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^"ruit Notes

Prepared by the Department of Plant & Soil Sciences.

UMass Extension, U. S. Department of Agriculture, and Massachusetts Counties Cooperating.

Editors: Wesley R. Autio and William J. Bramlage

Volume 62,'Q|^mber 1
WINTER ISSUE, 1997

Table of Contents

Positioning Unbaited Pyramid
Traps to Capture Plum Curculios

How Do Plum Curculios Approach
Host Trees and Pjrramid Traps?

Do Natural Sources of Odor Enhance
Plum Curculio Attraction to Traps?

Petal Fall is the Most Attractive Developmental Stage
of Mcintosh Apple Trees to Plum Curculio Adults

Jim Anderson Dies

Peach Cultivar Trials: Observations and Comments

Agri-Mek: A 1996 Field Trial in a Commercial Apple Orchard

Fruit Notes

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Fruit Notes

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Positioning Unbailed Pyramid Traps
to Capture Plum Curculios

Ronald Prokopy and Starker Wright

Department of Entomology, University of Massachusetts

In the 1996 Winter issue of Fruit Notes, we
reported results of our 1995 research on plum
curculio responses to unbaited "Tedders" traps.
These traps are pjrramidal in shape, dark in
color, and are placed on the ground. They
capture curculios that arrive on the trap
surface and subsequently crawl upward to the
tip, where they enter an inverted screen funnel
(a cotton boll weevil trap top) placed over the
tip, from which they cannot escape.

All reported tests to date using Tedders
traps (hereafter referred to as pyramid traps)
for capturing plum curculios have involved
deploying unbaited traps between canopies of
apple trees within rows. In 1996, we evaluated
unbaited pyramid traps at four different
positions on the ground in a small commercial
apple orchard (Prokopy orchard) in Conway,
MA. In addition, we compared curculio
captures by pyramid traps with captures by
unbaited cotton boll weevil trap tops placed in
tree canopies. For each position or type of trap,
we compared daily trap captures with daily
incidence of orchard fruit scarring by plum
curculios.

Materials & Methods

Each pyramid trap was black and measured
40 inches in vertical height, 22 inches in base
width, and 2 inches in top width. Each was
staked to the ground to prevent toppling by
wind. All traps were constructed from plywood
in our laboratory, but beginning in 1997, traps
of essentially identical type can be purchased
from Gemplers Inc., Mt. Horeb, WI (only known
supplier).

The orchard consisted of ten rows of five
trees per row. Tree trunks were 20 feet apart
between rows and 13 feet apart within rows.

Trees were about 12 feet tall and about 10 feet
in canopy diameter. Soil beneath tree canopies
was treated with glyphosate in April and was
devoid of vegetation throughout our study. The
remainder of the orchard floor was covered with
grass, which was maintained at a height of 2 to
4 inches. Dense woods, which we considered to
be prime overwintering habitat for plum
curculios, lay about 25 feet north of the end tree
of each row, and a large open field of grass lay
immediately south.

At the pink stage of bud development,
pyramid traps were placed in association with
each of the trees in the second through ninth
rows (Figure 1). One trap was placed 10 feet
north of the trunk of the northernmost tree (15
feet from the woods), one trap 10 feet south of
the trunk of the southernmost tree of a row (at
the edge of the open field), one trap mid-way
between the canopies of the northernmost and
next northernmost tree of a row, and one trap 1
foot from the trunk of the center tree of a row.
At the same time, a boll weevil trap top was
placed on the cut end of a 4-inch upright twig in
the upper part of northernmost trees in the
second through ninth rows.

Traps were examined daily at 7 AM from
time of installation (May 14) until four weeks
after petal fall (June 27). In addition to
recording numbers of curculios captured each
day, we also recorded daily (from full bloom on
May 23 until June 15) the number of fruit
receiving a curculio feeding or oviposition scar
in samples of five fruit per tree per day (200
fruit per day among 40 trees).

Orchard trees received no insecticide before
bloom but were treated with phosmet on May
28 (80% petal fall) and on June 15. All traps
were removed during treatment, which was
applied by a motorized back pack sprayer to the

Fruit Notes, Volume 62 (Number 1), Fall, 1997

1 Woods J

c ,f

15ft

-N

0000©

* 0*0000

* 00000

* 00000
' 00000

* 00000

* 00000
00000

Field

Figure 1. Pyramid-trap deplo5rment in this experiment in
relation to tree location.

Table 1. Numbers of plum curculios captured by pyramids capped by boll
weevil trap tops or by boll weevil trap tops alone at different locations in
a small commercial apple orchard, May 14-June 27, 1996, Conway, MA.

Trap type

Trap location

Average number
per trap*

PjTamid
Pyramid
Pyramid
P5Tamid
Trap top alone

Apple tree trunk 6.0a

Between apple tree canopies 0.8b

Between apple trees and woods 1.1b

Between apple trees and open field 1.1b

Apple tree canopy 0.4b

'Numbers followed by a different letter are significantly different at odds
of 19:1.

Fruit Notes, Vol

ume 62 (Number 1), Winter, 1997

12 -

10 ■

■ Scars

D Captured Adults

♦ Insecticide Application

r M I

6-Jun 8-Jun

10-Ju

12-Jun 14-Jun

23-May 25-May 27-May 29-May 31 -May 2-Jun 4-Jun

Figure 2. Egg-laying scars and trap captures from May 23 through June 15, 1996.

tree canopy and trunks.
Results

Unbaited pyramid traps placed adjacent to
tree trunks captured at least five times more
curculios than unbaited pyramid traps at any
other position and 15 times more curculios than
unbaited boll weevil trap tops placed in tree
canopies (Table 1).

Capture of substantial numbers of curculios
by unbaited pjn-amid traps next to tree trunks
could entice one to believe that such captures
might be used as a basis for determining need
for and timing of insecticide sprays against
curculio. Unfortunately, this did not prove to be
the case in the Conway orchard in 1996. In fact,
there was no trap position for which there was
even a faint positive correlation between daily

trap captures and daily numbers of sampled
fruit injured by plum curculios. Indeed, the
correlation between daily captures by pyramid
traps at tree trunks and daily fruit injuries was
a negative rather than a positive one (Figure 2).
In other words, during periods when captures
were greatest, injury was least.

Conclusions

Our findings show that placing black
pyramid traps next to apple tree trunks is the
most effective position in terms of capturing the
greatest numbers of plum curculios in an apple
orchard. Results of additional studies (see
following article) indicate that the principal
reason why this position is better than any
other position stems from the strong tendency
of curculios, when crawling, to move toward

Fruit Notes, Volume 62 (Number 1), Fall, 1997

areas of greatest darkness within an orchard
(that is, toward tree trunks). Placement of
black pyramid traps next to tree trunks
capitalizes on this behavioral tendency, which
is expressed just as strongly in an understory of
vegetation as on bare ground.

Even at this most favored tree-trunk
position, however, unbaited black p5Tamid
traps fall well short of being an effective means
of monitoring the occurrence of curculio injury
to apples. Additional studies (see following
article) indicate that a principal cause for the
failure of captures by unbaited pyramid traps
on ground to be good predictors of fruit injury in
tree canopies lies in the means by which
curculios approach pjrramid traps and ap-
proach tree canopies: by crawling or by flight.
Evidence suggests that during warm weather,
curculios may enter tree canopies directly by
flight, bypassing tree trunks and pjrramid
traps. Injury to fruit is greatest during periods
of warm weather, such as occurred from June 5
through June 9 in the Conway orchard in 1996

(Figure 2). It appears that during this time
period, most curculios arrived in tree canopies
by flight and not by crawling up tree trunks (or
up pyramid traps).

What might be a solution to this
shortcoming of pyramid traps during warm
weather? One solution might be to use a
powerful attractive odor in conjunction with a
pyramid trap positioned next to a tree trunk
(see following articles). Another solution might
be to develop an effective odor-baited trap for
use in the tree canopy. We are working toward
both solutions.

Acknowledgments

This work was supported by grants from the
USDA Northeast Regional IPM Competitive
Grants Program, the USDA SARE Program,
State/Federal IPM funds, and the New
England Tree Fruit Growers Research Com-
mittee.

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Fruit Notes, Volume 62 (Number 1), Winter, 1997

How Do Plum Curculios Approach
Host Trees and Pyramid Traps?

Ronald Prokopy and Starker Wright

Department of Entomology, University of Massachusetts

The means by which plum curcuhos
approach host trees, whether by flight or by
crawhng, can provide important background
information leading toward optimization of
design and location of traps for monitoring and
possibly even controlling curculios. We report
here on several studies conducted during 1996
aimed at learning more about movement
patterns of curculios toward host trees and
pyramid traps under varying sorts of weather
conditions.

Experiments & Results

Movement Toward Host Trees. In our

first experiment in a small unmanaged orchard
of 36 semi-dwarf trees owned by Hardigg
Industries of South Deerfield, MA, we wanted
to determine whether curculios entered the tree
by flying, by crawling, or by both means, and
whether mode of entry depended on weather
conditions. We coated the trunks of 12 trees
(every third tree) with a thick 1-inch-wide band
of Tangletrap about 2 feet above ground to
prevent curculios fi-om crawling up the trunk
and into the canopy. Direct observation of
curculios attempting to cross this sticky band
indicated that they were unsuccessful in doing
so. None of the tips of branches of these or any
other trees in the orchard reached closer than 2
feet above ground, thereby precluding curculios
from crawling onto branch trips to reach the
canopy. Height of grass was maintained below
4 inches. Another set of 12 trees (every third
tree) was not treated with Tangletrap to permit
curculio arrival both by crawling and by flight.
Every evening at 8 PM from May 19 (full bloom)
to June 7, we tapped the branches of each of
these 24 trees over white cloth sheets placed on
the ground beneath the canopy and collected all

fallen curculios. We also obtained an hourly
record of temperature at a nearby location for
each day from May 19 to June 7.

Results (Table 1, experiment 1) show that
that total number of curculios collected fi^om
trees having a band of Tangletrap was nearly
equal to that of trees without a band of
Tangletrap. Results (Table 1, experiment 1)
also show there was a significant positive
correlation between daily numbers tapped from
trees having a Tangletrap band, as well as from
trees without Tangletrap, and daily high
temperature.

These results provide two valuable pieces of
information. First, a band of Tangletrap
around the tree trunk is of no apparent value in
preventing curculios from accessing host trees
and causing injury to fruit. One reason for this
lack of deterring effect may be that those
curculios which crawl up tree trunks and are
unable to pass beyond a sticky barrier
subsequently fly into the tree canopy, provided
the temperature is warm enough to permit
flight. We did, in fact, observe directly some
curculios behaving in this manner on warm
days. Second, our prediction at the outset that
numbers of curculios in tree canopies would be
equal on trees with and without a Tangletrap
band on warm days (signifying movement into
canopies largely or solely by flight) but would be
greater on trees without than with a
Tangletrap band on cool days (signifying
movement into canopies largely solely by
crawling) was not supported by the data. On
warm days, numbers were large on both types
of trees, indicating that curculios were prone to
fly into tree canopies on warm days. On cool
days, numbers were few on both types of trees,
indicating little tendency of curculios either to
fly or to crawl into trees on cool days.

Fruit Notes, Volume 62 (Number 1), Fall, 1997

Table 1. Numbers of plum curculios found in daily collections at 8PM in each of three
experiments in Hardigg's unmanaged orchard, May 19 - June 7, 1996, South Deerfield, MA.

Number of
Exp. Treatment replicates

Average
number of
curculios*

Value of
correlation

with
temperature

1 Trees with a Tangletrap band 12
Trees without a Tangletrap band 12

2 Clear Plexiglas, low position 12
Clear Plexiglas, high position 12

3 Pyramid traps with a Tangletrap band 6
P3rramid traps without a Tangletrap band 6

100a
107a

16a
14a

7b
20a

0.56
0.46

0.43
0.48

0.73
0.39

*Numbers in each experiment followed by a different letter are significantly different at
odds of 19:1.

**A perfect positive correlation between daily numbers of curculios found in each treatment
and daily high temperature would be 1.00. Each correlation value shown here (except
P5Tamid traps without Tangletrap) indicates a significant positive relation at odds of 19:1.

In our second experiment, conducted in the
same orchard, we wanted to gain more direct
information on the extent of curculio flight into
tree canopies on warm versus cool days.
Therefore, on the remaining 12 trees in the
orchard (every third tree not involved in the
first experiment), we positioned two squares of
clear Plexiglass (2 feet by 2 feet) vertically on a
pole about 2 feet to the outside of the perimeter
foliage of each tree: one square at base height of
foliage and one square at top height of foliage.
The entire surface of each square facing away
from the canopy (but not the surface facing
toward the canopy) was coated with Tangletrap
to capture curculios flying toward the canopy.
Traps were emplaced on the same dates and
examined for captured curculios at the same
time (daily at 8 PM) as in the first experiment.

Results (Table 1, experiment 2) show that
there was no significant difi'erence in numbers
of captured curculios between the low-
positioned and the high-positioned traps.
Results (Table 1, experiment 2) also show there
was a significant positive correlation between

daily numbers captured at each position and
daily high temperature. Furthermore, there
were significant positive correlations between
daily captures on high or low traps and daily
numbers of curculios tapped from canopies of
trees with or without a Tangletrap band (data
not shown).

Together, these findings constitute strong
evidence that on warm days, curculios fly
directly into tree canopies, whereas on cool days
there is much less tendency to do so.

Movement Toward Pyramid Traps. In
our first experiment, we placed an unbaited
pyramid trap midway between the trunk and
canopy edge of each of the 12 trees that received
sticky-coated squares of Plexiglas at the
Hardigg orchard. Every other pyramid trap
received a band of Tangletrap 4 inches above
the base to prevent curculios from crawling to
the top. The remaining six traps did not receive
Tangletrap. All traps were in place fi"om May
25 to June 7 and were examined daily at 8 PM
for captured curculios.

Results (Table 1, experiment 3) show that

Fruit Notes, Volume 62 (Number 1), Winter, 1997

traps with Tangletrap captured about one-
third as many curculios as traps without
Tangletrap, signifying that about two-thirds of
the curcuHos captured by traps without
Tangletrap arrived on the traps by crawling
onto them rather than by flying onto them.

As with crawling curculios that encoun-
tered a Tangletrap band at the base of a tree
trunk, crawling curculios that encountered a
Tangletrap band at the base of a pyramid trap
likewise subsequently may have taken flight,
temperature permitting. Such flight appar-
ently did not result in landing on the middle or
upper part of a pyramid trap, however. Results
(Table 1, experiment 3) also show there was a
significant positive correlation between daily
numbers captured by pyramid traps with
Tangletrap (but not traps without Tangletrap)
and daily high temperature.

In our second experiment, conducted in
association with three large unmanaged trees
near Prokopy's home in Conway, we studied in
greater depth curculio captures by unbaited
pyramid traps that received a band of
Tangletrap at the base and traps that did not.
In all, there were two traps of each type
beneath each tree, midway between the trunk
and edge of canopy. Grass beneath each tree
was maintained below 4 inches in height.
Captured curculios were counted daily at 5AM
and 10PM from June 29 to July 14.

Results (Table 2) show that across the
entire 24-hour period of a day, traps with

Tangletrap captured about one-third as many
curculios as traps without Tangletrap, corrobo-
rating results of the preceding experiment at
Hardigg. Interestingly, traps without

Tangletrap captured about twice as many
curculios from SAM to 10PM as fi-om 10PM to
SAM, whereas traps with Tangletrap captured
more than 20 times as many curculios fi*om
SAM to 10PM as from 10PM to SAM. These
results signify that about twice as many
curculios arrive on pjrramid traps during
daylight as during darkness, that about half of
those arriving on pyramid traps during
daylight do so by flying and half by crawling,
and that almost all of those arriving on pyramid
traps during darkness do so by crawling. There
may be two reasons why very few curculios fly
onto pyramid traps during darkness: first, on
most nights, temperature during darkness may
be too cool to permit flight; and second,
curculios in flight during darkness may be
unable to see pyramid traps.

In our third experiment, beneath a plum
tree at Prokopy's in Conway, we released a
group of 40 field-collected plum curculios on the
ground mid-way between the tree trunk and
edge of the canopy. We did this on 12 evenings
at 7:30 PM between June 22 and July 14 when
the temperature was about 70°F and there was
no rain falling. Four of the releases were made
north of the tree on ground covered by 4 inches
of grass, four north of the tree on bare ground
(the grass was covered with soil), and four south

Table 2. Numbers of plum curculios captured by pyramid traps beneath
unmanaged apple trees at different times of day, June 29 - July 14, 1996,
Conway, MA.

Traps

Number of
replicates

Average number captured*

SAM - 10PM 10PM - S AM

With a band of Tangletrap 6

Without a band of Tangletrap 6

4.3b
7.8a

0.2c
3.Sb

^Numbers followed by a different letter are significantly different at odds of
19:1.

Fruit Notes, Volume 62 (Number 1), Fall, 1997

of the tree on bare ground. We placed one
unbaited pyramid trap next to the tree trunk
and one at the north edge of the canopy (when
releases were north) or south edge of the canopy
(when releases were south).

Results revealed that about 20% of released
curculios were captured by the trap at the
trunk and about 4% by the trap at the edge of
the canopy, irrespective of where released.
Further results revealed that of all released
curculios, about 15% eventually flew into the
tree canopy, about 15% flew toward open space,
about 1% flew onto the tree trunk, about 2%
flew onto the trunk trap, and about 1% flew
onto the edge trap. Interestingly, about 40% of
released curculios crawled toward the tree
trunk, with no more than 4% crawling in any
other direction. This was true irrespective of
whether curculios were released north or south
of the tree trunk.

These results support results reported in a
preceding article in this issue showing that
several times more curculios were captured by
pyramid traps next to tree trunks than by
pjrramid traps more distant from tree trunks.
Results here also indicate that when evening
temperatures are moderate (somewhat condu-
cive to flight but not highly so), only a very
small proportion of curculios that does fly
alights on pyramid traps. The great majority in
flight bypasses the traps. On the other hand, a
very high proportion of crawling curculios
moves toward the tree trunk, where they
encounter and ascend either the tree trunk or
an adjacent pyramid trap.

Conclusions

Perhaps the most important general

conclusion from this array of studies is that
when temperature is high enough to permit
plum curculio flight, curculios may fly directly
into tree canopies (either from overwintering
sites or from ground beneath trees). In so
doing, it appears that most are likely to bypass
unbaited pyramid traps, irrespective of trap
location. Unbaited pyramid traps, especially
when located next to tree trunks, appear to be
very good at capturing curculios that are
crawling toward the greatest area of darkness
in the habitat (that is, toward the center of the
tree). Substantial numbers of curculios appear
to crawl toward tree trunks and adjacent
pjrramid traps when temperatures are too low
and/or the amount of light is too little to permit
flight. Hence, unbaited pyramid traps at tree
trunks may afford an accurate representation
of curculio populations in orchard trees during
periods that favor curculio arrival in trees by
crawling but not during periods that favor
curculio arrival in trees by flight. Overall, as
shown here, a band of Tangletrap around the
tree trunk is of little value in preventing
curculios from achieving substantial numbers
in tree canopies.

Acknowledgments

This work was supported by grants from the
USDA Northeast Regional IPM Competitive
Grants Program, the USDA SARE Program,
the New England Tree Fruit Growers Research
Committee, and State/Federal IPM funds. We
thank Jim Hardigg of South Deerfield, MA for
permission to work in his orchard.

*X* *X» *X* *X* *X*

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Fruit Notes, Volume 62 (Number 1), Winter, 1997

Do Natural Sources of Odor Enhance
Plum Curcullo Attraction to Traps?

Ronald Prokopy and Tracy Leskey

Department of Entomology, University of Massachusetts

In a preceding article in this issue of Fruit
Notes, we suggested that addition of a powerful
attractive odor might enhance the capturing
power of a pyramid or cone trap to an extent
that such a trap could become reliable for
monitoring the abundance of plum curculios in
commercial orchards. Here, we report on 1996
tests in which we evaluated plum curculio
males, plum curculio females, whole stored
mature apples, pieces of stored mature apples,
and fresh immature apples as potential natural
sources of attractive odor for plum curculios.
We also evaluated ammonium carbonate (an
attractant for apple maggot flies) as a potential
attractant for plum curculios.

