M* 



** 



**** A cultivar tested in many areas and 
found worthy as a good risk for commer- 
cial recommendation. 
A very promising cultivar but with some 
possible limiting factors. 
A cultivar, new or old, worthy of testing 
for today's changing apple world. 

* A cultivar or strain that has been 
through enough testing and/or commer- 
cial trials to be classified as not worthy of 
commercial recommendation. 

T An upward-pointing arrow with a star 
indicates increasing interest 

i A downward-pointing arrow with a star 
indicates decreasing or waning interest. 



Akane (.***) continues to be one of the apple culti- 
vars that we favor. It is a very attractive apple and 
few apples in its season have the flavor that Akane 
does. It must be allowed to stay on the tree long 
enough to mellow. It is the most aromatic apple we 
evaluated. A m^or fault is that it is a shy bearer. 

Alkemene {**) is a yellow apple with a deep orange 
cheek. It is somewhat russeted which detracts from 
its overall attractiveness. It has a spicy, sprightly, 
flowery taste. Flavor was rated quite high. A 
problem is that it is competing with Gala, Elstar, and 
Arlet. It may not be different enough or better 
enough to compete successfully with these cultivars. 
It is a disease-resistant cultivar, however, and this 
characteristic may increase its appeal. 

Ambitious (*) has fiTiited for three years. It is a very 
late apple with too much competition from other 
cultivars to succeed. It ripened properly in only one 
of the three years. Fruit size is small. It is one of the 
ugliest apples in our plot with only fair flavor. Fruit 
are susceptible to Pseudomonas. 



Fruit Notes, Spring, 1993 



Cultivar 



Visual and sensory evaluation: 



Color 

Attractiveness 

Aroma 

Skin 

Crispness 

Juiciness 

Sweetness 

Acidity 

Starchiness 

Astringency 

Flavor 

Desirable 



Weight 
Color 



dull 

dislike 

none 

tough 

low 

low 

low 

bland 

low 

low 

dislike 

dislike 



Date 



bright 

like 

intense 

tender 

high 

high 

high 

tart 

high 

high 

like 

like 



Flesh firmness 
Soluble solids 



Figure 1. Cultivar evaluation form. 



ArkcharmP' AA-18 (**) is a very attractive light 
cherry red apple with semiprominent lenticels. It 
has a spicy taste, not sweet, flesh not too crisp, with 
acidity quite high. Fruit were harvested over a two- 
week period. Even when watercored, they still are 
very acid. Arkcharm warrants further evaluation. 

AA~44 (**t) is a large blotchy cherry red apple. 
Flavor is good but not strong. It is equal to Paulared 
in flavor and ripens slightly before Paulared. It 
shows some tendency to drop. This cultivar war- 
rants further evaluation. 

AA-62 (*) looks somewhat like a Golden Delicious 
and ripens at about the same time. The finish is 
good, with no russeting; however, fruit show severe 
bitter pit and Pseudomonas. Fruit have a good but 
not an outstanding taste with an anise flavor. It is 
more acid than Grolden Delicious. If it is not better 



than Golden Delicious it may not have a future. 

AA-63 (**) was a very pleasant early surprise. It has 
speckled red skin, perhaps like an Early Mcintosh. 
It £dso tastes like a very good early Mcintosh, with- 
out the sharp astringent taste. It is smaU with a very 
short shelf life. We rated it very high for color, flavor, 
and overall. It is better than Sumac which ripens at 
a similar time. 

Arlet (**T) remains high on the new cultivar list 
despite its three major faults: preharvest drop, 
russet, and poor color. It received one of the highest 
flavor rating. It has a good sugar-to-acid ratio that 
tends to favor acid. It stores quite well and keeps it 
taste for a long time. The greasiness that develops on 
Arlet is quite different from that developing on other 
apples, since it can be washed off. Even though it 
feels greasy, internal condition can still be very good. 



Fruit Notes, Spring, 1993 



There is a very good relationship between develop- 
ment of red color and drop. The quality of this apple 
is too good to discard right now, even with its faults. 

BC 9-17 (*) is a medium sized dull cherry red apple 
with semiprominent lenticels. The flavor is not 
strong, and when ripe it has a hint of perfume and 
pineapple. It is a fairly good apple, but certainly not 
outstanding. 

BC 78-9-28 (*) is a medium sized, attractive red 
apple. The skin is smooth and lightly striped. The 
flesh is slightly chalky and the flavor is like licorice. 
The very different taste makes it difficult to decide 
whether or not we like it. 

BC 8C-27-96 Sunrise i**i) is a very attractive 
apple but when it develops outstanding red color, it 
is too ripe. The flesh characteristics are outstanding. 
It is crisp, juicy, and just feels wonderful. A major 
weakness of this apple is that it has a very weak 
apple flavor and the flavor that it does have is 
acceptable but not outstanding. We do not rate 
Sunrise very high. 

BC 15-30 (*) is a large, light cherry red apple with 
prominent brown lenticels. Even when ripe (Sep- 
tember 1) acidity is high. It has a pronounced 
pineapple flavor that is not totally related to 
watercore. This apple was rated average for red 
color, fairly high on attractiveness, and average for 
taste and flavor. This fruit is neither outstanding 
nor poor. 

BC9P-14-32 (**t) was one of the pleasant surprises 
this year. It is not very attractive because the cherry 
red is not intense and there is considerable net-like 
russeting. Fruit size is medium, flesh is yellowish- 
white, flesh texture is good, and the sugar-to-acid 
ratio is good. The taste and appearance is reminis- 
cent of Arlet. This apple was rated among the 
highest for flavor and overall desirable. It is a very 
good apple. 

BC 2-8 (*) is a very attractive red apple that re- 
sembles Delicious; however, the beauty is only skin 
deep. Even when very ripe fruit were tasted, the acid 
level was almost off the scale. It is an attractive 
apple with only fair to good quality. Fniit were 
dropping on September 21. 

BC 8M-15-10 (**T) was the second British Columbia 
selection that we thought was truly outstanding. 
This apple has blotchy pink-red color. Overall it is 
not an attractive apple. The flesh is yellow with a 
mild banana flavor. It is extremely crisp and juicy. 



Unlike published reports, it does not remind us of 
Fuji, but is more reminiscent of Braebum. As far as 
taste, crispness, and juiciness are concerned, you 
could not ask for a better apple. It is outstanding. 

BC8B-1'^50(**) is a fairly attractive andfairly good 
tasting apple. It looks like a Delicious and has cream 
yellow flesh. Fruit are deep cherry red at the optimal 
harvest date. The longer fruit stayed on the tree the 
better it got, although flesh firmness and texture 
were poor. The flavor of this apple is very complex: 
fruity and tropical. Since the taste is different and 
it improves with age, this cultivar may benefit from 
a period of cold storage. 

DIR 98T-486 (**) is a very attractive deep red apple 
on a cream yellow ground color. The irregular 
surface detracts somewhat from the appearance, but 
still it was one of the most attractive to be evaluated 
this year. Flavor improve with time on the tree. 
Fruit harvested on October 5 were quite good but the 
ground color indicated that the shelf life then would 
be rather short. The fruit is very juicy, yellow-white 
fleshed, and slightly tough skinned. It is so attrac- 
tive, that based solely on appearance, it should be 
looked at further. 

BC 17-30 (**T) is a very attractive, dark-burgundy- 
red apple of the Mcintosh type. The flavor is remi- 
niscent of Mcintosh with Spartan overtones. Per- 
haps it tastes most like Acey Mac. The flavor may be 
a little bland but it is still a very good apple. Flesh 
is white with a greenish tinge. The pedicle is long 
and lenticels are semiprominent. This apple war- 
rants further evaluation. 

BC 8K-21-39 (**) is a fairly good apple with better 
than average appearance. It is round to conic, has 
yellowish-white flesh that is somewhat dry. Fruit 
shows some russeting. Where the surface is red it is 
attractive. The red looks muddy on the green-red 
interface. The longer the fruit remained on the tree 
the better it tastes. 

BC 8C-6-62 (*) is a dark cherry-red apple with a 
bumpy surface caused by raised lenticel. The flesh 
is yellowish white. The flesh was so acid that it was 
not possible to evaluate flavor effectively. This fruit 
was about the most highly acid apple that we evalu- 
ated this year. We were not impressed. 

Bonza (*). This is the second year that we have 
evaluated Bonza. It is somewhat attractive and red 
color is good. The surface of the apple is not smooth, 
the flesh is rather dry, and the flavor is acceptable 
but not outstanding. We are not encouraged to 



Fruit Notes, Spring, 1993 



Table 1. Taste evaluation of apple 


cultivars grown 


at the L 


niversity of Massachusetts Horticultural | 


Research Center. 


1992. 




















Red 








Overall 


Cultivar 


Date 


Attractiveness 


color 


Sweetness 


Acidity 


Flavor 


desirable 


AA63 


Aug. 6 


5.1 


6.8 


5.3 


6.1 


7.4 


6.7 


Sumac 


Aug. 6 


2.3 


3.0 


5.1 


6.4 


7.1 


5.3 


NY 66305-139 


Aug. 6 


3.6 


2.2 


1.8 


9.0 


3.3 


2.4 


BC 9-17 


Aug. 11 


4.5 


4.5 


4.0 


8.8 


6.5 


5.0 


Arkcharm (AA 18) 


Aug. 17 


7.9 


6.5 


2.7 


8.0 


5.3 


5.1 


Jerseymac 


Aug. 17 


5.5 


6.7 


5.6 


4.8 


6.2 


5.9 


BC 78-9-28 


Aug. 17 


6.9 


6.5 


6.5 


5.3 


5.0 


4.8 


BC 15-30 


Aug. 17 


4.8 


5.0 


2.4 


7.9 


4.4 


4.0 


Williams Pride 


Aug. 20 


5.6 


6.4 


4.5 


4.8 


6.1 


6.2 


Redfree 


Aug. 20 


8.4 


8.8 


5.2 


5.5 


7.6 


7.4 


OSU 31-19 


Aug. 20 


3.0 


3.6 


5.2 


6.1 


7.0 


6.8 


AA44 


Aug. 24 


5.5 


5.9 


5.1 


7.8 


5.7 


5.8 


Paulared 


Aug. 24 


6.3 


6.4 


2.3 


6.9 


5.0 


5.3 


BC 8C-27-96 


Sept. 1 


6.3 


5.0 


5.2 


5.5 


5.1 


5.3 


Sansa 


Sept. 1 


6.4 


6.3 


7.4 


5.5 


7.4 


7.4 


Nebuta 


Sept. 1 


6.5 


7.0 


5.5 


6.7 


5.1 


5.3 


BC 15-30 


Sept. 1 


5.7 


5.2 


5.2 


8.8 


5.1 


4.0 


Himekami 


Sept. 8 


7.0 


7.0 


3.3 


8.5 


4.1 


3.9 


Akane 


Sept. 8 


8.5 


8.4 


5.5 


6.9 


6.8 


6.8 


BC 9P- 14-32 


Sept. 8 


4.1 


4.4 


6.2 


7.0 


7.9 


7.4 


Dayton 


Sept. 8 


5.6 


6.3 


5.7 


6.4 


5.8 


5.1 


Ginger Gold 


Sept. 14 


8.0 


... 


6.5 


6.2 


5.8 


7.4 


Fiesta 


Sept. 14 


4.2 


3.5 


4.8 


5.0 


5.7 


5.2 


Tsugaru Homei 


Sept. 14 


5.2 


5.0 


8.1 


4.8 


6.3 


6.3 


Arlet 


Sept. 14 


4.7 


4.7 


5.6 


7.0 


7.5 


6.5 


Elstar 


Sept. 14 


4.5 


4.4 


3.2 


8.1 


4.7 


4.6 


NY 66305-289 


Sept. 14 


6.8 


6.8 


3.4 


7.1 


5.3 


5.9 


NY 74828-12 


Sept. 21 


6.7 


6.8 


3.4 


7.3 


5.5 


5.8 


Alkemene 


Sept. 21 


5.3 


5.6 


6.3 


6.8 


5.9 


5.6 


Honeycrisp 


Sept. 21 


2.9 


3.5 


6.8 


5.2 


6.3 


5.2 


BC2-8 


Sept. 21 


7.1 


6.9 


4.2 


8.2 


4.8 


5.3 


Shamrock 


Sept. 28 


4.8 


— 


5.7 


5.3 


7.0 


6.5 


NY 75414-1 


Sept. 28 


7.8 


7.8 


6.2 


7.0 


7.3 


7.4 


Natco 81 


Sept. 28 


6.7 


6.7 


5.3 


4.6 


6.3 


6.3 


BC 8M 15-10 


Sept. 28 


3.6 


4.2 


7.0 


5.2 


7.3 


7.0 


NY 75413-30 


Sept. 28 


6.8 


6.8 


4.7 


8.1 


3.6 


3.6 


Bonza 


Sept. 28 


6.4 


6.9 


3.3 


4.8 


5.5 


5.0 


BC 8B-20-13 


Sept. 28 


7.5 


— 


4.1 


7.6 


5.7 


5.8 


BC 8B-14-56 


Sept. 28 


5.0 


5.0 


5.6 


5.0 


6.2 


5.8 


Yataka 


Sept. 28 


5.1 


5.1 


7.1 


4.2 


6.9 


6.9 


Dulcet 


Sept. 28 


5.4 


5.3 


5.5 


5.0 


5.5 


5.5 


1 



continue evaluating this cultivar. Bonza tasted in 
Australia seemed to be quite different and far supe- 
rior to that grown in our trials. 

Braebum (*) was one of the poorest performing 
cultivars that we had in our plots. Fruit were 



harvested on October 19, and they appeared not to be 
ripe. Fruit were unattractive, high in acid, and not 
sweet. Theyjust did not taste mature. We have trees 
fruiting that came from two sources. The fruit from 
both sources are equally poor. This is the second 
year that fruit quality was very poor. We may not 



Fruit Notes, Spring, 1993 



Table 1 continued. | 








Red 








Overall 


Cultivar 


Date 


Attractiveness color 


Sweetness 


Acidity 


Flavor 


desirable 


DIR 98-T-486 


Oct. 5 


7.8 


8.4 


5.2 


5.0 


5.9 


6.3 


Yoko 


Oct. 5 


5.1 


5.0 


6.3 


6.5 


6.3 


5.9 


NY 65707-19 


Oct. 5 


6.3 


6.8 


5.1 


4.1 


6.3 


6.4 


Rubinette 


Oct. 8 


2.6 


2.6 


3.9 


7.1 


5.8 


5.1 


Freyburg 


Oct. 8 


5.3 


— 


7.0 


5.5 


6.8 


6.8 


NY 75441-67 


Oct. 13 


5.7 


6.3 


3.0 


7.5 


5.3 


4.8 


BC 17-30 


Oct. 13 


8.2 


8.4 


7.1 


5.3 


6.9 


7.1 


Jonagold 


Oct. 13 


5.7 


5.1 


6.9 


5.3 


7.5 


6.9 


Senshu 


Oct. 13 


5.1 


4.8 


6.5 


5.5 


6.9 


6.4 


NY 429 


Oct. 13 


7.8 


7.5 


3.9 


5.9 


6.1 


6.3 


Hawaii 


Oct. 13 


5.0 


— 


6.1 


3.5 


6.5 


5.9 


Shizuka 


Oct. 13 


5.9 


... 


5.2 


5.8 


7.4 


7.3 


Hokulo 


Oct. 13 


4.8 


4.6 


5.5 


4.4 


5.7 


5.6 


NY 617 


Oct. 13 


6.2 


6.1 


2.7 


8.4 


5.3 


5.5 


Splendour 


Oct. 13 


7.0 


6.2 


6.0 


3.8 


5.8 


6.8 


Brock 


Oct. 13 


4.4 


2.9 


5.5 


5.3 


6.1 


5.1 


NY 73334-35 


Oct. 13 


5.5 


5.5 


4.2 


7.6 


4.5 


5.0 


NY 75413-30 


Oct. 13 


6.9 


7.0 


5.5 


5.5 


4.8 


5.9 


Fantazja 


Oct. 13 


7.0 


7.0 


5.2 


6.8 


6.7 


6.7 


NY 752 


Oct. 13 


3.6 


3.5 


5.5 


5.6 


5.5 


5.1 


AA62 


Oct. 13 


4.8 


— 


5.3 


4.8 


5.9 


5.6 


BC 8C-5-62 


Oct. 13 


5.5 


5.5 


1.1 


9.6 


2.3 


2.4 


BC 8K-21-39 


Oct. 19 


5.9 


5.9 


5.8 


5.9 


6.8 


6.9 


Natco 24 


Oct. 19 


6.3 


5.9 


3.6 


7.0 


5.6 


5.8 


Coop 29 


Oct. 19 


4.2 


— 


3.6 


6.3 


5.9 


5.7 


Newtown Seedling 


Oct. 19 


5.6 


5.1 


4.8 


6.8 


5.0 


4.8 


Criterion 


Oct. 19 


6.1 


— 


4.6 


3.6 


5.5 


5.5 


Nittany 


Oct. 19 


5.8 


5.3 


5.2 


6.2 


6.2 


6.2 


Reinette Simirenko 


Oct. 19 


5.3 


... 


4.6 


6.3 


5.7 


5.5 


Fiorina 


Oct. 19 


6.3 


6.2 


7.1 


3.8 


7.1 


7.1 


Braeburn 


Oct. 19 


4.1 


3.9 


3.5 


8.2 


3.9 


4.0 


Ambitious 


Oct. 19 


2.9 


2.3 


6.5 


5.9 


4.1 


3.6 


Orin 


Oct. 19 


5.5 


— 


8.2 


4.1 


7.1 


6.5 


Kinsei 


Oct. 19 


4.4 


— 


7.9 


4.6 


7.4 


6.8 


NJ 100 


Oct. 19 


7.0 


— 


5.0 


4.6 


5.5 


5.9 


Natco 58 


Oct. 19 


5.7 


5.3 


3.2 


8.1 


3.5 


4.4 


Natco 3 


Oct. 19 


6.5 


4.1 


7.1 


36 


5.2 


5.8 


Suncrisp (NJ 55) 


Nov. 4 


5.2 


... 


4.8 


6.5 


7.0 


6.7 


All fruit characteristics were rated 


on a scale 


ranging from to 10. 








Color: dull = 0, bright = 10. 














Attractiveness, Flavor, and Overall desirable: 


dislike = 0, 


like = 10. 








Sweetness: low = 0, 


high = 10. 














Acidity: bland = 0, 


tart = 10. 















have environmental conditions that favor produc- 
tion of this cultivar. An added observation that may 
contribute to the poor taste is that mites show a 
distinct preference for Braeburn. Only Braeburn 
trees were heavily damaged by mites. Since trees 
were located in two different locations, it appears 



that this is a characteristic of Braeburn. We cannot 
recommend Braeburn for New England, based upon 
our observations this year. 

Brock (**i) was a good but not outstanding apple 
this year. Red color is not attractive with a burned 



8 



Fruit Notes, Spring, 1993 



or grayish cast. Flavor is better than appearance. 
We rate flavor as good but not outstanding. It tastes 
very much like a Spencer. Fruit was dropping on 
October 13. We have better apples than Brock. 

COOP 29 (**) is a green-yellow apple with a brown 
pink cheek. These characteristics, coupled with 
some russeting, make this apple not very attractive. 
Flesh was firm, tart, astringent, and crisp with a 
very distinct and strong strawberry taste. In fact, 
this is the only apple that we have ever tasted that 
even remotely reminds us of strawberries. Although 
it is unattractive and flavor only good, it is disease 
resistant and it may be different enough to make it. 

Criterion (*). We have not been able to mature 
Criterion properly for two out of three years. Fruit 
were mostly green on October 19, even when flesh 
firmness was only 13.5 pounds. Skin was tough, 
flesh whitish-green, and the flavor acceptable. Cri- 
terion is not going to replace Golden Delicious. 

Dayton (**). We evaluated Dayton for the first time 
this year. We were hoping for more than we got. It 
is a large, not-too-attractive, red apple with a bumpy 
irregular surface. It has a pleasant, perfumy, spicy 
flavor but other oiltivars ripening in early to the 
mid-September are better. It may have a future as 
a disease-resistant apple, but on its own it will not 
beat better apples in the same season. 

Dulcet (**) is a deep burgundy red apple with 
prominent lenticels. It is too dull a red to be a truly 
attractive apple. Although reminiscent of Delicious, 
it appears to have a fairly low L/D ratio. The flavor 
is sweet, buttery, but not overwhelming. The juice 
seemed quite thick and the whitish green flesh does 
not appear to brown when exposed to the air. Dulcet 
was a good but not an outstanding apple. 

Elstar (*) continues to leave us unimpressed after 
three years of evaluation. The color is not outstand- 
ing and the acid level is too high even when the 
ground color is yellow. Last year the trees 
overcropped. Even with a very light crop this year 
due to biennial bearing, firuit size was still unaccept- 
ably small. This is the same pattern that we observe 
here with Empire. Elstar is just not good enough to 
compete with other apples in its season (Gala and 
Arlet). If one places Elstar in storage to mellow, it 
still must then compete with other later cxiltivars 
that are vastly superior. We can not recommend 
Elstar. 

Fantazja (**t) was an unexpected surprise. It is a 
Polish apple that came from Dick Van Well of Van 
Well Nursery. We planted and cropped the same 



trees in 1992, so the October 13 harvest date may not 
be the correct harvest date, since trees were fhiiting 
in their first leaf. It is a very attractive red apple that 
resembles Mcintosh. It has white flesh and tastes 
similar to Mcintosh but it is crisper and has courser 
flesh and better flavor. We were quite impressed 
with our first look at this apple. 

Fiesta (**i). This is our second year looking at 
Fiesta. In both years, it showed severe preharvest 
drop. It is dull in color and quite unattractive. 
Although it is fairly large and we rated flavor quite 
high, we do not think it has what it takes to make it 
here. It is an OK apple, but certainly not very 
exciting. 

Fiorina {**) is a late-maturing, disease-resistant 
apple that is both attractive and has good taste. The 
flavor is very mild. The flesh is whitish-yellow and 
very crisp. It tastes sweet with a low acid level. This 
apple certainly deserves fiirther evaluation. 

Freyburg (♦*) is an elongated yellow apple that 
resembles Delicious in shape. The flesh is white and 
it seems dry. It is very sweet with a strong fi-uity 
flavor. The strong flavor may turn some people off. 

Gingergold (***) is one of the most attractive apples 
that we grow, regardless of the season. When ripe it 
is a beautiful yellow green that completely lacks 
russet or surface blemishes. It is the best early 
Golden Delicious type that we know of. It is firm 
crisp, but the apple flavor is not strong. September 
1 was too early to harvest this apple, and finiit 
harvested on September 8 were yellow but still 
starchy. Fruit harvested on September 14 were still 
very crisp and the seeds were still white. The proper 
time of harvest of this may be later than the sug- 
gested time. Regardless of time of harvest, this is an 
excellent apple that has a future. 

Hawaii (**). This is the first year we finiited 
Hawaii. It is a somewhat attractive yellow apple 
that resembles a Golden Delicious without the rus- 
set. It has a red cheek like Goldens get in the 
Northeast. It is fairly sweet, has low acidity and good 
flavor, with a strong banana taste. It bruises easily. 
It probably will no replace Golden Delicious. 

Himekami {*) is a very attractive apple that looks 
like a cherry-red Delicious ripening during the first 
week in September. We rated flavor and overall 
desirability quite low. The appearance of this apple 
is much better than its taste. We are not enthusiastic 
about Himekami. 

Hokuto (Norihem Star) (**). The brownish red. 



Fruit Notes, Spring, 1993 



muddy red color on the surface of this apple makes 
it somewhat unattractive. Even when the ground 
color is intensely green, it appears to be acceptable to 
eat. The flesh is somewhat sweet and sprightly, and 
this perception may be accentuated because acidity 
appears to be very low. We do not consider this to be 
an outstanding apple. There are better apples avail- 
able that ripen at the same time. 

Honeycrisp (**T) distinguished itself as one of the 
best apples that we evaluated. It was the most 
productive apple in our plot, producing over 1.5 
bushels of 3-inch apples per tree on M.26 in their 
third leaf. It was one of the least attractive apple 
that was evaluated. It was also one of the crispest 
and juiciest apples tasted. The flavor was good but 
not strong. It has outstanding storage potential. It 
maintains crispness, juiciness, and flavor after at 
least 20 weeks of regular air storage. This apple 
requires further evaluation but the more we taste 
Honeycrisp, especially out of storage, the better it 
looks. 

Kinaei (**t). This is the first year that we evaluated 
Kinsei. It is quite an unattractive apple but it is also 
one of the best tasting apples in our plot at harvest 
time. Following 15 weeks of regular air storage, it 
had lost much fruit condition and flavor that was 
present at harvest. The appearance and taste of this 
apple are not dissimilar to NJ 55. 

Jonagold (****) was evaluated more as a marker 
than a new cultivar. It clearly is an outstanding 
apple that should be planted. It has good size and 
outstanding flavor; however, it lacks long storage 
life. 

New Jersey 100 (**) is a large, very attractive 
yellow apple with a waxy smooth surface. It has a 
spicy licorice taste that was very strong. It is not 
very sweet and is low in acid. It may just be another 
apple that gets lost in the crowd. 

Natco 3 (**) is a fairly attractive yellow apple with 
a prominent reddish pink cheek. It appears to have 
a very large L/D ratio, perhaps 1.05 or greater. It 
tastes sweet and it has a distinctive, strong spicy 
flavor that lingers after your have eaten the apple. It 
is an extremely interesting and complex apple. 
Some fruit had watercore when they were harvested 
on October 19. 

Natco 24 (**) is a fairly attractive, large, dark 
cherry red apple with striped red over yellow-green 
ground color. Flavor is good but astringency is quite 
high. It probably can benefit from a period of 
storage. Flesh is somewhat dry and it did not appear 



to be ready to eat at harvest; however, it is attractive 
enough and the taste is good enough to warrant 
further evaluation. 

Natco 58 (*) was harvested on October 19, yet the 
acid was so high that it was difficult to identify or 
characterize the taste. Color and appearance are not 
exceptional. This cultivar does not appear to be a 
good prospect for the Northeast. 

Natco 81 (**T) is a very attractive apple that rated 
rather high in red color, appearance, flavor, and 
overall. It is Spartan-like in appearance and bears 
a striking resemblance to Acey Mac in flavor, ap- 
pearance, and time of ripening. Although they were 
not compared directly, they appear to be identical 
twins. 

Nehuta (.**l) is a somewhat attractive apple that 
resembles Delicious in many respects. It ripens at 
the end of August. It is somewhat irregular in shape, 
shows signs of uneven ripening, and is distinctly acid 
even when watercored. Flesh texture is somewhat 
undesirable. Overall, this apple has not distin- 
guished itself enough to be recommended. 

New York 429 (**) is a very attractive, large, 
smooth, red apple. It is somewhat irregular in 
shape. Flesh is purfumy, white with a green cast, 
and when ripe the flesh seems somewhat on the soft 
side. We believe that it is a good apple. Our major 
question is whether or not it is good enough to stand 
out among all of the other good apples. 

New York 617 (**) was an extremely large, some- 
what irregularly shaped red apple. Even though the 
ground color is yellow, fruit are still high in acid at 
the optimal harvest date. It is not a good fresh 
market fruit; however, it appears to have the flesh 
characteristics required for an outstanding process- 
ing apple. 

New York 752 (**) is a large, somewhat blotchy 
burned-red apple with yellow flesh. It has a spicy 
licorice-almond flavor that may be too distinctive to 
be acceptable. 

New York 66305-139 (**) is the earliest of the 
disease-resistant selections from New York. The 
major strength of this apple is that it is one of the first 
disease-resistant apples to ripen. Within a very 
short time, apples go from green and very tart to red, 
soft, and still tart. This apple is good enough to 
compete with Early Mcintosh or Puritan, but that is 
really not saying much. AA 63 or Sumac are better 
and they all ripen at about the same time. 

New York 66305-289 (**) is a very attractive dis- 



10 



Fruit Notes, Spring, 1993 



Table 2. Laboratory analysis of apple 


cultivars evaluated 


in 1992 


at the University of Massachusetts 




Horticultural Research Center. 


























Soluble 


Red 




Best 


Also 


Weight 


Diameter 


Firmness 


solids 


color 


Cultivar 


date 


evaluated 


(g) 


(in.) 


(lbs.) 


(%) 


(%) 


AA63 


Aug. 6 




99 


2.54 


9.8 


11.3 


74 


Sumac 


Aug. 6 




91 


2.48 


10.2 


12.5 


85 


NY 66305-139 


Aug. 6 


8/11 


115 


2.65 


15.4 


11.8 


50 


BC 9-17 


Aug. 1 1 & 17 




151 


2.84 


16.4 


13.9 


66 


Arkcharm (AA 18) 


Aug. 17 


8/24, 9/1 


196 


3.10 


13.8 


12.4 


73 


Jerseymac 


Aug. 17 




166 


3.03 


13.2 


10.8 


75 


BC-78-9-28 


Aug. 17 




135 


2.84 


13.8 


14.4 


90 


Williams Pride 


Aug. 20 


8/11, 8/17, 8/24 


202 


3.20 


15.6 


11.6 


80 


Redfree 


Aug. 20 




148 


... 


17.0 


11.8 


73 


OSU 31-19 


Aug. 20 


9/1 


... 


... 


... 


— 


— 


AA44 


Aug. 24 


8/17, 9/1 


264 


3.48 


16.7 


12.6 


68 


Paulared 


Aug. 24 




145 


2.94 


15.3 


10.4 


78 


BC 8C-27-96 


Sept. 1 


8/24, 9/8 


225 


3.21 


13.3 


12.9 


77 


Sansa 


Sept. 1 




183 


2.96 


15.9 


15.4 


86 


Nebuta 


Sept. 1 


8/24 


155 


2.84 


16.2 


13.9 


73 


BC 15-30 


Sept. 1 




300 


3.67 


18.6 


13.6 


70 


Himekami 


Sept. 8 


8/24 


154 


2.85 


16.0 


13.1 


79 


Akane 


Sept. 8 




194 


... 


15.7 


12.9 


93 


BC 9P- 14-32 


Sept. 8 




200 


3.08 


17.0 


15.5 


80 


Dayton 


Sept. 8 


9/14 


290 


3.52 


16.9 


12.9 


75 


Ginger Gold 


Sept. 14 


9/8 


259 


3.30 


20.0 


13.9 


— 


Fiesta 


Sept. 14 


9/21 


199 


3.19 


17.6 


13.4 


76 


Tsugaru Homei 


Sept. 14 


9/28 


216 


3.12 


15.6 


13.4 


72 


Arlet 


Sept. 14 


9/21 


195 


2.99 


17.8 


12.8 


67 


Elstar 


Sept. 14 




137 


2.76 


16.7 


13.5 


62 


NY 66305-289 


Sept. 14 


9/21 


183 


3.07 


15.7 


12.7 


85 


NY 74828-12 


Sept. 21 




149 


3.04 


17.3 


12.0 


86 


Alkemene 


Sept. 21 




156 


— 


16.5 


15.5 


— 


NY 75414-1 


Sept. 21 


9/8, 9/14, 9/28 


167 


3.07 


14.8 


12.1 


91 


Honeycrisp 


Sept. 21 


9/14, 9/28 


256 


3.34 


15.2 


12.0 


69 


BC2-8 


Sept. 21 




252 


3.42 


14.7 


12.1 


86 


Shamrock 


Sept. 28 


9/14, 9/21, 10/5 


178 


3.04 


17.8 


13.7 


— 


Natco 81 


Sept. 28 


9/21 


231 


3.40 


15.8 


11.9 


91 


BC 8M 15-10 


Sept. 28 




235 


3.07 


16.8 


14.7 


50 


NY 75413-30 


Sept. 28 




425 


4.01 


15.8 


12.9 


80 


Bonza 


Sept. 28 


10/5 


210 


3.30 


17.3 


11.9 


90 


BC 8B-20-13 


Sept. 28 


Pick Earlier 


337 


3.70 


11.6 


16.3 


... 


BC 8B-14-56 


Sept. 28 


10/5, 10/19 


228 


3.28 


14.6 


14.5 


90 


Yataka 


Sept. 28 


10/5, 10/19 


183 


2.99 


15.6 


14.6 


65 


1 



ease-resistant apple that resembles a Mcintosh ex- 
cept that it has dark cherry red color and a long thin 
pedicel. It has yellowish flesh, qviite tart, and differ- 
ent flesh texture than Mcintosh. It ripens between 
September 15 and 20 but ripen unevenly. This is a 
nice apple that should be evaluated further. 

New York 74828-12 (**) is a disease-resistant apple 
that looks and tastes like Jonamac. When the 



ground color changes to green-yellow the acidity is 
still very high. There is a tendency for this cultivar 
to ripen unevenly and show some preharvest drop. 
This apple was for the most part an average apple. 

New York 75414-1 (***). There was more excite- 
ment generated about this apple than any other 
disease-resistant apple. It is an extremely attractive 
medium-sized apple, that develops a deep burgundy 



Fruit Notes, Spring, 1993 



n 



Table 2 continued. 














Soluble 


Red 




Best 


Also 


Weight 


Diameter 


Firmness 


solids 


color 


Cultivar 


date 


evaluated 


(g) 


(in.) 


(lbs.) 


(%) 


(%) 


Dulcet 


Sept. 28 


10/8 


185 


3.03 


16.1 


13.2 


90 


EC 98T 486 


Oct. 5 


9/21, 9/28 


204 


3.08 


14.5 


11.0 


83 


Hudson 


Oct. 5 




210 


3.06 


20.4 


12.6 


... 


Yoko 


Oct. 5 


10/13 


225 


3.20 


19.6 


15.4 


65 


NY 65707-19 


Oct. 5 


10/13 


208 


3.18 


16.5 


11.2 


80 


Senshu 


Oct. 5 


10/13 


205 


3.10 


14.3 


13.8 


80 


Jonagold 


Oct. 8 




278 


3.43 


15.8 


13.3 


68 


Rubinette 


Oct, 8 


10/13 


155 


2.88 


15.1 


16.4 


50 


Freyburg 


Oct. 8 


10/19 


193 


2.97 


19.6 


16.5 


... 


Shizuka 


Oct. 8 


10/8, 10/19 


395 


3.83 


16.3 


14.3 


... 


NY 429 


Oct. 13 


10/5 


244 


3.37 


14.0 


12.1 


88 


Hawaii 


Oct. 13 




230 


2.95 


15.1 


13.1 


... 


Kinsei 


Oct. 13 


10/19 


216 


3.21 


16.1 


13.6 


... 


NY 75441-67 


Oct. 13 


9/28, 10/5 


258 


3.29 


16.3 


13.0 


92 


BC 17-30 


Oct. 13 


10/5 


237 


3.32 


12.5 


13.0 


95 


Hokuto 


Oct. 13 


10/8, 10/19 


302 


3.59 


15.0 


13.1 


65 


NY 617 


Oct. 13 


10/5 


420 


4.03 


13.8 


13.6 


70 


Splendour 


Oct. 13 


10/5, 10/19 


206 


3.20 


16.0 


11.8 


82 


Brock 


Oct. 13 


10/8, 10/19 


302 


3.56 


15.5 


13.5 


64 


NY 73334-35 


Oct. 13 


10/5 


252 


3.32 


16.8 


11.4 


89 


NY 75413-30 


Oct. 13 




205 


3.14 


15.8 


13.7 


90 


Fantazja 


Oct. 13 




138 


2.73 


14.7 


12.7 


85 


NY 752 


Oct. 13 




275 


3.46 


14.6 


12.3 


70 


AA62 


Oct. 13 




242 


3.26 


17.9 


13.5 


... 


BC 8C-5-62 


Oct. 13 




182 


3.00 


15.2 


14.2 


82 


BC 8K-21-39 


Oct. 19 




184 


2.98 


17.9 


13.0 


84 


Natco 24 


Oct. 19 


10/13 


250 


3.42 


17.1 


13.0 


85 


Coop 29 


Oct. 19 




196 


3.14 


17.8 


12.2 


... 


Newtown Seedling 


Oct. 19 




228 


3.33 


18.5 


12.1 


80 


Criterion 


Oct. 19 




185 


2.98 


13.5 


11.2 


... 


Nittany 


Oct. 19 




165 


2.87 


17.5 


13.3 


75 


Reinette Simirenko 


Oct. 19 




190 


3.07 


18.4 


12.2 


... 


Fiorina 


Oct. 19 




168 


2.97 


17.4 


12.6 


83 


Braeburn 


Oct. 19 




185 


2.97 


20.0 


12.3 


60 


Ambitious 


Oct. 19 




143 


2.80 


19.7 


13.0 


... 


Orin 


Oct. 19 




213 


3.06 


18.0 


14.2 


— 


NJ 100 


Oct. 19 




235 


3.34 


17.5 


12.4 


— 


Suncrisp (NJ 55) 


Oct. 19 




203 


3.06 


17.8 


14.2 


... 


Natco 58 


Oct. 19 




209 


3.10 


18.9 


12.8 


71 


Natco 3 


Oct. 19 




260 


3.21 


16.1 


12.2 


... 





red color. Its red color, prominent white lenticels, 
and slight scarf skin made it almost indistinguish- 
able from Macoun. The flesh is white, tart, not too 
sweet, and extremely crisp. This apple had the color 
to pick on September 8 but flavor and other at- 
tributes did not develop until later. Realistically, 
this apple showed no sign of drop and it could have 



been picked from the second week in September 
through the first week in October. Those who tried 
this apple knew that they would like it before they 
even tasted it. It was a classic Pavlov's dog response. 

New York 75413-30 (♦♦). This very large disease- 
resistant apple was harvested too early, on Septem- 



12 



Fruit Notes, Spring, 1993 



ber 28. The fruit were quite pitted and the flesh 
seemed dense and heavy. It was rated quite high for 
color and attractiveness but quite low for flavor. 
Judgment must wait for another year, but we were 
not too impressed this year. 

New York 65707-19 (**). This disease-resistant 
apple is fairly attractive, round, medium sized, and 
red with small white lenticels and greenish white 
flesh. The flavor is not strong but the flavor and 
acidity seemed to vary quite a bit from one fruit to 
another. On October 13, fruit were dropping. The 
jury is still out on this one. 

New York 75441-67 (*) is a deep-red disease-resis- 
tant apple showing some skin russeting or blemish- 
ing, liie flesh is white, the skin is tough, the flavor 
OK, but the acidity is so high that even when ripe it 
is difficult to recommend this one. 

New York 73334-35 (**) is a disease-resistant apple 
with good red color, but its irregular firuit shape 
detracts from its appearance. Harvest on October 5 
was too early while severe drop was noted on October 
13. Flesh is whitish green, and the skin is tough. The 
acid is high, the sugar is low, and the taste is not 
outstanding. There is a blueberry aflertaste. It was 
not an outstanding apple this year. 

New York 75413-30 (**) is a very attractive, red, 
disease-resistant apple the looks much better than it 
tastes. The shape is ovate to conic and ribbed. Flesh 
is white with a tinge of yellow. Skin has a chalky, odd 
taste. We rated flavor only fair to good. 

Nittany (**). Trees fruited in the first leaf, so the 
October 19 harvest date may not be representative of 
future harvests. This apple is fairly good tasting, but 
it is not as good as Nittany originating from Pennsyl- 
vania. We will continue to follow it. 

Orin (**) is green apple and is fairly attractive. It is 
a very sweet, subacid apple with a pleasant, slightly 
fruity taste. This sweet apple is worthy of fiirther 
evaluation. 

Redfree (***). We used Redfree as another marker 
in the evaluation process. It is one of the best August 
apples with a rating of at least *** now. It rates very 
high in red color, attractiveness, flavor, and overall. 
Even though it is a disease-resistant apple it can 
stand on its own merits. It will not store for a long 
time. 

Reinette Sindrenko (**) has a very distinctive 
green color, similar to an immature Granny Smith. 
Flesh is whitish green. Flavor is somewhat tart with 



a distinctive but spicy taste. At the time of our 
sample, flesh was still green and soluble solids were 
only 12.2. We believe that this apple was not ripe at 
the time of harvest, even though it did taste reason- 
ably good. The taste and condition of Reinette 
Simirenko was excellent following several weeks in 
regular air storage. This cultivar warrants further 
evaluation. 

Ruhinette (*). The blotchy red-pinkish-brown color 
make this apple rather unattractive. Also, the large 
lenticels give the impression of russet. This apple is 
fair to good tasting but the acidity and astringency 
detract from its flavor. We are not very excited about 
Rubinette. 

Sanaa (**T) is a fairly attractive medium sized 
apple. We were very impressed with the flavor, 
texture, crispness, and aroma. We consider Sansa 
one of the jewels this year. It matures at about the 
time of Sunrise, and when compared with Sunrise, 
Sansa is the clear winner. It tastes Gala-like but it 
ripens fully two weeks before Grala. We did not have 
enough fruit to evaluate it fully, but it is one apple 
that we will be looking forward to eating next year. 

Senshu (**). The blotchy or burned reddish brown 
stripes on this medium sized apple make it some- 
what unattractive. It has prominent calyx lobes and 
a swelled pedicel at the attachment like Gala. It has 
unusual orange-yellow flesh. It is a very good 
tasting apple. It is not too sweet with a slightly spicy 
flavor. Overall, this cultivar was rated quite high. 

Shamrock (**T) was evaluated over a three week 
period and it had acceptable quality over the whole 
time. It did not received the highest marks for flavor 
but the ratings were consistently good. In mid- 
September, it tastes green and Granny-like. Others 
who were offered this apple seemed to liked it. We 
believe that it is a good apple that fills a niche for a 
green apple in September and October. There is no 
other green apple that we have tasted that would 
compete in this market. Storage life is not long. 
Fruit soften in storage. As it softens, it assumes the 
taste of a very good Mcintosh. We can recommend 
Shamrock. 

Shizuka (**T) is a large, attractive, yellow apple 
with a pink cheek, and it has very good flavor. This 
apple resembles Mutsu in many ways, a fact that is 
not too surprising given their common parentage. 
However, it also differs from Mutsu in several impor- 
tant ways. It appears to be more elongated in shape. 
It ripens about a week before Mutsu. The flesh is 
finer, less dense, and tastes fruitier than Mutsu. 



Fruit Notes, Spring, 1993 



13 



Mutsu is plagued by Pseudomonas spotting, and we 
found none on Shizuka. Although vigorous, this will 
be a grower-firiendly tree. Shizuka was a very nice 
apple that should be evaluated further. 

Splendour (.**) is one of the most attractive apples 
evaluated. The fruit is round to conic, a good cherry 
red, with prominent tan lenticels. We evaluated this 
starting on October 5. It improved in flavor with 
subsequent harvests, but it never reached the top of 
the list in flavor. The flesh is yellow white and the 
flavor is mild and subacid. The skin is tender, thus 
it may not be able to stand up in commercial market- 
ing channels. It is a very grower-friendly tree. 

Spigold (***). We did not evaluate Spigold for- 
mally because we have already decided that this is 
one of the best apples available. It is large, some- 
what unattractive, and tends to bitter pit. We 
believe that it is destined only for a niche market, but 
what a wonderful tasting apple! It can be very 
biennial. 

Sumac (**) was one of the first apples to be evalu- 
ated in the season. It is small and quite unattractive. 
We rated flavor quite high, but considering every- 
thing, we would prefer AA 63 to Sumac for an apple 
this early in the season. 

SuncrUpâ„¢ (New Jersey 55) (**t). We made 
our lastharvestof mostapples on October 19. At that 
time NJ 55 had fair appearance, a pink red cheek, 
and a ground color that was still green. It was quite 
acid and had no better than average taste. The 
remaining NJ 55 were harvested on November 4. 
The ground color had changed and it appeared ready 
to harvest. Although it still tasted a little tart, we 
rated flavor very high. At that time it was a wonder- 
ful tasting apple that appeared to have the potential 
for quite long storage. Our major reservation about 
this apple is that we may not have a sufficiently long 
growing season to mature it properly. I would say 
that it matures up to a week after Fuji. 

Tsugaru Homei (**i). On September 14 this apple 
was not highly colored, but it had a red mottling over 
a pinkish red. Ithas a shape similar to Spencer. The 
apple has a good sweet, crisp, juicy, and somewhat 
spicy taste. When evaluated two weeks later it was 
cherry red and had developed an extremely sweet 
spicy flavor. We believe that September 20 may have 
been an appropriate harvest date. We do not know 
if it has enough going for it to make it. 



Williams Pride (**t) was one of the best disease- 
resistant apples evaluated. Fruit is large, red, and 
irregular in shape, and the skin not smooth. It is 
only moderately attractive but the taste is mild, 
subdued, and slightly spicy and good. When ripe the 
firuit is quite aromatic. Fruit show some bitterpit. 
People who tasted Williams Pride thought that it 
was a very good apple. This selection requires 
further evaluation, primarily to confirm the charac- 
terization of its flavor as good. 

Yataka (**t) was an excellent apple again this year. 
It is truly an early maturing strain of Fuji. It ripens 
fully two weeks ahead of other Fuji strains and it is 
ready to eat immediately. It is not an attractive 
apple, and it is definitely less attractive than strains 
ofRedFuji. Flavor was rated very high. OflFthetree, 
the taste of Yataka is better than any of the other 
strains of Fuji. We are uncertain about its storage 
potential. We rate Yataka quite high. 

Yoko (**). This medium-sized red apple has fair to 
good color and attractiveness. It taste is very sweet 
and spicy. There is russet in the calyx, similar to 
Arlet. We do not think that it is outstanding enough 
to compete with other apples. 

Summary 

1. Several apples were recognized from the evalu- 
ation in 1992 as being clearly superior. These 
include Arlet, Gingergold, Honeycrisp, Reinette 
Simirenko, Sansa, and Suncrisp"â„¢ (NJ 55). 
Other apples that fall into this category but they 
are unavailable to the general pubic for testing 
at this time. Included in this group are the 
British Columbia selections BC 9P-14-32, BC 
8M-15-10, BC 17-30, and Fantazja. 

2. A second group of apples were recognized as not 
being quite so outstanding, but they were suffi- 
ciently good to be given a designation of Honor- 
able Mention. These cultivars include: Akane, 
Kinsei, Orin, Shamrock, Shizuka, and Yataka. 

3. Several disease-resistant cultivars were recog- 
nized for their superior quality. This group 
includes: Alkemene, Fiorina, NY 75414-1, and 
Williams Pride. Liberty and Redfree are not 
included on this list because they already have 
been recognized as being good and accepted 
disease-resistant cultivars suitable for commer- 
cial planting. 



14 



Fruit Notes, Spring, 1993 



Implementation of the MARYBLYT 
Model for Fire Blight Control 



Roberta Spitko 

New England Fruit Consultants 

Fire blight, caused by the bacterium Erwinia 
amylovora, is one of the most destructive and diffi- 
cult to manage diseases encountered by tree fruit 
growers throughout the world. Some might argue 
that apple scab, caused by Venturia inaequalis, 
deserves this honor but with respect to apple scab, 
there is always next year and the chance to try again. 
A severe epidemic of fire blight can damage an 
orchard of susceptible apple or pear trees so severely 
that there is no next year; that is, the orchard block 
must be removed. 

New England Fruit Consultants (NEFCON) 
has been observing and studying this disease in 
Massachusetts, Vermont, and New Hampshire for 
more than a decade. Overall knowledge of this 
disease has increased significantly since the early 
1980s, much as a restilt of the excellent work of Dr. 
Paul Steiner and his colleagues as the University of 
Maryland. Their development of the MARYBLYT 
computer model to aid in the control decision making 
process is enabling us to understand disease devel- 
opment better and to fine tune our disease control 
strategies. It is not our intention to describe in detail 
the epidemiology of fire blight as there are many 
excellent sources already available (see U.S.D.A. 
Bulletin No. 631, Fire Blight- Its Nature, Prevention 
and Control). Our purpose is to describe our suc- 
cesses and frustrations regarding control, particu- 
larly with regard to the MARYBLYT model. 

NEFCON has been working with Dr. Steiner 
and Dr. Daniel Cooley at the University of Massa- 
chusetts since the mid-1980s as the fire blight model 
was being developed. We found that it described 
disease development accurately as we had observed 
it but we did not attempt to use it as a control 
strategy at that point. In the past several years as 
the model has become commercially available, we 
incorporated it fully into our fire blight management 
program. In 1992, we implemented the model in 
multiple sites in Massachusetts, New Hampshire, 
and Vermont. Our findings are as follows: 

1. The model predicts with extreme accuracy when 
overwintering canker activity will begin as well as 
when symptoms of canker blight, blossom blight, 



shoot blight, and trauma bUght will occur. This 
prediction facilitates detection and removal of 
blighted tissues if possible (numerous infections are 
probably best left for winter removal). 

2. If bloom phenology and meteorological data are 
kept judiciously, and Streptomycin sprays are used 
when the model predicts the risk for blossom blight 
is high or blossom infection has occurred, problem 
sites may be cleaned up, or major outbreaks of 
blossom blight in new sites may be avoided. 

3. Although keeping track of bloom and weather 
data may appear simple, it is important that these be 
extremely accurate as the model's predictions can 
only be as accurate as the human input allows it to 
be. In our experience, we found detailing bloom to be 
difficult. Most orchards have many different culti- 
vars blooming at different times; an entire bloom 
period may be several weeks long. Also, many 
cultivars which are highly susceptible to fire blight 
produce secondary blossoms (Paula Red, Rome, and 
Cortland, as well as many kinds of pears). It is 
possible to have 1/2-inch fruits and open blossoms in 
the same fruit cluster. It has been our experience 
that this route is a very common one by which severe 
epidemics become established. Growers must keep 
an eye out for these late blossoms in problem areas 
and be prepared to spray Streptomycin should 
weather conditions favor infection. 

With respect to weather data, daily maximum 
and minimum temperatures must be entered. An- 
other very important input is wettings, however 
slight they may seem. In several sites in 1992, the 
model did not predict blossom blight epidemics 
which occurred. When we revised the data to reflect 
dews which likely happened due to extreme tem- 
perature drop at night during bloom, the model 
accurately predicted that infection of the blossoms 
had occurred and when symptoms would be visible. 

