Full text of "Fruit notes of New England"

University of
Massachusetts

Amherst

L I B R

jivl/Mor

Volume 67, Number 1
WINTER ISSUE, 2002

fleiJuCnaland

Table of Contents

Apple-pomace Compost and Pre-plant Monoammonium Phosphate for Improving the Growth of Newly Planted Apple Trees

R.E. Moran and ].R. Schupp 1

Development of a Model for Predicting Flyspeck Risks in Blocks of Apple Trees

A. Tuttte, C. Bergweiler, J. Hall, L. Reisner, S. Christie, W. Autio, and D. Cooley 5

Effects of Gibberellin Synthesis Inhibition on Feeding Injury by Potato Leafhopper on Apple

K. Leahy, D. Greene, and W. Autio 9

Food Quality Protection Act: An Organophosphate Update - February 2002

G. Morm 13

Food Quality Protection Act: Cumulative Risk Assessment for the Organophosphate Pesticides

R. Spitko 16

Commercial-orchard Evaluation of Traps for Monitoring Plum Curculio: 2001 Results

R. Prokopy, B. Chandler, and ]. Pinero 17

An Odor-baited "Trap-tree" Approach to Monitoring Plum Curculio

R. Prokopy 23

IMPORTANT SUBSCRIPTION RENEWAL INFORMATION 25

rleu/Cngiand

Editors:

Wesley R. Autio
William J. Bramlage

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Fruit Notes

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Apple-pomace Compost and Pre-plant
Monoammonium Phosphate for
Improving the Growth of Newly Planted
Apple Trees

Renae E. Moran

Department of Animal and Horticultural Sciences, University of Maine

James R. Schupp

Hudson Valley Laboratory, Cornell University

In many orchards in the Northeast, early yield is
limited by tree growth, and trees are typically not
cropped until the third or fourth season because growth
IS not vigorous. Management practices that encourage
rapid early tree growth and early fruit production result
in economic advantages to growers by hastening a
return on investment. Decreasing the time required for
trees to fill their space would allow growers to increase
early yields.

Increasing early tree growth can be accomplished
by adding organic matter or phosphorus fertilizer to
the planting hole. Adding compost as a source of
organic matter to planting holes affected young apple
tree growth in experiments in Massachusetts and
Maine. Organic matter is often low in many existing
orchard soils. Increasing soil organic matter improves
its water and nutrient holding capacities, which
enhances root regeneration and promotes overall tree
vigor, but the effects of planting-hole treatments are
most visible during the year of planting. As root
growth extends beyond the volume of the planting
hole, the effects of planting-hole treatments diminish.
If organic matter amendments were broadcast
throughout the orchard soil, perhaps the beneficial
growth response could be sustained for a longer
period. For pre-plant compost to be a feasible
management practice, an economical, local source of
compost must be available. University of Maine
Cooperative Extension developed an apple-pomace
composting project in cooperation with Chick
Orchards in Monmouth, Maine. Apple pomace from
the cider operation was mixed with leaf waste from the

local waste transfer station, and chicken manure from
a local egg farm at a 2:6: 1 ratio by volume. Wood ash
was used to adjust the pH to 5.8 prior to composting.
Composting reduced the volume of apple-pomace
waste by 50% and converted it into a soil amendment
with highly desirable characteristics.

Newly transplanted trees have impaired root
systems, so P fertilizer is often recommended for new
plantings. Since P is very immobile in soil, this
nutrient is more beneficial when it can be incorporated
prior to planting. Research in British Columbia has
shown that monoammonium phosphate (MAP 1 1-55-
0) fertilizer, incorporated into the soil used to fill the
planting hole, increased tree growth in the first 2years
after planting and increased flower production and
fruit set in the early years of the planting. The addition
of MAP to the planting hole has become a common
practice in B.C. orchards, especially when replant
problems are anticipated. It has been suggested that
root uptake or utilization of P may be more efficient in
the presence of ammonium. Moreover, MAP could be
influencing tree growth by providing N. This study
was performed to determine if pre -plant-incorporated
apple-pomace compost and MAP, either alone or in
combination, would improve early apple tree growth
and precocity.

Methods

This experiment was conducted at Highmoor
Farm in Monmouth, Maine, on land which had been
fallow for 6 years, but in continuous apple production

Fruit Notes, Volume 67, Winter, 2002

for the previous 37 years. The soil was a fine sandy
loam, with a pH of 6.8 and an organic matter content of
4.7% before the addition of fertilizer or compost.
Macoun/B. 9 apple trees were planted using a tractor-
mounted tree planter on May 1,1998 into plots that had
received one of the following combinations of pre-
plant treatments: 1 ) urea fertilizer without compost; 2)
MAP fertilizer without compost; 3) both compost and
urea; and 4) both compost and MAP. Each plot
consisted of three trees at a spacing of 6 feet between
trees and 18 feet between rows. Cortland/B. 9 trees
were planted as a buffer between plots. Prior to
planting, MAP was applied to the plots at a rate of 332
lbs. per acre and urea at a rate of 79 lbs. per acre, so that
each treatment received an equivalent amount of N
(1 .44 oz. per tree). Apple-pomace compost was spread

over the planting strip and leveled to a uniform
thickness of 4 inches. All plots were then roto-tilled to
a depth of 6 inches. The trees were unfeathered whips,
headed to a height of 28 inches at planting. The trees
were attached to a galvanized conduit stake supported
by a single wire at 7 feet. The trees were minimally
pruned, and trained to the vertical axis system.
Insecticides, fungicides, and herbicides were applied
as needed.

Results

Tree growth was increased by compost, but not by
MAP. Compost increased trunk diameter in the first
two seasons, but by the third season, trunk diameter
was similar in both plots (Figure 1). Annual shoot

;£ 0.8

"S 0.6

^ 0.4

.- 0.2 H

I I No Compost
H Compost

200

One"

Two'

Three

One*

Two Three

Two

Three* Four

Three'

Figure 1 . Tree growth characteristics with and without pre-plant-incorporated compost. * Indicates that
compost had a significant effect in the indicated year after planting.

Fruit Notes, Volume 67, Winter, 2002

Table 1. Orchard soil properties following
compost (year of planting).

soil incorporation of phosphorous or

apple pomace

Treatment pH

Organic P
matter (%) (lbs / acre)

K
(lbs / acre)

Mg
(lbs / acre)

Ca
(lbs / acre)

Urea 6.4
MAP 6.4
Compost-Urea 6.9*
Compost-MAP 6.8*

4.5
4.4
5.3*
5.6*

9.9
13.0
79.6*
86.8*

285
272
679*
612*

291
301
496*

457*

2144
2071
3258*
3093*

* Indicates a significant effect due to compost

at odds of 1 9 to 1 .

growth was increased by compost in the first
season, but not significantly in the second or third
season. By the third season, tree height was
greater with compost. Compost increased the
amount of bloom. MAP had no effect on trunk
growth, shoot growth, number of growing points,
or tree height in any season of the study. We were
unable to determine if the increases in tree size
and flowering were large enough to increase early
yield, because the trees did not attain sufficient
size to permit cropping until after the third
growing season. The trees in this study were on
B.9 rootstock, which is less vigorous than M.9
EMLA, and may be insufficiently vigorous for
spur-type varieties such as Macoun in northern
New York and New England.

Tree growth was increased by pre-plant-
incorporated apple-pomace compost, similar to
results of other studies that showed organic matter
added to the planting hole increased shoot growth
and trunk girth. In those studies, the effect of
planting hole treatments was no longer evident by
the second or third season, and this result was
attributed to roots growing beyond the planting
hole. In our study, the effect of pre-plant organic
matter on trunk diameter and shoot growth also
diminished with time. The diminished effects
observed in our study were possibly due to the
depletion of soil K, Mg, and Ca (data not shown).
Soil K in the compost plots was twice as great as in
non-compost plots, but this difference was much
smaller by the third season. Although trunk and
shoot growth differences diminished with time,

4
3.5

3
2.5

2 H
1.5

1
0.5

2.5

S^ 2

i 1.5

C/)
TO

CL '

N+—

^ 0.5

No Compost
Compost

One'

Two* Three'

One"

Two*

Three"

Figure 2. Leaf nitrogen and potassium with and
without pre-plant-incorporated compost. *Indicates
that compost had a significant effect in the indi-
cated year after planting.

Fruit Notes, Volume 67, Winter, 2002

the greater tree height and bloom were evident in the
third season indicating that the cumulative effect of
compost on tree size was not short-lived.

Soil fertility was enhanced by the addition of
compost, but little influenced by the addition of MAP,
as shown for the year of planting in Table 1. The
addition of compost resulted in higher soil pH and
cation exchange capacity in each of the three seasons
after planting, compared to the plots without compost
(data not shown). Compost increased both soil organic
matter and P, while MAP and urea had no effect.
Compost also increased soil Mg, Ca, and K.

Compost increased tree growth and flowering by
improving soil fertility and tree nutrient status, and
most likely, by increasing soil water holding capacity
and soil aeration. An increase in the water holding
capacity of the soil would have been advantageous in

1998, when the newly planted trees were generating
new roots to replace those lost in transplanting, and in

1999, a season in which little precipitation occurred
before September. Foliar nutrient status was favorably
affected by compost (Figure 2). Compost increased
leaf N and K compared to trees in plots without
compost in all three seasons after planting. Leaf P and
Ca were not affected by compost. There was no
difference between urea and MAP in their effect on
leaf N or K, or leaf P, Ca, or Mg. Compost decreased
leaf Mg in the first season after planting, but had no
effect in the second or third season. The large increase
in soil K following compost incorporation may have
interfered with Ca and Mg uptake, so that even though
soil Ca and Mg were greater, foliar levels were not.
Leaf micronutrients were not affected by any of the
pre-plant treatments.

Pre-plant incorporation of P fertilizer had no effect
on tree growth or flowering in this study. In British
Columbia, P fertilization previously has been shown to

increase flowering when it results in greater leaf P. In
our study the soil level of P was within the optimum
range before treatment, and was increased to above
optimum by compost. Although the level of P in the
soil was increased with compost, there was no increase
in foliar P. These results are consistent with most
previous studies in showing no benefit from P
fertilization for apple.

Conclusions

Pre-plant compost incorporation was more
effective than P fertilization for increasing tree growth
during the establishment years. The practice of adding
P to the planting hole may not be appropriate for
Northeastern sites, particularly those where the soil
test indicates that P is adequate before planting. Soil
incorporation of compost increased tree growth and
flowering into the third year after planting. This was
most likely due to improved N and K status of the trees,
and through improved soil aeration and water-holding
capacity. Our results suggest that trees planted in soil
amended with apple-pomace compost would poten-
tially fill their space more quickly and be able to
support more fruit growth in the first years of cropping.

Ackno H'ledgem en ts

This project was supported in part by a grant from
the New England Tree Fruit Growers Research
Committee. The authors wish to thank Chick Orchards
for supplying the compost, and the technical staff at
Highmoor Farm for their assistance with this research.
Special thanks go to John McCue, Sheri Koller, and
Michelle Handley for maintaining this project during
the transition between project leaders.

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Fruit Notes, Volume 67, Winter, 2002

Development of a Model for Predicting
Flyspeck Risks in Blocks of Apple Trees

Arthur TYittle, Christopher Bergweiler, James Hall, Lisa Reisner, Steven Christie,
Wesley Autio, and Daniel Cooley
University of Massachusetts

For several years, we have been working toward
the elimination of summer fungicide applications in
apple orchards. The positive economic and
environmental impacts of achieving this goal are
considerable. Unfortunately, in the absence of
fungicides, the severity of flyspeck disease, and to a
lesser extent sooty blotch, can be significant. In apple
trees which are not sprayed in the summer, flyspeck
incidence varies dramatically, from barely existing in
some blocks of apple trees to infesting more than half
the fhiit in others.

How do we decide which trees need spraying and
which do not in a given year or month? We know that
the flyspeck fungus needs very high relative humidity
(97-100 %) to develop. By tracking leaf wetness,
rainfall, relative humidity, and temperature we can
estimate when specks will first show up in unsprayed
trees in or near an orchard. We can also estimate when
spray residues will be removed from apple trees by
rain, thanks to studies performed by Dave Rosenberger
at Cornell University's Hudson Valley Laboratory. It
remains a challenge, however, to estimate severity of
symptoms at harvest for a given block of trees.

Certain characteristics of blocks of apple trees,
such as slope, relative altitude in the orchard, and
spacing of rows and alleys are likely to influence air
drainage and relative humidity in the blocks. The size
and openness of tree canopies will also affect the
humidity surrounding an apple. The consensus among
plant pathologists working with apples is that the
inoculum for flyspeck disease overwinters on the waxy
cuticle of alternate host plants like blackberry, oak,
grape, and maple in wooded or shrubby borders near
the apple trees. Within the orchard block, flyspeck
does not colonize apple twigs. Flyspeck that grows on
fruit is removed at harvest or decays over the winter
on drops. The orchard border is home to over 100
species that maintain waxy cuticle suitable for flyspeck

and sooty blotch over a 12-month period on first year
growth.

Many relationships involving the block and the
borders seem worthy of investigation. Number and
size of borders around a block, distance between a block
and its borders, density of alternate host plants in the
borders, and density of the fungus on those hosts might
all have significant impacts on summer diseases in fruit
at harvest. We study these factors and their
relationships to flyspeck disease development in order
to create a predictive model to help growers safely
reduce fungicide inputs.

We reported on the first part of this study in the
Spring 1996 issue of Fruit Notes. This experiment
took place in six orchards over the 1995 and 1996
growing seasons. In each orchard, pairs of similar
blocks of apple trees were chosen. Some orchards
dedicated as many as 13 pairs of blocks to this
experiment. At each orchard, one block received no
fungicide after primary scab season (approximately
June 15), while the other block was managed according
to the grower's preferences using standard first-level
IPM. Flyspeck incidence was recorded weekly by
examining 200 fruit in each block from late-July
through mid-September. For each block, the following
orchard site characteristics were evaluated and
compared statistically to the flyspeck incidence or
severity data: slope of the ground, relative elevation
of the block compared to other blocks in the orchard,
closeness of shrubby or wooded borders to the apple
trees, density of a major alternate host plant in the
borders (blackberry), severity of flyspeck infestation
on those host plants, and density of apple tree canopies.

Table 1 lists the orchard site factors that had the
greatest effects on the flyspeck counts that were done
in the in 2-week period leading up to harvest in 1995
and 1996. Unless otherwise noted, analyses for this
report were performed on data from the blocks which

Fruit Notes, Volume 67, Winter, 2002

Table 1. Characteristics of blocks of apple trees or adjacent wooded or shrubby borders that positively affected the

amount of flyspeck on apples: in

order of

significance.

August 20 through harvest

August 20 through harvest August 29 through harvest

1995

1996 1995, 1996, 1998, and 1999

1. Lack of slope of block

1. Density of flyspeck on 1. Density of flyspeck
brambles in border on border host plants

2. Low relative elevation

2. Lack of slope of block 2. Number of borders

within the orchard

3. Height of apple trees

3. Closeness of apples to
borders

4. Density of brambles in

4. Lack of slope of block

border

5. Closeness of apple

trees to a border

received no summer fungicide. First-level IPM blocks
did not have enough flyspeck to analyze. In 1 995, there
were more flyspeck symptoms in blocks that were
relatively flat than in steep-sloped blocks (r", or amount
of variation explained, was 0.17, or 17%), and the
amount of flyspeck was higher in blocks that were
relatively low in elevation within the orchard (r- =
0. 12). Other factors that had positive but less significant
impacts (r^ < 0.03) were height of apple trees, proximity
of apples to border areas, and density of host-plants in
the borders.

hi 1996, the significant site factors (Table 1) were
density of flyspeck on host-plants in borders (r^ = 0.13),
lack of slope of the block (r^ = 0.05), and height of the
apple trees (r^ = 0.04). The factors which contributed
only marginally to explaining the variability in flyspeck
incidence (r^ < 0.03) were number of borders adjacent
to a block of apple trees and proximity of brambles in
the borders to the apples.

In summary, the site factors that were the most
important during 1995 and 1996 (explained at least
10% of the variability) were slope and relative
elevation in 1995 and density of flyspeck on host-
plants in borders in 1996.

In 1997-1999, a different group of blocks was
evaluated for site factors and flyspeck infection. In
this experiment, two of the key factors were planting
density/tree size and IPM level. A main objective of
the study was to evaluate the effectiveness of the range

of IPM strategies that had been developed using fairly
large semi-dwarf trees on plantings that included dwarf
trees at high densities. Each of eight participating
orchards provided two blocks of low density/large trees,
two blocks of medium density/medium-sized trees, and
two blocks of high density/small trees. The blocks that
had the same planting density were divided into two
groups: half were managed with first-level IPM
strategies and half with "third-level" IPM strategies.
The progression to third-level IPM was marked by the
integration of advance pest-management strategies with
horticultural strategies at the level of the whole orchard.
The third-level blocks, which were seeded with
beneficial mites and were managed with biologically-
based third-level strategies for insects, received reduced
rates or frequencies of fungicide applications, little or
no EBDC fungicide, and only captan or benomyl after
June 15. The first-level blocks were managed with the
growers' choices of materials and frequencies of
application. The blocks within a pair were not
contiguous. They were often at either end of a long
section of 'Mcintosh' or 'Cortland' rows and were
bordered by a wide variety of habitats. Some of the 48
blocks were surrounded by other rows of apple trees,
some by grassy fields, others by dense woods or
shrubby hedgerows.

During each growing season, the blocks and their
surrounding borders were rated for static orchard
factors which had proved significant in the earlier study.

Fruit Notes, Volume 67, Winter, 2002

These included: number of borders potentially
influencing flyspeck development in an orchard block,
distance between the trees and the borders, severity of
flyspeck in alternate host plants in the borders, density
of host plants themselves, foliar density of trees, height
and diameter of tree canopies, slope and relative
elevation of the block with respect to the orchard as a
whole, and planting density of the block (no. trees/
acre). We examined all known host plants (from the
ground to 6 ft. above ground), not just blackberry.
Apples in the adjacent blocks were examined weekly
or bi-weekly from mid-July to harvest.

At the end of each growmg season we looked at
the effect of each of the above-mentioned site factors
(and all factors combmed) on the amount of flyspeck
on the apples, to begin deriving a predictive model for
flyspeck mcidence at harvest. Prelimmary stepwise
regression analyses done separately for each year
suggested the importance of four variables: density
of flyspeck on alternate host plants in ttie borders,
number of borders, distance from apples to border,

and slope of the block. The other site factors did not
explain substantial amounts of the variation in flyspeck
incidence.

Combining data collected from unsprayed control
trees from the years 1995, 1996, 1998, and 1999, we
conducted a preliminary assessment usingg flyspeck
incidence data from various dates. Data from 1997
were not used, because all blocks received summer
fungicide sprays. Dates at or near harvest varied from
year to year primarily due to cultivar and weather
factors. Ultimately, we decided on a range of dates
allowing maximum inclusion of orchards in the data
set. Data from harvest or near-harvest ranged from 29
August to 23 September for the 4 years used in the
analysis.

We concluded the static factor phase of model
building by combining these four independent variables
with the most inclusive range of harvest dates and a
fifth derived variable, inoculum index. Inoculum index
was expressed as the product of amount of flyspeck on
alternate host plants and the density of those plants in

t 60

a.
S-40

20 -

■O

flyspeck incidence=inoculum index+no. of borders+slope

R-=0.27

• •

•

/ * *

•

100

Actual flyspeck incidence (% apples infected) at harvest

Figure 1. Predicted versus actual flyspect at harvest in Massachusetts orchards, 2000.

Fruit Notes, Volume 67, Winter, 2002

orchard borders. The best flyspeck prediction model
included inoculum index, number of borders, and slope.
We applied the model parameters derived here to
flyspeck incidence at 1 3 orchards in 2000 and compared
the resulting predicted values with observed flyspeck
incidence. The best-fit regression for the data
(R^=0.27) is presented in Figure 1. Given the high
"background noise" of variability in this kind of
investigation (different years, orchards, blocks, sizes
of trees, cultivars, prunmg regimens, types of borders,
etc.), we were gratified to see almost 30% of the
variability in flyspeck incidence explained by these
three site factors.

We applied the same model in 2001 to predict
flyspeck in 1 1 of the same orchard blocks used in 2000.
The relationship between model-predicted flyspeck and
actual flyspeck in the apples was not close (only 2%
of the variability was explained). However, 2001 was
very dry during most of the growing season, and 2000
was a very wet year. Weather factors as well as
differences in blocks at the different sites may have
made a bigger difference in a drier year. We plan to
develop a more comprehensive flyspeck model that
combines static orchard factors with dynamic weather
factors such as leaf wetness and rainfall. It would be
useful to adjust for accumulations in moisture during
a growing season. We may find that we need different
models for wet years as opposed to dry years. The
starting point, however, and key factor in rating a block

for flyspeck risk will probably always be a measure of
how much inoculum is in the orchard border areas at
the beginning of the growing season.

This study identifies several factors which can
combine to produce an environment which supports
flyspeck: density of flyspeck on alternate host plants
in borders, number of borders, distance from apples
to border, and slope of the block. Modification of
this environment in a number of ways, such as summer
pruning, clearing-back borders or removing host plants
or inoculum, or using high-density dwarf plantings
could reduce flyspeck pressure considerably. The most
stable management plans will involve several
strategies, such as border management, orchard design,
aggressive pruning, monitoring weather components,
and careful fungicide selection and timing.

A cknowledgem en ts

We are grateful to the growers who participated in
the three phases of this study: Keith Arsenault, Gerry
Bieme, Bill Broderick, Dave Chandler, Dave Cheney,
Aaron and Dana Clark, Tom Clark, Don & Chris
Greene, Tony Lincoln, Wayne Rice, Dave Shearer, Joe
Sincuk, Tim Smith, Mo Tougas, Bob Tuttle, and Steve
Ware & the folks at Davis Farms. This work was also
supported by State/Federal IPM Funds, SAKE Grant
#97 LNE 97-90 (USDA 96-COOP-1-2700), and a
Northeast Regional IPM Competitive grant.

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Fruit Notes, Volume 67, Winter, 2002

Effects of Gibberellin Synthesis
Inhibition on Feeding Injury by
Potato Leafhopper on Apple

Kathleen Leahy, Duane Greene, and Wesley Autio

Department of Plant & Soil Sciences, University of Massachusetts

Overview

Although the gibberellin synthesis inhibitor
Apogee (prohexadione-calcium) was introduced in
apple primarily as a horticultural tool to reduce shoot
length and thereby decrease the amount of necessary
pruning and associated costs, the inhibition of
gibberellin synthesis has also shown beneficial effects
in controlling some important pests of apple. The most
dramatic effect has been seen on the shoot-blight phase
of the bacterial disease fire blight, but some effects
have also been seen on flush-growth-feeding insects
such as green apple aphid and obliquebanded leafroller.
To date, however, no studies have been published on
the effects of Apogee on potato leafhoppers Empoasca
fabae (Harris) (Byers et al., 1997; Paulson and Hull,
1999;Yoderetal., 1999).

Potato leafhoppers are occasional orchard pests in
the mid-Atlantic and Northeast. These insects are not
able to winter in the north. They overwinter in the
southern United States and migrate northward on storm
systems over the course of the spring and early summer.
In apple, they feed in vascular tissue in rapidly-
developing shoot tissue. In mature trees, this injury is
not generally considered serious, although in young
trees it may be necessary to apply control measures
for a moderate to severe infestation. There is, however,
some evidence that potato leafhoppers may play a role
in facilitating the shoot-blight phase of fire blight, by
introducing feeding wounds in susceptible tissue on
which Erwiuia amylovora, the bacterium which causes
fire blight, is growing epiphytically (on leaf surfaces),
allowing the bacteria to invade the leaf and cause
infection (Koehler, 2000; Pfeiffer et al., 1999).

Since potato leafhoppers feed directly on tissue

likely to be affected by gibberellin synthesis inhibition,
we thought that the possibility of suppressing or even
completely controlling these leafhoppers with Apogee
or a similar gibberellin synthesis inhibitor was strong
enough to warrant further study. This work was done
as part of a larger study looking at the interactions of
gibberellin synthesis and potato leafhoppers with fire
blight.

Materials & Methods

A 200-tree section of a block of 15-year-old
Mclntosh/M.7 at Scott Farm in Dummerston, Vermont
was used for the study. A randomized-complete -block
design was used, with ten replications and two trees
per treatment within each replication. Buffer trees were
employed within the row, and a buffer row was
employed between treated rows. Apogee was applied
at the rate and timings recommended for commercial
growers in this area, 12 oz per 100 gallons dilute at
early petal fall (May 12) and a second application at
the same rate when growth would have been expected
to resume, June 1 .

There were two levels of two treatments used in
this experiment: Apogee treated and non-treated, and
potato leafhoppers excluded or permitted. The
insecticide Provado (imidacloprid) was used for
exclusion, at the highly reduced rate of 0.5 oz per 100
gallons dilute recommended by researchers at the
Cornell Hudson Valley Laboratory (Scaffolds
newsletter, June 2001). Provado was applied when
potato leafhoppers began to appear in the orchard, June
22, and was re-applied when numbers appeared to be
resurging, July 20.

Shoot length was measured using a measuring tape

Fruit Notes, Volume 67, Winter, 2002

on five shoots per tree ( 1 shoots per tree for the first
two sample sessions) at 10-day intervals beginning at
petal fall to assess the effectiveness of the Apogee
treatment. Potato leafhopper injury was evaluated with
a spectrophotometer early in the season, but this method
became cumbersome and was eventually supplemented
with a visual rating scale of injury, with being no
visible injury and 5 being severe injury. Because of
the high mobility of potato leafhopper adults, which
were the predominant life stage, we did not succeed in
getting a reliable count of leafhopper numbers per
shoot, hi future studies a field-adapted vacuum cleaner
device may be used for this purpose.

Results & Discussion

Shoot length measurements showed that Apogee
had a highly significant effect on shoot growth (Figure
1), both in the presence and absence of potato
leafhoppers. Potato leafhoppers arrived later than usual

in New England and did not reach high numbers in
any location, leading to a fairly low damage level in
the control. Using the visual rating scale assessment
of leafhopper injury, Apogee and Provado, individually,
had a highly significant effect on reducing leafliopper
injury (Figure 2). Where both materials were used
together, leafhopper injury was singificantly lower than
where either material was used alone. On the last
assessment date, August 15, 200 1 , the average level of
feeding injury where Apogee was used alone was 0.83,
where Provado was used alone was 0.78, and where
both were used together was 0.3 1 . Untreated control
trees showed an injury level of2. 13 for this date. Thus,
there appears to be a substantial benefit to potato
leafhopper control using Apogee either alone or in
combination with insecticide.

The mechanism by which gibberellin inhibition
affects leafhopper feeding is not known and will be
investigated further. The enhanced effect of Apogee
plus insecticide may be due to the reduction in new.

40
35
30 -

§25-

g 20-

-1

15 -

■^■■-V ■ ,

Figur

Provado only No Treatment Apogee only Apogee + Provado

e 1 . The effects of Apogee and Provado on shoot growth of 15-year-old Mclntosh/M.7 trees.

Fruit Notes, Volume 67, Winter, 2002

2.5

0.5

Notrt

Apogee

Provado

Ap + Prov

Figure 2. Potato leatTiopper damage (0-5 scale, with being no injury and 5 being severe injury) on 15-
year-old Mclntosh/M.7 trees as affected by Apogee and Provado.

untreated leaf area where shoot growth is inhibited.
For Apogee alone, it is possible that visual or chemical
cues used by the insects are muted by the treatment, or
it could be that the leafhoppers begin feeding but find
the treated plant unpalatable. Behavioral studies of
potato leafhoppers exposed to Apogee-treated and
nontreated foliage separately and in choice situations
will be conducted to try to elucidate the nature of the
response.

Regardless of the reason, however, the fact that
injury appears to be reduced by the inhibition of
gibberellin synthesis is of significance for growers
needing to control this insect. Specifically, where
Apogee has been used and leafhopper numbers are not
exceptionally high, there may be no need for an
insecticide directed at the leafhoppers. In cases where
a severe fire blight outbreak is in progress and
leafhopper numbers are high, an insecticide may still
be warranted, and should hopefully have greater
efficacy in combination with the Apogee.

More work needs to be done to understand the
nature of the effects of gibberellin synthesis inhibition
on leafhoppers and on to understand the relationship
between potato leafhoppers and fire blight. In addition.

it would be enlightening to repeat the experiment under
higher populations of potato leafhopper and see
whether or not the effects continues to hold true, or
are muted or enhanced under such conditions.

References

Byers, R.E., Yoder, K.S., and Smith, A.H. Jr. 1 997. The
effect of BAS-125W on apple tree growth, fruit quality
and fire blight suppression . HortScience 32:557.

Hildebrand, M., Dickler, E., and Geider, K. 2000.
Occurrence of Erwinia amylovora on insects in a fire
blight orchard. Phytopathology 148:251-256.

Koehler, GW. ed. 2000. 2000-2001 New England Apple
Pest Management Guide.

Maredia, K.M., Whalon, M.E., Gage, S.H., and Kaeb,
M.J. 1998. Observations of first occurrence and
severity of potato leafhopper Empoasca fabae (Harris),
(Homoptera:Cicadellidae) in the North Central and
Eastern United States. Great Lakes Entomologist
31:73-84.

Paulson, G.S. and Hull, L.A. 1999. Influence of Apogee

Fruit Notes, Volume 67, Winter, 2002

on selected apple and pear pests. Proceedings, 75th
Cumberland-Shenandoah Fruit Workers Conference,
Winchester, VA.

Pfeiffer, D.G., Killian, J.C, and Yoder, K.S. 1999.
Clarifying the roles of whiteapple leafhopper and potato
leafhopper (Homoptera:Cicadellidae) in fire blight
transmission in apple. J. Entomol. Soc. 34:314-321.

Plurad, S.B., Goodman, R.N., and Enns, W.R. 1967.
Factors influencing the efficacy of Aphis pomi as a

potential vector for Erwinia amylovora.
Phytopathology 57:1 060- 1063.

Sterner, P.W. and Lightner, G.W. 1992. Maryblyte 4.2:
A predictive program for forecasting fire blight disease
in apple and pear. University of Maryland.

Yoder, K.S., Miller, S.S., and Byers, R.E. 1999.
Suppression of fire blight in apple shoots by
Prohexadione-calcium following experimental and
natural inoculation. HortScience 34:1202-1204.

*%3^ %3^ %JU %Si^
^f% #1^ ^lg% ^j^

Fruit Notes, Volume 67, Winter, 2002

Food Quality Protection Act:
An Organopliosphate Update -
February 2002

Glenn Morin

New England Fruit Consultants, Montague, MA

As the six-year anniversary of the Food Quahty
Protection Act (FQPA) approaches, EPA continues to
focus on the regulation of the organophosphate (OP)
compounds. The protocols for tolerance reassessment
mandated by the FQPA were previously not described,
and the methodology by which they are ultimately
evaluated will be used to review the other classes of
compounds in the future. Therefore, EPA has
proceeded cautiously, opened the procedure to public
review, and provided for stakeholder input at each step
of the six-phase review process.

This process allows for the development of risk-
management recommendations by EPA and, when
combined with the previously ongoing re -registration
process, ultimately results in the publication of a Re-
registration Eligibility Document (RED). The RED
finalizes the regulatory process and outlines the
conditions under which continued use of the product
may occur.

In the case of the organophosphates, which must
still undergo a cumulative risk assessment as a class of
compounds (see related article in this issue oi Fruit
Notes), EPA has issued Interim Re-registration
Documents (IRED). These documents may include
risk reduction measures and other label changes that
will take effect prior to the final RED, which will be
released once the cumulative risks of the OP's have
been considered fully. It is anticipated that EPA will
conclude its review of the organophosphates sometime
later this year.

All seven of the active ingredients most commonly
used in commercial tree fruit production are currently
in the final phase of the individual risk assessment
process. The following is a summary of EPA's findings
and actions as of February 18, 2002.

Azinphos methyl - Initial label amendments for
azinphos methyl (Guthion) that effected tree fruit

production were voluntarily put in place by the
registrants prior to the 1999 growing season primarily
in response to EPA's concerns regarding dietary risk to
children. Further discussions among the registrants,
EPA, and the stakeholder community directed at
reducing the risk to agricultural workers and the
environment have continued since the release of the
revised risk assessment in the summer of 2000.

The results of these discussions were made
available for public comment on November 28, 2001
in the form of an IRED. This document proposes the
cancellation of 28 crop uses (including nectarines), a
four-year phase out of seven crop uses (including
peaches) and a 4-year, time-limited registration for
eight crop uses (including apples, pears, and sweet
cherries). Some highlights of the proposed label
changes concerning apple production are as follows:

limit of 3.5 lbs ai/acre per season east of the
Mississippi, 4.0 lbs ai/acre west of the Mississippi;

increase REI to 14 days for all activities;

require enclosed cabs or maximum personal
protective equipment (PPE) for applicators;

require closed mixing systems or water soluble
bags and closed transfer systems for mixing/
loading;

add 25-foot buffer zones for permanent surface
water;

add spray drift language; and

prohibit pick-your-own (PYO) usage or restrict
application to early season or establish 30 day pre
harvest interval (PHI) for PYO operations.

The public comment period for this document ended
on January 28, 2002. Questions concerning which label
amendments will ultimately be required, the timeframe

Fruit Notes, Volume 67, Winter, 2002

for implementing these changes, and the disposition
of product already in the distribution system remain
unanswered at this time. However, the registrant is
optimistic that no label changes will take effect for the
upcoming growing season.

Phosmet - EPA released its revised risk assessment
for phosmet (Imidan) at a technical briefing in February
2000. This document indicated that dietary risk was
not an issue for this compound and that exposure to
handlers could be managed satisfactorily with increased
PPE and engineering controls.

An IRED for phosmet was made public
simultaneously with that of azinphos methyl (AZM)
in the fall of 2001. Similar to AZM, EPA's present
concerns center around risks to agricultural workers
and ecological risks. Proposed agricultural use changes
that affect tree-fruit producers fall into two categories:
1) continued registration with new labeling
requirements for 33 crop uses (including sweet and
tart cherries) and 2) a 5 -year, time-limited registration
for nine crop uses (including apples, apricots,
nectarines, peaches, pears, and plum/prunes). Some
highlights of the proposed label changes concerning
apple production are as follows:

increase REI to 3 days;

require enclosed cabs or maximum PPE for
applicators;

require water soluble bags and closed transfer
systems;

add spray drift language; and

prohibit application during bloom period.

The registrant has reached an agreement with EPA that
allows for all product currently in the distribution
system or in possession at the farm level to be used
under the current label until all inventories have been
depleted. All product sold by the registrant after June
30, 2002 will reflect the changes mandated by the
IRED.

Diazinon - In December of 2000, EPA released its
revised risk assessment for this active ingredient. EPA
concluded this active ingredient posed significant risk
to birdlife as currently labeled and was a common
contaminant of surface water. Risk mitigation measures
center largely on phasing out, over the next three years,
most residential uses of products containing diazinon
(Spectracide) whether applied for structural or lawn-

care purposes.

Although agricultural uses contributed little in this
regard, risk to agricultural workers who apply these
products or harvest treated crops was of concern. When
the IRED IS made public, it is expected that EPA will
proposed the cancellation of about 30% of the current
agricultural uses and require "Restricted Use"
classification for the remaining uses so that applications
will be limited to trained, certified applicators.
Discussions with the registrant and other stakeholders
are ongoing.

Malathion - The revised risk assessment for
malathion was presented at a technical briefing in
November, 2000. Malathion is a lower priority for
regulatory action since it is used on less than 10% of
the nation's apple acreage. EPA's analysis suggested
that dietary risk, drinking water risk, and ecological
risks were of little or no concern. However, risks to
mixers/loaders/applicators and risk to workers entering
treated areas for post-application activities were cited.
Although the IRED has yet to be posted, additional
personal protective equipment (PPE) for handlers and
longer restricted entry intervals (up to 6 days) are
expected to be included.

Methyl parathion (Penncap-M) - EPA has
previously announced acceptance of the registrant's
voluntary cancellation of many of the significant food
crop uses for this material including apples, peaches,
pears, nectarines, cherries, and plums in order to
address the Agency's concern of dietary risk to children.

Chlorpyrifos (Lorsban) - EPA severely restricted
the use of this material on apples, tomatoes, and grapes
shortly after the release of the revised risk assessment
in August of 2000, again, due to dietary-risk issues.
Post-bloom use on apples has been prohibited since
December 31, 2000. The IRED was published in the
Federal Register on November 14, 2001 for which the
public comment period ended in mid January.

The first step of the review process mandated by
the FQPA is drawing to a close for the organphosphate
compounds. EPA will soon conclude the evaluation of
these active ingredients on an individual basis. This
initial evaluation contains a risk assessment that
considers all potential routes of exposure including
dietary, drinking water, residential, and occupational
means.

The second phase, cumulative assessment of the

Fruit Notes, Volume 67, 'Winter, 2002

risk posed by OPs as a class of compounds, has already
begun. EPA and USDA convened an advisory panel,
the Committee to Advise on Reassessment and
Transition (CARAT), to assist in this process in
February 2000. Dr. Robin Spitko of New England Fruit

Consultants is a member of this committee and has
been monitoring the proceedings for the tree-fruit
industry in the Northeast.

Further information can be found at http://
vvww.epa.gov/pesticides.

*^1^ ^If ^I^ ^t^
^{^ ^J^ ^J^ ^1%

Fruit Notes, Volume 67, Winter, 2002

Food Quality Protection Act:
Cumulative Risk Assessment for the
Organophosphate Pesticides

Roberta Spitko

New England Fruit Consultants, Montague, MA

The primary focus of EPA's Office of Pesticide
Programs activities over the past year has been the
development of a cumulative risk assessment for the
organophosphate pesticides (OPCRA). This risk
assessment is the most complicated, comprehensive
attempt to measure cumulative exposure to a particular
group of pesticides that has ever been undertaken.

The OPCRA final document exceeds 5,000 pages
in length. The methodologies developed by EPA to
collect and analyze the data are extremely sophisticated
and complex and have also been a source of much
controversy in the agricultural stakeholder community.
EPA is relying heavily on the advice of the FIFRA
Science Advisory Panel, a panel of expert scientists,
especially those in statistical modeling and toxicology,
for validation of the methods used. These
methodologies have been developed over the past 5
years, and represent a significant advance in EPA's
abilities to evaluate pesticides in a comprehensive
manner. It must be emphasized that the current risk
assessment, which was released in January 2002 for
public and scientific comment, is a preliminary
assessment. The Agency expects a large number of
comments to be submitted until the comment period
closes on March 8, 2002.

A cumulative risk assessment is the process of
combining exposure (the amount of pesticide to which
an individual is exposed) and hazard (the health effects
a pesticide could cause) from all substances that share
a common mechanism of toxicity. In assessing hazard
associated with the organophosphate pesticides, EPA
analyzed their common method of toxicity, inhibition
of acetylcholinesterase, as the means for assessing risk.

The goal of the organophosphate cumulative risk
assessment (OPCRA) is to measure the probability of
exposure to more than one organophosphate pesticide
and to assess the effects of this combined exposure.
The assessment incorporates possible OP exposures

from structural, recreational, and drinking water, as
well as from OP residues in consumed food. Each
component of the risk assessment uses the best
available data: data from surveys of what people eat
and drink, of their activities involving pesticide use
around the home and workplace, and monitoring studies
of pesticide residues in these environments.

A comprehensive assessment of the
organophosphates may raise concerns with growers
about further restnctions on materials available for crop
production. However, the results of the OPCRA may
not have much effect on current OP use. Much work
has been done previously on the individual
organophosphates to reduce their risks as they go
through the FQPA-mandated tolerance reassessment
process.

The risks for the individual OPs will be factored
into the cumulative equation at these lower levels.
Most structural and home-garden uses have already
been cancelled or significantly curtailed. Routes of
exposure through drinking water have already been
determined to be negligible.

It must be noted again that the recently released
OP cumulative risk assessment is preliminary. EPA is
continuing to seek input from the scientific community
and stakeholders and is aware that revisions and
refinements will be necessary. Determining cumulative
exposure is a huge task, and this is the first time EPA
has attempted develop a comprehensive profile of
human exposure to a group of chemicals with common
modes of toxicity. It will be an evolving process that
will take years to refine.

Following the comment period closure of March
8, 2002, EPA will consider submitted comments and
plans to issue a revised risk assessment in the summer
of2002.

The preliminary OPCRA may be accessed at
www.epa.gov/pesticides/cumulative.

*%X^ %1> %i^ %9^
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Fruit Notes, Volume 67, Winter, 2002

Commercial-orchard Evaluation of Traps
for Monitoring Plum Curculio:
2001 Results

Ronald Prokopy, Brad Chandler, and Jaime Pinero
Department of Entomology, University of Massachusetts

In the 2000 issue oi Fruit Notes, we reported our
year 2000 tests in which we compared odor-baited with
unbaited traps of three types (pyramid, cyHnder, and
Circle) for monitoring plum curculios (PC's) m
commercial apple orchards. Results suggested that traps
baited with grandisoic acid alone (= synthetic male sex
pheromone) captured no more PC's than unbaited traps.
However, when grandisoic acid was combined with
any one of three different synthetic host fruit volatiles
(benzaldehyde, ethyl isovalerate, or limonene),
captures by baited traps were about twice as great as
captures by unbaited traps. Addition of the synthetic
fruit volatiles decanal, hexyl acetate, and trans-2-
hexenal to grandisoic acid did not enhance captures.

Here, we report results of 2001 studies in
commercial orchards in which we further evaluated the
best odor combinations found in 2000, again in
association with pyramid, cylinder, and Circle traps.

Materials & Methods

The three types of traps were: (a) black pyramid
traps (24 inches wide at base x 48 inches tall) placed
on the ground next to apple tree trunks, (b) black
cylinder traps (3 inches diameter x 1 2 inches tall) fixed
vertically onto horizontal branches within tree
canopies, and (c) aluminum-screen "Circle" traps
(developed by a grower named Edmund Circle in
Alabama for pecan weevil), wrapped tightly around
the base of tree trunks so as to completely encircle the
trunk and afford maximum chance of intercepting
adults walking upward.

The three synthetic components of host fruit odor
were benzaldehyde, ethyl isovalerate, and limonene.
Each was purchased from Aldrich Chemical Company
and was deployed in small polyethylene vials that fit
into the screen-funnel top of a boll weevil trap that

capped each pyramid, cylinder, or Circle trap. The
release rate of each compound was about 10 milligrams
per day (achieved by adjusting the type or number of
vials per trap according to compound volatility). Each
baited trap also contained a plastic dispenser of
grandisoic acid (obtained from Great Lakes IPM)
designed to release about 1 milligram of pheromone
per day.

Traps were deployed in four plots of apple trees in
each of 12 commercial orchards. Each plot consisted
of seven perimeter trees. Each tree (save one) contained
one baited or one unbaited trap of the above three types.
All three baited traps in a plot received the same odor.
In each orchard, each of three plots received a synthetic
fruit volatile in combination with grandisoic acid. The
fourth plot received grandisoic acid alone.

All traps were deployed at pink (May 2-4). Traps
were examined for captured PC's beginning at petal
fall (May 14-16) and every 3-4 days thereafter for 7
weeks until June 28-30. Vials of benzaldehyde and
dispensers of grandisoic acid were renewed on May
28-30 (about mid-way through the experiment). At each
trap examination, 10 fruit on each of the six trapped
trees per plot (= row 1 trees) and five fruit on each of
six corresponding but untrapped trees on interior rows
3,5, and 7 were examined for PC oviposition scars. In
all, 102,800 fruit were examined for PC injury. All plots
received two or three sprays of azinphosmethyl or
phosmet to control PC.

Results

Figure 1 shows that across the entire PC season,
Circle traps baited with benzaldehyde plus grandisoic
acid (GA) captured numerically more PC's than any
other type of baited or unbaited trap, although not
significantly more than unbaited Circle traps in the

Fruit Notes, Volume 67, Winter, 2002

2-5 1

I
i 2

L
I

: 1-5
; 1

a I

BEN+GA

IB baited
D unbajted

BC BC

2.5 -

EIV-KJA

. ■ baited
D unbailed

1 2 •

^_ AB

= 1-

^ 0.5 -

■

0.5

pyramid cylinder

LIM+GA

Circle

e baited
D unbailed

pyramid

cylinder

Circle

AB AB

•»H"-

2.5 •

@ baited
D unbailed

2 ■

1.5 ■

^■1

1 ■

HH BC

OS ■

n ■

«W

pyramid

cylinder

TRAP TYPE

Circle

pyrannid

cylinder
TRAP TYPE

Circle

Figure 1. Mean number of PC's captured by each type of odor-baited and unbaited trap placed on
perimeter-row trees. Among all bars in this figure, those superscribed by the same letter are not
significantly different from one-another at odds of 19 to 1 .

1 -

0.8 -
0.6 ■
0.4
0.2

BEN+GA

■ baited
D unbaited

I -\
0.8
0.6
0.4
0.2

pyramid cylinder

LIM+GA

Circle

■ baited
D unbaited

1 1
0.8
0.6
0.4
0.2

EIV+GA

@ baited
D unbaited

pyramid

0.8
0.6
0.4
0.2 ■

cylinder

Circle

B baited

D unbaited

BWP

|V*^J_

pyramid

cylinder
TRAP TYPE

Circle

pyramid

cylinder
TRAP TYPE

Circle

Figure 2. For each trap type, degree of correlation between total amount of PC captures on perimeter-
row traps and percent sampled PC injury to fruit on penmeter-row trees in plots having that odor. The
higher the R^ value, the greater the extent of the correlation. An asterisk (*) indicates a statistically
significant correlation at odds of 19 to 1.

Fruit Notes, Volume 67, Winter, 2002

0.8
0.6
0.4
0.2

BEN+GA

■ baited
D unbaited

1 -l

EIV+GA

■ baited
D unbaited

0.8 -

0.6 -

0.4 -

0.2 -

■H 1

^=r^ .

pyramid

cylinder

LIM + GA

Circle

@ bailed
D unbailed

pyramid

cylinder
TRAP TYPE

Circle

1
0.8
0.6
0.4
0.2

cylinder

Circle

@ baited
□ unbailed

J I

pyramid

cylinder
TRAP TYPE

Circle

Figure 3. For each trap type, degree of correlation between phenology (time during the season) of PC
captures on perimeter-row traps and phenology of mjury to fruit on perimeter-row trees m plots havmg
that odor. The higher the R^ value, the greater the extent of the correlation. There were no statistically
significant positive correlations.

same plots, or Circle traps baited with ethyl isovalerate
plus GA, limonene plus GA, or GA alone. For each
type of odor bait, pyramid and cylinder traps captured
numerically fewer PC's than Circle traps.

Figure 2 shows, for each odor and trap type, the
degree of correlation between the total (season-long)
amount of PC captures and the percent sampled
perimeter-row fruit injured by PC's in plots having that
odor and trap type. A significant positive correlation
would indicate that orchards which showed
comparatively many captures for a given odor and trap
type also showed a comparatively large amount of PC
injury, whereas orchards which showed comparatively
few captures also showed a comparatively small
amount of PC injury. Among all odors and trap types.
Circle traps baited with benzaldehyde plus GA showed
the highest degree of positive correlation (0.75)
between trap captures and injury. What this means is
that after the PC season has ended, one can look back
and say with high confidence that the extent of PC
captures by Circle traps baited with benzaldehyde plus
GA reflected quite well the extent of PC injury that
occurred on trapped and other trees in the same plot.

Figure 3 shows, for each odor and trap type, the

degree of correlation between the phenology (time of
season) of PC captures and the phenology of PC injury
to perimeter-row fruit in plots having that odor and
trap type. A significant positive correlation would
indicate that a sampling period during which
comparatively many trap captures occurred also was a
sampling penod in which a comparatively large amount
of injury was initiated, whereas a sampling period
during which comparatively few (or no) trap captures
occurred was a sampling period in which comparatively
little (or no) fruit injury was initiated. Among all odor
and trap types, no trap showed a significant positive
correlation between phenology of captures and
phenology of injury. In fact, the highest degree of
positive correlation for any trap type was only 0.20,
and the correlation for Circle traps baited with
benzaldehyde plus GA was a mere 0.01. What this
means is that during the PC season, one could not have
any confidence whatsoever that the extent of PC
captures during any particular 3- to 4-day period
reflected the amount of PC injury that was initiated
during that period, even for the best-performing trap.
A deeper look into the phenology of captures by
Circle traps baited with benzaldehyde plus GA and the

Fruit Notes, Volume 67, Winter, 2002

1.2 1

r ^

1 -

\ '*

- 5

MEAN No.

0.8 -

\ - -•- - INJURY

- 4

MEAN %

PCs
TRAPPED

0.6 -

\ *

. 3 FRUIT
INJURY

0.4-

Vii^---^-^'*'"^---^^ -

- 2

0.2 -

A .

* *
*

- 1

U n

r U

PK-PF 0-2 WK AFTER 2-4 WK AFTER 4-6 WK AFTER

PF PF PF

Figure 4. For Circle traps baited with benzaldehyde plus GA, a graphic display of PC captures and |

amount of PC

injury to fruit during each of four 2-week periods from pink (PK) to 6 weeks after petal

fall (PF).

160

■ Gab, Fuji, Jonagokd
D Mcintosh, Empire

■ Gala, Fuji, Jonagokd
n Mcintosh, Empire

TRAP CAPTURES

FRUIT INJURY

Figure 5. Total captures of PC's on perimeter-row traps and PC injury to perimeter-row fruit in six
blocks of apple trees comprised of Gala, Fuji, or Jonagold as perimeter-row cultivars versus six blocks
comprised of Mcintosh or Empire as perimeter-row cultivars.

phenology of PC injury is helpful in understanding the
lack of relationship between these two entities. As
shown in Figure 4, PC captures were greatest during
the period of pink to petal fall but were low during
each 2-week period thereafter. Conversely, PC injury
to fruit was low (about 1 .5%) during the first 2 weeks
after petal fall, but increased in essentially a linear
fashion until 4 to 6 weeks after petal fall, when it
reached about 5.3%. Thus, the trends depicted in Figure

4 show clearly that the steady rise in PC fruit injury on
perimeter-row trees from petal fall to 6 weeks thereafter
was not accompanied by a rise in PC captures by
perimeter-row Circle traps baited with benzaldehyde
plus GA, accounting for the lack of correlation between
these variables.

Figure 5 shows that PC captures by all perimeter-
row traps combined and PC injury to perimeter-row
fruit were about 60% and 140% greater, respectively,

Fruit Notes, Volume 67, Winter, 2002

140 1
120-
100

■ woods
D hedge
Dopen

TRAP CAPTURES

.2, *

= 9

5 1

■ woods
D hedge

4 •
1 .

Dopen

2 ■

1 -
■

FRUIT INJURY

Figure 6. Total captures of PC's on perimeter-row traps and PC injury to perimeter-row fruit in blocks
of apple trees whose front rows bordered woods, hedgerow, or open field (four blocks of each type).

in blocks having Gala, Jonagold, or Fuji as perimeter-
row cultivars, compared with blocks having Mcfritosh
or Empire as perimeter-row cultivars. The average
number of insecticide sprays applied against PC was
the same in each case (2.7).

Figure 6 shows that PC captures by all perimeter-
row traps combined were greatest for blocks bordered
by woods, intermediate for blocks bordered by

hedgerows, and least for blocks bordered by open field.
However, PC injury to perimeter-row fruit was greatest
for blocks bordered by open field. The average number
of insecticide sprays applied against PC was about the
same in each case (2.8, 2.8, and 2.5, respecfively).

Figure 7 shows that season-long PC injury to fruit
on perimeter-row trees (row 1) averaged about 12 times
greater than on trees of interior rows 3, 5, or 7.

ROW

Figure 7. Mean percent PC-injured fruit on perimeter-row trapped frees(row 1) compared with injury
on non-trapped trees of interior rows 3, 5, and 7.

Fruit Notes, Volume 67, Winter, 2002

Conclusions

Circle traps baited with benzaldehyde plus GA,
when positioned so as to completely surround trunks
of perimeter-row apple trees, captured numerically
more PC's than any other trap type and afforded a strong
positive correlation between total amount of trap
captures and total amount of PC injury to perimeter-
row fruit. The year 2001 was the first year we used
Circle traps in this position on a tree (formerly they
were placed on lower limbs near the trunk and provided
a weaker correlation between total captures and total
injury). The strong correlation obtained in 2001
suggests that tree-trunk Circle traps baited with
benzaldehyde plus GA, if distributed along perimeter-
row apple trees, can be an excellent indicator of "hot
spots" requiring special attention for controlling PC
as well as "cool spots" requiring lesser attention.

Unfortunately, no trap type showed even a
moderate positive relationship between the time of
occurrence of PC captures and the time of occurrence
of PC injury to fruit. As depicted in Figure 4, even for
our best trap type (tree-trunk Circle traps baited with
benzaldehyde plus GA), captures fell off dramatically
soon after petal fall, whereas fruit injury rose steadily.
Thus, even for this best trap, the data obtained in 200 1
indicate that low trap captures after petal fall cannot
be relied upon as indicative of the lack of need to spray
against PC.

As revealed by other studies that we conducted in
2001 , there are at least three reasons why all three types
of traps used here may fail to capture representative
numbers of PC's active in canopies of commercial
orchard trees after petal fall. First, organophosphate
insecticide spray droplets falling on traps can be
repellent to PC's for 10 days or more after application.
Such droplets can also be repellent when on tree limbs
and branches, but repellency apparently is substantially
overcome by positive chemical stimuli inherent to
surfaces of limbs and branches. Such positive stimuli
are lacking on surfaces of current traps. Second, at
temperatures greater than about 70°F, especially when
accompanied by sun, PC's tend to fly directly into tree
canopies, thereby bypassing Circle and pyramid traps
associated with tree trunks. Temperatures tend to be

higher than 70°F after petal fall. Third, the release rate
of benzaldehyde from vials placed inside of trap tops
( 1 milligrams per day) is sufficient to attract PC's from
a distance, but may be repellent at close range. As tree
fruit grow and themselves release increasing amounts
of benzaldehyde and other attractants, there may be an
increasing tendency for attractive volatiles from the
fruit to outcompete attractive volatiles placed in traps.
Our attempts to increase the amount of benzaldehyde
used in association with traps, so as to be more
competitive with fruit volatiles, have been accompanied
by a decrease (rather than an increase) in PC captures
owing to repellency. Together, these three shortcomings
may limit the usefulness of Circle, pyramid, and
cylinder traps placed at or within canopies of
commercial-orchard trees for monitoring the extent of
threat by PC's after petal fall.