Experiments & Results

Curculios as Odor Sources. Curculios

used as odor sources were separated by sex
shortly after emergence in summer and then
were held over winter in containers outdoors
until ready for use here. For each experiment,
they were confined in a plastic container in
groups of 20 same-sex individuals per
container. Each container was cylindrical,
about 2 inches in diameter and 3 inches tall,
covered at the top with a clear-plastic lid to
prevent entry of rainfall, and covered at the
bottom with window screen to allow odor to
emanate from the cylinder. Each cylinder,
including "check" cylinders containing no
curculios, received eight fresh-picked imma-
ture apples (about 1/2 inch diameter), removed
every other day. Traps with which these
containers were associated were examined
daily at 5 AM, at which time captured curculios
were removed. On average, 15 of the 20

Table 1.

Mean numbers of plum curculios

captured per day in traps baited

with either male, female, or no

plum curculios.

Average number

Location of

Bait

Number of

captured

Exp.

bait containers

source

replicates

per day

Base of pjTamid trap

Males

4.9a

Females

4.5a

None

6.2a

Top of pyramid trap

Males

3.8a

Females

1.9a

None

5.1a

On boll weevil

Males

0.2a

trap tops on twigs

Females

0.6a

in tree canopy

None

0.4a

*In each

I experiment, numbers followed by s

I different letter are significantly

different at odds of 19:1.

Fruit Notes, Volume 62 (Number 1), FalJ, 1997

curculios per container remained alive during
the course of an experiment.

In the first experiment, three containers of
same-sex curcuhos were attached 8 inches
above ground to the wings of pyramid traps,
one container per wing. Traps were placed mid-
way between trunks and perimeters of
unmanaged apple trees from May 23 (full
bloom) until June 12. Results (Table 1) show
that traps baited with "check" containers
devoid of curculios captured similar numbers of
curculios than traps baited with live males or
live females.

In the second experiment, one container of
curculios was affixed to an open-trap boll weevil
trap top capping a p5rramid trap in such a way
that odor could move fi"om the container of
curculios through the boll weevil trap top and
down onto the pyramid. Traps were placed
mid-way between trunks and perimeters of
unmanaged apple trees from June 13 until
June 21. Results (Table 1) show that traps
baited with "check" containers devoid of
curculios captured similar number of curculios
than traps baited with live males or females.

In the third experiment, one container of

curculios was affixed to a boll weevil trap top in
the same manner as in the second experiment.
Then, each was placed on the end of an upright
twig at mid-height in the canopy of an
unmanaged apple tree from May 23 until June
21. Results (Table 1) show that few plum
curculios were captured by any of the traps,
with no significant differences in captures
among traps baited with males, females, or
empty traps.

Apples as Odor Sources. Apples used as
odor sources were either mature Fuji apples
stored over winter under refrigeration and
washed thoroughly before use or immature
Mcintosh apples (about 2/3 inch diameter)
attached to freshly cut unsprayed branchlets.

In the first experiment, 16 whole mature
Fuji apples were distributed evenly on the
ground at the base of each pyramid trap. Traps
were placed mid-way between trunks and
perimeters of unsprayed apple trees from May
21 (early bloom) until June 1. Results (Table 2)
show no enhancement of trap captures by
additions of whole mature apples at bases of
pyramid traps.

In the second experiment, a 2-inch wedge

Table 2. Mean numbers of plum curculios captured per day
immature apples or unbaited traps.

in traps baited with mature or

Exp.

Location of bait

Bait source

Number of
replicates

Average number

captured

per day

1
2
3

Base of pyramid trap

Boll weevil trap top
capping pyramid trap

Base of pjTamid trap

Whole mature

Fuji apples

Unbaited

Wedge of mature
Fuji apple
Unbaited

Branchlets bearing

immature Mcintosh apples

Unbaited

12
12
24
24
16
16

2.0a
2.5a
1.5a
2.2a
4.3a
6.0a

*In each experiment, numbers followed by a different letter are signifi
odds of 19:1.

cantly different at

Fruit Notes, volume 62 (Number 1), Winter, 1997

cut from a mature Fuji apple was placed inside
a boll weevil trap top capping a pyramid trap in
a way that odor could move down onto the
pyramid. Wedges were renewed daily. Traps
were placed mid-way between trunks and
perimeters of unmanaged apple trees from
June 3 until June 9. Results (Table 2) show no
enhancement of trap captures by additions of
apple wedges to boll weevil trap tops capping
pyramid traps.

In the third experiment, 4 branchlets (each
with 12 Mcintosh apples) were distributed
evenly on the ground at the base of each
pyramid trap. Traps were placed mid-way
between trunks and perimeters of unmanaged
apple trees from June 15-22. Results (Table 3)
show no enhancement of trap captures by
additions of fresh-cut branchlets bearing
immature apples at bases of pyramid traps.

Ammonium Carbonate as Odor Source.
Ammonium carbonate crystals were distrib-
uted so as to cover screen bases of cylindrical
containers of the type previously described for
housing live plum curculios.

In the first experiment, three containers of
ammonium carbonate were attached 8 inches
above ground to the wings of each pyramid
trap, one container per wing. Traps were
placed adjacent to trunks of unmanaged trees
from June 22 until June 24. Results (Table 3)
show that ammonium carbonate did not
enhance trap captures.

In the second experiment, a container of
ammonium carbonate was affixed to an open-
top boll weevil trap top capping a pjTamid trap
in such a way that odor could move from the
container through the boll weevil trap top and
down onto the p3nramid. Traps were placed
adjacent trunks of unmanaged trees from June
24 until June 26. Results (Table 3) show that
ammonium carbonate had a significantly
negative effect on trap captures.

Conclusions

Disappointingly, none of the sources of odor
we evaluated led to an increase in numbers of
plum curculios captured, either by pyramid
traps placed on the ground beneath tree
canopies or boll weevil trap tops placed within
tree canopies. What might have been some
causes of this lack of positive response of
curculios to odor baits evaluated in conjunction
with traps?

In the case of male or female curculios as
bait, we were quite puzzled by results until we
carried out some additional laboratory tests.
The way in which we conducted our field tests
was consistent with the way tests of potential
odor attractancy of one sex of insect to another
is normally evaluated in the field. We fully
expected to find that odor of male or female
curculios was attractive to individuals of the
same or opposite sex. This expectation was

Table 3. Mean numbers of plum curculios captured per day in traps baited
with ammonium carbonate (AC).

Average number

Location of

Bait

Number of

captured

Exp.

bait containers

source

replicates

per day

Base of pyramid trap

1.6a

None

2.3a

Top of pjTamid trap

1.4b

None

5.0a

*In each experiment, numbers followed by a different letter are
significantly different at odds of 19:1.

Fruit Notes, Volume 62 (Number 1), FaU, 1997

heightened part-way through our field tests
when a pubhcation appeared by chemists in
Ilhnois detaihng the chemical structure of a
pheromone (grandisoic acid) produced by male
plum curculios that is equally attractive to both
females and males, even when used in small
amounts. This was indeed exciting news. Our
follow-up laboratory tests showed, however,
that when curculios are confined to small areas
(such as the containers we used for curculios as
odor sources), they emit stress sounds and/or
odors alerting other curculios. These sounds or
odors apparently mask or outweigh the luring
power of attractive pheromone. This suggests
that the most rewarding way to evaluate
pheromonal odor in conjunction with traps in
the field would be to use synthetic pheromone
rather than a natural source of pheromonal
odor.

In the case of apple odor as bait, it appears

that if natural sources of odor are used in the
amounts evaluated here, either such an
amount is insufficient to compete with fruit
odor sources on adjacent trees, or natural
sources of apple odor lose attractiveness (odor
composition changes) rapidly after employ-
ment. As with synthetic sex pheromones,
sjrnthetic apple odor hopefully will become an
effective alternative to natural sources of apple
odor for attracting plum curculios to traps (see
following article).

Acknowledgments

This work was supported by grants from the
USDA Northeast Regional IPM Competitive
Grants Program, State/Federal IPM funds, the
USDA SAKE Program, and the New England
Tree Fruit Growers Research Committee.

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Fruit Notes, Volume 62 (Number 1), Winter, 1997

Petal Fall is the Most Attractive
Development Stage of Mcintosh
Apple Trees to Plum Curculio Adults

Tracy LeskeyS Michele Bakis^ Holly Gagne^ Larry Phelan^,

and Ronald Prokopy^

^Department of Entomology^ University of Massachusetts

^Ohio Agricultural Research & Development Center, Ohio State

University

In the 1996 winter issue oi Fruit Notes, we
reported the results of laboratory assays
conducted in 1995 aimed in part at examining
plum curculio responses to odors emitted from
Mcintosh apple trees. We obtained some
evidence indicating that attractive volatiles
were emitted from all parts of Mcintosh trees
(not just fruit) and were emitted in the most
attractive form at petal fall. Here, we report on
1996 laboratory bioassays of curculio responses
to extracts of Mcintosh twigs, leaves, and fruit
at eight different tree- developmental stages,
using different solvents.

Materials & Methods

Hexane and water extracts were made from
twigs, leaves, or fruit of Mcintosh at each of the
following stages of development: pink, bloom,
petal fall, and 2, 3, 4, 5, and 6 weeks after
bloom.

Curculios used in bioassays were collected
from unsprayed wild plum and apple trees and
sexed in the laboratory. For all tests, curculios
were starved for 24 hours prior to testing. Tests
were conducted at the beginning of darkness.
One curculio was placed into each petri dish
bioassay chamber and allowed to move toward
odors emitted from a hexane or water extract of
Mcintosh tissue (the treatment) or toward
hexane or water alone (used as a control).
Hexane was allowed to evaporate before testing
and curculios were given 2 hours to respond.

To measure the power of a Mcintosh odor
extract to stimulate curculio response, we used
a response index. The response index was
calculated by subtracting the number of
curculios responding to the control from the
number responding to the treatment, dividing
this amount by the total number of curculios
tested, and multiplying by 100. The greater the
value of the index, the more attractive was the
Mcintosh odor extract. We consider an index of
25 to be the minimum for suggesting
attractiveness.

Results

Hexane extracts of Mcintosh twigs, leaves,
or fruit at petal fall were more attractive than
hexane extracts made at any other develop-
mental stage (Figure 1). Hexane extracts of
fruit at petal fall (index = 43) were similarly
attractive to extracts of twigs or leaves at petal
fall (index = 40 for each). These response indices
are nearly identical to those recorded in 1995
for curculio responses to hexane extracts of
Mcintosh fruit, twigs, and leaves at petal fall.
Finally, both males and females responded
equally well to extracts made with hexane.

Water extracts of Mcintosh twigs, leaves, or
fruit at pink, petal fall, and two weeks after
bloom were the most attractive developmental
stages (Figure 2). At petal fall, extracts of
Mcintosh fruit (index = 71) were slightly more
attractive than extracts of Mcintosh twigs

Fruit Notes, Volume 62 (Number 1), Fall, 1997

Bloom

5 Wks

6 Wks

Figure 1. Response Indices for plum curculio adults during 2 hours of exposure to
hexane extracts of twigs (diamonds), leaves (squares), or fruit (triangles) from
Mcintosh trees at pink, bloom, petal fall, or 2, 3, 4, 5, or 6 weeks after bloom. If the
difference between two means of any stage exceeds 16 (based on a sample size of
12), then the means are significantly different at odds of 19 to 1.

(index = 58), whereas extracts of Mcintosh
leaves were marginally attractive (index = 25),
most likely because the waxy layer on leaf
surfaces prevented water from extracting
volatile components. Again, both males and
females responded equally well to extracts
made with water.

Conclusions

From these results and from what we
observed in 1995, we conclude that petal fall is
the most attractive developmental stage of
Mcintosh trees to plum curculio adults.
Further, we believe that all Mcintosh plant
tissues (twigs, leaves, and fruit) contain the
attractive odor components at this time. These
results further strengthen our hope that
synthetic equivalents of these attractive
Mcintosh plant odors can be identified and

synthesized, providing tools to enhance trap
effectiveness for monitoring and possibly even
controlling plum curculios. Further, were
believe that if synthetic host odors can be used
in conjunction with synthetic male-produced
pheromone identified in 1996 by Eller and
Bartlett of Illinois, the curculio-capturing
power of traps will be enhanced further. Our
next step will be to examine curculio responses
to host-plant odors used in combination with
male-produced pheromone.

Acknowledgments

Fruit Notes, volume 62 (Number 1), Winter, 1997

Wks

Figure 2. Response Indices for plum curculio adults during 2 hours of exposure
to water extracts of twigs (diamonds), leaves (squares), or fruit (triangles) from
Mcintosh trees at pink, bloom, petal fall, or 2, 3, 4, 5, or 6 weeks after bloom. If
the difference between two means of any stage exceeds 20 (based on a sample
size of 12), then the means are significantly different at odds of 19 to 1.

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Fruit Notes, Volume 62 (Number 1), FaU, 1997

Jim Anderson Dies

James F. Anderson, Emeritus Associate
Professor of Pomology, passed away on
February 8, 1997. Professor Anderson was
born in Morgantown, West Virginia, and
received his B.S. and M.S. degrees from the
University of West Virginia. He served in the
miUtary during World War II and participated
in the Battle of the Bulge.

Jim joined the faculty of the Pomology
Department of Massachusetts Agricultural
College in 1948 and retired from the
Department of Plant & Soil Sciences of the
University of Massachusetts in 1988. For
many years Jim was involved in evaluation of
new fruit cultivars, and he was expert at
identifying fruit cultivars by their vegetative
characteristics. However, his primary respon-
sibility during these years was teaching, and he
was honored by selection for a number of
Outstanding Teacher Awards by the Stockbridge
School students.

In an^ interview at the time of his
retirement, Jim said, 'Tou can't really learn

about trees from books. You have to get out
there with the trees." Many alums will
remember their orchard pruning experiences
with Jim in the dead of winter, because that is
when the pruning is done. "But the students
were all good about it; they never ambushed
me," Jim said. "They'd know that I'd be out
there in the cold with them."

Jim leaves his wife, Edna (18 Wildwood
Lane, Amherst, MA 01002). He also leaves his
former colleagues, who are saddened by the loss
of a true gentleman and friend, and by
generations of alums who learned much more
from him than was written in books.

In memory of Professor Anderson's love of
teaching, a memorial scholarship fund for
students in Plant & Soil Sciences is being
established. Anyone wishing to assist in this
memorial to Jim may send a contribution to the
Plant & Soil Sciences Scholarship Fund, c/o
William J. Bramlage, French Hall, University
of Massachusetts, Amherst, MA 01003.

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Fruit Notes, Volume 62 (Number 1), Winter, 1997

Peach Cultivar Trials:
Observations and Comments

Karen I. Hauschild

Department of Plant & Soil Sciences, University of Massachusetts

In the Fall 1995 issue of Fruit Notes, I
described and commented on the first plantings
of peaches and nectarines in my cultivar trial at
the University of Massachusetts Horticultural
Research Center in Belchertown. Since
another full growing season has passed, it
seems appropriate to add to the information
presented previously.

Additionally, in the spring of 1996, 1 added
three yellow-fleshed peaches, replaced three
yellow-fleshed peaches ft-om the 1993 trial,
added one white peach and replaced another,
and added three white-fleshed nectarines. The
peach cultivar trial now includes 20 yellow-
fleshed peaches, 7 white-fleshed peaches, 6
yellow-fleshed nectarines, and 3 white-fleshed
nectarines.

All cultivars planted prior to 1996 fruited in
1996. Following is updated information on the
cultivars that were planted in 1990, as well as
initial observations of fruit from the 1993 and
1994 plantings. I also will describe the
cultivars that were planted in 1996.

1990 Planting

Yellow- fleshed Peaches

Jerseydawn was very popular at the
Horticultural Research Center in 1996. For an
early fruit, the flavor in 1996 was excellent, size
was good, and split pits occurred in only about
20% of the crop.

Redhaven. Size was not impressive this year,
nor was flavor. There are several other
cultivars in this harvest window that have
better size and fruit quality than Redhaven.

Salem fruit were very good to excellent in 1996.
The flavor was excellent, size was good, and the
fruit was very attractive.

Flavorcrest fruit were very flavorful and had
high quality in 1996.

New Haven. Although fruit size in 1996 was
some-what smaller than ideal, fruit quality was
excellent. New Haven is a much better peach
than Redhaven.

Madison was an excellent peach. It had great
peach flavor, was good size, and was attractive.

Harrow Beauty was one of my favorites in
1996. The fruit had good size and great peach
flavor.

Jim Dandee fruit size was not as impressive in
1996 as it was in 1995, but the flavor of this
peach was very good.

Harcrest fruit were flavorful, had good size,
and had very impressive quality in 1996.

Fayette flavor was disappointing in 1996;
however, it was a good late season cultivar.

Encore may be too late for most growers,
especially those who harvest large acreages of
Mcintosh apples. It was a good peach for the
late season.

White-fleshed Peaches

Summer Pearl fruit were not as flavorful in
1996 as in previous years. Quality was good,
and size was good. Fruit do not hold up well
after harvest.

Nectarines

Earliscarlet fruit sized well and had excellent
flavor.

Fantasia sized well and had excellent flavor
and color but ripened in mid-September, a
problem for some growers.
Summer Beaut was an excellent nectarine.
Size was good, fruits were flavorful, and color

Fruit Notes, Volume 62 (Number 1), FaU, 1997

was good where trees were open.

1993 Planting

Yellow-fleshed Peaches

John Boy was a very large, flavorful peach. It
was attractive, but did not have the best
quality. Fruit were harvested a little late,
which may have influenced quality.

Sentry appeared to be a good peach, but
further evaluations are required.

White-fleshed Peaches

Lady Nancy fruit were of good size and quality
and very attractive.

Red Rose fruit were medium in size and had
good quality.

1994 Planting

White-fleshed Peaches

White Lady trees bore a few fruit in 1996, but
will reserve comment until next year.

Sugar Lady trees also bore fruit for the first
time in 1996. Fruit were good size and had
reason-able quality.

Nectarines

Easternglo produced a few fruit in 1996. Color
was excellent, but flavor was not great.

Sunglo produced few fruit in 1996. Fruit had
good size, good color, and good flavor.

1996 Planting

Descriptions below are based on catolog or
on evaluations from other areas of the country.

Yellow-fleshed Peaches

PF-1 fruit ripen 20 days before Redhaven, are

partial clingstone, and have very few split pits.
Trees are hardy. Color is 90% red over yellow.

PF-15A fruit ripen 13 days after Redhaven, are
large, red over yellow, and freestone. Trees
produce heavily and are hardy.

PF-17A fruit ripen 17 days after Redhaven, are
large, firm, and 70% red. Fruit are reported to
be excellent for shipping. Trees are hardy.

White-fleshed Peaches

Raritan Rose fruit ripen 4 days after
Redhaven, are firm, attractive, and freestone,
with good quality. Trees are vigorous, hardy,
and productive.

White-fleshed Nectarines

Arctic Glo fi"uit ripen 10 days before
Redhaven, are medium-large, very firm, highly
colored, and reported to ship well. Trees are
vigorous and productive.

Arctic Rose fi"uit ripen 7 days after Redhaven,
are medium size, firm, very sweet, and highly
colored.

Arctic Queen fi'uit ripen 29 days after
Redhaven, are large, firm, sweet, and highly
colored.

In 1997, I will conduct a more extensive
evaluation of all the cultivars in this trial. I will
evaluate fi"uit for size, color, taste, abnormali-
ties (such as split pits), and texture. Tree vigor
and productivity and disease resistance also
will be evaluated. Also less favorable cultivars
will be removed and possibly replaced with
additional early cultivars.

At this time, I recommend that Massachu-
setts growers plant on a trial basis the following
yellow-fleshed peach cultivars: Jerseydawn,
Salem, Flavorcrest, New Haven, Madison,
Harrow Beauty, Jim Dandee, and Harcrest.
For a white-fleshed peach, Summer Pearl
should be tried. Earliscarlet, Summer Beaut,
and Fantasia are nectarines worthy of trial.

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Fruit Notes, Volume 62 (Number 1), Winter, 1997

Agri-Mek: A 1996 Field Trial in
a Commercial Apple Orchard

Glenn Morin and Roberta Spitko

New England Fruit Consultants, Montague, Massachusetts

The 1996 growing season witnessed the
introduction of a new pest-management tool
with the federal registration of Agri-Mek
(Merck and Co.) for managing both leafminer
and mite in apples and pear psylla in pears.
Following the withdrawal of Omite from the
marketplace in April, most apple producers
were pleased to have another option for
European red mite (ERM) control. However,
Agri-Mek's late-spring registration combined
with the absence of experimental work
conducted in New England left most field
consultants and growers with limited informa-
tion on how this product would be utilized best
in the rapidly approaching season.

