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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
70Â °F. Peach trees are susceptible only during
the short period of bud swell to bud opening.
Symptoms appear about two weeks after leaf
emergence. Small, reddish areas develop on
small leaves. As the disease infection
progresses, the leaf wrinkles and puckers in
small areas or along the entire leaf. The m^'or-
ity of infected leaves drop. The fungus produces
ascospores which spend the summer on the
peach tree, but then produce overwintering bud
conidia.
Where leaf curl is severe, maintain tree vigor
by: 1) thinning fruit, 2) irrigating during periods
of drought, and 3) fertilizing by mid-June. A
dormant spray of a copper-containing fungicide
after leaf drop or before bud swell usually will
control leaf curl.
A recent study conducted by L. Burkham
("Alternatives for ControlHng Peach Leaf Curl"
appearing in Common Sense Pest Control Quar-
terly) found that organic growers in California
were able to control peach leaf curl by sprajdng
a seaweed fertiUzer once a month. Speculation
is that susceptibility to leaf curl may be related
to magnesium deficiency. Seaweed contains a
high level of this element.
Also, numerous nectarine and peach culti-
vars have been evaluated for susceptibility to
leaf cin-1. (Scorza, R. 1992. Evaluation of foreign
peach and nectarine introductions. Fruit Variet-
ies Journal 46: 141-144). All of the North Ameri-
can cultivars mentioned in this study (Harbelle,
Elberta, Redhaven, ReUance, Loring, and Sun-
Ught) showed varying degrees of susceptibility.
Peach Leaf Curl
Peach leaf curl is caused by the fungus
Taphrina deformans. Spores of the leaf curl
fungus are very resistant to adverse weather
and can remain dormant on twig surfaces for
two years or longer. Overwintering spores are
washed to the surfaces of leaf buds by spring
rains. These spores then multiply during wet
weather until leaf bud scales open. Once bud
scales become loose, spores are carried by water
X-disease
X-disease is caused by a virus-like organism
known as a mycoplasma. Leafhoppers carry the
disease from infected chokecherries or peaches
to other peach, nectarine, or cherry trees. Once
in the trees, mycoplasmas live in phloem cells, a
type of vascular conducting cell.
Symptoms of x-disease are leaf yellowing or
reddening with shot-holing appearing during
July and August. Affected leaves drop, leaving
Fruit Notes, Winter, 1993
"tufts" of green leaves at ends of twigs. As the
disease progresses through the tree, Umbs die
back and each year more of the tree becomes
infected. Fruit on infected trees at first appear
normal, but they most often drop prematurely.
Young trees infected with x-disease should
be removed and destroyed. In older trees, re-
moving infected Umbs may slow the spread of
the mycoplasmas; but once x-disease has
started, it is difficult to control. Antibiotic
therapy may help also.
Removing chokecherries near peach or-
chards is essential.
For additional information on any of these
pests, please refer to:
Jones, A.L. 1976. Diseases of Tree Fruits. (Cooperative
Extension Services of the Northeast States. NE 96.
LaRue, J.H. and RS. Johnson (eds.). 1989. Peaches,
Plums, and Nectarines: Growing and Handling for
Fresh Market. Cooperative Extension, University of
California. No. 331.
Prokopy, R.J., P.J. Powers, D.R. Cooley, and J.W.
Gamble. 1991. Peaches, Pears, Plums - Pest Control
Guide for Commercial Growers in Southern New En-
gland. University of Massachusetts Cooperative Ex-
tension System Circular C-159 R 1991-2.
^% •10 •i^ ^L0 ^|V
#J% rfi rf» •Y* •?•
Peach Pests IV: Diseases of
Peach Wood
Karen I. Hauschild
University of Massachusetts Cooperative Extension System
This is the last in a series of four articles
describing major insect and disease pests of
peaches in Massachusetts. In this article I wiU
describe diseases that attack peach wood, pri-
marily canker diseases.
In general canker diseases occur where
peach trees are stressed due to drought, poor
growing conditions, cold temperature, or poor
pruning. Healthy, vigorous trees are less sus-
ceptible to attack by canker diseases. Several
disease organisms cause canker formation on
peaches. Following are brief descriptions of the
major causal agents of perennial cankers found
on peaches and nectarines in Massachusetts
orchards.
Cytospora (Valsa) Canker
Two species oiCytospora are associated with
peach canker - C. leucostomia Saac. and C.
cincta Saac. Cytospora overwinter in cankers or
on dead peach wood. Bumps containing pyc-
nidia with small conidia are produced under
bark. These pycnidia grow through the bark and
expose spores to rain. Splashing rain or rain
driven by heavy winds spread conidia to other
infection sites on damaged or injured bark.
Canker growth is related to temperature and
growth habit of the peach tree itself C. cincta is
most active during spring and fall at tempera-
tures between 60 and 75°F. C. leucostomia is
more active at temperatures between 86 and
91°F, that is, during the summer months. Can-
ker development can occur in one of three ways.
First, cankers may extend down limbs toward
tree trunks, with Umb death occiirring at the
rate of one or two Umbs per year over a period of
several years until the entire tree eventually is
killed. This pattern is the classic "perennial
Fruit Notes, Winter, 1993
canker syndrome." Second, cankers may de-
velop in twigs, small branches, or around prun-
ing cuts but remain localized. This type of
canker generally results in only minor damage
to the tree. Third, trees may leaf out normally,
followed by sudden wilting and total tree death.
In cases like this the tree usually is severely
damaged by cold temperatures and the trunk
and lower scaffold Umbs quickly are colonized by
Cytospora. Again, tree health and environmen-
tal factors play a major role in the severity of
Cytospora.
Since both species of Cytospora reqmre a
wound or natural opening to infect peach trees,
proper priming and pest management practices
help prevent serious infections. Pruning in fall
or early winter can contribute to Cytospora
infections because pruning cuts made at these
times do not heal as quickly as those made in the
spring.
For injured or weak trees, there are no
chemical control measures for Cytospora that
have proven completely successful, partly be-
cause spores can be released throughout the
year. If only a few cankers are present, remov-
ing and destroying infected branches below any
sign of disease can be helpful. Do not plant new
pe ach orchards on poor si tes . Do not prune in the
fall or early winter. Additional measures that
will help prevent Cytospora canker infections
include the following:
1. fertiUze trees early in the spring to avoid late
growth spurts;
2. avoid mechanical injury to trees;
3. apply a fungicide spray after pruning, but
before a rain;
4. avoid weak crotch angles; and
5. whitewash southwest sides of trees and
lower limbs (this practice can help prevent
injury due to cold temperatures).
Brown Rot
As mentioned in "Peach Pest III," brown rot,
Monilia fructicola, can infect twigs. When the
fungus moves into woody tissues it causes the
development of small CEinkers. Cankers, as they
grow, can girdle twigs eventually, resulting in
withering and death of terminal growth. Gum-
mosis often accompanies spur blight and canker
formation.
Cankers caused by brown rot may develop as
a result of blossom blight or may move down
from the finiit pedicel into a twig or larger
branch. On twigs or small branches, brown rot
cankers normally are eUiptical, well-defined,
and brown. During wet weather, gummosis
appears, followed or accompanied by tufts of
grey spores. Cankers on larger branches caused
by rotted fruit appear (similar to those described
above, but likely to be much more severe and
eventually kill the infected branch). In the year
following severe canker development, leaves
above the girdling cankers first appear normal
then later turn yellow, wilt, and eventually die.
Phytophthora Root and Crown Rot
Crown rot does not appear to be a serious
problem in Massachusetts peach orchards, but a
brief description is given below.
Waterlogged soil, air temperature, plant
nutrient status, species of Phytophthora in-
volved, and susceptibility of host tissue all play
roles in the occurrence and severity of
Phytophthora infections. Most infections occur
during the spring, summer and fall months and
are spread by infected plants, soil, or water.
Infections that occur in crowns or larger roots
(especially of yoimg trees) spread rapidly, oft^n
killing trees in one or two seasons. Infected trees
may appear healthy in the fall, leaf out normally
in the spring, but then collapse when warmer
temperatures occur. Symptoms of infection
vary fi-om withered, bright rust-colored leaves
on severely infected trees to decreased overall
growth and smaller, yellow leaves on trees that
show slower decline. Infected roots or crowns
show reddish-brown necrosis of bark and outer
wood with a distinct, layered margin; however,
after some time roots decay and turn grey-black.
Avoiding waterlogged soils, proper schedul-
ing of irrigation, and proper planting practices
help prevent Phytophthora infections from oc-
curring and becoming severe.
Bacterial Canker
Bacterial canker, caused by either Pseudo-
Fruit Notes, Winter, 1993
monas syrincae or P. morsprunorium, is thought
to be an increasing problem in Massachusetts
peach orchards. Damage by Pseudomonas var-
ies among types of host fruit. On peaches, leaf
and flower buds fail to open in the spring and are
thought to have been infected during winter
months. Or, in other instances, infected spurs
show normal growth in the spring but collapse
during sunmier months, turning into wilted
leaves and dried-up fruit. If infection occurs
annually, trees lose bearing surface.
Bacteria overwinter in infected buds or can-
kers. Spring rains wash bacteria to unfolding
plant tissue. Frost-injvired leaves and blossoms
are thought to be more susceptible to Pseudo-
monas infection. Periods of cool, rainy weather
foster early-season infections and disease
spread. Disease spread also occurs under simi-
lar weather conditions in the fall.
Canker removal is the only known cultural
control practice
For additional information on any of these
diseases, please refer to references listed in
"Peach Pests III."
%% ^% %% %% %%
rj% •^ rj% rj* rj%
Apple Maggot Fly Behavior:
Probability of Fly Capture on
Red Sticky Spheres in Relation to
Fly Age and Fruit Maturity
Max P. Prokopy, Jian Jun Duan, Gabriela G. Galarza, and Ronald J.
Prokopy
Department of Entomology^ University of Massachusetts
To augment our current program of second-
level apple IPM involving the use of baited
sticky red spheres to intercept and capture apple
maggot flies (AMF), we have been tracking
foraging behavior patterns of female AMF. We
want to know if the probability of a fly being
captured on a sphere or of laying eggs in apples
changes as flies age or apples mature.
Methods Used
In 1991, two potted apple trees were placed
in screen cages on the campus of the University
of Massachusetts. Each tree had approximately
the same canopy size as a normal four-year-old
dwarf (M.9) fruit-bearing tree. We placed either
50 green or 50 red evenly-spaced Gravenstein
apples on a tree. The leaf-to-fruit ratio was
about 20: 1 . The green fruit were picked on June
19 and had a diameter of about 3 cm. The red
fruit were picked on August 1 and had a diam-
eterofabout4.5cm. In all, 36 AMF of each of five
ages were tested in the presence of only green
finiit, and 30 of each of five ages in the presence
of only red fruit. The flies were collected fix)m
naturally infested fruit and were 3, 7, 11, 15, or
19 days old when tested. FUes seven days old or
younger usually are not capable of lajdng eggs in
fruit.
A single fly was released onto a leaf at the
lower center of the tree. A sticky red sphere,
baited with one vial of the synthetic apple odor
Fruit Notes, Winter, 1993
Table 1. Behavior of apple maggot females of different ages when
released individually on a caged apple tree containing a sticky red
sphere baited with butyl hexanoate and 50 green or 50 red
Gravenstein apples.*
Flies that
Flies
Number of
laid one
Fruit that
captured
fVuit visited
or more
eggs
received an
(%)
Â¥*
per fly***
(%)***
egg(%)
Fly
age
(days) Green
Red
Green Red
Green
Red
Green Red
3 25 b
27 b
1.9 a 2.8 b
b
b
Ob Ob
7 68 a
47 a
2.7 a 3.9 a
6 b
b
2 b lb
11 61 a
57 a
1.8 a 3.8 a
22 a
10 a
12 a 6 b
15 71 a
57 a
1.7 a 4.3 a
26 a
13 a
10 a 5 b
19 64 a
57 a
1.6 a 2.7 b
19 a
30 a
8 a 19 a
**
Values in each column not followed by the same letter are
significantly different at an odds ratio of 19:1.
Represents flies captured on a sphere before leaving tree or
before one hour had elapsed.
*** Visits and egg laying before being captured on a sphere, before
leaving the tree, or before one hour had elapsed.
butyl hexanoate, was placed in the upper part of
the tree canopy. After the fly was released, its
movement was tracked during one hour of forag-
ing within the tree. Tracking involved recording
all leaves and fruit visited, all oviposition at-
tempts and ovi}X)sitions, and whether or not the
fly was captured on the sticky sphere. Any finiit
iQ which the fly made an oviposition, or an
attempt at it, was removed from the tree and
dissected to see if eggs had been laid.
Results
Fly captures when either green or red fruit
were on the tree increased significantly when
the flies were more than three days old (Table 1 ).
For flies seven or more days old, consistently
more were captured when fruit were green than
when they were red. Sixty-six percent of flies
seven or more days old were captured when fruit
were green; whereas, 55 percent were captured
when finiit were red.
Regardless of fly age, red fruit received more
visits than green fruit (Table 1). Flies 1 1 or more
days old were more hkely to oviposit in a frtiit
than were younger ones. Interestingly, except
for the oldest flies tested, a greater percentage of
green fruit than red fruit received eggs.
Conclusions
Our results demonstrate that the age or
maturity of a female AMF can strongly affect its
fruit foraging and egg laying behavior and the
probabihty of capture on a baited sticky red
sphere. Once a female reached seven days of
age, the chance that it would be captured on a
sticky red sphere baited with butyl hexanoate
hung in our test trees was 50% or better. As fly
age increased above seven days, the probability
of capture on a sphere did not increase, but the
probabihty that it would lay eggs before being
Fruit Notes, Winter, 1993
captured on a sphere did increase. This result
indicates that for greatest effectiveness in con-
troUing AMF, baited sticky red spheres should
be hung very early in the fly season, before
immigrating AMF have reached maturity. In
addition, our findings suggest that while green
apples may receive fewer visits by AMF than red
apples, green apples may be more susceptible to
oviposition by arriving AMF. This result again
affirms the need to hang baited sticky red
spheres early in the fly season for greatest
effectiveness in avoiding finiit injury by immi-
grating AMF.
Acknowledgements
This work was supported by the Science and
Education Administration of the U.S.D.A, im-
der grant 8900901 from the Cooperative Re-
search Grants OfBce and by a USDA grant
under the NE-156 Apple IPM project.
^% %% %% ^10 «^
rf* •^ rf% #J% rj%
Evaluation of Four Rootstocks and
Two Mcintosh Strains
Wesley R. Autio and Franklin W. Southwick
Department of Plant & Soil Sciences, University of Massachusetts
Through the 1960's and 1970's, the trend
in the New England apple industry was from
seedling-rooted trees to trees on M.7 or similar
sized rootstocks. In the latter part of the 1980's,
the trend shifted toward smaller trees. In the
1990's, growers are planting significant num-
bers of dwarf trees, mostly on M.9 and Mark
rootstocks. In 1979, a planting was established
at the University of Massachusetts Horticul-
tural Research Center to assess rootstocks in
the size range from M.7 to M.9.
The planting included Rogers Red Mcin-
tosh and Macspur Mcintosh on M.7A, M.26, M.9
(trained either to a post or on a 4- wire vertical
trelhs, seven-feet tall), andM.9/MM. 111. Seven
replications were planted, and each replication
had four trees of each cultivar/rootstock combi-
nation. Two trees of each group were used for
data collection, and any Macspur that reverted
to a nonspur habit was eliminated from the
experiment. Normal fertilization and pest man-
agement practices were used. All trees were
maintained as central leaders. With the excep-
tion of tjdng branches to the wires in the trellis
treatment, very Uttle limb positioning was per-
formed in the planting.
After 10 growing seasons, trees on M.7A
were the tallest, regardless of Mcintosh strain
(Table 1). Trees on M.26 and M.9/MM.1 1 1 were
similar in size and intermediate. Trees on M.9
were the shortest. Rogers trees were signifi-
cantly taUer than Macspur trees. Tree spread
followed a similar trend (Table 1); however,
trees on M.9 trained to a trellis had a greater
tree spread after 10 seasons than those trained
to a post. Clearly, this difference related to the
support provided to lateral branches by the
trelhs wires.
Tree spread was used to calculate poten-
tial tree density (Table 1). It was assumed that
trees could be planted 1 percent closer than the
spread measured after 10 seasons. Seven feet
Fruit Notes, Winter, 1993
Table 1. Tree size after 10 growing seasons and projected tree densities of Rogers Red
Mcintosh and Macspur Mcintosh on different rootstocks.
Tree height
Tree spread
Tree density
(fl)
(ft)
(trees/acre)*
Treatment
Rogers
Macspur
Rogers
Macspur
Rogers
Macspur
M.7A
14.8
a* 14.9
15.8
a 14.5
145
c 172
M.26
12.0
b 9.9
13.2
be 11.5
202
b 254
M.9 (post)
8.8
c 8.4
10.2
d 9.3
297
a 363
M.9 (trellis)
9.3
c 9.0
12.9
c 10.6
295
a 363
M.9/MM.111
11.5
b 10.0
14.3
b 12.0
172
b 239
Average
11.3
••• 10.4
13.3
- 11.5
222
- 278
Distance between trees within rows was projected to be 10% less than the natural tree
spread, allowing for overlap of trees. The distance between rows was the distance
between trees plus seven feet, with the exception of the trelhs, which was assumed to be
spaced 13 feet between rows.
For the three characteristics in this table, the relative differences between rootstock
treatments were statistically similar for each strain. The letter presented between the
Rogers and Macspur columns represents the differences among rootstock treatments only.
For a particular characteristic, if not represented by the same letter, rootstock treatments
are significantly different at odds of 19:1.
Rogers and Macspur averages are different at odds of 999:1.
were added to the distance between trees in a
row to determine between-row spacing, with the
exception of the trellis. Because of the shape of
the trelUs, it was assixmed that all trellis combi-
nations could be maintained at 13 feet. (This
assumption is conservative, and it depends on
the final width of the trellis rows.) Potential tree
density ranged from over 360 trees per acre of
Macspur/M.9 to 145 trees per acre for Rogers/
M.7A, Because of the difference in spread,
Macspur could be planted at approximately a 20
percent higher density than Rogers, assuming
no reversion.
Figures 1 and 2 show the cumulative
yield per tree for the rootstock treatments and
the Mcintosh strains, respectively. (jeneraUy,
larger trees )delded more per tree than smaller
trees, that is, trees on M.7A yielded more than
those on M.26, which yielded more than those on
M.9. The exception is M.9/MM. 111. Trees on
M.9/MM.111 yielded significantly less than the
trees on M.26, which were of similar size. Trees
on M.9 trained to a treUis yielded more than
those trained to a post. This result may have
occurred because the trellis maintains wood at
a more desirable angle for continued Smiting
and allows for upper branches to fill a larger
portion of the canopy than when no additional
support is provided. Additionally, the larger
Rogers trees yielded more than the Macspur
8
Fruit Notes, Winter, 1993
20
Rootstocks:
a
_
-»-M.7A
>
^15
-°-M.26
o>
-^ M.9 (post)
/ b
1
i»
^ M.9 (trellis)
Q.
|io
>>
-•-M.9/MM.111
1
y Ztf:=C^
Cumulative
...>^^'
1982 1983 1984 1985 1986 1987 1988
Figiire 1. Cumulative yield per tree through the tenth
growing season for each rootstock treatment (average of the
two Mcintosh strains).
20
— 15
o>
Q.
•55 10
>
E
3
o
Strains:
^*" Rogers
^ Macspur
/L^^^^'o
1982 1983
1984 1985
1986
1987
1988
Figure 2. Cumulative jdeld per tree through the tenth
growing season for each Mcintosh strain (average of the five
rootstock treatments).
Truit Notes, Winter, 1993
4
o
o
o
Rootstocks:
-•-M.7A
a.
k
33
-^M.26
-^ M.9 (post)
0C ^
r
1
•
2
^M.9 (trellis)
/ X^y^°
1.2
♦M.9/MM.111
y ///^ ^
>
«
>>
y1^^^^:^y^
?
3
E
3
u
.^^'^
1982 1983 1984 1985 1986 1987 1988
Figure 3. Cumulative yield per acre through the tenth
growing season for each roots tock treatment (average of the
two Mcintosh strains).
4
Strains:
^ Rogers
^3
"H- Macspur
a
1
y^ ^
£
u
y^^^b
//
•0
»
>>
^^^:^
>
3
E
3
1
^^---^
1982 1983 1984 1985 1986 1987 1988
Figure 4. Cumulative yield per acre through the tenth
growing season for each Mcintosh strain (average of the five
rootstock treatments).
10
Fruit Notes, Winter, 1993
Table 2. Economic comparison of the five rootstock treatments (average of both strains of
Mcintosh). Establishment costs were modified fi-om those presented in Fruit Notes 55(4): 1-5.
Growing and harvesting costs were modified from those presented in Fruit Notes 53(l):4-7.
Item
M.7A
M.26
M.9
(post)
M.9
(treUis)
M.9/
MM.lll
Costs:
Establishment
Growing
Harvesting
$920
$6,660
$4,780
$2,030
$6,540
$5,040
$2,980
$7,010
$5,170
$3,900
$7,190
$6,170
$1,730
$6,540
$3,730
Total yield (bu)*
2780 b
2930 b
3010 b
3590 a
2170 c
U.S. Extra Fancy,
1987 + 1988 (%)•
37 d
62 be
64 b
51 c
80 a
Fruit count per
42 lbs, 1988*
140 a
125 b
120 c
119 c
144 a
Estimated crop
value
$25,890
$36,210
$39,310
$42,650
$25,370
Net returns
$13,530
$22,610
$24,150
$25,390
$13,370
Within a row, means
19:1.
not followed by the same
letter are significantly different at odds of
trees.
Obviously, the amount of fi*\iit obtained
fix)m individual trees is of little importance
when the trees are at different densities. Fig-
ures 3 and 4 show the cumulative yield per acre
for the rootstock treatments and the Mcintosh
strains, respectively. M.9 trained to a trelHs
resulted in the highest jdelds per acre. M.9
trained to a post, M.26, and M.7 were statisti-
cally similar in cumulative yield, and M.9/
MM.lll resulted in the poorest yield per acre,
yielding only 60 percent of trees on M.9 trained
to a trelUs. Macspur trees outyielded Rogers
trees on a per-acre basis.
Factors other than yield must be consid-
ered before selecting the most desirable root-
stock or training system. Establishment, grow-
ing, and harvesting costs vary fi-om treatment to
treatment. Estimates of these differences are
presented in Table 2. Also, packout is an impor-
tant consideration. Table 2 presents the percent
of a whole-canopy random sample which made
the U.S. Extra Fancy grade in 1987 and 1988.
Trees on M.9/MM.111 produced the most high
grade fruit; whereas, trees on M.7A produced
the least. Of the M.9-rooted trees, those on posts
produced more U.S. Extra Fancy finiit than
those on trellises. These numbers were used to
approximate the grade distribution of fi-uit. It
was assimaed that one half of the fi-uit not
making U.S. Extra Fancy were Number 1 and
the other half were used for cider. These esti-
Fruit Notes, Winter, 1993
11
$30
o"
Rootstocks:
1 $25
-fr^M.TA
A
f
x^
2^ $20
u
10
-0-M.26
-^ M.9 (post)
0/
]
|$15
M
-A-M.9 (trellis)
♦ M.9/MM.111
1/ y
>
1 $10
yi'/ -^
^Z
c
ji^
Cumulative
U1 o
y^^^6^
^^
-$10
19
79 1980 1982 1982 1983 1984 1985 1986 1987 1988
Figure 5. Cumulative net returns per acre for the ten years
1979 through 1988.
mates are conservative, since the sample for
grading was random. Multiple pickings would
have resulted in greater percents in the highest
grade. Additionally, no summer pruning was
performed in our trellis treatment, and fruit
quahty clearly would have benefitted greatly
fi*om summer pruning.
Fruit size also varied significantly
among the treatments (Table 2). The average
fruit from trees on M.7 or M.9/MM.111 were
140-count or smaller. Fruit from trees on M.9
averaged nearly 120-count in size, and those
from trees on M.26 were somewhat smaller than
120-count.
When size and grade are considered,
along with yield, crop value can be estimated
(Table 2). Accomiting for crop value and costs,
Table 2 presents the net returns possible from
these treatments. The two M.9 and the M.26
treatments produced similar returns, with the
M.9 trellis treatment giving approximately five
percent more, and the M.26 treatment giving
approximately six percent less than the M.9
post. The M.7A treatment netted only 53 per-
cent of what the M. 9 trellis netted. M. 9/MM. Ill
was slightly less profitable than M.7A.
When evaluating different rootstocks
and training systems, it is necessary to assess
many different characteristics. Costs of estab-
hshment, training characteristics, jrield poten-
tial, fruit grade, fruit size, and costs of manage-
ment must all be considered before selecting an
appropriate combination. The best system is
the one that can be managed within the con-
straints of a particular grower and that provides
the best net returns to the orchard. In this
study, trees on M.9 and on M.26 were the most
profitable over the first ten years, and clearly
would be better choices than trees on either
M.7AorM.9/MM.lll.
^f^ %f^ %{« «£# %t«
0^ rj% rj% •Y* •Y*
12
Fruit Notes, Winter, 1993
Do Overwintering Red Mite Eggs
Portend Summer Mite Troubles?
Jennifer Mason, Margaret Christie, and Ronald Prokopy
Department of Entomology^ University of Massachusetts
Among foliar pests, European red mites
(ERM) remain a major problem for apple trees.
They can be particvdarly difGcvdt in second- level
IPM blocks, where growers are dependent on
predator mites to control summer ERM popula-
tions. In these blocks, current non-biological
control measures consist of one or two dormant
oil sprays in the spring prior to egg hatch. To
maintain control of ERM, predators build up to
levels capable of controlling the mites that
hatch. Unfortunately, it is difiicult to balance
spring oil control of ERM and encouragement of
a healthy population of predator mites. This
leads to the question: Can prebloom oil alone
effectively control summer ERM populations?
During January of 1992, we collected 200
buds per orchard from 11 orchards that partici-
pate in the second-level IPM project. Six of these
were full second-level IPM blocks, and five were
transitional second-level blocks. The percentage
of buds with ERM eggs present was recorded for
each block, and orchards were placed into three
categories: low (0-33%), medium (34-66%), and
high (67-100% of buds with mite eggs).
During late spring and summer months,
mite populations in each block were recorded as
part of normal IPM scouting procedures. ERM
presence or absence was counted on 200 fruit
cluster leaves beginning in May and continuing
through September. Examination of peak ERM
populations in the second-level IPM blocks in
May showed little or no apparent relationship
between winter ERM egg percentages and
spring mite numbers. Peak ERM populations in
June, however, were related to winter egg per-
centages (Table 1). The low and medium ERM
egg groups both had very low June ERM popula-
tions, but all orchards in the high ERM egg
group had substantial numbers of Jxine mites.
In first-level blocks there appeared to be no
consistent relationship between overwintering
egg numbers and June mites, which were low in
all of these orchard blocks (Table 1).
Of the second-level blocks, all received at
least one dormant oil spray prior to egg hatch in
the spring (Table 1). In the high group, two
blocks had received two sprays. In the low and
medium orchards, it appears that dormant oil
sprays were sufficient to control mite popula-
tions through June. In the orchards in the high
group, however, even those receiving two appli-
cations had thriving ERM populations by the
endof Jvme.
Further work needs to be done on the rela-
tionship between dormant oil sprays, overwin-
tering ERM eggs and resulting early summer
ERM populations before any firm conclusions
can be drawn. If these results are estabhshed as
fact, then oil spray recommendations may need
to be revised for blocks where high numbers of
overwintering ERM eggs are foxuid in winter
coimts. Without a strong predator population,
these orchards may be subjected to large sum-
mer ERM populations if they depend on normal
amoimts of prebloom oil to be effective. Higher
rates of oil (e.g., three gallons of oil per 100
gallons of water) at green tip or half -inch green
may be necessary, with a second oil treatment at
a lower rate at tight cluster. It is p>ossible,
however, that the higher mite numbers in the
high blocks may be "attractive" to predator
populations, and that these orchards may even-
tually become areas of good biological control.
Fruit Notes, Winter, 1993
13
Table 1.
Overwintering egg
and peak mite levels in eleven second-level and
eleven first-level IPM blocks.
Number of
Number of
dosage
Twigs with
Leaves with
prebloom oil
equivalents
overwintering
ERMin
Orchard
sprays
of oil
eggs (%)
June (peak %)
Second-level IPM blocks
A
3
1.8
4.5
2.5
B
2
0.9
8.5
0.0
C
1
1.0
16.0
0.5
D
2
1.5
35.0
0.0
E
2
44.5
0.0
F
2
1.3
56.0
0.5
G
2
1.5
58.0
1.5
H
1
0.8
81.0
13.0
I
1
0.3
90.0
19.5
J
2
1.0
90.0
13.0
K
2
1.5
92.0
19.5
First-level IPM blocks
A
3
1.8
4.5
2.5
B
2
1.3
31.0
1.5
E
2
37.5
2.0
F
2
1.3
40.0
2.5
G
2
1.5
44.0
0.5
C
1
1.0
63.0
0.5
J
2
0.8
75.5
6.5
I
2
0.8
78.5
0.0
D
2
1.5
81.0
0.0
K
2
1.5
81.5
0.0
H
1
1.0
87.0
4.0
1
Acknowledgements
We are grateful to the Massachusetts Soci-
ety for Promoting Agriculture, the USDA North-
east Regional IPM Competitive Grant Program,
and State/Federal IPM fimds for funding this
project.
%% %% ^t^ %% %f^
ry% •^ ry% ry% rj%
14
Fruit Notes, Winter, 1993
Evaluation of Red Coloring Strains of
Gala Apple
Duane W. Greene And Wesley R. Autio
Department of Plant & Soil Sciences, University of Massachusetts
Gala is an apple that has experienced a
recent and rapid rise in popularity throughout
the world. It is being planted heavily in Europe,
South America, New Zealand, and the United
States. Gala represented 25% of all apple trees
sold by Washington State nurseries in 1990.
Gala has many desirable characteristics,
including very high flesh quahty, attractive
appearance, precocity, and high productivity.
The original strain of Gala is not a red apple, but
rather, a cream-yellow one with an orange-red
cheek. Mutations in fruit skin coloring occur
readily. There is a general preference among
nurserymen and growers for red coloring strains
of a cultivar because there is the perception that
these strEuns are preferred by the consumer. It
is commonly accepted that the red coloring
strains of Delicious that are being sold today,
although very attractive, have decidedly infe-
rior quality compared
with the original Deli-
cious strain. Further,
production from some
strains of Delicious may
be only one third of more
productive strains.
There has been no
comprehensive evalua-
tion of the commonly-
available strains of Gala.
A Gala strain trial con-
taining Kidd's D-8 (stan-
dard). Royal, Regal
(Fulford), Imperial, and
Scarlet Gala was planted
at the University of Mas-
sachusetts Horticultural
Research Center in
Belchertown in 1988.
This report summarizes
growth, flowering, fruit characteristics, and
fi*uit quahty of these five strains of Gala.
lyees
Kidd's D-8 and Royal Gala were obtained
fi-om Stark Bros. Nursery, Louisiana, Missouri,
and Imperial and Regal Gala were obtained
fi-om Newark Nursery, Hartford, Michigan. All
trees were on M.26 roots tock and were similar in
caHper at planting. Propagating wood of Scarlet
Gala was obtained fix)m Txu-key Hollow Nursery
(Cumberland, Kentucky) in the spring of 1987,
bench grafted on M.26 rootstock and then lined
out in the nxirsery. In the spring of 1988, trees
were planted in a randomized complete block
design with eight rephcations. Each tree was
supported by a one-inch x 10-foot metal conduit
post set three feet in the ground. The first data
on these trees were collected in 1990.
Table 1. Growth in 1990 of five strains of Gala planted in 1988.
Strain
Kidd's
Royal
Scarlet
Imperial
Regal
Trunk cross-
Final
sectional
trunk
area
cross-
Tree
Tree
increase in
sectional
height (ft)
spread (ft)
1990 (in=^
area (in^)
9.6 a
7.9 a
1.4 a
5.3 a
9.9 a
7.6 a
1.5 a
5.6 a
8.9 a
5.0 b
1.4 a
4.0 b
10.2 a
7.6 a
1.7 a
5.2 a
9.2 a
6.9 a
1.6 a
4.9 a
Means within columns not followed by the same letter are
significantly diff'erent at odds of 19:1.
Fruit Notes, Winter, 1993
15
Growth
Prior to bud break in 1990, a line was
painted 20 inches above the soil surface and the
trunk circumference was measured. After leaf
fall, height, spread, and trunk circumference
were measured.
At the end of the third leaf. Gala strains
differed little in vegetative growth. The height
of all Gala strains was comparable, while the
spread of Scarlet was smaller than that of the
others (Table 1). The trunk circumference in-
crease of all Gala strains in 1990 was similar,
but the total cross-sectional area of Scarlet was
less. Scarlet Gala trees were smaller at planting
because they were bench grailed and grown for
only one year; the other strains were budded on
roots that were in the ground for one growing
season and grew an additional year after bud-
ding. Therefore, the small spread and trunk
cross-sectional area of Scarlet Gala trees is
probably a reflection of the tree size at planting
rather than inherent vigor of the strain.
Bloom, and Fruit Set
Two limbs per tree were selected at the pink
stage of flower development and the circumfer-
ences were measured. The numbers of blossom
clusters on one-year-old and two-year-old wood
were counted. In 1991, fi-uit set also was as-
sessed on these two hmbs in July by determining
separately the fruit persisting on one-year-old
and on older wood.
Spur bloom density was lowest on Scarlet
Gala and highest on Royal Gala in 1990, but
there were no differences in 1991 (Table 2).
Fruit set on all strains of Gala was comparable
Table 2.
Flower bud formation and fruit set of five strains of (Jala.*
Bloom density
Fruit set
(blossom clusters/in
Mimb
(firuit/in" limb
Strain
cross
.-sectional ar
ea)
cross-sectional area)
Spur
One-yr-old
Total
Spur
One-yr-old
Total
1990
Kidd's
52 ab
124 a
176 ab
..
Royal
63 a
123 a
186 a
~
~
~
Scarlet
16 c
128 a
144 be
—
~
~
Imperial
34 be
103 a
137 c
~
~
~
Regal
46 ab
102 a
148 be
1991
Kidd's
67 a
147 a
214 a
35 a
85 a
121 a
Royal
66 a
127 a
193 ab
44 a
77 a
121 a
Scarlet
61 a
132 a
192 ab
30 a
77 a
108 a
Imperial
48 a
117 a
164 b
25 a
67 a
92 a
Regal
52 a
134 a
185 ab
23 a
68 a
92 a
* Means
within columns and years not followed by
the same letter are
significantly different at odds of 19:1.
16
Fruit Notes, Winter, 1993
and very heavy. In general, the bloom density of
Imperial Gala was lower than that of the other
strains. Bloom on all trees was considered
'snowball* and excessive when compared to most
other cultivars. Although the lower bloom den-
sity of Imperial may have been real, it is of Uttle
practical significance because of the excessive
bloom that occurred on all strains in this trial.
All strains of Gala bloomed extensively and
comparably on one-year-old wood, accounting
for over two-thirds of the bloom. Following
June-drop, over two- thirds of the fruit that per-
sisted originated from one-year-old wood. Fruit
produced from bloom on one-year-old wood gen-
erally was small and the quality was inferior.
Since fruit size of Gala is normally small, and
lateral fi^dt are even smaller, it is important to
develop a thinning strategy for all strains of
Gala to remove fiiiit developing from lateral
bloom selectively.
Fruit Characteristics and Quality
At normal harvest, 15 fruit per tree were
sampled. Fruit were weighed, flesh firmness
and soluble soUds measured, ground color and
starch pattern were rated, and p>ercent red color
on each fi-uit was estimated to the nearest 10%.
In 1991, finit were harvested September 3, 12,
and 19. Additionally, stem-end cracking was
evaluated and the length-to-diameter ratio was
determined.
Table 3.
Fruit characteristics of five strains of Gala at harvest.*
Fruit
size
Flesh Soluble Red
Ground
1
i'edicel-end
(count/ firiimess
solids color
color
Starch
L/D
cracking
Strain
42-lb box)
(lbs)
(%) (%)
index**
index***
ratio
(%)****
1990
Kidd's
111 a
19.2 ab
14.2 b 74 b
7.1 b
5.6 a
__
__
Royal
114 a
19.9 a
14.6 b 88 a
7.1 b
5.0 a
~
~
Scarlet
119 a
19.7 a
15.0 ab 80 ab
7.2 b
5.4 a
—
—
Imperial
110 a
20.0 a
14.5 b 86 a
7.2 b
4.7 a
—
—
Regal
107 a
18.3 b
15.7 a 84 ab
1991
8.1 a
6.8 a
Kidd's
135 b
18.3 b
13.0 c 70 c
6.7 b
5.4 a
0.86
a 2.2 b
Royal
131 b
18.0 ab
13.2 b 77 b
6.8 b
5.2 a
0.87
a 1.1 b
Scarlet
126 b
19.6 a
14.2 a 78 b
6.9 b
5.1 a
0.86
a 4.6 b
Imperial
126 b
18.6 b
13.3 b 87 a
6.9 b
5.3 a
0.87
a 6.7 b
Regal
112 a
18.7 ab
14.4 a 89 a
7.5 a
5.9 a
0.86
a 21.1 a
* Means within col
umns and
years not followed by the same letter are significantly
different at odds of 19:1.
** Adapted from a
New Zealand Gala ground color
chart provided
by Dr. Ian
Warrington, 1 =
green; 10
= orange.
*** Starch chart developed by W. R. Autio, 1 =
immature; 9 = oveiinature. 1
*♦** Cracking on the third harvest, September 19, 1991.
Fruit Notes, Winter, 1993
17
There were no differences in fi-uit weight
among strains in 1990, but in 1991, Regal Gala
stood alone as the strain with the largest finiit
(Table 3). Strains differed in flesh firmness and
soluble solids but the differences were not con-
sistent in the two years evaluated. All strains of
Gala colored well, although red coloring selec-
tions generally had more red color. Quantitative
differences in red color among red coloring
sports were not consistent. Regal had the high-
est ground color rating, indicating a greater loss
of chlorophyll. Strains did not differ in either
starch index or length-to-diameter ratio. Sig-
nificant stem-end cracking did not occur vmtil
the last harvest in 1991 and then it occurred
only on Regal Gala.
There were clear indications that Regal Gala
was an early maturing strain. As Gala ripen,
ground color index, starch index, red color,
soluble sohds and finiit cracking increase. Regal
Gala differed consistently from the other strains
in each of these characteristics in a way that
indicated advanced ripening.
Cracking at harvest has been cited as a
problem with Gala in some areas, and that
problem may be associated with uneven ripen-
ing. If trees are thinned properly and pruned to
allow good light penetration, we have observed
that Gala can be picked injust two harvests. No
significant cracking occurred until the last har-
vest, and even then, it was restricted to Regal
Gala. All strains could have been harvested
before September 19, 1991, and Regal Gala a
week earlier, when cracking was minimal.
Therefore, we feel that cracking is not a problem
with Gala if finiit are harvested at the proper
time. When cracking does become a problem,
fi-uit maturity has advanced to a point where
fi-uit feel 'greasy*, and the postharvest life has
been diminished significantly.
Sensory and Visual Evaluation
In 1991, sensory and visued evaluation of
strains (Table 4) was done by 17 judges includ-
ing pomology faculty, pomology graduate stu-
dents, technical assistants, and students in an
orchard management class. Each panelist
evaluated three repUcations. A replication in-
cluded one fi-uit of each of the five strains and one
Table 4.
Visual and sensory evaluation of five strains of Gala at harvest*
Skin Flesh
Strain
Aroma
toughness crispness
Juiciness !
Sweetness
Acidity
Starchiness Flavor
Kidd'8
-0.1 a
0.2 a 0.1
b
0.2 a
0.2 a
-0.3
c
0.0 a 0.1c
Royal
-0.3 a
0.5 a 0.8
a
0.4 a
0.5 a
0.6
ab
-0.2 a 0.9 a
Scarlet
0.0 a
0.5 a 0.8
a
0.3 a
0.4 a
0.8
a
-0.1 a 0.7 ab
Imperial
-0.6 a
0.5 a 0.2
b
0.3 a
0.1 a
0.3
b
-0.2 a 0.4 be
Regal
-0.1 a
Color
0.6 a 0.4
Color
b
0.4 a
0.7 a
Overall
0.5
ab
0.0 a 1.1 a
Kidd'8
brightness
uniformity
Attractiveness
desirability
0.1c
-0.1 c
0.1 b
0.2 b
Royal
0.8 b
0.9 b
0.7 b
0.8 a
Scarlet
0.7 b
0.6 be
0.5 b
0.7 a
Imperial
0.7 b
0.8 b
0.8 b
0.5 ab
Regal
1.7 a
1.7 a
1.6 a
1.0 a
•Means within columns not followed by the
same letter
are significantly different at odds of 19:1.
18
Fruit Notes, Winter, 1993
reference fruit to which all of the strains were
compared. The reference fruit was Kidd's D-8,
and this fact was not divulged to the panehsts.
Judges scored each fi*uit on a horizontal scale
with opposite descriptive terms at each end of
the line and the center represented by the refer-
ence fruit. The intensity of the deviation of each
fi-uit from the reference fruit was recorded by a
pencil mark either to the right or left of the
reference fruit.
Taste pgmeUsts were able to distinguish dif-
ferences in quality and appearance among the
Gala strains. Royal, Scarlet, and Regal Gala all
were judged to have better flavor than Kidd's D-
8. Royal and Scarlet had the crispiest flesh. The
flesh of £dl red-coloring strains was more acid
than Kidd's D-8. There were no differences
eunong strains in aroma, skin toughness, juici-
ness, sweetness, or starchiness. Regal Gala was
judged to be the most attractive Gala strain. It
also had the brightest red color and the most
uniform color.
There are legitimate concerns that the Gala
strains selected solely on the basis of red skin
color may not have the same high quality char-
acteristics of the original Kidd's D-8 strain. Not
only were all strains judged to be equal to Kidd's
D-8, but when panelists considered all factors
and rated overall desirability, Royal, Scarlet,
and Regal Gala were selected as being better
than Kidd's D-8.
Conclusions
Growth Emd bloom characteristics of Gala
strains appeared to be similar; however, all
strains bloomed heavily on one-year-old wood.
Because of the lower value of fruit borne on this
wood, thinning strategies should target these
fruit.
Regal is an early maturing strain of Gala,
and was selected by paneUsts as the most attrac-
tive strain. Royal, Scarlet, and Regal were
judged to have better flavor and to be, overall,
more desirable than Kidd's D-8 Gala.
%|# %% %% ^f^ ^%
rj* #1% rj% #1% •Y*
Fruit Notes, Winter, 1993
19
Spiders in Second-level and First-level
Apple IPM Blocks
Joanna Wlsniewska, Yanghe Yang, and Ronald Prokopy
Department of Entomology^ University of Massachusetts
One of the principal practices of full second-
level IPM is to control key summer fruit pests by
a combination of behavioral and ecological tech-
niques, thus allowing beneficial predators and
parasitoids to increase enough to control sum-
mer foUar pests. Spiders may be an important
group of such predators. Insecticides can reduce
numbers and diversity of spiders in apple or-
chards. Therefore, full second-level IPM, which
eliminates insecticide use Eifter early June, may
allow spiders to prohferate in apple orchards.
In 1992, we assessed spider populations in
blocks of apple trees under full second- level IPM
compared with first-level IPM practices. Addi-
tionally, we conducted a laboratory test of the
effects of Guthionâ„¢, Thiodanâ„¢, and Omiteâ„¢ on
the most common spider species found in second-
level IPM blocks.
Besides these evaluations, we also were in-
terested in the effects of herbicides on spider
populations in these orchards. Frequently, veg-
etation growing under apple trees is controlled
in commercial orchards with herbicides applied
early in the growing season, v/hile vegetation
between the tree rows is mowed throughout the
season. These practices reduce competition for
nutrients, lower humidity (which may contrib-
ute to higher disease pressure), and eliminate
alternative sources of food and shelter for many
orchard pests. Herbicides can decrease spider
numbers in vegetable production systems
(Riechert and Bishop, 1990), but their effects
have not been examined in an orchard system.
Hence, in 1992, we examined the effects of
herbicide treatments on the number of spiders
on apple trees in second-level IPM blocks.
Spider Numbers in Full Second-level
and First-level IPM Blocks
Spiders were sampled in six apple orchards.
Each orchard contained a six- to nine-acre block
imder full second-level IPM and a nearby six- to
nine-acre block under grower-supervised first-
level IPM. Guthion and Thiodan were used in
both types of blocks through early or mid-June
to control early-season insect pests. After mid-
June, second-level blocks received no insecti-
cides while first-level blocks received an average
of 2 sprays of Guthion or Imidan (once in July
and once in August). All blocks were sprayed
with carbaryl in early June to thin finiit.
Beginning in early July, spiders were
sampled on twenty randomly chosen trees every
two to three weeks in both tjT)es of blocks in each
orchard by tapping tree branches with a rubber
mallet over a two-by-two-foot tray. Spiders were
preserved in 70% alcohol and returned to the
laboratory for identification, a process not yet
complete.
Figure 1 summarizes the results obtained
over the entire season. The mean number of
spiders collected per tree at the beginning of the
sampUng period (July 2) was very low and W£is
the same in both second-level and first-level
IPM blocks. As the season progressed, however,
these numbers increased to 1.5 spiders per tree
by late September in the second-level blocks
compared with 1.0 spiders per tree in the first-
level blocks. Data trends were similar for each
orchard considered, except for one orchard
where there seemed to be no difference between
the two types of blocks.
The low numbers of spiders per tree in early
July in all blocks may have been due to spraying
for plum curculio, which extended through early
to mid-June in all blocks. Beyond mid-June,
growers continued to use insecticides in the first-
level blocks but not in the second-level blocks.
This difference probably accounted for the
greater abundance of spiders in the second-level
20
Fruit Notes, Winter, 1993
1.8
1.6
-
O 2nd level IPM
• 1st level IPM
a
P
1)
t)
V
a.
1.4
1.2
-
/
/ -
V
•g
'q.
in
o
1.0
0.8
_
/ /
/•:
c
o
l>
2
0.6
0.4
-
c
/ /
V / b
0.2
_a
-4==^::^
»
b
0.0
7/2 7/17 7/30 B/23 9/10
Collection period
9/24
Figure 1. Numbers of spiders collected per tree ia full second-
level and first-level IPM blocks during 1992. Means within
each date accompanied by a different letter are significantly
different at odds of 19:1.
blocks during August and September, a conclu-
sion reinforced by laboratory findings (next sec-
tion).
Insecticide and Miticide Effects
on Spiders
To test the effects of insecticides and miti-
cides on spiders directly, a laboratory test was
conducted on the most common spider species
found in all six orchards: Araniella displicatta
(Araneidae). All individuals tested were imma-
ture, averaging 2 mm in size (the size found in
early September in the field). All were collected
at the same time in the same orchard. Spiders
ity to pesticides.
cation). Ten additional
jars were coated with
water as controls.
After 9 hours all 10
spiders in the Thiodan
jars were dead, as were 9
of the 10 in Guthion jars.
None died in the Omite or
control jars, although one
spider died in the Omite
jar after 45 hours.
These results indi-
cate that these insecti-
cides were highly toxic to
spiders, or at least to this
particular found species.
Omite, on the other hand,
was not very toxic to this
species of spider. It would
be inappropriate, how-
ever, to apply these find-
ings to all orchard pesti-
cide-use situations, in
that pesticide effects may
not be confined to pure
contact toxicity. Also,
many different spider
species exist and some
may differ from A.
displicatta in susceptibil-
Effects of Herbicides on Spiders
on Apple Trees
To determine if herbicide treatment of
ground cover affects the number of spiders on
trees, some trees in five second-level IPM blocks
were not treated with herbicide while a herbi-
cide treatment was apphed in May beneath
other trees. Two additional blocks (likewise
under full second-level IPM) at the University of
Massachusetts Horticultural Research Center
(HRC) in Belchertown also were employed in
this experiment. Herbicides vised included para-
were placed individually in glass jars coated quat and simizine in the HRC blocks, and these
with the substance to be tested. Ten jars were herbicides as well as Postâ„¢, amate, and
coated with Guthion, 10 with Thiodan, and 10 Fusiladeâ„¢ in the five second-level IPM blocks,
with Omite (each at standard field rate of appli- The two HRC blocks consisted of dwarf trees
Fruit Notes, Winter, 1993
21
3.5
3.0
" 2.5
«
a
m
\-
«)
â– o
â– q.
2.0
-s 1-5
o
u
2
1.0
0.5 -
0.0
O herbicides
• no herbicides
7/16 8/19
Collection period
8/31 9/15
Figure 2. Effects of herbicide treatment of ground cover on the
mean number of spiders per tree at different times of the
season. This portion of the study was conducted in two blocks
at the University of Massachusetts Horticultural Research
Center which were under second-level IPM. Means within
each date accompanied by a different letter are significantly
different at odds of 19:1.
(seven feet tall). On each sampling occasion (five
in all, starting Jvdy 1), spiders were collected
from 40 trees of each treatment. The five sec-
ond-level IPM blocks contained larger trees (10
to 13 feet tall). Forty to 65 of these in each
treatment were sampled on four different occa-
sions from each orchard. Sampling was carried
out by tapping the branches as described above.
In the five full second- level IPM blocks, her-
bicide treatments did not have any effect on the
number of spiders on trees. Mean numbers of
spiders per tree show the same seasonal trend
for herbicide as well as non-herbicide treat-
ments. In the two HRC blocks (Figure 2),
herbicide-treated trees contained significantly
more spiders in August
than non-herbicide-
treated trees. There were
no significant differences
earlier and later in the
season.
Lack of any difference
between herbicide- and
non-herbicide-treated
trees in the five second-
level IPM blocks might
have been due to the fact
that trees in these blocks
werematiire. Their cano-
pies reached well into the
vegetative region between
rows, diminishing the con-
trast between herbicide
and non-herbicide treat-
ments.
In general, it can be
concluded that no nega-
tive effect of herbicide
treatment on numbers of
spiders per tree has been
demonstrated by these
data. Among smaller
trees there may be a slight
positive effect. Perhaps
when an understory cover
exists directly beneath the
trees, spiders may forage
there for prey and be di-
verted away from the
trees. They may move back into the tree cano-
pies when there are more insect prey to be foimd
there than in the ground cover.
Conclusions
Spiders were found to be significantly more
abundant in second-level than in first-level IPM
blocks. This result suggests that elimination of
insecticide use after early or mid-June allows an
increase in population of at least one group of
natural enemies. High toxicity of broad-spec-
trum insecticides to spiders, as revealed in our
laboratory tests, supports this suggestion, £is do
findings of Mansour et al. (1980), Madsen and
22
Fruit Notes, Winter, 1993
Madsen (1982), and Bostonian et al. (1984) and
other authors.
The decreased number of spiders in first-
level IPM blocks may have been due not only to
direct contact toxicity of insecticide but also to
insecticide acting as a repellant to spiders, tox-
icity to spiders of prey feeding on insecticide-
treated plant material, lack of prey insects (as a
result of prey being killed or driven away by
pesticide), destruction of webs by turbulence
created by spraying, or a combination of these
and other factors.
Several questions stiU remain to be an-
swered. One of them is whether or not the
increased number of spiders in second-level IPM
blocks is great enough to contribute signifi-
cantly to the control of foliar pests. Can spiders
prey effectively on leafminers, leafhoppers, and
mites? Will they eat enough of such pests to
make a difference? We plan to address these
questions in the near futiu-e.
Acknowledgements
This project was funded by the Massachu-
setts Society for Promoting Agriculture, the
USDA Northeast Regional IPM Competitive
Grants Program, and State/Federal IPM funds.
We gratefully acknowledge this funding. We are
grateful to the following growers for their par-
ticipation and support: Dana Clark, Dave Chan-
dler, Dick Gilmore, Tony Lincoln, Wayne Rice,
and Joe Sincuk.
Literature Cited
Bostonian, N.J., CD. Dondale, M.R. Binns, D.
Pitre. 1984. Effects of pesticide use on spiders
(Araneae) in Quebec apple orchards. Canadian
Entomologist 116:663-675.
Madsen, H.F. and B.J. Madsen. 1982. Popula-
tions of beneficial and pest arthropods in an
organic and a pesticide treated apple orchard in
British Columbia. Canadian Entomologist
114:1083-1088.
Mansour, F., D. Rosen, and A. Sulov. 1980. A
survey of spider populations (Araneae) in
sprayed and unsprayed apple orchards in Israel
and their ability to feed on larvae of Spodoptera
littoralis (Boisd.). Acta Oecologica: Oecol.
Applic. 1:189-197.
Riechert,S.E. and L. Bishop. 1990. Prey control
by an assemblage of generalist predators: spi-
ders in garden test systems. Ecology 71:1441-
1450.
•^ ^JV •t» ^JV ^{f
^ ^ rfi rf» #Y*
Fruit Notes, Winter, 1993
23
Apple Integrated Pest Management
in 1992: Insects and Mites in
Second-level Orchard Blocks
Margaret Christie, Ronald Prokopy, Kathleen Leahy, Jennifer Mason,
Andrea Pelosi, and L. Kate White
Department of Entomology, University of Massachusetts
Last spring, in Fruit Notes [57(2):5-13], we
reported results of oiir first year of second-level
IPM trials in Massachusetts apple orchards.
Under second-level IPM, orchard management
is integrated across all classes of pests: insects,
mites, diseases, weeds, and vertebrates, rather
than focusing on a single type of pest. Here, we
report results of the second year of second- level
IPM trials on insects and mites in commercial
Massachusetts orchards.
Insect and mite management under second-
level IPM practices requires appUcation of three
to four selective insecticide sprays fi-om April to
early June to manage tarnished plant bug
(TPB), European apple sawfly (EAS), plum
curculio (PC), green fruitworm (GFW), the first
generations of codling moth (CM), lesser
appleworm (LAW), leafminer (LM), and leaf-
hopper (LH). Insecticide application to the inte-
rior of the block ceases after the final plum
ctu"cuho spray in early June, allowing natural
populations of predatory insects and parasitoids
to increase to levels we hope will be sufficient to
provide control of summer populations of foliar
pests. In full second-level IPM blocks, apple
maggot flies (AMF) are controlled by perimeter
interception traps. In transitional second-level
blocks, use of AMF interception traps is replaced
by perimeter row spraying with Guthion"â„¢ or
Imidan"â„¢ every three weeks beginning in early
Table 1. Average percent injury by early-season insect pests in second-level eind
first-level IPM blocks in 1992.*
Type of block
TPB
PC
EAS
GFW
Total
Full second-level 1.5 a 0.1 a 0.1a 0.0 a 1.7 a
First-level 2.3 a 0.1 a 0.1 a <0.1 a 2.5 a
Transitional second-level 1.1 a 0.5 a 0.1 a 0.2 a 1.9 a
First-level 0.7 a 0.1 a 0.1 a 0.1 a 1.0 a
* Means in each couplet in each column followed by a different letter are
significantly different at odds of 19:1. Two hundred fruit of each of three cultivars
(Mcintosh, Cortland, and Delicious) were sampled at harvest. TPB = tarnished
plant bug; PC = plum curculio; EAS = European apple sawfly; GFW = green
fruitworm.
24
Fruit Notes, Winter, 1993
July. In both typ>es of blocks, removal of
unmanaged apple and pear trees within 100
yards of each block reduces immigration of CM
and LAW. Removal of drops after harvest dis-
courages buildup of within-orchard populations
ofAMF, CM, andLAW.
In early April of 1 99 1 , we selected six full and
six transitional second-level IPM test blocks of
six to nine acres each. In 1992, we replaced one
of the transitional blocks (which had been sold
and was no longer available to us) with a new
block on another farm. Each second-level block
was matched with a nearby control block which
weis managed by the grower, using first-level
IPM methods.
Early-season Fruit-injuring Pests
For control of arthropod pests active up to
early June, second-level IPM reUes on early-
season pesticide treatment based on monitor-
ing. We monitored each orchard weekly begin-
ning in mid-April, then biweekly from mid-Jime
through September. Five each of four types of
sticky traps were hung in each block to monitor
for TPB, LM, and EAS. We examined 100 or 200
leaves or terminals per block for LM, LH,
aphids, mites, and mite predators. Fruit were
examined both by IPM scouts and growers for
fresh PC injury. Based on this monitoring,
recommendations were made to the grower for
treatment of the experimental block.
In second-level IPM blocks (both fiill and
transitional) in 1992, combined injuries from
early-season fruit pests were simUsu" to those in
nearby first-level IPM (grower control) blocks.
In both first- and second-level IPM blocks, TPB
caused the greatest amount of injiuy, followed
by PC, EAS, and GFW (Table 1). Early season
insecticide use was similar in both types of
blocks, probably because both types were man-
aged through identical first-level IPM tech-
niques (Table 2). Injury by these early-season
pests was lower in 1992 than in 1991.