Both cultivar composition of perimeter-row trees
and border area composition had an influence on extent
of trap captures and fruit injury by PC. As in 2000,
perimeter-row trees of Gala, Jonagold, or Fuji
experienced considerably more PC pressure than
perimeter-row trees of Mcintosh or Empire, even
though there was no difference in frequency of
insecticide applications. Also, as in 2000, trap captures
were greater in blocks bordering woods than in blocks
bordering hedgerows or open field. Finally, PC injury
to fruit on trees that received traps was far greater than
PC injury to fruit on interior trees, suggesting that
attractive odor placed on perimeter-row trees acts to
concentrate PC's there and reduce penetration into the
orchard interior.

Ackno wledgm ents.

We are grateful to the following growers for
participating in this study: Keith Arsenault, Gerry
Beime, Bill Broderick, Dave Chandler, Tom Clark, Don
Green, Tony Lincoln, Joe Sincuk, Mo Tougas, and
Steve Ware. This work was supported by Massachusetts
State Integrated Pest Management Funds, Northeast
Regional Competitive Integrated Pest Management
Funds, Northeast Regional Sustainable Agricultural
Research and Education Funds, and the New England
Tree Fruit Growers Research Committee.

*%1# %i^ %3^ ^f^
^j^ ^j|% ^1^ ^j^

Fruit Notes, Volume 67, Winter, 2002

An Odor-baited "Trap-tree" Approach to
Monitoring Plum Curculio

Ronald Prokopy

Department of Entomology, University of Massachusetts

As described in the preceding article, there are
shortcomings associated with placement of plum
curculio (PC) monitoring traps in commercial orchards
for purposes of determining when a spray is needed to
protect fruit against PC damage. Shortcomings are
particularly evident during the middle and latter part
of the PC season, when trap captures remain low
irrespective of trap type or attractive odor, but damage
increases. One of the principal shortcomings involves
need for baiting traps with an increasing amount of
synthetic attractive fruit odor as the PC season
progresses in order that odor might compete effectively
with the increasing amount of attractive odor emitted
by developing fruit in the tree canopy. When used in
association with traps, increasing amounts of synthetic

fruit odor become repellent at close range.

One possible solution to this dilemma could be to
create a "trap tree" where the tree canopy itself is baited
with a high amount of attractive fruit odor. Rather than
using amounts of PC's captured by traps as a potential
but indirect indicator of level of PC egglaying activity,
one would use amount of freshly injured fruit on the
trap tree as a direct indicator. A few such trap trees per
orchard could provide valuable information on sudden
rises in PC damage and hence on the need to apply a
protective spray. Placement of attractive odor directly
on tree branches would eliminate problems of close-
range repellency associated with placement of odor on
or in traps.

In 200 1 , 1 conducted a preliminary trial of this new

lij

0.
U. LU

6 -I

5 -

4 -

3 -

2 -

■ BAITED TREES
dUNBAITED TREES

WEEKS AFTER PETAL FALL

Figure 1. Amount of fruit injured by plum curculio on baited perimeter-row trap trees
and on unbaited trees midway between trap trees.

Fruit Notes, Volume 67, Winter, 2002

approach to monitoring PC's in a small block of apple
trees in Clarkdale Fruit Farm in Deerfield.

Materials & Methods

The entire study was conducted along a 125-yard
section of perimeter-row apple trees bordered by
woods. The trees were mixed cultivars on M.26
rootstock. On May 2 (mid-pmk), every sixth tree was
baited with two dispensers of grandisoic acid (each
releasing about 1 mg per day) and eight dispensers of
benzaldehyde (each releasing about 10 mg per day).
All dispensers were replaced with fresh ones on May
30.

One week after petal fall and weekly for 4 more
weeks, 20 fruit were examined on each of the five trap
trees and on each of four unbaited trees midway
between trap trees. Fruit were counted as injured if a
PC egglaying scar was evident. The trees received two
applications of insecticide to control PC without use
of fi-uit sampling information in guiding timing of spray.

Results

Figure 1 shows that fruit injury on the baited-trees
averaged about eight times greater than on unbaited
trees for samples taken at weeks 1 and 2 after petal fall
and about five times greater than on unbaited trees for

samples taken at weeks 3, 4, and 5 after petal fall. As
the PC season progressed, some of the injured fi-uit on
both types of trees fell to the ground, but total injury
remained the same or increased owing to appearance
of fresh injury.

Conclusions

The results of this preliminary test are very
encouraging in that baiting perimeter-row trees with
attractive odor acted to concentrate immigrating PC's
on the "trap trees." Further research is necessary to
optimize the composition and amount of attractive odor
before this approach can be recommended for
widespread use in monitoring PC's in commercial
orchards. Conceivably, a few odor-baited "trap trees"
along perimeter rows of an orchard might serve not
only as focal trees for monitoring extent of fresh injury
caused by PC but, if sufficiently attractive, might also
serve to aggregate enough of the immigrating PC
population to permit spraying only trap trees, allowing
other trees to remain unsprayed against PC.

Ackno wledgm ents

Thanks to Tom Clark for cooperating in this
experiment, and Jaime Pifiero for preparing the figure.

*%S^ %i^ %3^ %ju
^j^ ^f% ^g% #j^

Fruit Notes, Volume 67, Winter, 2002

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Fruit Notes, Volume 67, Winter, 2002

Fruit Notes

University of Massachusetts
frOH Department of Plant & Soil Sciences
ilOteS 205 Bowditch Hall

tliyU Amherst, MA 01003

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Table of Contents

Flyspeck Disease Management: Comparison of Flint versus Captan m Every-row versus Perimeter-row Sprays

A. Baj, A. Tuttle, and D. Cooley 1

Thmnmg Mcintosh Apple Trees With Blossom Thinners, With and Without Post-bloom NAA:

A Report to the New England Tree Fruit Growers Research Committee

J. Schupp and D. Greene 9

Evaluation of New Apple Varieties, 1998 Observations:

A Report to the New England Tree Fruit Growers Research Committee

D. Greene 13

Influence of Odor-bait, Cultivar Type, and Adjacent Habitat Composition on Performance of Perimeter Traps

for Controlling Apple Maggot Flies

S. Hoffmann, R. Mittenthal, B. Chandler, G. Lafleur, S. Wright, P. Appleton, M. Becker, 5. Dynok, and R. Prokopy .

.20

Editors:

Wesley R. Autio
William J. Bramlage

Publication Information:

Fruit Notes (ISSN 0427-6906) is pub-
lished each January, April, July, and
October by the University of Massachu-
setts in cooperation with the other New
England state universities.

The costs of subscriptions to Fruit
Notes are $10.00 for United States ad-
dresses and $12.00 for foreign ad-
dresses. Each one-year subscription
begins January 1 and ends December
31. Some back issues are available for $3.00 (United States addresses)
and $3.50 (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

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 UMass Extension, Stephen Demski, Director, m furtherance of the acts of May 8 and June 30,
1914. UMass Extension offers equal opportunity in programs and employrtienl.

Flyspeck Disease Management:
Comparison of Flint versus Captan
in Every-row versus Perimeter-row
Sprays

Andrew Baj, Arthur Tuttle, and Dan Cooley
Department of Microbiology, University of Massachusetts

In 2001, we began a 4-year study to evaluate new This study seeks to determine if the strategy of

pesticides (in this case, the environmentally benign spraying only the two perimeter-rows in blocks of apple

fungicide, Flint, for flyspeck disease) for apple pests trees during the summer months is adequate to man-

and a pesticide-reduction strategy (spraying only the age the disease at six orchards in Massachusetts. If

two rows of apple trees on the perimeter of the block), proven efficacious, this strategy could help offset high

Flyspeck (FS) disease, like apple maggot fly and plum costs of new materials and help reduce the pesticide

curculio, survives the winter on or in plant material in load on the environment,
the wooded or hedgerow borders and often infests an

orchard block with a significant disease gradient which Materials & Methods
decreases with distance into the block (Cooley, 1996).

The 2001 insect pest management results of the study The experiment took place in blocks of apple trees

were reported in Fruit Notes 66:14-18. at orchards in six Massachusetts towns: Harvard, Ber-

xxxxxxxxxxxxxx xxxxxxxxxxxxxx xxxx xxxxxxxxxxxxxx

xxxxxxxxxxxxx xxxxxxxxx xxxxxxxxxxxxxx xxxxxxx

xxxx xxxxxxxxxxxxxx xxxxxxxxxxxxxx xxxxxxxxxxxxxx

xxxxxxxxxxxxx xxxxx xxxxxxxxxxxxx xxxxxxxxxxxxx

Border area Border area Border area Border area

Flint (2.0 oz./acre) Captan 80 (2.5 Ib./acre) Flint (2.0 oz./acre) Captan 80 (2.5 Ib./acre)

4- + + + -1^ + + + -H -I- -I- 4- -I- -I- -I- + -I- + + + + + + + -I- + + + -I- -I- -I- -I- -I- -t- -I- -I-

+ + + + + + + + + + + + + + + -I- 4--I- -I--I- + + + + + + + + + + + + + + + +

+ + + + + + + -(-+ + + + + + + + + +

-I- + -1- -t- -I- + -t- + + -I- + + -(- + + -I- -1- -H

-I- -I- -I- -I- -I- -I- -I- -I- -I- + + + + + -1- 4- + +

-I- + -I- -I- -I- -I- -(- -I- -I- + + + + + + + + +

-I- -I- -I- + -I- 4- + + -I- + + + + + + + + +

Key: + = sprayed tree, — = unsprayed tree, X = trees, shrubs, and vines

Figure 1 . An example of a perimeter-row spray block with fungicide rates in six Massachusetts apple
orchards, 2001.

Fruit Notes, Volume 67, Spring, 2002

Key: Each block below represents a block of apple trees 7 rows deep by approx. 35 trees wide. Cardinal
directions are noted with a capital letter. Principal border is shown at top of block. Host density ratings
ranged from 1 (none to very few scattered) to 4 (continous deep patches of host plants). Flyspeck (FS)
density ratings range from (none) to 3 (high).

Berlin Site

Harvard Site

W Woods

Host den. 4

FS den. 2

S Woods

N Woods

Host den. 4

Host den. 3.5

FS den. 2

FS den. 1

Hawley Site

E Woods

Host den. 4
FS den. (ns)

S Woods
Host den. 4
FS den. (ns)

Warren Site

W Woods Host den. 3.5
FS den. 1

S Hedgerow Host den. 2

FS den. (ns)

W Hedgerow

Host den. 3
FS den. 1

N. Brookfield Site

N Woods

Host den. 3.5
FS den. 1

W Hedgerow
Host den. 2.5
FS den. 1

Shelburne Site

No Borders within 1 00m

Figure 2. Evaluation of alternate host density and flyspeck (FS) density in border area habitats at
six apple orchards in Massachusetts, 2001 .

Fruit Notes, Volume 67, Spring, 2002

Table 1 . Fungicide application schedule for 6 orchards

in Massachusetts, 2001.

Site

Harvard

23-May

31 -May

18-Jul

08-Aug

Berlin

23-May

31 -May

13-Jun

18-Jul

08-Aug

Warren

25-May

02-Jun

16-Jun

19-Jul

10-Aug

N. Brooktleld

25-May

02-Jun

24-Jun

19-Jul

10-Aug

Shelbume

24-May

01-Jun

18-Jul

09-Aug

Hawley

10-Jun

18-Jul

09-Aug

* Bold-face font indicates full cover spra>

; otherwise

2 row vs.

7 row spray

applied.

lin, Warren, North Brookfield, Shelbume, and Hawley.
Cultivars within the blocks were primarily mid-to-late
season, with planting densities ranging from 100 to
1000 trees per acre. The minimum block size was seven
rows deep by 28 trees long (Figure 1). Rows of trees
were divided into four sections, by colored flagging,
to correspond with the four separate post-petal-fall
pesticide treatments. There were two treatments us-
ing new, environmentally friendly materials (the fun-
gicide, Flint, and the insecticide, Avaunt) and two treat-
ments using conventional materials (the fungicide, cap-
tan, and the insecticide, Guthion). For each of these
treatments, there was a two-row perimeter-spray plot
and a full seven-row spray plot.

During the early season (up through petal-fall) the
growers applied fungicides of their choice. Petal-fall
occurred in mid-May at five of the six sites, with the
exception being Hawley, which reached petal-fall on
May 31. After petal-fall, the sites were sprayed ac-
cording to the experimental protocol with the
University's air-blast sprayer.

In early June, border areas within 100m of the ex-
perimental blocks were surveyed for alternate FS-host
density and density of FS on such hosts. Host density
was estimated on a four-point scale, and FS density
was estimated on a three-point scale after examining
known host plants throughout the border for fifteen
minutes (Figure 2). If any FS was found, a more pre-
cise measure was taken by examining 25 stems on al-

ternate hosts every 1 Om along the border.

Sprays applied by the University (Table 1 ) prior to
June 10 were full cover sprays, meaning all trees re-
ceived fungicide. Captan 80 was applied at 1.75
pounds/acre and Rubigan at 4.0 ounces/acre. At three
sites, scab persisted, so one additional unplanned cover
spray was needed in mid-June. For such applications,
Flint was applied at 2 ounces/acre.

Fungicides were applied twice in the summer, with
one spray on July 1 8 or 1 9 and the other on August 8
or 9. The two Flint treatments were applied to trees at
a rate of 2.0 ounces/acre, and Captan 80 was applied
at 2.5 pounds/acre. All sprays were delivered with the
equivalent of 150 gallons per acre.

FS counts began July 15. One hundred fruit were
sampled in rows 1,3, 5, and 7, in each of the four spray
treatments. Four hundred fruit were counted per treat-
ment, and 1600 fruit per block. Distance between rows
ranged from 8m (Shelbume) to 3m (Hawley). The
sample area was comprised of the bottom 6 feet of fruit,
on all sides of the tree. The typical sample was 20
fruit, from five trees, within each row. Also, the first
and last tree of each row, for each treatment, was not
sampled, since such trees could have been affected by
spray drift. Samples occurred weekly or semi weekly
until early September, when they were conducted
weekly. Counts continued until harvest, with the last
count on October 1 .

Fruit Notes, Volume 67, Spring, 2002

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Fruit Notes, Volume 67, Spring, 2002

f, ^n

aj zu

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7-Row captan treatment

• ^ "^

• __- — -'^'

"cl.

— — — — —

a.
<

^-^

. 2 r\ r^r\

1 - 0.00

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^ -10-

1 1 1

1 2

Flyspeck Density' (0-3) in the Borders

Figure 3. Flyspeck density observed on alternate host plants in the border area in June versus

the percentage of apples infected with flyspeck at harvest in the seven-row captan treatment.

Results

In the June border survey, host density ranged from
very high (4) at Harvard and Hawley, to moderate (2.2)
at Berlin, to none at Shelbume (Figure 2). FS density
on hosts ranged from moderate (2) at Harvard to low
(1) at N. Brookfield to none (0) at Hawley. Twenty
two percent of alternate host stems examined contained
FS at Harvard, while 6-9% of stems inspected con-
tained FS at Berlin, Warren, and N. Brookfield.

The Harvard block, with the highest rating for den-
sity of FS m the border, had the most FS in the apples
at harvest (Table 2). When data for the four sites with
the most FS at harvest were combined and tested, it
was clear that the amount of FS observed in the bor-
ders in June had a major influence on the amount of
infection in the apples at harvest. In the perimeter-
rows and seven-rows captan treatments, 53% and 60%,

respectively, of the variability in FS disease symptoms
at harvest was explained by this relationship (Figure 3
shows the seven-row captan treatment). In the Flint
treatments, the relationship was extant, but weaker
(31% and 10% of the variability explained).

Distance to principal border ranged from 3.1m at
Harvard, to 9.1m at Hawley (Table 2). Distance to
perpendicular end borders ranged from 3.9m at Berlin
to 53m at Hawley. At the Shelbume site, there were
no significant borders within 100 meters of the block.
The importance of the distance to a principal border
on the level of infection in the apples was less than the
importance of the amount of FS in the borders, but it is
worth noting. As Figure 4 shows for the perimeter-
rows captan treatment, 10% of the variability in fruit
infection counts was explained by this relationship.
Within the other three treatments, this relationship was
weaker.

Fruit Notes, Volume 67, Spring, 2002

>
X

(/5

■a

.4^

100

20 H

-20 -
-40 -
-60
-80

Perimeter-rows captan treatment

r^=0.10

95% Confidence Interval

— I —
60

Distance to Principal Border (m)

Figure 4. Percentage of apples infected with flyspeck at harvest versus the distance to princi-
pal border (parallel to the block): Harvard, Berlin, Warren, North Brookfield, perimeter-rows
captan treatment, 2001 .

FS was discovered in row 1 at the Harvard site on
July 16, in both the Flint (9%) and captan (13%) pe-
rimeter-rows spray treatments. At the Berlin site, FS
was found initially on August 27, in rows 3, 5, and 7,
of all but the seven-row Flint treatment. FS was first
discovered at the Warren site on August 29, in row 5
of the perimeter-row captan treatment. At the North
Brookfield site, FS was found on August 15, in both
the perimeter-rows Flint and captan treatments. The
Shelbume site first had apples infected with FS on
August 16, in the unsprayed rows of the perimeter-
row spray treatments of Flint and captan. FS was not
found at the Hawley site, despite counts continuing
into early October. It was not surprising, given the
absence of FS on alternate host plants within the sur-
rounding border in June.

When harvest counts (September 6 to 13) from all
treatments and all rows of all sites were compared (Fig-

ure 5, upper graph), Flint treatments had as little or
less FS than captan treatments in rows 1 , 3, and 7. The
perimeter-rows Flint count (6% infected fruit) was
slightly higher than the perimeter-rows captan treat-
ment (5%), but overall, Flint compared favorably to
captan. The lowest average FS incidence was found
in the seven-row Flint treatment. The perimeter-row
captan treatment had the most FS, with 17% of fruit
infected in row one. This high average number was
greatly intluencedby the 100%) incidence in this treat-
ment and row at the Harvard site. When the Harvard
data were omitted (Figure 5, lower graph), FS inci-
dence in this row and treatment was reduced to \%.
Row 5 of the perimeter-row Flint treatment had the
next highest FS incidence, with ?%> of fruit infected.
With Harvard omitted, FS incidence in row 5 of all
treatments was greater or equal to the FS incidence in
rows 3 and 7 of the respective treatment.

Fruit Notes, Volume 67, Spring, 2002

■ 2 Row Flint

• 2 Row captan 80 —A— 7 Row Flint —X— 7 Row captan 80

18%
16% ^

14% -

12% -

■4^

10% -

8% -

6% -

4% -

3 5

Row Position Relative to Border

All 6 Sites 9/6-9/13

-♦- 2 Row Flint

- 2 Row captan 80 —A— 7 Row Flint -^<r- 1 Row captan 80

7%
^ 6%

5 5%

« 4%

< 3% ^

■5 2%

.4J

3 5 7

Row Position Relative to Border

5 Sites (Harvard Omitted)

Figure 5. Percentage of apples infected with flyspeck at harvest in rows one (next to
border) through row seven (from border) in Massachusetts apple orchards with four
fungicide treatments, 2001.

Fruit Notes, Volume 67, Spring, 2002

Conclusions

The new environmentally benign fungicide, Flint,
performed as well or better than the older broad spec-
trum fungicide, captan. This finding was supported
by similar results in our twelve-block "Orchard Archi-
tecture" experiment in which a Flint-captan-Flint three-
spray summer program was as effective as a first-Level
IPM program. Other work of ours in small plot trials
in MA and RI and work reported by Dave Rosenberger
in New York indicate Flint and the other new strobilurin
fungicide, Sovran, are quite effective against FS and
scab. A task for 2002 is to determine the minimum
amount strobilurin necessary to control different lev-
els of FS infection.

At two of the sites, the perimeter-rows spray treat-
ment worked as well as the seven-row spray treatment.
These were sites with relatively low levels of FS in the
borders adjacent to the blocks. At the other four sites,
there was more FS in the apples in rows 3,5, and 7 of
the perimeter-rows spray treatment blocks than in the
corresponding rows of the seven-row spray treatment
blocks. Among unsprayed rows, row 5 had the most
FS, while row 3 had less (presumably due to spray drift
from rows 1 and 2), and row 7 had even less than row
3. FS showed-up earliest in the site which had the

highest amount of FS in the border in June (Harvard).
For adequate management of FS, blocks with rela-
tively high FS levels in the border areas will either
require spraying further into a block than row 2 or re-
moval or treatment of FS in the borders. We will test
these findings further in the second year of the study.
We will also attempt to control for spores that might
be entering the research blocks from border areas to
the sides and rear of the blocks.

References

Cooley, D.R. et al. 1996. Orchard site factors related
to incidence of FS in apples. Fruit Notes 6\{2): 1-4.

A ckn o wledgem en ts

We thank the following cooperating growers for
their participation in this study: Jerry Bieme, Dave
Bishop, Aaron Clark, Don and Chris Green, Tony Lin-
coln, and Bob and Mark Tuttle. We also thank Andy
Hamilton for applying post-petal-fall sprays, and Bayer
Corporation for supplying the Flint. This study was
supported by a grant from the USDA CSREES Crops
at Risk Program.

*%X^ %J> \3^ %S^
^1^ ^f% ^j% #^

Fruit Notes, Volume 67, Spring, 2002

Thinning IVIclntosli Apple Trees Witli
Blossom Thinners, With and Without
Post-bloom NAA: A Report to the New
England Tree Fruit Growers Research
Committee

James R. Schupp

Hudson Valley Laboratory, Cornell University

Duane W. Greene

Department of Plant and Soil Sciences, University of Massachusetts

The objective of these studies was to test the
efficacy of blossom thinners to replace carbaryl for
obtaining selective thinning of Mchitosh apples.

Evaluation in Maine
Materials & Method

Mature Rogers Mclntosh/M.7 apple trees growing
at Highmoor Farm, Monmouth, ME were selected for
uniform bloom. Treatment plots were surrounded on
all sides by one or more buffer trees, to prevent over-
spray. All thinning treatments were applied with an
airblast sprayer calibrated to apply 135 gallons of
dilute spray per acre, with 70% of the spray delivered
to the top half of the tree canopy. Blossom thinning
treatments were applied May 1 2, 1 998 when 70 to 80%
of the blossoms were open. The weather at the time of
application was sunny, temperatures was 72° F, with a
4 to 6 mph wind from the west. Blossom thinning
treatments were:

1 . Untreated control

2. Ammonium thiosulfate (National Chelating), 5
gallons per acre

3. Wilthin (Entek Corp.), 12 quarts per acre

4. Endothall (Elf Atochem), 2 pints per 100 gallons

5. NAA, 12.5 ppm

For plots that received post-bloom thinner, six
ppm NAA was applied on May 27,1 998 when fruitlet
diameter was 10 mm. The weather at the time of
application was sunny, temperature 64° F, with a 1 to 2
mph west wind. The treatments were arranged as a
split plot design. Blossom thinners were the main plot
treatment, postbloom NAA was the sub-plot
treatment, and there were five replications.

Fruit set was evaluated by limb counts and by
cluster counts. All the flower clusters on one or two
limbs per tree were counted at pink. The limb
circumference was measured, and limb cross-sectional
area (LCA) was calculated. The number of fruit on
each limb was counted, and fruit set was calculated as
the number of fruit per 100 clusters and as the number
of fruit per LCA. Fruit counts were done shortly after
petal fall and again in July to evaluate both initial and
final set. Twenty-five fiower clusters on each tree
were tagged, and the number of fiowers on each cluster
was recorded. The number of fruit on each cluster was
counted and fruit set was calculated as the ratio of fruit
to flowers for each cluster.

Yield per tree was determined in a single picking

The Maine portion of this study was conducted at the University of Maine Highmoor Farm, during the time that Dr
Schupp was with the University of Maine.

Fruit Notes, Volume 67, Spring, 2002

at harvest. Fruit size distribution was categorized
using a FMC Weight Sizer (PMC Corp. Lakeland, FL).
The weight sizer was adjusted to divide the fruit into
four diameter size categories: 57-63 mm, 64-69 mm,
70-75 mm, and greater than 75 mm. Twenty fruits of
the 70-75 mm category were selected from each tree
for fruit quality analysis. Red fruit color and russet
were estimated visually. Fruit firmness was measured
on the EPT-1 firmness tester (Lake City Technical
Products, Inc. Kelowna, BC, Canada), with two
opposing punctures per fruit. The soluble solids of the
fruit were determined using an Atago PR-101 digital
refractometer (Misco Products Divn., Cleveland, OH).
Seed number was counted.

set, especially on control trees, however, the rankings
of the treatments remained essentially unchanged.
There were no treatment interactions on fruit set, yield
or fruit characteristics between blossom thinners and
post-bloom NAA in this study. Wilthin, endothall and
NAA applied at bloom reduced yield (Table 1).
PostbloomNAA had no effect on yield. There were no
significant effects of thinners on fruit size distribution
(data not presented). There were no treatment etfects
on fruit red color, fruit firmness, soluble solids
concentration, or seed number (data not presented).
Fruit from trees treated with Wilthin had higher
incidence of russet than fruit irom NAA- or endothall-
treated frees (Table 1 ).

Results

Discussion

Fruit set was reduced by all blossom thinners,
while post-bloom NAA had no effect on fruit set
(Table 1). Final fruit set was much less than the initial

Environmental conditions during bloom and for
the following month were characterized by warm
temperatures and high sunlight, making favorable

Table 1 . Effect of ammonium

thiosulfate (ATS), Wilthia endotliall, and NAA used

as blossom thinners and NAA used as a

postbloomthumer on fhut set and fhut size of Rogers

Mcintosh'.

Maine.

Initial set

Final set

Fmit/cnr

Fmit/100

Fruit/cm"

Fnut/100

Russet

Yield/

limb cross-

blossom

limb cross-

blossom

Skin surface

tree

Treatment

sectional area

clusters

sectional area

clusters

(%)

(kg)

Blossom thinners

Control

17 a

143 a

3.4 a

31a

15 ab

67 a

ATS 5 gal/acre

91b

2.5 ab

28 ab

13 ab

60 ab

Wilthin 12 qt/acre

43 c

1.5 b

17c

28 a

50 c

Endothall 2 pt/acre

93 b

1.4 b

16c

40 d

NAA12.5ppm

105 b

2.0 b

24 b

10b

55 be

Postbloom NAA

None

2.1

NAA 6 ppm

2.2

Significance

Blossom thinner (BT)

***

Postbloom thinner (PBT)

BTxPBT

Fruit Notes, Volume 67, Spring, 2002

conditions for initial fruit set. All the blossom thinners
were effective in reducing the initial fruit set and
number of fruit per flower cluster during this period. A
prolonged period of heavy cloud cover from June 1 3 to
June 17, 1998 resulted in heavy June drop for all the
trees in this study. This episode of fruit drop
commenced on June 23, and was more severe than the
fruit drop caused by blossom thinners. Much of the
potential effect of chemical thinners on yield and fruit
characteristics at harvest was obscured by this natural
fruit drop.

The most effective blossom thinner, Wilthin,
caused severe phytotoxicity and fruit russet. Future
studies should address this concern by evaluating the
effect of lower rates of Wilthin. These data indicate

that blossom thinners show some promise. More study
is needed to select the best chemicals and to optimize
their use.

Evaluation in Massacliusetts

Materials & Methods

A block of mature Marshall Mclntosh/M.26 apple
trees growing at the University of Massachusetts
Horticultural Research Center, Belchertown, MA
were selected. Treatment trees were selected so that a
buffer tree was located on each side of a treatment tree
to prevent spray drift. Prior to bloom 2 limbs per tree,
1 to 15 cm in diameter, were selected and tagged. At

Table 2. Effects of Ammonium thiosulfate (ATS), Wilthin,

endothall and NAA used as

blossom thinner alone or combined with a

postbloom NAA

application.

Fruit set

Postbloom

Fruit/cm"

Fruit/

Fruit

NAA

limb cross-

100 blossom

weight

Treatment

(6 ppm)

sectional area

clusters

(g)

Control

6.9 a

66 a

146 e

NAA

5.9 a

55 a

158d

ATS 6 gal/acre

1.9b

23 b

175 abc

ATS 6 gal/acre

2.6 b

22 b

184 a

Wilthin 12qt/acre

2.6 b

28 b

170 be

Wilthin 12 qt/acre

2.2 b

21b

182 ab

Endothall2pt/100gal

3.1b

25 b

164 cd

Endothall2pt/100gal

3.3 b

37 b

158d

NAA 12 ppm

6.1 a

62 a

171 be

NAA 12 ppm

5.7 a

61 a

177 ab

Significance

Blossom thinner (BT)

***

NAA

BT X NAA

Within columns, means not followed by th

e same letter are significantly different at odds

of 19 to 1.

Fruit Notes, Volume 67, Spring, 2002

the pink stage of flower development all blossom
clusters were counted on the two tagged limbs.
Blossom cluster density was calculated using LCA.
Trees were replicated based upon blossom cluster
density. All thmnmg treatments were applied with an
airblast sprayer calibrated to apply 125 gallons of
dilute spray per acre. Blossom thinner treatments were
applied May 4, 1998. Full bloom occurred about 0.5
day before application. Weather at the time of
application was partly sunny and warm with
temperature reaching 70°F soon after application.
Blossom thinning treatments were:

ATS, Wilthin, and endothall thinned significantly and
comparably (Table 2). NAA did not thin when applied
as a bloom thinner. NAA at 6 ppm did not thin when
applied alone at the traditional postbloom timing or
when applied following any of the blossom thinner
treatments. All blossom thinning treatments increased
fruit size. NAA, when applied as a bloom thinner,
increased fruit size even though it did not significantly
reduce crop load. Likewise, the postbloom 6 ppm
application of NAA alone increased fruit size although
crop load was not significantly reduced. There were
no blossom thinner X NAA interactions.

1 . Untreated control

2. Ammonium thiosulfate (National Chelating) 6
gallons/acre

3. Wilthin (Entek Corp.), 12 quarts per acre

4. Endothall (Elf Atochem), 2 pints per 100 gallons

5. NAA 12 ppm

For plots that received post -bloom thinner, 6 ppm
NAA was applied on May 18, 1998 when fruit size
averaged 9.0 mm. Weather at the time of application
was sunny, warm and breezy with temperature at 76 to
78°F at application time and a high temperature of 80°
F was reached later in the day. Treatments were
arranged as a split plot design. Blossom thinners were
the main plot treatment, postbloom NAA was the sub-
plot treatment, and there were seven replications.

Fruit set was evaluated by first counting all
persisting fruit on the tagged limbs at the end of June
drop in July. The fruit set was calculated by dividing
the number of fruit by the LCA. At the normal harvest
time on September 10, 40 fruit from each tree were
harvested randomly from around the periphery of the
tree. The harvested fruit were then taken to the lab
where total weight was taken and the average fruit size
calculated. Observation of the harvested fruit
indicated that there appeared to be no russet attributed
to treatment.

Results

Soon after application phytotoxic effects were
observed on the flower petals and leaves of all
blossom-thinned trees except those receiving NAA.

Discussion

ATS, Wilthin, and endothall were used in previous
years on apples at rates of 1 %, 6 qts/acre and 1 .5 pints/
100 gallons, respectively, with disappointing results.
Little phytotoxicity was noted and minimal thinning
recorded. Higher rates were used this year in an
attempt to locate a rate where some thinning would be
achieved. Cool, damp, rainy weather immediately
preceded the application of blossom thinners in
Massachusetts. We speculate that the large amount of
phytotoxicity was attributed to greater penetration of
the thinner into the leaves because of the cool, cloudy,
and rainy weather the week before application rather
than due to an excessively high amounts of thinner.
While we have noted for years that absorption
following a cool wet penod can be increased, this may
be even more important when the thinner of choice,
thins by burning.

It IS also interesting to note that fruit size was
increased significantly even though crop load was not
reduced significantly. Crop load may have been
reduced enough to increase fruit size. It is also
interesting to note that early thinning at bloom time
may actually increase fruit size more than by thinning
later. Note fruit size on trees treated with post bloom
NAA as compared with NAA used as a blossom
thinner.

These data suggest that blossom thinning is a
viable and eftective way to reduce crop load. More
study is necessary to select the best chemical and
concentration to achieve appropriate thinning.

^f^ ^I^ %S^ %S^ %1^

#1^ ^{^ #1^ ^{^ ^{^

Fruit Notes, Volume 67, Spring, 2002

Evaluation of New Apple Varieties, 1998
Observations: A Report to the New
England Tree Fruit Growers Research
Committee

Duane W. Greene

Department of Plant and Soil Sciences, University of Massachusetts

During the growing season I evaluated about 1 25
named varieties and numbered selections. Below are
my observations on the performance of many of these
in 1998.

Arlet

I continue to be on the fence with this apple. It has
good, but not outstanding flavor. It does not suffer
from biennial bearing, and fruit size is good. It russets
here, up to 25% of the surface, it drops and it does
become greasy. A drop control compound is
appropriate with Arlet. I am cooperating with Sarah
Weis on storage of Arlet this year to get a better
assessment of its postharvest life.

Autumn Gold

This is my first year with this cultivar and I had j ust
a couple of fruit. I believe that I harvested it too late,
October 19. It is a medium to large apple with some
russet and is not too attractive. The ones I tasted were
neither crisp nor juicy but I believe that they were
overmature. There were longitudinal cracks in the
pedicel end, throwing up a red flag. Flavor was of
bananas, fruity and very pleasant. It had a good sugar
to acid ratio. I rated the flavor very high, even with the
faults.

AA 62 (Stellar)

I continue to favor this attractive lemon yellow
apple. It is extremely attractive and has a large L/D
ratio (over 1 .05) even here. It has no russet but it is

exfremely susceptible to apple scab. Flesh is crisp,
juicy, fruity, and very good. One thing that I did note
this year is that at harvest it had an ethanol (aldehyde)
taste that detracted from the flavor. It did have some
moldy core this year. I have noted this in other apples
in the past including HoneyCrisp. I will continue to
look at this one.

AA122

This is the first year of evaluation of this oblate
deep yellow apple. It has white inconspicuous
lenticels and yellow flesh. The flavor was OK, being
slightly sweet with a bitter after taste. It was rated in
the middle of the pack. If it does not have outstanding
flavor or crispness, the evaluation time of this apple
will be short.

Braeburn

It IS a somewhat unlikely candidate to be grown in
New England because of late maturity. It blooms
profusely and set can be excessive if not thinned very
well. I have used three applications of 6 ppm NAA
with or without carbaryl on Braeburn with success.
Fruit size is good and color is acceptable. It is not very
good at harvest but after a period of cold storage it does
taste very good. It has good postharvest life. I do
recommend planting this apple in New England.

Cameo***

I consider this to be one of the best new cultivars.
It ripens in mid-October here. It has good L/D ratio

Fruit Notes, Volume 67, Spring, 2002

and quite good if not quite different color. It is a highly
striped apple with about 80% of the surface a dark
reddish brown color. It is a very grower-friendly tree.
This tastes like a very good Delicious but the taste is
very mild. While I never hope that is will be sold as
Delicious, I think that it will appeal to people who
actually do have taste for it but are attached to the
unfortunate versions of Delicious available today. I
am high on this apple and think that it will sell here in
the East. It does have biennial bearing tendencies.

COOP 25 (Scarlet O 'Hara)

This IS a medium sized brownish red apple that I
have liked for two years. It can be picked, and actually
tastes very similar when harvested over a 4-week
period from late September to late October. It is one
of the crispest and best storing apples I evaluate. It
stores better than Fuji or Braebum but not quite as well
as HoneyCrisp. It has a mild, fruity, vanilla flavor with
a good sugar to acid ratio. I would plant this even if it
were not a scab resistant apple. Anyone who is looking
for a versatile scab resistant apple should be looking at
this. It is very susceptible to fire blight so areas where
this is a problem should proceed very carefully.

were sent to me by Stark from the Delbard Nursery in
France that fruited for the first time this year. It has an
80% dark maroon surface and looks like a Delicious.
Harvest date was on August 24, just about with Ginger
Gold. It has a distinctive sweet perfumy flavor. It is
quite crisp and veryjuicy but the skin in tough. I rated
it quite high and noted that it was a very good apple.

Delgorov

This is an extremely attractive bright orange-red
apple that is about 80% red striped. It is medium small,
fairly crisp, juicy, but the flesh seems somewhat dry. I
noted that it was a fairly good apple with a good sugar
to acid ratio. Harvest is 2 weeks before Gala.

Deljoron

The color of this apple is almost 100% dark
burgundy red. It in many ways reminds me of an
Empire in appearance and taste. The flesh is white
with a tinge of green. The skin is smooth somewhat
tough, with many tan lenticels. It ripens about with
Delicious. I was favorably enough impressed with it at
harvest to note that I should continue to look at it.

COOP 37

Delorina

I have looked at this cultivar for three years now. It
is very similar to GoldRush in appearance and time of
ripening. It is somewhat attractive with a 20 to 30%
orange cheek. It has a strong vanilla taste, veryjuicy,
and medium in size. I rate it good but not exceptional,
although my tasting notes include the comment 'look
at again'.

Creston

This was a difficult year for apples that are not
highly colored because of the heat. Creston suffered,
and consequently it was not very attractive. However,
compared with other apples evaluated it was one of the
crispest and juiciest. It was also rated very high in
flavor, and overall as being very desirable. It was also
large. We should continue to evaluate this apple.

Dalrouval

This is one of the several selections of apples that

A small dark cherry red apple ripening with and
looking somewhat like Delicious. It has yellow flesh
with yellow flecks, slightly sweet, moderate acidity,
and IS somewhat crisp and juicy. Flavor is tangy and
slightly fruity. I rated it fairly high.

Delshel

This is a an extremely dark red, medium to small
apple that is

Gala-like in appearance. It has scarf skin and reminds
me to a very large extent of Buckeye Gala. It has
prominent tan lenticels and a pleasant fruity taste. It
ripens about two weeks before Gala. I rated this quite
high.

Enterprise

The quality of this apple improved immensely this
year. It was near the bottom of the list last year. While
not on the top, it did move up quite a bit. What is the

Fruit Notes, Volume 67, Spring, 2002

difference? We had a very hot summer and I beUeve
that was the difference. It was extremely attractive,
medium size, sweet, crisp, juicy, and shghtly fruity.
Last year I described its flesh as tough, dry, and
sawdust-like. The bottom Ime here is that it is meant to
be grown in warmer climates. In warm years it will be
very good.

Fiorina

I hear very little about this apple, but it is very
good, especially for a disease resistant apple. It is very
attractive and its skin is glossy like a HoneyCrisp. It is
somewhat crisp, very juicy, with a good mild buttery
flavor. Fruit size is medium. I rated it very high.

Fortune

Although red color development was delayed, it
did come along. It was not very firm or crisp this year
and acidity was rather high. Although it was not at the
top of the list flavor, overall I rate it as an above
average apple. The iiTegular shape is a problem as is
its mammoth size. I have serious reservations about
whether this will make it with all of the good
competition.

Fuknishiki

This is the first year I evaluated this apple and it
may be my last. It is not attractive with 70% pinkish
red color. It has scarf skin and the flesh is greenish
yellow. The skin is extremely tough, and the flesh is a
nondescript, chalky and astringent flavor. It is not very
good.

Fukutami

A small bright cherry red apple. While the
cosmetics are good, the taste is not. Although it is
somewhat sweet, the flavor is masked by extremely
high acidity even when it has watercore. It is not good
enough.

Gala Supreme

A year ago I was quite impressed with Gala
Supreme. I am out of favor with this apple now for
several reasons. It has no better than "good"

appearance. It can be quite tart at harvest even though
sugars are quite high. The flesh is grainy and the taste
is nothing spectacular. It has a chalky aftertaste that I
attribute to high tannins. It has problems in storage in
that it loses firmness rapidly.

Ginger Gold

The luster of this apple was not tarnished this year.
It remains a very crisp, juicy, mild tasting apple that
has a great deal of customer appeal. It is often
harvested too early, when it is still too green. Even at
this stage it is good, certainly better than most. It does
not hold up well in storage so only those that can be
sold at harvest should be planted. It holds up well on
the tree. If one follows starch ratings, it loses starch
very slowly. It may go from 2 to 5 ( on a scale of 8 )
over a 2.5 week period, whereas others lose starch
much faster. This is definitely a winner in New
England.

Golden Supreme

This is a very high quality apple, both in looks and
in quality, but its faults may kill it. It is not precocious,
and it IS quite biennial. It ripens irregularly and
extensive preharvest drop is possible. Under ideal
conditions it is an absolutely beautiful apple. I still like
this one a lot and I am not willing to give up on it. It
does store quite well.

GoldRush

We had a hot summer and consequently this did
much better than it has in the past. Normally it is small,
russeted, with high acidity. Acidity does mellow in
storage, but not enough. This year it did do better, but
it will never be a good apple for us unless global
wanning pushes the mid- Atlantic region weather up to
New England. I do not recommend it for this area.

Hampshire

For New England or for cooler areas, I believe that
Hampshire has a place. It is medium size plus, quite
uniform in size, and attractive. It has a very mild taste
at harvest. The apple mellows after 4 to 6 weeks in
storage giving it a very tender yet pleasing taste and
texture. It holds up well in CA storage. I recommend

Fruit Notes, Volume 67, Spring, 2002

planting Hampshire, at least on a limited basis until we
get more out there to evaluate.

Hardy Cumberland

This is a very attractive nearly 100% blush dark
red apple. It has somewhat of an irregular shape.
Flavor is good but mild, not sweet, crisp, or juicy. I
evaluated it over a 3-week period from the end of
September to October 19, with similar results. I will
continue to look at this, since I have not formed an
opinion yet, other than it is good.

HotteyCrisp

The popularity of this apple is amazing but it has
so many things going for it that it deserves it. It is the
crispest and best storing apple that I have ever worked
with. Fuji is not even in the same category, but neither
are any other apples currently under test. Its faults or
problem are surfacing including leaf hopper suscepti-
bility???, poor growth, lack of color, off tastes to
mention a few. However, this apple has staying power
and it will be a dominant player at least in the East for
many years to come. We must work through the
apparent problems. I could mention many things here
but I believe that this apple has so much potential that
a whole article should be devoted to it. I am on my
third planting of HoneyCrisp, with no intention of
slowing down.

Hiianguan

This IS not an attractive or visually appealing
apple. It has 70% brownish red color that is somewhat
striped and mottled. It is quite crisp and very juicy.
The juice is extremely thick, unlike most other apples.
It has an extremely strong vanilla taste, to the point of
being objectionable. It is no better than medium size.
The poor appearance, the size problem and the very
strong flavor lead me to conclude that this is an apple
that will not make it.

Huashiiai

Huashuai is in the middle of the pack on too many
characteristics. It lacks too many distinguishing
features to have a bright future. It is very Delicious-

like in appearance and taste. It lacks character/flavor.
It IS not crisp enough or juicy enough to overcome
other deficiencies. It is similar to Cameo in some
respects, but Cameo will win because it is larger, has
better color, is more attractive, and I believe it tastes
better.

Hudson '5 Golden Gem

I have fruited this wonderful apple for several
years but have not reported on it because it is different,
a fringe apple. It is a completely russeted apple that
ripens in Golden Delicious time. The size is medium
to large, and the shape somewhat oblate to conic. The
taste IS pear-like, but lacking the grit. Everyone that
tastes this apple just loves it. It is somewhat sweet but
with enough acid and tannins to give it character. The
appearance is so different that it attracts attention. We
are planting two apple varieties in quantity this year,
Honeycrisp is one and Hudson's Golden Gem is the
other one.

Kinsei

This IS quite an unattractive apple that has very
good flavor. Where does it fit in? I do not know. I still
favor it and feel that it can develop a following if
properly promoted. It is not large enough or attractive
enough to be a dominant apple, but it may have a place.
It stores very well. I found out this year that it is very
susceptible to apple scab, in the Mcintosh category.

Kitanosachi

This IS another one of the Japanese apples that
makes me ask why? It is small with dirty red striping.
Flesh is green with a whitish tinge and the flesh feels
soft even though it is not. Even in the third week in
August there are better apples.

Monidel

This IS the first year of evaluation of this apple.
Shape is oblate to truncate, size medium to large, with
a light striped cherry red color, but only moderately
attractive. It is crisp, juicy, spicy, with a good sugar to
acid ratio. Vanilla and licorice are quite prominent. It
ripens at the end of August when the only real

Fruit Notes, Volume 67, Spring, 2002

competition is Paulared, Ginger Gold, and Sansa. My
notes indicate that this is a good apple that should be
evaluated more, and I underlined it .

Murasaki

It is medium in size and bruises easily. Flesh is
somewhat soft. It has an anise flavor that is almost
completely masked by very high acidity. It ripens
about with Pristine, and if given a choice, I would
select Pristine.

Quite irregular in shape and 100% muddy red
color characterize the appearance of this apple. It had
watercore in the second week of October but it was still
not sweet. Even though this was the first year of
evaluation, I believe that I will pull it out.

NJ 55 (Sun crisp)

I put Suncrisp in the same category as some of the
other apples that originated from the mid-Atlantic
region. We had a hot year last year and it did much
better than it has in the past. It develops a very
attractive orange red color in mid-October. Acidity
was down, sugars were up and flavor was very good. It
was a very good apple. It also stores well. In warm
years we can look forward to a very good tasting apple
in Suncrisp.

NJ90

There are few apples evaluated this year that are as
attractive as NJ 90. It is a flat Mcintosh type that has
a deep dark red color. It has excellent flavor that I
characterize as perfumy vanilla. It is extremely crisp,
slightly sweet, with a generous dose of acid and
tannins. The major drawback to this apple is that the
skin is extremely tough, so much so that it may be
fatally flawed.

NJlOO

This is a fairly attractive yellow apple that has no
russet. I rated it quite high in appearance, flavor, and
overall, with good sugars and acid. It is somewhat
crisp and very juicy. Ithasa very distinctive flavor. It
ripens at the end of September. Last year I did not rate
it too high so further testing is necessary to see how this
one sorts out.

NJ107

This is an extremely attractive white-yellow apple.

NJ109

An extremely attractive glossy yellow color
characterizes this apple. It is crisp, juicy with a very
mild flavor, so mild that I hardly taste anything. It
ripens just after Ginger Gold so the competition may
be too great for this apple. Although it is more
attractive than Ginger Gold, it is not better in any other
attribute.

NJ112

I rated NJ 1 1 2 in the middle of the pack in a number
of areas. It has a fairly attractive red color covering 80
to 90 % of the surface. The flavor is OK but not
outstanding and the skin is a little chewy. Fruit have
moldy core. It ripens in the first week in October when
there are many good fruit available. Just because there
are many better ones, this will not make it.

NJ116

I evaluated this apple four times over a three week
period starting on August 3 . It acts like a summer apple
in that ripening is uneven, and there can be mealy
apples on the tree while others are not ripe yet. It is an
extremely attractive yellow apple, that for the most
part I rated very high. It is crisp and juicy, and perhaps
its best trait is its earliness. It is similar to other NJ
yellow apples in that it is tart, has very weak flavor, and
is very attractive in that it is russet free. It is a viable
option for an early apple.

NY 460

I suspect that no one will comment on this apple.
However, I think that it is an excellent one. It has the
same parents as Fortune, Schoharie Spy X Empire. It
is very attractive, somewhat ribbed with some truit
having an irregular shape. Size is large but not too
large. It is crisp, firm, juicy and a very pleasant apple
to eat. It IS very susceptible to apple scab. It also

Fruit Notes, Volume 67, Spring, 2002

inherited the lack of precocity associated with
Northern Spy. It is a great apple to eat, and I guess I
will be one of the few who will have that opportunity.
I understand that this was one of Roger Ways personal
favorites.

NY 73334-35

I evaluated a number of NY scab resistant apples
this year and this is probably the best. It ripens in mid
October. It is large, extremely crisp and juicy and quite
attractive with 80 to 90% red color. The acidity is
fairly high and this may mask some of the flavor.
Essentially, it is a good apple.

Natco 3

This is a very distinctive apple and for that reason
alone it deserves comment. It is a very typey yellow
apple that has cosmetic/russet problems. It has
prominent tan lenticels and an orange red cheek
similar to Suncrisp. Other than the shape the
distinctive feature of this apple is its very strong taste.
It has a strong perfume-banana flavor with juice that is
buttery and extremely thick. It is one that I think that
you would either love or hate. The skin is chewy with
elevated levels of tannins.

Pristine

I am not a big fan of Pristine but in the first week in
August there are not too many choices of yellow
apples. This year the Pristine in my NE- 1 83 block was
totally off. They can be very biennial. Ifit is harvested
when not completely yellow the acids will be very high
and it will have very little flavor. It does have licorice
taste when it is ripe. I do believe that this is another one
of those apples that will do better in a warmer climate.

Runkel

Runkel develops good red color before it is ready
to harvest. It is large with 80 to 90% red color at
harvest time in October. The flavor is good, truity,
tropical. When it is ripe the flesh may be somewhat
soft and the skin appears to be tough. It is quite
susceptible to apple scab. Overall it was a good apple.

Sansa

This is still one of the top apples that I recommend.
It IS very Gala-like, only ripening 2 weeks earlier. It is
a lousy looking tree and it has the appearance of having
apple mosaic virus, but this is genetic. I am totally
convinced that an apple such as this has a place early in
the season. Some people like it better than Gala. It is
a weak tree and we must work to keep it growing well.
In taste evaluation it comes out very high.

Shizuka

I continue to like this apple although I am seeing
more of its faults. At harvest it was rated highest of all
of the good apples in NE-183 for crispness, juiciness
and flavor. The only apples that were rated higher,
relative to being overall desirable, were Sansa and
Golden Supreme. This is one of the apples in our
storage test this year. It is softer than Mutsu at harvest
and it does not hold up in storage as well as Mutsu. I
have not tried it in CA storage yet, but in regular
storage it is pretty well shot by the end of January or
earlier.

Sunrise

Sunrise is an excellent apple if you harvest it on the
right day. It acts like a summer apple in that it ripens
variably, and when it develops good red color it has
lost much shelf life. I agree with research in British
Columbia that reports that it must be harvested much
earlier, at starch level readings of 2 to 3 (on a scale of
8) to have good shelf life. If placed in cold storage it
will deteriorate rapidly. I do not recommend this apple
because of the multiple harvests and the problem with
short shelf life.

Takane

It IS very similar to Fuji. It is medium size, with a
rather unattractive pinkish red color. The taste is
similar to Fuji but perhaps better m that it may be
sweeter and have more fruity aromatic flavor. It does
not have the flesh firmness of Fuji. I will continue to
look at this apple but I think that Fuji has the edge in
appearance, and firmness.

Fruit Notes, Volume 67, Spring, 2002

Zestar (MN 1824)

This was another pleasant surprise from Minne-
sota. It is a large apple that has about 60% of the
surface with a pinkish red color. It is not very
attractive but it does have other attributes. It is my
understanding that it is meant to compete with
Paulared. It ripens about 5 days ahead of Paulared. It

is crisp and juicy but the flesh does not seem as dense
as others, almost pithy but not necessarily objection-
able. It is a very pleasant apple to taste. It is slightly
perfumy, sprightly, and yes, zesty. It is an apple that
grows on you, almost addictive. I believe that it will
compete successfully with Paulared even though it is
not as attractive.

*%1^ %X^ %i^ ^i^
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Fruit Notes, Volume 67, Spring, 2002

Influence of Odor-bait, CultivarType, and
Adjacent Habitat Composition on
Performance of Perimeter Traps for
Controlling Apple Maggot Flies

Sara Hoffmann, Robin Mittenthal, Brad Chandler, Gerald Lafleur, Starker Wright,
Paul Appleton, Max Becker, Sara Dynok, and Ron Prokopy
Department of Entomology, University of Massachusetts

Apple maggot flies (AMF) that immigrate into
commercial apple orchard blocks from surrounding
areas containing unmanaged host trees are the flies
responsible for the great majority of infestation of fruit
in commercial orchards. Previously, we have found
that using perimeter-row, odor-baited red spheres to
intercept immigrating AMF is an effective control
method. More specifically, our findings have suggested
that surrounding an apple orchard block with spheres
baited with butyl hexanoate (BH) and placed 5 m apart
will effectively prevent AMF from penetrating into the
block.

Here, we present the results of experiments
conducted in 2000 and 2001 designed to determine
whether (1) spacing spheres 10 m apart on perimeter-
row apple trees is as effective as spacing spheres 5 m
apart in preventing AMF penetration into orchard
blocks, (2) perimeter-row spheres baited with a five-
compound blend of fruit odor volatiles are more
effective than traditional BH-baited spheres in
preventing AMF penetration into interiors of blocks,
(3) the presence of AMF-susceptible compared with
AMF-tolerant cultivars comprising front-row apple
trees affects front-row-trap captures and AMF
penetration into interiors of blocks, and (4) adjacent
habitat affects AMF population numbers immigrating
into commercial orchards.

Materials & Methods

In 2001, 10 Massachusetts commercial orchard
blocks were involved in our experiment (initially, we
used 12 commercial orchard blocks in 2001, but for

the purpose of this article, we excluded two of them
due to unusually high AMF populations that would blur
data trends in the remaining 10 blocks). Five blocks
had front-row cultivars that were comparatively
susceptible to AMF (Gala, Jonagold, or Fuji) and five
blocks had comparatively tolerant front-row cultivars
(Mcintosh or Empire). Each orchard block had an
adjacent habitat of woods, hedgerow, or open field.
Each block in the 1 commercial orchards was divided
into three plots (Figure 1). Plots A and B had a 45m
length of front row and a depth of seven rows. The
front row in plots A and B contained five sticky red
spheres, spaced 10m apart. Each was baited with either
the five-compound blend (BH, hexyl butanoate, butyl
butanoate, pentyl hexanoate, and propyl hexanoate) or
BH alone. Plots A and B received no insecticide spray
to control AMF. Plot C (termed grower sprayed) had a
30m length of front row and a depth of seven rows. It
was sprayed by the grower two or three times with an
organophosphate insecticide to control AMF. Each
of the two sides of plots A and B, as well as the back
row (row 7), contained red spheres spaced 5 m apart,
baited with butyl hexanoate. Plot C had no perimeter,
side, or back-row spheres. Rows 3 and 4 contained six
unbaited sticky red spheres (four in the grower-sprayed
plot due to the smaller size) to monitor AMF
penetration into the interior of plots. Traps were
deployed in late June and remained through the
beginning of October. Every 2 weeks, traps were
cleaned and captured AMF were counted.