The active ingredient in Agri-Mek,
abamectin, is a naturally derived substance
produced by a soil microorganism and is
effective at extremely low rates. Agri-Mek is
not related to other currently registered
materials and therefore should prove useful in
managing tolerant pest populations and
prolonging the effective life of presently
available compounds when used
in a rotational program.
Abamectin is absorbed into the
leaf tissue where it forms a
reservoir of active ingredient
against foliar feeding pests. As
a result, Agri-Mek is currently
recommended within six weeks
after petal fall and in combina-
tion with horticultural oil in
order to maximize absorption.
Affected individuals essentially
are paralyzed, stop feeding, and
die within a few days.

Optimal timing is critical to
the cost-effective use of this
material. Ideally, one would

expect a single application to provide season-
long suppression of ERM and leafminer
populations. The focus of our trial was
European red mite, as this pest would likely be
the primary target for most Northeast growers
considering the use of this material. The two
most vulnerable periods for ERM within the
recommended application time frame are 1)
petal fall, when the majority of overwintering
egg hatch has been completed and 2) first-
generation egg hatch approximately 3-4 weeks
later. ERM populations are fairly synchronous
at these two times and are more easily
disrupted than when multiple life stages are
present. The following study was conducted to
determine which of these two application
timings would prove more effective in
managing ERM populations.

Procedure

Treatments were applied to adjacent, non-
replicated plots in a commercial apple orchard

Table 1. Materials, rates and application dates for
Agri-Mek trial, 1996. Materials were delivered in 150
gal /acre of water. All plots received 3 gal/acre oil on
April 24. Check plot was treated July 7 with 18 oz/acre
Carzol SP, July 25 with 5 lbs/acre Omite 30W, and
August 9 with 3 pts /acre Vydate.

Trt. Material + rate (product/acre)

Timing

1
2
3

Savey @ 3 oz

Agri-mek @ lOoz + oil @ 1 gal

Agri-mek @ 10 oz + oil @ 1 gal

Check

May 9
May 23
June 17

Fruit Notes, Volume 62 (Number 1), FaU, 1997

owned and operated by Marshall Farms Inc.,
Fitchburg, MA. Each 1.5-acre plot consisted of
three rows of primarily Mcintosh trees
approximately 12 feet high, planted on 16 x 24
foot spacing with a dilute tree row volume of
280 gallons per acre. Treatments were made
with a Hardie airblast sprayer calibrated to
deliver 150 gal per acre while operating at 2.5
miles per hour according to the treatment
schedule outlined in Table 1.

European red mite populations were
evaluated by selecting randomly 15 leaves per
tree from each of 4 trees per treatment.
Composite samples then were brushed unto
glass plates and populations estimated using
standard leaf-brushing protocol.

Results & Discussion

There were no substantial differences
between treatments with respect to European
red mite control in this study. Both Agri-Mek
timings as well as the prebloom Savey
application, included for comparison, were
successful in suppressing ERM populations
below injurious levels through the last week of
August. Estimated mite populations in these

plots ranged from 2.0 - 7.2 per/leaf on August
28 (Figure 1) with little or no foliar damage
evident. ERM populations in the check plot,
which received only a prebloom oil treatment,
built rapidly after first-generation egg hatch
and exceeded 15.0 mites per/leaf by early July.
Moderate foliar damage was noted at this time
and rescue treatments of miticide were applied
July 7 and July 25 to prevent excessive
damage. A third treatment was made on
August 9 to suppress late-season build up.

It is interesting to note that, although both
treatments were successful in suppressing
ERM populations below injurious levels, trees
receiving the later Agri-Mek treatment applied
on June 17 had more motile forms consistently
throughout the growing season. Pre-treatment
counts on June 14 revealed approximately 4.0
mites per/leaf, and although our application
was successful in reducing that population,
there were still significant numbers of motile
forms on July 3 when one would expect to see
full expression of the treatment. In contrast,
the petal-fall treatment applied May 23
suppressed ERM numbers to barely detectable
levels until early August and final counts on
August 28 were less than 50% of the later

16-,
14 ■

-•— Agri-Mek + oil 5/23

1 12.

«, 10-

I 8-

f «

3
C

2 -

1
i

—*— Agri-Mek + oil 6/17

5-Jun 14-Jun 19-Jun 3-Jul

7-Aug 28-Aug

Figure 1. Effect of various miticide treatments

on European red mite

populations.

Fruit Notes, Volume 62 (Number 1), Winter, 1997

treatment.

It is unclear why this later treatment did
not perform as well as the petal-fall treatment.
The increased amount of foliage present in mid
June may have adversely affected spray
penetration and allowed for greater survival of
mites in the inner tree canopy. Perhaps
hardening off of the leaf tissue was a factor.
This event may have decreased absorption of
active ingredient to the extent that nymphs
hatching several days post-application were
not well controlled.

Conclusion

It appears from the data presented here
that either a petal-fall application of Agri-Mek
or an application timed to coincide with first-
generation egg hatch can, under favorable

conditions, provide satisfactory season long
suppression of European red mite similar to
that provided by a prebloom application of
Savey.

The treatment directed at first-generation
egg hatch was less effective possibly due to
decreased spray coverage or decreased absorp-
tion of Agri-Mek into the leaf tissue. This
difference was of little consequence in this trial,
as summer weather conditions were relatively
cool with ample rainfall and season-long
suppression was ultimately achieved. How-
ever, had weather conditions been more
conducive to rapid mite build up, additional
summer miticides may have been necessary to
manage the residual population left by the later
treatment.

Based on these data, we suggest the petal-
fall application as the more desirable of the two
options presented here.

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Fruit Notes, Volume 62 (Number 1), FaU, 1997

Fruit Notes

University of Massachusetts

Department of Plant & Soil Sciences

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Amherst, MA 01003

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354

F68

'ruit Notes

I by the Department of Plant & Soil Sciences,
wividss, t^xtension, U. S. Department of Agriculture, and Massachusetts Counties Cooperating.

Eklitors: Wesley R. Autio and William J. Bramlage

CD
O

o
o

Voaime 62, N&nber 2
SPR^G ISSUE, 1997

Table of Contents

Improved Pesticide-treated Wooden Spheres
for Controlling Apple Maggot Flies

Comparative Level of Establishment of Released

Typhlodromus pyri Predatory Mites in First-level

and Second-level IPM Apple Orchard Blocks

New England-wide Demonstration of an Integrated

Pest Management (IPM) System for Apples and Consumer

Education in IPM as a Pollution-prevention Strategy

An Update on the 1994 NC-140 Apple Rootstock Trial

An Update on the 1994 NC-140 Peach Rootstock Trial

The Hay, Grain, and Feed Man:
G. O. Bunnell, Northfield, Massachusetts

Fruit Notes

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Fruit Notes, Volume 62 (Number 2), Spring, 1 997 1

Send this form and your check by September 30, 1997.
Make check payable to: UNIVERSITY OF MASSACHUSETTS.

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Fruit Notes, volume 62 (Number 2), Spring, 1997

Improved Pesticide-treated Wooden
Splieres for Controlling Apple
Maggot Files

Xing Ping Hu, Andrew Kaknes, and Ronald Prokopy
Department of Entomology, University of Massachusetts

In recent years, we have been working
toward development of pesticide-treated spheres
as a substitute for sticky spheres in controUing
apple maggot flies. In the Spring 1996 issue of
Fruit Notes, we reported on progress made
through 1995 on development of pesticide-
treated wooden spheres. Here, we assessed
residual effectiveness against apple maggot
flies of the best-performing version of pesticide-
treated wooden spheres developed through
1995 versus a new tjrpe developed in 1996. We
also evaluated the performance of each of these
sphere types in controlling apple maggot flies in
a small commercial orchard.

Materials and Methods

The 1995-version spheres consisted of three
layers of materials: first layer = 76% sugar, 4%
wheat flour, and 20% Glidden gloss red paint;
second layer = 1% Digon 4E (=0.5% dimethoate),
and 99% Glidden gloss red paint, third layer =
shellac. The layer of shellac was intended to
reduce the loss of fly feeding stimulant (sucrose)
from the sphere surface during rainfall. To a
significant degree, this loss was prevented.
However, following rainfall or a series of heavy
dews, spheres coated with shellac sometimes
turned whitish in color, rendering them less
visually attractive to apple maggot flies than
completely red spheres.

The 1996-version spheres featured a new
approach to extending the residual activity of
sucrose. Rather than rely on application of
shellac (or several other applied substances
that we evaluated prior to 1995) to extend the
residual activity of sucrose, we instead drilled

14 evenly spaced holes (1/4 inch diameter x V2
inch deep) into each sphere and filled each hole
with a mixture of 94% sucrose, 6% flour. This
was followed by application of 2 layers of paint
(same composition as first 2 layers of paint
applied to 1995 - version spheres).

To assess toxicity of spheres to apple
maggot flies, in early July of 1995, twelve 1995-
version spheres were hung fi-om branches of
apple trees near Prokopy's small commercial
orchard in Conway. Every other week
thereafter until apple harvest, two spheres
were brought to the laboratory for assays. In
early July of 1996, the same procedure was
followed for 1996-version spheres. For assays,
thirty flies were allowed to stay and feed on
each sphere for up to five minutes, follovdng
which, flies were placed in cages and examined
for mortality 24 hours later. Rainfall was
measured by a rain gauge placed near trees.

Comparison of pesticide-treated spheres
with sticky spheres for providing direct control
of apple maggot flies was made in the Prokopy
orchard, which consisted of 50 trees (10 rows x
5 trees per row, primarily Liberty/M.26). In
1995, each tree in the five eastern rows received
two 1995-version pesticide-treated spheres,
whereas each tree in the five western rows
received two sticky (Tangletrap-coated) spheres.
In 1996, the arrangement was reversed, with
each tree in the five eastern rows receiving two
sticky spheres and each tree in the five western
rows receiving two 1996-version pesticide-
treated spheres. Spheres were deployed in July
each year, were unbaited, and were positioned
optimally for attracting apple maggot flies. At
harvest, every tenth picked apple was

Fruit Notes, Volume 62 (Number 2), Spring, 1997

Table 1. Residual effectiveness of dimethoate-treated red spheres (before treatment) against
laboratory-tested apple maggot flies.

Spheres*

Weeks of sphere

exposure

Retreated
in orchard with

10 12 sucrose

1995 Version Fly mortality (%)

Cumulative rainfall (in.)

1996 Version Fly mortahty (%)

Cumulative rainfall (in.)

90
0.4

95
1.6

80
2.0

90
2.0

60
4.3

85
2.4

40
5.1

80
3.2

30 -- 70
5.7

70 55 75
7.2 10.2

*Spheres in 1995 received two coatings of paint and a third coating of shellac. Spheres in 1996
were drilled with 14 holes subsequently filled with a sucrose/flour mixture and received two
coatings of paint.

examined carefully for
maggot egglaying stings.

Results

presence of apple

Results of laboratory assays of residual
efifectiveness of pesticide-treated spheres against
flies (Table 1) show that after four weeks of
exposure and two inches of rainfall, 80% of flies
placed on 1995-version spheres died compared
with 90% that died when placed on 1996-
version spheres. In 1995, after ten weeks of
exposure (5.7 inches of rain), 1995-version
spheres killed only 30% of tested flies. In 1996,

after ten weeks of exposure (7.2 inches of rain),
1996-version spheres killed 70% of tested flies.
In fact, for every period when assayed, 1996-
version spheres outperformed 1995-version
spheres (Table 1). Retreating spheres with 16%
sucrose solution (in water) after twelve weeks
of exposure restored effectiveness of 1995
spheres to a level of 70% fly kill, demonstrating
that loss of sucrose as feeding stimulant and
not loss of dimethoate as toxicant was the
principal factor responsible for decreasing
performance.

Results of tests assessing the capability of
pesticide-treated spheres for providing direct

Table 2. Effectiveness of dimethoate-treated red spheres versus sticky-coated
red spheres in providing control of apple maggot flies in a small commercial
orchard.

Year

Treatment

Number of
fruit examined

Fruit with fly
egglaying stings (%)

1995
1996

Spheres - 1995 version
Sticky spheres

Spheres - 1996 version
Sticky spheres

1263
1294

896
913

1.0
0.9

0.6
0.7

Fruit Notes, volume 62 (Number 2), Spring, 1997

within-orchard control of flies (Table 2) show
that 1995-version spheres as well as 1996-
version spheres provided a level of control
essentially identical to that provided by sticky
spheres (1.0% fruit injury or less). In contrast,
96 and 97% of fruit on unmanaged apple trees
and about 250 yards away was injured by apple
maggot flies in 1995 and 1996, respectively. In
1995, pesticide-treated spheres were dipped in
a 16% sucrose solution weekly after the fifth
week of exposure to renew feeding stimulant.
In 1996, no such dipping was performed.

Conclusions

Our findings show that 1996-version
pesticide-treated spheres (each with 14 sugar-
filled holes) maintained high season-long
residual activity against apple maggot flies and

provided excellent control of this pest under
commercial orchard conditions. They have a
distinct advantage over earlier versions of
pesticide-treated spheres in requiring no re-
treatment with sucrose solution during the
growing season. Their major shortcoming is
the need to drill holes in each sphere and then to
fill each hole with sucrose/flour mixture
annually before painting. In the coming year,
we plan to determine the optimum number and
size of holes needed to attain season-long
sphere effectiveness and to determine if one
rather than two coats of paint will suffice.

Acknowledgments

This work was supported by a grant from
the USDA Northeast Regional IPM Competi-
tive grant and Hatch funds.

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Fruit Notes, Volume 62 (Number 2), Spring, 1997

Comparative Level of Establishment
of Released Typhlodromus pyri
Predatory Mites in First-level and
Second-level IPM Apple Orchard Blocks

Ronald Prokopy, Starker Wright, and Jennifer Mason
Department of Entomology, University of Massachusetts

Jan Nyrop, Karen Wentworth, and Carol Herring

Cornell University, NY Agricultural Experiment Station, Geneva

As described in the Spring 1994 issue of
Fruit Notes, Amblyseius fallacis is the most
commonly occurring predatory mite in Massa-
chusetts apple orchards. Unlike orchards in
many other states, few Massachusetts apple
orchards harbor detectable levels of
Typhlodromus pyri predatory mites. Previous
studies in Massachusetts have shown that A.
fallacis rarely builds to levels capable of
providing effective control of European red
mites until mid-July at the eairliest, and often
not until August. In contrast, studies in New
York have shown that T. pyri, where
established, can provide effective biocontrol of
European red mites beginning as early as May.

In 1995, we released T. pyri into two first-
level IPM and two second-level IPM block of
apple trees in each of six commercial apple
orchards in Massachusetts. Here, we report on
the abundance of T. pyri in samples taken in
September of 1995 and 1996 in each of these
blocks as well as in adjacent first- and second-
level IPM blocks where no T. pyri were
released.

Materials & Methods

All six orchards were located in west-central
or east-central Massachusetts. Each block was
comprised of about 60 trees of the cultivars

Mcintosh, Empire, or Cortland (on M.7 or M.26
rootstock). First-level IPM blocks received
pesticide sprays applied by growers timed
according to pest and weather-monitoring
activities that the growers themselves carried
out. Second-level IPM blocks were treated
identically to first-level blocks through early
June. Thereaft;er, no pesticide of any type was
applied to second-level blocks. Instead, a
combination of behavioral, cultural, and
biological control techniques was used.

In 1995, blossom clusters harboring T. pyri
were picked fi-om an orchard at the New York
State Agricultural Experiment Station at
Geneva, transported in a cooler by automobile
to Massachusetts on the same day when picked,
and placed the following day in targeted blocks.
This involved using twist-ties to attach 50
blossom clusters to the central tree of each
target block.

In September of 1995 and 1996, 25 leaves
were picked at random from the central tree
(that is, the release tree) in each block receiving
T. pyri and 25 leaves fi-om each of four trees
nearest the central tree. A similar protocol was
followed for sampling central and adjacent
trees in first- and second-level blocks not
receiving released T. pyri. Sample leaves were
cooled and shipped to Geneva, New York for
identification and counting of predatory mites.

Fruit Notes, volume 62 (Number 2), Spring, 1997

Table 1. Abundance of mite predators on leaves sampled in September from first-level and
second-level IPM blocks in which T. pyri were or were not released in May of 1995.

Species

Year

Average number of predators per leaf*

First-level IPM

Second-level IPM

Non-release
block

Release
block

Non-release
block

Release
block

T.pyri

A. fallacis

1995
1996

0.00 b

0.02 b

0.15 a
0.28 a

0.04 ab
0.19 ab

0.14 a
0.11a

0.00 b
0.01b

0.11a
0.13 a

0.07 a
0.42 a

0.19 a
0.18 a

*Values in

each row

followe

d by the same letter are

not significantly different at odds of 19 to 1.

Results

For T. pyri, the results (Table 1) show that
for the 1995 samples, small but detectable
numbers of this species were found in the
release blocks, but none were found in the non-
release blocks. For the 1996 samples, numbers
cf T. pyri in the release blocks averaged
considerably greater than they did in these
same blocks in 1995, suggesting that a buildup
of T. pyri had occurred. Almost no T. pyri were
detected in 1996 samples taken in the non-
release blocks. Interestingly, when data for
1995 and 1996 release blocks were pooled,
analysis indicated a significantly greater
average number of T. pyri in second-level than
in first-level IPM blocks.

For A. fallacis, the results (Table 1) show
quite similar numbers of predators of this
species present in each t3rpe of block each year.
When data for 1995 and 1996 were pooled,
analysis indicated no significant difference in
average number of A. fallacis between second-
level and first-level IPM blocks.

Examination of grower spray schedules
revealed that no insecticides other than
Guthion, Imidan, Lorsban, or Sevin (as a
thinner) and no acaricides other than oil.

Omite, Apollo or Savey were applied to any
blocks during either year. None of these
materials is known to be harmful to T. pyri. We
believe that the significant negative effect of
first-level compared with second-level IPM
practices on the buildup of T. pyri was due to
fungicide use from early June onward in the
first-level blocks. Fungicides used after early
June included Penncozeb, Dithane, Ziram,
Polyram, Benlate, Topsin, and Captan. The
first four of these materials are known to have
detrimental effects on T. pyri.

Conclusions

Our findings indicate that by the end of the
growing season of the year following their
release, T. pyri mite predators appeared in
readily detectable numbers in nearly all blocks
in which they were released. The only
exception occurred in one of the six orchards,
where they were detected in neither of the
release blocks. This orchard received 2
applications of Dithane annually in May, which
might have impacted establishment of T. pyri
negatively. It appears from our results that
pesticides, particularly certain fungicides, have

Frait Notes, Volume 62 (Number 2), Spring, 1997

a greater negative impact on buildup of T. pyri Acknowledgments

than on buildup of A. fallacis. We suggest,

therefore, that growers who are considering

releasing T. pyri to attain establishment do so

only in blocks that will not be treated with

pesticides that may be harsh on T. pyri,

including pyrethroid insecticides, acaricides

such as Carzol, and fungicides such as Ziram or

EBDC-based materials.

This work was supported by a USDA
Northeast Regional IPM Competitive Grant
and by State/Federal IPM funds.

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Fruit Notes, volume 62 (Number 2), Spring, 1997

New England-wide Demonstration of
an Integrated Pest Management (IPM)
System for Apples and Consumer
Education in IPM as a
Pollution-prevention Strategy

WilUam M. Coli and Craig S. HoUingworth
University of Massachusetts

James F. Dill
University of Maine

Alan T. Eaton

University of New Hampshire

Heather Faubert
University of Rhode Island

Lorraine M. Los
University of Connecticut

The strategies known collectively as IPM
have been recognized as one way to reduce the
amount of agricultural chemicals released into
the environment. IPM has been shown to
address the needs of New England agriculture,
and pollution prevention, by reducing and
optimizing pesticide use.

Many New England growers have been in
the forefront of widespread early adoption of
these new technologies, partly as a conse-
quence of aggressive, regional Cooperative
Extension outreach programs. In Massachu-
setts, for example, approximately 40% of the
state's cranberry and apple acreage, and about
20% and 9% of strawberry and sweet com
acreage, respectively, receive some form of IPM
monitoring and advice from private-sector

scouts or consultants, and still larger acreages
are managed under IPM by the growers
themselves. Such widespread grower adoption
of IPM has set the standard for environmen-
tally responsible agriculture.

However, although consumers typically
express concern about perceived public-health
and food-safety risks associated with
agrichemical use, a very small percentage of
the general public has even heard of IPM, and
still fewer recognize its potential benefits and
the extent of its use. More widespread
demonstration and consumer education of the
environmental benefits of IPM are likely to
enhance positive consumer attitudes towards
local agriculture.