4. With prolonged bloom periods and weather par- 
ticularly favorable to fire blight, the model MAY call 
for more Streptomycin sprays than should be ap- 
plied considering Streptomycin resistance manage- 



Fruit Notes, Spring, 1993 



15 



ment. In most years, however, it is unlikely that the 
model would call for more than three Streptomycin 
applications, which would be within resistance man- 
agement guidelines. 

5. The complexity of the fire blight disease cycle 
and the way that symptoms manifest themselves 
(several different phases showing up within a short 
period of time) makes it at times difficult to deter- 
mine what is happening in an epidemic situation. 
An excellent feature of the model is that data files are 
created and unusual or unexpected situations may 
be studied at a later date. We have increased our 
understanding of how this disease operates signifi- 
cantly by reviewing these files over the years. 

6. Although the MARYBLYT model is excellent for 
monitoring disease development and helpful in 
cleaning up known problem sites, much of the de- 
structiveness of fire blight is due to its erratic occur- 
rence. If an orchard has had no history of fire blight, 
there would be no incentive to implement an aggres- 
sive control program including Streptomycin 
sprays. Once a serious epidemic is in progress, it is 
too late for the model or Streptomycin sprays to be of 
much help. Repeatedly spraying Streptomycin on a 
raging epidemic can only favor resistance develop- 
ment and is of questionable value in stopping disease 
progression. 

Where an epidemic of fireblight will occur each 
year is still the overriding question. We have good 
tools now available to aid in control decisions, par- 
ticularly the MARYBLYT program, but where to 
implement them if a site has no prior history contin- 
ues to elude us. 

7. Our best strategies for fire blight management 
are as follows: 



A. Keep nitrogen levels in check. Pushing young 
trees with high nitrogen regimens favors lush 
growth that is highly susceptible to infection. 

B. Watch vector populations, primarily aphids, 
leafhoppers, and pear psylla. Keep them low. 

C. Implement a copper program annually in early 
spring on all pears and susceptible cultivars of 
apples. 

D. Avoid planting trees, if possible, where both 
scion and rootstock are highly susceptible to 
fire blight. 

E. Follow proper pruning techniques for winter 
removal of overwintering cankers. Major epi- 
demics are probably bestleflto nin their course 
in summer infections; a few minor strikes 
should be removed as soon as they are detected. 

F. Implement the MARYBLYT program as part of 
your regular orchard recordkeeping activities. 
If any stage of fireblight is detected in the 
orchard or general vicinity, use the model to 
time application of Streptomycin sprays in an 
aggressive control program for at least two 
successive years. 

In conclusion, with diligence and good manage- 
ment techniques it seems possible to obtain satisfac- 
tory control of fire blight in most growing seasons. 
Many questions remain unanswered, however, such 
as the role of systemically infected, asymptomatic 
trees in the disease cycle, and where major epidem- 
ics will strike from season to season. We are un- 
doubtedly making progress in our understanding of 
this complex disease. Hopefully, at some point we 
will achieve the knowledge we need to be successful 
consistently in its management. 



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16 



Fruit Notes, Spring, 1993 



Fish Hydrolysate Fertilizer Should Not 
Be Applied Foliarly to Apple 

J. R. Schupp, M^ Schupp, and M.M. Bates 
Highmoor Farm, University of Maine 



The four- tx) six-week period following bloom is a 
critical time for crop development in apples. During 
this period, the mfgority of seasonal vegetative 
growth takes place, and firuit set, return bloom, 
potential yield, and potential fruit size are deter- 
mined. Mineral nutrient reserves become depleted, 
as utilization is greater than root uptake, and nutri- 
ents, especially nitrogen, can become a Umiting 
factor to growlii, even though soil reserves are ad- 
equate. 

Foliar sprays of mineral nutrients during this 
critical period can be beneficial in supplementing 
ground-applied fertilizers. These applications do 
not replace the regular ground-applied fertilizer 
program, they simply fill the gap during the time 
that demand outstrips supply. Foliar nitrogen appli- 
cations in particular have been shown to increase 
fruit set and fruit size when applied at 8 to 12 lbs per 
acre during this time. Previous studies have shown 
that foliar urea sprays are a safe and effective 
method for fertilizing apple (Stiles and Reid, 1991). 

Fish hydrolysates, a byproduct of the fishing 
industry have recently been recommended as an 
organic nitrogen fertilizer for cranberry 
(DeMoranville, 1990), apple, and blueberry (Weis 
and Bramlage, 1992). The fishing industry is inter- 
ested in developing new uses for this material and in 



cooperation with the Portland (ME) Fish Exchange, 
we investigated the feasibility of using fish hydroly- 
sates as a foliar nitrogen source for apple. 

Mature Delicious/MM.lll and Golden Deli- 
cious/MM. 106 apple trees, growing at the University 
of Maine Highmoor Farm in Monmouth were used 
for this experiment. "Gulf of Maine" fertilizer, con- 
taining 2% N, 4% P, and 2% K was supplied by the 
Portland Fish Exchange. 

Treatments were as follows: 

1. Control, no foliar fertilizer. 

2. Fish hydrolysate, 3 gallons in 25 gallons of 
water. 

3. Urea, 1.25 lb in 25 gallons of water. 

Both fertilizer treatments, calculated to provide 
the equivalent amount of nitrogen as an application 
of 12 lb urea/acre, were applied as a dilute spray with 
a handgun. Three applications, at petal fall (PF), 
PF+7 days, and PF+14 days, were made on four 
repUcations of each cultivar. 

Fish hydrolysate fertilizer reduced fruit set of 
both cultivars (Table 1). Foliar urea increased fruit 
set and yield of Golden Delicious but had no effect on 
Delicious. Fruit from fish hydrolysate-treated 
Golden Delicious trees had higher soluble solids 
than those from urea-treated trees, and this appears 



Table 1. The effects of foliar sprays offish hydrolysate fertilizer and urea on fruit set, yield, fruit 
soluble solids, and russeting of Delicious and Golden Delicious apple. 



Fruit set (%) 



Treatment 



Del. 



Gold. 



Yield (kg) 
Del Gold. 



Soluble 
solids (%) 



Russeting* 



Del. 



Gold. 



Del. 



Gold. 



Control 73 a" 19 b 81 ab 54 b 10.2 a 13.5 ab 1.3 b 1.8 b 

Fish hydrolysate 38b 7c 64b 21 b 10.2 a 14.1 a 3.7 a 4.1 a 

Urea 64 a 34 a 92 a 128 a 9.8 a 12.8 b 1.0 b 2.0 b 

• Russeting was rated on a scale of l=none to 5=100% russeted. 

" Means within columns not followed by the same letter are significantly different at odds of 19:1. 



Fruit Notes, Spring, 1993 



17 



to be related to the difTerences in cropping between 
these treatments. Neither fertilizer affected leaf or 
fruit mineral nutrient content, fruit size, or fruit 
firmness at harvest (data not presented). 

Russeting is a rough brown netting over the 
surface of the fruit that occurs when the fruit epider- 
mis is killed. Ciolden Delicious is an economically 
important cultivar that is predisposed to russeting, 
while Delicious is much less sensitive to russeting. 
Russeting results in loss of grade when fruit are 
packed and must be kept to a minimum if an orchard 
is to remain profitable. Fish hydrolysate increased 
fruit russeting on both cultivars (Table 1). The 
conductivity of the fish hydrolysate fertilizer was 
45.6 mmhos/cm, the equivalent of a 29,000 ppm 
solution of KCl. It is probably this salt that reduced 



fruit set and caused the severe russeting. Regard- 
less of the cause, fish hydrolysate reduced fruit set 
and damaged the fruit and should not be foliarly 
applied to apple. 

Literature Cited 

DeMoranvUle, C. 1990. Fish hydrolysate fertilizer : 
its potential role in commercial cranberry produc- 
tion. HortScience 25:626 (abstract). 

Stiles, W.C. and W.S.Reid. 1991. Orchard Nutrition 
Management. Cornell Coop. Ext. Bui. 219. pp. 18-19. 

Weis, S.A. and W.J. Bramlage. 1992. Using fish 
waste hydrolysates as a fertilizer for apples and 
blueberries. Fruit Notes 57(3):15-19. 



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Comparative Effects of Margosan-0 
(Neem Extract) and Imidan on Plum 
Curculio and Apple Maggot 

Ronald J. Prokopy and Margaret Christie 
Department of Entomology, University of Massachusetts 

John Bemis 

Hutchins Farm, Concord 



We are continually on the lookout for safe new 
pesticides that can control some of our key apple 
pests, such as plum curculio and apple maggot. 
Extracts of seeds and other parts of neem trees have 
been used for centuries, even millennia, to control a 
wide variety of insects in India and other parts of 
Asia. These extracts appear to be remarkably safe 
for human consumption as well as environmentally 
safe. They are known to control insects by acting as 
insect repellents, antifeedants, or toxicants or by 
disrupting the growth of insects. Recently, W.R. 
Grace Company began distributing an extract of 
neem plants called Margosan-0 for use in green- 
houses, commercial nurseries, forests, and homes. 



Although no extract of neem, including 
Margosan-O, is yet registered for use on crops for 
human consumption, we decided to evaluate its 
eflFectiveness against plum curculio and apple mag- 
got on apple trees at Hutchins Farm in Concord, MA 
in 1992. Hutchins Farm grows produce organically 
and annually contends with moderate to high popu- 
lations of plum curculio and apple maggot. 

Methods Used 

Against plum curculio, a treatment of 
Margosan-0 at one gallon per 100 gallons was ap- 
plied with a mist blower at 300 gallons of water per 



18 



Fruit Notes, Spring, 1993 



Table 1. Comparative effects of Margosan-0 (neem extract) and 
Imidan on plum curculio and apple maggot. 

Injured fruit {%) 



Apple maggot 
larval tunnels 



Treatment 



Plum curculio 
stings 



On tree 



In drops 



Margosan-0 
Imidan 
Untreated check 



62 a* 
16 b 

63 a 



14 b 
13 b 
38 a 



42 b 
30b 
76 a 



'Means in each column followed by a different letter are signifi- 
cantly different at odds of 19:1. 



acre to 120 mature, semi-dwarf Liberty and 
Jonafree trees on May 22 (petal fall), May 26, May 
29, and June 2. As a control treatment, Imidan at 1.5 
pounds per 100 gallons was applied on May 22 and 
May 29 to 120 other Liberty and Jonafree trees. Yet, 
another 120 trees of these varieties remained 
unsprayed as checks. Sampling consisted of exam- 
ining20 fruit per tree on four replicates of eight trees 
each per treatment on June 8. 

Against apple maggot, a treatment of Margosan- 
O at one gallon per 100 gtdlons was applied with a 
mist blower at 300 gallon of water per acre to 60 
mature, semi-dwarf Prima and Burgundy trees on 
July 1, July 8, July 15, and July 22. As a control 
treatment, Imidan at 1.5 pounds per 100 gallons was 
applied on July 1 and July 15 to 60 other Prima and 
Burgundy trees. Yet, another 60 trees of these 
varieties remained unsprayed as checks. Sampling 
consisted of examining 10 on-tree and 10 dropped 
fruit per tree on six replicates of two trees each per 
treatment on August 19. Fruit were held at room 
temperature for one week (drops) or four weeks (on- 
tree fruit) before examining for larval trails in the 
fruit flesh. 

Results 

As shown in Table 1, use of Margosan-O failed to 
provide any detectable reduction in firuit injury by 
plum curculio compared with untreated check fruit, 
even though it was applied every three to four days 
from petal fall to within six days of sampling. Imidan 
applied every seven days provided reasonable 



curculio control in the face of the very high popula- 
tion of curculios. 

As shown in Table 1, use of Margosan-0 resulted 
in a significant decrease in percent fruit infested 
with apple maggot larval trails. In fact, it was little 
different from Imidan in this regard. Neither pro- 
duced a high level of maggot control, possibly be- 
cause there was a four-week gap between the last 
treatment and removal of fruit in sampUng for 
maggot injury. 

Conclusion 

We conclude that neem plant extract formulated 
and sold as Margosan-0 offers little or no promise for 
controlling plum curculio but does offer substantial 
promise for controlling apple maggot. We do not 
know if its effects on apple maggot were through 
reduction of fly egglaying punctures in fruit or 
through prevention of growth of larvae hatching 
from eggs. Either way, we can anticipate that 
application of Margosan-0 against apple maggot 
might need to be twice as frequent as application of 
Imidan to provide equivalent levels of control. We 
hope in the near future to be able to evaluate 
Margosan-0 against leafminer larvae and leafhop- 
per nymphs. Quite possibly, Margosan-0 might 
soon be registered for agricultural use. 

Acknowledgements 

This work was supported by a grant from the 
W.R. Grace Company, to whom we are grateful. 



Fruit Notes, Spring, 1993 



19 



Orchard Mineral Nutrition: Ground- 
appiied vs. Foiiar-applied Fertilizers 



James R. Schupp 

Highmoor Farm, University of Maine 



Why do apple growers spend time and money 
spraying fertilizers on foliage when for centuries we 
have been told that plants take up nutrients from the 
soil via their roots? They do it in an attempt to 
improve fruit quality and enhance its storage life. 
Apple is somewhat unique among fruit crops in that 
it is able to utilize a range of mineral nutrients 
through its leaves. 

Many new products are available to apple grow- 
ers for foliar feeding. Sometimes promotional mate- 
rials suggest that rather dramatic results can be 
obtained from using these products. One grower 
recently calculated the expected results for his or- 
chard based on such claims and found that if he 
would simply use several of these products, his 
yields would be 3000 bushels per acre with excellent 
fruit size and virtually 100% packout. This yield is 
three times that obtained in the best New England 
orchards and a level of production at which fruit size 
and quality would be very poor. Such an outcome is 
impossible of course, and most manufacturers of 
foliar nutrient products are careful to base their 
product claims within the realm of possibility. Still, 
many apple growers are uncertain what role foliar 
sprays should have in their nutrition plan. 

The first step to any orchard nutrition plan is soil 
and leaf analysis. Before applying any fertilizer in 
any manner it makes proper sense to determine 
whether or not there is need for nutrient supple- 
ments, which ones are needed, and in what amounts. 
This information provides the first answers to the 
ground-applied versus foliar-applied question. 

Macronutrients 

If leaf and soil analyses indicate the need for 
nitrogen, phosphorous, potassium, calcium, or mag- 
nesium, the cheapest and most efficient way to apply 
them is by ground application. Soil- applied fertiliz- 
ers can be applied early in the spring before the busy 
growing season and with little or no risk of damage 
to the fruit or foliage. Soil-applied nutrients also 
follow the natural pathway in the tree to all the 
locations where growth and development are taking 



place. By contrast, foliar-applied nutrients are less 
mobile and stay where they are absorbed. 

Micronutrienta 

Boron, manganese, copper, or zinc can be ap- 
plied to either soil or foliage; however, foliar applica- 
tions are more common, because it is easier to spray 
the small amounts needed than it is to apply them to 
the soU. Foliar applications allow "direct hits" to the 
fruit and foliage where supplemental nutrition is 
needed, and they allow for precision timing. The 
grower can apply the nutrient at a critical time in the 
growth stage when it is needed. Foliar fertilizers can 
harm the fruit and foliage that they contact, so 
usually, only small amounts are applied this way. 
Growers should pay particular attention to recom- 
mended rates and timings to avoid damage. Refer to 
the label of the product and the New England Apple 
Pest Management Guide for additional information 
on rates, timing, and nutrient compatibility in the 
spray tank. High-grade fertilizers, free from impu- 
rities, are needed for foliar application, adding to 
their cost. 

Special Nutrition Problems 

If a given nutrient is acutely deficient or if there 
is a special nutritional problem that is harmful to 
productivity or fruit quality, a combination of both 
soil- and foliar-applied nutrients may be justified. 
Table 1 lists several of the more common examples 
where supplemental foliar nutrients are used to 
correct specific problems. 

Perhaps the most common special nutritional 
problem in apple is low fruit calcium. Developing 
fruits compete with vegetative growth for calcium 
during the first five to six weeks following bloom. 
After this time, calcium uptake by the fruit via the 
tree's vascular system essentially stops. 

If soil calcium levels are low, or if vegetative 
growth is excessive, the fruit may be deficient in 
calcium, leading to the appears rce of cork spot or 
bitter pit and rapid loss of fruit q ality in storage. In 



20 



Fruit Notes, Spring, 1993 



Table 1. Foliar applications for special nutritional problems in apple. | 


Problem 


Problem 
nutrient 


Material 


Annual 
rate/acre* 


Timing* 


Comments 


Low fruit set, small fruit 
size 


Nitrogen 


Urea (45%) 


201b 


Pand 
PF 


Not recommended where 
calcium deficiency disorders 
are problems. 


Bitter pit, poor storing fruit 


Calcium 


Calcium chloride 
(80%CaCl,) 


15-50 lb 


1-7 


Do not substitute calcium 
nitrate. Do not premix 
calcium chloride with 
Solubor. 


Premature leaf & fruit drop 


Magnesium 


Magnesium 
sulfate (11%) 


151b 


PF 


May be applied in first or 
second cover. Compatible 
with pesticides. 


Low firuit Bet, poor quality 


Manganese 


Manganese 
sulfate (24%) 


5 1b 


DorPH 


Apply in spring before growth 
starts. 


Low frmt set, poor quality 


Copper 


Copper sulfate 
(22%Cu) 


4-6 lb 


DorPH 


Apply in spring before growth 
starts. 


Fruit pitting, shoot dieback 


Boron 


Solubor (20.5%B) 


4 1b 
81b 


PF& 1 
PH 


Make two applications of 
equal rates, but do not exceed 
8 pounds per acre per year 
fi-om Eill sources. 


Shoot dieback, low hardiness 


Zinc 


Zinc sulfate (89%) 


5.5-11 lb 


DorPH 


Apply before growth starts. 


â– Commercial formulation 

'Efedormant, P=pink stage, FB=full bloom, PF=petal fisdl, l-7=lst through 7th cover sprays, PH=postharve8t 

Adapted from Penn State Tree Fruit Production Guide, 1992-1993 and Orchard Nutrition Management, Cornell Coop. Ext Bui. 

219. 



cases where fruit calcium is marginal, the symptoms 
may be apparent only after long periods in storage. 
If soU calcium levels are low, the soU pH likely is 
acidic. The cheap, long-term solution to low soU 
calcium is liming to correct the acidity and to add 
calcium to the orchard soil; however, regardless of 
the cause of the fruit calcium problem, foliar calcium 
sprays are advisable. Foliar sprays of a calcium- 
containing fertilizer put calcium directly on the fruit 
where it can be taken up, and will reduce greatly the 
occurrence of costly blemishes and loss of fruit qual- 
ity. 

Brand Name Products vs. Salts 

A large number of products are available for 
applying foliar nutrients. Table 2 lists some of the 
foliar calcium products available to the apple 
grower. It is not possible to discuss the qualities of 
each individual product in a short forum such as this 
article, but several comparisons can be made be- 
tween brand name products versus calcium chloride 
salts. 

Brand name products, when applied to provide 
the same amount of calcium as provided by calcium 



chloride are no better or worse in their effectiveness 
in preventing frviit disorders. Thus brand name 
products are more expensive sources of calcium; 
however, brand name products may be safer to fhiits 
and foliage, easier to measure, and more conve- 
niently packaged. 

Calcium chloride contains oxide impurities that 
can increase the pH of the spray solution in the tank, 
thereby reducing the effectiveness of certain pesti- 
cides. If calcium chloride is to be tank-mixed with 
pesticides, a small amount of vinegar or buffering 
agent should be added to prevent this problem. 

Finally, brand name products may contain other 
nutrients, which may be beneficial, but only if they 
are nutrients that currently are needed by the tree. 
It is up to the individual grower to weigh the pros and 
cons of each product given his or her situation. 
Similar considerations result when growers make 
comparisons between brand name products and salt 
formulations for other mineral nutrients. 

Summary and Tips for Success 

Foliar fertilizers are an important tool for apply- 
ing micronutrients, correcting acute nutrient defi- 



Fruit Notes, Spring, 1993 



21 



Table 2. Calcium materials 


for use on a 


pples, with labeled rates per acre per application, per 


acre per season, and per acre per year. | 


Product 
name 


Percent 
calcium 


Pounds/ 
gal 


Pounds of 
calcium/ 
gal or lb 


Manufacturer 


Product/ 

A/spray 

mln.-max. 


No. of 
appL 


Total 
product/ 
A/aeaaon 
min.-max. 


ToUl 

calcium/ 

A/season 

Ob) 

mln.-max. 


CaB 


6.0 


10.0 


0.60 


Stoller, Inc 
(800-255-9548) 


3-6 pints 


8 


3-6 gal 


1.8-3.6 


CaBy 


10.0 


11.9 


L19 


Stoller, Inc 
(800-255-9548) 


2-4 qt 


8 


4-8 gal 


4.8-9.6 


Calcium 
chloride (77- 
80% CaCl2) 


27.8 


flakes 


0.28 


many 


1.8-6.2 lb 


8 


14.3-50 lb 


4.0- 14 


Calcium 
chloride (35% 
CaC12 liquid) 


12.6 


11.3 


1.42 


many 


.35-1.24 
gal 


8 


2.8-9.9 gal 


4.0-14 


Cor-Clear 
Dry 


34.5 


beads 


0.34 


SEGO Intl., Inc. 
(503-796-0133) 


4-8 lb 


8 


32-64 lb 


10.9-21.8 


Foliar 

Calcium 

Folical 


10.0 


9.6 


0.96 


Agrimar (3orp. 
(800-284-9898) 


Igal 


6-8 


6-8 gal 


6.8-7.7 


Fung-Aid 


10.0 


11.9 


1.19 


Stoller, Inc 
(800-255-9548) 


2-4 qt 


8-16 


6.5-8.2 gal 


6.5-9.7 


Link Calcium 
6% 


6.0 


10.3 


0.62 


Wilbur-Ellis Co. 
(509-248-6171) 


2-4 qt 


4 


2-4 gal 


1.2-2.5 


Mora-Leaf 
Calcium (94% 
CaCy 


34.0 


DRY 


0.34 


Wilbur-Ellis Co. 
(609-248-6171) 


4-8 lb 


3-6 


12-48 


4.1- 16.3 


Nutri-Cal 8% 

Calcium 

Solution 


8.0 


11.1 


0.89 


CSl Chemical Corp. 
(800-247-2480) 


1-2 qt 


3-8 


.75-4.0 gal 


.67-3.6 


Nutra-Phoa 
10 


10.0 


powder 


0.10 


Leffingwell Div. 
(800-262-3861) 


3-10 lb 


2-6 


20^0 lb 


2-4 


Nutra-Phoa 
12 


11.0 


powder 


0.11 


Leffingwell Div. 
(800-262-3861) 


3-10 lb 


2-6 


20-(01b 


2.2-4.4 


Nutra-Phoa 
24 


20.0 


powder 


0.20 


Leffingwell Div. 
(800-262-3861) 


3-10 lb 


2-6 


20-40 lb 


4-8 


Nutra-Phos 
Mg 


10.0 


powder 


0.10 


LefTingwell Div. 
(800-262-3861) 


3-10 lb 


2-6 


20-40 lb 


2-4 


Nutra-Plua 


6.0 


10.0 


0.60 


Custom Chemicides 
(209-264-0441) 


1-3 qt 


8-11 


2-8.2 gal 


1.2-4.9 


Pit-Stop 
Dry Con. 
Foliar Cal. 
32.6% 


32.6 


diy 


0.32 


Ag-Chem, Inc. 
(301-548-2200) 


4-6 lb 


4-6 


16-48 lb 


6.2-16.6 


Pit-Stop 
Foliar 
Calcium 12% 


12.0 


11.3 


1.36 


Ag-CJhem, Inc. 
(301-648-2200) 


1.5 gal 


4-6 


6-9 gal 


8.1-12.1 


Sett 


8.0 


11.4 


0.91 


Stoller, Inc 
(800-255-9548) 


Igal 


8-11 


8-11 gal 


7.3-100 


Sorba-Spray 
Cal. 


8.0 


10.75 


0.86 


LefHngwell Div. 
(800-262-3861) 


1-4 qt 


4-5 


1-6 gal 


0.9-4.3 


Sorba-Spray 
CaB 


SO 


10.0 


0.50 


Leffingwell Div. 
(800-262-3861) 


1-4 qt 


4-5 


1-6 gal 


0.6-2.5 


Stopit 

Calcium 

Concentr. 


12.0 


10.7 


1.28 


Shield-Brite Div. 
(206-827-8717) 


2-4 qt 


8-11 


4-11 gal 


5.1-14.1 


Tracite 
Calcium 6% 


6.0 


10.0 


0.60 


Helena (Jhem. Co. 
(901-748-3200) 


3-6 pU 


8 


3-6 gal 


1.8-3.5 


Traco PitCal 

Liquid 

Calcium 


12.0 


11.7 


1.40 


Traylor Chem. Co. 
(800-348-3361) 


0.5-2 gal 


7 


3.5-14 gal 


4.9-19.6 


Wuial 
Calcium 


10.7 


13.3 


1.42 


AGLUKON Div. 
(800-832-8788) 


3-4 pts 


5 


1.9-2.5 gal 


2.7.3.6 


Adapted from th 


e Ptnn State Trte Fruit Production Guidt, 1992-1993. 











22 



Fruit Notes, Spring, 1993 



ciencies, and solving special nutritional problems, 
such as getting calcium into apple fruit. For overall 
economy and tree health, most macronutrients 
should be soil-applied. 

When applying nutrients to apple foliage, the 
following suggestions will enhance the spray's effec- 
tiveness and safety: 

1. Think dilute. Apply fertilizers with as much 
water as is practical. Effectiveness will be aided 
via thorough coverage and better absorption. 

2. Watch the weather. Follow the 80/80 rule : avoid 



4. 



nutrient sprays when temperature or humidity 
values exceed 80 degrees or 80%, respectively. 
Following this nJe will reduce greatly the risk of 
fruit or foliage damage. 

Make sure that your sprayer is calibrated prop- 
erly and that its nozzles are adjusted to direct an 
even pattern to the tree canopy. 
More is not better, more often is better. Do not 
apply too much at one time. If you wish to apply 
more of a particular nutrient, consider soil appli- 
cation or repeating the foliar spray at a later 
date. 



*f^ •!# %f^ %% %f^ 

r|% rj% «^ r^ rj% 



Fruit Notes, Spring, 1993 



23 




Fruit Notes 



University of Massachiuetts 

Department of Plant & Soil Sciences 

a05 Bowditch Hall 

Amherst, &IA 01003 



Nonprofit Organization 
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PeimK No. 2 
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arriii 

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Fruit Notei 



-\ I V 1 



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ISSN 0427-6906 



rrepared by the Department of Plant & Soil Sciences. 
University of Massachusetts Cooperative Extension System. 



JHIVJOF f ASf 



Or 
5^ 






9> 



United States Department of Agriculture, and Massachusetts Counties Cooperatli^. 

i 



Editors: Wesley R. Autio and William J. Bramlage 




Volume 58, Number 3 
SUMMER ISSUE, 1993 

Table of Contents 

Costs and Returns from High Density Apple 
Plantings During the First Three Seasons 

Costs and Returns from Three Peach Training 
Systems During the First Three Seasons 

Optimal Positioning of Baited Sticky Red 
Spheres for Capturing Apple Maggot Flies 

Massachusetts Agriculture 



Fruit Notes 



Publication Information: 

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July, and October by the Department of Plant & Soil Sciences, University 
of Massachusetts. 



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Fruit Notes 

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University of Massachusetts 

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COOPERATIVE EXTENSION SYSTEM POLICY: 

All chcm ical uses suggested in Ihis publicalioo arc conlingcat upon continued registration. These chetn icals should 
be used in accordance with federal and state laws and regulations. Growers arc urged to be familiar with all current 
stale regulations. Where trade names are used for identification, no company endorsement or product discrim ination 
is intended. The University of Massachusetts makes no warranty or guarantee of any kind, expressed or implied, 
concerning the use of these products. USER ASSUMES ALL RISKS FOR PERSONAL IN JURY OR PROPERTY 
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offers equal opportunity in programs and employment. 



Costs and Returns from High Density 
Apple Plantings During the First 
Three Seasons 



Wesley R. Autio 

Department of Plant & Soil Sciences^ University of Massachusetts 



In the 1989 New England Apple Survey (Autio, 
1989), growers stated that 62% of the apple acreage 
to be planted in 1990-94 would be on dwarfing 
rootstocks. Since the survey, several acres of dwarf 
trees have been planted; however, little experience 



exists with methods of training these trees. Manage- 
ment is much different than for free-standing stan- 
dard or semi-dwarf trees. 

To become familiar with the peculiarities and to 
obtain accurate data on costs and returns of high- 



Table 1. Costs and returns per acre associated with Nicobel JonagoldTM.G in four | 


training systems. Land preparation costs 


were derived from White and Demarree 1 


(1992) and Fuller et al 


. (1991). Establishment costs include all those 


associated 1 


with trees, planting, 


support systems, 


and initial training (see Autio, 1990). | 


Growing costs, other than those associatec 


with training. 


were derived from White | 


and Demarree (1992) 


Training labor 


and suppUes 


were based 


on actual 


assessments from this 


planting. Picking, storing, packing, and selling 


costs were 


derived from Castaldi (1987). 










NE Central 


Slender 


Vertical 


Vertical 


Category 


leader 


spindle 


axis 


trellis 


Year 1 - 1990 










Land preparation 










Fertilizer and lime 


150 


150 


150 


150 


Seed 


20 


20 


20 


20 


Labor 


15 


15 


15 


15 


Equipment 


38 


38 


38 


38 


Establishment 


3904 


5206 


7172 


5146 


Growing costs 










Fertilizer 


55 


55 


55 


55 


Spray material 


47 


47 


47 


47 


General supplies 


15 


15 


15 


15 


Training labor 


14 


25 


57 


5 


Other labor 


200 


200 


200 


200 


Equipment 
Costs - Year 1 


133 


133 


133 


133 


4591 


5904 


7902 


5824 


Net - Year 1 


-$4591 


-$5904 


-$7902 


-$5824 


1 



Fruit Notes, Summer, 1993 



Table 1. Continued. 




NE Central 


Slender 


Vertical 


Vertical 


Category 


leader 


spindle 


axis 


trellis 


Year 2 - 1991 










Growing costs 










Fertilizer 


55 


55 


55 


55 


Spray materials 


45 


45 


45 


45 


Training supplies 


5 


23 


5 


8 


General supplies 


15 


15 


15 


15 


Training labor 


10 


96 


34 


29 


Other labor 


200 


200 


200 


200 


Equipment 


133 


133 


133 


133 


Fruit-related costs 










Picking 


2 


1 


52 





Storing 


3 


1 


65 





Packing 


3 


2 


86 





Selling 


1 





21 





Costs -- Year 2 


472 


571 


711 


485 


Returns - Year 2 


21 


10 


533 


1 


Net -- Year 2 


-$451 


-$561 


-$178 


-$484 


1 



density management systems, I established a trial of 
four training systems at the University of Massa- 
chusetts Horticultural Research Center 
(Belchertown) in the spring of 1990. This trial 
included Nicobel Jonagold/M.9 trained as a New 
England central leader, as a slender spindle, as a 
vertical axis, and on a four-wire vertical trellis. 
Previously, I published an article which included the 
various costs of establishment (Autio, 1990). Here, 
I have continued the discussion of this study, includ- 
ing the costs of managing these trees during the first 
three growing seasons and the returns obtained 
from the fruit. 

The Systems 

New England Central Leader. The NE central 
leader, simply, is a small central-leader tree (389 
trees per acre, 8' x 14'). Minimal pruning has been 
conducted, including removal only of those branches 
which inhibited the developmentof thecentral leader. 



Some limb spreading has been done with weights. 

Slender Spindle. The slender spindle is typical 
of a European slender spindle, i.e. a small central- 
leader tree with a relatively large amount of branch 
manipulation. Trees are spaced 6' x 14' (519 trees per 
acre). The new growth of the central leader was 
headed by half in the first dormant season to encour- 
age lateral development. The central shoot originat- 
ing from the heading cut was tied to the post in June 
of the second season, and competing laterals were 
bent to 90° from vertical with rubber bands. In early 
July of both the second and third growing seasons, 
lower laterals were tied to approximately 70°, cen- 
tral laterals were tied to approximately 90°, and 
upper laterals were tied to 100°. In some cases in 
1992, branches which bore fruit in 1991 were tied up 
to prevent devigoration. 

In 1991, a self-tapping sheet-metal screw was 
drilled into the bottom of the conduit-pipe post, and 
cotton kite twine was tied from this screw to limbs for 
positioning. This process was relatively time con- 



Fruit Notes, Summer, 1993 



Table 1. Continued. 




NE Central 


Slender 


Vertical 


Vertical 


Category 


leader 


spindle 


axis 


trellis 


Year 3 - 1992 










Growing costs 










Fertilizers 


57 


57 


57 


57 


Spray materials 


118 


118 


118 


118 


Training supplies 


5 


25 


5 


10 


General supplies 


15 


15 


15 


15 


Training labor 


7 


182 


12 


37 


Other labor 


200 


200 


200 


200 


Equipment 


133 


133 


133 


133 


Fruit-related costs 










Picking 


178 


251 


409 


136 


Storing 


223 


314 


511 


170 


Packing 


297 


419 


681 


227 


Selling 
Costs - Year 3 


74 


105 


170 


57 


1307 


1819 


2311 


1160 


Returns -- Year 3 


1840 


2596 


4227 


1405 


Net -- Year 3 


$533 


$777 


$1916 


$245 


1 



suming. In 1992, avis strapping material was used 
to tie limbs. This 1/2-inch, multi-stranded strapping 
material was split easily into five pieces of five 
strands each. The advantage of this material is that 
it can be tied directly to conduit pipe without the use 
of a screw and without slipping, therefore making it 
much easier to use than the previous method. 

Vertical Axis. The vertical axis utilizes a tall 
post to allow unrestricted tree growth to a height 
where it will fruit out. In this planting, posts extend 
10.5 feet out of the soil. Trees were spaced 6' x 14' 
(519 trees per acre). A number of lateral branches 
existed on trees at planting, and none were removed 
and trees were not headed. A small amount of 
pinching of vigorous, upright shoots was done in 
June each season. Also in each season, some vigor- 
ous limbs were bent with weights in early July. 

Vertical Trellis. The trellis used in this planting 
is seven feet tall and includes four wires, every 18 
inches beginning at 24 inches from the soil. Trees 
were spaced 8' x 14' (389 trees per acre). Trees were 



headed at approximately 22 inches from the soil. As 
branches grew, a central leader was chosen, and 
lateral branches were tied to the lowest wires at 
approximately 70°. Branches higher up in the canopy 
were tied at a greater angle. 

The Economics 

Table 1 summarizes the costs and returns asso- 
ciated with the four treatments used in this trial. 
Duringthe first season, the primary difference among 
the total costs related to differences in establishment 
costs (for details of establishment costs see Autio, 
1990). Some differences existed in the amount of 
labor involved with training, with the vertical axis 
requiring the most, followed by the slender spindle, 
central leader, and trellis. 

Duringthe second growing season, significantly 
more labor and supplies were required for the slen- 
der-spindle system than the others. The NE central 
leader was the least intensive and least costly. Ver- 



Fruit Notes, Summer, 1993 



Cumulative Net Returns (thousands/acre) 



$10 



-^ NE Central Leader 
-^Slender Spindle 
-*- Vertical Axis 
-"-Vertical Trellis 



/ r 




-$10 



1990 1991 1992 1993 1994 1995 

Figure 1. Cumulative net returns of four apple training 
systems. Dotted lines are projected returns. 



tical-axis trees fruited in the second season, yielding 
about 43 bushels per acre. Overall costs of the 
vertical axis were increased because of the costs of 
picking, storing, packing, and selling; however, $533 
were returned per acre in the second growing sea- 
son. 

During the third growing season again, the 
slender spindle required the most labor and supplies 
to manage. Year three was the first significant 
fruiting year, with yields of 148, 209, 341, and 113 
bushels per acre for the NE central leader, slender 
spindle, vertical axis, and vertical trellis, respec- 
tively. Net returns varied from the low of $245 from 
the trees on trellis to $1916 from trees trained to the 
vertical-axis system. 

Figure 1 presents the cumulative net returns for 
these four systems for their first three growing 
seasons, along with projections for the next three 



seasons. The most costly system 
was the vertical axis; however, it 
yielded sooner than the other sys- 
tems and is expected to net over 
$2000 per acre afler the fifth grow- 
ing season. The slender-spindle 
and trellis systems were similarly 
costly; however, the slender 
spindle yielded better in 1992 and 
is expected to yield more than the 
trellis for the next few seasons. 
The slender spindle will pay for 
itself by the end of the fifth grow- 
ing season, but the vertical trellis 
will not pay for itself until the end 
of the sixth growing season. The 
least costly system to establish 
was the NE central leader, but it 
is not expected to be as profitable 
as the slender spindle. 

Conclusions 



Significant differences in costs 
and returns existed among the 
four intensive apple-training sys- 
tems included in this planting. 
One factor came very much into 
play in determining what the early 
returns were from these trees. 
The early yields on a per-tree ba- 
sis were negatively related to the 
degree of pruning which was done 
at planting. The vertical axis trees 
were not pruned; therefore, one- 
year-old wood was retained at 
planting which set flower buds during the first 
growing season. Trees yielded in the second season. 
With no pruning, the canopies of these trees were 
larger than in the other systems and trees yielded 
significantly more in the third season. NE central- 
leader trees, slender-spindle trees, and vertical- 
trellis trees were all headed at planting, removing all 
lateral branches and most one-year-old wood and 
preventing them from settingflower buds during the 
first season. NE central-leader trees and slender- 
spindle trees were headed at 34 inches, and trellis 
trees were headed at 22 inches; the more severe the 
heading, the lower were the early yields. 

A second factor which also has come into play 
and will continue to be a factor is the planting 
density. The two systems that have been the lowest 
yielding on a per acre basis and probably will have 
the lowest returns for a number of years are at the 



Fruit Notes, Summer, 1993 



lowest density (NE central leader and vertical trel- 
lis). The highest yielding systems are at the highest 
density (vertical axis and slender spindle). 

Overall, it is clear that any of these systems can 
be relatively successful. Even the least productive is 
expected to pay back the initial investment by the 
end of the sixth season, significantly better than 
free-standing central-leader trees on M.7. Selection 
of a system, however, must be based not only on the 
overall economic considerations but on the grower's 
interests in, abUity for, and commitment to horticul- 
tursd management, i.e. can and will he or she become 
more intensively involved with training and other 
horticultural practices than normally is needed for 
free-standing trees. 



References 

Autio,W.R. 1989. Trends in the New England apple 
industry. Fruit Notes 54(4):12-17. 

Autio,W.R. 1990. Costs ofestablishing high density 
apple plantings. Fruit Notes 55(4):l-5. 

Autio, W. R. 1993. High-density Apple Training: 
Costs of Establishment. University of Massachu- 
setts Cooperative Extension System Factsheet F- 
110. 

Castaldi, M. 1987. Summary of Annual Apple 
Production Costs. Cornell Cooperative Extension. 

Fuller, E., W. Lazarus, and L. Carrigan. 1991. 
MinnesotaFarm Machinery Economic Costs for 1991. 
Minnesota Extension Service AG-FO-2308-C. 

White, G. B. and A. DeMarree. 1992. Economics of 
Apple Orchard Planting Systems. Cornell Coopera- 
tive Extension Bulletin 227. 



•J^ •^ •l^ •J>» •J!> 

0^ •<]>• 0^ 0^ •^ 



Fruit Notes, Summer, 1993 



Costs and Returns from Three Peach 
Training Systems During the First 
Three Seasons 



Wesley R. Autio 

Department of Plant & Soil Sciences, University of Massachusetts 



In southern New England, approximately 1000 
acres of land are planted to peach trees. Little 
research has addressed the problems of peach grow- 
ing, particularly in the area of cultural manage- 
ment. Training systems are an as- 
pect of cultural management that 
can affect the economic returns of an 
orchard greatly. 

The primary training system used 
for peach trees in southern New En- 
gland is a delayed-open-center sys- 
tem. In a tree ofthis form, the central 
trunk is dominant early in the life of 
the tree, and as the tree grows, lower 
scaffolds grow upward and become 
equal to or stronger than the central 
trunk. Ideally, the central trunk 
should be removed above the lower 
scaflFolds at maturity, leaving an open 
center tree; however, the central 
trunk often is left in the tree. The 
problem that arises from having a 
central trunk in this type of tree is 
that light penetration into the center 
of the canopy is very poor, and over 
time, productivity declines in a large 
portion of the tree's interior. 

Because of the high value of peach 
fruit, production efficiency should be 
a major concern of peach growers. 
Evaluation of production practices is 
critical to economic viability. To this 
end, I established a trial in 1990, 
including nine replications of Ernie's 
Choice/Lovell trained to an open cen- 
ter, a central leader, or a delayed 
open center. The goal ofthis planting 
is to evaluate fully the economic vi- 
ability of these three training sys- 
tems. 



The Systems 

Open Center. Open-center trees were spaced 18 
by 20 feet (121 trees per acre). Trees were headed 



Table 1. Costs and returns per acre associated with Ernie's Choice 
peach in three training systems. Land preparation costs were derived 
from V/hite and DeMarree (1992) and Fuller et al. (1991). 
Establishment costs were derived from actual measurements made 
during the planting of this trial. Growing costs, with the exception of 
pruning, were derived from Mizelle and Westberry (1989). Pruning 
labor costs were from actual measurements from this trial. 









Delayed 




Open 


Central 


open 


Category 


center 


leader 


center 


Year 1-1990 








Land preparation 








Fertilizer and lime 


150 


150 


150 


Seed 


20 


20 


20 


Labor 


15 


15 


15 


Equipment 


38 


38 


38 


Establishment 








HoleE--labor 


81 


145 


81 


Holes-equipment 


101 


182 


101 


Trees 


605 


1089 


605 


Planting labor 


48 


87 


48 


Initial pruning labor 


16 


15 


8 


Growing 








Fertilizer 


25 


25 


25 


Spray material 


38 


38 


38 


General supplies 


24 


24 


24 


General labor 


30 


30 


30 


Equipment 


56 


56 


56 



Costs - Year 1 



Net - Year 1 



1247 



-$1247 



1914 



-$1914 



1239 



-$1239 



Fruit Notes, Summer, 1993 



Table 1. Continued. 



Category 



at planting to leave four small 
shoots arising from the trunk be- 
tween 20 and 24 inches from the 
ground. Each of these shoots was 
headed to two viable buds. As the 
trees have developed, shoots grow- 
ing into the center of the trees have 
been removed, with either dormant 
or summer pruning, and outer lat- 
erals have been pruned to direct 
their growth at about 60° from ver- 
tical. The goal is to have trees with 
four major scaffolds growing out- 
ward from the trunk in a vase form 
and reaching a height of approxi- 
mately eight feet when they have 
filled their allotted space. In the 
mature tree, light distribution will 
be good, and only a small portion in 
the center of the tree will have too 
little light to maintain the produc- 
tion of fruiting wood. 

Central Leader. Central-leader 
trees were spaced 10 by 20 feet (218 
trees per acre). Very little pruning 
was done at planting. As trees 
have developed, scaffolds have been 
pruned to direct their growth at 
about 80° from vertical. Upper 
limbs have been kept short so that 
the trees have a conical shape. 
Upright shoots arising from the 
nearly flat lateral branches have 
been removed during summer 
pruning. The goal is to produce 
small trees that are eight feet tall 
at maturity with lower laterals that 
extend no more than five feet from 
the trunk. With this form, nearly 
all of the canopy will maintain the 
potential to produce fruiting wood. 
With more trees per acre than a 
standard system, higher early pro- 
duction should be obtained. 

Delayed Open Center. Delayed- 
open-center trees were spaced 18 by 20 feet (121 
trees per acre). Very little pruning was done at 
planting. As the trees have developed, lower scaf- 
folds have been treated much the same as in the 
open-center trees; however, a central trunk has been 
maintained. The goal of this system is to have an 
open-center tree at maturity, but the productivity is 
higher early in its life, because it has more canopy 
volume in the form of a central leader. The central 
leader must be removed before the shading in the 
center of the tree results in significant reductions in 







Delayed 


Open 


Central 


open 


center 


leader 


center 



Year 2 - 1991 










Growing 










Fertilizer 




49 


49 


49 


Spray material 




67 


67 


67 


General supplies 




35 


35 


35 


General labor 




59 


59 


59 


Equipment 




51 


51 


51 


Dormant pruning 


labor 


8 


10 


5 


Summer pruning 


labor 


8 


15 


8 



Costs - Year 2 277 

Net - Year 2 -$277 

year 3 - 1992 

Growing 

Fertilizer 53 

Spray materials 254 

General supplies 50 

General labor 40 

Equipment 65 

Dormant pruning labor 16 

Summer pruning labor 12 

Thinning labor 8 

Harvest and sales 

Harvest labor 38 

Packaging 24 

Selling 24 



Costs - Year 3 584 



Returns - Year 3 709 



Net -Year 3 $125 



286 



-$286 



53 
254 
50 
40 
65 
25 
22 
15 



89 
56 
56 



725 



1675 



$950 



274 



-$274 



53 
254 
50 
40 
65 
14 
12 
8 



64 
40 
40 



640 



1191 



$551 



the potential to produce fruiting wood. 

The Economics 

Table 1 presents the costs and returns over the 
first three growing seasons from this trial. Much of 
the growing costs were obtained from other sources 
as described in the caption of the table, but planting 
costs, training costs, and yields were obtained from 
this trial. For labor, $8 per hour was used through- 
out this analysis. Equipment costs were assessed at 



Fruit Notes, Summer, 1993 



Cumulative net returns (thousands/acre) 




1992 



1993 



Figure 1. Cumulative net returns of three peach training 
systems. Dotted lines are projected net returns based on 
projected costs and returns for 1993 and 1994. 



approximately $20 per hour but varied depending on 
the equipment used. Trees cost $5. Thinning, 
picking, packaging, and selling were assumed to cost 
$0,013, $0.04, $0,025, and $0,025 per pound of fruit, 
respectively. Yields were valued at $0. 75 per pound. 

For the first three seasons, central-leader trees 
were more costly to maintain than either of the other 
systems: total costs were $2108, $2925, and $2153 
for the open center, central leader, and delayed open 
center, respectively. The difference came primarily 
from the greater establishment costs, which ac- 
counted for more than 80 percent of the difference 
between the central leader and the other systems. 

During the third growing season (1992), trees in 
this trial yielded significantly. Yield per tree was 
related directly to canopy size, with the delayed open 



center yielding the most and the open 
center yielding the least per tree (8, 
10, and 13 pounds per tree for the 
open center, central leader, and de- 
layed open center, respectively). Once 
tree density was accounted for, the 
open-center, central-leader, and de- 
layed-open-center systems yielded 
945, 2234, and 1588 pounds of fruit 
per acre, respectively. The returns 
for the central leader systems were 
considerably greater than for the 
other systems. 

At this point in the trial, it is 
possible to say that the additional 
costs of planting the higher density 
central-leader system have been com- 
pensated for by the higher yields in 
the third season. Figure 1 presents 
the cumulative net returns from these 
systems and shows a projection of 
cumulative net returns for the fourth 
and fifth growing seasons (1993 and 
1994). For these early years, the 
central-leader trees should out-pro- 
duce the other systems because of 
their higher density of planting, and 
therefore, likely will net over $2,000 
per acre cumulatively by the end of 
the fourth growing season and nearly 
$10,000 per acre by the end of the 
fifth growing season. The other two 
systems likely will net less than half 
that amount by the end of the fifth 
growing season. 

This information is not enough, 
however, to determine the ideal sys- 
tem for growing peaches in southern 
New England. These trees must be 
followed to maturity and beyond to determine long- 
term differences in costs and returns. 

References 

Fuller, E., W. Lazarus, and L. Carrigan. 1991. 
Minnesota Farm Machinery Economic Costs for 1991. 
Minnesota Extension Service AG-FO-2308-C. 

Mizelle, W. O., Jr. and G. O. Westberry. 1989. Cost 
analysis, pp. 6-12. In: S. C. Meyers (ed.) Peach 
Production Handbook. University of Georgia Coop- 
erative Extension Service Handbook 1. 

White, G. B. and A. DeMarree. 1992. Economics of 
Apple Orchard Planting Systems. Cornell Coopera- 
tive Extension Bulletin 227. 



1994 



8 



Fruit Notes, Summer, 1993 



Optimal Positioning of Baited Sticky 
Red Spheres for Capturing Apple 
Maggot Flies 

Jian Jun Duan, Max P. Prokopy, Paul Des Georges, 

and Ronald J. Prokopy 

Department of Entomology^ University of Massachusetts 



In a previous article [Fruit Notes 56(4): 4-6], we 
reported that a combination of food odor (ammonia) 
and fruit odor (butyl hexanoate) significantly in- 
creased apple maggot fly (AMF) captures on three- 
inch baited red sticky spheres, thus enhancing the 
effectiveness of interception traps currently used in 
the second-level IPM program. Past studies by 
Reissig (1975) and Drummond et £il. (1984) showed 
that AMF captures on unbaited spheres were influ- 
enced significantly by position of spheres in the tree 
canopy, including height above ground, proximity 
to fruit and foliage, and distance from the outside 
edge of the tree canopy. We predicted that these 
variables would have less influence on AMF cap- 
tures on sticky spheres baited with food and fruit 
odor than on unbaited spheres. Here we report on 
studies testing this prediction. 

Materials and Methods 

Three experiments were conducted in 1992 in 
second-level IPM orchards (commercial orchards 
not sprayed with insecticide after early June). We 
first investigated the optimal distance of fruit and 
foliage from spheres not baited or baited with one 
dispenser of ammonium acetate and one two-dram 
polyethylene vial of butyl hexanoate (Experiment 
1). We next studied the effects of presence vs. 
absence of fruit within 20 inches of unbaited spheres 
or spheres baited with the same types of odor as in 
Experiment 1 (Experiment 2). In Experiment 3, we 
investigated the influence of height of sphere place- 
ment in the tree canopy on the efficacy of spheres 
not baited or baited with one polyethylene vial of 
butyl hexanoate. 