Table 2. Dosage equivalent
s (spray
events
in parentheses) of
insecticides and acaricides
used in second-level and first-level IPM blocks in 1992.*
Fruit pests
Mites
Before
After
mid-
mid-
Other
Type of block
June
June
Oil
miticides
LH
ABLM
Total
Full
second-level
2.4
0.0
0.9
0.0
0.2
1.1
4.6
(4.0)
(0.0)
(1.8)
(0.0)
(0.2)
(1.0)
(7.0)
First-level
2.8
2.0
1.1
0.1
0.0
0.4
6.4
(3.8)
(2.2)
(1.8)
(0.2)
(0.0)
(0.5)
(8.5)
Transitional
second-level
2.7
0.7
1.2
0.3
0.0
1.0
5.9
(3.4)
(2.6)
(2.0)
(0.2)
(0.0)
(1.0)
(9.2)
First-level
3.3
3.1
1.3
1.1
0.0
0.5
9.3
(3.6)
(3.2)
(2.0)
(1.0)
(0.0)
(0.6)
(10.4)
* LH = leafhopper; ABLM
= apple
blotch leafminer.
Fruit Notes, Winter, 1993
25
Table 3. Season-long apple maggot fly (AMF) injury and trap captures in second-level
IPM blocks and first-level IPM blocks in 1992.*
Interior
Perimeter
% AMF
monitoring
monitoring
Interception
injury
trap
trap
trap
to finiit
captures
captures
captures
Type of block
at harvest
per trap
per trap
per block
Full second-level
0.4 a
9.0 a
16.2 a
2430
First-level
0.1 a
6.9 a
14.4 a
-
Transitional second-level
0.2 a
3.5 a
5.9 a
„
First-level
0.1 a
3.7 a
5.6 a
—
* Means in each couplet in each column followed by a different letter are significantly
different at odds of 19:1. Two hundred finiit of each of three cultivars (Mcintosh,
Cortland, and Delicious) and two hundred border row fruit of mixed cultivars were
sampled at harvest.
Table 4. Fruit injury by codling moth (CM), leafrollers (LR), lesser
appleworms (LAW), and San Jose scale (SJS) in second-level and first-
level IPM blocks in 1992.*
Type of block
CM
LR
LAW
SJS
Full second-level
First-level
Transitional second-level
First-level
<0.1 a
0.2
a
0.0
a
0.0
a
<0.1 a
0.1
a
0.0
a
0.0
a
0.0 a
0.2
a
0.0
a
0.0
a
0.0 a
<0.1
a
0.0
a
0.0
a
* Means in each couplet in each column followed by a different letter
are significantly different at odds of 19:1. Two hundred fniit of each
of three cultivars (Mcintosh, Cortland, and Delicious) were sampled
at harvest, and for CM and LR and additional two hundred border-
row fruit of mixed cultivars were sampled at harvest.
26
Fruit Notes, Winter, 1993
Summer Fruit-injuring Pests:
Full Second-level IPM
Odor-baited sticky red spheres were hung
every five yards on perimeter apple trees of each
full second-level experimental block to intercept
immigrating AMF. These were baited with both
butyl hexanoate, a synthetic fi-uit odor deployed
in polyethylene vials, and ammonivun acetate, a
sjTithetic food odor released through a Consepâ„¢
membrane.
Interception trap captures averaged 2430 in
the six full second-level blocks, indicating that
AMF pressure was moderate in 1992. In 1991,
trap captures averaged 3562 in three blocks in
which traps were baited with both food and firuit
odor. Captures ofAMF on four interior unbEii ted
monitoring traps (indicative of AMF penetra-
tion into the block interior) were statistically
similar in second-level blocks and in nearby
first-level blocks. AMF injury to firuit at harvest
in second-level blocks was similar to that in
nearby first-level blocks (Table 3). One second-
level block, however, had 8% injury to Cortlands
in mid-September. The nearby first-level block
had no Cortlands , and all the Mcintosh had been
picked, so no comparison was available.
The second year of use of both butyl
hexanoate and ammonivim acetate (or carbon-
ate) to bait the AMF interception traps indicates
that this double-odor strategy may be very effec-
tive in large blocks. We ehminated the problem
of quick loss of ammonia by replacing polyethyl-
ene vials with slow release membranes. Tests
performed in our laboratory showed that flies
continue to be attracted to these membranes
even afler they have been in the field for several
months. Tests also indicated, however, that
fewer flies approached the trap if the membrane
flapped loosely in the wind. In addition, traps
may require more fi-equent cleaning than we
had previously thought, especially if the double-
odor trapping procedure results in the capture of
additional non-target insects. In 1992, we
cleaned our traps once a month, but in one
orchard, trap captures during a one-month pe-
riod were 271% higher on traps which were
cleaned of all insects than on those which were
not cleaned thoroughly, indicating that as in-
sects build up on the traps, trap captures de-
crease. In high-pressure situations, more fre-
quent trap cleaning may be necessary if AMF
are to be captured effectively.
Fruit injury by CM averaged less than 0.1%
in both block types for the second year.
LeafroUer (LR) injury averaged 0.2% in fuU
second-level blocks for the second year, and was
0.1% in nearby first-level blocks (Table 4). We
will continue to monitor carefiilly for leafrollers
because of concern that leafi-oller populations
may grow in blocks in which the interior is not
sprayed afler early or mid-June. No LAW or San
Jose scale (SJS) injury was found (Table 4).
No insecticides were apphed in second-level
blocks after mid-Jime. In the companion first-
level blocks, growers applied an average of 2.0
dosage equivalents of pesticide after mid-June,
and sprayed the block an average of 2.2 times
(Table 2).
Summer Fruit-injuring Pests:
Transitional Second-level IPM
Every three weeks after early June, i)erim-
eter row apple trees in transitional second-level
blocks were treated with insecticide to control
AMF. The block interior remained firee of insec-
ticide after early June. AMF injury averaged
0.2% in transitional second-level blocks and
0.1% in the nearby first-level blocks, slightly
lower in both cases than in 1991. On average,
3.5 AMF were captured on unbaited interior
monitoring traps in transitional second-level
blocks and 3.7 in first-level blocks, indicating
that in most cases relatively few AMF pen-
etrated into the orchard interior (Table 3). In-
secticide use after mid- June was reduced signifi-
cantly in transitional second-level blocks com-
pared to first-level blocks because apphcations
were made only to the block perimeter. Total
dosage equivalents of insecticide applied
against fi-uit pests afler mid-June averaged 0.7
in transitional second-level blocks and 3.1 in
first-level blocks. Growers also sprayed transi-
tional second-level blocks slightly less fre-
quently (Table 2).
Unmanaged apple and pear trees were re-
moved fi"om within 100 yards of the six transi-
Fruit Notes, Winter, 1993
27
Table 5. Peak levels of mites and mite predators in second-level and first-
level IPM blocks in 1992.*
Mite presence (% of leaves)
Type of block
ERM+TSM
Af
YM
Ratio of
ERM+TSM to Af
Full second-level 43.2 a
First-level 42.5 a
Transitional second-level 25.7 a
First-level 20.3 a
1.5 a
2.7 a
0.5 a
1.0 a
3.7 a
0.9 a
0.4 a
0.7 a
29:1
16:1
51:1
20:1
* Means in each couplet in each column followed by a different letter are
significantly different at odds of 19:1. ERM = European red mite; TSM
= two-spotted mite; Af = Amblysieus fallacis; YM = yellow mite.
Table 6. Foliar insect pest peak population and injury levels in second-level and first-level
blocks in 1992.*
Type of
PLH
WALK
block
PLH
injury
WALK
injury
ABLM
GAA
GAAP
WAA
Full
second-level
11.2 a
15.0 a
13.8 a
0.3 a
10.8 a
68.7 a
54.5 a
6.2 a
First-level
2.3 b
6.3 a
10.6 a
3.4 a
13.6 a
69.5 a
44.3 a
3.3 a
Transitional
second-level
7.2 a
4.5 a
6.1 a
9.3 a
10.8 a
77.3 a
55.3 a
8.2 a
First-level
0.5 b
0.5 a
1.1 a
0.4 a
11.8 a
65.3 a
57.0 a
11.0 a
* Means in each couplet in each column followed by a different letter are significantly
different at odds of 19:1. PLH = potato leafhopper, WALH = white apple leaftiopper;
ABLM = apple blotch leafminer; WAA = wooly apple aphid; GAA = green apple aphid;
GAAP = green apple aphid predators: cecidomyiids and syrphids. Data for PLH, PLH
injury, and WALH is in terms of percent of terminals examined. Data for WALH is in
terms of percent of fruit examined at harvest. Data for ABLM is in terms of the average
number of mines per 100 leaves. Data for GAA, GAAP, and WAA is in terms of the
percent of watersprouts examined.
28
Fruit Notes, Winter, 1993
tional second-level blocks. No CM injury was
seen in the transitional second-level blocks or
their companion first-level blocks. LR injury
was sUghtly, but not significantly higher in the
transitional second-level blocks than in the first-
level blocks. LR injury in transitional second-
level blocks was no higher in 1992 than in 1991.
No sampled fi-uit in either block were damaged
by SJS or LAW (Table 4).
Foliar Pests and Predators:
Full Second-level IPM
In 1991, we reported season-long average
population levels of fohar pests; this year we
noted their p>eak populations in an efifort to
reflect damage more accurately. Cool and wet
summer weather helped to maintain low popu-
lations of fohar pests in most cases.
Mite popxilations remained low in most
cases, as were populations ofAmblysieusfallacis
predators, which were not seen in full second-
level blocks until late August, £md were never
present in numbers thought to be sufficient to
achieve biocontrol. Yellow mite predator popu-
lations were slightly higher in second-level than
in first-level blocks throughout the summer, but
their abiUty to control any but the lowest mite
populations is questionable (Table 5).
Another predator, Typhlodemus pyri, which
is present in orchards in Western New York, was
released in two second-level IPM blocks. Sam-
pling one month after release revealed high
numbers of these mite predators on release
trees. We wiU not know until 1993 whether or
not they survived the winter and spring and
successfully colonized the blocks.
Both full second-level and nearby first-level
blocks were treated with about one dosage
equivadent of oil (Table 2). No other miticide was
used in full second-level blocks, and only one
grower apphed miticide to a first-level block.
Potato leafhopper peak population levels on
terminals were higher in full second-level than
in first-level blocks. Potato leafhoppers infested
11% of sampled terminals in full second-level
blocks and 2% in nearby first-level blocks. Peak
potato leafhopper injury to terminals was 15%
in second-level and 6% in first-level blocks.
White apple leafhoppers infested 14% of
sampled terminals in second-level blocks and
11% in first-level blocks; however, injury to fi-uit
averaged only 0.3% in second-level blocks, ver-
sus 3.4% in first-level blocks (Table 6). Injury in
first-level blocks, however, was confined prima-
rily to one orchard. In August, we identified rose
leafhoppers in all t)T)es of orchard blocks, but
further study is needed to determine their im-
portance in Massachusetts orchards. Pesticide
was applied against leafhoppers in early June in
only one second-level block, which had a signifi-
cant late-season infestation in 1991 (Table 2).
Average peak leafininer population levels
were similar in the second-level blocks and first-
level blocks (Table 6). All of the six fiill second-
level blocks were treated with DimUinâ„¢ against
leafminers (Table 2). Leafininer population
levels throughout the summer confirmed our
previous conclusion that apphcation of DimUin
against the overwintering generation of
leafininer adults, when indicated by trap cap-
tures, is the most effective and least invasive
technique for their control. Treatment with
Dimihn is preferable to use of other materials
which are harsher on beneficial insects and
mites. Dimilin was not available for vise in first-
level blocks, and few growers chose to treat
leafminers in those blocks. If registered, Dimilin
will be a good option for control of leafminers
without serious disruption of beneficials. We
chose to apply it before bloom so that it did not
affect leafi:x)ller and codling moth populations,
which we are trjdng to study in the absence of
insecticide use after mid-June. If registered,
Dimilin could be used later in the season after
first-generation mines have appeared, allowing
growers to avoid its use in years in which it may
not be needed.
In other articles, we provide data indicating
that predacious spiders are significantly more
abundant late in the growing season in second-
level blocks than in first-level IPM blocks, and
that some of these spiders feed on leafininer
larvae inside mines as well as on leafhopper
nymphs.
Green apple aphid (GAA) populations were
almost the same in the two types of blocks. At
their peak, aphids infested 69% of sampled
Fruit Notes, Winter, 1993
29
terminals in full second-level blocks and 70% in
nearby first-level blocks. Two aphid predators,
sjrrphid and cecidomyiid flies, were slightly
more prevalent in second-level blocks than in
first-level blocks. These high levels indicate
that predators achieved control of GAA in both
second-level and first- level IPM blocks. Infesta-
tion of terminals by wooly apple aphid (WAA)
was similar in second-level and first-level
blocks, but in both types of blocks WAA popula-
tions were lower in 1992 than in 1991 (Table 6).
Foliar Pests and Predators:
Transitional Second-level IPM
Very few Amblysieus fallacis predatory
mites were seen in transitional second-level or
nearby first-level blocks luitU September (Table
5). Mite levels in most cases remained low,
although one grower had European red mite
populations in his transitional second-level
block sufficient to warrant treatment with a
miticide in mid-summer (Table 2). Mid-season
miticides were applied in four of the six first-
level blocks, with an average of 1.1 dosage
equivalents of miticide per block (Table 2).
Potato leafhopper infestation levels on ter-
minals averaged higher in transitional second-
level blocks than in nearby first-level blocks. In
transitional second-level blocks, white apple
leafhoppers infested 6% and potato leaflioppers
7% of terminals at their peak, while in nearby
first-level blocks, both white apple leafhopper
and potato leafhopper populations peaked at
about 1% of terminals infested. White apple
leafhopper injury to frmt at harvest was statis-
tically simUar in transitioned second-level and
first-level blocks, and potato leaQiopper injury
also was statistically similar in transitioned
second-level and first-level blocks (Table 6). In
no case did these insects cause serious problems
for growers.
All six transitional second-level blocks were
treated with DimiUn against first generation
leafminers. Only two growers treated their
first-level blocks for leafminers (Table 2). Peak
numbers of mines on 100 leaves averaged 10.8
in transitional second-level blocks and 11.8 in
first-level blocks, considerably lower in both
blocks than in 1991 (Table 6).
GAA populations were higher in 1992 than
in 1991. At their peak, they infested an average
of 77% of terminals in transitional second-level
blocks and 65% of terminals in nearby first-level
blocks. Predator populations were higher this
year as well; their populations peaked at an
average of 55% of terminals infested in transi-
tional second-level blocks and 57% of terminals
in first-level blocks. In both cases predators
were adequate to provide control of aphid pests.
Similar numbers of terminals in the transitional
second-level blocks and in first-level blocks were
infested with wooly apple aphids (Table 6).
Conclusions
We continue to be pleased with the success of
implementation of second-level IPM for apple
insects and mites in six- to nine-acre blocks in
commercial orchards. In 1992, full second-level
IPM blocks received 28% less total dosage
equivalents of insecticide and miticide and 18%
fewer total spray events for insects and mites
than first-level IPM blocks. Excluding pre-
bloom sprays of oil (non-toxic in the environ-
ment), dosage equivalents were reduced 30%
and spray events were reduced 22%. Despite
this difference, total firut injury by insects was
similar in full second-level and first-level IPM
blocks, and peak populations of foUar pests were
not different, except for leafhoppers.
Early season fruit injury from PC, TPB,
EAS, and GFW was low in all cases, as was finiit
injury by CM, LR, LAW, and SJS. GAA were
controlled by predators in both second-level and
first-level blocks. We continue to work toward
gaining registration of Dimilin, which provides
good control of leafminers without disrupting
beneficial parasites and predators.
Transitional second-level IPM appears to be
an effective reduced-spray management pro-
gram for insect and mite pests in commercial
orchards. In 1992, transitional second-level
IPM blocks received 37% less total dosage
equivalents of insecticide and miticide and 12%
fewer total spray events for insects and mites
than first-level IPM blocks. Total fruit injury by
insects did, however, average sUghtly but not
30
Fruit Notes, Winter, 1993
significantly higher in transitional second-level
blocks than in first-level blocks. Peak popula-
tions of foUar pests were Uttle different, except
for leaflioppers, which were somewhat more
abundant in the transitional second-level
blocks.
For 1991 and 1992, combined, transitional
second-level IPM blocks received about 17%
more insecticide and miticide and 23% more
spray events than full second-level IPM blocks.
Insect-caused fi*uit injury averaged over both
years was virtually identical in full and transi-
tional second-level blocks.
Our main concern with the benefits of tran-
sitional second-level IPM over the long-term Ues
with the potential buildup of AMF from infested
fallen drops not removed at harvest. The odor
baits employed with the interception traps im-
der full second-level IPM can attract these AMF.
A second concern with the long-term benefits of
transitional second- level IPM Hes with potential
negative effects of perimeter-row sprays on im-
migration of beneficial predators and parasites.
Two more years of planned comparison of full
second-level IPM vs. transitional second-level
IPM vs. first-level IPM orchard practices should
provide more insight into the benefits and costs
of each practice.
A second year of trials has not answered all
of our questions about two foUar pests, mites
and leafhoppers. Although mites were rarely a
problem in this wet, cool summer, predator
populations were low even where pest mites
existed in numbers sufficient to support them.
We need to learn more about overwintering
locations of mite predators and about the exact
identity of predators in Massachusetts or-
chgirds. Further monitoring of the newly-re-
leased predator, Typhlodemus pyri, will help us
to determine if release of this pesticide-resistant
predator could help to control pest mites in
Massachusetts orchards. We will continue to
study the role of spiders in pre3dng on leafinLners
in mines and on leafhopper njrmphs.
In our judgement, the key to grower adop-
tion of second- level IPM practices for insects and
mites hes in availabihty of a low-cost approach
to interception trapping of AMF. At present,
costs of labor and materials to employ odor-
baited sticky red spheres exceeds by nearly
twofold the cost of applying insecticide sprays
against AMF and other summer finiit-injuring
insects. The fi:^quent cleaning of sticky traps
necessary to provide an effective capturing sur-
face is a major component of the cost of this
system. We believe that development of pesti-
cide-treated spheres (now in progress) as a sub-
stitute for sticky spheres will provide a cost-
effective approach to using interception traps
for this insect.
Even if we assume that a pesticide-treated
sphere interception trap system for AMF will be
no more costly than applying insecticide after
mid-Jime, why should a grower want to switch
from an insecticide-based first-level IPM ap-
proach? We believe there are at least four
reasons for doing so: ( 1) saving money on sprays
against foliar pests by allowing beneficial natu-
ral enemies to build up and provide control in the
absence of pesticide use; (2) reducing the UkeU-
hood that foHar pests will develop resistance to
pesticides, thereby preserving the long-term ef-
fectiveness of these pesticides; (3) reducing pes-
ticide intrusions on neighbors or the environ-
ment adjacent to orchards; and (4) greatly re-
ducing or eliminating pesticide residues on finait
at harvest. For some growers, these potential
advantages could be large.
Acknowledgements
This project was funded by the Massachu-
setts Society for Promoting Agriculture, the
USDA Northeast Regional IPM Competitive
IPM Grants Program, State/Federal IPM funds,
and the Northeast Region Sustainable Agricul-
ture Research and Education Program (for-
merly LISA). We gratefully acknowledge this
funding. We are also grateful for the participa-
tion and support of the following growers: Bill
Broderick, Dave Chandler, Dana Clark, Dick,
Greg, and Kevin Gilmore, Tony Lincoln, Jesse
and Wayne Rice, Joe Sincuk, Dave Shearer, Tim
Smith, £md Barry and Bud Wiles, and for the
scouting assistance of Ryan Elliott, Kathy
Hickey, James Gamble, £md Peter Winnick of
the Department of Plant Pathology.
Fruit Notes, Winter, 1993
31
Fruit Notes
University of Massachusetts
Department of Plant & Soil Sciences
205 Bowditch Hall
Amherst, MA 01003
Nonprofit Organization
U.S. Postage Paid
Permit No. 2
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SERIAL SECTION
UNIV. OF MASSACHUSEHS LIBRARY
AMHERST, MA 01003
Account No. 3-20685
ISSN 0427-6906
Fruit Notes
Prepared by the Department of Plant & Soil Sciences. j zsi j y Q F M A S S
University of Massachusetts Cooperative Extension System.
United States Department of Agriculture, and Massachusetts Counties Cooperating.
HP A P \^
APR -6 S3
Eklitors: Wesley R. Autio and William J. Bramlage
AJr(/yan shomhtos
£661 ZO -^w
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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Fruit Notes
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University of Massachusetts
Amherst, MA 01003
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J
Spiders That Feed on Leafhoppers
and Leafminer Larvae
Joanna \^sniewska and Ronald Prokopy
Department of Entomology, University of Massachusetts
Recently in Fruit Notes [58(1): 20-23], we
showed that spiders were signiRcantly more abun-
dant in second-level than in first-level IPM blocks.
We concluded by asking whether or not increased
numbers of spiders in second-level blocks were great
enough to contribute to the control of foliar pests.
Here, we describe 1992 laboratory studies in which
some of the most abundant types of spiders collected
in second-level blocks were offered white apple leaf-
hopper nymphs and adults and apple blotch
leafminer larvae as potential prey.
Each spider was placed in a waxed paper cup
(four inches tall by three inches in diameter) with a
plastic lid. Into each cup we introduced an apple leaf
kept turgid by placing its stem in water. The leaf
harbored one tissue-feeding (late instar) leafminer
larva and two
leafhopper
nymphs (or
one nymph
and one
adult). The
test lasted for
24 hours. Re-
sults
are
in
Table 1. Laboratory tests of orchard-collected spiders feeding on
potential prey.
Family
of spiders
Number
tested
a cat stalks a mouse before the final pounce. They
may even capture it in mid air and then climb back
to the leaf fVom which they have jumped using a
piece of silk previously attached to that leaf. Salticid
spiders are successful nine times out often. They are
active only during the day.
Of the Araneid spiders, 28% fed on leafhoppers.
Most of these spiders were smaU immature individu-
als otAraniella displicatta, which are found com-
monly on terminals of apple tree branches. They
build tiny orb webs stretching across dorsal surfaces
of leaves. Their webs are found at night and during
the day. These spiders prayed mostly on the adult
leafhoppers which got caught in their webs.
Only members of the Anyphaenid family fed on
leafminers. Predation on leafminer larvae took
place by 90%
of the
Anyphaenid
spiders
tested. In all
the
Spiders that
fed on
leafhoppers (%)
Spiders that fed
on leafminer
larvae (%)
Philodromidae
Araneidae
Salticidae
Anyphaenidae
Thomisidae
27
22
11
10
7
given
Table 1.
Of the
five families
of spiders ex-
a m i n e d , _^^^^^^___^^^^^^_^^^^^_
members of
three families fed on leafhoppers: Anyphaenidae
(hunting spiders), Salticidae (jumping spiders), and
Araneidae (orb web spiders). The Anaphyenid spi-
ders were the most voracious, as 100% of the tested
individuals fed on leafhopper nymphs and adults
(their behavior will be described later in conjunction
with predation on leafminers).
Of the Salticid spiders, 36% fed on leafhoppers.
These visually oriented spiders are often observed
running around on leaves and branches moving
their heads from side to side as they search for prey.
Once they locate a prey insect, they stalk it much as
4
28
36
100
90
cases
mines were
opened from
the underside
of the leaf and
the larvae
were missing.
It was not
possible to
identify the
specific spe-
cies, because they all were immature. But our best
guess is that 9 of the 10 individuals tested were
Aysha gracillis. These hunting spiders are common
on foliage. They forage for prey mostly by sensing
vibrations on leaves and (possibly) branches. They
were often found foraging at night but they may also
be active during the day.
The type of leafminer predation observed in this
experiment is characterized by a very specific mark
left on the leaves. For this reason it may be possible
to quantify predation by Anyphaenid spiders in the
field by counting the leaves which have the signs of
Fruit Notes, Spring, 1993
predation and those which do not, provided that
observations are made soon after predation. We
conducted a preliminary study to quantify predation
in this way.
In one of the three orchards where spiders were
collected for use in the feeding test (University of
Massachusetts Horticultural Research Center,
Belchertown), we inspected 600 randomly selected
leaves from 60 different apple trees on October 7. Of
these leaves, 228 had leafrniner mines, 20% of which
appeared damaged due to spider predation. In other
words, 20% of the leafrniner larvae in the orchard in
late September may have been prayed upon by
Anyphaenid spiders. To compare this finding with
what may be taking place in an orchard that has
more spiders, on November 5, we inspected 169
randomly selected leaves containing leafrniner lar-
vae on four apple trees in an abandoned apple
orchard (Orchard Hill area at the University of
Massachusetts at Amherst). Of these mines, 37%
appeared damaged due to predation of Anyphaenid
spiders.
Even though these findings are very prelimi-
nary, they suggest that spiders of at least three
families exhibiting different foragingstrategies may
be able to prey upon some of the most troublesome
foliar pests of apple orchards. Aysha species of the
family Anyphaenidae, in particular, may play a
beneficial role in leafhopper and leafrniner control.
In 1993, we plan to conduct feeding tests on more
spider species commonly found in second-level or-
chard blocks and more individuals of each species.
We also plan to conduct these tests under more
natural conditions than the highly confining condi-
tions of the laboratory used in 1992. We also hope to
investigate the relationship between spiders feeding
on leafminers and beneficial parasitoids feeding on
leafminers. For example, it would be important to
know if (and how much) spiders are likely to prey
upon parasitized leafminers. Are spiders beneficial
if they selectively extract parasitized leafrniner lar-
vae but leave unparasitized larvae alone? HopefuUy
our planned 1993 research wUI provide greater
insight into the value of spiders as biological control
agents of foliar apple pests.
Acknowledgments
This project was funded by the Massachusetts
Society for Promoting Agriculture, the USDA
Northeast Regional IPM Competitive Grant Pro-
gram, and State/Federal IPM funds. We gratefiilly
acknowledge this funding. We are grateful to the
following growers for their participation and sup-
port: Dana Clark, Dave Chandler, Dick Gilmore,
Tony Lincoln, Wayne Rice, and Joe Sincuk.
%f^ •S^ mS^ ^# •S^
0^ rj% w^ r{% 0^
Apple Growing in China
Ronald J. Prokopy, M^lliam M. Coli, and Jian Jun Duan
Department of Entomology, University of Massachusetts
In Jiine of 1992, we had the wonderful oppor-
tunity of visiting several apple orchards in vari-
ous parts of east-central China in combination
with a trip to the International Congress of
Entomology in Bejing. We thought it might be
interesting to convey some of the things that
impressed us.
First of all, a bit of history. According to our
Chinese colleagues, apples have been grown in
China for at least 2000 years. Apples are planted
on nearly four million acres in China, equal to
about one-third of all acreage devoted to horti-
cultural crops. China is roughly the size and
shape of the continental United State. This
means that a greater percent of the land area of
China is devoted to apples than in the United
States (which has about 500,000 acres in
apples). Although production per acre is not
nearly as great in China as in the United States,
total production is about the same: 230 million
bushels a year. Many Chinese orchards are
newly planted, thus partly accoiinting for low
Fruit Notes, Spring, 1993
average yield. In the United States, we produce
about one bushel for every person. In China,
production is about one bushel for every five
people. Because living standards are improving
very rapidly in China, there is a potential mar-
ket for firuit appearing from either a major
increase in Chinese apple production or mcgor
importation of apples fi:t)m abroad. The most
popular cxiltivars in China are DeUdous and
Golden Delicious and more recently Fuji and
"Red Snake."
Presently, most orchards are owned by com-
mimes. Each family in the commune is entitled
to lease about three acres of land firom the
commime and farm it in any way the family sees
fit. The family can keep whatever it earns. All
the trees that we saw were dwarf or semi-dwarf.
One of the fascinating things to us was that
every 20 rows or so were managed by a different
family and often in a different way. So your
immediate neighbor's horticultural practices
could have a very strong influence on your crop,
for better or for worse.
Another fascinating thing was the absence
of £my vegetation whatsoever beneath the trees
but the lush vegetation of other crops grown in
the allesrways between rows. These crops in-
cluded peanuts, cotton, strawberries, melons,
com, and several others. All vegetation beneath
trees was removed by stout Chinese hoes in
order to reduce the drain of vegetation on water
and nutrients. We wondered how it was fmssible
to run tractors and sprayers down the allejrways
without crushing the other crops. The answer
was: tractors and motorized sprayers are few
and far between. Nearly all the sprajdng is done
by attaching a hose 30 yards or so in length to an
outlet fi*om an imderground pipe that supplies
the spray mixtvire fi-om a central mixing point.
The farmer simply sprays all trees within reach
of the hose before picking up and moving on to
the next attachment site. Some sprajdng is also
done with backpack sprayers and "bucket-
pumps." In this way there is no harm to crops in
the alleyways (other than pesticide drift). Most
applicators did not seem concerned about poten-
tial dangers fi*om pesticide. They wore no gloves,
masks or other protection, much the way it was
in the United States in the 1940's!
Nearly all of the 20 or so orchards that we
saw were maintained in excellent condition.
Tree structure was particularly good, generally
better than the average Massachusetts block of
dwarf trees. It w£is mainly based on a three-
tiered, central-leader tree pruning and Umb
training system. Advice on tree planting, tree
training, fertiUzation, and pest control is given
to all apple-growing members of a commune at
least four times a year through visits by exten-
sion pomologists from the Division of Fruit and
Forestry. We were told that the average family
sprays about eight times a year, mainly against
mites, aphids, moth larvae, powdery mildew,
scab, and canker. From our perspective, tree
foUar growth was very lush (probably too lush).
So it was not siuprising that mites and aphids
took a strong liking to it. Maybe the lack of
competition for nutrients in the absence of
understory plants was too much of a good thing.
The high upright growth of many trees was at
least partly due to the common practice of t)dng
branches down to horizontal or below horizontal
positions, which then results in unnecessary
uprights. There was a great deal of interest in
biological control of mites and aphids but less
progress on this area than we ex{)ected.
We wondered how apples were stored and
sold aRer harvest. It turns out that cold storage
does not exist to any appreciable extent. The
fi-uit are trucked by the buyer to the local mar-
kets for immediate consumption. The storages
that do exist are mostly in undergroimd cellars
or in above-ground clay structures that are
periodicedly hosed with water for cooling.
Of all the many surprising things we encoun-
tered, perhaps the most siurprising of all was the
intent interest by the governor of a coimty of
about two million people in the possibility of
making applejuiceorcider. She questioned us at
length about how cider was made in the United
States. It seems that apples have never been
iised in this way in China. She said that her
people would love to have apple cider if they
knew a good way to make it. What an opportu-
nity for marketing low cost hand-operated cider
presses.
We were treated royally with unexcelled
hospitality (including 35-course Ivmches) wher-
ever we went. It was indeed an eye-opening,
unforgettable experience.
Fruit Notes, Spring, 1993
Evaluation of New Apple Cultivars
Duane W. Greene and Wesley R. Autio
Department of Plant & Soil Sciences, University of Massachusetts
In recent years, apple cultivars originating pri-
marily from New Zealand, Australia, or Japan have
gained considerable consumer acceptance in the
market place. Prices received for these new culti-
vars have exceeded those for the traditionally-grown
apples. This differential has led to a new awareness
and a hei^tened interest in planting new apple
cultivars. Many new apples are under test but there
is a dilemma about which of these to plant. The
decisions are made somewhat easier now since there
are a number of good and legitimate choices avail-
able to growers.
About iive years ago we started planting some of
the most promising new cultivars and numbered
selections. Scion wood was obtained for propagating
trees from several countries and from various breed-
ing programs. During the 1992 season many of these
cultivars fruited. This report presents evaluations
of some of these new cultivars.
Fruit evaluation started the first week in August
and continued weekly through the third week in
October. Where sufficient fruit were available, mul-
tiple harvests were made. Fruit on each harvest date
were evaluated in two ways. First, fruit were
weighed, counted, the diameter measured, and then
red color was estimated to the nearest 10% on red
coloring cultivars or on those yellow cultivars that
had a prominent red cheek. Flesh firmness and
soluble solids were measured. Fruit then were
evaluated visually and sensory characteristics were
judged on a specially prepared evaluation sheet
(Figure 1). Lines approximately 10 cm in length
were anchored at either end with descriptive terms.
In each category a line was drawn through the line
at a point that was judged to be appropriate for the
apple. For example, if the color was judged to be
neither dull nor bright a pencil mark was drawn half
way between the terms. The length of this was
measured from the zero point on the left and then
recorded in the blank. The numerical value given in
this instance would be 5.0. All other parameters
were eveiluated similarly and measured. A value of
6.5 is considered to be very good and a score of 7.5 or
greater is excellent. A summary of the taste, visual,
and laboratory evaluations of selected parameters
are presented in Tables 1 and 2. Cultivars are listed
in order of the harvest date at which they were
considered best.
A log was kept and notes were taken for each
cultivar at each harvest date. Below, listed by
alphabetical order, are summaries of observation
made on many of the cultivars evaluated. The star
rating system recommended by the Pacific North-
west Fruit Tester's Association was used.
*M*
**
**** A cultivar tested in many areas and
found worthy as a good risk for commer-
cial recommendation.
A very promising cultivar but with some
possible limiting factors.
A cultivar, new or old, worthy of testing
for today's changing apple world.
* A cultivar or strain that has been
through enough testing and/or commer-
cial trials to be classified as not worthy of
commercial recommendation.
T An upward-pointing arrow with a star
indicates increasing interest
i A downward-pointing arrow with a star
indicates decreasing or waning interest.
Akane (.***) continues to be one of the apple culti-
vars that we favor. It is a very attractive apple and
few apples in its season have the flavor that Akane
does. It must be allowed to stay on the tree long
enough to mellow. It is the most aromatic apple we
evaluated. A m^or fault is that it is a shy bearer.
Alkemene {**) is a yellow apple with a deep orange
cheek. It is somewhat russeted which detracts from
its overall attractiveness. It has a spicy, sprightly,
flowery taste. Flavor was rated quite high. A
problem is that it is competing with Gala, Elstar, and
Arlet. It may not be different enough or better
enough to compete successfully with these cultivars.
It is a disease-resistant cultivar, however, and this
characteristic may increase its appeal.
Ambitious (*) has fiTiited for three years. It is a very
late apple with too much competition from other
cultivars to succeed. It ripened properly in only one
of the three years. Fruit size is small. It is one of the
ugliest apples in our plot with only fair flavor. Fruit
are susceptible to Pseudomonas.
Fruit Notes, Spring, 1993
Cultivar
Visual and sensory evaluation:
Color
Attractiveness
Aroma
Skin
Crispness
Juiciness
Sweetness
Acidity
Starchiness
Astringency
Flavor
Desirable
Weight
Color
dull
dislike
none
tough
low
low
low
bland
low
low
dislike
dislike
Date
bright
like
intense
tender
high
high
high
tart
high
high
like
like
Flesh firmness
Soluble solids
Figure 1. Cultivar evaluation form.
ArkcharmP' AA-18 (**) is a very attractive light
cherry red apple with semiprominent lenticels. It
has a spicy taste, not sweet, flesh not too crisp, with
acidity quite high. Fruit were harvested over a two-
week period. Even when watercored, they still are
very acid. Arkcharm warrants further evaluation.
AA~44 (**t) is a large blotchy cherry red apple.
Flavor is good but not strong. It is equal to Paulared
in flavor and ripens slightly before Paulared. It
shows some tendency to drop. This cultivar war-
rants further evaluation.
AA-62 (*) looks somewhat like a Golden Delicious
and ripens at about the same time. The finish is
good, with no russeting; however, fruit show severe
bitter pit and Pseudomonas. Fruit have a good but
not an outstanding taste with an anise flavor. It is
more acid than Grolden Delicious. If it is not better
than Golden Delicious it may not have a future.
AA-63 (**) was a very pleasant early surprise. It has
speckled red skin, perhaps like an Early Mcintosh.
It £dso tastes like a very good early Mcintosh, with-
out the sharp astringent taste. It is smaU with a very
short shelf life. We rated it very high for color, flavor,
and overall. It is better than Sumac which ripens at
a similar time.
Arlet (**T) remains high on the new cultivar list
despite its three major faults: preharvest drop,
russet, and poor color. It received one of the highest
flavor rating. It has a good sugar-to-acid ratio that
tends to favor acid. It stores quite well and keeps it
taste for a long time. The greasiness that develops on
Arlet is quite different from that developing on other
apples, since it can be washed off. Even though it
feels greasy, internal condition can still be very good.
Fruit Notes, Spring, 1993
There is a very good relationship between develop-
ment of red color and drop. The quality of this apple
is too good to discard right now, even with its faults.
BC 9-17 (*) is a medium sized dull cherry red apple
with semiprominent lenticels. The flavor is not
strong, and when ripe it has a hint of perfume and
pineapple. It is a fairly good apple, but certainly not
outstanding.
BC 78-9-28 (*) is a medium sized, attractive red
apple. The skin is smooth and lightly striped. The
flesh is slightly chalky and the flavor is like licorice.
The very different taste makes it difficult to decide
whether or not we like it.
BC 8C-27-96 Sunrise i**i) is a very attractive
apple but when it develops outstanding red color, it
is too ripe. The flesh characteristics are outstanding.
It is crisp, juicy, and just feels wonderful. A major
weakness of this apple is that it has a very weak
apple flavor and the flavor that it does have is
acceptable but not outstanding. We do not rate
Sunrise very high.
BC 15-30 (*) is a large, light cherry red apple with
prominent brown lenticels. Even when ripe (Sep-
tember 1) acidity is high. It has a pronounced
pineapple flavor that is not totally related to
watercore. This apple was rated average for red
color, fairly high on attractiveness, and average for
taste and flavor. This fruit is neither outstanding
nor poor.
BC9P-14-32 (**t) was one of the pleasant surprises
this year. It is not very attractive because the cherry
red is not intense and there is considerable net-like
russeting. Fruit size is medium, flesh is yellowish-
white, flesh texture is good, and the sugar-to-acid
ratio is good. The taste and appearance is reminis-
cent of Arlet. This apple was rated among the
highest for flavor and overall desirable. It is a very
good apple.
BC 2-8 (*) is a very attractive red apple that re-
sembles Delicious; however, the beauty is only skin
deep. Even when very ripe fruit were tasted, the acid
level was almost off the scale. It is an attractive
apple with only fair to good quality. Fniit were
dropping on September 21.
BC 8M-15-10 (**T) was the second British Columbia
selection that we thought was truly outstanding.
This apple has blotchy pink-red color. Overall it is
not an attractive apple. The flesh is yellow with a
mild banana flavor. It is extremely crisp and juicy.
Unlike published reports, it does not remind us of
Fuji, but is more reminiscent of Braebum. As far as
taste, crispness, and juiciness are concerned, you
could not ask for a better apple. It is outstanding.
BC8B-1'^50(**) is a fairly attractive andfairly good
tasting apple. It looks like a Delicious and has cream
yellow flesh. Fruit are deep cherry red at the optimal
harvest date. The longer fruit stayed on the tree the
better it got, although flesh firmness and texture
were poor. The flavor of this apple is very complex:
fruity and tropical. Since the taste is different and
it improves with age, this cultivar may benefit from
a period of cold storage.
DIR 98T-486 (**) is a very attractive deep red apple
on a cream yellow ground color. The irregular
surface detracts somewhat from the appearance, but
still it was one of the most attractive to be evaluated
this year. Flavor improve with time on the tree.
Fruit harvested on October 5 were quite good but the
ground color indicated that the shelf life then would
be rather short. The fruit is very juicy, yellow-white
fleshed, and slightly tough skinned. It is so attrac-
tive, that based solely on appearance, it should be
looked at further.
BC 17-30 (**T) is a very attractive, dark-burgundy-
red apple of the Mcintosh type. The flavor is remi-
niscent of Mcintosh with Spartan overtones. Per-
haps it tastes most like Acey Mac. The flavor may be
a little bland but it is still a very good apple. Flesh
is white with a greenish tinge. The pedicle is long
and lenticels are semiprominent. This apple war-
rants further evaluation.
BC 8K-21-39 (**) is a fairly good apple with better
than average appearance. It is round to conic, has
yellowish-white flesh that is somewhat dry. Fruit
shows some russeting. Where the surface is red it is
attractive. The red looks muddy on the green-red
interface. The longer the fruit remained on the tree
the better it tastes.
BC 8C-6-62 (*) is a dark cherry-red apple with a
bumpy surface caused by raised lenticel. The flesh
is yellowish white. The flesh was so acid that it was
not possible to evaluate flavor effectively. This fruit
was about the most highly acid apple that we evalu-
ated this year. We were not impressed.
Bonza (*). This is the second year that we have
evaluated Bonza. It is somewhat attractive and red
color is good. The surface of the apple is not smooth,
the flesh is rather dry, and the flavor is acceptable
but not outstanding. We are not encouraged to
Fruit Notes, Spring, 1993
Table 1. Taste evaluation of apple
cultivars grown
at the L
niversity of Massachusetts Horticultural |
Research Center.
1992.
Red
Overall
Cultivar
Date
Attractiveness
color
Sweetness
Acidity
Flavor
desirable
AA63
Aug. 6
5.1
6.8
5.3
6.1
7.4
6.7
Sumac
Aug. 6
2.3
3.0
5.1
6.4
7.1
5.3
NY 66305-139
Aug. 6
3.6
2.2
1.8
9.0
3.3
2.4
BC 9-17
Aug. 11
4.5
4.5
4.0
8.8
6.5
5.0
Arkcharm (AA 18)
Aug. 17
7.9
6.5
2.7
8.0
5.3
5.1
Jerseymac
Aug. 17
5.5
6.7
5.6
4.8
6.2
5.9
BC 78-9-28
Aug. 17
6.9
6.5
6.5
5.3
5.0
4.8
BC 15-30
Aug. 17
4.8
5.0
2.4
7.9
4.4
4.0
Williams Pride
Aug. 20
5.6
6.4
4.5
4.8
6.1
6.2
Redfree
Aug. 20
8.4
8.8
5.2
5.5
7.6
7.4
OSU 31-19
Aug. 20
3.0
3.6
5.2
6.1
7.0
6.8
AA44
Aug. 24
5.5
5.9
5.1
7.8
5.7
5.8
Paulared
Aug. 24
6.3
6.4
2.3
6.9
5.0
5.3
BC 8C-27-96
Sept. 1
6.3
5.0
5.2
5.5
5.1
5.3
Sansa
Sept. 1
6.4
6.3
7.4
5.5
7.4
7.4
Nebuta
Sept. 1
6.5
7.0
5.5
6.7
5.1
5.3
BC 15-30
Sept. 1
5.7
5.2
5.2
8.8
5.1
4.0
Himekami
Sept. 8
7.0
7.0
3.3
8.5
4.1
3.9
Akane
Sept. 8
8.5
8.4
5.5
6.9
6.8
6.8
BC 9P- 14-32
Sept. 8
4.1
4.4
6.2
7.0
7.9
7.4
Dayton
Sept. 8
5.6
6.3
5.7
6.4
5.8
5.1
Ginger Gold
Sept. 14
8.0
...
6.5
6.2
5.8
7.4
Fiesta
Sept. 14
4.2
3.5
4.8
5.0
5.7
5.2
Tsugaru Homei
Sept. 14
5.2
5.0
8.1
4.8
6.3
6.3
Arlet
Sept. 14
4.7
4.7
5.6
7.0
7.5
6.5
Elstar
Sept. 14
4.5
4.4
3.2
8.1
4.7
4.6
NY 66305-289
Sept. 14
6.8
6.8
3.4
7.1
5.3
5.9
NY 74828-12
Sept. 21
6.7
6.8
3.4
7.3
5.5
5.8
Alkemene
Sept. 21
5.3
5.6
6.3
6.8
5.9
5.6
Honeycrisp
Sept. 21
2.9
3.5
6.8
5.2
6.3
5.2
BC2-8
Sept. 21
7.1
6.9
4.2
8.2
4.8
5.3
Shamrock
Sept. 28
4.8
—
5.7
5.3
7.0
6.5
NY 75414-1
Sept. 28
7.8
7.8
6.2
7.0
7.3
7.4
Natco 81
Sept. 28
6.7
6.7
5.3
4.6
6.3
6.3
BC 8M 15-10
Sept. 28
3.6
4.2
7.0
5.2
7.3
7.0
NY 75413-30
Sept. 28
6.8
6.8
4.7
8.1
3.6
3.6
Bonza
Sept. 28
6.4
6.9
3.3
4.8
5.5
5.0
BC 8B-20-13
Sept. 28
7.5
—
4.1
7.6
5.7
5.8
BC 8B-14-56
Sept. 28
5.0
5.0
5.6
5.0
6.2
5.8
Yataka
Sept. 28
5.1
5.1
7.1
4.2
6.9
6.9
Dulcet
Sept. 28
5.4
5.3
5.5
5.0
5.5
5.5
1
continue evaluating this cultivar. Bonza tasted in
Australia seemed to be quite different and far supe-
rior to that grown in our trials.
Braebum (*) was one of the poorest performing
cultivars that we had in our plots. Fruit were
harvested on October 19, and they appeared not to be
ripe. Fruit were unattractive, high in acid, and not
sweet. Theyjust did not taste mature. We have trees
fruiting that came from two sources. The fruit from
both sources are equally poor. This is the second
year that fruit quality was very poor. We may not
Fruit Notes, Spring, 1993
Table 1 continued. |
Red
Overall
Cultivar
Date
Attractiveness color
Sweetness
Acidity
Flavor
desirable
DIR 98-T-486
Oct. 5
7.8
8.4
5.2
5.0
5.9
6.3
Yoko
Oct. 5
5.1
5.0
6.3
6.5
6.3
5.9
NY 65707-19
Oct. 5
6.3
6.8
5.1
4.1
6.3
6.4
Rubinette
Oct. 8
2.6
2.6
3.9
7.1
5.8
5.1
Freyburg
Oct. 8
5.3
—
7.0
5.5
6.8
6.8
NY 75441-67
Oct. 13
5.7
6.3
3.0
7.5
5.3
4.8
BC 17-30
Oct. 13
8.2
8.4
7.1
5.3
6.9
7.1
Jonagold
Oct. 13
5.7
5.1
6.9
5.3
7.5
6.9
Senshu
Oct. 13
5.1
4.8
6.5
5.5
6.9
6.4
NY 429
Oct. 13
7.8
7.5
3.9
5.9
6.1
6.3
Hawaii
Oct. 13
5.0
—
6.1
3.5
6.5
5.9
Shizuka
Oct. 13
5.9
...
5.2
5.8
7.4
7.3
Hokulo
Oct. 13
4.8
4.6
5.5
4.4
5.7
5.6
NY 617
Oct. 13
6.2
6.1
2.7
8.4
5.3
5.5
Splendour
Oct. 13
7.0
6.2
6.0
3.8
5.8
6.8
Brock
Oct. 13
4.4
2.9
5.5
5.3
6.1
5.1
NY 73334-35
Oct. 13
5.5
5.5
4.2
7.6
4.5
5.0
NY 75413-30
Oct. 13
6.9
7.0
5.5
5.5
4.8
5.9
Fantazja
Oct. 13
7.0
7.0
5.2
6.8
6.7
6.7
NY 752
Oct. 13
3.6
3.5
5.5
5.6
5.5
5.1
AA62
Oct. 13
4.8
—
5.3
4.8
5.9
5.6
BC 8C-5-62
Oct. 13
5.5
5.5
1.1
9.6
2.3
2.4
BC 8K-21-39
Oct. 19
5.9
5.9
5.8
5.9
6.8
6.9
Natco 24
Oct. 19
6.3
5.9
3.6
7.0
5.6
5.8
Coop 29
Oct. 19
4.2
—
3.6
6.3
5.9
5.7
Newtown Seedling
Oct. 19
5.6
5.1
4.8
6.8
5.0
4.8
Criterion
Oct. 19
6.1
—
4.6
3.6
5.5
5.5
Nittany
Oct. 19
5.8
5.3
5.2
6.2
6.2
6.2
Reinette Simirenko
Oct. 19
5.3
...
4.6
6.3
5.7
5.5
Fiorina
Oct. 19
6.3
6.2
7.1
3.8
7.1
7.1
Braeburn
Oct. 19
4.1
3.9
3.5
8.2
3.9
4.0
Ambitious
Oct. 19
2.9
2.3
6.5
5.9
4.1
3.6
Orin
Oct. 19
5.5
—
8.2
4.1
7.1
6.5
Kinsei
Oct. 19
4.4
—
7.9
4.6
7.4
6.8
NJ 100
Oct. 19
7.0
—
5.0
4.6
5.5
5.9
Natco 58
Oct. 19
5.7
5.3
3.2
8.1
3.5
4.4
Natco 3
Oct. 19
6.5
4.1
7.1
36
5.2
5.8
Suncrisp (NJ 55)
Nov. 4
5.2
...
4.8
6.5
7.0
6.7
All fruit characteristics were rated
on a scale
ranging from to 10.
Color: dull = 0, bright = 10.
Attractiveness, Flavor, and Overall desirable:
dislike = 0,
like = 10.
Sweetness: low = 0,
high = 10.
Acidity: bland = 0,
tart = 10.
have environmental conditions that favor produc-
tion of this cultivar. An added observation that may
contribute to the poor taste is that mites show a
distinct preference for Braeburn. Only Braeburn
trees were heavily damaged by mites. Since trees
were located in two different locations, it appears
that this is a characteristic of Braeburn. We cannot
recommend Braeburn for New England, based upon
our observations this year.
Brock (**i) was a good but not outstanding apple
this year. Red color is not attractive with a burned
8
Fruit Notes, Spring, 1993
or grayish cast. Flavor is better than appearance.
We rate flavor as good but not outstanding. It tastes
very much like a Spencer. Fruit was dropping on
October 13. We have better apples than Brock.
COOP 29 (**) is a green-yellow apple with a brown
pink cheek. These characteristics, coupled with
some russeting, make this apple not very attractive.
Flesh was firm, tart, astringent, and crisp with a
very distinct and strong strawberry taste. In fact,
this is the only apple that we have ever tasted that
even remotely reminds us of strawberries. Although
it is unattractive and flavor only good, it is disease
resistant and it may be different enough to make it.
Criterion (*). We have not been able to mature
Criterion properly for two out of three years. Fruit
were mostly green on October 19, even when flesh
firmness was only 13.5 pounds. Skin was tough,
flesh whitish-green, and the flavor acceptable. Cri-
terion is not going to replace Golden Delicious.
Dayton (**). We evaluated Dayton for the first time
this year. We were hoping for more than we got. It
is a large, not-too-attractive, red apple with a bumpy
irregular surface. It has a pleasant, perfumy, spicy
flavor but other oiltivars ripening in early to the
mid-September are better. It may have a future as
a disease-resistant apple, but on its own it will not
beat better apples in the same season.
Dulcet (**) is a deep burgundy red apple with
prominent lenticels. It is too dull a red to be a truly
attractive apple. Although reminiscent of Delicious,
it appears to have a fairly low L/D ratio. The flavor
is sweet, buttery, but not overwhelming. The juice
seemed quite thick and the whitish green flesh does
not appear to brown when exposed to the air. Dulcet
was a good but not an outstanding apple.
Elstar (*) continues to leave us unimpressed after
three years of evaluation. The color is not outstand-
ing and the acid level is too high even when the
ground color is yellow. Last year the trees
overcropped. Even with a very light crop this year
due to biennial bearing, firuit size was still unaccept-
ably small. This is the same pattern that we observe
here with Empire. Elstar is just not good enough to
compete with other apples in its season (Gala and
Arlet). If one places Elstar in storage to mellow, it
still must then compete with other later cxiltivars
that are vastly superior. We can not recommend
Elstar.
Fantazja (**t) was an unexpected surprise. It is a
Polish apple that came from Dick Van Well of Van
Well Nursery. We planted and cropped the same
trees in 1992, so the October 13 harvest date may not
be the correct harvest date, since trees were fhiiting
in their first leaf. It is a very attractive red apple that
resembles Mcintosh. It has white flesh and tastes
similar to Mcintosh but it is crisper and has courser
flesh and better flavor. We were quite impressed
with our first look at this apple.
Fiesta (**i). This is our second year looking at
Fiesta. In both years, it showed severe preharvest
drop. It is dull in color and quite unattractive.
Although it is fairly large and we rated flavor quite
high, we do not think it has what it takes to make it
here. It is an OK apple, but certainly not very
exciting.
Fiorina {**) is a late-maturing, disease-resistant
apple that is both attractive and has good taste. The
flavor is very mild. The flesh is whitish-yellow and
very crisp. It tastes sweet with a low acid level. This
apple certainly deserves fiirther evaluation.
Freyburg (♦*) is an elongated yellow apple that
resembles Delicious in shape. The flesh is white and
it seems dry. It is very sweet with a strong fi-uity
flavor. The strong flavor may turn some people off.
Gingergold (***) is one of the most attractive apples
that we grow, regardless of the season. When ripe it
is a beautiful yellow green that completely lacks
russet or surface blemishes. It is the best early
Golden Delicious type that we know of. It is firm
crisp, but the apple flavor is not strong. September
1 was too early to harvest this apple, and finiit
harvested on September 8 were yellow but still
starchy. Fruit harvested on September 14 were still
very crisp and the seeds were still white. The proper
time of harvest of this may be later than the sug-
gested time. Regardless of time of harvest, this is an
excellent apple that has a future.
Hawaii (**). This is the first year we finiited
Hawaii. It is a somewhat attractive yellow apple
that resembles a Golden Delicious without the rus-
set. It has a red cheek like Goldens get in the
Northeast. It is fairly sweet, has low acidity and good
flavor, with a strong banana taste. It bruises easily.
It probably will no replace Golden Delicious.
Himekami {*) is a very attractive apple that looks
like a cherry-red Delicious ripening during the first
week in September. We rated flavor and overall
desirability quite low. The appearance of this apple
is much better than its taste. We are not enthusiastic
about Himekami.
Hokuto (Norihem Star) (**). The brownish red.
Fruit Notes, Spring, 1993
muddy red color on the surface of this apple makes
it somewhat unattractive. Even when the ground
color is intensely green, it appears to be acceptable to
eat. The flesh is somewhat sweet and sprightly, and
this perception may be accentuated because acidity
appears to be very low. We do not consider this to be
an outstanding apple. There are better apples avail-
able that ripen at the same time.
Honeycrisp (**T) distinguished itself as one of the
best apples that we evaluated. It was the most
productive apple in our plot, producing over 1.5
bushels of 3-inch apples per tree on M.26 in their
third leaf. It was one of the least attractive apple
that was evaluated. It was also one of the crispest
and juiciest apples tasted. The flavor was good but
not strong. It has outstanding storage potential. It
maintains crispness, juiciness, and flavor after at
least 20 weeks of regular air storage. This apple
requires further evaluation but the more we taste
Honeycrisp, especially out of storage, the better it
looks.
Kinaei (**t). This is the first year that we evaluated
Kinsei. It is quite an unattractive apple but it is also
one of the best tasting apples in our plot at harvest
time. Following 15 weeks of regular air storage, it
had lost much fruit condition and flavor that was
present at harvest. The appearance and taste of this
apple are not dissimilar to NJ 55.
Jonagold (****) was evaluated more as a marker
than a new cultivar. It clearly is an outstanding
apple that should be planted. It has good size and
outstanding flavor; however, it lacks long storage
life.
New Jersey 100 (**) is a large, very attractive
yellow apple with a waxy smooth surface. It has a
spicy licorice taste that was very strong. It is not
very sweet and is low in acid. It may just be another
apple that gets lost in the crowd.
Natco 3 (**) is a fairly attractive yellow apple with
a prominent reddish pink cheek. It appears to have
a very large L/D ratio, perhaps 1.05 or greater. It
tastes sweet and it has a distinctive, strong spicy
flavor that lingers after your have eaten the apple. It
is an extremely interesting and complex apple.
Some fruit had watercore when they were harvested
on October 19.
Natco 24 (**) is a fairly attractive, large, dark
cherry red apple with striped red over yellow-green
ground color. Flavor is good but astringency is quite
high. It probably can benefit from a period of
storage. Flesh is somewhat dry and it did not appear
to be ready to eat at harvest; however, it is attractive
enough and the taste is good enough to warrant
further evaluation.
Natco 58 (*) was harvested on October 19, yet the
acid was so high that it was difficult to identify or
characterize the taste. Color and appearance are not
exceptional. This cultivar does not appear to be a
good prospect for the Northeast.
Natco 81 (**T) is a very attractive apple that rated
rather high in red color, appearance, flavor, and
overall. It is Spartan-like in appearance and bears
a striking resemblance to Acey Mac in flavor, ap-
pearance, and time of ripening. Although they were
not compared directly, they appear to be identical
twins.
Nehuta (.**l) is a somewhat attractive apple that
resembles Delicious in many respects. It ripens at
the end of August. It is somewhat irregular in shape,
shows signs of uneven ripening, and is distinctly acid
even when watercored. Flesh texture is somewhat
undesirable. Overall, this apple has not distin-
guished itself enough to be recommended.