The protocol for our 2001 experiment was based
on results of a test conducted in 2000, in which we
evaluated AMF penetration into orchard blocks by

Fruit Notes, Volume 67, Spring, 2002

Woods, hedgerow or open field

45 m

30 m

PLOT A

PLOTB

PLOTC

Figure 1. Schematic illustration of the 2001 season block layout for evaluation of sticky red
sphere traps for controlling AMF: ? = odor-baited traps, wherein front-row traps in Plot A were
baited with a five-component blend, front-row traps in Plot B were baited with butyl hexanoate,
and all other baited traps received butyl hexanoate; ? = unbaited interior monitoring traps in rows
three and four; x = unbaited apple trees. No insecticide was applied to any tree in Plot A or Plot
B, but was applied two to three times to all trees in Plot C in July and August.

comparing AMF captures on red spheres baited with
the five-compound blend and placed either 5 or 10 m
apart on front-row trees. Methods were, in general,
similar to those for 200 1 with the following differences:
(1) for 2000, we included data for all 12 orchard blocks
initially considered for 2001, (2) in 2000, the perimeter
row of each plot was only 30 m long, and (3) in 2000,
fraps placed on sides and back rows were spaced 10 m
apart. Results of that study are also presented in this
article.

Results

Results from 2000. Experiments that we
conducted in 2000 show that across all five sample
periods and all 12 orchard blocks, about 26% more
wild AMF were captured per trap on front-row traps
that were spaced 5 m apart (mean=27) than 10 m apart
(mean=22), but there was virtually no difference in wild
AMF penetration into interiors of the plots (respective
means of 9 and 8/trap/plot) (Figure 2A). Thus, front-
row traps that were spaced at 5 m or 1 m apart captured
about three times more wild AMF per trap than interior
monitoring traps. Interior-row traps in grower-sprayed
plots captured 33 and 12% fewer AMF, respectively,
than interior-row traps in plots with perimeter traps 5

or 10 m apart. The ratio of front-rovv/interior-row trap
captures was markedly higher for tolerant cultivars
(3.8:1) than for susceptible cultivars (2.3:1) (Figure
2C and E). For susceptible cultivars, interior
monitoring traps in trapped plots captured about 45%
more AMF than interior monitoring traps in grower-
sprayed plots (Figure 2C). For tolerant cultivars,
interior traps in trapped plots captured about 6% fewer
AMF than interior traps in grower-sprayed plots (Figure
2E).

Overall AMF captures in 2001. In 2001 (with
much higher AMF population numbers than in 2000),
across all six sample periods and all 1 orchard blocks,
57% more wild AMF per trap were captured by front-
row traps baited with the five-compound blend (termed
blend plots) than by front-row traps baited with BH
(termed BH plots)(Figure 2B). Unbaited interior
monitoring traps in BH plots captured about 1 3% more
AMF than interior traps in blend plots and about 47%
more AMF than interior traps in the grower-sprayed
plots (about 7/trap/plot). About seven times more wild
AMF per trap were caught by front-row traps in blend
plots than by interior monitoring traps, whereas only
about five times more wild AMF were caught by front-
row traps in BH plots than by interior traps.

The effect of front-row cultivar type on AMF

Fruit Notes, Volume 67, Spring, 2002

A _ All Cultivare: 2000 ■ ^"""^r^"-

B J All Cultivars 2001 ■ BLBgD

° a 5m apart

D-

S- 120 , a BH

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Monitoring

rrxsnitoring

C _ Susceptible Front Row Cultivars: 2000

D 5 Susceptible Front Row Culti\«rs: 2001

t 120 T -r ■ BLEND

1 120.

■ 10 m apart
□ 5 m apart

t 100

3 80

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monitoring

E Tolerant Front Row Cultivars: 2000

F S Tolerant Front Row Culti\Qrs: 2001

t 120, -BLEND

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Front row Interbr Back row 1

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monitoring

Monitoring

Figure 2. For 2000 and 2001, across all sample penods

sum of mean numbers of wild AMF captured by odor-

baited spheres placed on front rows or back rows of plots or unbaited spheres placed at interior of plots for all |

plots (A and B) and for plots where the front rows were

composed of susceptible (C and D) or tolerant cultivars 1

(E and F). In 2000, only the five-compound blend was evaluated. In 2001, all ft-ont-row traps were placed 10 m |

apart.

captures in 2001. For susceptible cultivars, front-row
traps in blend plots captured somewhat more wild AMF
per trap than front-row traps in BH plots (about 33%
more), whereas for tolerant cultivars, front-row traps
in blend plots captured substantially more ( 1 36% more)

wild AMF than front-row traps in BH plots (Figure 2D
and F). Front-row traps in blend and BH plots of
susceptible cultivars captured substantially more AMF
(85% and 228% more, respectively) than front-row
traps in corresponding plots in tolerant cultivars. When

Fruit Notes, Volume 67, Spring, 2002

averaged across both types of trapped plots and grower-
sprayed plots, interior monitoring traps in susceptible
cultivars captured substantially more ( 1 30% more) wild
AMF than in tolerant cultivars. The ratio of front-row-
trap/interior-row-trap captures in blend and BH plots
was the same within each cultivar type as it was for
both cultivars together (about 7: 1 for blend and about
5:1 forBH).

Effects of adjacent habitat in 2000 and 2001. In
2000, of the total number of AMF captured by all traps
in all orchards, 41% were captured in blocks adjacent
to woods (Figure 3). A similar percentage (37%)) was
captured in blocks bordering hedgerows. The smallest
percentage of total captured flies was found in blocks
bordering open fields (21%).

In 2001, blocks bordering hedgerows had the
highest percentage (47%) of total fly captures, followed
by orchard blocks bordering woods (32%), and blocks
that were adjacent to open fields (21%)) (Figure 3).

Conclusions

In 2000, in the same orchards studied in 200 1 , data
suggested that there was virtually no difference in AMF
penetration into orchard blocks when front-row traps
baited with the five-compound blend were placed either
1 m or 5 m apart. In 200 1 (with front-row traps spaced

10 m apart), front-row traps in blend plots captured
more flies than front-row traps in BH plots. Although
there was little difference in the mean number of wild
AMF that penetrated into the interior of the two baited
plots, the ratio of front-row to interior-row-trap captures
was higher when front-row traps were baited with
blend. Inasmuch as blend appears to be more capable
than BH of drawing AMF to the vicinity of traps (based
on front-row-trap captures), these data suggest that
blend odor-bait is better than BH in preventing AMF
from penetrating into the interior of orchards.

Orchard blocks with tolerant front-row cultivars
experienced substantially more AMF captures on front-
row traps baited with blend than BH. The difference
was much less for blocks with susceptible front-row
cultivars. This suggests that baiting front-row traps
with blend in tolerant cultivars attracts many more flies
than baiting tolerant trees with BH. In both 2000 and
200 1 , and in trapped as well as grower-sprayed plots,
more total AMF were captured in orchard blocks with
susceptible front-row cultivars than in those with
tolerant front-row cultivars. However, the ratio of
front-row to interior-row-trap captures remained the
same regardless of cultivar. This suggests that each
odor bait is just as effective in one cultivar type as it is
in the other cultivar type in preventing AMF penetration
into the orchard interior.

Percent of Total AMF Captures
2000 2001

woods
42%

Figure 3. In 2000 and 2001, across all blocks, all traps, and all sample
periods, percentage of the total AMF captures according to adjacent habitat
(woods, hedgerow, or open field). For the purpose of this figure, all 12
orchard blocks were considered in 200 1 .

Fruit Notes, Volume 67, Spring, 2002

Results from both 2000 and 2001 show that orchard
blocks that have woods or hedgerow as adjacent habitat
are subject to higher AMF pressure than blocks
bordered by open field. Orchard blocks that bordered
an open field had consistently lower fly captures than
blocks that bordered either woods or hedgerow
(habitats that typically support wild host plants).

Based on our findings, it appears that odor-baited
red sphere traps are effective in preventing AMF
penetration into orchard blocks when they are spaced
at 10 m apart on the perimeter row, especially when
baited with blend. Regardless of cultivar type, the blend
bait appears to be better than the BH bait at preventing
flies from penetrating into the interiors of orchard
blocks. In 2002, we plan to evaluate further the

capability of different odors on perimeter-row traps for
intercepting wild AMF immigrating into commercial
orchards.

Ackno yvledgm eiits

We are grateful to the following growers for
participating in this study: Keith Arsenault, Gerry
Beime, Bill Broderick, Dave Chandler, Tom Clark, Don
Green, Tony Lincoln, Joe Sincuk, Mo Tougas, and
Steve Ware. This work was supported by Massachusetts
State Integrated Management Funds, Northeast
Regional Competitive Integrated Pest Management
Funds, and Northeast Regional Sustainable Agricultural
Research and Education Funds.

*%S^ %Si^ %3^ %s^
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Fruit Notes, Volume 67, Spring, 2002

Notts

Fruit Notes

University of Massachusetts

Department of Plant & Soil Sciences

205 Bowditch Hall

Amherst, MA 01003

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Volume 67, Number 3
SUMMER ISSUE, 2002

rleu/ungland

Table of Contents

Comparing the Harvest and Storage Characteristics of Mutsu and Shizuka Apples

S. Weis, D. Greene, and W. Bramlage 1

1-MCP: How Useful Can It Be on New England Apples?

5. Weis and W. Bramlage 5

Species Composition of Third-generation Leafminers in Massachusetts Apple Orchards: 1997-1999

5. Wright, B. Zhao, and R. Prokopy 10

Population Dynamics of Leafminers and Their Parasitoids in Massachusetts Apple Orchards: 1999 Studies

B. Zhao, S. Wright, and R. Prokopy 14

Performance of the V Series Apple Rootstocks During Six Growing Seasons

W. Autioand]. Krupa 18

Editors:

Wesley R. Autio
William J. Bramlage

Publication Information:

Fruit Notes (ISSN 0427-6906) is pub-
lished each January, April, July, and
October by the University of Massachu-
setts in cooperation with the other New
England state universities.

Correspondence should be sent to:

Fruit Notes

Department of Plant & Soil Sciences
205 Bowditch Hall
University of Massachusetts
Amherst, MA 01003

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,
concermng the use of these products. USER ASSUMES ALL RISKS FOR PERSONAL INJURY
OR PROPERTY DAMAGE.

Issued by UMass Extension, Stephen Demski, Director, in furtherance of the acts of May 8 and June 30,
1914. UMass Extension offers equal opportunity in programs and employment.

Comparing the Harvest and Storage
Characteristics of IVIutsu and Shizul<a
Apples

Sarah A. Weis, Duane W. Greene, and William J. Bramlage
Department of Plant & Soil Sciences, University of Massachusetts

There is interest, especially among apple growers
who are retailing fruit, to find new "niche" varieties
which consumers like and which can be profitably
grown and sold. A green/yellow Fall cultivar is
something customers look for (the Granny Smith
influence). We have been attempting to identify some
of the most promising varieties suitable for growing in
the northeast by planting and systematically evaluat-
ing apples at the University of Massachusetts' Cold
Spring Orchard Research & Education Center
(CSOREC) in Belchertown, MA. For the past four
years we have been evaluating storage qualities of
Mutsu and Shizuka. Mutsu, also knowoi as Crispin, is
a variety which has consumer following, but it is
susceptible to Blister Spot, a bacterial disease which
renders fruit unsaleable. Shizuka is a similar apple
(same parents. Golden Delicious x Indo) which
appears to be resistant to Blister Spot and has been

suggested to be an alternative to Mutsu. The two
apples are quite similar in appearance. They are large
fairly round green/yellow fruit which often develop a
pink blush. Shizuka may be considered slightly more
attractive as its skin is smoother and it has less
tendency to russet (although russet is not severe on
Mutsu, either). Lenticels are attractive and are more
noticeable on Shizuka than on Mutsu. We have
compared storage qualities of these two varieties over
the past four seasons.

Harvest Information

Three trees of each cultivar from a block at
CSOREC were used for the evaluations. Trees were
planted in 1991, and all are on Mark rootstock. Each
tree produced 3 to 4 bushels of fruit in each of the four
years.

Table 1. Assessments

of Mutsu and Shizuka fruit at harvest,

1998-2001

Harvest
year

Grams

per fruit

Internal ethylene
(ppm)

Starch index

Firmness

(pounds)

Mutsu

Shizuka

Mutsu Shizuka

Mutsu

Shizuka

Mutsu

Shizuka

1998
1999
2000
2001

Average

Comment

282 290
333 292

345 268
311 213

318 266

Mutsu larger

1 3
4 1

2 6
9 3

4 3

Not different

3.9

3.2
3.8
3.2

3.5

Shizuka

4.4
4.8
5.3
3.9

4.6

'riper"

19.6 16.7
19.1 16.2
18.3 15.8
20.0 18.1

19.3 16.7

Mutsu firmer

Fruit Notes, Volume 67, Summer, 2002

Table 2. Changes

in average

starch index and firmness of Mutsu

and Shizuka apples as harvest

progressed,

1998-2001

Harvest date

Starch index

Fimmess

(pounds)

Mutsu

Shizuka

Mutsu

Shizuka

Sept 22-25

2.6

3.5

20.4

16.8

Sept 26-29

3.2

3.9

20.5

17.6

Sept 30- Oct 3

3.3

4.5

19.3

16.7

Oct 4-7

4.0

5.2

18.1

16.1

Oct 8-11

4.4

5.9

18.5

15.9

Oct 12-16

4.8

6.3

17.5

15.9

Oct 23

6.5

8.0

17.0

15.2

In an attempt to determine optimum time of
harvest for stored fruit, both varieties were harvested
over the period of late September through mid October
in 1 998, 1 999, 2000, and 200 1 . At each harvest, ten to
thirty representative fruit were selected from each
variety, and brought to the lab for measurement of size,
internal ethylene and starch hydrolysis to estimate
fruit maturity, and firmness as a crude indicator of
quality. Internal ethylene was measured by gas
chromatography, starch degradation was rated using
the Cornell Generic Starch Index, and firmness was
measured with either a Wagner pressure tester or an
EPTl pressure tester. A bushel or more of fruit was
harvested from each cultivar on
selected harvest dates and placed
in refrigerated air storage at 32°F.
Fruit from one harvest in 1998
were also stored in controlled
atmosphere storage (CA), at 38°F,
2.8%02, and varying CO^ up to
5%.

Harvest data are presented in
Tables 1 and 2. Table 1 shows
extensive year-to-year differences
in harvest qualities of the fruit.
All factors listed in the table
varied significantly from year to
year. Harvest dates were not
exactly the same every year (as
shown in Table 2), but the same

time span was evaluated. The fact that
the Shizuka were not as firm as the
Mutsu may be atfributed in part to
earlier ripening rather than being
inherently less firm.

Table 2 illustrates the influence of
harvest date on firmness of Mutsu and
Shizuka. Starch Index is an indicator of
progression of ripening. As expected,
firmness decreased with later harvest
of both cultivars, and Starch Index
increased with later harvest. Year-to-
year differences in all three measure-
ments were found, but in all years
Mutsu was the firmer apple and had a
lower starch index on any given date.
Starch degradation appears to be a good
indicator of fruit ripening in both Mutsu and Shizuka.
Even taking into consideration that Shizuka could
probably have been harvested up to a week earlier than
Mutsu at comparable starch scores, Shizuka was never
as firm an apple as Mutsu. Internal ethylene
concentrations were quite variable and are not shown.
Since Mutsu and Shizuka are both green to yellow
fruit, color should be a minor factor in choosing time of
harvest, although both cultivars can develop an
attractive pink blush during the ripening period. Over
half of the fruit of both cultivars did develop this pink
blush covering at least 5% of the fruit's surface area.
Further, the conversion from green to yellow would be

Table 3. Fiminess (Ibs)^ of Mutsu and Shizuka fruit on removal from
storage.

Mutsu

Shizuka

Harvest year

December

January

December

January

1998

14.7

12.8

12.1

11.1

1999

14.3

13.1

12.4

11.0

2000

15.4

14.0

12.9

12.0

2001

16.8

15.8

15.2

14.7

Firmness was measured with a Wagner penetrometer in 1998 and with an
EPTl inl999, 2000, and 2001.

Fruit Notes, Volume 67, Summer, 2002

Table 4. Results of poststorage taste tests to assess flavor
and overall desirability of 32F air-stored Mutsu and Shizuka
apples.

Desirability'

December

January

Harvest

year

Mutsu

Shizuka

Mutsu

Shizuka

1998

3.2

2.7

2.1

2.3

1999

3.8

3.6

3.2

2.5

2000

3.8

3.2

3.3

2.7

Rating is on a scale of 1 to 5, with l=poor, 2=fair,
3=acceptable, 4=very good, 5=outstanding, and,
incorporates firmness, flavor, acidity, crispness, and
appearance components.

influenced by nitrogen level, as well as by fruit
maturity.

Storage Information

Fruit were placed in cold storage immediately
following harvest. Half the fruit were removed from
storage for evaluation in mid December and the other
half were removed a month later (7 weeks later 1998-
99). hi addition, some fruit were stored in
controlled atmosphere (CA: 38°F, 2.8%02, up
to S%CO^) for the 1998-99 season. Those
fruit were removed for evaluation on February
12, 1999. Results of CA storage will be
discussed separately.

There were three parts to the fruit
evaluation. (I) At the time of each removal
from storage, half the removed fruit were
immediately pressure tested. (2) The pressure
tested fruit were kept refrigerated and were
taste tested over a few days following removal
from the cold storage. (3) The removed fruit
which were not pressure tested were kept at
room temperature ( 68°F) for a week and then
evaluated for storage disorders.

Table 3 shows the condition of the fruit on

removal from cold storage. Fruit firmness
after storage was greater for Mutsu than for
Shizuka, and these differed significantly
from year to year. There was a significant
drop in firmness from mid-December to
mid-January for both varieties. The Mutsu
lost more firmness between December and
January than did the Shizuka, but still
remained the firmer apple in January. If we
arbitrarily assign a firmness of 12 pounds at
removal from storage to be the lower limit of
acceptability, then the Shizuka were
dropping below the level of acceptability by
mid January. Taste tests, results of which
are shown in Table 4, confirm this.
Unfortunately no taste tests were done in the
2001-02 season in which the fruit were
firmest.

"Desirability" incorporates assessments
of firmness, flavor, crispness, atfractive-
ness, acidity, juiciness, and astringency. A
score of less than 3 is considered less than acceptable.
In the December ratings, time of harvest was not a
factor, but in the January ratings, the earlier harvests
were judged higher for both varieties. Both varieties
were in the acceptable range in December (except for
Shizuka in 1998), but a month later even the Mutsu
were not consistently acceptable. Some of the poor
showing for desirability in the January rating of the
1998 fruit may be because the mid-January removal

Table 5.

Poststorage

disorders of Mutsu and Shizuka

apples rated after 3 2F storage until mid-December and mid- |

January followed by 1 week at 70F.

Percent

superficial

Harvest
year

Percent breakdown

scald 1

Mutsu

Shizuka

Mutsu

Shizuka

1998

1999

2000

2001

Fruit Notes, Volume 67, Summer, 2002

Table 6.
1998.

Some storage characteristics of Mutsu and Shizuka apples harvested October 2,

Storage through:

Superficial scald (%)

Mutsu Shizuka

Firmness^

Desirability^^

Mutsu Shizuka

12/15/98 (32Fau-) 25 3.0 1.8 3.3 2.5

2/1/99 (32F air) 83 1.5 1.5 2.0 2.2

2/8/99 (CA) 4 2.3 2.5 3.5 3.0

^ Firmness and desirability are both rated on a scale of 1 to 5, with l=poor, 2=fair,

3=acceptable, 4=very good, 5=outstanding.
'' Desirability includes firmness, flavor, acidity, crispness, and appearance conponents.

"soft" room;
38°F, 2.8%0
varying CO^
5%. Table 6
shows how dra-
matically CA
storage im-
proved some
poststorage
characteristics
of Mutsu and
Shizuka. The
reduction in su-
perficial scald
development on
Mutsu is of par-
ticular interest.

from storage actually happened on February 1, 1999.
Assessment of poststorage fruit disorders was
made following a week at room temperature, and
results of the assessments are shown in Table 5.
Because findings were similar for fruit removed from
cold storage in December and January, results have
been combined. Table 5 shows that poststorage
disorders did not occur with consistency. Senescent
breakdown was a problem in Mutsu following the
1999-2000 storage season. However, no significant
senescent breakdown was found in either variety
following storage and a week at room temperature the
following two years, and very little developed in the
1998-99 storage season. There was a substantial
amount of superficial scald following storage in 1998-
99, but much less in the following years. Mutsu was
more scald susceptible than was Shizuka. Neither
scald nor breakdown could be attributed to time of
harvest, although the year with the most scald (1998)
was one in which there was no late harvest, and scald
is most likely to develop on early harvested fruit.
Other disorders assessed were bitter pit and decay,
neither of which occurred with enough frequency to
analyze. We did note moderate skin greasiness on
Shizuka from the late harvests of 2000 and 2001 after
they had spent a week at room temperature in January.

Controlled Atmosphere (CA) Storage

Fruit were stored in CA as well as in refrigerated
air during the 1998-99 storage season. The CA was a

Conclusions

Based on the 1998-99 storage season's data, CA
appears to be necessary for both Mutsu and Shizuka if
they are to be stored beyond mid-December. Even in
mid-December the Shizuka did not emerge from air
storage in good condition in 1998, although they did
better in subsequent years. The Shizuka had probably
reached the limit of their quality CA life in 1998-99
when they were tested in February, while the Mutsu
could have gone longer in CA and emerged in
acceptable condition. The quality difference between
air and CA storage was dramatic for both cultivars.

Mutsu retains good quality in storage longer than
Shizuka. The areas in which Shizuka fared better were
appearance (3.1 vs 2.7 on the I to 5 scale) and scald
resistance. Shizuka does tend to be a smaller apple
which could be an advantage, since both cultivars can
be very large. Where blister spot is not a limiting
factor, Mutsu would be the more highly recommended
cultivar in a marginal storage situation. Shizuka could
be an acceptable substitute if the fruit were marketed
primarily in the fall or stored in CA. It is a more
attractive fruit than Mutsu, and for the September
market, Shizuka has the advantage of ripening slightly
earlier. If Shizuka is to be stored longer than mid-
December, it should be placed in CA.

Either Mutsu or Shizuka can be an acceptable
large green/yellow apple for the autumn market if
handled properly after harvest.

it "k it it it

Fruit Notes, Volume 67, Summer, 2002

1-MCP: How Useful Can It Be on
New England Apples?

Sarah A. Weis and William J. Bramlage

Department of Plant & Soil Sciences, University of Massachusetts

Fruit ripening is initiated by ethylene, and to some
extent, the rate at which ripening proceeds is regulated
by its concentration in the fruit. Fruit generally soften
faster at high ethylene levels, but ethylene is also
needed to stimulate formation of flavor producing
volatiles in the fruit. Low temperature air storage
slows the progress of ripening but does not prevent the
changes it produces. Controlled atmosphere (CA)
storage, however, can interfere with ethylene actions
and alter the quality of ripened fruit.

For ethylene to have an effect, it must first be
bound on the surface of the cells. 1-

Methylcyclopropene ( 1 -MCP) i s a new compound that
can block this ethylene binding and prevent or
seriously interfere with ethylene induced fruit ripening
and its effects on fruit quality. Recent studies of 1-
MCP treatment of apples have produced some exciting
results, including substantial retention of firmness and
dramatic reduction of superficial scald. However,
effects have not been entirely consistent, especially on
Mcintosh, and further tests to characterize responses
to 1-MCP are clearly needed.

1-MCP is obtained as a powder that is used to
generate 1-MCP gas within a closed area containing
harvested fruit. Following treatment the fruit can be
placed into air or CA storage and will require no
follow-up 1-MCP treatment. The material is not yet
commercially available, but since it does not leave any
residue on the fruit and is incorporated into the iruit in
minute concentrations, no health issues have arisen to
our knowledge, so its labeling might occur soon

There are many questions surrounding potential
use of 1-MCP. Results do not appear to be uniform
across cultivars. If ripening has begun before a fi^it is
treated, presumably it will continue despite treatment,
making time of harvest a crucial concern. If ripening is
blocked, will a fruit recover sufficiently to develop
quality attributes, especially flavor? For these
reasons, in Fall 2001 we initiated experiments to

evaluate 1 -MCP effects on apples under New England
conditions.

We surveyed 1-MCP effects on a range of
cultivars from early- to late-maturing, and at different
harvest times for individual cultivars. Cultivars
reported here are Ginger Gold, Gala, Mcintosh,
Delicious, and Spigold. All fhiit were stored in 32F air
following treatment, the durations of storage varying
among cultivars. For all cultivars, internal ethylene
concentration and fruit firmness were evaluated.
Occurrence of storage disorders was recorded, and, for
Delicious, fruit weight loss was determined since there
IS some evidence that 1-MCP reduces it during and
following storage.

Application

The 1-MCP is provided as a powder. When mixed
with water, 1 -MCP is released as a gas. This is not an
instantaneous reaction. Apples were harvested and
cooled overnight at 32F. A sample of approximately
one bushel was then removed from the cold storage
and placed in a 33 gallon plastic trash barrel. A petri
dish with 200 mg of the 1-MCP powder was then
placed on top of the apples and was mixed with 5 ml of
warm water. The barrel was immediately covered with
plexiglass and sealed with silicon vacuum grease. This
procedure was to produce a concentration of 1 part per
million 1-MCP in the barrel. The barrel was then
returned to cold storage. After 24 hours the barrel was
removed from cold storage, the apples were removed,
returned to conventional boxes, and put back into cold
storage.

We looked at only some of the known effects of 1 -
MCP on fruit. Internal ethylene and fruit firmness
were measured at harvest and following storage. Some
fruit were weighed at these times as well, as it had been
reported that I -MCP could influence weight loss in
apple. Background color was recorded for Royal Gala.

Fruit Notes, Volume 67, Summer, 2002

Table 1 . Effects of 1 -MCP on ethylem

: content and firmness GingerGold apples

after 32F air

storage for 3

or 8 weeks,

each followed by a week at 70F to evaluate shelf life.

Harvest

After 3 wks Plus 1 wk

After 8

Plus 1 wk

Treatment

date

harvest

at 32F at 70F

wks at 32F

at70F

Internal ethylene concentration

(ppm)

Check

8/20

101 710

109

483

8/27

474

335

663

1-MCP

8/20

0.4 1.1

1.4

4.4

8/27

1.5

3.3

13.2

Firmness (pounds pressure)

Check

8/20

19.8

16.3 11.6

15.4

13.8

8/27

18.9

15.0 11.1

14.3

12.0

1-MCP

8/20

19.8

17.9 19.7

16.6

17.9

8/27

18.9

17.9 18.2

16.3

15.6

Table 2. Effects of 1-MCP on internal ethylene concentration, firmness, and background color of
Royal Gala apples after 32F air storage for 90 or 150 days, each followed by 1 week at 70F to
evaluate shelf life.

Harvest

After 90

Plus 1 wk at

After 150

Plus 1 wk at

Treatment

date

harvest

days at 32F

70F

days at 32F

70F

Internal ethylene

concentration

(ppm)

9/4

0.8

195

169

Check

9/11

2.3

169

215

1-MCP

9/4

0.8

0.3

0.7

0.5

0.4

9/11

2.3

0.8

0.6

0.3

0.4

Firmness (pounds pressure)

Check

9/4

20.4

17.5

16.4

16.1

15.3

9/11

19.4

16.9

14.9

15.1

14.9

1-MCP

9/4

20.4

18.9

18.8

17.9

17.3

9/11

19.4

17.1

17.2

16.5

16.6

Background color''

Check

9/4

6.5

7.4

7.8

7.7

9/11

6.4

7.8

8.3

8.1

1-MCP

9/4

6.0

6.8

7.2

9/11

6.4

7.1

6.5

7.9

Background color ratings of 1 - 1 move from green ( 1 ) through white-green to yellow (10).
The dividing line between green/white-green and yellow was between 6 and 7.

Fruit Notes, Volume 67, Summer, 2002

Results by Cultivar

Ginger Gold. Ginger Gold is not a
cultivar normally associated with long
storage. We tested it primarily to test the
application method, but results were
striking (Table 1 ). Fruit were stored for
either three or eight weeks in 32F air, after
which half the fruit were evaluated and
the rest were kept at room temperature for
a week before being evaluated.

1-MCP greatly suppressed ethylene
levels in the fruit. In fact, for the August
27 harvest it caused the ethylene present
at harvest to drop sharply during and
following storage. However, over time,
both in storage and after storage, the
ethylene gradually rose as the fruit slowly
overcame the 1-MCP effect.

Firmness of untreated fruit predict-
ably dropped rapidly during and follow-
ing storage, producing unacceptably soft
apples. 1 -MCP treated fruit also softened
during storage, but far less. In particular,
little additional softening occurred at
room temperature following storage,
whereas untreated fruit softened greatly
after storage.

Ginger Gold apples treated with 1-MCP were
still firm and appealing after eight weeks in air
storage plus one week at room temperature, whereas
untreated fruit were unacceptable.

Royal Gala. Royal Gala were harvested on two
dates, treated with 1-MCP like Ginger Gold, and
stored in 32F air, but for longer times, i.e., 90 and 1 50
days. Untreated fruit increased in ethylene content
during and following storage, but their maximum
levels were only about one-third the maximum levels
in Ginger Gold (Table 2). 1-MCP treatment severely
suppressed ethylene levels in Royal Gala. Again, at
second harvest 1 -MCP suppressed the ethylene levels
in treated frui to below what was there at harvest, but
in this cultivar, ethylene levels never gave any
indication of increasing following treatment.

Untreated fruit softened during and following
storage, and also developed a progressively yellower
background color. Treated fruit also softened during
storage, but like Ginger Gold, did not soften at room
temperature following storage and were substantially

Table 3. Effects of 1-MCP on ethylene concentration, fruit
firmness, and superficial scald development of Mcintosh apples
in two experiments. Data were collected after 7 days at 70F
following each air storage period at 32F to evaluate shelf life.

After 7 days at 70F

Treatment

Days in

32F
storage

Ethylene Firmness
(ppm) (lbs) Scald (%)

Mean

of three strains har\>ested 9/10

Check

0.04 17.2

743 10.7 3

175

972 9.2 100

1-MCP

0.04 17.2

52 12.4 3

175

816 11.6

Retain

""-treated fruit harvested 10/1

Check

2.2 14.4

381 10.1

150

649 9.1

1-MCP

2.2 14.4

1 12.3

150

35 10.8

firmer than the untreated ones at all evaluations.
Treated fruit also became yellower with time, but were
generally less yellow than the controls. Harvest date
did not influence the effect of 1-MCP; harvest
differences were retained, but not changed.

Mcintosh. Mcintosh is of particular interest in
New England and two experiments were conducted. In
the first, three strains (Rogers, Morspur, and SpurMac)
were harvested on September 10 when the fruit were
just beginning to produce ethylene. The strains were
all treated as described above, and stored at 32F in air
for 90 or 175 days, plus 7 days at 70F prior to
evaluation. In the second experiment, some Retain'"
treated fruit were harvested on October 1 , and treated
and stored the same as the strains, except for a
maximum of 150 rather than 175 days. This is a late
harvest date, and fruit averaged over 2 ppm internal
ethylene at harvest.

The three strains all responded similarly to 1 -MCP
so only their averages are presented in Table 3. (Note
that Rogers were about 3/4 pound softer than the

Fruit Notes, Volume 67, Summer, 2002

others, but this was true
across time and treatment
and was not treatment-re-
lated). Untreated fruit accu-
mulated very high ethylene
concentrations, and 1-MCP
only delayed the rise, the
fruit eventually reaching
about the same level as the
untreated ones. Untreated
ones softened excessively,
although it should be noted
that they were stored beyond
the normal limits for Mcin-
tosh. 1-MCP-treated fruit
also softened, but much less,
and were still acceptably
firm after the longer storage
time. The untreated fruit also
scalded during the longer
storage time, whereas 1-
MCP treatment prevented this from happening.

The Retain"" treated fruit harvested three weeks
later responded much the same as the three strains,
except that ethylene increased far less and no scald
developed. These differences are not likely associated
with 1 -MCP, but rather occurred because Retain™ has
the effect of reducing ethylene, and late harvest
reduces scald.

Delicious. Redchief Delicious were harvested on
October 1 and October 1 1 , treated with 1 -MCP, and
stored in 32F air for 90 or 1 50 days, and then for 7 more
days at 70F. Subsamples were weighed at harvest,
placed in paper bags, and stored like the others, and
reweighed at removal from storage and again after 7
days at room temperature.

Fruit from the two harvests responded the same to
treatment and storage, so in Table 4 the means of the
two harvests are presented. Ethylene content of
untreated fruit increased substantially with storage
time and after transfer to 70F. 1 -MCP again caused
ethylene content during storage to fall below that at
harvest, but it rose over time and during fruit warming,
although it never approached the ethylene levels of
untreated fruit. Untreated fruit softened greatly during
storage and at room temperature. 1-MCP treated fruit
also softened, but not nearly as much as the untreated
fruit. Both treated and untreated Delicious lost weight
during and following storage, but 1-MCP reduced the

Table 4. Effects of 1-MCP on internal ethylene concentration, fruit firmness,
and weight loss of Redchief Delicious apples after 32F air storage for 90 or
150 days, each followed by 1 week at 70F to evaluate shelf life.

Fruit

Treatment

Storage
time (days)

Ethylene
(ppm)

Firmness
(lbs)

weight
(grams)

Weight
loss (%)

Check

17.4

164

159

14.8

158

3.2

90+7

309

13.9

156

4.6

150

266

13.2

150+7

401

12.7

1-MCP

17.4

166

15.9

162

2.7

90+7

16.1

159

4.0

150

15.4

150+7

15.2

size of this loss.

Spigold. In order to determine if 1-MCP could
inhibit ethylene production even if fruit were already
producing substantial ethylene, Spigold were har-
vested October 22 (very late!) with average Starch
Index of 7.6 (Cornell generic chart) and average
internal ethylene concentration of 3 1 ppm. Fruit were
treated like the other cultivars, and stored for 90 or 1 50
days in 32F air, plus 7 days at 70F. Table 5 shows that
the ability of 1-MCP to reduce ethylene production
was significant despite the fact that the fruit were
already producing a substantial amount of ethylene
prior to the 1-MCP treatment. 1-MCP treated fruit
were firmer, too, although there was substantial fruit-
to-fruit variation in firmness due to very large fruit
sizes.

Discussion

Treatment with 1-MCP consistently resulted in
firmer fruit following cold storage. This firmness
advantage remained or was enhanced after fruit were
left at room temperature for a week. 1-MCP-treated
fruit did, however, soften over time, just not as much as
did the untreated fruit. Ethylene production was
suppressed well into the storage period. The duration
of this suppression was cultivar dependent. Ethylene
production was essentially shut down by 1-MCP

Fruit Notes, Volume 67, Summer, 2002

Table 5. Effects of 1-MCP on internal ethylene concentration and fruit
firmness on Spigold apples harvested October 22 following 32F air storage
for 90 or 150 days, each followed by 1 week at 70F to evaluate shelf life.

90 days cold storage 1 50 days cold storage

1-MCP
applied

At harvest

1 day
warm

7 days
warm

1 day
warm

7 days
warm

Check
1-MCP

14.6

Internal ethylene concentration (ppm)

180 359 209

49 39 64

Firmness (pounds)

10.2 10.0 9.4

11.0 11.8 10.6

384
185

9.1

10.0

treatment for at least 150 days in Gala. Ethylene
production in 1-MCP treated Mcintosh reached levels
of control fruit by 1 75 days of cold storage in fruit
which had not been treated with Retain"". Weight loss
during cold storage was significantly reduced in
Delicious, and weight loss during a week at room
temperature following cold storage was reduced by 1-
MCP treatment of Mcintosh (data not shown) and
Delicious. A very significant result was that all
cultivars harvested on different dates showed the same
results between harvest dates, except that changes that
occurred before harvest were not reversed. Thus, 1-
MCP had some benefit regardless of ripeness at
harvest. Two important effects were not measured.
We did not measure volatile production (or aroma),
although we did observe that aroma was lacking in the
1 -MCP-treated Gala following storage. We did not do
taste tests, as the product is not registered for use. The
only 1 -MCP-treated fruit which fully recovered
ethylene production were the non-Retain™ Mcintosh
harvested on September 10 and stored for 175 days in
32F air. Even these fruit retained their firmness

advantage over untreated fruit
and did not develop superficial
scald as the other fruit did. The
Ginger Gold, Retain'"-treated
Mcintosh, Delicious, and
Spigold which had been treated
with 1-MCP all started produc-
ing more ethylene after a time in
storage, but did not come close
to catching up with their
untreated counterparts.

Based on this preliminary
investigation, 1 -MCP treatment
appears promising for increased
firmness retention in a broad
spectrum of apple cultivars,
including Mcintosh as well as
for scald control. We observed
scald only on Mcintosh m this
study, but others have observed
similar results on other cultivars, so a general response
may exist although further tests are essential. Since
maximum 1-MCP effect may depend on early harvest,
at least in some cultivars, scald protection would be an
extremely valuable benefit. Combining 1-MCP
treatment with CA might enhance the effect of either
one alone. Taste tests will be essential to determine if
the firmness advantage is offset by losses in flavor or
aroma. If so, this is likely to be cultivar dependent.
Seasonal variation in effectiveness of 1 -MCP has been
reported, so we need to determine how repeatable
these results are. Finally it remains to be determined
how 1-MCP can be applied efficiently on a
commercial scale. Nevertheless, despite these issues,
this is an extremely interesting new material.

A cknowledgm ent

We would like to thank Harlow Warner of
AgroFresh, Inc . for supplying the 1-MCP used in these
experiments.

it it it it it

Fruit Notes, Volume 67, Summer, 2002

Species Composition of Tliird-
generation Leafminers in IVIassachusetts
Apple Orchiards: 1997-1999

Starker Wright, Baige Zhao, and Ronald Proliopy
Department of Entomology, University of Massachusetts

In Massachusetts, leafminers (LM) have been a
consistent threat to the quality of apple foliage in
commercial orchards ever since their initial rise to
prominence in the late 1970s due largely to the onset
of resistance to organophosphate insecticides. Over
the past 10 years or so, LM in Massachusetts orchards
exhibited three rather distinctly different patterns of
population growth. In some orchards, growth has been
slight or at most moderate, never exceeding a threshold
requiring insecticide treatment. In other orchards,
growth also has been slight, owing to annual or biannual
application of a preventative insecticide spray against
LM. In still other orchards, populations have
undergone a period of explosive grov^h, followed by
rapid decline subsequent to insecticide treatment, only
to be followed by another period of explosive growth.

Several factors might account for these observed
differences in characteristic form of LM population
growth. They include: (1 ) amounts, types and timings
of pesticides directed against other orchard pests, (2)
amounts, types and timings of pesticides directed
against LM, (3) the nature of the habitat adjacent to
commercial orchards, (4) the species composition and
diversity of parasitoids that can provide biocontrol of
LM, and (5) the species composition of LM themselves.

In regard to the latter, through the 1980s,
commercial orchards in Massachusetts were dominated
by the apple blotch leafminers (ABLM) Phyllonorycter
crataegella, which is native to the USA and infests a
rather wide variety of plant species. During the 1990s,
however, we saw a rise in numbers of spotted tentiform
leafminers (STLM) Phyllonorycter blancardella,
which is an introduced species from Europe and infests
only apples and crabapples.

Here, we report results of a study conducted from
1997-1999 aimed primarily at characterizing the
species composition of third-generation LM in 12

commercial apple orchards in Massachusetts during
this three-year period. Our secondary aim was to
attempt to relate LM species composition with LM
population density and patterns of insecticide use
against LM. Other articles in this and future issues of
Fruit Notes will deal with LM populations as
influenced by parasitism, border area composition, and
type of perimeter-row cultivar.

Materials & Methods

In November in each of three years (1997-1999),
we sampled 10 leaves on each of 30 trees in each of 12
commercial orchards, pointing blindly toward the tree
canopy and picking the first leaf encountered by hand.
We counted the total number of third-generation mines
in the 300-leaf sample. After this, we picked as many
mine-infested leaves as could be found in a one-hour
search of the orchard (maximum of 300 leaves) and
returned them to the laboratory for examination of
pupae under a microscope. Pupae can be classified
according to LM species on the basis of the structure
of minute "hooks" present on the posterior end. In
1999, we also sampled mined leaves from four orchards
that had been abandoned for at least 5 years.

Results

To facilitate presentation of results, sampled
commercial orchards are grouped according to three
geographical areas in Massachusetts: Orchards A, B,
and C in the west, orchards D, E, F, and G in the center,
and orchards H, I, J, K, and L in the east.

Data in Table 1 show that in each of these three
geographical regions, at least one sampled orchard
experienced a rather high LM density level in at least
one of the three years, and at least one sampled orchard

Fruit Notes, Volume 67, Summer, 2002

Table 1.

Density of third

-generat

ion

leafminers

in 12

commerc

al and 4 unmanaged

apple orchards in |

Massachusetts (1997-1999).

Number of mines

per

100 leaves

Orchard

Location

1997

1998

1999

Ashfield

104

Shelbume

Colrain

Belchertown

Brimfield

Warren

304

Brookfield

191

Princeton

Leominster

203

311

Sterling

Northboro

305

Ashfield*

—

Deerfield*

—

Leominster*

—

Sterling*

—

* Abandoned orchards.

remained at a rather low LM density throughout the
three years. Similarly, data in Table 2 show that in
each of the three geographical regions, at least one
sampled orchard was dominated by ABLM across the
three years and at least one other commercial orchard
was dominated by STLM across the three years. Thus,
neither the population density nor the species
composition of LM appeared to be affected by
geographical location within Massachusetts.

In all, there were five commercial orchards (A, F,
G, I, L) wherein the density of third-generation mines
reached 100 per 100 leaves in at least one of the three
years (Table 1). In three of these five orchards (A, F,
I), the dominant species each year was STLM (Table
2). In the fourth orchard (G), ABLM dominated in
1997 but STLM in 1998 and 1999. In the fifth orchard
(L), ABLM dominated each year. In the remaining

seven orchards (B, C, D, E, H, J, K), the
density of third-generation mines did not
reach 100 mines per 100 leaves in any of
the three years (Table 1). In six of these
seven orchards, the dominant species each
year was ABLM (Table 2). In the seventh
orchard (D), ABLM was distinctly
dominant m 1997 but STLM was distinctly
dominant in 1998 and 1999. Thus, the
highest densities of leafminers were
associated largely with dominance by
STLM, whereas lower densities were
associated largely with dominance by
ABLM.

As summarized in Table 3, none of the
four abandoned orchards (M, N, O, P)
received an insecticide treatment against
LM during any of the three years, and five
of the commercial orchards (A, D, F, G, I)
received no insecticide treatment against
LM in 1997 and 1998, although four of the
five received such treatment in 1999. All
nine of these orchards were dominated by
STLM in 1998 and 1999. In contrast, seven
of the commercial orchards (B, C, E, H, J,
K, L) received an insecticide treatment
targeted against LM in two or all three
years. Each year, all seven of these orchards
were dominated by ABLM.

Thus, no or infrequent spraying against
leafminers appears to be associated with the
nse of STLM to the status of dominance,
whereas frequent spraying seems to be associated with
dominance by ABLM. Our data are insufficient for
establishing a relationship between time since
application of an insecticide against leafminers and the
rise of ABLM to dominance, although the data in Table
3 for 1 999 for orchards A, D, G, and I suggest that such
a rise to dominance by ABLM does not occur during
the same year that insecticide is applied.

Conclusions

Results of this three-year study suggest that
dominance in species composition of LM in
Massachusetts orchards was (1) not associated with
any particular geographical region within the state, (2)
was apparently associated with LM density, and (3)
was apparently associated with frequency of insecticide

Fruit Notes, Volume 67, Summer, 2002

Table 2.

Species compositi

on of third-generation leaftniner pupae

in 12 commercial

apple orchards (1997-1999) and

four abandoned apple orchards (1999) in

Massachusetts. Appl

s blotch

leafminer = ABLM.

Spotted

tentiform

leafminei

= STLM.

1997

1998

1999

No.

ABLM

STLM

No.

ABLM

STLM

No.

ABLM

STLM

Orchard

Location

pupae

(%)

pupae

(%)

pupae

(%)

Ashfield

245*

Shelbume

19*

100

90*

100

Colrain

100

33*

178*

100

Belchertown

109

121*

Brimfield

181*

76*

139*

Warren

250

Brookfield

199

124

13*

Princeton

18*

100

44*

161*

Leominster

164*

Sterling

113*

84*

189*

Sterling

102*

58*

184*

Northboro

23*

100

79*

100

M**

Ashfield

—

100

N**

Deerfield

—

122

100

O**

Leominster

—

100

P**

Sterling

—

* Indicates that either Pounce, Asana, Provado, or Agri-

Viek was

applied against first-generation

LM that-

year.

** Abandoned orchards.

Table 3. Relationship between frequency of application
species in Massachusetts orchards.

of insecticide

against leafminers and dominant leafminer

Orchards

Insecticide applied against LM

Dominant species of LM

1997 1998

1999

1997

1998

1999

Abandoned (M.N.O.P)
Commercial (A,D,F,G,1)
Commercial (B,C,E,H,J,K,L)

None None
None None
B, E,H,J,K,L C,E,H,J,K

None

A,D,G,1

B,C,E,H,J,K,L

STLM
STLM*
ABLM

STLM
STLM
ABLM

* ABLM in orchards D and G

Fruit Notes, Volume 67, Summer, 2002

application targeted against LM. With little exception,
dominance by STLM in commercial orchards was
associated with higher LM population density and no
or infrequent use of insecticide to control LM.
Conversely, dominance by ABLM was associated with
lower LM population density and rather frequent use
of insecticide to control LM.

In any scientific investigation, establishment of a
strong association or correlation between two variables
should not be taken to imply cause and effect. Further
study is needed to determine the true cause or causes
underlying the dominance of ABLM or STLM in a
given orchard.

Even so, one can postulate a possible scenario with
the following steps: (1) dominance of STLM in
abandoned apple orchards either because of apple being
a more favored host of STLM than it is of ABLM,
because STLM is less susceptible to parasitism than is
ABLM, because STLM is a better competitor for host

resources than is ABLM, or a combination of these,
(2) movement of STLM adults into an orchard currently
colonized by ABLM, (3) more rapid and extensive
buildup of STLM in commercial orchards than is
characteristic of ABLM, leading to (4) application of
a targeted insecticide against LM that exerts a greater
effect on STLM than ABLM and results in (5)
temporary dominance by ABLM. Further study is
needed to evaluate this possible scenario.

A cknowledgem en ts

We thank the apple growers who participated in
this study: John Blanchard, Bill Broderick, Dave
Chandler, Dave Cheney, Dana Clark, Tom Lincoln,
Dave Chandler, Joe Sincuk, Tim Smith, Mo Tougas,
and Bob Tuttle. We are also grateful for the support of
a USDA Northeast Region S ARE grant and State IPM
funds.

"k i: "k ic "k

Fruit Notes, Volume 67, Summer, 2002

Population Dynamics of Leafminers and
Their Parasitoids in IViassachusetts
Apple Orchards: 1999 Studies

Baige Zhao, Starker Wright, and Ronald Prokopy
Department of Entomology, University of Massachusetts

In the preceding article, we presented information
on the species composition of third-generation
leafminers found in 12 commercial and four abandoned
Massachusetts apple orchards during 1997, 1998, and
1999. Results showed that each year, all four
abandoned orchards and three of the commercial
orchards were dominated by spotted tentiform
leafminers (STLM). Conversely, each year seven of
the commercial orchards were dominated by apple
blotch leafminers (ABLM). Two of the commercial
orchards were dominated by ABLM in 1997 but by
STLM in 1 998 and 1 999. We concluded that the degree
to which apple is a preferred host of STLM relative to
ABLM and the degree to which STLM relative to
ABLM is susceptible to insecticides could be principal
factors associated with dominance by STLM vs. ABLM
but suggested that parasitoid species composition and
abundance might also be contributing factors.

Here, we present information on the species
composition and abundance of leafminers and their
principal parasitoids for each of the three generations
of leafminers that occurred in 1999 in these 12
commercial and four abandoned orchards.

Materials & Methods

In June, August, and November of 1999, we
sampled 10 leaves on each of 30 trees in each
commercial and abandoned orchard for total numbers
of first-, second-, and third-generation mines,
respectively, in each 300-leaf sample. After taking each
sample, we collected as many infested leaves
(containing tissue-feeding mines) as possible during a
1 -hour search of the orchard up to a maximum of 1 00
mines per orchard for the first and second generations
and 300 mines per orchard for the third generation.

Mined leaves were returned to the laboratory for

examination under a microscope to determine presence
and identity of parasitoids and identity of leafminers.
A complete categorization of the extent of parasitism
of mined leaves would include presence of holes in
leaf tissue made by parasitoid adults seeking to feed
upon leafminer larvae as well as presence or evidence
of parasitoid eggs. Because such evidence of parasitism
was very difficult to determine with certainty, we
confined our confirmation of parasitism to presence
of parasitoid larvae, pupae (or their remains), and
adults. Consequently, the values presented here for
extent of parasitism of leafminers were undoubtedly
lower than actual percentages occurring in orchards.

Results

Data in Table 1 show the abundance of leafminers
in each generation in each orchard. Data in Table 2
show the species composition of leafminers and
percentages of leafminer larvae parasitized by the two
dominant parasitoids {Sympiesis tnarylandensis and
Pholetesor ornigis) in each generation in each orchard.
Owing to insufficient abundance of first-generation
mines in some orchards, there are some unfortunate
gaps in the data set for this generation of leafminers.

In the four abandoned orchards (M, N, O, P),
STLM was the exclusive (or nearly exclusive)
leafminer species present in each of the three
generations. In five of the commercial orchards (A,
D, F, G, I), STLM dominated in the second and third
generations. STLM dominated also in the first
generation in two of these orchards (A and I). ABLM
slightly dominated STLM in the first generation in
Orchard D, and no first-generation data were available
for Orchards F and G. In the other seven commercial
orchards (B, C, E, H, J, K, L), ABLM was markedly
dominant in the second and third generations as well

Fruit Notes, Volume 67, Summer, 2002

Table 1.

Density of first-,

second-, and third-generation

leafminers

in 12 commerc

al and four

abandoned apple

orchards ir

I Massachusetts in

1999.

Number of mines per

100 leaves

First

Second

Third

Orchard

generation

6.7

2.5

21.0

4.3

9.5

14.5

0.7

22.5

8.5

1.3

0.5

12.5

1.0

5.0

23.0

0.3

29.0

89.0

0.0

2.5

10.5

1.0

3.0

7.0

19.7

6.5

21.5

0.0

7.0

0.3

2.0

10.5

5.3

0.5

4.5

23.7

8.0

15.0

17.5

4.5

23.0

70.0

17.0

8.0

15.7

2.0

11.0

* Abandoned orchards.

as in the first generation where data were available (B,
C, E, J). Thus, with the exception of Orchard D, data
indicate that the leafminer species that dominated in
the first generation remained dominant in the second
and third generations.

To faciHtate comparisons, the 16 orchards were
categorized into four groups (Table 3). Data in Table
3 show that for abandoned orchards M, N, O, and P, all
of which were dominated by STLM and none of which
received insecticide in 1999, LM population density
decreased (on average) by more than half from the first
to the third leafminer generation. In contrast, for
commercial orchard F, likewise dominated by STLM
and likewise having received no insecticide treatment
against LM in 1999, LM population density increased
89-fold from the first to the third leafminer generation.
In commercial orchards A, D, G, and I, also dominated
by STLM but having received an insecticide treatment

against LM in May of 1999, LM
population density increased by an average
of about two-fold from the first to the third
leafminer generation. Finally, in
commercial orchards B, C, E, H, J, K, and
L, dominated by ABLM and having
received an insecticide treatment against
LM in May of 1999, LM population
density increased by an average of about
five-fold from the first to the third
leafminer generation.

For all four categories of orchards,
parasitism by S. maiylandensis decreased
progressively from the first to the third LM
generation, averaging (across all
generations) 36% for abandoned orchards,
26% for commercial orchards dominated
by STLM and treated against LM in 1 999,
and 18% for commercial orchards
dominated by ABLM. Parasitism by P.
ornigis across all three generations
averaged 1 1 % for abandoned orchards, 9%
for commercial orchards dominated by
STLM and treated against LM in 1999,
and 2% for commercial orchards
dominated by ABLM, with no consistent
trend toward increasing or decreasing
abundance across generations.

Together, data in Table 3 suggest that
the high amount of total parasitism of LM
(47%) in the abandoned orchards may
have been a principal factor associated with the
decrease rather than an increase in LM population
density from the first to the third LM generation. The
level of total parasitism in Orchard F was only about
one-third that in the abandoned orchards and was
insufficient to prevent the 89-fold increase in LM
population density from the first to the third generation.
The substantially greater amount of total parasitism
(35%) m STLM-dominated orchards treated against
LM in 1999 than total parasitism (20%) in ABLM-
dominated orchards treated against LM m 1999 may
have played a role in the lower rate of first-to-third-
generation LM population growth in the former (two-
fold) compared with the latter (five-fold).

Finally, the data m Table 3 indicate that P. ornigis
parasitoids were considerably more abundant in
abandoned as well as LM-treated orchards dominated
by STLM than in LM-treated orchards dominated by

Fruit Notes, Volume 67, Summer, 2002

Table 2.

Species

composition of leafminers

and percentages

of leafminer

larvae

parasitized during the

first, second, and third generations of leafminers in

12 commercial and four abandoned app

e orchards in |

Massachusetts in

1999.

Orchard

First generation (%)

Second generation (%)

Third generation (%)

No.*

ABLM

** S.m.*** P.o***

. ABLM

S.m.

P.O.

No.

ABLM

S.m.

P.O.

103

100

145

104

100

126

102

202

100

177

102

100

113

100

103

* Numbers of mature mines examined.

** Percent of total pupae

identified

as ABLM; remaining percent was STLM.

*** Percent of LM larvae

parasitized by Sympiesis maiylandet

isis (S

m.) or

Pholetesor omigis (P.o

•)•

Table 3. Relationship betweer

leafminer-targeted insecticide treatments.

dominant

species

and population buildup of 1

jafminers and

extent of parasitism of leafminers m Massachusetts ore

lards in

1999.

Numbe

of mines

per 100

Parasitism by

Parasitism by P

omigis

Insecticide

leaves

marylandensis (%)

(%)

treatment
against LM

Dominant
species of

First

Second

Third

First

Second

Third

First

Second

Third

Orchards

m 1999

gen.

Abandoned (M.N.O.P)

STLM

Commercial (F)

STLM

Commercial (A,[),G,1)

Yes

STLM

Commercial (B,C,E,H,J,K,L)

Yes

ABLM

Fruit Notes, Volume 67, Summer, 2002

AELM, suggesting a possible preference of P. ornigis
for STLM.