Experiments 1 and 2 were conducted in 
Clarkdale Fruit Farm, West Deerfield, MA, which 
consisted of a mixture of 25-year-old Early Mcin- 
tosh and Gravenstein trees. The trees were about 12 



to 16 feet in canopy diameter. In Experiment 1, we 
hung four sticky spheres in each of ten trees and 
removed the foliage and fruit surrounding the spheres 
to distances of 2, 10, 20, or 40 inches. On five of the 
trees, we placed one dispenser of ammonium acetate 
(about 5 grams) and one vial of butyl hexanoate 
(about 5 milliliters) about six inches from the sphere. 
Spheres on the other five trees were not baited with 
any type of odor. In Experiment 2, we placed two 
sticky spheres in each of 14 trees. On seven of the 
trees, spheres were baited with ammonium acetate 
and butyl hexanoate in the same manner as in Ex- 
periment 1. Spheres on the other seven trees were not 
baited. One of the two spheres in each tree was 
cleared of all fruit within 10 inches. The other sphere 
was cleared of all fruit within 20 inches. The foliage 
surrounding each sphere was removed within a con- 
stant distance of 10 inches. 

Experiment 3 was conducted at the University of 
Massachusetts Horticultural Research Center, 
Belchertown, MA, in a block of four-to-five-year-old 
Liberty trees having a canopy three to five feet in 
diameter and a height of six to eight. In this experi- 
ment, we placed only one sphere (either not baited or 
baited with one polyethylene vial of butyl hexanoate) 
on each tree. Spheres were placed in trees at three 
different heights: upper 1/3, middle 1/3, or lower 1/3 
of the canopy. Foliage and fruit within 10 inches of 
each sphere were removed. 

For all experiments, captured male and female 
AMF were counted and spheres were cleared of all 
insects captured every two weeks. In Experiments 1 
and 2, unbaited and baited spheres were emplaced on 
July 28 and rotated among trees at each examination 
(every two weeks) until September 8, when the test 
ended. Experiment 3 began on July 27 and ended on 
September 11. Spheres were not rotated among 
trees. 



Fruit Notes, Summer, 1993 



Table 1 . Average number of apple maggot flies captured on baited or unbaited sticky red spheres hung in 
fruiting trees and surrounded at different distances by foliage and/or fruit (July 28 - September 8, 1992).^ 







Distance (in 
Foliage 


) of clearing of 
Fruit 


Baited spheres 


Unbaited spheres 


Experiment 


Female 


Male 


Total 


Female 


Male 


Total 


1 


2 


2 


14 b 


19 b 


33 b 


9 b 


13 b 


22 b 




10 


10 


24 a 


35 a 


59 a 


18 a 


29 a 


47 a 




20 


20 


25 a 


37 a 


62 a 


19 a 


25 a 


45 a 




40 


40 


16 b 


20 b 


36 b 


14 ab 


17 b 


27 b 


2 


10 


10 


27 a 


50 a 


77 a 


15 a 


28 a 


44 a 




10 


20 


19 a 


39 b 


57 b 


15 a 


18 b 


33 b 



^ Five replicates per treatment type in Experiment 1 and seven replicates in Experiment 2. Values within 
columns and within experiment followed by the same letter are not significantly different at odds of 19:1. 



Results 

The results of Experiment 1 (Table 1) showed 
that for both baited and unbaited spheres, nearly 
twice as many AMF were captured on spheres with 
foliage and fruit cleared to a distance of 10 to 20 
inches compared with 2 or 40 inches. Baited spheres 
captured 25 to 50% more flies than unbaited spheres 
at each distance. A previous study by Martin Aluja 
showed that fruit odor attracts flies from long dis- 
tances to a host tree or a portion of a host tree, but 
once a fly arrives on a tree, it primarily will use 
vision to find an individual fruit or fruit-odor-baited 
sphere. Surrounding foliage and fruit which influ- 
ence the visibility of a fruit-odor-baited sphere would 
therefore influence the probability of a fly finding 
the sphere. Until our test here, however, we had no 
knowledge that addition of food odor would fail to 
overcome the need for making a sphere conspicuous 
to AMF. 

The results of Experiment 2 (Table 2) indicated 



that when the surrounding foliage was cleared to a 
constant distance of 10 inches from a sphere, spheres 
cleared of all fruit within 10 inches captured 33% 
(unbaited) and 35% (baited) more flies than spheres 
cleared of all fruit within 20 inches. Possibly, fruit at 
10 to 20 inches from a sphere attracted more AMF 
(either by visual or odor stimuli) toward the sphere 
than fruit 20 inches or further did. 

Results of Experiment 3 (Table 2) showed that 
for unbaited as well as baited spheres, spheres 
placed in the upper 1/3 or the middle 1/3 of the tree 
canopy captured about three times more AMF than 
spheres placed in the lower 1/3 of the canopy. DiflFer- 
ences in performance of spheres at the lower versus 
the middle or upper tree positions were greater than 
differences between baited and unbaited spheres at 
any height. Diffierences in AMF captures on both 
unbaited and baited spheres among different tree 
canopy heights likely stem from fruit-foraging be- 
havioral patterns of AMF within trees. A recent 



Table 2. Average number of apple maggot flies captured on baited or unbaited sticky red 
spheres hung in fruiting trees at different tree canopy heights (July 27 -September 11,1 992).^ 







Baited spheres 


Unbaited spheres 


Position in the canopy 


Female 


Male 


Total 


Female 


Male Total 


Upper 1/3 
Middle 1/3 
Lower 1/3 


13 a 

21 a 

6 b 


31 a 

21 a 

7 b 


34 a 
42 a 
13 b 


13 a 

12 a 

4 b 


20 a 32 a 

19 a 31 a 

5 b 9 b 



^ Fourteen replicates per treatment type. Values within columns followed by the same letter 
are not significantly different at odds of 19:1. 



10 



Fruit Notes, Summer, 1993 



study by Martin Aluja indicated that fruit-foraging 
AMF have a propensity to move upward when forag- 
ing for fruit and spend more time foraging in the 
middle and upper part of the tree canopy. 

Conclusions 

Our findings indicate that the performance of 
sticky red spheres whether baited or not with syn- 
thetic food and fruit odor, is affected strongly by 
clearing of surrounding foliage or fruit, as well as by 
height of placement in the tree canopy. Baited spheres 
capture more flies than unbailed spheres under all 
conditions. To intercept AMF immigrating into or- 
chards, spheres should be placed in the middle 1/3 or 
upper 1/3 of the tree canopy and surrounded by as 
much foliage and fruit as possible except for a 10- 
inch radius around. This placement will optimize the 
finding of spheres by AMF within a tree. 



Selected References 

Drummond, F., E. Groden, and R. J. Prokopy, 1984. 
Comparative efficacy and optimal positioning of traps 
for monitoring apple maggot flies (Diptera: 
Tephritidae). Environmental Entomology 13: 232 - 
235. 

Reissig, W. H. 1975. Performance of apple maggot 
traps in various apple tree canopy positions. Journal 
of Economic Entomology 68: 534 - 538. 



Acknowledgments 

We thank Tom Clark for the use of his orchard. 
This work was supported by the Northeast Regional 
Project on Integrated Management of Apple Pests 
(NE-156). 



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Fruit Notes, Summer, 1993 



11 



Massachusetts Agriculture 



Robert L. Christensen and N. Eugene Engel 

Department of Resource Economics, University of Massachusetts 



In 1991, Massachusetts farmers sold $474 mil- 
lion of crop and livestock products, ranking forty- 
second out of fifty states. Massachusetts ranked 
number one, however, in cranberry production, 
number twelve in apple production, and number 
seventeen in greenhouse/nursery crop production. 
Table 1 reports the annual cash receipts of selected 
commodities in Massachusetts. 



According to the U.S. Census, the estimated 
number of farms in Massachusetts increased from 
5,400 in 1974 to 6900 in 1991. Table 2 gives the 
number of farms by county in 1982 and 1987, and 
Table 3 gives the acreage by county. Approximately 
615,000 acres of land are used by Massachusetts 
farms. The average size of a farm is 100 acres, as 
compared to the U.S. average of 467 acres. Average 



Table 1. Cash receipts in thousands of dollars by sel( 


3Cted commodities in 


Massachu- 


setts. Data were compiled from Economic Indicators 


of the Farm Sector - 


- Financial 


Summary, 1991, U.S. Department of Agriculture, Economic Research Service, ECIFS | 


11-2, March, 1993. 






Commodity 


1990 


1991 


All commodities 


445,874 


475,540 


Livestock and products 


124,706 


120,745 


Meat animals 


13,750 


15,919 


Dairy products 


70,054 


64,977 


Poultry and eggs 


24,411 


23,662 


Aquaculture 


8,245 


8,245 


All other livestock 


7,725 


7,645 


Crops 


321,168 


354,795 


Hay 


5,037 


4,689 


Tobacco 


13,442 


14,571 


Potatoes 


4,677 


4,522 


Sweet corn 


9,088 


9,883 


Tomatoes 


8,760 


6,300 


Miscellaneous vegetables 


40,000 


39,000 


Apples 


20,337 


19,180 


Peaches 


893 


867 


Cranberries 


62,737 


96,818 


Other berries 


5,345 


5,885 


Miscellaneous fruits and nuts 


1,000 


1,000 


Maple products 


922 


1,483 


Other field crops 


3,700 


2,920 


Floriculture 


35,551 


35,364 


Nursery and ornamentals 


108,000 


108,000 


1 



12 



Fruit Notes, Summer, 1993 



Table 2. Number of farms 


in Massachusetts by counties. Data are 


from 7987 Census 


of Agriculture, 


Bureau of the Census, U.S. Department of Commerce, Washington, | 


D.C. 










County 




1987 


1982 


Change (%) 


Barnstable 




158 


123 


+28 


Berkshire 




392 


352 


+11 


Bristol 




675 


597 


+13 


Dukes 




58 


40 


+45 


Essex 




439 


372 


+18 


Franklin 




616 


521 


+18 


Hampden 




490 


392 


+25 


Hampshire 




624 


559 


+12 


Middlesex 




569 


567 





Nantucket 




12 


6 


+100 


Norfolk 




212 


205 


+3 


Plymouth 




775 


649 


+19 


Suffolk 




5 


4 


+25 


Worcester 




1191 


1014 


+17 


Total 




6216 


5401 


+15 


1 



Table 3. Land in farms (acres' 


in Massachusetts by counties. 


Data 


are from 1987 


Census of Agriculture, 


Bureau of the 


Census, 


U.S. Department 


of Commerce, 


Washington, D.C. 














County 




1987 




1982 




Change (%) 


Barnstable 




* 




5,010 




— 


Berkshire 




70,792 




73,434 




-4 


Bristol 




42,562 




41,883 




+2 


Dukes 




7,314 




7,355 




-1 


Essex 




30,940 




30,283 




+2 


Franklin 




82,864 




79,412 




+4 


Hampden 




46,747 




43,835 




+7 


Hampshire 




64,567 




63,624 




+1 


Middlesex 




38,709 




40.173 




-4 


Nantucket 




* 




* 




~ 


Norfolk 




13,124 




13,398 




-2 


Plymouth 




77,140 




80,392 




-4 


Suffolk 




* 




* 




— 


Worcester 




134,689 




133,612 




+1 


Total 




615,185 




612,819 







* Withheld to avoid disclosing 


data for i 


ndividual farms. 







Fruit Notes, Summer, 1993 



13 



Table 4. Farm balance sheet for Massachusetts in millions of dollars. Data 
were derived from Economic Indicators of the Farm Sector - Financial 
Sum.mary, 1991 , U.S. Department of Agriculture, Economic Research Service, 
ECIFS 11-2, March, 1993. 



Item 



1990 



1991 



Assets 

Real estate 

Livestock and poultry' 
Machinery and motor vehicles'' 
Crops (inventory) 
Purchased inputs 
Financial 

Debt 



Real estate 
Nonreal estate' 

Debt/asset ratio 



3,553.6 


3,407.7 


3,092.3 


2,939.2 


57.4 


57.9 


212.8 


214.7 


22.6 


20.9 


8.9 


8.9 


159.5 


166.1 


299.0 


295.7 


115.1 


117.9 


183.9 


177.8 



8.4 



8.7 



Excludes horses, mules, and broilers. 

Includes only the farm share for trucks and autos. 

Excludes debt for non-farm purposes. 



net farm income for Massachusetts is $20,841, while 
the U.S. average is $17,950. Of greatest significance 
is the fact that net farm income per acre in Massa- 
chusetts averages $208, nearly 5.5 times the U.S. 
average per acre of $38. 

Massachusetts farmers control assets of $3.4 
billion, with a debt load of under $300 million (Table 
4). This debt-to-asset ratio is among the ten lowest 
in the nation and is less than half the national 



average. Massachusetts farmers per year purchase 
$160 million worth of farm inputs, pay local property 
taxes of $22 million, employ a hired labor force with 
a payroll of $77 million, and pay $24 million in 
interest to Massachusetts financial institutions and 
other lenders (Table 5). 

Finally, Massachusetts farmers provide Massa- 
chusetts consumers with food that is locally grown, 
fresh, wholesome, and reasonably priced. 



14 



Fruit Notes, Summer, 1993 



Table 5. Massachusetts farm income statistics in millions of dollars. Data were 
compiled from Economic Indicators of the Farm Sector - Financial Summary. 1991, 
U.S. Department of Agriculture, Economic Research Service, ECIFS 11-2, March, 
1993. 



Item 


1990 


1991 


Gross farm income 


505.4 


527.6 


Farm marketings of crops 


321.2 


354.8 


Farm marketings of livestock products 


124.7 


120.7 


Government payments 


3.0 


1.5 


Farm-related income 


17.2 


15.5 


Non-cash income' 


38.0 


36.0 


Inventory adjustment 


1.3 


-0.9 


Total productions expenses 


334.3 


336.6 


Feed purchased 


31.7 


30.6 


Livestock and poultry purchased 


1.4 


1.4 


Seed purchased 


6.8 


7.6 


Fertilizer and lime 


10.1 


10.0 


Pesticides 


9.3 


10.3 


Fuel and oil 


13.3 


12.7 


Electricity 


7.0 


7.0 


Repair and maintenance 


29.0 


26.4 


Miscellaneous 


46.4 


53.7 


Interest on real estate debt 


8.8 


8.5 


Interest on other debt 


15.6 


15.4 


Contract and hired labor expense 


77.3 


77.2 


Capital consumption (depreciation) 


58.9 


57.3 


Property taxes 


21.9 


21.7 


Net rent to landlords 


-3.2 


-3.1 


Net farm income 


171.2 


191.0 


Returns to operators'' 


158.0 


178.7 



' Includes: value of home consumption and rental value of operator and hired labor 

dwellings. 
" Returns to operators is equivalent to net farm income, excluding the income and 

expenses associated with farm operator's dwellings. 



vT> •^ vi>» •^ •Jt* 

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Fruit Notes, Summer, 1993 15 




Fruit Notes 



University of Massachusetts 

Department of Plant & Soil Sciences 

205 Bowditch Hall 

Amherst, MA 01003 



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ISSN 0427-6906 



Fruit Notes rr. 

Prepared by the Department of Plant & Soil Sciences. _ — U ^SS • 

University of Massachusetts Cooperative Extension System, '^^Or- 

United States Department of Agriculture, and Massachusetts Counties CooperM^. 



Editors: Wesley R. Autio and William J. Bramlage 




Volume 58, Number 4 
FALL ISSUE, 1993 

Table of Contents 

Evaluation of Several Apple Roots tocks 
in the 1984 NC-140 Planting 



Effects of Orchard Spray Program on Plant-feeding and 
Predatory Spider Mites in Massachusetts Apple Orchards 

A Sampling Method for Detecting 
Root-feeding Woolly Apple Aphids 

Chemical Growth Control: Ethephon as a Growth Retardant 

Food Prices, Expenditures, and Income 



Fruit Notes 

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July, and October by the Department of Plant & Soil Sciences, University 
of Massachusetts. 



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Fruit Notes 

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All chemical uses suggested in this publication arc contingentupon continued registration. These chem icals should be 
used in accordance with federal and state laws and regulations. Growers arc urged to be familiar with all current state 
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offers equal opportunity in programs and employment. 



Evaluation of Several Apple 
Rootstocks in the 
1984 NC-140 Planting 

Wesley R.Autio 

Department of Plant & Soil Sciences, University of Massachusetts 



New England apple growers have been 
planting trees on clonally propagated rootstocks 
for a number of years. Early plantings were 
entirely on semidwarf and semistandard 
rootstocks, usually M.7, MM. 106, or MM.lll. 
During the 1970's, some growers experimented 
with M.9 and interstem trees, and now, several 
growers are using fully dwarf rootstocks. Until 



recently, plantings have used a relatively small 
number of roots tock clones, because only a few 
clones were available. Now several breeding 
programs have released rootstocks for trial, in- 
cluding the "Polish Series" from Poland, the 
"Budagovsky Series" from Russia, the "Ottawa 
Clonal Series" from Canada, the "Kentville 
Stock Clone Series" from Canada, the "Michigan 



Table 1. Characteristics in 1992 of Starkspur Supreme Delicious trees 


on several rootstocks in 


the 1984 NC-140 Cooperative 


Planting.' 














Tnmk cross- 








1992 Cumulative 








sectional 


1992 


Cumulative 


Yield 


yield 


C 


rop 




area 


Yield 


yield 


eflfieiency 


efficiency 


load 


Rootstock 


(in^) 


(bu) 


(bu) 


(bu/in^) 


(huJin^ 


(fruit/in') 


Bud.9 


3.4 efg 


2.0 


fg 


5.6 g 


0.57 ab 


1.60 ab 


57 


ab 


MAC-1 


13.8 be 


5.1 


c 


11.0 de 


0.36 de 


0.80 d 


37 


cd 


MAC-39 


4.5 ef 


2.1 


fg 


5.8 g 


0.43 bede 


1.21 c 


36 


d 


P.l 


8.8 d 


3.8 


de 


11.1 de 


0.43 bede 


1.31 c 


42 


cd 


P.22 


1-2 g 


0.4 


h 


1.5 h 


0.30 e 


1.29 e 


30 


d 


Seedling 


15.8 ab 


4.9 


c 


11.3 cde 


0.31 e 


0.70 d 


30 


d 


M.4 


11.8 c 


6.6 


a 


15.3 a 


0.56 ab 


1.30 c 


62 


a 


M.7 EMLA 


8.1 d 


4.4 


cd 


11.8 bed 


0.62 a 


1.62 ab 


58 


ab 


M.26 EMLA 


5.5 e 


2.5 


fg 


7.1 fg 


0.47 bed 


1.34 be 


41 


cd 


Bud.490 


14.2 abc 


5.4 


be 


11.8 bed 


0.38 de 


0.85 d 


35 


d 


P.2 


2.8 fg 


1.6 


g 


4.8 g 


0.56 ab 


1.69 a 


51 


abed 


P.16 


1.2 g 


0.5 


h 


1.6 h 


0.54 abc 


1.67 a 


53 


abc 


P.18 


16.7 a 


6.6 


a 


14.2 ab 


0.40 cde 


0.85 d 


40 


cd 


C.6 


5.5 ef 


2.9 


ef 


8.6 ef 


0.55 ab 


1.61 ab 


45 


bed 


Ant.313 


16.3 ab 


6.2 


ab 


13.9 abc 


0.39 cde 


0.89 d 


39 


cd 


' Means within columns not followed by the same letter 


are significantly different at odds of 


19:1. 



















FruH Notes, Fall, 1993 



Table 2. Characteristics in 


1992 of fruit from Starkspur Supreme Delicious 


trees on several rootstocks in the 1984 NC-140 Cooperative Planting.' 




Soluble 






Date of 


Fruit 




solids 


Starch Watercore 


1 ppm 


weight 


Rootstock 


(%) 


index'' 


index" 


CjH 


4 


(g) 


Bud.9 


9.8 cd 


3.6 abc 


1.0 b 


10-11 


bed 


217 abed 


MAC-1 


9.8 cd 


2.8 def 


1.1b 


10-12 


abc 


181 f 


MAC-39 


10.4 b 


3.2 bcde 


1.3 a 


10-11 


bed 


232 ab 


P.l 


10.1 bed 


3.2 bcde 


1.1b 


10-11 


bed 


203 bedef 


P.22 


11.0 a 


3.7 ab 


1.0 b 


10-11 


bed 


182 f 


Seedling 


9.7 cd 


2.8 def 


1.0 b 


10-13 


ab 


185 ef 


M.4 


9.6 d 


2.6 f 


1.0 b 


10-12 


abc 


192 def 


M.7 EMLA 


10.1 bed 


2.8 def 


1.1b 


10-9 


d 


215 abede 


M.26 EMLA 


10.1 bed 


3.3 abed 


1.2 ab 


10-9 


d 


214 abede 


Bud.490 


9.6 d 


2.9 def 


1.1b 


10-14 


a 


200 edef 


P.2 


10.1 bed 


3.3 abed 


1.2 ab 


10-11 


bed 


225 abc 


P.16 


10.2 be 


3.8 a 


1.0 b 


10-10 


cd 


204 bedef 


P. 18 


9.8 cd 


2.6 f 


1.0 b 


10-12 


abc 


191 def 


C.6 


10.1 bed 


3.1 edef 


1.1b 


10-10 


cd 


237 a 


Ant.313 


9.6 d 


2.7 ef 


1.0 b 


10-13 


ab 


191 def 


' Means within 


columns not followed by the same letter are 


significantly 


different at odds of 19:1. Soluble solids 


starch index, watercore index, and 1 


fruit weight were assessed 


on October 5-6, 1992. 


Date of 1 ppm C2H4 was 1 


assessed with several weekly samples throughout the harvest 


season. 


'' Starch index: 


1 = dense 


starch staining, very 


immature; 9 


= no starch 


staining, very 


overmature. 












* Watercore index: 1 = no watercore; 5 = 


severe watercore 







Apple Clone Series" from Michigan State Uni- 
versity, and the "Cornell-Geneva (or Geneva) 
Series" from the New York State Agricultural 
Experiment Station. In 1984, a trial of a num- 
ber of these new rootstocks was planted at 
approximately 30 locations throughout the 
United States and Csmada. One of the plantings 
is at the University of Massachusetts Horticul- 
tural Research Center in Belchertown, Mass. 
This article will report the results from this 
planting through its ninth growing season. 

In April 1984, Starkspur Supreme Delicious 
trees on Bud.9, MAC-1, MAC-39, P.l, P.22, 
seedling, M.4, M.7 EMLA, M.26 EMLA, 



Bud.490, P.2, P.16, P.18, C.6, or Ant.313 were 
planted in a randomized complete block design 
with 10 replications. The soil is a Montauk fine 
sandy loam. Mcintosh and Golden Delicious 
trees were included in each rephcation for polli- 
nation. All trees were trained as central leaders 
and supp>orted by a post only when they leaned 
more than 45° from vertical. All trees received 
the same fertilizer apphcations, pest control 
treatments, and chemical thinning sprays. 

Table 1 reports the trunk cross-sectional 
area, yield, jdeld efficiency, and crop load of 
these trees. MAC-1, seedling, Bud.490, P.18, 
and Ant.313 produced trees of standard size. 



Fruit Notes, Fall, 1993 



Over their first nine years, trees on MAC-1, 
seedling, or Bud.490 jdelded a total of 11 to 12 
bushels. Those on P. 18 or Ant.313 yielded 
approximately 14 bushels. P.l, M.4, or M.7 
EMLA produced trees in the semidwarf to 
semistandard category. Trees on M.4 have 
yielded the most in the trial, more than 15 
bushels per tree ciunulatively. Trees on P.l or 
M.7 EMLA yielded between 11 and 12 bushels 
cumulatively. Bud.9, MAC-39, M.26 EMLA, 
P.2, and C.6 produced trees in the dwarf cat- 
egory. In this category, C.6 and M.26 EMLA 
have resulted in the greatest )delds, 8.6 and 7.1 
bushels, respectively, per tree on a cumulative 
basis. The other dwarf roots tocks have resulted 
in yields between 4.8 and 5.8 bushels per tree. 
The smallest trees in the planting are on P.22 or 
P. 16. These trees are in the very dwarf category, 
and they have yielded only about 1.5 bushels per 
tree cumulatively. 

To accurately assess performance of a par- 
ticular tree, it is important to look not only at 
size and yield but also at jdeld efficiency. Effi- 
ciency relates yield to tree size and gives an 
assessment of relative yield per acre. Over the 
life of the planting, the most yield-efficient trees 
have been on P.2, P. 16, M.7 EMLA, C.6, or 
Bud.9. M.7 EMLA is the biggest surprise in this 
group, because in other plantings that we have, 
it has not been very yield-efficient. The least 
efficient trees have been those of the standard 
size category. 



Table 2 reports fruit characteristics from 
this planting in 1992. For the four years that 
fruit have been assessed, no dramatic, consis- 
tent differences have occurred in bruit ripening, 
but fruit fi-om trees on C.6 often have been some 
of the largest in the planting, as they were in 
1992. 

Overall, the most promising new rootstocks 
in this trial are P.2, C.6, and Bud.9. All are of the 
dwarf category. P.2 and Bud.9 produce trees 
similar in size to those produced by M.9, and C.6 
produces a tree very similar in size to one pro- 
duced by M.26. They seem well adapted to our 
conditions, they were very precocious, and they 
have continued to be productive for their size. 
The only concern is with the potential of trees on 
P.2 or Bud.9 to "runt out." Trees on P.2 or Bud.9 
were nearly spur-bound after nine seasons. 
High productivity likely will not continue imless 
they are pushed to produce new vegetative 
growth. This trial, however, is with a spur-type 
variety. Newer trials include these two 
rootstocks with more vigorous, nonspur variet- 
ies, and I do not expect that they will become 
spur bovmd as readily. 

We shall continue to evaluate new 
rootstocks in Massachusetts. We have a plant- 
ing scheduled for the spring of 1994 which will 
contain 19 of the newest dwarfing rootstocks, 
including some from the "Vineland Series," the 
newest of the "Geneva Series," and a host of M.9 
strains from Europe. 



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Fruit Notes, Fall, 1993 



Effects of Orchard Spray Program on 
Plant-feeding and Predatory Spider 
l\/lites in IVIassachusetts 
Apple Orchards 

William M. Coli and Randolph CiurUno 

Department of Entomology, University of Massachusetts 



Since the inception in 1978 of the University 
of Massachusetts Apple Integrated Pest Man- 
agement Program, growers have heard a num- 
ber of presentations concerning the importance 
of selecting orchard pesticides based on their 
impacts on not only the target pest but also 
beneficial organisms. In recent years, the New 
England Apple Pest Management Spray Guide 
has contained a table of pesticide toxicities to 
beneficial species, with data fix)m a number of 
pubhshed studies conducted in Pennsylvania, 
New York, New Jersey, Virginia, West Virginia, 



Massachusetts, and Canada. 

In 1987, we initiated a study of the effects of 
orchard groundcover comix)sition on plant-feed- 
ing and predatory mites. As a component of this 
study, we reviewed the spray records of 28 
commercial apple orchards in Massachusetts. 
Spray programs that included carbamate insec- 
ticides, pyrethroid insecticides, certain 
acaricides, or certain herbicides known to be 
detrimental to predatory mites were classified 
as "hard" programs. Those that avoided such 
materials were classified as "soft" programs. 



Table 1. Effects of orchard 
apple leaves by phjrtophagoi 


spray program on average 
IS and predatory mites.' 


percent infestation of 


Mite species 




Leaf infestation (%) 


1988 




1989 


"Hard" 


"Soft" 


"Hard" "Soft" 


European red mite 
Two-spotted spider mite 
Amblyseius fallacis 
Zetzellia mali 


9.7 a 
1.0 a 
1.5 a 
0.3 b 


8.6 b 
1.0 a 
1.9 a 
4.2 a 


31.4 a 33.0 a 
1.7 a 0.3 b 
1.4 b 2.4 a 
0.0 b 3.3 a 


" Within row and year, meems not followed by the same 
different at odds of 19:1. 


letter are significantly 



Fruh Notes, Fall, 1993 



Those which used two or fewer appUcations of 
benzimidazole fungicides, whose detrimental 
effects on mite predators are not agreed upon 
universally, likewise were classified as "soft" 
programs. Due to seasonal variability of spray 
programs, blocks were reevaluated yearly and 
reclassified by the tjT)es of pesticide used during 
the previous production season. In total, the 
study included 14 orchards using "hard" pro- 
grams and 14 using "soft" programs. 

In 1988, the "hard" program resulted in 
slightly higher infestations by European red 
mite than did the "soft" program (Table 1). The 
relationship, however, varied with saimpling 
date, i.e. for some sampling dates, "hard" pro- 
grams had more European red mites, and for 
other dates, "soft" programs had more. Spray 
program had no impact on the amount of Euro- 
pean red mites present in 1989. The lack of a 
difference in 1989 likely was due to an aggres- 
sive spray program directed at mites in "hard" 
blocks which kept plant-feeding mite numbers 
comparable to those in "soft" blocks in spite of 
lower predator numbers. 

The "hard" spray program resulted in sig- 
nificantly more two-spotted spider mites than 
the "soft" program in 1989, but in 1988, there 
was no difference between programs (Table 1). 
The first sample in 1989, however, found fewer 
two- spotted spider mites in the "hard" program 
orchards than in the "soft" ones. Because of the 
differences fi"om year to year and the lack of a 
consistent relationship between programs, even 
when significant differences were noted, we can- 
not state conclusively that numbers of two- 
spotted spider mites were related to spray pro- 
gram in this study. 

"Hard" spray programs had a significantly 
lower proportion of leaves infested with the 
Phytoseiid predator Amblyseius fallacis in 
1989,butnotin 1988 (Table 1). The relationship 



between programs, however, again varied with 
sample date, as with European red mite and 
two-spotted spider mite. Hence, these results 
also must be considered inconclusive. 

Lack of consistent spray-program effects on 
European red mites, two-spotted spider mites, 
and A. fallacis may be related to the initial 
grouping of spray programs, which considered 
the use of limited applications of potentially 
toxic benzimidazole fungicides as part of "soft" 
programs. Other factors independent of spray 
program, such as low prey numbers in previous 
years or high overwintering predator mortality 
in certain orchards, also could have affected 
predator numbers. 

Results were more conclusive in the case of 
the Stigmaeid Zetzellia mali, which was found 
in significantly higher numbers in "soft" pro- 
gram orchards in both 1988 and 1989 (Table 1). 
Differences were maintained across all sam- 
pling dates in both years. The more consistent 
results are not surprising withZ. mali, because 
this predator spends its entire life either on the 
tree or at its base Eind consequently would be 
expected to be affected severely by harsh chemi- 
cal sprays. Differences in time of appearance of 
Z. mali were particularly evident (data not 
shown), with individuals observed in "hard"- 
program orchards only in very low numbers on 
the last sample round in 1988. In 1989, only a 
single individual was found in a "hard" orchard 
over all sampling dates. 

Although, some aspects of this study were 
inconclusive, we believe that the results give 
some confirmation that insecticides, fungicides, 
and herbicides can affect densities of prey and 
predatory mites in apple trees. A clear implica- 
tion of this finding is that growers wishing to 
enhance the numbers of endemic mite predators 
should avoid materials which can adversely 
affect them. 



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Fruit Notes, Fall, 1993 



A Sampling Method for Detecting 
Root-feeding Wooiiy Appie Apliids 

M. W. Brown 

USDAf Agricultural Research Service, Appalachian Fruit Research 

Station, Kearneysville, WV 



The woolly apple aphid generally is consid- 
ered to be a minor pest of apple world-wide, 
seldom becoming abundant enough to justify 
chemical control. This aphid is most often found 
at pruning scars, other wound sites and at the 
base of petioles on current year's growth. It also 
feeds on roots of apple trees where it survives the 
winter and can remain throughout the year. I 
have been investigating this root-feeding insect 
and its effects on apple tree growth and produc- 
tion. The research literature contains only a few 
studies of this problem, and those deal with 
nursery stock. I found that root-feeding woolly 
apple aphids reduced tree growth in young 
nonbearing orchards (Brown and Schmitt, 
1990) and caused a significant economic loss in 
a seven-year-old 'Delicious' orchard (Brown et 
al., in preparation). 

The sampling method that I used in my 
research was to uproot trees and evaluate the 
root system. This method is efficient for re- 
search but not for pest management programs, 
for obvious reasons. To determine if some form 
of treatment is needed, a sampling method must 
be quick and easy enough to use with minimum 
training. The method described in this paper is 
based on woolly apple aphid biology. During 
spring, first-instar nymphs migrate up the tree 
from overwintering populations on roots to re- 
colonize above-ground portions of the tree (Hoyt 
and Madsen, 1960). Trapping these migrating 
woolly apple aphid njnuphs should give an indi- 
cation of the presence and intensity of root 
infestation. 

A two-inch-wide strip of masking tape was 
placed around the trunk of apple trees, one to 
two feet above the ground but below the lowest 
scaffold limb. The tape was placed on the 



smoothest section of trunk available. A continu- 
ous barrier, about 1/8-inch deep and one-inch 
wide, of Tangle-trapâ„¢ was apphed in the center 
of the masking tape. A portion of the masking 
tape band was exposed both above and below 
the Tangle-trap barrier. The trees that were 
used in this study were planted in 1985 at 308 
trees per acre. The block contained Frazier 
(joldspur, Smoothee (jolden Delicious, both on 
M.7A, and Bisbee Spur Dehcious on M.7 EMLA. 
The orchard was located at the Appalachian 
Fruit Research Station in Kearneysville, West 
Virginia, and was managed using standard 
commercial practices. 

Trees were banded to coincide with specific 
tree phenologies from green tip to first cover. 
Twenty five trees, selected randomly, were 
banded at each of four sample periods in 1993, 
as shown in Table 1. One group of 25 trees was 
banded for the entire green-tip to petal-fall pe- 
riod. An additional eleven trees with evidence of 
aphid migration up the tree during bloom were 
banded at petal fall. At the end of the designated 
sample periods the bands were removed and 
field counts of woolly apple aphid nymphs were 
made. Examination of the tape bands was with 
the unaided eye, using a hand lens only to verify 
questionable nymph sightings. On May 25, the 
trees were uprooted, the number of woolly apple 
aphid colonies on roots was recorded, and the 
amount of root galling was evaluated on a scale 
of to 1. The root gall rating scale incorporated 
both the proportion of the root system with root 
galls and the intensity of galling on those roots 
infested. It can be thought of as the proportion 
of the root system affected by woolly apple 
aphids, scored from none (0) to complete infesta- 
tion (1). 



FruH Notes, Fall, 1993 



Table 1. Sample periods, trap captures, 


and root infestations of wooly apple aphids. 


Sample 
date 


Tree Trees with 
phenology trapped nymphs 


Trees with 
root colonies 


Average 
root rating' 


April 7-19 


Green tip- 
1/2 inch green 


5 


3 ' 


0.24 " 


April 19-27 


1/2 inch 
green-pink 





X 


X 


April 27- 
May 10 


Pink- 
petal fall 


3 


3 


0.19 


April 7- 
May 10 


Green tip- 
petal fall 


9 


12 


0.22 


May 10-21 


Petal fall- 
first cover 


3 


8 


0.18 


May 11-21* 


Petal fall- 
first cover 


6 


7 


0.31 


' Root rating is on a scale of to 1 and reflects the proportion of the root system 

infested with woolly apple aphids. 
'' Only 16 trees of the 25 sampled were uprooted, 5 with nymphs and 11 without. 
' Not uprooted because no nymphs were trapped. 
" Eleven trees that had been sampled in the green tip to petal fall (5) or pink to petal 


fall (6) sample period. 









There were two distinct periods of woolly trapped, only 16 trees were uprooted, the five 

apple aphid migration from roots to above- with njmiphs and eleven without nymphs. The 

ground portions of the tree (Table 1). Few aphid level of root infestation was the same for trees 

nymphs were trapped between green tip and with and without trapped n5anphs. Therefore, 

half inch green; five trees had one nymph each, trapping for migrating woolly apple aphid 

These nymphs were a different form than nsmiphs during the green tip to half inch green 

nymphs trapped later and non-migrating period would not be a useful sampling method, 

nymphs found in the summer. These No nymphs were trapped during the half 

earlynymphs were black and had httle wax (the inch green to pink sample period. First-instar 

chEiracteristic white woolly covering), whereas nymphs were trapped on several trees that were 

the typical form for first-instar nymphs is hght banded during both the pink to petal-fall and the 

purple with a waxy covering over the body and green-tip to petal-fall sample periods (Table 1). 

obvious tufts of wax. Because of the small In both sets oftrees the aphid nsonphs appeared 

number of trees on which early nymphs were to have been trapped recently and were either 



Fruit Notes, Fall, 1993 



Table 2. Relationship 
infestation rating. 


of trap captures 


to root colonies and root 


Variable 


Number of trees 
with nymphs 


Number of trees 
without nymphs 


Root Colonies 






>0 root colonies 
root colonies 


12 
3 


12 

48 


Root Infestation 






>0.21 rating 
<0.21 rating 


11 
4 


13 

47 


1 



still active or at least had not begun to shrivel. 
N3Tnphs in the petal-fall to first-cover sample 
appeared to have been trapped early in the 
period and were inactive, darkened, and had 
begun to shrivel. Eleven trees that had the tape 
traps removed at petal fall were re-banded to 
investigate further the timing of migration. In 
all eleven trees, those that had njmiphs trapped 
on bands prior to petal fall also had nymphs 
after petal fall, and those that did not have 
nymphs trapped on bands did not have any after 
petal fall. From these results, I conclude that 
the majority of root migration takes place within 
a few days before and after petal fall. All three 
samples, therefore, that included petal fall were 
pooled and analyzed as one sample, because the 
presence or absence of migrating nymphs, not 
the nvmiber of nymphs, was used as the predic- 
tor variable. 

From traps on the 75 trees in the pooled 
sample, fifteen (20%) had first-instar woolly 
apple aphid nymphs (the median number of 
nymphs per trap was 8 but ranged fi-om 1 to 
2883). Trees that had traps with migrating 
nymphs had a larger number of root colonies 
and a more severe root infestation than trees 
without migrating njrmphs (Table 2). For trees 
on which nymphs were trapped, 80% had root 
colonies, and 73% had root gall infestation rat- 



ings greater than 0.21. For trees without 
trapped nymphs, only 20% had root colonies and 
only 22% had root gall infestations greater than 
0.21. F\ui,her, the mean nimiber of root colonies 
and root gall infestations were 4.1 and 0.3 for 
trees with trapped nymphs, respectively, and 
0.5 and 0.2 for trees without trapped njmaphs, 
respectively. 

Conclusions 

The presence of n5Tnphs migrating up the 
tree fi*om roots during petal fall is an indication 
of the size of the woolly apple aphid population 
on the roots of that tree. Masking tape with a 
Tangle-trap^" barrier was successful in trap- 
ping these migrating njmiphs. By sampling an 
orchard, one can estimate the number of trees 
that have serious woolly apple aphid root infes- 
tations by comparing the number of trees with 
migrating nymphs versus those without. One 
could also identify portions of an orchard that 
may have a woolly apple aphid problem and 
take suitable action: apply insecticides against 
above-ground feeding aphids which would even- 
tually lower root-feeding populations, delay re- 
planting or plant other crops for a year or two, or 
apply insect parasitic nematodes, which is a 
promising potential control method (Brown et 
al., 1992). 



8 



Fruit Notes, Fall, 1993 



More trials of this sampling method are 
needed, especially to test regions outside the 
Shenandoah Valley. This study showed that 
presence of migrating nymphs indicates trees 
that are highly likely to have root-feeding 
aphids. Further trials will enable a more quan- 
titative prediction using the number of nymphs 
trapped and determination of a treatment 
threshold number of trees infested per acre. 
Cooperators are currently being sought in the U. 
S. and Canada to help refine this sampling 
method. 

Acknowledgements 

I thank Dr. S. S. Miller, USDA, ARS, Appa- 
lachian Fruit Research Station, for his coopera- 
tion in the use of his orchard; J. J. Schmitt and 

C. Cornell for their hard work in collecting data; 
and J. J. Schmitt, G. J. Puterka, S. S. Miller, B. 

D. Horton (Appalachian Fruit Research Sta- 
tion), and H. W. Hogmire (West Virginia Univer- 



sity) for comments on an earUer draft of this 
paper. 

References 

Brown, M.W., J.J. Jaeger, A.E. Pye, and J.J. 
Schmitt. 1992. Control of edaphic populations 
of woolly apple aphid using entomopathogenic 
nematodes and a systemic aphicide. J. Entomol. 
Sci. 27:224-232. 

Brown, M.W. and J.J. Schmitt. 1990. Growth 
reduction in nonbearing apple trees by woolly 
apple aphids (Homoptera: Aphididae) on roots. 
J. Econ. Entomol. 83:1526-1530. 

Brown, M.W., J.J. Schmitt, S. Ranger, and H.W. 
Hogmire. In. Prep. Yield reduction in apple by 
edaphic woolly apple aphid populations. J. 
Econ. Entomol. (in preparation). 

Hoyt, S.C. and H.F. Madsen. 1960. Dispersal 
behavior of the first ins tar nymphs of the woolly 
apple aphid. Hilgardia 30:267-299. 



%£• %i* %f# mS^ mS^ 
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Fruit Notes, Fall, 1993 



Chemical Growth Control: 
Ethephon as a Growth Retardant 

Wesley R. Autio and Duane W. Greene 

Department of Plant & Soil Sciences, University of Massachusetts 



With the loss of Alar*, the only chemical 
available for reducing vegetative growth is ethe- 
phon. It functions as a growth retardant in the 
same way that it initiates early ripening: it 
releases ethylene within the plant tissues after 
application, and ethylene can retard growth. In 
1991 and 1992, we conducted a study to deter- 



mine the effects of ethephon and a number of 
mechanical growth-retarding treatments (scor- 
ing, ringing, and root pruning) on growth and 
fruit characteristics. Results from other treat- 
ments were discussed previously in Fruit Notes 
[1992, 57(3):l-5,6-9]. Here we report the effects 
of spring ethephon application. 



80 










70 


— ^^ 




^60 


Ethephon / 






/ y^ 




g-50 


/ y^ 




§40 


/ ^"^^ 




Cumulati 

lO CO 

o o 


/ / Control 




10 


1 Ay\ A.-'<i 1 1 1 1 1 1 1 1 1 




9/15 9/23 10/1 10/9 10/17 


Date 


Figure 1 . Cumulative drop from control and ethephon-treated Gardiner Delicious/MM. 106 
trees in 1991. Ethephon was applied at 500 ppm on May 16, 1991. 



10 



Fruh Notes, Fall, 1993 



100 






^^ 




90 


^^ 




80 


^^^-^^•"^ 




g 70 


Ethephon/^ / 




Q. 

2 60 
â– o 


/ / 




Cumulative 
o o o 


/ ^^^--ic''"^Control 




20 


/^"^"""^^ 




10 


j^C \ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 




9/7 9/15 9/22 9/29 10/6 10/13 


Date 


Figure 2. Cumulative drop from control and ethephon-treated Rogers Red Mcintosh/ 
MM. 106 trees in 1992. Ethephon was applied at 500 ppm on May 26, 1992. 



In 1991, mature, vigorous Gardiner Deli- 
cious/MM.106 trees were treated with 500 ppm 
ethephon eight days after petal fall, and in 1992, 
mature, vigorous Rogers Red Mcintosh/ 
MM. 106 trees were treated with 500 ppm ethe- 
phon four days after petal fall. During the 
season of treatment, we assessed fruit set, veg- 
etative growth, frxdt ripening, fruit drop, and 
fruit size. 

Use of ethephon soon after bloom, as was 
done in this study, has been shown to thin fruit, 
and in fact, ethephon is used as a chemical 
thinner in some locations around the world. In 
this experiment, however, the ethephon treat- 
ment did not thin significantly and had very 



little effect on fruit set. We all know that 
chemical thinners do not work every year, and 
they do not work under all circumstances. The 
lack of a thinning response from ethephon in 
this study should not be taken to mean that 
ethephon will not thin fruit under our condi- 
tions. From a practical standpoint, if ethephon 
is to be used as a growth retardant, the grower 
must be prepared for a potential reduction in 
fruit set, even if it Likely will not occur in all 
circimistances. 

Research by others has shown that ethep- 
hon has only a moderate effect at best on termi- 
nal growth reduction. The most noticeable 
growth reduction comes from preventing spurs 



fruit Notes, Fall, 1993 



11 



from growing into lateral 
shoots. In this experiment, we 
measured terminal length, 
terminal diameter, and the 
time required for dormant 
pruning. Not surprisingly, 
ethephon did not significantly 
alter terminal growth, but it 
did reduce the time required 
for dormant pruning of Deli- 
cious by approximatlely 25%, 
which likely was related to a 
reduction in the number of lat- 
eral shoots produced from 
spurs. 

When used on excessively 
vigorous, young trees that are 
essentially nonbearing, ethep- 
hon may be very effective at 
reducing all excessive vegeta- 
tive growth, but indirectly, 
since it can stimulate flower 
bud formation. In this way, 
the tree can be shifted from a 
vegetative habit to a bearing 
habit the year after ethephon 
application. In our experi- 
ment, we were using mature, 
bearing trees, so this was not a 
factor. 

Very importantly, the ef- 
fects of spring-applied ethep- 
hon were apparent in the fall. 
Figures 1 and 2 show the fruit 
drop that occurred from ethep- 
hon-treated and untreated 
trees. Overall, for ethephon- 
treated trees, drop was nearly 
double that of untreated trees. 
Fruit from ethephon-treated 
trees also ripened sooner (Fig- 
ure 3), and for Mcintosh, they 
were significantly smaller 
than fruit from untreated 
trees (Figure 4). 

In conclusion, several 
points should be understood 











Delicious 




i 

^ 




. . 


















^->-^ 




Mcintosh 


ethophofl 












1 


1 


1 



9/15 9/20 9/25 9/30 

Date of 1 ppm ethylene 



10/5 



Figure 3. Effects of spring-applied ethephon on the time 
of ripening of fruit from Gardiner Delicious/MM.106 
trees and Rogers Red Mclntosh/MM.106 trees. 



Average count per 42-lb box 



140 



130 



120 



110 



100 



90 



80 







&tt«ph*m 



y >jk 



^ioi^^i^^S^^^ 



Cont|t)l 



Ethephon 



Delicious 



Mcintosh 



Figure 4. Effects of spring-applied ethephon on size, 
presented as average counts per 42-lb. box, of fruit from 
Gardiner Delicious/MM. 106 trees and Rogers Red Mcln- 
tosh/MM.106 trees. 



12 



Fruit Notes, Fall, 1993 



before ethephon is used to retard growth of 
mature, bearing trees: 1) ethephon is a poten- 
tial thinner, so significant thinning may result if 
appropriate conditions exist; 2) extension 
growth may not be reduced dramatically, but 
lateral shoot development may be reduced, pro- 
ducing more of a spur-type growth habit and 
reducing the time required to dormant prune 
trees; 3) ripening may be advanced and drop 
may be increased, so plans must be made to 
harvest ethephon-treated trees earUer than 
normal; and 4) fruit size may be reduced. The 
potential reduction in size is of major concern 
and may negate any positive effects of ethephon 
treatment on bearing trees. 

A strategy that was used with Alar® was to 



direct the spray into the top, vigorous portions of 
the canopy. Using this technique, carryover 
effects and reduction in fruit size were mini- 
mized. This approach may not work with ethe- 
phon, since it would cause finiit in the top of the 
tree to ripen earlier than the rest, making har- 
vest troublesome and possibly resulting in dam- 
age to lower fruit from upper frmt dropping 
through the canopy. 

For vigorous,nonfruiting trees, ethephon 
may be more beneficial than for bearing trees. 
In young trees, its major positive response is to 
initiate flower bud formation. The season fol- 
lowing the ethephon treatment should see en- 
hanced finiit production and, therefore, less veg- 
etative growth. 



«1# *f# %{# %f# %f# 

r{« 0^ #j« #2% 0^ 



Fruit Notes, Fall, 1993 



13 



Food Prices, Expenditures, 
and Income 



Robert L. Christensen and Donald R. Marion 

Department of Resource EconomicSy University of Massachusetts 



Have consumer expenditures for food been 
increasing or decreasing, and if so, by how 
much? What happens to the consumer's food 
dollar; what share do farmers get, and how 
much is absorbed by firms involved in the mar- 
keting process? What determines how the con- 
sumer food dollar is divided, and do those who 
receive the largest part of consumer expendi- 
tures have the largest profits, or vice-versa? 

These questions are among those most fre- 
quently asked about the U.S. food system. A 
recent U.S.D.A. publication (Dunham, D. 1993. 
Food Costs ... From Farm to Retail in 1992. 
Economic Research Service, USDA, Agricul- 
tural Information Bulletin Number 669) con- 
tains many of the answers, plus some additional 
insights into issues such as recent changes in 
food prices, consumer food expenditures, and 
the farmers' share. The following discussion 
addresses the above questions and some other 
highhghts from that publication. 

Food Prices and Expenditures 

Changes in consumer prices, including food 
prices, are measvired by the Consumer Price 
Index (CPI) which, in turn, is used as the mea- 
sure of inflation or changes in the cost of Uving. 
In 1991 and 1992, food prices increased less 
than the rate of inflation — the prices of aU. 
consumer goods. In other words, the modest 
increase in food prices helped to moderate the 
overall rate of inflation. For 1991 and 1992, the 
CPI rose by 4.2 and 3.0 percent, respec 
tively, while food prices rose by only 2.9 and 1.2 
percent, respectively. 

During the same two years, total consumer 
expenditures for food increased slightly more 
(3.6 and 2.3 percent, respectively) reflecting the 
combined effects of food price increases, popula- 
tion increases, and possible changes in con- 



sumption patterns. 

In 1991, U.S. consumers spent a total of 
$492 bilhon for food, which amounts to $4,367 
annually per household of 2.6 persons, or $1,680 
per person per year, $37.30 per week, and $4.60 
per day. Of that total, 62 percent was spent for 
food consumed at home and 38 percent away 
from home. 