New York 429 (**) is a very attractive, large,
smooth, red apple. It is somewhat irregular in
shape. Flesh is purfumy, white with a green cast,
and when ripe the flesh seems somewhat on the soft
side. We believe that it is a good apple. Our major
question is whether or not it is good enough to stand
out among all of the other good apples.
New York 617 (**) was an extremely large, some-
what irregularly shaped red apple. Even though the
ground color is yellow, fruit are still high in acid at
the optimal harvest date. It is not a good fresh
market fruit; however, it appears to have the flesh
characteristics required for an outstanding process-
ing apple.
New York 752 (**) is a large, somewhat blotchy
burned-red apple with yellow flesh. It has a spicy
licorice-almond flavor that may be too distinctive to
be acceptable.
New York 66305-139 (**) is the earliest of the
disease-resistant selections from New York. The
major strength of this apple is that it is one of the first
disease-resistant apples to ripen. Within a very
short time, apples go from green and very tart to red,
soft, and still tart. This apple is good enough to
compete with Early Mcintosh or Puritan, but that is
really not saying much. AA 63 or Sumac are better
and they all ripen at about the same time.
New York 66305-289 (**) is a very attractive dis-
10
Fruit Notes, Spring, 1993
Table 2. Laboratory analysis of apple
cultivars evaluated
in 1992
at the University of Massachusetts
Horticultural Research Center.
Soluble
Red
Best
Also
Weight
Diameter
Firmness
solids
color
Cultivar
date
evaluated
(g)
(in.)
(lbs.)
(%)
(%)
AA63
Aug. 6
99
2.54
9.8
11.3
74
Sumac
Aug. 6
91
2.48
10.2
12.5
85
NY 66305-139
Aug. 6
8/11
115
2.65
15.4
11.8
50
BC 9-17
Aug. 1 1 & 17
151
2.84
16.4
13.9
66
Arkcharm (AA 18)
Aug. 17
8/24, 9/1
196
3.10
13.8
12.4
73
Jerseymac
Aug. 17
166
3.03
13.2
10.8
75
BC-78-9-28
Aug. 17
135
2.84
13.8
14.4
90
Williams Pride
Aug. 20
8/11, 8/17, 8/24
202
3.20
15.6
11.6
80
Redfree
Aug. 20
148
...
17.0
11.8
73
OSU 31-19
Aug. 20
9/1
...
...
...
—
—
AA44
Aug. 24
8/17, 9/1
264
3.48
16.7
12.6
68
Paulared
Aug. 24
145
2.94
15.3
10.4
78
BC 8C-27-96
Sept. 1
8/24, 9/8
225
3.21
13.3
12.9
77
Sansa
Sept. 1
183
2.96
15.9
15.4
86
Nebuta
Sept. 1
8/24
155
2.84
16.2
13.9
73
BC 15-30
Sept. 1
300
3.67
18.6
13.6
70
Himekami
Sept. 8
8/24
154
2.85
16.0
13.1
79
Akane
Sept. 8
194
...
15.7
12.9
93
BC 9P- 14-32
Sept. 8
200
3.08
17.0
15.5
80
Dayton
Sept. 8
9/14
290
3.52
16.9
12.9
75
Ginger Gold
Sept. 14
9/8
259
3.30
20.0
13.9
—
Fiesta
Sept. 14
9/21
199
3.19
17.6
13.4
76
Tsugaru Homei
Sept. 14
9/28
216
3.12
15.6
13.4
72
Arlet
Sept. 14
9/21
195
2.99
17.8
12.8
67
Elstar
Sept. 14
137
2.76
16.7
13.5
62
NY 66305-289
Sept. 14
9/21
183
3.07
15.7
12.7
85
NY 74828-12
Sept. 21
149
3.04
17.3
12.0
86
Alkemene
Sept. 21
156
—
16.5
15.5
—
NY 75414-1
Sept. 21
9/8, 9/14, 9/28
167
3.07
14.8
12.1
91
Honeycrisp
Sept. 21
9/14, 9/28
256
3.34
15.2
12.0
69
BC2-8
Sept. 21
252
3.42
14.7
12.1
86
Shamrock
Sept. 28
9/14, 9/21, 10/5
178
3.04
17.8
13.7
—
Natco 81
Sept. 28
9/21
231
3.40
15.8
11.9
91
BC 8M 15-10
Sept. 28
235
3.07
16.8
14.7
50
NY 75413-30
Sept. 28
425
4.01
15.8
12.9
80
Bonza
Sept. 28
10/5
210
3.30
17.3
11.9
90
BC 8B-20-13
Sept. 28
Pick Earlier
337
3.70
11.6
16.3
...
BC 8B-14-56
Sept. 28
10/5, 10/19
228
3.28
14.6
14.5
90
Yataka
Sept. 28
10/5, 10/19
183
2.99
15.6
14.6
65
1
ease-resistant apple that resembles a Mcintosh ex-
cept that it has dark cherry red color and a long thin
pedicel. It has yellowish flesh, qviite tart, and differ-
ent flesh texture than Mcintosh. It ripens between
September 15 and 20 but ripen unevenly. This is a
nice apple that should be evaluated further.
New York 74828-12 (**) is a disease-resistant apple
that looks and tastes like Jonamac. When the
ground color changes to green-yellow the acidity is
still very high. There is a tendency for this cultivar
to ripen unevenly and show some preharvest drop.
This apple was for the most part an average apple.
New York 75414-1 (***). There was more excite-
ment generated about this apple than any other
disease-resistant apple. It is an extremely attractive
medium-sized apple, that develops a deep burgundy
Fruit Notes, Spring, 1993
n
Table 2 continued.
Soluble
Red
Best
Also
Weight
Diameter
Firmness
solids
color
Cultivar
date
evaluated
(g)
(in.)
(lbs.)
(%)
(%)
Dulcet
Sept. 28
10/8
185
3.03
16.1
13.2
90
EC 98T 486
Oct. 5
9/21, 9/28
204
3.08
14.5
11.0
83
Hudson
Oct. 5
210
3.06
20.4
12.6
...
Yoko
Oct. 5
10/13
225
3.20
19.6
15.4
65
NY 65707-19
Oct. 5
10/13
208
3.18
16.5
11.2
80
Senshu
Oct. 5
10/13
205
3.10
14.3
13.8
80
Jonagold
Oct. 8
278
3.43
15.8
13.3
68
Rubinette
Oct, 8
10/13
155
2.88
15.1
16.4
50
Freyburg
Oct. 8
10/19
193
2.97
19.6
16.5
...
Shizuka
Oct. 8
10/8, 10/19
395
3.83
16.3
14.3
...
NY 429
Oct. 13
10/5
244
3.37
14.0
12.1
88
Hawaii
Oct. 13
230
2.95
15.1
13.1
...
Kinsei
Oct. 13
10/19
216
3.21
16.1
13.6
...
NY 75441-67
Oct. 13
9/28, 10/5
258
3.29
16.3
13.0
92
BC 17-30
Oct. 13
10/5
237
3.32
12.5
13.0
95
Hokuto
Oct. 13
10/8, 10/19
302
3.59
15.0
13.1
65
NY 617
Oct. 13
10/5
420
4.03
13.8
13.6
70
Splendour
Oct. 13
10/5, 10/19
206
3.20
16.0
11.8
82
Brock
Oct. 13
10/8, 10/19
302
3.56
15.5
13.5
64
NY 73334-35
Oct. 13
10/5
252
3.32
16.8
11.4
89
NY 75413-30
Oct. 13
205
3.14
15.8
13.7
90
Fantazja
Oct. 13
138
2.73
14.7
12.7
85
NY 752
Oct. 13
275
3.46
14.6
12.3
70
AA62
Oct. 13
242
3.26
17.9
13.5
...
BC 8C-5-62
Oct. 13
182
3.00
15.2
14.2
82
BC 8K-21-39
Oct. 19
184
2.98
17.9
13.0
84
Natco 24
Oct. 19
10/13
250
3.42
17.1
13.0
85
Coop 29
Oct. 19
196
3.14
17.8
12.2
...
Newtown Seedling
Oct. 19
228
3.33
18.5
12.1
80
Criterion
Oct. 19
185
2.98
13.5
11.2
...
Nittany
Oct. 19
165
2.87
17.5
13.3
75
Reinette Simirenko
Oct. 19
190
3.07
18.4
12.2
...
Fiorina
Oct. 19
168
2.97
17.4
12.6
83
Braeburn
Oct. 19
185
2.97
20.0
12.3
60
Ambitious
Oct. 19
143
2.80
19.7
13.0
...
Orin
Oct. 19
213
3.06
18.0
14.2
—
NJ 100
Oct. 19
235
3.34
17.5
12.4
—
Suncrisp (NJ 55)
Oct. 19
203
3.06
17.8
14.2
...
Natco 58
Oct. 19
209
3.10
18.9
12.8
71
Natco 3
Oct. 19
260
3.21
16.1
12.2
...
red color. Its red color, prominent white lenticels,
and slight scarf skin made it almost indistinguish-
able from Macoun. The flesh is white, tart, not too
sweet, and extremely crisp. This apple had the color
to pick on September 8 but flavor and other at-
tributes did not develop until later. Realistically,
this apple showed no sign of drop and it could have
been picked from the second week in September
through the first week in October. Those who tried
this apple knew that they would like it before they
even tasted it. It was a classic Pavlov's dog response.
New York 75413-30 (♦♦). This very large disease-
resistant apple was harvested too early, on Septem-
12
Fruit Notes, Spring, 1993
ber 28. The fruit were quite pitted and the flesh
seemed dense and heavy. It was rated quite high for
color and attractiveness but quite low for flavor.
Judgment must wait for another year, but we were
not too impressed this year.
New York 65707-19 (**). This disease-resistant
apple is fairly attractive, round, medium sized, and
red with small white lenticels and greenish white
flesh. The flavor is not strong but the flavor and
acidity seemed to vary quite a bit from one fruit to
another. On October 13, fruit were dropping. The
jury is still out on this one.
New York 75441-67 (*) is a deep-red disease-resis-
tant apple showing some skin russeting or blemish-
ing, liie flesh is white, the skin is tough, the flavor
OK, but the acidity is so high that even when ripe it
is difficult to recommend this one.
New York 73334-35 (**) is a disease-resistant apple
with good red color, but its irregular firuit shape
detracts from its appearance. Harvest on October 5
was too early while severe drop was noted on October
13. Flesh is whitish green, and the skin is tough. The
acid is high, the sugar is low, and the taste is not
outstanding. There is a blueberry aflertaste. It was
not an outstanding apple this year.
New York 75413-30 (**) is a very attractive, red,
disease-resistant apple the looks much better than it
tastes. The shape is ovate to conic and ribbed. Flesh
is white with a tinge of yellow. Skin has a chalky, odd
taste. We rated flavor only fair to good.
Nittany (**). Trees fruited in the first leaf, so the
October 19 harvest date may not be representative of
future harvests. This apple is fairly good tasting, but
it is not as good as Nittany originating from Pennsyl-
vania. We will continue to follow it.
Orin (**) is green apple and is fairly attractive. It is
a very sweet, subacid apple with a pleasant, slightly
fruity taste. This sweet apple is worthy of fiirther
evaluation.
Redfree (***). We used Redfree as another marker
in the evaluation process. It is one of the best August
apples with a rating of at least *** now. It rates very
high in red color, attractiveness, flavor, and overall.
Even though it is a disease-resistant apple it can
stand on its own merits. It will not store for a long
time.
Reinette Sindrenko (**) has a very distinctive
green color, similar to an immature Granny Smith.
Flesh is whitish green. Flavor is somewhat tart with
a distinctive but spicy taste. At the time of our
sample, flesh was still green and soluble solids were
only 12.2. We believe that this apple was not ripe at
the time of harvest, even though it did taste reason-
ably good. The taste and condition of Reinette
Simirenko was excellent following several weeks in
regular air storage. This cultivar warrants further
evaluation.
Ruhinette (*). The blotchy red-pinkish-brown color
make this apple rather unattractive. Also, the large
lenticels give the impression of russet. This apple is
fair to good tasting but the acidity and astringency
detract from its flavor. We are not very excited about
Rubinette.
Sanaa (**T) is a fairly attractive medium sized
apple. We were very impressed with the flavor,
texture, crispness, and aroma. We consider Sansa
one of the jewels this year. It matures at about the
time of Sunrise, and when compared with Sunrise,
Sansa is the clear winner. It tastes Gala-like but it
ripens fully two weeks before Grala. We did not have
enough fruit to evaluate it fully, but it is one apple
that we will be looking forward to eating next year.
Senshu (**). The blotchy or burned reddish brown
stripes on this medium sized apple make it some-
what unattractive. It has prominent calyx lobes and
a swelled pedicel at the attachment like Gala. It has
unusual orange-yellow flesh. It is a very good
tasting apple. It is not too sweet with a slightly spicy
flavor. Overall, this cultivar was rated quite high.
Shamrock (**T) was evaluated over a three week
period and it had acceptable quality over the whole
time. It did not received the highest marks for flavor
but the ratings were consistently good. In mid-
September, it tastes green and Granny-like. Others
who were offered this apple seemed to liked it. We
believe that it is a good apple that fills a niche for a
green apple in September and October. There is no
other green apple that we have tasted that would
compete in this market. Storage life is not long.
Fruit soften in storage. As it softens, it assumes the
taste of a very good Mcintosh. We can recommend
Shamrock.
Shizuka (**T) is a large, attractive, yellow apple
with a pink cheek, and it has very good flavor. This
apple resembles Mutsu in many ways, a fact that is
not too surprising given their common parentage.
However, it also differs from Mutsu in several impor-
tant ways. It appears to be more elongated in shape.
It ripens about a week before Mutsu. The flesh is
finer, less dense, and tastes fruitier than Mutsu.
Fruit Notes, Spring, 1993
13
Mutsu is plagued by Pseudomonas spotting, and we
found none on Shizuka. Although vigorous, this will
be a grower-firiendly tree. Shizuka was a very nice
apple that should be evaluated further.
Splendour (.**) is one of the most attractive apples
evaluated. The fruit is round to conic, a good cherry
red, with prominent tan lenticels. We evaluated this
starting on October 5. It improved in flavor with
subsequent harvests, but it never reached the top of
the list in flavor. The flesh is yellow white and the
flavor is mild and subacid. The skin is tender, thus
it may not be able to stand up in commercial market-
ing channels. It is a very grower-friendly tree.
Spigold (***). We did not evaluate Spigold for-
mally because we have already decided that this is
one of the best apples available. It is large, some-
what unattractive, and tends to bitter pit. We
believe that it is destined only for a niche market, but
what a wonderful tasting apple! It can be very
biennial.
Sumac (**) was one of the first apples to be evalu-
ated in the season. It is small and quite unattractive.
We rated flavor quite high, but considering every-
thing, we would prefer AA 63 to Sumac for an apple
this early in the season.
SuncrUpâ„¢ (New Jersey 55) (**t). We made
our lastharvestof mostapples on October 19. At that
time NJ 55 had fair appearance, a pink red cheek,
and a ground color that was still green. It was quite
acid and had no better than average taste. The
remaining NJ 55 were harvested on November 4.
The ground color had changed and it appeared ready
to harvest. Although it still tasted a little tart, we
rated flavor very high. At that time it was a wonder-
ful tasting apple that appeared to have the potential
for quite long storage. Our major reservation about
this apple is that we may not have a sufficiently long
growing season to mature it properly. I would say
that it matures up to a week after Fuji.
Tsugaru Homei (**i). On September 14 this apple
was not highly colored, but it had a red mottling over
a pinkish red. Ithas a shape similar to Spencer. The
apple has a good sweet, crisp, juicy, and somewhat
spicy taste. When evaluated two weeks later it was
cherry red and had developed an extremely sweet
spicy flavor. We believe that September 20 may have
been an appropriate harvest date. We do not know
if it has enough going for it to make it.
Williams Pride (**t) was one of the best disease-
resistant apples evaluated. Fruit is large, red, and
irregular in shape, and the skin not smooth. It is
only moderately attractive but the taste is mild,
subdued, and slightly spicy and good. When ripe the
firuit is quite aromatic. Fruit show some bitterpit.
People who tasted Williams Pride thought that it
was a very good apple. This selection requires
further evaluation, primarily to confirm the charac-
terization of its flavor as good.
Yataka (**t) was an excellent apple again this year.
It is truly an early maturing strain of Fuji. It ripens
fully two weeks ahead of other Fuji strains and it is
ready to eat immediately. It is not an attractive
apple, and it is definitely less attractive than strains
ofRedFuji. Flavor was rated very high. OflFthetree,
the taste of Yataka is better than any of the other
strains of Fuji. We are uncertain about its storage
potential. We rate Yataka quite high.
Yoko (**). This medium-sized red apple has fair to
good color and attractiveness. It taste is very sweet
and spicy. There is russet in the calyx, similar to
Arlet. We do not think that it is outstanding enough
to compete with other apples.
Summary
1. Several apples were recognized from the evalu-
ation in 1992 as being clearly superior. These
include Arlet, Gingergold, Honeycrisp, Reinette
Simirenko, Sansa, and Suncrisp"â„¢ (NJ 55).
Other apples that fall into this category but they
are unavailable to the general pubic for testing
at this time. Included in this group are the
British Columbia selections BC 9P-14-32, BC
8M-15-10, BC 17-30, and Fantazja.
2. A second group of apples were recognized as not
being quite so outstanding, but they were suffi-
ciently good to be given a designation of Honor-
able Mention. These cultivars include: Akane,
Kinsei, Orin, Shamrock, Shizuka, and Yataka.
3. Several disease-resistant cultivars were recog-
nized for their superior quality. This group
includes: Alkemene, Fiorina, NY 75414-1, and
Williams Pride. Liberty and Redfree are not
included on this list because they already have
been recognized as being good and accepted
disease-resistant cultivars suitable for commer-
cial planting.
14
Fruit Notes, Spring, 1993
Implementation of the MARYBLYT
Model for Fire Blight Control
Roberta Spitko
New England Fruit Consultants
Fire blight, caused by the bacterium Erwinia
amylovora, is one of the most destructive and diffi-
cult to manage diseases encountered by tree fruit
growers throughout the world. Some might argue
that apple scab, caused by Venturia inaequalis,
deserves this honor but with respect to apple scab,
there is always next year and the chance to try again.
A severe epidemic of fire blight can damage an
orchard of susceptible apple or pear trees so severely
that there is no next year; that is, the orchard block
must be removed.
New England Fruit Consultants (NEFCON)
has been observing and studying this disease in
Massachusetts, Vermont, and New Hampshire for
more than a decade. Overall knowledge of this
disease has increased significantly since the early
1980s, much as a restilt of the excellent work of Dr.
Paul Steiner and his colleagues as the University of
Maryland. Their development of the MARYBLYT
computer model to aid in the control decision making
process is enabling us to understand disease devel-
opment better and to fine tune our disease control
strategies. It is not our intention to describe in detail
the epidemiology of fire blight as there are many
excellent sources already available (see U.S.D.A.
Bulletin No. 631, Fire Blight- Its Nature, Prevention
and Control). Our purpose is to describe our suc-
cesses and frustrations regarding control, particu-
larly with regard to the MARYBLYT model.
NEFCON has been working with Dr. Steiner
and Dr. Daniel Cooley at the University of Massa-
chusetts since the mid-1980s as the fire blight model
was being developed. We found that it described
disease development accurately as we had observed
it but we did not attempt to use it as a control
strategy at that point. In the past several years as
the model has become commercially available, we
incorporated it fully into our fire blight management
program. In 1992, we implemented the model in
multiple sites in Massachusetts, New Hampshire,
and Vermont. Our findings are as follows:
1. The model predicts with extreme accuracy when
overwintering canker activity will begin as well as
when symptoms of canker blight, blossom blight,
shoot blight, and trauma bUght will occur. This
prediction facilitates detection and removal of
blighted tissues if possible (numerous infections are
probably best left for winter removal).
2. If bloom phenology and meteorological data are
kept judiciously, and Streptomycin sprays are used
when the model predicts the risk for blossom blight
is high or blossom infection has occurred, problem
sites may be cleaned up, or major outbreaks of
blossom blight in new sites may be avoided.
3. Although keeping track of bloom and weather
data may appear simple, it is important that these be
extremely accurate as the model's predictions can
only be as accurate as the human input allows it to
be. In our experience, we found detailing bloom to be
difficult. Most orchards have many different culti-
vars blooming at different times; an entire bloom
period may be several weeks long. Also, many
cultivars which are highly susceptible to fire blight
produce secondary blossoms (Paula Red, Rome, and
Cortland, as well as many kinds of pears). It is
possible to have 1/2-inch fruits and open blossoms in
the same fruit cluster. It has been our experience
that this route is a very common one by which severe
epidemics become established. Growers must keep
an eye out for these late blossoms in problem areas
and be prepared to spray Streptomycin should
weather conditions favor infection.
With respect to weather data, daily maximum
and minimum temperatures must be entered. An-
other very important input is wettings, however
slight they may seem. In several sites in 1992, the
model did not predict blossom blight epidemics
which occurred. When we revised the data to reflect
dews which likely happened due to extreme tem-
perature drop at night during bloom, the model
accurately predicted that infection of the blossoms
had occurred and when symptoms would be visible.
4. With prolonged bloom periods and weather par-
ticularly favorable to fire blight, the model MAY call
for more Streptomycin sprays than should be ap-
plied considering Streptomycin resistance manage-
Fruit Notes, Spring, 1993
15
ment. In most years, however, it is unlikely that the
model would call for more than three Streptomycin
applications, which would be within resistance man-
agement guidelines.
5. The complexity of the fire blight disease cycle
and the way that symptoms manifest themselves
(several different phases showing up within a short
period of time) makes it at times difficult to deter-
mine what is happening in an epidemic situation.
An excellent feature of the model is that data files are
created and unusual or unexpected situations may
be studied at a later date. We have increased our
understanding of how this disease operates signifi-
cantly by reviewing these files over the years.
6. Although the MARYBLYT model is excellent for
monitoring disease development and helpful in
cleaning up known problem sites, much of the de-
structiveness of fire blight is due to its erratic occur-
rence. If an orchard has had no history of fire blight,
there would be no incentive to implement an aggres-
sive control program including Streptomycin
sprays. Once a serious epidemic is in progress, it is
too late for the model or Streptomycin sprays to be of
much help. Repeatedly spraying Streptomycin on a
raging epidemic can only favor resistance develop-
ment and is of questionable value in stopping disease
progression.
Where an epidemic of fireblight will occur each
year is still the overriding question. We have good
tools now available to aid in control decisions, par-
ticularly the MARYBLYT program, but where to
implement them if a site has no prior history contin-
ues to elude us.
7. Our best strategies for fire blight management
are as follows:
A. Keep nitrogen levels in check. Pushing young
trees with high nitrogen regimens favors lush
growth that is highly susceptible to infection.
B. Watch vector populations, primarily aphids,
leafhoppers, and pear psylla. Keep them low.
C. Implement a copper program annually in early
spring on all pears and susceptible cultivars of
apples.
D. Avoid planting trees, if possible, where both
scion and rootstock are highly susceptible to
fire blight.
E. Follow proper pruning techniques for winter
removal of overwintering cankers. Major epi-
demics are probably bestleflto nin their course
in summer infections; a few minor strikes
should be removed as soon as they are detected.
F. Implement the MARYBLYT program as part of
your regular orchard recordkeeping activities.
If any stage of fireblight is detected in the
orchard or general vicinity, use the model to
time application of Streptomycin sprays in an
aggressive control program for at least two
successive years.
In conclusion, with diligence and good manage-
ment techniques it seems possible to obtain satisfac-
tory control of fire blight in most growing seasons.
Many questions remain unanswered, however, such
as the role of systemically infected, asymptomatic
trees in the disease cycle, and where major epidem-
ics will strike from season to season. We are un-
doubtedly making progress in our understanding of
this complex disease. Hopefully, at some point we
will achieve the knowledge we need to be successful
consistently in its management.
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16
Fruit Notes, Spring, 1993
Fish Hydrolysate Fertilizer Should Not
Be Applied Foliarly to Apple
J. R. Schupp, M^ Schupp, and M.M. Bates
Highmoor Farm, University of Maine
The four- tx) six-week period following bloom is a
critical time for crop development in apples. During
this period, the mfgority of seasonal vegetative
growth takes place, and firuit set, return bloom,
potential yield, and potential fruit size are deter-
mined. Mineral nutrient reserves become depleted,
as utilization is greater than root uptake, and nutri-
ents, especially nitrogen, can become a Umiting
factor to growlii, even though soil reserves are ad-
equate.
Foliar sprays of mineral nutrients during this
critical period can be beneficial in supplementing
ground-applied fertilizers. These applications do
not replace the regular ground-applied fertilizer
program, they simply fill the gap during the time
that demand outstrips supply. Foliar nitrogen appli-
cations in particular have been shown to increase
fruit set and fruit size when applied at 8 to 12 lbs per
acre during this time. Previous studies have shown
that foliar urea sprays are a safe and effective
method for fertilizing apple (Stiles and Reid, 1991).
Fish hydrolysates, a byproduct of the fishing
industry have recently been recommended as an
organic nitrogen fertilizer for cranberry
(DeMoranville, 1990), apple, and blueberry (Weis
and Bramlage, 1992). The fishing industry is inter-
ested in developing new uses for this material and in
cooperation with the Portland (ME) Fish Exchange,
we investigated the feasibility of using fish hydroly-
sates as a foliar nitrogen source for apple.
Mature Delicious/MM.lll and Golden Deli-
cious/MM. 106 apple trees, growing at the University
of Maine Highmoor Farm in Monmouth were used
for this experiment. "Gulf of Maine" fertilizer, con-
taining 2% N, 4% P, and 2% K was supplied by the
Portland Fish Exchange.
Treatments were as follows:
1. Control, no foliar fertilizer.
2. Fish hydrolysate, 3 gallons in 25 gallons of
water.
3. Urea, 1.25 lb in 25 gallons of water.
Both fertilizer treatments, calculated to provide
the equivalent amount of nitrogen as an application
of 12 lb urea/acre, were applied as a dilute spray with
a handgun. Three applications, at petal fall (PF),
PF+7 days, and PF+14 days, were made on four
repUcations of each cultivar.
Fish hydrolysate fertilizer reduced fruit set of
both cultivars (Table 1). Foliar urea increased fruit
set and yield of Golden Delicious but had no effect on
Delicious. Fruit from fish hydrolysate-treated
Golden Delicious trees had higher soluble solids
than those from urea-treated trees, and this appears
Table 1. The effects of foliar sprays offish hydrolysate fertilizer and urea on fruit set, yield, fruit
soluble solids, and russeting of Delicious and Golden Delicious apple.
Fruit set (%)
Treatment
Del.
Gold.
Yield (kg)
Del Gold.
Soluble
solids (%)
Russeting*
Del.
Gold.
Del.
Gold.
Control 73 a" 19 b 81 ab 54 b 10.2 a 13.5 ab 1.3 b 1.8 b
Fish hydrolysate 38b 7c 64b 21 b 10.2 a 14.1 a 3.7 a 4.1 a
Urea 64 a 34 a 92 a 128 a 9.8 a 12.8 b 1.0 b 2.0 b
• Russeting was rated on a scale of l=none to 5=100% russeted.
" Means within columns not followed by the same letter are significantly different at odds of 19:1.
Fruit Notes, Spring, 1993
17
to be related to the difTerences in cropping between
these treatments. Neither fertilizer affected leaf or
fruit mineral nutrient content, fruit size, or fruit
firmness at harvest (data not presented).
Russeting is a rough brown netting over the
surface of the fruit that occurs when the fruit epider-
mis is killed. Ciolden Delicious is an economically
important cultivar that is predisposed to russeting,
while Delicious is much less sensitive to russeting.
Russeting results in loss of grade when fruit are
packed and must be kept to a minimum if an orchard
is to remain profitable. Fish hydrolysate increased
fruit russeting on both cultivars (Table 1). The
conductivity of the fish hydrolysate fertilizer was
45.6 mmhos/cm, the equivalent of a 29,000 ppm
solution of KCl. It is probably this salt that reduced
fruit set and caused the severe russeting. Regard-
less of the cause, fish hydrolysate reduced fruit set
and damaged the fruit and should not be foliarly
applied to apple.
Literature Cited
DeMoranvUle, C. 1990. Fish hydrolysate fertilizer :
its potential role in commercial cranberry produc-
tion. HortScience 25:626 (abstract).
Stiles, W.C. and W.S.Reid. 1991. Orchard Nutrition
Management. Cornell Coop. Ext. Bui. 219. pp. 18-19.
Weis, S.A. and W.J. Bramlage. 1992. Using fish
waste hydrolysates as a fertilizer for apples and
blueberries. Fruit Notes 57(3):15-19.
•Im %t^ «£• •!# 9^0
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Comparative Effects of Margosan-0
(Neem Extract) and Imidan on Plum
Curculio and Apple Maggot
Ronald J. Prokopy and Margaret Christie
Department of Entomology, University of Massachusetts
John Bemis
Hutchins Farm, Concord
We are continually on the lookout for safe new
pesticides that can control some of our key apple
pests, such as plum curculio and apple maggot.
Extracts of seeds and other parts of neem trees have
been used for centuries, even millennia, to control a
wide variety of insects in India and other parts of
Asia. These extracts appear to be remarkably safe
for human consumption as well as environmentally
safe. They are known to control insects by acting as
insect repellents, antifeedants, or toxicants or by
disrupting the growth of insects. Recently, W.R.
Grace Company began distributing an extract of
neem plants called Margosan-0 for use in green-
houses, commercial nurseries, forests, and homes.
Although no extract of neem, including
Margosan-O, is yet registered for use on crops for
human consumption, we decided to evaluate its
eflFectiveness against plum curculio and apple mag-
got on apple trees at Hutchins Farm in Concord, MA
in 1992. Hutchins Farm grows produce organically
and annually contends with moderate to high popu-
lations of plum curculio and apple maggot.
Methods Used
Against plum curculio, a treatment of
Margosan-0 at one gallon per 100 gallons was ap-
plied with a mist blower at 300 gallons of water per
18
Fruit Notes, Spring, 1993
Table 1. Comparative effects of Margosan-0 (neem extract) and
Imidan on plum curculio and apple maggot.
Injured fruit {%)
Apple maggot
larval tunnels
Treatment
Plum curculio
stings
On tree
In drops
Margosan-0
Imidan
Untreated check
62 a*
16 b
63 a
14 b
13 b
38 a
42 b
30b
76 a
'Means in each column followed by a different letter are signifi-
cantly different at odds of 19:1.
acre to 120 mature, semi-dwarf Liberty and
Jonafree trees on May 22 (petal fall), May 26, May
29, and June 2. As a control treatment, Imidan at 1.5
pounds per 100 gallons was applied on May 22 and
May 29 to 120 other Liberty and Jonafree trees. Yet,
another 120 trees of these varieties remained
unsprayed as checks. Sampling consisted of exam-
ining20 fruit per tree on four replicates of eight trees
each per treatment on June 8.
Against apple maggot, a treatment of Margosan-
O at one gallon per 100 gtdlons was applied with a
mist blower at 300 gallon of water per acre to 60
mature, semi-dwarf Prima and Burgundy trees on
July 1, July 8, July 15, and July 22. As a control
treatment, Imidan at 1.5 pounds per 100 gallons was
applied on July 1 and July 15 to 60 other Prima and
Burgundy trees. Yet, another 60 trees of these
varieties remained unsprayed as checks. Sampling
consisted of examining 10 on-tree and 10 dropped
fruit per tree on six replicates of two trees each per
treatment on August 19. Fruit were held at room
temperature for one week (drops) or four weeks (on-
tree fruit) before examining for larval trails in the
fruit flesh.
Results
As shown in Table 1, use of Margosan-O failed to
provide any detectable reduction in firuit injury by
plum curculio compared with untreated check fruit,
even though it was applied every three to four days
from petal fall to within six days of sampling. Imidan
applied every seven days provided reasonable
curculio control in the face of the very high popula-
tion of curculios.
As shown in Table 1, use of Margosan-0 resulted
in a significant decrease in percent fruit infested
with apple maggot larval trails. In fact, it was little
different from Imidan in this regard. Neither pro-
duced a high level of maggot control, possibly be-
cause there was a four-week gap between the last
treatment and removal of fruit in sampUng for
maggot injury.
Conclusion
We conclude that neem plant extract formulated
and sold as Margosan-0 offers little or no promise for
controlling plum curculio but does offer substantial
promise for controlling apple maggot. We do not
know if its effects on apple maggot were through
reduction of fly egglaying punctures in fruit or
through prevention of growth of larvae hatching
from eggs. Either way, we can anticipate that
application of Margosan-0 against apple maggot
might need to be twice as frequent as application of
Imidan to provide equivalent levels of control. We
hope in the near future to be able to evaluate
Margosan-0 against leafminer larvae and leafhop-
per nymphs. Quite possibly, Margosan-0 might
soon be registered for agricultural use.
Acknowledgements
This work was supported by a grant from the
W.R. Grace Company, to whom we are grateful.
Fruit Notes, Spring, 1993
19
Orchard Mineral Nutrition: Ground-
appiied vs. Foiiar-applied Fertilizers
James R. Schupp
Highmoor Farm, University of Maine
Why do apple growers spend time and money
spraying fertilizers on foliage when for centuries we
have been told that plants take up nutrients from the
soil via their roots? They do it in an attempt to
improve fruit quality and enhance its storage life.
Apple is somewhat unique among fruit crops in that
it is able to utilize a range of mineral nutrients
through its leaves.
Many new products are available to apple grow-
ers for foliar feeding. Sometimes promotional mate-
rials suggest that rather dramatic results can be
obtained from using these products. One grower
recently calculated the expected results for his or-
chard based on such claims and found that if he
would simply use several of these products, his
yields would be 3000 bushels per acre with excellent
fruit size and virtually 100% packout. This yield is
three times that obtained in the best New England
orchards and a level of production at which fruit size
and quality would be very poor. Such an outcome is
impossible of course, and most manufacturers of
foliar nutrient products are careful to base their
product claims within the realm of possibility. Still,
many apple growers are uncertain what role foliar
sprays should have in their nutrition plan.
The first step to any orchard nutrition plan is soil
and leaf analysis. Before applying any fertilizer in
any manner it makes proper sense to determine
whether or not there is need for nutrient supple-
ments, which ones are needed, and in what amounts.
This information provides the first answers to the
ground-applied versus foliar-applied question.
Macronutrients
If leaf and soil analyses indicate the need for
nitrogen, phosphorous, potassium, calcium, or mag-
nesium, the cheapest and most efficient way to apply
them is by ground application. Soil- applied fertiliz-
ers can be applied early in the spring before the busy
growing season and with little or no risk of damage
to the fruit or foliage. Soil-applied nutrients also
follow the natural pathway in the tree to all the
locations where growth and development are taking
place. By contrast, foliar-applied nutrients are less
mobile and stay where they are absorbed.
Micronutrienta
Boron, manganese, copper, or zinc can be ap-
plied to either soil or foliage; however, foliar applica-
tions are more common, because it is easier to spray
the small amounts needed than it is to apply them to
the soU. Foliar applications allow "direct hits" to the
fruit and foliage where supplemental nutrition is
needed, and they allow for precision timing. The
grower can apply the nutrient at a critical time in the
growth stage when it is needed. Foliar fertilizers can
harm the fruit and foliage that they contact, so
usually, only small amounts are applied this way.
Growers should pay particular attention to recom-
mended rates and timings to avoid damage. Refer to
the label of the product and the New England Apple
Pest Management Guide for additional information
on rates, timing, and nutrient compatibility in the
spray tank. High-grade fertilizers, free from impu-
rities, are needed for foliar application, adding to
their cost.
Special Nutrition Problems
If a given nutrient is acutely deficient or if there
is a special nutritional problem that is harmful to
productivity or fruit quality, a combination of both
soil- and foliar-applied nutrients may be justified.
Table 1 lists several of the more common examples
where supplemental foliar nutrients are used to
correct specific problems.
Perhaps the most common special nutritional
problem in apple is low fruit calcium. Developing
fruits compete with vegetative growth for calcium
during the first five to six weeks following bloom.
After this time, calcium uptake by the fruit via the
tree's vascular system essentially stops.
If soil calcium levels are low, or if vegetative
growth is excessive, the fruit may be deficient in
calcium, leading to the appears rce of cork spot or
bitter pit and rapid loss of fruit q ality in storage. In
20
Fruit Notes, Spring, 1993
Table 1. Foliar applications for special nutritional problems in apple. |
Problem
Problem
nutrient
Material
Annual
rate/acre*
Timing*
Comments
Low fruit set, small fruit
size
Nitrogen
Urea (45%)
201b
Pand
PF
Not recommended where
calcium deficiency disorders
are problems.
Bitter pit, poor storing fruit
Calcium
Calcium chloride
(80%CaCl,)
15-50 lb
1-7
Do not substitute calcium
nitrate. Do not premix
calcium chloride with
Solubor.
Premature leaf & fruit drop
Magnesium
Magnesium
sulfate (11%)
151b
PF
May be applied in first or
second cover. Compatible
with pesticides.
Low firuit Bet, poor quality
Manganese
Manganese
sulfate (24%)
5 1b
DorPH
Apply in spring before growth
starts.
Low frmt set, poor quality
Copper
Copper sulfate
(22%Cu)
4-6 lb
DorPH
Apply in spring before growth
starts.
Fruit pitting, shoot dieback
Boron
Solubor (20.5%B)
4 1b
81b
PF& 1
PH
Make two applications of
equal rates, but do not exceed
8 pounds per acre per year
fi-om Eill sources.
Shoot dieback, low hardiness
Zinc
Zinc sulfate (89%)
5.5-11 lb
DorPH
Apply before growth starts.
â– Commercial formulation
'Efedormant, P=pink stage, FB=full bloom, PF=petal fisdl, l-7=lst through 7th cover sprays, PH=postharve8t
Adapted from Penn State Tree Fruit Production Guide, 1992-1993 and Orchard Nutrition Management, Cornell Coop. Ext Bui.
219.
cases where fruit calcium is marginal, the symptoms
may be apparent only after long periods in storage.
If soU calcium levels are low, the soU pH likely is
acidic. The cheap, long-term solution to low soU
calcium is liming to correct the acidity and to add
calcium to the orchard soil; however, regardless of
the cause of the fruit calcium problem, foliar calcium
sprays are advisable. Foliar sprays of a calcium-
containing fertilizer put calcium directly on the fruit
where it can be taken up, and will reduce greatly the
occurrence of costly blemishes and loss of fruit qual-
ity.
Brand Name Products vs. Salts
A large number of products are available for
applying foliar nutrients. Table 2 lists some of the
foliar calcium products available to the apple
grower. It is not possible to discuss the qualities of
each individual product in a short forum such as this
article, but several comparisons can be made be-
tween brand name products versus calcium chloride
salts.
Brand name products, when applied to provide
the same amount of calcium as provided by calcium
chloride are no better or worse in their effectiveness
in preventing frviit disorders. Thus brand name
products are more expensive sources of calcium;
however, brand name products may be safer to fhiits
and foliage, easier to measure, and more conve-
niently packaged.
Calcium chloride contains oxide impurities that
can increase the pH of the spray solution in the tank,
thereby reducing the effectiveness of certain pesti-
cides. If calcium chloride is to be tank-mixed with
pesticides, a small amount of vinegar or buffering
agent should be added to prevent this problem.
Finally, brand name products may contain other
nutrients, which may be beneficial, but only if they
are nutrients that currently are needed by the tree.
It is up to the individual grower to weigh the pros and
cons of each product given his or her situation.
Similar considerations result when growers make
comparisons between brand name products and salt
formulations for other mineral nutrients.
Summary and Tips for Success
Foliar fertilizers are an important tool for apply-
ing micronutrients, correcting acute nutrient defi-
Fruit Notes, Spring, 1993
21
Table 2. Calcium materials
for use on a
pples, with labeled rates per acre per application, per
acre per season, and per acre per year. |
Product
name
Percent
calcium
Pounds/
gal
Pounds of
calcium/
gal or lb
Manufacturer
Product/
A/spray
mln.-max.
No. of
appL
Total
product/
A/aeaaon
min.-max.
ToUl
calcium/
A/season
Ob)
mln.-max.
CaB
6.0
10.0
0.60
Stoller, Inc
(800-255-9548)
3-6 pints
8
3-6 gal
1.8-3.6
CaBy
10.0
11.9
L19
Stoller, Inc
(800-255-9548)
2-4 qt
8
4-8 gal
4.8-9.6
Calcium
chloride (77-
80% CaCl2)
27.8
flakes
0.28
many
1.8-6.2 lb
8
14.3-50 lb
4.0- 14
Calcium
chloride (35%
CaC12 liquid)
12.6
11.3
1.42
many
.35-1.24
gal
8
2.8-9.9 gal
4.0-14
Cor-Clear
Dry
34.5
beads
0.34
SEGO Intl., Inc.
(503-796-0133)
4-8 lb
8
32-64 lb
10.9-21.8
Foliar
Calcium
Folical
10.0
9.6
0.96
Agrimar (3orp.
(800-284-9898)
Igal
6-8
6-8 gal
6.8-7.7
Fung-Aid
10.0
11.9
1.19
Stoller, Inc
(800-255-9548)
2-4 qt
8-16
6.5-8.2 gal
6.5-9.7
Link Calcium
6%
6.0
10.3
0.62
Wilbur-Ellis Co.
(509-248-6171)
2-4 qt
4
2-4 gal
1.2-2.5
Mora-Leaf
Calcium (94%
CaCy
34.0
DRY
0.34
Wilbur-Ellis Co.
(609-248-6171)
4-8 lb
3-6
12-48
4.1- 16.3
Nutri-Cal 8%
Calcium
Solution
8.0
11.1
0.89
CSl Chemical Corp.
(800-247-2480)
1-2 qt
3-8
.75-4.0 gal
.67-3.6
Nutra-Phoa
10
10.0
powder
0.10
Leffingwell Div.
(800-262-3861)
3-10 lb
2-6
20^0 lb
2-4
Nutra-Phoa
12
11.0
powder
0.11
Leffingwell Div.
(800-262-3861)
3-10 lb
2-6
20-(01b
2.2-4.4
Nutra-Phoa
24
20.0
powder
0.20
Leffingwell Div.
(800-262-3861)
3-10 lb
2-6
20-40 lb
4-8
Nutra-Phos
Mg
10.0
powder
0.10
LefTingwell Div.
(800-262-3861)
3-10 lb
2-6
20-40 lb
2-4
Nutra-Plua
6.0
10.0
0.60
Custom Chemicides
(209-264-0441)
1-3 qt
8-11
2-8.2 gal
1.2-4.9
Pit-Stop
Dry Con.
Foliar Cal.
32.6%
32.6
diy
0.32
Ag-Chem, Inc.
(301-548-2200)
4-6 lb
4-6
16-48 lb
6.2-16.6
Pit-Stop
Foliar
Calcium 12%
12.0
11.3
1.36
Ag-CJhem, Inc.
(301-648-2200)
1.5 gal
4-6
6-9 gal
8.1-12.1
Sett
8.0
11.4
0.91
Stoller, Inc
(800-255-9548)
Igal
8-11
8-11 gal
7.3-100
Sorba-Spray
Cal.
8.0
10.75
0.86
LefHngwell Div.
(800-262-3861)
1-4 qt
4-5
1-6 gal
0.9-4.3
Sorba-Spray
CaB
SO
10.0
0.50
Leffingwell Div.
(800-262-3861)
1-4 qt
4-5
1-6 gal
0.6-2.5
Stopit
Calcium
Concentr.
12.0
10.7
1.28
Shield-Brite Div.
(206-827-8717)
2-4 qt
8-11
4-11 gal
5.1-14.1
Tracite
Calcium 6%
6.0
10.0
0.60
Helena (Jhem. Co.
(901-748-3200)
3-6 pU
8
3-6 gal
1.8-3.5
Traco PitCal
Liquid
Calcium
12.0
11.7
1.40
Traylor Chem. Co.
(800-348-3361)
0.5-2 gal
7
3.5-14 gal
4.9-19.6
Wuial
Calcium
10.7
13.3
1.42
AGLUKON Div.
(800-832-8788)
3-4 pts
5
1.9-2.5 gal
2.7.3.6
Adapted from th
e Ptnn State Trte Fruit Production Guidt, 1992-1993.
22
Fruit Notes, Spring, 1993
ciencies, and solving special nutritional problems,
such as getting calcium into apple fruit. For overall
economy and tree health, most macronutrients
should be soil-applied.
When applying nutrients to apple foliage, the
following suggestions will enhance the spray's effec-
tiveness and safety:
1. Think dilute. Apply fertilizers with as much
water as is practical. Effectiveness will be aided
via thorough coverage and better absorption.
2. Watch the weather. Follow the 80/80 rule : avoid
4.
nutrient sprays when temperature or humidity
values exceed 80 degrees or 80%, respectively.
Following this nJe will reduce greatly the risk of
fruit or foliage damage.
Make sure that your sprayer is calibrated prop-
erly and that its nozzles are adjusted to direct an
even pattern to the tree canopy.
More is not better, more often is better. Do not
apply too much at one time. If you wish to apply
more of a particular nutrient, consider soil appli-
cation or repeating the foliar spray at a later
date.
*f^ •!# %f^ %% %f^
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Fruit Notes, Spring, 1993
23
Fruit Notes
University of Massachiuetts
Department of Plant & Soil Sciences
a05 Bowditch Hall
Amherst, &IA 01003
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J354
Fruit Notei
-\ I V 1
5 ^3
ISSN 0427-6906
rrepared by the Department of Plant & Soil Sciences.
University of Massachusetts Cooperative Extension System.
JHIVJOF f ASf
Or
5^
9>
United States Department of Agriculture, and Massachusetts Counties Cooperatli^.
i
Editors: Wesley R. Autio and William J. Bramlage
Volume 58, Number 3
SUMMER ISSUE, 1993
Table of Contents
Costs and Returns from High Density Apple
Plantings During the First Three Seasons
Costs and Returns from Three Peach Training
Systems During the First Three Seasons
Optimal Positioning of Baited Sticky Red
Spheres for Capturing Apple Maggot Flies
Massachusetts Agriculture
Fruit Notes
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Fruit Notes
Department of Plant & Soil Sciences
205 Bowditch Hall
University of Massachusetts
Amherst, MA 01003
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Costs and Returns from High Density
Apple Plantings During the First
Three Seasons
Wesley R. Autio
Department of Plant & Soil Sciences^ University of Massachusetts
In the 1989 New England Apple Survey (Autio,
1989), growers stated that 62% of the apple acreage
to be planted in 1990-94 would be on dwarfing
rootstocks. Since the survey, several acres of dwarf
trees have been planted; however, little experience
exists with methods of training these trees. Manage-
ment is much different than for free-standing stan-
dard or semi-dwarf trees.
To become familiar with the peculiarities and to
obtain accurate data on costs and returns of high-
Table 1. Costs and returns per acre associated with Nicobel JonagoldTM.G in four |
training systems. Land preparation costs
were derived from White and Demarree 1
(1992) and Fuller et al
. (1991). Establishment costs include all those
associated 1
with trees, planting,
support systems,
and initial training (see Autio, 1990). |
Growing costs, other than those associatec
with training.
were derived from White |
and Demarree (1992)
Training labor
and suppUes
were based
on actual
assessments from this
planting. Picking, storing, packing, and selling
costs were
derived from Castaldi (1987).
NE Central
Slender
Vertical
Vertical
Category
leader
spindle
axis
trellis
Year 1 - 1990
Land preparation
Fertilizer and lime
150
150
150
150
Seed
20
20
20
20
Labor
15
15
15
15
Equipment
38
38
38
38
Establishment
3904
5206
7172
5146
Growing costs
Fertilizer
55
55
55
55
Spray material
47
47
47
47
General supplies
15
15
15
15
Training labor
14
25
57
5
Other labor
200
200
200
200
Equipment
Costs - Year 1
133
133
133
133
4591
5904
7902
5824
Net - Year 1
-$4591
-$5904
-$7902
-$5824
1
Fruit Notes, Summer, 1993
Table 1. Continued.
NE Central
Slender
Vertical
Vertical
Category
leader
spindle
axis
trellis
Year 2 - 1991
Growing costs
Fertilizer
55
55
55
55
Spray materials
45
45
45
45
Training supplies
5
23
5
8
General supplies
15
15
15
15
Training labor
10
96
34
29
Other labor
200
200
200
200
Equipment
133
133
133
133
Fruit-related costs
Picking
2
1
52
Storing
3
1
65
Packing
3
2
86
Selling
1
21
Costs -- Year 2
472
571
711
485
Returns - Year 2
21
10
533
1
Net -- Year 2
-$451
-$561
-$178
-$484
1
density management systems, I established a trial of
four training systems at the University of Massa-
chusetts Horticultural Research Center
(Belchertown) in the spring of 1990. This trial
included Nicobel Jonagold/M.9 trained as a New
England central leader, as a slender spindle, as a
vertical axis, and on a four-wire vertical trellis.
Previously, I published an article which included the
various costs of establishment (Autio, 1990). Here,
I have continued the discussion of this study, includ-
ing the costs of managing these trees during the first
three growing seasons and the returns obtained
from the fruit.
The Systems
New England Central Leader. The NE central
leader, simply, is a small central-leader tree (389
trees per acre, 8' x 14'). Minimal pruning has been
conducted, including removal only of those branches
which inhibited the developmentof thecentral leader.
Some limb spreading has been done with weights.
Slender Spindle. The slender spindle is typical
of a European slender spindle, i.e. a small central-
leader tree with a relatively large amount of branch
manipulation. Trees are spaced 6' x 14' (519 trees per
acre). The new growth of the central leader was
headed by half in the first dormant season to encour-
age lateral development. The central shoot originat-
ing from the heading cut was tied to the post in June
of the second season, and competing laterals were
bent to 90° from vertical with rubber bands. In early
July of both the second and third growing seasons,
lower laterals were tied to approximately 70°, cen-
tral laterals were tied to approximately 90°, and
upper laterals were tied to 100°. In some cases in
1992, branches which bore fruit in 1991 were tied up
to prevent devigoration.
In 1991, a self-tapping sheet-metal screw was
drilled into the bottom of the conduit-pipe post, and
cotton kite twine was tied from this screw to limbs for
positioning. This process was relatively time con-
Fruit Notes, Summer, 1993
Table 1. Continued.
NE Central
Slender
Vertical
Vertical
Category
leader
spindle
axis
trellis
Year 3 - 1992
Growing costs
Fertilizers
57
57
57
57
Spray materials
118
118
118
118
Training supplies
5
25
5
10
General supplies
15
15
15
15
Training labor
7
182
12
37
Other labor
200
200
200
200
Equipment
133
133
133
133
Fruit-related costs
Picking
178
251
409
136
Storing
223
314
511
170
Packing
297
419
681
227
Selling
Costs - Year 3
74
105
170
57
1307
1819
2311
1160
Returns -- Year 3
1840
2596
4227
1405
Net -- Year 3
$533
$777
$1916
$245
1
suming. In 1992, avis strapping material was used
to tie limbs. This 1/2-inch, multi-stranded strapping
material was split easily into five pieces of five
strands each. The advantage of this material is that
it can be tied directly to conduit pipe without the use
of a screw and without slipping, therefore making it
much easier to use than the previous method.
Vertical Axis. The vertical axis utilizes a tall
post to allow unrestricted tree growth to a height
where it will fruit out. In this planting, posts extend
10.5 feet out of the soil. Trees were spaced 6' x 14'
(519 trees per acre). A number of lateral branches
existed on trees at planting, and none were removed
and trees were not headed. A small amount of
pinching of vigorous, upright shoots was done in
June each season. Also in each season, some vigor-
ous limbs were bent with weights in early July.
Vertical Trellis. The trellis used in this planting
is seven feet tall and includes four wires, every 18
inches beginning at 24 inches from the soil. Trees
were spaced 8' x 14' (389 trees per acre). Trees were
headed at approximately 22 inches from the soil. As
branches grew, a central leader was chosen, and
lateral branches were tied to the lowest wires at
approximately 70°. Branches higher up in the canopy
were tied at a greater angle.
The Economics
Table 1 summarizes the costs and returns asso-
ciated with the four treatments used in this trial.
Duringthe first season, the primary difference among
the total costs related to differences in establishment
costs (for details of establishment costs see Autio,
1990). Some differences existed in the amount of
labor involved with training, with the vertical axis
requiring the most, followed by the slender spindle,
central leader, and trellis.
Duringthe second growing season, significantly
more labor and supplies were required for the slen-
der-spindle system than the others. The NE central
leader was the least intensive and least costly. Ver-
Fruit Notes, Summer, 1993
Cumulative Net Returns (thousands/acre)
$10
-^ NE Central Leader
-^Slender Spindle
-*- Vertical Axis
-"-Vertical Trellis
/ r
-$10
1990 1991 1992 1993 1994 1995
Figure 1. Cumulative net returns of four apple training
systems. Dotted lines are projected returns.
tical-axis trees fruited in the second season, yielding
about 43 bushels per acre. Overall costs of the
vertical axis were increased because of the costs of
picking, storing, packing, and selling; however, $533
were returned per acre in the second growing sea-
son.
During the third growing season again, the
slender spindle required the most labor and supplies
to manage. Year three was the first significant
fruiting year, with yields of 148, 209, 341, and 113
bushels per acre for the NE central leader, slender
spindle, vertical axis, and vertical trellis, respec-
tively. Net returns varied from the low of $245 from
the trees on trellis to $1916 from trees trained to the
vertical-axis system.
Figure 1 presents the cumulative net returns for
these four systems for their first three growing
seasons, along with projections for the next three
seasons. The most costly system
was the vertical axis; however, it
yielded sooner than the other sys-
tems and is expected to net over
$2000 per acre afler the fifth grow-
ing season. The slender-spindle
and trellis systems were similarly
costly; however, the slender
spindle yielded better in 1992 and
is expected to yield more than the
trellis for the next few seasons.
The slender spindle will pay for
itself by the end of the fifth grow-
ing season, but the vertical trellis
will not pay for itself until the end
of the sixth growing season. The
least costly system to establish
was the NE central leader, but it
is not expected to be as profitable
as the slender spindle.
Conclusions
Significant differences in costs
and returns existed among the
four intensive apple-training sys-
tems included in this planting.
One factor came very much into
play in determining what the early
returns were from these trees.
The early yields on a per-tree ba-
sis were negatively related to the
degree of pruning which was done
at planting. The vertical axis trees
were not pruned; therefore, one-
year-old wood was retained at
planting which set flower buds during the first
growing season. Trees yielded in the second season.
With no pruning, the canopies of these trees were
larger than in the other systems and trees yielded
significantly more in the third season. NE central-
leader trees, slender-spindle trees, and vertical-
trellis trees were all headed at planting, removing all
lateral branches and most one-year-old wood and
preventing them from settingflower buds during the
first season. NE central-leader trees and slender-
spindle trees were headed at 34 inches, and trellis
trees were headed at 22 inches; the more severe the
heading, the lower were the early yields.
A second factor which also has come into play
and will continue to be a factor is the planting
density. The two systems that have been the lowest
yielding on a per acre basis and probably will have
the lowest returns for a number of years are at the
Fruit Notes, Summer, 1993
lowest density (NE central leader and vertical trel-
lis). The highest yielding systems are at the highest
density (vertical axis and slender spindle).
Overall, it is clear that any of these systems can
be relatively successful. Even the least productive is
expected to pay back the initial investment by the
end of the sixth season, significantly better than
free-standing central-leader trees on M.7. Selection
of a system, however, must be based not only on the
overall economic considerations but on the grower's
interests in, abUity for, and commitment to horticul-
tursd management, i.e. can and will he or she become
more intensively involved with training and other
horticultural practices than normally is needed for
free-standing trees.
References
Autio,W.R. 1989. Trends in the New England apple
industry. Fruit Notes 54(4):12-17.
Autio,W.R. 1990. Costs ofestablishing high density
apple plantings. Fruit Notes 55(4):l-5.
Autio, W. R. 1993. High-density Apple Training:
Costs of Establishment. University of Massachu-
setts Cooperative Extension System Factsheet F-
110.
Castaldi, M. 1987. Summary of Annual Apple
Production Costs. Cornell Cooperative Extension.
Fuller, E., W. Lazarus, and L. Carrigan. 1991.
MinnesotaFarm Machinery Economic Costs for 1991.
Minnesota Extension Service AG-FO-2308-C.
White, G. B. and A. DeMarree. 1992. Economics of
Apple Orchard Planting Systems. Cornell Coopera-
tive Extension Bulletin 227.
•J^ •^ •l^ •J>» •J!>
0^ •<]>• 0^ 0^ •^
Fruit Notes, Summer, 1993
Costs and Returns from Three Peach
Training Systems During the First
Three Seasons
Wesley R. Autio
Department of Plant & Soil Sciences, University of Massachusetts
In southern New England, approximately 1000
acres of land are planted to peach trees. Little
research has addressed the problems of peach grow-
ing, particularly in the area of cultural manage-
ment. Training systems are an as-
pect of cultural management that
can affect the economic returns of an
orchard greatly.