Conclusions

Several of the data trends shown and discussed here
and in the preceding article for Massachusetts orchards
are similar to trends reported earlier by Chris Maier,
whose outstanding work on leafminers in Connecticut
orchards inspired our studies. Notable among the
trends for both Connecticut and Massachusetts are ( 1)
a strong tendency toward a shift in dominance from
ABLM to STLM with decreasing frequency of annual
insecticide treatment against LM, (2) a strong tendency
toward lower parasitism of LM in sprayed than
unsprayed (abandoned) orchards, and (3) generally
greater levels of LM parasitism by S. maiylandensis
than by P. ornigis, especially among populations of
ABLM.

Parasitoids alone appear to be sufficient to exert
effective population suppression of LM in abandoned
orchards and may have contributed to population
suppression of LM in those commercial orchards
designated here as A, D, F, G, and L which received no
insecticide treatments against LM in 1997 and 1998.
Even so, four of these five STLM-dominated orchards
(A, D, G, I) did require a LM -targeted treatment in 1 999,
suggesting that parasitoids alone were insufficient to
effectively suppress STLM below potentially damaging

levels. The lowest levels of LM parasitism found in
1999 were in orchards designated here as B, C, E, H,
J, K, and L, all of which were dominated by ABLM
and all of which received a LM-targeted insecticide in
1999 (all seven of these orchards also received a LM-
targeted insecticide in 1997 and/or 1998).

The 89-fold level of first- to third-generation
population increase in STLM-dominated Orchard F in
1999 was explosive in comparison with the decrease
in average first- to third-generation population density
that characterized STLM-dominated abandoned
orchards in 1999. For reasons yet unknown but
possibly associated with apple being the principal host
of STLM and only one among many different hosts of
ABLM, unattended populations of STLM in
commercial orchards could represent a greater threat
than populations of ABLM. We hope to explore this
possibility in future research.

A cknowledgements

We thank the apple growers who participated in
this study: John Blanchard, Bill Broderick, Dave
Chandler, Dave Cheney, Dana Clark, Tony Lincoln,
Dave Shearer, Joe Sincuk, Tim Smith, Mo Tougas, and
Bob Tuttle. We are also grateful for the support of a
USDA Northeast Region SARE grant and state IPM
funds.

it it it *k it

Fruit Notes, Volume 67, Summer, 2002

Performance of the V Series
Apple Rootstocks During Six
Growing Seasons

Wesley Autio and James Krupa

Department of Plant & Soil Sciences, University of Massachusetts

The Vineland (V) series of apple rootstocks was
from open pollinated seeds from Kerr applecrab (a
cross between Dolgo crabapple and Haralson apple).
Dr. Aleck Hutchinson collected seeds from 1957
through 1960. Trees were planted in Vineland,
Ontario, and seedlings were selected based on the
potential for dwarfing, hardiness, ease of propagation,
and field resistance to powdery mildew, fireblight, and
wooly apple aphid. By 1971, when the rootstock
breeding project was terminated in Vineland, seven
clones (V.l, V.2, V.3, V.4, V.5, V.6, and V.7) had
been selected. The first evaluation of these clones as
rootstocks began with a tnal in 1974. In these early
evaluations, V.l and V.3 were determined to produce
trees similar to M.9 in size, V.2 produced M.26-sized
trees, and V.4 resulted in trees similar in size to those
on M.7. The Vineland rootstocks were almost
forgotten for a number of years, but interest was
rekindled in the early-mid 1990s. V.l and V.3 were

included in NC-140 trials, a New England/Nova Scotia
trial, and a Northeastern U.S. trial. (For more details of
the history of the Vineland series, see the following
article: Elfving, D.C., I. Schecter, and A. Hutchinson.
1993. The history of the Vineland (V.) apple
rootstocks. Fruit Varieties Journal Al •.52-5%.)

To study performance of the V rootstocks under
Massachusetts conditions, a small trial was estab-
lished in 1 996 at the University of Massachusetts Cold
Spring Orchard Research & Education Center in
Belchertown, including Rogers Red Mcintosh on V. 1 ,
V.2, V.3, V.4, V.7, and M.26 EMLA. Trees were
individually staked and generally maintained as
slender spindles. Each year, trunk circumference was
measured and total yield was assessed.

After six growing seasons, dramatic differences in
tree size existed. Trees on V.4 were more than twice as
large as the next largest trees (Table 1). Under our
conditions, these trees likely would be larger than

Table 1 . Performance of Roge

rs Red Mcintosh apple

trees on

several rootstocks

planted

in 1996 at the

University of Massachusetts Cold Spring

Orchard Research & Education Center.

Yield efficiency

Yield

per tree (kg)

(kg/cm- TCA)

Fruit

weight (g)

T" 1

1 ruriK cross-

sectional

Cumulative

Average

Rootstock

area (cm^)

2001

(1998-2001)

2001

(1998-2001)

2001

(1998-2001)

V.l

13.1

0.7

1.7

138

147

V.2

17.3

0.6

1.3

147

148

V.3

10.6

0.6

2.1

135

140

V.4

48.2

0.3

0.7

155

148

V.7

19.6

0.3

1.3

121

139

M.26 EMLA

18.0

0.7

1.5

148

154

Fruit Notes, Volume 67, Summer, 2002

comparable trees on M.7. Trees on V.2 and V.7 were
similar in size to those on M.26 EMLA. Next smallest
were trees on V. 1 . In another trial at the UMass Cold
Spring Orchard, trees on V.l were somewhat larger
thna trees on M.26 EMLA. The smallest trees were on
V.3, likely similar in size to comparable trees on M.9.
To date, cumulative yield (1998-2001) was
highest from the largest trees (Table 1). However,
when adjusted for tree size, the most yield efficient
trees were on V.3, V.l, and M.26 EMLA (Table 1).
The least yield efficient trees were on V.4. In 2001,

V.4 resulted in significantly larger fruit than did V.7,
but overall, there was no consistent effect of rootstock
on fruit size

These trees are too young to make a great number
of conclusions, but these results along with those from
three other trials at the UMass Cold Spring Orchard
suggest that V.l and V.3 are promising, dwarfing
rootstocks. Their hardiness, potential disease
resistance, and yield efficiency make them worthy of
continued trial.

ic ic i: i: "k

Fruit Notes, Volume 67, Summer, 2002

Fruit Notes

University of Massachusetts
Friilt Department of Plant & Soil Sciences
lllllgj 205 Bowditch Hall

ni^-i Amherst, MA 01003

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Notes

ijewC'mlana

Volume 67, Number 4
FALL ISSUE, 2002

Table of Contents

Evaluation of Formulations and Release Rates of Benzaldehyde, an Attractive Fruit Odor for Plum Curculios

Jaime Pihero, Sara Hoffmann, and Ronald Prokopy ^

Influence of Insecticide on the Ability of Traps to Capture Plum Curculios

Jaime Pinero, Sara Hoffmann, Everardo Bigurra, and Ronald Prokopy °

Devising an Attractive Bait to Monitor the Seasonal Course of Plum Curculio Immigration into Apple Orchards using Traps

Jaime Pinero, Sara Hoffman, Everardo Bigurra, and Ronald Prokopy ^^

Editors:

Wesley R. Autio
William J. Bramlage

Publication Information:

Fruit Notes (ISSN 0427-6906) is pub-
lished each January, April, July, and
October by the University of Massachu-
setts in cooperation with the other New
England state universities.

Correspondence should be sent to:

Fruit Notes

Department of Plant & Soil Sciences
205 Bowditch Hall
University of Massachusetts
Amherst, MA 01003

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 UMass Extension, Stephen Demski, Director, in furtherance of the acts of May 8 and June 30,
1914. UMass Extension offers equal opportunity in programs and employment.

Evaluation of Formulations and Release
Rates of Benzaldehyde, an Attractive
Fruit Odor for Plum Curculios

Jaime Pinero, Sara Hoffmann, and Ronald Prokopy
Department of Entomology, University of Massachusetts

In the 2000 Issue of Fruit Notes, we reported on a
2000 study showing that benzaldehyde in association
with plum curculio (PC) pheromone (grandisoic acid)
was the most attractive odor bait combination for PCs
when compared with other odor baits affixed to panel
and pyramid traps. In that study, we also found that
although traps baited with benzaldehyde plus
pheromone were very effective at determining the
beginning, peak, and end of PC immigration into apple
orchards from overwintering sites, benzaldehyde
seemed to be less attractive to PCs after -10 days of
exposure to sunlight. Subsequently, we found that the
clear high-density polyethylene vials used in that study
allowed UV-polymerization of about 10% of the
benzaldehyde contained in the vials, which may have
diminished or masked some of the attractiveness of
benzaldehyde. We concluded from that study that
research should be aimed at improving the formulation
and longevity of benzaldehyde and optimizing the
amount of benzaldehyde used as odor bait.

Here, in an attempt to improve trap ability to
capture PCs, we compared different formulations,
release rates, and positions of benzaldehyde-releasing
dispensers in tops of branch-mimicking cylinder traps
placed on apple tree limbs. We also evaluated different
amounts of benzaldehyde in association with PC
pheromone in Circle traps, which are wrapped
completely and tightly around apple tree trunks and
are designed to intercept adults crawling up tree trunks.

Materials & Methods

We performed four different experiments. The first
three were conducted in 200 1 and involved use of black
cylinder traps. The fourth was carried out in 2002 and
involved use of Circle traps. All evaluations were
performed in unsprayed sections of apple orchards or

in backyards containing unsprayed apple trees.

Experiment 1. In this test, conducted from June 6
to July 3 (200 1 ) in Atkins orchard (Belchertown, MA),
we evaluated (using cylinder traps) four different
formulations of benzaldehyde alone (without
pheromone) released from dispensers placed either
inside or outside of the frap tops. Formulations tested
were: (1) Great Lakes IPM (Vestaburg, MI), (2) IPM
Technologies (Portland, OR), (3) four 400-'/4l high-
density clear polyethylene vials (VWR Scientific
Products; Boston, MA), each filled with 4OOV4I of
benzaldehyde (as in 2000), and (4) one 1-ml low-
density white polyethylene vial (Wheaton; Millville,
NJ) filled with 1 ml of benzaldehyde. Unbaited traps
served as a control treatment. For each formulation,
the estimated release rate of benzaldehyde was about
1 mg per day except for the white vials, which released
about 2.5 mg of benzaldehyde per day. Each treatment
was replicated 4-5 times.

Traps were deployed in perimeter-row apple frees
and on apple frees located in rows 2, 3, and 4. Traps
were inspected for PC captures 2 to 3 times per week.
At each inspection session, trap tops were rotated
(within a replicate) one position (clockwise).

Experiment 2. This test, conducted from May 29
to July 3, 2001 in Atkins orchard, was aimed at
evaluating different amounts of benzaldehyde released
from 1-ml low-density white polyethylene vials in
association with cylinder traps. Each white vial released
about 2.5 mg of benzaldehyde per day.

Treatments evaluated were: (1) one white vial
(placed inside a frap top), (2) one white vial (placed
outside a frap top), (3), five white vials (inside), (4)
five white vials (outside), (5) 15 white vials (outside),
and (6) unbaited traps as a confrol freatment. For
treatments 2 and 4, vials were hung vertically from the
periphery of the frap top using copper wire, about 2

Fruit Notes, Volume 67, Fall, 2002

inches away from the trap base. For treatment 5, the
15 vials were hung from a wooden stick (about 10
inches long) using wire. The stick holding
benzaldehyde-releasing vials was then attached
horizontally to apple tree branches using wire so that
bases of vials were located about 4 inches above a
cylinder trap top.

In this test, benzaldehyde was evaluated in
combination with grandisoic acid (PC pheromone)
(ChemTica Intemacional, S.A., San Jose, Costa Rica).
One pheromone dispenser, releasing about 1 mg of
grandisoic acid per day, was placed inside each
benzaldehyde-baited trap top.

All vials containing benzaldehyde were replaced
on June 15. Traps were deployed within a single row
of apple trees and were inspected for PC captures 2-3
times per week. Trap tops were rotated one position
(clockwise) at each inspection.

Experiment 3. This evaluation was performed from
May 25 to June 20, 2001, simultaneously at the
UMASS Cold Spring Orchard Research & Education
Center in Belchertown, Atkins orchard, and in backyard
trees in Amherst, MA. The experiment was aimed at
determining the longevity of four different formulations
of benzaldehyde alone (without pheromone) using
cylinder traps. The formulations evaluated were the
same as those described in experiment 1. All
benzaldehyde-releasing dispensers were positioned
inside cylinder trap tops. Traps
were inspected for PC captures
2 to 3 times per week, rotating
the trap tops one position
(clockwise) at each inspection.

Experiment 4. This test was
conducted from June 26 to July
2, 2002 in backyard trees in
South Deerfield, MA, using
Circle traps. The purpose was to
determine the influence of
different release rates of
benzaldehyde, in association
with PC pheromone, on PC
captures. We evaluated three
different release rates of
benzaldehyde (10, 20, and 40
mg/day) together with a control
treatment without benzaldehyde.

Benzaldehyde was released
from 15-ml low-density white

polyethylene vials (Wheaton, Millville NJ). Each vial
was filled with 15 ml of benzaldehyde to achieve a
release rate of ~10 mg/day. Each vial was hung by its
neck from a wire and placed inside an inverted, green
266-ml plastic cup to provide additional protection for
this chemical against polymerization by UV light and
rainfall. Cups were hung from tree trunks using wire
in such a way that bases of cups were about 4 inches
above Circle trap tops. Depending on the treatment,
either no, one, two, or four cups were positioned above
the Circle trap tops.

In all, 32 Circle traps were deployed on unsprayed
apple tree trunks. Each was baited with one of the
abovementioned treatments and one dispenser releasing
PC pheromone (release rate: 1 mg/day) placed inside
the Circle trap top. Traps were inspected for PC
captures one week after bait deployment.

Results

In the first experiment, no appreciable differences
among odor-formulations were noticed when
comparisons were made among vials placed outside
of trap tops (Table 1 ). However, when vials were placed
inside of trap tops, the '4 clear vials' formulation proved
to be the most attractive formulation for PCs, followed
by the '1 white vial' formulation. When PC captures
by traps were compared according to position of vials

Table 2. PC captures by cylinder traps

baited with benzaldehyde (in

combination with PC pheromone)

according to the number and position |

of 1-ml white vials.

Amount of

benzaldehyde

Number of

released per

vials

day (mg)

Inside

Outside

Total PCs

2.5

12.5

37.5

—

unbailed traps

0.0

—

TOTAL

Fruit Notes, Volume 67, Fall, 2002

Table 1. PC captures by black cylinder traps baited with
formulations of benzaldehyde alone (without pheromone), posi
outside of trap tops.

four different
tioned inside or

Formulation

Amount of

benzaldehyde

released per

day (mg)

Inside

Outside

Total PCs

Great Lakes IPM
IPM Technologies
White vial
4 Clear vials
Unbailed traps

10.0
10.0
2.5
10.0
0.00

2
2
5
8

7
9
6

9
11
11
15

TOTAL

within the same formulation, we found that traps baited
with the 'Great Lakes IPM' and 'IPM Tech'
formulations deployed outside the trap tops captured
3.5 and 4.5 times (respectively) more PCs than traps
having the same type of formulation but placed inside
the trap tops. For both clear and white vials, no

differences in captures
were noticed between vials
placed inside or outside the
trap top (Table 1).

In the second
experiment, traps having
five white vials placed
outside of trap tops
captured the most PCs
(Table 2). Traps having 15
vials (which released a
total of -37.5 mg of
benzaldehyde per day)
captured the fewest PCs,
only slighter more than
unbaited traps. Overall,
about four times more PCs
were captured when vials
were positioned outside of
trap tops than inside.

In the third

experiment, wherein all
formulations of benzaldehyde were placed inside of
cylinder trap tops, results indicated that during the first
8 days of evaluation, traps baited with one white vial
captured numerically more PCs than any other bait
treatment (Table 3). From days 9-16, clear vials
outperformed the other formulations. During this time

Table 3. PC captures by black cylinder traps baited with different formulations of benzaldehyde
(placed inside of trap tops and without pheromone) according to the number of days elapsed
after bait deployment.

Treatment

Amount of

benzaldehyde

released per

day (mg)

1-8

9-16

17-24

Total
25-32 PCs

Great Lakes IPM
IPM Technologies
1 White 1 -ml vial
4 Clear vials
Unbaited traps

10.0
10.0

2.5
10.0

0.0

6
4
9
5
5

4
8

5
5
2
1
6

4 19
9

2 17

3 17

4 16

TOTAL

13 78

Fruit Notes, Volume 67, Fall, 2002

T3
Q)

Q.
CD
O

ro
.o

10 20 30 40

Amount of benzaldehyde released (mg/day)

Figure 1. Relationship between total PC captures by Circle traps and amount of
benzaldehyde released from 15-ml white polyethylene vials positioned ~4 inches above
trap tops. Amounts of benzaldehyde released were 0, 10, 20, and 40 mg/day, each in
association with PC pheromone (1 mg of grandisoic acid per day).

period, traps baited with the 'IPM Technologies'
formulation did not capture any PCs. However, 17-24
days after the initial baiting, the 'IPM Technologies'
and the 'Great Lakes IPM' formulations performed
better than the white vial and the clear vials but,
nevertheless, did not perform better than unbailed traps.
From 25-32 days, all traps captured similar numbers
of PCs except traps baited with the 'IPM Technologies'
formulation, which captured no PCs. Overall, the
formulations '4 clear vials', '1 white vial', and the
'Great Lakes IPM' were about equally attractive to PCs,
whereas the 'EPM Technologies' formulation was the
least attractive.

In the fourth experiment, wherein all dispensers
of benzaldehyde were placed 4 inches above Circle
trap tops, results show a strong linear relationship
between the amount of benzaldehyde released (in
association with PC pheromone) and the total number
of PCs captured by Circle traps (Fig. 1 ). This suggests
that, at least for Circle traps, the response of PCs to
benzaldehyde in association with PC pheromone
increases as the amount of benzaldehyde increases (up
to the maximum release rate tested of about 40 mg per
day).

Conclusions

Four conclusions can be drawTi from this series of
experiments.

First, white polyethylene vials releasing
benzaldehyde performed as well as either the clear vials
used in the 2000 field test or the other formulations of
benzaldehyde evaluated (Great Lakes IPM and IPM
Technologies). Therefore, white polyethylene vials
(particularly the UV-light-protected 15-ml vials [see
below]) can be used as devices to dispense
benzaldehyde effectively in future tests.

Second, results from the first and second
experiments suggest, for the most part, that when
dispensers are placed inside of cylinder trap tops, the
odor of benzaldehyde may become repellent at close
range, thus reducing the ability of cylinder traps to
capture PCs. This was particularly true for both the
'Great Lakes IPM' and 'IPM Technologies'
formulations but not for the ' 1 -white-vial' or '4-clear-
vials' formulations (in experiment 1), and the '5 -white-
vials' treatment (in experiment 2). Consequently, we
believe that benzaldehyde-releasing dispensers should
be placed outside of trap tops to avoid close-range

Fruit Notes, Volume 67, Fall, 2002

negative effects while preserving (or even enhancing)
attractiveness to PCs. Results from experiment 4
(involving Circle traps), in which vials were placed
outside of trap tops, further support this conclusion.

Third, 1-ml white vials releasing benzaldehyde
were found to perform best during the first 8 days after
deployment (experiment 3) and, after that time, their
attractiveness decreased considerably. A close
examination of the 1-ml white polyethylene vials
revealed the formation of whitish/yellowish crystals
m the area of necks of vials after 8 days of use. In
contrast, the 15-ml white polyethylene vials used in
experiment 4 showed no signs of such crystals on any
parts of the vials after one week (experiment 4) or
several weeks (data from other field studies) of use.
This difference may be due largely to the type of screw
cap used in association with the white vials in each
year. In 2001, the 1-ml white polyethylene vials were
enclosed by white polypropylene caps that lacked
Teflon® liner as a sealant, and thus oxygen may have
interacted with benzaldehyde altering its chemical
composition. On the contrary, in 2002 the 1 5-ml white
vials were enclosed by black phenolic Teflon®-lined
caps, which apparently prevented oxygen from
interacting with the benzaldehyde contained in the
vials. Also, in 2002 the use of plastic cups provided
extra protection against UV light and rainfall.

Fourth, results from the fourth experiment strongly
suggest that there was an increase in PC captures by
Circle traps associated with an increase in the
concentration of benzaldehyde. In this experiment, the
maximum release rate of benzaldehyde tested was -40
mg per day. Hence, it is possible that even higher
amounts of benzaldehyde may increase the
attractiveness of benzaldehyde to PCs. This aspect is
particularly important not only in relation to the
determination of amount of benzaldehyde to be used
to bait traps to monitor the onset, course, and end of
PC immigration, but also to the determination of
amount of benzaldehyde to be employed in perimeter-
row odor-baited trap trees (see the 2002 winter issue
of Fruit Notes) to follow accurately the course of plum
curculio injury to fruit in commercial apple orchards
in Massachusetts.

Acknowledgments

We thank Everardo Bigurra and Phillip McGowan
for field assistance. This study was supported with
funds provided by a USDA Northeast Regional IPM
grant, a Hatch grant, a grant from USDA Crops at Risk
program, and the New England Tree Fruit Research
Committee.

*1^ «1^ «£# ^f^ «1^
^f% ^j^ #1^ ^^ «^

Fruit Notes, Volume 67, Fall, 2002

Influence of Insecticide on the Ability of
Traps to Capture Plum Curcullos

Jaime Pinero, Sara Hoffmann, Everardo Bigurra, and Ronald Prokopy
Department of Entomology, University of Massachusetts

Several factors may influence the effectiveness of
different types of traps for capturing and monitoring
plum curculios (PCs). We have determined, for
example, that temperature is an important factor
influencmg the ability of both Plexiglas panels (traps
capturing flying PCs) and pyramid traps (traps
capturing crawling PCs) to monitor extent and timing
of PC immigration when traps are deployed at the edges
of an orchard, in close proximity to woods. We found
that panel traps are more effective than pyramid traps
on warm days and, conversely, that pyramid traps
outperform panel traps on cool days.

For both branch-mimicking cylinder traps (which
are positioned vertically on apple tree branches) and
Circle traps (which are wrapped around orchard tree
trunks), weather may have a lesser effect because the
purpose of such traps is either to capture PCs already
present within tree canopies (cylinder traps), or to
intercept adults crawling up tree trunks into canopies
(Circle traps). However, as indicated in the 2002 Winter
issue of Fruit Notes, odor-baited cylinder traps have
yet to demonstrate value for predicting extent of PC
injury to fruit when deployed in commercial orchards.
Similarly, odor-baited Circle traps, although able to
capture numerous PCs under unsprayed orchard
conditions, have not proven to be effective as a tool
for predicting, in commercial orchards, the timing of
PC injury to fruit based on extent of PC captures.

The principal aim of this study was to determine
the influence of insecticide presence (via orchard spray
application) on surfaces of cylinder, pyramid, and
Circle traps on trap performance.

Materials & Methods

Field studies. Studies were performed from May
16 to June 28 (2001) at the UMASS Cold Spring
Orchard Research & Education Center, and from May
22 to June 6 (2002) at Atkin's Farm. Both orchards are

located in Belchertown, MA. The UMASS orchard
block consisted of Delicious/M.7 and Cortland/M.7.
The Atkins' block consisted of Idared/M.7.

2001 Field study. In 2001, we evaluated two trap
types: (1) a black cylinder trap (3 inches diameter x 12
inches tall) and (2) a reduced version of a pyramid trap
(6.5 inches at base x 12 inches tall). Cylinders were
made from PVC pipe. Pyramids were made from
plywood. Both trap types were painted black using flat
black latex paint.

On May 16, just after petal fall, 14 traps of each
type were deployed on branches of perimeter-row trees.
Only one trap was used per tree. For every tree bearing
a trap (central tree), there were two trees without traps
(adjacent trees), one on either side (Figure 1). A few
hours before an insecticide application was made (using
a tractor-driven mist blower delivering 150 gallons of
water per acre), seven traps of each type were covered
with plastic bags. Traps were uncovered the morning
after spray application. These traps will be referred as
"unsprayed" traps. The remaining 14 traps, along with
all tree canopies, received an application of Imidan®
(70% WSB) at 3/4 pound per 100 gallons water. These
traps will be referred as "sprayed" traps. This procedure
(trap covering and uncovering) was repeated three
times, once in association with each insecticide
application against PC: May 16, May 25, and June 14.

Each trap was baited with one 1-ml white, low-
density polyethylene vial containing 1 ml of
benzaldehyde (release rate: ~2.5 mg per day) and one
dispenser releasing PC pheromone ( 1 mg of grandisoic
acid per day). Both baits were placed inside the trap
tops that capped cylinder traps. Benzaldehyde and
pheromone dispensers were replaced once (on June 11).

All traps were inspected twice per week (11
inspections in total) to determine PC captures. At every
inspection, 20 fruit were sampled for PC injury in each
trap-bearing tree and each of two adjacent trees (Figure
1). For presentation of results, we arranged data on

Fruit Notes, Volume 67, Fall, 2002

Woods

o •

"^^

O • O

• O

•

• o

O •

o •

O •

Figure

1. Schematic illustrat

on of the

plot used for the experiment. Trees

were Cortland and

Delicious in alternating row;

.. For each row,

the first three perimeter

-row

trees were used. A

small

pyramid or cylinder trap was placed in

the central tree (black dot)

Twenty

fruit were

inspected for PC damage in

each trap-

bearing

; tree and each

adjacent

non-

trapped

tree (white

dots).

captures and PC damage in the following manner: (1)
1-10 days after an application of insecticide, (2) 11 -20
days after application, and (3) more than 20 days after
application.

2002 Field study. In 2002 we evaluated four trap
types: (a) black cylinders, (b) small black pyramids,
(c) Circle traps made of aluminum screen and wrapped
entirely and tightly around tree trunks, and (d) Circle
traps as above but made of plastic screen.

On May 24, just after petal fall, eight traps of each
type were deployed on apple trees located in a sprayed
section of the orchard that received an application of
Imidan® (as above). After application, all traps were
removed and deployed, along with unsprayed traps,
on branches (cylinders and small pyramids) or tree
trunks (Circle traps) of perimeter-row trees located in
an unsprayed section of the orchard. Traps were
deployed in pairs (i.e., one sprayed trap of one type
adjacent to one unsprayed trap of the same type). There
were eight replicates for each trap type and insecticide
regime.

In 2002, all traps were baited with one 15 ml white
low-density polyethylene vial containing 15 ml of
benzaldehyde (release rate: ~10 mg per day) and one
dispenser releasing PC pheromone (~1 mg of
grandisoic acid per day). To protect benzaldehyde from

sunlight and rainfall, each vial was hung by the neck
using a wire and placed inside an inverted plastic cup.
Each plastic cup was suspended from the tree trunk
using wire in such a way that its base was -10 cm above
each trap top. Each pheromone-releasing dispenser was
placed inside the trap top. Benzaldehyde and
pheromone dispensers were not replaced during the
study.

All traps were inspected on a daily basis for 12
days after application of insecticide. On June 10, all
sprayed traps were removed and transported to the
sprayed section of the orchard, where they received a
second spray of Imidan®. Afterwards, traps were
deployed again in the unsprayed section of the orchard
but the position of each member of pair of sprayed and
unsprayed traps was inverted.

This study differed from the 2001 study in that 1)
all traps were inspected on a daily basis for 12 days
after application of insecticide, and 2) we did not
inspect fruit to determine injury by PC. For presentation
of results, we organized data on PC captures in the
following manner: (1) 1-6 days after an application of
insecticide, (2) 7-12 days after application.

Laboratory observations. Behavioral observations
were conducted in a laboratory during July 2000 and
July 2001 to assess the effects of insecticide application

Fruit Notes, Volume 67, Fall, 2002

on the propensity of PCs to
crawl upon sprayed traps.
For comparative purposes,
in 2000 the insecticide
evaluated was Guthion®,
and in 2001, Imidan* was
used (same dose as above).
PC behavior was observed
inside of Plexiglas cages
with no top. Traps
evaluated were as
described above, but we
also evaluated sprayed and
unsprayed apple tree limbs
(diameter: 2 inches; length:
12 inches). No attractive
odors were used in these
tests. In all instances,
observations were performed 1
limbs (taken from trees in the
application of insecticide. For

Table 1. Total PC captures by sprayed (Imidan®) and unsprayed small
pyramid and cylinder traps (field study, 2001). Data are presented according
to the nimiber of days elapsed after an application of insecticide.

Days after Pyramid
spray unsprayed

Pyramid
sprayed

Cylinder
unsprayed

Cylinder
sprayed

0-10 5
11-20 3
>20

1
2

3
1

TOTAL 8

-3 days after traps or placed a PC on the floor facing one of the test traps
orchard) received an and recorded, for a time period of up tolO minutes,
the observations, we whether the PC was able to reach the top of the trap.

UNSPRAYED SMALL PYRAMID TRAPS SPRAYED SMALL PYRAMID TRAPS

35
30

~^ TRAP.eEARING TREE (r- 0-01)
■D. ADJACENTTREES |r= 0.28)

^•.^ TRAP-BEARING TREE (r= 0.56)
D. ADJACENT TREES (1=0.06)

•

■D

10
5

• •

D D

n . n

^11:=::^:^:- ^

0.0 0.2 0.4 0.6 0.8 1.0 1.2 o.O 0.2 0.4 0.6 0.8 1.0 1

*-*

40
35

UNSPRAYED CYLINDER TRAPS SPRAYED CYLINDER TRAPS

"».. TRAP-BEARING TREE (r= -0.1 1 )
a._ ADJACENT TREES (r= 0.01)

^^ TRAP-BEARING TREE (r= 0)
~Ck ADJACENT TREES (r- 0)

•

□

0.0 0.2 0.4 0.6 0.8 1.0 1.2 0.0 0.2 0.4 0.6 0.8 1.0 1

NUMBER OF PCs NUMBER OF PCs

Figure 2. Degree of correlation between the total number of PCs captured by traps of each type and the percent fruit injured
by PCs in trees bearing a trap and in adjacent trees. The higher the r value, the greater the extent of correlation.

Fruit Notes, Volume 67, Fall, 2002

Results

2001 Field study. Table 1 shows that within the
first 10 days after spraying, unsprayed traps
(particularly pyramids) captured more PCs than
sprayed traps. From 11 to 20 days after insecticide
application, all traps captured similar numbers of PCs.

Only one PC was captured after 20 days (by a sprayed
cylinder trap). Overall, at least twice as many PCs were
captured by unsprayed small pyramid traps than by any
other trap type.

Figure 2 depicts, for the first 10 days after
insecticide application, the degree of correlation
between the extent of PC captures by a trap and the

14
12
10
8
6
4
2

14 -
12 -
10 -

8 -
6 -
4 -

2 -
-

0-10 DAYS AFTER SPRAY

■ Trap-bearing tree
□ Adjacent trees

^^^H

SPRAYED

UNSPRAYED

11-20 DAYS AFTER SPRAY

■ Trap-bearing tree
□ Adjacent trees

SPRAYED

UNSPRAYED

> 21 DAYS AFTER SPRAY

■ Trap-bearing tree
D Adjacent trees

SPRAYED

UNSPRAYED

Figure 3. Amount of fruit injured by PCs on perimeter-row apple trees having a trap (i.e., trap-bearing
tree) or on two adjacent non-trapped trees (adjacent trees). Data combined for pyramid and cylinder
traps (2001 field study).

Fruit Notes, Volume 67, Fall, 2002

amount of PC injury to fruit located in trees having a
trap or in adjacent trees. A strong positive correlation
(i.e., a value close to 1) would indicate that high PC
captures reflect high damage to fruit by PC, and that
low PC captures reflect low damage to fruit. If a strong
correlation were found, we would be able to predict
fruit injury based on trap captures. However, we found
that all trap types (even the unsprayed ones) showed a
poor ability to predict injury to fruit by PCs based on
captures. Even though the strongest correlation (0.56)
was found in the case of sprayed pyramid traps, the
fact that few PCs were captured by traps of this type
during the first 10 days does not allow us to consider
such a correlation as convincing.

Figure 3 shows that, in each one of the three time

periods after insecticide application, fruit located in
trees bearing both sprayed and unsprayed traps received
consistently more damage than fruit located in adjacent
trees. Such a pattern was especially pronounced after
20 days, when fruit injury was 2.4 times greater on
trees bearing sprayed traps than on adjacent trees and
about 1 .9 times greater on trees beanng unsprayed traps
than on adjacent frees.

2002 Field study. Figure 4 reveals that regardless
of the time period elapsed since insecticide spray, the
application of Imidan® seems to have had little
influence on the ability of any frap type to capture PCs.
Both types of Circle fraps captured similar numbers of
PCs, and these two trap types captured substantially
more PCs than small pyramid or cylinder traps.

1-6 DAYS

■ sprayed
D unsprayed

Circle metallic Circle plastic

Pyramid

12 n

^ 10 H

i S

c
rs

6-
4-

7-12 DAYS

Cylinder

■ sprayed
D unsprayed

Circle metallic

Circle plastic Pyramid

TRAP TYPE

Cylinder

Figure 4. PC captures by each type of odor-baited trap placed on perimeter-row trees (2002 field
study).

Fruit Notes, Volume 67, Fall, 2002

Table 2. In laboratory tests, proportions of PCs that reached the top of
unsprayed and sprayed tree limbs, small pyramid traps, and black
cylinders. The insecticide evaluated in 2000 was Guthion®, and in 2001
was Imidan®.

Trap type

2000

2001

No PCs
% TOP tested

No PCs

% TOP tested

Limb unsprayed
Limb sprayed
Pyramid unsprayed
Pyramid sprayed
Cylinder unsprayed
Cylinder sprayed

91% 11
44% 16
67% 6
0% 12
75% 4
25% 4

100% 16
65% 20
100% 17
59% 22
94% 16
50% 22

Laboratory observations. Table 2 shows that in
2000 (when Guthion® was evaluated), 91, 67, and 75
% of total PCs reached the top of unsprayed limbs,
pyramids, and cylinders, respectively, whereas for
sprayed counterparts, only 44, 0, and 25%, respectively,
reached the top. Table 2 also reveals that in 2001 (when
Imidan® was evaluated), 100, 100, and 94% of total
PCs reached the top of unsprayed limbs, pyramids, and
cylinders, respectively, whereas for sprayed
counterparts, only 65, 59, and 50%, respectively,
reached the top. Comparatively, Guthion® exerted a
greater negative effect than Imidan® on the propensity
of PCs to crawl up the structures evaluated.

Conclusions

Results from the 200 1 field experiment suggest that
when orchard trees are sprayed with Imidan® to protect
against PC damage, PC captures by cylmder traps are
strongly compromised during the first 10 days after
application. This suggests that, particularly during this
period of time, PC captures by cylinder traps would be
very poor indicators of PC population levels in tree
canopies, with a remarkably poor ability to forecast
PC injury to fruit. In 2001, the negative effects of
insecticide application were not apparent after 10 days
following an application of Imidan®.

Several of our studies have shown that odor-baited

cylinder traps, when deployed in
commercial orchards, offer little
or no value for predicdng extent
of PC injury to fruit, which we
have attributed, in part, to the
presence of insecticide on the trap
surface. As found in the 2001
study, even unsprayed traps failed
to reflect the amount of PC injury
to fruit located in trap-bearing or
adjacent trees. Such poor ability
could have been due then to the
possibility that very few PCs were
present on sprayed trees. Even so,
PC presence was sufficiently great
to inflict damage to fruit.

In both 2001 and 2002,
unsprayed black pyramids
captured numerically more PCs
than unsprayed black cylinders,
which suggests that small
pyramids offer a stronger visual stimulus to PCs than
cylinders.

Results from the laboratory observations confirmed
the negative effect of organophosphate insecticide
application on trap performance found in the 200 1 field
study. Here, there was strong evidence that, in the
absence of any odor bait, PCs are reluctant to crawl
upward on traps sprayed with Guthion® or Imidan®.
Nonetheless, tree limbs sprayed with organophosphate
insecticide proved considerably less deterrent to PCs,
possibly because tree limbs possess positive contact
stimuli that tend to override negative effects of
insecticide.

Results from the 2002 field study, however, failed
to show an effect of insecticide application on trap
captures even when the same insecticide (Imidan®) and
dose (3/4 pound per 1 00 gallons water) was utilized as
in the 2001 study. This may be due to the fact that the
amount of benzaldehyde used to bait traps in 2002 was
four times greater than in 2001 (2.5 mg/day vs. 10 mg/
day in 2001 and 2002, respectively). Therefore, in 2002
PCs may have been more strongly drawn to enter the
trap tops, overcoming the negative effect of insecticide.
Combined results suggest that, in the absence of
any odor (as in our lab study), PCs are substanfially
repelled from climbing up organophosphate-sprayed
traps. However, such negative effect seems to be less
pronounced as the amount of odor bait (i.e.

Fruit Notes, Volume 67, Fall, 2002

benzaldehyde) is increased, as found in the field
studies. As mentioned, the amount of benzaldehyde
used in the field studies was increased from 2.5 mg/
day (in 2001) to 10 mg/day (in 2002), which seems to
have overcome negative effects of the presence of
insecticide on the trap surface.

Based on our findings, we conclude that (1)
unsprayed cylmder or small pyramid traps may be more
effective in capturing PCs than sprayed cylinder or
small pyramid traps, and (2) even though Circle traps
may offer more promise for capturing PCs than
unsprayed cylinders or small pyramids, other
approaches to monitoring PC, such as an 'odor-baited

trap tree' approach (see the 2002 winter issue of Fruit
Notes), may be much more rewarding.

A cknowledgm ents.

We thank Joe Sincuk for aid in both the scheduling
and execution of the insecticide applications and Phillip
McGowan for technical aid. This study was supported
with funds provided by a USDA Northeast Regional
IPM grant, a Hatch grant, a grant from USDA Crops at
Risk program, and the New England Tree Fruit
Research Committee.

%S^ %S^ %i^ «1^ %x^

#1^ #^ #^ #^ #Y*

Fruit Notes, Volume 67, Fall, 2002

Devising an Attractive Bait to IVIonitor
the Seasonal Course of Plum Curculio
Immigration into Apple Orchards
using Traps

Jaime Piiiero, Sara Hoffman, Everardo Bigurra, and Ronald Prokopy
Department of Entomology, University of Massachusetts

To reduce insecticide use against plum curculio
(PC), management strategies should consider the time
of first appearance of PCs on host trees after
overwintering in woods, as well as the peak and the
end of immigration. One approach to tracking the
seasonal course of PC immigration is the use of a trap
baited with a lure that is highly attractive to PCs. In
the 2000 issue of Fruit Notes, we reported that both
panel and pyramid traps baited with benzaldehyde
(BEN) in combination with PC pheromone called
grandisoic acid (GA) were very good indicators of the
seasonal course of immigration into apple orchards
when deployed in close proximity to woods. In that
study, we also found that ethyl isovalerate (EIV) and
limonene (LIM), in combination with GA, showed
some degree of attractiveness to PCs, but to a lesser
extent when compared to the high luring power of
BEN+GA.

Here, we report on two field studies performed in
Massachusetts in 2001 and 2002 using panel and
pyramid traps. The 2001 study was aimed at evaluating
the three most attractive fruit odors (BEN, EFV, and
LIM) found in our 2000 study to confirm the high
attractiveness of the combination BEN+GA to PCs. The
2002 study was performed to evaluate PC response to
four different amounts of BEN (the most attractive fruit
odor found in the 2001 study) and two different
amounts of GA to determine the amount of each odor
needed to maximize the performance of monitoring
traps.

Materials & Methods

Both studies were conducted in an unsprayed
section of a commercial apple orchard at the UMASS

Cold Spring Orchard Research & Education Center
(Belchertown, MA). As in 2000, traps evaluated in 200 1
and 2002 were clear Plexiglas panels (2x2 feet, with
the woods-facing side coated with Tangletrap) and
black pyramid traps (24 inches wide at base x 48 inches
tall) (Figure 1). Whereas panel traps capture mainly
PCs in flight (particularly on warm days), pyramid traps
capture primarily crawling PCs (mostly during cool
days or at night).

2001 Study. This study was undertaken from April
30 to June 30, 2001. Host plant odors evaluated were
benzaldehyde (BEN), ethyl isovalerate (EFV), and
limonene (LIM), all purchased from Sigma-Aldrich
Chemical Co. (Milwaukee, WI). Three different groups
of odor treatments were arranged, each involving a
single host volatile alone, GA alone, a combination of
host volatile and GA, and a no-odor (control) treatment.
By testing each fruit odor alone and in combination
with GA, we sought to determine the extent to which
each of the synthetic host plant volatiles tested
enhanced PC responsiveness to GA. There were four
replicates for each trap type and odor combination.

BEN was released from 1-ml low-density white
polyethylene vials in order to prevent polymerization
of this chemical by UV light (as found in 2000 when
using high-density clear polyethylene vials). Because
this problem was not found for EFV and LIM, these
two chemicals were tested (as in 2000) using 400 'Al
high-density clear polyethylene vials. A white vial filled
with 1 ml of BEN released -2.5 mg/day of BEN. Only
one vial of this type was used per trap. Two vials
containing LIM and three vials containing EIV were
needed per trap to accomplish a release rate of ~10
mg/day of each chemical. Each pheromone dispenser
released ~1 mg/day of GA.

Fruit Notes, Volume 67, Fall, 2002

5.6 ft

Pheroitione
dispenser

Clear Plexigla&
sticky panel

BEN-releasin*

vial capped

bv a CUD

Black PV(
sleeve

Permanent
bottom

Figure 1. View of a panel and a pyramid trap used in the 2001 and 2002 studies to
evaluate synthetic odors for attractiveness to PCs. Traps were deployed in pairs in
close proximity (~lm) to woods to intercept immigrating PCs.

Vials containing fruit volatiles were attached to
the lower edge of a panel using binder clips, whereas
one GA dispenser was attached to the upper edge of a
panel. For pyramid traps, both fruit volatile- and GA-
releasing dispensers were placed inside a boll weevil
frap top. Vials containing BEN were replaced every 2
weeks to maintain a consistent release rate. Vials
containing EFV and LEM, along with GA dispensers,
were replaced twice (3 and 6 weeks after trap
deployment).

2002 Study. In 2002, we evaluated four different
amounts of BEN (0, 2.5, 10, and 40 mg/day), hereafter
referred to as no-BEN, low, medium, and high release
rates, respectively, and two amounts of GA ( 1 and 2
mg/day), hereafter referred to as low and high release
rates, respectively. The low release rate of BEN (-2.5
mg/day) was achieved by filling 1-ml low-density white
polyethylene vials with 1 ml of BEN (1 vial/trap), as
in 2001. The medium release rate (~10 mg/day) was
achieved by using one 15-ml low-density white
polyethylene vial filled with 15 ml of BEN (1 vial/
frap). The high release rate (-40 mg/day) was achieved
by using four such 15-ml vials per trap. Since each

pheromone
dispenser released
-1 mg of GA per
day, the high release
rate of GA (2 mg/
day) was achieved
by using two GA
dispensers per trap.
In total, eight
treatments were
evaluated. Each was
replicated six times
for each trap type.

In 2002,
besides using white
vials to protect BEN
from UV light, we
employed green
266-ml plastic cups
to provide additional
protection against
UV light and
rainfall. Each vial
containing BEN was
hung by its neck
from a wire and
positioned inside a plastic cup. For use with pyramid
traps, cups were hung in inverted position from the
end of a wooden pole (buried in the ground at a 45°
angle) in such a way that bases of cups were - 4 inches
above pyramid frap tops (see Figure 1). Depending on
the treatment, either one or four cups were attached to
each pole. Cups holding BEN-dispensing vials were
attached to the bottom edge of panels using wire and
steel binder clips. GA dispensers were attached to the
upper edge of panels using binder clips, or were placed
inside the inverted screen funnel capping pyramid traps.
All vials releasing BEN and all GA dispensers were
replaced once (four weeks after initial trap
deployment).

Trap deployment. In both years, panel and pyramid
traps were deployed in pairs (1 yard apart) along the
periphery of the apple orchard, in close proximity (-1
yard) to woods. This approach allowed traps to
intercept PC adults presumably immigrating into the
orchard after overwintering in the woods. Each pair of
traps was baited with the same odor combination and
spaced 10 yards from other trap pairs on either side.
Traps were inspected for PC captures on a daily basis.

Fruit Notes, Volume 67, Fall, 2002

although for the purposes of this article, results for each were baited during the tight cluster stage of apple tree
year show PC captures by panel or pyramid traps across phenology (on April 29 in 2001 and on April 16 in
the entire period of immigration. In both years, traps 2002).

'^ 25 n

a. 20 H

<
o

q! 15

LU 10

5 -

LU UJ

E E

a
tu
a:

Z3
I-
Q.
<
O

(A
O

Q.
u.

OH
LU

25 1

■ I ' ' I ■ ' I ' 'I

Ol LU _l

> LU LU

BEE

E E

1* 'I' ' I ' ' I ' 'I

S LJJ LU _l

- E E g

Figure 2. PC captures by A) panel traps and B) pyramid traps in the 2001 study. For each
graph, bars in each group not superscribed by the same letter are significantly different at
odds of 19:1.

Fruit Notes, Volume 67, Fall, 2002

u
u

O
d

1/1

-♦- 1 mg GA/day ^

- ■ - 2 mg GA/day .■-...

A.-''
- - ' ' ab^^^^

- -ill^-J;- — — ""^

■ ■ -■

1 1 1

2.5

1 mg GA/day

2 mg GA/day ^

2.5 10 40

AMOUNT OF BENZALDEHYDE (mg/day)

Figure 3. PC captures by A) panel traps and B) pyramid traps in the 2002 study as a function of amounts
of BEN (benzaldehyde) and GA (grandisoic acid) used. For each graph, points in each Hne not
superscribed by the same letter are significantly different at odds of 19:1.

Results

2001 Study. Overall, 538 PCs were captured by
traps (312 PCs by panels and 226 PCs by pyramids)
over the period of 62 days that encompassed the PC

season in 2001 (April 30-June 30).

In 2001, BEN was the only host volatile that for
both trap types significantly enhanced the response of
PCs to GA. To illustrate, panel traps baited with
BEN+GA captured 1 5 times more PCs than unbaited

16.

Fruit Notes, Volume 67, Fall, 2002

traps of the same type, and captured twice as many
PCs as traps baited with GA alone (Figure 2A). Panel
traps baited with GA alone captured more PCs than
panel traps baited with BEN alone or unbaited traps.
Pyramid traps baited with BEN+GA captured 5 times
more PCs than unbaited pyramid traps and 2.5 times
more PCs than pyramid traps baited with GA alone.
Pyramid traps baited with BEN alone or GA alone
captured more PCs than unbaited pyramid traps (Figure
2B).

For both trap types, the presence of EFV or LIM
did not enhance the attractiveness of GA to PCs (Figure
2A and B). Also, for both trap types, consistently more
PCs were captured by traps baited with GA alone than
by traps baited with EfV alone, LIM alone, or unbaited
traps. In no case did EIV or LIM alone significantly
enhance adult response above that to control traps.

2002 Study. In all, 1,305 PCs were captured by
traps (662 PCs by panels and 643 PCs by pyramids)
over the period of 82 days that comprised the PC season
in 2002 (April 17 -July 8).

Figure 3A shows PC captures by panel traps
according to amounts of BEN and GA evaluated.
Overall, panel traps baited with the high release rate
of GA captured about 35% more PCs than panel traps
baited with the low release rate of GA. When we
examined PC captures by panel traps baited with the
low release rate of GA, we found a significant positive
linear relationship between the amount of BEN and
the extent of captures. As depicted in Figure 3A,
increases in the amount of BEN released corresponded
to increases in captures by panel traps, with the
maximum number of PCs captured corresponding to
the high release rate of BEN (40 mg/day). For panel
traps baited with the high release rate of GA, we found
that the most attractive release rate of BEN was again
40 mg/day, although differences among BEN
treatments were only numerical.

Figure 3B presents PC captures by pyramid traps
according to amounts of BEN and GA used. Pyramid
traps captured similar numbers of PCs regardless of
the amount of GA used. For pyramid traps baited with

the low release rate of GA, we found that the mere
addition of BEN, regardless of the dose, enhanced PC
captures relative to traps baited with GA alone (Figure
3B). For pyramid traps baited with the high release
rate of GA, we found an increase in captures as the
amount of BEN released increased but only up to a
maximum of 10 mg/day. Beyond that amount, BEN
did not enhance, but rather decreased the attractiveness
ofGA.

Conclusions

Our results from the 2001 study indicate that,
among all odor combinations evaluated, BEN in
association with GA was the most attractive bait for
PCs. Results from the 2002 study, as well as an
assessment of cost of both BEN (as formulated by us)
and GA (obtained from Great Lakes EPM), indicate that
a high release rate of BEN (40 mg/day/trap) in
association with a low release rate of GA (1 mg/day/
trap) seems to be the most cost-effective bait
combination to be used for panel as well as pyramid
traps. With our approach, BEN provided sustained
attractiveness to PCs across the entire period of
immigration (82 days in 2002). Placement of BEN-
releasing vials outside of trap tops (for pyramid traps)
appeared to preclude the kind of close-range repellency
found in previous studies in which BEN-releasing vials
had been positioned inside the tops of pyramid, Circle,
or cylinder traps.

We conclude that BEN (at 40 mg/day of release)
in association with GA (at 1 mg/day of release)
constitutes a powerful lure that may greatly improve
the effectiveness of monitoring traps for PC.

A cknowledgm ents

We thank Phillip McGowan for assistance. This
study was supported with funds provided by a USDA
Northeast Regional IPM grant, a Hatch grant, the New
England Tree Fruit Research Committee, and the
UMass HRC Trust Fund.

«1^ «1« %X^ %S^ «1^
^* #1^ #1^ 'l^ ^s^

Fruit Notes, Volume 67, Fall, 2002

Fruit Notes

University of Massachusetts
ff lilt Department of Plant & Soil Sciences
lilies 205 Bowditch Hall

«^ Amherst, MA 01003

Nonprofit Organization
U.S. Postage Paid

Permit No. 2
Amherst, MA 01 002

-1

SERIAL SECTION

UMASS

AMHERST, MA 01003

A1 04911

Notes

Volume 68, Number 1 ihwCn^LJ
WINTER ISSUE, 2003

Table of Contents

Comparison of Avaunt versus Guthion in Every-row versus Perimeter-row Sprays Against

Key Apple Insect Pests: 2002 Results and Project Summary

Ronald Prokopy, Matthew Harp, Andrew Hamilton, Bradley Chandler, and Isabel Jacome 1

Comparison of Traps and Trap Trees for Monitoring Plum Curculios: 2002 Results

Ronald Prokopy, Bradley Chandler, Sara Dynok, Elisa Gray, Matthew Harp, Anne Talley, and Jaime Pifiero 5

Evaluation of Odor Combinations for Attractmg Plum Curculios to Trap Trees

Ronald Prokopy, Bradley Chandler, Sara Dynok, Elisa Gray, Matthew Harp, Anne Talley, and Jaime Pinero 11

Can a Band of Tangletrap Around a Tree Trunk Suppress Plum Curculio Injury to Fruit?

Ronald Prokopy 13

Helping Kids Do Farm Jobs Safely: Know Which Tasks Are Appropriate for Your Children

George Cook 15

Visual Exposure: Farm Logos and Signs Tell Your Story

Judith Powell 17

Editors:

Wesley R. Autio
William J. Bramlage

Publication Information:

Fruit Notes (ISSN 0427-6906) is pub-
lished each January, April, July, and
October by the University of
MassachusettsAmherst in cooperation
with the other New England state uni-
versities.

Correspondence should be sent to:

Fruit Notes

Department of Plant & Soil Sciences
205 Bowditch Hall
University of Massachusetts Amherst
Amherst, MA 01003

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 UMass Extension, Stephen Demski, Director, in furtherance of the acts of May 8 and June 30,
1914. UMass Extension offers equal opportunity in programs and employment.

Comparison of Avaunt versus Guthion
in Every-row versus Perimeter-row
Sprays Against Key Apple Insect Pests:
2002 Results and Project Summary

Ronald Prokopy, Matthew Harp, Andrew Hamilton, Bradley Chandler, and

Isabel Jacome

Department of Entomology, University of Massachusetts

In the 2001 issue oi Fruit Notes, we presented
results from the first year of a planned two-year study
comparing the effects of Avaunt versus Guthion in
every-row versus perimeter-row sprays against plum
curculio (PC), apple maggot (AM), summer leafrollers
(LR) and internal Lepidoptera (a combination of
codling moth, oriental fruit moth and lesser
appleworm). Avaunt is a recently-labelled oxadiazine
insecticide for use against these and other orchard pests.
Guthion has been our standard organophosphorous
material for general-purpose insect control for several
decades, but its status for use in orchards beyond 2005
is uncertain. Conceivably, Avaunt might be an effective
substitute for Guthion against key orchard insect pests.

Avaunt and most other recently labelled
insecticides are substantially more expensive than
Guthion and other older insecticides. If the amount of
Avaunt needed to achieve effective pest control could
be reduced through modification of pattern of spray
application (such as limiting application to only
peripheral-row trees), then considerable cost savings
could be achieved without sacrifice of fruit quality

Here, we present results of our second and final
year of research comparing effects of Avaunt versus
Guthion in every-row versus perimeter-row sprays
against PC, AM, LR, and internal Lepidoptera. We also
present combined data from our two years of research
on this subject.

Materials & Methods

In April of 2001, four plots were established in
each of six commercial apple orchards in

Massachussetts (24 plots in all). Rootstocks and
cultivars varied among orchards, but all trees in a given
orchard were on the same rootstock (either M.7, M.26,
or M.9) and of the same cultivar (either Mcintosh,
Empire, Cortland, Gala, or Delicious). Each plot was
about 40 X 40 yards in size and consisted of seven rows
of apple trees. The perimeter row bordered woods,
hedgerow, or open field and was subjected to pressure
ft-om immigrating PCs and AM. In 2002, one of the six
orchards was so heavily damaged by firost that it could
not be used in our 2002 research.

In 2002, as in 2001, growers themselves sprayed
all rows of all plots with azinphosmethyl or phosmet
through petal fall. Thereafter, all sprays were applied
by Andrew Hamilton using our own tractor-mounted
mist blower. Plots in each orchard received four sprays
after the petal fall spray: 10 days and again in 20 days
after petal fall against PC, and on July 1 9-2 1 and again
on August 9-11 against AM. Spray was delivered at
the equivalent of 1 50 gallons of water per acre. Guthion
(50 WP) was applied at the rate of 30 ounces of
formulated material per acre against PC and 24 ounces
of formulated material per acre against AM. Avaunt
(30% WG) was applied at the rate of 6 ounces of
formulated material per acre against both PC and AM.
After the petal-fall spray, plots designated as "all row"
plots received insecticide applied to both sides of trees
on all seven rows, whereas plots designated as
"perimeter-row" plots received insecticide sprays
applied to both sides of trees of the perimeter (=first)
and second rows but no insecticide applied to trees of
the third through seventh rows (Figure 1). After the
petal-fall spray, Andrew Hamilton applied

Fruit Notes, Volume 68, Winter, 2003

azinphosmethyl or phosmet to trees in the eighth
interior row and to orchard trees bordering plots on
either side.