Consumer Expenditures and Income 

For all consumers combined, 1992 food ex- 
penditures represented 11.4 percent of personal 
disposable income, though that percentage var- 
ied widely with variations in income levels. 
Households with disposable income of $5,000 to 
$9,999 spent 32.6 percent of their income for 
food, while those whose incomes were $30,000 to 
$39,999 spent only 15.2 percent for food. At 
higher income levels, even smaller proportions 
were spent for food. 

The share of consumer disposable income 
spent for food has, in general, been declining 
since 1960, when consumers spent 17.5 percent 
of disposable income for food. In 1970, that 
percentage had declined to 13.9 percent, in 1980 
to 13.5 percent, and 11.7 percent in 1990. Food 
consumed at home has been the major factor in 
that decline. In fact, consumer spending for food 
eaten away from home rose from 3.5 percent of 
personal disposable income in 1960to 4.4 per- 
cent in 1980, and has fallen sUghtly to 4.2 
percent in 1992. Why? The answer is that prices 
for food away from home have risen more than 
the prices of food consumed at home and that, 
year by year, we have been eating an increasing 
share of our meals away from home, a trend that 
has slowed somewhat in recent years. 

The fact that food expenditures in total have 
been declining as a percentage of income is a 
result of incomes increasing more rapidly than 



14 



Fruit Notes, Fall, 1993 



food prices, and also a demand for agricultural 
products that is income inelastic (when income 
increases by one percent, food expenditures in- 
crease by something less than one percent). 

The Farm Share 

Modestly increasing food prices, which have 
contributed to the declining share of income 
spent for food, have occurred partly because of 
efficiencies and competition in food marketing, 
but also, because of very slowly increasing farm 
prices. The farm value of a "market basket" of 
food purchased by consumers increased by only 
five percent from 1982 to 1992 - less than one- 
half of one percent per year. (The "market bas- 
ket" referred to here is a group of 74 domestically 
produced food products used by the U.S.D.A. for 
its food price and cost studies.) In contrast, 
Massachusetts per capita, personal disposable 
income increased more than 200 percent from 
1980 to 1991: $10,612 to $22,897 (Andrews and 
McNeel. 1993. Personal income per capita in 
current dollars by state. 1970-91. p. 244. In: 
The Universal Almanac - 1993). 

Over the same time, retail prices for food 
products increased by 40 percent, resulting in a 
decline in the farm share of consumer expendi- 
tures for the U.S.D.A. "market basket." For 
example, in 1982, farmers received 35 percent of 
the dollars spent by consumers for food, as 
payment for their products. By 1992, that share 
had fallen to 26 percent. 

The farm share of consumer expenditures 
varies widely among food products. It tends to be 
greatest for products requiring httle packaging, 
processing, and handling, and vice-versa. Thus, 
farmers receive a relatively large share (over 
50%) of the retail price of products such as eggs, 
chicken, and beef and 10 percent or less for 
others such as tomatoes, bread, and com syrup. 

The difference between retail prices and the 
amount received by farmers for an equivalent 
amount of product (e.g., it takes an average of 
2.4 pounds of Choice grade steer, to produce 
each pound of beef sold in retail stores) is re- 
ferred to as the farm-to-retail price spread. The 
farm-to- re tail price spread might be considered 
the marketing cost (or "marketing msu-gin") for 
farm products, being absorbed by the labor. 



packaging, promotion, energy, and other costs 
involved in the processing and marketing of 
farm products. In recent years that cost has 
risen at an average rate of 5.6 percent, meaning 
that the cost of marketing farm products has 
been increasing faster than the farm value of 
those same products. 

There are two important points to be made 
here. First, whether the farm share (or the 
marketing margin) is increasing or decreasing 
says very httle about the welfare of farmers or 
the relative profitability of farming vs. market- 
ing. Products sold in retail stores are much 
different from those sold by farmers, and the 
cost of creating those differences is included in 
the farm-to-retail price spread. If, as has been 
occurring recently, consumers purchase in- 
creasing amounts of the more highly- processed 
products, the farm-to-retail price spread must 
increase, even if farmers continue to receive the 
same prices for their products. 

Second, there are major differences in the 
different markets involved that contribute to 
the fact that farmers often receive lower price 
increases for their products than do the market- 
ing firms. There is little benevolence in any 
market; market participants pay what they 
have to pay to receive needed products and 
services. In the markets where farmers sell their 
products, they usually have less bargaining 
power than do the buyers to whom they must 
sell. As a result, farmers tend to be "residual 
claimants" to returns in the market place. 

On the other hand, in the market for inputs 
such as labor, energy, and packaging materials, 
marketing firms encounter sellers with bargain- 
ing power equal to or greater than their own, 
£uid the resulting prices are negotiated or bar- 
gained prices. In the market for the final prod- 
ucts, marketing firms usually have sufficient 
marketing power visa- viz consumers, to at least 
be able to obtain adequately profitable prices. 

Who Gets What Part Of The 
Consumer Food Dollar? 

The final question addressed in this article 
is, where does the consumer food dollar go; who 
receives what part of it? In 1992, 26 cents of 
every food dollar spent by consumers was re- 



FruH Notes, Fall, 1993 



15 



ceived by fanners. Of the remainder (some- 
times referred to as the "marketing bill"), 35 
cents was used to pay salaries and wages for the 
workers involved, and 8 cents, the cost of pack- 
aging. Transportation, depreciation, advertis- 
ing, energy, and rent costs each accounted for 
3.5 to 4.5 cents. About 6.5 cents was divided 
among a large number of costs, including re- 
pairs, insurance, professional services, prop>erty 
taxes, and many other items. The remaining 3.5 
cents represented before-tax profits. 

Consumer Value and Their 
Food Dollars 

In conclusion, it appears that consumers 
have benefitted fi-om very moderate increases in 
retail food costs in recent years. Personal dispos- 
able incomes have risen at a faster rate than 
food costs and the percentage of income spent on 
food has fallen. At the same time the farm share 
of the consumer's dollar has steadily dechned 
while the farm-to-retail margin has gradually 



increased. 

Do U.S. consumers get a good value for their 
food dollars? Undoubtedly they do. Could it be 
better? Of course it could, and it is probably 
getting better, especially with the increased use 
of information about nutrition and healthful- 
ness of food products. Do farmers and marketers 
receive fair values for their contributions? Prob- 
ably so, at least if you base your conclusion on 
the availability of adequate supplies of food of 
adequate quality and in reasonable variety. In 
addition, most would conclude that food market- 
ing firms receive reasonable, though not ex- 
travagant, returns for their investments. The 
case for farmers is less clear; certainly their 
profits are not excessive. For U.S. farmers 
whose major occupation is farming, household 
net farm incomes in 1991 averaged $10,228 
fi"om gross cash farm income of $94,027 and 
farm assets valued at $491,241 (USDA-ERS. 
1993. Agricultural Income and Finance - Situ- 
ation and Outlook Report. Economic Research 
Service, USDA, AFO-49). 



%f# «f^ *f^ *fi» •^0 

r|% #1% #^ #1% r{% 



16 



Fruit Notes, Fall, 1993 




Fruit Notes 



University of Massachusetts 

Department of Plant & Soil Sciences 

205 Bowditch Hall 

Amherst, MA 1003 



Nonprofit Organization 
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Permit No. 2 
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Fruit Notes 



ISSN0427-6906 



' !:]RmRY 

HAR-7 914 



Prepared by the Department of Plant & Soil Sciences. . ^ r r \ / r\r- n k n r 

JHIV. OF MASS. 

University of Massachusetts Cooperative Elxtenslon System, 

United States Department of Agriculture, and Massachusetts Counties Cooperating. 

eiOLOGCAL 
Editors: Wesley R. Autio and William J. Bramlage 



MAR 04 1994 



SCIENCES UBRARY 




Volume 59, Number 1 
WINTER ISSUE, 1994 

Table of Contents 

Apple Integrated Pest Management in 1993: 
Insects and Mites in Second-level Orchard Blocks 

Second-level IPM in Blocks of 
Scab-resistant Apple Cultivars 

New Publication Available 

Second-level Integrated Pest 
Management, 1991 to 1993: Diseases 

Tax Pointers for Farmers in 1993 



Fruit Notes 



Publicationlnformation: 

/^Mi/iVbtesaSSN0427-6906)ispublishedthefirstdayofJanuary,April, 
July, and Octoberby the Department ofPlant & Soil Sciences, University 
ofMassachiisetts. 



The costs of subscriptions toFruit Notesare $7.00 for United States 
addresses and $9.00 for foreign addresses. Each one-year subscription 
begins January 1 and ends Decembers 1. Somebackissues are available 
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ments must be in United States currency and should be made to the 
University ofMassachusetts. 



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Fruit Notes 

Department ofPlant & Soil Sciences 

205BowditchHall 

University ofMassachusetts 

Amherst, MA01003 



COOPERATIVE EXTENSION SYSTEM POLICY: 

Mdiemicalusessuggestedin this pubUcation are cQntingentupona)ntinuedregistration.TTiese chemicals slxnildte 
usedinaai)rdarK)ewithfedera] and slate laws and regulations. Growers are urged to befamiliarwithaDcurrentstate 
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offersequalopportunityinprogramsandemploymenL 



Apple Integrated Pest Management in 
1993: Insects and Mites in Second-level 
Orchard Blocks 



Jennifer Mason, Ronald Prokopy, Starker Wright, Sarah Goodall, 
Kristian Jones, Yu Ma, Vanessa Mohr, and Miyu Nogaki 
Department of Entomology, University of Massachusetts 



For the past two years we have reported results 
of our ongoing program of second-level IPM trials in 
Massachusetts apple orchards. Under second-level 
IPM, orchard management is integrated across all 
classes of pests: insects, mites, diseases, weeds, and 
vertebrates, rather than focusing on a single type of 
pest. Here we report results of the third year of 
second-level IPM trials on insects and mites in 
commercial Massachusetts orchards. 

Insect and mite management under second-level 
IPM practices require application of three to four 
selective insecticide sprays from April to early June 
to manage tarnished plant bug (TPB), European 
apple sawfly (EAS), plum curculio (PC), green fruit- 
worm (GFW), and the first generations of codling 
moth (CM), lesser appleworm (LAW), leafminer 
(LM), and white apple leafhopper (WALH). Insecti- 
cide application to the interior of the block ceases 
after the final plum curculio spray in early June, 
hopefully allowing populations of predatory insects 
and parasitoids to increase to levels sufficient to 
provide control of summer populations of foliar 
pests. In full second-level IPM blocks, apple 
maggot fiies (AMP) are controlled by perimeter in- 
terception traps. In transitional second-level 
IPM blocks, use of AMF interception traps is re- 
placed by perimeter-row spraying with Guthionâ„¢* or 
Imidan''''^ every three weeks beginning in early July. 
In both types of blocks, removal of unmanaged apple 
and pear trees within 100 yards of each block reduces 
immigration of CM and LAW. Removal of drops 
during and after harvest discourages buildup of 
within-orchard populations of AMF, CM, and LAW. 

We believe there are at least four distinct poten- 
tial benefits of employing biologically-based meth- 
ods as a substitute for insecticides from early June 
until harvest. These include reduction in insecticide 
residue on fruit at harvest, reduction in impact of 
insecticide on areas bordering orchards, reduction in 



selection pressure leading to pest resistance to insec- 
ticides, and buildup of beneficial natural enemies in 
the absence of insecticide use afi-er early season 
sprays. For some growers and some intended mar- 
kets, one or more of these potential benefits could be 
important in the near future, if not now. 

In 1993, we continued work in the same six full 
and six transitional second-level IPM test blocks 
used in 1991 and 1992. Each second-level block was 
matched with a nearby control block that was man- 
aged by the grower, using first-level IPM methods. 

Early-Season Fruit-injuring Pests 

For control of arthropod pests active up to early 
June, second-level IPM relies on early-season pesti- 
cide treatment based on monitoring. We monitored 
each orchard weekly beginning in mid-April, then 
biweekly from mid-June through September. Five 
each of four types of sticky traps were hung in each 
block to monitor for TPB, LM, and EAS. We exam- 
ined 100 or 200 leaves or watersprouts per block for 
LM, LH, aphids, mites, and mite predators. During 
PC season, scouts examined fruit on perimeter trees 
for evidence of fresh injury, while growers were 
urged to do likewise on a daily basis. On the basis of 
this monitoring, recommendations were made to the 
grower for treatment of the experimental block. 

In second-level IPM blocks (both full and transi- 
tional) in 1993, combined injuries from early- season 
fruit pests were rather similar to those in nearby 
first-level IPM (grower control) blocks. In both first- 
and second- level IPM blocks, TPB caused by far the 
most damage, followed by PC and EAS (Table 1). 
Due to a lack of alternatives to pesticidal control of 
early-season fruit pests, both first- and second-level 
blocks had similar management and therefore simi- 
lar insecticide use(Table2).Thisyear sawa marked 
increase in TPB damage over 1992 in all blocks, 
though injury due to PC and EAS remained similar. 



Fruit Notes, Winter, 1994 



Table 1. Average percent injury by early-season insect pests in second- 
level and first-level IPM blocks in 1993.* 



Type of block 


TPB 


PC 


EAS 


GFW 


Total 


Full second-level 
First-level 

Transitional second-level 
First level 


7.0 a 

6.5 a 

2.6 a 
1.2 a 


0.3 a 
0.1 a 

0.3 a 
0.3 a 


0.1 a 
0.1 a 

0.1 a 
0.1 a 


0.0 a 
0.0 a 

0.0 a 
0.0 a 


7.4 a 
6.7 a 

3.0 a 
1.6 a 



* Means in each couplet in each column followed by a different letter 
are significantly different at odds of 19:1. Two hundred fruit of each 
cultivar present in both second-level and corresponding first level 
blocks were sampled at harvest. All blocks contained at least 1 of 
the following cultivars, and some contained up to 3 of these: 
Mcintosh, Cortland, Delicious, Empire, Golden Delicious. Average 
number of fruit sampled per block = 500. When sampling a cultivar, 
we examined 10 fruit on each of 20 interior trees and 10 on each of 
10 perimeter-row trees (when cultivar present on a perimeter row). 
TPB = tarnished plant bug; PC = plum curculio; EAS = European 
apple sawfiy; GFW = green fi-uitworm. 



Table 2. Dosage equivalents (spray events in parentheses) of insecticides and 
acaricides used in second-level and first-level IPM blocks in 1993.* 



Type of block 



Fruit pests 


















Mites 










After 




Before 








mid- 


mid- 




Other 








June 


June 


Oil 


miticides 


LH 


ABLM 


Total 


2.7 


0.0 


1.4 


1.0 


0.2 


0.3 


5.6 


(3.3) 


(0.0) 


(2.5) 


(0,8) 


(0.3) 


(0.5) 


(7.4) 


2.7 


1.0 


1.0 


1.2 


0.2 


0.0 


6.1 


(3.3) 


(2.2) 


(2.1) 


(1.3) 


(0.2) 


(0.0) 


(9.1) 


2.2 


0.7 


1.1 


0.5 


0.0 


0.2 


4.7 


(3.2) 


(3.2) 


(2.2) 


(0.6) 


(0.0) 


(0.2) 


(9.4) 


2.2 


1.2 


1.5 


1.7 


0.0 


0.0 


6.6 


(3.0) 


(2.8) 


(2.5) 


(1.5) 


(0.0) 


(0.0) 


(9.8) 



Full second-level 
First-level 

Transitional second-level 
First-level 



LH = leafhopper, ABLM = apple blotch leafminer. 



FruH Notes, Winter, 1994 



Summer Fruit-injuring Pests: 
Full Second-level IPM 

Odor-baited sticky red spheres were hung every 
five yards on perimeter apple trees of each full 
second-level experimental block to intercept immi- 
grating AMF. These were baited with both butyl 
hexanoate, a synthetic fruit odor deployed in poly- 
ethylene vials, and ammonium acetate, a synthetic 
food odor released through a Consep^'* membrane. 
Traps were cleaned biweekly, based on data from 
1992 suggesting a loss of capturing power with 
increase of length of time between cleanings. 

Interception trap captures averaged 5023 in the 
six full second-level blocks, as compared with 2430 in 
1992 and 3562 in 1991, indicating that AMF pres- 
sure was exceptionally high in 1993. Even so, 
captures of AMF on four interior unbaited monitor- 
ing traps (indicative of AMF penetration into the 
block interior) were similar in full second-level 
blocks and nearby first-level blocks (Table 3). AMF 



injury to fruit at harvest averaged slightly but not 
significantly greater in second-level than first-level 
blocks (0.7 vs. 0.3) (Table 3). The power of intercep- 
tion traps for controlling AMF is illustrated in one 
full second-level block of 10 acres where more than 
21,000 AMF were captured on the traps but less than 
1% of Mcintosh, Cortland, and Delicious apples were 
injured by AMF. It should be noted, however, that 
late-ripening cultivars (e.g., Delicious and Golden 
Delicious) consistently have proven to be more sus- 
ceptible to AMF injury than mid- or earlier-ripening 
cultivars under full second-level practices. 

The problem of effective control of AMF in late- 
ripening cultivars remains a challenging one for us. 
In one block that suffered 8% AMF injury to 
Cortlands in late September of 1992, we hung perim- 
eter traps significantly higher in the tree in 1993 
than in 1992 in an attempt to increase trap captures 
of AMF before fruit injury occurred. We found only 
1% AMF damage to the Cortlands at harvest this 
year, though it should be noted that the fruit was 



Table 3. Season-long apple maggot fly (AMF) injury and trap captures in second- 
level IPM blocks and first-level IPM blocks in 1993.* 









Perimeter 








Interior 


monitoring 






AMF injury 


monitoring 


trap 


Interception 




to fruit at 


trap captures 


captures 


trap captures 


Type of block 


harvest (%) 


per trap 


per trap 


per block 


Full second-level 


0.7 a** 


7.7 a 


22.9 a 


5023 


First-level 


0.3 a** 


11.0 a 


10.7 a 


— 


Transitional second-level 


0.8 a 


8.4 a 


8.8 a 





First-level 


0.4 a 


9.7 a 


9.7 a 


— 



Means in each couplet in each column followed by a different letter are 
significantly different at odds of 19:1. Two hundred fruit of each cultivar present 
in both second-level and corresponding first-level blocks were sampled at harvest. 
All blocks contained at least one of the following cultivars, and some contained 
three of these: Mcintosh, Cortland, Delicious, Empire, Golden Delicious. 
Average number of fruit sampled per block = 500. When sampling a cultivar, we 
examined 10 fi-uit on each of 20 interior trees and 10 on each of 10 perimeter-row 
trees (when cultivar present on a perimeter row). 

Data on AMF injury to fruit from one orchard have been excluded due to 
excessively high late-season damage to several cultivars in both the second and 
first-level blocks possibly caused by lack of AMF control methods by grower in 
surrounding blocks. 



Fruh Notes, Winter, 1994 



picked slightly earlier than 
in 1992. In other blocks, 
problems with AMF arose 
in cases where perimeter 
rows were comprised of 
early ripening cultivars, 
necessitating immediate 
movement of interception 
traps to interior trees upon 
harvest. Due to time con- 
straints we wereunable to 
move the spheres soon 
enough after harvest, al- 
lowing injury to occur in 
later-ripening cultivars. 

We continue to look for 
an appropriate method of 
hanging ammonium ac- 
etate membranes that will 
keep their fluttering mo- 
tion to a minimum so as not 
to scare AMF away. This 
year we attempted to stitch 
a wire through the top of the 
membrane packet only to 
find that the contents 
drained out within a few 
weeks. 

Fruit injury by CM, LR, 
and LAW were similar in second-level and first-level 
blocks (Table 4). CM averaged 0.2% in the second- 
level blocks while it was 0% in the adjacent first-level 
blocks. Leafroller injury was up from 1992, averag- 
ing 0.8% in second-level and 1.0% in first level 
blocks. LAW injury also increased, averaging 0.4% 
in second-level blocks and less than 0.1% in first- 
level blocks. 

No insecticide was applied against any fruit- 
injuring pest after mid-June. In adjacent first-level 
blocks growers applied an average of 1.0 dosage 
equivalents of insecticide against fruit pests after 
mid-June and sprayed the block an average of 2.2 
times (Table 2). 

Summer Fruit-injuring Pests: 
Transitional Second-level IPM 

Every three weeks after early June, perimeter 
row apple trees in transitional second-level blocks 
were treated with insecticide to control AMF. The 
block interior remained free of insecticide after early 
June. AMF injury at harvest averaged 0.8% in 
transitional second-level blocks and 0.4% in nearby 
first-level blocks, somewhat higher for both types of 



Table 4. Fruit injury by codling moth (CM), leafrollers (LR), and 
lesser appleworm (LAW) in second-level and first-level IPM 
blocks in 1993.* 



Type of block 




CM 


LR 


LAW 


Full second-level 
First-level 

Transitional second-level 
First-level 


0.2 a 
0.0 a 

0.1 a 
0.0 a 


0.8 a 
1.0 a 

0.7 a 
0.2 a 


0.4 a 
<0.1 a 

0.4 a 
0.0 a 



Means in each couplet in each column followed by a diff'erent 
letter are significantly different at odds of 19:1. Two hundred 
fruit of each cultivar present in both second-level and 
corresponding first level blocks were sampled at harvest. All 
blocks contained at least 1 of the following cultivars, and some 
contained 3 of these: Mcintosh, Cortland, Delicious, Empire, 
Golden Delicious. Average number of fruit sampled per block 
= 500 When sampling a cultivar, we examined 10 fruit on 
each of 20 interior trees and 10 on each of 10 perimeter-row 
trees (when cultivar present on a perimeter row). 



blocks than in 1992 (Table 3). Captures of AMF on 
interior unbaited monitoring traps were similar in 
transitional second-level blocks and in first-level 
blocks. Total insecticide used afi^r early June aver- 
aged 0.7 dosage equivalents in second-level blocks 
compared with 1.2 dosage equivalents in first-level 
blocks (Table 2). The relative similarities between 
the two sets of blocks may be explained by some 
growers using exclusively border row sprays for 
AMF in first-level blocks, mainly due to financial 
constraints. 

CM damage was very low in both types of blocks 
(0.1% or less). Both LR and LAW injury were 
somewhat (but not significantly) greater in the tran- 
sitional blocks (0.7 and 0.4%) than in the first-level 
blocks (0.2 and 0%) (Table 4). 

Foliar Pests and Predators: 
Full Second-level IPM 

In 1992, we reported peak populations of foliar 
pests; this year we return to season-long averages 
from time of first to last appearance of the pest on 
foliage. Hot, dry weather played a major role in 
inciting higher foliar pest populations in 1993. 



Fruit Notes, Winter, 1994 



Table 5. Seasonal average populations of mites and mite predators in 
second-level and first-level IPM blocks in 1993. * 


Mite presence 
(% of leaves) 


Ratio of 
ERM-t-TSM 
YM to Af 


ERM+ 
Type of block TSM Af 


Full second-level 22.4 a 0.7 a 
First-level 18.6 a 2.0 a 

Transitional second-level 19.6 a 2.1 a 
First-level 16.2 a 1.0 a 


4.3 a 32:1 
4.5 a 9:1 

3.1 a 9:1 

1.2 a 16:1 


* Means in each couplet in each column followed by a different letter are 
significantly different at odds of 19:1. ERM = European red mite; TSM 
= two-spotted mite; Af = Amblysieus fallacis; YM = yellow mite. 



Table 6. Foliar insect pest average population levels in second-level and first-level blocks in 
1993.* 



Type of block 


PLH 


WALH 


RLH 


ABLM 


GAA 


GAAP 


WAA 


Full second-level 
First-level 

Transitional second-level 
First-level 


8.9 a 
6.7 a 

6.4 a 
6.9 a 


4.2 a 
4.2 a 

2.2 a 
1.4 a 


7.5 a 
2.4 a 

2.4 a 
0.8 a 


8.0 a 
17.2 a 

6.8 a 
4.4 a 


28.7 a 
27.1 a 

35.3 a 
28.9 a 


17.1 a 
13.4 a 

19.0 a 

10.1 a 


8.1 a 
7.6 a 

4.3 a 

4.5 a 



Means in each couplet in each column followed by a different letter are significantly different 
at odds of 19:1. PLH = potato leafhopper, WALH = white apple leafhopper; RLH = rose 
leafhopper, ABLM = apple blotch leafminer; GAA = green apple aphid; GAAP = green apple 
aphid predators: cecidomyiids and syrphids, WAA = woolly apple aphid. PLH, WALH, and 
RLH data are average percentages based on bi-weekly samples of 100 or 200 fruit cluster or 
terminal leaves. ABLM data are the average number of mines per 100 leaves based on bi- 
weekly samples of 100 or 200 fruit cluster or terminal leaves. GAA, GAAP, and WAA data 
are percentage watersprouts infested based on bi-weekly samples of 200 watersprouts. 



Fruit Notes, Winter, 1994 



Mite populations were high in most orchards, 
appearing early in the season (Table 5). In several 
orchards mite problems in second-level blocks may 
have been inadvertently assisted by our setting 
aside of small areas (approximately one acre ) in the 
block to be left untreated with dormant oil. This was 
done in the hope of providing a reasonable food 
source for early phytoseiid mite predator popula- 
tions. Unfortunately Amblyseius fallacis suffered 
extremely heavy late winter mortality, and these 
areas proved useful only for raising large numbers of 
European red mites. Yellow mite predators were 
eventually present in large numbers in some or- 
chards. There tended to be little difference, how- 
ever, in densities of mite predators between full- 
second-level and first-level blocks (Table 5). 
Typhlodemus pyri obtained from Geneva, New York 
were released in two blocks in 1992 and again this 
past summer. Repeated sampling of the release sites 
leads us to believe that both attempts at colonization 
were unsuccessful. 

Full second-level blocks were treated with 
slightly higher dosage equivalents of pre-bloom and 
mid-season oil than nearby first-level blocks (1.4 vs. 
1.0) while receiving slightly less other miticide (1.0 
vs. 1.2 dosage equivalents) (Table 2). The use of post- 
bloom miticides in the full second-level blocks was 
mainly due to a need to regain control over mite 
populations in the areas that did not receive oil in the 
spring. 

White apple leafhopper populations were equal 
in both the full second-level and first-level blocks. 
Potato leafhoppers were slightly, although not sig- 
nificantly, higher in the full second-level blocks. The 
major leafhopper problem this year proved to be rose 
leafhopper (RLH) migrating into blocks from border- 
ing wild rosebushes and brambles. In several loca- 
tions RLH were present in high enough numbers to 
be a major irritation at harvest, and one full second- 
level block required late season treatment of insecti- 
cidal soap. RLH averaged 7.5 % infestation in full 
second-level blocks, versus 2.4% infestation in the 
first-level blocks (Table 6). 

Average leafminer populations were lower, al- 
though not significantly, in full second-level blocks 
than in first-level blocks (Table 6). Dimilinâ„¢ was 
used in three of the six full second-level blocks 
against overwintering LM adults and eggs even 
though only two of these blocks required a treat- 
ment. Late stage tissue mines were collected from 
each orchard and brought back to the lab for parasit- 
ism readings. The average parasitism rate of second 
generation larvae was 55% in full second-level 
blocks but only 37% in first level blocks. Research 



into parasitism of LM continues to be an area of 
interest in that parasitism appears a potentially 
very effective means of controlling one of our major 
foliar pests. 

Green apple aphids infested 29% and 27% of the 
watersprouts in full second-level blocks and in first- 
level blocks, respectively. Levels of two aphid preda- 
tors were also similar in both types of blocks, and 
achieved efficient control of GAA. Levels of woolly 
apple aphids on watersprouts were also similar in 
both types of blocks, but were considerably higher 
than in 1992. 

Foliar Pests and Predators: 
Transitional Second-level IPM 

Mite levels were moderate to high in most of the 
transitional second-level blocks and adjacent first- 
level blocks. Dosage equivalents of oil averaged 1.1 
in second-level blocks and 1.5 in first-level blocks. 
Other miticide applications averaged 0.5 dosage 
equivalents in second-level blocks and 1.7 dosage 
equivalents in first-level blocks. Mid-season miticide 
application occurred in one second-level block as 
compared to three first-level blocks (Table 2). 

White apple leafhopper and potato leafhopper 
populations were about the same in second-level and 
first-level blocks. RLH levels were less of a problem 
in transitional second-level blocks than in full sec- 
ond-level blocks, possibly becauseperimeter row in- 
secticide applications every three weeks during the 
summer killed immigrating RLH. 

Only one transitional second-level block was 
treated with Dimilinâ„¢ against first generation 
leafminers. Leafminer numbers were slightly 
higher in second-level blocks than in first-level 
blocks, yet the parasitism of second generation lar- 
vae was slightly lower (38% vs. 44%). LM levels were 
similar to those found in 1992. 

Green apple aphid infestation levels were some- 
what higher in second-level blocks than in first-level 
blocks, as were both types of aphid predators moni- 
tored. In both types of blocks predators were suffi- 
cient to provide control of GAA populations. Woolly 
apple aphid populations were similar in both types of 
blocks (Table 6). 

Conclusions 

With regard to full second-level IPM practices 
that involve substitution of cultural, behavioral, and 
biological control methods for insecticide use after 
early June, we conclude the following after three 
consecutive years of implementation. 



Fruit Notes, Winter, 1994 



(1) No buildup of codling moth or leafroller beyond 
a level existing in nearby first-level IPM blocks. 

(2) Slight buildup of lesser appleworm in 1993. 

(3) Slightly greater injury by apple maggot flies, 
especially in late-ripening cultivars. 

(4) No buildup of pest mites under slightly reduced 
miticide use but insufficient buildup of preda- 
tory mites to permit truly substantial reduction 
in miticide use. 

(5) Considerable buildup of parasitoids of 
leafminers, possibly sufficient to reduce or elimi- 
nate need for spray against leafminers. 

(6) No buildup of apple aphids, woolly apple aphids, 
or white apple leafhoppers beyond acceptable 
levels. 

(7) Substantial mid- and late-summer immigration 
(into some blocks) of rose leafhoppers from 
nearby rose bushes and brambles, causing ex- 
crement spotting of fi"uit and nuisance to pick- 
ers. 

With respect to transitional second-level IPM 
practices that involve no application of insecticide to 
the block interior aft.er early June but rely on perim- 
eter-row sprays instead of traps for controlling apple 
maggot flies, we conclude the following after three 
consecutive years of implementation. 

(1) No buildup of codling moth but slightly more 
injury by leafrollers compared with nearby first- 
level IPM blocks. 

(2) Slight buildup of lesser appleworm in 1993. 

(3) Slightly greater injury by apple maggot fly. 

(4) No buildup of pest mites under slightly reduced 
miticide use but not enough buildup of predatory 
mites to allow much reduction in miticide use. 

(5) No buildup of parasitoids of leafminers. 

(6) No buildup of apple aphids, woolly apple aphids, 
or white apple leaflioppers beyond acceptable 
levels. 

(7) No unacceptable immigration of rose leafhop- 
pers during mid- and late-summer. 

In sum, transitional second-level IPM offers an 
advantage over first-level IPM in terms of substan- 
tial reduction in pesticide use during summer 



months. Growers using transitional second-level 
IPM should, however, keep a careful eye on buildup 
of apple maggot, leafrollers, and leafminers. In the 
long run, we believe that if pesticide-treated spheres 
can be developed and registered as a substitute for 
sticky spheres to control apple maggot (see accompa- 
nying article), full second-level IPM will be as eco- 
nomical to employ and as effective in controlling 
pests as first-level IPM while offering several dis- 
tinct advantages outlined in the introduction. 

To verify further the advantages and shortcom- 
ings of second-level IPM, we plan to evaluate in 1994 
the same full and transitional second-level practices 
in the same blocks used from 1991 to 1993. This will 
provide four consecutive years of data, which ought 
to be sufficient for drawing firm conclusions. We also 
plan to carry out intensive studies on refining those 
aspects of full second-level IPM that to date have 
proven to be shortcomings. These include: enhanc- 
ing the residual effectiveness of pesticide-treated 
spheres; studying within-orchard movement pat- 
terns of apple maggot flies from early- to mid- to late- 
ripening cultivars; evaluating elimination of rose- 
bushes and brambles near orchards as a means of 
controlling rose leafhopper; and evaluating the im- 
pact of summer applications of benomyl and 
mancozeb on mite predators, which we now believe 
may be the principal reason for lack of sufficient mite 
predator buildup to provide biocontrol of mites in 
second-level blocks. 

Acknowledgements 

This project was funded by the Massachusetts 
Society for Promoting Agriculture, the USDA North- 
east Regional IPM Competitive IPM Grants Pro- 
gram, State/Federal IPM funds, and the Northeast 
Region Sustainable Agriculture Research and Edu- 
cation Program (formerly LISA). We gratefully 
acknowledge this funding. We are also grateful for 
the participation and support of the following grow- 
ers: Bill Broderick, David Chandler, Dana Clark, 
Dick, Greg, and Kevin Gilmore, Tony Lincoln, 
Jesse and Wayne Rice, Joe Sincuk, Dave Shearer, 
Tim Smith, and Barry and Bud Wiles. 



•!• %l0 •!» %% •^ 
•Y» •^ •((»• •li* •(!>• 



Fruit Notes, Winter, 1994 



Second-level IPM in Blocks of 
Scab-resistant Apple Cultivars 

Daniel R. Cooley, Jennifer Mason, Jian Jun Duan, Xing Ping Hu, 
Ryan Elliott, and Ronald J. Prokopy 
Departments of Plant Pathology and Entomology^ 
University of Massachusetts 



Previously, we have described methods designed 
to eHminate orchard applications of insecticide and 
miticide after early June. We have also described 
our concept of the evolution of integrated pest man- 
agement (IPM) programs, moving from first level 
approaches which integrate methods for controlling 
one class of pests, to a second level which integrates 
methods for controlling all classes of orchard pests. 
In 1991, we initiated a second-level IPM program in 
12 Massachusetts commercial apple orchards com- 
prised of Mcintosh, Cortland, Empire, and Delicious 
cultivars. Our strategy used pesticides from April to 
early June against early-season arthropod pests 
(particularly mites, plant bug, sawfly, and plum 
curculio), early-season disease pests (apple scab and 
blossom-end rot) and early-season weed growth be- 
neath the tree canopy. After early June, the strategy 
called for few if any pesticide applications. Instead, 
cultural, behavioral, and biological control methods 
replaced pesticides. We felt that this strategy would 
allow natural enemies of arthropod pests to increase 
in numbers and provide biological control (especially 
of foliar-damaging arthropods), slow rates at which 
pests develop resistance to pesticides, and reduce 
potential human risks from pesticide residues on 
fruit at harvest. 

Over the first two years of the program, we saw 
successes and some problems in all pest areas, but 
one of the most troublesome areas was disease man- 
agement. In the second-level blocks, growers used 
4.6 fungicide dosage equivalents (DEs) during the 
primary apple scab season. They also used 2.2 
fungicide DEs to control summer diseases, notably 
flyspeck and sooty blotch. By comparison, in first- 
level IPM blocks, growers used 4.8 early-season 
fungicide DEs and 3.0 summer fungicide DEs. While 
the second-level blocks showed very modest fungi- 
cide savings, fungicide use still presented a major 
impediment in our efforts to reduce pesticide appli- 
cations, particularly late in the season. 

In addition to reducing risk to humans from 



exposure to pesticide residues, eliminating insecti- 
cides and miticides late in the season can assist pest 
control overall, since these materials oflne destroy 
natural enemies. Fungicides, however, also can 
have a negative impact on natural biocontrol. 
Benomyl is the best example, and has been shown to 
sterilize predaceous phytoseiid mites (Crofl, 1990), 
and eliminating fungicides from an orchard can 
stimulate biocontrol (Bower et al., 1993). Further- 
more, fungi that infect and kill insects and mites in 
the natural setting may be inhibited by fungicides 
(e.g.,Loriaetal., 1983; Tedders, 1981). Additionally, 
there appear to be some pesticide impacts on spiders, 
which may play a role in mite biocontrol 
(Wisniewska et al., 1993). Therefore, it is worth 
examining the effect of fungicide reduction or elimi- 
nation in the orchard. 

One approach to fungicide reduction is to use 
scab-resistant apple cultivars (SRCs). Our experi- 
ences (in the Northeast Apple Sustainable Agricul- 
ture Research and Education Project and in our own 
blocks) indicate that SRCs at leastwill allow the 
elimination of scab fungicides. The degree to which 
SRCs will allow us to eliminate summer fungicides 
needs to be determined. However, we sought to test 
the effects of fungicide elimination in second-level 
blocks, and in 1993, we added genetic control (host 
plant resistance) to the tactics of cultural, behav- 
ioral, and biological apple pest management. Spe- 
cifically, we emphasized a second-level IPM ap- 
proach in three commercial orchards having two- 
acre blocks of SRCs, primarily Liberty and Priscilla. 
The SRCs were propagated on M.26 rootstock and 
planted in 1988. 

We also introduced a new technique to tackle 
another problem: the need to clean red sphere 
maggot traps frequently. Sticky red spheres have 
been used in second-level IPM to trap apple maggot 
fiies at the orchard perimeter. For the first time in 
any commercial orchard, we used pesticide-treated 
spheres as a substitute for sticky-coated spheres as 



8 



Fruit Notes, Winter, 1994 



a behavioral method of controlling apple maggot 
flies. 

Each of the three blocks was divided in half 
With respect to arthropods, one half was managed 
under first-level IPM practices that involved moni- 
toring pest abundance and weather and then apply- 
ing pesticide as dictated by monitoring information. 
The other half was managed as follows. 

Arthropods 

Two applications of superior oil were made be- 
fore bloom against overwintering European red mite 
eggs followed by two applications of phosmet or 
azinphosmethyl against European apple sawfly and 
plum curculio (one at petal fall in mid-May and one 
two weeks later in late May). All unmanaged wild 
apple trees within 100 yards of the 
block perimeter were cut down as a 
cultural method of controlling co- 
dling moth by reducing or prevent- 
ing immigration of females from 
nearby wild host trees (very few 
codling moth females appear to 
disperse 100 yards or more within 
their lifetime under northeastern 
US conditions). Odor-baited pesti- 
cide-treated eight-cm wooden red 
spheres were hung five to six yards 
apart on perimeter trees in late 
June as a behavioral method of 
controlling apple maggot flies. 
Two types of odor baits were used: 
semi-permeable membranes that 
released the food-type attractant 
ammonium acetate, and polyethyl- 
ene vials that released the fruit- 
type attractant butyl hexanoate. 
Odor baits were hung a few inches 
from spheres and released attrac- 
tive odor over the entire three- 
month period of trap use. Prior to 
emplacement, the spheres were 
dipped in a mixture of 40% latex 
paint, 44% corn syrup, 15% water, 
and 1% Cygon (dimethoate). The 
latex paint allowed dimethoate to 
be released very slowly on the 
sphere surface. Periodic tests 
showed that, provided the sphere 
surface contained sufficient su- 
crose as a feeding stimulant, 70% 
or more ofalightingfiies died. This 
was true even in late September, 



three months after initial treatment with 
dimethoate; however, rainfall can wash away the 
corn syrup. Without it, flies did not feed and there- 
fore did not acquire a fatal dose of dimethoate. 
Hence, we or the growers were obliged to dip each 
sphere in a 20% aqueous solution of table sugar after 
every rainfall. Following harvest, drops were re- 
moved to decrease wi thin-orchard buildup of codling 
moth and apple maggot. 

Diseases 

No fungicide was applied in the SRC blocks. We 
simply eliminated fungicides from the management 
program, in spite of the expectation that there would 
be some damage from flyspeck and sooty blotch. 
Most trees had not yet reached full maturity and had 



Table 1. Numbers of insecticide and miticide treatments 
and percent arthropod-injured finiit at harvest* in three 
blocks of scab-resistant cultivars under first-level versus 
second-level IPM management. 


Pesticide 


Number of applications 


First-level 


Second-level 


Insecticide 
Miticide 


4.0 
2.0 


2.0 
2.0 


Pest 


Injured fruit (%) 


First-level 


Second-level 


European sawfly 
Plum curculio 
Codling moth 
Lesser appleworm 
Leafroller 
Apple maggot 

Total insect 


0.2 
0.3 
0.0 
0.1 
0.3 
0.1 

1.0 


0.6 
0.8 
0.0 
0.0 
2.5 
0.3 

4.2 


* Four hundred fruit 


per block were 


sampled at harvest. 



Fruit Notes, Winter, 1994 



comparatively open cano- 
pies that do not show a 
significant disease re- 
sponse to summer prun- 
ing, therefore we did not 
summer prune the blocks 
for disease management. 
In order to compare 
disease impacts of the 
SRC systems and a con- 
ventional IPM system, we 
observed disease inci- 
dence in conventional 
cultivars under normal 
first-level IPM practices 
using a block on each of 
the three farms consist- 
ing of conventional culti- 
vars (Mcintosh, 
Cortland, Delicious). We 
did not compare these 
blocks to the SRC blocks 
for management of and 
damage by arthropod 
pests. 

Pesticide Use and 
Injury 

Table 1 shows the 
mean number of miticide 
and insecticide treat- 
ments applied to each 
block. Table 1 also shows 
the mean number of ar- 
thropod-injured fruit at 
harvest. We focus here on 
fruit injury initiated after 
early June, the time when 

second-level IPM practices against insects diverged 
from first-level IPM practices. Injury by apple 
maggot was slightly greater and injury by leafroller 
was substantially greater in second-level compared 
with first-level blocks. Very little injury by codling 
moth or lesser appleworm occurred in these blocks. 
Not shown are fruit injury levels caused by larvae in 
one orchard that we identified as apple pith moth 
larvae. This injury was slightly greater in the 
second-level block, but definitive identification of 
the larvae (new to us) is pending. 

Table 2 shows the number of fungicides applied 
in the SRC blocks and the conventional blocks, as 
well as the disease incidence in each block type. 
Sooty blotch and flyspeck damage far exceeded any 



Table 2. Mean number of fiingicide treatments and mean percent 
disease-injured fruit at harvest* in three orchards comparing three 
systems: conventional cultivars under first-level IPM; scab-resistant 
cultivars under first-level IPM; and scab-resistant cultivars under 
second-level IPM. 


Pesticide 


Number of applications 


Standard 
cultivars 
first-level 


SRCs SRCs 
first-level second-level 


Fungicide 


8.0 


0.0 0.0 


Pest 




Diseased fruit (%) 


Standard 
cultivars 
first-level 


SRCs SRCs 
first-level second-level 


Apple scab 
Blossom end rot 
Sooty blotch 
Fly speck 

Total disease 


0.1 
0.1 
0.1 
0.4 

0.7 


0.0 0.0 
0.0 0.0 
7.0 7.3 
5.0 4.1 

12.0 11.4 


* Four hundred fruit 


per block were 


sampled at harvest. 



other fruit injury in each block type. This result was 
not surprising, since several observations have 
shown that in orchards which receive no fungicides 
in Massachusetts, there will be significant levels of 
sooty blotch and fiyspeck at harvest. In blocks of 
standard cultivars, fungicide applications greatly 
reduced sooty blotch and fiyspeck damage, but fiy- 
speck remained the most damaging disease. 

Table 3 shows mean abundance of principal 
arthropod pests of the fohage and their principal 
natural enemies. Notable among pests is the lower 
average European red mite population but the 
higher average white apple leafhopper and rose 
leafiiopper populations in the second-level blocks. 
Notable among natural enemies is the substantially 



10 



Fruit Notes, Winter, 1994 



Table 3. Mean percent sampled leaves* infected with arthropod foliar 
pests and their natural enemies in 3 blocks of scab-resistant cultivars 
under first-level vs. second-level IPM management. 


Foliar pest 


Infested leaves (%) 


First-level 


Second-level 


Apple aphids 
Leafminers (2"'* gen.) 
European red mites 
White apple leafhoppers 
Rose leafhoppers 


21 

29 

29 

5 

2 


13 
36 
18 
10 

8 


Natural enemies 


Infested leaves (%) 


First-level 


Second-level 


Aphid predators 

Leafminer parasatoids (2"'' gen.) 
Phytoseiid mite predator 
Stigmaeiid mite predator 


7 
46 

4 
38 


5 
71 

7 
66 


* Samples of 200 leaves per block were taken at bi-i 
from mid-June to mid-September. 


A'eekly intervals 



greater incidence of leafminer parasitoids and mite 
predators (particularly Stigmaeiid yellow mites) in 
the second-level blocks. 

Conclusions 

Our findings in this first year of applying second- 
level IPM practices to blocks of scab-resistant culti- 
vars indicate promise as well as some potential 
problems for future application. Among arthropods, 
the most promising aspectswere the success of pes- 
ticide-treated spheres in controlling apple maggot 
flies, the very low incidence of codling moth and 
lesser appleworm, and the buildup of leafminer 
parasitoids and mite predators (particularly yellow 
mites). 

Among diseases, the most promising aspects 
were (not surprisingly) the absence of apple scab and 



blossom end rot. The most 
problematic aspects were 
buildup of leafroller (ex- 
clusively oblique-banded) 
and flyspeck. 

From the perspective 
of arthropod manage- 
ment, use of pesticide- 
treated spheres is the key 
element of second-level 
IPM. These spheres are 
far simpler to prepare and 
maintain than sticky 
spheres. The only real 
problem (aside from gain- 
ing EPA registration for 
use) involves the current 
necessity of dipping the 
sphere in aqueous sugar 
solution after each rain- 
fall. This is a rapid pro- 
cess: 10 minutes to re- 
move, dip and re-hang one 
acre's worth of spheres. 
But if it is not done almost 
immediately after rainfall 
has ended, there is no pro- 
tection against apple mag- 
got fly invasion. In 1993, 
there were several un- 
avoidable lapses of a day 
or two in dipping spheres 
after rainfall, possibly ac- 
counting for the slightly 
greater amount of maggot 
injury in second-level 
blocks. We need to find a new polymer capable of 
releasing sucrose at a slow rate rather than losing all 
of the sucrose during rainfall. 

With regard to leafrollers and flyspeck, virtually 
all of the injury in 1993 was restricted to just one of 
the three orchards. Another of the orchards had 
almost all of the leafhoppers found; invading rose 
leaflioppers at harvest were especially troublesome. 
Perhaps the vegetation surrounding these orchards 
harbored substantial "inocula" of these two pests. 
This demands further study. 

Our experience in 1993 suggests much promise 
for applications of low-labor second-level IPM prac- 
tices in scab-resistant blocks. If we can keep sucrose 
on pesticide-treated spheres during rainfall and 
control flyspeck, leafroller, and leafhoppers using 
habitat management and early-season fungicides, 
then foliar pests such as mites and leafminer might 



Fruit Notes, Winter, 1994 



be controlled solely through natural enemies. As a 
result growers would no longer need to apply any 
pesticide in scab-resistant blocks after early June. 

Aknowledgements 

This work was supported by the USDA Sustain- 
able Agriculture and Research Education Program- 
-Northeast Region and the Massachusetts Society 
for promoting Agriculture. 

References 

Bower, K. N., L. P. Berkett, and J. F. Costante. 1993. 
Non-target effect of a fungicide on phytophagous 
and predacious mite populations in a disease resis- 
tant apple orchard. Proceedings of the Disease 
Resistant Apple Cultivar Workshop, Jan. 24-26, 



Hersey, PA (Abstract; Proceedings in press. Fruit 
Var. J.) 

Croft, B.A. 1990. Arthropod Biological Control 
Agents and Pesticides. Wiley and Sons. New York. 

Loria, R., S. Galaini, and D. W. Roberts. 1983. 
Survival of inoculum of the entomopathogenic fun- 
gus Beauveria bassianan as influenced by fungi- 
cides. Environ. Entomol. 12:1724-1726. 

Tedders, W. L. 1981. In vitro inhibition of the 
entomopathogenic fiingi Beauveria bassiana and 
Metarhizium anisopliae by six fungicides used in 
pecan culture. Environ. Entomol. 10:346-349. 

Wisniewska, J., Y. Yang and R. Prokopy. 1993. 
Spiders in second-level and first-level apple IPM 
blocks. Fruit Notes 58(l):20-23. 



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New Publication Available 



In June, 1993 the Sixth International Controlled 
Atmosphere Research Conference was held at 
Cornell University, Ithaca, New York. Presenta- 
tions at this three-day conference covered recent 
developments in use of modified (MA) and controlled 
(CA) atmospheres during storage and shipment of 
fruits, vegetables, and flowers. 

Proceedings of this conference are now avail- 
able. They are divided into two volumes, totaling 
nearly 900 pages. The first volume includes bio- 
chemical changes that occur during MA and CA, use 
of MA and CA during transport, recent engineering 
and equipment developments, and new information 



on disease and insect control during MA and CA. 
The second volume focuses on current research on 
CA storage of specific fruits, vegetables, and flowers. 
It concludes with three summary sections that 
present precise, current recommendations for MA 
and CA conditions for (1) vegetables, (2) apples, 
pears, and noshi (Asian pears), and (3) other fruits. 
These Proceedings are available for $85.00 from 
the Northeast Regional Agricultural Engineering 
Service, Cooperative Extension, 152 Riley-Robb 
Hall, Ithaca, NY 14853-5701. They are of great value 
to persons with interest in the application of MA and 
CA to storage and handling of horticultural crops. 



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12 



Fruit Notes, Winter, 1994 



Second-level Integrated Pest 
Management, 1991 to 1993: Diseases 

Daniel R. Cooley and Ryan Elliott 

Department of Plant Pathology, University of Massachusetts 

Jennifer Mason and Starker Wright 

Department of Entomology, University of Massachusetts 

Wesley R. Autio 

Department of Plant & Soil Sciences, University of Massachusetts 



Over the past three seasons, we have been at- 
tempting to develop disease-management strategies 
for apple which will both optimize fungicide use 
against diseases and integrate pest management 
across disciplines. The approach relies heavily on 
monitoring pathogen development for two key apple 
diseases, using cultural approaches to manage these 
diseases, and using fungicides which will have the 
least non-target efiFects. It is obvious that manage- 
ment of diseases in apples without fungicides is not 
possible, but we feel that it is possible to improve the 
efficiency of summer fungicide use by developing a 
better understanding of and appropriate monitoring 
techniques for summer disease pathogens, particu- 



Table 


1. 