The primary training system used
for peach trees in southern New En-
gland is a delayed-open-center sys-
tem. In a tree ofthis form, the central
trunk is dominant early in the life of
the tree, and as the tree grows, lower
scaffolds grow upward and become
equal to or stronger than the central
trunk. Ideally, the central trunk
should be removed above the lower
scaflFolds at maturity, leaving an open
center tree; however, the central
trunk often is left in the tree. The
problem that arises from having a
central trunk in this type of tree is
that light penetration into the center
of the canopy is very poor, and over
time, productivity declines in a large
portion of the tree's interior.
Because of the high value of peach
fruit, production efficiency should be
a major concern of peach growers.
Evaluation of production practices is
critical to economic viability. To this
end, I established a trial in 1990,
including nine replications of Ernie's
Choice/Lovell trained to an open cen-
ter, a central leader, or a delayed
open center. The goal ofthis planting
is to evaluate fully the economic vi-
ability of these three training sys-
tems.
The Systems
Open Center. Open-center trees were spaced 18
by 20 feet (121 trees per acre). Trees were headed
Table 1. Costs and returns per acre associated with Ernie's Choice
peach in three training systems. Land preparation costs were derived
from V/hite and DeMarree (1992) and Fuller et al. (1991).
Establishment costs were derived from actual measurements made
during the planting of this trial. Growing costs, with the exception of
pruning, were derived from Mizelle and Westberry (1989). Pruning
labor costs were from actual measurements from this trial.
Delayed
Open
Central
open
Category
center
leader
center
Year 1-1990
Land preparation
Fertilizer and lime
150
150
150
Seed
20
20
20
Labor
15
15
15
Equipment
38
38
38
Establishment
HoleE--labor
81
145
81
Holes-equipment
101
182
101
Trees
605
1089
605
Planting labor
48
87
48
Initial pruning labor
16
15
8
Growing
Fertilizer
25
25
25
Spray material
38
38
38
General supplies
24
24
24
General labor
30
30
30
Equipment
56
56
56
Costs - Year 1
Net - Year 1
1247
-$1247
1914
-$1914
1239
-$1239
Fruit Notes, Summer, 1993
Table 1. Continued.
Category
at planting to leave four small
shoots arising from the trunk be-
tween 20 and 24 inches from the
ground. Each of these shoots was
headed to two viable buds. As the
trees have developed, shoots grow-
ing into the center of the trees have
been removed, with either dormant
or summer pruning, and outer lat-
erals have been pruned to direct
their growth at about 60° from ver-
tical. The goal is to have trees with
four major scaffolds growing out-
ward from the trunk in a vase form
and reaching a height of approxi-
mately eight feet when they have
filled their allotted space. In the
mature tree, light distribution will
be good, and only a small portion in
the center of the tree will have too
little light to maintain the produc-
tion of fruiting wood.
Central Leader. Central-leader
trees were spaced 10 by 20 feet (218
trees per acre). Very little pruning
was done at planting. As trees
have developed, scaffolds have been
pruned to direct their growth at
about 80° from vertical. Upper
limbs have been kept short so that
the trees have a conical shape.
Upright shoots arising from the
nearly flat lateral branches have
been removed during summer
pruning. The goal is to produce
small trees that are eight feet tall
at maturity with lower laterals that
extend no more than five feet from
the trunk. With this form, nearly
all of the canopy will maintain the
potential to produce fruiting wood.
With more trees per acre than a
standard system, higher early pro-
duction should be obtained.
Delayed Open Center. Delayed-
open-center trees were spaced 18 by 20 feet (121
trees per acre). Very little pruning was done at
planting. As the trees have developed, lower scaf-
folds have been treated much the same as in the
open-center trees; however, a central trunk has been
maintained. The goal of this system is to have an
open-center tree at maturity, but the productivity is
higher early in its life, because it has more canopy
volume in the form of a central leader. The central
leader must be removed before the shading in the
center of the tree results in significant reductions in
Delayed
Open
Central
open
center
leader
center
Year 2 - 1991
Growing
Fertilizer
49
49
49
Spray material
67
67
67
General supplies
35
35
35
General labor
59
59
59
Equipment
51
51
51
Dormant pruning
labor
8
10
5
Summer pruning
labor
8
15
8
Costs - Year 2 277
Net - Year 2 -$277
year 3 - 1992
Growing
Fertilizer 53
Spray materials 254
General supplies 50
General labor 40
Equipment 65
Dormant pruning labor 16
Summer pruning labor 12
Thinning labor 8
Harvest and sales
Harvest labor 38
Packaging 24
Selling 24
Costs - Year 3 584
Returns - Year 3 709
Net -Year 3 $125
286
-$286
53
254
50
40
65
25
22
15
89
56
56
725
1675
$950
274
-$274
53
254
50
40
65
14
12
8
64
40
40
640
1191
$551
the potential to produce fruiting wood.
The Economics
Table 1 presents the costs and returns over the
first three growing seasons from this trial. Much of
the growing costs were obtained from other sources
as described in the caption of the table, but planting
costs, training costs, and yields were obtained from
this trial. For labor, $8 per hour was used through-
out this analysis. Equipment costs were assessed at
Fruit Notes, Summer, 1993
Cumulative net returns (thousands/acre)
1992
1993
Figure 1. Cumulative net returns of three peach training
systems. Dotted lines are projected net returns based on
projected costs and returns for 1993 and 1994.
approximately $20 per hour but varied depending on
the equipment used. Trees cost $5. Thinning,
picking, packaging, and selling were assumed to cost
$0,013, $0.04, $0,025, and $0,025 per pound of fruit,
respectively. Yields were valued at $0. 75 per pound.
For the first three seasons, central-leader trees
were more costly to maintain than either of the other
systems: total costs were $2108, $2925, and $2153
for the open center, central leader, and delayed open
center, respectively. The difference came primarily
from the greater establishment costs, which ac-
counted for more than 80 percent of the difference
between the central leader and the other systems.
During the third growing season (1992), trees in
this trial yielded significantly. Yield per tree was
related directly to canopy size, with the delayed open
center yielding the most and the open
center yielding the least per tree (8,
10, and 13 pounds per tree for the
open center, central leader, and de-
layed open center, respectively). Once
tree density was accounted for, the
open-center, central-leader, and de-
layed-open-center systems yielded
945, 2234, and 1588 pounds of fruit
per acre, respectively. The returns
for the central leader systems were
considerably greater than for the
other systems.
At this point in the trial, it is
possible to say that the additional
costs of planting the higher density
central-leader system have been com-
pensated for by the higher yields in
the third season. Figure 1 presents
the cumulative net returns from these
systems and shows a projection of
cumulative net returns for the fourth
and fifth growing seasons (1993 and
1994). For these early years, the
central-leader trees should out-pro-
duce the other systems because of
their higher density of planting, and
therefore, likely will net over $2,000
per acre cumulatively by the end of
the fourth growing season and nearly
$10,000 per acre by the end of the
fifth growing season. The other two
systems likely will net less than half
that amount by the end of the fifth
growing season.
This information is not enough,
however, to determine the ideal sys-
tem for growing peaches in southern
New England. These trees must be
followed to maturity and beyond to determine long-
term differences in costs and returns.
References
Fuller, E., W. Lazarus, and L. Carrigan. 1991.
Minnesota Farm Machinery Economic Costs for 1991.
Minnesota Extension Service AG-FO-2308-C.
Mizelle, W. O., Jr. and G. O. Westberry. 1989. Cost
analysis, pp. 6-12. In: S. C. Meyers (ed.) Peach
Production Handbook. University of Georgia Coop-
erative Extension Service Handbook 1.
White, G. B. and A. DeMarree. 1992. Economics of
Apple Orchard Planting Systems. Cornell Coopera-
tive Extension Bulletin 227.
1994
8
Fruit Notes, Summer, 1993
Optimal Positioning of Baited Sticky
Red Spheres for Capturing Apple
Maggot Flies
Jian Jun Duan, Max P. Prokopy, Paul Des Georges,
and Ronald J. Prokopy
Department of Entomology^ University of Massachusetts
In a previous article [Fruit Notes 56(4): 4-6], we
reported that a combination of food odor (ammonia)
and fruit odor (butyl hexanoate) significantly in-
creased apple maggot fly (AMF) captures on three-
inch baited red sticky spheres, thus enhancing the
effectiveness of interception traps currently used in
the second-level IPM program. Past studies by
Reissig (1975) and Drummond et £il. (1984) showed
that AMF captures on unbaited spheres were influ-
enced significantly by position of spheres in the tree
canopy, including height above ground, proximity
to fruit and foliage, and distance from the outside
edge of the tree canopy. We predicted that these
variables would have less influence on AMF cap-
tures on sticky spheres baited with food and fruit
odor than on unbaited spheres. Here we report on
studies testing this prediction.
Materials and Methods
Three experiments were conducted in 1992 in
second-level IPM orchards (commercial orchards
not sprayed with insecticide after early June). We
first investigated the optimal distance of fruit and
foliage from spheres not baited or baited with one
dispenser of ammonium acetate and one two-dram
polyethylene vial of butyl hexanoate (Experiment
1). We next studied the effects of presence vs.
absence of fruit within 20 inches of unbaited spheres
or spheres baited with the same types of odor as in
Experiment 1 (Experiment 2). In Experiment 3, we
investigated the influence of height of sphere place-
ment in the tree canopy on the efficacy of spheres
not baited or baited with one polyethylene vial of
butyl hexanoate.
Experiments 1 and 2 were conducted in
Clarkdale Fruit Farm, West Deerfield, MA, which
consisted of a mixture of 25-year-old Early Mcin-
tosh and Gravenstein trees. The trees were about 12
to 16 feet in canopy diameter. In Experiment 1, we
hung four sticky spheres in each of ten trees and
removed the foliage and fruit surrounding the spheres
to distances of 2, 10, 20, or 40 inches. On five of the
trees, we placed one dispenser of ammonium acetate
(about 5 grams) and one vial of butyl hexanoate
(about 5 milliliters) about six inches from the sphere.
Spheres on the other five trees were not baited with
any type of odor. In Experiment 2, we placed two
sticky spheres in each of 14 trees. On seven of the
trees, spheres were baited with ammonium acetate
and butyl hexanoate in the same manner as in Ex-
periment 1. Spheres on the other seven trees were not
baited. One of the two spheres in each tree was
cleared of all fruit within 10 inches. The other sphere
was cleared of all fruit within 20 inches. The foliage
surrounding each sphere was removed within a con-
stant distance of 10 inches.
Experiment 3 was conducted at the University of
Massachusetts Horticultural Research Center,
Belchertown, MA, in a block of four-to-five-year-old
Liberty trees having a canopy three to five feet in
diameter and a height of six to eight. In this experi-
ment, we placed only one sphere (either not baited or
baited with one polyethylene vial of butyl hexanoate)
on each tree. Spheres were placed in trees at three
different heights: upper 1/3, middle 1/3, or lower 1/3
of the canopy. Foliage and fruit within 10 inches of
each sphere were removed.
For all experiments, captured male and female
AMF were counted and spheres were cleared of all
insects captured every two weeks. In Experiments 1
and 2, unbaited and baited spheres were emplaced on
July 28 and rotated among trees at each examination
(every two weeks) until September 8, when the test
ended. Experiment 3 began on July 27 and ended on
September 11. Spheres were not rotated among
trees.
Fruit Notes, Summer, 1993
Table 1 . Average number of apple maggot flies captured on baited or unbaited sticky red spheres hung in
fruiting trees and surrounded at different distances by foliage and/or fruit (July 28 - September 8, 1992).^
Distance (in
Foliage
) of clearing of
Fruit
Baited spheres
Unbaited spheres
Experiment
Female
Male
Total
Female
Male
Total
1
2
2
14 b
19 b
33 b
9 b
13 b
22 b
10
10
24 a
35 a
59 a
18 a
29 a
47 a
20
20
25 a
37 a
62 a
19 a
25 a
45 a
40
40
16 b
20 b
36 b
14 ab
17 b
27 b
2
10
10
27 a
50 a
77 a
15 a
28 a
44 a
10
20
19 a
39 b
57 b
15 a
18 b
33 b
^ Five replicates per treatment type in Experiment 1 and seven replicates in Experiment 2. Values within
columns and within experiment followed by the same letter are not significantly different at odds of 19:1.
Results
The results of Experiment 1 (Table 1) showed
that for both baited and unbaited spheres, nearly
twice as many AMF were captured on spheres with
foliage and fruit cleared to a distance of 10 to 20
inches compared with 2 or 40 inches. Baited spheres
captured 25 to 50% more flies than unbaited spheres
at each distance. A previous study by Martin Aluja
showed that fruit odor attracts flies from long dis-
tances to a host tree or a portion of a host tree, but
once a fly arrives on a tree, it primarily will use
vision to find an individual fruit or fruit-odor-baited
sphere. Surrounding foliage and fruit which influ-
ence the visibility of a fruit-odor-baited sphere would
therefore influence the probability of a fly finding
the sphere. Until our test here, however, we had no
knowledge that addition of food odor would fail to
overcome the need for making a sphere conspicuous
to AMF.
The results of Experiment 2 (Table 2) indicated
that when the surrounding foliage was cleared to a
constant distance of 10 inches from a sphere, spheres
cleared of all fruit within 10 inches captured 33%
(unbaited) and 35% (baited) more flies than spheres
cleared of all fruit within 20 inches. Possibly, fruit at
10 to 20 inches from a sphere attracted more AMF
(either by visual or odor stimuli) toward the sphere
than fruit 20 inches or further did.
Results of Experiment 3 (Table 2) showed that
for unbaited as well as baited spheres, spheres
placed in the upper 1/3 or the middle 1/3 of the tree
canopy captured about three times more AMF than
spheres placed in the lower 1/3 of the canopy. DiflFer-
ences in performance of spheres at the lower versus
the middle or upper tree positions were greater than
differences between baited and unbaited spheres at
any height. Diffierences in AMF captures on both
unbaited and baited spheres among different tree
canopy heights likely stem from fruit-foraging be-
havioral patterns of AMF within trees. A recent
Table 2. Average number of apple maggot flies captured on baited or unbaited sticky red
spheres hung in fruiting trees at different tree canopy heights (July 27 -September 11,1 992).^
Baited spheres
Unbaited spheres
Position in the canopy
Female
Male
Total
Female
Male Total
Upper 1/3
Middle 1/3
Lower 1/3
13 a
21 a
6 b
31 a
21 a
7 b
34 a
42 a
13 b
13 a
12 a
4 b
20 a 32 a
19 a 31 a
5 b 9 b
^ Fourteen replicates per treatment type. Values within columns followed by the same letter
are not significantly different at odds of 19:1.
10
Fruit Notes, Summer, 1993
study by Martin Aluja indicated that fruit-foraging
AMF have a propensity to move upward when forag-
ing for fruit and spend more time foraging in the
middle and upper part of the tree canopy.
Conclusions
Our findings indicate that the performance of
sticky red spheres whether baited or not with syn-
thetic food and fruit odor, is affected strongly by
clearing of surrounding foliage or fruit, as well as by
height of placement in the tree canopy. Baited spheres
capture more flies than unbailed spheres under all
conditions. To intercept AMF immigrating into or-
chards, spheres should be placed in the middle 1/3 or
upper 1/3 of the tree canopy and surrounded by as
much foliage and fruit as possible except for a 10-
inch radius around. This placement will optimize the
finding of spheres by AMF within a tree.
Selected References
Drummond, F., E. Groden, and R. J. Prokopy, 1984.
Comparative efficacy and optimal positioning of traps
for monitoring apple maggot flies (Diptera:
Tephritidae). Environmental Entomology 13: 232 -
235.
Reissig, W. H. 1975. Performance of apple maggot
traps in various apple tree canopy positions. Journal
of Economic Entomology 68: 534 - 538.
Acknowledgments
We thank Tom Clark for the use of his orchard.
This work was supported by the Northeast Regional
Project on Integrated Management of Apple Pests
(NE-156).
vj>» •^ •^ •X* vl>
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Fruit Notes, Summer, 1993
11
Massachusetts Agriculture
Robert L. Christensen and N. Eugene Engel
Department of Resource Economics, University of Massachusetts
In 1991, Massachusetts farmers sold $474 mil-
lion of crop and livestock products, ranking forty-
second out of fifty states. Massachusetts ranked
number one, however, in cranberry production,
number twelve in apple production, and number
seventeen in greenhouse/nursery crop production.
Table 1 reports the annual cash receipts of selected
commodities in Massachusetts.
According to the U.S. Census, the estimated
number of farms in Massachusetts increased from
5,400 in 1974 to 6900 in 1991. Table 2 gives the
number of farms by county in 1982 and 1987, and
Table 3 gives the acreage by county. Approximately
615,000 acres of land are used by Massachusetts
farms. The average size of a farm is 100 acres, as
compared to the U.S. average of 467 acres. Average
Table 1. Cash receipts in thousands of dollars by sel(
3Cted commodities in
Massachu-
setts. Data were compiled from Economic Indicators
of the Farm Sector -
- Financial
Summary, 1991, U.S. Department of Agriculture, Economic Research Service, ECIFS |
11-2, March, 1993.
Commodity
1990
1991
All commodities
445,874
475,540
Livestock and products
124,706
120,745
Meat animals
13,750
15,919
Dairy products
70,054
64,977
Poultry and eggs
24,411
23,662
Aquaculture
8,245
8,245
All other livestock
7,725
7,645
Crops
321,168
354,795
Hay
5,037
4,689
Tobacco
13,442
14,571
Potatoes
4,677
4,522
Sweet corn
9,088
9,883
Tomatoes
8,760
6,300
Miscellaneous vegetables
40,000
39,000
Apples
20,337
19,180
Peaches
893
867
Cranberries
62,737
96,818
Other berries
5,345
5,885
Miscellaneous fruits and nuts
1,000
1,000
Maple products
922
1,483
Other field crops
3,700
2,920
Floriculture
35,551
35,364
Nursery and ornamentals
108,000
108,000
1
12
Fruit Notes, Summer, 1993
Table 2. Number of farms
in Massachusetts by counties. Data are
from 7987 Census
of Agriculture,
Bureau of the Census, U.S. Department of Commerce, Washington, |
D.C.
County
1987
1982
Change (%)
Barnstable
158
123
+28
Berkshire
392
352
+11
Bristol
675
597
+13
Dukes
58
40
+45
Essex
439
372
+18
Franklin
616
521
+18
Hampden
490
392
+25
Hampshire
624
559
+12
Middlesex
569
567
Nantucket
12
6
+100
Norfolk
212
205
+3
Plymouth
775
649
+19
Suffolk
5
4
+25
Worcester
1191
1014
+17
Total
6216
5401
+15
1
Table 3. Land in farms (acres'
in Massachusetts by counties.
Data
are from 1987
Census of Agriculture,
Bureau of the
Census,
U.S. Department
of Commerce,
Washington, D.C.
County
1987
1982
Change (%)
Barnstable
*
5,010
—
Berkshire
70,792
73,434
-4
Bristol
42,562
41,883
+2
Dukes
7,314
7,355
-1
Essex
30,940
30,283
+2
Franklin
82,864
79,412
+4
Hampden
46,747
43,835
+7
Hampshire
64,567
63,624
+1
Middlesex
38,709
40.173
-4
Nantucket
*
*
~
Norfolk
13,124
13,398
-2
Plymouth
77,140
80,392
-4
Suffolk
*
*
—
Worcester
134,689
133,612
+1
Total
615,185
612,819
* Withheld to avoid disclosing
data for i
ndividual farms.
Fruit Notes, Summer, 1993
13
Table 4. Farm balance sheet for Massachusetts in millions of dollars. Data
were derived from Economic Indicators of the Farm Sector - Financial
Sum.mary, 1991 , U.S. Department of Agriculture, Economic Research Service,
ECIFS 11-2, March, 1993.
Item
1990
1991
Assets
Real estate
Livestock and poultry'
Machinery and motor vehicles''
Crops (inventory)
Purchased inputs
Financial
Debt
Real estate
Nonreal estate'
Debt/asset ratio
3,553.6
3,407.7
3,092.3
2,939.2
57.4
57.9
212.8
214.7
22.6
20.9
8.9
8.9
159.5
166.1
299.0
295.7
115.1
117.9
183.9
177.8
8.4
8.7
Excludes horses, mules, and broilers.
Includes only the farm share for trucks and autos.
Excludes debt for non-farm purposes.
net farm income for Massachusetts is $20,841, while
the U.S. average is $17,950. Of greatest significance
is the fact that net farm income per acre in Massa-
chusetts averages $208, nearly 5.5 times the U.S.
average per acre of $38.
Massachusetts farmers control assets of $3.4
billion, with a debt load of under $300 million (Table
4). This debt-to-asset ratio is among the ten lowest
in the nation and is less than half the national
average. Massachusetts farmers per year purchase
$160 million worth of farm inputs, pay local property
taxes of $22 million, employ a hired labor force with
a payroll of $77 million, and pay $24 million in
interest to Massachusetts financial institutions and
other lenders (Table 5).
Finally, Massachusetts farmers provide Massa-
chusetts consumers with food that is locally grown,
fresh, wholesome, and reasonably priced.
14
Fruit Notes, Summer, 1993
Table 5. Massachusetts farm income statistics in millions of dollars. Data were
compiled from Economic Indicators of the Farm Sector - Financial Summary. 1991,
U.S. Department of Agriculture, Economic Research Service, ECIFS 11-2, March,
1993.
Item
1990
1991
Gross farm income
505.4
527.6
Farm marketings of crops
321.2
354.8
Farm marketings of livestock products
124.7
120.7
Government payments
3.0
1.5
Farm-related income
17.2
15.5
Non-cash income'
38.0
36.0
Inventory adjustment
1.3
-0.9
Total productions expenses
334.3
336.6
Feed purchased
31.7
30.6
Livestock and poultry purchased
1.4
1.4
Seed purchased
6.8
7.6
Fertilizer and lime
10.1
10.0
Pesticides
9.3
10.3
Fuel and oil
13.3
12.7
Electricity
7.0
7.0
Repair and maintenance
29.0
26.4
Miscellaneous
46.4
53.7
Interest on real estate debt
8.8
8.5
Interest on other debt
15.6
15.4
Contract and hired labor expense
77.3
77.2
Capital consumption (depreciation)
58.9
57.3
Property taxes
21.9
21.7
Net rent to landlords
-3.2
-3.1
Net farm income
171.2
191.0
Returns to operators''
158.0
178.7
' Includes: value of home consumption and rental value of operator and hired labor
dwellings.
" Returns to operators is equivalent to net farm income, excluding the income and
expenses associated with farm operator's dwellings.
vT> •^ vi>» •^ •Jt*
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Fruit Notes, Summer, 1993 15
Fruit Notes
University of Massachusetts
Department of Plant & Soil Sciences
205 Bowditch Hall
Amherst, MA 01003
Nonprofit Organization
U.S. Postage Paid
Permit No. 2
Amherst, MA 01002
-0
SERIAL SECTION
UNIV. OF MASSACHUSETTS UBRARY
AMHERST, MA 01003
Account No. 3-20685
5A
ISSN 0427-6906
Fruit Notes rr.
Prepared by the Department of Plant & Soil Sciences. _ — U ^SS •
University of Massachusetts Cooperative Extension System, '^^Or-
United States Department of Agriculture, and Massachusetts Counties CooperM^.
Editors: Wesley R. Autio and William J. Bramlage
Volume 58, Number 4
FALL ISSUE, 1993
Table of Contents
Evaluation of Several Apple Roots tocks
in the 1984 NC-140 Planting
Effects of Orchard Spray Program on Plant-feeding and
Predatory Spider Mites in Massachusetts Apple Orchards
A Sampling Method for Detecting
Root-feeding Woolly Apple Aphids
Chemical Growth Control: Ethephon as a Growth Retardant
Food Prices, Expenditures, and Income
Fruit Notes
Publication Information:
FrM/rA^ore5(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). Pay-
ments 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 arc contingentupon continued registration. These chem icals should be
used in accordance with federal and state laws and regulations. Growers arc urged to be familiar with all current state
regulations. Where trade names are used for identification, no company endorsement or product discrimination is
itttended. The University of Massachusetts makes no warranty or guarantee of any kind, expressed or implied,
concerning the use of these products. USER ASSUMES ALL RISKS FOR PERSONAL INJURY OR PROPERTY
DAMAGE.
Issued by the University of Massachusetts Cooperative Exunsion System, Robert G. Helgesen, Director, in
furtherance of the acts of May 8 and June 30, 1 914. The University (^Massachusetts Cooperative Extension System
offers equal opportunity in programs and employment.
Evaluation of Several Apple
Rootstocks in the
1984 NC-140 Planting
Wesley R.Autio
Department of Plant & Soil Sciences, University of Massachusetts
New England apple growers have been
planting trees on clonally propagated rootstocks
for a number of years. Early plantings were
entirely on semidwarf and semistandard
rootstocks, usually M.7, MM. 106, or MM.lll.
During the 1970's, some growers experimented
with M.9 and interstem trees, and now, several
growers are using fully dwarf rootstocks. Until
recently, plantings have used a relatively small
number of roots tock clones, because only a few
clones were available. Now several breeding
programs have released rootstocks for trial, in-
cluding the "Polish Series" from Poland, the
"Budagovsky Series" from Russia, the "Ottawa
Clonal Series" from Canada, the "Kentville
Stock Clone Series" from Canada, the "Michigan
Table 1. Characteristics in 1992 of Starkspur Supreme Delicious trees
on several rootstocks in
the 1984 NC-140 Cooperative
Planting.'
Tnmk cross-
1992 Cumulative
sectional
1992
Cumulative
Yield
yield
C
rop
area
Yield
yield
eflfieiency
efficiency
load
Rootstock
(in^)
(bu)
(bu)
(bu/in^)
(huJin^
(fruit/in')
Bud.9
3.4 efg
2.0
fg
5.6 g
0.57 ab
1.60 ab
57
ab
MAC-1
13.8 be
5.1
c
11.0 de
0.36 de
0.80 d
37
cd
MAC-39
4.5 ef
2.1
fg
5.8 g
0.43 bede
1.21 c
36
d
P.l
8.8 d
3.8
de
11.1 de
0.43 bede
1.31 c
42
cd
P.22
1-2 g
0.4
h
1.5 h
0.30 e
1.29 e
30
d
Seedling
15.8 ab
4.9
c
11.3 cde
0.31 e
0.70 d
30
d
M.4
11.8 c
6.6
a
15.3 a
0.56 ab
1.30 c
62
a
M.7 EMLA
8.1 d
4.4
cd
11.8 bed
0.62 a
1.62 ab
58
ab
M.26 EMLA
5.5 e
2.5
fg
7.1 fg
0.47 bed
1.34 be
41
cd
Bud.490
14.2 abc
5.4
be
11.8 bed
0.38 de
0.85 d
35
d
P.2
2.8 fg
1.6
g
4.8 g
0.56 ab
1.69 a
51
abed
P.16
1.2 g
0.5
h
1.6 h
0.54 abc
1.67 a
53
abc
P.18
16.7 a
6.6
a
14.2 ab
0.40 cde
0.85 d
40
cd
C.6
5.5 ef
2.9
ef
8.6 ef
0.55 ab
1.61 ab
45
bed
Ant.313
16.3 ab
6.2
ab
13.9 abc
0.39 cde
0.89 d
39
cd
' Means within columns not followed by the same letter
are significantly different at odds of
19:1.
FruH Notes, Fall, 1993
Table 2. Characteristics in
1992 of fruit from Starkspur Supreme Delicious
trees on several rootstocks in the 1984 NC-140 Cooperative Planting.'
Soluble
Date of
Fruit
solids
Starch Watercore
1 ppm
weight
Rootstock
(%)
index''
index"
CjH
4
(g)
Bud.9
9.8 cd
3.6 abc
1.0 b
10-11
bed
217 abed
MAC-1
9.8 cd
2.8 def
1.1b
10-12
abc
181 f
MAC-39
10.4 b
3.2 bcde
1.3 a
10-11
bed
232 ab
P.l
10.1 bed
3.2 bcde
1.1b
10-11
bed
203 bedef
P.22
11.0 a
3.7 ab
1.0 b
10-11
bed
182 f
Seedling
9.7 cd
2.8 def
1.0 b
10-13
ab
185 ef
M.4
9.6 d
2.6 f
1.0 b
10-12
abc
192 def
M.7 EMLA
10.1 bed
2.8 def
1.1b
10-9
d
215 abede
M.26 EMLA
10.1 bed
3.3 abed
1.2 ab
10-9
d
214 abede
Bud.490
9.6 d
2.9 def
1.1b
10-14
a
200 edef
P.2
10.1 bed
3.3 abed
1.2 ab
10-11
bed
225 abc
P.16
10.2 be
3.8 a
1.0 b
10-10
cd
204 bedef
P. 18
9.8 cd
2.6 f
1.0 b
10-12
abc
191 def
C.6
10.1 bed
3.1 edef
1.1b
10-10
cd
237 a
Ant.313
9.6 d
2.7 ef
1.0 b
10-13
ab
191 def
' Means within
columns not followed by the same letter are
significantly
different at odds of 19:1. Soluble solids
starch index, watercore index, and 1
fruit weight were assessed
on October 5-6, 1992.
Date of 1 ppm C2H4 was 1
assessed with several weekly samples throughout the harvest
season.
'' Starch index:
1 = dense
starch staining, very
immature; 9
= no starch
staining, very
overmature.
* Watercore index: 1 = no watercore; 5 =
severe watercore
Apple Clone Series" from Michigan State Uni-
versity, and the "Cornell-Geneva (or Geneva)
Series" from the New York State Agricultural
Experiment Station. In 1984, a trial of a num-
ber of these new rootstocks was planted at
approximately 30 locations throughout the
United States and Csmada. One of the plantings
is at the University of Massachusetts Horticul-
tural Research Center in Belchertown, Mass.
This article will report the results from this
planting through its ninth growing season.
In April 1984, Starkspur Supreme Delicious
trees on Bud.9, MAC-1, MAC-39, P.l, P.22,
seedling, M.4, M.7 EMLA, M.26 EMLA,
Bud.490, P.2, P.16, P.18, C.6, or Ant.313 were
planted in a randomized complete block design
with 10 replications. The soil is a Montauk fine
sandy loam. Mcintosh and Golden Delicious
trees were included in each rephcation for polli-
nation. All trees were trained as central leaders
and supp>orted by a post only when they leaned
more than 45° from vertical. All trees received
the same fertilizer apphcations, pest control
treatments, and chemical thinning sprays.
Table 1 reports the trunk cross-sectional
area, yield, jdeld efficiency, and crop load of
these trees. MAC-1, seedling, Bud.490, P.18,
and Ant.313 produced trees of standard size.
Fruit Notes, Fall, 1993
Over their first nine years, trees on MAC-1,
seedling, or Bud.490 jdelded a total of 11 to 12
bushels. Those on P. 18 or Ant.313 yielded
approximately 14 bushels. P.l, M.4, or M.7
EMLA produced trees in the semidwarf to
semistandard category. Trees on M.4 have
yielded the most in the trial, more than 15
bushels per tree ciunulatively. Trees on P.l or
M.7 EMLA yielded between 11 and 12 bushels
cumulatively. Bud.9, MAC-39, M.26 EMLA,
P.2, and C.6 produced trees in the dwarf cat-
egory. In this category, C.6 and M.26 EMLA
have resulted in the greatest )delds, 8.6 and 7.1
bushels, respectively, per tree on a cumulative
basis. The other dwarf roots tocks have resulted
in yields between 4.8 and 5.8 bushels per tree.
The smallest trees in the planting are on P.22 or
P. 16. These trees are in the very dwarf category,
and they have yielded only about 1.5 bushels per
tree cumulatively.
To accurately assess performance of a par-
ticular tree, it is important to look not only at
size and yield but also at jdeld efficiency. Effi-
ciency relates yield to tree size and gives an
assessment of relative yield per acre. Over the
life of the planting, the most yield-efficient trees
have been on P.2, P. 16, M.7 EMLA, C.6, or
Bud.9. M.7 EMLA is the biggest surprise in this
group, because in other plantings that we have,
it has not been very yield-efficient. The least
efficient trees have been those of the standard
size category.
Table 2 reports fruit characteristics from
this planting in 1992. For the four years that
fruit have been assessed, no dramatic, consis-
tent differences have occurred in bruit ripening,
but fruit fi-om trees on C.6 often have been some
of the largest in the planting, as they were in
1992.
Overall, the most promising new rootstocks
in this trial are P.2, C.6, and Bud.9. All are of the
dwarf category. P.2 and Bud.9 produce trees
similar in size to those produced by M.9, and C.6
produces a tree very similar in size to one pro-
duced by M.26. They seem well adapted to our
conditions, they were very precocious, and they
have continued to be productive for their size.
The only concern is with the potential of trees on
P.2 or Bud.9 to "runt out." Trees on P.2 or Bud.9
were nearly spur-bound after nine seasons.
High productivity likely will not continue imless
they are pushed to produce new vegetative
growth. This trial, however, is with a spur-type
variety. Newer trials include these two
rootstocks with more vigorous, nonspur variet-
ies, and I do not expect that they will become
spur bovmd as readily.
We shall continue to evaluate new
rootstocks in Massachusetts. We have a plant-
ing scheduled for the spring of 1994 which will
contain 19 of the newest dwarfing rootstocks,
including some from the "Vineland Series," the
newest of the "Geneva Series," and a host of M.9
strains from Europe.
•1^ %f« «f# «f^ «f#
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Fruit Notes, Fall, 1993
Effects of Orchard Spray Program on
Plant-feeding and Predatory Spider
l\/lites in IVIassachusetts
Apple Orchards
William M. Coli and Randolph CiurUno
Department of Entomology, University of Massachusetts
Since the inception in 1978 of the University
of Massachusetts Apple Integrated Pest Man-
agement Program, growers have heard a num-
ber of presentations concerning the importance
of selecting orchard pesticides based on their
impacts on not only the target pest but also
beneficial organisms. In recent years, the New
England Apple Pest Management Spray Guide
has contained a table of pesticide toxicities to
beneficial species, with data fix)m a number of
pubhshed studies conducted in Pennsylvania,
New York, New Jersey, Virginia, West Virginia,
Massachusetts, and Canada.
In 1987, we initiated a study of the effects of
orchard groundcover comix)sition on plant-feed-
ing and predatory mites. As a component of this
study, we reviewed the spray records of 28
commercial apple orchards in Massachusetts.
Spray programs that included carbamate insec-
ticides, pyrethroid insecticides, certain
acaricides, or certain herbicides known to be
detrimental to predatory mites were classified
as "hard" programs. Those that avoided such
materials were classified as "soft" programs.
Table 1. Effects of orchard
apple leaves by phjrtophagoi
spray program on average
IS and predatory mites.'
percent infestation of
Mite species
Leaf infestation (%)
1988
1989
"Hard"
"Soft"
"Hard" "Soft"
European red mite
Two-spotted spider mite
Amblyseius fallacis
Zetzellia mali
9.7 a
1.0 a
1.5 a
0.3 b
8.6 b
1.0 a
1.9 a
4.2 a
31.4 a 33.0 a
1.7 a 0.3 b
1.4 b 2.4 a
0.0 b 3.3 a
" Within row and year, meems not followed by the same
different at odds of 19:1.
letter are significantly
Fruh Notes, Fall, 1993
Those which used two or fewer appUcations of
benzimidazole fungicides, whose detrimental
effects on mite predators are not agreed upon
universally, likewise were classified as "soft"
programs. Due to seasonal variability of spray
programs, blocks were reevaluated yearly and
reclassified by the tjT)es of pesticide used during
the previous production season. In total, the
study included 14 orchards using "hard" pro-
grams and 14 using "soft" programs.
In 1988, the "hard" program resulted in
slightly higher infestations by European red
mite than did the "soft" program (Table 1). The
relationship, however, varied with saimpling
date, i.e. for some sampling dates, "hard" pro-
grams had more European red mites, and for
other dates, "soft" programs had more. Spray
program had no impact on the amount of Euro-
pean red mites present in 1989. The lack of a
difference in 1989 likely was due to an aggres-
sive spray program directed at mites in "hard"
blocks which kept plant-feeding mite numbers
comparable to those in "soft" blocks in spite of
lower predator numbers.
The "hard" spray program resulted in sig-
nificantly more two-spotted spider mites than
the "soft" program in 1989, but in 1988, there
was no difference between programs (Table 1).
The first sample in 1989, however, found fewer
two- spotted spider mites in the "hard" program
orchards than in the "soft" ones. Because of the
differences fi"om year to year and the lack of a
consistent relationship between programs, even
when significant differences were noted, we can-
not state conclusively that numbers of two-
spotted spider mites were related to spray pro-
gram in this study.
"Hard" spray programs had a significantly
lower proportion of leaves infested with the
Phytoseiid predator Amblyseius fallacis in
1989,butnotin 1988 (Table 1). The relationship
between programs, however, again varied with
sample date, as with European red mite and
two-spotted spider mite. Hence, these results
also must be considered inconclusive.
Lack of consistent spray-program effects on
European red mites, two-spotted spider mites,
and A. fallacis may be related to the initial
grouping of spray programs, which considered
the use of limited applications of potentially
toxic benzimidazole fungicides as part of "soft"
programs. Other factors independent of spray
program, such as low prey numbers in previous
years or high overwintering predator mortality
in certain orchards, also could have affected
predator numbers.
Results were more conclusive in the case of
the Stigmaeid Zetzellia mali, which was found
in significantly higher numbers in "soft" pro-
gram orchards in both 1988 and 1989 (Table 1).
Differences were maintained across all sam-
pling dates in both years. The more consistent
results are not surprising withZ. mali, because
this predator spends its entire life either on the
tree or at its base Eind consequently would be
expected to be affected severely by harsh chemi-
cal sprays. Differences in time of appearance of
Z. mali were particularly evident (data not
shown), with individuals observed in "hard"-
program orchards only in very low numbers on
the last sample round in 1988. In 1989, only a
single individual was found in a "hard" orchard
over all sampling dates.
Although, some aspects of this study were
inconclusive, we believe that the results give
some confirmation that insecticides, fungicides,
and herbicides can affect densities of prey and
predatory mites in apple trees. A clear implica-
tion of this finding is that growers wishing to
enhance the numbers of endemic mite predators
should avoid materials which can adversely
affect them.
^^ %f# •Im •Im %f^
r|% 0^ «|% 0^ 0^
Fruit Notes, Fall, 1993
A Sampling Method for Detecting
Root-feeding Wooiiy Appie Apliids
M. W. Brown
USDAf Agricultural Research Service, Appalachian Fruit Research
Station, Kearneysville, WV
The woolly apple aphid generally is consid-
ered to be a minor pest of apple world-wide,
seldom becoming abundant enough to justify
chemical control. This aphid is most often found
at pruning scars, other wound sites and at the
base of petioles on current year's growth. It also
feeds on roots of apple trees where it survives the
winter and can remain throughout the year. I
have been investigating this root-feeding insect
and its effects on apple tree growth and produc-
tion. The research literature contains only a few
studies of this problem, and those deal with
nursery stock. I found that root-feeding woolly
apple aphids reduced tree growth in young
nonbearing orchards (Brown and Schmitt,
1990) and caused a significant economic loss in
a seven-year-old 'Delicious' orchard (Brown et
al., in preparation).
The sampling method that I used in my
research was to uproot trees and evaluate the
root system. This method is efficient for re-
search but not for pest management programs,
for obvious reasons. To determine if some form
of treatment is needed, a sampling method must
be quick and easy enough to use with minimum
training. The method described in this paper is
based on woolly apple aphid biology. During
spring, first-instar nymphs migrate up the tree
from overwintering populations on roots to re-
colonize above-ground portions of the tree (Hoyt
and Madsen, 1960). Trapping these migrating
woolly apple aphid njnuphs should give an indi-
cation of the presence and intensity of root
infestation.
A two-inch-wide strip of masking tape was
placed around the trunk of apple trees, one to
two feet above the ground but below the lowest
scaffold limb. The tape was placed on the
smoothest section of trunk available. A continu-
ous barrier, about 1/8-inch deep and one-inch
wide, of Tangle-trapâ„¢ was apphed in the center
of the masking tape. A portion of the masking
tape band was exposed both above and below
the Tangle-trap barrier. The trees that were
used in this study were planted in 1985 at 308
trees per acre. The block contained Frazier
(joldspur, Smoothee (jolden Delicious, both on
M.7A, and Bisbee Spur Dehcious on M.7 EMLA.
The orchard was located at the Appalachian
Fruit Research Station in Kearneysville, West
Virginia, and was managed using standard
commercial practices.
Trees were banded to coincide with specific
tree phenologies from green tip to first cover.
Twenty five trees, selected randomly, were
banded at each of four sample periods in 1993,
as shown in Table 1. One group of 25 trees was
banded for the entire green-tip to petal-fall pe-
riod. An additional eleven trees with evidence of
aphid migration up the tree during bloom were
banded at petal fall. At the end of the designated
sample periods the bands were removed and
field counts of woolly apple aphid nymphs were
made. Examination of the tape bands was with
the unaided eye, using a hand lens only to verify
questionable nymph sightings. On May 25, the
trees were uprooted, the number of woolly apple
aphid colonies on roots was recorded, and the
amount of root galling was evaluated on a scale
of to 1. The root gall rating scale incorporated
both the proportion of the root system with root
galls and the intensity of galling on those roots
infested. It can be thought of as the proportion
of the root system affected by woolly apple
aphids, scored from none (0) to complete infesta-
tion (1).
FruH Notes, Fall, 1993
Table 1. Sample periods, trap captures,
and root infestations of wooly apple aphids.
Sample
date
Tree Trees with
phenology trapped nymphs
Trees with
root colonies
Average
root rating'
April 7-19
Green tip-
1/2 inch green
5
3 '
0.24 "
April 19-27
1/2 inch
green-pink
X
X
April 27-
May 10
Pink-
petal fall
3
3
0.19
April 7-
May 10
Green tip-
petal fall
9
12
0.22
May 10-21
Petal fall-
first cover
3
8
0.18
May 11-21*
Petal fall-
first cover
6
7
0.31
' Root rating is on a scale of to 1 and reflects the proportion of the root system
infested with woolly apple aphids.
'' Only 16 trees of the 25 sampled were uprooted, 5 with nymphs and 11 without.
' Not uprooted because no nymphs were trapped.
" Eleven trees that had been sampled in the green tip to petal fall (5) or pink to petal
fall (6) sample period.
There were two distinct periods of woolly trapped, only 16 trees were uprooted, the five
apple aphid migration from roots to above- with njmiphs and eleven without nymphs. The
ground portions of the tree (Table 1). Few aphid level of root infestation was the same for trees
nymphs were trapped between green tip and with and without trapped n5anphs. Therefore,
half inch green; five trees had one nymph each, trapping for migrating woolly apple aphid
These nymphs were a different form than nsmiphs during the green tip to half inch green
nymphs trapped later and non-migrating period would not be a useful sampling method,
nymphs found in the summer. These No nymphs were trapped during the half
earlynymphs were black and had httle wax (the inch green to pink sample period. First-instar
chEiracteristic white woolly covering), whereas nymphs were trapped on several trees that were
the typical form for first-instar nymphs is hght banded during both the pink to petal-fall and the
purple with a waxy covering over the body and green-tip to petal-fall sample periods (Table 1).
obvious tufts of wax. Because of the small In both sets oftrees the aphid nsonphs appeared
number of trees on which early nymphs were to have been trapped recently and were either
Fruit Notes, Fall, 1993
Table 2. Relationship
infestation rating.
of trap captures
to root colonies and root
Variable
Number of trees
with nymphs
Number of trees
without nymphs
Root Colonies
>0 root colonies
root colonies
12
3
12
48
Root Infestation
>0.21 rating
<0.21 rating
11
4
13
47
1
still active or at least had not begun to shrivel.
N3Tnphs in the petal-fall to first-cover sample
appeared to have been trapped early in the
period and were inactive, darkened, and had
begun to shrivel. Eleven trees that had the tape
traps removed at petal fall were re-banded to
investigate further the timing of migration. In
all eleven trees, those that had njmiphs trapped
on bands prior to petal fall also had nymphs
after petal fall, and those that did not have
nymphs trapped on bands did not have any after
petal fall. From these results, I conclude that
the majority of root migration takes place within
a few days before and after petal fall. All three
samples, therefore, that included petal fall were
pooled and analyzed as one sample, because the
presence or absence of migrating nymphs, not
the nvmiber of nymphs, was used as the predic-
tor variable.
From traps on the 75 trees in the pooled
sample, fifteen (20%) had first-instar woolly
apple aphid nymphs (the median number of
nymphs per trap was 8 but ranged fi-om 1 to
2883). Trees that had traps with migrating
nymphs had a larger number of root colonies
and a more severe root infestation than trees
without migrating njrmphs (Table 2). For trees
on which nymphs were trapped, 80% had root
colonies, and 73% had root gall infestation rat-
ings greater than 0.21. For trees without
trapped nymphs, only 20% had root colonies and
only 22% had root gall infestations greater than
0.21. F\ui,her, the mean nimiber of root colonies
and root gall infestations were 4.1 and 0.3 for
trees with trapped nymphs, respectively, and
0.5 and 0.2 for trees without trapped njmaphs,
respectively.
Conclusions
The presence of n5Tnphs migrating up the
tree fi*om roots during petal fall is an indication
of the size of the woolly apple aphid population
on the roots of that tree. Masking tape with a
Tangle-trap^" barrier was successful in trap-
ping these migrating njmiphs. By sampling an
orchard, one can estimate the number of trees
that have serious woolly apple aphid root infes-
tations by comparing the number of trees with
migrating nymphs versus those without. One
could also identify portions of an orchard that
may have a woolly apple aphid problem and
take suitable action: apply insecticides against
above-ground feeding aphids which would even-
tually lower root-feeding populations, delay re-
planting or plant other crops for a year or two, or
apply insect parasitic nematodes, which is a
promising potential control method (Brown et
al., 1992).
8
Fruit Notes, Fall, 1993
More trials of this sampling method are
needed, especially to test regions outside the
Shenandoah Valley. This study showed that
presence of migrating nymphs indicates trees
that are highly likely to have root-feeding
aphids. Further trials will enable a more quan-
titative prediction using the number of nymphs
trapped and determination of a treatment
threshold number of trees infested per acre.
Cooperators are currently being sought in the U.
S. and Canada to help refine this sampling
method.
Acknowledgements
I thank Dr. S. S. Miller, USDA, ARS, Appa-
lachian Fruit Research Station, for his coopera-
tion in the use of his orchard; J. J. Schmitt and
C. Cornell for their hard work in collecting data;
and J. J. Schmitt, G. J. Puterka, S. S. Miller, B.
D. Horton (Appalachian Fruit Research Sta-
tion), and H. W. Hogmire (West Virginia Univer-
sity) for comments on an earUer draft of this
paper.
References
Brown, M.W., J.J. Jaeger, A.E. Pye, and J.J.
Schmitt. 1992. Control of edaphic populations
of woolly apple aphid using entomopathogenic
nematodes and a systemic aphicide. J. Entomol.
Sci. 27:224-232.
Brown, M.W. and J.J. Schmitt. 1990. Growth
reduction in nonbearing apple trees by woolly
apple aphids (Homoptera: Aphididae) on roots.
J. Econ. Entomol. 83:1526-1530.
Brown, M.W., J.J. Schmitt, S. Ranger, and H.W.
Hogmire. In. Prep. Yield reduction in apple by
edaphic woolly apple aphid populations. J.
Econ. Entomol. (in preparation).
Hoyt, S.C. and H.F. Madsen. 1960. Dispersal
behavior of the first ins tar nymphs of the woolly
apple aphid. Hilgardia 30:267-299.
%£• %i* %f# mS^ mS^
rj» •Y* *J* *V* *♦*
Fruit Notes, Fall, 1993
Chemical Growth Control:
Ethephon as a Growth Retardant
Wesley R. Autio and Duane W. Greene
Department of Plant & Soil Sciences, University of Massachusetts
With the loss of Alar*, the only chemical
available for reducing vegetative growth is ethe-
phon. It functions as a growth retardant in the
same way that it initiates early ripening: it
releases ethylene within the plant tissues after
application, and ethylene can retard growth. In
1991 and 1992, we conducted a study to deter-
mine the effects of ethephon and a number of
mechanical growth-retarding treatments (scor-
ing, ringing, and root pruning) on growth and
fruit characteristics. Results from other treat-
ments were discussed previously in Fruit Notes
[1992, 57(3):l-5,6-9]. Here we report the effects
of spring ethephon application.
80
70
— ^^
^60
Ethephon /
/ y^
g-50
/ y^
§40
/ ^"^^
Cumulati
lO CO
o o
/ / Control
10
1 Ay\ A.-'<i 1 1 1 1 1 1 1 1 1
9/15 9/23 10/1 10/9 10/17
Date
Figure 1 . Cumulative drop from control and ethephon-treated Gardiner Delicious/MM. 106
trees in 1991. Ethephon was applied at 500 ppm on May 16, 1991.
10
Fruh Notes, Fall, 1993
100
^^
90
^^
80
^^^-^^•"^
g 70
Ethephon/^ /
Q.
2 60
â– o
/ /
Cumulative
o o o
/ ^^^--ic''"^Control
20
/^"^"""^^
10
j^C \ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
9/7 9/15 9/22 9/29 10/6 10/13
Date
Figure 2. Cumulative drop from control and ethephon-treated Rogers Red Mcintosh/
MM. 106 trees in 1992. Ethephon was applied at 500 ppm on May 26, 1992.
In 1991, mature, vigorous Gardiner Deli-
cious/MM.106 trees were treated with 500 ppm
ethephon eight days after petal fall, and in 1992,
mature, vigorous Rogers Red Mcintosh/
MM. 106 trees were treated with 500 ppm ethe-
phon four days after petal fall. During the
season of treatment, we assessed fruit set, veg-
etative growth, frxdt ripening, fruit drop, and
fruit size.
Use of ethephon soon after bloom, as was
done in this study, has been shown to thin fruit,
and in fact, ethephon is used as a chemical
thinner in some locations around the world. In
this experiment, however, the ethephon treat-
ment did not thin significantly and had very
little effect on fruit set. We all know that
chemical thinners do not work every year, and
they do not work under all circumstances. The
lack of a thinning response from ethephon in
this study should not be taken to mean that
ethephon will not thin fruit under our condi-
tions. From a practical standpoint, if ethephon
is to be used as a growth retardant, the grower
must be prepared for a potential reduction in
fruit set, even if it Likely will not occur in all
circimistances.
Research by others has shown that ethep-
hon has only a moderate effect at best on termi-
nal growth reduction. The most noticeable
growth reduction comes from preventing spurs
fruit Notes, Fall, 1993
11
from growing into lateral
shoots. In this experiment, we
measured terminal length,
terminal diameter, and the
time required for dormant
pruning. Not surprisingly,
ethephon did not significantly
alter terminal growth, but it
did reduce the time required
for dormant pruning of Deli-
cious by approximatlely 25%,
which likely was related to a
reduction in the number of lat-
eral shoots produced from
spurs.
When used on excessively
vigorous, young trees that are
essentially nonbearing, ethep-
hon may be very effective at
reducing all excessive vegeta-
tive growth, but indirectly,
since it can stimulate flower
bud formation. In this way,
the tree can be shifted from a
vegetative habit to a bearing
habit the year after ethephon
application. In our experi-
ment, we were using mature,
bearing trees, so this was not a
factor.
Very importantly, the ef-
fects of spring-applied ethep-
hon were apparent in the fall.
Figures 1 and 2 show the fruit
drop that occurred from ethep-
hon-treated and untreated
trees. Overall, for ethephon-
treated trees, drop was nearly
double that of untreated trees.
Fruit from ethephon-treated
trees also ripened sooner (Fig-
ure 3), and for Mcintosh, they
were significantly smaller
than fruit from untreated
trees (Figure 4).
In conclusion, several
points should be understood
Delicious
i
^
. .
^->-^
Mcintosh
ethophofl
1
1
1
9/15 9/20 9/25 9/30
Date of 1 ppm ethylene
10/5
Figure 3. Effects of spring-applied ethephon on the time
of ripening of fruit from Gardiner Delicious/MM.106
trees and Rogers Red Mclntosh/MM.106 trees.
Average count per 42-lb box
140
130
120
110
100
90
80
&tt«ph*m
y >jk
^ioi^^i^^S^^^
Cont|t)l
Ethephon
Delicious
Mcintosh
Figure 4. Effects of spring-applied ethephon on size,
presented as average counts per 42-lb. box, of fruit from
Gardiner Delicious/MM. 106 trees and Rogers Red Mcln-
tosh/MM.106 trees.
12
Fruit Notes, Fall, 1993
before ethephon is used to retard growth of
mature, bearing trees: 1) ethephon is a poten-
tial thinner, so significant thinning may result if
appropriate conditions exist; 2) extension
growth may not be reduced dramatically, but
lateral shoot development may be reduced, pro-
ducing more of a spur-type growth habit and
reducing the time required to dormant prune
trees; 3) ripening may be advanced and drop
may be increased, so plans must be made to
harvest ethephon-treated trees earUer than
normal; and 4) fruit size may be reduced. The
potential reduction in size is of major concern
and may negate any positive effects of ethephon
treatment on bearing trees.
A strategy that was used with Alar® was to
direct the spray into the top, vigorous portions of
the canopy. Using this technique, carryover
effects and reduction in fruit size were mini-
mized. This approach may not work with ethe-
phon, since it would cause finiit in the top of the
tree to ripen earlier than the rest, making har-
vest troublesome and possibly resulting in dam-
age to lower fruit from upper frmt dropping
through the canopy.
For vigorous,nonfruiting trees, ethephon
may be more beneficial than for bearing trees.
In young trees, its major positive response is to
initiate flower bud formation. The season fol-
lowing the ethephon treatment should see en-
hanced finiit production and, therefore, less veg-
etative growth.
«1# *f# %{# %f# %f#
r{« 0^ #j« #2% 0^
Fruit Notes, Fall, 1993
13
Food Prices, Expenditures,
and Income
Robert L. Christensen and Donald R. Marion
Department of Resource EconomicSy University of Massachusetts
Have consumer expenditures for food been
increasing or decreasing, and if so, by how
much? What happens to the consumer's food
dollar; what share do farmers get, and how
much is absorbed by firms involved in the mar-
keting process? What determines how the con-
sumer food dollar is divided, and do those who
receive the largest part of consumer expendi-
tures have the largest profits, or vice-versa?
These questions are among those most fre-
quently asked about the U.S. food system. A
recent U.S.D.A. publication (Dunham, D. 1993.
Food Costs ... From Farm to Retail in 1992.
Economic Research Service, USDA, Agricul-
tural Information Bulletin Number 669) con-
tains many of the answers, plus some additional
insights into issues such as recent changes in
food prices, consumer food expenditures, and
the farmers' share. The following discussion
addresses the above questions and some other
highhghts from that publication.
Food Prices and Expenditures
Changes in consumer prices, including food
prices, are measvired by the Consumer Price
Index (CPI) which, in turn, is used as the mea-
sure of inflation or changes in the cost of Uving.
In 1991 and 1992, food prices increased less
than the rate of inflation — the prices of aU.
consumer goods. In other words, the modest
increase in food prices helped to moderate the
overall rate of inflation. For 1991 and 1992, the
CPI rose by 4.2 and 3.0 percent, respec
tively, while food prices rose by only 2.9 and 1.2
percent, respectively.
During the same two years, total consumer
expenditures for food increased slightly more
(3.6 and 2.3 percent, respectively) reflecting the
combined effects of food price increases, popula-
tion increases, and possible changes in con-
sumption patterns.
In 1991, U.S. consumers spent a total of
$492 bilhon for food, which amounts to $4,367
annually per household of 2.6 persons, or $1,680
per person per year, $37.30 per week, and $4.60
per day. Of that total, 62 percent was spent for
food consumed at home and 38 percent away
from home.
Consumer Expenditures and Income
For all consumers combined, 1992 food ex-
penditures represented 11.4 percent of personal
disposable income, though that percentage var-
ied widely with variations in income levels.
Households with disposable income of $5,000 to
$9,999 spent 32.6 percent of their income for
food, while those whose incomes were $30,000 to
$39,999 spent only 15.2 percent for food. At
higher income levels, even smaller proportions
were spent for food.
The share of consumer disposable income
spent for food has, in general, been declining
since 1960, when consumers spent 17.5 percent
of disposable income for food. In 1970, that
percentage had declined to 13.9 percent, in 1980
to 13.5 percent, and 11.7 percent in 1990. Food
consumed at home has been the major factor in
that decline. In fact, consumer spending for food
eaten away from home rose from 3.5 percent of
personal disposable income in 1960to 4.4 per-
cent in 1980, and has fallen sUghtly to 4.2
percent in 1992. Why? The answer is that prices
for food away from home have risen more than
the prices of food consumed at home and that,
year by year, we have been eating an increasing
share of our meals away from home, a trend that
has slowed somewhat in recent years.
The fact that food expenditures in total have
been declining as a percentage of income is a
result of incomes increasing more rapidly than
14
Fruit Notes, Fall, 1993
food prices, and also a demand for agricultural
products that is income inelastic (when income
increases by one percent, food expenditures in-
crease by something less than one percent).