Weekly from petal fall until harvest in September,
100 fruit m each of rows 1, 3, 5, and 7 of each plot
were sampled for mjury by PC and AM. In addition,
two unbaited sticky red sphere traps were hung toward
the center of each row of each plot to monitor AM.
Finally, at harvest, 100 fruit in each of rows 1,3, 5 and
7 of each plot were sampled for injury by summer LR
and internal Lepidoptera.

Results

Incidence of each pest type, as averaged across all
samples of fruit or traps in rows I, 3, 5, and 7 of each
plot, is given in Table 1. As in 2001, results for 2002
show no significant differences among any of the four
treatments (all-row versus perimeter-row sprays of
Guthion versus Avaunt) in incidence of fruit injury by
PC, trap captures of AM, Iruit injury by AM, fruit injury
by summer LR, or fruit injury by internal Lepidoptera.

Injury by PC in 2002 was sufficiently great to
justify comparison of PC damage to fruit on perimeter-
row trees with damage to fruit on interior trees.
Combined date for all-row plus perimeter-row sprays
of Guthion revealed that injury to fruit on perimeter-
row trees (row 1) averaged about 10 times greater

(1.275%) than the mean amount of injury to fruit on
trees in row 3, 5, and 7 (0.125%). These data suggest
that PCs which immigrate into orchards after a petal
fall spray has been applied confine their activity to
peripheral-row trees and infrequently penetrate into
interior rows of orchards.

Figure 2 displays combined data for each pest for
2001 and 2002. All-row sprays of Avaunt were
approximately equal to all-row sprays of Guthion in
protecting against PC, AM, summer LR and internal
Lepidoptera. For both PC and AM, perimeter-row
sprays of Guthion performed as well as all-row sprays
of Guthion in providing plot-wide control. For PC and
especially for AM, perimeter-row sprays of Avaunt
were not as effective as all-row sprays of Avaunt in
providing plot-wide control. For both summer LR and
internal Lepidoptera, perimeter-row sprays were not
as effective as all-row sprays in providing plot-wide
control in the case of Guthion as well as Avaunt.

Conclusions

There were no statistical differences among any
of the four treatments evaluated here in ability to
control target pests in either 2001 or 2002. Indeed,
combined data for both years indicate that all-row
sprays of Avaunt were approximately as effective as
all-rows sprays of Guthion in ability to confrol PC,

Table 1 . Effectiveness of Guthion versus Avaunt against pest insects when applied to all rows
versus the two perimeter rows of seven-row plots in five commercial apple orchards in
Massachusetts in 2002. Values represent data averaged across all samples taken in rows 1, 3, 5
and 7 of plots.

Incidence of pest

Pest

Plum curculio (% fhiit with injury)*
Apple maggot (no. captured per sphere)*
Apple maggot (% fruit with injury)*
Summer leafrollers (% fruit with injury)*
Internal Lepidoptera (% fruit with injiu^)*

Guthion

Avaunt

All rows

Perimeter

All rows

Perimeter

sprayed

rows sprayed

sprayed

rows sprayed

0.45

0.30

0.45

0.47

6.58

8.78

7.28

10.83

0.13

0.08

0.09

0.18

1. 00

1.70

0.90

1.60

0.05

0.15

0.00

0.15

"No statistically significant differences among treatments at odds of 19: 1 .

Fruit Notes, Volume 68, Winter, 2003

Guthion

Habitat Bordering Orchard
Guthion Avaunt

Avaunt

Figure 1. Schematic illustration of pattern of spray application in four experimental plots of a commercial orchard.
Plot treatments differed in location within each orchard block.
= Trees sprayed by hired applicator.

0.5
I 0.4
i 0.3
5 0.2
^ 0.1

1.5

li- 05

PLUM CURCULIO

GU
ALL

GU
PER

AV
ALL

AV
PER

SUMMER LEAFROLLERS

GU
ALL

GU
PB%

AV
ALL

AV
PER

K 0.4

i 0.3

5 02

III. I

APPLE MAGGOT

GU
PB?

AV AV

ALL PB?

INTERNAL LEPIDOPTERA

GU
PER

AV
ALL

AV
PB?

Figure 2. Two-year average (2001 and 2002) of data on effectiveness of Guthion (GU) versus Avaunt
(AV) against pest insects when applied to all rows (ALL) versus the two perimeter rows (PER) of
seven-row plots in commercial orchards in Massachusetts. Values represent data averaged across all
samples taken each year in rows 1, 3, 5 and 7 of plots.

Fruit Notes, Volume 68, Winter, 2003

AM, summer LR, and internal Lepidoptera. Further,
combined data for both years indicate that applying
Guthion only to perimeter-row trees from the first cover
spray onward was just as effective in protecting interior
rows agamst injury by PC and AM as applying Guthion
to all trees in a block from the first cover spray onward.
In the case of Avaunt, however, all-row sprays were
numerically (though not statistically) superior to
perimeter-row sprays in providing protection against
injury by PC and AM on interior rows.

We conclude that Avaunt can be an effective
substitute for Guthion against PC, AM, summer LR,

and internal Lepidoptera when applied to all trees in
an orchard but may be less effective than Guthion in
providing orchard-wide control of PC and AM if
applied only to perimeter-row trees.

A ckn o wledgem ents

We thank the five cooperating growers: Gerry
Beime, Aaron Clark, Don Green, Tony Lincoln, and
Bob Tuttle. This work was supported by a grant from
the USDA CSREES Crops at Risk Program and a grant
from DuPont Corporation.

it it it it it

Fruit Notes, Volume 68, Winter, 2003

Comparison of Traps and Trap Trees
for Monitoring Plum Curculios:
2002 Results

Ronald Prokopy, Bradley Chandler, Sara Dynok, Elisa Gray, Matthew Harp, Anne

Talley, and Jaime Pinero

Department of Entomology, University of Massachusetts

In the 2002 Winter issue of Fruit Notes, we reported
on year 2001 tests in which we compared odor-baited
with unbailed traps of three types (pyramid, cyhnder
and Circle) for monitoring plum curculios (PCs) in
several commercial apple orchards. All traps were
placed beneath or within canopies of perimeter-row
apple trees. Results indicated that Circle traps baited
with benzaldehyde (BEN, a component of host plant
odor) plus grandisoic acid (GA, male-produced
aggregation pheromone) captured numerically more
PCs than any other baited or unbaited traps. However,
no trap type showed even a moderate positive
relationship between the time of occurrence of PC
captures by the trap (first, second, third, etc. week after
petal fall) and time of occurrence of PC injury to fruit.
Even for Circle traps baited with BEN plus GA,
captures fell off dramatically soon after petal fall,
whereas fruit injury rose steadily. Thus, low trap
captures after petal fall could not be taken as indicative
of a lack of need to spray against PC.

In the 2002 Fall issue of Fruit Notes, we reported
that pyramid traps and sticky-coated Plexiglas panel
traps baited with BEN plus GA and placed at orchard
border areas were effective in monitoring the seasonal
course of immigration of overwintered PC adults into
a small unsprayed orchard. This finding suggested that
such traps placed in border areas might be useful for
monitoring PCs in commercial orchards.

Finally, in the 2002 Winter issue of Fruit Notes,
we reported on a preliminary study in a single
commercial apple orchard involving the establishment
of odor-baited "trap trees" as a potentially new and
effective approach to monitoring PCs. This approach
involves baiting the branches of a few perimeter-row
trees in an orchard with BEN plus GA and examining

fruit solely on these few baited trees for signs of fresh
PC injury, thereby eliminating the need to examine fruit
or a large number of trees to gain an accurate estimate
of the degree of current threat of PC injury to fruit.
Moreover, a trap tree approach might overcome various
shortcomings of odor-baited traps that have afflicted
our ability to rely on extent of trap captures as indicative
of extent of threat of PC injury to fruit.

Here, we report results of a 2002 study in
commercial apple orchards in which we compared the
performance of odor-baited-sticky clear Plexiglas
panels and black pyramids (both types of traps placed
in orchard border areas) with the performance of odor-
baited Circle traps (attached to trunks of perimeter-
row apple trees) and the performance of odor-baited
perimeter-row trap trees for monitoring the seasonal
course of PC egglaying damage to developing apples.

Materials & Methods

The three types of traps were: (a) a clean Plexiglas
panel (24 x 24 inches) attached vertically at head height
to a wooden post, coated with Tangletrap on the side
facing the orchard border area, (b) a black pyramid
trap (24 inches wide at base x 48 inches tall), and (c)
an aluminum-screen "Circle" trap, wrapped tightly
around the base of a tree trunk so as to completely
encircle the trunk.

Each trap and trap tree were baited with four
polyethylene-vial dispensers of BEN (Aldrich
Chemical Company) that together released 40 mg of
BEN per day plus 1 dispenser of GA (Great Lakes IPM)
that released 1 mg of pheromone per day. Each vial of
BEN was suspended inside of an inverted colored,
plastic drinking cup to minimize the potential negative

Fruit Notes, Volume 68, Winter, 2003

impact of ultraviolet light on the stability of BEN. Vials
of BEN were not renewed during the course of our test
but dispensers of GA were renewed once (after 5
weeks). Dispensers of BEN and GA were suspended
from the bottom edge of panel traps and from the
branches of trap trees. For pyramid and Circle traps,
dispensers of BEN were suspended in such a way that
the open bottoms of the protective drinking cups were
4 inches above the inverted screen funnel (that capped
each trap) to reduce close- range repellency of BEN,
and the dispenser of GA was placed inside of the screen
funnel. Four plots were established along a continuous
132 yard section of a perimeter row of apple trees in
each of 1 1 commercial orchards. Each plot was 33 yards
long by 7 rows of trees deep and contained one of the
four trap treatment types. Traps or trap trees were
positioned midway along the 33 yard length of the
perimeter row of a plot. Panel and pyramid traps were
placed in orchard border areas, 7 yards from the near
edge of the canopy of the central perimeter-row tree of
a plot. Circle traps and trap trees were assigned to the
central perimeter-row tree of a plot.

Traps and trap trees were installed at the pink stage
of bud development (April 22-24) and remained for
10 weeks (June 24-26). Weekly beginning at petal fall
(May 13-15), we counted and removed all PCs from
traps and examined
100 fruit per plot on
perimeter trees for
evidence of fresh PC
egglaying scars. In
all, 20 fruit were
sampled on the
central perimeter-
row tree (directly
opposite a panel or
pyramid trap or
containing a Circle
trap or functioning
as a trap tree) and 20
fruit were sampled
on each of two
evenly-spaced trees
to the right and again
to the left of the
central tree. Fresh
scars were those
considered to have
been made within

the past 7 days. It is the appearance of fresh scars (not
older scars) that ought to drive a grower's decision to
spray against PC.

Each grower applied three sprays of
azinphosmethyl or phosmet to control PC in the plots.

Results

Across the entire season, panel traps captured
significantly more PCs than either pyramid or Circle
traps (Figure 1). Even so, for none of these three trap
types was there a significant positive correlation
between total captures of PCs per plot (across all weeks
from petal fall through June) and mean percent of
sampled perimeter-row fruit per plot exhibiting fresh
egglaying scars (across all weeks from petal fall
through June) (Figure 2).

Furthermore, for none of the three traps types was
there a significant positive correlation between sample-
week trap captures per plot and sample-week percent
of penmeter-row fruit per plot having fresh egglaying
scars (Figure 3). A significant positive correlation
would indicate that a week during which comparatively
many trap captures occurred also was a week in which
a comparatively large amount of fruit was injured by
PC, whereas a week during which comparatively few

3
Q.

u
(/)
O
Q.

c
re

D -

4 -

3 -

2 -

1 -

' 1 '

Panel

Pyramid
Season-long captures

Circle

Figure 1. Season-long captures ot overwintered plum curculio adults by odor-baited
panel, pyramid and Circle traps placed in association with plots of perimeter-row
apple trees. Means superscribed by the same letter are not significantly different at
odds of 19:1.

Fruit Notes, Volume 68, Winter, 2003

<fl 2.0

"S 1-5

10
(O

"3 1.0

PANEL
r=0.14

8 10 12 14

w
o

CD
0)

2.0

1.5

1.0

0.5

0.0

PYRAMID

r = 0.00

8 10 12 14

CIRCLE

r = 0.25

4 6 8 10

TOTAL CAPTURES ACROSS ALL WKS

Figure 2. For panel pyramid and Circle traps, relationship between total
captures of plum curculio adults per plot (across all weeks from petal fall
through June) and mean percent of sampled perimeter-row fruit per plot
having fresh ovipositional injury (across all weeks from petal fall through
June). N=l 1 plots (hence 1 1 data points) per trap type. ?= two overlapping
data points.
-•-= three overlapping data points.

Fruit Notes, Voluine 68, Winter, 2003

PANEL

? 4

r = 0.17

injured i

• 1

Fruit

• 4

• 7 • 4 • 2 • '

• 37 • 6 • 1 9 1 • 1

12 3 4 5 6

PYRAMID

r = 0.09

■o

• 2

■52

• S • 1

• 9 •2

• 36 • s ■ _________^^

12 3 4 5 6

• 1

• ' CIRCLE

r = 0.18 ^^

is
-2

• 4 ^ — -"^

1—

• 5 ^^^.^'^'''^

• 50 • 2 •2

12 3 4 5 6

No. CAPTURED

Figure 3. For panel, pyramid and Circle traps, relationship between number

of plum curculio adults per plot captured each week (from petal fall through

June) and percent of sampled perimeter-row fruit in corresponding plots and

weeks having fresh ovipositional injury. N= 66 data points per trap type (1 1

plots X 6 wk). Tlie number alongside of each ? indicates the number of data

points corresponding to that position on the graph.

Fruit Notes, Volume 68, Winter, 2003

Q
liJ

a
m

2.00
1.60
1.20
0.80
0.40
0.00

CENTRAL TREE PLUS OTHER TREES

2.00
1.60
1.20
0.80
0.40
0.00

Trap tree

CENTRAL TREE

OTHER TREES

Panel

Pyramid

Figure 4. Percentages of freshly-injured fhiit (averaged across all six sampling weeks) on central and
four other sampled perimeter-row trees of treatment plots. Means superscribed by the same letter are
not significantly different at odds of 19:1.

(or no) trap captures occurred was a week in which
comparatively little (or no) fruit injury was initiated.
Correlation values were only 0.17, 0.09, and 0.18 for
panel, pyramid and Circle traps, respectively, indicating
weak correspondence in time between rises in levels
of fruit injury and rises in levels of trap captures.

Mean percentages of perimeter-row fruit with fresh
injury were not significantly different among trap tree
plots and plots having panel, pyramid or Circle traps
when fruit from all sampled trees (the central tree plus
the four other sampled trees per plot) were combined

(Figure 4). This finding indicates that presence of a
trap tree in a plot did not lead to any greater amount of
plot-wide injury to fruit than would have occurred in
the absence of a trap tree in a plot.

Importantly, for central trees in a plot, percentages
of fruit with fresh injury were significantly greater in
trap tree plots than in any other plots (Figure 4).
Furthermore, for all other (non-central) sampled trees
in a plot, percentages of fruit with fresh injury were
less in trap tree plots than in any other plots (Figure 4).
These results indicate that freshly injured fruit were

Fruit Notes, Volume 68, Winter, 2003

significantly concentrated on trap trees and were not
significantly concentrated on central trees associated
with a panel, pyramid or Circle trap.

Conclusions

Our findings show that even though panel traps
placed in border areas adjacent to perimeter rows of
apples trees captured significantly more PCs than
similarly-placed pyramid traps or Circle traps placed
on trunks of perimeter-row trees, none of these trap
types (all baited with BEN plus GA) exhibited amounts
of captures that correlated significantly and positively
with either weekly or season-long amounts of fresh
ovipositional injury to fruit. How can the unsatisfactory
performance of these traps be explained?

In the case of panel and pyramid traps placed in
orchard border areas, immigrant PCs may continue to
be captured but fail to cause injury because of sufficient
residual effectiveness of a previous insecticide
application. Indeed, in 13 (=20%) of the 66 instances
(6 weeks x 1 1 plots) in which weekly captures of PC
adults by panel traps were compared with weekly
percentages of freshly injured fruit, at least one PC
was captured but no fresh injury was detected. Thus,
based on captures by these traps, insecticide might have
been applied needlessly.

In the case of Circle traps attached to tree trunks,
we know from our previous studies that when
temperature reaches 70 degrees Fahrenheit or more,
progressively more adults tend to enter tree canopies
by flight rather than by crawling up tree trunks. The
wanner the temperature, the greater the probability of
PC injury to fruit. In 12 (=18%) of the 66 instances (6
weeks X 1 1 plots) in which weekly captures of PCs by

Circle traps were compared with weekly percentages
of freshly injured fruit, 1 % or more of fruit was found
injured but no captures occurred At a failure rate of
18% to detect injury-causing PCs using Circle traps,
such traps can not be recommended for grower use.

Our new approach of using trap trees baited with
BEN plus GA circumvents the above shortcomings
associated with use of captures of PCs by panel,
pyramid or Circle traps as a guide for degree of threat
of damage by PCs and goes directly to the assessment
of damage itself. Our findings here indicate that odor
baited trap trees established on perimeter rows act to
congregate immigrant PCs, resulting in a 15-fold level
of aggregation of egglaying injury. No greater amount
of orchard-wide PC injury to fruit occurs as a
consequence of establishing trap trees than occurs in
the absence of trap trees. The establishment of a few
trap trees on perimeter rows in an orchard would appear
to be a simple and effective way of aggregating PC
injury and allowing growers and consultants to focus
exclusively on trap trees to gain an estimate of the
current status of PC damage to fruit.

Results of a further 2002 experiment on a trap-
tree approach to monitoring PCs are given in the next
article in this issue of Fruit Notes.

A ckn o wledgem en ts

We are grateful to the following growers for
participating in this study: Keith Arsenault, Gerry
Beime, Bill Broderick, Dave Chandler, Don Green,
Tony Lincoln, Joe Sincuk, Mo Tougas, and Steve Ware.
This work was supported by funds from a USDA
Northeast Regional EPM grant, a USDA Northeast
Regional SARE grant, and a USDA Crops at Risk grant.

it it it ^ it

Fruit Notes, Volume 68, Winter, 2003

Evaluation of Odor Combinations
for Attracting Plum Curculios to
Trap Trees

Ronald Prokopy, Bradley Chandler, Sara Dynok, Elisa Gray, Matthew Harp,

Anne Talley, and Jaime Pinero

Department of Entomology, University of Massachusetts

In the preceding article, we presented data showing
that apple trees whose branches were baited with a
combination of benzaldehyde (BEN) plus grandisoic
acid (GA) functioned as "trap trees" for plum curculios
(PCs). Adult PCs aggregated preferentially on such trap
trees, thereby paving the way for growers and
consultants to sample only trap trees (rather than
additional other trees) for signs of fresh PC injury to
fruit.

Here, we report results of a 2002 study in
commercial apple orchards in which we evaluated
several different odor combinations in association with
trap trees to determine if there might be a more
attractive combination than BEN plus GA. The
rationale underlying this study lay in the proposition
that the more attractive the odor bait, the more attractive
the trap tree and hence the fewer number of trap trees
needed to acquire an accurate assessment of the
seasonal course of PC injury to fruit.

Materials & Methods

We established nine treatment types in each of 1 1
commercial apple orchards. These included BEN plus
GA plus one of five other host-derived odor sources
known from previous studies (Fruit Notes 2000) to be
at least somewhat attractive to PCs: ethyl isovalerate,
limonene, hexyl acetate, Z-3 hexenyl acetate and E-2-
hexenal. Also included as treatments were BEN plus
GA, GA alone, BEN alone, and no odor (control). As
described in the preceding article, BEN was released
fi^om polyethylene vials at a rate of 40 mg per day per
tree and GA at a rate of 1 mg per day per tree. The
other five odor sources likewise were deployed in
polyethylene vials and likewise released odor at a rate

of about 40 mg per day per tree. None of the vials were
replaced except ones with limonene, where vials were
renewed after 4 weeks. Dispensers of GA were replaced
after 5 weeks.

A continuous perimeter row of apple trees about
220 yards long was selected in each orchard. Treatment
trees, all on the perimeter row, were about 30 yards
apart in order to separate treatments. Odors were
deployed on May 6-8 and remained until June 24-26.
Weekly beginning at petal fall (May 13-15), 40 fhiit
were examined per tree for evidence of fresh PC
egglaying scars.

Results

Results (Figure 1 ) show that trees baited with BEN
plus GA received significantly more fresh egglaying
injury than trees baited with GA alone, BEN alone or
trees without odor bait. Addition of ethyl isovalerate,
limonene, E-2-hexenal, Z-3-hexenyl acetate or hexyl
acetate did not significantly enhance the attractiveness
of BEN plus GA as an odor bait guiding PCs to trap
trees. Trees baited with BEN plus GA received about
15 times more PC egglaying scars than unbailed trees.

Conclusions

Our findings indicate that BEN plus GA represents
a potent combination of attractive odors whose use, in
both this study and the study reported in the preceding
article, culminates in an aggregation of PC egglaying
injury about 1 5-fold greater than that which occurs on
unbailed trees. Findings here further indicate that BEN
plus GA represents a synergistic odor combination
whose stimulating effects, as a combination,

Fruit Notes, Volume 68, Winter, 2003

Li.

Z
UJ

z
<

BEN BEN BEN BEN BEN BEN
GA GA GA GA GA GA
ElV LIM E2H Z3H HA

GA BEN CON

Figure 1. Mean percent of sampled fruit on trap trees baited with different combinations of odor
that received fresh ovipositional injury by plum curculio across 6 weeks from petal fall through
June. Means superscribed by the same letter are not significantly different at odds of 19; 1. BEN=
benzaldehyde; GA= grandiosic acid; EIV=ethyl isovalerate; LIM= limonene, E2H=trans-2-hexenal;
Z3H=cis-3-hexenyl acetate; HA=hexyl acetate; CON= control (without odor bait).

substantially exceed the effects of adding PC response
to BEN alone plus response GA alone. Finally, the
findings here indicate that even though each of the other
five fruit odor components has been found to be at least
somewhat attractive when tested alone, none enhanced
the potency of BEN plus GA when used in a blend.
Although use of trap trees baited with BEN plus GA
appears to be a very promising new approach to
monitoring PC, we can not yet recommend it for
adoption by commercial growers until the following
have been determined: (a) optimum amounts of BEN
plus GA to deploy per trap tree, (b) optimum spacing
of trap trees along perimeter rows, and (c) percent
freshly damaged fruit on trap trees that would justify
insecticide application to all peripheral-row trees. Also,

a commercial supplier of user-friendly BEN dispensers
would have to come forward to complement the current
commercial supplier of GA dispensers.

A ckn o H'ledgem eiits

We are grateful to the following growers for
participating in this study: Gerry Beime, Carlson
Brothers, Dave Chandler, Don Green, Tony Lincoln,
Sean McGlaughlin, Mo Tougas, and Steve Ware. This
work was supported by a USDA Specialty Crops
research grant (via the Massachusetts Department of
Food and Agriculture and the New England Tree Fruit
Growers Research Committee).

*k it it it it

Fruit Notes, Volume 68, Winter, 2003

Can a Band of Tangletrap Around
a Tree Trunk Suppress Plum
Curculio Injury to Fruit?

Ronald Prokopy

Department of Entomology, University of Massachusetts

Operators of small apple orchards and homeowners
have for decades been on the lookout for effective ways
of controlling plum curculio (PC) without having to
resort to use of insecticidal sprays. Approaches such
as daily tapping of tree branches to dislodge PCs
followed by removal fallen PCs from a cloth sheet
placed beneath the tree canopy have proven ineffective.
So also have a variety of non-toxic sprays designed to
repel PCs (such as sprays of garlic). We know from
studies by colleagues in Quebec that PCs enter and
leave apple tree canopies almost on a daily basis as
they search for food and egglaying sites and thereafter
shelter. We also know from some of our own behavioral
observations that during cool weather and also during
night hours, PCs tend to enter apple tree canopies by
crawling up tree trunks, whereas durine warm weather

they tend to enter tree canopies by flight.

Here, we asked whether a band of Tangletrap
around a tree trunk could prevent PCs from entering
the tree canopies to an extent that afforded protection
of fruit against injury.

Materials & Methods

The study was carried out in 2002 in a block of
unsprayed frees at the UMASS Cold Spring Orchard
Research and Educational facility in Belchertown. Half
of the frees were Mcintosh, and half were Delicious.
All were bearing trees on M.26 rootstock. Trees were
pruned in such a way that none of the branches of any
tree involved in the study touched the branches of any
adiacent tree or touched the eround. Herbicide

Q
HI

UJ
Q.

50
40
30
20
10

■ Tangletrap-Banded
D Non-Banded

ii_

2 3 4

WEEKS AFTER PETAL FALL

Figure \. Percent of sampled fruit injured by plum curculio on Tangletrap-banded and non
banded apple trees.

Fruit Notes, Volume 68, Winter, 2003

treatment beneath the canopy and mowing grass in the
alleyway kept understory growth from reachmg any
branches. These measures insured that PCs could gam
entry into the canopy only by crawling up the tree trunk
or by flight into the canopy.

On April 18 at the tight cluster stage of bud
development, a band of white cloth 3 inches wide was
wrapped tightly around the trunk of each of seven
Mcintosh and seven Red Delicious trees at a height of
12 inches above ground. The cloth was firmly stapled
to the trunk, after which the cloth was coated with a
thick layer of Tangletrap, 2 inches wide. The Tangletrap
was maintained free of debris for the duration of the
PC season. Adjacent to each Tangletrap-banded tree
was a check tree of like cultivar, devoid of Tangletrap.

Weekly beginning one week after petal fall (May
15) and ending when fruit reached 1 inch diameter
(June 10), ten fruit were sampled on each of the 14
Tangletrap-banded and 14 check trees for presence or
absence of PC egglaying scars.

Results

Results (Figure 1) show that very little fruit injury
occurred on either Tangletrap-banded or non-banded
apple trees during the first and second weeks after petal

fall. By the third week, when fruit averaged about 1/2-
inch diameter, there were slightly fewer injured fruit
on banded than non-banded trees. The weather was
unusually cool and damp during the first 3 weeks after
petal fall. During the fourth and fifth weeks after petal
fall, temperatures warmed and injury to fruit by PC
increased substantially on both banded and non-banded
trees. By the fifth week, there was essentially no
difference in percent injured fruit on banded and non-
banded trees.

Conclusions

Findings from this experiment are in agreement
with findings of our previous studies. In cool weather,
PCs tend to enter tree canopies primarily by crawling
up tree trunks. Under such conditions, a band of
Tangletrap around the tree trunk can aid (at least
slightly) in reducing the number of PCs entering the
canopy and thereby reduce damage to fruit. In warm
weather, PCs tend to enter tree canopies primarily by
flight. Under such conditions, which are the most
favorable of all for PC egglaying, a band of Tangletrap
around the tree trunk is of little or no help in preventing
PC entry into the canopy and hence of little or no help
in preventing damage to fiaiit.

it it it it it

Fruit Notes, Volume 68, Winter, 2003

Helping Kids Do Farm Jobs Safely:
Know Which Tasks Are Appropriate
for Your Children

George Cook

Extension Maple Specialist, University of Vermont

Many injuries occur on farms because children are
involved in farm work that exceeds their physical and
mental abilities. As one father, a fourth generation
farmer says, "Our sons help somewhat, when they can.
You always have to consider age-appropriate tasks."
His other job, as a farm safety and Emergency Medical
Services instructor, serves as an acute reminder of the
human tragedy behind these statistics:

• About 1 04 children die each year from agricultural
injuries;

• Children younger than 16 years of age are victims
of up to 20 percent of all farm fatalities in both the
U.S. and Canada;

• Children who do not live on farms are victims of
one-third to one-half of nonfatal childhood agri-
cultural injuries.

For farm parents, there is a resource available to
help match children's abilities with agricultural job
requirements. How much weight can a 10-year-old
safely lift? What type of machinery is a child capable
of operating? Does your child have good eye-hand
coordination? Can an adult supervise as recom-
mended? Suggested parameters for these and other
questions are included in the North American
Guidelines for Children's Agricultural Tasks
(NAGCAT).

"We hope these guidelines will help promote a
strong work ethic for young people by giving them safe
and appropriate opportunities for work experience
under adult supervision," says Barbara Lee, Ph.D. Dr.

Lee led the team of parents, specialists in both
agricultural safety and child development, and other
key partners from the U.S., Canada, and Mexico that
developed the guidelines. This task was at the request
of farm parents who wanted guidance in assigning
appropriate tasks to children.

There were five youth advisors to this planning
team. Says one 17-year-old participant, "It's a great
start, and I'm very enthused. We need to take a stand
on safety. The Guidelines can be another useful tool in
preventing injuries on farms and raising awareness."

The guidelines cover 62 agricultural jobs focusing
on the most common childhood farm jobs (like
"feeding milk to calves"). Categories are Animal
Care, Manual Labor, Haying Operations, Implement
Operations, Specialty Production, Tractor Fundamen-
tals, and General Activities.

The guidelines are based on a child's physical,
mental, and emotional development rather than a
child's age. "Kids develop at their own pace and are
influenced by their environment," Lee said. "If we
said a 10-year-old could do a certain job, we might put
half of them at risk."

Each individual guideline includes a section on
Adult Responsibilities, Main Hazards, Child's
Ability, Supervision Required, Training To Do, and
Remember - PPE required. These guidelines are
colorful and easy to read with practical diagrams and
descriptive pictures.

Being a parent always has been a balancing act.
Farm parents, in particular, face unique challenges.
These guidelines can help them offer their children a

Copyright©2002 by Moose River Publishing Company. Reprinted with permission from Fanning, The Journal of
Northeast Agriculture, Volume 5, Number 3 (March), 2002, pp. 11-12. For subscription information, call Moose River
Publishing Company at (800) 422-7147 or write to Fanning, The Journal of Northeast Agriculture, P.O. Box 449, St.
Johnsbury, VT 05819-9929.

Fruit Notes, Volume 68, Winter, 2003

chance to develop a safe work ethnic and gain
valuable, lifelong experience.

These guidelines, developed for parents, are
recommendations, not mandates. Like recommenda-
tions on children's toys and games, the guidelines
serve as a point of reference that require assessment
and decision making by adults. Says Lee; "We help
them make informed choices about activities their
children do. Our top priority always comes back to
children, a child's first 'job' should be to grow up
healthy, happy, and strong."

A new, user-friendly Web site, www.nagcat.org.
offers complete information about the guidelines. A
professional resource manual and parent resources are
available for purchase from Gempler's safety supply
company, 800-282-8473 or www.gemplers.com/
nagcat.htm. While University of Vermont Extension
does not recommend one company over another, this is
the only source for these guidelines, at this time.

Reference credits given to Cheryl Tevis,
Successful Farming, May-June 1999.

«1^ %1^ %i^ «J^ vf^

#^ #Y* 'lii* *j|i* *ii*

Fruit Notes, Volume 68, Winter, 2003

Visual Exposure:

Farm Logos and Signs Tell Your Story

Judith M. Powell
Whitefleld, Maine

Deciding what sign and logo best represent you is
a challenging and important business decision.
Signage and logo make a statement about the farm and
the people behind it. The objective is to reach out and
hit a target audience of customers you are striving to
connect with, while at the same time motivating a
positive response by communicating what you are
about. These are marketing tools that make a promise
of quality, in the mind's eye of what your public
perceives.

Perception is a subconscious response computed
in the course of a fleeting moment. Webster's
Dictionary defines it as intuitiveness, sense of
awareness, insight, and understanding - rolled into
one. What perception is generated from your logo and
signs? If your enterprise does not have a logo already.

Signs: Things to Consider

• Avoid using the shapes and colors the
highway department uses, so your sign will
stand out.

• Keep the sign well-painted and well-
managed. Appearance is very important.

• Place it out in the open, where it will be
lighted by the sun not shaded by a tree or
building.

• Avoid tall grasses, fences, trees, and
houses for readability.

• Know zoning restrictions and state and
local regulations, including setback
restrictions.

now is a good time to take this on as a project. It also
could be that an existing logo might need an update or
face-lift.

It is easy to keep a daunting task like deciding on a
logo on the back burner. An already-too-long list of
immediate things-to-do provides good justification.
Then, there is not knowing how to begin and not
knowing how much it is going to cost to get this done.
These seem like reasonable excuses. Priorities should
relate to payoff, and your investment in marketing will
pay offover and over again. Take it slowly. This is not
a project to be completed in an evening or a week, but
one that should be slept on so your subconscious can
help out.

A good starting point is thinking through where
the farm began, and where you are going. Every farm
is a unique story. Usually, it is a good story. Your
story is about history, family commitment, land
stewardship and environment, heritage, lifestyle, and
passions. Typically, these represent the same reasons
consumers want to support you and will acknowledge
their appreciation through their dollars. Make lists of
key words that represent what is important in your
mind. These key words are your message ingredients.
Next, cluster these into groups to identify relationships
and characteristics that naturally fall together until a
theme emerges or an image formulates in your mind.
The logo and signage convey personality and place.

If the exercise seems difficult, a different tact is to
define the audience you are targeting - customers who
may think like you do and seek the products and
services you can supply. All customers are not the
same, so your marketing challenge is finding those
who need what you have to sell. Your logo and signage

Copyright©! 00 2 by Moose River Publishing Company. Reprinted with permission from Farming, The Journal of
Northeast Agriculture, Volume 5, Number 4 (April), 2002, pp. 29-32. For subscription information, call Moose River
Publishing Company at (800) 422-7147 or write to Farming, The Joumal of Northeast Agriculture, P.O. Box 449, St.
Johnsbury, VT 05819-9929.

Fruit Notes, Volume 68, Winter, 2003

VISIBILITY

Maximum number o

f words which can be

Distance from

read by

the average

motorist travehng at

which sign must

various speeds

be visible to be
fully read

Minimum
letter height

30 mph

40 mph

50 mph

60 mph

(feet)

(inches)

1.75

100

3,5

200

300

400

500

17.5

will help customers find you and your products.

Thinking through your marketing niche is thinking
about your customers. What are the people you hope to
reach looking for, and what might drive them to
connect with you? Why is your farm or enterprise one
that they should want to connect with? The point of
this, of course, is that consumers want to find local
suppliers who are bringing to the marketplace the
products they want, grown or made in a way that fits
their philosophy. They are searching and screening to
see if what they want are the products you, as seller,
have. The consumer, as buyer, wants you to reach out
and make a connection. Your image, communicated
through your signs and logo, can be the lifeline.

As the farm's image is planted in the minds of
neighbors, business associates, and customers, it
becomes a familiar identifier and acts as a reminder
that the farm is in business and invites patronage. The
logo can be put on anything and go anywhere. It should
be used on letterhead and invoices, business cards,
point-of-sale tags and cards, vehicles, and Web site. It
can work hard and extend your message beyond people
driving by the farm. The value of familiarity is
immeasurable, and exposure is key.

Detail is important. Color, design, size, and
materials all make statements. By selecting carefully,
a package will evolve into your trademark that
expresses your vision. Colors should be chosen to
reinforce your intentions. If color is not a forte of
someone in the family, your local paint store is a handy
resource. Browse the displays of paint shades and

tones and consider finish
options. Weed out the colors
that do not fit, and bring home
chips that you think do. Take
enough time, remembering
that it is OK to change your
mind, scrap it, and start over.
Ask a local art teacher,
relative, or print shop to look
at what you have come up
with, and ask their opinion.
Ask what your image says to
them to see if it is in line with
your intentions.

Original artwork may be
expensive, unless a willing
friend or family member has
talent. Trying some pencil sketches can help
crystallize everyone's thinking. Cost can be managed
by using a computer-generated image instead of hiring
an artist for an original rendering. A local design
company using "desktop-publishing" software may fit
the bill, and later modifications, such as sizing, can be
handled easily.

The ultimate goal is a picture that reflects the
essence of the message you want to send. Now it is
time to make a budget. There are options. This
expenditure should be thought of as an investment
important to the credibility of a business venture, but
how much to spend can be hard to decide. Cost
considerations can be managed by breaking down the
project into steps and by extending the development or
the execution over time. Artwork can be purchased
one year, leaving the building of the permanent sign
until the next. Meanwhile, the logo image can be
applied to letterhead and point-of-purchase signage.
Once scanned into your computer, it can be placed on
invoices and any print fliers, posters, or other
disposables tailored to an event, function, or mailing.
Implementing step-by-step is a good way to
manage cost. Your list might look like this. Year one,
get the artwork for the logo, get it scanned into the
computer for application on print materials, and have
business cards made. Year two, have farm sign made,
buy the hardware and posts, and put it up. Year three,
add flood lights and an attractive base around the sign
pole and have vehicle decals made and applied. Year
four, have sale price tags, price board for retail site,

Fruit Notes, Volume 68, Winter, 2003

posters, farm brochures, etc. made. Now, your
marketing program is well underway and affordable.
One more thought about the stand-alone sign. It is
usually the biggest expense item, depending on
materials used and who builds it, size and complexity,
and how it will be affixed. When planning the sign you
really would like to have, do not forget to research and
cost-out the style of post and hardware needed to
support your theme and design. The post, hinges, and
metal hangers can cost as much as the sign itself. They

might not be readily available locally and may need to
be handcrafted or ordered. Also include costs if
someone will need to be hired to put it up. Check out
fees for state and local permitting or zoning, and, if the
sign will be placed on someone else's property, will
there be rent? Research town or highway restrictions
to be sure your plans will be in compliance.

When approached in small steps, your sign and
logo can be achieved.

%i^ %i^ %i^ «1^ %i^
0T% ^r% ^r% «T« #T*

Fruit Notes, Volume 68, Winter, 2003

Fruit Notes

University of Massachusetts
fmil Department of Plant &c Soil Sciences
IJIllljj 205 Bowditch Hall

«^ Amherst, MA 01003

Nonprofit Organization
U.S. Postage Paid

Permit No. 2
Amherst, MA 01 002

- 1
SERIAL SECTION
UMASS
AMHERST, MA 01003

104911

JM/Scit 1

-'er

354

-&a

Table of Contents

An Apppeal for Early Hariesi of Honeycrisp
Sarah Wets

Finding and Keeping Ihe Right Employees; Ideas to Bail the Hook

Judnh Powell *

Esiablishineni and BiocoDtrol Potential of Released Typhlodromus pyri Predator Miles in Massachusetts Apple Orchards: 2000-2003

R<in,:l Prokopy. Starker W'rtghl. Isabel Jacome. Wtlttam Colt, Jan Nyrop. Karen Wentworth. and Carol Hiring '

Real Buzz Words: Beekeeping Sits for All Levels

Diane Baedeker Pettt

SJP8-t Winter Hardy Dvi-aif Apple Rootstock Series from Agriculture and Agri-Food Canada National High Value Crop Breeding: Program
Shahrokh Khanizadeh. Yvon Groleau, Raymond Granger, Gtlles Rouselle. and Campbell Davidson

Summertime Heat & Health: Prevention Is the Best Medicine
George Cook

A Comparison of Six Strains of M 9 Over 10 Years

Wesley Aulto. James Kntpa. and Jon Clements

Be Avk-are: Protection During Lightning Storms

George Cook

An Early Look at a Few of the Geneva Series Apple Rootstocks in Massachusetts

Weiley Autio. James Kntpa, and Jon Clements

How Does B.9 Stack Up Compared to M 9?

Weslev Aulto

, 26

Editors:

Wesley R. Autio
William J. Bramlage

Publication Information:

Fruit Notes (ISSN 0427-6906) is pub-
lished each January, April, July, and
October by the University of
MassachusettsAmherst in cooperation
with the other New England state uni-
versities.

Correspondence should be sent to:

Fruit Notes

Department of Plant & Soil Sciences
205 Bowditch Hall
University of Massachusetts Amherst
Amherst, MA 01003

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 DAM.AGE.

Issued by UMass Extension, Stephen Demski, Director, in furtherance of the acts of May 8 and June 30,
1914. UMass Extension offers equal opportunity in programs and employment.

An Appeal for Early Harvest
of Honeycrisp

Sarah Weis

Department of Plant & Soil Sciences, University of Massachusetts

It has been proposed by Dr. Chris Watkins of
Cornell University that soft scald in Honeycrisp may
be avoided, or at least substantially reduced, by
delaying cold storage. Soft scald has been a serious
problem on Honeycrisp grown in some areas of the US,
one of which being New York. He found that if
har\'ested fruit are kept at room temperature for a
period of time (perhaps 1-7 days) before being
transferred to cold storage temperatures, development
of soft scald can be reduced or eliminated. It has
always been recommended that harvested fruit be
placed in cold storage as quickly as possible in order to
maintain high quality for consumers. If cold storage is
delayed in order to avoid soft scald, it is important to
consider possible negative effects on other fruit
qualities such as firmness and development of

disorders such as decay (to which Honeycrisp is quite
susceptible), senescent breakdown, and internal
browning.

This study looked at the effects of delaying cold
storage on these qualities. Honeycrisp fruit were
harvested from three orchard blocks at the University
of Massachusetts Cold Spring Orchard Research &
Education Center in Belchertown. MA on September
1 6 and 23, 2002. Fruit were divided into three groups.
One group was placed in cold storage at 32F
immediately following harvest, one group was kept at
room temperature for 1 day prior to cold storage, and
the third group was kept at room temperature for 4 days
before being placed in 32F air storage. Fruit were
removed for observation (for about 10 minutes) after
approximately 90 days of cold storage and then

Table 1 . Effects of delaying cold storage of Honeycrisp har\

ested September 16 and 2

3.2002.

Days from

Delay to 32F cold

storage

Percent of fruit developing: harvest

(approximate)

None

1 Day

4 Days

Signif

Soft scald (%)

90^

0.5

Decay (%)

150^

157"

Internal browning (%)

157

Senescent breakdown (%)

157

Skin greasiness (%)

157

Off taste (%)'

157

Average flesh firmness (lbs)

157

13.6

14.1

13.9

^ ns, * Differences statistically nonsignificant or

significant

at odds of 19:1, respectively.

^ Obsenations made at 90 days were on cold fix

it just removed from storage.

" Obsenations made at 1 50 days

were on cold fruit just remo\ed from

storage.

" Obser\ations made at 157 days

, were on fruit which had been at room temperature for one |

week. Note that the same fruit

were being repeatedly obser^-ed.

" Off taste has been described as an aldehyde or

ermentation flavor with correspond

ng odor.

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

Table 2. Effects of delaying har\est of Honeycrisp, 2002.

Percent of fruit de\ eloping:

Days from
harvest

Date of harvest

(approximate) September 16 September 23 Signif

Soft scald C; o)
Decay (%)

Internal browning (%)
Senescent breakdovvn (%)
Skin greasiness (%)
Off taste (%r
Average flesh fimuiess (lbs)

90-'
90

150"

157"
157
157
157
157
157

14.5

13
25
35
42
9

40
25
13.3

ns
ns

***

ns
**

ns, *, **, *** Differences statistically insignificant or significant at odds of 19:1, 99:1, or

999:1, respectively.

Observations made at 90 days were on cold fruit just removed from storage.

Observations made at 150 days were on cold fruit just removed from storage.

Observations made at 157 days were on fruit which had been at room temperature for one

week. Note that the same fruit were being repeatedly observed.

Off taste has been described as an aldehyde or fermentation flavor with corresponding odor.

Table 3. Effects of delaying harvest

of Honeycr

sp, 2002.

Days from

Date of harvest

Percent of fruit developing: harvest

(approximate)

9/5

9/10

9/16

9/23

Signif

Soft scald (%)

90^

0.6

8.0

Decay (%)

150'

157"

Internal browning Co)

157

*++

Senescent breakdown (%)

157

Skin greasiness (%)

157

***

Off taste (%r

157

Average flesh firmness (lbs)

157

16.0

15.6

14.2

13.1

***

' ns, *, **, *** Differences statis

tically insignificant or

significant at odds of 19:1

, 99:1, or

999:1, respectively.

^ Observations made at 90 days were on cold fruit just removed from storage.

" Observations made at 1 50 daj's

were on cold fruit just removed from storage.

* Observations made at 157 davs

were on frui

t which had been at room

temperature for one |

week.

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

Table 4. Averages of some qualities of Honeycrisp at

harvest.

2002.

Harvest Date

Signif

Characteristic

9/5

9 10

9/16

9/23

Percent Red Color 51

***

Firmjiess (lbs) 17.0

16.8

15.1

14.0

***

Starch^ 5.7

6.0

6.7

7.6

***

Internal Browning (%)"

' *** Differences statistically sign

ficant at odds of 999:1.

' Starch index is from Cornell Generic Starch Chart.

^ Internal browning is percent of fruit %>.

hich had internal browning. |

Fruit from the first two harvest

s were

not cut to

observe

internal

disorders.

replaced in cold storage for another 60 days.
Following the 150 days, fruit were again removed for
obsenation, kept at room temperature for 7 days to
approximate conditions to which they might be
subjected prior to consumption, and then pressure
tested and tasted.

Table 1 shows the storage disorders observed on
the fruit following cold storage, as well as the flesh
firmness at the end of the 1 50 days of cold storage and
week at room temperature. The only disorder which
was significantly influenced by the delay of cold
storage was soft scald. Delaying cold storage
essentially eliminated soft scald; however, soft scald
was not much of a problem. Only 4% of fruit
de\ eloped the disorder even when cold storage was not
delayed. Delaying storage would be recommended if
soft scald were a problem, but it did not appear to be a
problem for us (at least in 2002). Decay, internal
browning, skin greasiness, and off fla\ or development
were much greater problems, but treatments did not
influence these problems differently.

Delaying cold storage did not appear to have a
significant negative effect on quality of stored
Honeycrisp fruit. The storage problems that were
evident were not made worse by delaying storage up to
4 days, so that if soft scald were a problem, this
solution would not have a substantial down side, other
than that of the inconvenience of moving the fruit an

e.xtra time. This is not to suggest
that it is not generally important to
cool fruit as quickly as possible,
but to suggest that in the case of
Honeycrisp the benefit of delay
may outweigh the risks.

More important to us than soft
scald have been decay and internal
browning. Internal browning is
especially problematic, since it is
not visible on the packing line, and
therefore seen first by the con-
sumer. The browning tends to
show up as a light brown
sponginess of a large portion of
the cortex of the apple. 0\erall.
25% of the fruit harvested Sep-
tember 16 and 23, 2002 suffered
from internal browning after 5 months of cold storage
and I week at room temperature.

Time of hanest had a powerful effect on internal
browning as well as other qualities of stored fruit
(Table 2). Decay was not affected by time of hanest,
but internal browning, skin greasiness, and off flavors
of fruit were significantly reduced less frequent in truit
harvested on September 16 compared to those
harvested on September 23. The earlier harvested trait
were also fimier.

In another experiment including two earlier
harvest dates but no storage delay, the effect of time of
harvest on post-storage frait quality was even more
dramatic (Table 3). The only storage disorder that
developed on fruit har\'ested on September 5 or 1 was
decay, plus a trace of internal browning. It should be
noted, too, that while superficial scald can be a post-
storage problem on early-har\'ested fruit, it did not
develop on these Honeycrisp.

It is possible to use measurements of fruit ripening
to assess a ban est date for Honeycrisp that will result
in fewer storage problems (Table 4). A starch index of
5.5 to 6.0 has been recommended for Honeycrisp. In
2002, harvest of Honeycrisp fruit with starch index
values in this range would have resulted in little
development of storage disorders. Further, frait were
significantly firmer at the earlier harvests. Lack of red
color is the only negative aspect of early harvest.

'k i: :k ^ :k

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

Finding and Keeping the Right
Employees: Ideas to Bait the Hook

Judith M. Powell
Whitefield, ME

The right employees bring good fortune. How-
ever, finding the right just doesn't happen right out of
the blue. Having capable, eager and motivated people
come a-knocking on your door, asking to do the kind
of work you need done, happens in fair> tales. In real
life, managing people is a big challenge that eats up
precious time and can cause frustration. Not selecting
the best candidate, or losing an enthusiastic worker,
can signal that it's time to examine your human re-
source approach.

Tom Maloney, senior Extension associate in the
Department of Applied Economics and Management
at Cornell University, has spent the last 15 years of his
career focusing on labor issues and policy. He's been
visiting with farmers over the past three years at New
England dairy seminars. Hiring, managing and suc-
ceeding with farm employees are his specialties.

"You need help, and you know the kind of person
you wish you could find," Maloney begins his talk at
the Maine Dairy Seminar held in Augusta. He asks
the audience what counts. "A person who wants to
work around animals," someone says.
"Reliable— someone who will show up on time," is
mentioned. Others say, "mechanical ability, can work
independently, someone I can trust." Getting the per-
son you want is within reach, Maloney says.

So, where to begin? Finding the right person starts
by getting a handle on the job. The first step is defin-
ing what you expect to have done. What exactly will
you assign the new person to do? What are the spe-
cific tasks, and when must they be done? Must they
be done in a certain way or at a certain time? Thinking
through details makes it easier to determine what tal-
ents and skills are needed for both the employer and
employee to succeed.

Farm-owner operators and family manage all kinds
of jobs every day. They somehow leam them over time.
But expectations must be realistic for a new hire on
the fann. A person who is happily mucking out stalls
may not efficiently pull reports out of the database or
serve customers \\\\o drop by the fann stand. Employ-
ees who are happy with what ihey are doing and are
satisfied with their work environment are generally
more productive.

The first step in a systematic approach to success-
ful human resource management is recruitment,
Maloney says. "You want to develop the broadest pool
of potential job candidates." He encourages using
"traditional" sources like government job services agen-
cies, farm internship programs, community bulletin
board postings and advertisement in local and agricul-
tural publications. However, he says, the best source
is word-of-mouth. "Some of the best leads come from
current employees. They know what the job is and
have a vested interest in making sure their coworkers
will be good," he explains. "Offer a bonus if the new
person stays six months. A S50 or $200 bonus can
make the grapevine or e-mail buzz!"

"Don't be afraid to be creative by exploring "non-
traditional" sources like homemakers, retirees, teach-
ers with summers off Don't narrow the field and ex-
clude people who might perform these very well and
be happy doing it." Maloney says. Farms offer work
variety, fiexible hours and the chance to work outside
with animals. These are great benefits, which some
people prefer over wages. "Not everybody wants to
fry hamburgers for McDonald's, even though they
might get $7 an hour. Farms should capitalize on their
unique setting and mix of opportunities."

The next step in the process is writing a "help

Copyright©2003 by Moose River Publishing Company. Reprinted with permission from Fanning, The Journal of
Northeast Agriculture. Volume 6, Number 1 (January), 2003. pp. 36-38. For subscription information, call Moose River
Publishing Company at (800) 422-7147 or write to Farming, The Journal of Northeast Agriculture, P.O. Box 449, St.
Johnshurv, VT 05819-9929.

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

wanted" ad that sells the position. There are many
positive attributes that may draw people into your pro-
spective applicant pool. Think of everyday "luxuries"
your farm offers and draft some help wanted ads:

"Looking or fresh air and exercise? Need variety
and a challenge? Family business offers good work-
ing conditions, flexible hours, done by 4 p.m."

Choosing the best applicant out of those you inter-
view can be tricky. Be prepared and keep an open
mind, Maloney says. He suggests developing a short
list of questions and asking all the questions each time,
so the interviewer has a consistent means of compar-
ing and evaluating candidates' responses. Asking what
people like to do in their free time is one way to get at
what tasks the person may excel at. Does the person
prefer to work independently or with others? If your
crew works as a team, it's important to select for this
personality trait.

One of the hardest areas in managing employees
is keeping the right ones and getting rid of the others.
The U.S. Department of Labor reports that respect— not
money, nor benefits, but respect— is the number one
thing employees say they want first and foremost.
Workers need to know how important the boss thinks
their roles are within the total scheme of the opera-
tion. An open and friendly atriiosphere along with
positive acknowledgement for good work will do won-
ders. What can be easier than thanking people when
they make special contributions, like stay late, work
lunch, or go the extra mile when they could have got-
ten by easier? Don't wait; make the acknowledgement
immediately. "Positive reinforcement has to be earned.
You cannot just give it away. Giving superfluous com-
pliments is not respect," Maloney says. "If the em-
ployee does something you did not like, tell him or her
as quickly as you can. On the other hand, if he or she
performs exceptionally well, tell that employee and
everybody else too!"

"Your goal is to build loyalty and an atmosphere
of mutual respect," Maloney says, adding that the best
way to accomplish this is keeping an open, friendly

attitude. ".An employee is more apt to ask questions
before she he acts on his own, when the boss' atiritude
encourages it." Maloney advises.

Assigning a title to positions is. an easy way lo ex-
press the importance of the job and regard for how this
role fits into tfae larger farm. The title a person carries
tells the employee and others what you think of him.
The title shouJd refer to the main job responsibility.

Feedback is critical. Giving feedback becomes
easier when performance is rated on a regular basis,
such as quarterly or semiannually Using just three
ratings — excellent, okay, unsatisfactory— will commu-
nicate your regard for the person's performance. Evalu-
ate the things that matter— such as timeliness, avoid-
ing waste, safety, job skill, care of equipment, willing-
ness, honesty, pride, use of time, reliability. Be can-
did. Use the dme to go over problem issues and give
praise, stressing performance rather than personal char-
acteristics. Keeping dated notes provides documenta-
tion for future reference.

Finally, protect the investment you have made by
developing your good workers who your needs. "No
one is in busirBess just to make friends or because they
like to work." Maloney says. Employees must feel ap-
preciated and have opportunity to progress. If the fam-
ily farm cannot increase wages and benefits or offer
advancement, the best workers may mo\e on to greener
pastures, unless they know that you want them to stay.
Instead of a rajse, the employer and worker might dis-
cuss together vahat else could be done to replace mtoney.
Sometimes, options like flex time, job sharing, a:>.sign-
ment of new casks, supervising or learning something
new is reward enough. Keeping good workers satis-
fied and at peaik performance is important. Otherwise,
\ou may be filling vacancies again and starting all over
The goal is to keep good workers who enjoy perfomi-
ing in a friendly and open working environment and
who know their roles are important within the whole
operation. Feeling an important part of an organiza-
tion contributes to everyone's success.