Fungicide 


use (dosage 


equivalents) 


in 1991 


throu 


gh 


1993. 










Year 


Treatm.ent 


Total 


Primary 


S 


ammer 


1991 




Test 


5.9 


4.8 




1.1 






Check 


6.8 


5.0 




1.8 


1992 




Test 


7.5 


4.3 




3.2 






Check 


8.5 


4.5 




4.1 


1993 




Test 


6.8 


5.3 




1.5 






Check 


6.6 


4.5 




2.2 


All 




Test 


6.7 


4.8 




1.9 






Check 


7.3 


4.7 




2.7 


1 



larly the flyspeck fungus, and such efficiencies, 
combined with second-level arthropod management 
methods (e.g., Christie et al., 1992) may reduce the 
impact that pesticides have on mites and other non- 
target arthropods (Wisniewska et al., 1993). This 
article summarizes the results of the program in 
commercial blocks consisting of scab-susceptible 
cultivars. Other aspects of the research, dealing 
with summer pruning for disease management, fly- 
speck epidemiology, and the effects of the second- 
level IPM approach in blocks of scab-resistant 
apples, are reported separately. 

Early Season Management 

For purposes of disease management, 
the apple production season can be divided 
into two parts. These parts coincide closely 
with the two parts of the season used in 
second-level arthropod management. For 
diseases, early season management focuses 
on apple scab. We have used a delayed sterol 
inhibitor program (Cooley and Spitko, 1992) 
enhanced by measurement of potential as- 
cospore dose (PAD). For the purposes of 
second-level IPM, we have used a threshold 
of 500 ascospores per square meter (Dr. 
William McHardy, pers. comm.). PAD data 
were not available for 199 1, because funding 
was not available in the fall of 1990 when 
such assessments would have been done. 

Summer Management 

After primary scab season, which usu- 
ally ends by mid-June, the main diseases 
concern in apples are the summer diseases, 
typically sooty blotch and flyspeck. At the 



Fruit Notes, Winter, 1994 



13 



Table 2 


. Potential ascospore 


dose (PAD) and scab incidence (%) by block 


in second-level IPM blocks 


in 1992 


and 1993. 


























Year 










] 


Jlock number 












1 


2 


3 


4 


5 


6 


7 


8 


9 


10 


11 


12 


PAD 


1992 


2041 


37 


2578 


300 


368 


19 


11 


21 


183 


166 


10 







1993 


6131 


14338 


2765 


1864 


1537 


2992 


30 


12 


5333 











Scab 


1992 


1.0 


0.5 


0.5 


1.5 


0.0 


1.0 


0.0 


0.0 


2.0 


0.8 


0.0 


0.5 




1993 


0.3 


0.1 


0.0 


0.0 


0.0 


0.0 


0.0 


0.0 


0.3 


0.3 


0.0 


0.0 


1 



beginning of this project, we had limited data sug- 
gesting that summer pnmingcould reduce or elimi- 
nate the need for fungicides in the summer. We have 
described the results of this work elsewhere (Cooley 
et al., 1992). We have concluded that summer 
pruning reduces flyspeck and sooty blotch on trees 
with dense canopies, but additional measures are 
necessary to reduce levels below economic thresh- 
olds. In 1993, we focused summer fungicide applica- 
tions on primary inoculum for flyspeck, which was 
released during June and early July. Our program 
recommended no fungicides after June in second- 
level IPM blocks. 



Results 



gram has received wide-spread adoption in all or- 
chards, which often use first level IPM. This being 
so, we would expect few differences between checks 
and second-level blocks in terms of primary season 
fungicides. Second, in 1993, high levels of inoculum 
in many second-level blocks led to recommendations 
for an extra fimgicide application near the half-inch 
green stage, and more frequent use of scab fungi- 
cides in general. 

Table 2 shows the increase in PAD from 1992 to 
1993. Two orchards exceeded the PAD threshold in 
1992, and seven exceeded it in 1993. There was no 



From the disease perspec- 
tive, the terms "full" and "transi- 
tional" second-level blocks re- 
ferred to in other articles was of 
minor importance, and the data 
from both are combined here. 
During the early season, the 
fungicide use in all blocks gener- 
ally was the same (Table 1). In 
1991 and 1992, similar fungicide 
use occurred in second-level 
blocks as in conventionally man- 
aged (check) blocks in the pri- 
mary season. In 1993, some- 
what more fungicide was used in 
primary season in the second- 
level blocks. There are two fac- 
tors which contributed to this 
trend. First, the delayed SI pro- 



Table 


3. Disease incidence (%) 


in 1991 through 


1993. 










Sooty 


Blossom 


Year 


Treatment 


Scab 


Flyspeck 


blotch 


end rot 


1991 


Test 


0.3 


4.3 


0.3 


0.0 




Check 


0.7 


3.6 


0.8 


0.3 


1992 


Test 


1.2 


4.0 


0.1 


0.1 




Check 


0.6 


0.8 


0.0 


0.1 


1993 


Test 


0.2 


6.7 


0.1 


0.0 




Check 


0.1 


4.1 


0.1 


0.1 


All 


Test 


0.6 


5.0 


0.2 


0.0 




Check 


0.5 


2.8 


0.3 


0.2 


1 



14 



FruH Notes, Winter, 1994 



Table 


4. Flyspeck 


incidence 


(%) in 


second-level IPM 


block 


3 in 


early 


and late 


season 


harvests in 


1991 through 1993. 


Year 


Treatment 


Before 9/15 After 9/15 


1991 


Test 




1.5 




22.3 




Check 




1.5 




18.8 


1992 


Test 




1.3 




8.9 




Check 




1.3 




0.0 


1993 


Test 




0.3 




7.9 




Check 




0.2 




5.0 


All 


Test 




1.0 




13.0 




Check 




1.0 




7.9 





correlation, however, between PAD and scab inci- 
dence in the blocks. Also, there was no correlation 
between scab on fruit in 1992 and PAD in 1993, 
indicating the danger of trying to use fruit scab 
incidence to predict scab inoculum in the orchard. 
Summer fimgicide use was higher in the check 
blocks than in the test blocks (Table 1), with check 
blocks receiving about 0.8 DE more than the test 
blocks. Flyspeck, however, was nearly twice as great 
in the test blocks compared to check blocks, though 
sooty blotch incidence was similar in both block 
types (Table 3). There was no correlation between 
the DEs of summer fungicide and flyspeck. The time 
of harvest was critical to flyspeck incidence (Table 4). 
Fruit harvested after September 15 were much more 
likely to have flyspeck than those harvested before 
that date. In fact, fruit harvested before September 
15 (largely Mcintosh) had virtually the same fly- 
speck incidence in either check or test blocks. In 
fruit harvested later (Delicious, Cortland, and 
Golden Delicious), the incidence of flyspeck was 



higher in test blocks than in checks, but the inci- 
dence in either block far exceeded that in the early 
harvest. From these results, two points stand out. 
First, our major cultivar, Mcintosh, may get only 
marginal benefit from summer fungicide sprays. 
Second, minimal fungicide applications will control 
sooty blotch. 

Fungicides present a particularly difficult prob- 
lem to second-level IPM in apples. The nature of 
scab, and its potential for severe damage, limit 
options for further early season fungicide reduc- 
tions; however, the potential for reducing summer 
fungicides remains good. We will need to examine 
the role that alternative hosts,such as brambles and 
roses, play in providing inoculum for summer dis- 
eases. Removing these hosts may make flyspeck 
management much easier. Relatively little fungi- 
cide is needed to control sooty blotch under our 
conditions. It may be possible to spray late-season 
cultivars selectively. Alternatively, if early fungi- 
cide applications can be used to delay the epidemic, 
even later season cultivars may be harvested before 
flyspeck develops. Certainly, weather will also guide 
fungicide applications in summer. There are many 
unanswered questions, but the prospect for at least 
reducing, and possibly eliminating, summer fungi- 
cides in Massachusetts appears good. 

References 

Christie, M., R. J. Prokopy, K Leahy, J. Mason, A. 
Pelosi, and K. White. 1993. Apple integrated pest 
management in 1992: Insects and mites in second- 
level orchard blocks. Fruit Notes 58(1):24-31. 

Cooley, D. R., W. R. Autio, and J. W. Gamble. 1992. 
Second-level apple integrated pest management: 
The effects of summer pruning and a single fungi- 
cide application on flyspeck and sooty blotch. Fruit 
Notes 57(1):16-17. 

Cooley, D. R. and R. S. Spitko. 1992. Using sterol 
inhibitors. American Fruit Grower 112(l):30-32. 

Wisniewska, J., Y. Yang, and R. Prokopy. 1993. 
Spiders in second-level and first-level apple IPM 
blocks. Fruit Notes 58il):20-23. 



%f» VU fcA* %V ^if 
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Fruit Notes, Winter, 1994 



15 



Tax Pointers for Farmers in 1993 

P. Geoffrey Allen 

Department of Resource Economics, University of Massachusetts 

Tax advice given below is intended as general advice and is believed to be correct. It does 
not substitute for a detailed review of the circumstances of an individual taxpayer by a 
professional tax practitioner. 



The Revenue Reconciliation Act of 1993 (1993 
RRA), enacted on August 10, 1993 contains a large 
number of changes to the tax laws. One complication 
is that some items are retroactive to 1992, some to 
the beginning of 1993, and some only take effect in 
1994. To take advantage of the retroactive changes 
for 1992, you must submit an amended return (Form 
1040X). 

General Features 

The most publicized aspect of the 1993 RRA is 
that more of the tax burden will be carried by higher 
income taxpayers. For example, the new 36% rate 
applies to married taxpayers filing jointly who have 
taxable income over $140,000 in 1993. They, as well 
as all other filers, would also pay a 39.6% rate on 
taxable income over $250,000. For estates and trusts 
the new rates affect taxable income over $5,000 and 
$7,500, respectively, effective January 1, 1993. Some 
changes affect all income levels. For example, busi- 
ness meals and entertainment expenses that were 
80% deductible will only be 50% deductible, effective 
January 1, 1994. Some expiring laws are reinstated. 
For example, for estate and gift taxes, the 1993 RRA 
reinstates expiring law so that the top rates and the 
$600,000 exemption remain the same. 

Health Insurance 

If you were a self-employed person in 1992 (or an 
S-corporation shareholder) who deducted (on line 26 
of your 1992 Form 1040) 25% of half of your health 
insurance premium you may now take 25% of all of 
your 1992 premium. The 1993 RRA reinstated the 
deduction retroactive to July 1, 1992. You may file 
for a refund on Form 1040X. The only exception is if 
your total medical expenses exceeded the 7.5% floor 
in your 1992 tax year and you already claimed the 
rest of the premium as medical expense on your 1992 
Schedule A. 



Example: Bill is self-employed. Bill and 
Jane file jointly, with 1992 taxable income 
of $21,400 and family health insurance pre- 
miums of $3000. They deducted $375 (^2 of 
25% of $3000) in 1992. They may now file 
Form 1040X and deduct a further $375. 

In 1993, note that the eligibility for the 25% deduc- 
tion for the health insurance premium is made on a 
monthly basis. Also, unless the law is further ex- 
tended, the deduction will expire on December 31, 
1993. 

Example: If Jane had worked from Novem- 
ber 1, 1992 until March 31, 1993 for an 
employer who provided subsidized health 
insurance for her and her family, none of 
the $3000 premium paid in 1992 would have 
been deductible on Form 1040. If the same 
premium was paid in 1993 then the amount 
allocated to the period January 1 to March 
31 is ineligible for deduction on Hne 26 of 
Form 1040. The amount deductible is 
$562.50 (3/4 of 25% of $3000). 

Charitable Contributions 

Did you make charitable contributions of appre- 
ciated property in 1992 or 1993? Taxpayers subject 
to alternative minimum tax (AMT) may get some 
relief. Appreciated property is property that has a 
fair market value that exceeds its basis (which is 
usually your cost). Under the 1993 RRA, the appre- 
ciated amount (the difference between fair market 
value and adjusted basis) of property (real, tangible, 
and intangible) donated to a charity is no longer a tax 
preference item included in computing AMT income. 
The property must be used for the donee's tax- 
exempt purpose. The benefit does not apply to dona- 
tions of inventory, other ordinary income property 
and short-term capital gain property. 

Different kinds of property have different effec- 



16 



Fru'n Notes, Winter, 1994 



tive dates. For contributions of tangible personal 
property this potential tax saving is retroactive to 
July 1, 1992 (and therefore continues prior law). 

Example: Earl donated a 10-year old trac- 
tor on August 1, 1992 to a charity that ships 
them to needy fanners overseas. The fair 
market value was $3,000 and his adjusted 
basis in the tractor (its cost less deprecia- 
tion) was $2,000. Earl paid AMT in 1992. He 
entered $1000 on line 6a of Form 6251. If he 
still has some AMT liability after the adjust- 
ment he will save $240 (The AMT rate in 
1992 of 24% on $1000). Earl can now file an 
amended return (Form 1040X) for 1992 
claiming the $240 refund. 

From January 1, 1993, the appreciated amount of 
donated real and intangible property will not be 
subject to AMT either. 

Example: Arthur gave the development 
rights on a piece of land to an organization 
whose charitable purpose was to preserve 
land from development. The rights have a 
fair market value of $2000. Arthur claims 
$2000 of charitable deductions on Schedule 
A (provided his adjusted gross income is 
sufficient to prevent the percentage limita- 
tions on charitable deductions coming into 
effect). He reduces his basis in the land by 
$2000. There is no AMT tax preference 
item. 

Effective January 1, 1994, single charitable do- 
nations of $250 or more may be deducted (on Sched- 
ule A) only if the charity provides you with written 
substantiation, including a good-faith estimate of 
the value of any good or service that you provided. If 
you donated money, you may not rely solely on a 
cancelled check as substantiation. Separate pay- 
ments to the same charity (e.g., by withholding from 
wages) will be treated as separate contributions, 
even if they aggregate to more than $250. 

Section 179 Expensing 

The limit on election to expense certain tangible 
property (Section 179 expensing) is raised from 
$10,000 to $17,500 for tax years beginning after 
December 31, 1992. All other provisions remain the 
same, including reductions in the limit for purchases 
over $200,000 in any one year and carryover rules. 
However, the IRS has issued final regulations (T.D. 
8455, effective date January 25, 1993) that provide 
clarification for some of the provisions. The main 



issue appears to be the need for, or at least desirabil- 
ity of, precise record keeping. If you have to 
carryover some Section 179 expense deduction, you 
must select the property or properties to which the 
carryover is allocated. The selection must be re- 
corded in the year in which the properties are placed 
in service. If you fail to make and record the selec- 
tion, the IRS will assume the carryover is appor- 
tioned according to cost. 

Example: In 1993, Joe purchased a tractor 
for $20,000 and a baler for $10,000. He 
elected to deduct $17,500 ($12,500 on the 
tractor, $5,000 on the baler) but his taxable 
income was only $7,500 so he carried over 
$10,000. He recorded the carryover as 
$5,000 against the tractor and $5,000 
against the baler. Had he not done so, the 
IRS would have assumed two-thirds 
($6,667) for the tractor and one-third 
($3,333) for the baler. 

When only part of the carryover is used in a subse- 
quent year, you must first use up the oldest 
carryover, but within the year, you may choose. 

Example: If Joe purchases another 
$10,000 machine in 1994 and elects to ex- 
pense the entire $10,000, he can only use 
$7,500 of carryover before reaching the an- 
nual limit (of $17,500). Assuming his tax- 
able income in 1994 is at least $17,500, he 
might choose to take the baler carryover 
first ($5,000) and part of the tractor 
carryover, leaving $2,500 carryover on the 
tractor to go forward. 

There is no limit on how long Section 179 deductions 
can be carried forward. However, if a property is 
sold, exchanged, or given away, unused section 179 
carryover must be dealt with. 

Example: (no gain or loss) Joe gives his 
baler to a relative in 1994. He took half-year 
depreciation in 1993 of $357 (1/2 of 1/7 of 
$5,000, assuming MACRS straight line de- 
preciation) and $357 in 1994. His adjusted 
basis for the baler at time of transfer is 
$4,286 ($5,000 - $357 - $357). He must 
increase the basis at the time of transfer by 
the amount of Section 179 carryover 
($5,000) and reduce his Section 179 
carryover by the same amount. The recipi- 
ent has an initial basis of $9,286 ($5,000 + 
$4,286). 

Example: (gain on sale) Joe sells his baler 



Fruit Notes, Winter, 1994 



17 



in 1994 for $9,500. He has a gain on the sale 
of $214 ($9,500 - $9,286). His depreciation 
and Section 179 deduction is $714 (he actu- 
ally took no Section 179 deduction on the 
baler in 1993). The amount to be recaptured 
on Form 4797 is the lesser ($214). Joe's 
Section 179 carryover is reduced by $5,000. 

Purchase and Sale of Livestock 

You purchased, transported and vaccinated 
some young cattle in 1993, intending to sell them in 
1994. As a farmer using the cash basis method of 
accounting, how do you report this? The purchase 
and transportation are your basis in the cattle, 
included in your 1994 Schedule F, line 2. Vaccination 
is a current expense, line 33 of your 1993 Schedule F. 

Do you pay self-employment tax on gain or loss 
from the sale of breeding livestock? Yes, if it is held 
for sale in the ordinary course of business. Report on 
Schedule F. No, otherwise. Report in the appropriate 
part of Form 4797, as follows: 

Held less than 12 months (24 months for cattle 
and horses). Also poultry (unless held for sale in 
the ordinary course of business) 

Part II of Form 4797 
Held more than 12 months (24 months for cattle 
and horses) and (1) purchased and sold at a loss 
or raised (gain or loss) 

Part I of Form 4797 
or (2) purchased and sold for a gain (depreciation 
recapture) 

Part III of Form 4797 

Example: Robert breeds replacement heif- 
ers for his dairy herd. When they are two 
years old, he selects the number required to 
maintain his herd and sells the rest. Even if 
some heifers are sold as breeding livestock, 
all sales are reported on Schedule F. 

Example: Dana breeds replacement heif- 
ers. All are added to the dairy herd unless 
they fail to breed. Those that turn out to be 
poor milkers are sold. Dana can report all 
sales on Form 4797, since her intent was to 
keep them all for breeding. 

Investment Interest 

Previously, individual taxpayers could deduct 
investment interest (interest on indebtedness 
allocable to property held for investment) only to the 
extent of their net investmentincome for that year. 
Net investment income generally excluded capital 



gains, and the disallowed interest expense had to be 
carried forward. Now there is a faster way to use up 
the interest carry-forward. Effective January 1, 
1993, a taxpayer may elect to include any amount of 
the net capital gain from Schedule D in investment 
income. The capital gain transferred to Form 1040 
must be reduced by the same amount. For a taxpayer 
in the 28% marginal tax bracket, the only effect is to 
use up the investment interest carryover, reducing 
total taxes in the present year rather than some 
future year. Higher income taxpayers should take 
care to elect to include only as much gain as will 
offset the interest carried forward. Any larger 
amount would be subject to tax at rates of 31%, 36%, 
or 39.6%. 

Example: Fred and Emily have $10,000 
unused investment interest expense from 
1992 and $15,000 net long-term capital 
gains in 1993. On their 1993 return, they 
elect to treat $ 10,000 of the gain as ordinary 
income. They pay tax (maximum rate 28%) 
on $5,000 long-term capital gain. They de- 
duct the $10,000 investment interest ex- 
pense on Schedule A. 

The following sections are taken from material 
published by Larry C. Jenkins, Department of 
Agricultural Economics and Rural Sociology, 
Pennsylvania State University. 

Earned Income Tax Credit (EITC) 

The new rules for earned income credit involve 
only a basic credit; the extra credits for a child under 
one year of age and for health insurance coverage 
were eliminated in the 1993 legislation. Comment: 
The new law results in a decrease in benefits in 1994, 
compared to benefits from the earned income credit 
in 1992, for a family with one child under one year of 
age, and qualifying for the supplemental health 
insurance credit. For such a family, based on earned 
income of $7,750, the EITC in 1992 would have been 
$2,151. Under the new rules, the credit is $2,038. 

In a departure from previous earned income 
credit rules, the new law extends the credit to 
taxpayers with no qualifying children. The credit is 
available to taxpayers over age 25 and below age 65. 
For these taxpayers, the EITC is 7.65 percent of the 
first $4,000 of earned income (for a maximum credit 
of $306 in 1994). The maximum credit is reduced by 
7.65 percent of earned income (or adjusted gross 
income, if greater) above $5,000. In 1994, the credit 
is completely phased out for taxpayers with earned 



18 



Fruit Notes, Winter, 1994 



income (or adjusted gross income, if greater) over 
$9,000. This credit is not available on an advance 
payment basis. 

Tax on Social Security Benefits 

Prior to the new law, if the sum of modified 
taxable income plus one-half of Social Security ben- 
efits (the sum of the two is called provisional income) 
exceeded $25,000 for an unmarried taxpayer or 
$32,000 for a married couple filing a joint return, up 
to 50% of Social Security benefits were subject to 
income tax. 

Under the new law, taxpayers will be subject to 
tax on up to 85% of their Social Security benefits, 
effective for tax years beginning after 1993. The 
existing rule (as explained in the above paragraph) 
will continue to apply to taxpayers whose provi- 
sional income is less that $34,000 for unmarried 
taxpayers and $44,000 for married couples filing a 
joint return. If provisional income exceeds these 
levels, gross income will include the lesser of: 

(a) 85% of the taxpayer's Social Security benefit, or 

(b) The sum of: 

(1) The smaller of : 



(i) the amount included under pre-'93 law, 

or 
(ii) $3,500 for unmarried taxpayers or 

$4,000 for a married couple filing a join 

return plus 
(2) 85% of provisional income over the new 
$34,000 1 $44,000 threshold. 

For married taxpayers filing separate returns, gross 
income will include the lesser of: 

(a) 85% of the taxpayer's Social Security benefit, or 

(b) 85% of the taxpayer's provisional income. 

For purposes of the above calculation, a taxpayer's 
provisional income (modified adjusted gross income 
plus one-half of the taxpayer's Social Security ben- 
efit) is calculated in the same manner as under pre- 
93 law. 

Without implicating them in any way, I thank 
Robert Christensen, Department of Resource 
Economics and Michael Whiteman, Department 
of Accounting and Information Systems, School 
of Management, both from the University of 
Massachusetts, for their helpful comments. 



%£• ttl^ ^t« «% %i« 
ej* •(J^ *T^ •(f* •!»• 



Fruh Notes, Winter, 1994 



19 




Fruit Notes 



University of Massachusetts 

Department of Plant & Soil Sciences 

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Amherst, MA 01003 



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ruit Notes 



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iricpared by the Department of Plant & Soil Sciences. 

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United States Department of Agriculture, and Massachusetts Counties Cooperating. 



Editors: Wesley R. Autio and Williaxn J. Braxnlage 







Volume 59, Number 2 
SPRING ISSUE. 1994 

Table of Contents 

Pinal Report on the 1980 NC-140 Apple 

Rootstock Planting: Starkspur Supreme 

Delicious on Eight Rootstocks 

Buildup of Bugs Causes Decline in EfTectiveness of Sticky 
for Capturing Apple Maggot Flies on Red Sphere Traps 

What Species of Predaceous Mites Exist in Massachusetts 

Commercial Apple Orchards? 



How Beneficial are Pre-bloom Oil Sprays Against European Red Mites? 

North American Strawberry Growers Meet in Ontario 

Promising New Apple Cultivars for 1994 

Suggestions for the Use of the New Postbloom Thinner Accel* 



J 



Fruit Notes 



Publication Information: 

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January, April, July, and October by the Department of Plant 
& Soil Sciences, University of Massachusetts. 



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Fruit Notes 

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Final Report on the 1980 NC-140 Apple 
Rootstock Planting : Starkspur Supreme 
Delicious on Eight Rootstocks 

Wesley R. Autio and William J. Lord 

Department of Plant & Soil Sciences^ University of Massachusetts 



Finding the apple rootstock that adapts the 
best to various conditions, is resistant to pests, 
gives an appropriate degree of dwarfing, gives 
the greatest precocity, results in the highest 
jdelds, and gives the best £ruit quality has been 
a research and breeding goal for nearly a cen- 



tury. Growers in New England, however, did 
not begin to look at clonally propagated 
rootstocks seriously until the ISeCs, when the 
use of semidwarfing rootstocks, such as M.7, 
began in earnest. During the late 1980's, seri- 
ous planting of fully dwarfing rootstocks began, 



Tree spread (ft) 



"T 
2 



I 
4 



I 
6 



8 



10 



12 



"T" 
14 



16 

14 

12 

10 

8 

6 

4 

- 2 

- 



Figure 1. Relative canopy dimensions of Starkspur Supreme Delicious trees on eight rootstocks 
at the end of the forteenth growing season. 






0) 




16 

M.7 EMLA 

OAR1 

M.26 EMLA 

0.3 

MAC.9 

M.9 EMLA 

M.9 

M.27 EMLA 



Fru'n Notes, Spring, 1994 



including M.9, Mark, and M.26. Now, more 
than fifty percent of all trees being planted in 
New England are on fully dwarf rootstocks. 
This trend has been seen throughout the apple 
growing regions of North America. Throughout 
this period when clonal rootstock material be- 
came more important to the apple industry, 
knowledge of rootstock characteristics became 
essential. 

To help evaluate both new and old clonal 
rootstock material, the NC-140 Technical Re- 
search Committee was established. A group of 
scientists fi"om various universities across the 
country formed this committee in association 
with the U. S. Department of Agriculture. Indi- 
viduals fi-om five Canadian provinces cooper- 
ated in the formation and participate in the 
execution of the responsibilities of this commit- 
tee. One of the first major plantings by the 
committee included Starkspur Supreme DeU- 
cious on 0.3 (Ottawa 3), M.7 EMLA (the EMLA 
designation suggesting that the latent viruses 
were removed fi-om the mother plant), M.9 
EMLA, M.26 EMLA, M.27 EMLA, M.9, MAC.9 
(later, a virus indexed version was named 
Mark), and OARl (Oregon Apple Rootstock 1). 
These combinations were included in random- 



ized complete blocks, each with five replications 
at 27 sites in the U. S. and southern Canada. 
Most sites removed their plantings after the 
tenth growing season, i.e. after harvest in 1989. 
In this article, we report on the Massachusetts 
portion of this trial, including four years of data 
beyond the termination of the joint trial. 

Materials & Methods 

Trees were planted at a spacing of 11.5 x 18 
feet in the spring of 1980 at the University of 
Massachusetts Horticvdtural Research Center 
in Belchertown. Trees were trained as central 
leaders, using minimal pruning. Some contain- 
ment pruning was required when trees reached 
maturity. Stakes were added for support only 
when trees leemed past 45 degrees. Standard 
pest and fertility management practices were 
used. Tree size and yield were measured annu- 
ally; however, trees were not allowed to finiit 
until the fourth growing season (1983). 

Results & Discussion 

Table 1 gives the trunk cross-sectional area, 
height, and spread of these trees after the four- 
teenth growing season (1993), and Figure 1 



Table 1. Size 


of Starkspur Supreme 


Delicious trees on eight rootstocks after theii 


• fourteenth 


growing season. 


Also presented are 


estimated tree density and 


spacing.' 












Trunk 














cross- 


Estimated 












sectional 


density 


Estimated 






Height 


Spread 


area 


(trees per 


spacing 


Rootstock 




(ft) 


(ft) 


(in^) 


acre) 


(ft) 


0.3 




10.1 b 


11.1 be 


9.8 c 


256 


10x17 


M.7 EMLA 




14.9 a 


14.7 a 


21.3 a 


132 


15x22 


M.9 EMLA 




8.2 c 


9.2 cd 


5.7 de 


363 


8x15 


M.26 EMLA 




10.6 b 


12.6 ab 


14.0 b 


191 


12x19 


M.27 EMLA 




5.6 d 


5.4 e 


L9 f 


726 


5x12 


M.9 




5.7 d 


7.2 de 


3.1 ef 


496 


6.5x13.5 


MAC.9 




7.5 c 


8.4 d 


8.4 cd 


401 


7.5x14.5 


OARl 




11.4 b 


13.4 a 


13.6 b 


191 


12x19 


' Within column 


, means not followe 


d by the same 


letter are sign 


ificantly different at odds of | 


19 to 1. 















Fruit Notes, Spring, 1994 



25 
















@0.3 








^ M.7 EMLA 






?20 


— 


tI^ M.9 EMLA 
* M.26 EMLA 


y 




(0 
(0 




M M.27 EMLA 
♦ m.9 


y^ 




cross-sectional 

O Ol 


- 


AmAC.9 
'S'OARI 


/ 








/ n_^--''^1 




— 




^X\x^^ 


Trunk 

Ul 


.<:^^^r:^^ 




nE 


^^2=;^ 




3 


i&-^ "X— 7* — i^r~ h ^^— -M — ^ ^ 




=^SP=i 


a^ — fjfc] ]g S B- 1^ '^ 








1980 1982 1984 1986 1988 1990 1992 


Figure 2. Trvink cross-sectional area of Starkspur Supreme Delicious trees on eight rootstocks from 


the end of the first growing season through the end of the fourteenth. 



depicts the relative canopy dimensions of these 
trees. M.7 EMLA produced the largest trees. 
Trees on M.26 EMLA and OARl were the next 
smaller in terms of trunk cross-sectional area, 
followed by trees on 0.3 and MAC. 9. Trees on 
M.9 EMLA were smaller still, and the smallest 
trees in the planting were on M.9 and M.27 
EMLA. Clearly, M.9 and M.27 EMLA were not 
vigorous enough rootstocks for Starkspur Su- 
preme Delicious, since trees did not reach six 
feet in height. With a canopy this smgdl, ad- 
equate yields are not possible. 

Figure 2 plots the trunk cross-sectional area 
of these trees from 1980 through 1993, and 
shows that for most trees, there was a relatively 
constant rate of growth throughout the experi- 
ment. MAC. 9, however, resulted in a relatively 



fast growth rate for the first five growing sea- 
sons, but for the next nine seasons, had a signifi- 
cantly slower growth rate. In other words, the 
initial growth rate of trees on MAC. 9 was nearly 
as great as that of trees on M.7 EMLA, but later 
on, the growth rate was only similar to that of 
trees on M.9 EMLA. This reduction in growth 
rate corresponded to the onset of heavy produc- 
tion from trees on MAC. 9. 

Table 1 also gives estimates of spacing and 
density for these combinations. For most com- 
binations, the estimated in-row spacing is ap- 
proximately ninety percent of the tree spread; 
however, this assessment was not adequate for 
trees that had filled their allotted space and had 
required containment pruning. Specifically, 
the estimated spacing of trees on M.7 EMLA 



fruit Notes, Spring, 1994 



8 
















®0.3 








^5^ M.7 EMLA 










)l^ M.9 EMLA 






6 


— 


* M.26 EMLA 
S M.27 EMLA 










4- M.9 








A MAC.9 


/ A \ / \ 




Q> 
0) 




'S'OARI 


/ Aa\ \ / ^^ 1 


7 


14 
Q. 






/ /K\ \ ^^t^^^K 








r-^ sy<r^ 


â– o 

0) 


,fc.J%./AM2^ 


1 


2 






ol, 


^ T 1 1 1 1 ^ 1 1 


3 


1983 1985 1987 1989 1991 1993 


Figure 3. Annual yield per tree from Starkspur Supreme Delicious trees on eight rootstocks. 



would be artificially low if based solely on mea- 
sured spread, since they were kept in a spacing 
of only 11.5 feet. In other words, measured tree 
spread in 1993 was an assessment of how much 
the tree grew beyond the 11.5-feet allotted 
space in 1993, since it was pruned to 11.5 feet 
during the previous dormant season. Further- 
more, when trees are planted closer together, 
tree-to-tree competition likely will inhibit 
growth and spread, resulting in a further reduc- 
tion in the ideal spacing. Therefore, spacings 
presented here are meant only to be rough 
guides to allow for the estimation of per-acre 
yields. 

Annual jdeld per tree is given in Figure 3. 
Yield was variable and in somewhat of a bien- 
nial cycle, but trees on M.7 EMLA clearly 
jdelded the most per tree with an average yield 



for the last five years of 5.2 bushels. Trees on 
M.26 EMLA, 0.3, MAC.9, and M.9 EMLA aver- 
aged 4.4, 3.3, 2.4, and 2.3 bushels per tree, 
respectively, over the last five years. Trees on 
M.27 EMLA averaged only 0.4 bushels per tree. 
Cumulative yield per tree is presented in Table 
2, and relationships among rootstocks were 
similar to that for the average production dis- 
cussed above. 

More important than yield per tree is yield 
per acre. Potential 3rield per acre was calculated 
on an annual basis using the tree densities 
presented in Table 1, and these data are plotted 
in Figiire 4. Clearly, this is only a rough esti- 
mate but does pKjint to some significant results. 
Trees on MAC.9 produced very high yields from 
the sixth growing season on, exceeding 1000 
bushels per acre in three years. 0.3 and M.9 



Fruit Notes, Spring, 1994 



Table 2. Cumulative yield of Starksp 


ur Supreme Delicious trees on 


eight rootstocks through their fourteenth growing 


seasor 


1.' 






Cumulative yield (bu) 








Per in^ 












trunk cross- 












sectional 






Rootstock 


Per tree 


area 




Per acre 


0.3 


24.0 


be 


2.47 b 




6140 b 


M.7 EMLA 


38.3 


a 


L80 c 




5060 be 


M.9 EMLA 


17.3 


d 


3.08 a 




6290 b 


M.26 EMLA 


27.9 


b 


2.03 c 




5330 be 


M.27 EMLA 


3.8 


e 


1.99 c 




2770 d 


M.9 


7.8 


e 


2.49 b 




3890 cd 


MAC.9 


20.6 


cd 


2.43 b 




8270 a 


OARl 


14.3 


d 


1.05 d 




2730 d 


' Within column, means not followed by the same 


letter 


are signifi- 


cantly different at 


odds of 19 to 1. 









EMLA also were very productive on a per acre 
basis. Averaged over the last five years, trees on 
MAC.9, 0.3, M.9 EMLA, M.26 EMLA, and M.7 
EMLA produced annually 940, 840, 830, 730, 
and 680 bushels per acre, respectively. Over the 
same period, trees on M.27 EMLA produced 
only 310 bushels per acre annually. Table 2 
presents cumulative )deld per acre. Trees on 
MAC.9 produced 8270 bushels on a per acre 
basis over the life of the planting. Trees on M.9 
EMLA and 0.3 produced 6290 and 6140 bush- 
els, respectively. Trees on M.27 EMLA pro- 
duced only 2770 bushels per acre, partly be- 
cause of inadequate canopy height and there- 
fore small bearing surface per acre. 

Conclusions 

Several conclusions about specific 
rootstocks can be made from this study. First, 
however, it must be emphasized that these data 
were collected fi-om Starkspur Supreme Deli- 
cious, a low-vigor cultivar, and some results 
may have been different with a more vigorous 
cultivar such as Mcintosh. Secondly, some of 
the conclusions must be tempered by results 



obtained in other locations. 

0.3. This rootstock performed very well. It 
was relatively precocious, and produced high 
3delds over the fourteen-year life of the planting. 
Tree size was slightly smaller than M.26 
EMLA, so trees were very manageable. Fruit 
size was large from trees on 0.3. Even though 
most of the trees in this planting were not 
staked, staking should be considered a require- 
ment with 0.3. One problem with 0.3 is that it 
is of limited availability, because it is so difficult 
to propagate. Specifically, it does notdevelop 
roots very readily in the stool bed. Some work 
suggests that this problem may be overcome in 
the nursery, but has not yet resulted in a signifi- 
cant quantity of 0.3. Overall, it is a rootstock 
very much worthy of trial if you can get it. 

M.7 EMLA. This rootstock performed very 
well with a spur-type Delicious as a scion. It was 
somewhat more precocious than normally ob- 
served. Generally, it was not as productive as 
0.3, M.9 EMLA, and Mark, but still performed 
very well. Trees are vigorous and do not lend 
themselves to high-density planting, but it is 
probably still the best choice for a free-standing, 
semidwarf tree. 



Fruit Notes, Spring, 1994 



1,500 - 



3 
XI 



d) 1,000 



u 

(0 

a. 



500 



®0.3 


^ M.7 EMLA 


^ M.9 EMLA 


-^ M.26 EMLA 


S M.27 EMLA 


-^M.9 


â–² MAC.9 


«§»OAR1 




1983 



1985 



1987 



1989 



1991 



1993 



Figure 4. Annual yield per acre from Starkspur Supreme Delicious trees on eight rootstocks. 



M.9 EMLA. This strain of M.9 performed 
very well in this planting. Trees were preco- 
cious and productive. Tree size was nearly 
perfect for this spur-tj^je Delicious, and tree 
training was almost not required. Fruit size 
from trees on M.9 EMLA were the largest in the 
planting in most years. Trees on M.9 EMLA 
must be supported fully. This strain of M.9 is 
commonly available and is one of a few strains 
that you might have received if you ordered M.9 
and did not specify the strain. Overall, M.9 
EMLA is worth asking for specifically. 

M.26 EMLA. Trees on M.26 EMLA per- 
formed well, giving relatively high yields. Tree 
size was at the large end of the dwarf category, 
but trees were still very manageable. As with 
all fully dwarfing rootstocks, trees must be 
staked. If available we would prefer 0.3 to M.26 



EMLA. 

M.27 EMLA. Starkspur Supreme Delicious 
is too weak to propagate on M.27 EMLA. Trees 
do not grow sufficiently to attain adequate 
canopy volume per acre, and they do not grow 
enough to renew fruiting wood. Trees on M.27 
EMLA were "runted out" in just a few years 
after planting and did not perform well. In other 
parts of the country, M.27 EMLA has done well 
with vigorous cultivars and in high-density, 
fully supported plantings. 

M.9. This strain of M.9 is often referred to as 
"dirty 9", because it has not had latent virus 
removed from it. It was significantly smaller 
than M.9 EMLA in this trial and performed 
similarly to M.27 EMLA. With vigorous culti- 
vars, it is known to perform very well in high- 
density, fully supported plantings. 



FruH Notes, Spring, 1994 



MAC.9. This rootstock is very similar to 
Mark, the only difference being that Mark has 
been virus indexed. It is thought to perform 
nearly identically to Mark. In this trial, it was 
the most precocious and productive combina- 
tion. Tree size was between M.9 EMLA and 0.3. 
Based on these data, it is the best rootstock in 
this group; however, it suffers from a few prob- 
lems. In this planting, it overfruited early, and 
growth slowed and fruit quahty began to de- 
cline. It nearly "runted out", but with heavy 
pruning we were able to restore some shoot 
growth for renewal of frmting wood. Other 
problems have been observed in other locations, 
particularly related to its sensitivity to drought. 
At approximately three years after planting, 
trees develop a noticeable swelling at and below 
the soil line. The water transport system in this 
part of the tree is very disorganized (as seen by 
research in Michigan) and is inefficient in water 
transport. If moisture is limiting, trees on Mark 
(or MAC.9) will suffer more than those on other 
rootstocks. It appears that in locations where 
water is not hmiting, trees on Mark (or MAC.9) 
perform very well, such as in our trial in 
Belchertown. The cause of this swelling is 
unknown, and there is no known cure for the 



problem, except possibly frequent irrigation. 
The future of Mark is in great jeopardy because 
of this problem, and many nurseries have re- 
moved most of their Mark stoolbeds. Hopefully, 
we wiU not lose a rootstock that can be very good 
in some locations. It should still be considered 
seriously for sites that have good moisture lev- 
els throughout the season. 

OARl. This rootstock produced a tree simi- 
lar in size to M.26 EMLA; however, it was not 
productive and fruit size was very small. There 
is no reason to consider OARl for commercial 
planting. 

Overall, the rootstock picture is changing 
rapidly. In this trial, M.9 EMLA, 0.3, and Mark 
were the ones that performed best. From the 
1984 NC-140 planting, others will be added to 
the hst of good rootstocks, including C.6, B.9, 
P. 2, and MAC. 39. A planting will be established 
this year that includes new potentially good 
rootstocks, such as B.146, B.469, G.65, and 
several strains of M.9. As we move into the next 
century, many rootstocks will be bred and se- 
lected; however, it is likely that not much will be 
gained in terms of productivity. Pest resistance 
and site adaptability likely will be the major foci 
of the future breeding programs. 



«1^ %f^ %f# %i« %f# 

r|% 0^ rj^ r^ r{% 



Fruit Notes, Spring, 1994 



Buildup of Bugs Causes Decline in 
Effectiveness of Sticky for 
Capturing Apple Maggot Flies 
on Red Sphere Traps 

Jian Jiin Duan, Xingping Hu, Max P. Prokopy, and Ronald J. Prokopy 
Department of Entomology, University of Massachusetts 



Red spheres coated with sticky 
(TangletrapTM) have been used for 25 years as 
effective traps for monitoring apple maggot fly 
abundance in commercial orchards. Once sticky 
spheres have been emplaced, a treatment of 
pesticide is recommended when cumulative cap- 
tures of maggot flies reach one or two per 
unbaited trap or five per trap baited with syn- 
thetic apple odor (butyl hexanoate). We and 
others have long suspected that buildup of in- 
sects and debris on the sphere surface might 
cause a progressive decrease in the probability 
of capturing an ahghting maggot fly. In 1993, 
we evaluated the rate of decline in the power of 
traps to capture maggot flies. 

On Jiuie 28, we hung 24 freshly-coated 
sticky red spheres in optimum positions on 
apple trees in a commercial orchard. Each 
sphere was baited with one vial of butyl 
hexanoate and one packet of ammonium ac- 
etate in a manner typical for spheres used in 
trapping apple maggot flies in second-level IPM 
blocks. Eight freshly-coated spheres were placed 
in a cardboard box in a closet at 70°F as checks. 
After 7, 14, and 28 days, eight spheres on each 
date were removed from the orchard and like- 
wise placed in cardboard boxes in the closet. In 
early August, spheres of each treatment were 
hung in potted apple trees in field cages to test 
their fly capturing power. Ten flies were re- 
leased toward the bottom of the tree canopy, 
which contained a single sphere. The sphere 
was observed continuously for one hour, after 
which all flies were removed from the cage. We 
recorded the number of flies alighting, the num- 



ber captured, and the number that escaped. We 
also estimated the percent of the surface area 
occupied by captured insects. Once a trial 
ended, we hung up a sphere of the next treat- 
ment and released 10 more flies. We did this 
until all 32 spheres were tested. 

As time of sphere exp>osure in commercial 
orchard trees increased fi-om to 28 days, the 
proportion of released flies caught decreased 
significantly firom 49% to 13% (Figure lA). 
There was no significant effect of time of sphere 
exposure in commercial orchards on propensity 
of flies to alight on spheres (Figure IB). Of the 
ahghting flies, only 3% escaped from spheres 
kept continuously in the closet (never emplaced 
in commercial orchards) compared with 38, 43, 
and 73% escapees fi-om spheres exposed in or- 
chards for 7, 14, and 28 days, respectively 
(Figure IC). As days of exposure in orchard 
trees increased, the percentage of sphere sur- 
face area occupied by captured insects increased 
significantly from to 16, 24, and 38% afler 7, 
14, and 28 days of exposure, respectively (Fig- 
ure ID). 

We conclude from this test that sticky red 
spheres become progressively less effective in 
capturing alighting apple maggot flies as the 
number of insects caught on the spheres in- 
creases over time. It appears that under com- 
mercial orchard conditions, odor-baited sticky 
spheres lose nearly half of their maggot fly 
capturing power after two weeks without clean- 
ing. After four weeks without cleaning, they 
lose about three-fourths of their maggot fly 
capturing power. We therefore recommend 



8 



Fru'n Nates, Spring, 1994 




7 14 21 

Days of Exposura In Field 




7 14 21 

Day* of Expoaura In Flald 




7 14 21 

Days of Exposure In Field 



< 

9 
U 

3 

m 

8 



o 




7 U 21 

Days of Exposure In Field 



Figure 1. Effects of duration of exposure to weather in a commercial orchard on 
effectiveness of sticky spheres in capturing alighting apple maggot flies: (A) proportion of 
released flies captured, (B) mean number of flies observed alighting, (C) proportion of 
alighting flies that escaped, and (D) mean % of surface area occupied by previously 
captured insects. 



cleaning sticky spheres of insects and debris 
every two weeks to retain reasonable fly captur- 
ing power for either control or monitoring pur- 
poses. If spheres are not cleaned, control may 
fail or thresholds for pesticide treatment would 
have to be adjusted. 



Acknowledgments 

The study was supported by grants from the 
USDA Sustainable Agricultural Research and 
Education Program and the USDA Northeast 
Regional EPM Program. 



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Fruit Notes, Spring, 1994 



What Species of Predaceous Mites 
Exist in IVIassaciiusetts Commercial 
Apple Orchards? 

Xingping Hu and Ronald Prokopy 

Department of Entomology, University of Massachusetts 



Under favorable orchard pest management 
conditions, predaceous mites can provide a mod- 
erate to high level of control of pest mites such 
as European red mites and two-spotted spider 
mites. Reports from New York State clearly 
suggest considerable variation among different 
species of predaceous mites in ability to control 
pest mites. For example, the predator 
Typhlodromus pyri is better able to survive 
harsh winter temperatures and to provide sea- 
son-long control of low to moderate pest mite 
numbers than is the predator Amblyseius 
fallacis. In turn, the latter is better able thanT. 
pyri to control rapidly building numbers of pest 
mites in the summer. A third predator, ZeteeZZta 
mali, appears rather similar in biology to T. 
pyri, but rather Uttle is known about its ability 
to suppress pest mites. 

In 1977, we conducted a survey of 21 com- 
mercial apple orchards scattered throughout 
Massachusetts to determine the proportion of 
sampled orchards that 
contained each of these 
three species of preda- 
ceous mites. We surveyed 
again in 1993 in 12 dif- 
ferent commercial or- 
chards scattered across 
the state. Samples con- 
sistedof 100 leaves taken 
weekly in each orchard 
from April through June 
and 50 leaves taken bi- 
weekly from July through 
September. Leaves were 
placed in a cooler imme- 



diately after picking and returned to the labora- 
tory for predator identification. Identification 
involved removing the predators fi'om leaves, 
mounting them on microscope shdes, and using 
taxonomic keys to distinguish between some 
species on the basis of the number and location 
of tiny hairs on the body surface. 

There was remarkably little change over 1 6 
years in species composition of predators (Table 
1). In both surveys, A. fallacis was present in 
81 to 92% of sampled orchards, Z. mali in 30 to 
33%, and T. pyri in to 8%. The similarity in 
data patterns across years is even more re- 
markable given the fact that all orchards 
sampled in 1977 were different from the ones 
sampled in 1993. 

We conclude that if we want to achieve 
biocontrol of pest mites with existing preda- 
ceous mites in Massachusetts orchards , we ought 
to pay particular attention to A. fallacis and 
ways of encouraging its buildup. T. pyri, which 



Table 1. Percentage of Massachusetts commercial apple 
orchards sampled in 1977 and 1993 containing predaceous 
mites. 



Year 



Number of 
orchards 
sampled 



Species of predator 



Amblyseuis Typhlodromus Zetzellia 
fallacis pyri mali 



1977 
1993 



21 

12 



81 
92 





8 



30 
33 



10 



Fruit Notes, Spring, 1994 



appears identical to A. fallacis even under a 
powerful hand lens, can not be counted on at 
this point to provide mite biocontrol in any but 
a small minority of orchards. In an attempt to 
establish T. pyri in additional orchards, we 



released hundreds of nymphs and adults (ob- 
tained from Geneva, New York) in 1992 and 
1993 in two orchards. Unfortunately, there is 
no evidence to date that these releases have 
resulted in estabUshment of T. pyri. 



•Sm m^M •^ •9^ %% 
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How Beneficial Are Pre-bloom Oii 
Sprays Against European Red IVIites? 

Ronald Prokopy, Jennifer Mason, and Xingping Hu 
Department of Entomology, University of Massachusetts 



For decades, most Massachusetts apple 
growers have been applying pre-bloom oil sprays 
against overwintering eggs of European red 
mites. Just how beneficial to spring and sum- 
mer mite control are these sprays? Further- 
more, does the reduction in number of hatching 
mites after spraying oil cause our principal mite 
predator, Amblyseuis fallacis, to leave apple 
trees in search of more prey elsewhere? 

To answer these questions, in 1993, we 
cooperated with commercial growers in con- 
ducting a test in two-acre blocks of apple trees in 
each of nine orchards. Half of each block re- 
ceived no oil or other miticide through May. The 
other half received two applications of oil: one 
during half-inch green to tight cluster and the 
other during tight cluster to early pink. Each 
application was at a rate of about one gallon of 
oil to 100 gallons of water, with 100 to 300 
gallons of water used per acre. Duiing the third 
week of May, following egg hatch, 200 leaves 
per untreated and treated block were examined 
for presence of motile red mites and A. fallacis. 

In the untreated blocks, an average of 35% 
of sampled leaves had motile red mites com- 



pared with an average of only 5% in the oil- 
treated blocks (an 86% reduction in mite num- 
bers). Nearly all untreated blocks required 
repeat applications of miticide beginning after 
petal fall. None of the treated blocks required 
miticide apphcation until July or August. In 
two sampled blocks that received only a single 
pre-bloom application of oil, numbers of motile 
mites were reduced 45% compared with un- 
treated blocks. 

No A. fallacis were found on any of the 
blocks in leaf samples taken before oil applica- 
tion began in April or during May, although by 
August, all of the blocks had at least some A. 
fallacis. Evidently, cold winter temperatures 
reduced populations of A. fallacis to such low 
levels that it was inconsequential whether or 
not red mite prey were low or high in numbers 
in May. 

We conclude from these 1993 tests that two 
pre-bloom applications of oil against red mite 
eggs pay high dividends in suppressing red mite 
populations through spring and early summer, 
and in some years, possibly through the entire 
growing season. 



