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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 


(%) 


¥* 


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 Guthion™, Thiodan™, and Omite™ 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 Post™, amate, and 

coated with Guthion, 10 with Thiodan, and 10 Fusilade™ 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 

\- 
«) 
■o 
■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"™ or 
Imidan"™ 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 Consep™ 
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 DimUin™ 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 

Department of Plant & Soil Sciences 

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Amherst, MA 01003 



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Fruit Notes 

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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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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 


—