In spite of the potential benefits to

Fnilt Notes, Volume 62 (Number 2), Spring, 1997

agriculture of increased adoption and consumer
awareness, successful IPM strategies demon-
strated in one state have not always been
adopted regionally. This is partly due to a
tendency of growers to emphasize uncertainty
associated with farm-to-farm or state-to-state
differences in pest complexes, weather, normal
cultural practices, intended markets, etc. Since
IPM adoption has not been universal, there
remains a need for regionally-consistent
systems to evaluate progress toward the
Federal-policy goal of IPM implementation on
75% of managed acres by the year 2000.

One possible way to measure extent of
grower IPM adoption is by use of commodity-
specific IPM definitions, known as IPM
Guidelines, originally developed in Massachu-
setts. These guidelines, in the form of
checklists and a related point system, have
been used since 1990 as the basis for successful
implementation of the state Farm Services
Agency (formerly ASCS) cost-sharing program
in Integrated Crop Management (ICM) and a
related state-endorsed consumer education and
marketing effort known as Partners With
Nature.

With this background in mind, in 1994, a
small group of New England Extension and
research specialists successfully acquired a
Region I USEPA Pollution Prevention Incen-
tives to the States (PPIS) grant which sought to
address some of the issues identified above.

The principal goals of the project, for which
the University of Massachusetts served as lead
unit, were: to develop consistent, well-defined,
and quantifiable apple IPM guidelines for each
New England state; to test state IPM
guidelines as a pollution prevention methodol-
ogy at the state and regional level; and to
educate the media and the general public about
IPM and its benefits.

Our specific objectives were: to involve
University research and extension staff,
growers, and private-sector IPM professionals
in the design of apple IPM Guidelines for each
of the New England states; to demonstrate the
resultant state guidelines on one 5-to-lO-acre
block in each state, and compare results to a
similar sized check block managed with a

calendar-based spray program without pest
monitoring; to calculate and compare the
Environmental Impact Quotient (Kovach et al.,
1992) for each block, as a measure of pollution
prevention; and, to hold a field day in each state
on the farm of the demonstrating grower to
which the press and general public are invited.

To the best of our knowledge, until this
project, no successful attempt had been made
within Region I to develop consistent IPM
guidelines for several states in a region, to carry
out an extensive and regionally-coordinated
IPM demonstration for any crop, nor to use the
results to educate the general public about
environmentally-sound agricultural practices.

An initial project planning meeting of
several state collaborators was held in
conjunction with the New England Fruit
Meetings in January, 1995. Due to delays in
getting the project organized, no growers
participated in this meeting. Subsequently
(Spring 1995), however, ME, CT, RI, and NH
formed a Guideline Design Committee (GDC)
consisting of 6-14 members, and each
committee met at least once. The University of
Massachusetts investigators participated in
the ME and RI meetings. Each committee
reviewed the University of Massachusetts
guidelines template, and elected to modify it to
fit the pest-management situation in that
state. Modifications included: elimination and
addition of some practices in the MA guidelines
and changes to the point system used.

In Massachusetts, an IPM Certification
Study Committee was formed by the Massa-
chusetts Fruit Growers' Association late in
1994, and this group solicited input on
guideline modifications from growers, private
IPM consultants, and University staff indepen-
dently of the EPA-funded project. Modified
guidelines were compiled by the University of
Massachusetts investigators. Development of
all state-specific apple IPM guidelines was
completed by June, 1995.

Each state identified one or more demon-
strating growers (DG) who implemented the
farm-specific IPM system, and conducted other
planned activities. Cooperating growers who
agreed to demonstrate the IPM system were:

Frait Notes, volume 62 (Number 2), Spring, 1997

Massachusetts, Joe Sincuk (Uni-
versity of Massachusetts Horti-
cultural Research Center,
Belchertown); Connecticut, Ken
Shores (Johnny Appleseed's
Apple Orchard, Ellington); Rhode
Island, Randy McKenzie (Phan-
tom Farms, Cumberland); New
Hampshire, Ben Ladd and
Melanie Stephens (Great Brook
Farm, Canterbury), Steve
Gatcomb (Manager of Upland
Farm, Peterborough); and Maine,
Reed Markley (Lakeside Or-
chards, Manchester).

Original plans called for each
cooperator to demonstrate the state IPM
system, and compare results to a "convention-
ally managed" block. However, given that all
cooperators had been identified because of their
knowledge and use of IPM, none were willing to
"go backward" (i.e., apply pesticides on a
preventative basis), even when funds to
purchase extra chemical were offered. Al-
though this development compromised the
original project design somewhat, it provided
testimony to the level of commitment to IPM
common in the region.

Hence, only the demonstration at the
University of Massachusetts Horticultural
Reserch Center (HRC) included both an IPM
block, and a conventional (i.e., modified
preventative spray program) block. The HRC,
while a University research facility, is also a
commercial orchard, with support for the farm
dependent almost completely on fruit sales, just
as with a private-sector orchard. The site has a
long history of IPM adoption.

Pesticide application results in HKC
IPM and "conventional" blocks. IPM
blocks received regular monitoring and spray
recommendations by University-affiliated staff.
The sole comparison block was designed to
reflect the number of sprays that could be
applied if a grower were inclined to use a
preventative spray program. In actual fact, the
"conventional" program was very conservative,
using as it did only one spray for apple maggot

Table 1. Number of spray events in traditional and IPM
blocks, University of Massachusetts Horticultural
Research Center, 1995.

Conventional

IPM

Acaricides
Fungicides

Insecticides (incl. 2 oil)
Herbicides

TOTAL

10
7
1

4
6
5
1

fly, not the 2 to 3 that might normally be
applied.

As shown in Table 1, weekly monitoring of
the IPM block and use of appropriate action
thresholds resulted in 24% fewer spray
application events compared to the modified
preventative spray program. While this
represents a savings in labor and other costs
associated with spray application (e.g., fuel, oil,
wear and tear) and one can hypothesize a
reduced potential impact on the environment,
the number of spray events alone gives no
information on potential environmental im-
pacts of IPM use.

One measure of potential environmental
benefit from IPM, calculation of the Environ-
mental Impact Quotient (Kovach, et al., 1992),
which takes into account toxicity of individual
pesticides, is reported on elsewhere for all
participating demonstration sites. A second
measure, the dosage equivalent (DE), which
reflects the rate of pesticide used as a
percentage of the recommended rate, was
completed for the HRC (Table 2). From Table 2,
it can be seen that the IPM block received
nearly 32% fewer pesticide DE's than the
traditionally managed block. We believe this
difference represents a typical situation in a
grower orchard, where full recommended rates,
which are known to have a wide margin for
error, are rarely used. The implication of using
dosage equivalents rather than spray events is

Fruit Notes, Volume 62 (Number 2), Spring, 1997

Table 2. Dosage equivalents of pesticide used in conventionally

managed and IPM blocks, University of Massachusetts Horticultural

Research Center

1995.

Conventional

IPM

Difference

% Difference

Acaricide

3.2

3.0

0.2 DE

Fungicide

13.6

7.9

5.7 DE

42%

Herbicide

1.4

0.7

0.7 DE

52%

Insecticide

6.1

3.6

2.5 DE

40%

Oil

1.3

1.1

0.2 DE

15%

Total

Non-oU

21.3

14.5

6.8 DE

32%

most noticeable in the case of herbicide, where
both blocks received a single application, but
52% less actual pesticide was applied in the
IPM block.

In spite of the lower dosage equivalents of
pesticide use, pest damage appeared to be no
different among the two blocks. No harvest
survey data are presented because the entire
crop was heavily damaged (over 80% injury)
from a hail storm in late May. As a consequence
of this extensive damage, normal harvest
surveys could not be conducted easily.

Pesticide residue analysis, HRC. Al-
though not originally proposed as a project
activity, location of the Massachusetts Pesti-
cide Analj^ical Lab (MPAL) at Amherst,
presented an opportunity to conduct a
comparison of pesticide residues in the IPM and
traditional blocks at the HRC. Such
comparative residue data largely are lacking,
and should provide useful baseline information
for gauging the true environmental and public-
health impacts of IPM use. Fruit samples were
collected from each block type and frozen for
later analysis during fall and winter. The
authors would like to offer special acknowledg-
ment for the cooperation and assistance offered
to us by John Clark, Lab Director, and his staff,
Dan Tessier and Andy Curtis.

Table 3 shows results of residue analysis

performed for 9 of 11 pesticides applied. No
data are presented for azinphosmethyl
(Guthion"") due to applicator error, and no
analysis was attempted for the acaracide
fenbutatin oxide (Vendex'*"). It is important to
note that no residues were detected at a limit of
detection of 0.2 ppm for seven of the materials
applied in either the IPM or Conventional
block. This finding is consistent with residue
test results in the literature, which t5Tjically
show that a minimum of 50% of all produce
samples tested contain no detectable residues.
Unfortunately, it is often assumed that the
percent of produce containing pesticide resi-
dues is much higher than it actually is. This
discrepancy offers further compelling evidence
of the need to educate the media and the
general public about the realities of agricul-
ture.

For the benzimidazole fungicide benomyl,
residues were no different in IPM and
conventional blocks, but both showed residues
in the parts per billion (ppb) range, orders of
magnitude below the allowable tolerance.
Residues of propargite, registration of which
was recently canceled voluntarily by the
registrant, also were well below tolerances, and
represented the sole example of significantly
lower residues in response to an IPM strategy.
In this case, although more propargite

Fruit Notes, Volume 62 (Number 2), Spring, 1997

Table 3. Pesticide residues on apples at harvest in IPM and Traditional blocks,
University of Massachusetts Horticultural Research Center, 1995.

Total pesticide residues

Chemical

Brand name

IPM

Conventional

Benomyl^

(Benlate"°)

0.02 ppb

Captan

(Captan*")

ND"

Carbaryl

(Sevin'")

Endosulfan

(Thiodan'")

Fenarimol

(Rubigan™)

Mancozeb

(Penncozeb"")

Permethrin

(Ambush"")

Phosmet

amidan"")

Propargite'"

(Omite"")

0.49 ppm

* 0.75 ppm

tolerance of benomyl = 7 ppm.

''ND = nondetectable, limit of detection = 0.2 ppm.

"Tolerance of propargite = 3 ppm.

*StatisticaUy significant difference existed between IPM conventional at odds of 19 to

applications were used in the IPM block based
on monitoring results, a lower rate was applied,
and resultant residues were lower statistically.
Such a low-dose strategy may represent a way
for the material to be used again in the future.

Environmental Impact Quotient (EIQ).
Although each of the measures described above
(i.e. numbers of sprays applied, dosage
equivalents applied, and harvest residues)
gives some information on potential reduction
in environmental and other pollution, the
actual measurement of such reductions is
another matter. In addition to the fact that
there is no agreement on the best techniques for
measuring environmental impacts of pesti-
cides, environmental testing of any sort is very
expensive and demands the utmost care in
sample collection and analysis.

Partly in response to the need for some
measure of environmental impacts of agricul-
tural chemicals, Kovach and his colleagues at
Cornell University devised the Environmental
Impact Quotient (EIQ). The EIQ assigns
values to chemicals based on such parameters

as mode of action (i.e., non-systemic, systemic);
toxicity to humans, bees, rabbits, birds,
beneficial arthropods, and fish; soil residue half
life; plant surface residue half life; and leaching
and runoff potential. Although the resultant
EIQ nvmabers have no meaning per se, they are
intended to provide growers and others with a
means to determine relative differences among
pesticides or pest-management strategies.

It should be noted that a number of flaws in
the EIQ have been pointed out by Dushoff et al.
(1994) in the journal American Entomologist.
In addition to problems with scaling, weighting
of effects, and inert ingredients, those authors
point out that "...even benign substances are
given ... an EIQ of at least 6.7." By way of
illustrating an extreme example, "...if water
were considered a pesticide, it would have an
EIQ of 9.3. This means that 20 lbs per acre of
water would be considered worse than a 1 lb
application of parathion..." Of course, water is
not a pesticide. However, another example
using actual orchard pesticides can be seen in a
comparison of the EIQ Field Use Rating for

Fruit Notes, Volume 62 (Number 2), Spring, 1997

dormant oil (EIQ value of 37.7) and a 25 WP
formulation of permethrin (EIQ value of 56.4).
The EIQ Field Use Rating is determined by
multiplying the EIQ Value (from a table) times
the percent active ingredient (% A.I.) Of the
material times the rate of pesticide application
per acre, or:

EIQ Field Use Rating =

EIQ Value * % A.I. * Rate per Acre

For Permethrin, used at 5 oz. per 100 gal.
and applying 300 gal. per acre (or 0.9 lbs. per
acre), this results in an EIQ Field Use Rating of
13 (56.4 X .25 X 0.9 lbs). This is obviously much
lower than the field use rating of 226 for oil used
at a rate of 2 gal. per 100 gal. and applying 300
gal. per acre (37.7 x 1 x 6 gal), because oil is
100% active ingredient, and is used at a much
higher per-acre rate. In spite of the flavors in the
EIQ, no other more appropriate model is in
widespread use, to the best of our knowledge,
although several were reviewed in 1994 by Lois
Levitan and colleagues at Cornell in a report to
the Northeast Sustainable Agriculture Re-
search and Extension (SARE) program. Hence,
with all the provisions noted above, the EIQ for
each of the blocks in our demonstration is
presented in Table 4.

If nothing else, the EIQ numbers point out
that IPM is not a "one size fits all" strategy, and

that differences in pest pressure, environmen-
tal conditions, and grower management style
often govern both the choice of pesticides and
their application frequency. For example,
while fungicides contributed the largest portion
of the EIQ number in five out of six IPM blocks,
one site in New Hampshire, which used a new
insecticide (imadacloprid) which is very safe to
predator mites but highly toxic to bees, had a
much higher insecticide/acaricide EIQ than
any of the other blocks. This probably does not
actually represent greater environmental
damage, however, because imidacloprid is
applied after petals have fallen, and bees are no
longer foraging in fruit trees. Nonetheless, use
of the material results in a substantially higher
EIQ rating.

Total EIQ numbers ranged from as low at
50% of the comparison traditional block to as
high as 87% of that block, once again pointing
out the normal differences among blocks for
reasons described above. Ideally, had it been
possible to set up a comparison block in each
state which would have been subjected to the
same weather and pest pressure, such
comparisons would have had a much stronger
biological basis, and their validity would have
been strengthened.

Field days. Field days were held
successfully in four participating states in
1995. Maine held their event on May 24, 1996

Table 4. EIQ calculations for IPM demonstration blocks in five New England states, compared to
a traditionally-managed block at the University of Massachusetts Horticultural Research Center,
1995.

Pesticide type

Conventional

IPM block by state

block
MA MA RI

NHl

NH2

Insecticides/
acaricides
Fungicides
Herbicides
EIQ Totals

586 438 765

1341 617 865

52 57 **

1979 1112 1630

222

777
**

999

1007

334

1341

439

1288

1727

306

1047

1353

**Not calculated

Fruit Notes, volume 62 (Number 2), Spring, 1997

to coincide with bloom, a time when orchards
are very attractive. In facihtating planning for
these events University of Massachusetts
distributed information to collaborators on how
to stage and run a field day, and how to write a
press release. In addition, we provided
examples of press releases and other related
materials. Press releases sent, informational
handouts about each farm, and educational
materials handed out at the events included: a
3-page fact sheet on disease-resistant apples, a
fact sheet on IPM in Connecticut Apple
Orchards, an "IPM Impacts" fact sheet, a 8-
page handout on the Maine IPM Program, fact
sheets defining relevant terms, a seven-page
handout on insect and mite pests of apples, an
apple pest chronology calendar and a descrip-
tion of selected biological control agents (both
taken fi-om the New England Apple Pest
Management Guide), and a summary of
comparative results (at the Massachusetts site
only).

Each field day consisted of a "walking tour"
of the demonstration block with stops at
various points of interest. For example,
Connecticut collaborators (L. Los, G. Nixon, J.
Clark and S. Olsen) staged a self-led walking
tour which directed attendees through the
orchard to view 12 different IPM "stations".
Each station had a poster (approximately 2x2
feet) which explained an important apple pest
and included pictures of life stages, damage,
etc. Next to each poster, insect traps with
appropriate insects affixed, or weather moni-
toring equipment for monitoring apple scab
infection periods were displayed. In addition to
displays within the orchard, the Connecticut
IPM group provided two large display boards in
a movable stand used for the orchard's pick
your own operation. One board displayed the
impacts of all IPM projects in the state, and the
other dealt with beneficial insects. A total of
about 700 people either came by the booth or
took the walking tour. The large turnout was
partly due to having a "built-in" audience
available at a large pick-your-own orchard on a
good fall day. Results were such that
Connecticut plans to hold a similar event (self-
funded) next fall as well.

The Rhode Island field day also consisted of
stops at sites in the IPM blocks, as well as
samples and displays (i.e., display board of
"Pest Control Then and Now", photos of insect
and disease pests, fi-uit and leaf damage,
beneficial insects, samples of scab-resistant
cultivars, and several insect monitoring traps).
An estimated 1,000 people participated in the
field day, and the event received publicity on
local TV channels. In addition, a front-page
article about the project also ran in the
Woonsocket Call.

Although attendance at the Massachusetts
field day was less spectacular, the University of
Massachusetts Daily Collegian (circulation of
17,000 throughout the 5-college area) sent a
reporter who later wrote an article. New
Hampshire had the greatest success in
publicizing IPM by virtue of one front page
article in the, July 16 Concord Monitor
(circulation 23,500), a second fi-ont page article
in the September 24 Sunday Union Leader, one
Associated Press article sent out on the wire
and at minimum picked up by the July 17, 1995
Union Leader (cir. 89,000), and reported on by
WTSN, Dover, NH (listenership 63,000), a live
interview on WNHQ, Milford, NH on July 17
(listenership 45,000), and a second AP article
picked up by the September 25 Union Leader.
In addition to the two IPM demonstration sites
identified earlier, two other sites (the Hardy
famiiys Brookdale Fruit Farm in Hollis, and
Chuck and Diane Souther's Apple Hill Farm in
Concord) also participated in the media tours.

Cooperators in Maine arranged for the
Governor to proclaim May 24 as "Maine IPM
Technology Day", and the Commissioner of
Agriculture delivered the Governor's proclama-
tion at the event. The field day was announced
to the apple grower community at the Trade
Show in January, at the preseason IPM
meeting in March, in the Pesticide Control
Board Communicator newsletter, in the Apple
Pest Report newsletter, at meetings of the
Maine State Pomological Society Executive
Council, and was advertised in several
newspapers. The event was attended by about
75 persons and featured displays from the
Maine State Pomological Society; the USDA/

Fruit Notes, volume 62 (Number 2), Spring, 1997

Downeast Resource Conservation & Develop-
ment Cranberry IPM Program; the University
of Maine Strawberry, Potato, Sweet Corn,
Greenhouse, Blueberry, and Apple IPM
Programs; the Maine Department of Agricul-
ture; and the Maine Pesticide Control Board.
In addition to the hosts, five other apple
farmers agreed to serve as spokespersons and
to answer questions. Arrangements were made
to have a live InternetAVorld Wide Web
connection, projector, and screen at the event,
to demonstrate a developing technology with
potential applicability for IPM users.

Conclusions

By virtue of the successful development of
state-specific IPM guidelines in 5 of 6 New
England states, by demonstrating (once again)

that IPM can result in lower pesticide
applications, lower dosage equivalents, and a
lower EIQ rating, and by generating substan-
tial media and consumer exposure for IPM
throughout the region, the investigators
believe that all project goals were achieved.

Acknowledgments

We sincerely wish to thank all the growers,
consultants, university staff, and other apple
industry members who participated in the
guidelines design activity and the field
demonstrations. Special thanks to those
growers who allowed us to demonstrate the
IPM systems and hold field days on their farm.
Extra special thanks to Ken Shores who
donated enough cider for 700 attenders of the
Connecticut field day.

«1« «1« «£« «% %1U

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Fruit Notes, volume 62 (Number 2), Spring, 1997

An Update on the 1994 NC-140
Apple Rootstock Trial

Wesley R. Autio

Department of Plant & Soil Sciences, University of Massachusetts

The NC-140 Technical Committee is
comprised of about 75 university and govern-
ment pomologists from the United States,
Canada, and Mexico. During the more than 20
years of this group's existence, several trials

have been established, managed, and reported
in a cooperative manner. In 1994, a trial was
established at 25 locations throughout the
United States and Canada, and it is managed
by Rich Marini from Virginia Tech. Each

Table 1. Trunk cross-sectional area, yield, yield efficiency, and fruit weight

in 1996

of Gala on several rootstocks in the

1994 NC-140 Apple Rootstock Trial in |

Massachusetts.'