%i« %i# %% %% %% 

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Fruit Notes, Spring, 1994 



11 



North American Strawberry Growers 
Meet in Ontario 



The North American Strawberry Growers 
Association held its seventeenth annual meet- 
ing February 13-16, 1994 in Niagara Falls, 
Ontario. Over three hundred and fifty members 
firom the United States, Canada, and England 
gathered to learn the latest information on 
strawberry production and marketing. 

Dave Whittamore of Markham, Ontario 
was elected President and Susan Butler of 
Germantown, MD was elected Vice President. 
Two new directors were elected to the Board: 
John Dzen of S. Windsor, CT and Mike Reilly of 
Pittsburg, PA. 

The annual meeting followed a one-day pro- 
gram emphasizing bramble culture sponsored 
by the Ontario Berry Growers Association 
(OBGA). NASGA's opening session was pre- 
ceded by a delightful wine and cheese reception 
hosted by OBGA. The evening program was 
highlighted by Dr. Tim Ball, Winnipeg, 
Manitoba, who entertained the crowd with his 
delightful talk "Whatever Happened to Global 
Warming?", a factual and fictional discussion of 
long-term environmental changes. 

NASGA was started by growers in 1977 and 
is run by growers today with over 400 members. 
Highly committed to improving strawberry pro- 
duction through research, more than 25% of 
membership dues is allocated to research each 
year. In 1992, the NASGA Research Founda- 



tion was formed to increase fimding. This year 
NASGA received 24 proposals requesting more 
than $95,000 for strawberry research. The Re- 
search Committee recommended funding 17 
projects with a total of $34,000. Approximately 
55% of the grants were for plant breeding im- 
provements and 40% for pest management 
studies. NASGA publishes the research journal 
Advances in Strawberry Research. 

A 10-day tour to study agriculture and small 
fi-uit growing in Eiux)pe has been arranged by 
NASGA. The tour will depart August 21, 1994 
for stops in England, Holland, Belgium, Ger- 
many, and Switzerland. Reservations are on a 
first-come first-serve basis and non-NASGA 
growers/researchers are invited to participate. 
For information contact Linda Struye, tele- 
phone/FAX (414) 921-4784. 

The next annual meeting is scheduled for 
February 12-15, 1995 at the Sheraton Plaza 
Hotel at the Florida Mall in Orlando, Florida. 
The North American Bramble Growers will 
meet February 11-12, and immediately follow- 
ing NASGA, the Fourth National Strawberry 
Research Conference will be held, which 
NASGA is pleased to help cosponsor. 

For more information about NASGA and its 
publications, write to Bill & Treva Courter, P.O. 
Box 160, West Paducah, KY 42086, telephone/ 
FAX (502) 488-2116. 



%l0 %i^ ml^ %% mj^ 

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12 



Fruit Notes, Spring, 1994 



Promising New Apple Cuitivars for 1994 

Duane W. Greene and Wesley R. Autio 

Department of Plant & Soil Sciences, University of Massachusetts 



Diiring the past three seasons, we have 
evaluated over 100 new apple cuitivars. Some 
of these cuitivars are newly named and are 
available currently, while others are only num- 
bered selections and are not available widely. 
Last year we reported on all cuitivars evaluated 
in 1992 [Fruit Notes 58(2):4-14]. This year we 
are reporting only on those cxiltivars that ap- 
pear to have promise in wholesale operations or 
fit into a special slot in retail sales operations. 

Fruit evaluation began the first week in 
July and ended the fourth week in October. 
Where sufficient fi*uit were available, multiple 
harvests were made. Fruit were evaluated both 
objectively and subjectively (similar to the ways 
reported last year). Ten fruit were harvested 
fi"om each cultivar one to five times at weekly 
intervals, and flesh firmness, percent red color 
(or percent red cheek if the apple was yellow), 
diameter, and weight were assessed. Fruit also 
were cut and dipped into iodine solution and 
starch was evaluated using a generic starch 
chart developed at Cornell University. The 
starch chart allowed us to assess taste at times 
when the fi-uit were ripening, and it also gave us 
an idea when fruit should be harvested for 
storage. Fruit were evaluated for visual and 
sensory characteristics using a specially de- 
signed sheet with subjective rating scales simi- 
lar to the one described last year. Mcintosh was 
evaluated at four different times and included 
in this report as a commercial cultivar check. 

The Most Promising 
New Apple Cuitivars 

Below are listed what we consider to be the 
most promising new cuitivars for New England. 
They appear in alphabetical order. 



was introduced in 1983. Arlet was an outstand- 
ing apple again this year even though it has 
several major faults: surface russetting, 
preharvest drop, and a greasy feel when fi*uit 
ripen. Individuals hking a tart apple may select 
Arlet over Gala, which is harvested in the same 
season. It is conic, has yellowish white flesh, 
and a finiity pineapple taste. Firmness is main- 
tained over a long period of time. If a stop-drop 
chemical is appUed, drop can be controlled and 
firaiit will develop a very attractive cardinal red 
color without losing much firmness. The deep 
red color more-or-less masks the russet even 
though as much as 25% of the surface can be 
russetted. It is one of the best storing apples 
that was evaluated. Grease that developed on 
the surface can be washed off easily. 

Ginger Gold 

Ginger Gold emerged as the best early yel- 
low apple and one of the top apples evaluated. It 
is a large apple that has a very attractive waxy 
lemon yellow color and no apparent russet. 
Ginger Gold can be picked over a long period. 
Fruit had acceptable flavor and good appear- 
ance on August 24, in late Paulared season. 
Three weeks later the starch rating was only 
3.3, with firmness nearly 20 pounds, and fruit 
were still crisp. Ginger Grold has a pleasant but 
weak apple flavor. Fruit were harvested weekly 
and placed in cold storage at four different times 
starting on August 24. Two months later fruit 
fi-om all harvest dates tasted mealy and unap- 
pealing and firmness had dropped to 13.5 
fKJunds. Ginger Gold should not be considered a 
long storing apple; however, it is an outstanding 
apple at harvest and afl;er a short period of 
storage. 



Arlet Golden Glory 

This apple originated in Switzerland and This limb sport ofSmoothee produces a very 



Fruit Notes, Spring, 1994 



13 



Table 1. Laboratory analy 


ses and bloom 


dates of the most 


promising new a 


pple cultivars evaluated 


at the University of Massachusetts Horticultural Research Center 


in 1993, with Mcintosh shown | 


as a reference. 






















Best 


Also 








Soluble 


Red 








harvest 


evlauated 


Weight 


Diameter 


Firmness 


solids 


color 


Starch 


Bloom 


Cultivar 


date 


on: 


(g) 


(in) 


(lbs) 


(%) 


(%) 


index* 


time** 


Arlct 


9/20 


9/14,9/28 


186 


2.92 


17.4 


13.8 


80 


6.4 


E 


Ginger Gold 


9/7 


8/24. 9/2, 9/13 


283 


3.35 


21.0 


14.0 


30 


2.2 


M 


Golden Glory 


10/13 


10/5, 10/18 


244 


3.24 


16.4 


15.5 


13 


6.3 


ML 


Golden Supreme 


10/4 


9/20,9/27 


265 


3.28 


16.9 


13.9 


— 


6.0 


L 


Honeycrisp 


9/7 


9/13, 9/20, 9/27 


292 


3.47 


17.4 


14.2 


68 


4.8 


M 


NY 429 


10/13 


— 


244 


3.37 


14.0 


12.1 


88 


— 


— 


NY 75414-1 


10/5 


9/20,9/28 


194 


3.21 


13.1 


14.3 


96 


5.5 


M 


Sansa 


9/13 


8/24, 9/2, 9/7 


178 


2.94 


16.3 


14.2 


84 


6.8 


ML 


Suncrisp 


10/18 


— 


216 


3.10 


19.3 


15.1 


40 


6.0 


ML 


Mcintosh 


9/27 


9/7, 9/13. 9/20 


202 


3.20 


13.8 


11.6 


85 


7.0 


M 


* Starch rating: 


1-3 = immature, 4-6 = 


: mature 


, and 7-8 


= overmature. 








** Bloom time: E = early, 


EM = early-middle, ML = middle-late, and L = 


late. 







Table 2. Taste and sensory 


evaluations of th 


e most promising new apple cultivars evaluated at the 


University of Massachusetts Horticultural Research Center in 


1993, with Mcintosh she 


wn as a 


reference.* 


















Best 


Also 














harvest 


evlauated 




Red 








Cultivar 


date 


on: 


Attractiveness 


color 


Crispness 


Flavor 


Overall 


Arlet 


9/20 


9/14,9/28 


5.5 


6.7 


5.7 


7.2 


6.6 


Ginger Gold 


9/7 


8/24. 9/2. 9/13 


7.7 


— 


7.9 


6.0 


7.6 


Golden Glory 


10/13 


10/5, 10/18 


7.1 


— 


5.3 


7.1 


7.1 


Golden Supreme 


10/4 


9/20, 9/27 


9.0 


— 


5.7 


6.7 


7.7 


Honeycrisp 


9/7 


9/13, 9/20, 9/27 


4.2 


4.2 


6.4 


6.3 


6.3 


NY 429 


10/13 


— 


7.8 


7.5 


— 


6.1 


6.3 


NY75414-1 


10/5 


9/20. 9/28 


7.1 


7.1 


4.4 


6.2 


6.7 


Sansa 


9/13 


8/24. 9/2, 9/7 


7.3 


7.3 


7.0 


8.9 


8.9 


Suncrisp 


10/18 


— 


6.7 


~ 


7.1 


6.9 


6.8 


Mcintosh 


9/27 


9/7, 9/13. 9/20 


7.2 


7.2 


6.6 


5.8 


6.2 


* All fruit characteristics 


were rated on a 


scale from 1 to 10. 


Color: = dull and 10 = 


: bright. 


Attractiveness, flavor, and overall disirability: = dislike and 10 = like. Crispness: = 


low and 


1 = high. 

















attractive apple and the tree has a somewhat 
spur-type habit. It produces heavy crops of 
large attractive apples somewhat regularly, 
indicating that it may not be as biennial as one 
would expect. Fruit do russet but they still are 
very attractive. Although definitely a Golden 
Delicious type, we would rate this selection 
higher than either Golden Delicious or 



Smoothee for appearance, taste, and potential 
productivity. 

Golden Supreme 

This chance seedling was discovered in 
Idaho. We evaluated it for the first time in 1993. 
It is truly an outstanding apple. It is a very 



14 



Fruit Notes, Spring, 1994 



attractive apple with a glossy lemon-yellow rus- 
set-free finish and a pink-red cheek. It ripens 
about seven to ten days before Golden Delicious, 
but some uneven ripening may force two har- 
vests. It shows some tendency to drop prema- 
txirely. Flavor was fruity, sweet and perfumy, 
with a taste of Ucorice. The tree is spujr-type and 
upright, and some reports indicate that it may 
not be too productive. This apple is unsurpassed 
for appearance and flavor. 

Honeycrisp 

This Minnesota selection is the result of a 
cross between Honeygold and Macoun. Many 
Honeycrisp trees will be planted in the next few 
years because it has outstanding storage poten- 
tial and fruit following regular air storage have 
'explosive crispness'. Fruit harvested on Sep- 
tember 14 with firmness of 17.8 pounds still had 
firmness above 17 pounds at the end of January 
in air storage. Honeycrisp is a very large apple 
but its not too attractive, because color is slow to 
develop and is striped rather than blush. Qual- 
ity at harvest is good but not exceptional, and 
the longer Honeycrisp stays in storage the bet- 
ter it looks compared with other cultivars. 
Honeycrisp fruit from Massachusetts were in- 
cluded in a replicated taste evaluation at the 
Mid-Atlantic Fruit Variety Showcase in West 
Virginia in January. Numerically, Honeycrisp 
was judged to be the best tasting apple and 
statistically it was equal to Fuji and Braebum. 
Over the past four years Honeycrisp on M.26 
has been the most productive apple in our culti- 
var evaluation plots. It produced over 1.5 bush- 
els per tree in the fourth leaf 

NY 429 

This very large burgundy-red apple is from 
the New York breeding program. It has very 
good quahty and the flesh is creamy white. 
Even when cropped very heavily, fruit wiU size 
to 3.25 inches or larger. It may be biennial if not 
thinned. Trees are very productive. NY 429 is 
already in commercial production in the 
Hudson Valley of New York and prices of $20 



per bushel were reported in 1993 in the Apple 
Report for the Massachusetts Department of 
Food and Agriculture. NY 429 will be named 
soon. 

NY 75414-1 

This cultivar is the best disease-resistant 
apple from New York. It is medium large, red, 
and a Macoun look-alike. Scarf skin may be a 
problem in some areas but in New England it is 
a plus because it is also a characteristic of 
Macoun. It is attractive, somewhat tart, and 
very crisp. Taste is Macoun- and Mclntosh-like. 
Trees are vigorous and nonspur. 

Sansa 

This outstanding apple is the result of a 
cross between Gala and Akane. It was one of the 
highest rated apples, regardless of the season of 
harvest. Fruit were attractive, very crisp, aro- 
matic, sweet, and the flavor was subtly spicy at 
first but it soon developed into a fully flavored 
apple with pineapple, banana, and licorice 
taste. Sansa did not drop and it could have been 
harvested over a three-week period (the three 
weeks prior to Gala). It stored for up to two 
months. Although it softened, it maintained 
flavor, unlike Gala which maintains firmness 
and crispness but loses the essence of the flavor 
that makes it Gala. Fruit were of medium size. 
Sansa is the best tasting apple that ripens 
before Mcintosh. The first commercial 
plantings wiU go in the ground in 1995. 

Suncrisp (NJ 55) 

This cultivar produces medium to large late- 
season yellow apples. Finish on this apple was 
not very good but the striped orange-red cheek 
over lemon-yeUow ground color is distinctive 
and somewhat attractive. Fruit is conic with a 
crisp yellow flesh. The acidity is quite high at 
harvest but the sharpness and tartness mellow 
in storage. Flavor is excellent. It is a very good 
apple to help spread out the harvest season and 
it has good storage potential. 



Fruit Notes, Spring, 1994 



15 



Table 3. Laboratory analyses and bloom dates of the most 


promising new apple cu 


Itivars with local 


or niche market potential evaluated at the University of Massachusetts Horticultural Research | 


Center in 1993. 




















Best 


Also 








Soluble Red 








harvest 


evlauated 


Weight 


Diameter 


Firmness 


solids color 


Starch 


Bloom 


Cultivar 


date 


on: 


(g) 


(in) 


(lbs) 


(%) (%) 


index* 


time*' 


ArkCharm 


8/12 


8/5,8/9 


246 


3.30 


15.9 


13.0 77 





ML 


MonArk 


a/19 


8/12 


239 


3.29 


16.3 


12.0 71 


— 


M 


Nittany 


10/18 


— 


154 


2.75 


19.5 


13.8 77 


7.1 


L 


Shamrock 


9/27 


9/13, 9/20, 10/4 


179 


3.04 


17.5 


12.7 34 


3.9 


ML 


Splendour 


10/13 


10/18 


241 


3.24 


20.1 


13.3 88 


2.9 


L 


Williams Pride 


8/19 


8/12 


164 


2.95 


15.7 


11.3 94 


— 


ML 


* Starch rating: 


1-3 = immature, 4-6 = 


: mature 


, and 7-8 


- overmature. 






** Bloom time: E 


= early, 


EM = early-middle, ML = middle-late. 


and L = late. 







Table 4. Taste and sensory evaluations of the most promising new apple cultivars with local or 
niche market potential evaluated at the University of Massachusetts Horticultural Research 
Center in 1993.* 





Best 


Also 














harvest 


evlauated 




Red 








Cultivar 


date 


on: 


Attractiveness 


color 


Crispness 


Flavor 


Overall 


ArkCharm 


8/12 


8/5, 8/9 


4.8 


4.2 


3.8 


5.6 


5.1 


MonArk 


8/19 


8/12 


5.3 


5.5 


4.7 


5.6 


5.8 


Nittany 


10/18 


— 


6.7 


6.7 


8.0 


6.7 


7.0 


Shamrock 


9/27 


9/13, 9/20, 10/4 


5.2 


— 


5.2 


6.4 


6.2 


Splendour 


10/13 


10/18 


7.2 


7.1 


4.6 


6.7 


6.8 


Williams Pride 


8/19 


8/12 


6.0 


7.0 


4.0 


5.9 


6.2 



All fruit characteristics were rated on a scale from 1 to 10. Color: = dull and 10 = bright. 
Attractiveness, flavor, and overall disirability: = dislike and 10 = like. Crispness: = low and 
1 = high. 



Apples Worthy of Limited 
Planting 

Some apples may not be recommended for 
extensive planting but they have some out- 
standing characteristics that make them appro- 
priate to plant for niche markets. We feel that 
the following group of apples are worthy of 
consideration for limited planting. 

Akane 

Akane continues to be a cultivar that we 
favor. It is extremely attractive and few apples 



have the flavor and aroma of Akane. It ripens 
during the first two weeks of September. It 
develops deep cherry red color before it is ready 
to harvest, so it fii^quently is harvested imma- 
ture and tart. When allowed to ripen, it has 
excellent flavor. It may be a shy bearer. 

ArkCharm (AA 18) 

This large blotchy red apple from Arkansas 
ripens a little before Jerseymac and Paulared. 
Fruit is tarter than sweet but fruit quality is 
quite good. Storage life is rather short but it is 
one of the best apples for the season. 



16 



Fruit Notes, Spring, 1994 



Monarch (AA 44) 

This cultivar is another blotchy cherry-red 
apple from Arkansas. Quahty is very good for 
this season. It has a good perfumy taste but 
because of extensive preharvest drop, few may 
reach the proper stage of maturity without the 
use of a stop-drop treatment. Acidity is quite 
high. It ripens slightly before Pavdared, but it is 
superior to Paulared in taste. 

Nittany 

Very little is heard about this open polU- 
nated seedling of York. It is fairly attractive, 
oblong, and light cherry red. It ripens late, in 
Rome Beauty season. It has a good sweet-tart 
flavor that we rated very high. Although some 
Nittany are grown in Pennsylvania, we believe 
that we can grow a more attractive and perhaps 
a better Nittany in southern New England. It is 
a vigorous tree and fruit suffer from calcium 
problems. 

Shamrock 

This cross between a spur Golden Delicious 
and a spur Mcintosh is not reported to have high 
quality, but we feel that it is versatile and a 
potentially valuable cultivar. It tastes Granny 
Smith-hke if picked just prior to Mcintosh sea- 
son. The quality is at least as good as the 
Granny Smith apples found in the store at this 



time of year. If allowed to stay on the tree iintil 
late September or early October it develops a 
very good Mcintosh taste. We feel that it is the 
best green apple in the season. The tree is 
grower-friendly, a semi-spur type, precocious, 
and it is not biennial. 

Splendour 

This late-ripening red apple is from New 
Zealand. It is attractive and has very good 
flavor, but the skin is so thin that it cannot 
withstand the rigors of packing, handling, and 
long-distance shipping. The tree is a semi-spur 
and very grower-friendly. It is a parent of the 
new generation of apples from New Zealand and 
British Columbia. 

Williams PHde 

This disease-resistant apple ripens with 
Paulared but the quality is superior to 
Paulared. Fruit are large, red, and somewhat 
irregular in shape and the skin is not smooth. 
White lenticels are prominent. Fruit is aro- 
matic and flavor is mild but fruity and lively. 

We have several other cultivars under test 
that we feel have the potential to go all the way 
to the top, although they are not commercially 
available yet. The most promising from the list 
are: BC 8M 15-10, BC 17-30, Fantazja, and 
NJ90. 



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Fru'n Notes, Spring, 1994 



17 



Suggestions for Use of the New 
Postbloom Thinner Accel® 

Duane W. Greene and Wesley R. Autio 

Department of Plant and Soil Sciences^ University of Massachusetts 



Chemical thinning of apples continues to be 
one of the most important management activi- 
ties. It is reqviired nearly every year to assure 
adequate fruit size at harvest and to encourage 
repeat bloom the following year. Carbaryl and 
NAA are the two most commonly used thinners. 
Both have their faults. Orchardists frequently 
are reluctant to use carbaryl because of the 
potential detrimental effect that it can have on 
mite predators, and it is a relatively weak thin- 
ner. When used alone, often it is not potent 
enough to thin adequately. NAA is stronger, 
but it also has several detrimental effects. 
Overthinning is possible if either cloudy or hot 
weather immediately follows apphcation. It 
can retard finiit growth, even when used accord- 
ing to label directions. Under these conditions, 
NAA may not increase fruit size, even when it 
causes significant thinning. This lack of size 
increase is emerging as a major problem associ- 
ated with NAA. Finally, NAA cannot be used on 
some cultivars because it causes pygmy finait. 

In the 1980's benzyladenine (BA) was found 
to have chemical thinning capabiUties. Since 
then, researchers have demonstrated repeat- 
edly that BA is a consistent and effective thin- 
ner with some unique properties that may make 
it the postbloom thinner of choice. Accel® re- 
cently was approved as a chemical thinner on 
apples. Accel is an altered Promalinâ„¢ formula- 
tion, but the primary active thinning compo- 
nent is B A. The purpose this article is to explain 
some of the characteristics of BA that make it a 
unique thinner, and to make suggestions for 
successful use of BA when applied in the Accel 
formulation. 



General Effects of Accel 

Thinning Activity 

BA can thin over a wide range of concentra- 
tions, starting fi*om as low as 25 ppm. Undesir- 
able side effects may be noted if it is appUed 
above 150 ppm; however, label restrictions on 
the active ingredient per acre make it unlikely 
that too high a concentration will be applied. 
BA has been applied in heavy set years and in 
light set years, and the thinning response to 
varying concentrations is linear. Although con- 
centrations as low as 25 ppm can be effective, 50 
to 100 ppm generally are required to do an 
effective job. 

Comparison with other 
Chemical Thinners 

BA has been compared with NAA and car- 
baryl in several thinning trials in Massachu- 
setts. It thins as consistently, if not more 
consistently, than either NAA or carbaryl when 
applied at the proper time and at an appropriate 
temperature. The activity of chemical thinners 
differs fix)m year to year, depending on weather 
and other factors; however, when applied at the 
appropriate tree row volume, 75 ppm BA thins 
Mcintosh comparably to 1 Ib/100 gal carbaryl 
(50% WP Sevin) and 6 ppm NAA. BA has been 
shown to have no detrimental effects on mite 
predators, a problem frequently associated with 
the use of carbaryl. When applied alone, BA 
does not have the negative effects of NAA, such 
as leaf epinasty, reduced fruit size, or pygmy 
fruit. 



18 



Fruit Notes, Spring, 1994 



Return Bloom 

One of the primary reasons for thinning is to 
assure adequate return bloom. BA appears to 
be quite effective at stimulating flower bud 
formation, and therefore, BA compares favor- 
ably with NAA and carbaryl at stimvdating 
return bloom. In some years, BA will enhance 
flower bud formation beyond that which would 
be promoted by the level of frmt thinning that it 
causes. 

Time of Application 

BA can thin over a three- week period. It will 
thin modestly when applied at full bloom to 
petal fall, but fruit are most susceptible to BA 
and it is most effective when it is applied at the 
8- to 10-mm stage of fruit development (14 to 18 
days after fuU bloom). Once iniit reach about 20 
mm and trees experience several days of sunny 
weather in the 80's, no thinner, including BA, 
will thin. 

Spray Coverage 

Good and uniform spray coverage is impor- 
tant. Translocation and redistribution of 
foliarly appHed BA is limited. Further, research 
has shown that BA must come in direct contact 
with the spvu" leaves for fruit in that cluster to be 
thinned. BA application directly to the young 
fruit wiU increase fruit size and flesh firmness 
at harvest but wiU not influence fruit abscis- 
sion. 

Fruit Effects 

Perhaps the biggest advantage that BA has 
over other chemical thinners is its effects on 
fruit. 

Fruit Size 

Generally, chemical thinners increase fruit 
size by lowering fruit numbers, thus reducing 
competition for metabolites among the remain- 
ing fruits. Although BA enhances size by reduc- 
ing competition, it also causes increased fruit 
size independent of and in addition to this effect. 
This effect on fruit size independent of thinning 



is unique to BA. BA is especially effective at 
increasing fruit size on Mclntosh-tjrpe cultivars 
such as Mcintosh and Empire. 

Flesh Firmness and Sugars 

It is rare for chemical thinners to increase 
flesh firmness because they usually increase 
finiit size, and there is an inverse relationship 
between fruit size and flesh firmness. BA, 
however, increases flesh firmness approxi- 
mately half of the time, even though it also 
increases finiit size. Because BA is a cytokinin 
(a group of plant hormones) it likely increases 
flesh firmness by increasing the number of cells 
in an apple. Also, BA increases the sugar 
content of fruit about half the time. Thinners 
can increase sugar because they increase the 
leaf-to-fruit ratio. 

Red Color and Fruit Asymmetry 

If used at high concentrations, BA can re- 
duce red color and increase finiit asymmetry. 
Given the label restrictions per acre per applica- 
tion, we do not believe that either one of these 
situations is likely to occur. 

Cultivars 

BA is not equally effective on all cultivars. 
BA is especially effective on Empire and Mcin- 
tosh and extremely useful on Jonamac, Rome, 
Idared, and Golden Delicious. 

Recommendations for 
the Use of Accel* 

Accel is the first step by Abbott Laboratories 
to make BA available as a thinner on apples. It 
is not a perfect product, but it is a start. It is an 
altered Promalin formulation so GA, , is in- 

4+7 

eluded, but it is present only at 1/10 the level 
found in the original Promalin formulation. 
Also, on the present label is a limit of 35.6 fluid 
ounces of Accel (20 g active ingredient, ai) per 
acre p>er application, and this level may limit its 
effectiveness when used on large trees that 
have a high tree-row-volume requirement. 



* Please see the end of this article for a discussion of a 
pending label change. 



Fruit Notes, Spring, 1994 



19 



Concentration 

Twenty five ppm in a dilute spray is the 
minimum concentration to get any thinning 
response. If the tree row volume of a block 
requires 200 gallons per acre in a dilute spray, 
the label would allow only a concentration of 26 
ppm (at 35.6 fluid oxinces of Accel or 20 g ai/acre) 
to be used. Furthermore, in situations where 
aggressive thinning is necessary and the tree 
row volume is only 100 gal/acre, the desired 
level of thinning may not be reached with the 
use of BA alone, since the label will allow only a 
concentration of 53 ppm (at 35.6 flxiid ounces of 
Accel or 20 g ai/acre). In these situations, 
additional thinning strategies may be neces- 
sary. 

Accel should be apphed in 50 to 200 gallons 
of water per acre. Applications in volumes less 
than 50 gallons per acre may result in poor 
coverage. 

Cultivars 

Use Accel on responsive cultivars first until 
you feel comfortable and until you see how it 
performs in your orchard. Responsive cultivars 
include Empire, Rome, Mcintosh, and Idared. 

Time of Application 

If using a single application of Accel, apply 
at the 8 to 10 mm stage (3/8 in), firom 12 to 18 
days after full bloom. 

The label allows up to two applications of 
Accel per season. The research has not yet been 
done to determine the specific effects of multiple 
applications, so proceed with caution. If two 
applications are made, do not exceed a total of 
71.2 fluid ounces of Accel (40 g ai) per acre for 
the season. With two applications, the first 
should be applied at the 5-mm fruit stage, and 
the second should be applied at no later than the 
10-mm stage. 

Combinations with other Thinners 

BA has been used effectively in combination 



with NAA on Mcintosh. The response was 
additive; however, Accel interacts with NAA on 
Dehcious to produce small and pygmy fruit. 
Therefore, the label specifically states that NAA 
should not be used in any Accel thinning pro- 
gram. Where aggressive thinning is required, 
carbaryl should be included in the thinning 
program. We have tank mixed BA with car- 
baryl successfully. The thinning response was 
additive. The label does not prohibit tank mix- 
ing with carbaryl but the practice is discour- 
aged. 

Weather 

Attention to temperature is critical for effec- 
tive thinning with Accel. It should be applied 
only when the temperature is 65°F or higher. 
Ideally, the temperature should rise into the 
80's within three days following application. If 
warm temperatures do not follow the applica- 
tion, thinning results are hkely to be disappoint- 
ing. Cloudy weather following application, Uke 
warm temperature, may increase the thinning 
response. 

Label Change Pending 

There is a label change pending for Accel as 
this issue goes to press. There are two signifi- 
cant changes that may occtu*. The rate of Accel 
per apphcation may be increased to 53.5 fluid 
ounces (30 g ai) per acre, and the total per 
season may be increased to 107 fluid ounces (60 
g ai) per acre. This change must be noted, 
because overthinning may occur of Mcintosh, 
Idared, Rome, and Empire if the new maximum 
rate is used and tree row volume reqires less 
than 100 gallons per acre for a dilute spray. 

Conclusions 

In this first season of commercial use, use 
Accel cautiously and follow label directions. Use 
it first on a responsive cultivar, and do not apply 
it unless temperature conditions are appropri- 
ate. 



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20 



Fruit Notes, Spring, 1994 




Emit Notes 



University of Massachusetts 

Department of Plant & Soil Sciences 

205 Bowditch Hall 

Amherst, MA 01003 



Nonprofit Organization 
U.S. Postage Paid 

Permit No. 2 
Amiierst, miA 01002 



Account No. 3-20685 



Fruit Notes 

Prepared by the Department of Plant & Soil Sciences. 

University of Massachusetts Cooperative Ebrtenslon System. 

United States Department of Agriculture, and Massachusetts Counties Coopj 

Editors: Wesley R. Autio and William J. Bramlage 



ISSN0427-6906 

LISRARi 
JUL \h 9'4 
JNIV. OF MA3 




Volume 59. Number 3 
SUMMER ISSUE, 1994 

Table of Contents 

Could Bacteria in Nature be Detoxifying 
Compounds for the Apple Maggot Fly? 

A New Book on Tree Fruit Nutrition 

Some Thoughts on Depreciation 

Effects of Low Temperature, Ripening, and Light 
on Scald Susceptibility of Apples at Harvest 

Final Report on the 1984 NC-140 Cooperative Apple Rootstock Ranting 
in Massachusetts: Starkspur Supreme Delicious on Fifteen Rootstocks 

O' Say Can You See Mite Predators in Apple Orchards? 

Apple Orchards in Switzerland: EHfferences Small and Large 



Fruit Notes 



Publication Information: 

Fruit Notes (ISSN 0427-6906) is published the first day of 
January, April, July, and October by the Department of Plant 
& Soil Sciences, University of Massachusetts, 



The costs of subscriptions to Fruit Notes are $7.00 for United 
States addresses and $9.00 for foreign addresses. Each one- 
year subscription begins January 1 and ends December 31. 
Some back issues are available for $2.00 (United States ad- 
dresses) and $2.50 (foreign addresses). Payments must be in 
United States currency and should be made to the University of 
Massachusetts. 



Correspondence should be sent to: 

Fruit Notes 

Department of Plant & Soil Sciences 

205 Bowditch Hall 

University of Massachusetts 

Amherst, MA 01003 



COOPERATIVE EXTENSION SYSTEM POLICY: 

All chemical uses suggested in this pubhcation are contingent upon continued registration. These 
chemicals should be used in accordance with federal and state laws and regulations. Growers are 
urged to be familiar with all current state regulations. Where trade names are used for 
identification, no company endorsement or product discrimination is intended. The University of 
Massachusetts makes no warranty or guarantee of any kind, expressed or implied, concerning the 
use of these products. USER ASSUMES ALL RISKS FOR PERSONAL INJURY OR PROPERTY 
DAMAGE. 



Issued by the University of Massachusetts Cooperative Extension System, Robert G. Helgesen, 
Director, in furtherance of the acts of May 8 and June 30, 1914. The University of Massachusetts 
Cooperative Extension System offers equal opportunity in programs and employment. 



Could Bacteria in Nature be 
Detoxifying Compounds for tlie 
Apple IVIaggot Fly? 



Carol R. Lauzon, Bernard J. Robert*, Teresa G. Bussert, and 
Ronald J. Prokopy 

Department of Entomology, University of Massachusetts 
*Department of Plant & Soil Science, University of Vermont 



Insects are exposed, almost continuously, to 
a variety of harmful compounds. Adults and 
larvae may come into contact with harmful 
synthetic chemicals, such as pesticides, or harm- 
ful natural compounds, such as plant 
allelocompounds (plant substances that often 
protect it against pests). Insects may be exposed 
to these harmful compounds either through 
contact or through feeding. Either way, the 
mechanisms for ridding these poisons from the 
body are important survival processes. These 
processes, referred to as detoxification mecha- 
nisms, involve enzymes (proteins that facilitate 
chemical reactions) which alter the structure of 
the compound and make it more excretable (less 
toxic). This can be achieved by removal or 
addition of a chemical group. 

Generally, pesticides apphed by growers are 
in amounts that overwhelm the insect's ability 
to detoxify them. As time goes on, the pesticide 
on plants is broken down by sunhght, wind, 
rain, and other natural processes. Eventually, 
residues may reach concentrations where the 
insect C£in survive ingestion or contact. With 
repeated exposure, the insect may evolve to 
handle effectively a toxin in concentrations ear- 
lier found to be lethal, i.e. develop pesticide 
resistance. 

The apple maggot fly, Rhagoletis pomonelUt, 
typically is controlled by two or three applica- 
tions of azinphosmethyl (Guthion ), an orga- 
nophosphate that is a potent inhibitor of cho- 



Unesterase, an enzyme responsible for normal 
nervous system functioning. Azinphosmethyl 
also is used to control other orchard pests such 
as codling moth. Although no information exists 
to date regarding resistance to azinphosmethyl 
for the apple maggot fly, resistance has been 
reported for codling moth. 

Mechanisms of insecticide resistance tradi- 
tionally have been examined using genetic tech- 
niques focused on resistant individuals and cre- 
ation of models of gene flow between resistant 
and susceptible insects. Less attention has been 
paid to the potential involvement of bacteria 
either within or on host plants or within insects 
in the development of insecticide resistance. 

Interestingly, enzymes in bacteria capable 
of converting toxic compounds into less toxic 
compounds that are more easily excretable in- 
clude the same enzymes that insects themselves 
use in detoxification. In fact, many bacteria can 
detoxify compounds internally or secrete en- 
zymes responsible for metabolizing foreign com- 
pounds into their surrounding environment. 
Numerous reports exist on the abilities of cer- 
tain species of bacteria to degrade and detoxify 
a variety of compounds, including 
azinphosmethyl and plant allelocompounds. 

Here we report on studies designed to deter- 
mine if bacteria associated with the apple mag- 
got fly could degrade, and subsequently detoxify, 
azinphosmethyl and plant allelocompounds 
likely to be consumed by this insect. 



Fruit Notes, Summer, 1994 



Materials & Methods 

Pesticide degradation and detoxification . 
Enterobacter agglomerans, a bacterium found 
to inhabit both the gut of the apple maggot fly 
and apple leaf surfaces in nature, was added to 
sterile preparations of azinphosmethyl at a con- 
centration typical of one sprayed by a grower. 
The bacteria/pesticide solutions and sterile pes- 
ticide solutions (void of any bacteria) were incu- 
bated at 73°F for 3 days. Cholinesterase was 
extracted from apple maggot flies and mixed 
with the bacteria/p)esticide solutions to deter- 
mine whether or not azinphosmethyl still was 
capable of reducing cholinesterase activity after 
exposure to the bacteria. Also, small amounts 
fi-om each sample were fed to 25 apple maggot 
flies and mortality values were recorded at 24- 
and 40-hour intervals. Additionally, the solu- 
tions were analyzed for degradation products of 
azinphosmethyl. The experiment was done twice. 

Plant allelocompound degradation and 
detoxification . We also studied four 
allelocompounds considered to be toxic to apple 
maggot and typically found in the habitat of 
apple maggot flies. They were: naringenin, 
phloridzin, cafieic acid and cinnamic acid. Each 
solution was inoculated with Enterobacter 
agglomerans and incubated at 87°F for 24 hours. 
Sterile solutions also were incubated along with 
the bacterial solutions. Degradation of each 
compound was measured by changes in pH (a 
typical phenomenon associated with degrada- 
tion) and by the presence or absence of degrada- 
tion products. Also, small amounts from each 
solution were fed to 10 flies individually, and 
mortality values were recorded after 12 days. 

Results 

Mixing cholinesterase extracted from apple 
maggot flies with azinphosmethyl resulted in 
low to no cholinesterase activity (14.8 active 
units). However, activity of cholinesterase was 
10 times greater when mixed with 
azinphosmethyl in which bacteria had grown 
for three days (144.1 active units). The higher 
value indicates that cholinesterase activity was 
not inhibited as much in the bacterial solution 



and therefore, the pesticide was less effective. 
We found that loss of effectiveness was the 
result of chemical alteration of azinphosmethyl 
by bacteria 

Forty hours afl«r a 48-hour-old solution of 
bacteria and pesticide was fed to apple maggot 
flies, only three of 50 flies were dead. In con- 
trast, when flies were fed the sterile pesticide 
solution, 47 of 50 were dead after 40 hours. Fifty 
flies serving as controls were fed only water. All 
were alive after 40 hours. 

In the allelocompound solutions that con- 
tained bacteria, we saw changes in pH (indica- 
tive of chemical changes) which were not ob- 
served in the sterile solutions, and we were able 
to detect degradation products in the bacterial 
solutions that were not present in the sterile 
solutions. Therefore, bacteria also degraded the 
plant allelocompoiuids. When apple maggot 
flies were fed sterile solutions of the four 
allelocompounds, all were dead after 12 days; 
however, when solutions inoculated with bacte- 
ria were fed to the flies, none died. 

Conclusions 

Our laboratory findings indicate that 
Enterobacter agglomerans possesses the abihty 
to degrade and subsequently detoxify 
azinphosmethyl and certain plant 
allelocompounds that normally are toxic to apple 
maggot flies. This finding is an important first 
step in establishing the contribution of bacteria 
toward detoxification of harmful compounds 
encountered in nature by this and other insects. 

We are continuing our work in this area by 
studying (1) precisely how the bacteria degrade 
toxic compounds, (2) how fly longevity and fe- 
cundity are affected by detoxification, and (3) if 
detoxification mechanisms inherent to flies are 
enhanced by degradation processes of bacteria. 
Further comprehension of ways insects handle 
chemicals in the environment should contribute 
to pest management progrguns. Such knowl- 
edge also may lead to creation of new ways to 
decrease or eliminate pesticide crops or on spray 
equipment. For example, it is conceivable that a 
bacterial or enz)Tnatic preparation could be 
sprayed on trees before harvest so that the 



Fru'n Notes, Summer, 1994 



residues may be decreased or eliminated through 
detoxification. Envision also, after completion of 
spraying, a tablet containing bacteria that one 
drops into the spray tank and a few hours later, 
the equipment is free from any pesticide. These 
are exciting possibilities. 

Acknowledgments 

We thank George MacCoUom of the Univer- 
sity of Vermont for supplying apple maggot flies 
during the early stages of this work (which took 
place at the University of Vermont), Evan 
Thackaberry (also of the University of Vermont) 
for his assistance with visualization of pesticide 
degradation products, and Sylvia Cooley for 
technical assistance with plant allelocom pound- 
fly mortality studies. This work was supported 



in part by the National Agricultural Pesticide 
Impact Assessment Program Grant #92-34050- 
7268 and USDA National Research Initiative 
Competitive Grant #893715. 

Selected References 

Brattsen, L.B. and C.F. Wilkinson. 1977. Herbi- 
vore-plant interactions: Mixed-function oxidase 
and secondary plant substances. Science June 
17: 1349-1352. 

Robertson, J.L., K.F. Armstrong, D.M. Suck- 
Ung, and H.K. Preisler. 1990. Effects of host 
plants on toxicity of azinphosmethyl to suscep- 
tible and resistant light brown apple moth (Lepi- 
doptera: Tortricidae).J. Econ. Entomol. 83: 2124- 
2129. 



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A New Book on Tree Fruit Nutrition 



In February, 1992, a shortcourse on the 
Management of Tree Fruit Nutrition was held in 
Wenatchee, Washington. The proceedings from 
that conference have been pubhshed by Good 
Fruit Grower and is available for purchase. 

The book consists of 22 generally easy-to- 
read chapters and totals over 200 pages. It 
begins with three general chapters on fruit tree 
growth and development, root development and 
physiology, and soil characteristics. This base is 
followed by 12 chapters on minerals and ap- 
proaches to meeting their needs in trees and 
finiit. There are also three chapters on diagnos- 



ing nutritional needs in orchards, and a chapter 
on fertilizer effects on water quahty. Finally, 
the book concludes with three chapters on 
fertigation. Eighteen different authors contrib- 
uted to the shortcourse and the proceedings. 

This is an outstanding reference for frmt 
growers, and will certainly become a standard 
reference on nutritional problems in orchards. 
Copies can be obtained from the Good Fruit 
Grower, P.O. Box 9219, Yakima, WA 98909. 
Cost is $15.00 plus $3.50 for shipping. We 
strongly urge growers to obtain a copy £md to 
refer to it often. 



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Fruh Notes, Summer, 1994 



Some Thoughts on Depreciation 

Robert L. Christensen 

Department of Resource Economics^ University of Massachusetts 



Depreciation may be the most misunder- 
stood topic in financial management. It is prob- 
ably the most complicated exercise in the devel- 
opment of the business financial statement, and 
it is a critical element in preparation of income 
tax returns. In fact, the complexity of IRS rules 
and some computational methods can obscure 
the concept that underhes depreciation and lead 
to a misunderstanding of true costs and busi- 
ness profitability. 

Depreciation is an annual non-cash expense 
that reflects the amount by which an asset 
decreases in value due to use, age, and obsoles- 
cence. It apphes only to assets like buildings, 
machines, and breeding animals, as well as to 
improvements hke roads, bridges, fences, and 
drainageways that have useful hves of more 
than one year. Depreciation recognizes the fact 
that these assets can wear out with use. That is, 
eventually they become so worn that they be- 
come useless or repair costs become excessive. 

Depreciation also occurs through aging. 
Even without use, wooden or rubber compo- 
nents can rot, metal can rust or become brittle 
and break, and plastic can lose strength and 
crack. Assets also can become obsolete as new 
technology is developed to perform the same 
tasks more efficiently and at lower cost, or if the 
asset is no longer relevant to the nature of the 
business (e.g. , a mUking machine becomes obso- 
lete if the dairy herd is sold). 

While depreciation is a non-cash expense, 
there is a "day of reckoning" that comes when 
the asset must be replaced. One might consider 
the annual depreciation amounts as money to be 
put in a reserve account to accumulate until the 
day when the asset is replaced. In theory, the 
business then will have the capital accimiulated 
to replace the asset with little or no need to incur 
new debt. More often, however, no such reserve 
account exists. 

One sometimes observes situations where 
the annual income statement of a business 



shows a low or even negative net income and 
there is a suggestion of insolvency. One might 
immediately ask how the operator can continue 
in business and take care of family hving ex- 
penses if net income is negative. One expla- 
nation is that depreciation is subtracted as a 
cost in the income statement. It's important to 
recall that depreciation is a non-cash expense. 
Since depreciation is a non-cash cost, that 
amount actually is available from cash flow for 
debt repa)rment, other business expenses, and 
for family living costs. 

Another answer might be that past earnings 
in the form of savings are being depleted in order 
to meet costs and debt obligations. Still another 
explanation could be that additional debt is 
being incurred that allows the business to con- 
tinue and family living expenses to be met. This 
situation can continue untU the time of reckon- 
ing when depreciable assets must be replaced. 
Even though replacement might be possible 
from borrowed funds, it may be difficult to con- 
vince lenders that theyshould make the loan 
when past income statements show low or nega- 
tive net income. 

Comphcating the subject of depreciation are 
the IRS procedures relating to depreciation. For 
tax purposes, depreciation is a deductible ex- 
pense of the business just as if it were a cash cost. 
Regulations define what kinds of assets may 
and may not be depreciated. They also establish 
acceptable methods of calculating depreciation 
and stipulate recovery periods (the number of 
years over which different classes of property 
may be depreciated). Once a particular method 
has been established for an asset you cannot 
change to another method, but you can use 
different methods for different assets. 

It's not the purpose of this article to describe 
depreciation methods and procedures. Rather, 
only a few points will be made concerning depre- 
ciation and tax liability. First, the amount of 
depreciation taken on business assets can affect 



Fru'n Nous, Summer, 1994 



tax liability substantially. Second, the selection 
of the method of depreciation for property can 
affect tax Uabihty not only in the current year 
but also in future years (e.g., accelerated meth- 
ods reduce tax UabiUty in early years of owner- 
ship and increase liability in later years as 
compared with straight line methods). It should 
be noted that depreciation calculations may 
have little actual relation to the depreciation 
costs that relate to wear, aging, and obsoles- 
cence of the assets of a particular business. For 
example, a single purpose farm building with 
integrally installed equipment can become obso- 
lete or worn out in less than the 10-year recovery 
period for the IRS General Depreciation System 
(GDS) regulation. On the other hand, the GDS 
time period for most farm machinery is seven 
years. Yet for practical purposes, a fully depre- 
ciated tractor (one with a "book value" of zero) 
may retain its essential usefulness for two or 
more decades and, therefore, still have real 
value as an asset. 

What this means is that depreciation values 
can overstate or understate the actual asset 
value. When assets last longer than the recov- 
ery period, the result is an income statement 
which understates actual net farm income and 
overstates production costs. In situations, how- 



ever, where rapid technological innovation 
causes assets to become obsolete more quickly 
than the guideline recovery period, the result is 
an overstatement of net incomes and an under- 
statement of true costs. It often is argued that, 
since the business typically has a set of different 
types of assets acquired at different times, these 
under- and over-statements "wash". That is, 
they tend to balance out and approximate the 
real value for the entire set of assets. 

There also are imphcations for the net worth 
statement for the business. Assets may be 
valued according to market value or cost value. 
Using cost valuation one would use the "book 
value" or depreciated value for the asset. Very 
often the market value of the asset is greater 
than the book value, especially when acceler- 
ated depreciation methods have been used. As 
a result, net worth may be understated and the 
solvency position of the business will be lower 
than is actually the case. This, in turn, may 
have a negative impact on the ability of the 
owner to obtain needed credit for the business. 
For this reason, when seekingadditional credit, 
the potential borrower might find it more ad- 
vantageous to present the lender with a net 
worth statement with assets stated in market 
value terms. 



%2^ ^S^ ^10 %f# %% 

rj% rji ry» •^ ^J^ 



Fruit Notes, Summer, 1994 



Effects of Low Temperature, Ripening, 
and Light on Scald Susceptibility of 
Apples at Harvest 

Cynthia L. Harden* and William J. Bramlage 

Department of Plant and Soil Sciences, University of Massachusetts 

*Present address: Pennsylvania State University, 

Fruit Research Laboratory, Biglerville, PA. 



Many factors influence scald susceptibility 
of apples, including cultivar, orchard locality, 
weather, harvest maturity, and storage condi- 
tions. For example, Cortland and Delicious are 
very susceptible, Mcintosh is moderately sus- 
ceptible, and Empire and Gala seldom if ever 
develop scald. Also, it has long been recognized 
that fruit generally become less susceptible as 
they become more mature. Among weather 
conditions, preharvest temperature is espe- 
cially important, with cool temperatures before 
harvest reducing scald susceptibility. Another 
potentially significant factor is light, since scald 
is usually more prevalent on the green (shaded) 
portion of a fruit than on the red (sunlit) portion, 
and frmt from the interior of the tree usually are 
more susceptible than ones from the exterior. 

We have been attempting to predict scald 
susceptibility from preharvest temperature 
records, using hours below 50°F as our tempera- 
ture indicator. In attempting to apply such a 
predictor to orchard conditions, however, it is 
important to understand how much some of the 
other key factors contribute to changes in scald 
susceptibility, for if they are major contributors, 
they must also be included in a predictor system 
to avoid potential errors in predictions. 

Consequently, we conducted a three-year 
study (1988 through 1990) of the effects of 
preharvest hours below 50°F, fruit maturity, 
and light intensity on scald susceptibility of 
Cortland and Delicious apples grown at the 
University of Massachusetts Horticultural Re- 
search Center, Belchertown. 



Three experiments were conducted. In the 
first, both Cortland and Delicious were har- 
vested at three or four weekly intervals in each 
year, and stored at 32°F for 20 weeks, with scald 
being evaluated after an additional seven days 
at room temperature. Preharvest temperatures 
were recorded continuously in an enclosed shel- 
ter in the orchard, so hours below 50°F after 
August 1 could be counted at each harvest date. 
Fruit maturity at harvest was measured both by 
internal ethylene content of the fruit and by 
their average starch score, obtained by staining 
10 fruit per sample with an iodine-potassium 
iodide solution and comparing their stain inten- 
sity to standard charts, with one indicating 
complete staining (very immature) and nine 
indicating no staining (very mature). With each 
succeeding harvest date, fruit were more ma- 
ture, as shown by increasing starch index and 
increasing internal ethylene content (Table 1). 
In all but one instance, however, fruit from each 
succeeding harvest date also had experienced 
more hours below SO'F, so later harvest repre- 
sented a combination of both riper fruit and 
more preharvest exposure to cool temperatures. 

After 20 weeks at 32°F plus one week at room 
temperature, scald development was quite vari- 
able among samples (Table 1). In general, scald 
decreased with later harvest but there were 
exceptions; for example, scald did not decrease 
from the September 15 to the September 22 
harvests in 1989 on Cortland. Also, scald sus- 
ceptibility on corresponding dates in different 
years was not always comparable; for example. 



Fruit Notes, Summer, 1994 



Table 1. 


Changes 


in scald susceptibility of apples harvested at weekly 


intervals 


in three years. 
