The Farm Share
Modestly increasing food prices, which have
contributed to the declining share of income
spent for food, have occurred partly because of
efficiencies and competition in food marketing,
but also, because of very slowly increasing farm
prices. The farm value of a "market basket" of
food purchased by consumers increased by only
five percent from 1982 to 1992 - less than one-
half of one percent per year. (The "market bas-
ket" referred to here is a group of 74 domestically
produced food products used by the U.S.D.A. for
its food price and cost studies.) In contrast,
Massachusetts per capita, personal disposable
income increased more than 200 percent from
1980 to 1991: $10,612 to $22,897 (Andrews and
McNeel. 1993. Personal income per capita in
current dollars by state. 1970-91. p. 244. In:
The Universal Almanac - 1993).
Over the same time, retail prices for food
products increased by 40 percent, resulting in a
decline in the farm share of consumer expendi-
tures for the U.S.D.A. "market basket." For
example, in 1982, farmers received 35 percent of
the dollars spent by consumers for food, as
payment for their products. By 1992, that share
had fallen to 26 percent.
The farm share of consumer expenditures
varies widely among food products. It tends to be
greatest for products requiring httle packaging,
processing, and handling, and vice-versa. Thus,
farmers receive a relatively large share (over
50%) of the retail price of products such as eggs,
chicken, and beef and 10 percent or less for
others such as tomatoes, bread, and com syrup.
The difference between retail prices and the
amount received by farmers for an equivalent
amount of product (e.g., it takes an average of
2.4 pounds of Choice grade steer, to produce
each pound of beef sold in retail stores) is re-
ferred to as the farm-to-retail price spread. The
farm-to- re tail price spread might be considered
the marketing cost (or "marketing msu-gin") for
farm products, being absorbed by the labor.
packaging, promotion, energy, and other costs
involved in the processing and marketing of
farm products. In recent years that cost has
risen at an average rate of 5.6 percent, meaning
that the cost of marketing farm products has
been increasing faster than the farm value of
those same products.
There are two important points to be made
here. First, whether the farm share (or the
marketing margin) is increasing or decreasing
says very httle about the welfare of farmers or
the relative profitability of farming vs. market-
ing. Products sold in retail stores are much
different from those sold by farmers, and the
cost of creating those differences is included in
the farm-to-retail price spread. If, as has been
occurring recently, consumers purchase in-
creasing amounts of the more highly- processed
products, the farm-to-retail price spread must
increase, even if farmers continue to receive the
same prices for their products.
Second, there are major differences in the
different markets involved that contribute to
the fact that farmers often receive lower price
increases for their products than do the market-
ing firms. There is little benevolence in any
market; market participants pay what they
have to pay to receive needed products and
services. In the markets where farmers sell their
products, they usually have less bargaining
power than do the buyers to whom they must
sell. As a result, farmers tend to be "residual
claimants" to returns in the market place.
On the other hand, in the market for inputs
such as labor, energy, and packaging materials,
marketing firms encounter sellers with bargain-
ing power equal to or greater than their own,
£uid the resulting prices are negotiated or bar-
gained prices. In the market for the final prod-
ucts, marketing firms usually have sufficient
marketing power visa- viz consumers, to at least
be able to obtain adequately profitable prices.
Who Gets What Part Of The
Consumer Food Dollar?
The final question addressed in this article
is, where does the consumer food dollar go; who
receives what part of it? In 1992, 26 cents of
every food dollar spent by consumers was re-
FruH Notes, Fall, 1993
15
ceived by fanners. Of the remainder (some-
times referred to as the "marketing bill"), 35
cents was used to pay salaries and wages for the
workers involved, and 8 cents, the cost of pack-
aging. Transportation, depreciation, advertis-
ing, energy, and rent costs each accounted for
3.5 to 4.5 cents. About 6.5 cents was divided
among a large number of costs, including re-
pairs, insurance, professional services, prop>erty
taxes, and many other items. The remaining 3.5
cents represented before-tax profits.
Consumer Value and Their
Food Dollars
In conclusion, it appears that consumers
have benefitted fi-om very moderate increases in
retail food costs in recent years. Personal dispos-
able incomes have risen at a faster rate than
food costs and the percentage of income spent on
food has fallen. At the same time the farm share
of the consumer's dollar has steadily dechned
while the farm-to-retail margin has gradually
increased.
Do U.S. consumers get a good value for their
food dollars? Undoubtedly they do. Could it be
better? Of course it could, and it is probably
getting better, especially with the increased use
of information about nutrition and healthful-
ness of food products. Do farmers and marketers
receive fair values for their contributions? Prob-
ably so, at least if you base your conclusion on
the availability of adequate supplies of food of
adequate quality and in reasonable variety. In
addition, most would conclude that food market-
ing firms receive reasonable, though not ex-
travagant, returns for their investments. The
case for farmers is less clear; certainly their
profits are not excessive. For U.S. farmers
whose major occupation is farming, household
net farm incomes in 1991 averaged $10,228
fi"om gross cash farm income of $94,027 and
farm assets valued at $491,241 (USDA-ERS.
1993. Agricultural Income and Finance - Situ-
ation and Outlook Report. Economic Research
Service, USDA, AFO-49).
%f# «f^ *f^ *fi» •^0
r|% #1% #^ #1% r{%
16
Fruit Notes, Fall, 1993
Fruit Notes
University of Massachusetts
Department of Plant & Soil Sciences
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Fruit Notes
ISSN0427-6906
' !:]RmRY
HAR-7 914
Prepared by the Department of Plant & Soil Sciences. . ^ r r \ / r\r- n k n r
JHIV. OF MASS.
University of Massachusetts Cooperative Elxtenslon System,
United States Department of Agriculture, and Massachusetts Counties Cooperating.
eiOLOGCAL
Editors: Wesley R. Autio and William J. Bramlage
MAR 04 1994
SCIENCES UBRARY
Volume 59, Number 1
WINTER ISSUE, 1994
Table of Contents
Apple Integrated Pest Management in 1993:
Insects and Mites in Second-level Orchard Blocks
Second-level IPM in Blocks of
Scab-resistant Apple Cultivars
New Publication Available
Second-level Integrated Pest
Management, 1991 to 1993: Diseases
Tax Pointers for Farmers in 1993
Fruit Notes
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Fruit Notes
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Apple Integrated Pest Management in
1993: Insects and Mites in Second-level
Orchard Blocks
Jennifer Mason, Ronald Prokopy, Starker Wright, Sarah Goodall,
Kristian Jones, Yu Ma, Vanessa Mohr, and Miyu Nogaki
Department of Entomology, University of Massachusetts
For the past two years we have reported results
of our ongoing program of second-level IPM trials in
Massachusetts apple orchards. Under second-level
IPM, orchard management is integrated across all
classes of pests: insects, mites, diseases, weeds, and
vertebrates, rather than focusing on a single type of
pest. Here we report results of the third year of
second-level IPM trials on insects and mites in
commercial Massachusetts orchards.
Insect and mite management under second-level
IPM practices require application of three to four
selective insecticide sprays from April to early June
to manage tarnished plant bug (TPB), European
apple sawfly (EAS), plum curculio (PC), green fruit-
worm (GFW), and the first generations of codling
moth (CM), lesser appleworm (LAW), leafminer
(LM), and white apple leafhopper (WALH). Insecti-
cide application to the interior of the block ceases
after the final plum curculio spray in early June,
hopefully allowing populations of predatory insects
and parasitoids to increase to levels sufficient to
provide control of summer populations of foliar
pests. In full second-level IPM blocks, apple
maggot fiies (AMP) are controlled by perimeter in-
terception traps. In transitional second-level
IPM blocks, use of AMF interception traps is re-
placed by perimeter-row spraying with Guthionâ„¢* or
Imidan''''^ every three weeks beginning in early July.
In both types of blocks, removal of unmanaged apple
and pear trees within 100 yards of each block reduces
immigration of CM and LAW. Removal of drops
during and after harvest discourages buildup of
within-orchard populations of AMF, CM, and LAW.
We believe there are at least four distinct poten-
tial benefits of employing biologically-based meth-
ods as a substitute for insecticides from early June
until harvest. These include reduction in insecticide
residue on fruit at harvest, reduction in impact of
insecticide on areas bordering orchards, reduction in
selection pressure leading to pest resistance to insec-
ticides, and buildup of beneficial natural enemies in
the absence of insecticide use afi-er early season
sprays. For some growers and some intended mar-
kets, one or more of these potential benefits could be
important in the near future, if not now.
In 1993, we continued work in the same six full
and six transitional second-level IPM test blocks
used in 1991 and 1992. Each second-level block was
matched with a nearby control block that was man-
aged by the grower, using first-level IPM methods.
Early-Season Fruit-injuring Pests
For control of arthropod pests active up to early
June, second-level IPM relies on early-season pesti-
cide treatment based on monitoring. We monitored
each orchard weekly beginning in mid-April, then
biweekly from mid-June through September. Five
each of four types of sticky traps were hung in each
block to monitor for TPB, LM, and EAS. We exam-
ined 100 or 200 leaves or watersprouts per block for
LM, LH, aphids, mites, and mite predators. During
PC season, scouts examined fruit on perimeter trees
for evidence of fresh injury, while growers were
urged to do likewise on a daily basis. On the basis of
this monitoring, recommendations were made to the
grower for treatment of the experimental block.
In second-level IPM blocks (both full and transi-
tional) in 1993, combined injuries from early- season
fruit pests were rather similar to those in nearby
first-level IPM (grower control) blocks. In both first-
and second- level IPM blocks, TPB caused by far the
most damage, followed by PC and EAS (Table 1).
Due to a lack of alternatives to pesticidal control of
early-season fruit pests, both first- and second-level
blocks had similar management and therefore simi-
lar insecticide use(Table2).Thisyear sawa marked
increase in TPB damage over 1992 in all blocks,
though injury due to PC and EAS remained similar.
Fruit Notes, Winter, 1994
Table 1. Average percent injury by early-season insect pests in second-
level and first-level IPM blocks in 1993.*
Type of block
TPB
PC
EAS
GFW
Total
Full second-level
First-level
Transitional second-level
First level
7.0 a
6.5 a
2.6 a
1.2 a
0.3 a
0.1 a
0.3 a
0.3 a
0.1 a
0.1 a
0.1 a
0.1 a
0.0 a
0.0 a
0.0 a
0.0 a
7.4 a
6.7 a
3.0 a
1.6 a
* Means in each couplet in each column followed by a different letter
are significantly different at odds of 19:1. Two hundred fruit of each
cultivar present in both second-level and corresponding first level
blocks were sampled at harvest. All blocks contained at least 1 of
the following cultivars, and some contained up to 3 of these:
Mcintosh, Cortland, Delicious, Empire, Golden Delicious. Average
number of fruit sampled per block = 500. When sampling a cultivar,
we examined 10 fruit on each of 20 interior trees and 10 on each of
10 perimeter-row trees (when cultivar present on a perimeter row).
TPB = tarnished plant bug; PC = plum curculio; EAS = European
apple sawfiy; GFW = green fi-uitworm.
Table 2. Dosage equivalents (spray events in parentheses) of insecticides and
acaricides used in second-level and first-level IPM blocks in 1993.*
Type of block
Fruit pests
Mites
After
Before
mid-
mid-
Other
June
June
Oil
miticides
LH
ABLM
Total
2.7
0.0
1.4
1.0
0.2
0.3
5.6
(3.3)
(0.0)
(2.5)
(0,8)
(0.3)
(0.5)
(7.4)
2.7
1.0
1.0
1.2
0.2
0.0
6.1
(3.3)
(2.2)
(2.1)
(1.3)
(0.2)
(0.0)
(9.1)
2.2
0.7
1.1
0.5
0.0
0.2
4.7
(3.2)
(3.2)
(2.2)
(0.6)
(0.0)
(0.2)
(9.4)
2.2
1.2
1.5
1.7
0.0
0.0
6.6
(3.0)
(2.8)
(2.5)
(1.5)
(0.0)
(0.0)
(9.8)
Full second-level
First-level
Transitional second-level
First-level
LH = leafhopper, ABLM = apple blotch leafminer.
FruH Notes, Winter, 1994
Summer Fruit-injuring Pests:
Full Second-level IPM
Odor-baited sticky red spheres were hung every
five yards on perimeter apple trees of each full
second-level experimental block to intercept immi-
grating AMF. These were baited with both butyl
hexanoate, a synthetic fruit odor deployed in poly-
ethylene vials, and ammonium acetate, a synthetic
food odor released through a Consep^'* membrane.
Traps were cleaned biweekly, based on data from
1992 suggesting a loss of capturing power with
increase of length of time between cleanings.
Interception trap captures averaged 5023 in the
six full second-level blocks, as compared with 2430 in
1992 and 3562 in 1991, indicating that AMF pres-
sure was exceptionally high in 1993. Even so,
captures of AMF on four interior unbaited monitor-
ing traps (indicative of AMF penetration into the
block interior) were similar in full second-level
blocks and nearby first-level blocks (Table 3). AMF
injury to fruit at harvest averaged slightly but not
significantly greater in second-level than first-level
blocks (0.7 vs. 0.3) (Table 3). The power of intercep-
tion traps for controlling AMF is illustrated in one
full second-level block of 10 acres where more than
21,000 AMF were captured on the traps but less than
1% of Mcintosh, Cortland, and Delicious apples were
injured by AMF. It should be noted, however, that
late-ripening cultivars (e.g., Delicious and Golden
Delicious) consistently have proven to be more sus-
ceptible to AMF injury than mid- or earlier-ripening
cultivars under full second-level practices.
The problem of effective control of AMF in late-
ripening cultivars remains a challenging one for us.
In one block that suffered 8% AMF injury to
Cortlands in late September of 1992, we hung perim-
eter traps significantly higher in the tree in 1993
than in 1992 in an attempt to increase trap captures
of AMF before fruit injury occurred. We found only
1% AMF damage to the Cortlands at harvest this
year, though it should be noted that the fruit was
Table 3. Season-long apple maggot fly (AMF) injury and trap captures in second-
level IPM blocks and first-level IPM blocks in 1993.*
Perimeter
Interior
monitoring
AMF injury
monitoring
trap
Interception
to fruit at
trap captures
captures
trap captures
Type of block
harvest (%)
per trap
per trap
per block
Full second-level
0.7 a**
7.7 a
22.9 a
5023
First-level
0.3 a**
11.0 a
10.7 a
—
Transitional second-level
0.8 a
8.4 a
8.8 a
First-level
0.4 a
9.7 a
9.7 a
—
Means in each couplet in each column followed by a different letter are
significantly different at odds of 19:1. Two hundred fruit of each cultivar present
in both second-level and corresponding first-level blocks were sampled at harvest.
All blocks contained at least one of the following cultivars, and some contained
three of these: Mcintosh, Cortland, Delicious, Empire, Golden Delicious.
Average number of fruit sampled per block = 500. When sampling a cultivar, we
examined 10 fi-uit on each of 20 interior trees and 10 on each of 10 perimeter-row
trees (when cultivar present on a perimeter row).
Data on AMF injury to fruit from one orchard have been excluded due to
excessively high late-season damage to several cultivars in both the second and
first-level blocks possibly caused by lack of AMF control methods by grower in
surrounding blocks.
Fruh Notes, Winter, 1994
picked slightly earlier than
in 1992. In other blocks,
problems with AMF arose
in cases where perimeter
rows were comprised of
early ripening cultivars,
necessitating immediate
movement of interception
traps to interior trees upon
harvest. Due to time con-
straints we wereunable to
move the spheres soon
enough after harvest, al-
lowing injury to occur in
later-ripening cultivars.
We continue to look for
an appropriate method of
hanging ammonium ac-
etate membranes that will
keep their fluttering mo-
tion to a minimum so as not
to scare AMF away. This
year we attempted to stitch
a wire through the top of the
membrane packet only to
find that the contents
drained out within a few
weeks.
Fruit injury by CM, LR,
and LAW were similar in second-level and first-level
blocks (Table 4). CM averaged 0.2% in the second-
level blocks while it was 0% in the adjacent first-level
blocks. Leafroller injury was up from 1992, averag-
ing 0.8% in second-level and 1.0% in first level
blocks. LAW injury also increased, averaging 0.4%
in second-level blocks and less than 0.1% in first-
level blocks.
No insecticide was applied against any fruit-
injuring pest after mid-June. In adjacent first-level
blocks growers applied an average of 1.0 dosage
equivalents of insecticide against fruit pests after
mid-June and sprayed the block an average of 2.2
times (Table 2).
Summer Fruit-injuring Pests:
Transitional Second-level IPM
Every three weeks after early June, perimeter
row apple trees in transitional second-level blocks
were treated with insecticide to control AMF. The
block interior remained free of insecticide after early
June. AMF injury at harvest averaged 0.8% in
transitional second-level blocks and 0.4% in nearby
first-level blocks, somewhat higher for both types of
Table 4. Fruit injury by codling moth (CM), leafrollers (LR), and
lesser appleworm (LAW) in second-level and first-level IPM
blocks in 1993.*
Type of block
CM
LR
LAW
Full second-level
First-level
Transitional second-level
First-level
0.2 a
0.0 a
0.1 a
0.0 a
0.8 a
1.0 a
0.7 a
0.2 a
0.4 a
<0.1 a
0.4 a
0.0 a
Means in each couplet in each column followed by a diff'erent
letter are significantly different at odds of 19:1. Two hundred
fruit of each cultivar present in both second-level and
corresponding first level blocks were sampled at harvest. All
blocks contained at least 1 of the following cultivars, and some
contained 3 of these: Mcintosh, Cortland, Delicious, Empire,
Golden Delicious. Average number of fruit sampled per block
= 500 When sampling a cultivar, we examined 10 fruit on
each of 20 interior trees and 10 on each of 10 perimeter-row
trees (when cultivar present on a perimeter row).
blocks than in 1992 (Table 3). Captures of AMF on
interior unbaited monitoring traps were similar in
transitional second-level blocks and in first-level
blocks. Total insecticide used afi^r early June aver-
aged 0.7 dosage equivalents in second-level blocks
compared with 1.2 dosage equivalents in first-level
blocks (Table 2). The relative similarities between
the two sets of blocks may be explained by some
growers using exclusively border row sprays for
AMF in first-level blocks, mainly due to financial
constraints.
CM damage was very low in both types of blocks
(0.1% or less). Both LR and LAW injury were
somewhat (but not significantly) greater in the tran-
sitional blocks (0.7 and 0.4%) than in the first-level
blocks (0.2 and 0%) (Table 4).
Foliar Pests and Predators:
Full Second-level IPM
In 1992, we reported peak populations of foliar
pests; this year we return to season-long averages
from time of first to last appearance of the pest on
foliage. Hot, dry weather played a major role in
inciting higher foliar pest populations in 1993.
Fruit Notes, Winter, 1994
Table 5. Seasonal average populations of mites and mite predators in
second-level and first-level IPM blocks in 1993. *
Mite presence
(% of leaves)
Ratio of
ERM-t-TSM
YM to Af
ERM+
Type of block TSM Af
Full second-level 22.4 a 0.7 a
First-level 18.6 a 2.0 a
Transitional second-level 19.6 a 2.1 a
First-level 16.2 a 1.0 a
4.3 a 32:1
4.5 a 9:1
3.1 a 9:1
1.2 a 16:1
* Means in each couplet in each column followed by a different letter are
significantly different at odds of 19:1. ERM = European red mite; TSM
= two-spotted mite; Af = Amblysieus fallacis; YM = yellow mite.
Table 6. Foliar insect pest average population levels in second-level and first-level blocks in
1993.*
Type of block
PLH
WALH
RLH
ABLM
GAA
GAAP
WAA
Full second-level
First-level
Transitional second-level
First-level
8.9 a
6.7 a
6.4 a
6.9 a
4.2 a
4.2 a
2.2 a
1.4 a
7.5 a
2.4 a
2.4 a
0.8 a
8.0 a
17.2 a
6.8 a
4.4 a
28.7 a
27.1 a
35.3 a
28.9 a
17.1 a
13.4 a
19.0 a
10.1 a
8.1 a
7.6 a
4.3 a
4.5 a
Means in each couplet in each column followed by a different letter are significantly different
at odds of 19:1. PLH = potato leafhopper, WALH = white apple leafhopper; RLH = rose
leafhopper, ABLM = apple blotch leafminer; GAA = green apple aphid; GAAP = green apple
aphid predators: cecidomyiids and syrphids, WAA = woolly apple aphid. PLH, WALH, and
RLH data are average percentages based on bi-weekly samples of 100 or 200 fruit cluster or
terminal leaves. ABLM data are the average number of mines per 100 leaves based on bi-
weekly samples of 100 or 200 fruit cluster or terminal leaves. GAA, GAAP, and WAA data
are percentage watersprouts infested based on bi-weekly samples of 200 watersprouts.
Fruit Notes, Winter, 1994
Mite populations were high in most orchards,
appearing early in the season (Table 5). In several
orchards mite problems in second-level blocks may
have been inadvertently assisted by our setting
aside of small areas (approximately one acre ) in the
block to be left untreated with dormant oil. This was
done in the hope of providing a reasonable food
source for early phytoseiid mite predator popula-
tions. Unfortunately Amblyseius fallacis suffered
extremely heavy late winter mortality, and these
areas proved useful only for raising large numbers of
European red mites. Yellow mite predators were
eventually present in large numbers in some or-
chards. There tended to be little difference, how-
ever, in densities of mite predators between full-
second-level and first-level blocks (Table 5).
Typhlodemus pyri obtained from Geneva, New York
were released in two blocks in 1992 and again this
past summer. Repeated sampling of the release sites
leads us to believe that both attempts at colonization
were unsuccessful.
Full second-level blocks were treated with
slightly higher dosage equivalents of pre-bloom and
mid-season oil than nearby first-level blocks (1.4 vs.
1.0) while receiving slightly less other miticide (1.0
vs. 1.2 dosage equivalents) (Table 2). The use of post-
bloom miticides in the full second-level blocks was
mainly due to a need to regain control over mite
populations in the areas that did not receive oil in the
spring.
White apple leafhopper populations were equal
in both the full second-level and first-level blocks.
Potato leafhoppers were slightly, although not sig-
nificantly, higher in the full second-level blocks. The
major leafhopper problem this year proved to be rose
leafhopper (RLH) migrating into blocks from border-
ing wild rosebushes and brambles. In several loca-
tions RLH were present in high enough numbers to
be a major irritation at harvest, and one full second-
level block required late season treatment of insecti-
cidal soap. RLH averaged 7.5 % infestation in full
second-level blocks, versus 2.4% infestation in the
first-level blocks (Table 6).
Average leafminer populations were lower, al-
though not significantly, in full second-level blocks
than in first-level blocks (Table 6). Dimilinâ„¢ was
used in three of the six full second-level blocks
against overwintering LM adults and eggs even
though only two of these blocks required a treat-
ment. Late stage tissue mines were collected from
each orchard and brought back to the lab for parasit-
ism readings. The average parasitism rate of second
generation larvae was 55% in full second-level
blocks but only 37% in first level blocks. Research
into parasitism of LM continues to be an area of
interest in that parasitism appears a potentially
very effective means of controlling one of our major
foliar pests.
Green apple aphids infested 29% and 27% of the
watersprouts in full second-level blocks and in first-
level blocks, respectively. Levels of two aphid preda-
tors were also similar in both types of blocks, and
achieved efficient control of GAA. Levels of woolly
apple aphids on watersprouts were also similar in
both types of blocks, but were considerably higher
than in 1992.
Foliar Pests and Predators:
Transitional Second-level IPM
Mite levels were moderate to high in most of the
transitional second-level blocks and adjacent first-
level blocks. Dosage equivalents of oil averaged 1.1
in second-level blocks and 1.5 in first-level blocks.
Other miticide applications averaged 0.5 dosage
equivalents in second-level blocks and 1.7 dosage
equivalents in first-level blocks. Mid-season miticide
application occurred in one second-level block as
compared to three first-level blocks (Table 2).
White apple leafhopper and potato leafhopper
populations were about the same in second-level and
first-level blocks. RLH levels were less of a problem
in transitional second-level blocks than in full sec-
ond-level blocks, possibly becauseperimeter row in-
secticide applications every three weeks during the
summer killed immigrating RLH.
Only one transitional second-level block was
treated with Dimilinâ„¢ against first generation
leafminers. Leafminer numbers were slightly
higher in second-level blocks than in first-level
blocks, yet the parasitism of second generation lar-
vae was slightly lower (38% vs. 44%). LM levels were
similar to those found in 1992.
Green apple aphid infestation levels were some-
what higher in second-level blocks than in first-level
blocks, as were both types of aphid predators moni-
tored. In both types of blocks predators were suffi-
cient to provide control of GAA populations. Woolly
apple aphid populations were similar in both types of
blocks (Table 6).
Conclusions
With regard to full second-level IPM practices
that involve substitution of cultural, behavioral, and
biological control methods for insecticide use after
early June, we conclude the following after three
consecutive years of implementation.
Fruit Notes, Winter, 1994
(1) No buildup of codling moth or leafroller beyond
a level existing in nearby first-level IPM blocks.
(2) Slight buildup of lesser appleworm in 1993.
(3) Slightly greater injury by apple maggot flies,
especially in late-ripening cultivars.
(4) No buildup of pest mites under slightly reduced
miticide use but insufficient buildup of preda-
tory mites to permit truly substantial reduction
in miticide use.
(5) Considerable buildup of parasitoids of
leafminers, possibly sufficient to reduce or elimi-
nate need for spray against leafminers.
(6) No buildup of apple aphids, woolly apple aphids,
or white apple leafhoppers beyond acceptable
levels.
(7) Substantial mid- and late-summer immigration
(into some blocks) of rose leafhoppers from
nearby rose bushes and brambles, causing ex-
crement spotting of fi"uit and nuisance to pick-
ers.
With respect to transitional second-level IPM
practices that involve no application of insecticide to
the block interior aft.er early June but rely on perim-
eter-row sprays instead of traps for controlling apple
maggot flies, we conclude the following after three
consecutive years of implementation.
(1) No buildup of codling moth but slightly more
injury by leafrollers compared with nearby first-
level IPM blocks.
(2) Slight buildup of lesser appleworm in 1993.
(3) Slightly greater injury by apple maggot fly.
(4) No buildup of pest mites under slightly reduced
miticide use but not enough buildup of predatory
mites to allow much reduction in miticide use.
(5) No buildup of parasitoids of leafminers.
(6) No buildup of apple aphids, woolly apple aphids,
or white apple leaflioppers beyond acceptable
levels.
(7) No unacceptable immigration of rose leafhop-
pers during mid- and late-summer.
In sum, transitional second-level IPM offers an
advantage over first-level IPM in terms of substan-
tial reduction in pesticide use during summer
months. Growers using transitional second-level
IPM should, however, keep a careful eye on buildup
of apple maggot, leafrollers, and leafminers. In the
long run, we believe that if pesticide-treated spheres
can be developed and registered as a substitute for
sticky spheres to control apple maggot (see accompa-
nying article), full second-level IPM will be as eco-
nomical to employ and as effective in controlling
pests as first-level IPM while offering several dis-
tinct advantages outlined in the introduction.
To verify further the advantages and shortcom-
ings of second-level IPM, we plan to evaluate in 1994
the same full and transitional second-level practices
in the same blocks used from 1991 to 1993. This will
provide four consecutive years of data, which ought
to be sufficient for drawing firm conclusions. We also
plan to carry out intensive studies on refining those
aspects of full second-level IPM that to date have
proven to be shortcomings. These include: enhanc-
ing the residual effectiveness of pesticide-treated
spheres; studying within-orchard movement pat-
terns of apple maggot flies from early- to mid- to late-
ripening cultivars; evaluating elimination of rose-
bushes and brambles near orchards as a means of
controlling rose leafhopper; and evaluating the im-
pact of summer applications of benomyl and
mancozeb on mite predators, which we now believe
may be the principal reason for lack of sufficient mite
predator buildup to provide biocontrol of mites in
second-level blocks.
Acknowledgements
This project was funded by the Massachusetts
Society for Promoting Agriculture, the USDA North-
east Regional IPM Competitive IPM Grants Pro-
gram, State/Federal IPM funds, and the Northeast
Region Sustainable Agriculture Research and Edu-
cation Program (formerly LISA). We gratefully
acknowledge this funding. We are also grateful for
the participation and support of the following grow-
ers: Bill Broderick, David Chandler, Dana Clark,
Dick, Greg, and Kevin Gilmore, Tony Lincoln,
Jesse and Wayne Rice, Joe Sincuk, Dave Shearer,
Tim Smith, and Barry and Bud Wiles.
•!• %l0 •!» %% •^
•Y» •^ •((»• •li* •(!>•
Fruit Notes, Winter, 1994
Second-level IPM in Blocks of
Scab-resistant Apple Cultivars
Daniel R. Cooley, Jennifer Mason, Jian Jun Duan, Xing Ping Hu,
Ryan Elliott, and Ronald J. Prokopy
Departments of Plant Pathology and Entomology^
University of Massachusetts
Previously, we have described methods designed
to eHminate orchard applications of insecticide and
miticide after early June. We have also described
our concept of the evolution of integrated pest man-
agement (IPM) programs, moving from first level
approaches which integrate methods for controlling
one class of pests, to a second level which integrates
methods for controlling all classes of orchard pests.
In 1991, we initiated a second-level IPM program in
12 Massachusetts commercial apple orchards com-
prised of Mcintosh, Cortland, Empire, and Delicious
cultivars. Our strategy used pesticides from April to
early June against early-season arthropod pests
(particularly mites, plant bug, sawfly, and plum
curculio), early-season disease pests (apple scab and
blossom-end rot) and early-season weed growth be-
neath the tree canopy. After early June, the strategy
called for few if any pesticide applications. Instead,
cultural, behavioral, and biological control methods
replaced pesticides. We felt that this strategy would
allow natural enemies of arthropod pests to increase
in numbers and provide biological control (especially
of foliar-damaging arthropods), slow rates at which
pests develop resistance to pesticides, and reduce
potential human risks from pesticide residues on
fruit at harvest.
Over the first two years of the program, we saw
successes and some problems in all pest areas, but
one of the most troublesome areas was disease man-
agement. In the second-level blocks, growers used
4.6 fungicide dosage equivalents (DEs) during the
primary apple scab season. They also used 2.2
fungicide DEs to control summer diseases, notably
flyspeck and sooty blotch. By comparison, in first-
level IPM blocks, growers used 4.8 early-season
fungicide DEs and 3.0 summer fungicide DEs. While
the second-level blocks showed very modest fungi-
cide savings, fungicide use still presented a major
impediment in our efforts to reduce pesticide appli-
cations, particularly late in the season.
In addition to reducing risk to humans from
exposure to pesticide residues, eliminating insecti-
cides and miticides late in the season can assist pest
control overall, since these materials oflne destroy
natural enemies. Fungicides, however, also can
have a negative impact on natural biocontrol.
Benomyl is the best example, and has been shown to
sterilize predaceous phytoseiid mites (Crofl, 1990),
and eliminating fungicides from an orchard can
stimulate biocontrol (Bower et al., 1993). Further-
more, fungi that infect and kill insects and mites in
the natural setting may be inhibited by fungicides
(e.g.,Loriaetal., 1983; Tedders, 1981). Additionally,
there appear to be some pesticide impacts on spiders,
which may play a role in mite biocontrol
(Wisniewska et al., 1993). Therefore, it is worth
examining the effect of fungicide reduction or elimi-
nation in the orchard.
One approach to fungicide reduction is to use
scab-resistant apple cultivars (SRCs). Our experi-
ences (in the Northeast Apple Sustainable Agricul-
ture Research and Education Project and in our own
blocks) indicate that SRCs at leastwill allow the
elimination of scab fungicides. The degree to which
SRCs will allow us to eliminate summer fungicides
needs to be determined. However, we sought to test
the effects of fungicide elimination in second-level
blocks, and in 1993, we added genetic control (host
plant resistance) to the tactics of cultural, behav-
ioral, and biological apple pest management. Spe-
cifically, we emphasized a second-level IPM ap-
proach in three commercial orchards having two-
acre blocks of SRCs, primarily Liberty and Priscilla.
The SRCs were propagated on M.26 rootstock and
planted in 1988.
We also introduced a new technique to tackle
another problem: the need to clean red sphere
maggot traps frequently. Sticky red spheres have
been used in second-level IPM to trap apple maggot
fiies at the orchard perimeter. For the first time in
any commercial orchard, we used pesticide-treated
spheres as a substitute for sticky-coated spheres as
8
Fruit Notes, Winter, 1994
a behavioral method of controlling apple maggot
flies.
Each of the three blocks was divided in half
With respect to arthropods, one half was managed
under first-level IPM practices that involved moni-
toring pest abundance and weather and then apply-
ing pesticide as dictated by monitoring information.
The other half was managed as follows.
Arthropods
Two applications of superior oil were made be-
fore bloom against overwintering European red mite
eggs followed by two applications of phosmet or
azinphosmethyl against European apple sawfly and
plum curculio (one at petal fall in mid-May and one
two weeks later in late May). All unmanaged wild
apple trees within 100 yards of the
block perimeter were cut down as a
cultural method of controlling co-
dling moth by reducing or prevent-
ing immigration of females from
nearby wild host trees (very few
codling moth females appear to
disperse 100 yards or more within
their lifetime under northeastern
US conditions). Odor-baited pesti-
cide-treated eight-cm wooden red
spheres were hung five to six yards
apart on perimeter trees in late
June as a behavioral method of
controlling apple maggot flies.
Two types of odor baits were used:
semi-permeable membranes that
released the food-type attractant
ammonium acetate, and polyethyl-
ene vials that released the fruit-
type attractant butyl hexanoate.
Odor baits were hung a few inches
from spheres and released attrac-
tive odor over the entire three-
month period of trap use. Prior to
emplacement, the spheres were
dipped in a mixture of 40% latex
paint, 44% corn syrup, 15% water,
and 1% Cygon (dimethoate). The
latex paint allowed dimethoate to
be released very slowly on the
sphere surface. Periodic tests
showed that, provided the sphere
surface contained sufficient su-
crose as a feeding stimulant, 70%
or more ofalightingfiies died. This
was true even in late September,
three months after initial treatment with
dimethoate; however, rainfall can wash away the
corn syrup. Without it, flies did not feed and there-
fore did not acquire a fatal dose of dimethoate.
Hence, we or the growers were obliged to dip each
sphere in a 20% aqueous solution of table sugar after
every rainfall. Following harvest, drops were re-
moved to decrease wi thin-orchard buildup of codling
moth and apple maggot.
Diseases
No fungicide was applied in the SRC blocks. We
simply eliminated fungicides from the management
program, in spite of the expectation that there would
be some damage from flyspeck and sooty blotch.
Most trees had not yet reached full maturity and had
Table 1. Numbers of insecticide and miticide treatments
and percent arthropod-injured finiit at harvest* in three
blocks of scab-resistant cultivars under first-level versus
second-level IPM management.
Pesticide
Number of applications
First-level
Second-level
Insecticide
Miticide
4.0
2.0
2.0
2.0
Pest
Injured fruit (%)
First-level
Second-level
European sawfly
Plum curculio
Codling moth
Lesser appleworm
Leafroller
Apple maggot
Total insect
0.2
0.3
0.0
0.1
0.3
0.1
1.0
0.6
0.8
0.0
0.0
2.5
0.3
4.2
* Four hundred fruit
per block were
sampled at harvest.
Fruit Notes, Winter, 1994
comparatively open cano-
pies that do not show a
significant disease re-
sponse to summer prun-
ing, therefore we did not
summer prune the blocks
for disease management.
In order to compare
disease impacts of the
SRC systems and a con-
ventional IPM system, we
observed disease inci-
dence in conventional
cultivars under normal
first-level IPM practices
using a block on each of
the three farms consist-
ing of conventional culti-
vars (Mcintosh,
Cortland, Delicious). We
did not compare these
blocks to the SRC blocks
for management of and
damage by arthropod
pests.
Pesticide Use and
Injury
Table 1 shows the
mean number of miticide
and insecticide treat-
ments applied to each
block. Table 1 also shows
the mean number of ar-
thropod-injured fruit at
harvest. We focus here on
fruit injury initiated after
early June, the time when
second-level IPM practices against insects diverged
from first-level IPM practices. Injury by apple
maggot was slightly greater and injury by leafroller
was substantially greater in second-level compared
with first-level blocks. Very little injury by codling
moth or lesser appleworm occurred in these blocks.
Not shown are fruit injury levels caused by larvae in
one orchard that we identified as apple pith moth
larvae. This injury was slightly greater in the
second-level block, but definitive identification of
the larvae (new to us) is pending.
Table 2 shows the number of fungicides applied
in the SRC blocks and the conventional blocks, as
well as the disease incidence in each block type.
Sooty blotch and flyspeck damage far exceeded any
Table 2. Mean number of fiingicide treatments and mean percent
disease-injured fruit at harvest* in three orchards comparing three
systems: conventional cultivars under first-level IPM; scab-resistant
cultivars under first-level IPM; and scab-resistant cultivars under
second-level IPM.
Pesticide
Number of applications
Standard
cultivars
first-level
SRCs SRCs
first-level second-level
Fungicide
8.0
0.0 0.0
Pest
Diseased fruit (%)
Standard
cultivars
first-level
SRCs SRCs
first-level second-level
Apple scab
Blossom end rot
Sooty blotch
Fly speck
Total disease
0.1
0.1
0.1
0.4
0.7
0.0 0.0
0.0 0.0
7.0 7.3
5.0 4.1
12.0 11.4
* Four hundred fruit
per block were
sampled at harvest.
other fruit injury in each block type. This result was
not surprising, since several observations have
shown that in orchards which receive no fungicides
in Massachusetts, there will be significant levels of
sooty blotch and fiyspeck at harvest. In blocks of
standard cultivars, fungicide applications greatly
reduced sooty blotch and fiyspeck damage, but fiy-
speck remained the most damaging disease.
Table 3 shows mean abundance of principal
arthropod pests of the fohage and their principal
natural enemies. Notable among pests is the lower
average European red mite population but the
higher average white apple leafhopper and rose
leafiiopper populations in the second-level blocks.
Notable among natural enemies is the substantially
10
Fruit Notes, Winter, 1994
Table 3. Mean percent sampled leaves* infected with arthropod foliar
pests and their natural enemies in 3 blocks of scab-resistant cultivars
under first-level vs. second-level IPM management.
Foliar pest
Infested leaves (%)
First-level
Second-level
Apple aphids
Leafminers (2"'* gen.)
European red mites
White apple leafhoppers
Rose leafhoppers
21
29
29
5
2
13
36
18
10
8
Natural enemies
Infested leaves (%)
First-level
Second-level
Aphid predators
Leafminer parasatoids (2"'' gen.)
Phytoseiid mite predator
Stigmaeiid mite predator
7
46
4
38
5
71
7
66
* Samples of 200 leaves per block were taken at bi-i
from mid-June to mid-September.
A'eekly intervals
greater incidence of leafminer parasitoids and mite
predators (particularly Stigmaeiid yellow mites) in
the second-level blocks.
Conclusions
Our findings in this first year of applying second-
level IPM practices to blocks of scab-resistant culti-
vars indicate promise as well as some potential
problems for future application. Among arthropods,
the most promising aspectswere the success of pes-
ticide-treated spheres in controlling apple maggot
flies, the very low incidence of codling moth and
lesser appleworm, and the buildup of leafminer
parasitoids and mite predators (particularly yellow
mites).
Among diseases, the most promising aspects
were (not surprisingly) the absence of apple scab and
blossom end rot. The most
problematic aspects were
buildup of leafroller (ex-
clusively oblique-banded)
and flyspeck.
From the perspective
of arthropod manage-
ment, use of pesticide-
treated spheres is the key
element of second-level
IPM. These spheres are
far simpler to prepare and
maintain than sticky
spheres. The only real
problem (aside from gain-
ing EPA registration for
use) involves the current
necessity of dipping the
sphere in aqueous sugar
solution after each rain-
fall. This is a rapid pro-
cess: 10 minutes to re-
move, dip and re-hang one
acre's worth of spheres.
But if it is not done almost
immediately after rainfall
has ended, there is no pro-
tection against apple mag-
got fly invasion. In 1993,
there were several un-
avoidable lapses of a day
or two in dipping spheres
after rainfall, possibly ac-
counting for the slightly
greater amount of maggot
injury in second-level
blocks. We need to find a new polymer capable of
releasing sucrose at a slow rate rather than losing all
of the sucrose during rainfall.
With regard to leafrollers and flyspeck, virtually
all of the injury in 1993 was restricted to just one of
the three orchards. Another of the orchards had
almost all of the leafhoppers found; invading rose
leaflioppers at harvest were especially troublesome.
Perhaps the vegetation surrounding these orchards
harbored substantial "inocula" of these two pests.
This demands further study.
Our experience in 1993 suggests much promise
for applications of low-labor second-level IPM prac-
tices in scab-resistant blocks. If we can keep sucrose
on pesticide-treated spheres during rainfall and
control flyspeck, leafroller, and leafhoppers using
habitat management and early-season fungicides,
then foliar pests such as mites and leafminer might
Fruit Notes, Winter, 1994
be controlled solely through natural enemies. As a
result growers would no longer need to apply any
pesticide in scab-resistant blocks after early June.
Aknowledgements
This work was supported by the USDA Sustain-
able Agriculture and Research Education Program-
-Northeast Region and the Massachusetts Society
for promoting Agriculture.
References
Bower, K. N., L. P. Berkett, and J. F. Costante. 1993.
Non-target effect of a fungicide on phytophagous
and predacious mite populations in a disease resis-
tant apple orchard. Proceedings of the Disease
Resistant Apple Cultivar Workshop, Jan. 24-26,
Hersey, PA (Abstract; Proceedings in press. Fruit
Var. J.)
Croft, B.A. 1990. Arthropod Biological Control
Agents and Pesticides. Wiley and Sons. New York.
Loria, R., S. Galaini, and D. W. Roberts. 1983.
Survival of inoculum of the entomopathogenic fun-
gus Beauveria bassianan as influenced by fungi-
cides. Environ. Entomol. 12:1724-1726.
Tedders, W. L. 1981. In vitro inhibition of the
entomopathogenic fiingi Beauveria bassiana and
Metarhizium anisopliae by six fungicides used in
pecan culture. Environ. Entomol. 10:346-349.
Wisniewska, J., Y. Yang and R. Prokopy. 1993.
Spiders in second-level and first-level apple IPM
blocks. Fruit Notes 58(l):20-23.
«f« •!# %i« %t# «%
v|« rj« #1% #j% vj«
New Publication Available
In June, 1993 the Sixth International Controlled
Atmosphere Research Conference was held at
Cornell University, Ithaca, New York. Presenta-
tions at this three-day conference covered recent
developments in use of modified (MA) and controlled
(CA) atmospheres during storage and shipment of
fruits, vegetables, and flowers.
Proceedings of this conference are now avail-
able. They are divided into two volumes, totaling
nearly 900 pages. The first volume includes bio-
chemical changes that occur during MA and CA, use
of MA and CA during transport, recent engineering
and equipment developments, and new information
on disease and insect control during MA and CA.
The second volume focuses on current research on
CA storage of specific fruits, vegetables, and flowers.
It concludes with three summary sections that
present precise, current recommendations for MA
and CA conditions for (1) vegetables, (2) apples,
pears, and noshi (Asian pears), and (3) other fruits.
These Proceedings are available for $85.00 from
the Northeast Regional Agricultural Engineering
Service, Cooperative Extension, 152 Riley-Robb
Hall, Ithaca, NY 14853-5701. They are of great value
to persons with interest in the application of MA and
CA to storage and handling of horticultural crops.
•^ •^ mlm ^f« ttl»
rj% ry» rj% »^ rj»
12
Fruit Notes, Winter, 1994
Second-level Integrated Pest
Management, 1991 to 1993: Diseases
Daniel R. Cooley and Ryan Elliott
Department of Plant Pathology, University of Massachusetts
Jennifer Mason and Starker Wright
Department of Entomology, University of Massachusetts
Wesley R. Autio
Department of Plant & Soil Sciences, University of Massachusetts
Over the past three seasons, we have been at-
tempting to develop disease-management strategies
for apple which will both optimize fungicide use
against diseases and integrate pest management
across disciplines. The approach relies heavily on
monitoring pathogen development for two key apple
diseases, using cultural approaches to manage these
diseases, and using fungicides which will have the
least non-target efiFects. It is obvious that manage-
ment of diseases in apples without fungicides is not
possible, but we feel that it is possible to improve the
efficiency of summer fungicide use by developing a
better understanding of and appropriate monitoring
techniques for summer disease pathogens, particu-
Table
1.
Fungicide
use (dosage
equivalents)
in 1991
throu
gh
1993.
Year
Treatm.ent
Total
Primary
S
ammer
1991
Test
5.9
4.8
1.1
Check
6.8
5.0
1.8
1992
Test
7.5
4.3
3.2
Check
8.5
4.5
4.1
1993
Test
6.8
5.3
1.5
Check
6.6
4.5
2.2
All
Test
6.7
4.8
1.9
Check
7.3
4.7
2.7
1
larly the flyspeck fungus, and such efficiencies,
combined with second-level arthropod management
methods (e.g., Christie et al., 1992) may reduce the
impact that pesticides have on mites and other non-
target arthropods (Wisniewska et al., 1993). This
article summarizes the results of the program in
commercial blocks consisting of scab-susceptible
cultivars. Other aspects of the research, dealing
with summer pruning for disease management, fly-
speck epidemiology, and the effects of the second-
level IPM approach in blocks of scab-resistant
apples, are reported separately.
Early Season Management
For purposes of disease management,
the apple production season can be divided
into two parts. These parts coincide closely
with the two parts of the season used in
second-level arthropod management. For
diseases, early season management focuses
on apple scab. We have used a delayed sterol
inhibitor program (Cooley and Spitko, 1992)
enhanced by measurement of potential as-
cospore dose (PAD). For the purposes of
second-level IPM, we have used a threshold
of 500 ascospores per square meter (Dr.
William McHardy, pers. comm.). PAD data
were not available for 199 1, because funding
was not available in the fall of 1990 when
such assessments would have been done.
Summer Management
After primary scab season, which usu-
ally ends by mid-June, the main diseases
concern in apples are the summer diseases,
typically sooty blotch and flyspeck. At the
Fruit Notes, Winter, 1994
13
Table 2
. Potential ascospore
dose (PAD) and scab incidence (%) by block
in second-level IPM blocks
in 1992
and 1993.
Year
]
Jlock number
1
2
3
4
5
6
7
8
9
10
11
12
PAD
1992
2041
37
2578
300
368
19
11
21
183
166
10
1993
6131
14338
2765
1864
1537
2992
30
12
5333
Scab
1992
1.0
0.5
0.5
1.5
0.0
1.0
0.0
0.0
2.0
0.8
0.0
0.5
1993
0.3
0.1
0.0
0.0
0.0
0.0
0.0
0.0
0.3
0.3
0.0
0.0
1
beginning of this project, we had limited data sug-
gesting that summer pnmingcould reduce or elimi-
nate the need for fungicides in the summer. We have
described the results of this work elsewhere (Cooley
et al., 1992). We have concluded that summer
pruning reduces flyspeck and sooty blotch on trees
with dense canopies, but additional measures are
necessary to reduce levels below economic thresh-
olds. In 1993, we focused summer fungicide applica-
tions on primary inoculum for flyspeck, which was
released during June and early July. Our program
recommended no fungicides after June in second-
level IPM blocks.
Results
gram has received wide-spread adoption in all or-
chards, which often use first level IPM. This being
so, we would expect few differences between checks
and second-level blocks in terms of primary season
fungicides. Second, in 1993, high levels of inoculum
in many second-level blocks led to recommendations
for an extra fimgicide application near the half-inch
green stage, and more frequent use of scab fungi-
cides in general.
Table 2 shows the increase in PAD from 1992 to
1993. Two orchards exceeded the PAD threshold in
1992, and seven exceeded it in 1993. There was no
From the disease perspec-
tive, the terms "full" and "transi-
tional" second-level blocks re-
ferred to in other articles was of
minor importance, and the data
from both are combined here.
During the early season, the
fungicide use in all blocks gener-
ally was the same (Table 1). In
1991 and 1992, similar fungicide
use occurred in second-level
blocks as in conventionally man-
aged (check) blocks in the pri-
mary season. In 1993, some-
what more fungicide was used in
primary season in the second-
level blocks. There are two fac-
tors which contributed to this
trend. First, the delayed SI pro-
Table
3. Disease incidence (%)
in 1991 through
1993.
Sooty
Blossom
Year
Treatment
Scab
Flyspeck
blotch
end rot
1991
Test
0.3
4.3
0.3
0.0
Check
0.7
3.6
0.8
0.3
1992
Test
1.2
4.0
0.1
0.1
Check
0.6
0.8
0.0
0.1
1993
Test
0.2
6.7
0.1
0.0
Check
0.1
4.1
0.1
0.1
All
Test
0.6
5.0
0.2
0.0
Check
0.5
2.8
0.3
0.2
1
14
FruH Notes, Winter, 1994
Table
4. Flyspeck
incidence
(%) in
second-level IPM
block
3 in
early
and late
season
harvests in
1991 through 1993.
Year
Treatment
Before 9/15 After 9/15
1991
Test
1.5
22.3
Check
1.5
18.8
1992
Test
1.3
8.9
Check
1.3
0.0
1993
Test
0.3
7.9
Check
0.2
5.0
All
Test
1.0
13.0
Check
1.0
7.9
correlation, however, between PAD and scab inci-
dence in the blocks. Also, there was no correlation
between scab on fruit in 1992 and PAD in 1993,
indicating the danger of trying to use fruit scab
incidence to predict scab inoculum in the orchard.
Summer fimgicide use was higher in the check
blocks than in the test blocks (Table 1), with check
blocks receiving about 0.8 DE more than the test
blocks. Flyspeck, however, was nearly twice as great
in the test blocks compared to check blocks, though
sooty blotch incidence was similar in both block
types (Table 3). There was no correlation between
the DEs of summer fungicide and flyspeck. The time
of harvest was critical to flyspeck incidence (Table 4).
Fruit harvested after September 15 were much more
likely to have flyspeck than those harvested before
that date. In fact, fruit harvested before September
15 (largely Mcintosh) had virtually the same fly-
speck incidence in either check or test blocks. In
fruit harvested later (Delicious, Cortland, and
Golden Delicious), the incidence of flyspeck was
higher in test blocks than in checks, but the inci-
dence in either block far exceeded that in the early
harvest. From these results, two points stand out.
First, our major cultivar, Mcintosh, may get only
marginal benefit from summer fungicide sprays.
Second, minimal fungicide applications will control
sooty blotch.
Fungicides present a particularly difficult prob-
lem to second-level IPM in apples. The nature of
scab, and its potential for severe damage, limit
options for further early season fungicide reduc-
tions; however, the potential for reducing summer
fungicides remains good. We will need to examine
the role that alternative hosts,such as brambles and
roses, play in providing inoculum for summer dis-
eases. Removing these hosts may make flyspeck
management much easier. Relatively little fungi-
cide is needed to control sooty blotch under our
conditions. It may be possible to spray late-season
cultivars selectively. Alternatively, if early fungi-
cide applications can be used to delay the epidemic,
even later season cultivars may be harvested before
flyspeck develops. Certainly, weather will also guide
fungicide applications in summer. There are many
unanswered questions, but the prospect for at least
reducing, and possibly eliminating, summer fungi-
cides in Massachusetts appears good.
References
Christie, M., R. J. Prokopy, K Leahy, J. Mason, A.
Pelosi, and K. White. 1993. Apple integrated pest
management in 1992: Insects and mites in second-
level orchard blocks. Fruit Notes 58(1):24-31.
Cooley, D. R., W. R. Autio, and J. W. Gamble. 1992.
Second-level apple integrated pest management:
The effects of summer pruning and a single fungi-
cide application on flyspeck and sooty blotch. Fruit
Notes 57(1):16-17.
Cooley, D. R. and R. S. Spitko. 1992. Using sterol
inhibitors. American Fruit Grower 112(l):30-32.
Wisniewska, J., Y. Yang, and R. Prokopy. 1993.
Spiders in second-level and first-level apple IPM
blocks. Fruit Notes 58il):20-23.
%f» VU fcA* %V ^if
0^ ^^ rj^ ey* ^V*
Fruit Notes, Winter, 1994
15
Tax Pointers for Farmers in 1993
P. Geoffrey Allen
Department of Resource Economics, University of Massachusetts
Tax advice given below is intended as general advice and is believed to be correct. It does
not substitute for a detailed review of the circumstances of an individual taxpayer by a
professional tax practitioner.
The Revenue Reconciliation Act of 1993 (1993
RRA), enacted on August 10, 1993 contains a large
number of changes to the tax laws. One complication
is that some items are retroactive to 1992, some to
the beginning of 1993, and some only take effect in
1994. To take advantage of the retroactive changes
for 1992, you must submit an amended return (Form
1040X).
General Features
The most publicized aspect of the 1993 RRA is
that more of the tax burden will be carried by higher
income taxpayers. For example, the new 36% rate
applies to married taxpayers filing jointly who have
taxable income over $140,000 in 1993. They, as well
as all other filers, would also pay a 39.6% rate on
taxable income over $250,000. For estates and trusts
the new rates affect taxable income over $5,000 and
$7,500, respectively, effective January 1, 1993. Some
changes affect all income levels. For example, busi-
ness meals and entertainment expenses that were
80% deductible will only be 50% deductible, effective
January 1, 1994. Some expiring laws are reinstated.
For example, for estate and gift taxes, the 1993 RRA
reinstates expiring law so that the top rates and the
$600,000 exemption remain the same.
Health Insurance
If you were a self-employed person in 1992 (or an
S-corporation shareholder) who deducted (on line 26
of your 1992 Form 1040) 25% of half of your health
insurance premium you may now take 25% of all of
your 1992 premium. The 1993 RRA reinstated the
deduction retroactive to July 1, 1992. You may file
for a refund on Form 1040X. The only exception is if
your total medical expenses exceeded the 7.5% floor
in your 1992 tax year and you already claimed the
rest of the premium as medical expense on your 1992
Schedule A.
Example: Bill is self-employed. Bill and
Jane file jointly, with 1992 taxable income
of $21,400 and family health insurance pre-
miums of $3000. They deducted $375 (^2 of
25% of $3000) in 1992. They may now file
Form 1040X and deduct a further $375.
In 1993, note that the eligibility for the 25% deduc-
tion for the health insurance premium is made on a
monthly basis. Also, unless the law is further ex-
tended, the deduction will expire on December 31,
1993.
Example: If Jane had worked from Novem-
ber 1, 1992 until March 31, 1993 for an
employer who provided subsidized health
insurance for her and her family, none of
the $3000 premium paid in 1992 would have
been deductible on Form 1040. If the same
premium was paid in 1993 then the amount
allocated to the period January 1 to March
31 is ineligible for deduction on Hne 26 of
Form 1040. The amount deductible is
$562.50 (3/4 of 25% of $3000).
Charitable Contributions
Did you make charitable contributions of appre-
ciated property in 1992 or 1993? Taxpayers subject
to alternative minimum tax (AMT) may get some
relief. Appreciated property is property that has a
fair market value that exceeds its basis (which is
usually your cost). Under the 1993 RRA, the appre-
ciated amount (the difference between fair market
value and adjusted basis) of property (real, tangible,
and intangible) donated to a charity is no longer a tax
preference item included in computing AMT income.
The property must be used for the donee's tax-
exempt purpose. The benefit does not apply to dona-
tions of inventory, other ordinary income property
and short-term capital gain property.
Different kinds of property have different effec-
16
Fru'n Notes, Winter, 1994
tive dates. For contributions of tangible personal
property this potential tax saving is retroactive to
July 1, 1992 (and therefore continues prior law).
Example: Earl donated a 10-year old trac-
tor on August 1, 1992 to a charity that ships
them to needy fanners overseas. The fair
market value was $3,000 and his adjusted
basis in the tractor (its cost less deprecia-
tion) was $2,000. Earl paid AMT in 1992. He
entered $1000 on line 6a of Form 6251. If he
still has some AMT liability after the adjust-
ment he will save $240 (The AMT rate in
1992 of 24% on $1000). Earl can now file an
amended return (Form 1040X) for 1992
claiming the $240 refund.
From January 1, 1993, the appreciated amount of
donated real and intangible property will not be
subject to AMT either.
Example: Arthur gave the development
rights on a piece of land to an organization
whose charitable purpose was to preserve
land from development. The rights have a
fair market value of $2000. Arthur claims
$2000 of charitable deductions on Schedule
A (provided his adjusted gross income is
sufficient to prevent the percentage limita-
tions on charitable deductions coming into
effect). He reduces his basis in the land by
$2000. There is no AMT tax preference
item.
Effective January 1, 1994, single charitable do-
nations of $250 or more may be deducted (on Sched-
ule A) only if the charity provides you with written
substantiation, including a good-faith estimate of
the value of any good or service that you provided. If
you donated money, you may not rely solely on a
cancelled check as substantiation. Separate pay-
ments to the same charity (e.g., by withholding from
wages) will be treated as separate contributions,
even if they aggregate to more than $250.