Trunk cross-

Yield

Fruit

weight

sectional area

per

tree

efficiency

(average

Rootstock

(in^)

(lbs)

(lbs/in' TCA)

box count)

M.9 EMLA

2.1 def

4.8

cdef

2.6 bedef

bed

M.26 EMLA

2.8 be

2.2

efg

0.9 fg

114

M.27EMTA

0.7 i

1.3

1.7 defg

107

bcde

M.9 RN29

2.5 cd

5.7

bcde

2.1 cdefg

bed

M.9 Pajam 1

2.4 de

6.4

bed

2.8 bcdef

114

M.9 Pajam 2

3.0 ab

9.0

3.1 bcde

B.9

1.9 ef

4.2

defg

2.6 bcdef

105

bed

B.491

0.9 hi

2.6

defg

2.7 bcdef

129

0.3

2.0 def

5.7

bcde

2.8 bcdef

112

V.l

3.3 a

8.1

2.6 bedef

100

bed

P. 2

2.1 def

0.4

0.1 g

—

P. 16

1.2 gh

2.0

efg

1.7 defg

112

ede

Mark

2.3 de

9.2

4.3 be

105

bcde

P.22

0.8 hi

3.5

defg

4.5 b

109

ede

B.469

1.2 gh

4.8

cdef

3.8 bed

110

cde

M.9 Fleuren 56

1.6 fg

2.9

defg

2.0 defg

104

bed

M.9 NAKBT337

1.9 ef

3.7

defg

2.1 cdefg

bed

DeliciousM.26 EMLA"

1.8 ef

1.3

0.9 efg

Liberty/M.9 NAKBT337

1.9 ef

13.0

7.2 a

bed

Fuji/Mark"

2.2 de

8.6

3.7 bed

' Means within columns

not followed by the same letter are significantly different

at odds of 19 to 1.

' Delicious, Liberty, and Fuji are pollenizers

within each replication

Fruit Notes, Volume 62 (Number 2), Spring, 1997

M.9 Fleuren 56

M.9 NAKBT337

M.9 EMLA

M.9 Pajam 1

M.9 RN29 1 .::m

M.9 Pajam 2

Trunk cross-sectional area (in^)

Figure 1. Trunk cross-sectional area in 1996 of Gala on six clones of M.9 in the 1994 NC-140
Apple Rootstock Trial in Massachusetts.

M.9 Fleuren 56

M.9 NAKBT337

M.9 EMLA

M.9 RN29

M.9 Pajam 1

M.9 Pajam 2

0.0 2.0 4.0 6.0 8.0

Yield per tree (lbs)

10.0

Figure 2. Yield per tree in 1996 of Gala on six clones of M.9 in the 1994 NC-140 Apple
Rootstock Trial in Massachusetts.

Fruit Notes, Volume 62 (Number 2), Spring, 1997

■ : :-

,4^

i^ ■:" '^

illi^i:r

'" ^;: ;;

^'^■'

taiiftaMi;:.jan>.watu-.->H^,.. >^j.t. ,*■,.... - ^1 a.^>v^^.>.

ISli^^^^****'^

M.9 Pajam 1

M.9 Fleuren 56

M.9 EMLA

M.9 NAKBT337

M.9 RN29

M.9 Pajam 2 ^^^

60 70 80 90 100 110 120
Fruit size (average box count)

Figure 3. Fruit size in 1996 of Gala on six clones of M.9 in the 1994 NC-140 Apple Rootstock
Trial in Massachusetts.

plating includes Gala on 17 dwarf rootstocks,
replicated 10 times. The Massachusetts
planting is located in Belchertown at the
University of Massachusetts Horticultural
Research Center. This article will give a brief
update on tree performance through the third
growing season.

After three growing seasons, the largest
Gala trees were on V.l, M.9 Pajam 2, and M.26
EMLA (Table 1). The smallest trees were on
P.22, B.491, and M.27 EMLA. The range in
trunk cross-sectional area from smallest to
largest was more than four fold. Yield per tree
in 1996 (Table 1) was greatest for trees on V.l,
M.9 Pajam 2, and Mark (ignoring the
pollenizers) and least for trees on M.26 EMLA,
P. 16, M.27 EMLA, and P.2. Relating yield to
tree size, jdeld efficiency (Table 1) was greatest
for trees on Mark and P.22 (ignoring the
pollenizers) and smallest for trees on M.26
EMLA and P.2. Fruit size (Table 1) was
greatest for trees on M.9 Pajam 2 and least for
trees on M.26 EMLA, M.9 Pajam 1, 0.3, and

B.491.

Among these 17 rootstocks, it is
particularly interesting to look at the differ-
ences among the six M.9 clones in the study.
The range was more than expected. Trees on
M.9 Pajam 2 were the largest of the M.9-rooted
trees, nearly double the trunk cross-sectional
area of trees on M.9 Fleuren 56 (Figure 1). M.9
EMLA resulted in a tree intermediate in the
range. Yield followed a similar pattern, with
trees on M.9 Pajam 2 producing nearly three
times the fi-uit of trees on M.9 Fleuren 56
(Figure 2). Trees on M.9 Pajam 2 produced the
largest fruit, averaging between 80 count and
96 count (Figure 3). Fruit from trees on M.9
Pajam 1, on the other hand averaged only a bit
larger that 120 count.

Clearly these data are only preliminary.
A few more years will be required to begin solid
evaluation of these rootstocks, but it is
interesting to observe significant differences in
these young trees.

%1a %i« •Im «1« «£•

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Fruit Notes, Volume 62 (Number 2), Spring, 1997

An Update on the 1994 NC-140
Peach Rootstock Trial

Wesley R. Autio

Department of Plant & Soil Sciences, University of Massachusetts

According the 1991A^eu; England Fruit Tree
Inventory, conducted by the New England
Agricultural Statistics Service, peaches com-
prise only 7% (380 acres) of the tree-fruit
acreage in Massachusetts; however, most of
these fruit are sold directly to the consumer and
are profitable. Further, acreage is expected to
increase at a rate of 2-3% per year for the near
future. Therefore, peaches are an important
part of the Massachusetts tree-fruit industry.

Peaches have a number of horticultural
problems: they are subject to early decline;
they can bloom too early and therefore be
frosted, they often express too much vegetative

vigor, and the flower buds or whole tree can be
killed by winter cold. Rootstock can impact any
or all of these problems.

To begin to study the potential for using
rootstock to overcome some limitations of peach
growing, Massachusetts participated in an NC-
140 trial studying the effects of 12 rootstocks
and one interstem combination on the
performance of Redhaven peach. The
Massachusetts planting was established in
1994 at the University of Massachusetts
Horticultural Research Center in Belchertown
and included eight replications. Rootstocks
included were as follows with descriptions

Table 1. Tnink cross-sectional area

yield per tree,

yield efficiency, and fi-uit size in

1996 of Redhaven peach trees planted

in 1994 as

part of the 1994 NC-140 Peach

Rootstock Trial in

Massachusetts.^

Trunk cross-

Yield

Fruit

sectional area

per tree

efficiency

weight

Rootstock

(in^)

(lbs)

(lbs/in' TCA)

(oz)

Lovell

6.4 a

19.4 be

3.1 a

6.9 a

Bailey

4.7 be

27.9 ab

6.2 a

7.6 a

TN 281-1

4.4 be

17.6 be

4.0 a

7.2 a

Stark's Redleaf

4.5 be

27.9 ab

6.0 a

7.8 a

GF305

4.7 be

27.5 ab

6.0 a

7.1 a

Higama

5.6 ab

33.0 a

6.0 a

6.8 a

Montclar

5.3 ab

20.2 be

4.0 a

6.4 a

Rubira

3.4 cd

18.7 be

5.7 a

6.8 a

Ishtara

2.4 d

11.9 c

4.8 a

6.7 a

H7338019

3.2 cd

16.3 be

5.1 a

6.4 a

BY520-8

3.9 c

18.3 be

4.8 a

6.9 a

Guardian

6.3 a

25.1 ab

4.0 a

5.9 a

Ta Tao 5/Lovell

4.2 be

18.3 be

4.4 a

6.8 a

' Means within col

umns not followed by the same

letter are significantly

different

at odds of 19 to 1

Fruit Notes, volume 62 (Number 2), Spring, 1997

Ishtara

H7338019 ETT

Rubira

BY520-8 ^^^^^

Ta Tao 5/Lovell

TN 281-1

Stark's Redleaf

GF305

Bailey

Montclar gSgBW

Higama

Guardian

Lovell

t:X?!^i^iS^:Sg^^^»ss^Stismf'i^y

mm^^m^'im^fi^i^A'^i^im^^^^^^'^^t^

^^^^^3

0.0

2.0 4.0 6.0

Trunk cross-sectional area (in^)

8.0

Figure 1. Trunk cross-sectional area of Redhaven peach trees planted in 1994 as part of the 1994
NC-140 Peach Rootstock Trial in Massachusetts.

Ishtara

H7338019

TN 281-1

BY520-8

Ta Tao 5/Lovell

Rubira

Lovell

Montclar

Guardian

GF305

Stark's Readleaf

Bailey

Higama

Yield per tree (lbs)

Figure 2. Yield of Redhaven peach trees planted in 1994 as part of the 1994 NC-140 Peach
Rootstock Trial in Massachusetts.

Fruit Notes, Volume 62 (Number 2), Spring, 1997

provided by Greg Reighard (Clemson Univer-
sity), the coordinator of the NC-140 trial:

Lovell

Bailey

TN 281-1
Stark Redleaf

GF 305

Higama

Montclar

Rubira

Ishtara

H7338019
BY520-8

Chance seedling of peach from
California named in 1882,
propagated by seed;
Selection of peach from Iowa
named in 1890, propagated by
seed;

Selection in Tennessee of "wild"
peach, propagated by seed;
Selection by Stark Bro's from a
Tennessee Natural-tj^je root-
stock, propagated by seed;
Selection in 1940 in France
from Montreuil peach, propa-
gated by seed;

Selection in France of peach
from Japan, propagated by
seed;

Selection in France of peach,
propagated by seed;
Selection in France of peach,
propagated by seed;
Selection in France of a plum-
peach hybrid, propagated by
cutting;

Selection in Ontario of peach,
propagated by seed;
Selection in Georgia of peach,
propagated by seed;

Guardian Selection in Georgia of peach,

propagated by seed;

Ta Tao 5 Selection in China of peach,

propagated by grafting, used in
the study as an interstem with
Lovell as the rootstock.

After three growing seasons, significant
differences existed in trunk cross-sectional area
(Table 1, Figure 1). Of the trees with pure
peach rootstocks, H7338019 resulted in a tree
only half the size of those on Lovell, the largest.
Rubira also produced a small tree, and
Montclar, Higama, and Guardian also pro-
duced large trees. Ishtara, the plum-peach
hybrid, resulted in the smallest trees, ones that
on average were only 38% of the size of trees on
Lovell. Yield varied similarly (Table 1, Figure
2), with trees on Higama, Bailey, Stark's
Redleaf, GF 305, and Guardian producing the
most, and trees on Ishtara producing the least.
Because, in general, the largest trees produced
the most fi-uit, yield efficiency (the expression of
5deld per unit tree size) did not vary
significantly among rootstocks (Table 1).
Likewise finiit size did not vary significantly
among rootstocks (Table 1).

Although several more years will be
required to evaluate these rootstock ad-
equately, it is interesting to observe the
significant differences that have developed in
this first fruiting season.

♦ mi^ ml^ •i^ •Ia
#{« «^ 0^ 0^

Fruit Notes, volume 62 (Number 2), Spring, 1997

EDITORS' NOTE: The following piece was sent to us by W. Lockeretz (Tufts
University). It is from the Life Histories Collection from the Federal Writers'
Project of the Works Progress Administration. It is a transcript of an interview of
Mr. G. O. Bunnell during 1938 and 1939. At the time of the interview, Mr. Bunnell
was 75-80 years old.

The Hay, Grain, and Feed Man:

G. O. Dunnell, Northfield, Massachusetts

I'm getting this axe ready to fix the fences
on Christian Hill that the hurricane busted.
Not that the hurricane blew 'em down but it did
blow down some trees. And the trees is what
busted the fences. I dim' over one. Had to, to
get to camp, and I see they was more down.
Couldn't do anything that night because it was
getting da'k, and I had to come home, but I'm
going back just as soon as the roads get settled
enough so's I can.

It's a funny thing, but I don't think that, as
a rule, there was as much wind over that way as
we got here. What did most of the damage was
the water. And, another funny thing I noticed
was that of the trees that come down in the
apple orchards, it was the ones that had never
been grafted. Those that had been grafted
stood up.

How'd I know? I know most every apple tree
they is on Colrain and Shelbume mountains,
and in the north part of the town of Greenfield.
'Cause I was the feller that grafted 'em, that's
why! I used to go all over grafting trees. And I
had ten or twelve hundred trees of my own, too,
that I'd no business leaving. But people would
come tease me and tell me how much extry they
were willing to pay for my trouble, that I was
generally on the move. Once I went to
Greenfield. And I didn't get home for a week.
Spent the nights there with the different ones.

'Course, theys a trick to it. But 'most
anybody can put on a scion so's it'll grow. But
that ain't all they is to it. You got to figure what
the tree's going to be shaped like. You shouldn't
get the scions growing into each other the way
most people do. And you ought to fix; the tree

so's somebody can pick the apples without tying
a couple of ladders together or hiring a balloon.

Apple trees like to grow among the rocks -
that is, most kinds do. The hills each side of our
valley here are just right. All we can grow here
that's any good is the Blue Pearmain. And they
got such a tough skin that people don't like 'em.
They are an awful good flavor, though, until
they got mealy - oh, they^s others; russets and
early transparent and so on. But what I was
getting at is the way I found the best of raising
good flavored apples. Apples grow wild over in
Colrain. It is just as natural to find a wild apple
tree in Colrain as it is to find a birch in
Warwick. I had a lot of 'em in my woods.
'Course, the fruit of a wild apple tree is no good
except for cider. But the trees themselves is
generally healthy. I'd find a good one, then I'd
saw off such limbs as I thought should be off,
and put a scion in it. If it was a fairly big limb
that I figured would pinch the scion off if I didn't
do something about it, I'd whittle a little thin
wedge and put that in just beyond the scion, for
the limb to pinch on to. What do I mean by
scion? What that's a little shoot fi-om the brand
of tree I wanted. I had Baldwin scions and
Mcintosh scions and Porter scions, and all
kinds of scions. I cut 'em in March - that's the
best time to graft around here. Maybe, I'd
make a Baldwin tree out of a wild apple tree, or
a Greening, or a Northern Spy. Sometimes I
fixed 'em so's they had different kind of apples
on every limb. But that's nothing but a kind of
joke. Nobody that runs an orchard wants trees
with fruit all mixed up on 'em.

I said I only put one scion to a limb. I always

Fruit Notes, Volume 62 (Number 2), Spring, 1997

put two, 'cause somethin' might happen to one.
They break off in ice storms sometimes. And I
always put 'em one above the other 'cause I
figured it's better and stronger that way. You
whittle off one side the scion and stick it in the
crack you've made with your knife in such a
way that the live bark on the scion presses up
against the live bark on the tree. And then you
hold the scion in place with wax. Then you cut
off all the limbs below the one that you've
grafted. The sap has to go somewheres. And
when it finds that the limbs have been cut off,
and they ain't no place to go, except into the
bark of the scions, that's where it goes. You've
got to figger not to cut too many limbs off,
though. For if thej^s more sap than can get into
the scion and make it grow, it'll leak out under
the w£ix and rot the scion off. I generally left the
top of the tree pretty much alone until I found
out how the scions were doing. If they were
growing all right, I'd cut the top off then.

Lot of people put on two scions the way I
done. But when them both growed they let 'em
grow together. That makes a crotch. And a
crotch ain't strong. I always cut off one scion
just before they growed together. And the bark
would grow over the place and make a smooth
branch.

Once, I grafted a whole tree. And that tree
stood up through the hurricane, too. Yer see,
when a crust comes on the snow, or anjrthing
happens so the mice can't hunt, you're supposed
to go around the orchard tromping down the
snow around the trees. You tromp it down hard
right around the trunk, and the mice won't get
to the bark. But I missed this tree someways.
Or the mouse, maybe, was a wood rat. Anyway,
it ett the bark all the way 'round. It was a good
tree. Had good roots, and as it would die if I
didn't do something about it, I thought I better
try. I cut the trunk of the tree off and put scions
all the way 'round in the bark. Enough of 'em
grew so I managed to raise a tree. I told the
feller who owns the place about it, and he found
it hard to believe for it don't look no different
than any other tree to him.

Lots of people insist on growing an orchard
from nursery stock, that's all right if you want
to wait ten or fifteen years for a crop. But if you

want your trees to begin bearing in three-four
years you want to graft a few scions on to a full
grown tree. If you take your scions from a tree
that has apples you like, you can be sure that
you'll get the same flavor apple when the scions
begin to bear. But when you buy from a nursery
you got to wait ten or twelve years to find out if
you got what you paid for. 'Course, the/s some
crook nursery men, I s'pose, but they ain't
many. It's the agent who's the crook. And it's a
pretty good game when a feller don't know he's
been gypped until ten-twelve years. By that
time the agent ain't no longer in the employ of
the company, probably. And if he was, nobody
would know who made the mistake and the
whole thing be outlawed so's you couldn't get it
into court. I don't say that a good nursery
wouldn't be awful sorry it happened and make
good, too. But the way they'd make good would
be to give you some guaranteed new trees that
you could wait for to bear for another ten-
twelve years.

When Doc Brown and his brother first come
they lived in houses side by side. And they
planted the two back lots for an orchard. I told
the Doc that this wasn't a good place to raise
apples, but the Doc said, "No, no," I was wrong.
That he'd had the soil analyzed down at the
State College. And that they said it was good
soil and all right. "All right, Mister" I says.
"Now you take out your little book and you
write down what I'm going to tell yer. So's you
won't forget it, I says. But you see more money
when you took out your pocketbook to pay for
them trees than you'll ever see coming back into
it from your orchard." But, oh no, I was wrong.

"What kind of trees be they," I wanted to
know. "Baldwins," he says. And it seemed he
had paid an extry price to get some real good
trees.

I see they wan't no use talking to him and
trjdng to help him so I forgot about it 'til several
years had gone by when I saw him and his
brother working in the orchard. You know,
they's a pest of borers that bores holes in the
trunks of apple trees right above the ground,
and if you're quick enough you can ram a wire
in and either kill the borer, or fish him out, but
if he's bored 'round a bend or two, you are out of

Fruit Notes, volume 62 (Number 2), Spring, 1997

luck - your tree is gone. So it pays to watch your
orchard. Was a time when yer didn't need to
spray your trees. But you do now - two-three
times.

Well, I goes down into the orchard and asks
what they was doing. They told me. And I
asked what kind of trees these was. 'Baldwins,"
they told me. A few of 'em are, I admitted. But
most of 'em is Gravensteins. "Oh, no!" Says the
Doc, "that can't be! It was a reliable firm we
bought them of and they was guaranteed
Baldwins - a 'specially good brand.' "Well," I
says, "You still get your little book? Now, put it
down, so you won't forget it, or tie a string
around the trees, or somethin', and you just
wait 'til theys apples on 'em and see.'

But they didn't wait. The brother sold out to
a poor, little runt of a mean, miserable, cuss
that I don't want nothin' to do with. But I didn't
know what a kind of low-lived skunk he was
then, so I tried to be neighborly. I asked him
what kind of trees he had in his orchard. He
says that they was Baldwins. That that was
what the ministers said that sold him the place.
"Well, they ain't," I says. "They is Gravensteins
- most of 'em." But they ain't no good!" he says.

I told him I didn't think they was any good
myself- not even for cider. He wanted to know
how how I was so siire. And I showed him the
difference in the leaves. He thought he had
better wait and make sure before he did
anything about it. That it didn't seem to him
that ministers would lie. I told him he needn't
wait to find that out. That everybody in
Northfield knowed that ministers are the
biggest liars they is, 'cause they honestly
believe their lies themselves. That if he aimed
to become a bonnie fidie resident of Northfield,
he'd better find that out, and learn to set one
against the other. That some places you needed
lawyers to do business for you, but here in
Northfield you needed ministers, and if you
didn't have one you were all out of luck.