Ethylene 






Harvest 


Hours below 


Starch 


concentration 


Scald 


Year 


date 


SOT 


index^ 


(log ppm) 


(%) 


Cortland 










1988 


Sept 13 


73 


1.2 


-1.13 


71 




Sept 22 


102 


2.0 


-1.00 


36 




Sept 29 


134 


4.0 


-0.65 


11 




Oct 6 


187 


5.0 


0.15 


4 


1989 


Sept 15 


62 


1.0 


-1.06 


99 




Sept 22 


62 


1.7 


-0.86 


99 




Oct 4 


152 


4.7 


0.08 


29 


1990 


Sept 17 


21 


1.3 


-0.97 


98 




Sept 24 


79 


1.5 


-1.19 


78 




Oct 3 


127 


4.3 


0.23 


46 




Oct 11 


150 


6.8 


2.08 


49 


Delicious 










1988 


Oct 1 


160 


1.3 


-1.57 


12 




Oct 8 


232 


1.6 


-2.52 


2 




Oct 13 


365 


1.9 


-1.16 


2 


1989 


Sept 29 


125 


1.4 


-0.71 


83 




Oct 5 


170 


2.6 


0.32 


72 


1990 


Sept 21 


62 


1.2 


-1.54 


94 




Sept 26 


104 


1.6 


-0.96 


88 




Oct 3 


127 


3.2 


-0.26 


69 




Oct 11 


150 


5.5 


1.18 


51 


^1 = very 


immature 


9 - very mature. 









Delicious harvested October 1, 1988 developed 
12% scald, while ones harvested on October 3, 
1990 developed 69% scald,even though the 1990 
fruit were somewhat more mature than those in 
1988. 

In a second experiment, Cortland apples 
were sprayed in August with ethephon to induce 
ripening before they had experienced substan- 
tial amounts of preharvest cool temperatures. 
In 1989, only 500 ppm ethephon was applied, 
but in 1990 both 250 and 500 ppm were used. 
Both concentrations caused fruit to ripen in 
early September. In 1989, some hours below 



50°F were recorded before the harvests, but in 
1990 none had occurred, so any effect of treat- 
ment on scald in 1990 should have been due 
entirely to more advanced maturity. In both 
years, ethephon treatment significantly re- 
duced scald after storage (Table 2); however, 
differences usually were small. In particular, in 
1990 when fruit ripened in the absence of any 
hours below 50°F, all samples developed scald 
on more than 90% of the fruit. Ethephon sprays 
have been reported to reduce scald on Granny 
Smith and Delicious in several parts of the 
world, but clearly under our conditions, ethep- 



Fruit Notes, Summer, 1994 



Table 2. 


Effects of ethephon on ripeness 


at harvest and 


on scald development on 


Cortland apples after storage. 


Ethephon was applied on 


August 16, 1989 and on 


August 20, 1990. 


















Ethylene 




Harvest 


Ethephon Hours below 


Starch 


concentration 


Scald 


date 


(ppm) 


5(yF 


index' 


(log ppm) 


(%) 


1989 












Sept 6 





52 


1.2 


-1.05 


87 




500 




7.4 


2.00 


81 


Sept 13 





62 


1.3 


-0.64 


96 




500 




8.4 


2.13 


67 


1990 












Septl 








1.0 


-2.35 


97 




250 




4.8 


1.86 


90 




500 




5.9 


2.08 


92 


Sept 6 








1.3 


-1.82 


99 




250 




7.3 


2.12 


91 




500 




6.9 


1.95 


96 


^1 = very 


immature; 9 = very mature. 









hon treatment was not effective on Cortland, as 
Windus and Shutak (J. Amer. Soc. Hort. Sci. 
102:715-718) also reported in 1977. 

The third experiment was designed to test 
the importance of light intensity on scald sus- 
ceptibility. In 1989 and 1990, Cortland apples 
were enclosed individually in brown kraft paper 
bags in mid-to-late August, and kept in these 
bags until they were harvested. Bags had al- 
most no effect on fruit temperature. Each year 
two harvests were made. Bagging did not affect 
fruit maturity significantly in either year (Table 
3); however, it resulted in fruit with greater 
scald susceptibility, and differences usually 
were quite large. Thus, under our conditions 
severe reduction of light intensity increased 
scald susceptibility, but it should be noted that 
even bagged fruit were becoming less scald sus- 
ceptible with later harvest, indicating that 
bright light is not required in order for the 
maturity and temperature factors to affect scald 



susceptibility. 

These results showed that under our condi- 
tions preharvest temperature was the most im- 
portant factor affecting scald susceptibility of 
Cortland and Delicious apples. In Figure 1, all 
three years of data were used to illustrate this 
effect. For Cortland, scald susceptibility began 
to decline when the fruit had experienced 
slightly less than 100 hours below 50°F between 
August 1 and harvest. By about 150 hours, 
susceptibility had fallen to the point where 40 to 
50% of fruit scalded, and as they approached 200 
hours, only about 10% scalded. Delicious re- 
quired about 25 more hours below 50°F to reach 
these same levels of susceptibility. 

The effects of temperature differences 
among different harvests and years can be seen 
in Table 1. For example, in 1989 no loss of scald 
susceptibility of Cortland occurred when har- 
vest was delayed from September 15 to 22, and 
it can be seen that temperatures were continu- 



8 



FruH Notes, Summer, 1994 



Table 3. Effects of bagging on ripeness at harvest and on 


scald 


development after storage of Cortland apples. Fruit were bagged August 21 | 


to 25, 1989 and August 13 to 14, 1990. 
















Ethylene 




Harvest 




Hours 


Starch 


concentration Scald | 


date 


Treatment 


below 50°F 


index' 


(log ppm) 


(%) 


1989 












Sept 18 


Control 


62 


1.3 


-1.18 


95 




Bagged 




1.6 


-1.27 


100 


Oct 2 


Control 


147 


5.1 


-0.21 


27 




Bagged 




4.4 


0.02 


90 


1990 












Octl 


Control 


107 


3.2 


-0.07 


31 




Bagged 




3.4 


0.24 


62 


Oct 9 


Control 


150 


6.4 


1.21 


13 




Bagged 




6.0 


1.41 


42 


Significance'' 










1989 


Bagging 




NS 


NS 


* 




Hours below 50°F 


*** 


NS 


** 


1990 


Bagging 




NS 


NS 


* 




Hours below 50°F 


*** 


** 


NS 




Bagging x 


Hours 


NS 


NS 


NS 


'1 = Very immature; 9 = 


very mature. 








"NS = not 


significant; * = 


= odds of 19:1;" = 


= odds of 99:1 


; *** = odds of 999:1. 



ally above 50°F between these dates. In Deli- 
cious, there was almost no scald in 1988 even 
though fruit were quite immature; this was a 
very cool year, and 160 hours below 50°F had 
been recorded by the first harvest date. Harvest 
of Dehcious on similar dates in 1989 and 1990 
resulted in much more scald development than 
in 1988, and in these years fewer hours below 
50°F had been recorded by the harvest dates 
than in 1988. 

Clearly, maturity and light also played roles 
in loss of scald susceptibility by the apples, since 
ethephon treatment reduced scald and bagging 
increased it. The results with ethephon (Table 
2) are interesting in that in 1989, when some 



hours below 50°F had been recorded before har- 
vest, ethephon reduced scald more than in 1990, 
when no hours had been recorded. This suggests 
that cool temperature increased the effect of 
ripening (or vice versa) in reducing scald suscep- 
tibility, that is, that temperature and ripening 
worked together in reducing scaldsusceptibility. 
Nevertheless, cool temperature clearly was the 
more important factor in this relationship. 

How important light is in this relationship 
cannot be measured by our results, since we 
used nearly complete light exclusion by bagging 
the fruit. Yet, it is likely that reducing scald 
susceptibility is one more reason for encourag- 
ing light penetration into the tree interior, for 



Fruit Notes, Summer, 1994 



100 






♦\ * \ A Delicious 






\^ \ A • Cortland 




80 


\ \ A 

\ *\ 




-7- 60 


\\ 




(0 
O 

CO 40 






20 


♦ A ^^ 


L 



( 


D 50 100 150 200 250 300 350 




Hours Below IOC 


Figure 1. Calculated changes in scald susceptibility (percent of fruit that 
develop scald after storage) with increasing hours below 50°F between August 
1 and fruit harvest date. 



example, by summer pruning. Shaded fruit 
probably require more cool temperature and 
ripening to become less scald susceptible than 
do exposed fruit. 

Our results show how rapidly scald suscep- 
tibility can change during the harvest period, 
and that cool temperature is the most important 
factor in this change. In Figure 1 you can see 
that if a couple of days occur when the tempera- 
ture is almost continually below 50°F, scald 
susceptibility can drop dramatically; this situa- 
tion commonly occurs in early October in Massa- 
chusetts. Conversely, if the temperature re- 
mains constantly above 50°F for a period of time, 
httle or no loss of scald susceptibility will occur, 



even though the fruit may ripen substantially. 
We are attempting to develop a practical, 
reliable predictive system so that growers can 
estimate at harvest how scald susceptible their 
fruit are, and determine their scald control 
method according to need. At Belchertown, just 
counting hours below 50°F at harvest has 
worked well. In other regions, however, it is not 
as effective, which raises questions about the 
relationships between temperature and scald in 
"unusual years" in Massachusetts. The results 
here show that maturity and light also can be 
important factors, and we hope to have a much 
clearer picture of scald predictions in the near 
future. 



%% •i^ %I# •i^ •S^ 

^^ r{% rj% rj% rf* 



10 



Fruh Notes, Summer, 1994 



Final Report on the 1984 NC-140 
Cooperative Apple Rootstock Planting 
in Massachusetts: Starkspur Supreme 
Delicious on Fifteen Rootstocks 



Wesley R. Autio 

Department of Plant & Soil Sciences, University of Massachusetts 

Dwarfing rootstocks clearly are part of the exceeded by returns, apple growers must take 
future of the apple industry in New England. At advantage of all opportunities to reduce costs or 
a time when production costs often are not increase returns. Dwarfing rootstocks may al- 



Height and spread (ft) 
4 6 8 10 12 



14 



P.I 8 

A. 313 

Seedling 



W\W.VWVVVV\VVVVVVWVWVW\.'wV\.V\S.VWVVW\W v~^~^ 



MAC.1 ^^^^^^^^^^^^^^^^^^^^^ 



B.490 

M.4 

M.7 EMLA 

P.I 

M.26 EMLA 

C.6 

MAC.39 



.vwvvvvvvvvvvvvvvvvvvvvvvvvwvwvvvwvv 



5S 



BiBSfiBi 



^^ 



^^k^ki^MMMri^y^il^^uMffi^^^ 



WWWN 



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SfififiB 



i 



— ^^^^^^^^^^^^^ 



vvvvvvvv 



SS55S&5fiS^5SiS^fiSS5B^^^^^^^^ 



^SiSS&ifiK^ 



1 



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1 



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xxxxxxxx" 



^^^^^^^^^o 

^^^ 



^^^^^^^^^^ 



vvvvwwv 



^ 



X\\\\\\\\\\\\\\\\\\\N 



de 



S^^^^^^^ 






P.2 
P.I 6 



^^^^^^ 



^V\VVV.VV.VV.\V.VV\VN 



Dtca 

^Height 
H Spread 



P.22tHi^^^^^ 



5 10 15 20 

Trunk cross-sectional area (in^) 



16 



25 



Figure 1. Trunk cross-sectional area, height, and spread of Starkspur Supreme Delicious trees on 
various rootstocks after 10 growing seasons. Trunk cross-sectional area means are significantly 
different at odds of 19:1 if bars do not contain the same letter. 



Fruit Notes, Summer, 1994 



11 



M.4 
P.18 
A.313 
B.490 
M.7 EMLA| 
Seedling ^ 
MAC.1 § 
P.1 ^ 

eel 

M.26 EMLA 

MAC. 39 

B.9 

P.2 

P.1 6 

P.22 



ab 
ab 



be 



c 
c 

cd 

cd 



J^^^^^^^^M^^Mm^^ 


$$^$MJ^^m^^^$^^^ 


ef 


^^^^M^^mm^ 


fg 




:$^^$^$$M^M$$$^ 




MM^M^^ 9 





de 



10 



15 



20 



Cumulative yield per tree (bu) 



Figure 2. Cumulative yield (per tree, 1987-93) of Starkspur Supreme Delicious trees on various 
rootstocks. Means are significantly different at odds of 19:1 if bars are not followed by the same 
letter. 



low both. Qiiicker return on the investment of 
establishment, potentially higher yields, higher 
packout because of better light penetration into 
the canopy, less pesticide needed to treat each 
acre, and lower labor needs for harvesting and 
pruning all make dwarf trees a very desirable 
alternative when compared to semidwarf or 
standard trees. 

In the last issue of Fruit Notes, I gave the 
final report of a rootstock trial that began in 
1980 as part of a cooperative planting of the NC- 
140 Technical Research Committee. In this 
article, I will detail the final report of the Mas- 
sachusetts portion of the 1984 NC-140 Coopera- 
tive Apple Rootstock Plgmting. 



Materials & Methods 

Starkspur Supreme Delicious trees on B.9 
(Budagovsky 9), B.490, MAC.l (Michigan Agri- 
cultural College 1), MAC.39, P.1 (Polish 1), P.2, 
P.16, P.18, P.22, M.4 (Mailing 4), M.7 EMLA, 
M.26 EMLA, C.6, A.313 (Antonovka 313), and 
domestic seedling were planted at a spacing of 
12 X 18 feet at the University of Massachusetts 
Horticultural Research Center in the spring of 
1984. Trees were trained as central leaders 
using minimal pruning and limb spreading as 
needed. Containment pruning was required for 
many of the larger trees. Stakes were added for 
support only when trees leaned more than 45 



12 



Fruit Notes, Summer, 1994 



degrees. Standard pest and fertility manage- 
ment practices were used. 

Tree size and yield were measured annually; 
however, trees were not allowed to fruit until the 
fourth growing season (1987). In 1989, 1990, 
1992, and 1993, periodic harvests of four fruit 
per tree were made throughout the harvest 
season for the assessment of internal ethylene 
concentrations. Single harvests often fruit per 
tree were made on October 3, 1990, October 3, 
1991, October 5-6, 1992, and October 11, 1993 
for the assessment of soluble solids concentra- 
tion, starch loss, and watercore development. 

7y*ce Size and Productivity 

Figure 1 reports the average height, spread. 



and trunk circiunference of trees from this 
planting. Due to the need for containment 
priming of trees that exceeded the 12-foot spac- 
ing, height and spread do not present an accu- 
rate picture of trees on P. 18, A.313, seedling, 
MAC.1,B.490,M.4, M.7EMLA,orP.l. Trunk 
cross-sectional area likely is a more accurate 
measure of relative tree size. These trees broke 
into a few distinct size groupings. Standard- 
sized trees were produced by P. 18, A.313, seed- 
ling, MAC.l, and B.490. M.4 resulted in semi- 
standard trees. M.7 EMLA and P.l produced 
semi-dwarf trees. M.26 EMLA, C.6, and 
MAC.39 resulted in large dwarf trees, and P.22 
and P. 16 produced subdwarfs. B.9 and P.2 
produced trees intermediate in size to these last 
two categories. 









P.16H 


^^^^^^^^^^^^^^^^HI^^^I^^^Ih 3 




P.2B 


^^^^^^^^^^^^^^l^^^^^^^^^^^^l a 


B.gp 


^^^^^^^^^^^^HI^^^^^^^^^H 3 


ceH 


^^^^^^^^^^^^^H^BIH^^^^^I a 


M.26 emlaH 




â–  b 

â–  b 


P.22& 




P.1 ^^^^^â– ^^^^^â– H 


b 
b 


maU 


^^^H^^^^^^HH 


b 
) 

1 1 


MAC.39P 

A.313P 




p.isB 


^^^^^^^^^^^1 c 


B.490 â–  


^^^^^^^I^HIH c 


MAC.iP 


^^^^^^^H c 


Seedling U 


^^^^^M c 


0.0 0.5 1.0 1.5 2.0 
Cumulative yield efficiency (bu/in^ TCA) 

Figure 3. Cumulative yield efficiency (1987-93) of Starkspur Supreme Delicious trees on varic 
rootstocks. Means are significantly different at odds of 19:1 if bars are not followed by the sai 
letter. 


us 
Tie 



Fruit Notes, Summer, 1994 



13 



Yield per tree (Figure 2) roughly correlated 
with tree size, with the largest trees producing 
the most fruit and the smallest trees producing 
the least. It is more important, however, to 
compare potential yield relative to tree size, i.e. 
more smaller trees can be planted per acre, 
which may or may not result in more overall 
5deld. Yield efficiency is a somewhat accurate 
assessment of relative jdeld potential. It pre- 
sents 5deld per trimk cross-sectional area. Fig- 
ure 3 gives cumulative 3rield efficiencies for trees 
in this planting. The rootstocks break clearly 
into three groups. The most efficient trees were 
on P. 16, P.2, B.9, or C.6. The least efficient were 
on A.313, P. 18, B.490, MAC.l, or seedling. 
Trees on M.26 EMLA, P.22, M.7 EMLA, P.l, 
M.4, or MAC. 39 were intermediate in efficiency. 
A less accurate method for assessing potential 
3deld uses estimates of planting density based 
on tree spread (Table 1). In this planting, more 
containment pruning was used for the largest 
trees than for the smallest, so potential planting 



Table 1. Projected spacing and tree density of 
Starkspur Supreme Delicious on various 
rootstocks in the 1984 NC-140 Cooperative 
Planting in Massachusetts. 

Spacing 





Between 


Between 


of trees 


Rootstock 


trees 


rows 


per acre 


P. 18 


17 


24 


107 


A313 


17 


24 


107 


Seedling 


17 


24 


107 


MAC.l 


16 


23 


118 


B.490 


16 


23 


118 


M.4 


15 


22 


132 


M.7 EMLA 


14 


21 


148 


PI 


13 


20 


168 


M.26 EMLA 


9 


16 


303 


C.6 


8.5 


15.5 


331 


MAC.39 


8.5 


15.5 


331 


B.9 


7.5 


14.5 


401 


P.2 


6.3 


13.3 


520 


P. 16 


3.9 


10.9 


1025 


P.22 


2.8 


9.8 


1587 



densities were very rough estimates, particu- 
larly for the largest trees. Multiplying density 
by yield per tree gives potential 3deld per acre. 
Figure 4 plots )deld per acre by year from 1987 
through 1993. Figure 5 gives potential yield per 
acre on a cumulative basis over the seven fi*uit- 
ing years of these trees. The results were similar 
to those obtained when comparing yield efficien- 
cies among rootstocks. The highest yields per 
acre may be expected from trees on C.6, P.2, 
P.22, B.9, or M.26 EMLA. The lowest may be 
expected from trees on P. 18, A.313, B.490, 
MAC.l, or seedling. 

Fruit Ripening 

Knowledge of the effects on finiit ripening is 
a critical component of rootstock evaluation. 
The potential for advancement or delay in ripen- 
ing must be known so that harvest can be 
managed appropriately. If the delay or ad- 
vancement is predictable, it may be beneficial to 
use it to expand the harvest season. 

To assess the effects of rootstock on ripening, 
internal ethylene, soluble solids (sugars) con- 
centration, watercore development, and starch 
loss were measured in fruit fi"om this planting. 
Ethylene is a gaseous hormone present in all 
plants, but is very important to ripening in a 
number of fruits. Ethylene is a trigger of rip>en- 
ing and during the course of ripening, it in- 
creases many fold in apple fruit. It is possible to 
track ripening of apples by measuring ethylene 
concentration in the core cavity. Table 2 reports 
the date in 1989, 1990, 1992, and 1993 when the 
average internal ethylene concentration 
reached one ppm. Results were not entirely 
consistent from year to year, but a few 
rootstocks were consistently either in the lowest 
or highest category. Specifically, fi-uit from 
trees on B.9, MAC.39, M.7 EMLA, M.26 EMLA, 
or P. 16 consistently were among the first few to 
reach one ppm internal ethylene. Fruit from 
trees on seedling, M.4, B.490, P. 18, or A.313 
consistently were among the last to reach one 
ppm internal ethylene. 

Internal ethylene is one of the most accurate 
measures of the progress of ripening; however, it 



14 



FruH Notes, Summer, 1994 



Yield per acre (bu) 


1,200 






— B.9 








+ MAC.1 








^ MAC. 39 






1,000 


•DP.1 

^P.22 

-0- Seedling 

^M.4 


â–  




800 


9 M.7 EMLA 
Om.26 EMLA 


yf^^ 






^B.490 


^ x' Jf£S^^>-^\^^^s^ ' ' 






Ap.2 


•/ \. / •' yW^ji^ ^V^!^! 


c 


600 


BP.16 

â– Spis 




\ 






••■C.6 




^ 


400 

> 


•Xa.313 


i/ff ^ v^*^ y^^ ^'j^^ mTI / Jr ^\ x.^^v\ 


y 


^^___ 




200^ 


r^^^^^ 




0^ 


^^^^y^ -»"jr 








1987 1988 1989 1990 1991 1992 1993 


Figure 4. Yield (per acre) of Starkspur Supreme Delicious trees on various rootstocks from 1987 


through 1993. Estimates of appropriate spacings were used to calculate potential yield on a per-acre 


basis. 



is necessary to assess additionally other charac- 
teristics to get the most accurate picture of the 
difference in ripening. Soluble solids (or sugars) 
generally increase in concentration during the 
course of ripening as the result of the breakdown 
in starches. Table 3 give the soluble solids 
concentration of fruit from these trees in 1990, 
1991, 1992, and 1993. Fruit from trees on B.9, 
MAC.39, P.22, P.2, or P. 16 consistently were 
among those with the highest levels of soluble 
soUds. On the other hand, fruit from trees on 
MAC.l, seedhng, M.4, M.7 EMLA, B.490, P.18, 
or A.313 were consistently among the lowest. 

Starch breakdown is measured easily by 
staining cut apples with an iodine-potassium 
iodide solution. Iodine stains the starch blue. 



leaving a distinctive pattern. This pattern 
changes during ripening in a regular way and 
can be compared to a standard chart to assess 
the progress of ripening. The index used in this 
study ranged from one to nine, with one staining 
densely and nine not staining at all. The index, 
therefore, increases during the course of ripen- 
ing. Table 4 reports starch index values from 
this study for 1990, 1991, 1992, and 1993. Fruit 
from trees on B.9, P.22, P.2, or P. 16 consistently 
were among the highest for starch index; 
whereas, fruit from trees on seedling, MAC.l, 
M.4, A.313, or P.18 consistently were among the 
lowest. 

As starch breaks down to sugar, osmotic 
imbalances may occur in the flesh of apples 



Fril/t Holts, Summer, 1994 



15 









c.6 

P.2 

P.22 

B.9 

M.26 EMLA 

MAC. 39 

M.4 

P.16 

P.I 

M.7 EMLA 

P.18 

A.313 

B.490 

MAC.1 

Seedling 


a 




ab 


abc 


a be 


abed 


bede 


bede 


bede 


bede 


ede 


de 


de 


e 


e 


e , 


12 3 4 
Cumulative yield per acre (xlOOO bu) 

Figure 5. Cumulative yield (per acre, 1987-93) of Starkspur Supreme Delicious trees on various 
rootstocks. Estimates of appropriate spacing were used to calculate potential yield on a per-acre 
basis. Means are significantly different at odds of 19:1 if bars are not followed by the same letter. 



which result in the development of watersoaked 
areas. This disorder is referred to as watercore. 
Watercore generally becomes more severe as 
ripening progresses. Table 5 reports watercore 
index values from this study for 1990, 1991, 
1992, and 1993. The index used ranges from one 
to seven, with one representing no watercore 
and seven representing severe watercore. Fruit 
from trees on B.9, MAC.39, P.22, P.2, or P.16 
consistently were among the ones with the most 
watercore when there were differences. Fruit 
from trees on seedling, M.4, B.490, or P.18 were 
consistently among the lowest. 

Taking all of these characteristics into con- 
sideration, it appears that B.9 and P.16 consis- 



tently advanced ripening. MAC.39, P.2, and 
P.22 were less consistent but also may have 
resulted in an advancement of ripening. Seed- 
ling, M.4, and P. 18 delayed ripening. B.490 and 
A.313 were less consistent but also may have 
delayed ripening. MAC.1, P.l, M.7 EMLA, M.26 
EMLA, and C.6 were either intermediate in 
their effects on ripening or were inconsistent. 

It is important for the grower to note the 
potential effects that rootstocks can have on 
apple ripening. In this planting, however, those 
effects were variable and unpredictable, pre- 
venting them from being exploited to expand the 
harvest season. Hopefully, other rootstocks will 
be found that have more predictable effects. 



16 



FruH Notes, Summer, 1994 



Table 2. Date when the average internal ethylene concentration of Starkspur 
Supreme Delicious fruit reached one ppm. Fniit were from trees on various 
rootstocks in the 1984 NC-140 Cooperative Planting in Massachusetts. Means 
were adjusted for the effects of crop load.' 



Rootstock 



1989 



1990 



1992 



1993 



P. 16 

M.26 EMLA 

B.9 

M.7 EMLA 

C.6 

P.l 

P. 18 

P.2 

P.22 

MAC.39 

B.490 

Seedling 

MAC.l 

M.4 

A.313 



— 




— 




10/9 


cd 


10/4 


ef 


9/23 


d 


10/7 


e 


10/9 


d 


10/5 


ef 


9/24 


cd 


10/6 


e 


10/11 


abed 


10/5 


ef 


9/24 


cd 


10/5 


e 


10/9 


cd 


10/7 


ede 


9/27 


be 


10/6 


e 


10/9 


ed 


10/9 


be 


9/25 


bed 


10/6 


c 


10/11 


abed 


10/9 


bed 


9/27 


bed 


10/6 


c 


10/11 


abed 


10/9 


bed 


— 




10/13 


b 


10/10 


abed 


10/6 


def 


— 




10/21 


a 


10/10 


bed 


10/3 


f 


9/26 


bed 


10/6 


c 


10/11 


abed 


10/7 


cde 


9/26 


bed 


10/6 


e 


10/13 


a 


10/9 


bed 


— 




— 




10/13 


ab 


10/8 


bed 


9/28 


ab 


10/6 


e 


10/12 


abe 


10/7 


cde 


10/1 


a 


10/6 


e 


10/12 


abed 


10/10 


ab 


— 




— 




10/13 


ab 


10/13 


a 



'â–  Means within a column not followed by the same letter are significantly 
different at odds of 19:1. 



Table 3. Soluble solids concentration (%) of Starksp 


ur Supreme Delicious fruit 


from trees on various rootstocks in 


the 1984 NC-140 Coo 


perative Planti 


ng in 


Massachusetts. 


Means were adjusted for the effects of crop load.' 






Rootstock 


1990 


1991 


1992 


1993 


P.22 


10.7 


ab 


13.7 


ab 


10.8 


a 


12.7 


a 


MAC.39 


10.3 


abe 


13.3 


abe 


10.3 


b 


12.4 


abe 


B.9 


10.8 


a 


13.2 


be 


9.8 


bed 


12.4 


ab 


P.2 


10.5 


abe 


13.8 


a 


10.0 


bed 


11.9 


bed 


M.26 EMLA 


10.6 


ab 


13.1 


e 


10.0 


bed 


12.1 


be 


P. 16 


— 




13.3 


abe 


10.2 


be 


12.2 


be 


C.6 


10.6 


ab 


12.8 


cd 


10.0 


bed 


11.5 


d 


P.l 


10.5 


abe 


12.6 


de 


10.0 


bed 


11.8 


cd 


MAC.l 


9.9 


d 


11.8 


gh 


9.7 


cd 


12.2 


abe 


M.4 


10.0 


cd 


12.3 


ef 


9.6 


cd 


12.0 


bed 


M.7 EMLA 


10.2 


bed 


12.0 


% 


10.0 


bed 


11.8 


cd 


B.490 


9.8 


d 


— 




9.5 


d 


11.9 


bed 


Seedling 


— 




— 




9.5 


d 


11.8 


cd 


A.313 


— 




— 




9.5 


d 


12.0 


bed 


P. 18 


9.8 


d 


11.4 


h 


9.7 


cd 


11.9 


bed 


'â–  Means within a 


I column not followed by the same letter are significantly different | 


at odds of 19:1 



















Fru'n Notes, Summer, 1994 



17 



Table 4. Starch index values of Starkspur Supreme Delicious fruit from trees on 
various rootstocks in the 1984 NC-140 Cooperative Planting in Massachusetts. 
The starch index used ranged from one to nine, with fruit rated as one having 
almost complete starch staining and those rated as nine having no starch 
staining. Means were adjusted for the effects of crop load.' 



Rootstock 



1990 



1991 



1992 



1993 



P.22 

P. 16 

P.2 

B.9 

M.26 EMLA 

P.l 

MAC.39 

C.6 

M.7 EMLA 

B.490 

MAC.l 

A.313 

P. 18 

Seedling 

M.4 



4.5 


a 


4.1 


a 


3.7 


ab 


5.2 


a 


— 




4.1 


a 


3.8 


a 


4.4 


be 


3.9 


b 


3.9 


a 


3.2 


abed 


4.6 


b 


3.9 


b 


3.5 


abc 


3.5 


abc 


4.0 


bed 


3.4 


be 


3.7 


ab 


3.3 


abed 


4.4 


be 


3.4 


be 


3.0 


ed 


3.2 


abed 


4.6 


b 


3.7 


be 


3.5 


abc 


3.1 


bede 


4.2 


bed 


3.3 


be 


3.2 


bed 


3.1 


bcde 


4.3 


bed 


3.6 


be 


3.2 


bed 


2.8 


de 


4.2 


bed 


3.4 


be 


— 




2.9 


cde 


4.3 


bed 


3.4 


be 


3.1 


ed 


2.8 


de 


4.1 


bed 


.. 




— 




2.7 


de 


4.3 


bed 


3.5 


be 


2.9 


d 


2.5 


e 


4.0 


bed 


— 




— 




2.8 


de 


3.8 


ed 


3.2 


c 


2.8 


d 


2.5 


e 


3.7 


d 



Means within a column not followed by the same letter are significantly different 
at odds of 19:1. 



Table 5. Watercore index values of Starkspur Supreme Delicious fruit from trees 
on various rootstocks in the 1984 NC-140 Cooperative Planting in Massachusetts. 
The watercore index used ranged from one to seven, with fruit rated as one having 
no watercore and those rated as seven having severe watercore. Means were 
adjusted for the effects of crop load.' 



Rootstock 



1990 



1991 



1992 



1993 



P. 16 

MAC.39 

B.9 

P.2 

P.22 

P.l 

M.26 EMLA 

M.7 EMLA 

MAC.l 

A313 

C.6 

B.490 

P. 18 

Seedling 

M.4 



1.1 


a 


1.1 


a 


1.2 


a 


1.0 


a 


1.1 


a 


1.1 


a 


1.1 


a 


1.0 


a 


1.1 


a 


1.0 


a 


1.0 


a 



1.0 a 



2.5 


ab 


1.1 


a 


2.4 


abc 


1.4 


a 


2.3 


abc 


1.1 


a 


2.3 


abc 


1.2 


a 


2.3 


abc 


1.1 


a 


2.5 


a 


1.2 


a 


2.0 


bed 


1.3 


a 


2.1 


abed 


1.2 


a 


1.9 


ed 


1.2 


a 


— 






a 


2.3 


abc 




a 


— 






a 


1.8 


d 




a 


— 






a 


2.1 


abed 




a 



4.3 


a 


3.2 


be 


3.5 


b 


2.9 


ed 


3.0 


c 


1.8 


fg 


2.8 


ed 


2.4 


de 


2.3 


e 


2.2 


ef 


1.7 


gh 


1.9 


efg 


1.9 


efg 


1.6 


gh 


1.3 


h 



Means within a column not followed by the same letter are significantly different 
at odds of 19:1. 



18 



Fruit Notes, Summer, 1994 



Table 6. Fruit size, presented as 


the number of fruit per 42-lb box, for Starkspur Supreme Delicious 


trees on various 


rootstocks in the 1984 NC-140 Cooperative 


Planting in 


Massachusetts. 


Fruit size 


was adjusted to account for differences in crop 


load 


z 












Rootstock 


1988 


1989 


1990 


199] 




1992 


1993 


C.6 


80 


a 


77 


ab 


76 


a 


108 


a 


75 


a 


90 ab 


MAC.39 


82 


ab 


73 


a 


78 


a 


113 


a 


77 


ab 


86 a 


P.2 


86 


abc 


81 


abed 


76 


a 


109 


a 


78 


abc 


88 ab 


B.9 


88 


abed 


82 


abed 


78 


a 


109 


a 


81 


abed 


88 ab 


M.26 EMLA 


86 


abc 


83 


abed 


82 


abc 


107 


a 


82 


abed 


88 ab 


M.7 EMLA 


93 


bcde 


81 


abed 


87 


abed 


102 


a 


81 


abed 


91 ab 


P. 16 


96 


cde 


83 


abed 


82 


abc 


103 


a 


86 


bcde 


91 ab 


P.l 


88 


abed 


82 


abed 


86 


abed 


106 


a 


86 


bcde 


102 be 


P. 22 


92 


bcde 


79 


abc 


81 


ab 


100 


a 


97 


e 


114 c 


M.4 


102 


de 


93 


d 


85 


abed 


105 


a 


90 


de 


93 ab 


Seedling 


106 


e 


91 


d 


78 


a 


108 


a 


95 


e 


96 ab 


P. 18 


93 


bcde 


82 


abed 


108 


e 


99 


a 


92 


de 


91 ab 


B.490 


95 


cde 


87 


bed 


93 


cd 


102 


a 


88 


cde 


88 ab 


MAC.l 


103 


e 


90 


cd 


90 


bed 


107 


a 


96 


e 


90 ab 


A.313 


96 


cde 


87 


bed 


95 


de 


102 


a 


92 


de 


91 ab 


' Means within a column not followed by the same letter are signifi 


cantly different at odds of 19:1. 



Fruit Size 

Fruit size is a very important determinant of 
financial return for the apple grower. In this 
study, fi-uit size was assessed annually from 
1988 through 1993 (Table 6). Effects of root- 
stock on fruit size varied somewhat from year to 
year, but some rootstocks were more consistent 
in their effects than others. Fruit from trees on 
C.6, MAC.39, P.2, B.9, or M.26 EMLA always 
were among the largest; whereas, frmt from 
trees on A.313 or P. 18 were among the smallest. 
The potential effects that a rootstock can have 
on finiit size should be factored into the rootstock 
selection process. 

The Winners 

Standard sized trees are no longer economi- 
cally viable alternatives for orchard planting. 
Semidwarf trees are quickly losing their eco- 
nomic viability, because of labor requirements 



for harvest and management, fruit quality, and 
return on investment. As mentioned in the 
introduction, growers must move to dwarf trees 
to enhance the viability of their businesses. In 
this planting, trees on the various rootstocks 
ranged from standard sized to subdwarf The 
rootstocks that have the most potential based on 
their effects on tree size are M.26 EMLA, C.6, 
MAC.39, B.9, P.2, P. 16, or P.22, from the largest 
to the smallest, respectively. All result in what 
would be considered dwarf trees. As a general 
category, the dwarf trees outperformed other 
trees in the planting. In terms of potential 
productivity (taking into account yield efficiency 
and the potential yield per acre), C.6, P.2, and 
B.9 performed the best in the planting . These 
three also resulted in fruit in the largest cat- 
egory each year when there were differences 
related to rootstock. Trial plantings of C.6, P.2, 
and B.9 should be established by growers to 
determine further their suitability for New En- 
gland conditions. 



%f« %f^ %£• 9A0 •S^ 
rj% r|% r|% 0^ 0^ 



Fru'n Notes, Summer, 1994 



19 



O' Say Can You See Mite Predators in 
Apple Orchards? 

Ronald J. Prokopy, Xingping Hu, and Jennifer Mason 
Department of Entomologyy University of Massachusetts 



Most apple growers recognize the impor- 
tance of spider mites as potential pests and 
predatory mites as potential beneficials in or- 
chards. We in fruit research and extension often 
advise growers to scout trees both for predatory 
mites and pest mites before deciding whether or 
not to apply a miticide. The ratio of predatory to 
pest mites frequently is used as one of the bases 
for a spray decision. If there are one or more 
predators to every five pest mites, then there is 
reason to believe that predators can provide 
effective control without pesticide treatment. 
Making such a determination through scouting 
sounds simple enough, but in fact, it is quite 
demanding. Sampling a representative set of 
leaves in the orchard is difficult, but even more 
difficult is seeing predatory mites emd distin- 
guishing them from pest mites or mites that are 
neither friend nor foe. 

Here, we report on a study conducted in 
1993 in which mite predator abundance on tree 
leaves assessed in the field by IPM scouts com- 
pared with mite predator abundance on tree 
leaves taken to the laboratory and examined 
under a microscope by a skilled mite taxono- 
mist. 

Materials & Methods 

We sampled leaves an average of 12 times 
(May to September) from a second-level IPM 
test block and an adjacent first-level IPM check 
block in each of 12 orchards, for a total of 298 
sample events. For each event, we picked 10 
leaves at random from each of 20 trees. All 10 
leaves from each tree were examined immedi- 
ately by one or another member of the six- 
member IPM scouting team using an Optivisor 
(3x power). Five of these leaves (chosen at ran- 
dom) were placed immediately in a cooler and 



returned the same day to a refrigerator at 40F 
in our laboratory, where soon afterward they 
were examined under a microscope ( 15x power). 
In all, 59,600 leaves were examined in the field 
and 29,800 in the laboratory. We did not count 
every predator seen. Rather, we recorded the 
percentage of leaves in each 100-leaf batch that 
had predatory mites. 

Results 

Of all sampled leaves, only 0.8% were ob- 
served to have phytoseiid mite predators (ivory- 
colored Amblyseuis fallacis or ivory colored 
Typhlodromus pyri) by IPM scouts in orchards 
compared with 3.5% under a laboratory micro- 
scope (Table 1). For stigmaeid mite predators 
(yellow-coloredZetee//ia mali), percentages were 
2.2 and 5.5, respectively. 

Among the 298 batches of sampled leaves, 
17.9% were classified by both IPM scouts and 
lab exam as having phytoseiids present, 9.8% 
were classified by lab exam but not by IPM 
scouts as having phytoseiids, and 4.8% were 
classified by IPM scouts but not by lab exam as 
having phytoseiids (Table 2). For stigmaeid 



Table 1. Percent of all sampled leaves 
observed as having mite predators by 
IPM scouts in orchards versus by exami- 
nation under a microscope in the labora- 
tory. 



Type of 
predator 



IPM 
scouts 



Laboratory 
microscope 



Phytoseiid 
Stigmaeid 



0.8 
2.2 



3.5 
5.5 



20 



Fru'n Notes, Summer, 1994 



Table 2. Percent of the 298 sampled leaf batches for which IPM scouting and 
laboratory microscopic examination did and did not agree on presence or absence 
of mite predators in the batch. 


Type of 
predator 


IPM absent, 
lab absent 


IPM present, 
lab present 


IPM absent, 
lab present 


IPM present, 
lab absent 


Phytoseiid 
Stigmaeid 


67.5 
63.5 


17.9 
19.8 


9.8 
9.5 


4.8 
7.2 


1 



mite predators, corresponding percentages were 
19.8, 9.5, and 7.2. Remaining batches were 
classified by both IPM scouts and lab exam as 
having no predators. 

Conclusions 

Our findings indicate that the presence of 
predatory mites was detected more often under 
a microscope than by IPM scouts, particularly in 
the case of phytoseiids. In fact, among ail leaves 
examined, phytoseiids were detected more than 
four times as often and stigmaeids more than 
twice as often under a microscope than by IPM 
scouts. 

At least three factors may have contributed 
to this pattern of results. First, the greater 
magnifying power of a microscope may have 
facilitated detection of small, newly-hatched 
predators that are difficult to detect using an 
Optivisor or hand lens. Second, at least six IPM 
scouts were involved over the growing season in 
examining leaves for mites in orchards, and 
there may have been substantial variation 
among these scouts' ability to detect and iden- 
tify predators. In contrast, the same person 
performed all of the examinations under the 
microscope. Third, there may have been some 
redistribution of predators among leaves during 
transport to the laboratory, possibly resulting in 



the spread of predators to a greater prop>ortion of 
leaves. We believe, however, that this factor 
was minor compared with the first two factors. 

Regrettably, our findings suggest that a 
grower (who might be less skilled than an IPM 
scout in identif5ring mite predators) cannot rely 
on his or her counting of mite predators using a 
hand lens or Optivisor as providing an accurate 
assessment of the level of predators actually 
present. New York state IPM personnel have 
recognized this shortcoming and have created a 
tripartite sampling procedure for pest mites 
that excludes the need to sample for and identify 
mite predators. A slightly modified version of 
this procedure for use by Massachusetts grow- 
ers is described in detail in the 1994 March 
Message to Massachusetts Fruit Growers. 

In sum, we will continue to sample for mite 
predators in our monitored test and check IPM 
blocks but recommend that growers use caution 
in interpreting their mite predator monitoring 
results. Predators could be more abundant than 
meets the eye. 

Acknowledgments 

This work was supported by grants from the 
Massachusetts Society for Promoting Agricul- 
ture and the USDA Northeast Regional IPM 
Competitive Grants Program. 



%% %% ftl^ %% •^ 

0^ r{^ 9^ rj^ r|% 



Fruit Notes, Summer, 1994 



21 



Apple Orchards in Switzerland: 
Differences Small and Large 

Donald C. Weber 

Institute of Plant Sciences I Applied Entomology, 

Swiss Federal Institute of Technology, CH-8092 Zurich Switzerland 



Since the beginning of 1993, when I left the 
University of Massachusetts, I have worked as 
a tree fruit research entomologist for the Swiss 
Federal Institute of Technology in Zurich. Since 
I also had experience with orchards in north- 
eastern U.S.A., I have found the differences in 
orchards and pest management between the 
U.S.A. and Europe to be quite fascinating. Eu- 
ropean agriculture offers some features which I 
feel could improve American pest management, 
and certainly some other features which should 
not be emulated! Most of my comments pertain 
in particular to Switzerland, but are more or less 
apphcable to neighboring countries as well. 

Small-scale and Intensive 

One of the most striking features of orchards 
in Switzerland is their small size, both in stature 
and in area. For the fresh market, dwarf 
roots tocks are the rule, and very high-density 
plantings (arovmd 1000 trees per acre) are trel- 
lised and on rootstocks such as M.9 and M.26. 
Fresh-market cultivars differ from those in the 
U.S.A. In Switzerland, Golden Delicious is the 
single most abundant cultivar, accounting for 
about 25% of the acreage; other important culti- 
vars are Idared, Maigold, Jonagold, Boskoop, 
Glocken, Gloster, Gravenstein, and Jonathan. 
Gala is being planted widely, but Cox Orange 
Pippin is not so common, although it is a leading 
cultivar in Holland and Great Britain. In Swit- 
zerland, the orchard acreages for any one 
farmer generally are small, family-owned, and 
often part of mixed farming including especially 
dairy cattle, sheep, and field crops. Government 
policy encourages diversified, intensive small 
farms which include animal husbandry. 



Big Money, Big Trees 

That is it for the small things. Two features, 
though, loom large: subsidies in the form of 
direct government payments, and the presence 
of large numbers of more-or-less unmanaged, 
high-stemmed (standard) apples and pears in 
the landscape. The Swiss people consider both 
their agriculture and their "Kulturlandschaft," 
or culturally -influenced landscape, to be a part 
of the national heritage. Agriculture is subsi- 
dized strongly. Because of changes in Swiss law 
made last year, payments to growers are based 
now on acreage and desirable management 
practices (including crop rotation and inte- 
grated production), rather than quantity of har- 
vest marketed. This is allowed by the so-called 
"Green Box" of GATT, under which member 
countries can encourage environmentally- 
sound practices through financial incentives. 
The Swiss economy is also highly regulated, 
aiding marketing associations in the formation 
of cartels that then fix quite high prices for 
agricultural and other goods. This combination 
of subsidies and quasi -monopoly marketing re- 
sults in food prices that are among the highest in 
the world. This may not be something to wish on 
the consumer, perhaps, but farming is more 
profitable! 

Now for the other large thing. Large pear 
and apple trees abound in this landscape, and 
are considered not only scenic but ecologically 
valuable. Most are minimally managed, and the 
apples and pears are harvested for cider. The 
pears thrive, thanks to the (until now)absence of 
fire blight. But the problem for pest manage- 
ment of fresh-market apples and pears is that 
these high-stemmed trees are great refuges for 



22 



Fru'n Notes, Summer, 1994 



Obstbaume , 

vom Fachmann 

Fur die Pflanzsaison 1993/94 smd noch 
folgende Obslsonen erhalilich: 

M26 IVI27' 
M27 • 



Gravensteiner Rellstab 


M9 


Summerred 


M9 


Discovery 


M9 


Prime Rouge 


M9 


Cox Orange T-1 2 


M9 


CoxT-21, Korallo 


M9 


Spartan 


M9 


Kidd s Orange 


M9 


Empire 


M9 


Fiesta â–  


M9 


Rubinetle ' 


MS 


Royal Gala * 


M9 


Gala Emia 


M9 


Elslar • 


M9 


Arlet 


M9 


Sir Price V schoriresistent 


M9 


Flonna ". schorlresistent 


M9 


Libeny. schorlresisteni 


M9 


Boskoop Schmta-HiJbsch 


M9 


Jonagold 


Mg 


Jonagold Rubinslar ' 


M9 


Jonagold Wiimuta " 


M9 


Jonagored " 


M9 


Jonica • 


M9 


Glockenaplel 


M9 


Golden Klon B 


M9 


Golden, Smoolhee 


1VI9 


Golden Reinders * 


M9 


Caiagolden ' 


IVI9 


Gloster 69 


IVI9 


Idared 


M9 


Maigold 


M9 


Meran ' 


IVI9 


Granny Smith 


M9 



M25 

M26 
M25 
K/127- 

M27 â–  

M26 

M26 



M26 
M26 

M26 
M26 
ti(l26 
M27 
M27 
M27 
M26 

M26 

M26 
M26 
M26 
M26 
M26 
M27 



M27 



M27 



M27 •, 



M27 



Sortenschut2 




Zudem fuhren wir noch 
mehrere Aplelsorten sowie 
ein grosses Angebot an 
Tafelbirnen-, Zwetschgen- 
und KIrschbaumen sowie ein 
grosses Sortlment an Apfel-, 
Moslbirnen-. Zwetschgen- 
und Kirschhochstammen. 

Erich Dickenmann AG 
Dipl. Obstbautechnlker HTL 
8566 Ellighausen TG 
TbI.072 68 16 29 
Fax 072 6810 29 



Typical offerings from a Swiss nursery. 
Note abundance of cultivars on M.9 and 
M.27. 



pests, particularly codling moths, and diseases. 
Not only is one not allowed to just cut them 
down, but the federal government rewards 
farmers for planting more! So the proposal of 
Ron Prokopy to eliminate untreated apples 
within 100 yards of commercial orchards, to 
reduce greatly codling moth colonization, would 
be viewed as heresy in Switzerland. 

Pest and Pesticide Differences 

The pest complex of European apple or- 
chards varies from country to coLintry, but in 
general the major insect pests are tortricids 
(codling moth and others), and aphids, particu- 
larly Dysaphis species, relatives of the rosy 
apple aphid. Relatively selective treatments are 
available to suppress these key pests, resulting 
in an enormous decrease in mite problems. 
These selective treatments include IGRs (insect 
growth regulators), primarily diflubenzuron 
(Dimilin''"'*), fenoxycarb (Insegar''""), and 
teflubenzuron (Nomolt'"'") for tortricids. All tor- 
tricid species are not equally susceptible. Spe- 
cies-specific viral preparations are available for 
codling moth and summer fruit tortrix 
(Adoxyphes orana). These require three to four 
applications against each generation of codhng 
moth, and superficial injury may occur never- 
theless because of delayed mortality of the 
young larvae. 

Pirimicarb (Pirimor"^") is a selective 
aphidicide (with some action against other 
piercing-sucking insects) registered worldwide 
for about 20 years, except in the U.S.A. It is 
extremely valuable not only in apples but in 
crops such as cole crops where aphids can be 
controlled without upsetting biological control 
of other pests. The availabihty of selective 
insecticides has reduced some pest problems, 
but it has increased others. Broad-spectrum 
insecticides against codhng moths previously 
also suppressed other tortricids. Non-selective 
treatments directed against aphids oflen re- 
duced populations of apple sawfly (the satoe one 
found in North America) and other early-s-eason 
pests to below economically-damaging levels. 
Now, more research is necessary to address 
these previously unimportant pest problems. 



FruH Notes, Summer, 1994 



23 



MIGROSSAIMO 

m 

1/a 



Aus 

nafurqerechtem 

Anbau 




Full-page advertisement by Migros Supermarket (largest Swiss grocery chain) in the Tages 
Anzeiger, the largest daily newspaper in Switzerland. Text reads: Apple growing for the 
Migros-Sano program is regularly brought under close scrutiny. This assures an early 
knowledge of pests. And gives us the opportunity, to eliminate the problem with mild 
treatments and lower doses. For the benefit of nature and the environment! You can 
recognize apples from Migros-Sano-Production by this [orange and green] symbol: ["Aus 
naturgerechtem Anbau" = from agriculture which is fair to nature]. 



Luckily for European growers, apple maggot 
and plum curculio are not (yet) present, and 
therefore both are quarantine pests. 

IPM: Moving Forward 

A major difference in Europeem apple IPM 
(known as IP or Integrated Production, encom- 
passing more than just pest management) from 
that in the USA is that since at least three 
decades ago, the orchard working group of the 



International Organization of Biological Con- 
trol (lOBC, Western European section) has 
taken a lead role in development and implemen- 
tation of provisional treatment thresholds for 
the region, which now are fairly consistent 
among different countries. These thresholds 
first allowed reduction in use of broad-spectrum 
insecticides, which now have been replaced 
largely with more selective materials, resulting 
in a double benefit to predators and parasites, 
especially phytoseiid predatory mites. The 



24 



Fruit Notes, Summer, 1994 



lOBC recently has proposed a comprehensive 
set of IP guidelines for grower certification, 
which will work through supervised participa- 
tion of grower groups at national and provincial 
levels. These would include fertilization, soil 
management, restrictions on size of monocul- 
tures, and other guidelines, in addition to regu- 
lation of pest management practices. The spe- 
cifics for individual crops, however, Eire still in 



process. 