'k :k i: ic 'k

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

Establishment and Biocontrol Potential
of Released Typhlodromus pyri
Predator Mites in Massachusetts
Apple Orchards: 2000-2003

Ronald Prokopy, Starker Wright, Isabel Jacome, and William Coll
Department of Entomology, University of Massachusetts

Jan Nyrop, Karen Wentworth, and Carol Hering

Department of Entomology, Cornell University, NYSAES, Geneva, New York

In the 2000 issue of Fruit Notes, we reported the
results of a 3-year project (1997-1999) aimed at
establishing the predator mite Typhlodromus pyri in
Massachusetts apple orchard blocks of different tree
sizes. Results showed that following release in 1997,
T. pyri became established in all eight blocks by the
following year, spreading fastest from tree to tree
among cultivars on M.9 rootstock and slowest from
tree to tree among cultivars on M.7 rootstock. Result
also showed that even in blocks on M.7 rootstock, by
1999 T. pyri had spread to the most distant trees in the
49-tree blocks and provided effective block-wide
suppression of European red mites.

Encouraged by results of this 1997-1999 project,
in 2000 we launched a 4-year study to further
characterize the establishment and spread of released
T. pyri in commercial apple orchards in Massachusetts.
We asked five questions. First, would the addition of
pollen to trees in which T. pyri were released enhance
the buildup of T. pyri'? This predator is known to feed
on pollen when prey mites are low in abundance and
previous research has shown that supplementary pollen
could elevate predator numbers. Second, in which
direction is T. pyri likely to spread fastest following
release from trees on row 4 of a block: toward row 1
(the perimeter) or toward row 7 (the interior)? Third,
would the establishment of American hazel trees
opposite plots in which T. pyri were released contribute
to the buildup of T. pyri and/or Amblyseius fallacis as

predator mites? American hazel trees have been found
b\ others to harbor substantial populations of predaiory
mites. Fourth, what is the relationship between the
abundance of T. pyri and the abundance of Amblyseius
fallacis as predatory mites? Fifth, w ould the release of
T. pyri in 2000 guarantee effectne biocontrol of
European red mites in subsequent years? Here, we
present data that address each of these questions.

Materials & Methods

Our experiment was conducted in 12 blocks of
apple trees in ten commercial orchards. Each block was
about 140 meters long by seven rows deep and was
di\ ided into four equal-size plots. The perimeter row
of each block was bordered by woods, hedgerow or
open field. Trees were on M.9, M.26. or M.7 rootsiock
and were principally Mc Intosh. Cortland, Gala,
Empire, Jonagold or Fuji.

There were four treatments at the outset in May of
2000 (one per plot): (1)7^ pyri released in the presence
of fresh cattail pollen, which was applied to the tree
canopy by a commercial pollen applicator (E-Z Power
Duster, Firman Pollen Co, Yakima. WA) at the rate of
one-seventh ounce of pollen (about 100,000 pollen
grains) per tree, (2) T. pyri released in the absence of
pollen amendment; (3) no release of T. pyri but, as with
the first and second treatments, no insecticide applied
after mid-June (apple maggot flies were controlled by

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

odor-baited red sphere traps), and (4) no release of T.
pyri and organophosphate insecticide applied during
July and August to control apple maggot. For the first
and second treatments, T. pyri were released at bloom
at the rate of about 100-200 individuals per tree on
two trees in the fourth row of each plot, one tree to the
right and one to the left of the center tree of the plot.
Releases were made by wrapping a burlap band that
contained T. pyri around the trunk of a release tree. In
autumn of 1999, such bands had been placed around
trunks of apple trees at Geneva, NY to collect T. pyri
seeking overwintering sites.

In 2000, we sampled 25 leaves per tree on each of
two trees in rows 1, 4 and 7 in each plot. We did this
twice during July and twice during August. One of the
sampled trees was immediately to the right and the other
immediately to the left of the center tree of the row
(for rov\ 4, these were the same trees in which T. pyri
were released). For 2001, 2002 and 2003, we no longer
segregated samples according to plot and sampled five
leaves on each often trees (50 in all) on each of rows
1, 4 and 7 in each block. We did this twice in 2001
(once in July and once in August), once in 2002 (in
July) and twice in 2003 (once in July and once in
August).

In 2000, in four of the blocks we planted 20
seedling trees of American hazel in hedgerows opposite
and about 5 meters away from plots in which T. pyri
were released. Our intent was to sample leaves from
these seedlings for abundance of predatory mites as
soon as the seedlings achie\ ed reasonable growth
(reached 1 meter height). Hence, in 2002 and 2003,
we sampled five leaves from each often American hazel
seedlings (50 leaves in all) once during August in each
of the four blocks.

All sampled leaves were sent by overnight mail to
Geneva. New York for the identification and counting
of pest and predatory mites.

From 2000-2003, none of the sampled plots
received pyrethroid or carbamate insecticide (except
carban. 1 as thinner), none received EBDC fungicide
after mid-June, and none received miticide (except
prebloom oil). The only exception was orchard F, which
received a spot-treatment of Acramite in August of 2003
against European red mite.

Results

With respect to our first question, data for 2000
presented in Figure 1 show that addition of cattail
pollen had no detectable effect on the buildup of T.
pyri in trees in which these predators were released.
Peak populations of T. pyri in 2000 were just as great
in trees not receiving cattail pollen as in those that did
receive pollen, and were roughly twice as great (on
sampled center trees in row 4) in plots where T. pyri
were released as in plots where no T. pyri were released.
Conversely, peak populations of European red mites
on sampled trees averaged about twice as great in plots
where no T. pyri were released and which received
insecticide during July and August as in plots where T.
pyri were released and received no insecticide after
mid-June. Peak populations of A. fallacis averaged
roughK the same in all plots. For each of the four plot
types. A- fallacis was less abundant than T. pyri.

In regard to our second question, there was no
statistical evidence that spread of T. pyri differed among
the rows of trees, although data for 2001 shown in Fig.
2 hint that T. pyri released in 2000 on trees in row 4
may ha\ e spread faster to trees in row 7 than to trees

S 1.5

Figure 1. For 2000, peak abundance of 7! /J'>T/(TP),/4./a//acK (AF) and European red mites (ERM) in two trees
in row 4 of each of four plots in each of 12 orchard blocks: trees in which TP were released and cattail pollen was
added (TPP), trees in which TP were released but no pollen was added (TPNP), trees in which no TP were
released, no pollen was added and apple maggot was controlled by baited red sphere traps (NTP) and same as
preceding except apple maggot was controlled by grower-applied insecticide (GC).

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

2001

02, '" 02,

*' 2,

ERM

S0.15- JO'S-
|005. ^^B ^^M ^^M

^^^^^^1 ^^^^^H ^^^^^H

; 1 5 -

o ,,
|0.5,

J — ^ ^ ^

1 4 7

14 7 14 7

2002

02, '"

ERM

0.1, ^H ^H ^H

|1.5
g 1-
_ |0 5-

J— ^ Q

1 4 7

14 7 14 7

2003

I"''- !0.15.

1°" ^ IH ^ 1 °^

oJ-^ ^ ^™-

1 4 7

1 15
|05

ERM

1 4 7

Figure 2. For 2001, 2002 and 2003, average abundance (across all sampling dates) of T. pyh (TP), A. fallacis \

(AF) and European red mites (ERM) in rows 1

, 4 and 7 of 1 2 orchard blocks in which TP were released in row 4

in 2000.

in row 1. By 2002 and 2003, however, T. pyh were
equally abundant in rows 1 , 4 and 7. A. fallacis showed
no clear pattern in abundance according to row across
2001, 2002 and 2003 . The same was true for European
red mites.

Our third question focused on the potential value
of establishing American hazel trees in border areas as
a way of promoting buildup of predatory mites and
enhancing populations of predators in adjacent blocks
of orchard trees. However, as shown in Fig. 3 for the

four orchard blocks involved in this evaluation, the
abundance of T. pyri and especially A. fallacis was low
on leaves of American hazel trees in border areas.
Moreover, neither of these predators was more
abundant in row 1 trees than in row 4 or row 7 trees,
which could have been expected if substantial numbers
of predators were moving from American hazel trees
toward orchard blocks.

Our fourth question concerned the relationship
between T. pyri and A. fallacis. Data from our study of

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

2002

0.2 1

S 0-15 H

0.2

S 0.15

0.1 -

> 0.05
<

2003

0.2

0.2 -I

Row

Figure 3. For 2002 and 2003, average abundance (across all sampling dates) of T. pyri (TP) and A.fallacis (AF)
in American hazel trees (H) in border areas adjacent to four orchard blocks and in rows 1. 4, and 7 of these four
blocks (in which TP were released in row 4 in 2000).

0.2

™ 0.15

0.05

Figure 4. For 2001, 2002 and 2003, average abundance (across rows 1, 4 and 7 and across all sampling dates) of
T. pyri (TP), and A.fallacis (AF) across 12 orchard blocks in which TP were released in 2000.

Fruit Notes, Volume 68, Spring, Summer, & Fall. 2003

oTyphlodromus pyn +Amblyseius fallacis

c
<u
•o

'o
c
o
tr
o

1 -

ODODnnnn

OCnXDCCtD

OODO-I- 00

0.8-

0.6-

04-

o
o

0.2-

-f-

+I--H- -H-H-

CDI 1 1 1 1 1 4+4+

1 1 in^HTTTnTll 1

2001

2002
Year

2003

CD o

0)
Q.

■D

.2-

2003
Q

20011

2002

TO
(D
Q.
O

^ 25

a; 20

10^

i 5-

aPaDoSbafflaP

-SG>-

-S>-

o
—rr- ■

1 2 3

T pyn density

0.4

n 1 r

"T I I I I 1 I r

Orchard

Figure 5. A) Proportions of piiytoseiid mites identified as either T. pyri or A. fallacis in each of 12 orchard blocks
over three years. Within a year there are 12 sets of circles denoting the T. pyn proportions and 12 + symbols
denoting the A. fallacis proportions. At some sites, no phytoseiids were collected and these are denoted by a circle
enclosing a + symbol. B) Maximum densities of European red mites in relation to the average density of T. pyri.
Each circle represents data collected from a block in one of the years 2001, 2002 or 2003. The dashed line was
fit by eye. C) Average densities of T. pyri in orchards over the years 2001, 2002 and 2003. Each set of three
connected circles represents three years of data from an orchard block, arranged in sequence (left to right) for
2001, 2002 and 2003. Circles with a + symbol indicate no T. pyri were collected in the samples.

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

1997-1999 reported in the 2000 issue of Fruit Notes
suggested that increasing abundance of T. pyri was
correlated with decreasing abundance of A. fallacis.
This pattern has been observed elsewhere and occurs
because establishment of T. pyri usually leads to low
levels of European red mites. A. fallacis are only
abundant in apple trees when there is a ready supply
of pest mites for food. In this study, nearly all the
orchards had populations of T. pyri prior to their release
in 2000. Therefore, we would expect low numbers of
A fallacis. Our resuls are in accord with this
expectation. As shown in Fig. 4, data for 2001, 2002
and 2003 averaged across all 12 orchard blocks indicate
that overall, T. pyri was about ten times more abundant
than A. fallacis on sampled leaves. Another way of
looking at this relationship is to compare the
proportions of T. pyri and A. fallacis found in each
orchard (Fig. 5A). In 2001 A. fallacis were found in
only four orchards and these were sites where some
European red mites were also found. In 2002 there
was but one orchard \\ here A. fallacis was collected
and in 2003 this number increased to two. Note that in
2003 there were four orchards where no phytoseiids
were collected and five orchards where no T. pyri were
collected. At present, we have no explanation for this.
Our final question asked whether establishment and
conservation of T. pyri would assure effective
biocontrol of European red mites. Previous research
has shown that T. pyri. when sufficiently abundant, can
keep European red mites at non-damaging densities.
Recalll that T. pyri were present in most orchards prior
to their release and by 2001, T. pyri were recoverd in
all the orchards (Fig. 5A). Shown in Fig. 5B a is the
relationship between the maximum density of European
red mites observed and the average density of T. pyri .
The dashed line was fitted by eye to the data points
that reflect the highest European red mite numbers in
relation to predator density. This graph shows that
when T. pyri numbers are low (< 0.15 per leaf), there
is a possibility that European red mite will become
problematic. Note that even when T. pyri densities are
low, pest mites do not always reach high densities, but
the potential is there. On the other hand, when T. pyri
were more numerous, European red mites never
reached high numbers. It is also helpful to examine
changes in the abundance of T. pyri over time because

our experience has been that once established in an
orchard, these predators usually persist in relatively
high numbers. As shown in Fig. 5C, this was not the
case, as in 2r»03 we did not collect any T. pyri in five
of the 12 orchards studied. At present, we can offere
no explanation for this decline in predator numbers

Conclusions

Across the four years of our study (2000-2003),
we gained much useful information on the ecology and
biocontrol potential of T. pyri in Massachusetts. Our
findings lead us to the following conclusions. First,
addition of a substantial amount of cattail pollen (as a
food supplerr»ent) to trees in which T. pyri were released
in 2000 had no detectable effect on buildup of T. pyri.
Thus, there is sufficient alternate food to allow for
establishment of T. pyri provided no pesticides harmful
to this predator are used. Second, by 2002 T. pyri were
equally abundant in plots where they were released or
not released, with the exception of two sites where they
were only found in plots where they were released,
and they were equally abundant among the sampled
rows (1, 4, 7). This likely reflects that T. pyri were
present in most blocks prior to release. Third,
establishment of American hazel trees (known to harbor
mite predators) in border areas adjacent to plots of
orchard trees did not substantially enhance populations
of either T. pyri or A. fallacis in such plots. Fourth,
commencing in 200 1 , T. pyri predominated in the study
blocks, with A. fallacis absent or at very low levels in
most blocks. Only where European red mites were
moderately to very abundant were A. fallacis found.
Finally, in a majority of orchard blocks T. pyri were
sufficiently abundant by 2001 to provide what appeared
to be consistently effective biocontrol of European red
mites. In some orchard blocks, however, T. pyri did
not build to appreciable levels or declined in abundance
(for reasons unknown, but apparently not associated
with use of offensive pesticides). In some of these
blocks in some years, European red mites reached
threatening levels.

Overall, as in our 1 997- 1 999 study, T. pyri showed
much promise as an effective biocontrol agent of
European red mites in most of the blocks in which it is
established and conserved.

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

A ckn o H'ledgm en ts

We are grateful to the ten growers participating in Broderick, Dave Chandler, Tom Clark, Don Green,

this study. Each made a special effort to refrain from Tony Lincoln. Joe Sincuk, Mo Tougas and Steve Ware,

applying pesticides potentially detrimental to T. pyri. This work was supported by a grant from the Northeast

The> were Keith Arsenault, Gerry Beirne, Bill Sustainable Agncultural Res. & Education Program.

:k ic ic it 'k

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

Real Buzz Words: Beekeeping Sites for
All Levels

Diane Baedeker Petit

Massachusetts Department of Agricultural Resources

It's no surprise that beekeeping is a traditional
farming activity. Bees provide a much-needed service
by pollinating crops, and the honey they produce is a
great product to offer at farmstands and farmers'
markets. Whether you're just thinking about getting
into beekeeping, or if you're an experienced apiarist
looking for new ideas or suppliers, the Internet is
swamiing with information on the subject.

The following are several good general reference
Web sites, but these will, in turn, lead you to more
specific resources on beekeeping and honey sites
around the world.

BeeSource.com (www.beesource.com) is a nicely
designed site that provides new sources of bees, books,
supplies, plans for constructing beehives, information
on beekeeping laws, equipment and issuer; there's also
a page of links to other beekeeping Web sites.

If you're looking to share infomiation with other
beekeepers, this site provides its own bulletin board
for discussion on various beekeeping topics, as well
as links to other beekeeping discussion groups, news
groups and more.

The Mid-Atlantic Apiculture Research and
Extension Consortium Beekeeping Information Index
(http://maarec. cas.psu. edu/Beeinfoindex. html) is a
simple Web site that provides all the basics of
apiculture. This site is organized and reads more like
a manual. It provides everything you need to know
about beekeeping from honeybee biology to beekeeping
equipment, and colony management to diseases, pests
and parasites and pollination.

The Colony Management section includes
infomiation on managing for honey production and
managing for pollination. Other management topics
are organized by season. There's even advice on
contracting with growers for pollination services.

The design of this site is not fancy, but links and
information are presented in an easy to navigate format.

Only a small amount of the infomiation here is specific
to the Mid-Atlantic region. Most of it is applicable to
beekeeping anywhere.

There's a page of additional resources, which
provides names, addresses and phone numbers of
organizations, industry journals and experts. The page
is dated 1996 so you have to wonder if some of the
infomiation is out of date. The glossary of beekeeping
terms is quite extensive.

The Beehive {www.xensei.com/users/alwine/),
based in Massachusetts, is an electric mix of useful
beekeeping information and games. In addition to
practical resources such as bee anatomy, how to start
beekeeping and how to store and use honey, there is
also fun stuff here as well, such as a beehive crossword
puzzle, a trivia quiz and a game called "Sting Me."
There are articles on how bees were used as weapons
of war and city beekeeping, as wells as frequently asked
questions about bees.

The programs that you can download from this site
also reflect the mix of serious information and fun.
Included in the download section are an e-book on
Beginning Beekeeping, and a beehive jigsaw puzzle
program that is fun and easy to complete.

This light-hearted site would be a good resource
for young people just getting into beekeeping.

National Honey Board (www.nhb.org) is a broad
resource for honey producers including national news,
business information, marketing resources, quality
control infomiation and statistics on national honey
production and consumption. There are also numerous
articles here on honey research, legislation, organic
standards and the like.

All of these sites are great resources worth
bookmarking, but don't stop there. Be sure to follow
the many links to more resources that these sites provide
to round out your research in apiculture.

'k ic ic 'k :k

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

SJP84 Winter Hardy Dwarf Apple
Rootstock Series from Agriculture and
Agri-Food Canada National High Value
Crop Breeding Program

Shahrokh Khanizadeh, Yvon Groleau, Audrey Levasseur, Raymond Granger, and
Gilles Rousselle

Agriculture and Agri-Food Canada Research Station, St-Jean-sur-Richelieu, Quebec

Campbell Davidson

Agriculture and Agri-Food Canada Cereal Research Centre, Morden, Manitoba

Apple production potential in Quebec is between
5.5 and 7 million bushels per annum. In 1 986 and 1 987,
there were severe low temperature injuries, and yields
were reduced to 2.8 million bushels and 4.0 million
bushels, respectively. This loss represents
approximately SI 8 million in 1986 and $12 million in
1987, and a concomitant increase in the volume of
apples imported to the province. In 1 993-1 994. similar
damage was reported by Quebec apple growers
(Khanizadeh et al., 2000a). Cold winter temperatures
is one of the most limiting factor in many apple-growing
regions, especially in Northern Central Canada when
the winter temperature dropped below -30°C (Granger,
1981; Asnong, 1 982; Khanizadeh et al., 200021.

Cold tolerance of many plant species has been
extensively reviewed and studied (Chen and Li. 1980;
Gustaetal., 1982; Li, 1987; Sakai and Larcher. 1987
Khanizadeh et al., 1989a; Khanizadeh et al.. 1989b
Khanizadeh, 1991; Khanizadeh et al., 1992a
Khanizadeh et al., 1992b; Khanizadeh et al.. 1994).
Our previous studies have compared the concentration
of amino acids, protein, sugars, starch, sorbitol, N, P,
and K of cropped and non-cropped trees in relation to
cold hardiness (Khanizadeh et al., 1989b; Khanizadeh
et al., 1992a; Khanizadeh et al., 1994). It has been
shown that cropped trees that progress into the winter
with lower nutrient levels in their buds are more
vulnerable to low temperatures than those on non-
cropped trees (Khanizadeh et al., 1989b; 19923).

There have been many studies of: 1 )cold resistance
and metabolic changes in apple woody tissue, (Brown,
19^8; Li, 1987; Sakai and Larcher, 1987; Khanizadeh
etaJ., 1989a; 1989b; 1992a; 1994), 2) types of freezing
injury ( Weiser, 1 970; Granger, 1 98 1 ); 3 ) breeding hardy
varieties or using hardy intermediate framestocks
(Soishnoff, 1972; Spangeloetal., 1974; Granger etal.,
19*91; 1992; 1993); 4) inactivating icenucleating
bacteria (Lindow and Connell, 1984; Lindow et al.,
19SI9); 5) use of chemical cryoprotectants (Ketchie and
Munren, 1976); 6) cultural manipulation to slow growth
and induce wood matunty in early autumn (Collins et
al.. 1978; Stang et al., 1978); and 7) autumn sprays of
grov^lh regulators to delay bud break. The use of winter
hardy rootstocks and \arieties, hovve\er, seems to be
the most desirable approach to avoid winter injury and
are used in international trials to screen this specific
trajit(Marinietal., 2001a; 2001b).

Many reports have been published on the winter
hardiness and survival of selected rootstocks (Granger
et al., 1993; Doroshenko et al., 1995; Skrivele et al.,
19*95; Fisher & Fisher, 1996; Yang etal., 1995; Witney,
19*96; Khanizadeh et al., 2000a; Khanizadeh et al.,
20<00b; Marini et al., 2001a; Marini et al., 2001b;
Webster, 2003). Alnarp 2 (A2) was reported to have
the highest survival rate when exposed to low soil
temperatures, followed by MM.104, Antonovka, M.26,
MM. Ill, M.4, MM. 106, M.9, and M.7, respectively
(Zagaza, 1977). 0.3 and 0.8 were reported to be

Fruit Notes, Volume 68. Spring, Summer, & Fall, 2003

hardier than M.26 and MM. 106 (Heeney, 1981), and
Bugadovsky was reported to be as hardy as M.26
(Czynczyk, 1979).

A part of the Agriculuire and .Agri-Food Canada
(AAFC) National High \alue Crop (NHVC) breeding
program is devoted to de\elopment of adapted, dwarf
and semidwarf, winter-hardy, and disease-resistant
apple rootstocks. The original rootsiock-breeding
program began in early 1950 in Ottawa. Ottawa 3 (0.3)
was the first commercialK released clonal rootstock,
released in 1974 from this National program, and the
rest was send to Quebec for further testing along with
others developed in Ottax'.a and in Manitoba.

The identification of new, well adapted, winter-
hardy, disease-resistant apple rootstocks that propagate
easily will have a direct impact on the apple industry
in the northern U.S. and in Canada by reducing
production fluctuation caused by cold-temperature tree
damage.

Materials & Methods

Several crosses were made in 1975 including
Mains robiista R-5 with M.26 or with Budagovsky
579490, and also some seeds was collected from open
pollinated 0.3. Seeds were germinated under
greenhouse conditions and planted in a nursery in 1980.
Budding to Spartan was conducted in Ii982, and trees
with bud failure were cleft-ijrafted in 1983. All trees

were planted in 1984 (5.5 x 3.0m) at the experimental
farm of AAFC in Frelighsburg, Quebec. Standard
orchard management practices were applied each year
(Anon., 1976). Of the 908 trees started in 1984, only
499 were used for evaluation and the rest eliminated
from the program due to their lack of winter hardiness,
disease susceptibility, or other undesirable characters,
like extreme difficulty to propagate in stool bed. Data
are shown only for those nine superior rootstocks
(Table 1 ) which have not shown any w inter injury since
1984 and were not eliminated for other reasons.

Trunk circumference was measured at 25 cm abo\ e
the graft union and used to calculate trunk cross-
sectional area in 1990. Yield and incidence of root
suckers were recorded annually from 1988-1990. Tree
height and spread were measured as the maximum
vertical extension of the tree and the maximum
horizontal extension of the canopy, respectively (Table

1).

Two other sites were also established to examine
the ease of propagation and suitabilit> of the rootstocks
for commercial grafting compare to M26, M9, and 0.3
(data not shown).

"Summerland Mcintosh' was used as scion for the
nine superior rootstocks (Table 2). They were planted
in four selected locations including L'Acadie (AAFC,
Experimental site) and also tested under controlled
conditions at two commercial grower sites Dunham
and Mont St-Gregoire (Verger Dupuis Inc., 587 Hudon,

Table 1. Performance of se.ec

ted nine superior

rootstocks

with Spanan as the scion.

^elected from

908 seedl

ings planted in

19S'4 in Frelighsburg, Quebec

Canopy

size

TCA'

Cumulative
Yield

YE^

1990

Cumulative

Height

Spread

no of

Test Code

Selectior.

Parentage

(cm')

(kgl

(kg/cm')

(m)

Root suckers

SJP84-5218

75-13-0?:

R5xM.26

13.2

22.95

1.73

2.6

5.3

SJP84-5217

75-13-065

R5xB 574*0

9.7

10.05

1.04

2.1

2.6

7.3

SJP84-5230

75-13-r9

R5.\M.26

23.0

28.65

1.25

2.9

2.5

0.0

SJP84-5198

75-13-lSi:i

R5xM.26

13.0

17.25

1.32

2.2

3.1

0.6

SJP84-5162

75-13-lS.-

R5xM.26

14.2

25.5

1.81

2.9

2,4

13.0

SJP84-5231

75-13-209

R5xM.26

6.7

6.15

0.91

1.6

0.9

9.0

SJP84-5174

75-13-219

R5xM.26

18.9

20.70

1.10

3.4

3.5

7.0

SJP84-5189

75-13-246

R5xM.26

13.0

22.35

1.71

1.6

2.8

8.3

SJP84-5180

75-13-296

R5xM.2&

17.7

19.S

1.12

2.9

2.6

6.3

' TCA = trunk

cross-sectional

area.

- YE = yield e

fficiency (cumu

lative yicldTCA)

Fruit Notes,"Volume 68, Spring, Summer, & Fall, 2003

Table 2 Performance of nine sl

perior

rootslocks an

AO.^h

with 5

ummcrland Mcl"

osh as the i;;^on compared to M.26,

M.9. M

:-. MM.UIand |

0.3 pijiiiied in

1995 in Mont St-

Grego

re, Verg

er Yvan Due

lesne (

avera

jeof3

tree;

?er repl

caie

Yiei;

kg)

c
o

"e
<

O
f-

o
o
o

r".

li
o as

ti. s

.1 ~C0

- c

— 2

SJP84-5:i8

75-13-032

175

2.5

3.5

1.2

14.3

29 .-

58.1

lo:- }

4.2

724

116

1.5

SJP8-l-5:i7

75-13-065

."6

213

}_2

3.5

2.3

12.6

46.6

"6-i

; 1

544

126

: 5

SJP8-1-5230

75-13-179

■i;9

107

2 3

2.2

0.5

3.1

13.^

18.8

35 i

3.9

293

106

; 2

0.0

SJP84-5198

75-13-180

;:8

155

2.7

3.0

0.1

2.9

13:

36.1

52 7

2.8

403

124

;.8

0.0

SJP84-5162

75-13-183

;:3

149

2.8

2.7

0.6

6.3

12:

28.8

4^2

2.8

359

119

! 8

3.0

SJP84-5231

75-13-209

"^9

120

2.3

0.0

3.1

9i:

18.5

3( -

249

112

2 5

0.0

SJP84-5174

75-13-219

;54

187

2.9

3.2

0.1

4.9

15 >

42.6

63 :■

2.3

461

132

2.0

0.0

SJP84-5189

75-13-246

;36

165

2.9

3.0

0.2

5.8

35.3

49:-

2.0

368

136

1.5

0.0

SJP84-5I80

75-13-296

;34

162

3.0

3.3

0.0

5.7

30.9

54 ^

2,6

323

172

3,5

4.0

0.3A

:i6

141

2.7

2.8

0.9

8.7

18 V

30.8

59 :

3.7

420

125

1.3

1.7

M.26

-.51

183

3.3

3.2

0.6

3.9

32.1

4S-

1.8

292

163

0.0

M.9

100

121

2.4

2.5

0.5

6.7

10:

25.5

43 2

3.7

306

133

2.8

2.7

MM. Ill

230

280

4 1

2.9

0.9

3 f

19.9

T^ "i

179

133

0.3

M.27

2.1

0.2

3.2

9.2

19-1

2.6

136

133

1.5

0.0

0.3

132

160

2.7

3.1

0.1

5.1

17.:

32.1

54 ~

2.8

398

128

0.3

2.7

LSD'

1.2

5.4

8.^

19.8

20 i

1.1

207

1.9

3.8

' Vigour: Trunk circumference a

} a percent of M.9.

-' Fruit

weiL

t (g) was talin usmg 25

randomly selected fru;t5

Truni circumference and crosi-sectional area (TCA) 25

cm above

' Burrknoi -

-ting:

= de5;r3

ble. 10 =

undesirable.

graft union.

Average r

.mber o

f sutlers ciounled during the 2002 season.

' 1999-2002 =

cumulative yield

from

999-2002.

' If differerce between r--o

means exceeds LSD, then it

^ sign

ficant at

' Efficiency: (cumulative yield TCA)

odds of 1^

Dunham. Qc, Canada; Verger Ivan Duchesne Inc., 1 1 8
oh. Sous-Bois, Mont St-Gregoire, Qc, Canada ) in 1997
using three trees per sites/replicates. Several
commercially grown cultivars (Gala, Spartan,
Mcintosh, Lobo) were also grafted onto these
rootstocks to assess graft compatibility. During the
multiplication and evaluation of the rootstocks, we
discovered a clone of 0.3 (0.3A) to be different from
original 0.3 developed earlier by Spangelo et. al.
(1974). 0.3A appears to produce wider branch angle
and have a better rooting efficiency in stool beds
compared to the original 0.3. This rootstock (0.3A)
was also tested along with advanced SJM rootstocks
in all sites. M.27 was planted only at one commercial
site due to the insufficient number rootstocks.

Results & Discussion

The majority of the superior rootstocks came from
R.5 X M.26 crosses, and only one (75-13-065) came
from R5 x B57490. The superior rootstocks showed

no incompatibilit]. with tested commercial scion
culti\ ars. All rootstcucks produced trees that were dwarf
or semi-dwarf and were easier to propagate and
numencally more efficient than trees on M.26 (Table

2).

Generally the trees were more vigorous in Dunham
(Table 3) than in Mont St-Gregoire (Table 2) based on
the trunk circumference. SJP84-5230. M.9, and M.27
were the least \ igorous rootstocks in Dunham (Table
3) and Mont St-Gregoire (Table 2); how ever, there was
not a significant difference between M.2'', SJP84-5230.
SJP8--5231, and M.9 in Mont St-Gregoire. MM.lll
was the most vigonous at both sites.

S.iP84-5218 and SJP84-5217 were the most
precocious rooistocks at both sites. M.Mlll was the
least precocious. In Dunham, SJP84-5 1 98, SJP84-5 1 89,
SJP84-5162, and SJIP84-5217 had higher cumulative
yield than did .M.26, SJP84-523 1 , MM. ill, M.9, and
SJP84-5230 (Table 3). In Mont St-Gregoire, SJP84-
52 1 8. SJP84-52 1 7. SJP84-5 1 74, SJP84-5 1 80, 0.3, and
0.3 A had higher aumulative yield than did MM.lll

Fruit Notes, Volume 68, Spring, Summer. & Fall, 2003

Table ." Performance of nine superior

rootstocks ar

J 0..

?A with Sum

merlan

d Mclr

tosh as

the sc

on compared to

M.26, M.9

M.26,

MM.llI and 0.3 planted in

1995 in Dunham

Vergei

Dupu

is Inc.

(average of 2

-3 trees

per /replicate^

E
_E
<-*

'^
M

?
-o

Yield (kg)

i-E

3 it

£ 2

c ^

6 S
Z -

5 -S
u. S

f^i

o
o

SJPS4-5:iS

75-13-032

173

150

1.9

2.4

2.3

S.9

5.2

15.2

31.8

1.8

263

118

3.8

SJP84-5:i7

75-13-065

172

149

1.9

2.3

2.7

9.0

4.0

18.1

33. S

1.9

279

114

2.2

SJPS4-5:30

75-13-179

108

1.4

1.3

0.8

3.9

0.8

4.0

9.4

1.5

126

1.5

SJP84-5I98

75-13-180

153

132

2.3

4.0

10.1

5.5

17.1

36.7

2.6

294

114

2.5

SJP84-5I62

75-13-183

169

146

1.7

2.7

3.3

S.7

7.5

14.4

33.8

2.0

260

118

3.5

SJP84-523I

75-13-209

122

105

1.7

1.3

3.2

-;.7

2.9

9.2

20.1

2.1

171

126

2.8

SJP84-5I74

75-13-219

205

177

1.9

2.2

0.5

- -

9.3

15.4

33.0

1.3

296

1.0

SJP84-5189

75-13-246

182

157

2.8

2.1

6.6

19.9

36.0

1.9

319

100

1.8

SJP84-5180

75-13-296

0.3A

160

139

1.9

2.2

3.2

S.3

6.7

13.1

31.2

2.0

270

102

0.7

M.26

173

149

1.8

2.7

1.6

5 7

2.4

12.6

22.2

1.3

185

119

3.3

M.9

100

1.8

1.6

0.8

2 5

1.7

5.3

10.3

1.8

116

3.0

MM. Ill

224

194

3.2

2.1

0.0

■; ->

3.4

9.0

15.6

0.6

119

130

2.2

0.3

156

135

1.9

2.7

1.9

~,5

8.1

11.8

29.2

2.1

242

104

1.7

LSD*

2.0

--'

5.6

6.0

10.8

0.9

1.9

' Vigour; Trunk circumfereni.

e as a percent of M.9.

ruit weight (g

was taken us:

-1% 25 randomly selected fruits

^ Trunk circumference and

cross-sectional

area i

:CA)

25 cm *■ Buni^not rating

= desirable

10 = undesirable

abo\e era ft

union.

verace number of sue

kers cc

anted d

jring the

2002 season

' l999-:002

= cumulative >ield from 1999-2002.

* If difference

between lu o

means

exceeds

LSD, then

it IS

^ Efficiency:

(cumulative yield ATCA).

significant at odds of 1 9: 1 .

and M.27 (Table 2).

The most efficient rootstocks were SJP84-5198 in
Dunham (Table 3) and SJP84-5218 in Mont St-
Gregoire (Table 2). MM. Ill resulted in the lowest
efficiency at both sites. Few differences existed in
burrknot rating (Tables 2 and 3) or root suckering
(Table 2).

Based on the observation made since 1984 in six
orchards, nine of the SJP84 series are being released
for commercial testing and evaluation. All the retained
SJP84 senes are winter hardy, easier to propagate in
stool bed than 0.3, and produce a thick and vertical
growing sucker in stool bed. No mildew, scab, or
woolly aphid was observed on these rootstocks. To date,
no graft incompatibility has been observed.

SJP84-5218 and SJP84-5198 stand out from the
superior group, based on the visual tree observation
(height, spread, branch angle, fruit distribution, tree
form, graft union, root suckers, and burr knots) in five
locations and also on their performance in stool beds.

A patent is pending for all of the SJP84 series
rootstocks. A limited number of rootstocks are available
for research purposes from the author (SK). Non-
exclusive multiplication licences can be obtained from
Agriculture and Agri-Food Canada. European nurseries
can obtain a multiplication licence from Meiosis Ltd.
(Bradboume House, Siable Block, East Mailing, Kent
ME19 6DZ).

Literature Cited

Anon. 1976. Pommier-culture. Agdex 211/20.
Publication 333. Conseils des productions
vegetales du Quebec (production Guide).

Asnong, J. 1982. L'industrie de la pomme au Quebec:
Etat de la situation. Conference socioeconomique
sur l'industrie de la pomme. Min. Agr. Pecheres et
alimentation du Quebec.

Brown, G.N. 1978. Protein synthesis mechanisms
relative to cold hardiness, in Plant cold hardiness

Fruit Notes, Volume 68, Spring, Summer. & Fall, 2003

and freezing stress, (P. H. Li and A. Sakai, eds.),

pp. 153-163. Academic Press, New York. NY.
Chen, H.H, and RH. Li. 1980. Characteristics of cold

acclimation and deacclimation in tuber bearing

solanum species. Plant Physiol. 65:1 146-1 148.
Collins, M.D., P.B. Lombard, and J.W. Wolfe. 1978.

Effects of evaporative cooling for bloom delay on

Bartlett and Bosc pear tree performance. J. Amer.

Soc. Hort. Sci. 103:185-187.
Czynczyk. A. 1979. Effect of M.9, B.9, and M.26

rootstocks on fruiting and frost resistance of apple

tree cultivars. Fruit Sci. Reports 4:144-152.
Doroshenko, T.N., E.V. Makarova, and G.N. Nikulin.

1 995. .A. rapid selection of winterhardy stock-scion

combinations in fruit crops. Sadovodstvo i

Vinogradarstvo 5:5-6 (abstract).
Fisher, C. and M. Fisher. 1996. Results in apple

breeding at Dresden-Pillnitz: review.

Gartenbauwissenschaft 6 1 : 1 39- 1 46.
Granger, R.L. 1981. Notes concerning the harsh winter

of 1 980/ 1 98 1 . Fruit Notes. 46: 1 4- 1 6.
Granger, R.L., G.L. Rousselle, M. Meheriuk. and A.H.

Quamme. 1991. Promising winter hardy apple

roostock from a breeding program at Morden,

Manitoba. Fruit Var. J. 45(3): 185- 186.
Granger, R.L., G.L. Rousselle, M. Meheriuk. and S.

Khanizadeh. 1992. Performance of 'Cortland' and

'Mcintosh' on fourteen rootstocks in Quebec. Fruit

Var. J. 46(2): 114-1 15.
Granger, R.L., M. Meheriuk, S. Khanizadeh. and Y.

Groleau. 1993. Performance of 'StarkspurSuperm

Delicious' on 25 rootstocks in Quebec. Fruit Var.

J. 47(4):226-229.
Gusta,A.L., D.B. Fowler, and N.J. Tyler. 1982. Factors

influencing hardening and survival in winter wheat.

//; Plant cold hardiness and freezing stress, (P. H.

Li & A. Sakai, eds.), pp. 23-40. Academic Press,

New \'ork, NY.
Heeney, H.B. 1981. Apple rootstock studies at

Smithfield Experiment Farm, 51 p. Technical

Bulletin No. 3.
Ketchie. D.O. and C. Murren. 1976. Use of

cryoprotectants on apple and pear trees. J. Amer.

Soc. Hort. Sci. 101:57-59.
Khanizadeh, S., D. Buszard, and C.G. Zarkadas. 1989a.

Seasonal variation of proteins and amino acids in

apple flower buds (Malus pumila Mill. Mcintosh/

M7). J. Agr Food Chem. 37:1 246- 1 252.
Khanizadeh, S., D. Buszard, and C.G Zarkadas. 1989b.

Effect of crop load on seasonal variation in
chemical composition and spring frost hardiness
of apple flower buds. Can. J. Plant Sci. 69:1277-
1284.

Khanizadeh, S. 1991. Controlling temperature by
microcomputer. HortScience 26(5):607.

Khanizadeh, S., D. Buszard, and C.G Zarkadas. 1992a.
Effect of crop load on hardiness, protein and amino
acid content of apple flower buds at several stages
of development. J. Plant Nutrition 15(11):2441-
2455.

Khanizadeh, S., D. Buszard, and C.G Zarkadas. 1992b.
Comparison of three methods for calculating
protein content in developing apple flower buds.
J. Assoc. Off Anal. Chem. 75(4):734-737.

Khanizadeh, S., D. Buszard, and C.G Zarkadas. 1994.
Seasonal variation of hydrophilic, hydrophobic,
and charged amino acids in developing apple
flower buds. Journal of Plant Nutrition
17(ll):2025-2030.

Khanizadeh, S., C. Brodeur, R. Granger, and D.
Buszard. 2000a. Factors associated with winter
injury to apple trees. Acta. Hort. 514:179-192.

Khanizadeh, S., Y. Groleau, R. Granger, J. Cousineau,
and G. L. Rousselle. 2000b. New hardy rootstocks
from the Quebec apple breeding program Acta
Hort. 538:719-721.

Li. P.H. 1987. Plant cold hardiness. Alan R. Liss, Inc.,
New York, NY.

Lindow, S.E. and J.H. Connell. 1 984. Reduction of frost
injury to almond by control of ice nucleation active
bacteria. J. Amer Soc. Hort. Sci. 109:48-53.

Lkidow, S.E., N.J. Panopoulos, and B.L. McFarland.
1989. Genetic engineering of bacteria from
managed and natural habitats. Science 244:1300-
1302.

Marini R.P, B.H. Barritt, J. A. Barden, J. Cline, R.L.
Granger, M.M. Kushad, M. Parker, R.L. Perry, T.
Robinson, S. Khanizadeh, and C.R. Unrath.
2001 a.Perfomiance of "Gala" apple on eight dwarf
rootstocks: ten-year summary of the 1 990 NC- 1 40
rootstock trial. Journal American Pomological
Society. 55(4): 197-204.

Marini R.P, B.H. Barritt, J. A. Barden, J. Cline, E.E.
Hoover, R.L. Granger, M.M. Kushad, M. Parker,
R.L. Perry, T. Robinson, S. Khanizadeh, and C.R.
Unrath. 2001b. Performance often apple orchard
systems: ten year summary of the 1990 NC-180
systems trial. Journal American Pomological

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

Society. 55(4):222-238.
Sakai, A. and W. Larcher. 1987. Frost survival of

plants. Responses and adaptation to freezing stress.

SpringerVerlag, New York, NY.
Skrivele. M., M. Bluknianis, L. Ikase, E. Kaufmane,

S. Ruisa, and S. Strautina. 1995. Fruit breeding

in Latvia: current problems. Proc. Larvian Acad.

Sci. Section b, NaiL Sci. 5-6: 109-1 1 3.
Spangelo. L.RS., S.O. Fejer, S.J. Leuty. and R.L.

Granger. 1974. Ottawa 3 colonal apple rootstock.

Can. J. Plant Sci. 54(3):601-603.
Stang, E. J., D.C. Ferree, RR. Hall, and R.A. Spotts.

1 97S. Overtree misting for bloom delay in Golden

Delicious apple. J. Amer. Soc. Hort. Sci. 103:82-

87.
StushnotT, C. 1972. Breeding and selection methods

for cold hardmess in deciduous fruit crops-.

HortScience 7:10-13.
Webster, A. D. 2003. Breeding and selections of apple

and pear rootstocks. Acta Hort. 622(499-512)
Weiser, C. J. 1970. Cold resistance and acclimation in

woody plants (A review). HortScience 5:403-40S.
Witney, G. 1996. Tree condition and cold tolerance.

Good Fruit Grower 47:24-26.
Yang, J. M., Y Z. .Xiu, Z. H. Zhang, and D. W. Zhu.

1995. Breeding of Green Delicious, a tolerant to

drought and cold resistant apple variety. Acta

Horticulturae 403:78-80.
Zagaza, S.W. 1977. Transmission of disease resistance

and winter hardiness from selected fruit of Asiatic

and East European. PI. 480 Res. Inst. Sac.

Pomology, Skiemiewice, p. 5-16.

%i^ %i^ «1^ %i^ %S^

^T% #T» ^T% ^T% *T^

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

Summertime Heat & Health:
Prevention Is the Best Medicine

George Cook

Extension Maple Specialist, University of Vermont

Folks boast of their dark tan; many think a dark tan
looks healthy, but in reality, skin cancer is the most
common of all cancers. The main cause of skin cancer
is overexposure to the sun, even here in the Northeast.
We may even be more susceptible. Much of our
weather is a combination of sun and clouds, so when
the sun does shine, we peel off the clothes to take full
advantage of it.

Our body's natural defense against damaging
ultraviolet radiation from the sun is a pigment called
melanin; however, even the darkest skin does not
contain enough melanin to prevent damage resulting
from exposure to the sun.

Farmers have an increased risk of skin cancer, due
to the hours spent working in the sun. Remember, the
sun's rays are brightest between 10 AM and 3 PM.
There are a few preventive steps you can tbllow to
protect your skin from skin cancer.

A wide-rimmed hat is recommended over the ever-
popular "baseball" cap that many of us wear. They
provide a sun shield for not only your eyes, but also for
your ears, neck, and shoulders. These are all common
locations of skin cancer outbreaks.

Fabric provides an excellent source of protection
against the sun. Darker colors, though warmer, tend to
block more sun. Some clothing manufacturers are
beginning to put Sun Protection Factor (SPF) ratings
on their clothes. You should look for a rating of 1 5 or
higher. Generally, a tighter weave of fabric gives more
protection. For example, denim jeans have an SPF of
1 ,700. A hat should have a 4-inch rim all around, or a
broad bill and flap to cover your ears.

Sunscreen is the best way to protect any exposed
skin. It is important that you use the right SPF for you.

There are two factors to consider. First, how many
minutes can your unprotected skin be in the midday
sun before it begins to redden and bum? Second, how
many minutes will you be working in the sun? You can
then figure the minimum SPF rating suncreen you need
to apply (SPF = Minutes to be spent in the sun divided
by .Minutes before skm reddens).

Always use a sunscreen with a minimum rating of
15. They are available at 30, 45, and higher. If you
sweat heavily, use a waterproof or sports sunscreen.

You should apply sunscreen 20 to 30 minutes
before going outside to give it time to penetrate your
skin and protect your cells. It does not last all day,
check the label to see how often you should repeat the
application. Also, the sun's rays can reach through
thin clouds, so apply sunscreen even on a cloudy day.

Your lips are also at risk, so use an SPF lip balm to
provide protection for them.

Finally, when \ou purchase farm equipment,
consider the benefits of features such as enclosed cabs
or sun shades. Your skin's health is vitally important
to your overall health.

It was 9:30, I had been working for three hours
already, the humidity was high, the air hot and close. I
had a headache, and I began to pant and feel nauseated.
My skin felt hot and dry; I was near collapse. I had only
had a small sip of water all morning. My friends called
the emergency medical service. The emergency
personnel came and immediately administered first
aid. Later, they said 1 nearly died.

Heat stroke is a serious illness caused by
erheating. It if life threatening, and must be treated
as an emergency. S> mptoms include dry, hot, red or

Copyright's 2002 by Moose River Publishing Company. Reprinted with permission from Fanning, The Journal of
Northeast Agriculture, Volume 5, Number 7 (July), 2002. pp. 28-29. For subscription information, call Moose River
Publishing Company at (SOD) 422-7147 or write to Farming, The Journal of Northeast Agriculture. P.O. Box 449, St.
Johnshun: IT 05819-9929.

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

spotted skin. The victim becomes extremely weak and
may lose consciousness, but with rapid, strong pulse.
If not treated immediately, it can lead to convulsions,
brain damage, and death.

First Aid

Put the person in a cool or shady area, and fan them
to promote cooling. An air conditioned tractor cab
may be just what the doctor ordered. Remove the
victim's clothing, and sponge the skin with cool water.
Call an ambulance immediately.

Prevention Is the Best Medicine

WTio is a prime target'!* Overweight and elderly
persons, small children, diabetics, alcoholics and drug
users, people with high blood pressure, and people
taking certain medications. Precautions should be
taken when working in hot. humid environments such
as in the field or in hot, confined spaces with poor
ventilation.

Heat stroke can be largely avoided by following
basic health and safety practices. Get enough sleep
every night. Your body needs adequate rest, and this is
especially true for farm-workers and others who do
manual labor. Eat a good breakfast before going to
work. Like a tractor, our bodies need fuel to function
properly.

Dress appropriately for the warm \v eather. A long-
sleeved shirt, long pants, and wide bnmmed hat give
the best protection from the sun. Clothes made of
cotton are cool and allow air to circulate on the skin's
surface.

Drink plenty of water during the cay. Our bodies
lose water from sweating, and the w ater lost must be
replaced constantly. Provide an adequate water supply
in the field, and take breaks often to ge; a drink. If you
are feeling thirsty, you have waited too long. It is best
to carry a water bonle with you. Do not drink beer or
other alcoholic beverages; the alcohol actually
dehydrates your body.

Take breaks to cool off and rest. This will extend
your energy and will actually increase the amount of
work done each day. If you feel dizzy, weak, or
overheated, stop working and go to a cool place. Sit or
lie down, drink water, and wash your face with cool
water. If you do not feel better soon, notify your boss
or supervisor so you can be treated properly.

We can always find excuses for failing to take all
these preventive measures. But remember, it is as
much your responsibility to protect >ourself, as it is
your employer's. Everyone should be aware of the
conditions that cause heat stress and do what is
necessary to prevent it, and know ho\'. to deal with its
symptoms.

As farm workers, we need strong, healthy bodies
to v\ork. We should strive to keep them in top shape.

*1^ *1^ ^1* ^1^ *1^
^j^ ^J^ ^j^ #y* #^

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

A Comparison of Six Strains of M.9
Over 1 Years

Wesley Autio, James Krupa, and Jon Clements

Department of Plant & Soil Sciences, University' of Massachusetts

Serious interest in the use of clonal, dwarfing
rootstocks for apples developed in the United States
only in the latter half of the 1900's. The use of dwarf
apple trees, however, dates back more than 2,000
years, and the identification of potentially useful
materia] for rootstocks likely began about 500 years
ago. L"p through the 1800's, these rootstocks were
categorized as either Doucin (semidwarf) or Paradise
(full dwarf). The variety of clones within these two
categories and the misidentification of clones led the
researchers at the East Mailing Research Station in
Kent, England to collect, name, and properly describe
24 different apple rootstocks. They were given the
names East Mailing I through East Mailing XXIV.
One of these rootstocks, EM. IX (later changed to M.9)
was originally found in France in 1 879. It originated as
a chance seedling and was given the name Jaune de
Metz. Subsequently, it became known as the fully
dwarf rootstock of
choice, and now is
the most widely
planted apple root-
stock in the world.

All living organ-
isms are subject to
occasional mutation
in their genetic code.
Apples are no excep-
tion. Obvious ex-
amples of random
mutations (or sports)
are seen in some
varieties more than
others. Delicious,
Gala, and Jonagold,
for example, are
prone to obvious
skin-color mutations.
Marshall Mcintosh
is a random mutation

of Rogers Red Mcintosh found at Marshall Farms in
Fitchburg, MA. Rootstocks also express mutations
from time to time. Since much of the plant is belov^
ground, however, most mutations are not obvious, and
even ones that may be beneficial are lost. Even so.
several genetically different strains of M.9 have been
characterized over the years. Until relatively recently.
U.S. growers have had access only to M.9 and M.9
EMLA. In the last 1 or more years, other strains have
entered the U.S. market, most notably M.9
NAKBT337. These strains offer some variation in the
grafted tree. Likely, the most obvious difference is in
the degree of dwarfing, but other characteristics may
change with mutations. It is important for nurseries
and growers to understand strain differences, so that
the best possible rootstocks and management systems
are used.

In 1994, the NC-140 Multistate Research

100
_ 90
80

E
a

70 -
60 -

c
o

■^ 50

tf)
in

40
30 -
20
10

M.26
EMLA

M.9
Pajam 2

M.9 M.9 M.9 M.9 M.9 M.27

RN29 Pajam 1 EMLA T337 Fleuren EMLA

56
Figure 1. Trunk cross-sectional area of Gala apple trees on various strains of M.9
and on M.26 EMLA and M.27 EMLA, after 10 growing seasons. Bars topped by
different letters are signficantly different at odds of 19: 1 .

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

400 -

350 -
■g- 300 -
S 250 -

"-■•#■■■

^ 200-
,t 150 -

i
i

100 -

50 -

■1

M.26 M.9 M.9 M.9 M.9 M.9

Ml.9 M.27

EMLA Pajam 2 RN29 Pajam 1 EMLA T337

Fleuren EMLA

Figure 2. Height of Gala apple trees on various strains of M.9 aad om M.26 EMLA |

and M.27 EMLA, after 10 growing seasons. Bars topped b>

different letters are

signficantly different at odds of 1 9: 1 .

Committee established a trial including 17 rootstocks
with Gala as the scion cultivar at 25 locations. Six of
the rootstocks were different strains of M.9. In this
article, we report the results gathered from one
location after 10 years of trial, concentrating on the
M.9 strains.

M.26 EMLA and
M.27 EMLA are in-
cluded in this article
for comparison (they
also were part of this
trial). Trees were
planted in April of
1 994 at the University
of Massachusetts Cold
Spring Orchard Re-
search & Education
Center in

Belchertown. MA in a
randomized-com-
plete-block design
with 10 replications.
All trees were staked
and maintained
roughly as vertical
axes. Pest and fertil-
ity management was
per local recommen-
dations. Root suckers were counted and cut annually.
Yield per tree and fruit size were assessed each year
from I99»6 to 2003. Trunk cross-sectional area (20"
abo\ e the graft union), canopy spread, and tree height
were measured at the end of the 2003 growing season.

Materials
& Met hods

Gala trees were
budded on various
rootstocks during 1992
growing season and
grown in the nursery
through the 1993 sea-
son. Trees were dug in
the fall, stored, and
shipped to cooperators
in the Spring of 1994.
The rootstocks of in-
terest in this article are
M.9 EMLA, M.9
Fleuren 56, M.9 Pajam
1, M.9 Pajam 2, M.9
RN29, and M.9
NAKBT337. Data for

350 -

^ ab

^^1 ^^1 at)c

300

E
o
-250-

^1 ^H ^H ■■ ^H ^^

a. 200

o 150 -

c
ra

" 100 -

^H ^H ^H ^H ^H ^H ^H

50 -

III 1 1 1 1 1

^1 , H , ^1 . Hi , H , ^1 ,^H , ^1

M.26 M.9 M.9 M.9 M.9 M.9 M.9 M.27

EMLA Pajam 2 RN29 Pajam 1 EMLA T337 Fleuren EMLA

Figure 3. Canopy spread of Gala apple trees on various strains of M.9 and on M.26

EMLA and M.27 EMLA. after 10 grovring seasons. Bars topped by different letters

are signficantly different at odds of 19:11.

Fruit Notes, Volume 68, Spring, Summer, & Fall. 2003

^^^^^^H

S 40

^^H

T»

^^^^^1

^^^1

® 35

S 30

^^H abc ^^1

^^H abc ^^^ ^^H

125-

^H ^H ^H ^H

^^^^^1 ^^^^^1 ^^^^^H ^^HHiia ^^^^^^

a 20

^^1 ^H ^^1 ^H ^^M

5 15

^H ^H ^H ^^^ ^H ^H

^^H ^^H ^^H gmgn ^^1 ^^1

e 10

^1 H ^M ^M H ^1 de

1 5

e ■■■■■■■

i oJ

■MH , IIMi ^.■■^■■_^AB_M9_HK_^H_

*J M.26 M.9 M.9 M.9 M.9 M.9 M.9 M.27

EMLA Pajam 2 RN29 Pajam 1 EMLA T337 Fleuren EI\^LA

Figure 4. Cumulative root suckering of Gala apple trees on various strains of M.9

and on M.26 EMLA and M.27 EMLA, over 10 growing seasons. Bars topped by

different letters are signficantly different at odds of 1 9: 1 .