He was going to cut down the Gravensteins
but I told him no, and showed him how to graft
'em with scions fi-om the Baldwins. The little
cuss never did it, though, he turned out to be too
dimab lazy. That old fool was over eighty when
he broke his hip. It mended good as new. The
fall would a killed any decent person. And you
know the saying, "The Good Die Young." Guess
that's a fact.

mi^ mi^ %i« «f^ m^

0^ 0^ 0^ ^« 0^

Fruit Notes, Volume 62 (Number 2), Spring, 1997

Fruit Notes

University of Massachusetts

Department of Plant & Soil Sciences

205 Bowditch Hall

Amherst, MA 01003

Nonprofit Organization
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354

F6B

Yuit Notes

Prepared by the Department of Plant & Soil Sciences.

UMass Extension, U. S. Department of Agriculture, and Massachusetts Counties Cooperating.

Editors: Wesley R. Autio and IX^lliam J. Bramlage

re r:
BIOLOGICAL^ ^,

APR 01 1998 1 -^

SCIENCE3 LIBRARY

Volume 62, Number 3
SUMMER ISSUE, 1997

Table of Contents

Effects of Natural Food Sources on Attraction
of Apple Maggot Flies to Baited Traps

What Part Do Flyspeck Ascospores Play
in Disease Development?

Tax Pointers for Farmers and Landowners in 1997
and Planning Notes for 1998

Evaluation of Peach and Nectarine Cultivars
for Massachusetts Orchards

Fruit Notes

Publication Information:

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

Correspondence should be sent to:

Fruit Notes

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

UMASS EXTENSION POLICY:

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

Issued by UMass Exlensmn. Robert G. Helf^esen. Direcuir. infunherunre iifthe acts (>l MiiySaiuLlune SU.
1914. UMass Extension offers eqiiiil opportunity in proi^rams and employment.

Effects of Natural Food Sources on
Attraction of Apple Maggot Flies
to Baited Traps

Juan Rull, Alan Reynolds, Michelle Balds, HoUy Gagne, and

Ronald Prokopy

Department of Entomology, University ofMiissachusetts

The effectiveness of visually attractive red
sticky spheres can be increased by the addition
of odor lures. In recent study in commercial
orchards by Reynolds and Prokopy (1996), it
was shown that red sphere traps baited with
butyl hexanoate (an odor emitted by ripening
apples) realized a four-fold increase in captures
of apple maggot flies (AMF) when compared to
unbaited spheres. However, the addition of
ammonium carbonate (an odor emitted by
sources of food) to red sphere traps did not
enhance capture of flies on baited traps. The
above study involved trapping wild flies
entering commercial orchards. Their physi-
ological state was unknown.

While the nature of fly attraction to butyl
hexanoate was clear, the cause underlying lack
of attractiveness of ammonium carbonate was
uncertain. In order to reach a better
understanding of AMF response to both lure
types, we decided to perform an experiment in
which flies of known physiological and
nutritional state (mature protein fed or
immature protein starved) would be released in
blocks where different combinations of lures
would be displayed. Further, all treatments
would be replicated in blocks where natural
food sources were added or suppressed. In this
way, we could assess which synthetic lures are
attractive to flies of different physiological
states and whether or not the presence of
natural food in orchards interferes with
attraction to lures.

Materials & Meth(fds

Four sets of six square blocks of 49 apple
trees each were selected in four commercial

orchards, with one set of blocks per orchard. In
every block, red sticky spheres were positioned
on every perimeter tree. In two of the blocks,
sources of butyl hexanoate and ammonium
carbonate were placed 15 cm away from every
sphere. In two other blocks, only butyl
hexanoate was added to spheres. Spheres in
the remaining two blocks were not lured. One
block of each lure-type treatment was treated
with Provado''''^ to prevent buildup of aphid and
leafhopper honeydew (natural food sources).
The other block of each lure-type treatment
received a large amount of bird droppings (also
a natural food source) that was distributed by
hand (in slurry form) onto the foliage of each
tree. Thus, half of the blocks of each treatment
type had a paucity of natural fly food; whereas,
the remaining blocks had abundant natural fly
food.

Apple maggot flies of known physiological
state were released into the central tree of each
block. The flies emerged in our laboratory and
were subjected either to a diet including
protein and sugar for 14 days (mature flies) or
a diet limited to sugar for four days (immature
flies). When ready to be released, flies were
marked on the back of the thorax with a small
dot of paint. Approximately 50 mature flies and
50 immature flies were released in each block.
Flies of each physiological state released in
each block bore a distinct color (12 different
colors used across all blocks in an orchard).
Flies captured by the traps in each block were
counted after four days. The percentage of flies
recaptured was used to compare response to
treatments. Wild flies captured in the different
blocks were also counted and their numbers
compared.

Fruit Notes, Volume 62 (Number 3), Summer, 1997

F igure 1 :

ponse o

f marked released mature flies

50 T

o
<1>

45
40
35 '

^HHi

-«■ ^^_^

c
(1>

•o

2
a

15 -

■ t^m .^-^

1 -

' ■

■ ^fl r^

5-
n -

m iju

o
o

AC+Food
BH+Food

-AC-Food

No lure
+Food

ure -Food

X
CD

+ ^ —

I n: o

m -^ Z

BH= Butyl hiexanoote, AC

= Ammonium carbonate, Food =

Presence or absence of natural

sources of food on trees .

-n

Percentage of markec c
flies captured q

2: R

esponse of marked released Immature fli

15 -

10 -

^ ^

^M ^ ^

m ^H ^H .^^

"D
O
O

U-

X
CO

H = Butyl

ood = P r(

•o

U-

o
<

X
m

tiexanoc
Bs ence o

n T! ^ ^
n o O O
n o O O
>? £ ^ ^

o o
z z

ite, AC = Ammonium carbonate,

r absence of natural sources of

food on trees

Results

Similar to the earlier findings of Reynolds
and Prokopy {Fruit Notes 61(4): 1-2, 1996) on
response of wild flies, we found that the

addition of butyl hexanoate resulted in nearly
a four-fold increase in capture of released
mature flies on spheres. Presence of ammo-
nium carbonate did not add to the attractive-
ness of traps to mature flies, even in the

Fruit Notes, Volume 62 (Number 3), Summer, 1997

Figure 3: R esponse of unmarked wild flies

25 -

0) -D

I t

a> o
a

1 5

BH= B u tyl hex anoate, AC= Ammonium

carbonate, Food = Presence or absence of

natural sources of food on trees

absence of food on the apple trees (Figure 1).
Response of immature flies to lures and traps
was much lower than that of mature flies.
Although the combination of butyl hexanoate
and ammonium carbonate in the presence as
well as the absence of food was the trap
treatment that caught the most immature flies
(Figure 2), captures were well below those of
mature flies on traps with lures. Responses of
wild flies were similar to those of released
mature flies (Figure 3). Again, captures on
traps having butyl hexanoate alone were
nearly four-fold greater than captures on
unbaited traps. Again, addition of ammonium
carbonate did not enhance trap capture.

Conclusions

Our results support the combined use of
sticky red spheres and butyl hexanoate lures as
an alternative to insecticides to control AMF.
Addition of ammonium carbonate lures did not

enhance captures of released mature flies or
wild flies, and its slight enhancement of trap
captures of immature flies was not great
enough to justify its use. Presence or absence of
natural food in orchard blocks had little
detectable effect on response patterns of either
released mature, released immature, or wild
flies. Response patterns of wild flies seem to
indicate that their populations consisted
mainly of mature flies.

Our findings support use of a behavioral
control strategy based on the employment of
visually attractive red spheres together with
butyl hexanoate as an odor lure.

Acknowledgments

We are grateful to Stanley Baj, Dana Clark,
and the Peck brothers for generously allowing
use of their orchards. This work was supported
by USDA CSRS NRI grant 95-37313-1890 and
Cooperative agreement 94-COOP-1-0482.

vT^ •^ *^ •sL^ *^

•^ •<J>» r^ 0^ •^

Fruit Notes, Volume 62 (Number 3), Summer, 1997

What Part do Flyspeck Ascospores
Play in Disease Deveiopment?

S. Lemer, T. Kliorina, and D. R. Cooley

Department of Microbiology, University of Massachusetts

Flyspeck is one of the major summer-
disease concerns of apple growers in the
Northeast. Yet for most of the season, there is
little evidence of the fungus within the orchard.
In a dry year, signs of infection may not appear
until as late as August.

For several years we have been conducting
investigations aimed at gaining a better
understanding of the natural biology of this
fungus. We know that it survives the winter on
a number of wild hosts that are common to most
orchard borders such as blackberry, maple,
grape, Virginia creeper, and red oak. We also
know that, like the apple scab fungus, it
produces two types of spores: ascospores in the
late spring and repeating cycles of conidia or
asexual spores later in the season.

However, unlike apple scab, which pro-
duces its first cycle of spores within the orchard
where well-timed sprays can control the
disease, flyspeck ascospores are produced
primarily in the orchard borders on alternate
hosts. We wanted to know what part these
early spores play in disease development later
in the season.

The flyspeck spots that form on apples,
blackberries, and other hosts in late summer
are pseudothecia, the overwintering structure
of the organism. By late winter these
structures have matured and are ready to
produce spores. In the laboratory, we have seen
that spore development is driven by both
temperature and humidity. Humidity must be
quite high - mature spores are produced at 99%
humidity but not at 96%. Average tempera-
tures above 50°F are also necessary for spores
to develop and mature. In New England, these
conditions can be met for significant portions of
the day in the field by late May.

In the spring of 1997, blackberry canes with
pseudothecia were gathered weekly from three
sites in Western Massachusetts from late May
into July. Fifty pseudothecia from each cane
were examined microscopically and the
presence of mature spores was recorded. Table
1 shows the results of this study.

The 1997 information conforms with data
gathered in Amherst during 1996 that showed
that there is a single period of ascospore release
that occurs in late spring to early summer. An
unusually warm, wet spring in 1996 com-
pressed the period of ascospore maturity to a
shorter period of time, earlier in the season.
Apple-tree phenology can be used as an aid to
predict when this period will occur in a given
year.

The ascospores produced on the host plants
in the orchard borders are released into the air
but we do not know if they are transported as
far as the orchard block.

Even if these initial spores are carried to
apple trees however, it is likely that the spray
program aimed at controlling apple scab
ascospores will also control early-season
infections of flyspeck.

Information from Dr. David Rosenberger
indicates that the broad-spectrum protectant
fungicides commonly used for scab, Mancozeb
and Captan, will protect against flyspeck for a
significant period. Mancozeb used at 1 lb/100
gal. or Captan SOW at 2 lb/100 gal. will protect
fruit for at least 21 days or 2.5 inches of rain,
whichever comes first. Captan SOW at lb/100
gal. protects for 14 days or 2 inches of rain. If
the last scab spray of the season contains one of
these fungicides, and is made in early to mid-
June, fruit will be protected to late June or
early July.

Fruit Notes, Volume 62 (Number .3), Summer, 1997

Table 1 . Flyspeck

ascospore maturity

in relation to apple tree

jjhenology.

Site

First mature spores

Last mature spores I

Date

Apple phenology

Date

Apple phenology

Amherst, 1997
Shelburne, 1997
Sterling, 1997

Amherst, 1996

May 24
June 3
May 20

May 13

mid petal fall

90% petal fall

full bloom

late bloom

July 3

July 6

July 10

May 29

1 1/8" fruit

1 1/4" fruit

1 " fruit

1/4" fruit

If infections from the initial cycle of spores
are not the primary cause of late season
symptoms in the orchard, then conidia must be.
We wanted to know if inoculum could be
building up in the woods and borders, in the
form of conidia, and moving into the orchard
sometime later in the summer.

Previous studies have shown that trees
closer to the borders have a much higher
incidence of flyspeck {Fruit Notes 61(2): 1-4,
1996). But flyspeck symptoms are rarely seen
before the end of July and have never been seen
early in the season.

Based on the fact that there are repeated
yearly infections of the numerous host plants in
the orchard border, we knew that ascopores
germinate in the field and cause infections. The
typical lifecycle of the fungus begins with the
ascospore germinating to form a colorless
mycelium which live off the nutrients of the
waxy surface layer of its host. Repeating cycles
of conidia or asexual spores form on this
mycelium, and then the typical flyspeck
symptoms appear.

It is possible that ascospores create local
infections in the borders and cycles of conidia
proliferate on these hosts creating a reservoir
of additional infections and inoculum that can
move into the orchard block when environmen-
tal conditions are conducive. We know from
research conducted by Dr. T.B. Sutton that
flyspeck conidia are discharged primarily in
the early morning hours, after periods of high
humidity or heavy dews or rain, and as the

levels of high humidity decrease (Sutton, Plant
Disease 74:643-646, 1990).

During the summer of 1997 we attempted
to find out if and when asexual spores or
conidia were typically present within an
orchard in Shelburne, Mass. The trees had
been sprayed following a first-level integrated
pest management schedule with the last spray
of Rubigan and Pencozeb occurring on June 4.
Spore traps were placed within the blackberry
border, in the first row of trees about seventeen
feet from the border, and in the third row of
trees about seventy feet from the border. Spore
trapping rods were brought back to the
laboratory and spores counted twice a week
starting in mid-July.

Actual numbers of spores caught on the
traps were too small to analyze statistically.
However, the number of conidia trapped
increased dramatically during the second week
of August, coinciding with an increase in heavy
morning dews. The first symptoms of flyspeck
were observed two weeks later on August 31.
Additional data are needed to be able to predict
the environmental conditions that will lead to
an increase in conidial inoculum in the orchard.
It does seem, though, that there is a period of
time between the end of primary scab season
and mid-July to mid-August, particularly in
dry years, when there are few conidia in the
blocks and the likelihood of flyspeck infection is
very low.

In the orchard where spores were trapped.

Fruit Notes, Volume 62 (Number 3). Summer, 1997

the first row of trees was sprayed only on the
side away from the border. The border side of
those trees was highly vulnerable to infection
by ascospores, being unprotected by fungicide
and in close proximity to the blackberries. Yet
no flyspeck occurred until late summer, when it
also occurred on the sprayed side of the trees as
well as in other blocks in the orchard. This
coincided with a change in environmental
conditions that either stimulated the fungus to
grow or promoted an influx of conidial
inoculum into the orchard from the borders.
This supports our contention that ascospores
play little or no role in direct infections on fruit,
but instead it is conidia moving from border
plants that inoculate the crop.

In summary, flyspeck ascospores form in

the orchard borders and surrounding woods
rather than in the orchard. Ascospores are
released during a single discrete period in the
late spring and early summer, making it
possible to relate the period of heaviest
inoculum dose to apple tree phenology,
generally 10 to 14 days after petal fall. These
spores probably cause infections on border
plants but not on orchard fruit. If any infection
occur, sprays aimed at controlling scab will
most likely control them. Therefore, ascospores
do not seem to play a major role in producing
the flyspeck symptoms that are seen in late
summer in Massachusetts, and efforts need to
be focused on controlling infections caused by
conidia from mid-July thru harvest.

•sl^ •^ •J^ •J^ •^

•^ #^ 0^ #^ #Y*

Fruit Notes, Volume 62 (Number 3), Summer, 1997

Tax Pointers for Farmers and
Landowners in 1997 and
Planning Notes for 1998

P. Geoffrey Allen

Department of Resource Economics, University of Massachusetts

Tax advice given below is intended as
general advice and is believed to be correct. It
does not substitute for a detailed review of the
circumstances of an individual taxpayer by a
professional tax practitioner. For more details,
you and your tax adviser may wish to consult
the sources referenced in the square brackets
[thus] (I.R. C. = Internal Revenue Code; Tres.
Reg. = Treasury Regulations).

New Legislation

The Taxpayer Relief Act of 1997 "TRA97"
(Public Law 105-34) is one of the longest and
most complex pieces of tax legislation passed by
Congress. It has been called "mind-numbing"
by members of the accounting profession. It
also contains errors and omissions, some of
which would have been fixed by the Technical
Corrections Bill, had it been passed before the
end of the 105"" session of Congress. Many
provisions become effective January 1, 1998,
although some, most notably those affecting
capital gains and sale of a principal residence,
take effect during 1997. Note that instructions
given in the Farmers' Tax Guide (Publication
225) on how to deal with capital gains and
losses are out of date (or are correct only for
sales of assets made before May 7, 1997).
Income averaging that was repealed in 1986
has been re-instituted in a limited way for farm
incomes only, starting in 1998.

Self-employed Health Insurance
Deduction

Under the tax act passed in 1996, self-

employed individuals can deduct fi-om adjusted
gross income (on line 27 of Form 1040) 40% of
the amount paid in 1997 for health insurance
for their spouses and dependents. TRA97
increases the maximum deduction to 100% by
2007 and speeds up the rate of increase. The
part of the insurance premium not deducted is
allowed as a medical expense on schedule A,
though this will benefit very few people. [I.R.C.
§ 16(a)(1)(B)]

Long-term Care Insurance

TRA97 applies the rules for the deduction of
health insurance expenses separately for
health plans that cover long-term care and for
those that do not.

Example: an employed husband might have
employer-provided coverage that excluded
long-term care. His self-employed wife could
obtain long-term care insurance for both of
them and deduct from adjusted gross income
the same 40% of the insurance premium as
shown in the previous section. [I.R.C. § 162]

Self employment Tax on
Rental Income

If you rent farmland to another entity
(individual, partnership, corporation) you do
not pay SE tax on the rental income unless: 1 .
There is an arrangement that you will
materially participate in the production of
agricultural or horticultural commodities, and
2. You actually do materially participate in
production. The material participation rule
applies to land only. Rent of personal property

Fruit Notes, Volume 62 (Number 3), Summer, 1997

used with the land is not subject to SE tax.
[I.R.C. §§ 1401(a), 1402(a) and (b)]

Example: Bruce Bullock owns a farm and
rents out the land for $20,000, buildings for
$5,000 and machinery for $10,000 to a family
partnership in which he materially partici-
pates. He mus pay SE tax on the $20,000 land
rent but not on the $5,000 building rent. Rent
on personal property is in general subject to SE
tax so he must pay SE tax on the machinery
rental of $10,000. The IRS is not likely to treat
it as falling under the exception for personal
property rented with real estate. [I.R.C. §
1402(a)(1)] Note: If Bruce's wife had owned the
farm and she was not a member of the
partnership, then she probably would avoid SE
tax on the land and building rental.

Like-kind Exchanges

Property used in a trade or business, or held
for investment, that is replaced by similar
property will be a like-kind exchange if certain
conditions are met. Any capital gain or loss
realized on the property given up in a like-kind
exchange must be deferred and the basis of the
new property adjusted accordingly. Deferral is
not elective. [I.R.C. § 1031] Form 8824 is used
to report the transfer and the basis of the
property acquired. It should be filed the year
the exchange takes place.

Like-kind for real estate is interpreted
quite broadly. For example, timberland for
bare land, undeveloped farm land for a
commercial building. For personal property,
like-kind has a narrower definition. Automo-
biles, light general-purpose trucks (under
13,000 pounds actual unloaded weight) and
heavy general-purpose trucks are separate
categories. A trade from one category to
another is not a like-kind exchange. Any two
assets that are in the same four-digit SIC
(Standard Industrial Classification) code are
like-kind. Farm machinery qualifies since it is
all in SIC code 3523. However, small farm tools
and equipment are in several different
categories. [Treas. Reg. § 1.1031(a)-2]

Sale of Principal Residence

Up to $250,000 ($500,000 if married, fihng
jointly) of gain on the sale of a principal
residence is excluded from tax if all the
following requirements are met: 1. The
taxpayer (or either spouse) owned the home
for two or more years during the five-year
period preceding the sale; 2. The taxpayer (or
both spouses) used the home as personal
residence for two or more years during the five-
year period preceding the sale; 3. The taxpayer
(or neither spouse) has used the new exclusion
during the two-year period preceding the sale;
and 4. The sale occurred after May 6, 1997.

A person who moves house every two years
could claim the exclusion each time. For sales
after May 6, 1997, few homeowners should be
faced with pa5ang capital gains on the sale of
their home. Form 2119 that was used to
rollover the gain on sale is no longer needed and
will be discontinued. (Note to Massachusetts
homeowners: the Commonwealth still follows
the Internal Revenue Code of previous years.
Presumably State tax forms will in future
include a substitute for Form 2119.) [I.R.C. §
121. I.R.C. § 1034, containing the rollover
provisions, has been repealed.]

If part of the residence was used as an
office, or for business, and had been
depreciated, any gain allocated to that portion
would be subject to capital gains tax. See Table
1.