Section 179 Expensing
The limit on election to expense certain tangible
property (Section 179 expensing) is raised from
$10,000 to $17,500 for tax years beginning after
December 31, 1992. All other provisions remain the
same, including reductions in the limit for purchases
over $200,000 in any one year and carryover rules.
However, the IRS has issued final regulations (T.D.
8455, effective date January 25, 1993) that provide
clarification for some of the provisions. The main
issue appears to be the need for, or at least desirabil-
ity of, precise record keeping. If you have to
carryover some Section 179 expense deduction, you
must select the property or properties to which the
carryover is allocated. The selection must be re-
corded in the year in which the properties are placed
in service. If you fail to make and record the selec-
tion, the IRS will assume the carryover is appor-
tioned according to cost.
Example: In 1993, Joe purchased a tractor
for $20,000 and a baler for $10,000. He
elected to deduct $17,500 ($12,500 on the
tractor, $5,000 on the baler) but his taxable
income was only $7,500 so he carried over
$10,000. He recorded the carryover as
$5,000 against the tractor and $5,000
against the baler. Had he not done so, the
IRS would have assumed two-thirds
($6,667) for the tractor and one-third
($3,333) for the baler.
When only part of the carryover is used in a subse-
quent year, you must first use up the oldest
carryover, but within the year, you may choose.
Example: If Joe purchases another
$10,000 machine in 1994 and elects to ex-
pense the entire $10,000, he can only use
$7,500 of carryover before reaching the an-
nual limit (of $17,500). Assuming his tax-
able income in 1994 is at least $17,500, he
might choose to take the baler carryover
first ($5,000) and part of the tractor
carryover, leaving $2,500 carryover on the
tractor to go forward.
There is no limit on how long Section 179 deductions
can be carried forward. However, if a property is
sold, exchanged, or given away, unused section 179
carryover must be dealt with.
Example: (no gain or loss) Joe gives his
baler to a relative in 1994. He took half-year
depreciation in 1993 of $357 (1/2 of 1/7 of
$5,000, assuming MACRS straight line de-
preciation) and $357 in 1994. His adjusted
basis for the baler at time of transfer is
$4,286 ($5,000 - $357 - $357). He must
increase the basis at the time of transfer by
the amount of Section 179 carryover
($5,000) and reduce his Section 179
carryover by the same amount. The recipi-
ent has an initial basis of $9,286 ($5,000 +
$4,286).
Example: (gain on sale) Joe sells his baler
Fruit Notes, Winter, 1994
17
in 1994 for $9,500. He has a gain on the sale
of $214 ($9,500 - $9,286). His depreciation
and Section 179 deduction is $714 (he actu-
ally took no Section 179 deduction on the
baler in 1993). The amount to be recaptured
on Form 4797 is the lesser ($214). Joe's
Section 179 carryover is reduced by $5,000.
Purchase and Sale of Livestock
You purchased, transported and vaccinated
some young cattle in 1993, intending to sell them in
1994. As a farmer using the cash basis method of
accounting, how do you report this? The purchase
and transportation are your basis in the cattle,
included in your 1994 Schedule F, line 2. Vaccination
is a current expense, line 33 of your 1993 Schedule F.
Do you pay self-employment tax on gain or loss
from the sale of breeding livestock? Yes, if it is held
for sale in the ordinary course of business. Report on
Schedule F. No, otherwise. Report in the appropriate
part of Form 4797, as follows:
Held less than 12 months (24 months for cattle
and horses). Also poultry (unless held for sale in
the ordinary course of business)
Part II of Form 4797
Held more than 12 months (24 months for cattle
and horses) and (1) purchased and sold at a loss
or raised (gain or loss)
Part I of Form 4797
or (2) purchased and sold for a gain (depreciation
recapture)
Part III of Form 4797
Example: Robert breeds replacement heif-
ers for his dairy herd. When they are two
years old, he selects the number required to
maintain his herd and sells the rest. Even if
some heifers are sold as breeding livestock,
all sales are reported on Schedule F.
Example: Dana breeds replacement heif-
ers. All are added to the dairy herd unless
they fail to breed. Those that turn out to be
poor milkers are sold. Dana can report all
sales on Form 4797, since her intent was to
keep them all for breeding.
Investment Interest
Previously, individual taxpayers could deduct
investment interest (interest on indebtedness
allocable to property held for investment) only to the
extent of their net investmentincome for that year.
Net investment income generally excluded capital
gains, and the disallowed interest expense had to be
carried forward. Now there is a faster way to use up
the interest carry-forward. Effective January 1,
1993, a taxpayer may elect to include any amount of
the net capital gain from Schedule D in investment
income. The capital gain transferred to Form 1040
must be reduced by the same amount. For a taxpayer
in the 28% marginal tax bracket, the only effect is to
use up the investment interest carryover, reducing
total taxes in the present year rather than some
future year. Higher income taxpayers should take
care to elect to include only as much gain as will
offset the interest carried forward. Any larger
amount would be subject to tax at rates of 31%, 36%,
or 39.6%.
Example: Fred and Emily have $10,000
unused investment interest expense from
1992 and $15,000 net long-term capital
gains in 1993. On their 1993 return, they
elect to treat $ 10,000 of the gain as ordinary
income. They pay tax (maximum rate 28%)
on $5,000 long-term capital gain. They de-
duct the $10,000 investment interest ex-
pense on Schedule A.
The following sections are taken from material
published by Larry C. Jenkins, Department of
Agricultural Economics and Rural Sociology,
Pennsylvania State University.
Earned Income Tax Credit (EITC)
The new rules for earned income credit involve
only a basic credit; the extra credits for a child under
one year of age and for health insurance coverage
were eliminated in the 1993 legislation. Comment:
The new law results in a decrease in benefits in 1994,
compared to benefits from the earned income credit
in 1992, for a family with one child under one year of
age, and qualifying for the supplemental health
insurance credit. For such a family, based on earned
income of $7,750, the EITC in 1992 would have been
$2,151. Under the new rules, the credit is $2,038.
In a departure from previous earned income
credit rules, the new law extends the credit to
taxpayers with no qualifying children. The credit is
available to taxpayers over age 25 and below age 65.
For these taxpayers, the EITC is 7.65 percent of the
first $4,000 of earned income (for a maximum credit
of $306 in 1994). The maximum credit is reduced by
7.65 percent of earned income (or adjusted gross
income, if greater) above $5,000. In 1994, the credit
is completely phased out for taxpayers with earned
18
Fruit Notes, Winter, 1994
income (or adjusted gross income, if greater) over
$9,000. This credit is not available on an advance
payment basis.
Tax on Social Security Benefits
Prior to the new law, if the sum of modified
taxable income plus one-half of Social Security ben-
efits (the sum of the two is called provisional income)
exceeded $25,000 for an unmarried taxpayer or
$32,000 for a married couple filing a joint return, up
to 50% of Social Security benefits were subject to
income tax.
Under the new law, taxpayers will be subject to
tax on up to 85% of their Social Security benefits,
effective for tax years beginning after 1993. The
existing rule (as explained in the above paragraph)
will continue to apply to taxpayers whose provi-
sional income is less that $34,000 for unmarried
taxpayers and $44,000 for married couples filing a
joint return. If provisional income exceeds these
levels, gross income will include the lesser of:
(a) 85% of the taxpayer's Social Security benefit, or
(b) The sum of:
(1) The smaller of :
(i) the amount included under pre-'93 law,
or
(ii) $3,500 for unmarried taxpayers or
$4,000 for a married couple filing a join
return plus
(2) 85% of provisional income over the new
$34,000 1 $44,000 threshold.
For married taxpayers filing separate returns, gross
income will include the lesser of:
(a) 85% of the taxpayer's Social Security benefit, or
(b) 85% of the taxpayer's provisional income.
For purposes of the above calculation, a taxpayer's
provisional income (modified adjusted gross income
plus one-half of the taxpayer's Social Security ben-
efit) is calculated in the same manner as under pre-
93 law.
Without implicating them in any way, I thank
Robert Christensen, Department of Resource
Economics and Michael Whiteman, Department
of Accounting and Information Systems, School
of Management, both from the University of
Massachusetts, for their helpful comments.
%£• ttl^ ^t« «% %i«
ej* •(J^ *T^ •(f* •!»•
Fruh Notes, Winter, 1994
19
Fruit Notes
University of Massachusetts
Department of Plant & Soil Sciences
205 Bowditch Hall
Amherst, MA 01003
Nonprofit Organization
U.S. Postage Paid
Permit No. 2
Amherst, MA 01002
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SERIAL SECTION
UNIV. OF MASSACHUSETTS LIBRARY
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F68
ruit Notes
ISSN0427-6906
iricpared by the Department of Plant & Soil Sciences.
University of Massachusetts Cooperative Ebctenslon System,
United States Department of Agriculture, and Massachusetts Counties Cooperating.
Editors: Wesley R. Autio and Williaxn J. Braxnlage
Volume 59, Number 2
SPRING ISSUE. 1994
Table of Contents
Pinal Report on the 1980 NC-140 Apple
Rootstock Planting: Starkspur Supreme
Delicious on Eight Rootstocks
Buildup of Bugs Causes Decline in EfTectiveness of Sticky
for Capturing Apple Maggot Flies on Red Sphere Traps
What Species of Predaceous Mites Exist in Massachusetts
Commercial Apple Orchards?
How Beneficial are Pre-bloom Oil Sprays Against European Red Mites?
North American Strawberry Growers Meet in Ontario
Promising New Apple Cultivars for 1994
Suggestions for the Use of the New Postbloom Thinner Accel*
J
Fruit Notes
Publication Information:
Fruit Notes (ISSN 0427-6906) is published the first day of
January, April, July, and October by the Department of Plant
& Soil Sciences, University of Massachusetts.
The costs of subscriptions to Fruit Notes are $7.00 for United
States addresses and $9.00 for foreign addresses. Each one-
year subscription begins January 1 and ends December 31.
Some back issues are available for $2.00 (United States ad-
dresses) and $2.50 (foreign addresses). Payments must be in
United States currency and should be made to the University of
Massachusetts.
Correspondence should be sent to:
Fruit Notes
Department of Plant & Soil Sciences
205 Bowditch Hall
University of Massachusetts
Amherst, MA 01003
COOPERATIVE EXTENSION SYSTEM POLICY:
All chemical uses suggested in this publication are contingent upon continued registration. These
chemicals should be used in accordance with federal and state laws and regulations. Growers are
urged to be familiar with all current state regulations. Where trade names are used for
identification, no company endorsement or product discrimination is intended. The University of
Massachusetts makes no warranty or guarantee of any kind, expressed or implied, concerning the
use of these products. USER ASSUMES ALL RISKS FOR PERSONAL INJURY OR PROPERTY
DAMAGE.
Issued by the University of Massachusetts Cooperative Extension System, Robert G. Helgesen,
Director, in furtherance of the acts of May 8 and June 30, 1914. The University of Massachusetts
Cooperative Extension System offers equal opportunity in programs and employment
Final Report on the 1980 NC-140 Apple
Rootstock Planting : Starkspur Supreme
Delicious on Eight Rootstocks
Wesley R. Autio and William J. Lord
Department of Plant & Soil Sciences^ University of Massachusetts
Finding the apple rootstock that adapts the
best to various conditions, is resistant to pests,
gives an appropriate degree of dwarfing, gives
the greatest precocity, results in the highest
jdelds, and gives the best £ruit quality has been
a research and breeding goal for nearly a cen-
tury. Growers in New England, however, did
not begin to look at clonally propagated
rootstocks seriously until the ISeCs, when the
use of semidwarfing rootstocks, such as M.7,
began in earnest. During the late 1980's, seri-
ous planting of fully dwarfing rootstocks began,
Tree spread (ft)
"T
2
I
4
I
6
8
10
12
"T"
14
16
14
12
10
8
6
4
- 2
-
Figure 1. Relative canopy dimensions of Starkspur Supreme Delicious trees on eight rootstocks
at the end of the forteenth growing season.
0)
16
M.7 EMLA
OAR1
M.26 EMLA
0.3
MAC.9
M.9 EMLA
M.9
M.27 EMLA
Fru'n Notes, Spring, 1994
including M.9, Mark, and M.26. Now, more
than fifty percent of all trees being planted in
New England are on fully dwarf rootstocks.
This trend has been seen throughout the apple
growing regions of North America. Throughout
this period when clonal rootstock material be-
came more important to the apple industry,
knowledge of rootstock characteristics became
essential.
To help evaluate both new and old clonal
rootstock material, the NC-140 Technical Re-
search Committee was established. A group of
scientists fi"om various universities across the
country formed this committee in association
with the U. S. Department of Agriculture. Indi-
viduals fi-om five Canadian provinces cooper-
ated in the formation and participate in the
execution of the responsibilities of this commit-
tee. One of the first major plantings by the
committee included Starkspur Supreme DeU-
cious on 0.3 (Ottawa 3), M.7 EMLA (the EMLA
designation suggesting that the latent viruses
were removed fi-om the mother plant), M.9
EMLA, M.26 EMLA, M.27 EMLA, M.9, MAC.9
(later, a virus indexed version was named
Mark), and OARl (Oregon Apple Rootstock 1).
These combinations were included in random-
ized complete blocks, each with five replications
at 27 sites in the U. S. and southern Canada.
Most sites removed their plantings after the
tenth growing season, i.e. after harvest in 1989.
In this article, we report on the Massachusetts
portion of this trial, including four years of data
beyond the termination of the joint trial.
Materials & Methods
Trees were planted at a spacing of 11.5 x 18
feet in the spring of 1980 at the University of
Massachusetts Horticvdtural Research Center
in Belchertown. Trees were trained as central
leaders, using minimal pruning. Some contain-
ment pruning was required when trees reached
maturity. Stakes were added for support only
when trees leemed past 45 degrees. Standard
pest and fertility management practices were
used. Tree size and yield were measured annu-
ally; however, trees were not allowed to finiit
until the fourth growing season (1983).
Results & Discussion
Table 1 gives the trunk cross-sectional area,
height, and spread of these trees after the four-
teenth growing season (1993), and Figure 1
Table 1. Size
of Starkspur Supreme
Delicious trees on eight rootstocks after theii
• fourteenth
growing season.
Also presented are
estimated tree density and
spacing.'
Trunk
cross-
Estimated
sectional
density
Estimated
Height
Spread
area
(trees per
spacing
Rootstock
(ft)
(ft)
(in^)
acre)
(ft)
0.3
10.1 b
11.1 be
9.8 c
256
10x17
M.7 EMLA
14.9 a
14.7 a
21.3 a
132
15x22
M.9 EMLA
8.2 c
9.2 cd
5.7 de
363
8x15
M.26 EMLA
10.6 b
12.6 ab
14.0 b
191
12x19
M.27 EMLA
5.6 d
5.4 e
L9 f
726
5x12
M.9
5.7 d
7.2 de
3.1 ef
496
6.5x13.5
MAC.9
7.5 c
8.4 d
8.4 cd
401
7.5x14.5
OARl
11.4 b
13.4 a
13.6 b
191
12x19
' Within column
, means not followe
d by the same
letter are sign
ificantly different at odds of |
19 to 1.
Fruit Notes, Spring, 1994
25
@0.3
^ M.7 EMLA
?20
—
tI^ M.9 EMLA
* M.26 EMLA
y
(0
(0
M M.27 EMLA
♦ m.9
y^
cross-sectional
O Ol
-
AmAC.9
'S'OARI
/
/ n_^--''^1
—
^X\x^^
Trunk
Ul
.<:^^^r:^^
nE
^^2=;^
3
i&-^ "X— 7* — i^r~ h ^^— -M — ^ ^
=^SP=i
a^ — fjfc] ]g S B- 1^ '^
1980 1982 1984 1986 1988 1990 1992
Figure 2. Trvink cross-sectional area of Starkspur Supreme Delicious trees on eight rootstocks from
the end of the first growing season through the end of the fourteenth.
depicts the relative canopy dimensions of these
trees. M.7 EMLA produced the largest trees.
Trees on M.26 EMLA and OARl were the next
smaller in terms of trunk cross-sectional area,
followed by trees on 0.3 and MAC. 9. Trees on
M.9 EMLA were smaller still, and the smallest
trees in the planting were on M.9 and M.27
EMLA. Clearly, M.9 and M.27 EMLA were not
vigorous enough rootstocks for Starkspur Su-
preme Delicious, since trees did not reach six
feet in height. With a canopy this smgdl, ad-
equate yields are not possible.
Figure 2 plots the trunk cross-sectional area
of these trees from 1980 through 1993, and
shows that for most trees, there was a relatively
constant rate of growth throughout the experi-
ment. MAC. 9, however, resulted in a relatively
fast growth rate for the first five growing sea-
sons, but for the next nine seasons, had a signifi-
cantly slower growth rate. In other words, the
initial growth rate of trees on MAC. 9 was nearly
as great as that of trees on M.7 EMLA, but later
on, the growth rate was only similar to that of
trees on M.9 EMLA. This reduction in growth
rate corresponded to the onset of heavy produc-
tion from trees on MAC. 9.
Table 1 also gives estimates of spacing and
density for these combinations. For most com-
binations, the estimated in-row spacing is ap-
proximately ninety percent of the tree spread;
however, this assessment was not adequate for
trees that had filled their allotted space and had
required containment pruning. Specifically,
the estimated spacing of trees on M.7 EMLA
fruit Notes, Spring, 1994
8
®0.3
^5^ M.7 EMLA
)l^ M.9 EMLA
6
—
* M.26 EMLA
S M.27 EMLA
4- M.9
A MAC.9
/ A \ / \
Q>
0)
'S'OARI
/ Aa\ \ / ^^ 1
7
14
Q.
/ /K\ \ ^^t^^^K
r-^ sy<r^
â– o
0)
,fc.J%./AM2^
1
2
ol,
^ T 1 1 1 1 ^ 1 1
3
1983 1985 1987 1989 1991 1993
Figure 3. Annual yield per tree from Starkspur Supreme Delicious trees on eight rootstocks.
would be artificially low if based solely on mea-
sured spread, since they were kept in a spacing
of only 11.5 feet. In other words, measured tree
spread in 1993 was an assessment of how much
the tree grew beyond the 11.5-feet allotted
space in 1993, since it was pruned to 11.5 feet
during the previous dormant season. Further-
more, when trees are planted closer together,
tree-to-tree competition likely will inhibit
growth and spread, resulting in a further reduc-
tion in the ideal spacing. Therefore, spacings
presented here are meant only to be rough
guides to allow for the estimation of per-acre
yields.
Annual jdeld per tree is given in Figure 3.
Yield was variable and in somewhat of a bien-
nial cycle, but trees on M.7 EMLA clearly
jdelded the most per tree with an average yield
for the last five years of 5.2 bushels. Trees on
M.26 EMLA, 0.3, MAC.9, and M.9 EMLA aver-
aged 4.4, 3.3, 2.4, and 2.3 bushels per tree,
respectively, over the last five years. Trees on
M.27 EMLA averaged only 0.4 bushels per tree.
Cumulative yield per tree is presented in Table
2, and relationships among rootstocks were
similar to that for the average production dis-
cussed above.
More important than yield per tree is yield
per acre. Potential 3rield per acre was calculated
on an annual basis using the tree densities
presented in Table 1, and these data are plotted
in Figiire 4. Clearly, this is only a rough esti-
mate but does pKjint to some significant results.
Trees on MAC.9 produced very high yields from
the sixth growing season on, exceeding 1000
bushels per acre in three years. 0.3 and M.9
Fruit Notes, Spring, 1994
Table 2. Cumulative yield of Starksp
ur Supreme Delicious trees on
eight rootstocks through their fourteenth growing
seasor
1.'
Cumulative yield (bu)
Per in^
trunk cross-
sectional
Rootstock
Per tree
area
Per acre
0.3
24.0
be
2.47 b
6140 b
M.7 EMLA
38.3
a
L80 c
5060 be
M.9 EMLA
17.3
d
3.08 a
6290 b
M.26 EMLA
27.9
b
2.03 c
5330 be
M.27 EMLA
3.8
e
1.99 c
2770 d
M.9
7.8
e
2.49 b
3890 cd
MAC.9
20.6
cd
2.43 b
8270 a
OARl
14.3
d
1.05 d
2730 d
' Within column, means not followed by the same
letter
are signifi-
cantly different at
odds of 19 to 1.
EMLA also were very productive on a per acre
basis. Averaged over the last five years, trees on
MAC.9, 0.3, M.9 EMLA, M.26 EMLA, and M.7
EMLA produced annually 940, 840, 830, 730,
and 680 bushels per acre, respectively. Over the
same period, trees on M.27 EMLA produced
only 310 bushels per acre annually. Table 2
presents cumulative )deld per acre. Trees on
MAC.9 produced 8270 bushels on a per acre
basis over the life of the planting. Trees on M.9
EMLA and 0.3 produced 6290 and 6140 bush-
els, respectively. Trees on M.27 EMLA pro-
duced only 2770 bushels per acre, partly be-
cause of inadequate canopy height and there-
fore small bearing surface per acre.
Conclusions
Several conclusions about specific
rootstocks can be made from this study. First,
however, it must be emphasized that these data
were collected fi-om Starkspur Supreme Deli-
cious, a low-vigor cultivar, and some results
may have been different with a more vigorous
cultivar such as Mcintosh. Secondly, some of
the conclusions must be tempered by results
obtained in other locations.
0.3. This rootstock performed very well. It
was relatively precocious, and produced high
3delds over the fourteen-year life of the planting.
Tree size was slightly smaller than M.26
EMLA, so trees were very manageable. Fruit
size was large from trees on 0.3. Even though
most of the trees in this planting were not
staked, staking should be considered a require-
ment with 0.3. One problem with 0.3 is that it
is of limited availability, because it is so difficult
to propagate. Specifically, it does notdevelop
roots very readily in the stool bed. Some work
suggests that this problem may be overcome in
the nursery, but has not yet resulted in a signifi-
cant quantity of 0.3. Overall, it is a rootstock
very much worthy of trial if you can get it.
M.7 EMLA. This rootstock performed very
well with a spur-type Delicious as a scion. It was
somewhat more precocious than normally ob-
served. Generally, it was not as productive as
0.3, M.9 EMLA, and Mark, but still performed
very well. Trees are vigorous and do not lend
themselves to high-density planting, but it is
probably still the best choice for a free-standing,
semidwarf tree.
Fruit Notes, Spring, 1994
1,500 -
3
XI
d) 1,000
u
(0
a.
500
®0.3
^ M.7 EMLA
^ M.9 EMLA
-^ M.26 EMLA
S M.27 EMLA
-^M.9
â–² MAC.9
«§»OAR1
1983
1985
1987
1989
1991
1993
Figure 4. Annual yield per acre from Starkspur Supreme Delicious trees on eight rootstocks.
M.9 EMLA. This strain of M.9 performed
very well in this planting. Trees were preco-
cious and productive. Tree size was nearly
perfect for this spur-tj^je Delicious, and tree
training was almost not required. Fruit size
from trees on M.9 EMLA were the largest in the
planting in most years. Trees on M.9 EMLA
must be supported fully. This strain of M.9 is
commonly available and is one of a few strains
that you might have received if you ordered M.9
and did not specify the strain. Overall, M.9
EMLA is worth asking for specifically.
M.26 EMLA. Trees on M.26 EMLA per-
formed well, giving relatively high yields. Tree
size was at the large end of the dwarf category,
but trees were still very manageable. As with
all fully dwarfing rootstocks, trees must be
staked. If available we would prefer 0.3 to M.26
EMLA.
M.27 EMLA. Starkspur Supreme Delicious
is too weak to propagate on M.27 EMLA. Trees
do not grow sufficiently to attain adequate
canopy volume per acre, and they do not grow
enough to renew fruiting wood. Trees on M.27
EMLA were "runted out" in just a few years
after planting and did not perform well. In other
parts of the country, M.27 EMLA has done well
with vigorous cultivars and in high-density,
fully supported plantings.
M.9. This strain of M.9 is often referred to as
"dirty 9", because it has not had latent virus
removed from it. It was significantly smaller
than M.9 EMLA in this trial and performed
similarly to M.27 EMLA. With vigorous culti-
vars, it is known to perform very well in high-
density, fully supported plantings.
FruH Notes, Spring, 1994
MAC.9. This rootstock is very similar to
Mark, the only difference being that Mark has
been virus indexed. It is thought to perform
nearly identically to Mark. In this trial, it was
the most precocious and productive combina-
tion. Tree size was between M.9 EMLA and 0.3.
Based on these data, it is the best rootstock in
this group; however, it suffers from a few prob-
lems. In this planting, it overfruited early, and
growth slowed and fruit quahty began to de-
cline. It nearly "runted out", but with heavy
pruning we were able to restore some shoot
growth for renewal of frmting wood. Other
problems have been observed in other locations,
particularly related to its sensitivity to drought.
At approximately three years after planting,
trees develop a noticeable swelling at and below
the soil line. The water transport system in this
part of the tree is very disorganized (as seen by
research in Michigan) and is inefficient in water
transport. If moisture is limiting, trees on Mark
(or MAC.9) will suffer more than those on other
rootstocks. It appears that in locations where
water is not hmiting, trees on Mark (or MAC.9)
perform very well, such as in our trial in
Belchertown. The cause of this swelling is
unknown, and there is no known cure for the
problem, except possibly frequent irrigation.
The future of Mark is in great jeopardy because
of this problem, and many nurseries have re-
moved most of their Mark stoolbeds. Hopefully,
we wiU not lose a rootstock that can be very good
in some locations. It should still be considered
seriously for sites that have good moisture lev-
els throughout the season.
OARl. This rootstock produced a tree simi-
lar in size to M.26 EMLA; however, it was not
productive and fruit size was very small. There
is no reason to consider OARl for commercial
planting.
Overall, the rootstock picture is changing
rapidly. In this trial, M.9 EMLA, 0.3, and Mark
were the ones that performed best. From the
1984 NC-140 planting, others will be added to
the hst of good rootstocks, including C.6, B.9,
P. 2, and MAC. 39. A planting will be established
this year that includes new potentially good
rootstocks, such as B.146, B.469, G.65, and
several strains of M.9. As we move into the next
century, many rootstocks will be bred and se-
lected; however, it is likely that not much will be
gained in terms of productivity. Pest resistance
and site adaptability likely will be the major foci
of the future breeding programs.
«1^ %f^ %f# %i« %f#
r|% 0^ rj^ r^ r{%
Fruit Notes, Spring, 1994
Buildup of Bugs Causes Decline in
Effectiveness of Sticky for
Capturing Apple Maggot Flies
on Red Sphere Traps
Jian Jiin Duan, Xingping Hu, Max P. Prokopy, and Ronald J. Prokopy
Department of Entomology, University of Massachusetts
Red spheres coated with sticky
(TangletrapTM) have been used for 25 years as
effective traps for monitoring apple maggot fly
abundance in commercial orchards. Once sticky
spheres have been emplaced, a treatment of
pesticide is recommended when cumulative cap-
tures of maggot flies reach one or two per
unbaited trap or five per trap baited with syn-
thetic apple odor (butyl hexanoate). We and
others have long suspected that buildup of in-
sects and debris on the sphere surface might
cause a progressive decrease in the probability
of capturing an ahghting maggot fly. In 1993,
we evaluated the rate of decline in the power of
traps to capture maggot flies.
On Jiuie 28, we hung 24 freshly-coated
sticky red spheres in optimum positions on
apple trees in a commercial orchard. Each
sphere was baited with one vial of butyl
hexanoate and one packet of ammonium ac-
etate in a manner typical for spheres used in
trapping apple maggot flies in second-level IPM
blocks. Eight freshly-coated spheres were placed
in a cardboard box in a closet at 70°F as checks.
After 7, 14, and 28 days, eight spheres on each
date were removed from the orchard and like-
wise placed in cardboard boxes in the closet. In
early August, spheres of each treatment were
hung in potted apple trees in field cages to test
their fly capturing power. Ten flies were re-
leased toward the bottom of the tree canopy,
which contained a single sphere. The sphere
was observed continuously for one hour, after
which all flies were removed from the cage. We
recorded the number of flies alighting, the num-
ber captured, and the number that escaped. We
also estimated the percent of the surface area
occupied by captured insects. Once a trial
ended, we hung up a sphere of the next treat-
ment and released 10 more flies. We did this
until all 32 spheres were tested.
As time of sphere exp>osure in commercial
orchard trees increased fi-om to 28 days, the
proportion of released flies caught decreased
significantly firom 49% to 13% (Figure lA).
There was no significant effect of time of sphere
exposure in commercial orchards on propensity
of flies to alight on spheres (Figure IB). Of the
ahghting flies, only 3% escaped from spheres
kept continuously in the closet (never emplaced
in commercial orchards) compared with 38, 43,
and 73% escapees fi-om spheres exposed in or-
chards for 7, 14, and 28 days, respectively
(Figure IC). As days of exposure in orchard
trees increased, the percentage of sphere sur-
face area occupied by captured insects increased
significantly from to 16, 24, and 38% afler 7,
14, and 28 days of exposure, respectively (Fig-
ure ID).
We conclude from this test that sticky red
spheres become progressively less effective in
capturing alighting apple maggot flies as the
number of insects caught on the spheres in-
creases over time. It appears that under com-
mercial orchard conditions, odor-baited sticky
spheres lose nearly half of their maggot fly
capturing power after two weeks without clean-
ing. After four weeks without cleaning, they
lose about three-fourths of their maggot fly
capturing power. We therefore recommend
8
Fru'n Nates, Spring, 1994
7 14 21
Days of Exposura In Field
7 14 21
Day* of Expoaura In Flald
7 14 21
Days of Exposure In Field
<
9
U
3
m
8
o
7 U 21
Days of Exposure In Field
Figure 1. Effects of duration of exposure to weather in a commercial orchard on
effectiveness of sticky spheres in capturing alighting apple maggot flies: (A) proportion of
released flies captured, (B) mean number of flies observed alighting, (C) proportion of
alighting flies that escaped, and (D) mean % of surface area occupied by previously
captured insects.
cleaning sticky spheres of insects and debris
every two weeks to retain reasonable fly captur-
ing power for either control or monitoring pur-
poses. If spheres are not cleaned, control may
fail or thresholds for pesticide treatment would
have to be adjusted.
Acknowledgments
The study was supported by grants from the
USDA Sustainable Agricultural Research and
Education Program and the USDA Northeast
Regional EPM Program.
%£• «1^ %f# %f^ %£•
r|% #5% #5% rj* ^^
Fruit Notes, Spring, 1994
What Species of Predaceous Mites
Exist in IVIassaciiusetts Commercial
Apple Orchards?
Xingping Hu and Ronald Prokopy
Department of Entomology, University of Massachusetts
Under favorable orchard pest management
conditions, predaceous mites can provide a mod-
erate to high level of control of pest mites such
as European red mites and two-spotted spider
mites. Reports from New York State clearly
suggest considerable variation among different
species of predaceous mites in ability to control
pest mites. For example, the predator
Typhlodromus pyri is better able to survive
harsh winter temperatures and to provide sea-
son-long control of low to moderate pest mite
numbers than is the predator Amblyseius
fallacis. In turn, the latter is better able thanT.
pyri to control rapidly building numbers of pest
mites in the summer. A third predator, ZeteeZZta
mali, appears rather similar in biology to T.
pyri, but rather Uttle is known about its ability
to suppress pest mites.
In 1977, we conducted a survey of 21 com-
mercial apple orchards scattered throughout
Massachusetts to determine the proportion of
sampled orchards that
contained each of these
three species of preda-
ceous mites. We surveyed
again in 1993 in 12 dif-
ferent commercial or-
chards scattered across
the state. Samples con-
sistedof 100 leaves taken
weekly in each orchard
from April through June
and 50 leaves taken bi-
weekly from July through
September. Leaves were
placed in a cooler imme-
diately after picking and returned to the labora-
tory for predator identification. Identification
involved removing the predators fi'om leaves,
mounting them on microscope shdes, and using
taxonomic keys to distinguish between some
species on the basis of the number and location
of tiny hairs on the body surface.
There was remarkably little change over 1 6
years in species composition of predators (Table
1). In both surveys, A. fallacis was present in
81 to 92% of sampled orchards, Z. mali in 30 to
33%, and T. pyri in to 8%. The similarity in
data patterns across years is even more re-
markable given the fact that all orchards
sampled in 1977 were different from the ones
sampled in 1993.
We conclude that if we want to achieve
biocontrol of pest mites with existing preda-
ceous mites in Massachusetts orchards , we ought
to pay particular attention to A. fallacis and
ways of encouraging its buildup. T. pyri, which
Table 1. Percentage of Massachusetts commercial apple
orchards sampled in 1977 and 1993 containing predaceous
mites.
Year
Number of
orchards
sampled
Species of predator
Amblyseuis Typhlodromus Zetzellia
fallacis pyri mali
1977
1993
21
12
81
92
8
30
33
10
Fruit Notes, Spring, 1994
appears identical to A. fallacis even under a
powerful hand lens, can not be counted on at
this point to provide mite biocontrol in any but
a small minority of orchards. In an attempt to
establish T. pyri in additional orchards, we
released hundreds of nymphs and adults (ob-
tained from Geneva, New York) in 1992 and
1993 in two orchards. Unfortunately, there is
no evidence to date that these releases have
resulted in estabUshment of T. pyri.
•Sm m^M •^ •9^ %%
«^ r{% r{% r{% r{%
How Beneficial Are Pre-bloom Oii
Sprays Against European Red IVIites?
Ronald Prokopy, Jennifer Mason, and Xingping Hu
Department of Entomology, University of Massachusetts
For decades, most Massachusetts apple
growers have been applying pre-bloom oil sprays
against overwintering eggs of European red
mites. Just how beneficial to spring and sum-
mer mite control are these sprays? Further-
more, does the reduction in number of hatching
mites after spraying oil cause our principal mite
predator, Amblyseuis fallacis, to leave apple
trees in search of more prey elsewhere?
To answer these questions, in 1993, we
cooperated with commercial growers in con-
ducting a test in two-acre blocks of apple trees in
each of nine orchards. Half of each block re-
ceived no oil or other miticide through May. The
other half received two applications of oil: one
during half-inch green to tight cluster and the
other during tight cluster to early pink. Each
application was at a rate of about one gallon of
oil to 100 gallons of water, with 100 to 300
gallons of water used per acre. Duiing the third
week of May, following egg hatch, 200 leaves
per untreated and treated block were examined
for presence of motile red mites and A. fallacis.
In the untreated blocks, an average of 35%
of sampled leaves had motile red mites com-
pared with an average of only 5% in the oil-
treated blocks (an 86% reduction in mite num-
bers). Nearly all untreated blocks required
repeat applications of miticide beginning after
petal fall. None of the treated blocks required
miticide apphcation until July or August. In
two sampled blocks that received only a single
pre-bloom application of oil, numbers of motile
mites were reduced 45% compared with un-
treated blocks.
No A. fallacis were found on any of the
blocks in leaf samples taken before oil applica-
tion began in April or during May, although by
August, all of the blocks had at least some A.
fallacis. Evidently, cold winter temperatures
reduced populations of A. fallacis to such low
levels that it was inconsequential whether or
not red mite prey were low or high in numbers
in May.
We conclude from these 1993 tests that two
pre-bloom applications of oil against red mite
eggs pay high dividends in suppressing red mite
populations through spring and early summer,
and in some years, possibly through the entire
growing season.
%i« %i# %% %% %%
ry» ry% ry» rj% #y*
Fruit Notes, Spring, 1994
11
North American Strawberry Growers
Meet in Ontario
The North American Strawberry Growers
Association held its seventeenth annual meet-
ing February 13-16, 1994 in Niagara Falls,
Ontario. Over three hundred and fifty members
firom the United States, Canada, and England
gathered to learn the latest information on
strawberry production and marketing.
Dave Whittamore of Markham, Ontario
was elected President and Susan Butler of
Germantown, MD was elected Vice President.
Two new directors were elected to the Board:
John Dzen of S. Windsor, CT and Mike Reilly of
Pittsburg, PA.
The annual meeting followed a one-day pro-
gram emphasizing bramble culture sponsored
by the Ontario Berry Growers Association
(OBGA). NASGA's opening session was pre-
ceded by a delightful wine and cheese reception
hosted by OBGA. The evening program was
highlighted by Dr. Tim Ball, Winnipeg,
Manitoba, who entertained the crowd with his
delightful talk "Whatever Happened to Global
Warming?", a factual and fictional discussion of
long-term environmental changes.
NASGA was started by growers in 1977 and
is run by growers today with over 400 members.
Highly committed to improving strawberry pro-
duction through research, more than 25% of
membership dues is allocated to research each
year. In 1992, the NASGA Research Founda-
tion was formed to increase fimding. This year
NASGA received 24 proposals requesting more
than $95,000 for strawberry research. The Re-
search Committee recommended funding 17
projects with a total of $34,000. Approximately
55% of the grants were for plant breeding im-
provements and 40% for pest management
studies. NASGA publishes the research journal
Advances in Strawberry Research.
A 10-day tour to study agriculture and small
fi-uit growing in Eiux)pe has been arranged by
NASGA. The tour will depart August 21, 1994
for stops in England, Holland, Belgium, Ger-
many, and Switzerland. Reservations are on a
first-come first-serve basis and non-NASGA
growers/researchers are invited to participate.
For information contact Linda Struye, tele-
phone/FAX (414) 921-4784.
The next annual meeting is scheduled for
February 12-15, 1995 at the Sheraton Plaza
Hotel at the Florida Mall in Orlando, Florida.
The North American Bramble Growers will
meet February 11-12, and immediately follow-
ing NASGA, the Fourth National Strawberry
Research Conference will be held, which
NASGA is pleased to help cosponsor.
For more information about NASGA and its
publications, write to Bill & Treva Courter, P.O.
Box 160, West Paducah, KY 42086, telephone/
FAX (502) 488-2116.
%l0 %i^ ml^ %% mj^
rj^ rj% rf» •J^ ^J*
12
Fruit Notes, Spring, 1994
Promising New Apple Cuitivars for 1994
Duane W. Greene and Wesley R. Autio
Department of Plant & Soil Sciences, University of Massachusetts
Diiring the past three seasons, we have
evaluated over 100 new apple cuitivars. Some
of these cuitivars are newly named and are
available currently, while others are only num-
bered selections and are not available widely.
Last year we reported on all cuitivars evaluated
in 1992 [Fruit Notes 58(2):4-14]. This year we
are reporting only on those cxiltivars that ap-
pear to have promise in wholesale operations or
fit into a special slot in retail sales operations.
Fruit evaluation began the first week in
July and ended the fourth week in October.
Where sufficient fi*uit were available, multiple
harvests were made. Fruit were evaluated both
objectively and subjectively (similar to the ways
reported last year). Ten fruit were harvested
fi"om each cultivar one to five times at weekly
intervals, and flesh firmness, percent red color
(or percent red cheek if the apple was yellow),
diameter, and weight were assessed. Fruit also
were cut and dipped into iodine solution and
starch was evaluated using a generic starch
chart developed at Cornell University. The
starch chart allowed us to assess taste at times
when the fi-uit were ripening, and it also gave us
an idea when fruit should be harvested for
storage. Fruit were evaluated for visual and
sensory characteristics using a specially de-
signed sheet with subjective rating scales simi-
lar to the one described last year. Mcintosh was
evaluated at four different times and included
in this report as a commercial cultivar check.
The Most Promising
New Apple Cuitivars
Below are listed what we consider to be the
most promising new cuitivars for New England.
They appear in alphabetical order.
was introduced in 1983. Arlet was an outstand-
ing apple again this year even though it has
several major faults: surface russetting,
preharvest drop, and a greasy feel when fi*uit
ripen. Individuals hking a tart apple may select
Arlet over Gala, which is harvested in the same
season. It is conic, has yellowish white flesh,
and a finiity pineapple taste. Firmness is main-
tained over a long period of time. If a stop-drop
chemical is appUed, drop can be controlled and
firaiit will develop a very attractive cardinal red
color without losing much firmness. The deep
red color more-or-less masks the russet even
though as much as 25% of the surface can be
russetted. It is one of the best storing apples
that was evaluated. Grease that developed on
the surface can be washed off easily.
Ginger Gold
Ginger Gold emerged as the best early yel-
low apple and one of the top apples evaluated. It
is a large apple that has a very attractive waxy
lemon yellow color and no apparent russet.
Ginger Gold can be picked over a long period.
Fruit had acceptable flavor and good appear-
ance on August 24, in late Paulared season.
Three weeks later the starch rating was only
3.3, with firmness nearly 20 pounds, and fruit
were still crisp. Ginger Grold has a pleasant but
weak apple flavor. Fruit were harvested weekly
and placed in cold storage at four different times
starting on August 24. Two months later fruit
fi-om all harvest dates tasted mealy and unap-
pealing and firmness had dropped to 13.5
fKJunds. Ginger Gold should not be considered a
long storing apple; however, it is an outstanding
apple at harvest and afl;er a short period of
storage.
Arlet Golden Glory
This apple originated in Switzerland and This limb sport ofSmoothee produces a very
Fruit Notes, Spring, 1994
13
Table 1. Laboratory analy
ses and bloom
dates of the most
promising new a
pple cultivars evaluated
at the University of Massachusetts Horticultural Research Center
in 1993, with Mcintosh shown |
as a reference.
Best
Also
Soluble
Red
harvest
evlauated
Weight
Diameter
Firmness
solids
color
Starch
Bloom
Cultivar
date
on:
(g)
(in)
(lbs)
(%)
(%)
index*
time**
Arlct
9/20
9/14,9/28
186
2.92
17.4
13.8
80
6.4
E
Ginger Gold
9/7
8/24. 9/2, 9/13
283
3.35
21.0
14.0
30
2.2
M
Golden Glory
10/13
10/5, 10/18
244
3.24
16.4
15.5
13
6.3
ML
Golden Supreme
10/4
9/20,9/27
265
3.28
16.9
13.9
—
6.0
L
Honeycrisp
9/7
9/13, 9/20, 9/27
292
3.47
17.4
14.2
68
4.8
M
NY 429
10/13
—
244
3.37
14.0
12.1
88
—
—
NY 75414-1
10/5
9/20,9/28
194
3.21
13.1
14.3
96
5.5
M
Sansa
9/13
8/24, 9/2, 9/7
178
2.94
16.3
14.2
84
6.8
ML
Suncrisp
10/18
—
216
3.10
19.3
15.1
40
6.0
ML
Mcintosh
9/27
9/7, 9/13. 9/20
202
3.20
13.8
11.6
85
7.0
M
* Starch rating:
1-3 = immature, 4-6 =
: mature
, and 7-8
= overmature.
** Bloom time: E = early,
EM = early-middle, ML = middle-late, and L =
late.
Table 2. Taste and sensory
evaluations of th
e most promising new apple cultivars evaluated at the
University of Massachusetts Horticultural Research Center in
1993, with Mcintosh she
wn as a
reference.*
Best
Also
harvest
evlauated
Red
Cultivar
date
on:
Attractiveness
color
Crispness
Flavor
Overall
Arlet
9/20
9/14,9/28
5.5
6.7
5.7
7.2
6.6
Ginger Gold
9/7
8/24. 9/2. 9/13
7.7
—
7.9
6.0
7.6
Golden Glory
10/13
10/5, 10/18
7.1
—
5.3
7.1
7.1
Golden Supreme
10/4
9/20, 9/27
9.0
—
5.7
6.7
7.7
Honeycrisp
9/7
9/13, 9/20, 9/27
4.2
4.2
6.4
6.3
6.3
NY 429
10/13
—
7.8
7.5
—
6.1
6.3
NY75414-1
10/5
9/20. 9/28
7.1
7.1
4.4
6.2
6.7
Sansa
9/13
8/24. 9/2, 9/7
7.3
7.3
7.0
8.9
8.9
Suncrisp
10/18
—
6.7
~
7.1
6.9
6.8
Mcintosh
9/27
9/7, 9/13. 9/20
7.2
7.2
6.6
5.8
6.2
* All fruit characteristics
were rated on a
scale from 1 to 10.
Color: = dull and 10 =
: bright.
Attractiveness, flavor, and overall disirability: = dislike and 10 = like. Crispness: =
low and
1 = high.
attractive apple and the tree has a somewhat
spur-type habit. It produces heavy crops of
large attractive apples somewhat regularly,
indicating that it may not be as biennial as one
would expect. Fruit do russet but they still are
very attractive. Although definitely a Golden
Delicious type, we would rate this selection
higher than either Golden Delicious or
Smoothee for appearance, taste, and potential
productivity.
Golden Supreme
This chance seedling was discovered in
Idaho. We evaluated it for the first time in 1993.
It is truly an outstanding apple. It is a very
14
Fruit Notes, Spring, 1994
attractive apple with a glossy lemon-yellow rus-
set-free finish and a pink-red cheek. It ripens
about seven to ten days before Golden Delicious,
but some uneven ripening may force two har-
vests. It shows some tendency to drop prema-
txirely. Flavor was fruity, sweet and perfumy,
with a taste of Ucorice. The tree is spujr-type and
upright, and some reports indicate that it may
not be too productive. This apple is unsurpassed
for appearance and flavor.
Honeycrisp
This Minnesota selection is the result of a
cross between Honeygold and Macoun. Many
Honeycrisp trees will be planted in the next few
years because it has outstanding storage poten-
tial and fruit following regular air storage have
'explosive crispness'. Fruit harvested on Sep-
tember 14 with firmness of 17.8 pounds still had
firmness above 17 pounds at the end of January
in air storage. Honeycrisp is a very large apple
but its not too attractive, because color is slow to
develop and is striped rather than blush. Qual-
ity at harvest is good but not exceptional, and
the longer Honeycrisp stays in storage the bet-
ter it looks compared with other cultivars.
Honeycrisp fruit from Massachusetts were in-
cluded in a replicated taste evaluation at the
Mid-Atlantic Fruit Variety Showcase in West
Virginia in January. Numerically, Honeycrisp
was judged to be the best tasting apple and
statistically it was equal to Fuji and Braebum.
Over the past four years Honeycrisp on M.26
has been the most productive apple in our culti-
var evaluation plots. It produced over 1.5 bush-
els per tree in the fourth leaf
NY 429
This very large burgundy-red apple is from
the New York breeding program. It has very
good quahty and the flesh is creamy white.
Even when cropped very heavily, fruit wiU size
to 3.25 inches or larger. It may be biennial if not
thinned. Trees are very productive. NY 429 is
already in commercial production in the
Hudson Valley of New York and prices of $20
per bushel were reported in 1993 in the Apple
Report for the Massachusetts Department of
Food and Agriculture. NY 429 will be named
soon.
NY 75414-1
This cultivar is the best disease-resistant
apple from New York. It is medium large, red,
and a Macoun look-alike. Scarf skin may be a
problem in some areas but in New England it is
a plus because it is also a characteristic of
Macoun. It is attractive, somewhat tart, and
very crisp. Taste is Macoun- and Mclntosh-like.
Trees are vigorous and nonspur.
Sansa
This outstanding apple is the result of a
cross between Gala and Akane. It was one of the
highest rated apples, regardless of the season of
harvest. Fruit were attractive, very crisp, aro-
matic, sweet, and the flavor was subtly spicy at
first but it soon developed into a fully flavored
apple with pineapple, banana, and licorice
taste. Sansa did not drop and it could have been
harvested over a three-week period (the three
weeks prior to Gala). It stored for up to two
months. Although it softened, it maintained
flavor, unlike Gala which maintains firmness
and crispness but loses the essence of the flavor
that makes it Gala. Fruit were of medium size.
Sansa is the best tasting apple that ripens
before Mcintosh. The first commercial
plantings wiU go in the ground in 1995.
Suncrisp (NJ 55)
This cultivar produces medium to large late-
season yellow apples. Finish on this apple was
not very good but the striped orange-red cheek
over lemon-yeUow ground color is distinctive
and somewhat attractive. Fruit is conic with a
crisp yellow flesh. The acidity is quite high at
harvest but the sharpness and tartness mellow
in storage. Flavor is excellent. It is a very good
apple to help spread out the harvest season and
it has good storage potential.
Fruit Notes, Spring, 1994
15
Table 3. Laboratory analyses and bloom dates of the most
promising new apple cu
Itivars with local
or niche market potential evaluated at the University of Massachusetts Horticultural Research |
Center in 1993.
Best
Also
Soluble Red
harvest
evlauated
Weight
Diameter
Firmness
solids color
Starch
Bloom
Cultivar
date
on:
(g)
(in)
(lbs)
(%) (%)
index*
time*'
ArkCharm
8/12
8/5,8/9
246
3.30
15.9
13.0 77
ML
MonArk
a/19
8/12
239
3.29
16.3
12.0 71
—
M
Nittany
10/18
—
154
2.75
19.5
13.8 77
7.1
L
Shamrock
9/27
9/13, 9/20, 10/4
179
3.04
17.5
12.7 34
3.9
ML
Splendour
10/13
10/18
241
3.24
20.1
13.3 88
2.9
L
Williams Pride
8/19
8/12
164
2.95
15.7
11.3 94
—
ML
* Starch rating:
1-3 = immature, 4-6 =
: mature
, and 7-8
- overmature.
** Bloom time: E
= early,
EM = early-middle, ML = middle-late.
and L = late.
Table 4. Taste and sensory evaluations of the most promising new apple cultivars with local or
niche market potential evaluated at the University of Massachusetts Horticultural Research
Center in 1993.*
Best
Also
harvest
evlauated
Red
Cultivar
date
on:
Attractiveness
color
Crispness
Flavor
Overall
ArkCharm
8/12
8/5, 8/9
4.8
4.2
3.8
5.6
5.1
MonArk
8/19
8/12
5.3
5.5
4.7
5.6
5.8
Nittany
10/18
—
6.7
6.7
8.0
6.7
7.0
Shamrock
9/27
9/13, 9/20, 10/4
5.2
—
5.2
6.4
6.2
Splendour
10/13
10/18
7.2
7.1
4.6
6.7
6.8
Williams Pride
8/19
8/12
6.0
7.0
4.0
5.9
6.2
All fruit characteristics were rated on a scale from 1 to 10. Color: = dull and 10 = bright.
Attractiveness, flavor, and overall disirability: = dislike and 10 = like. Crispness: = low and
1 = high.
Apples Worthy of Limited
Planting
Some apples may not be recommended for
extensive planting but they have some out-
standing characteristics that make them appro-
priate to plant for niche markets. We feel that
the following group of apples are worthy of
consideration for limited planting.
Akane
Akane continues to be a cultivar that we
favor. It is extremely attractive and few apples
have the flavor and aroma of Akane. It ripens
during the first two weeks of September. It
develops deep cherry red color before it is ready
to harvest, so it fii^quently is harvested imma-
ture and tart. When allowed to ripen, it has
excellent flavor. It may be a shy bearer.
ArkCharm (AA 18)
This large blotchy red apple from Arkansas
ripens a little before Jerseymac and Paulared.
Fruit is tarter than sweet but fruit quality is
quite good. Storage life is rather short but it is
one of the best apples for the season.
16
Fruit Notes, Spring, 1994
Monarch (AA 44)
This cultivar is another blotchy cherry-red
apple from Arkansas. Quahty is very good for
this season. It has a good perfumy taste but
because of extensive preharvest drop, few may
reach the proper stage of maturity without the
use of a stop-drop treatment. Acidity is quite
high. It ripens slightly before Pavdared, but it is
superior to Paulared in taste.
Nittany
Very little is heard about this open polU-
nated seedling of York. It is fairly attractive,
oblong, and light cherry red. It ripens late, in
Rome Beauty season. It has a good sweet-tart
flavor that we rated very high. Although some
Nittany are grown in Pennsylvania, we believe
that we can grow a more attractive and perhaps
a better Nittany in southern New England. It is
a vigorous tree and fruit suffer from calcium
problems.
Shamrock
This cross between a spur Golden Delicious
and a spur Mcintosh is not reported to have high
quality, but we feel that it is versatile and a
potentially valuable cultivar. It tastes Granny
Smith-hke if picked just prior to Mcintosh sea-
son. The quality is at least as good as the
Granny Smith apples found in the store at this
time of year. If allowed to stay on the tree iintil
late September or early October it develops a
very good Mcintosh taste. We feel that it is the
best green apple in the season. The tree is
grower-friendly, a semi-spur type, precocious,
and it is not biennial.
Splendour
This late-ripening red apple is from New
Zealand. It is attractive and has very good
flavor, but the skin is so thin that it cannot
withstand the rigors of packing, handling, and
long-distance shipping. The tree is a semi-spur
and very grower-friendly. It is a parent of the
new generation of apples from New Zealand and
British Columbia.
Williams PHde
This disease-resistant apple ripens with
Paulared but the quality is superior to
Paulared. Fruit are large, red, and somewhat
irregular in shape and the skin is not smooth.
White lenticels are prominent. Fruit is aro-
matic and flavor is mild but fruity and lively.
We have several other cultivars under test
that we feel have the potential to go all the way
to the top, although they are not commercially
available yet. The most promising from the list
are: BC 8M 15-10, BC 17-30, Fantazja, and
NJ90.
•S^ %£• %£• %f^ •S^
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Fru'n Notes, Spring, 1994
17
Suggestions for Use of the New
Postbloom Thinner Accel®
Duane W. Greene and Wesley R. Autio
Department of Plant and Soil Sciences^ University of Massachusetts
Chemical thinning of apples continues to be
one of the most important management activi-
ties. It is reqviired nearly every year to assure
adequate fruit size at harvest and to encourage
repeat bloom the following year. Carbaryl and
NAA are the two most commonly used thinners.
Both have their faults. Orchardists frequently
are reluctant to use carbaryl because of the
potential detrimental effect that it can have on
mite predators, and it is a relatively weak thin-
ner. When used alone, often it is not potent
enough to thin adequately. NAA is stronger,
but it also has several detrimental effects.
Overthinning is possible if either cloudy or hot
weather immediately follows apphcation. It
can retard finiit growth, even when used accord-
ing to label directions. Under these conditions,
NAA may not increase fruit size, even when it
causes significant thinning. This lack of size
increase is emerging as a major problem associ-
ated with NAA. Finally, NAA cannot be used on
some cultivars because it causes pygmy finait.
In the 1980's benzyladenine (BA) was found
to have chemical thinning capabiUties. Since
then, researchers have demonstrated repeat-
edly that BA is a consistent and effective thin-
ner with some unique properties that may make
it the postbloom thinner of choice. Accel® re-
cently was approved as a chemical thinner on
apples. Accel is an altered Promalinâ„¢ formula-
tion, but the primary active thinning compo-
nent is B A. The purpose this article is to explain
some of the characteristics of BA that make it a
unique thinner, and to make suggestions for
successful use of BA when applied in the Accel
formulation.
General Effects of Accel
Thinning Activity
BA can thin over a wide range of concentra-
tions, starting fi*om as low as 25 ppm. Undesir-
able side effects may be noted if it is appUed
above 150 ppm; however, label restrictions on
the active ingredient per acre make it unlikely
that too high a concentration will be applied.
BA has been applied in heavy set years and in
light set years, and the thinning response to
varying concentrations is linear. Although con-
centrations as low as 25 ppm can be effective, 50
to 100 ppm generally are required to do an
effective job.
Comparison with other
Chemical Thinners
BA has been compared with NAA and car-
baryl in several thinning trials in Massachu-
setts. It thins as consistently, if not more
consistently, than either NAA or carbaryl when
applied at the proper time and at an appropriate
temperature. The activity of chemical thinners
differs fix)m year to year, depending on weather
and other factors; however, when applied at the
appropriate tree row volume, 75 ppm BA thins
Mcintosh comparably to 1 Ib/100 gal carbaryl
(50% WP Sevin) and 6 ppm NAA. BA has been
shown to have no detrimental effects on mite
predators, a problem frequently associated with
the use of carbaryl. When applied alone, BA
does not have the negative effects of NAA, such
as leaf epinasty, reduced fruit size, or pygmy
fruit.
18
Fruit Notes, Spring, 1994
Return Bloom
One of the primary reasons for thinning is to
assure adequate return bloom. BA appears to
be quite effective at stimulating flower bud
formation, and therefore, BA compares favor-
ably with NAA and carbaryl at stimvdating
return bloom. In some years, BA will enhance
flower bud formation beyond that which would
be promoted by the level of frmt thinning that it
causes.
Time of Application
BA can thin over a three- week period. It will
thin modestly when applied at full bloom to
petal fall, but fruit are most susceptible to BA
and it is most effective when it is applied at the
8- to 10-mm stage of fruit development (14 to 18
days after fuU bloom). Once iniit reach about 20
mm and trees experience several days of sunny
weather in the 80's, no thinner, including BA,
will thin.
Spray Coverage
Good and uniform spray coverage is impor-
tant. Translocation and redistribution of
foliarly appHed BA is limited. Further, research
has shown that BA must come in direct contact
with the spvu" leaves for fruit in that cluster to be
thinned. BA application directly to the young
fruit wiU increase fruit size and flesh firmness
at harvest but wiU not influence fruit abscis-
sion.
Fruit Effects
Perhaps the biggest advantage that BA has
over other chemical thinners is its effects on
fruit.