(Figure 4). Cumula-
ti\ ely, trees on Pajam
2 produced 42 suck-
ers on average;
whereas, those on
EMLA produced only
14. The differences
in suckering were not
strictly related to tree
vigor, since trees on
Fleuren 56 were the
least vigorous but
produced the second
most root suckers. As
a comparison, trees
on M.26 EMLA pro-
duced only nvo suck-
ers on average in the
10 years of this trial.
Cumulative yield
per tree (Figure 5)
was closely related to

Results

tree size. The more vigorous the M.9 strain, the greater
the yield. When the yield was adjusted for tree size.

After 10 growing seasons, differences among the that is was assessed as yield efficiency, the strains of
six M.9 strains were striking, particularly related to M.9 were similar (Figure 6). It is mteresting to note
tree size. Of the six, the largest trees were on Pajam 2, that trees on all strains of M.9 were significantly more
and the smallest were
on Fleuren 56 (Figures
1, 2. and 3). Trees on
Pajam 2 were nearly
VC/o larger than those
on Flueren 56. The
order of tree size from
largest to smallest was
Pajam 2, RN29, Pajam
I, EMLA,

NAKBT337, and
Fleuren 56. Trees on
Pajam 2 were some-
what smaller than
those on M.26 EMLA,
and trees on Fleuren
56 were substantially
larger than those on
M.27 EMLA.

Root suckering
varied greatly over the
10 years of the trial

Af\n *

S 350-

S 300-
S 250 -

«u

abc

:cd

bed rd

\j\j

^ 200 -

•a

■I 150

<i)

1 100-
i 50-

M.26 M.9 M.9 U.9 M.9 M.9 M.9 M.27

EMLA Pajam 2 RN29 Pajam 1 EMLA T337 Fleuren EMLA

Figure 5. Cumulative yield of Gala ayple Irees on various strains of M.9 and on

M.26 EMLA and M.27 EML.\, over eight finuiting seasons. Bars topped by differeinit

letters are signficantly different at odds of 19: 1 .

Fruit Notes. Volume 68, Spring, Summer, & FalU 2003

yield efficient than trees
on M.26 EMLA.

Fmit size averaged
over the fruiting life of
the trial, like yield effi-
ciency, was not affected
by M.9 strain ( Figure 7).
Interestingly, fruit from
trees on M.26 EMLA
were larger than those
from trees on three of
the M.9 strains, and fruit
trom trees on M.27
EMLA were signifi-
cantly smaller than those
from trees on any of the
.\1.9 strains.

Conclusions

Dramatic differ-
ences in tree size and
relatively similar differ-
ences in per-tree yield
resulted from the six
different M.9 strains.
Differences in yield effi-
ciency and fruit size did
not result from the
different strains. So, the
important M.9 qualities
of high yield and large
fruit did not vary among
the strains evaluated
here. The degree of
dwarfing, however, did
\ary. Growers must
therefore be careful not
so much in the choice of
M.9 strain but in the
planting system and tree
spacings utilized with
the particular M.9 strain.

M.26
EMLA

M.9
Pajam 1

M.9
EMLA

M.9
T337

M.9 M.27

Fleuren EMLA
56
Figure 6. Cumulative yield efficiency of Gala apple trees on various strains of M.9
and on M.26 EMLA and M.27 EMLA, over eight fruiting seasons. Bars topped by
different letters are signficantly different at odds of 19:1.

« 150-
o

% 145-
en

ab 1 1 ab

S 140 -

^ 135-

S, 130-

< 125 -

120 -

M.26 M.9 M.9 M.9 M.9 M.9 M.9 M.27

EMLA Pajam 2 RN29 Pajam 1 EMLA T337 Fleuren EMLA

Figure 7. Average size of fruit harvested from Gala apple trees on various strains of

M.9 and on M.26 EMLA and M.27 EMLA, over eight fruiting seasons. Bars topped

by different letters are signficantly different at odds of 1 9: 1 .

%1« %X^ %1^ %i^ %1^

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Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

Be Aware:

Protection During Lightning Storms

George Cook

Extension Maple Specialist, University of Vermont

Lightning is a random and unpredictable event.
Lightning strikes may generate electrical current
levels that exceed 400 kA, temperauires that reach
50,000°F and hit at speeds approaching one-third the
speed of light. Globally, some 2,000 ongoing
thunderstorms cause about 100 lightning strikes to
earth each second. Lightning causes more than 26,000
fires annually in the United States with damage to
property in excess of $5 to 6 billion, according to the
National Lightning Safety Institute.

Thunderstorms and lightning are most likely to
develop on hot, humid days. Lightning is a frequent
weather hazard impacting outdoor recreation and
farm-work situations. If lightning is seen or heard, take
protective action immediately. Being prepared can
reduce the risk of the lightning hazard and raise safet>'
levels.

Lightning Safety for Outdoor Workers

If you can see lightning or hear thunder, activate
your safety plan. Resume activities only when
lightning and thunder have not been observed for 30
minutes.

Advance planning is the single most important
means to lightning safety. The following steps may
help avoid injury. Designate a responsible person to
monitor weather conditions. An inexpensive portable
weather radio will provide regular weather condition
updates. An emergency procedure should include:
suspending activities, moving people to safety,
monitoring conditions, then resuming activities.
Identify safe locations beforehand. These include
fully enclosed metal vehicles with windows up or

substantial and pemianent buildings. Unsafe areas
include small structures, including huts and rain
shelters, and nearby metallic objects like fences, gates,
instrumentation, electrical equipment, wires and
power poles. Also avoid trees, water, open fields, and
using the (hard wired) telephone and headsets.

If outdoors, avoid water, high ground, and open
spaces, get off farm machinery, get out of the water if
you are swimming or boating, and avoid all metal
objects including electric wires, fences, motors, power
tools, clotheslines, metal pipes, rails, etc. Unsafe
places include underneath canopies, small picnic or
rain shelters, or near trees. However, standing under a
group of trees, shorter than others in the area, is better
than being in the open.

Put down any object that might conduct
electricity, such as a rake, hoe, or shovel. Seek low
ground, preferably a ditch or gully. If you are outside
with no protection, get to a low spot. Make your body
low to the ground, but do not lie flat on the earth. Learn
the Lightning Safety Crouch. If hopelessly isolated
from shelter during close-in lightning, adopt a low
crouching position with feel together and hands on
ears. If lightning is striking nearby when you are
outside, you should assume the Lightning Safety
Crouch.

Avoid proximity (minimum of 15 feet) to other
people. If there is a group of people, spread out. If
someone feels his or her hair stand on end, it may mean
lightning is about to strike. Stay calm and keep low.
This will help reduce your chances of being struck by
lightning.

If indoors, avoid water, stay away from doors and
windows, do not use the telephone, and take off

Copynght©2002 by Moose River Publishing Company. Reprinted with permission from Fanning, The Journal of
Northeast Agriculture, Volume 5. Number 9 (September). 2002, p. 15. For subscription information, call Moose River
Publishing Company at (800) 422-7147 or write to Farming, The Journal of Northeast Agriculture, P.O. Box 449. St.
Johnsbury. VT 05819-9929.

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

headsets. Postpone baths, showers, and doing dishes
until the storm passes. Turn off, unplug, and stay away
from appliances, computers, power tools, and TV sets.
Lightning may strike exterior electric and phone lines,
inducing shocks to inside equipment. Computers
should be surge protected. Suspend activities for 30
minutes after the last observed lightning or thunder.

Lightning-caused Hazards

Do not touch fallen wires. Report them to police or
local utility immediately. If an appliance or tool
catches fire, try to unplug it or turn off the current at the
fuse box. Donot pour water on the fire. Use a Class C
fire extinguisher, or throw baking soda on the fire.
Before it gets out of control, call the local fire
department and get everyone outside.

First Aid for Lightning Victims

People who have been struck by lightning do not
carry an electrical charge and are safe to handle. Apply
first aid immediately, if you are qualified to do so. Call
911, or send for help immediately.

Besides bums, lightning can also cause ner\ous

system damage, broken bones, and loss of hearing or
eyesight. Victims may experience confusion and
memory loss. First aid for lightning victims needs to
be carried out immediately. After the lightning strikes,
get to the victim as quickly as possible. Check
breathing and pulse, if the victim is unconscious. If the
victim has a pulse, but is not breathing, begin mouth-
to-mouth resuscitation. If there is no pulse, begin
cardiopulmonary resuscitation (CPR). Check for
other injuries, such as possible fractures. Do not move
a suspected spinal-injury victim. Cover the electrical
bum with a dry, sterile dressing, but do not cool the
bum. There may be more than one bum area, one
where the current entered the body and another where
it left. Keep the victim from getting chilled until help
arrives. If a person stmck by lightning appears only
stunned or otherwise unhurt, medical attention may
still be needed. Check for bums, especially at fingers
and toes, and areas next to buckles and jewelry. Make
sure all lightning victims have a medical examination,
even if they do not seem to need it.

Two helpful Web sites are http://
lightninijsafetv.com/nlsi, which is the site for the
National Lightning Safety Institute, and www. cdc.gov/
nasd/, the National Ag Safety Database.

^t^ «1^ %i^ %i^ VL^

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Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

An Early Look at a Few of the
Geneva Series Apple Rootstocks
In Massachusetts

Wesley Autio, James Krupa, and Jon Clements

Department of Plant & Soil Sciences, University of Massachusetts

The Cornell-Geneva Rootstock Breeding Program
began in earnest in 1 968 by Dr. Jim Cummins. Its goal
was to produce rootstocks which resulted in a high
degree of precocity, high productivity, size control,
and resistance to pests. A particular focus of the
program was to breed fireblight resistance into
dwarfing rootstocks. Recent years have brought the
release of a number of rootstocks from this program,
but we have had very little experience with them in
Massachusetts. The first significant trial including
one of the recent releases was planted in 1 998, and the
next two were planted in 1999. This article will
provide early results from these three trials. Please
note that the first part of the rootstock name is "G" for
those Cornell-Geneva rootstocks that have been
commercially released. The names of those under trial
but not yet released begin with "CG."

1998 NC-140 Apple Rootstock Trial

As part of the 1998 NC-140 Apple Rootstock
Trial, a planting was established at the University of
Massachusetts Cold Spring Orchard Research &
Education Center, including Gala on M.9, M.9 EMLA,
and G.16. Trees were staked and maintained as
vertical axes. Trunk cross-sectional area, root
suckering, yield, and fruit size were assessed annually.

After six growing seasons, trees on G.16 were
larger than those on M.9 or M.9 EMLA (Table 1).
Suckering has been low and comparable among the
three rootstocks. Trees on G.16 yielded more
cumulatively (1999-2003) than either strain of M.9,
but yield efficiencies were similar. Average fruit size
from 1999 through 2003 was smaller from trees on
G.16 than from either M.9 strain.

Table 1. Trunk cross-sectional area, suckering, yiel± yield efficiency, and fruit weight in 2003 of Gala trees on
various rootstocks in the Massachusetts planting of the 1998 NC-140 Apple Rootstock TriaJ.'

Trunk
cross-
sectional
Rootstock area (cm^)

Root

suckers

(no. /tree,

1998-2003)

Yield per tree (kg)

Yield efficiency
(kg/cm^ TCA)

Fruit weight (g)

Cumulative
2003 (1999-2003)

Average
2003 (1999-2003)

G.16 17.8 a
M.9 11.7 b
M.9 EMLA 10.6 b

0.4 a
0.3 a
0.3 a

15.7 a 40 a
6.5 a 24 b
5.3 a 20 b

0.97 a 2.26 a
0.56 a 2.05 a
0.48 a 1.89 a

131a 104 b
162 a 132 a
143 a 125 a

' Means

within columns not followed by

the same letter are significant at odds of 19: 1.

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

Table 2. Trunk cross-sectional area, suckering. yield, yield effici

ency, and fruit weight in

2003 of Mcintosh trees on

several rootstocks in the Massachusetts planting of the 1999 NC

-140 Dwarf Apple Rootstock Trial.

Root

Yield efficiency

Trunk

suckers

Yield pe

- tree (kg)

(kg/cm

-TCA)

Fruit w eight (g)

(no./tree,
1999-

sectional

Cumulative

Average

Rootstock

area (cm")

2003)

2003

(2001-03)

2003

(2001-03)

2003

(2001-03)

CG.3041

16.4 cd

1.2 a

23.4 bed

35 bed

1 .42 ab

2.14 ab

162 a

155 ab

CG.4013

29.9 a

1.2 a

42.0 a

66 a

1.41 ab

2.19a

164 a

160ab

CG.5179

21.9 be

0.7 a

30.5 ab

49 ab

1 .40 ab

2.25 a

165 a

158 ab

CG.5202

25.2 ab

0.0 a

31.3 ab

49 ab

1.29 ab

2.01 ab

161 a

160ab

G.16N

13.3 d

0.0 a

16.0 bed

26 bed

1.12 ab

1.82 ab

154 a

147 ab

G.16T

14.6 cd

0.2 a

17.6 bed

28 bed

1.22 ab

1.95 ab

145 a

144 ab

M.26 EMLA

16.5 cd

0.0 a

15.0 cd

20 cd

0.88 b

1.19b

162 a

158 ab

M.9NAKBT337

9.2 d

0.0 a

11.4d

17d

1.25 ab

1.89 ab

173 a

169 a

Supporter 1

ll.Sd

0.0 a

19.5 bed

30 bed

1.63 a

2.42 a

145 a

139 ab

Supporter 2

15.3 cd

0.6 a

25.2 bed

37 bed

1.66 a

2.50 a

141 a

134 b

Supporter 3

16.3 cd

0.0 a

25.3 be

41 be

1.56 a

2.53 a

145 a

146 ab

^ Means \\ ithin columns not followed by the same

etter are signi

ficant at oddsof 19:1.

Table 3. Trunk cross-sectional area, suckering. yield, yield efficiency, and fruit weight in 2003 of Mcintosh trees on
several rootstocks in the Massachusetts planting of the 1999 NC-140 Semidwarf Apple Rootstock Trial.

Trujik

Root

Yield per tree (kg)

Yield efficiency
(kg/cm^ TCA)

Fruit

weight (g)

suckers

(no./tree,

1999-2003)

Rootstock

sectional
area (cm^)

2003

Cumulative
(2001-03)

2003

Cumulative
(2001-03)

2003

Average
(2001-03)

CG.4814

13.1 c

11.2ab

24.3 ab

37 ab

1.87 a

2.82 a

175 a

154 a

CG.7707

16.8 c

3.5 be

20.3 b

29 be

1.20 ab

1.73 b

175 a

168 a

G.30N

31.5 a

0.5 be

37.9 a

53 a

1.25 ab

1.71 b

175 a

169 a

M.26 EMLA

15.3 c

0.0 c

13.7b

19c

0.88 b

1.23 b

177 a

168 a

M.7 EMLA

30.6 ab

15.2 a

23.2 b

30 be

0.75 b

0.96 b

153 a

163 a

Supporter 4

29.7 b

1.2 be

22.6 b

32 be

0.79 b

1.12b

164 a

169 a

^ Means within columns not followed by

the same

letter are signi

ficant at oddsof 19:1.

Fruit Notes, Volume 68, Spring, Summer, & Fail, 2003

1999 NC-140 Dwarf Apple Rootstock Trial

As part of the 1999 NC-140 Dwarf Apple
Rootstock Trial, a planting was established at the
University of Massachusetts Cold Spring Orchard
Research & Education Center, including Mcintosh on
CG.3041, CG.4013, CG.5179, CG.5202, G.16 (both
tissue cultured and stool bedded), M.26 EMLA, M.9
NAKBT337. Supporter 1. Supporter 2, and Supporter
3. Trees were individually staied and maintained as
vertical axes. Trunk cross-sectional area, root
suckering, yield, and fruit size were assessed annually.

After fi\e growing seasons, trees on CG.4013
were the largest, followed by those on CG.5202 and
CG.5179 (Table 2). The rest had statistically similar
trunk cross-sectional areas. Cumulative yield (2001-
03) was greatest for trees on CG.4013. Across all
rootstocks, however, yield was roughly related to tree
size. Cumulative yield efficiency (adjusting yield for
tree size) was similar for all but trees on M.26 EMLA.
Those trees were significantly less efficient than trees
on CG.4013. CG.5179, or any of the Supporter
rootstocks. Fruit size was not dramatically affected by
rootstock. The only statistically significant difference
was that fruit from trees on M.9 NAKBT337 were
larger than those from trees on Supporter 2.

1999 NC-140 Semidwarf Apple
Rootstock Trial

As part of the 1999 NC-140 Semidwarf Apple
Rootstock Tnal, a planting was established at the
University of Massachusetts Cold Spring Orchard
Research & Education Center, including Mcintosh on
CG.4814, CG.7707, G.30. M.26 EMLA, M.7 EMLA,

and Supporter 4. Trees were maintained as free-
standing central leaders. Trunk cross-sectional area,
root suckering, yield, and fruit size were assessed
annually.

After five growing seasons, trees on G.30 were
significantly larger than all other except those on M.7
EMLA (Table 3). The smallest tree was on CG.4814,
which was obviously misplaced in the semidwarf
group. Its trunk cross-sectional area, yield, and yield
efficiency were similar to the dwarf trees in the trial
reported above. G.30 resulted in many fewer root
suckers than did M.7 EMLA, and had significantly
greater yield per tree (2001-03). Although the
difference was not statistically significant, trees on
G.30 were 75% more efficient than those on M.7
EMLA. Fruit size was apparently unaffected by
rootstock.

Conclusions

It is much too early to make conclusions based on
the data reported here. The variability that exists now
will dissipate over the next few years and expose more
statistically significant differences. That said, G.16
apjjears to be producing a tree somewhat larger than
does M.9 but one that is comparably yield efficient.
Fruit size from trees on G.16, however, bears
watching. Trees on G.30 have performed very well
for semidwarf trees, similar in size to those on M.7
EMLA, but without many root suckers and with
app>arently greater yield. The other Cornell-
Geneva rootstocks in these trials (CG.3041,
CG.4013, CG.4814, CG.5179, CG.5202, and
CG-7707) all appear to be performing well but vary
considerably in size, from full dwarf to semidwarf

%X^ %i^ %i^ %i^ *A^

#T* #T* #T^ *T* #T*

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

How Does B.9 Stack Up
Compared to M.9?

Wesley Autio

Department of Plant & Soil Sciences, University of Massachusetts

In a previous article (pp. 22-25 in this issue), the
various M.9 apple rootstock strains were compared.
These were part of the 1994 NC-140 Apple Rootstock
Trial, with Gala as the scion. Budagovsky 9 (B.9) was
also part of that trial, planted in 1994 and maintained
for 10 years.

In this brief article, the data for B.9, M.9 Fleuren
56 (the smallest M.9 strain in the trial), and M.9 Pajam
2 (the largest M.9 strain in the trial) are presented
(Figure 1). After 10 growing seasons, trees on B.9
were comparable in size to those on M.9 Fleuren 56 but

significantly smaller than those on M.9 Pajam 2. Root
suckering from B.9 was lower than from M.9 Pajam 2.
Yield of trees on B.9 was comparable to trees on M.9
Fleuren 56 and lower than trees on M.9 Pajam 2. B.9
resulted in yield efficiency and fruit size similar to the
two M.9 strains.

Over the 10 years of this trial, B.9 performed well,
producing a small M.9-sized tree with similar yield
characteristics. We now have 20 years experience
with B.9 and have no negative aspects of the rootstock
to report.

-S4-

9 -

-aso-

300 ■

240

180 -

120 -

60 -

5 -

2 -

-4«e-

150 -

120

30 -

!#::

Trunk cross-sect,
area (cm2)

Cumulative
suckers per tree

Cumulative yield
per tree (kg)

Yield efficiency
(kg/cm2 TCA)

Average fruit size

(g)

Figure 1 . Trunk cross-sectional area, root suckering, yield, yield efficiency, and fruit size of Gala apple trees on
B.9, M.9 Fleuren 56, and M.9 Pajam 2, after 10 growing seasons. Bars with different letters are significantly
different at odds of 1 9: 1 .

Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003

Fruit Notes

Unisersity of Massachusetts
fPIIJt Department of Plant & Soil Sciences
jjgtgS 205 Bowditch Hall

>l£L Amherst, MA 01003

Nonprofit Organization
U.S. Postage Paid

Permit No. 2
Amherst, MA 01002

-1
SERIAL SECTION
UMASS
AMHERST, MA 01003

104911

Per
SB

F68

Volume 69, Number 1
WINTER ISSUE, 2004

Table of Contents

rleu/Cnaland

Effectiveness of Peripheral-row vs. All-row Sprays against Plum Curculio
Ronald Prokopy

Are Adult Plum Curculios Capable of Overwintering Within Apple Orchards?

Jaime Pineru, Everardo Bigurra, Isabel Jdcome, Guadalupe Trujillo, and Ronald Prokopy .

Extent of Early-season Plum Curculio Penetration into Commercial Apple Orchards

Jaime Pinero, Isabel Jdcome, Everardo Bigurra, Guadalupe Trujillo, and Ronald Prokopy ....

Establishing Characteristics of Odor-baited Trap Trees for Monitoring Plum Curculio

Ronald Prokopy, Isabel Jdcome, Eliza Gray, Guadalupe Trujillo, Mareana Ricci, and Jaime Pinero.

A Threshold for Spraying Against Plum Curculio Using Odor-baited Trap Trees

Ronald Prokopy, Isabel Jdcome, and Jaime Pinero

What Size of Apple is the Most Prone to Plum Curculio Attack Early in the Season?
Jaime Pinero, Everardo Bigurra, Sara Hoffmann, and Ronald Prokopy

Photographs of Fresh and Older Egglaying Scars of Plum Curculio on Apples
Jon Clements, Jaime Pinero, and Ronald Prokopy

f leu/Unaland

Editors:

Wesley R. Autio
William J. Bramlage

Publication Information:

Fruit Notes (ISSN 0427-6906) is pub-
lished each January, April, July, and
October by the University of
MassachusettsAmherst in cooperation
with the other New England state uni-
versities.

The cost of subscriptions to Fruit Notes is
$20.00 per year. Each one-year subscription
begins January 1 and ends December 31.
Some back issues are available for $5.00.
Payments must be in United States currency

and should be made to the University of Massachusetts Amherst.

Correspondence should be sent to:

Fruit Notes

Department of Plant & Soil Sciences
205 Bowditch Hall
University of Massachusetts Amherst
Amherst, MA 01003

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 UMass Extension, Stephen Demski, Director, in furtherance of the act.': of May S and June JO,
1914. UMass Extension offers equal opportunity in programs and employment.

Effectiveness of Peripheral-row vs.
All-row Sprays against Plum Curculio

Ronald Prokopy

Department of Entomology, University of Massachusetts

Studies by Chouinard et al. (1992) and Vincent et
al. (1997) suggest that spraying only peripheral rows
of trees as opposed to all rows of trees can be an
effective approach to plum curculio (PC) control in many
Quebec apple orchards. This approach is rooted m the
presumption that most PCs overwinter in woods or
hedgerows outside of orchards and when entering
orchards in spring do not move beyond peripheral rows
of apple trees before settling down to feed and lay eggs.
The proportion of overwintering PCs that satisfies this
presumption under New England conditions is uncertain.
Such uncertainty invites evaluation of peripheral-row
vs. all-row sprays against PC in New England orchards.

Here, in 2003 in one orchard in Vermont and two
orchards in New Hampshire, we compared three
different approaches to spraying PC that differed m
location of trees (peripheral vs. interior rows)
designated to receive sprays.

Materials & Methods

There were three experimental plots in each
orchard. Each plot contained seven rows of apple
trees. The perimeter row of each plot bordered
woods. All rows within a plot were of the same
length (80- 1 20 yards). All plots in the same orchard
received the same insecticide at each spray event
against PC: Avaunt in orchard X and Guthion in
orchards Y and Z (each at label-recommended
rate).

Treatment protocols in each orchard were as
follows:

Plot Petal fall spray P' & 2"'' cover spray

A
B
C

All rows
All rows
Rows 1 and 2

All rows
Rows 1 and 2
Rows 1 and 2

The petal fall spray was applied within 5 days after
90% petal fall (June 1, June 4, and June 8,

respectively, for orchards X, Y, and Z). The first cover
spray was applied when fruit on odor-baited trap trees
reached a pre-determined threshold of two fresh
egglaying scars out of 100 fruit sampled beginning 7
days after the last insecticide spray. A trap tree baited
with one dispenser of attractive pheromone (grandisoic
acid) plus four dispensers of attractive fruit odor
(benzaldehyde) was located at the center of the
perimeter row of each plot. In all, 33 or 34 fruit were
sampled twice per week on each trap tree, giving a
total of 100 fruit per sampling date across all three trap
trees in an orchard. In response to sampling information,
the first cover spray was applied on June 1 5 in each
orchard. Sampling fruit on trap trees indicated no need
to apply a second cover spray in orchards X and Y,
whereas orchard Z received a second cover spray on

Table 1. Effectiveness of different spray treatment
protocols for controlling plum curculio (PC) in three
commercial apple orchards.

Fruit with PC injury (%)

Orchard

Plot A**

PlotB** PlotC**

X
Y
Z

Average

1.7
0.9
0.3

1.0a

1.9
0.3
1.0

1.1a

2.0
1.1
6.5

3.2a

* Average values followed by the same letter are not
significantly different at odds of 19: 1 .
** Plot A: all rows sprayed at petal fall and first and
second cover. Plot B: all rows sprayed at petal fall;
only rows 1 and 2 sprayed at first/second cover. Plot
C: only rows 1 and 2 sprayed at petal fall and first
and second cover.

Fruit Notes, Volume 69, Winter, 2004

June 23. For spray applications only to rows 1 and 2,
the tractor was driven outside of row 1 and between
rows 1 and 2.

On June 26, we sampled 100 fruit in each of the
seven rows in each plot for signs of any PC injury.

Results

Data in Table 1 show that across all three orchards,
plot-wide injury to fruit by PC averaged 1.0, 1.1, and
3.2% for plots A, B, and C, respectively. Although
these values did not differ significantly from one
another, injury trends were similar for each orchard,
with plot C always showing the greatest injury.

Conclusions

Results from this experiment indicate that applying
a petal fall spray against PC only to peripheral rows 1
and 2 (as in plot C) is unlikely to provide effective
orchard-wide control. However, applying a petal fall
spray to all rows followed by subsequent sprays only
to rows 1 an 2 (as in plot B) appears to be just as
effective as applying a petal fall spray and subsequent
sprays to all rows (as in plot A).

Our data from 2003, therefore, suggest the PC
behavior and ecology might be slightly different in New
England compared with Quebec, possibly due to the
colder climate of Quebec. It seems that either more
PCs overwinter within orchards in New England than
in Quebec or that, prior to petal fall, more PCs move
deeper into orchards in New England than Quebec after

emerging from overwintering sites in woods (see the
next two articles in this issue of Fruil Notes for further
information on these two questions). Whichever, based
on results here, we tentatively recommend that growers
apply insecticide against PC to the entire orchard at or
shortly after petal fall and spray only peripheral rows 1
and 2 in subsequent treatments against PC.

We recognize that data from trials in only three
orchards provide a somewhat thin foundation for the
above recommendation. We therefore plan to repeat
this experiment in these same orchards in 2004.

Ackno wledgem ents

Many thanks to Zeke Goodband, Erick Leadbeater,
and Steve Wood for participating in this experiment and
to Lupita Trujillo and Mareana Ricci for assistance in
sampling. This study was supported by a grant from
the USDA Crops at Risk Program.

References

Chouinard, G, S. B. Hill, C. Vincent and N. N.
Bartakur. 1992. Border row sprays for control of plum
curculio in apple orchards. Journal of Economic
Entomology S5: 1307-1317.

Vincent, C, G Chouinard, N. J. Bostanian and Y. Monn.
1997. Peripheral zone treatments for plum curculio
management: validation in commercial apple orchards.
Entomologia Experimentalis Applicata 84: 1-8.

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Fruit Notes, Volume 69, Winter, 2004

Are Adult Plum Curculios Capable of
Overwintering Within Apple Orchards?

Jaime Piiiero, Everardo Bigurra, Isabel Jacome, Guadalupe Trujillo, and

Ronald Prokopy

Department of Entomology, University of Massachusetts

In the preceding article on the effectiveness of
peripheral-row vs. all-row sprays against plum curculio
(PC), results indicated that spraying only peripheral rows
of apple trees beginning at petal fall was insufficient
for adequate orchard-wide control of PC. Two reasons,
alone or in combination, were put forward to explain
this insufficiency: ( 1 ) enough PCs overwintered within
the intenor of commercial orchards (inside of peripheral
rows) to cause excessive fruit injury on interior trees
that were left untreated against PC, and (2) excessive

fruit injury on interior trees was caused by PCs that
overwintered in woods and hedgerows and penetrated
into interior rows before a petal fall spray was applied
to peripheral rows.

Here, we report results of an experiment conducted
in 2003 aimed at addressing the first explanation. We
asked whether PCs were able to overwinter
successfully inside of two blocks of a commercial
orchard in Massachusetts that differed primarily with
respect to type of management (weed control).

PLOT A (managed)

PLOT B (unmanaged)

n 5

WOODS

m A

ii 3 ALLEYWAY

^y ( ) :( ) ( r% )

:)CMK) :()

: ) ( ) ( I:( u ).

Figure 1. Representation of trap deployment in Plot A (subjected to weed management) and Plot B (not
subjected to weed management) to determine distribution of PC overwintering in 2003. For each plot, 60
emergence traps were arranged in 12 transects (only one transect is shown). Each transect consisted of five
emergence traps located at different sites (denoted as 1-5) along each transect.

Fruit Notes, Volume 69, Winter, 2004

Materials & Methods

Study site. This study was
performed during April-June of 2003
in two unsprayed plots of a
commercial apple orchard (University
of Massachusetts Cold Spring
Orchard Research & Education
Center, Belchertown, MA) that
differed in level of management. For
each plot, the perimeter row selected
for our expenment had a similar length
(about 150 yards) and orientation
(west). For each plot there was an
alleyway (about 20 yards width)
separating penmeter-row trees from
woods (which were composed
primarily of deciduous trees) (Figure
1). These two alleyways were mowed
in August, 2002.

In the first plot (Plot A),
fungicides, insecticides, and herbicides
were applied throughout 2002. Thus,
area beneath tree canopies was
devoid of vegetation. At the time of trap deployment in
plot A (see below), approximately 120 fruit (from the
previous year) were present beneath each tree. The
second plot (Plot B) was not managed, with no
insecticide, herbicide, or fungicide applied for at least 6
years. Thus, there were tall grass and other vegetation
growing beneath tree canopies. In this plot, there were
fewer fruit present beneath each tree (approximately
30) than in Plot A due to low fruit load the previous
year (2002).

Trap deployment. For our study, we used
pyramidal emergence traps (depicted in Figure 2) that
were 1 . 1 x 1.1 yards at base and were made of PVC
and steel screen. Traps were purchased from Pest
Management Innovations (Harpers Ferry, WV). A
plastic device topping each trap permitted the capture
of PCs that, upon emergence from hibernation, walked
upward on the interior surface of the trap.

For each plot, 60 emergence traps were deployed
in 12 transects. Each transect consisted of five
emergence traps arranged in the following manner: ( 1 )
a trap placed next to the trunk of a perimeter-row tree
(denoted perimeter-row trap), (2) a trap placed in the
alleyway, in close proximity to the edge of the canopy
of a penmeter-row tree (denoted canopy-edge trap).

Figure 2. Depiction of a pyramidal emergence trap used for the
detemiination of PC overwintering within two orchard plots in
Massachusetts. Trap dimensions: 1.1 x 1.1 yards at base. Traps
were purchased from Pest Management Innovations (Harpers
Ferry, WV).

(3) a trap placed in the alleyway, midway between
perimeter-row trees and woods (denoted alleyway trap),

(4) a trap placed at the edge of woods (denoted woods-
edge trap), and (5) a trap placed 6-8 yards inside the
woods (denoted woods-interior trap) (see Figure I).
Traps were deployed in such a way that no PCs
emerging in the area covered by a trap could exit, and
no PCs could enter a trap from the outside.

Traps were deployed on April 15 (at the silver tip
stage). Each trap was baited with one PC pheromone
dispenser (releasing 1 mg of grandisoic acid per day)
to draw PCs towards the capturing device. All traps
were inspected for PCs two to three times per week
until late June.

Results

Figure 3 reveals that for the plot subjected to weed
management (plot A), 50% of the total number of PCs
was captured by perimeter-row traps, whereas 36%
of the total was captured by woods-interior traps. For
the unmanaged plot (plot B), 62% of the total number
of PCs was captured by perimeter-row traps, whereas
25%) of the total was captured by woods-interior traps.
For both plots, canopy-edge and woods-edge traps

Fruit Notes, Volume 69, Winter, 2004

80 n

PCs 40

CAPTURED

H Plot A (managed) N= 14
D Plot B (unmanaged) N= 56

Perimeter-
row

(1)

canopy-
edge

(2)

Alleyway Woods-
edge

Woods-
interior

(3)

(4)

(5)

Figure 3. Distribution of PC overwintering that took place within two apple orchard plots in Massachusetts that
differed in type of weed management. For each plot, "N" refers to the total number of PCs captured across all (60)
emergence traps.

caught low percentages of PCs (5-7%) relative to the
total number of PCs captured across all traps. For both
plots, no PCs were found in traps located in the
alleyways.

Conclusions

Based on our results, we conclude that (1) PCs
are able to overwinter inside apple orchards in
Massachusetts, and (2) extent of overwintering seems
to be influenced by type of weed management. Our
findings, when combined with those reported by
researchers in Quebec (e.g., LaFleur et al., 1987),
suggest that geographical zone along with weather
conditions prevalent in a given year, in particular during
late summer and early autumn when PCs seek
overwintenng sites, might also influence the distribution
of overwintering PCs. We plan to repeat this study in

2004 to determine if results presented here are
consistent over a two-year period.

A ckn a wledgm ents

This study was supported with funds provided by a
USDA Northeast Regional IPM grant, a Hatch grant,
a grant from USDA Crops at Risk program, and the
New England Tree Fruit Research Committee.

Literature Cited

Lafleur, G, Hill, S.B., and Vincent, C. 1987. Fall
migration, hibernation site selection, and associated
winter mortality of plum curculio (Coleoptera:
Curculionidae) in a Quebec apple orchard. Journal of
Economic Entomology 80: 1 152-1 1 72.

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Fruit Notes, Volume 69, Winter, 2004

Extent of Early-season Plum Curculio
Penetration into Commercial
Apple Orchards

Jaime Pinero, Isabel Jacome, Everardo Bigurra, Guadalupe Trujillo, and

Ronald Prokopy

Department of Entomology, University of Massachusetts

In the first article in this issue oi Fruit Notes, we
evaluated the effectiveness of peripheral-row vs. all-
row sprays in controlling plum curculios in New England
apple orchards. We proposed two possibilities to explain
why confining sprays exclusively to peripheral rows
led to unacceptable PC control. In the preceding article,
we provided information supporting the first possibility:
some PCs are able to overwinter inside of orchards,
and thereby they may escape sprays applied only to
peripheral rows against immigrant adults. We suggested
that one of the main factors influencing the amount of
ovei-wintenng inside orchards might be type of orchard
management, such as presence of vegetation beneath
orchard trees, particularly during the period of time at
which adult PCs seek overwintering sites in the autumn.
Here, we report results of a study conducted in 2003
aimed at addressing the second possibility. We asked
whether PCs overwintering in woods or hedgerows
outside of orchards move into interior rows of orchards
before petal fall and thereby escape effects of petal
fall and subsequent sprays when they are confined only
to peripheral rows.

Materials & Methods

This study was performed during April/May of 2003
in eight commercial apple orchards in Massachusetts.
Within each orchard, blocks selected had similar length
(about 200 yards of perimeter-row trees) and depth (at
least 80 yards). For each block, trees used were of a
particular size: either large (M.7 rootstock), medium
(M.26 rootstock), or small (M.9 rootstock).

For this study we used Circle traps (originally
developed by Edmund Circle, a pecan grower in

Oklahoma), which are made of either aluminum or vinyl-
coated polyester screen with a PC-capturing device
integrated on top. Traps are wrapped around the base
of tree trunks so as to completely encircle the trunk,
thereby intercepting adults walking upward.

For each selected block, 20 Circle traps were
deployed on April 24 (at the green-tip tree stage) on
trees located in the central part (about 60-70 yards in
length) of each orchard to minimize potential penetration
of PCs from the lateral or back sides (Figure 1). For
each block, traps were arranged in four transects of
five traps each, starting on perimeter-row trees.
Because there were different inter-row distances and
tree densities due to the different tree sizes, blocks
having large trees received traps deployed in
consecutive rows (1-5), blocks having medium-sized
trees received traps deployed in rows 1,3,5, 7, and 9,
and blocks having small trees received traps deployed
in rows 1,4,7, 10, and 1 3 . Under this approach, traps
were deployed at similar distances mside a block: on
perimeter-row trees (A), and on trees about 12, 22, 32
and 42 yards inside of perimeter-row trees (B-E)
(Figure 1).

On May 8 (at mid-pink), traps corresponding to
two of the four transects in each block were baited
with one dispenser of PC pheromone (grandisoic acid,
releasing 1 mg per day) (GA) in association with one
dispenser releasing the attractive host plant odor
benzaldehyde (BEN) at a very low release rate (2.5
mg/day). Traps for the two remaining transects per
block were left unbailed (Figure 1). Results show
combined captures (baited + unbailed traps) because
no differences in captures by either baited or unbailed
traps were found. All traps were inspected for PCs on

Fruit Notes, Volume 69, Winter, 2004

WOODS OR HEDGEROW

~70 yards

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-42
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-80
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-200 yards

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(M.7)

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B

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-200 yards

Medium
(M.26)

WOODS OR HEDGEROW

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DOO

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300

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300
DOO

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-42
yards

-80
yards

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Small
(M.9)

Figure 1 . Layout of trap deployment in eight blocks of commercial apple orchard trees in
Massachusetts, according to tree size. For each block, 20 Circle traps were deployed, arranged
in four transects each having five traps (shown as A-E). Of the 20 traps used per block, ten
were baited (denoted as closed circles) and 10 remained unbaited (denoted as hatched circles).

Fruit Notes, Volume 69, Winter, 2004

100 n

PCs

CAPTURED

80
60
40
20-1

■ small (M.9)
n medium (M. 26)
D large (M.7)

■ nl^^

Perimeter
row

DISTANCE (in yards)

Figure 2. Distribution of overwintered PCs that penetrated into commercial orchard blocks according
to tree size and distance (from perimeter-row trees) at which Circle traps were deployed (20 traps per
orchard block).

May 23-24, just after the petal fall spray of insecticide
against PC. Thus, results show captures that occurred
during a two-week period.

Results

Figure 2 reveals that extent of PC penetration into
commercial orchard blocks varied considerably
according to tree size. For blocks having large and
medium trees, most PCs were captured by Circle traps
located on perimeter-row trees (about 70 and 67%,
respectively). For blocks having small trees, most PCs
(about 78%) penetrated into interior rows.

Conclusions

Based on our findings, we conclude that by petal
fall: (1) most PCs were congregated on perimeter-row
trees in blocks of large or medium-sized trees (M.7 or
M.26 rootstock), and (2) a substantial number of PCs
was able to penetrate inside blocks (at least up to 42

yards in our study) where trees were small (M.9
rootstock). An alternative explanation is that PCs may
have overwintered within rather than penetrated into
interiors of some blocks. Our results here, when
combined with findings reported in the preceding article,
may explain why growers who might limit all insecticide
application against PC exclusively to peripheral-row
trees would attain unacceptable PC control. We aim to
repeat this study in 2004 to corroborate our findings
here.

A ckn o wledgm en ts

We are grateful to Keith Arsenault, Gerry Beime,
Bill Broderick, Aaron Clark, Don Green, Tony Lincoln,
Joe Sincuk, and Steve Ware for permitting use of
orchards for this study. This work was supported by
funds from a USDA Northeast Regional IPM grant, a
USDA Northeast Regional SARE grant, a Hatch grant,
and a USDA Crops at Risk grant.

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Fruit Notes, Volume 69, Winter, 2004

Establishing Characteristics of
Odor-baited Trap Trees for IVIonitoring
PlumCurculio

Ronald Prokopy, Isabel Jacome, Eliza Gray, Guadalupe Trujillo, Mareana

Ricci, and Jaime Pinero

Department of Entomology, University of Massachusetts

In the three preceding articles in this issue of Fruit
Notes, evidence was presented that enough plum
curculio (PC) adults are present on interior rows of
apple trees at petal fall to justify a petal fall application
of insecticide to all rows of an orchard block rather
than just peripheral rows. In the first article, evidence
was also presented to suggest that following a petal
fall application of insecticide, subsequent insecticide
applications against PC (first/second cover sprays) can
provide effective block-wide control if confined only to
perimeter rows 1 and 2. The question now arises as to
which blocks in an orchard require cover-sprays for
perimeter rows and what is the best timing for such
perimeter-row sprays.

In the 2003 Winter issue of Fruit Notes, we
reported that penmeter-row apple trees baited with a
combination of synthetic attractive pheromone
(grandisoic acid) plus synthetic attractive fruit odor
(benzaldehyde) could function as "trap trees" that
aggregated PC injury. We suggested that sampling for
PC injury to ascertain where and when to apply
perimeter-row sprays could be restricted to trap trees
rather than spread out among many different trees in a
block.

Here, we present results of 2003 experiments
addressing five questions relevant to practical
implementation of an odor-baited trap tree approach to
monitoring PC: (1) what are optimum amounts of
grandisoic acid (GA) and benzaldehyde (BEN) to deploy
per trap tree; (2) over what distances do trap trees act
to aggregate injury to fruit by PCs; (3) does a trap tree
at the intersection of two perimeter rows (i.e., at a
comer) outperform one midway along a perimeter row;
(4) within a trap tree, is fruit injury likely to be greatest
in the vicinity of the odor source; and (5) within a trap
tree, where should a grower or consultant examine fruit

to gain a representative sample of injury?

Materials & Methods

For all experiments, odor-baited trap trees were
located on perimeter rows of blocks of commercial-
orchard apple trees in Massachusetts. Tree size,
spacing, and cultivar composition were the same for all
treatments within a replicate, but these characteristics
varied among replicates and experiments. Perimeter-
row trees received three or four grower-applied sprays
of Guthion or Imidan at label-recommended rate for
PC control. Applications commenced in late May,
shortly after petal fall and ended in mid or late June.

BEN was introduced into 1 5 ml capped polyethylene
vials in the amount of 8 ml of liquid per vial: 9 parts
BEN plus 1 part of 1 , 2, 4-trichlorobenzene as stabilizing
agent. Each vial was suspended by wire inside of an
inverted red plastic drinking cup to minimize potential
negative impact of ultraviolet light on the stability of
BEN. Both cup and vial were suspended by wire
protruding through the bottom of the inverted cup. Vials
deployed in this manner were found to release about
10 mg per day of BEN per vial. Each dispenser of
pheromone was designed by the manufacturer to
release about 1 mg per day of GA. All dispensers of
attractive odor were deployed during bloom of apple
trees (mid-May) and remained (unrenewed) for 7
weeks (through late June), when all experiments ended.
Unless indicated otherwise, each trap tree received
four dispensers of BEN plus one dispenser of GA hung
at head height near the tree trunk.

In all experiments, PC response to treatments was
assessed by examining fruit for signs of ovipositional
injury, which comprises 90% or more of all injury to
apples by PC. Sampling in each experiment occurred

Fruit Notes, Volume 69, Winter, 2004

once during each of 4 weeks in June, beginning when
fruit averaged 9 mm diameter and ending when fruit
averaged 3 1 mm diameter. Unless indicated otherwise,
samphng was accomplished by selecting haphazardly
(at approximately head height and m an evenly-spaced
manner as possible) 20 fruit from the outer half of the
canopy and 20 fruit from the inner half of the canopy
of each designated tree. Unless indicated otherwise, a
fruit was classified as injured if an ovipositional scar
was fresh. Fresh scars were those considered to have
been made within the past 7 days (see pictures in the
last article m this issue of Fruit Notes). We chose to
record only fresh scars because it is the appearance of
fresh scars (not older scars) that ought to drive a
grower's decision to apply insecticide for PC control.

Experiment 1 : Amount of Odor. In 1 3 blocks of
orchard trees, each having a perimeter row at least
225 yards long bordered by continuous woods or
hedgerow, we selected nine treatment trees spaced 33
yards apart for evaluation of optimum amount of odor
to deploy in a trap tree. Four of the trees received one
dispenser of GA plus one, two, four or eight dispensers
of BEN. Four other trees received two dispensers of
GA plus one, two, four or eight dispensers of BEN.
One tree remained unbaited. Within each block,
treatments were randomized in position.

Experiment 2: Distance of Response. In 18
blocks of orchard trees, each having a perimeter row

at least 90 yards long bordered by continuous woods or
hedgerow, we chose one tree at the approximate center
of the perimeter row to be the odor-baited trap tree (no
other tree received odor bait). The degree to which
ovipositional injury on perimeter-row trees was
aggregated on the trap tree was determined by
comparing the proportion of sampled fruit injured on
the trap tree with that injured on each of four perimeter-
row trees to the right and each of four perimeter-row
trees to the left of the trap tree. Such trees were 7-9,
15-17, 25-27, or 34-36 yards the right or left of the trap
tree.

Experiment 3: Trap Tree Location along
Perimeter Row. In 10 square blocks of orchard trees,
each having three perimeter rows about 90 yards long
bordered by continuous woods or hedgerow, we chose
as odor-baited trap trees two comer trees and two other
perimeter-row frees midway between and about 45
yards from comer frees. We compared incidence of
fresh ovipositional injury on comer trees vs. midway
trees.

Experiment 4: Nearness of Injury to Odor
Source. In eight blocks of large orchard trees (M.7
rootstock), each having a perimeter row bordered by
continuous woods or hedgerow, we chose four
perimeter-row trees as trap trees. For each of the 32
trees, we randomly assigned one quadrant to receive
BEN plus GA and the opposite quadrant to remain

E 5-1

Q
Pi

4 -

3 -
2 -
1 -

I I

1 GA 1 GA 1 GA 1 GA 2 GA 2 GA 2 GA 2 GA
10 BEN 20 BEN 40 BEN 80 BEN 10 BEN 20 BEN 40 BEN 80 BEN

CON

RELEASE RATE (mg/day)

Figure 1. Mean percent of sampled fruit on perimeter-row trap trees baited with different
amounts of grandisoic acid (GA) and benzaldehyde (BEN) or unbaited (CON) that received
fresh ovipositional injury by plum curculio. Means superscribed by the same letter are not
significantly different at odds of 19:1.

Fruit Notes, Volume 69, Winter, 2004

OS
b

z
<
u

8 -

7 -
6
5
4
3
2 -
1 -

34-36 25-27 15-17 7-9 TT 7-9 15-17 25-27

DISTANCE (YARDS) FROM TRAP TREE

34-36

Figure 2. Mean percent of sampled fruit on a perimeter-row trap tree (TT) baited with grandisoic
acid (1 mg/day) plus benzaldehyde (40 mg/day) and on perimeter-row unbaited trees at varying
distances from the trap tree that received fresh ovipositional injury by plum curculio. Means
superscribed by the same letter are not significantly different at odds of 19:1.

unbaited. Within a quadrant, lures were positioned at
head height withm an imaginary circle about 1 yard
from the outennost canopy foliage and 4-5 yards distant
from a corresponding imaginary circle on the opposite

as
o

5 n

4 -

3 -

S 2-

1 -

CORNER

MIDWAY

LOCATION

side of the tree. To assess incidence of ovipositional
injury near and far from the source of odor, we examined
20 apples in each of the two imaginary circles.

Experiment 5: Representative Sample of
Injured Fruit within Trap Trees.
In each of eight blocks of 1 8 large-
size (M.7 rootstock) apple frees, we
chose three perimeter-row trap
frees. We examined 20 fhiit at head
height in the outer half of the
canopy, 20 fruit at head height in
the inner half of the canopy, and 20
fruit in the upper central part of the
canopy in each tree for evidence
of ovipositional injury. Sampling
was confined to the last week of
June. For this experiment, fruit with
fresh as well as older damage was
counted as injured.

Figure 3. Mean percent of sampled fruit on perimeter-row trap trees
baited with grandisoic acid (1 mg/day) plus benzaldehyde (40 mg/day)
located at comers of orchard blocks (intersection of two perimeter rows)
vs. midway between and at least 45 yards distant from comer trees that
received fresh ovipositional injury by plum curculio. Means
superscribed by the same letter are not sigmficantly different at odds of
19:1.

Results

In the first experiment, there
were no significant differences in
amounts of fresh injury among trap
frees baited with one dispenser of
GA plus four or eight dispensers of
BEN and frap frees baited with two

Fruit Notes, Volume 69, Winter, 2004

4 -

3 -

5 5n

Z 2

<
S

T 1

0-1 M FROM ODOR 4-5 M FROM ODOR
LOCATION

Figure 4. Mean percent of sampled fruit on penmeter-row trap trees that
received fresh ovipositional injury by plum curculio when sampled fruit
were within an imaginary circle (1 yard diameter) containing grandisoic
acid (1 mg/day) plus benzaldehyde (40 mg/day) or within an imaginary
circle (1 yard diameter) lacking odor bait on opposite side of the tree (4-
5 yards from odor source). Means superscribed by the same letter are not
significantly different at odds of 19: 1 .

E 1 ■^

b
O

S 0.4 H

0.8

0.6 -

0.2 -

■P

OUTER HALF INNER HALF UPPER PART
LOCATION

Figure 5. Mean percent of sampled fruit on penmeter-row trap trees
baited with grandisoic acid (1 mg/day) plus benzaldehyde (40 mg/day)
(both positioned near the center of the tree) that received ovipositional
injury (fresh and older injury combined) to fruit at head height in the
outer half of the canopy, at head height in the inner half of the canopy
and in the upper central part of the canopy in samples taken during the
last week of June. Means superscribed by the same letter are not
significantly different at odds of 19:1.

dispensers of GA plus one, two,
four, or eight dispensers of BEN
(Figure 1). All six of these
treatments received significantly
more fresh injury than trap trees
baited with one dispenser of GA
plus one dispenser of BEN and than
unbailed trees. Numerically, just as
much fresh injury occurred on trap
trees baited with one dispenser of
GA (releasing 1 mg/day) plus four
dispensers of BEN (releasing a
total of 40 mg/day) as on trees of
any other treatment, with injury on
trees receiving this treatment about
eight-fold greater than on unbailed
trees.

In the second experiment, the
amount of fresh injury on trap trees
was significantly greater (about
eight-fold greater) than on unbailed
trees 34-36 or 25-27 yards distant
from trap trees, and was likewise
significantly greater (about seven-
fold and five-fold greater,
respectively) than on unbailed trees
1 5 - 1 7 or 7-9 yards distant from trap
trees (Figure 2).

In the third experiment,
perimeter-row trap trees located at
comers of orchard blocks received
an almost identical amount of injury
(no significant difference) as
perimeter-row trap trees located
midway between corner trees
(Figure 3).

In the fourth experiment, there
was only a slight (and insignificant)
tendency for within-canopy injury
on trap trees to be greater in the
vicinity (within 1 yard) of the source
of attractive odor compared with
4-5 yards distant from the odor
source (Figure 4).

In the fifth experiment, a
nearly identical amount of injury on
trap trees was found among fruit
sampled at head height at the outer

Fruit Notes, Volume 69, Winter, 2004

half of the canopy as among fruit sampled at head height
at the inner half of the canopy, with injury among fruit
sampled in the upper part of the canopy (above head
height) bemg slightly though not significantly less (Figure
5). In this experiment, odor sources were positioned at
head height and near the tree trunk.

Conclusions

Our findings indicate that perimeter-row trap trees
baited with one dispenser of GA plus four dispensers
of BEN performed as well as or better than trap trees
baited with greater or lesser amounts of these
attractants. They also indicate that the distance over
which a trap tree baited with such an amount of odor is
effective in luring PCs extended to at least 34-36 yards
along a perimeter row of apple trees and that trap trees
at comers of orchard blocks were equally as alluring to
PCs as perimeter-row trap trees midway between
comer trees. Further, our findings suggest that within
the canopy of a trap tree, PC injury to fruit tended only

slightly (and not significantly) to be concentrated near
the source of attractive odor when such odor was
positioned at the periphery of the canopy. When
attractive odor was positioned near the center of the
canopy, fruit injury tended to be rather evenly distnbuted
among various sectors of the canopy.

Together, these findings set the stage for an
experiment to determine a threshold of injury to fruit
on a trap tree that would justify spray applied to
perimeter rows 1 and 2 to control PC following
application of a petal fall spray to all rows.

A ckn o H'ledgeni en ts

This work was supported by funds from a USDA
Northeast Regional IPM grant, a USDA Northeast
Regional SARE grant, a USDA Crop at Risk grant, a
USDA Specialty Crops Research grant, the
Massachusetts Society for Promoting Agriculture, and
the New England Tree Fruit Research Committee.

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Fruit Notes, Volume 69, Winter, 2004

A Threshold for Spraying Against Plum
Curculio Using Odor-baited Trap Trees

Ronald Prokopy, Isabel Jacome, and Jaime Pinero
Department of Entomology, University of Massachusetts

In the preceding article, we established several
characteristics that an odor-baited trap tree ought to
have in order to qualify as a site for monitoring fruit
injury by plum curculio (PC).

Here, we present results of a 2003 experiment
aimed at determining a tentative threshold of PC injury
to fruit on a trap tree that would justify insecticide
application to rows 1 and 2 of an orchard block following
a whole-block spray at petal full.

Materials & Methods

We selected 12 blocks of frees in commercial
orchards in Massachusetts. Each block was comprised
of at least eight rows of trees and was bordered along
its entire 200 yard perimeter by continuous woods or
hedgerow. Each block was located in a different
orchard and was divided into three equal-size plots. A
trap tree baited with 1 dispenser ofgrandisoic acid plus
four dispensers of benzaldehyde (see preceding article)
was established at the center of the perimeter row of
each plot, 33 yards from either edge. Each of the three
plots per block was pre-assigned at random a threshold
of either 1, 2 or 4 freshly injured fruit out of 50 fruit
sampled on the trap tree. Each trap tree was sampled
for freshly injured fruit three times per week (Monday,
Wednesday, Friday), beginning 7 days after a petal fall
spray of insecticide. We presumed that residual activity
of insecticide extended at least 7 days after application.
Sampling involved examining 50 haphazardly chosen
fruit per tree at head height; 25 in the outer half of the
canopy, 25 in the inner half. Sampling was tenninated
on June 30, when no fresh injury was detected in
samples on any trap tree for two consecutive sampling
periods.