Capital Grain

Schedule D of Form 1040, which was 23
lines in 1996 has grown to 54 lines in 1997,
thanks to the complexities introduced by
TRA97. Profitable sales of assets held for one
year or less are short-term gains, whenever
sold. Profitable sales of assets held for 18
months or less, sold after July 28, 1997 are
short-term gains. These are taxed at the same
rate as ordinary income (maximum of 28%).
For sales of long-term assets after May 6, 1997
there are three rates: 28% (or 15% for

Fruit Notes, Volume 62 (Number 3), Summer, 1997

taxpayers in the 15% bracket) on collectibles
(works of art, coins, etc.), on recaptured
depreciation of personal property, and on
recaptured depreciation on real property that
exceeds the straight line depreciation amount;
25% (or 15% for taxpayers in the 15% bracket)
on the depreciation of real estate taken on a
straight line basis note this change, all real
estate depreciation is now recaptured, not
just the excess over straight line depreciation;
or 20% (10% for taxpayers in the 15% bracket)
on all other sales this rate is the basic rate for
capital gains and losses except for the
situations described for the higher rate.
Beginning in 2001, the 20% rate drops to 18%
(10% drops to 8%) for assets purchased on or
after January 1, 2001 and then held for five
years.

The way to treat capital losses was not clear
from TRA97. On Schedule D of Form 1040, the
IRS has followed the anticipated changes in the
Technical Corrections Bill that still awaits
passage. Basically, short-term losses, if any,
are applied first to reduce short-term gains,
then to reduce long-term gains in the order:
gains in the 28%, 25%, then 20% group. Long-
term losses in the 28% group are used against
the 25%, then the 20% group. Losses in the 20%
group are set off first against the 28% group,
then the 25% group.

Massachusetts capital gains rules are
different. Gain on property held more than one
year is taxed at 5% and on property held more
than two years at 4%. In each succeeding future
year, the rate will drop one percentage point for
each additional year that the property is held.

Alternative Minimum Tax

If you recently sold a commodity on a
deferred-payment contract and paid alterna-
tive minimum tax, you can defer the payment
for both regular income tax and AMT
purposes. TRA97 repealed I.R.C. § 56(a)(b),
effective 1987. You can amend your return for
any past year that is still open to amendment
(usually the prior three years).

Example: You delivered corn to an elevator
in 1995 and received pajonent for it in 1996. For

regular income tax purposes, you treated the
sale as 1996 income. For AMT purposes it had
to be treated as income in 1995. You paid AMT
in 1995. You may file amended returns (1040X)
for 1995 and 1996.

Alternative Minimum Tax
Depreciation Aef/ustment

TRA97 allows the same recovery period for
both regular tax and (AMT) purposes.
Previously (AMT) required a longer alternative
MACRS recovery period. Both regular and
AMT recovery periods are now the same for
assets placed in service after 1998.

Income Averaging /or Farmers

To give farmers subject to year-to-year
fluctuations in income some relief, TRA97
institutes a new code section (I.R.C. § 1301)
that permits taxpayers "engaged in the
farming business" (as defined in I.R.C. §
263A(e)(4)) to average over the three prior
years all or a portion of their taxable income
derived fi"om farming. The provision is effective
for the tax years 1998, 1999 and 2000. An
eligible taxpayer elects to have all or part of
farming income averaged. The election is
irrevocable (cannot be changed by filing an
amended return in later years). Gains from the
sale of assets (other than land) "regularly
used by the taxpayer in the farming business
for a substantial period" can be averaged also.
One-third of the amount averaged ("elected
farm income") is allocated to each of the three
prior years. Tax of an electing farmer would be
the tax on the amount remaining after
allocation (say in 1998) plus the additional
taxes that would have been paid in 1995, 1996,
and 1997 if the one-third of elected farm income
had actually been received in each of those
years. Presumably, the IRS will develop a tax
form where the election and the necessary
calculations can be made. The amount of
income allocated to prior years stays in those
years as additional income, reducing the
benefits from income averaging in succeeding
years.

Fruit Notes, Volume 62 (Number 3), Summer, 1997

Septic Credit

If you own and occupy a principal residence
in Massachusetts and you incur expenses to
make your sewer system comply with Title V
you may claim a credit directly against taxes on
your Massachusetts return. The credit is 40%
of the costs up to $15,000 for design and
construction to repair or replace a failed
cesspool or septic system. The maximum
aggregate credit of $6,000 is limited to $1,500
in any year. Unused credit may be carried
forward for up to three years. Massachusetts
Schedule SC must be completed and enclosed
with the tax return claiming the credit.

Individual Retirement
Accounts (JRAsJ

Several kinds of IRA are now available:

1. Deductible IRA (input is deducted from
gross income, output is taxable). The
maximum amount is $2000 per spouse, the
amount phases out at higher incomes, and
the phase-out levels keep changing. Under
prior law, a spouse not covered by a
retirement plan could not make a deductible
IRA contribution if the other spouse was
covered by a qualified retirement plan.
TRA97 permits a non-covered spouse to
make a deductible IRA deduction. No
contributions may be made after age 70.5 at
which point required withdrawals must
begin. [I.R.C. § 408 and § 219(b), (c) and (g)]

2. Non-deductible IRA (non-deductible input,
taxable output). Where phase-out rules
have limited the amount contributed as a
deductible IRA, non-deductible
contributions can be made (into the same
account if desired; Form 8606 must be filed
and establishes the tax-free basis of the
non-deductible IRA).

3. "Roth IRA" (non-deductible input, non-
taxable output). The Roth IRA will be
available starting in 1998. It is more
flexible than existing IRA's. For an
investment made more than 5 years ago

and withdrawn after age 59.5, the earnings
are not taxable. Not subject to the current
minimum distribution requirements at age
70.5. Contributions can be made after that
age. The maximum contribution that can
be made to a Roth IRA is phased out for
individuals with AGI between $95,000 and
$110,000 and for joint filers with AGI
between $150,000 and $160,000. Only
taxpayers with AGI of less than $100,000
are eligible to roll over or convert a current
IRA into a Roth IRA. In 1998, all or part of
a current IRA can be rolled into a Roth IRA
with the income tax spread over a four-year
period. In no case can contributions to all an
individual's IRAs for a taxable year exceed
$2,000. [I.R.C. § 408A]

Which IRA to choose? At a constant tax rate
there is no difference to the taxpayer between a
deductible IRA and a Roth IRA. (The difference
is to the Government; tax payments are
accelerated.) If your marginal tax rate will rise
after retirement, choose the Roth IRA; if it will
fall, choose the deductible IRA. In general,
always make a contribution to a deductible IRA
if you can, then to a Roth IRA, and then to a
non-deductible IRA. If you want to increase the
amount you put into a retirement fund over the
$2000 per year allowed for each person's
combined IRAs, consider the SIMPLE described
below.

SIMPLE Simplified Employee
Pension IRAs

Beginning in 1997, small-business
employers can set up SIMPLE (Savings
Incentive Match Plan for Employees) retirement
plans. A self-employed person can set one up
also. Generally, the SIMPLE plan must be the
only retirement plan of the employer.

SIMPLE plans are written qualified
salary reduction arrangements that allow an
employee to elect to reduce his or her
compensation by a certain percentage each pay
period and have the employer contribute the
salary reductions to the SIMPLE plan on behalf
of the employee. Any employee qualifies who

Fruit Notes, Volume 62 (Number 3), Summer, 1997

Table 1 . Example: Jane Carter used one room (10%) of her personal residence as a home office. She
purchased the house in 1993 for $120,000 and sold it in June 1997 for $200,000. She lived in the
house during the four years and took $3,000 depreciation on the business part. Jane has two
transactions.

Personal residence portion

Business portion

Amount of sale

(90% of $200,000)

Cost basis (90% of $ 1 20,000)

Amount of sale
$ 1 80,000 ( 1 0% of $200,000)

$20,000

Realized and excluded gain

108,000

Unadjusted basis (10% of
$120,000)

$12,000

Depreciation

3,000

Adjusted basis

9,000

72,000

Recognized (taxable) gain

11,000

received at least $5,000 in compensation from
the employer last year and is reasonably
expected to make at least that amount next
year. For 1997, the amount of the employee's
salary reductions cannot exceed $6,000,
however it is not subject to percentage
limitations. Therefore, an employed person
who has a part-time self-employment activity
that earns $6,000 could deposit the entire
$6,000 in a SIMPLE plan. Employers are also
required to make contributions to the SIMPLE
plan on behalf of eligible employees, an equal

match up to 3% of pay of each contributing
employee or a flat 2% of pay of all employees,
whether they contribute or not. Contributions
to a SIMPLE plan are not subject to income tax
until they are distributed. The IRS has
provided forms (Form 5303-SIMPLE for use
with a designated financial institution and
Form 5304-SIMPLE for use with no designated
financial institution). These forms are not filed
with the IRS but form the legal contract
between employer and employees for
implementation of the SIMPLE IRA.

•J> Vl> •^1^ •si-* •X*

•^ •^ rp» 0^ •^

Fruit Notes, Volume 62 (Number .3), Summer, 1997

Evaluation of Peach and Nectarine
Cultivars for Massachusetts Orchards

Karen I. Hauschild

Deparfment of Plant & Soil Sciences, University ofMcissachusetts

As Massachusetts apple growers face in-
creasing competition from producers worldwide,
they are turning to retail sales to maintain or
enhance their economic viability. Additionally,
the popularity of new apple cultivars has con-
tributed to the decline in market share for Mcin-
tosh, the major variety.

As an alternative to apples, Western Mas-
sachusetts growers have been especially suc-
cessful with peaches. They rarely lose a crop to
cold or frost injury, and have a clientele base
that is looking for local, tree-ripened fruit. Cen-
tral and Eastern Massachusetts retail growers
also grow peaches, but these areas have been
more likely to experience partial or full crop
losses due to spring frosts. These growers, then,
are constantly searching for hardier cultivars.

For most retail growers, the decision to grow
or add additional peaches is an easy one. Choos-
ing cultivars is more difficult. In an effort to
assist Massachusetts growers with cultivar
choices, a cultivar trial was established at the
University of Massachusetts Horticultural Re-
search Center (HRC), included Flower bud har-
diness, fruit size, harvest season, and fruit qual-
ity have been evaluated.

The first trees in the cultivar evaluation
trial were planted in 1990, and cultivars were
added in 1998, 1994, and 1996. Trees were pur-
chased from commercial nurseries and planted
in a 10' X 20' spacing. Four-tree plots of each
cultivar were used. Trees were mananged as
in commercial plantings.

Results

Cultivars included in the trial are listed in
Table 1 was evaluated following a test winter
of 1993-4 during which a low of -15EF was re-
corded at Quabbin Reservoir (approx. 1.5 miles

north of the HRC). On 4 May 1994, 1 evaluated
bloom visually on all trees that were planted in
1990. I estimated bud survival on the top and
bottom (below 4 feet) half of each tree. Table 2
lists cultivars that averaged more than 30% bud
survival. From these results it appears that
Madison has relatively hardy flower buds. Al-
though most of the trees in the 1990 planting
began fruiting in 1991 or 1992, data recorded
from 1991-96 is incomplete. Fruit quality was
evaluated yearly, and yield data is available for
several cultivars during this time, however

In 1997, at least one 10-fruit sample per cul-
tivar (except the 1996 planting) was weighed,
measured, and judged for quality. Table 3 lists
the most promising cultivars based on size, as
well as average weight, average size, and har-
vest date.

Recommendations

Of the yellow-fleshed cultivars that met the
three-inch size criterion determined by grow-
ers, eight also met the criteria for quality:
Bounty, Encore, Fayette, Flavorcrest,
JimDandee, Madison, Salem, and Sentry. Al-
though the size and quality assessments of both
Fayette and Encore were very favorable, the har-
vest timings of both cultivars very likely are
too late for the majority of growers whose main
crop is apples. Summer Pearl was the only
white-fleshed peach that met size and quality
criteria. It is 75% -i- red to dark red; firm, juicy,
with sweet, melting flesh. Of the nectarines
evaluated, Earliscarlet and Fantasia have both
consistently maintained heavy yields, good size,
excellent color and exceptional fruit quality.

Of the cultivars that met the size criteron,
but did not meet quality standards in 1997, sev-
eral have shown promise in other years:

Fruit Notes, Volume 62 (Number 3), Summer, 1997

Table I. List of cultivars by years planted in the Massachusetts Peach Cultivar
Evaluation Trial.

Ripening

Year date relative

Cultivar planted to Redhaven Type^

Jerseydawn 1990 -5 Y

Redhaven Y

Salem +6 Y

Summer Pear! +20* W

Flavorcrest

-1-20

Newhaven

Madison

+24

Earliscarlet

-10

Fantasia

+31

Redgold

+29

Summer Beaut

Bounty

Encore

+36

Fayette

+30*

Harcrest

+26*

NJ 275 (Ernie's

Choice)

+9*

Harrow Beauty

+21*

Jim Dandee

+8*

Earlired

1993

-19

Beekman

+20

JohnBoy

Sentry

-12

Mt. Rose

+ 15*

Lady Nancy

+31*

Red Rose

+15*

Sugar Lady

1994

+ 11

White Lady

+15

Eastemglo

-10

Sunglo

+ 12

PF- 1 (Flaming Fury Series)

1996

-20

PF-15A

+ 13

PF-17A

+17

Raritan Rose

Arctic Glo

-10

Arctic Rose

Arctic Queen

+28

*N = yellow-fles

hed nectarine; Y =

= yellow-fleshed

peach; W =

white-fleshed peach;

WN = white-fleshed nectarine.

Fruit Notes, Volume 62 (Number 3), Summer, 1997 13

Table 2. Percentage bud survival

, averaged

over four trees per cultivar.

Cultivar

Lower

Upper

Flavorcrest

25%

75%

Newhaven

10%

75%

Earliscarlet

10%

50%

Fantasia

10%

60%

Redgold

40%

60%

Summer Beaut

10%

60%

Madison

75%

90%

Harcrest

10%

60%

Table 3.

Average size, size range, average

weight, percentage

of split pits, and harvest dates for more promising cultivars. |

Fruit

Diameter

weight

Splits

Harvest

Cultivar

(in.)

(g)

(%)

date

Jerseydawn

2.9

195

14 Aug.

Sentry

3.1

278

4 Aug.

Earliscarlet

2.9

202

15 Aug.

Newhaven

2.9

205

19 Aug.

Flavorcrest

3.0

209

19 Aug.

Bounty

3.1

278

27 Aug.

Salem

3.1

255

26 Aug.

Jim Dandee

3.2

261

26 Aug.

Sugar Lady

3.0

231

26 Aug.

Mt. Rose

3.0

217

26 Aug.

White Lady

3.0

227

27 Aug.

Red Rose

3.0

235

4 Sept.

Beekman

2.9

234

4 Sept.

Lady Nancy

3.1

232

10 Sept.

Madison

3.2

259

15 Sept.

Fantasia

3.0

273

15 Sept.

Sum. Pearl

2.9

224

15 Sept.

Harcrest

2.9

207

15 Sept.

Redgold

3.0

267

15 Sept.

Encore

3.1

256

1 Oct.

Fayette

3.1

252

25 Sept.

Fruit Notes, Volume 62 (Number 3), Summer, 1997

Newhaven, Sugar Lady, White Lady, Mt. Rose,
Harcrest, Redgold, and Summer Beaut.

Trees in the 1993 planting did not do well.
They were planted late, and suffered from a dry,
hot summer. Trees of four of the cultivars in
this planting were replanted in 1996, and should
bear enough fruit for evaluation in 1998.
JohnBoy is one cultivar that should perform
well.

Data from the 1990 planting will be collected
for at least one more year Because the de-
mand for peaches and nectarines has been high
at the Horticultural Research Center
farmstand, these trees will most likely remain

until other, commercial, plantings come into
production. Cultivars from all plantings should
bear fruit in 1998, and data will be collected for
at least two more seasons from the 1993, 1994,
and 1996 plantings.

Acknowledgments

The author wishes to recognize Mr. Joe
Sincuk, Mr. Jim Krupa, and the field crew at
the Horticultural Research Center. This work
would not have been possible without their as-
sistance.

•X» •^ •^ •kl> •sl^

0^ r^ #^ •^ r^

Fruit Notes, Volume 62 (Number 3), Summer, 1997

Fruit Notes

University of Massachusetts

Department of Plant & Soil Sciences

205 Bowditch Hall

Amherst, MA 01003

Nonprofit Organization
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Ffe8

'rult Notes

Prepared by the Department of Plant & Soil Sciences.

UMass Extension, U. S. Department of Agriculture, and Massachusetts Counties Cooperating.

Editors: Wesley R. Autio and William J. Braxnlage

BIOLOGICAL s

— :s3

vJD •V>.

MAY 2 1 1998

SCIENCES LIBRARY

Volume 62, Number 4
PALL ISSUE, 1997

Table of Contents

Tests of Imidacloprid-treated Spheres
for Controlling Apple Maggot Fly

A Preliminary Study of 1PM Options for Peaches: Brown Rot

Establishment and Spread of Released Typhlodromus pyri Predator
Mites in Apple Orchard Blocks of Different Tree Size: 1997 Results

An Update on the 1991 Mcintosh Strain/Rootstock Trial

Comparison of Ladd Traps, Red Spheres, and Yellow Panels for
Capturing Apple Maggot Flies in Commercial Apple Orchards

Can We Predict Flyspeck Development?

Fruit Notes

Publication Information:

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

The costs of subscriptions to Fruit Notes are $ 1 0.00 for United States
addresses and $ 1 2.00 for foreign addresses. Each one-year subscription
begins January 1 and ends December 3 1 . Some back issues are available
for $3.00 (United States addresses) and $3.50 (foreign addresses). Pay-
ments must be in United States currency and should be made to the
University of Massachusetts.

Correspondence should be sent to:

Fruit Notes

Department of Plant & Soil Sciences
205 Bowditch Hall
University of Massachusetts
Amherst, MA 01 003

UMASS EXTENSION POLICY:

Issued by UMass Exleiisinii. Ruben G Hetjtesen. Direclnr, in lurlberance of the iicis of May H and June 30,
1914. UMiiss Extension offers equal apparlunily in pnif;ianis and empliiynienl.

Tests of Imidacloprid-treated Spheres
for Controlling Apple Maggot Fly

Starker Wright, Xing Ping Hu, and Ronald Prokopy
Department of Entomology, University of Massachusetts

In the 1996 and 1997 Spring issues oi Fruit
Notes, we reported on studies aimed at devel-
opment of pesticide-treated spheres (PTS) as a
substitute for sticky spheres for direct control
of apple maggot flies. In concept, a PTS would
be coated with a mixture of insecticide, fly feed-
ing stimulant, and residue-extending agent. A
fly landing on such a sphere would feed, ingest
insecticide, and die before laying any eggs. The
need to use labor-intensive sticky substances
(such as Tangletrap) to capture alighting flies
would be eliminated. Several earlier trials in-
dicated that dimethoate was the most effective
among orchard-labeled insecticides for use on
spheres, but its high human toxicity poses too
great a risk to the handler. In 1996, we found
that the newly-labeled insecticide imidacloprid
was a safer alternative to dimethoate and was
seemingly as effective.

Sucrose (table sugar) has proven to be, by
far, the most effective fly feeding stimulant.
However, while mixing with latex paint pre-
serves the residual activity of the insecticide,
all sugar is lost from the sphere surface follow-
ing rainfall. We have taken two separate ap-
proaches to preserving residual activity of su-
crose: (1) development of a method in which
the activity of sucrose is extended on reusable
wooden spheres, which are annually coated with
a mixture of sucrose, insecticide, and latex paint;
and (2) development of a method in which the
entire sphere body is constructed of a mixture
of sucrose, flour, and glycerin, coated with a mix-
ture of insecticide and latex paint so as to cre-
ate a biodegradable sphere. Here we report on
two experiments leading to refinement of resi-
due-extending agent, fly-killing agent, and
evaluation of each sphere type for direct con-
trol of apple maggot flies in commercial or-
chards.

Materials & Methods

In our first experiment, we evaluated in
laboratory studies three formulations of
imidacloprid (EC, WP, technical grade) in com-
bination with each of three formulations (flat,
semi-gloss, gloss) of each of four commercial
brands of red latex paint (36 treatments in all).
We found the EC and WP formulations of
imidacloprid in Glidden Red Latex Gloss
Enamel paint to be the most promising. We then
placed wooden spheres coated with two concen-
trations of each formulation of imidacloprid in
orchard trees and evaluated them for their abil-
ity to kill apple maggot flies at 0, 3, 6, 9, and 12
weeks after placement.