Fruit Size
Generally, chemical thinners increase fruit
size by lowering fruit numbers, thus reducing
competition for metabolites among the remain-
ing fruits. Although BA enhances size by reduc-
ing competition, it also causes increased fruit
size independent of and in addition to this effect.
This effect on fruit size independent of thinning
is unique to BA. BA is especially effective at
increasing fruit size on Mclntosh-tjrpe cultivars
such as Mcintosh and Empire.
Flesh Firmness and Sugars
It is rare for chemical thinners to increase
flesh firmness because they usually increase
finiit size, and there is an inverse relationship
between fruit size and flesh firmness. BA,
however, increases flesh firmness approxi-
mately half of the time, even though it also
increases finiit size. Because BA is a cytokinin
(a group of plant hormones) it likely increases
flesh firmness by increasing the number of cells
in an apple. Also, BA increases the sugar
content of fruit about half the time. Thinners
can increase sugar because they increase the
leaf-to-fruit ratio.
Red Color and Fruit Asymmetry
If used at high concentrations, BA can re-
duce red color and increase finiit asymmetry.
Given the label restrictions per acre per applica-
tion, we do not believe that either one of these
situations is likely to occur.
Cultivars
BA is not equally effective on all cultivars.
BA is especially effective on Empire and Mcin-
tosh and extremely useful on Jonamac, Rome,
Idared, and Golden Delicious.
Recommendations for
the Use of Accel*
Accel is the first step by Abbott Laboratories
to make BA available as a thinner on apples. It
is not a perfect product, but it is a start. It is an
altered Promalin formulation so GA, , is in-
4+7
eluded, but it is present only at 1/10 the level
found in the original Promalin formulation.
Also, on the present label is a limit of 35.6 fluid
ounces of Accel (20 g active ingredient, ai) per
acre p>er application, and this level may limit its
effectiveness when used on large trees that
have a high tree-row-volume requirement.
* Please see the end of this article for a discussion of a
pending label change.
Fruit Notes, Spring, 1994
19
Concentration
Twenty five ppm in a dilute spray is the
minimum concentration to get any thinning
response. If the tree row volume of a block
requires 200 gallons per acre in a dilute spray,
the label would allow only a concentration of 26
ppm (at 35.6 fluid oxinces of Accel or 20 g ai/acre)
to be used. Furthermore, in situations where
aggressive thinning is necessary and the tree
row volume is only 100 gal/acre, the desired
level of thinning may not be reached with the
use of BA alone, since the label will allow only a
concentration of 53 ppm (at 35.6 flxiid ounces of
Accel or 20 g ai/acre). In these situations,
additional thinning strategies may be neces-
sary.
Accel should be apphed in 50 to 200 gallons
of water per acre. Applications in volumes less
than 50 gallons per acre may result in poor
coverage.
Cultivars
Use Accel on responsive cultivars first until
you feel comfortable and until you see how it
performs in your orchard. Responsive cultivars
include Empire, Rome, Mcintosh, and Idared.
Time of Application
If using a single application of Accel, apply
at the 8 to 10 mm stage (3/8 in), firom 12 to 18
days after full bloom.
The label allows up to two applications of
Accel per season. The research has not yet been
done to determine the specific effects of multiple
applications, so proceed with caution. If two
applications are made, do not exceed a total of
71.2 fluid ounces of Accel (40 g ai) per acre for
the season. With two applications, the first
should be applied at the 5-mm fruit stage, and
the second should be applied at no later than the
10-mm stage.
Combinations with other Thinners
BA has been used effectively in combination
with NAA on Mcintosh. The response was
additive; however, Accel interacts with NAA on
Dehcious to produce small and pygmy fruit.
Therefore, the label specifically states that NAA
should not be used in any Accel thinning pro-
gram. Where aggressive thinning is required,
carbaryl should be included in the thinning
program. We have tank mixed BA with car-
baryl successfully. The thinning response was
additive. The label does not prohibit tank mix-
ing with carbaryl but the practice is discour-
aged.
Weather
Attention to temperature is critical for effec-
tive thinning with Accel. It should be applied
only when the temperature is 65°F or higher.
Ideally, the temperature should rise into the
80's within three days following application. If
warm temperatures do not follow the applica-
tion, thinning results are hkely to be disappoint-
ing. Cloudy weather following application, Uke
warm temperature, may increase the thinning
response.
Label Change Pending
There is a label change pending for Accel as
this issue goes to press. There are two signifi-
cant changes that may occtu*. The rate of Accel
per apphcation may be increased to 53.5 fluid
ounces (30 g ai) per acre, and the total per
season may be increased to 107 fluid ounces (60
g ai) per acre. This change must be noted,
because overthinning may occur of Mcintosh,
Idared, Rome, and Empire if the new maximum
rate is used and tree row volume reqires less
than 100 gallons per acre for a dilute spray.
Conclusions
In this first season of commercial use, use
Accel cautiously and follow label directions. Use
it first on a responsive cultivar, and do not apply
it unless temperature conditions are appropri-
ate.
%% %% %fi» %{>• •^0
rj% r{^ rj% rj% r{%
20
Fruit Notes, Spring, 1994
Emit Notes
University of Massachusetts
Department of Plant & Soil Sciences
205 Bowditch Hall
Amherst, MA 01003
Nonprofit Organization
U.S. Postage Paid
Permit No. 2
Amiierst, miA 01002
Account No. 3-20685
Fruit Notes
Prepared by the Department of Plant & Soil Sciences.
University of Massachusetts Cooperative Ebrtenslon System.
United States Department of Agriculture, and Massachusetts Counties Coopj
Editors: Wesley R. Autio and William J. Bramlage
ISSN0427-6906
LISRARi
JUL \h 9'4
JNIV. OF MA3
Volume 59. Number 3
SUMMER ISSUE, 1994
Table of Contents
Could Bacteria in Nature be Detoxifying
Compounds for the Apple Maggot Fly?
A New Book on Tree Fruit Nutrition
Some Thoughts on Depreciation
Effects of Low Temperature, Ripening, and Light
on Scald Susceptibility of Apples at Harvest
Final Report on the 1984 NC-140 Cooperative Apple Rootstock Ranting
in Massachusetts: Starkspur Supreme Delicious on Fifteen Rootstocks
O' Say Can You See Mite Predators in Apple Orchards?
Apple Orchards in Switzerland: EHfferences Small and Large
Fruit Notes
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Fruit Notes
Department of Plant & Soil Sciences
205 Bowditch Hall
University of Massachusetts
Amherst, MA 01003
COOPERATIVE EXTENSION SYSTEM POLICY:
All chemical uses suggested in this pubhcation are contingent upon continued registration. These
chemicals should be used in accordance with federal and state laws and regulations. Growers are
urged to be familiar with all current state regulations. Where trade names are used for
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Cooperative Extension System offers equal opportunity in programs and employment.
Could Bacteria in Nature be
Detoxifying Compounds for tlie
Apple IVIaggot Fly?
Carol R. Lauzon, Bernard J. Robert*, Teresa G. Bussert, and
Ronald J. Prokopy
Department of Entomology, University of Massachusetts
*Department of Plant & Soil Science, University of Vermont
Insects are exposed, almost continuously, to
a variety of harmful compounds. Adults and
larvae may come into contact with harmful
synthetic chemicals, such as pesticides, or harm-
ful natural compounds, such as plant
allelocompounds (plant substances that often
protect it against pests). Insects may be exposed
to these harmful compounds either through
contact or through feeding. Either way, the
mechanisms for ridding these poisons from the
body are important survival processes. These
processes, referred to as detoxification mecha-
nisms, involve enzymes (proteins that facilitate
chemical reactions) which alter the structure of
the compound and make it more excretable (less
toxic). This can be achieved by removal or
addition of a chemical group.
Generally, pesticides apphed by growers are
in amounts that overwhelm the insect's ability
to detoxify them. As time goes on, the pesticide
on plants is broken down by sunhght, wind,
rain, and other natural processes. Eventually,
residues may reach concentrations where the
insect C£in survive ingestion or contact. With
repeated exposure, the insect may evolve to
handle effectively a toxin in concentrations ear-
lier found to be lethal, i.e. develop pesticide
resistance.
The apple maggot fly, Rhagoletis pomonelUt,
typically is controlled by two or three applica-
tions of azinphosmethyl (Guthion ), an orga-
nophosphate that is a potent inhibitor of cho-
Unesterase, an enzyme responsible for normal
nervous system functioning. Azinphosmethyl
also is used to control other orchard pests such
as codling moth. Although no information exists
to date regarding resistance to azinphosmethyl
for the apple maggot fly, resistance has been
reported for codling moth.
Mechanisms of insecticide resistance tradi-
tionally have been examined using genetic tech-
niques focused on resistant individuals and cre-
ation of models of gene flow between resistant
and susceptible insects. Less attention has been
paid to the potential involvement of bacteria
either within or on host plants or within insects
in the development of insecticide resistance.
Interestingly, enzymes in bacteria capable
of converting toxic compounds into less toxic
compounds that are more easily excretable in-
clude the same enzymes that insects themselves
use in detoxification. In fact, many bacteria can
detoxify compounds internally or secrete en-
zymes responsible for metabolizing foreign com-
pounds into their surrounding environment.
Numerous reports exist on the abilities of cer-
tain species of bacteria to degrade and detoxify
a variety of compounds, including
azinphosmethyl and plant allelocompounds.
Here we report on studies designed to deter-
mine if bacteria associated with the apple mag-
got fly could degrade, and subsequently detoxify,
azinphosmethyl and plant allelocompounds
likely to be consumed by this insect.
Fruit Notes, Summer, 1994
Materials & Methods
Pesticide degradation and detoxification .
Enterobacter agglomerans, a bacterium found
to inhabit both the gut of the apple maggot fly
and apple leaf surfaces in nature, was added to
sterile preparations of azinphosmethyl at a con-
centration typical of one sprayed by a grower.
The bacteria/pesticide solutions and sterile pes-
ticide solutions (void of any bacteria) were incu-
bated at 73°F for 3 days. Cholinesterase was
extracted from apple maggot flies and mixed
with the bacteria/p)esticide solutions to deter-
mine whether or not azinphosmethyl still was
capable of reducing cholinesterase activity after
exposure to the bacteria. Also, small amounts
fi-om each sample were fed to 25 apple maggot
flies and mortality values were recorded at 24-
and 40-hour intervals. Additionally, the solu-
tions were analyzed for degradation products of
azinphosmethyl. The experiment was done twice.
Plant allelocompound degradation and
detoxification . We also studied four
allelocompounds considered to be toxic to apple
maggot and typically found in the habitat of
apple maggot flies. They were: naringenin,
phloridzin, cafieic acid and cinnamic acid. Each
solution was inoculated with Enterobacter
agglomerans and incubated at 87°F for 24 hours.
Sterile solutions also were incubated along with
the bacterial solutions. Degradation of each
compound was measured by changes in pH (a
typical phenomenon associated with degrada-
tion) and by the presence or absence of degrada-
tion products. Also, small amounts from each
solution were fed to 10 flies individually, and
mortality values were recorded after 12 days.
Results
Mixing cholinesterase extracted from apple
maggot flies with azinphosmethyl resulted in
low to no cholinesterase activity (14.8 active
units). However, activity of cholinesterase was
10 times greater when mixed with
azinphosmethyl in which bacteria had grown
for three days (144.1 active units). The higher
value indicates that cholinesterase activity was
not inhibited as much in the bacterial solution
and therefore, the pesticide was less effective.
We found that loss of effectiveness was the
result of chemical alteration of azinphosmethyl
by bacteria
Forty hours afl«r a 48-hour-old solution of
bacteria and pesticide was fed to apple maggot
flies, only three of 50 flies were dead. In con-
trast, when flies were fed the sterile pesticide
solution, 47 of 50 were dead after 40 hours. Fifty
flies serving as controls were fed only water. All
were alive after 40 hours.
In the allelocompound solutions that con-
tained bacteria, we saw changes in pH (indica-
tive of chemical changes) which were not ob-
served in the sterile solutions, and we were able
to detect degradation products in the bacterial
solutions that were not present in the sterile
solutions. Therefore, bacteria also degraded the
plant allelocompoiuids. When apple maggot
flies were fed sterile solutions of the four
allelocompounds, all were dead after 12 days;
however, when solutions inoculated with bacte-
ria were fed to the flies, none died.
Conclusions
Our laboratory findings indicate that
Enterobacter agglomerans possesses the abihty
to degrade and subsequently detoxify
azinphosmethyl and certain plant
allelocompounds that normally are toxic to apple
maggot flies. This finding is an important first
step in establishing the contribution of bacteria
toward detoxification of harmful compounds
encountered in nature by this and other insects.
We are continuing our work in this area by
studying (1) precisely how the bacteria degrade
toxic compounds, (2) how fly longevity and fe-
cundity are affected by detoxification, and (3) if
detoxification mechanisms inherent to flies are
enhanced by degradation processes of bacteria.
Further comprehension of ways insects handle
chemicals in the environment should contribute
to pest management progrguns. Such knowl-
edge also may lead to creation of new ways to
decrease or eliminate pesticide crops or on spray
equipment. For example, it is conceivable that a
bacterial or enz)Tnatic preparation could be
sprayed on trees before harvest so that the
Fru'n Notes, Summer, 1994
residues may be decreased or eliminated through
detoxification. Envision also, after completion of
spraying, a tablet containing bacteria that one
drops into the spray tank and a few hours later,
the equipment is free from any pesticide. These
are exciting possibilities.
Acknowledgments
We thank George MacCoUom of the Univer-
sity of Vermont for supplying apple maggot flies
during the early stages of this work (which took
place at the University of Vermont), Evan
Thackaberry (also of the University of Vermont)
for his assistance with visualization of pesticide
degradation products, and Sylvia Cooley for
technical assistance with plant allelocom pound-
fly mortality studies. This work was supported
in part by the National Agricultural Pesticide
Impact Assessment Program Grant #92-34050-
7268 and USDA National Research Initiative
Competitive Grant #893715.
Selected References
Brattsen, L.B. and C.F. Wilkinson. 1977. Herbi-
vore-plant interactions: Mixed-function oxidase
and secondary plant substances. Science June
17: 1349-1352.
Robertson, J.L., K.F. Armstrong, D.M. Suck-
Ung, and H.K. Preisler. 1990. Effects of host
plants on toxicity of azinphosmethyl to suscep-
tible and resistant light brown apple moth (Lepi-
doptera: Tortricidae).J. Econ. Entomol. 83: 2124-
2129.
mS^ mS^ •Sm %f^ ^f^
rj% ry» •Y* •T* •^
A New Book on Tree Fruit Nutrition
In February, 1992, a shortcourse on the
Management of Tree Fruit Nutrition was held in
Wenatchee, Washington. The proceedings from
that conference have been pubhshed by Good
Fruit Grower and is available for purchase.
The book consists of 22 generally easy-to-
read chapters and totals over 200 pages. It
begins with three general chapters on fruit tree
growth and development, root development and
physiology, and soil characteristics. This base is
followed by 12 chapters on minerals and ap-
proaches to meeting their needs in trees and
finiit. There are also three chapters on diagnos-
ing nutritional needs in orchards, and a chapter
on fertilizer effects on water quahty. Finally,
the book concludes with three chapters on
fertigation. Eighteen different authors contrib-
uted to the shortcourse and the proceedings.
This is an outstanding reference for frmt
growers, and will certainly become a standard
reference on nutritional problems in orchards.
Copies can be obtained from the Good Fruit
Grower, P.O. Box 9219, Yakima, WA 98909.
Cost is $15.00 plus $3.50 for shipping. We
strongly urge growers to obtain a copy £md to
refer to it often.
«1# •S^ •^0 %|^ •S^
rj% #J% rj% rj% •^
Fruh Notes, Summer, 1994
Some Thoughts on Depreciation
Robert L. Christensen
Department of Resource Economics^ University of Massachusetts
Depreciation may be the most misunder-
stood topic in financial management. It is prob-
ably the most complicated exercise in the devel-
opment of the business financial statement, and
it is a critical element in preparation of income
tax returns. In fact, the complexity of IRS rules
and some computational methods can obscure
the concept that underhes depreciation and lead
to a misunderstanding of true costs and busi-
ness profitability.
Depreciation is an annual non-cash expense
that reflects the amount by which an asset
decreases in value due to use, age, and obsoles-
cence. It apphes only to assets like buildings,
machines, and breeding animals, as well as to
improvements hke roads, bridges, fences, and
drainageways that have useful hves of more
than one year. Depreciation recognizes the fact
that these assets can wear out with use. That is,
eventually they become so worn that they be-
come useless or repair costs become excessive.
Depreciation also occurs through aging.
Even without use, wooden or rubber compo-
nents can rot, metal can rust or become brittle
and break, and plastic can lose strength and
crack. Assets also can become obsolete as new
technology is developed to perform the same
tasks more efficiently and at lower cost, or if the
asset is no longer relevant to the nature of the
business (e.g. , a mUking machine becomes obso-
lete if the dairy herd is sold).
While depreciation is a non-cash expense,
there is a "day of reckoning" that comes when
the asset must be replaced. One might consider
the annual depreciation amounts as money to be
put in a reserve account to accumulate until the
day when the asset is replaced. In theory, the
business then will have the capital accimiulated
to replace the asset with little or no need to incur
new debt. More often, however, no such reserve
account exists.
One sometimes observes situations where
the annual income statement of a business
shows a low or even negative net income and
there is a suggestion of insolvency. One might
immediately ask how the operator can continue
in business and take care of family hving ex-
penses if net income is negative. One expla-
nation is that depreciation is subtracted as a
cost in the income statement. It's important to
recall that depreciation is a non-cash expense.
Since depreciation is a non-cash cost, that
amount actually is available from cash flow for
debt repa)rment, other business expenses, and
for family living costs.
Another answer might be that past earnings
in the form of savings are being depleted in order
to meet costs and debt obligations. Still another
explanation could be that additional debt is
being incurred that allows the business to con-
tinue and family living expenses to be met. This
situation can continue untU the time of reckon-
ing when depreciable assets must be replaced.
Even though replacement might be possible
from borrowed funds, it may be difficult to con-
vince lenders that theyshould make the loan
when past income statements show low or nega-
tive net income.
Comphcating the subject of depreciation are
the IRS procedures relating to depreciation. For
tax purposes, depreciation is a deductible ex-
pense of the business just as if it were a cash cost.
Regulations define what kinds of assets may
and may not be depreciated. They also establish
acceptable methods of calculating depreciation
and stipulate recovery periods (the number of
years over which different classes of property
may be depreciated). Once a particular method
has been established for an asset you cannot
change to another method, but you can use
different methods for different assets.
It's not the purpose of this article to describe
depreciation methods and procedures. Rather,
only a few points will be made concerning depre-
ciation and tax liability. First, the amount of
depreciation taken on business assets can affect
Fru'n Nous, Summer, 1994
tax liability substantially. Second, the selection
of the method of depreciation for property can
affect tax Uabihty not only in the current year
but also in future years (e.g., accelerated meth-
ods reduce tax UabiUty in early years of owner-
ship and increase liability in later years as
compared with straight line methods). It should
be noted that depreciation calculations may
have little actual relation to the depreciation
costs that relate to wear, aging, and obsoles-
cence of the assets of a particular business. For
example, a single purpose farm building with
integrally installed equipment can become obso-
lete or worn out in less than the 10-year recovery
period for the IRS General Depreciation System
(GDS) regulation. On the other hand, the GDS
time period for most farm machinery is seven
years. Yet for practical purposes, a fully depre-
ciated tractor (one with a "book value" of zero)
may retain its essential usefulness for two or
more decades and, therefore, still have real
value as an asset.
What this means is that depreciation values
can overstate or understate the actual asset
value. When assets last longer than the recov-
ery period, the result is an income statement
which understates actual net farm income and
overstates production costs. In situations, how-
ever, where rapid technological innovation
causes assets to become obsolete more quickly
than the guideline recovery period, the result is
an overstatement of net incomes and an under-
statement of true costs. It often is argued that,
since the business typically has a set of different
types of assets acquired at different times, these
under- and over-statements "wash". That is,
they tend to balance out and approximate the
real value for the entire set of assets.
There also are imphcations for the net worth
statement for the business. Assets may be
valued according to market value or cost value.
Using cost valuation one would use the "book
value" or depreciated value for the asset. Very
often the market value of the asset is greater
than the book value, especially when acceler-
ated depreciation methods have been used. As
a result, net worth may be understated and the
solvency position of the business will be lower
than is actually the case. This, in turn, may
have a negative impact on the ability of the
owner to obtain needed credit for the business.
For this reason, when seekingadditional credit,
the potential borrower might find it more ad-
vantageous to present the lender with a net
worth statement with assets stated in market
value terms.
%2^ ^S^ ^10 %f# %%
rj% rji ry» •^ ^J^
Fruit Notes, Summer, 1994
Effects of Low Temperature, Ripening,
and Light on Scald Susceptibility of
Apples at Harvest
Cynthia L. Harden* and William J. Bramlage
Department of Plant and Soil Sciences, University of Massachusetts
*Present address: Pennsylvania State University,
Fruit Research Laboratory, Biglerville, PA.
Many factors influence scald susceptibility
of apples, including cultivar, orchard locality,
weather, harvest maturity, and storage condi-
tions. For example, Cortland and Delicious are
very susceptible, Mcintosh is moderately sus-
ceptible, and Empire and Gala seldom if ever
develop scald. Also, it has long been recognized
that fruit generally become less susceptible as
they become more mature. Among weather
conditions, preharvest temperature is espe-
cially important, with cool temperatures before
harvest reducing scald susceptibility. Another
potentially significant factor is light, since scald
is usually more prevalent on the green (shaded)
portion of a fruit than on the red (sunlit) portion,
and frmt from the interior of the tree usually are
more susceptible than ones from the exterior.
We have been attempting to predict scald
susceptibility from preharvest temperature
records, using hours below 50°F as our tempera-
ture indicator. In attempting to apply such a
predictor to orchard conditions, however, it is
important to understand how much some of the
other key factors contribute to changes in scald
susceptibility, for if they are major contributors,
they must also be included in a predictor system
to avoid potential errors in predictions.
Consequently, we conducted a three-year
study (1988 through 1990) of the effects of
preharvest hours below 50°F, fruit maturity,
and light intensity on scald susceptibility of
Cortland and Delicious apples grown at the
University of Massachusetts Horticultural Re-
search Center, Belchertown.
Three experiments were conducted. In the
first, both Cortland and Delicious were har-
vested at three or four weekly intervals in each
year, and stored at 32°F for 20 weeks, with scald
being evaluated after an additional seven days
at room temperature. Preharvest temperatures
were recorded continuously in an enclosed shel-
ter in the orchard, so hours below 50°F after
August 1 could be counted at each harvest date.
Fruit maturity at harvest was measured both by
internal ethylene content of the fruit and by
their average starch score, obtained by staining
10 fruit per sample with an iodine-potassium
iodide solution and comparing their stain inten-
sity to standard charts, with one indicating
complete staining (very immature) and nine
indicating no staining (very mature). With each
succeeding harvest date, fruit were more ma-
ture, as shown by increasing starch index and
increasing internal ethylene content (Table 1).
In all but one instance, however, fruit from each
succeeding harvest date also had experienced
more hours below SO'F, so later harvest repre-
sented a combination of both riper fruit and
more preharvest exposure to cool temperatures.
After 20 weeks at 32°F plus one week at room
temperature, scald development was quite vari-
able among samples (Table 1). In general, scald
decreased with later harvest but there were
exceptions; for example, scald did not decrease
from the September 15 to the September 22
harvests in 1989 on Cortland. Also, scald sus-
ceptibility on corresponding dates in different
years was not always comparable; for example.
Fruit Notes, Summer, 1994
Table 1.
Changes
in scald susceptibility of apples harvested at weekly
intervals
in three years.
Ethylene
Harvest
Hours below
Starch
concentration
Scald
Year
date
SOT
index^
(log ppm)
(%)
Cortland
1988
Sept 13
73
1.2
-1.13
71
Sept 22
102
2.0
-1.00
36
Sept 29
134
4.0
-0.65
11
Oct 6
187
5.0
0.15
4
1989
Sept 15
62
1.0
-1.06
99
Sept 22
62
1.7
-0.86
99
Oct 4
152
4.7
0.08
29
1990
Sept 17
21
1.3
-0.97
98
Sept 24
79
1.5
-1.19
78
Oct 3
127
4.3
0.23
46
Oct 11
150
6.8
2.08
49
Delicious
1988
Oct 1
160
1.3
-1.57
12
Oct 8
232
1.6
-2.52
2
Oct 13
365
1.9
-1.16
2
1989
Sept 29
125
1.4
-0.71
83
Oct 5
170
2.6
0.32
72
1990
Sept 21
62
1.2
-1.54
94
Sept 26
104
1.6
-0.96
88
Oct 3
127
3.2
-0.26
69
Oct 11
150
5.5
1.18
51
^1 = very
immature
9 - very mature.
Delicious harvested October 1, 1988 developed
12% scald, while ones harvested on October 3,
1990 developed 69% scald,even though the 1990
fruit were somewhat more mature than those in
1988.
In a second experiment, Cortland apples
were sprayed in August with ethephon to induce
ripening before they had experienced substan-
tial amounts of preharvest cool temperatures.
In 1989, only 500 ppm ethephon was applied,
but in 1990 both 250 and 500 ppm were used.
Both concentrations caused fruit to ripen in
early September. In 1989, some hours below
50°F were recorded before the harvests, but in
1990 none had occurred, so any effect of treat-
ment on scald in 1990 should have been due
entirely to more advanced maturity. In both
years, ethephon treatment significantly re-
duced scald after storage (Table 2); however,
differences usually were small. In particular, in
1990 when fruit ripened in the absence of any
hours below 50°F, all samples developed scald
on more than 90% of the fruit. Ethephon sprays
have been reported to reduce scald on Granny
Smith and Delicious in several parts of the
world, but clearly under our conditions, ethep-
Fruit Notes, Summer, 1994
Table 2.
Effects of ethephon on ripeness
at harvest and
on scald development on
Cortland apples after storage.
Ethephon was applied on
August 16, 1989 and on
August 20, 1990.
Ethylene
Harvest
Ethephon Hours below
Starch
concentration
Scald
date
(ppm)
5(yF
index'
(log ppm)
(%)
1989
Sept 6
52
1.2
-1.05
87
500
7.4
2.00
81
Sept 13
62
1.3
-0.64
96
500
8.4
2.13
67
1990
Septl
1.0
-2.35
97
250
4.8
1.86
90
500
5.9
2.08
92
Sept 6
1.3
-1.82
99
250
7.3
2.12
91
500
6.9
1.95
96
^1 = very
immature; 9 = very mature.
hon treatment was not effective on Cortland, as
Windus and Shutak (J. Amer. Soc. Hort. Sci.
102:715-718) also reported in 1977.
The third experiment was designed to test
the importance of light intensity on scald sus-
ceptibility. In 1989 and 1990, Cortland apples
were enclosed individually in brown kraft paper
bags in mid-to-late August, and kept in these
bags until they were harvested. Bags had al-
most no effect on fruit temperature. Each year
two harvests were made. Bagging did not affect
fruit maturity significantly in either year (Table
3); however, it resulted in fruit with greater
scald susceptibility, and differences usually
were quite large. Thus, under our conditions
severe reduction of light intensity increased
scald susceptibility, but it should be noted that
even bagged fruit were becoming less scald sus-
ceptible with later harvest, indicating that
bright light is not required in order for the
maturity and temperature factors to affect scald
susceptibility.
These results showed that under our condi-
tions preharvest temperature was the most im-
portant factor affecting scald susceptibility of
Cortland and Delicious apples. In Figure 1, all
three years of data were used to illustrate this
effect. For Cortland, scald susceptibility began
to decline when the fruit had experienced
slightly less than 100 hours below 50°F between
August 1 and harvest. By about 150 hours,
susceptibility had fallen to the point where 40 to
50% of fruit scalded, and as they approached 200
hours, only about 10% scalded. Delicious re-
quired about 25 more hours below 50°F to reach
these same levels of susceptibility.
The effects of temperature differences
among different harvests and years can be seen
in Table 1. For example, in 1989 no loss of scald
susceptibility of Cortland occurred when har-
vest was delayed from September 15 to 22, and
it can be seen that temperatures were continu-
8
FruH Notes, Summer, 1994
Table 3. Effects of bagging on ripeness at harvest and on
scald
development after storage of Cortland apples. Fruit were bagged August 21 |
to 25, 1989 and August 13 to 14, 1990.
Ethylene
Harvest
Hours
Starch
concentration Scald |
date
Treatment
below 50°F
index'
(log ppm)
(%)
1989
Sept 18
Control
62
1.3
-1.18
95
Bagged
1.6
-1.27
100
Oct 2
Control
147
5.1
-0.21
27
Bagged
4.4
0.02
90
1990
Octl
Control
107
3.2
-0.07
31
Bagged
3.4
0.24
62
Oct 9
Control
150
6.4
1.21
13
Bagged
6.0
1.41
42
Significance''
1989
Bagging
NS
NS
*
Hours below 50°F
***
NS
**
1990
Bagging
NS
NS
*
Hours below 50°F
***
**
NS
Bagging x
Hours
NS
NS
NS
'1 = Very immature; 9 =
very mature.
"NS = not
significant; * =
= odds of 19:1;" =
= odds of 99:1
; *** = odds of 999:1.
ally above 50°F between these dates. In Deli-
cious, there was almost no scald in 1988 even
though fruit were quite immature; this was a
very cool year, and 160 hours below 50°F had
been recorded by the first harvest date. Harvest
of Dehcious on similar dates in 1989 and 1990
resulted in much more scald development than
in 1988, and in these years fewer hours below
50°F had been recorded by the harvest dates
than in 1988.
Clearly, maturity and light also played roles
in loss of scald susceptibility by the apples, since
ethephon treatment reduced scald and bagging
increased it. The results with ethephon (Table
2) are interesting in that in 1989, when some
hours below 50°F had been recorded before har-
vest, ethephon reduced scald more than in 1990,
when no hours had been recorded. This suggests
that cool temperature increased the effect of
ripening (or vice versa) in reducing scald suscep-
tibility, that is, that temperature and ripening
worked together in reducing scaldsusceptibility.
Nevertheless, cool temperature clearly was the
more important factor in this relationship.
How important light is in this relationship
cannot be measured by our results, since we
used nearly complete light exclusion by bagging
the fruit. Yet, it is likely that reducing scald
susceptibility is one more reason for encourag-
ing light penetration into the tree interior, for
Fruit Notes, Summer, 1994
100
♦\ * \ A Delicious
\^ \ A • Cortland
80
\ \ A
\ *\
-7- 60
\\
(0
O
CO 40
20
♦ A ^^
L
(
D 50 100 150 200 250 300 350
Hours Below IOC
Figure 1. Calculated changes in scald susceptibility (percent of fruit that
develop scald after storage) with increasing hours below 50°F between August
1 and fruit harvest date.
example, by summer pruning. Shaded fruit
probably require more cool temperature and
ripening to become less scald susceptible than
do exposed fruit.
Our results show how rapidly scald suscep-
tibility can change during the harvest period,
and that cool temperature is the most important
factor in this change. In Figure 1 you can see
that if a couple of days occur when the tempera-
ture is almost continually below 50°F, scald
susceptibility can drop dramatically; this situa-
tion commonly occurs in early October in Massa-
chusetts. Conversely, if the temperature re-
mains constantly above 50°F for a period of time,
httle or no loss of scald susceptibility will occur,
even though the fruit may ripen substantially.
We are attempting to develop a practical,
reliable predictive system so that growers can
estimate at harvest how scald susceptible their
fruit are, and determine their scald control
method according to need. At Belchertown, just
counting hours below 50°F at harvest has
worked well. In other regions, however, it is not
as effective, which raises questions about the
relationships between temperature and scald in
"unusual years" in Massachusetts. The results
here show that maturity and light also can be
important factors, and we hope to have a much
clearer picture of scald predictions in the near
future.
%% •i^ %I# •i^ •S^
^^ r{% rj% rj% rf*
10
Fruh Notes, Summer, 1994
Final Report on the 1984 NC-140
Cooperative Apple Rootstock Planting
in Massachusetts: Starkspur Supreme
Delicious on Fifteen Rootstocks
Wesley R. Autio
Department of Plant & Soil Sciences, University of Massachusetts
Dwarfing rootstocks clearly are part of the exceeded by returns, apple growers must take
future of the apple industry in New England. At advantage of all opportunities to reduce costs or
a time when production costs often are not increase returns. Dwarfing rootstocks may al-
Height and spread (ft)
4 6 8 10 12
14
P.I 8
A. 313
Seedling
W\W.VWVVVV\VVVVVVWVWVW\.'wV\.V\S.VWVVW\W v~^~^
MAC.1 ^^^^^^^^^^^^^^^^^^^^^
B.490
M.4
M.7 EMLA
P.I
M.26 EMLA
C.6
MAC.39
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5S
BiBSfiBi
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WWWN
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i
— ^^^^^^^^^^^^^
vvvvvvvv
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de
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P.2
P.I 6
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^V\VVV.VV.VV.\V.VV\VN
Dtca
^Height
H Spread
P.22tHi^^^^^
5 10 15 20
Trunk cross-sectional area (in^)
16
25
Figure 1. Trunk cross-sectional area, height, and spread of Starkspur Supreme Delicious trees on
various rootstocks after 10 growing seasons. Trunk cross-sectional area means are significantly
different at odds of 19:1 if bars do not contain the same letter.
Fruit Notes, Summer, 1994
11
M.4
P.18
A.313
B.490
M.7 EMLA|
Seedling ^
MAC.1 §
P.1 ^
eel
M.26 EMLA
MAC. 39
B.9
P.2
P.1 6
P.22
ab
ab
be
c
c
cd
cd
J^^^^^^^^M^^Mm^^
$$^$MJ^^m^^^$^^^
ef
^^^^M^^mm^
fg
:$^^$^$$M^M$$$^
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de
10
15
20
Cumulative yield per tree (bu)
Figure 2. Cumulative yield (per tree, 1987-93) of Starkspur Supreme Delicious trees on various
rootstocks. Means are significantly different at odds of 19:1 if bars are not followed by the same
letter.
low both. Qiiicker return on the investment of
establishment, potentially higher yields, higher
packout because of better light penetration into
the canopy, less pesticide needed to treat each
acre, and lower labor needs for harvesting and
pruning all make dwarf trees a very desirable
alternative when compared to semidwarf or
standard trees.
In the last issue of Fruit Notes, I gave the
final report of a rootstock trial that began in
1980 as part of a cooperative planting of the NC-
140 Technical Research Committee. In this
article, I will detail the final report of the Mas-
sachusetts portion of the 1984 NC-140 Coopera-
tive Apple Rootstock Plgmting.
Materials & Methods
Starkspur Supreme Delicious trees on B.9
(Budagovsky 9), B.490, MAC.l (Michigan Agri-
cultural College 1), MAC.39, P.1 (Polish 1), P.2,
P.16, P.18, P.22, M.4 (Mailing 4), M.7 EMLA,
M.26 EMLA, C.6, A.313 (Antonovka 313), and
domestic seedling were planted at a spacing of
12 X 18 feet at the University of Massachusetts
Horticultural Research Center in the spring of
1984. Trees were trained as central leaders
using minimal pruning and limb spreading as
needed. Containment pruning was required for
many of the larger trees. Stakes were added for
support only when trees leaned more than 45
12
Fruit Notes, Summer, 1994
degrees. Standard pest and fertility manage-
ment practices were used.
Tree size and yield were measured annually;
however, trees were not allowed to fruit until the
fourth growing season (1987). In 1989, 1990,
1992, and 1993, periodic harvests of four fruit
per tree were made throughout the harvest
season for the assessment of internal ethylene
concentrations. Single harvests often fruit per
tree were made on October 3, 1990, October 3,
1991, October 5-6, 1992, and October 11, 1993
for the assessment of soluble solids concentra-
tion, starch loss, and watercore development.
7y*ce Size and Productivity
Figure 1 reports the average height, spread.
and trunk circiunference of trees from this
planting. Due to the need for containment
priming of trees that exceeded the 12-foot spac-
ing, height and spread do not present an accu-
rate picture of trees on P. 18, A.313, seedling,
MAC.1,B.490,M.4, M.7EMLA,orP.l. Trunk
cross-sectional area likely is a more accurate
measure of relative tree size. These trees broke
into a few distinct size groupings. Standard-
sized trees were produced by P. 18, A.313, seed-
ling, MAC.l, and B.490. M.4 resulted in semi-
standard trees. M.7 EMLA and P.l produced
semi-dwarf trees. M.26 EMLA, C.6, and
MAC.39 resulted in large dwarf trees, and P.22
and P. 16 produced subdwarfs. B.9 and P.2
produced trees intermediate in size to these last
two categories.
P.16H
^^^^^^^^^^^^^^^^HI^^^I^^^Ih 3
P.2B
^^^^^^^^^^^^^^l^^^^^^^^^^^^l a
B.gp
^^^^^^^^^^^^HI^^^^^^^^^H 3
ceH
^^^^^^^^^^^^^H^BIH^^^^^I a
M.26 emlaH
â– b
â– b
P.22&
P.1 ^^^^^â– ^^^^^â– H
b
b
maU
^^^H^^^^^^HH
b
)
1 1
MAC.39P
A.313P
p.isB
^^^^^^^^^^^1 c
B.490 â–
^^^^^^^I^HIH c
MAC.iP
^^^^^^^H c
Seedling U
^^^^^M c
0.0 0.5 1.0 1.5 2.0
Cumulative yield efficiency (bu/in^ TCA)
Figure 3. Cumulative yield efficiency (1987-93) of Starkspur Supreme Delicious trees on varic
rootstocks. Means are significantly different at odds of 19:1 if bars are not followed by the sai
letter.
us
Tie
Fruit Notes, Summer, 1994
13
Yield per tree (Figure 2) roughly correlated
with tree size, with the largest trees producing
the most fruit and the smallest trees producing
the least. It is more important, however, to
compare potential yield relative to tree size, i.e.
more smaller trees can be planted per acre,
which may or may not result in more overall
5deld. Yield efficiency is a somewhat accurate
assessment of relative jdeld potential. It pre-
sents 5deld per trimk cross-sectional area. Fig-
ure 3 gives cumulative 3rield efficiencies for trees
in this planting. The rootstocks break clearly
into three groups. The most efficient trees were
on P. 16, P.2, B.9, or C.6. The least efficient were
on A.313, P. 18, B.490, MAC.l, or seedling.
Trees on M.26 EMLA, P.22, M.7 EMLA, P.l,
M.4, or MAC. 39 were intermediate in efficiency.
A less accurate method for assessing potential
3deld uses estimates of planting density based
on tree spread (Table 1). In this planting, more
containment pruning was used for the largest
trees than for the smallest, so potential planting
Table 1. Projected spacing and tree density of
Starkspur Supreme Delicious on various
rootstocks in the 1984 NC-140 Cooperative
Planting in Massachusetts.
Spacing
Between
Between
of trees
Rootstock
trees
rows
per acre
P. 18
17
24
107
A313
17
24
107
Seedling
17
24
107
MAC.l
16
23
118
B.490
16
23
118
M.4
15
22
132
M.7 EMLA
14
21
148
PI
13
20
168
M.26 EMLA
9
16
303
C.6
8.5
15.5
331
MAC.39
8.5
15.5
331
B.9
7.5
14.5
401
P.2
6.3
13.3
520
P. 16
3.9
10.9
1025
P.22
2.8
9.8
1587
densities were very rough estimates, particu-
larly for the largest trees. Multiplying density
by yield per tree gives potential 3deld per acre.
Figure 4 plots )deld per acre by year from 1987
through 1993. Figure 5 gives potential yield per
acre on a cumulative basis over the seven fi*uit-
ing years of these trees. The results were similar
to those obtained when comparing yield efficien-
cies among rootstocks. The highest yields per
acre may be expected from trees on C.6, P.2,
P.22, B.9, or M.26 EMLA. The lowest may be
expected from trees on P. 18, A.313, B.490,
MAC.l, or seedling.
Fruit Ripening
Knowledge of the effects on finiit ripening is
a critical component of rootstock evaluation.
The potential for advancement or delay in ripen-
ing must be known so that harvest can be
managed appropriately. If the delay or ad-
vancement is predictable, it may be beneficial to
use it to expand the harvest season.
To assess the effects of rootstock on ripening,
internal ethylene, soluble solids (sugars) con-
centration, watercore development, and starch
loss were measured in fruit fi"om this planting.
Ethylene is a gaseous hormone present in all
plants, but is very important to ripening in a
number of fruits. Ethylene is a trigger of rip>en-
ing and during the course of ripening, it in-
creases many fold in apple fruit. It is possible to
track ripening of apples by measuring ethylene
concentration in the core cavity. Table 2 reports
the date in 1989, 1990, 1992, and 1993 when the
average internal ethylene concentration
reached one ppm. Results were not entirely
consistent from year to year, but a few
rootstocks were consistently either in the lowest
or highest category. Specifically, fi-uit from
trees on B.9, MAC.39, M.7 EMLA, M.26 EMLA,
or P. 16 consistently were among the first few to
reach one ppm internal ethylene. Fruit from
trees on seedling, M.4, B.490, P. 18, or A.313
consistently were among the last to reach one
ppm internal ethylene.
Internal ethylene is one of the most accurate
measures of the progress of ripening; however, it
14
FruH Notes, Summer, 1994
Yield per acre (bu)
1,200
— B.9
+ MAC.1
^ MAC. 39
1,000
•DP.1
^P.22
-0- Seedling
^M.4
â–
800
9 M.7 EMLA
Om.26 EMLA
yf^^
^B.490
^ x' Jf£S^^>-^\^^^s^ ' '
Ap.2
•/ \. / •' yW^ji^ ^V^!^!
c
600
BP.16
â– Spis
\
••■C.6
^
400
>
•Xa.313
i/ff ^ v^*^ y^^ ^'j^^ mTI / Jr ^\ x.^^v\
y
^^___
200^
r^^^^^
0^
^^^^y^ -»"jr
1987 1988 1989 1990 1991 1992 1993
Figure 4. Yield (per acre) of Starkspur Supreme Delicious trees on various rootstocks from 1987
through 1993. Estimates of appropriate spacings were used to calculate potential yield on a per-acre
basis.
is necessary to assess additionally other charac-
teristics to get the most accurate picture of the
difference in ripening. Soluble solids (or sugars)
generally increase in concentration during the
course of ripening as the result of the breakdown
in starches. Table 3 give the soluble solids
concentration of fruit from these trees in 1990,
1991, 1992, and 1993. Fruit from trees on B.9,
MAC.39, P.22, P.2, or P. 16 consistently were
among those with the highest levels of soluble
soUds. On the other hand, fruit from trees on
MAC.l, seedhng, M.4, M.7 EMLA, B.490, P.18,
or A.313 were consistently among the lowest.
Starch breakdown is measured easily by
staining cut apples with an iodine-potassium
iodide solution. Iodine stains the starch blue.
leaving a distinctive pattern. This pattern
changes during ripening in a regular way and
can be compared to a standard chart to assess
the progress of ripening. The index used in this
study ranged from one to nine, with one staining
densely and nine not staining at all. The index,
therefore, increases during the course of ripen-
ing. Table 4 reports starch index values from
this study for 1990, 1991, 1992, and 1993. Fruit
from trees on B.9, P.22, P.2, or P. 16 consistently
were among the highest for starch index;
whereas, fruit from trees on seedling, MAC.l,
M.4, A.313, or P.18 consistently were among the
lowest.
As starch breaks down to sugar, osmotic
imbalances may occur in the flesh of apples
Fril/t Holts, Summer, 1994
15
c.6
P.2
P.22
B.9
M.26 EMLA
MAC. 39
M.4
P.16
P.I
M.7 EMLA
P.18
A.313
B.490
MAC.1
Seedling
a
ab
abc
a be
abed
bede
bede
bede
bede
ede
de
de
e
e
e ,
12 3 4
Cumulative yield per acre (xlOOO bu)
Figure 5. Cumulative yield (per acre, 1987-93) of Starkspur Supreme Delicious trees on various
rootstocks. Estimates of appropriate spacing were used to calculate potential yield on a per-acre
basis. Means are significantly different at odds of 19:1 if bars are not followed by the same letter.
which result in the development of watersoaked
areas. This disorder is referred to as watercore.
Watercore generally becomes more severe as
ripening progresses. Table 5 reports watercore
index values from this study for 1990, 1991,
1992, and 1993. The index used ranges from one
to seven, with one representing no watercore
and seven representing severe watercore. Fruit
from trees on B.9, MAC.39, P.22, P.2, or P.16
consistently were among the ones with the most
watercore when there were differences. Fruit
from trees on seedling, M.4, B.490, or P.18 were
consistently among the lowest.
Taking all of these characteristics into con-
sideration, it appears that B.9 and P.16 consis-
tently advanced ripening. MAC.39, P.2, and
P.22 were less consistent but also may have
resulted in an advancement of ripening. Seed-
ling, M.4, and P. 18 delayed ripening. B.490 and
A.313 were less consistent but also may have
delayed ripening. MAC.1, P.l, M.7 EMLA, M.26
EMLA, and C.6 were either intermediate in
their effects on ripening or were inconsistent.
It is important for the grower to note the
potential effects that rootstocks can have on
apple ripening. In this planting, however, those
effects were variable and unpredictable, pre-
venting them from being exploited to expand the
harvest season. Hopefully, other rootstocks will
be found that have more predictable effects.
16
FruH Notes, Summer, 1994
Table 2. Date when the average internal ethylene concentration of Starkspur
Supreme Delicious fruit reached one ppm. Fniit were from trees on various
rootstocks in the 1984 NC-140 Cooperative Planting in Massachusetts. Means
were adjusted for the effects of crop load.'
Rootstock
1989
1990
1992
1993
P. 16
M.26 EMLA
B.9
M.7 EMLA
C.6
P.l
P. 18
P.2
P.22
MAC.39
B.490
Seedling
MAC.l
M.4
A.313
—
—
10/9
cd
10/4
ef
9/23
d
10/7
e
10/9
d
10/5
ef
9/24
cd
10/6
e
10/11
abed
10/5
ef
9/24
cd
10/5
e
10/9
cd
10/7
ede
9/27
be
10/6
e
10/9
ed
10/9
be
9/25
bed
10/6
c
10/11
abed
10/9
bed
9/27
bed
10/6
c
10/11
abed
10/9
bed
—
10/13
b
10/10
abed
10/6
def
—
10/21
a
10/10
bed
10/3
f
9/26
bed
10/6
c
10/11
abed
10/7
cde
9/26
bed
10/6
e
10/13
a
10/9
bed
—
—
10/13
ab
10/8
bed
9/28
ab
10/6
e
10/12
abe
10/7
cde
10/1
a
10/6
e
10/12
abed
10/10
ab
—
—
10/13
ab
10/13
a
'â– Means within a column not followed by the same letter are significantly
different at odds of 19:1.
Table 3. Soluble solids concentration (%) of Starksp
ur Supreme Delicious fruit
from trees on various rootstocks in
the 1984 NC-140 Coo
perative Planti
ng in
Massachusetts.
Means were adjusted for the effects of crop load.'
Rootstock
1990
1991
1992
1993
P.22
10.7
ab
13.7
ab
10.8
a
12.7
a
MAC.39
10.3
abe
13.3
abe
10.3
b
12.4
abe
B.9
10.8
a
13.2
be
9.8
bed
12.4
ab
P.2
10.5
abe
13.8
a
10.0
bed
11.9
bed
M.26 EMLA
10.6
ab
13.1
e
10.0
bed
12.1
be
P. 16
—
13.3
abe
10.2
be
12.2
be
C.6
10.6
ab
12.8
cd
10.0
bed
11.5
d
P.l
10.5
abe
12.6
de
10.0
bed
11.8
cd
MAC.l
9.9
d
11.8
gh
9.7
cd
12.2
abe
M.4
10.0
cd
12.3
ef
9.6
cd
12.0
bed
M.7 EMLA
10.2
bed
12.0
%
10.0
bed
11.8
cd
B.490
9.8
d
—
9.5
d
11.9
bed
Seedling
—
—
9.5
d
11.8
cd
A.313
—
—
9.5
d
12.0
bed
P. 18
9.8
d
11.4
h
9.7
cd
11.9
bed
'â– Means within a
I column not followed by the same letter are significantly different |
at odds of 19:1
Fru'n Notes, Summer, 1994
17
Table 4. Starch index values of Starkspur Supreme Delicious fruit from trees on
various rootstocks in the 1984 NC-140 Cooperative Planting in Massachusetts.
The starch index used ranged from one to nine, with fruit rated as one having
almost complete starch staining and those rated as nine having no starch
staining. Means were adjusted for the effects of crop load.'
Rootstock
1990
1991
1992
1993
P.22
P. 16
P.2
B.9
M.26 EMLA
P.l
MAC.39
C.6
M.7 EMLA
B.490
MAC.l
A.313
P. 18
Seedling
M.4
4.5
a
4.1
a
3.7
ab
5.2
a
—
4.1
a
3.8
a
4.4
be
3.9
b
3.9
a
3.2
abed
4.6
b
3.9
b
3.5
abc
3.5
abc
4.0
bed
3.4
be
3.7
ab
3.3
abed
4.4
be
3.4
be
3.0
ed
3.2
abed
4.6
b
3.7
be
3.5
abc
3.1
bede
4.2
bed
3.3
be
3.2
bed
3.1
bcde
4.3
bed
3.6
be
3.2
bed
2.8
de
4.2
bed
3.4
be
—
2.9
cde
4.3
bed
3.4
be
3.1
ed
2.8
de
4.1
bed
..
—
2.7
de
4.3
bed
3.5
be
2.9
d
2.5
e
4.0
bed
—
—
2.8
de
3.8
ed
3.2
c
2.8
d
2.5
e
3.7
d
Means within a column not followed by the same letter are significantly different
at odds of 19:1.
Table 5. Watercore index values of Starkspur Supreme Delicious fruit from trees
on various rootstocks in the 1984 NC-140 Cooperative Planting in Massachusetts.
The watercore index used ranged from one to seven, with fruit rated as one having
no watercore and those rated as seven having severe watercore. Means were
adjusted for the effects of crop load.'
Rootstock
1990
1991
1992
1993
P. 16
MAC.39
B.9
P.2
P.22
P.l
M.26 EMLA
M.7 EMLA
MAC.l
A313
C.6
B.490
P. 18
Seedling
M.4
1.1
a
1.1
a
1.2
a
1.0
a
1.1
a
1.1
a
1.1
a
1.0
a
1.1
a
1.0
a
1.0
a
1.0 a
2.5
ab
1.1
a
2.4
abc
1.4
a
2.3
abc
1.1
a
2.3
abc
1.2
a
2.3
abc
1.1
a
2.5
a
1.2
a
2.0
bed
1.3
a
2.1
abed
1.2
a
1.9
ed
1.2
a
—
a
2.3
abc
a
—
a
1.8
d
a
—
a
2.1
abed
a
4.3
a
3.2
be
3.5
b
2.9
ed
3.0
c
1.8
fg
2.8
ed
2.4
de
2.3
e
2.2
ef
1.7
gh
1.9
efg
1.9
efg
1.6
gh
1.3
h
Means within a column not followed by the same letter are significantly different
at odds of 19:1.
18
Fruit Notes, Summer, 1994
Table 6. Fruit size, presented as
the number of fruit per 42-lb box, for Starkspur Supreme Delicious
trees on various
rootstocks in the 1984 NC-140 Cooperative
Planting in
Massachusetts.
Fruit size
was adjusted to account for differences in crop
load
z
Rootstock
1988
1989
1990
199]
1992
1993
C.6
80
a
77
ab
76
a
108
a
75
a
90 ab
MAC.39
82
ab
73
a
78
a
113
a
77
ab
86 a
P.2
86
abc
81
abed
76
a
109
a
78
abc
88 ab
B.9
88
abed
82
abed
78
a
109
a
81
abed
88 ab
M.26 EMLA
86
abc
83
abed
82
abc
107
a
82
abed
88 ab
M.7 EMLA
93
bcde
81
abed
87
abed
102
a
81
abed
91 ab
P. 16
96
cde
83
abed
82
abc
103
a
86
bcde
91 ab
P.l
88
abed
82
abed
86
abed
106
a
86
bcde
102 be
P. 22
92
bcde
79
abc
81
ab
100
a
97
e
114 c
M.4
102
de
93
d
85
abed
105
a
90
de
93 ab
Seedling
106
e
91
d
78
a
108
a
95
e
96 ab
P. 18
93
bcde
82
abed
108
e
99
a
92
de
91 ab
B.490
95
cde
87
bed
93
cd
102
a
88
cde
88 ab
MAC.l
103
e
90
cd
90
bed
107
a
96
e
90 ab
A.313
96
cde
87
bed
95
de
102
a
92
de
91 ab
' Means within a column not followed by the same letter are signifi
cantly different at odds of 19:1.
Fruit Size
Fruit size is a very important determinant of
financial return for the apple grower. In this
study, fi-uit size was assessed annually from
1988 through 1993 (Table 6). Effects of root-
stock on fruit size varied somewhat from year to
year, but some rootstocks were more consistent
in their effects than others. Fruit from trees on
C.6, MAC.39, P.2, B.9, or M.26 EMLA always
were among the largest; whereas, frmt from
trees on A.313 or P. 18 were among the smallest.
The potential effects that a rootstock can have
on finiit size should be factored into the rootstock
selection process.
The Winners
Standard sized trees are no longer economi-
cally viable alternatives for orchard planting.
Semidwarf trees are quickly losing their eco-
nomic viability, because of labor requirements
for harvest and management, fruit quality, and
return on investment. As mentioned in the
introduction, growers must move to dwarf trees
to enhance the viability of their businesses. In
this planting, trees on the various rootstocks
ranged from standard sized to subdwarf The
rootstocks that have the most potential based on
their effects on tree size are M.26 EMLA, C.6,
MAC.39, B.9, P.2, P. 16, or P.22, from the largest
to the smallest, respectively. All result in what
would be considered dwarf trees. As a general
category, the dwarf trees outperformed other
trees in the planting. In terms of potential
productivity (taking into account yield efficiency
and the potential yield per acre), C.6, P.2, and
B.9 performed the best in the planting . These
three also resulted in fruit in the largest cat-
egory each year when there were differences
related to rootstock. Trial plantings of C.6, P.2,
and B.9 should be established by growers to
determine further their suitability for New En-
gland conditions.
%f« %f^ %£• 9A0 •S^
rj% r|% r|% 0^ 0^
Fru'n Notes, Summer, 1994
19
O' Say Can You See Mite Predators in
Apple Orchards?
Ronald J. Prokopy, Xingping Hu, and Jennifer Mason
Department of Entomologyy University of Massachusetts
Most apple growers recognize the impor-
tance of spider mites as potential pests and
predatory mites as potential beneficials in or-
chards. We in fruit research and extension often
advise growers to scout trees both for predatory
mites and pest mites before deciding whether or
not to apply a miticide. The ratio of predatory to
pest mites frequently is used as one of the bases
for a spray decision. If there are one or more
predators to every five pest mites, then there is
reason to believe that predators can provide
effective control without pesticide treatment.
Making such a determination through scouting
sounds simple enough, but in fact, it is quite
demanding. Sampling a representative set of
leaves in the orchard is difficult, but even more
difficult is seeing predatory mites emd distin-
guishing them from pest mites or mites that are
neither friend nor foe.
Here, we report on a study conducted in
1993 in which mite predator abundance on tree
leaves assessed in the field by IPM scouts com-
pared with mite predator abundance on tree
leaves taken to the laboratory and examined
under a microscope by a skilled mite taxono-
mist.
Materials & Methods
We sampled leaves an average of 12 times
(May to September) from a second-level IPM
test block and an adjacent first-level IPM check
block in each of 12 orchards, for a total of 298
sample events. For each event, we picked 10
leaves at random from each of 20 trees. All 10
leaves from each tree were examined immedi-
ately by one or another member of the six-
member IPM scouting team using an Optivisor
(3x power). Five of these leaves (chosen at ran-
dom) were placed immediately in a cooler and
returned the same day to a refrigerator at 40F
in our laboratory, where soon afterward they
were examined under a microscope ( 15x power).
In all, 59,600 leaves were examined in the field
and 29,800 in the laboratory. We did not count
every predator seen. Rather, we recorded the
percentage of leaves in each 100-leaf batch that
had predatory mites.
Results
Of all sampled leaves, only 0.8% were ob-
served to have phytoseiid mite predators (ivory-
colored Amblyseuis fallacis or ivory colored
Typhlodromus pyri) by IPM scouts in orchards
compared with 3.5% under a laboratory micro-
scope (Table 1). For stigmaeid mite predators
(yellow-coloredZetee//ia mali), percentages were
2.2 and 5.5, respectively.
Among the 298 batches of sampled leaves,
17.9% were classified by both IPM scouts and
lab exam as having phytoseiids present, 9.8%
were classified by lab exam but not by IPM
scouts as having phytoseiids, and 4.8% were
classified by IPM scouts but not by lab exam as
having phytoseiids (Table 2). For stigmaeid
Table 1. Percent of all sampled leaves
observed as having mite predators by
IPM scouts in orchards versus by exami-
nation under a microscope in the labora-
tory.