All 36 plots received a grower-applied treatment
of Guthion or Imidan across the entire plot within 4
days after petal fall. Thereafter, only the first (=
perimeter) and second rows of a plot received
insecticide as applied by growers, who sprayed both
sides of first-row trees and the perimeter-facing side
of second-row trees. In all cases, such treatments were

made within 24 hours of our sampling a trap tree and
our determination that the proportion of sampled fruit
showing injury had reached the pre-established
threshold of 1 , 2, or 4 freshly injured fruit. Once a plot
had received an insecticide treatment to rows 1 and 2,
we allowed 6-7 days before resuming examination of
fruit on trap trees for injury. Then, for each plot, we
waited until fresh injury to sampled fruit on a trap tree
again reached the pre-established threshold for that plot
before calling for the next insecticide application to rows
I and 2. To guard against invasion of PCs into plots
from an exposed lateral side or from rows deeper than
the seventh row, growers applied insecticide at 7-to-
1 0-day intervals to orchard trees abutting trees in test
plots.

To evaluate the plot-wide outcome of insecticide
application against PC as driven by varying thresholds
of allowable injury on trap trees, during the first week
of July we examined 20 fruit at head height in the outer
half of the canopy on each of five trees in each of
rows I, 2, 3, 5, and 7 of each plot for evidence of any
injury caused by PC (total of 100 fruit per row per
plot). Fruit on the trap tree were excluded from
consideration, because such fruit would normally
comprise a very low percentage of all fruit in an orchard
block. For example, for a 2.5 acre square block of
medium-size trees on M.26 rootstock, fruit from a trap
tree at the center of a 110 yard perimeter row would
constitute less than 0.2% of the total amount of fruit in
the block.

Results

The mean number of insecticide applications made by
glowers to trees in rows 1 and 2 declined successively
(though not significantly) from 1.56 to 1.44 and 0.89
sprays as the pre-assigned threshold calling for spray
application increased successively from I to 2 and 4
freshly injured fruit out of 50 fruit sampled on trap trees
(Table 1). Conversely, the mean proportion of fruit
injured by PC in samples taken during the first week of
July (i.e., at the conclusion of the injury season) on

Fruit Notes, Volume 69, Winter, 2004

Table 1 . For apple orchard plots that received insecticide application on rows 1 and 2
whenever a pre-set threshold of 1, ,2 or 4 freshly injured fruit out of 50 fruit sampled
on a trap tree was reached 7 days or more after the preceding application, mean number
of insecticide applications and mean percent fruit injured by plum curculio in samples
of 100 fruit per row taken during the first week of July.

Mean no.

insecticide

applications

Mean % fruit inj

ured*

Pre-set injury

threshold on

trap tree

Rows

1+2

Rows

3-7

Rows

1-7

1
2
4

1.56a

1.44 a
0.89 a

1.61 a
2.33 a
2.39 a

0.43 a
0.71 a
0.82 a

0.77a
1.17a
1.27a

*Means in each column followed by the same letter are not significantly different at
odds of 19:1.

rows 1 and 2 combined increased successively (though
not significantly) from 1.61 to 2.33 and 2.39% as the
pre-assigned threshold calling for spray application
increased successively from 1 to 2 and 4 freshly-injured
fruit out of 50 fruit sampled on trap trees (Table 1 ).
The same was true for fruit sampled from rows 3-7
combined (Table 1), where injury increased
successively from 0.43 to 0.71 and 0.82% with
increasing pre-assigned threshold. Combined injury fi"om
all rows in a plot shows that whole-plot injury averaged
0.77, 1.17, and 1.27%, respectively, for plots having
pre-assigned thresholds of 1 , 2, or 4 injured fruit out of
50 fruit sampled on a trap tree.

Conclusions

Findings from the first article in this issue indicate
that a whole-block spray against PC is needed at petal
fall to control PCs that many have overwintered within
or immigrated into interior rows. Findings from that
article also suggest that effective control of PC after a
whole-block petal fall spray can be attained by applying
insecticide only to perimeter rows 1 and 2.
There appears to be no need to continue spray all rows
m a block against PC after an all-row spray shortly

after petal fall.

To know
where and when
to apply post-
petal-fall spray to
control PC,

findings here
suggest that a
threshold of 1
freshly injured
fruit per 50 fruit
sampled on an
odor-baited
perimeter-row trap
tree may be used
provisionally as an
indicator of the
need to apply an
insecticide spray
to all trees on
rows 1 and 2 to
prevent block-
wide damage from
exceeding an injury level of 1%. Further, our data
suggest that a spray-driven threshold of 2 or more
freshly injured fruit per 50 fruit sampled on a trap tree
may be too great to prevent block-wide damage from
exceeding \%.

Further studies are needed to confirm the provisional
threshold suggested fi"om results here. Special attention
should be paid to assessing effects of orchard
architecture (size of blocks, spacing of trees,
arrangement of cultivars, size, and pruning of trees, etc.)
on candidate thresholds.

A ckn o H'ledgm ents

We are sincerely grateful to the growers who
allowed use of orchards blocks for this experiment and
who responded rapidly when sampling indicated the need
for insecticide treatment: Keith Arsenault, Gerry Beime,
Bill Broderick, Dave Chandler, Bob Davis, Don and
Chris Green, Tony Lincoln, Mo Tougas, Bob Tuttle, and
Steve Ware. This work was supported by funds from a
USDA Northeast Regional IPM grant, a USDA
Northeast Regional SARE grant, and Massachusetts
Society for Promoting Agriculture.

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Fruit Notes, Volume 69, Winter, 2004

What Size of Apple is the Most Prone to
Plum Curculio Attack Early in the Season?

Jaime Pifiero, Everardo Bigurra, Sara Hoffmann, and Ronald Prokopy
Department of Entomology, University of Massachusetts

In the 2000 Issue of Fruit Notes, we reported on
the distribution of fruit injury by plum curculios (PC)
within the canopies of large, medium, and small trees
that were not baited with attractive odor. Our findings
indicated that, for large trees, early-season damage to
fruit by PC was greatest at tree tops, which was the
area in the canopy that also had the largest truit. For
medium and small trees, however, damage to fruit by
PC was distributed similarly among different sectors
of tree canopies, a result that coincided with the
distribution of fruit size.

Here, we aimed at assessing the relationship
between fruit size and early-season damage to fruit by
PC in large, medium, and small unbailed trees located

in unsprayed blocks of commercial orchards in

Massachusetts.

Materials & Methods

This study was performed at Atkins Farm and
University of Massachusetts Cold Spring Orchard
Research & Education Center (Belchertown, MA) in
2000. In all, 760 fruit were sampled haphazardly (about
30 fruit per tree on each sampling date) from six large
(Cortland/M.7), four medium (Priscilla/M.26), and six
small (Mclntosh/M.9) trees. Sampling began 2 weeks
after petal fall, which occurred by May 18 in 2000.
Sampling was performed on June 2 for large trees. May

E INJURED
D UNINJURED

Small Small Medium Medium

(May 24) (May 31) (May 23) (May 30)

TREE SIZE (AND SAMPLING DATE)

Large
(June 2)

Figure 1. Association between fruit size (expressed as diameter in mm) and early-season injury by
PC. Fruit were sampled from small, medium, and large unsprayed apple trees in MassachuseUs in
2000. For each doublet of bars, means not superscribed by the same letter are significantly different at
odds of 19:1.

Fruit Notes, Volume 69, Winter, 2004

23 and May 30 for medium trees, and May 24 and
May 31 for small trees. Each mdividual fruit was
categorized as injured or uninjured based on the
presence or absence of PC egglaying scars (fresh or
old), and its diameter was recorded. To assess the
relationship between fruit size and occurrence of injury
to fruit by PC, comparisons of the diameter (in mm) of
fruit having or lacking PC scars were performed.

Results

Figure 1 clearly shows that, regardless of tree size,
fruit sampled early in the season that showed PC injury
were significantly larger than uninjured fruit. The
smallest size of a fruit having a PC scar was 4.8 mm in
diameter, which corresponded to the first sampling date
in small Mcintosh trees.

Conclusions

trees where fruit are larger (e.g., upper part of the
canopy of large trees, exterior zone of branches). As
the season progresses, however, it is likely that smaller
fruit may be more likely to be attacked by PC, possibly
because, as suggested by Levine and Hall ( 1 977), late-
season mortality of PC larvae is greater in large fruit
due to the higher internal pressure of the growing cells.
None of the trees in our study was baited with attractive
odor. Results on the distribution of PC injury among
fruit in various tree sectors could be different for odor-
baited trap trees.

A cknowledgnients

This study was supported with funds provided by a
USDA Northeast Regional IPM grant, a Hatch grant,
a grant from USDA Crops at Risk program, and the
New England Tree Fruit Research Committee.

Our findings lead us to conclude that, early in the
season, larger fruit are much more prone to attack by
PC than are smaller fruit, probably because abscission
of fruit damaged by PC is more likely to occur when
fruit are small. Thus, early-season sampling of unbailed
trees should be conducted preferentially in areas of the

Literature Cited

Levine, E., and Hall, F.R. 1977. Effect of feeding and
oviposition by the plum curculio on apple and plum fruit
abscission. Journal of Economic Entomology 70: 603-
607.

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Fruit Notes, Volume 69, Winter, 2004

Photographs of Fresh and
Older Egglaying Scars of
Plum Curculio on Apples

Jon Clements

Department of Plant and Soil Sciences, University of Massachusetts Amherst

Jaime Pinero and Ronald Prokopy

Department of Entomology, University of Massachusetts Amherst

The use of odor-baited trap trees to aggregate plum
curculio (PC) adults should simplify monitoring for PC
by confining sampling to just a few odor-baited trees in
an entire orchard. Under this approach, sampling would
involve examination of about 50 fruit on a trap tree for
signs of fresh PC egglaying scars. As discussed in a
previous article in this issue, application of a perimeter-
row spray would occur when one fruit out of 50 sampled
fruit shows fresh injury. The question then becomes:
how to tell a fresh injury from an older injury. Here, we
present photographs of fresh and older PC injury from
a study conducted m 2003.

Materials & Methods

At petal fall, cloth bags were placed over several
terminals of unsprayed Mcintosh and Delicious trees
at the University of Massachusetts Cold Spring Orchard
Research & Education Center in Belchertown. Each
Monday beginning when king fruit averaged 6 mm
diameter, two mated PC females were introduced into
each bag and allowed to remain until Tuesday, when
they were removed. On Wednesday, Friday, and the
following Monday, a digital camera (Nikon CoolPix 990)
was used to photograph some of the egglaying scars.
Each scar shown here was therefore 1 , 3, or 6 days old
when photographed.

Results

Figures 1 -4 show, respectively, egglaying scars that
were photographed over 6-day periods for the weeks
of May 28, June 4, June 1 1 and June 1 8. For Mcintosh,
fruit size averaged 6, 8, 14, and 19 mm diameter,
respectively, when injury was initiated, whereas for
Delicious fruit size averaged 6, 7, 10, and 14 mm
diameter, respectively.

Regardless of the week when injury was initiated,
photographs show that 1 -day-old scars appear as
narrow crescents (from top to bottom) similar to an
eighth moon. Reflecting fruit growth, 3-day-old scars
appear as somewhat broader crescents, with 6-day-
old scars appearing as crescents that are broader still
(much like a half moon) or as scars that have begun to
lose their crescent shape.

Scars initiated on 6 mm fruit (week of May 28)
show little sign of a stem and have little resemblance
to a mushroom (Figure 1). Scars initiated on 10-14 mm
fruit (week of June 1 1 ) show a distinct stem and strongly
resemble a mushroom (or the cloud of an atomic bomb)
(Figure 3). By 6 days after egglaying, even the most
pronounced mushroom shape of a 1 -day-old scar (as
m Figure 3) has begun to fade.

It should be noted that the change in appearance
from fresh to older PC egg-laying scars as described
above is most accurate for Mcintosh. With Delicious,
the change in appearance is not quite as distinct - some
caution is advised when looking at different cultivars
as the age of PC egg-laying scars may be more difficult
to judge than it is on Mcintosh. More observations of
other cultivars (such as Gala) are needed.

Conclusions

Once a grower or consultant has firmly in mind the
image of a fresh (e.g., 1-day) versus an older (e.g., 6-
day) scar, that mental image can be carried to the field
to aid in interpretation of the age of PC scars on odor-
baited trap trees.

Ackno wledgem en ts

This study was supported by USDA Hatch funds.

Fruit Notes, Volume 69, Winter, 2004

"W '

^ '4C1

ipun iLt-" r

^ik

Delicious
-3 days

6 days

Figure 1 . Appearance of PC eggla\ ing scars on Mcintosh (6 nun) and Red Delicious (6 nun) apples (left to right) that
were initiated on Max 27 and photographed w hen 1. 3 and 6 days old (top to bottom)

Fruit Notes. Volume 69, Winter, 2004

Mcintosh'
3 days ^

-^£sa?a

^sasi^'S-

Delicious
6 days

Figure 2 Appearance of PC eggla\ mg scars on Mcintosh (S mm) and Red Delicious (7 nun) apples (left lo right) that
were initiated on June 3 and photographed when I. o and 6 da>s old (top to bottom)

Fruit Notes, Volume 69, Winter, 2004

Mcintosh
1 day

fe.

Delicious
1 day

Mcintosh
6 days

Figure 3 Appearance of PC eggla> ing scars on Mcintosh ( 14 nun) and Red Delicious ( 10 nun) apples (left to right) tliat
were initiated on June 10 and photographed when 1. 3 and 6 da\ s old (top to bottom).

Fruit Notes. Volume 69, Winter, 2004

■^

I [ H 1 1 1 < • \~:A

1 day

cintosh
days

Figure 4. Appearance of PC egglaMiig scars on Mcintosh (19 mm) and Red Delicious ( 14 mm) apples (left to right) that
were initiated on June 17 and photograpiied \^hen 1. 3 and 6 da> s old (top to bottom)

Fruit Notes, Volume 69, Winter, 2004

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Fruit Notes, Volume 69, Winter, 2004

Fruit Notes

University of Massachusetts
fruit IJcparlment of Plant & Soil Sciences
Uglgj 205 Bowditch Hall

ni^ Amherst, MA 01003

^^^^\ C/ass Ma;7

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Volume 69, Number 2
SPRING ISSUE, 2004

Table of Contents

rIewCnaiand

A Fruit Notes Issue in Honor of Ronald J. Prokopy
Wesley Autio

Remembering Ron

William Coli

Ron's Papers
Daniel Cooley .

Optimizing Distances Between Odor-baited Spheres on Perimeter Apple Tree
Ronald Prokopy, Isabel Jdcome, and Everardo Bigurra

Ideal Within-canopy Positioning of Odor-baited Red Spheres for Monitoring
Sara Hoffman, Isabel Jdcome, Everardo Bigurra, and Ronald Prokopy

Evaluation of Pesticide-treated Spheres for Control of Apple Maggot Flies in
Ronald Prokopy, Isabel Jdcome, Everardo Bigurra, and Marina Blanco

gland

.. 15

.. 21

A Tribute to Ronald J. Prokopy (1935-2004)

Editors:

flewCnaland

Wesley R.Autio
William J. Bramlage

Publication Infonnation:

Fruit Notes (ISSN 0427-6906) is published
each January, April, July, and October by the
University of Massachusetts Amherst in coop-
eration with the other New England state
universities.

The cost of subscriptions to Fruit Notes is
$20.00 per year. Each one-year subscription
begins January 1 and ends December 3 1 .
Some back issues are available for $5.00.
Payments must be in United States cun-ency
and should be made to the University of
Massachusetts Amherst.

Correspondence should be sent to:

Fruit Notes

Department ofPlant, Soil, & Insect Sciences
205 Bowditch Hall
University of Massachusetts Amherst
Amherst, MA 01 003

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 cirrrent 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 UMass Extension, Robert Schroder, Acting Director, in furtherance of the acts of May 8 and June
30, 1914. UMass Extension offers equal opportunity in programs and employment.

A Fruit Notes Issue in Honor of
Ronald J. Prokopy

Wesley R. Autio

Department of Plant, Soil, & Insect Sciences, University of Massachusetts

I still have a hard time believing that we have lost
our friend and colleague Ron Prokopy in May, 2004.
His contribution to the science and practice of apple
pest management will never be forgotten.

Ron Prokopy was the entomological side of the
UMass Fruit Program. He contributed regularly to
Fruit Notes, Healthy Fruit, and the New England
Apple Pest Management Guide. He wrote twenty-
six Annual March Messages, an update on the state
of tree-fruit insect control for fruit growers, and he
spoke at all but three or four of the nearly 60 Twilight

Grower Meetings since I joined the faculty 19 years
ago. Further, he was always available to assist grow-
ers with their problems. This tally, however, does not
adequately capture how Ron extended the research of
UMass to the fruit industry. His outreach efforts were
borne from a deep-seated concern for the well being
of the tree-fruit industry and the growers as individuals
and from an unquenchable enthusiasm for the details
of insect pest management. He understood the con-
straints imposed on farmers both by the natural world
and by society. This understanding helped Ron mold

Fruit Notes, Volume 69, Spring, 2004

his outreach to guide our tree-fruit industry to a level
which put them among the most progressive pest man-
agers in the World.

This extremely effective outreach effort was sup-
ported by one of the most productive research pro-
grams in the University. With hundreds of research
articles to his credit, Ron Prokopy was one of the most
respected entomological scientists in the World. He
helped mold the concepts which are the foundation of
current and future integrated pest management (IPM).
It was both remarkable and inspirational how his re-
search spanned the spectrum from basic to applied.
All his research, even the most fundamental, was clearly
focused on solving a practical problem.

There are many examples of how Ron brought his
research and outreach together, but I particularly en-
joyed his talk at one of our twilight meetings a few
years ago. Plum curculio is one of the most difficult
pests for orchardists and scientists alike. Ron focused
much of the last 10 years on this troublesome insect.
He spent much time watching and recording curculio
movement into and around apple trees. At a mid-June
twilight meeting, Ron spent a good portion of his 20
minutes (which usually lasted at least 40 minutes) de-
scribing how curculios found an apple tree. This talk
was given mostly from the orchard floor, that is Ron
was lying down and crawling along the ground (and
speaking) showing the growers how the curculio saw
the world. This enthusiasm for the actions of plum
curculio, and also for apple maggot tlies, gave Ron the
ability make great strides in research, interpret those
results, and develop and transfer the knowledge nec-

essary to help growers.

Members of the Fruit Program cooperate on a num-
ber of fronts, from research to educational programs,
but we are always together at nine twilight grower
meetings per year (three series of three meetings each).
For at least one of each of these series over the last
several years, three or four of us would travel together.
This tnp usually was to Plymouth County, Bnstol County,
or Rhode Island and was as much as a two-hour ride
from Amherst. We always had to study the weather
forecast before heading that way with Ron. If it was
going to be hot (and Ron loved hot, humid weather),
we tried to get the largest vehicle available, usually a
van. Most of us enjoy the benefits of automotive air
conditioning in hot weather, but not Ron. The large
vehicle allowed us to make him ride in the far back,
away from the air conditioning and near his own open
window. Some of Ron's other eccentricities included
power naps, eating a head of lettuce for supper, re-
viewing papers while driving, and his numerous pillows,
sweaters, and bags that always traveled with him. These
"quirks" punctuated his honest and unwavering con-
cern for people. He cared about all of us, growers,
students, colleagues, and friends.

This issue of Fruit Notes is dedicated to Ron's
memory. It begins with a few memories of Ron and
ends with the last three articles that he wrote for Fruit
Notes (in the few weeks before his death, thanks to
Isabel Jacome for typing these articles).

Ron Prokopy was an amazing individual. He was
among the best scientists, the best extension educa-
tors, and the best people that we will ever know.

^{^ %1^ %1^ «1^ *x*
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Fruit Notes, Volume 69, Spring, 2004

Remembering Ron

William M. Coli

Department of Plant, Soil, & Insect Sciences, University of Massachusetts

By now, orcharding and University communities
all over the world have learned that we have all lost a
rare and unique individual: Dr. Ron Prokopy. As Wes
Autio put it so well in a recent email, "Ron's boundless
support of the apple industry will be sorely missed, and
his extensive research contributions will never be for-
gotten."

As Ron
would have
wanted, and in
spite of the
depth of our
feelings of loss,
I hope we can
all focus on how
he lived his life
rather than on
this untimely
loss. I'm sure
there will be a
lot of sharing of
stories at the
memorial ser-
vice planned for
May 22 at his
beloved farm in
Conway. For
those who can
not attend, I'd
like to offer just
a few recollec-
tions about the
29 years I have
known Ron.

The first time I ever met him, I knew right away
that Ron was not your typical University faculty mem-
ber. I don't know if it was the longer than normal hair
style, the South American knit bag that he always car-
ried with him (and which inevitably contained bags of
neatly sliced, home grown carrots), or his propensity to
take his little "rests" (cat naps that he would always
take while we were on route to some place or another).

When he first arrived at UMass Amherst in 1975,
he was already well known in Entomology circles for
his ground-breaking and innovative work developing ef-
fective, multi-colored, sticky sphere traps for monitor-
ing fruit flies. The story goes that when another fac-
ulty member (Dr. John Stoffolano) was introducing Ron

to the clerical
staff in Femald
Hall, he was ob-
viously excited
to have this new
high-powered
behavioral
ecologist in the
department .
John, assuming
perhaps that the
clencal staff was
familiar with
Ron's earlier re-
search said:
"This is Ron
Prokopy, our
new faculty Ex-
tension Ento-
mologist. You
know, he's the
guy with the red
and yellow
sticky balls!!"
Once all present
stopped laugh-
ing, John told
them what he really meant to say.

While working on a special research project on traps
for the blueberry maggot fly with Ron, I continued to
gain a better perspective on this unique guy. I learned
that he was about the hardest working person I'd ever
known. There was never a single field day that Ron
wouldn't be out there counting flies with me. When the
data were finally analyzed, he was insistent that we
write the results up for a paper to submit to an Ento-

Fruit Notes, Volume 69, Spring, 2004

mological journal. Those researchers who know him
well are probably saying "What? Only one paper?" since
Ron, in addition to arguably knowing more than anyone
else in the world about the Family Tephritidae (fruit
flies), was also incredibly productive in his publication
record.

In spite of his brilliant intellect, Ron was very down
to earth, very easy to talk with, and incredibly commit-
ted to extension work: once again not typical of Uni-
versity Faculty in general. He loved his days in the field.
There was literally nothing he preferred more than sit-
ting in the orchard observing his beloved insect sub-
jects. Ron always joked that when he died, he wanted

to be reincarnated as an apple maggot fly. I hope for
all our sakes that he does not get his wish, because I
envision apple maggot becoming A LOT BIGGER prob-
lem if the species has Ron's incredible knowledge and
energies to draw upon.

Ron Prokopy was truly deserving of the 'one-of-
a-kind' label. While it is comforting to know that Ron
was following his passions right to the last, and that his
passing was peaceful, the fruit industry, the science of
Entomology, the University of Massachusetts, his many
graduate students, and all his many friends and col-
leagues will miss him dearly.

%1^ *A^ %1^ *1^ «1^
^r% ^r% ^f% ^r* ^r%

Fruit Notes, Volume 69, Spring, 2004

Ron's Papers

Daniel R. Cooley

Department of Plant, Soil, & Insect Sciences, University of Massachusetts

There was no doubt in my mind that Ron Prokopy
would hve until he was at least 90. I also knew he
wouldn't stop his life's work, ever. And now that only
one of those certamties has proven true, I can't yet
see how our world of New England apple growers and
researchers, the world of insect ecologists, our univer-
sity, or my own world will function in quite the same
way. Half the time I forget that he isn't home in
Conway, isn't at his Femald Hall office, and isn't check-
ing curculio traps.

Maybe as a way to make my mind adjust, I've
been focusing on just one facet of his life. I've been
wondering how Ron Prokopy ever managed to write
all those papers, over 450 publications, an almost in-
comprehensible number. As the main form of academic
research currency, the number of publications a per-
son writes gives other academics a quick read on the
stature and impact a scientist carries. It's a career
batting average, and Ron was a Ted Williams when it
comes to writing. Very good scientists would be happy
to write one or two hundred articles, chapters and other
pieces over a career. And just as every hit Williams
got represented hundreds of swings and hours of prac-
tice, every article a scientist writes represents hours of
grant writing, lab and field experiments, data analysis
and finally, the actual writing.

Naturally, some scientists cook the books a bit, ac-
cepting partial credit for papers to which they may have
made little or no real contribution. It's like Enron re-
porting millions in imaginary earnings so that the com-
pany will look much more substantial. In science, this
sort of "pub padding" can make author lists that read
like an Old Testament genealogy. Ron never indulged
in this sort of publication inflation, and he contributed a
meaningful part in any research that carried his name,
making his accomplishment all the more remarkable.

So I wonder, how did he do it? Perhaps it was
because he frequently had trouble sleeping, and would
not so much complain as comment on the fact that he
had gotten only 4 hours of sleep the previous night.
Getting along on a sleep regimen that could crack hard-
ened spies certainly could explain some of Ron's pro-

ductivity.

He did need an occasional recharge. When we
were out on the road, between orchards he might say
that he really needed a little rest, if I didn't mind, and
he would doze off for 10 or 15 minutes. He revived,
dragging his palm from forehead to chin as if it would
wipe away the last vestiges of his nap, and emerging
from his pupae-like slumber he'd launch full flight into
an intense discussion concerning how we might arrange
tests in the next orchard to serve multiple research
tasks. Couldn't we use Broderick's old Mac block for
the curculio work, and the maggot work, and the fly-
speck work, making data collection visits even more
productive? Ron lived with a New England farmer's
kind of efficiency, carrying lettuce and carrot lunches
in washed and re-used plastic bags, sporting an eclec-
tic wardrobe of Goodwill clothes, and always trying to
squeeze every bit of data possible from an experiment.

While Ron always got the most from a dollar, I'm
not sure his Yankee frugality always contributed to re-
search efficiency. He grew up on a Connecticut farm,
and eeking a living from rocky New England soils means
a lot of getting by and making do. For better or worse,
he carried those habits into his research projects. And
since the sort of research and teaching he did extended
beyond brick and ivy to the orchards of New England,
Ron and his lab group drove hours to and from research
sites every day. The several vehicles needed for this
were much like his clothes, a sort of Goodwill collec-
tion, including such classics as a vintage Korean War
surplus MASH ambulance, a banana yellow Ford
Torino with vestigial brakes, and cabin-cruiser like sta-
tion wagons with rotted floors, all vehicles that had been
rescued from the scrap-heap. They had far outlived
their usefulness in polite society but could still carry
people, tools and various objects covered with sticky
goop around the state. I don't think Ron could fully
conceive of buying a new car, or even a late-model
used car, not when the same money could be used for
an extra summer assistant. In fact, I think the rusty
roof of a 10 year old LTD appealed to Ron not only
because it was cheap, but because it said to growers

Fruit Notes, Volume 69, Spring, 2004

that Ron didn't care what things looked Hke, that we
were not some well-funded, effete research institute,
but rather people who got by and could be trusted. On
the other hand, whether these crates would start reli-
ably or keep chugging through sparsely populated parts
of the state was another issue. Some days, I think
Ron's powerful will to understand the orchard ecosys-
tem was the only thing that kept those cars going.

Ron used time much the way he used research
dollars, squeezing the minutes. When he drove one of
the old heaps himself, he wasn't content to just think or
listen to the radio. He had to read, review and, some
say, even write papers while navigating the notonously
narrow, rock- and tree-lined roads between New En-
gland orchards. His approach to driving pretty much
insured that if someone else was joining him, they vol-
unteered to get behind the wheel. Ron could then re-
treat to the back seat to fully devote attention to his
papers without the distraction of an on-coming cement

truck. For longer trips, every plane ride, every hotel
room served as an office and study for the constant,
nearly undecipherable pencil scribbling on page after
page of yellow lined paper. That single-minded atten-
tion to filling in what might otherwise be downtime with
writing undoubtedly helped Ron's publication record.

Technology didn't. Ron never allowed computers
to make his writing and research more efficient. He
tried a laptop computer once, thinking it might save ev-
erybody time if they didn't have to download his email,
then read and type his responses, not to mention typing
up the pages of pencil scrawled manuscripts. And with
a laptop, Ron could still write as he traveled, or when
he sat in an orchard. It was a good theory, but Ron's
mind never adapted to the keys and electronic screen.
Within a few weeks, his son Josh had inherited the un-
used computer for his own use. Ron stayed with the
yellow lined paper.

Naturally, rather than a PDA, Ron had a unique

Fruit Notes, Volume 69, Spring, 2004

paper organizational system. For day-to-day opera-
tions, he would penodically pull a small pile of recycled
scraps from his pocket, consult 2 or 3 of them, and
then make a phone call, ask a student to copy a re-
search paper, or do whatever else the notes remmded
him needed to be done. To my knowledge, Ron never
had a date book or notebook; he had stacks of recycled
paper scraps filled with his cryptic scrawl.

He did have a relatively inflexible organization to
his year that probably contributed to efficiency; he could
more easily plan ahead. His field experiments would
be, for the most part, planned by the time we started
the twilight grower meetings in the spring. Ron looked
forward to those drafty bam sessions, talking with grow-
ers about the latest way to deal with tarnished plant
bug or leaf miner. He remembered going to them as a
kid with his uncle and seeing scientists from the Con-
necticut Expenment Station. Then, after getting his Ph.
D. in entomology at Cornell, he went back to the Con-
necticut Agricultural Experiment Station to take on the
position working with insects and mites in apples. The
happy homecoming only lasted a little while, and the
stories are vague. Evidently, Ron got involved in late
60 's radical politics in New Haven. Ron left the sta-
tion, traveling Europe with Linda, his wife, in a VW
microbus. Being Ron, traveling Europe meant going
behind the Iron Curtain rather than to the Riviera. On
his return, he tried starting his own research station in
Wisconsin and spent time in Texas working with semi-
nal figures in the IPM movement just as it was start-
ing. Then in 1975, he landed in Massachusetts.

But I'm digressing. As I said, Ron's year began
with twilight meetings and grower visits, and it contin-
ued with 1 6 hour or longer days filled with field experi-
ments, circus-like tents over apple trees, and all man-
ner of contraptions designed to figure out why apple
insects behaved the way they did. Ron digested data
as it came in, on a daily basis, but by the end of the
summer, he would already be putting it together into a
bigger picture. The fall meetings would start in late
October with a gathering of apple IPM researchers
and advisors in Vermont, where the very latest results
from that year would be presented and shared. A little
later, more polished presentations would be made at
the national entomology meetings and as the New Year
began to growers at the New England Fruit Meetings.
At Amherst, Ron would teach his IPM course each
fall. In January, he would disappear to the library each
day, reading articles that would be assimilated into

grants or papers, as well as the March Message. The
March Message included all the latest apple pest man-
agement information a grower could want, and Ron
created it because the standard pest management ma-
terial couldn't or wouldn't keep up with the pace he
wanted to set. Delivered just before the growing sea-
son started, Ron would joke that it was good bathroom
material. Wherever they read it, growers would make
sure that they had. By the time the March Message
was ready for press, Ron would be leaving for his an-
nual trip to Hawaii. Of course his New England heri-
tage wouldn't let himjust go and enjoy Hawaii though
he loved the place, so Ron had a long-running grant to
study fruit flies there. Anyone he took with him soon
discovered that the research agenda was just as 24-7
in Hawaii as it was in Amherst. As soon as he got
back to Amherst, the twilight meetings and grower vis-
its would start again. Woven into this annual fabric
were daily meetings with grad students, lab assistants
and technicians, post-docs, other faculty and visiting
scientists. And all this was punctuated by special meet-
ings and talks in which any successful scientist engages,
talks in China or Washington, or meetings in Europe
and Australia. Around this schedule Ron wrote the
huge number of grant proposals and publications that
mystifies me.

I know that it made a few people feel better to
write-off Ron's publication record as the results of a
monomaniacal workaholic. It wasn't that, and Ron,
while he worked hard, didn't eliminate family, friends,
recreation or the arts from his life. Some of the other
parts of Ron's life seem totally at odds with his image
as hard-working, salt-of-the-earth academic. For ex-
ample, Ron played golf When I went a round with
him, he showed up carrying a battered, ancient set of
clubs, wearing his Larry Bird short shorts and a T-shirt.
It occurred to me that golf must be some concession
Ron had reluctantly made to recreation, that someone
had told him he needed a hobby, so he'd looked around
a thrift store, seen golf clubs and determined that he
would go play a round every week for Recreation.
About the 6h hole, I began to see a pattern that sug-
gested a different story. Short, but straight drives on
the fairway, uncannily accurate approaches to the best
part of the green, and consistent putting had Ron at par
or better, while everyone else in the group was at least
5 strokes over. Ron was playing winning golf, and thor-
oughly enjoying it.

In fact, he had several athletic hobbies, done in

Fruit Notes, Volume 69, Spring, 2004

less-than-conventional ways that fit his schedule. He
probably swam in every orchard pond in the state, fol-
lowing a day counting insects in apple trees, and maybe
a short jog. On his own farm, he kept a muddy pond
that doubled as a hockey rink. I remember one game
when Ron had magnanimously taken a few of the
weaker skaters, among them my wife, on his team.
Because we had a shortage of real hockey sticks, Ron
volunteered to use a broom. Not surprisingly, Ron's
team quickly slipped behind. Ron's frustration grew
more visible as the debacle played out, and as one of
his sons threatened to score against Ron's group yet
again, Ron swooped over to my wife, grabbed her stick,
stole the puck from his 10-year-old, and skated the
length of the ice to score himself He followed that
with enough goals to satisfy himself that he would not
be humiliated. I suspect Ron's competitive nature also
had a significant effect on his research record as well.

I can't fit his love of opera into an explanation of
his publishing record, except that it was probably one
of those releases any intense person needs to keep from
imploding. Not being an opera aficionado, I failed, on
several levels, to understand Ron's trips to New York
to see Carmen or some lesser-known production. I do
like non-musical theater, and music without theater, and
Ron, knowing this, would be the one who organized
evenings to see a summer play at Smith or a jazz per-
formance in Northampton. Releases though these may
have been, I still wonder how a man doing the grant
writing, experiments, analysis and publication work
necessary for 15 or so publications a year could have
time for any of this? Or the baseball trips to Fenway
Park. Or the hikes. Or the dinners with students, col-
leagues and friends. Or singing with the local chorus.

Teaching a course sets limits on research, and
many successful scientists consider teaching a burden.
Most have no idea what it means to work with people
outside the university, people like New England apple
growers. For many of the most successful scientists,
their exclusive priority is the production of research
papers. In contrast, Ron reveled in his role as advisor
and colleague to the apple growers of New England,
and devoted himself to teaching IPM to university stu-
dents. He never considered ignoring the growers or
students so that he might focus on more on research.
Ron loved apples, the people that grow them, the places
they grow, the insects that feed on them, all of it. Just
as important, and less obvious, he knew that his work
in the orchards led to better research and teaching.

He knew that teaching growers how to manage apple
pests taught him how to develop ecological theories
that worked in the real world. It made his classroom
more relevant and real to his university-based students.
The time it takes to do all this, of course, makes those
450 papers even more astounding.

Ron uniquely bridged the space between academ-
ics and apple growers. I think it's difficult for purists in
either group to appreciate how well he did it. For ex-
ample, he and a colleague discovered that Rhagoletis
pominella (the apple maggot fly) had moved from its
native American host, the hawthorn (Crataegus sp.),
to an imported host, the domestic apple (Malus
domestica). They held this up as an exciting example
of sympatric speciation (one species diverges into two
separate species in a single geographic location) by
publishing in the world's best scientific journals and
speaking at major academic meetings. It's still a clas-
sic example in ecology. At the same time Ron showed
that the apple maggot's predilection for round, red ob-
jects could be useful to growers, telling them when the
damaging flies were present in their orchards, and just
as importantly, when they were not. For a few years,
I'm sure Ron totally disrupted the market for croquet
and bocce balls, buying them up, painting them red,
covenng them in sticky goo, and hanging them in apple
trees to determine whether growers needed to apply
an insecticide.

I'm still not sure how Ron sold LPM to apple grow-
ers. He came into the job with some pressure, as the
previous two apple entomologists at UMass had been
fired. When he started his Extension work, Ron still
had most of his long hair from the 60's and carried his
ever-present paperwork and field equipment in a wo-
ven Guatemalan shoulder bag. It's hard to remember
now, but at that time EPM ran counter to standard pest
management dogma. For years. Extension and pesti-
cide salesmen had been telling orchardists that they
needed to spray chemicals weekly, sometimes more,
to eliminate any possibility of pests and disease in
apples. Along came Ron, asking them to hang colored
sheets of sticky cardboard and bocce balls in their trees,
count bugs, and above all, not to spray pesticides until
the pests actually started their invasion. I know many
growers, looking at Ron and the colored bocce balls,
were worried that this ivory tower hippie from the
University was trying to lead them into disaster.

But Ron, having grown up on a fruit farm, was not
an ivory tower scientist. He may have been an idealist

Fruit Notes, Volume 69, Spring, 2004

but he understood growing apples. And after talking
with him, a few influential growers recognized that.
Perhaps more importantly. Bill Pearse, probably the
most influential quality control man working for the larg-
est apple wholesaler in Massachusetts, saw the prom-
ise of better pest management with fewer pesticides.
Ron was a little different and intense, but I know Bill
liked and respected him, and the feelings were mutual.
I'm sure BUI quietly suggested that growers give some
of this IPM stuff a try, and at the same time, set Ron
straight as to how far growers might actually be willing
to go. In the next decades, even after Bill's death.
New England apple growers would be leaders in using
IPM, because Ron wanted to do more than just hide in
the University and write papers.

But of course he did write all those papers too. I
probably never will really understand how, but I'm glad
that he did it, that he managed to get down on paper so
much of the knowledge he gained. Ron collected
knowledge, from growers and other scientists, from
everyone he met, from his experiments, he gathered it
in, processed it in his own inimitable way, and wrote so
much of it down. What a tremendous legacy. While no
one will ever touch each of us the way Ron did, I re-
main hopeful that some of his students, or perhaps his
students' students, will be able to bridge that widening
gap between academics and our agricultural resources,
and carry on Ron's dream of a truly ecological, sus-
tainable orchard.

*1^ %l0 %i^ %t^ %i^
^^ ^f% ^^ ^f% #^

Fruit Notes, Volume 69, Spring, 2004

Optimizing Distances Between Odor-
baited Spheres on Perimeter Apple
Trees for Control of Apple Maggot Flies

Ronald Prokopy, Isabel Jacome, and Everardo Bigurra

Department of Plant, Soil, & Insect Science, University of Massachusetts

For several decades, spraying apple trees with
insecticide in July and August has been the standard
approach to apple maggot fly (AMF) control. While
this approach is likely to continue to be the standard in
most orchards for decades to come, some growers
would like an alternative approach that eliminates the
need for insecticide application during summer months.
One alternative that we have been studying for more
than a decade is the surrounding of orchard blocks with
odor-baited spheres on perimeter apple trees to
intercept immigrating AMF before they can penetrate
into interior rows.

hi the Spring 2002 issue oi Fruit Notes, we reported
that the most effective odor bait to use in conjunction
with perimeter spheres for maximizing AMF control
under a broad range of orchard conditions is a five-
component blend of synthetic attractive apple volatiles
developed at Cornell University. In other issues of Fivil
Notes preceding 2002, we presented data suggesting
that odor-baited spheres deployed on perimeter trees
may be more effective (a) in orchards comprised of
small or medium trees than in orchards of large trees,
(b) in orchards having particular arrangements of
susceptible versus tolerant cultivars, and (c) in orchards
bordered by open space than by hedgerow or woods.
In addition, we suspected that sphere effectiveness
might be greater in well-pruned than poorly-pruned
perimeter trees.

To qualify as a viable alternative to spraying an
orchard for AMF control, use of odor-baited spheres
on perimeter trees must be cost-competitive; the fewer
the number of spheres needed, the less the cost. Until
now, distances between perimeter spheres in apple
orchards have been assigned largely on an arbitrary
basis (devoid of established guiding principles), varying
from 2 to 45 yards apart.

Here, we developed an approach to assigning

distances between odor-baited spheres or perimeter
trees of apple orchards. It employs an index
incorporating characteristics of four environmental
variables: size of orchard trees, quality of pruning,
cultivar composition and nature of bordering habitat.

Materials & Methods

Block layout. Our experiment was conducted in
12 blocks of apple trees in ten commercial orchards in
Massachusetts. Each block consisted of seven rows
of apple trees, was about 120 yards long, and averaged
35 yards deep in extension from a perimeter row that
bordered open field, hedgerow, or woods to the seventh
interior row. Each block was divided into two plots:
one plot about 90 yards long, the other about 30 yards
long. Blocks consisted of either small (M.9 rooted),
medium (M.26 rooted), or large (M.7 rooted) trees that
were either well, moderately, or poorly pruned in 2003.
Each row of a block was comprised of the same cultivar,
which was considered as being of relatively low
susceptibility to AMF if Mcintosh or Empire, moderate
susceptibility if Cortland or Delicious, and high
susceptibility if Fuji, Gala, or Jonagold. Each of the four
sides of a block was bordered by grower-sprayed
orchard trees, open field, hedgerow, or woods.

Pesticide sprays. Each plot in each block was
sprayed by cooperating growers with insecticide and
fungicide in April, May, and June to control a variety of
insects and diseases. Thereafter, the smaller (30 x 35
yards) plot received two or three grower-applied sprays
of insecticide in July and August to control AMF;
whereas, the larger (90 x 35 yards) plot received no
insecticide after June but received odor-baited spheres
to control AMF.

Spheres. Each sphere trap was 3.5 inches in
diameter, red in color, and coated with Tangletrap to

Fruit Notes, Volume 69, Spring, 2004

Table 1. Values ascribed to characteristics of four environmental variables as components of an index for
assigning distances between odor-baited spheres on perimeter apple trees.

Value

Tree size

Quality of pruning

Cultivar
susceptibility

Bordering habitat

1
2
3

Large

Medium

Small

Poor

Fair

Good

High

Moderate

Low

Woods

Hedgerow

Open*

*Also applies to

bordering

habitat consisting of grower-sprayed

orchard trees.

capture alighting AMF. Spheres placed on perimeter
trees to intercept immigrating adults were accompanied
by a blend of five synthetic attractive fruit volatiles
contained in a polyethylene vial. Spheres placed on
interior trees to monitor adults that penetrated into plots
were not baited. All spheres were deployed during the
last week of June (before arrival of adults) and
remained through harvest (in September). Deployment
was at mid-canopy height in a way that maximized visual
conspicuousness and attractiveness.

Index for assigning distances between
spheres. The index used for assigning distances
between odor-baited spheres on each side of each
targeted plot was created by first prescribing a value
of 1, 2, or 3 for each of tree size, quality of pruning,
cultivar susceptibility, and bordering habitat for that side
(Table 1) and then using the sum of the four values to
determine distance between spheres (Table 2). Based
on previous studies conducted in Massachusetts and
Quebec, we chose 6 yards as a minimum distance
between spheres and 1 8 yards as maximum distance.
Given that this was the first year of using such an index
and given that all test blocks were in commercial
orchards where valuable fruit was at risk, we were
reluctant to deploy spheres at distances greater than
18 yards apart. In some cases, the structure of a block
(spacing of trees within and among rows) did not allow
us to position spheres precisely according to assigned
distances. In such cases, we compromised in favor of
an assigned distance closest to the original.

Assessment of treatment performance. We
used two methods of assessing treatment performance.
First, every other week from trap deployment until
harvest we counted and removed all AMF captured by

eight unbaited spheres placed on interior trees of row 4
of baited-sphere plots and by four similarly-positioned
unbaited spheres in grower-sprayed plots. Captures
by such spheres were used as an indicator of relative
numbers of adults that penetrated into interiors of plots.
At the same time, we counted and removed all AMF
captured by odor-baited spheres on perimeter trees and
cleaned all baited and unbaited spheres of insects and
debris, re-coating spheres with Tangletrap if necessary.
Second, at harvest we sampled 20 fruit on each of five
trees on each of the four sides of each baited-sphere
and each grower-sprayed plot plus ten fruit on each of

Table 2. Index for

assigning distances

between odor-baited spheres on perimeter

apple trees. Sum of values is derived from

qualities of four environmental variables

as given in Table 1 .

Distance between

Sum of values

spheres (yards)

7.5

10.5

13.5

16.5

Fruit Notes, Volume 69, Spring, 2004

five interior trees in each of rows 3 and 5 of each plot
(total of 500 fruit per plot). All sampled fruit were picked
and kept in a greenhouse for one month before
examination for ovipositional punctures, confirmed by
dissection of punctured fruit for signs of larval growth.
Treatment comparisons and data analysis. In
both 2001 and 2002, the same 12 baited-sphere plots
used here received odor-baited spheres on each side
of each plot at arbitrarily prescribed distances of 6 or

1 1 yards apart. Also, m both 2001 and 2002, the same

12 grower-sprayed plots used here received similar
pesticide treatments as here. Use of unbaited spheres
on interior trees to monitor penefration of adults into
plots and sampling of fruit for AMF damage m 2001
and 2002 were equivalent to procedures used here. To
compare outcomes of the index -based approach of 2003
with the arbitrary approach of 2001 and 2002 for
assigning distances between spheres, we subjected
each year's data on number of baited spheres used on
perimeter trees, number of AMF captured per unbaited
monitoring sphere, and percent sampled fruit injured
by AMF to analysis of variance.

For 2003 data, we used correlation analysis to
determine the relationship between percent injured fruit

on each of the four sides of each of the 12 baited-
sphere plots and the value (1 , 2, or 3) ascribed to that
side for each of the following: tree size, quality of
pruning, cultivar susceptibility, and bordering habitat.
In addition, we used correlation analysis to determine
relationships between mean numbers of AMF captured
by interior unbaited monitoring traps in baited-sphere
plots or percent fruit injured on interior frees of baited-
sphere plots (100 fruit per plot) and tree size or quality
of pruning for that plot. Whereas, in every case, tree
size and quality of pruning were the same for all
perimeter trees in a plot, thus permitting such analysis,
cultivar susceptibility and border habitat differed among
perimeter trees of the same plot and thus were
excluded.

Results

Compared with the mean number of odor-baited
spheres deployed on perimeter trees per plot in 2001
and 2002, the mean number deployed in 2003 was
significantly fewer (33-39% fewer) (Figure I). Even
so, mean values in Figure 2 show that captures of
AMF on unbaited monitoring fraps at interiors of plots

45. 1

^ 1 1

no. baited spheres
deployed

S 15 -

n -

U 1

1 . 1 . ■ 1

2001 2002 2003

Figure 1 . Mean number of odor-baited spheres deployed on perimeter apple trees in the same 1 2 plots in

commercial orchards in 2001, 2002 and 2003. Means superscribed by the same letter are not significantly

different at odds of 1 9; 1 .

Fruit Notes, Volume 69, Spring, 2004

15 1

2001

a»

17 ■

at:

9 ■

6 ■

C
O

3 ■

I Baited sphere plots
n Grower-sprayed plots

Captures

15 1

2002

(/I

1? -

(/I

9 ■

■♦-*

B
O

3 ■

A .

■ Baited sphere plots
n Grower-sprayed plots
A

Captures

15 T 2003

■ Baited sphere plots
D Grower-sprayed plots

Captures

s
'a

■ Baited sphere plots
D Grower-sprayed plots

Injury

■ Baited sphere plots
D Grower-sprayed plots

Injury

0.6 1

0.5 -

0.4 -

n.3 -

0.2 •

0.1 -
•

■ Baited sphere plots
n Grower-sprayed plots

Injury

Figure 2. Mean number of AMF captured on interior unbailed monitoring spheres and mean percent injured
fruit in baited sphere and grower- sprayed plots in 2001, 2002, and 2003. For each comparison, means
superscribed by the same letter are not significantly different at odds of 19: 1 .

and plot-wide percent fruit injury were not significantly
greater in baited-sphere plots (relative to sprayed plots)
m any of the three years (2001, 2002, or 2003).

For 2003, percent fruit injured on perimeter trees
comprising the four sides of baited spheres plots was
significantly negatively correlated (at odds of 15 to 1)
with values prescribed for quality of pruning but not

significantly correlated with values prescribed for tree
size, cultivar susceptibility or border habitat. For 2003,
captures of adults by unbailed monitoring traps on
interiors of baited sphere plots were significantly
negatively correlated (at odds of 10 to 1) with values
prescribed for tree size and quality of pruning but not
with values prescribed for cultivar susceptibility or

Fruit Notes, Volume 69, Spring, 2004

border habitat. Percent fruit injured on interior trees
of baited-sphere plots was not correlated with values
prescribed for tree size or quality of pruning.

Conclusions

Our findings for 2003 indicate that assigning
distances between odor-baited spheres (on perimeter
trees of plots in commercial apple orchards) according
to an index incorporating characteristics of four
environmental variables (tree size, quality of pruning,
cultivar susceptibility, and border habitat) resulted in a
level of AMF control no different from that achieved
by sprays of insecticide in 2003 and no different from
that of arbitrary assignment of distances between odor-
baited perimeter spheres in the same plots in 2001 and
2002. Only 61-67% as many spheres were used under
our new index system for determining distances
between spheres in 2003 as under the arbitrary system
used in 2001 and 2002.

Correlation analyses suggested that the index used
here for assigning distances between odor-baited
spheres on perimeter trees was reliable with respect to
values prescribed for cultivar susceptibility and border
habitat, but for future use it may require adjustment
with respect to tree size and quality of pruning. Some
of the analyses showed a significant negative
correlation between tree size or quality of pruning and
fruit injury by AMF or captures of AMF by interior
monitoring traps, suggesting that distances between
spheres prescribed by the index used here may have
been too great to ensure high performance in plots of
large and/or poorly pruned trees. One potential solution
to this possible shortcoming would be to prescribe a
value of less than 1 (rather than the value of 1 used
here) for perimeter trees of large size and poor pruning.
Doing so could, in some cases, require that spheres be
placed closer than 6 yards apart. Conversely, for small-
size perimeter trees that are pruned well, it may prove
possible to assign a value 4 or more (rather than the
value of 3 used here) and achieve acceptable control
of AMF using odor-baited spheres positioned greater
than 18 yards apart (the maximum distance apart
allowed here).

On average, each of the 12 plots in this study
received 24 odor-baited sticky spheres 1 2 yards apart
on perimeter trees that encompassed about 1 acre of
orchard. We estimate that it cost about $10 per sticky

sphere for all materials and labor ($1.50 tor sphere,
Tangletrap, and odor plus $8.50 for labor to apply sticky,
deploy spheres, periodically clean spheres of insects
and debris, and replenish sticky). The estimated cost
per plot of controlling AMF using odor-baited sticky
spheres was therefore $240, compared with an
estimated cost of about $45 per plot for control using
insecticide (materials, spray equipment, and labor). If
odor-baited sticky spheres were used to encompass a
block of 10 acres rather than a 1 acre plot of apple
trees, then 72 spheres (at 12 yards apart) would have
been needed, costing a total of $720, or $72 per acre.
This still IS substantially greater than the cost of applying
insecticide to control AMF ($45 per acre) and calls
into question the economic wisdom of using sticky
spheres for this purpose.

Ultimately, a replacement for sticky spheres is
needed that is both less expensive and less messy to
deploy and maintain. Such a replacement is on the
horizon in the form of a red sphere topped by a disc
comprised of spinosad (as insecticide), sugar (as
feeding stimulant) and paraffin wax (as binder) (see a
following article in this issue). Under high humidity,
morning dew, or rainfall, spinosad and sugar seep from
the disc onto the sphere surface, where they are ingested
by alighting AMF, which then die. The total annual cost
per odor-baited sphere of this type, amortized over a
10-year period, is estimated by its manufacturer (Pest
Management Innovations, Harpers Ferry, West Virginia)
to be about $3. Following initial deployment, such disc-
capped spheres would require no further attention
through harvest. Deploying odor-baited, disc-capped
spheres on penmeter apple trees at distances prescribed
by an index such as that put forward here could render
behavioral control of AMF as effective and affordable
as insecticide sprays, especially for large blocks of apple
trees that are on dwarfing rootstock and well pruned.

Acknowledgements

We thank Eliza Gray, Guadalupe Trujillo and
Mareanna Ricci for technical assistance and Jaime
Pifiero for statistical analyses. This study was
supported by a USDA Northeast region SARE grant,
a USDA Northeast Region IPM grant, a USDA Crops
at Risk grant, and the Massachusetts Society for
Promoting Agriculture.

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Fruit Notes, Volume 69, Spring, 2004

Ideal Within-canopy Positioning of
Odor-baited Red Spheres for
IVIonitoring or Control of
Apple Maggot Flies

Sara Hoffmann, Isabel Jacome, Everardo Bigurra, and Ronald J. Prokopy
Department of Plant, Soil, & Insect Science, University of Massachusetts

About 20 years ago, we conducted tests aimed at
establishing favorable positions within canopies of apple
trees for deploying unbaited sticky red spheres to
capture apple maggot flies (AMF). We found that
removal of all foliage and fruit within 10 to 20 inches of
a red sphere resulted m greater AMF captures than
allowmg foliage and fruit to encroach within 3 mches
of a sphere or removing all foliage and fruit within 40
inches of a sphere. Since the time of this initial study,
researchers at the New York Agricultural Experiment
Station in Geneva have developed a blend of synthetic,
attractive apple volatiles that draws AMF toward blend-
baited trees and enhances captures of AMF by red
spheres deployed in blend-baited trees.

Here, we report on expenments conducted in 2002
and 2003 aimed at defining favorable positions within
apple trees for deployment of blend-baited red spheres
for capturing AMF. We asked three questions. First,
we asked which distance between a baited red sphere
trap and the nearest foliage and fruit gave rise to the
greatest AMF captures. Second, we asked which part
of the tree canopy (outer half or inner half) was the
more favorable for positioning a baited red sphere trap
to maximize captures. Finally, we asked whether the
distance to which foliage and fruit were cleared away
from a red sphere trap was of greater consequence to
trap performance when traps were baited or when
traps were not baited. For each question, we examined
effects of season on the pattern of AMF response to
traps.

Materials & Methods

All experiments were conducted in a city-ov^ned
apple orchard in Leominster, Massachusetts dedicated

to honor Johnny Appleseed (a.k.a. John Chapman, who
was bom in Leominster). We used Jersey Mac trees
on M.26 rootstock, which had a moderate amount of
fruit each year. We also used Golden Delicious trees
on M.7 rootstock, which also had a moderate amount
of fruit each year. All trees involved in our trials were
moderately well pruned and received periodic season-
long treatments of fungicide to protect against apple
diseases. They received insecticide treatments through
May to protect fruit against ear