Another major difference relates to the 
awareness of IPM on the part of the consumer. 
Supermarkets and strongly-coordinated grower 
associations have promoted IPM awareness. I 
will address this story, and more about specific 
pest-management innovations, in future ar- 
ticles. 



•Am mlm •Im •9^ %£• 
•^ r{% r{% 0^ r{% 



Fruit Notes, Summer, 1994 



25 




Fruit Notes 

University of Massachusetts 

Department of Plant & Soil Sciences 

205 Bowditch Hall 

Amherst, MA 01003 



Nonprofit Organization 
U.S. Postage Paid 

Permit No. 2 
Amherst, MA 01002 



SERIAL SECTION 

UNIV. OF MASSACHUSETTS LIBRARY 

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Account No. 3-20685 



Fruit Notes 

Prepared by the Department of Plant & Soil Sciences. 

University of Massachusetts Cooperative Ebctension System. '^ 

United States Department of Agriculture, and Massachusetts Counties Coopei^fttr^^^^' 

Editors: Wesley R. Autio and William J. Bramlage 



ISSN0427-6906 







Volume 59, Number 4 
FALL ISSUE, 1994 

Table of Contents 

Lighting Systems for Fruit Sorting 

A Test of a Potential Non-chemical Approach 
to Scald Control on Apples 

Influence of Understory Growth and Quantity of Drops 
on the Establishment of Voles in Apple Orchards 

Is Diphenylamine a Natural Compound in Apples and Pears? 

Do Bloom Applications of Fungicides Affect Fruit Set? 

Can Synthetic Scent of Predators Repel Deer in Orchards? 



J 



Fruit Notes 



Publication Information: 

Fruit Notes (ISSN 0427-6906) is published the first day of 
January, April, July, and October by the Department of Plant 
& Soil Sciences, University of Massachusetts. 



The costs of subscriptions to Fruit Notes are $8.00 for United 
States addresses and $10.00 for foreign addresses. Each one- 
year subscription begins January 1 and ends December 31. 
Some back issues are available for $2.00 (United States ad- 
dresses) and $2.50 (foreign addresses). Payments must be in 
United States currency and should be made to the University of 
Massachusetts. 



Correspondence should be sent to: 

Fruit Notes 

Dep£u-tment of Plant & Soil Sciences 

205 Bowditch Hall 

University of Massachusetts 

Amherst, MA 01003 



COOPERATIVE EXTENSION SYSTEM POLICY: 

All chemical uses suggested in this publication are contingent upon continued registration. These 
chemicals should be used in accordance with federal and state laws and regulations. Growers are 
urged to be famiUar with all current state regulations. Where trade names are used for 
identification, no company endorsement or product discrimination is intended. The University of 
Massachusetts makes no warranty or guarantee of any kind, expressed or implied, concerning the 
use of these products. USER ASSUMES ALL RISKS FOR PERSONAL INJURY OR PROPERTY 
DAMAGE. 



I 



Issued by the University of Massachusetts Cooperative Extension System, Robert G. Helgesen, 
Director, in furtherance of the acts of May 8 and June 30, 1914. The University of Massachusetts 
Cooperative Extension System offers equal opportunity in programs and employment. 



Lighting Systems for Fruit Sorting 

Daniel Guyer, Roger Brool(, and Edwin Timm 

Agricultural Engineering Department, Michigan State University 

This article is modified from one that appeared in the Washington State University Tree Fruit 
Postharvest Journal, Vol. 5, No. 1, which was modified from Michigan State University -- Cooperative 
Extension Service Agricultural Information Series, AEIS 618, January, 1994. 



Fruits and vegetables are inspected prior to most 
processing or packing operations. While some sorting 
is accomplished with optical or electronic technology, 
much sorting is done by manual visual inspection. Each 
woricer must look at a few hundred items each minute 
and accurately discard those that are unacceptable. 
Good lighting conditions are required to perform this 
task. 

Sorting table lighting may not currently match the 
specific task for which it is intended. Specific guide- 
lines for lighting system design in fruit and vegetable 
sorting and packinglines in the U.S. do not exist. 
Manufacturers of packingline equipment have left 
lighting decisions up to the individual operation. 

Sorting table lighting must have both adequate 
intensity and color quality to enhance or reveal defects 
rather than to obscure or mask them. Improper lighting 
design promotes woilcer fatigue and eye strain, result- 
ing in poor sorting efficiency. Studies of several 
operations involving inspection of a range of commodi- 
ties have shown that many lighting systems are not 
adequate for the required task. These studies suggested 
that improved sorting results could be expected if 
relatively inexpensive changes in illumination sources, 
illumination intensities, and background colors were 
adopted in sorting areas. 

Principles of Lighting and Color 

Two common uses of lighting are (a) general area 
lighting, and (b) task lighting. General area lighting's 
purpose is to illuminate a room or building for general 
activity. This type of lighting is usually mounted in the 
ceiling or well above the floor area. Task lighting is 
much more specific and is concentrated in an area to 
enhance the ability to perform a task. Task lighting is 
the primary concern of this article which focuses on the 
task of manually sorting fruits and vegetables. 



Three major components interact in the process of 
visualizing a "color": 

1 . li ght energ y from a lamp or light fixture; 

2. color reflectance potential of a fruit, caUed 
spectral reflectance : and 

3. sensitivity of the eye to color, called receptor 
sensitivitv. 

For example, to "see" the color red there must exist a 
light source containing red color light, a surface which 
can reflect the red light and a receptor sensitive to 
reflected red light. 

Light Energy 

Light energy, or a source of light, is required to 
produce the actual visible color light which the eye can 
detect The natural light source is the sun which 
produces all visible colors in addition to energy outside 
the visible spectrum (ultraviolet, infrared, etc.). 
Colorsproduced by artificial light are influenced by 
tube coatings, such as phosphor in fluorescent tubes, 
gases, or other components contained in filament bulbs. 
Artificial light sources are rated by: 

1. Color temperature; black body temperature 
generation; 

2. CRI: Color Rendering Index; and 

3. CPI: Color Preference Index. 

These ratings are explained briefly in the footnotes of 
Table 1. 

Of the three major components in visualizing color, 
light energy is the one most easily controlled. The 
important factor relating to artificial light is the spectral 
irradiance curve for a given light source. A spectral 
irradiance curve is a measured representation of a given 
light source showing the amount of specific light en- 
ergy or color contained in the source over the spectrum 
of colors. Spectral irradiance curves are generally 
available from lamp manufacturers. The spectral irra- 



Fruh Notes, Fall, 1994 



Table 1. Artificial lighting characteristics and visual effects on common prod 


ice colors, 


1992." 












Light source 




Rel 


Color 






Rel 








Visual effect on specified color 






















(fluorescent tubes) 


Mfgr 


cost 


temp 


CRI 


CPI 


light 


Maroon 




Red 


Green 


Brown 


Blue 


Purple 


Yellow 


SP-30 


1 


1.8 


3000 


70 


80 


105 


E 




E 


B 


E 


D 


E 


E 


SPX-30 


I 


5.9 


3000 


82 


100 


105 


E 




E 


B 


E 


D 


E 


E 


Ultralume-30 


2 


3.7 


3000 


85 


100 


105 


E 




E 


B 


E 


D 


E 


E 


Warm White 


2 


1.3 


3000 


53 


37 


102 


E 




E 


D 


E 


D 


D 


E 


Warm White Deluxe 


2 


2.1 


3000 


79 


90 


68 


E 




E 


D 


E 


D 


E 


E 


Oplima-32 


3 


4.9 


3200 


82 


— 


81 


E 




E 


B 


E 


D 


E 


E 


Natural 


2 


3.1 


3400 


81 


93 


66 


E 




E 


E 


D 


E 


E 


W 


Cool White 


2 


1.0 


4100 


67 


58 


100 


D 




D 


E 


W 


E 


D 


W 


SPX-41 


1 


6.5 


4100 


82 


100 


103 


E 




E 


E 


W 


E 


E 


W 


Cool White Deluxe 


2 


3.2 


4200 


89 


94 


70 


E 




E 


D 


D 


E 


E 


D 


Colortonc-50 


1 


3.2 


5000 


90 


92 


70 


E 




E 


E 


W 


E 


E 


W 


Ultralume-50 


2 


4.1 


5000 


85 


100 


105 


E 




E 


E 


W 


E 


E 


W 


OpUma-50 


3 


5.2 


5000 


91 


— 


81 


E 




E 


E 


W 


E 


E 


W 


ViuLite Plus 


3 


5.7 


5500 


91 


— 


100 


E 




E 


E 


W 


W 


E 


D 


Daylight 


2 


1.7 


6500 


79 


72 


83 


D 




D 


E 


W 


E 


D 


W 


Colorlone-75 


1 


4.2 


7500 


95 


97 


64 


E 




E 


E 


w 


E 


E 


W 


'Manufacturer: 1 = General Electric; 2 = 


Phillips; 


3 = Dure Test. 




















Rel cost: Relative bulb cost ratio to Cool White. 
























Color temp: Lamp appearance 


in degrees Kelvin 
























CRl: Color Rendering 


Index = 


effect the 


light source has on appearance of colored objecL 


. 100 


= perfect 


appearance. 








CPI: Color Prefoence Index = 


how wel 


people 


recognize colors 


in that light, 100 = perfect recognition. 










Rel light; Relative initial lumen/watt output as a 


percentage 


of Cool White. 


















Visual effect of tube on specified colon 


B = brownish cast; D = 


larker; E = 


enhanced; 


W 


= whitish cast 


Cool White effects arc relative to midday 1 


diffuse outdoor light, other tubes are relative to Cool White. 























diance for a light source can be altered with various 
types of "filters" covering the lamp. These include 
undesirable coatings of dust and dirt. 

Spectral Reflectance 

Spectral reflectance of an object is basically the 
"color" of the object -- the ability of a fruit to reflect 
certain colors of light in the presence of natural light. In 
fruits, the chlorophyll, anthocyanin, or other natural 
pigments dictate the item's color. The apparent color of 
an item can be altered by changing the light source or by 
incomplete color receptor capability. Some defective 
and nondefective measurements for the same commod- 
ity vary in their reflectance over the entire spectrum 
while others either vary only in certain regions of the 
spectrum or they vary httle at all. 

Many defects that need to be detected on fruits and 
vegetables are of brown or grayish color. One might 
assume, therefore, that simply finding the light source 
with the most energy in the color regions making up the 



brown color would be ideal for all applications. The 
objective in selecting the best light source for a given 
task, however, is to light a commodity with a source that 
will accentuate the color difference between the sound 
tissue and the defects. For example, if we wish to find 
brown discoloration on red cherries, then we want to use 
an inspection light of a color that will accentuate brown 
against the normal red color of the cherry. The key is 
to fiTKi a color of inspection lighting that wiU make the 
defects show up the most, i.e., to make the commodity 
look its worst. 

Receptor Sensitivity 

The third component in perceiving a color is the 
receiving or sensing of the light. In this case, the human 
eye is the receptor. There is no adjustment to the human 
eye. The only variability is in the individual's sensitiv- 
ity to the color and quantity of the light. Sensitivity 
decreases with age and this should be a consideration 
during lighting design. 



Fruit Notes, Fall, 1994 



o 



0.20 



0.15- 



S 0.10-I 



t; 0.05H 

At 



o.oo 



Doric Sw««t Cherry 

r40SP30 ot 500 ft-c<»ndl«» 




9t 

o 



V 
CD 



c 
91 



^1 



"S 
o: 



Wavelength 

Figure la. Perceived color based on spectral irradiance, reflectance curves, and receptor 
sensitivity (Brown et al., 1993). 



1 .00- 



i 0.80H 

E 

^ 0.60H 
«> 
<J 

c 
g 

1 0.40H 



^ 



0.20- 



0.00 



F4.0SP3O 




3i 
o 







Wavelength 



Figure lb. Spectral irradiance curve of SP-30 lights. 



Fruit Notes, Fall, 1994 



Perceived Color 

Figure 1 demonstrates the combining of all compo- 
nents (spectral irradiance, reflectance curves, and re- 
ceptor sensitivity) which affect color perception. The 
perceived color is termed the "total spectral energy 
distribution" and is the product of the spectral irradi- 
ance X spectralreflectance x human eye sensitivity or 
response. The goal of the lighting design is to have 
"peaks" in the distribution at the wavelengths or colors 
of the commoditv and at the defect color, thus resulting 
in a good perceivable contrast . Figure la shows the 
peaks in the perceived color of a dark red cherry, and 
Figure lb shows that these same peaks are strong in 
light from an SP-30 light, so a good match exists. 

Performances of Commercially 
Available Light Sources 

Theoretically the product of the spectral irradiance, 
spectral reflectance, and eye sensitivity should provide 
the information to design a proper lighting scheme. 
USDA-ARS researchers at Michigan State University 
evaluated several commercially available light sources. 
They measured individual spectral irradiance, using 
color chips to subjectively analyze and compare perfor- 
mance in color perception tests. Table 1 siunmarizes 
their findings and provides technical and relative cost 
information. Results indicated that the "image" curves 
resulting from the combination of spectral reflectance x 
spectral power x eye sensitivity generally agreed with 
the subjective/visual results for the test with the color 
chips and real produce items. 

The ability to recognize differences between good 
and defective areas on produce was lowest under Cool 
White (CW) light, which was very similar to that for 
CW Deluxe, Warm White, Warm White Deluxe, Day- 
light, Natural, Optima 32, Optima 50, C-50, and C-75. 
Consequently, these lights should qqi be used for task 
lighting in fruit and vegetable inspection areas. U.S. 
federal energy standards may eliminate CW and similar 
type fluorescent lamps by 1995 because they do not 
meet proposed efficiency levels. Fluorescent tubes of 
8-foot lengths of all types also are scheduled to be 
removed from production. 

Visual color comparisons suggested that although 
the SP-30 light had a low color rendering index (CRI), 
it performed better than higher CRI fluorescent lights 
for the visual sorting of most fruits and vegetables. The 



relative light output of the SP-30 lamp is among the 
highest tested. Its relative cost is only 1.8 times that of 
CW. These factors indicate that it should be an appro- 
priate choice for most sorting operations when both 
sorting perfoimance and lighting cost are considered 
(Figures la and lb). Note how the spectral irradiance 
curve of SP-30 closely matches the perceived cherry 
color. 

Except for metal halide, the high intensity dis- 
charge (HID) lights were undesirable for produce sort- 
ing as they severely darkened most colors. Tests will be 
necessary using metal halide light to determine if 
sorting performance is acceptable. Tungsten halogen 
quartz (quartz) light also produced good color recogni- 
tion and enhanced ability to see brown-colored defects 
on daik-colored produce. Both metal halide and quartz 
lighting will be more costly than SP-30 fluorescent 
lighting. More specific discussion of the tests will not 
be covered here but can be found in the cited reference. 

Requirements of Light Intensity 

The average illumination intensity needed on pro- 
duce items foreffective visual sorting seems to be in the 
range of 250 to 500 foot-candles, based on the reactions 
of woricers 20 to 70 years old. The lower intensitv 
seems adequate for li ght -colored (high reflectance) 
produce, and the hi gher intensitv for dark-colored flow 
reflectance) produce. The actual light intensity may 
need to be adjusted, depending on the design consider- 
ations discussed below. Insituations where kinds or 
varieties of produce covering the entire color range 
must be insp)ected on the same packing line, the low and 
high intensity levels should be selectable by the sorting 
woricers. This easily can be accomplished by using 
four-tube fluorescent fixtures wired so that either the 
two outside tubes or all four tubes can be turned on. The 
amount of light falling upon a surfce can be measured 
with commercially available light (foot-candle) meters. 

Design Considerations 

Several physical design characteristics will impact 
on sorting efficiency and overall worker attitude and 
performance. 

Background color of sorting s urface fl^elt). 
Reflected light energy from the sorting surface should 
not be greater than that from the produce. Use belts 



Fruit Notes, Fall, 1994 



Screen, block, or direct all task 
light sources so that they cannot 
glare in the workers' eyes. 




Select similar dark colors for 
equipment parts and woricer clothing 
in the sorting area so that bright areas 
cannot interfere with the wooers' 
established vision conditions. 



u 






I 



Use SP-30 (or equivalent) 
illumination at the sorting area of 
most fresh produce pacldnglines. 



z: 



:x 



(o o od) 

Adjust lamp power levels (number of 
tubes) and fixture height so that light- 
colored produce receives approximately 
250 foot-candles of illumination and 
dark-colored produce, approximately 
SOO foot-candles of illuminadon. 



Minimize the influence of 
natural, stray, and general area 
lighting in the sorting area. 



..o oo 



Use a dark background color (black, gray, dark brown) on 
the conveyor surface carrying the produce so that reflected 
light energy from this surface is not greater than that from 
the produce; avoid a glossy finish on the surface of the belt 

Figure 2. Primary design and management criteria for lighting at sorting areas. 



which are black or dark gray, but not glossy finish. 

Surrounding colors. 
Surfaces near sorting areas and the clothing of inspec- 
tion personnel should not be bright or highly reflective 
and should not cause glare. 

Placement of fixtures. 
Placement should be such that the light source will not 
be directly in the sorters' eyes, i.e., unshielded, or too 
low so as to obstruct the sorters' view or the sorting 
surface. The fixture also must be placed at such a height 
as to provide the proper level of light at the sorting 
surface. This wiU depend on the amount and type of 
light used and the considerations mentioned above. For 
an SP30 light, this height will be about 32 inches above 
the sorting surface, as shown in Figure 2. 



Type of lighting . 
Light type should be appropriate for the sorting task and 
the colors involved. Area lighting also should be 
considered as it can have negative impacts on the color 
evaluation and on eye-strain. 

For more information, the following references are 
listed. 

1. Affeldt, H. A. and P.W. Winner. 1991. Lighting 
practice and principles for manual citrus inspec- 
tion. Paper No. 9 1 3549, AS AE, 2950 Niles Rd. , St. 
Joseph, Ml 49085. 

2. Brown,G.K. 1991. Lighting for manual sorting of 
apples and sweetcherries. Paper No. 913553, 
ASAE, 2950 Niles Rd., St. Joseph, Ml 49085. 



Fruit Notes, Fall, 1994 



3. Brown, G. K., D. E. Marshall and E. J. Timm. 
1993. Lighting for fruit and vegetable sorting. 
Paper No. 936069, ASAE, 2950 NUes Rd., St. 
Joseph, MI 49085. 

4. Davies, J. and R. M. Perkins. 1991. Effect of 
illumination in grading dates. Paper No. 912547, 
ASAE, 2950 Niles Rd., St. Joseph, MI 49085. 



6. Hyde, G. M. 1991. Lighting envirorunent for 
manual sorting of potatoes and onions. Paper No. 
913548, ASAE, 2950 Niles Rd., St. Joseph, MI 
49085. 

7. Kantowitz, B. and R. Soricin. 1983. Human 
factors, understanding people-system-relation- 
ships. John Wiley & Sons, Inc., pp. 102. 



5. Delwiche, M. J., J. F. Thompson and R. S. Johnson. 
1991. Sorting table illumination on stone fruit 
packing Hnes in California. Paper No. 913551, 
ASAE, 2950 Niles Rd., St. Joseph, MI 49085. 



Kupferman, E. M. 1991. Cherry sorting table 
lighting. PaperNo. 913552, ASAE, 



*X» *kL» •X* •sL» •X# 

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Fruh Notes, Fall, 1994 



A Test of a Potential Non-chemical 
Approach to Scald Control on Apples 

William J. Bramlage 

Department of Plant & Soil Sciences, University of Massachusetts 

James R. Schupp 

Highmoor Farm, University of Maine, Monmouth ME 04259 



Scald Development on Apples 
After Storage is a Threat 

There is risk of scald development during and 
following long-term storage on a number of important 
apple cultivars. Since the 1960's this risk has been 
minimized by prestorage application of diphenylamine 
(DPA), an antioxidant that has proven to be very 
effective in scald control. Today, however, some 
markets will not accept DPA-treated apples because 
they have been treated chemically, so alternatives to 
DPA are being sought. 

Numerous non-chemical scald-control procedures 
have been proposed, but none are as easy to apply or as 
reliable as the use of DPA. The most effective probably 
is low-oxygen controlled atmosphere storage, where O^ 
iskeptnearorbelow 1%. Itisusedforcommercial scald 
control in some parts of the worid; however, in the 
Northeast we are unable to use low-Oj storage because 
the risk of fruit fermentation is excessive. 

One non-chemical procedure that has been tested is 
warming of fruit after a short time at low temperature. 
In New Zealand, Dr. Chris Watkins and I found that 
when Granny Smith apples were warmed at 70°F for 
five days after they had been at 32°F for two weeks, 
warming was as effective as DPA in preventing scald 
development. Subsequent tests indicated that this 
warming time and temperature was about optimum for 
scald control on Granny Smiths. In 1992, we tested this 
warming procedure on Cortland and Delicious in Mas- 
sachusetts, and found that it caused significant fruit 
ripening and gave little or no scald control. However, 
we had used fruit that were immature and extremely 
scald susceptible, so the treatment might have given 
better results if the fruit become less scald susceptible. 
It is likely that as fruit become less scald suscep- 



tible, scald becomes easier to control. We found several 
years ago that as Cortland and Delicious become less 
scald susceptible, lower concentrations of DPA become 
effective in controlling scald. It is our hypothesis that 
at lower levels of scald susceptibility, non-chemical 
control measures may be as effective as DPA. The 
problem is how to determine at harvest when fruit have 
relatively low scald susceptibility. However, we have 
found that in Massachusetts, preharvest hours below 
50°F is a reasonably reliable indicator of scald suscep- 
tibility on Cortland and Delicious (see Fruit Notes 
59(3):6-10). Therefore, it is conceivable that by moni- 
toring preharvest temperature, a grower could know 
when DPA is necessary for scald control, and when a 
non-chemical procedure might be used instead. 

Experimental Procedures 

In 1993, the Maine State Pomological Society 
provided funding for a test of this concept. Fruit for the 
study were provided from the University of Maine's 
Highmoor Farm, and treatments, storage, and fruit 
evaluations were done at the University of Massachu- 
setts Horticultural Research Center (HRC). 

Three cultivars were tested: Mcintosh, Cortland, 
and Delicious. Fruit were harvested from the same trees 
when 75 , 1 1 9, 1 50. and 200 hours below 50°F had been 
recorded at Highmoor Farm. Harvest dates were Sep- 
tember 20 and 27 and October 1 and 5. All three 
cultivars were harvested on these dates. Maturity was 
assessed by using a starch test within one day of harvest, 
and by measuring ground color and firmness after 
transport to the HRC. Within a week of harvest, one set 
of one-bushel samples of each cultivar was dipped for 
two minutes in DPA (1000 ppm for Mcintosh, 2000 
ppm for Cortland and Delicious). After two weeks at 



Fruit Notes, Fall, 1994 



Table 1. 


Effects of 


warming and DPA treatments 


on scald development on 


apples grown 


at Monmouth 


, Maine. 




Han-est 


Starch 


Firmness 




Ground 




Percent scald 






Scald score 
















date 


score' 


(lbs) 




color' 


Control Warmmg 


DPA 


Control 


Warming 


DPA 














Mcintosh 










20 Sept 


2.5 


17.4 




4.5 


8 


46 


1 


1.1 


1.3 


1.4 


27 Sept 


4.4 


17.3 




4.1 


2 


12 


2 


1.0 


1.0 


1.0 


1 Oct 


5.2 


14.5 




2.7 


I 


7 


1 


1.1 


1.0 


1.0 


5 Oct 


6.3 


13.9 




1.8 


1 


6 
Cortland 


1 


1.0 


1.0 


1.0 


20 Sept 


2.0 


18.1 




4.3 


9 


79 


1 


1.1 


1.1 


1.0 


27 Sept 


1.5 


17.3 




3.6 


64 


75 


33 


1.0 


1.1 


1.0 


1 Oct 


2.4 


14.8 




1.9 


33 


80 


22 


1.0 


1.1 


1.0 


5 Oct 


3.7 


14.3 




1.8 


33 


66 
Delicious 


18 


1.0 


1.0 


1.0 


20 Sept 


2.0 


18.4 







86 


48 


6 


2.1 


1.4 


1.3 


27 Sept 


2.8 


18.5 




— 


31 


10 


1 


1.3 


1.2 


1.0 


1 Oct 


2.9 


17.5 




... 


17 


2 


9 


1.5 


1.9 


1.1 


5 Oct 


2.8 


17.5 




... 


14 


1 


5 


1.1 


1.0 


11 


M = Very 


immature 


8 = Very mature. 
















'5 = Very 


green; 1 = 


= Very yellow. 


















'1 = 1 to 


10%; 2 = 


1 1 to 33%; 3 = 


34 


to 67%; 4 


= >67% 


of fruit surface affected. 









32°F, a second set of samples was transferred to 70°F for 
five days and then returned to 32°F. A third set of 
samples was not treated in any way and served as 
controls. 

Mcintosh and Cortland were kept at 32°F for 22 
weeks, and Delicious for 25 weeks. At the end of 
storage all samples were kept at 70°F for 7 days and then 
evaluated for scald, measuring its intensity on the scale 
of 1 = 1 to 10%, 2 = 1 1 to 33%. 3 = 34 to 67%, and 4 
= more than 67% of the fruit surface affected. 

Results 

Results ofthe experiment are shown in Table 1. As 
expected, Mcintosh ripened the most during the har- 
vests and Dchcious ripx^ned the least, but in all cultivars, 
changes took place. After storage, little scald devel- 
oped on any of the control Mcintosh, but considerable 
amounts developed on Cortland and Delicious. DPA 
was very effective in controlling scald on Mcintosh and 
Delicious, but was only partly effective on Cortland. 
Warming had two opposite effects: it reduced scald on 
Delicious, but it markedly increased scald on Mcintosh 
and Cortland. 



Discussion 

As expected, as preharvest hours below 50°F in- 
creased, scald susceptibility of Delicious decreased, 
although the rate of decrease was somewhat more rapid 
than we have usually seen. We have not attempted to 
construct a predictive curve for Mcintosh because scald 
has occurred too infrequently in our tests. However, our 
predictive curve for Cortland is similar to that for 
Delicious, and the data for controls in Table 1 do not fit 
that curve. The first harvest should have produced 
nearly 100% scald, but produced only 9% scald. We 
have seen this happen before occasionally on early- 
picked fruit, and do not know what causes it to occur. Of 
more concern was the failure of scald to fall to very low 
levels with more than 150 hours below 50°F (the final 
two harvests of Cortland). Not only did the scald 
susceptibility not decline as expected, but these fruit 
also failed to respond fully to 2000 ppm DPA. (It is 
possible that an unusual form of scald developed, one 
that was not as controllable by DPA.) In our attempts 
to predict scald susceptibility, we are more concerned 
about underpredicting than about overpredicting scald, 
because in the former case a grower might experience 



8 



Fruit Notes, Fall, 1994 



serious financial losses. Thus, we are continuing to try 
to refine our scald prediction system. 

The effects of warming on scald control on Deli- 
cious were just as we hypothesized. Warming reduced 
scald at all harvests, but only when susceptibility was 
relatively low did warming provide satisfactory scald 
control. For Mcintosh and Cortland, however, instead 
of reducing scald, warming clearly increased it. We 
have not seen this result in previous tests. The fact that 
all three cultivars were produced in the same orchard, 
harvested on the sameday, treated simultaneously, and 
stored in the same room shows that response to warm- 
ing can be very different among cultivars. We believe 
that the opposite results seen here among cultivars are 
related to the fact that Mcintosh and Cortland produce 
much more ethylene than Delicious, and ethylene has 
complex effects on scald development. 



These findings illustrate the risk involved in at- 
tempting to use a non-chemical scald-control proce- 
dure. Under the conditions of this experiment, using the 
predictive curve to determine when to rely on warming 
for scald control would have been a resounding success 
for Delicious. However, the predictive curve was not 
adequate for Cortiand, and warming was never effec- 
tive on Cortiand or Mcintosh. 

Whether or not warming is a suitable scald control 
procedure is not yet clear. Noticeable ripening can 
occur during warming, and it would entail major logis- 
tical problems to change fruit temperatures. However, 
the objective of this study was to use warming as an 
example of a non-chemical procedure applied in con- 
junction with scald prediction, and from this viewpoint 
it can be seen that at this point in time, it's a very risky 
approach, one that we caimot recommend. 



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Fruit Notes, Fall, 1994 



Influence of Understory Growth 
and Quantity of Drops on the 
Establishment of Voles in 
Apple Orchards 

Ronald Prokopy and Jennifer Mason 

Department of Entomology, University of Massachusetts 



When abundant, meadow voles and pine voles can 
cause severe damage to the bark or roots of apple trees, 
sometimes causing tree mortality. Growers are well 
aware that problems with voles can be especially great 
during winter. 

Under second-level IPM, a strong effort is made to 
integrate pest management practices across all classes 
of pests, including vertebrate pests such as voles. We 
report here on the effects on vole establishment of two 
IPM practices directed mainly at other kinds of pests. 
The first practice concerns management of understory 
growth (weeds) by mowing or herbicide application. In 
particular we wondered whether or not allowing imder- 
story growth to remain at a substantial height during 
autumn months would encourage vole establishment. 
The second practice concerns picking up drops during 
and after harvest. This practice is 
directed primarily at reducing 
emergence from drops of pest in- 
sect larvae such as apple maggot, 
codling moth, and lesser 
appleworm. Reduction in larval 
emergence from drops translates 
into reduced numbers of larvae 
overwintering within the orchard 
and hence reduction in threat to 
next year's crop. We wondered if 
allowing large numbers of drops 
to remain beneath orchard trees 
during autumn months would 
lead to vole establishment. 

Methods 



gust of 1993, we placed an asphalt roofing shingle (1 1 
X 36 inches) beneath each of 10 perimeter-row apple 
trees in each of 12 second-level IPM test blocks and 
each of 12 nearby first-level IPM check blocks. The 
shingles were spaced evenly around the perimeter of a 
block. In October of each year, we lifted each shingle 
and examined the ground beneath for signs of vole 
establishment, either a trail or a hole into the earth. At 
the same time, we measured the height of grass or other 
foliage beneath the tree and categorized the number of 
drops in a range from few to many. 

Results 

There was no detectable difference in average plant 
height or average number of drops between second- 



In August of 1992 and Au- 



Table 1. Height of understory cover during October in relation to 
proportion of shingles that showed evidence of vole activity. Blocks 
represent a fu-sl-level and a second level block in each of 12 orchards 
in both 1992 and 1993, with years u-eated separately. 


Number of 
orchard blocks 


Height 
of cover (in) 


Shingles with 
vole activity (%) 


11 

5 

10 

14 

8 


0-5 
6-10 
11-15 
16-20 
21-25 


10 
24 
36 
39 
48 


1 



10 



Fruh Notes, Fall, 1994 



Table 2. Amount 
1993, in relation 
vole activity. 


of drops on the ground during October, 1992 and 
to proportion of shingles that showed evidence of 


Number of 
orchard blocks 


Estimated amount 
of drops 


Shingles with 
vole activity (%) 


9 
11 

14 
11 

3 


Few 
Few to Medium 

Medium 

Medium to Large 

Large 


43 
45 
32 
33 
30 


1 



level and first-level IPM blocks. Such lack of differ- 
ence suggests that growers were applying understory 
management and drop pick-up practices equally to both 
types of blocks, even though our recommendation 
called for more intensive management of the second- 
level blocks. 

As shown in Table 1, there was a marked tendency 
toward increasing incidence of vole establishment with 
increasing height of grass. Orchards treated with herbi- 
cide or in which height of understory growth did not 
exceed 5 inches at time of sampling in October showed 
an average incidence of 10% of the shingles with vole 
activity, which we consider to be a comparatively non- 
damaging population level. In contrast, orchards in 
which understory growth exceeded an average of 21 
inches showed an average incidence of 48% of the 
shingles with vole activity, a potentially very damaging 



population level. 

As shown in Table 2, there 
was no clear relationship between 
numberof drops and incidence of 
voles. Ifanything, vole establish- 
ment beneath shingles tended to 
be slightly greater in blocks with 
fewer drops than in blocks with 
greater numbers of drops. 

Conclusions 



We conclude form this two- 
year study that growers who 
maintain understory plant growth 
at a low height during autumn 
months have a much better 
chance of escaping establishment 
of voles than growers who do not. This conclusion may 
be particularly applicable to meadow voles. Many 
factors can affect the numberof voles immigrating into 
an apple orchard during autumn and becoming estab- 
lished beneath the trees. For example, a high abimdance 
of alternate food such as acorns might tend to discoiu-- 
age vole immigration into orchards. But in years when 
alternate food is sparse or in locales where orchards 
closely border woods containing many oak or ever- 
green trees, growers could substantially lower the risk 
of vole invasion by frequent mowing. 

Acknowledgments 

This study was supported by grants from the Mas- 
sachusetts Society for Promoting Agriculture and the 
USDA Northeast Regional 1PM Program. 



»T^ *^ vT^ *T# *^ 

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Fruit Notes, Fall, 1994 



11 



Is Diphenylamine a Natural 
Compound in Apples and Pears? 

William J. Bramlage and Zhigao Ju 

Department of Plant & Soil Sciences, University of Massachusetts 

Thomas L. Potter 

Mass Spectrometry Facility, University of Massachusetts 



For over 30 years, dipping fruit in diphenylamine 
(DP A) before storage has been the standard commercial 
procedure to control superficial scald (scald) develop- 
ment on apples during and after long-term storage. 
However, this procedure is controversial since it consti- 
tutes a chemical treatment, and legally, DPA must be 
considered as a food additive. Some countries have 
banned treatment with DPA, and some prohibit impor- 
tation of DPA- 

treated fruit. In the U.S. and Canada, DPA is permitted 
and the maximum residue of 10 ppm should never be 
exceeded if DPA is applied correctly. Nevertheless, 
many American markets will not accept DPA-treated 
fruit because they have been chemically treated. 

In 1984, a report was published (Karawya and 
Wahab.y.Afamra/ProducW 47(5): 775-780) that DPA 
was found in relatively high concentrations as a natural 
product in mature onions, and that it was effective in 
lowering blood sugar levels in diabetics. 
The report also showed data that DPA was 
a natural product in tea. In that same year, 
a report of the Food and Agriculture Orga- 
nization of the United Nations ("Pesticide 
Residues in Food - 1984") stated that there 
"...is reasonable evidence that dipheny- 
lamine occurs naturally in apples though 
the level appears to be at or below 1 mg/kg 
(ppm)." No data to support this statement 
were cited, but in studies of DPA residues 
on apples, controls almost always contain 
measurable amounts of DPA. 

We became interested in this question 
when what appeared to be DPA was de- 
tectable, even though no DPA had been 
applied, during our measurements of ma- 
terials in apple peel that might be associ- 



ated with scald development. In 1993, the Massachu- 
setts Fruit Growers' Association provided us with a 
grant to pursue this question, and results of our study are 
reported here. 

In April, 1993 10-fruit samples were taken fiom 
bins of apples stored at the University of Massachusetts 
Horticulture Research Center (HRC), Belchertown. 
Five cullivars were sampled, and fruit were extracted in 
hexane. The extract was tested for presence of DPA 
using gas chromatography and mass spectroscopy, 
employing selected-ion-monitoring for maximum sen- 
sitivity. Results are shown in Table 1. All samples gave 
positive indication of DPA in their peel, ranging from 
0.03 to 0.13 ppm, despite the fact that none had been 
treated with DPA after harvest. 

DPA is somewhat volatile, so to test for the pres- 
ence of DPA residues in the rooms at the HRC, one- 
square-foot areas of walls and doors in three different 



Table 1. DPA concentration in hexane extracts 


of apples stored 6 


to 7 months in 0°C air. 


April, 1993. 






DPA 


Sample 


(ppm fr. wt. of fruit) 


Blank 


<0.01 


Delicious 


0.03 


Mcintosh 


0.03 


Golden Delicious 


0.13 


Empire 


0.13 


Cortland 


0.10 


1 



12 



FruH Notes, Fall, 1994 



Table 2. DPA concentrations in freshly harvested fruit 


. 1993. 




Cultivar 


Immature 


- 




Mature 


Weight 


DPA 


Weight 


DPA 




(g) 


(ppm fr.wt.) 




(g) 


(ppm fr.wt.) 


Mcintosh 


440 


0.002 


(9/22) 


1382 


0.002 








(10/7) 


1190 


0.001 


Cortland 


659 


0.002 




1620 


0.001 


RI Greening 


319 


0.003 




1190 


0.002 


Empire 


316 


0.007 




1147 


0.002 


Delicious 


430 


0.003 




1396 


0.003 


Golden Delicious 


510 


0.004 




1641 


0.001 


Anjou pear 


— 


— 




2334 


0.001 


1 



rooms were swabbed with dry cotton balls that had been 
pre-rinsed in hexane. The swabs were then extracted in 
hexane, which was monitored for DPA. All samplings 
produced DPA residues on storage surfaces, ranging 
from 0.4 to 13.1 ug/meter^ of surface. Thus, DPA in 
apple peel could have been the result of contamination 
from residues in the storage. 

To eliminate this possibility, 10-fruit samples of 
fruit were taken direcdy from trees at the HRC in 
August, 1993 while fruit were immature. The same four 
cultivars tested out of storage were sampled from the 
trees, and also fruit were taken from an organically- 
grown treeof Rhode Island Greening. Fruit again were 
sampled from these trees when they were mature. In 
addition, Mcintosh were sampled again when they were 
ovenmature, and Anjou pears were sampled at maturity. 
All of these samples were extracted in hexane immedi- 
ately after harvest, and the extracts were frozen until 
analysis. All samples exhibited the presence of DPA 
(Table 2), although the concentrations were about one- 
tenth those found in stored fruit. It is interesting to note 
the increase in fruit weight between the two harvests, 
without a reduction in DPA concentration, which indi- 
cates that the material continued to accumulate as the 
fruit grew. 

These results strongly supported the suggestion 
that DPA is a natural product in apples... and also in 
pears. However, for additional confirmation, two more 
tests were run. First, a Mcintosh extract was spiked 



with a minute amount of authentic DPA to make sure 
the method was recovering and measuring DPA. Spik- 
ing doubled the DPA measurement, with a 61% recov- 
ery of added DPA, so the procedure is capable of 
extracting and measuring DPA. 

A more rigorous evaluation of the procedure was 
made by producing a derivative of DPA, i.e., attaching 
another molecule to it, and separating and measuring 
the deri vatized molecule. This procedure is a test to see 
if it is truly DPA that was being measured. 
Derivatization produced three different ions; DPA plus 
the derivatizing substance, DPA plus part of the 
derivatizing substance, and DPA with a single proton 
removed from it. Using authentic DPA, these ions were 
in a ratio of about 1.0:0.6:0.3. When fruit extracts were 
derivatized, the three ions were not present in that ratio, 
raising doubts that we truly were measuring DPA. 

To test this further, 10-fruit samples of Delicious 
apples, from the same tree, that had and had not been 
dipped in DPA before storage were taken from storage 
in March, extracted, derivatized, and measured. The 
DPA-treated fruit contained 10 times as much 
derivatized DPA as did the non-u-eated fruit, and in the 
treated fruit the ion ratio was 1 .0:0.6:0.3, indicating that 
it was DPA that was being measured. In the non-treated 
fruit, the ratio was about 1.0:0.3:0.2, just as we found in 
the freshly harvested fruit. 

That result reaffirmed that at least part of what we 
were measuring as "DPA" in apple extracts probably 



Fru'n Notes, Fall, 1994 



13 



was something very similar to DPA, but not DPA itself. 
This does not mean that apples and pears do not contain 
natural DPA. If only half of the derivatized material in 
the Delicious extract was DPA, it could produce the ion 
ratio that was obtained. Therefore, our results leave 
imanswered the question, "Is DPA a natural compound 
in apples?" Clearly, something very similar to DPA is 
produced, and possibly some of what we were measur- 
ing was DPA. 

There is an important ramification of this study. 
Clearly, DPA or DPA-like compounds are being mea- 
sured on fruit that have not been treated with this 
chemical. It is present at harvest and accumulates 
during storage, since our fruit out of storage showed 10- 
times the concentrations of the fruit picked directly off 
the tree. 

DPA is a somewhat volatile compound, and the 
abundant residues we measured on the walls of our 
storage rooms show that there is likelihood of contami- 
nation of untreated fruit with DPA from the atmosphere 
in the storage or possibly from contact with bins and 
other equipment. Large quantities of DPA are used in 
industry as an antioxidant/stabilizer. For example, 
rubber products commonly contain DPA. Thus, fruit 
may absorb some DPA directly or indirectly from 



industrial products. If a test of fruit indicates the 
presence of DPA, its source could be any or all of the 
following: 

1 . DPA application. 

2. Contamination from residues in fruit storages, 
containers, or equipment. 

3. Contamination from industrial use of DPA. 

4. A natural product in apples that while not being 
DPA, is being measured as DPA. 

5. Possibly, natural-product DPA in the fruit. 
Therefore, measurement of "DPA" in fruit is not proof 
that fruit were treated with DPA. There apparently is no 
such thing as "zero DPA" in apples. Conclusions must 
be based on the quantity ofDPA present in the fruit, not 
on its absolute presence. 

In conclusion, we have not resolved the question of 
whether or not DPA is a natural product in apples and 
pears. Small quantities of something very similar to 
DPA, and possibly of DPA itself, is/are naturally occur- 
ring, but remain to be identified. However, we have 
shown clearly that conclusions drawn from DPA resi- 
due analyses must be based on quanfities measured, not 
on its presence in the fruit. An analysis showing the 
presence of DPA in fruit is not positive evidence of 
DPA application to the fruit. 



•X» *^ •X* *J>* *-£-• 
ry% •^ rp» #Y* •T* 



14 



Fruit Notes, Fall, 1994 



Do Bloom Applications of Apple 
Fungicides Affect Fruit Set? 

Daniel R. Cooley 

Department of Plant Pathology^ University of Massachusetts 

Duane W. Greene 

Department of Plant & Soil Sciences, University of Massachusetts 



We reported previously [Fruit Notes 56(4): 18- 
1991] that researchers in Great Britain found that 
fungicide captan may be toxic to apple pollen, 
and thereby reduce fruit set. Since then, a test 
in Virginia has shown similar reductions in fruit 
set, apparently caused by captan applied at 
bloom. Furthermore, growers have on occasion 
speculated that sterol-inhibiting fungicides re- 
duce fruit set. In the work reported here, we 
asked two questions. First, does captan or the 
sterol-inhibiting fungicide, fenarimol, applied 
at bloom reduce fruit set? Second, does captan 
or fenarimol interact with oil or copper to 
reduce fruit set? 

In 1992, mature Mclntosh/M.7 apple trees 
were selected at the University of Massachu- 
setts Horticultural Research Center in 
Belcherlown. In the first experiment, six limbs 
of similar blossom density were selected per 
tree. Three of the limbs were treated with 
copper hydroxide (Kocide 50 WP, 2 lbs/100 
gal.) at tight cluster. Each of the three limbs 
treated with copper hydroxide and each of the 
three not treated with it were sprayed with 
captan (Captan 50 WP, 2 lbs/100 gal.) or 
fenarimol (Rubigan 1.6 EC, 12oz./100gal.)or 
left untreated. A second experiment was iden- 
tical except that oil (1 gal./lOO gal.) appUed at 
tight cluster replaced the copper hydroxide 
treatment. For both experiments, fungicide 
applications began when the primary blossoms 
were expanded completely, and captan and 
fenarimol applications continued at seven- or 
ten-day intervals, respectively, until mid-June. 
Treatments were applied to the drip point using 
a handgun. After June drop was complete, final 



19, fruit set was counted on each limb, 
the In the first year of study, captan and fenarimol, with 

or without oil or copper hydroxide application, did not 



Table 1. Fruit set following various treaunents in 1992 and 


1994. Within an experiment, no si 


gnificant differences were 


found among treaUnent means. 








Fruit set 


Treatment 




(number/cm^ 


1992, Experiment 1 






Check 




3.8 


Captan 




5.7 


Fenarimol 




6.7 


Copper hydroxide 




5.7 


Copper hydroxide plus 


captan 


5.8 


Copper hydroxide plus 


fenarimol 


5.1 


1992, Experiment 2 






Check 




5.8 


Captan 




8.3 


Fenarimol 




6.8 


Oil 




4.9 


Oil plus captan 




5.3 


Oil plus fenarimol 




4.6 


1994 Experiment 






Check 




4.2 


Captan at king bloom 




5.3 


Captan at king bloom + 1 day 


5.6 


Captan at king bloom + 2 days 


4.4 


1 



Fruit Notes, Fall, 1994 



15 



alter fruit set significantly (Table 1 ). The results from 
Great Britain were very specific in terms of time of 
sensitivity to captan, possibly explaining some of the 
lack of effect that we observed. 

In 1994, we conducted an additional experiment to 
study the specific timing of captan application. Mature 
Marshall Mclntosh/M.26 trees were selected and 
blocked according to blossom density. Within each 
block, one tree was treated with captan (Captan 50 WP, 
2 lbs/ 100 gal.) when king blossoms were expanded 
fully, one was treated one day later, and one was treated 
two days later. A fourth tree was left untreated. Other 



than these captan treatments at bloom, all trees were 
managed similarly. After June drop was complete, final 
fruit set was counted on two limbs per tree. 

The different timings of captan application did not 
result in any significant reduction in fruit set (Table 1). 
Therefore, none of our experiments confirmed the 
results of studies conducted in Great Britain and Vir- 
ginia. We can only speculate that our growing condi- 
fions in 1992 and 1994 did not interact with captan in a 
way that caused reduced fruit set. Qearly, New En- 
gland apple growers should not be overly concerned 
that captan will reduce fruit set on Mcintosh. 



•1^ •l^ %1a •^ •J^ 
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Publications Available 



Two publications recently released by Agriculture and Agri-Food Canada should be of interest 
to many readers of Fruit Notes. One is titled "Techniques for controlled atmosphere storage of fruits 
and vegetables" (Research Branch Technical Bulletin 1993- 18E), and it is a brief general review of the 
techniques currently in use for CA storage. The second is tided "Postharvest disorders of apples and 
pears" (Publication 1737/E), and it is a detailed review and update on postharvest physiological disorders 
of these fruit, including numerous photographs of the disorders. Both of these publications can be 
obtained without cost by sending your request to: 

The Librarian 

Agriculture and Agri-Food Canada Research Center 

Kentville, Nova Scotia B4N 1J5 CANADA 



16 



FruH Notes, Fall, 1994 



Can Synthetic Scent of Predators 
Repel Deer in Orcliards? 

Ronald Prokopy and Jennifer Mason 

Department of Entomology, University of Massachusetts 



There is a growing number of studies suggesting 
that predator odors are repellent to potential prey. 
Repellency appears to stem at least in part from chemi- 
cal constituents of predator urine or feces. Deer can be 
very troublesome pests in apple orchards, especially 
during winter months, when they chew apple buds and 
twigs. Cougars and other large members of the cat 
family are among predators which deer fear the most. 
We report here on a small pilot study that we conducted 
to evaluate potential repellency to deer of synthetic odor 
of cougar feces. 

Materials and Methods 

TTie odor consisted of a 50:50 mixture of 3-propyl- 
1 ,2-dithiolane and 2-propylthietane, encapsulated in 
polymeric plastic fibers to provide slow release. Both 
components of this mixture are present in cougar feces. 
Together, they convey a strong sulfur-like stench 



vaguely similar to the smell of a skunk but more 
pungent. The odorous fibers are still in a developmental 
stage, not yet available commercially. They were 
provided to us by Phero Tech Inc. of Delta, British 
Columbia. 

In November of 1992 and December of 1993, we 
hung 4 fibers on each of 25 perimeter-row apple trees at 
Rice's fruit farm in Wilbraham, Massachusetts. Each 
tree with fibers was separated by three perimeter-row 
trees without fibers, the middle tree of which served as 
the check tree. Ten twigs on each treated and check tree 
were examined for signs of deer injury just before 
emplacement of fibers and again one to three months 
afterward. 

Results and Conclusions 

The data in Table 1 show there was little if any 
repellent effect of the odorous fibers against deer feed- 



Table 1 . Percent of sampled twigs showing evidence of feeding by deer in plots of 
apple trees with and without synthetic odor of cougar feces. 


Test 




Injured twigs 


in trees (%) 


Sampling 
time 


With odor 


No odor 


1 

2 


November, 1992' 
January, 1993 
February, 1993 

December, 1993" 
January, 1994 



36 
38 

3 
11 


1 

37 
40 

2 
5 


'Samples 


taken just prior to odor emplacement 







Fruit Notes, Fall, 1994 



17 



ing on apple trees in Rice's orchard. We were disap- 
pointed in this finding, especially because in a 1993 
study, the fibers had shown strong repeUency for as 
long as 3 months against deer feeding on Sitka spruce 
seedlings in a plantation in McClinton, British Colum- 
bia. 

Several factors may have been responsible for the 
lack of repellency in our study. First, the number of 
fibers used (four per tree) may have been too few to 
provide effective repeUency, although employment of 
more than four per tree would have been too expensive 
for practical commercial use. Second, the fibers may 
emit too little odor under cold winter weather tempera- 
tures in New England to be effective against deer. 
Perhaps they are better suited for use imder warmer 
West Coast winter conditions. Third, the deer at Rice's 
may have been so hungry for winter food that hunger 



compromised their instinctive fear of cougars. 

Despite this lack of encouraging result, we firmly 
believe that improved knowledge of the chemical ecol- 
ogy of predators of orchard pests such as deer and voles 
will some day lead to development and fomiulation of 
blends of predator odor that wiU indeed effectively 
repel these orchard vertebrate pests, just as synthetic 
plant and insect odors are now being used effectively in 
managing orchard insect pests. 



A cknowledgments 

We thank Phero Tech Inc. for providing us with the 
odorous fibers. This work was supported by the Mas- 
sachusetts Society for Promoting Agriculture and the 
USDA Northeast Regional IPM Program. 



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18 



Fru'n Nates, Fall, 1994 



3^1 



9 



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Fruit Notes 



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