Type of
predator
IPM
scouts
Laboratory
microscope
Phytoseiid
Stigmaeid
0.8
2.2
3.5
5.5
20
Fru'n Notes, Summer, 1994
Table 2. Percent of the 298 sampled leaf batches for which IPM scouting and
laboratory microscopic examination did and did not agree on presence or absence
of mite predators in the batch.
Type of
predator
IPM absent,
lab absent
IPM present,
lab present
IPM absent,
lab present
IPM present,
lab absent
Phytoseiid
Stigmaeid
67.5
63.5
17.9
19.8
9.8
9.5
4.8
7.2
1
mite predators, corresponding percentages were
19.8, 9.5, and 7.2. Remaining batches were
classified by both IPM scouts and lab exam as
having no predators.
Conclusions
Our findings indicate that the presence of
predatory mites was detected more often under
a microscope than by IPM scouts, particularly in
the case of phytoseiids. In fact, among ail leaves
examined, phytoseiids were detected more than
four times as often and stigmaeids more than
twice as often under a microscope than by IPM
scouts.
At least three factors may have contributed
to this pattern of results. First, the greater
magnifying power of a microscope may have
facilitated detection of small, newly-hatched
predators that are difficult to detect using an
Optivisor or hand lens. Second, at least six IPM
scouts were involved over the growing season in
examining leaves for mites in orchards, and
there may have been substantial variation
among these scouts' ability to detect and iden-
tify predators. In contrast, the same person
performed all of the examinations under the
microscope. Third, there may have been some
redistribution of predators among leaves during
transport to the laboratory, possibly resulting in
the spread of predators to a greater prop>ortion of
leaves. We believe, however, that this factor
was minor compared with the first two factors.
Regrettably, our findings suggest that a
grower (who might be less skilled than an IPM
scout in identif5ring mite predators) cannot rely
on his or her counting of mite predators using a
hand lens or Optivisor as providing an accurate
assessment of the level of predators actually
present. New York state IPM personnel have
recognized this shortcoming and have created a
tripartite sampling procedure for pest mites
that excludes the need to sample for and identify
mite predators. A slightly modified version of
this procedure for use by Massachusetts grow-
ers is described in detail in the 1994 March
Message to Massachusetts Fruit Growers.
In sum, we will continue to sample for mite
predators in our monitored test and check IPM
blocks but recommend that growers use caution
in interpreting their mite predator monitoring
results. Predators could be more abundant than
meets the eye.
Acknowledgments
This work was supported by grants from the
Massachusetts Society for Promoting Agricul-
ture and the USDA Northeast Regional IPM
Competitive Grants Program.
%% %% ftl^ %% •^
0^ r{^ 9^ rj^ r|%
Fruit Notes, Summer, 1994
21
Apple Orchards in Switzerland:
Differences Small and Large
Donald C. Weber
Institute of Plant Sciences I Applied Entomology,
Swiss Federal Institute of Technology, CH-8092 Zurich Switzerland
Since the beginning of 1993, when I left the
University of Massachusetts, I have worked as
a tree fruit research entomologist for the Swiss
Federal Institute of Technology in Zurich. Since
I also had experience with orchards in north-
eastern U.S.A., I have found the differences in
orchards and pest management between the
U.S.A. and Europe to be quite fascinating. Eu-
ropean agriculture offers some features which I
feel could improve American pest management,
and certainly some other features which should
not be emulated! Most of my comments pertain
in particular to Switzerland, but are more or less
apphcable to neighboring countries as well.
Small-scale and Intensive
One of the most striking features of orchards
in Switzerland is their small size, both in stature
and in area. For the fresh market, dwarf
roots tocks are the rule, and very high-density
plantings (arovmd 1000 trees per acre) are trel-
lised and on rootstocks such as M.9 and M.26.
Fresh-market cultivars differ from those in the
U.S.A. In Switzerland, Golden Delicious is the
single most abundant cultivar, accounting for
about 25% of the acreage; other important culti-
vars are Idared, Maigold, Jonagold, Boskoop,
Glocken, Gloster, Gravenstein, and Jonathan.
Gala is being planted widely, but Cox Orange
Pippin is not so common, although it is a leading
cultivar in Holland and Great Britain. In Swit-
zerland, the orchard acreages for any one
farmer generally are small, family-owned, and
often part of mixed farming including especially
dairy cattle, sheep, and field crops. Government
policy encourages diversified, intensive small
farms which include animal husbandry.
Big Money, Big Trees
That is it for the small things. Two features,
though, loom large: subsidies in the form of
direct government payments, and the presence
of large numbers of more-or-less unmanaged,
high-stemmed (standard) apples and pears in
the landscape. The Swiss people consider both
their agriculture and their "Kulturlandschaft,"
or culturally -influenced landscape, to be a part
of the national heritage. Agriculture is subsi-
dized strongly. Because of changes in Swiss law
made last year, payments to growers are based
now on acreage and desirable management
practices (including crop rotation and inte-
grated production), rather than quantity of har-
vest marketed. This is allowed by the so-called
"Green Box" of GATT, under which member
countries can encourage environmentally-
sound practices through financial incentives.
The Swiss economy is also highly regulated,
aiding marketing associations in the formation
of cartels that then fix quite high prices for
agricultural and other goods. This combination
of subsidies and quasi -monopoly marketing re-
sults in food prices that are among the highest in
the world. This may not be something to wish on
the consumer, perhaps, but farming is more
profitable!
Now for the other large thing. Large pear
and apple trees abound in this landscape, and
are considered not only scenic but ecologically
valuable. Most are minimally managed, and the
apples and pears are harvested for cider. The
pears thrive, thanks to the (until now)absence of
fire blight. But the problem for pest manage-
ment of fresh-market apples and pears is that
these high-stemmed trees are great refuges for
22
Fru'n Notes, Summer, 1994
Obstbaume ,
vom Fachmann
Fur die Pflanzsaison 1993/94 smd noch
folgende Obslsonen erhalilich:
M26 IVI27'
M27 •
Gravensteiner Rellstab
M9
Summerred
M9
Discovery
M9
Prime Rouge
M9
Cox Orange T-1 2
M9
CoxT-21, Korallo
M9
Spartan
M9
Kidd s Orange
M9
Empire
M9
Fiesta â–
M9
Rubinetle '
MS
Royal Gala *
M9
Gala Emia
M9
Elslar •
M9
Arlet
M9
Sir Price V schoriresistent
M9
Flonna ". schorlresistent
M9
Libeny. schorlresisteni
M9
Boskoop Schmta-HiJbsch
M9
Jonagold
Mg
Jonagold Rubinslar '
M9
Jonagold Wiimuta "
M9
Jonagored "
M9
Jonica •
M9
Glockenaplel
M9
Golden Klon B
M9
Golden, Smoolhee
1VI9
Golden Reinders *
M9
Caiagolden '
IVI9
Gloster 69
IVI9
Idared
M9
Maigold
M9
Meran '
IVI9
Granny Smith
M9
M25
M26
M25
K/127-
M27 â–
M26
M26
M26
M26
M26
M26
ti(l26
M27
M27
M27
M26
M26
M26
M26
M26
M26
M26
M27
M27
M27
M27 •,
M27
Sortenschut2
Zudem fuhren wir noch
mehrere Aplelsorten sowie
ein grosses Angebot an
Tafelbirnen-, Zwetschgen-
und KIrschbaumen sowie ein
grosses Sortlment an Apfel-,
Moslbirnen-. Zwetschgen-
und Kirschhochstammen.
Erich Dickenmann AG
Dipl. Obstbautechnlker HTL
8566 Ellighausen TG
TbI.072 68 16 29
Fax 072 6810 29
Typical offerings from a Swiss nursery.
Note abundance of cultivars on M.9 and
M.27.
pests, particularly codling moths, and diseases.
Not only is one not allowed to just cut them
down, but the federal government rewards
farmers for planting more! So the proposal of
Ron Prokopy to eliminate untreated apples
within 100 yards of commercial orchards, to
reduce greatly codling moth colonization, would
be viewed as heresy in Switzerland.
Pest and Pesticide Differences
The pest complex of European apple or-
chards varies from country to coLintry, but in
general the major insect pests are tortricids
(codling moth and others), and aphids, particu-
larly Dysaphis species, relatives of the rosy
apple aphid. Relatively selective treatments are
available to suppress these key pests, resulting
in an enormous decrease in mite problems.
These selective treatments include IGRs (insect
growth regulators), primarily diflubenzuron
(Dimilin''"'*), fenoxycarb (Insegar''""), and
teflubenzuron (Nomolt'"'") for tortricids. All tor-
tricid species are not equally susceptible. Spe-
cies-specific viral preparations are available for
codling moth and summer fruit tortrix
(Adoxyphes orana). These require three to four
applications against each generation of codhng
moth, and superficial injury may occur never-
theless because of delayed mortality of the
young larvae.
Pirimicarb (Pirimor"^") is a selective
aphidicide (with some action against other
piercing-sucking insects) registered worldwide
for about 20 years, except in the U.S.A. It is
extremely valuable not only in apples but in
crops such as cole crops where aphids can be
controlled without upsetting biological control
of other pests. The availabihty of selective
insecticides has reduced some pest problems,
but it has increased others. Broad-spectrum
insecticides against codhng moths previously
also suppressed other tortricids. Non-selective
treatments directed against aphids oflen re-
duced populations of apple sawfly (the satoe one
found in North America) and other early-s-eason
pests to below economically-damaging levels.
Now, more research is necessary to address
these previously unimportant pest problems.
FruH Notes, Summer, 1994
23
MIGROSSAIMO
m
1/a
Aus
nafurqerechtem
Anbau
Full-page advertisement by Migros Supermarket (largest Swiss grocery chain) in the Tages
Anzeiger, the largest daily newspaper in Switzerland. Text reads: Apple growing for the
Migros-Sano program is regularly brought under close scrutiny. This assures an early
knowledge of pests. And gives us the opportunity, to eliminate the problem with mild
treatments and lower doses. For the benefit of nature and the environment! You can
recognize apples from Migros-Sano-Production by this [orange and green] symbol: ["Aus
naturgerechtem Anbau" = from agriculture which is fair to nature].
Luckily for European growers, apple maggot
and plum curculio are not (yet) present, and
therefore both are quarantine pests.
IPM: Moving Forward
A major difference in Europeem apple IPM
(known as IP or Integrated Production, encom-
passing more than just pest management) from
that in the USA is that since at least three
decades ago, the orchard working group of the
International Organization of Biological Con-
trol (lOBC, Western European section) has
taken a lead role in development and implemen-
tation of provisional treatment thresholds for
the region, which now are fairly consistent
among different countries. These thresholds
first allowed reduction in use of broad-spectrum
insecticides, which now have been replaced
largely with more selective materials, resulting
in a double benefit to predators and parasites,
especially phytoseiid predatory mites. The
24
Fruit Notes, Summer, 1994
lOBC recently has proposed a comprehensive
set of IP guidelines for grower certification,
which will work through supervised participa-
tion of grower groups at national and provincial
levels. These would include fertilization, soil
management, restrictions on size of monocul-
tures, and other guidelines, in addition to regu-
lation of pest management practices. The spe-
cifics for individual crops, however, Eire still in
process.
Another major difference relates to the
awareness of IPM on the part of the consumer.
Supermarkets and strongly-coordinated grower
associations have promoted IPM awareness. I
will address this story, and more about specific
pest-management innovations, in future ar-
ticles.
•Am mlm •Im •9^ %£•
•^ r{% r{% 0^ r{%
Fruit Notes, Summer, 1994
25
Fruit Notes
University of Massachusetts
Department of Plant & Soil Sciences
205 Bowditch Hall
Amherst, MA 01003
Nonprofit Organization
U.S. Postage Paid
Permit No. 2
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SERIAL SECTION
UNIV. OF MASSACHUSETTS LIBRARY
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Account No. 3-20685
Fruit Notes
Prepared by the Department of Plant & Soil Sciences.
University of Massachusetts Cooperative Ebctension System. '^
United States Department of Agriculture, and Massachusetts Counties Coopei^fttr^^^^'
Editors: Wesley R. Autio and William J. Bramlage
ISSN0427-6906
Volume 59, Number 4
FALL ISSUE, 1994
Table of Contents
Lighting Systems for Fruit Sorting
A Test of a Potential Non-chemical Approach
to Scald Control on Apples
Influence of Understory Growth and Quantity of Drops
on the Establishment of Voles in Apple Orchards
Is Diphenylamine a Natural Compound in Apples and Pears?
Do Bloom Applications of Fungicides Affect Fruit Set?
Can Synthetic Scent of Predators Repel Deer in Orchards?
J
Fruit Notes
Publication Information:
Fruit Notes (ISSN 0427-6906) is published the first day of
January, April, July, and October by the Department of Plant
& Soil Sciences, University of Massachusetts.
The costs of subscriptions to Fruit Notes are $8.00 for United
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Correspondence should be sent to:
Fruit Notes
Dep£u-tment of Plant & Soil Sciences
205 Bowditch Hall
University of Massachusetts
Amherst, MA 01003
COOPERATIVE EXTENSION SYSTEM POLICY:
All chemical uses suggested in this publication are contingent upon continued registration. These
chemicals should be used in accordance with federal and state laws and regulations. Growers are
urged to be famiUar with all current state regulations. Where trade names are used for
identification, no company endorsement or product discrimination is intended. The University of
Massachusetts makes no warranty or guarantee of any kind, expressed or implied, concerning the
use of these products. USER ASSUMES ALL RISKS FOR PERSONAL INJURY OR PROPERTY
DAMAGE.
I
Issued by the University of Massachusetts Cooperative Extension System, Robert G. Helgesen,
Director, in furtherance of the acts of May 8 and June 30, 1914. The University of Massachusetts
Cooperative Extension System offers equal opportunity in programs and employment.
Lighting Systems for Fruit Sorting
Daniel Guyer, Roger Brool(, and Edwin Timm
Agricultural Engineering Department, Michigan State University
This article is modified from one that appeared in the Washington State University Tree Fruit
Postharvest Journal, Vol. 5, No. 1, which was modified from Michigan State University -- Cooperative
Extension Service Agricultural Information Series, AEIS 618, January, 1994.
Fruits and vegetables are inspected prior to most
processing or packing operations. While some sorting
is accomplished with optical or electronic technology,
much sorting is done by manual visual inspection. Each
woricer must look at a few hundred items each minute
and accurately discard those that are unacceptable.
Good lighting conditions are required to perform this
task.
Sorting table lighting may not currently match the
specific task for which it is intended. Specific guide-
lines for lighting system design in fruit and vegetable
sorting and packinglines in the U.S. do not exist.
Manufacturers of packingline equipment have left
lighting decisions up to the individual operation.
Sorting table lighting must have both adequate
intensity and color quality to enhance or reveal defects
rather than to obscure or mask them. Improper lighting
design promotes woilcer fatigue and eye strain, result-
ing in poor sorting efficiency. Studies of several
operations involving inspection of a range of commodi-
ties have shown that many lighting systems are not
adequate for the required task. These studies suggested
that improved sorting results could be expected if
relatively inexpensive changes in illumination sources,
illumination intensities, and background colors were
adopted in sorting areas.
Principles of Lighting and Color
Two common uses of lighting are (a) general area
lighting, and (b) task lighting. General area lighting's
purpose is to illuminate a room or building for general
activity. This type of lighting is usually mounted in the
ceiling or well above the floor area. Task lighting is
much more specific and is concentrated in an area to
enhance the ability to perform a task. Task lighting is
the primary concern of this article which focuses on the
task of manually sorting fruits and vegetables.
Three major components interact in the process of
visualizing a "color":
1 . li ght energ y from a lamp or light fixture;
2. color reflectance potential of a fruit, caUed
spectral reflectance : and
3. sensitivity of the eye to color, called receptor
sensitivitv.
For example, to "see" the color red there must exist a
light source containing red color light, a surface which
can reflect the red light and a receptor sensitive to
reflected red light.
Light Energy
Light energy, or a source of light, is required to
produce the actual visible color light which the eye can
detect The natural light source is the sun which
produces all visible colors in addition to energy outside
the visible spectrum (ultraviolet, infrared, etc.).
Colorsproduced by artificial light are influenced by
tube coatings, such as phosphor in fluorescent tubes,
gases, or other components contained in filament bulbs.
Artificial light sources are rated by:
1. Color temperature; black body temperature
generation;
2. CRI: Color Rendering Index; and
3. CPI: Color Preference Index.
These ratings are explained briefly in the footnotes of
Table 1.
Of the three major components in visualizing color,
light energy is the one most easily controlled. The
important factor relating to artificial light is the spectral
irradiance curve for a given light source. A spectral
irradiance curve is a measured representation of a given
light source showing the amount of specific light en-
ergy or color contained in the source over the spectrum
of colors. Spectral irradiance curves are generally
available from lamp manufacturers. The spectral irra-
Fruh Notes, Fall, 1994
Table 1. Artificial lighting characteristics and visual effects on common prod
ice colors,
1992."
Light source
Rel
Color
Rel
Visual effect on specified color
(fluorescent tubes)
Mfgr
cost
temp
CRI
CPI
light
Maroon
Red
Green
Brown
Blue
Purple
Yellow
SP-30
1
1.8
3000
70
80
105
E
E
B
E
D
E
E
SPX-30
I
5.9
3000
82
100
105
E
E
B
E
D
E
E
Ultralume-30
2
3.7
3000
85
100
105
E
E
B
E
D
E
E
Warm White
2
1.3
3000
53
37
102
E
E
D
E
D
D
E
Warm White Deluxe
2
2.1
3000
79
90
68
E
E
D
E
D
E
E
Oplima-32
3
4.9
3200
82
—
81
E
E
B
E
D
E
E
Natural
2
3.1
3400
81
93
66
E
E
E
D
E
E
W
Cool White
2
1.0
4100
67
58
100
D
D
E
W
E
D
W
SPX-41
1
6.5
4100
82
100
103
E
E
E
W
E
E
W
Cool White Deluxe
2
3.2
4200
89
94
70
E
E
D
D
E
E
D
Colortonc-50
1
3.2
5000
90
92
70
E
E
E
W
E
E
W
Ultralume-50
2
4.1
5000
85
100
105
E
E
E
W
E
E
W
OpUma-50
3
5.2
5000
91
—
81
E
E
E
W
E
E
W
ViuLite Plus
3
5.7
5500
91
—
100
E
E
E
W
W
E
D
Daylight
2
1.7
6500
79
72
83
D
D
E
W
E
D
W
Colorlone-75
1
4.2
7500
95
97
64
E
E
E
w
E
E
W
'Manufacturer: 1 = General Electric; 2 =
Phillips;
3 = Dure Test.
Rel cost: Relative bulb cost ratio to Cool White.
Color temp: Lamp appearance
in degrees Kelvin
CRl: Color Rendering
Index =
effect the
light source has on appearance of colored objecL
. 100
= perfect
appearance.
CPI: Color Prefoence Index =
how wel
people
recognize colors
in that light, 100 = perfect recognition.
Rel light; Relative initial lumen/watt output as a
percentage
of Cool White.
Visual effect of tube on specified colon
B = brownish cast; D =
larker; E =
enhanced;
W
= whitish cast
Cool White effects arc relative to midday 1
diffuse outdoor light, other tubes are relative to Cool White.
diance for a light source can be altered with various
types of "filters" covering the lamp. These include
undesirable coatings of dust and dirt.
Spectral Reflectance
Spectral reflectance of an object is basically the
"color" of the object -- the ability of a fruit to reflect
certain colors of light in the presence of natural light. In
fruits, the chlorophyll, anthocyanin, or other natural
pigments dictate the item's color. The apparent color of
an item can be altered by changing the light source or by
incomplete color receptor capability. Some defective
and nondefective measurements for the same commod-
ity vary in their reflectance over the entire spectrum
while others either vary only in certain regions of the
spectrum or they vary httle at all.
Many defects that need to be detected on fruits and
vegetables are of brown or grayish color. One might
assume, therefore, that simply finding the light source
with the most energy in the color regions making up the
brown color would be ideal for all applications. The
objective in selecting the best light source for a given
task, however, is to light a commodity with a source that
will accentuate the color difference between the sound
tissue and the defects. For example, if we wish to find
brown discoloration on red cherries, then we want to use
an inspection light of a color that will accentuate brown
against the normal red color of the cherry. The key is
to fiTKi a color of inspection lighting that wiU make the
defects show up the most, i.e., to make the commodity
look its worst.
Receptor Sensitivity
The third component in perceiving a color is the
receiving or sensing of the light. In this case, the human
eye is the receptor. There is no adjustment to the human
eye. The only variability is in the individual's sensitiv-
ity to the color and quantity of the light. Sensitivity
decreases with age and this should be a consideration
during lighting design.
Fruit Notes, Fall, 1994
o
0.20
0.15-
S 0.10-I
t; 0.05H
At
o.oo
Doric Sw««t Cherry
r40SP30 ot 500 ft-c<»ndl«»
9t
o
V
CD
c
91
^1
"S
o:
Wavelength
Figure la. Perceived color based on spectral irradiance, reflectance curves, and receptor
sensitivity (Brown et al., 1993).
1 .00-
i 0.80H
E
^ 0.60H
«>
<J
c
g
1 0.40H
^
0.20-
0.00
F4.0SP3O
3i
o
Wavelength
Figure lb. Spectral irradiance curve of SP-30 lights.
Fruit Notes, Fall, 1994
Perceived Color
Figure 1 demonstrates the combining of all compo-
nents (spectral irradiance, reflectance curves, and re-
ceptor sensitivity) which affect color perception. The
perceived color is termed the "total spectral energy
distribution" and is the product of the spectral irradi-
ance X spectralreflectance x human eye sensitivity or
response. The goal of the lighting design is to have
"peaks" in the distribution at the wavelengths or colors
of the commoditv and at the defect color, thus resulting
in a good perceivable contrast . Figure la shows the
peaks in the perceived color of a dark red cherry, and
Figure lb shows that these same peaks are strong in
light from an SP-30 light, so a good match exists.
Performances of Commercially
Available Light Sources
Theoretically the product of the spectral irradiance,
spectral reflectance, and eye sensitivity should provide
the information to design a proper lighting scheme.
USDA-ARS researchers at Michigan State University
evaluated several commercially available light sources.
They measured individual spectral irradiance, using
color chips to subjectively analyze and compare perfor-
mance in color perception tests. Table 1 siunmarizes
their findings and provides technical and relative cost
information. Results indicated that the "image" curves
resulting from the combination of spectral reflectance x
spectral power x eye sensitivity generally agreed with
the subjective/visual results for the test with the color
chips and real produce items.
The ability to recognize differences between good
and defective areas on produce was lowest under Cool
White (CW) light, which was very similar to that for
CW Deluxe, Warm White, Warm White Deluxe, Day-
light, Natural, Optima 32, Optima 50, C-50, and C-75.
Consequently, these lights should qqi be used for task
lighting in fruit and vegetable inspection areas. U.S.
federal energy standards may eliminate CW and similar
type fluorescent lamps by 1995 because they do not
meet proposed efficiency levels. Fluorescent tubes of
8-foot lengths of all types also are scheduled to be
removed from production.
Visual color comparisons suggested that although
the SP-30 light had a low color rendering index (CRI),
it performed better than higher CRI fluorescent lights
for the visual sorting of most fruits and vegetables. The
relative light output of the SP-30 lamp is among the
highest tested. Its relative cost is only 1.8 times that of
CW. These factors indicate that it should be an appro-
priate choice for most sorting operations when both
sorting perfoimance and lighting cost are considered
(Figures la and lb). Note how the spectral irradiance
curve of SP-30 closely matches the perceived cherry
color.
Except for metal halide, the high intensity dis-
charge (HID) lights were undesirable for produce sort-
ing as they severely darkened most colors. Tests will be
necessary using metal halide light to determine if
sorting performance is acceptable. Tungsten halogen
quartz (quartz) light also produced good color recogni-
tion and enhanced ability to see brown-colored defects
on daik-colored produce. Both metal halide and quartz
lighting will be more costly than SP-30 fluorescent
lighting. More specific discussion of the tests will not
be covered here but can be found in the cited reference.
Requirements of Light Intensity
The average illumination intensity needed on pro-
duce items foreffective visual sorting seems to be in the
range of 250 to 500 foot-candles, based on the reactions
of woricers 20 to 70 years old. The lower intensitv
seems adequate for li ght -colored (high reflectance)
produce, and the hi gher intensitv for dark-colored flow
reflectance) produce. The actual light intensity may
need to be adjusted, depending on the design consider-
ations discussed below. Insituations where kinds or
varieties of produce covering the entire color range
must be insp)ected on the same packing line, the low and
high intensity levels should be selectable by the sorting
woricers. This easily can be accomplished by using
four-tube fluorescent fixtures wired so that either the
two outside tubes or all four tubes can be turned on. The
amount of light falling upon a surfce can be measured
with commercially available light (foot-candle) meters.
Design Considerations
Several physical design characteristics will impact
on sorting efficiency and overall worker attitude and
performance.
Background color of sorting s urface fl^elt).
Reflected light energy from the sorting surface should
not be greater than that from the produce. Use belts
Fruit Notes, Fall, 1994
Screen, block, or direct all task
light sources so that they cannot
glare in the workers' eyes.
Select similar dark colors for
equipment parts and woricer clothing
in the sorting area so that bright areas
cannot interfere with the wooers'
established vision conditions.
u
I
Use SP-30 (or equivalent)
illumination at the sorting area of
most fresh produce pacldnglines.
z:
:x
(o o od)
Adjust lamp power levels (number of
tubes) and fixture height so that light-
colored produce receives approximately
250 foot-candles of illumination and
dark-colored produce, approximately
SOO foot-candles of illuminadon.
Minimize the influence of
natural, stray, and general area
lighting in the sorting area.
..o oo
Use a dark background color (black, gray, dark brown) on
the conveyor surface carrying the produce so that reflected
light energy from this surface is not greater than that from
the produce; avoid a glossy finish on the surface of the belt
Figure 2. Primary design and management criteria for lighting at sorting areas.
which are black or dark gray, but not glossy finish.
Surrounding colors.
Surfaces near sorting areas and the clothing of inspec-
tion personnel should not be bright or highly reflective
and should not cause glare.
Placement of fixtures.
Placement should be such that the light source will not
be directly in the sorters' eyes, i.e., unshielded, or too
low so as to obstruct the sorters' view or the sorting
surface. The fixture also must be placed at such a height
as to provide the proper level of light at the sorting
surface. This wiU depend on the amount and type of
light used and the considerations mentioned above. For
an SP30 light, this height will be about 32 inches above
the sorting surface, as shown in Figure 2.
Type of lighting .
Light type should be appropriate for the sorting task and
the colors involved. Area lighting also should be
considered as it can have negative impacts on the color
evaluation and on eye-strain.
For more information, the following references are
listed.
1. Affeldt, H. A. and P.W. Winner. 1991. Lighting
practice and principles for manual citrus inspec-
tion. Paper No. 9 1 3549, AS AE, 2950 Niles Rd. , St.
Joseph, Ml 49085.
2. Brown,G.K. 1991. Lighting for manual sorting of
apples and sweetcherries. Paper No. 913553,
ASAE, 2950 Niles Rd., St. Joseph, Ml 49085.
Fruit Notes, Fall, 1994
3. Brown, G. K., D. E. Marshall and E. J. Timm.
1993. Lighting for fruit and vegetable sorting.
Paper No. 936069, ASAE, 2950 NUes Rd., St.
Joseph, MI 49085.
4. Davies, J. and R. M. Perkins. 1991. Effect of
illumination in grading dates. Paper No. 912547,
ASAE, 2950 Niles Rd., St. Joseph, MI 49085.
6. Hyde, G. M. 1991. Lighting envirorunent for
manual sorting of potatoes and onions. Paper No.
913548, ASAE, 2950 Niles Rd., St. Joseph, MI
49085.
7. Kantowitz, B. and R. Soricin. 1983. Human
factors, understanding people-system-relation-
ships. John Wiley & Sons, Inc., pp. 102.
5. Delwiche, M. J., J. F. Thompson and R. S. Johnson.
1991. Sorting table illumination on stone fruit
packing Hnes in California. Paper No. 913551,
ASAE, 2950 Niles Rd., St. Joseph, MI 49085.
Kupferman, E. M. 1991. Cherry sorting table
lighting. PaperNo. 913552, ASAE,
*X» *kL» •X* •sL» •X#
•Y* *Y* *T* *v* *T*
Fruh Notes, Fall, 1994
A Test of a Potential Non-chemical
Approach to Scald Control on Apples
William J. Bramlage
Department of Plant & Soil Sciences, University of Massachusetts
James R. Schupp
Highmoor Farm, University of Maine, Monmouth ME 04259
Scald Development on Apples
After Storage is a Threat
There is risk of scald development during and
following long-term storage on a number of important
apple cultivars. Since the 1960's this risk has been
minimized by prestorage application of diphenylamine
(DPA), an antioxidant that has proven to be very
effective in scald control. Today, however, some
markets will not accept DPA-treated apples because
they have been treated chemically, so alternatives to
DPA are being sought.
Numerous non-chemical scald-control procedures
have been proposed, but none are as easy to apply or as
reliable as the use of DPA. The most effective probably
is low-oxygen controlled atmosphere storage, where O^
iskeptnearorbelow 1%. Itisusedforcommercial scald
control in some parts of the worid; however, in the
Northeast we are unable to use low-Oj storage because
the risk of fruit fermentation is excessive.
One non-chemical procedure that has been tested is
warming of fruit after a short time at low temperature.
In New Zealand, Dr. Chris Watkins and I found that
when Granny Smith apples were warmed at 70°F for
five days after they had been at 32°F for two weeks,
warming was as effective as DPA in preventing scald
development. Subsequent tests indicated that this
warming time and temperature was about optimum for
scald control on Granny Smiths. In 1992, we tested this
warming procedure on Cortland and Delicious in Mas-
sachusetts, and found that it caused significant fruit
ripening and gave little or no scald control. However,
we had used fruit that were immature and extremely
scald susceptible, so the treatment might have given
better results if the fruit become less scald susceptible.
It is likely that as fruit become less scald suscep-
tible, scald becomes easier to control. We found several
years ago that as Cortland and Delicious become less
scald susceptible, lower concentrations of DPA become
effective in controlling scald. It is our hypothesis that
at lower levels of scald susceptibility, non-chemical
control measures may be as effective as DPA. The
problem is how to determine at harvest when fruit have
relatively low scald susceptibility. However, we have
found that in Massachusetts, preharvest hours below
50°F is a reasonably reliable indicator of scald suscep-
tibility on Cortland and Delicious (see Fruit Notes
59(3):6-10). Therefore, it is conceivable that by moni-
toring preharvest temperature, a grower could know
when DPA is necessary for scald control, and when a
non-chemical procedure might be used instead.
Experimental Procedures
In 1993, the Maine State Pomological Society
provided funding for a test of this concept. Fruit for the
study were provided from the University of Maine's
Highmoor Farm, and treatments, storage, and fruit
evaluations were done at the University of Massachu-
setts Horticultural Research Center (HRC).
Three cultivars were tested: Mcintosh, Cortland,
and Delicious. Fruit were harvested from the same trees
when 75 , 1 1 9, 1 50. and 200 hours below 50°F had been
recorded at Highmoor Farm. Harvest dates were Sep-
tember 20 and 27 and October 1 and 5. All three
cultivars were harvested on these dates. Maturity was
assessed by using a starch test within one day of harvest,
and by measuring ground color and firmness after
transport to the HRC. Within a week of harvest, one set
of one-bushel samples of each cultivar was dipped for
two minutes in DPA (1000 ppm for Mcintosh, 2000
ppm for Cortland and Delicious). After two weeks at
Fruit Notes, Fall, 1994
Table 1.
Effects of
warming and DPA treatments
on scald development on
apples grown
at Monmouth
, Maine.
Han-est
Starch
Firmness
Ground
Percent scald
Scald score
date
score'
(lbs)
color'
Control Warmmg
DPA
Control
Warming
DPA
Mcintosh
20 Sept
2.5
17.4
4.5
8
46
1
1.1
1.3
1.4
27 Sept
4.4
17.3
4.1
2
12
2
1.0
1.0
1.0
1 Oct
5.2
14.5
2.7
I
7
1
1.1
1.0
1.0
5 Oct
6.3
13.9
1.8
1
6
Cortland
1
1.0
1.0
1.0
20 Sept
2.0
18.1
4.3
9
79
1
1.1
1.1
1.0
27 Sept
1.5
17.3
3.6
64
75
33
1.0
1.1
1.0
1 Oct
2.4
14.8
1.9
33
80
22
1.0
1.1
1.0
5 Oct
3.7
14.3
1.8
33
66
Delicious
18
1.0
1.0
1.0
20 Sept
2.0
18.4
86
48
6
2.1
1.4
1.3
27 Sept
2.8
18.5
—
31
10
1
1.3
1.2
1.0
1 Oct
2.9
17.5
...
17
2
9
1.5
1.9
1.1
5 Oct
2.8
17.5
...
14
1
5
1.1
1.0
11
M = Very
immature
8 = Very mature.
'5 = Very
green; 1 =
= Very yellow.
'1 = 1 to
10%; 2 =
1 1 to 33%; 3 =
34
to 67%; 4
= >67%
of fruit surface affected.
32°F, a second set of samples was transferred to 70°F for
five days and then returned to 32°F. A third set of
samples was not treated in any way and served as
controls.
Mcintosh and Cortland were kept at 32°F for 22
weeks, and Delicious for 25 weeks. At the end of
storage all samples were kept at 70°F for 7 days and then
evaluated for scald, measuring its intensity on the scale
of 1 = 1 to 10%, 2 = 1 1 to 33%. 3 = 34 to 67%, and 4
= more than 67% of the fruit surface affected.
Results
Results ofthe experiment are shown in Table 1. As
expected, Mcintosh ripened the most during the har-
vests and Dchcious ripx^ned the least, but in all cultivars,
changes took place. After storage, little scald devel-
oped on any of the control Mcintosh, but considerable
amounts developed on Cortland and Delicious. DPA
was very effective in controlling scald on Mcintosh and
Delicious, but was only partly effective on Cortland.
Warming had two opposite effects: it reduced scald on
Delicious, but it markedly increased scald on Mcintosh
and Cortland.
Discussion
As expected, as preharvest hours below 50°F in-
creased, scald susceptibility of Delicious decreased,
although the rate of decrease was somewhat more rapid
than we have usually seen. We have not attempted to
construct a predictive curve for Mcintosh because scald
has occurred too infrequently in our tests. However, our
predictive curve for Cortland is similar to that for
Delicious, and the data for controls in Table 1 do not fit
that curve. The first harvest should have produced
nearly 100% scald, but produced only 9% scald. We
have seen this happen before occasionally on early-
picked fruit, and do not know what causes it to occur. Of
more concern was the failure of scald to fall to very low
levels with more than 150 hours below 50°F (the final
two harvests of Cortland). Not only did the scald
susceptibility not decline as expected, but these fruit
also failed to respond fully to 2000 ppm DPA. (It is
possible that an unusual form of scald developed, one
that was not as controllable by DPA.) In our attempts
to predict scald susceptibility, we are more concerned
about underpredicting than about overpredicting scald,
because in the former case a grower might experience
8
Fruit Notes, Fall, 1994
serious financial losses. Thus, we are continuing to try
to refine our scald prediction system.
The effects of warming on scald control on Deli-
cious were just as we hypothesized. Warming reduced
scald at all harvests, but only when susceptibility was
relatively low did warming provide satisfactory scald
control. For Mcintosh and Cortland, however, instead
of reducing scald, warming clearly increased it. We
have not seen this result in previous tests. The fact that
all three cultivars were produced in the same orchard,
harvested on the sameday, treated simultaneously, and
stored in the same room shows that response to warm-
ing can be very different among cultivars. We believe
that the opposite results seen here among cultivars are
related to the fact that Mcintosh and Cortland produce
much more ethylene than Delicious, and ethylene has
complex effects on scald development.
These findings illustrate the risk involved in at-
tempting to use a non-chemical scald-control proce-
dure. Under the conditions of this experiment, using the
predictive curve to determine when to rely on warming
for scald control would have been a resounding success
for Delicious. However, the predictive curve was not
adequate for Cortiand, and warming was never effec-
tive on Cortiand or Mcintosh.
Whether or not warming is a suitable scald control
procedure is not yet clear. Noticeable ripening can
occur during warming, and it would entail major logis-
tical problems to change fruit temperatures. However,
the objective of this study was to use warming as an
example of a non-chemical procedure applied in con-
junction with scald prediction, and from this viewpoint
it can be seen that at this point in time, it's a very risky
approach, one that we caimot recommend.
•T^ •T^ •Xa •sL* vL»
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Fruit Notes, Fall, 1994
Influence of Understory Growth
and Quantity of Drops on the
Establishment of Voles in
Apple Orchards
Ronald Prokopy and Jennifer Mason
Department of Entomology, University of Massachusetts
When abundant, meadow voles and pine voles can
cause severe damage to the bark or roots of apple trees,
sometimes causing tree mortality. Growers are well
aware that problems with voles can be especially great
during winter.
Under second-level IPM, a strong effort is made to
integrate pest management practices across all classes
of pests, including vertebrate pests such as voles. We
report here on the effects on vole establishment of two
IPM practices directed mainly at other kinds of pests.
The first practice concerns management of understory
growth (weeds) by mowing or herbicide application. In
particular we wondered whether or not allowing imder-
story growth to remain at a substantial height during
autumn months would encourage vole establishment.
The second practice concerns picking up drops during
and after harvest. This practice is
directed primarily at reducing
emergence from drops of pest in-
sect larvae such as apple maggot,
codling moth, and lesser
appleworm. Reduction in larval
emergence from drops translates
into reduced numbers of larvae
overwintering within the orchard
and hence reduction in threat to
next year's crop. We wondered if
allowing large numbers of drops
to remain beneath orchard trees
during autumn months would
lead to vole establishment.
Methods
gust of 1993, we placed an asphalt roofing shingle (1 1
X 36 inches) beneath each of 10 perimeter-row apple
trees in each of 12 second-level IPM test blocks and
each of 12 nearby first-level IPM check blocks. The
shingles were spaced evenly around the perimeter of a
block. In October of each year, we lifted each shingle
and examined the ground beneath for signs of vole
establishment, either a trail or a hole into the earth. At
the same time, we measured the height of grass or other
foliage beneath the tree and categorized the number of
drops in a range from few to many.
Results
There was no detectable difference in average plant
height or average number of drops between second-
In August of 1992 and Au-
Table 1. Height of understory cover during October in relation to
proportion of shingles that showed evidence of vole activity. Blocks
represent a fu-sl-level and a second level block in each of 12 orchards
in both 1992 and 1993, with years u-eated separately.
Number of
orchard blocks
Height
of cover (in)
Shingles with
vole activity (%)
11
5
10
14
8
0-5
6-10
11-15
16-20
21-25
10
24
36
39
48
1
10
Fruh Notes, Fall, 1994
Table 2. Amount
1993, in relation
vole activity.
of drops on the ground during October, 1992 and
to proportion of shingles that showed evidence of
Number of
orchard blocks
Estimated amount
of drops
Shingles with
vole activity (%)
9
11
14
11
3
Few
Few to Medium
Medium
Medium to Large
Large
43
45
32
33
30
1
level and first-level IPM blocks. Such lack of differ-
ence suggests that growers were applying understory
management and drop pick-up practices equally to both
types of blocks, even though our recommendation
called for more intensive management of the second-
level blocks.
As shown in Table 1, there was a marked tendency
toward increasing incidence of vole establishment with
increasing height of grass. Orchards treated with herbi-
cide or in which height of understory growth did not
exceed 5 inches at time of sampling in October showed
an average incidence of 10% of the shingles with vole
activity, which we consider to be a comparatively non-
damaging population level. In contrast, orchards in
which understory growth exceeded an average of 21
inches showed an average incidence of 48% of the
shingles with vole activity, a potentially very damaging
population level.
As shown in Table 2, there
was no clear relationship between
numberof drops and incidence of
voles. Ifanything, vole establish-
ment beneath shingles tended to
be slightly greater in blocks with
fewer drops than in blocks with
greater numbers of drops.
Conclusions
We conclude form this two-
year study that growers who
maintain understory plant growth
at a low height during autumn
months have a much better
chance of escaping establishment
of voles than growers who do not. This conclusion may
be particularly applicable to meadow voles. Many
factors can affect the numberof voles immigrating into
an apple orchard during autumn and becoming estab-
lished beneath the trees. For example, a high abimdance
of alternate food such as acorns might tend to discoiu--
age vole immigration into orchards. But in years when
alternate food is sparse or in locales where orchards
closely border woods containing many oak or ever-
green trees, growers could substantially lower the risk
of vole invasion by frequent mowing.
Acknowledgments
This study was supported by grants from the Mas-
sachusetts Society for Promoting Agriculture and the
USDA Northeast Regional 1PM Program.
»T^ *^ vT^ *T# *^
•^ 0^ 0^ •^ 0^
Fruit Notes, Fall, 1994
11
Is Diphenylamine a Natural
Compound in Apples and Pears?
William J. Bramlage and Zhigao Ju
Department of Plant & Soil Sciences, University of Massachusetts
Thomas L. Potter
Mass Spectrometry Facility, University of Massachusetts
For over 30 years, dipping fruit in diphenylamine
(DP A) before storage has been the standard commercial
procedure to control superficial scald (scald) develop-
ment on apples during and after long-term storage.
However, this procedure is controversial since it consti-
tutes a chemical treatment, and legally, DPA must be
considered as a food additive. Some countries have
banned treatment with DPA, and some prohibit impor-
tation of DPA-
treated fruit. In the U.S. and Canada, DPA is permitted
and the maximum residue of 10 ppm should never be
exceeded if DPA is applied correctly. Nevertheless,
many American markets will not accept DPA-treated
fruit because they have been chemically treated.
In 1984, a report was published (Karawya and
Wahab.y.Afamra/ProducW 47(5): 775-780) that DPA
was found in relatively high concentrations as a natural
product in mature onions, and that it was effective in
lowering blood sugar levels in diabetics.
The report also showed data that DPA was
a natural product in tea. In that same year,
a report of the Food and Agriculture Orga-
nization of the United Nations ("Pesticide
Residues in Food - 1984") stated that there
"...is reasonable evidence that dipheny-
lamine occurs naturally in apples though
the level appears to be at or below 1 mg/kg
(ppm)." No data to support this statement
were cited, but in studies of DPA residues
on apples, controls almost always contain
measurable amounts of DPA.
We became interested in this question
when what appeared to be DPA was de-
tectable, even though no DPA had been
applied, during our measurements of ma-
terials in apple peel that might be associ-
ated with scald development. In 1993, the Massachu-
setts Fruit Growers' Association provided us with a
grant to pursue this question, and results of our study are
reported here.
In April, 1993 10-fruit samples were taken fiom
bins of apples stored at the University of Massachusetts
Horticulture Research Center (HRC), Belchertown.
Five cullivars were sampled, and fruit were extracted in
hexane. The extract was tested for presence of DPA
using gas chromatography and mass spectroscopy,
employing selected-ion-monitoring for maximum sen-
sitivity. Results are shown in Table 1. All samples gave
positive indication of DPA in their peel, ranging from
0.03 to 0.13 ppm, despite the fact that none had been
treated with DPA after harvest.
DPA is somewhat volatile, so to test for the pres-
ence of DPA residues in the rooms at the HRC, one-
square-foot areas of walls and doors in three different
Table 1. DPA concentration in hexane extracts
of apples stored 6
to 7 months in 0°C air.
April, 1993.
DPA
Sample
(ppm fr. wt. of fruit)
Blank
<0.01
Delicious
0.03
Mcintosh
0.03
Golden Delicious
0.13
Empire
0.13
Cortland
0.10
1
12
FruH Notes, Fall, 1994
Table 2. DPA concentrations in freshly harvested fruit
. 1993.
Cultivar
Immature
-
Mature
Weight
DPA
Weight
DPA
(g)
(ppm fr.wt.)
(g)
(ppm fr.wt.)
Mcintosh
440
0.002
(9/22)
1382
0.002
(10/7)
1190
0.001
Cortland
659
0.002
1620
0.001
RI Greening
319
0.003
1190
0.002
Empire
316
0.007
1147
0.002
Delicious
430
0.003
1396
0.003
Golden Delicious
510
0.004
1641
0.001
Anjou pear
—
—
2334
0.001
1
rooms were swabbed with dry cotton balls that had been
pre-rinsed in hexane. The swabs were then extracted in
hexane, which was monitored for DPA. All samplings
produced DPA residues on storage surfaces, ranging
from 0.4 to 13.1 ug/meter^ of surface. Thus, DPA in
apple peel could have been the result of contamination
from residues in the storage.
To eliminate this possibility, 10-fruit samples of
fruit were taken direcdy from trees at the HRC in
August, 1993 while fruit were immature. The same four
cultivars tested out of storage were sampled from the
trees, and also fruit were taken from an organically-
grown treeof Rhode Island Greening. Fruit again were
sampled from these trees when they were mature. In
addition, Mcintosh were sampled again when they were
ovenmature, and Anjou pears were sampled at maturity.
All of these samples were extracted in hexane immedi-
ately after harvest, and the extracts were frozen until
analysis. All samples exhibited the presence of DPA
(Table 2), although the concentrations were about one-
tenth those found in stored fruit. It is interesting to note
the increase in fruit weight between the two harvests,
without a reduction in DPA concentration, which indi-
cates that the material continued to accumulate as the
fruit grew.
These results strongly supported the suggestion
that DPA is a natural product in apples... and also in
pears. However, for additional confirmation, two more
tests were run. First, a Mcintosh extract was spiked
with a minute amount of authentic DPA to make sure
the method was recovering and measuring DPA. Spik-
ing doubled the DPA measurement, with a 61% recov-
ery of added DPA, so the procedure is capable of
extracting and measuring DPA.
A more rigorous evaluation of the procedure was
made by producing a derivative of DPA, i.e., attaching
another molecule to it, and separating and measuring
the deri vatized molecule. This procedure is a test to see
if it is truly DPA that was being measured.
Derivatization produced three different ions; DPA plus
the derivatizing substance, DPA plus part of the
derivatizing substance, and DPA with a single proton
removed from it. Using authentic DPA, these ions were
in a ratio of about 1.0:0.6:0.3. When fruit extracts were
derivatized, the three ions were not present in that ratio,
raising doubts that we truly were measuring DPA.
To test this further, 10-fruit samples of Delicious
apples, from the same tree, that had and had not been
dipped in DPA before storage were taken from storage
in March, extracted, derivatized, and measured. The
DPA-treated fruit contained 10 times as much
derivatized DPA as did the non-u-eated fruit, and in the
treated fruit the ion ratio was 1 .0:0.6:0.3, indicating that
it was DPA that was being measured. In the non-treated
fruit, the ratio was about 1.0:0.3:0.2, just as we found in
the freshly harvested fruit.
That result reaffirmed that at least part of what we
were measuring as "DPA" in apple extracts probably
Fru'n Notes, Fall, 1994
13
was something very similar to DPA, but not DPA itself.
This does not mean that apples and pears do not contain
natural DPA. If only half of the derivatized material in
the Delicious extract was DPA, it could produce the ion
ratio that was obtained. Therefore, our results leave
imanswered the question, "Is DPA a natural compound
in apples?" Clearly, something very similar to DPA is
produced, and possibly some of what we were measur-
ing was DPA.
There is an important ramification of this study.
Clearly, DPA or DPA-like compounds are being mea-
sured on fruit that have not been treated with this
chemical. It is present at harvest and accumulates
during storage, since our fruit out of storage showed 10-
times the concentrations of the fruit picked directly off
the tree.
DPA is a somewhat volatile compound, and the
abundant residues we measured on the walls of our
storage rooms show that there is likelihood of contami-
nation of untreated fruit with DPA from the atmosphere
in the storage or possibly from contact with bins and
other equipment. Large quantities of DPA are used in
industry as an antioxidant/stabilizer. For example,
rubber products commonly contain DPA. Thus, fruit
may absorb some DPA directly or indirectly from
industrial products. If a test of fruit indicates the
presence of DPA, its source could be any or all of the
following:
1 . DPA application.
2. Contamination from residues in fruit storages,
containers, or equipment.
3. Contamination from industrial use of DPA.
4. A natural product in apples that while not being
DPA, is being measured as DPA.
5. Possibly, natural-product DPA in the fruit.
Therefore, measurement of "DPA" in fruit is not proof
that fruit were treated with DPA. There apparently is no
such thing as "zero DPA" in apples. Conclusions must
be based on the quantity ofDPA present in the fruit, not
on its absolute presence.
In conclusion, we have not resolved the question of
whether or not DPA is a natural product in apples and
pears. Small quantities of something very similar to
DPA, and possibly of DPA itself, is/are naturally occur-
ring, but remain to be identified. However, we have
shown clearly that conclusions drawn from DPA resi-
due analyses must be based on quanfities measured, not
on its presence in the fruit. An analysis showing the
presence of DPA in fruit is not positive evidence of
DPA application to the fruit.
•X» *^ •X* *J>* *-£-•
ry% •^ rp» #Y* •T*
14
Fruit Notes, Fall, 1994
Do Bloom Applications of Apple
Fungicides Affect Fruit Set?
Daniel R. Cooley
Department of Plant Pathology^ University of Massachusetts
Duane W. Greene
Department of Plant & Soil Sciences, University of Massachusetts
We reported previously [Fruit Notes 56(4): 18-
1991] that researchers in Great Britain found that
fungicide captan may be toxic to apple pollen,
and thereby reduce fruit set. Since then, a test
in Virginia has shown similar reductions in fruit
set, apparently caused by captan applied at
bloom. Furthermore, growers have on occasion
speculated that sterol-inhibiting fungicides re-
duce fruit set. In the work reported here, we
asked two questions. First, does captan or the
sterol-inhibiting fungicide, fenarimol, applied
at bloom reduce fruit set? Second, does captan
or fenarimol interact with oil or copper to
reduce fruit set?
In 1992, mature Mclntosh/M.7 apple trees
were selected at the University of Massachu-
setts Horticultural Research Center in
Belcherlown. In the first experiment, six limbs
of similar blossom density were selected per
tree. Three of the limbs were treated with
copper hydroxide (Kocide 50 WP, 2 lbs/100
gal.) at tight cluster. Each of the three limbs
treated with copper hydroxide and each of the
three not treated with it were sprayed with
captan (Captan 50 WP, 2 lbs/100 gal.) or
fenarimol (Rubigan 1.6 EC, 12oz./100gal.)or
left untreated. A second experiment was iden-
tical except that oil (1 gal./lOO gal.) appUed at
tight cluster replaced the copper hydroxide
treatment. For both experiments, fungicide
applications began when the primary blossoms
were expanded completely, and captan and
fenarimol applications continued at seven- or
ten-day intervals, respectively, until mid-June.
Treatments were applied to the drip point using
a handgun. After June drop was complete, final
19, fruit set was counted on each limb,
the In the first year of study, captan and fenarimol, with
or without oil or copper hydroxide application, did not
Table 1. Fruit set following various treaunents in 1992 and
1994. Within an experiment, no si
gnificant differences were
found among treaUnent means.
Fruit set
Treatment
(number/cm^
1992, Experiment 1
Check
3.8
Captan
5.7
Fenarimol
6.7
Copper hydroxide
5.7
Copper hydroxide plus
captan
5.8
Copper hydroxide plus
fenarimol
5.1
1992, Experiment 2
Check
5.8
Captan
8.3
Fenarimol
6.8
Oil
4.9
Oil plus captan
5.3
Oil plus fenarimol
4.6
1994 Experiment
Check
4.2
Captan at king bloom
5.3
Captan at king bloom + 1 day
5.6
Captan at king bloom + 2 days
4.4
1
Fruit Notes, Fall, 1994
15
alter fruit set significantly (Table 1 ). The results from
Great Britain were very specific in terms of time of
sensitivity to captan, possibly explaining some of the
lack of effect that we observed.
In 1994, we conducted an additional experiment to
study the specific timing of captan application. Mature
Marshall Mclntosh/M.26 trees were selected and
blocked according to blossom density. Within each
block, one tree was treated with captan (Captan 50 WP,
2 lbs/ 100 gal.) when king blossoms were expanded
fully, one was treated one day later, and one was treated
two days later. A fourth tree was left untreated. Other
than these captan treatments at bloom, all trees were
managed similarly. After June drop was complete, final
fruit set was counted on two limbs per tree.
The different timings of captan application did not
result in any significant reduction in fruit set (Table 1).
Therefore, none of our experiments confirmed the
results of studies conducted in Great Britain and Vir-
ginia. We can only speculate that our growing condi-
fions in 1992 and 1994 did not interact with captan in a
way that caused reduced fruit set. Qearly, New En-
gland apple growers should not be overly concerned
that captan will reduce fruit set on Mcintosh.
•1^ •l^ %1a •^ •J^
ry* •^ •Y* •T* "T*
Publications Available
Two publications recently released by Agriculture and Agri-Food Canada should be of interest
to many readers of Fruit Notes. One is titled "Techniques for controlled atmosphere storage of fruits
and vegetables" (Research Branch Technical Bulletin 1993- 18E), and it is a brief general review of the
techniques currently in use for CA storage. The second is tided "Postharvest disorders of apples and
pears" (Publication 1737/E), and it is a detailed review and update on postharvest physiological disorders
of these fruit, including numerous photographs of the disorders. Both of these publications can be
obtained without cost by sending your request to:
The Librarian
Agriculture and Agri-Food Canada Research Center
Kentville, Nova Scotia B4N 1J5 CANADA
16
FruH Notes, Fall, 1994
Can Synthetic Scent of Predators
Repel Deer in Orcliards?
Ronald Prokopy and Jennifer Mason
Department of Entomology, University of Massachusetts
There is a growing number of studies suggesting
that predator odors are repellent to potential prey.
Repellency appears to stem at least in part from chemi-
cal constituents of predator urine or feces. Deer can be
very troublesome pests in apple orchards, especially
during winter months, when they chew apple buds and
twigs. Cougars and other large members of the cat
family are among predators which deer fear the most.
We report here on a small pilot study that we conducted
to evaluate potential repellency to deer of synthetic odor
of cougar feces.
Materials and Methods
TTie odor consisted of a 50:50 mixture of 3-propyl-
1 ,2-dithiolane and 2-propylthietane, encapsulated in
polymeric plastic fibers to provide slow release. Both
components of this mixture are present in cougar feces.
Together, they convey a strong sulfur-like stench
vaguely similar to the smell of a skunk but more
pungent. The odorous fibers are still in a developmental
stage, not yet available commercially. They were
provided to us by Phero Tech Inc. of Delta, British
Columbia.
In November of 1992 and December of 1993, we
hung 4 fibers on each of 25 perimeter-row apple trees at
Rice's fruit farm in Wilbraham, Massachusetts. Each
tree with fibers was separated by three perimeter-row
trees without fibers, the middle tree of which served as
the check tree. Ten twigs on each treated and check tree
were examined for signs of deer injury just before
emplacement of fibers and again one to three months
afterward.
Results and Conclusions
The data in Table 1 show there was little if any
repellent effect of the odorous fibers against deer feed-
Table 1 . Percent of sampled twigs showing evidence of feeding by deer in plots of
apple trees with and without synthetic odor of cougar feces.
Test
Injured twigs
in trees (%)
Sampling
time
With odor
No odor
1
2
November, 1992'
January, 1993
February, 1993
December, 1993"
January, 1994
36
38
3
11
1
37
40
2
5
'Samples
taken just prior to odor emplacement
Fruit Notes, Fall, 1994
17
ing on apple trees in Rice's orchard. We were disap-
pointed in this finding, especially because in a 1993
study, the fibers had shown strong repeUency for as
long as 3 months against deer feeding on Sitka spruce
seedlings in a plantation in McClinton, British Colum-
bia.
Several factors may have been responsible for the
lack of repellency in our study. First, the number of
fibers used (four per tree) may have been too few to
provide effective repeUency, although employment of
more than four per tree would have been too expensive
for practical commercial use. Second, the fibers may
emit too little odor under cold winter weather tempera-
tures in New England to be effective against deer.
Perhaps they are better suited for use imder warmer
West Coast winter conditions. Third, the deer at Rice's
may have been so hungry for winter food that hunger
compromised their instinctive fear of cougars.
Despite this lack of encouraging result, we firmly
believe that improved knowledge of the chemical ecol-
ogy of predators of orchard pests such as deer and voles
will some day lead to development and fomiulation of
blends of predator odor that wiU indeed effectively
repel these orchard vertebrate pests, just as synthetic
plant and insect odors are now being used effectively in
managing orchard insect pests.
A cknowledgments
We thank Phero Tech Inc. for providing us with the
odorous fibers. This work was supported by the Mas-
sachusetts Society for Promoting Agriculture and the
USDA Northeast Regional IPM Program.
•X« •^ •sL» •sL* VL*
•^ •^ •^ r^ •^
18
Fru'n Nates, Fall, 1994
3^1
9
8
Fruit Notes
University of Massachusetts
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Amherst, MA 01003
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