In our second experiment, two sphere types
were assessed in an attempt to extend the re-
sidual activity of sucrose on the sphere surface.
Each wooden PTS was fitted with a 3-cm-di-
ameter ring of specially formulated caramelized
sucrose around the hook at the top of the sphere.
The sucrose spread down the sides of the sphere
after each rainfall, continually replenishing the
sugar supply on the sphere surface. This type
of sphere was developed as a replacement for
spheres tested in 1996 in which holes were
drilled and filled with sucrose prior to paint-
ing, as described in the Spring 1997 issue of
Fruit Notes. Further testing of the 'spheres with
holes' revealed that construction was far too
costly and time consuming to be of practical
value. For sugar/flour biodegradable spheres,
the following composition of ingredients proved
best: sucrose/fructose syrup (25%),
pregelatinized corn flour (25%), wheat flour
(25%), glycerin (10%), and water (15%). After
hardening in the laboratory, such spheres emit
a continuous supply of sugar to the surface, ir-
respective of rainfall amount.

Fruit Notes, Volume 62 (Number 4), Fall, 1997

We then compared the effectiveness of our
best wooden PTS and our best sugar/flour PTS
with sticky-coated spheres for direct season-
long control of apple maggot flies in commer-
cial orchards. In all, we used eight orchards,

each having four blocks of medium-sized trees
(49 trees/block). Each block receiving spheres
was surrounded by 26 spheres of the same type,
five yards apart, each baited with butyl
hexanoate.

Table 1. Residual activity
concentrations of imidaclopric
orchard trees and exposed to w

of two different formulations and two different
in latex paint on sucrose-treated spheres hung in
eather.

Fly mortality (%)*

Weeks of
Exposure

0.5% EC

1.5% EC

0.5% WP

1.5% WP

Check

97a

96a

98a

96a

93a

90a

95a

70b

92a

85a

94a

60b

90a

80a

90a

45c

87ab

75b

90a

No. eggs laid in artificial fruit*

26b

28b

25b

21b

24b

Median lethal feeding time*

30a

20a

30a

20a

80b

40a

75b

35a

182b

45a

180b

40a

240b

50a

210b

45a

300c

100a

240b

60a

* Three replicates of 20 flies per treatment. Numbers
different letters are significantly different at odds of 19:1.

within rows

followed by

Fruit Notes, Volume 62 (Number 4), Fail, 1997

Table 2. Control of apple maggot flies by odor-baited wooden pesticide treated
spheres (PTS), sugar/flour PTS, sticky spheres or three applications of
azinphosmethyl in blocks of apple trees in commercial orchards.

Mean % maggot-injured apples'*

Wooden
PTS

Sugar/flour
PTS

Sticky
Spheres

Azinphosmethyl

0.56b

0.32ab

0.11a

* Total of 2800 fruit per treatment (100 fruit per block on each of four sampling
dates-2 weeks apart-from late July until harvest). Numbers followed by a different
letter are significantly different at odds of 19:1.

Results

Laboratory bioassays revealed (Table 1) that
after 12 weeks of exposure to outdoor sunlight
and 11 inches of natural rainfall, wooden
spheres treated with 1.5% a.i. imidacloprid WP
in Glidden paint killed 90% of arriving flies.
Such treatment also rendered all flies incapable
of lajdng eggs after feeding and required that a
fly feed on the sphere surface for a median time
of only 60 seconds to ingest enough toxicant to
die. Performance of wooden spheres treated
with 1.5% imidacloprid EC was slightly but not
significantly inferior, killing 87% of arriving
flies. At lower concentrations (0.5% a.i.), nei-
ther the WP nor EC formulation performed as
well (75% and 45% kill, respectively) as the 1.5%
a.i. WP formulation.

In our second experiment (Table 2), sugar/
flour PTS coated with 1.5% imidacloprid WP in
Glidden paint performed as well as sticky
spheres in providing direct control of apple
maggot. Wooden PTS coated with 1.5%
imidacloprid in Glidden paint and fitted with a
3-cm-diameter sucrose ring were inferior Two-
to-three insecticide sprays resulted in the least
damage.

Conclusions

Our first experiment provided us with the
formulation of a low dose of a safe and highly
effective insecticide (1.5% a.i. imidacloprid WP)
that can be combined with a particular type of
paint (Glidden Red Latex Gloss Enamel) which
offers very long and effective residual activity
of imidacloprid under field conditions.

Although all sphere types used in the sec-
ond experiment performed quite well in the face
of high fly pressure, shortcomings need to be
addressed and improvements need to be made
before future use of PTS for controlling apple
maggot in commercial orchard IPM blocks.
Regarding wooden PTS, the caramelized sucrose
rings melted away before the end of the field
season, contributing to the reduced effective-
ness of these spheres. Some of the sugar/flour
PTS were eaten by birds and rodents while oth-
ers were overgrown by fungi on the sphere sur-
face, thus reducing the number of effective
spheres comprising the barrier to fly entry into
some blocks.

For 1998 deployment of wooden PTS, we
plan to reformulate the sucrose ring atop the
sphere to improve residual effectiveness of the

Fruit Notes, Volume 62 (Number 4), Fall, 1997

spheres. For sugar/flour biodegradable PTS, we
will evaluate various bird/rodent-feeding deter-
rents and various fungicides incorporated into
the body of the sphere.

Acknowledgments

This work was supported by state/federal

IPM funds and grants from the New England
Tree Fruit Growers Research Committee and
the USDA Northeast Regional IPM Competi-
tive Grants Program. We are grateful to the
eight growers that participated in this study:
Bill Broderick, Dana Clark, Dave Chandler,
Tony Lincoln, Wayne Rice, Dave Shearer, Joe
Sincuk, and Tim Smith.

*\a •Jt* •X^ •Xa •Xa
ry% #Y* *T* *T* *T*

Fruit Notes, Volume 62 (Number 4), Fall, 1997

A Preliminary Study of IPI\/I Options for
Peaches: Brown Rot

Daniel Cooley and Arthur Tuttle

Department of Microbiology, University of Massachusetts

Karen Hauschild and Joe Sincuk

Department of Plant & Soil Sciences, University of Massachusetts

Peaches have gained more attention from
Massachusetts tree-fruit growers, who in
recent years have been looking for crop options
in addition to apples. Peaches can produce
highly saleable fruit earlier in the season, and
usually command a good price, particularly for
direct market sales. High quality peaches
which have been allowed to ripen on the tree
longer than peaches shipped from California,
New Jersey, or the South can get a premium
price. However, the riper a peach is, the higher
the chances are that it will develop brown rot or
other postharvest decays. This may happen on
the tree, or worse yet, on the customer's shelf.
While other rots can be a problem, peach brown
rot, caused by the fungus Monilinia fruciico/a,
is the most serious fungal disease problem for
Massachusetts growers, and fungicides used on
peaches primarily are aimed at managing this
disease. The timing of these fungicide
applications is based largely on tree develop-
ment, but it is not clear what timing scheme is
most effective and efficient.

The biology of the fungus suggests that
there are two critical times when peaches
should be protected: bloom and fruit ripening.
Brown rot infections on peach develop during
these two phenological stages. Blossom blight
may cause flowers to wither, turn brown, and
die, and later produce spores which later infect
fruit. These blossom infections may also move
into twigs and cause significant damage when
conditions for disease development are highly
favorable. Normally blossom infections remain
quiescent, or latent, until fruit starts to ripen.

Then, the infections will start to grow, produce
spores, and spread to other ripe fruit. Between
bloom and harvest, fruit susceptibility to
brown rot remains quite low from pit hardening
to 2 weeks before full ripeness (Biggs and
Northover, 1988). By monitoring pit hardening
and ground color, growers might eliminate
fungicide sprays during this period, and get
better brown rot control.

Materials & Methods

To examine the effect of reducing fungicide
use for managing brown rot during pit
hardening, an experiment was conducted at the
University of Massachusetts Horticultural
Research Center during the 1996 growing
season. The experiment was conducted in two
blocks of peaches, one Redhaven and the other
Glohaven. Each treatment plot consisted of
three trees. There were three replications of
the experiment in the Redhaven block and four
in the Glohaven block.

Sampling for pit hardening was done in
mid- through late June. Until pit hardening in
early June, all treatment plots received
standard calendar-based fungicide applica-
tions every 7 to 10 days, starting at early bloom.
These consisted Captan 80WP at 1 lb/100 gal.
After that time, fungicides were applied
according to four treatment patterns. In one
treatment, the calendar applications were
continued at 7 to 14 day intervals, using
Captan (SOW, 1 Ib./lOO gal.) on the early spray
dates or the same rate of Captan plus Benlate

Fruit Notes, Volume 62 (Number 4), Fall, 1997

Table 1. Fungicide treatments in Redhaven
Massachusetts Horticultural Research Center, B(

and Glohaven
jlchertown, MA,

peach
1996.

3s at

the

University of

Pesticide (rate/100 gal.)

Dates

Fungicide applications
after pit hardening
(no. after 10 July)

Full spray

Captan

SOWPdlb.)

17 June, 2 July, 14 July

Captan

80WP + Benlate 50DF (6 fl oz.)

25 July, 2 Aug.

Reduced spray

Captan

SOWPdlb.)

2 July, 14 July

Captan

80WP + Benlate 50DF (6 fl oz.)

2 Aug.

Low spray

Captan

SOWPdlb.)

2 July

Captan

80WP + Benlate 50DF (6 fl oz.)

2 Aug.

No spray

None

none

(50DF 6 fl oz./lOO gal.) on later dates. In a
second treatment, one fungicide application
was made between pit hardening and fruit
ripening, with one additional fungicide applica-
tion during fruit ripening using the same
fungicides and rates. In the third treatment, no
fungicide applications were made following pit
hardening and one fungicide application was
made during fruit ripening using the same
fungicides and rates. A fourth treatment was
not sprayed at all. These treatments with the
numbers and dates of applications are detailed
in Table 1.

Redhaven fruit were harvested on 15 and 2 1
Aug.; Glohaven fruit were harvested on 3 Sept.
Therefore, the last fungicide applications were
made from 2 to 4 weeks before harvest,
depending on the cultivar, and 2 to 4 weeks
after pit hardening. Therefore the experiment
evaluated the effect of different numbers of
fungicide sprays applied during pit hardening.

from no sprays to five sprays.

Evaluation of fruit rot damage was done at
harvest, and 5 to 7 days after harvest. Brown
rot and other rots were distinguished on the
basis of symptoms. Disease incidence is the
number of fruit which show any disease.
Disease severity estimates the extent of fruit
rot using a 1 to 5 scale, with 1 the least severe
and 5 the most severe.

Results & Discussion

The number of fungicide applications after
pit hardening but before ripening had an effect
on brown rot and other rots, but it was not
consistent. In Redhaven fruit at harvest, there
was significantly less rot in the full spray and
reduced spray treatments compared with the
low spray treatment (Table 2). However, the no
spray treatment also had significantly less
brown rot at harvest compared with the low

Fruit Notes, Volume 62 (Number 4), Fall, 1997

Table 2. Disease evaluations on Redhaven
schedules, University of Massachusetts Hortic

peach fruit under different pesticide
ultural Research Center, 1996.*

treatment

At harvest

Postharvest

Brown rot
incidence
Treatment (%)

Brown rot
severity

Incidence
of other
rots (%)

Severity

of other

rots

Brown rot
incidence

(%)

Incidence
of other
rots (%)

Full spray 2 b
Reduced spray 4 b
Low spray 8 a
No spray 4 b

0.02 c
0.11b
0.19 a
0.07 c

Ob
Ob
2a
Ob

0.01 b
0.00 b
0.05 a
0.00 b

24 b
21b
31b
49 a

14 a

21 a

14 a

9 a

* Severity; 1 = least severe, 5 = most severe. Means in each
not differ significantly from each other at odds of 19:1.

column followed by the same letter do

Table 3. Disease evaluations on Glohaven peach fruit under different pesticide treatment
schedules, University of Massachusetts Horticultural Research Center, 1996.*

At harvest

Postharvest

Brown rot

Incidence

Severity

Brown rot

Incidence

incidence

Brown rot

of other

incidence

of other

Treatment

{%)

severity

rots (%)

rots

(%)

rots (%)

Full sprays

0.18 c

1 a

O.Ola

37 a

20 a

Reduced spray

20 b

0.52 b

1 a

O.Ola

60 a

28 a

Low spray

10 c

0.30 c

2 a

0.02 a

32 a

12 a

No spray

48 a

1.30 a

1 a

0.01 a

58 a

36 a

* Severity: 1 = least severe, 5 - most severe. Means in each column followed by the same letter
do not differ significantly from each other at odds of 19:1.

spray regime. Approximately one week after
harvest, none of the sprayed treatments had
significantly different brown rot incidences.

and all were lower than the no spray treatment.

In Glohaven fruit, the pattern was closer to

what one would expect (Table 3). At harvest,

Fruit Notes, Volume 62 (Number 4), Fall, 1997

the no spray treatment had more brown rot and
more severe brown rot than any of the spray
treatments. Again, brown rot was lowest in the
full spray trees. However, in this cultivar,
brown rot was just as low in the low spray
treatment, and significantly higher in the
reduced spray treatment.

Unfortunately, this test did little to resolve
the usefulness of fungicides during the period
between pit hardening and harvest. None of
the reduced-spray options consistently did as
well as the five-spray program. It is difficult to
explain the failure of two fungicide applica-
tions vs. no applications in Redhaven, and of
three applications vs. two applications in
Glohaven. It is possible that there was
contamination caused by fungicide drift.
Beyond that, there may have been differences
in inoculum or other factors which were not
adequately controlled.

This test did not conform to the recommen-
dations made by Biggs and Northover. Rather
than eliminating or reducing sprays after pit
hardening, and then making one or two
applications very near harvest as fruit ripened,
this test looked at different numbers of
fungicide applications made after pit harden-
ing but stopping all fungicides at least two
weeks before harvest. This may account for the
results, as Captan and Benlate would not
generally persist for more than a week against
heavy brown rot pressure. Any small, random
outbreak of brown rot would have been able to
spread in all treatments during the 2 to 3
unprotected weeks before harvest. Only the
heaviest fungicide treatment consistently
reduced this problem.

A similar experiment, focusing on bloom
and harvest fungicide applications, will need to
be done to resolve these problems.

•sL* vj> vL* vl>» vL*
#Y* *T* "T* *T* *Y*

Fruit Notes, Volume 62 (Number 4), Fall, 1997

Establishment and Spread of Released
Typhlodromus pyri Predator Mites in
Apple Orchard Blocks of Different Tree
Size: 1997 Results

Ronald Prokopy, Starker Wright, and Jonathan Black
Department of Entomology, University of Massachusetts

Jan Nyrop, Karen Wentworth, and Carol Herring

Cornell University, NY Agricultural Expe?ime?it Station, Geneva

Pest mites are usually completely controlled
by predatory mites on unmanaged apple trees
that receive no insecticide or fungicide. Some
commonly-used orchard pesticides (e.g.,
synthetic pyrethroid insecticides, EBDC
fungicides) kill or otherwise harm predatory
mites, leading to pest mite outbreaks and need
for miticide application. In Massachusetts, the
predatory mite Amblyseius fallacis is present
in about 90% of commercial orchards (see 1994
Spring issue oi Fruit Notes) but usually not in
numbers sufficient for providing mite biocontrol
until August. Studies in New York have shown
that the predatory mite Typhlodromus pyri,
where established, can be an extremely
effective season-long biocontrol agent of pest
mites. This is a result of their ability to endure
cold winter temperatures and periods of short
supply of pest mites as food much better than^.
fallacis. Unfortunately, few Massachusetts
orchards appear to harbor significant natural
populations of T. pyri.

In the 1997 Spring issue oi Fruit Notes, we
reported that when T. pyri obtained from
Geneva, New York were released in 1995 into
blocks of apple trees in six commercial orchards
in Massachusetts, they became established in
all blocks save those in one of the six orchards.
On average, after two years, they had built to
greater numbers in blocks managed under
second-level IPM practices (no pesticide of any

type used after early June) than in blocks
managed under first-level IPM (sprayed with
fungicide and insecticide through summer).
These findings stimulated us to conduct
further research on the establishment oiT.pyri
released in Massachusetts apple orchards.

We report here first-year results of a study
in which T.pyri were released in 1997 on single
trees in the center of blocks comprised of small,
medium, or large trees and managed under
third-level IPM practices.

Materials & Methods

Our experiment was conducted in six blocks
of apple trees in each of eight commercial
orchards. Of the six blocks per orchard, two
each contained trees on M.9, M.26, or M.7
rootstock, designated as small, medium-size, or
large trees. One block of each pair received
first-level IPM practices, wherein growers
applied insecticide and fungicide materials of
their own choosing and timing of application,
which extended from April through August.
The other block of each pair received third-level
IPM practices, wherein the intent was that no
synthetic pjrrethroid insecticide was to be used
at any time, use of EBDC fungicides was to be
minimized, no insecticide of any type was to be
used after mid June, and captan or benomyl
were the only fungicides to be used after mid

Fruit Notes, Volume 62 (Number 4), Fall, 1997

June. T. pyri is known to be highly adversely
affected by synthetic pyrethroid insecticide and
also adversely affected by EBDC fungicide
(when applied from bloom onward) but not by
captan or benomyl. Each block was comprised
of 49 trees (7 rows x 7 trees per row) and of the
cultivars Mcintosh, Empire, and Cortland.
Third-level IPM is similar to second-level IPM
in focus on using biologically-based pest
management practices, but it embraces
integration with horticultural concerns (such
as tree size) as an added component.

In May, blossom clusters harboring T. pyri
were picked from an orchard at the New York
State Agricultural Experiment Station at
Geneva, sent by overnight mail to
Massachusetts, and within three days were
distributed to orchard blocks. Each third-level
IPM block recieved 100 clusters, which were
attached to twigs on the center tree of the block
using twist ties. No T. pyri were released in
first-level IPM blocks. Every 3 weeks from late
July through early September in each of the 48
blocks, we sampled 25 leaves from the center
tree, 15 leaves from each of the two outermost
trees in the center row, and 15 leaves each from
the center tree in each of the two outermost
rows. The leaves were sent by overnight mail to
Geneva, New York for the identification and
counting of pest and predatory mites. In all,
about 2,600 leaves were sampled for each of the
three sampling periods.

Results

As shown in Table 1, significantly more T.
pyri-were present on the center (release) tree on
each sampling date in blocks of each tree size
than on outer trees in center rows of blocks
(that is, the fourth tree up row and the fourth
tree down row from the center tree in a block) or
on center trees in outer rows of blocks (that is,
the fourth tree directly across row to either side
of the center tree of a block). In fact, extremely
few or no T. pyri were found on any tree except
those on which they were released. In contrast,
there were no significant differences among
tree locations within plots in numbers of A.
fallacis sampled on each sampling date in

blocks of each tree size (data not shown). The
same was true for European red mites (data not
shown).

The finding that, on average, numbers of
European red mites were not significantly
fewer on release trees than on non-release trees
on any sampling date in blocks of any tree size
suggests that T. pyri were not able to build to
sufficient numbers to provide biocontrol of
European red mites during the three months
following release. This was not a surprising
result because T. pyri populations grow slowly
and usually are not capable of rapidly
controlling moderate to high density red mite
populations. Even so, there was one block of
small trees in which T. pyri were released
where every tree (save one) in that block (as
well as every tree in each of the other five study
blocks in that orchard) was heavily bronzed as
a consequence of mite injury. The only tree that
was not bronzed was the center tree on which T.
pyri were released.

Data in Table 2 summarize information of
all leaves sampled in a block and compare
average numbers of T. pyri, A. fallacis and
European red mites per leaf between first-level
IPM blocks and third-level IPM blocks and
among small, medium, and large trees within
each sampling date. For each sampling date,
there was no significant difference among
blocks of small, medium-sized, and large trees
in numbers of 7! pyri found in third-level IPM
blocks. In every case, third-level IPM blocks
had significantly more T. pyri than first-level
IPM blocks. For A. fallacis there were no
significant differences in numbers found
between first-level and third-level IPM blocks
or among tree sizes for any sampling date. The
same was true for European red mites.

Information on type and amount of
insecticide, acaricide, and fungicide used
before bloom, from bloom through mid-June,
and after mid- June is given in Table 3. Blocks
of small, medium, and large trees in the same
orchard were treated in the same manner.
With respect to insecticide, some Asana was
used before bloom and some Lorsban after mid-
June in first-level blocks. Both of these
materials are known to be detrimental to T.

Fruit Notes, Volume 62 (Number 4), Fall, 1997

Table 1. Abundance of T. pyri mite predators on leaves sampled in July, August, and September
in 1997 from first-level and third-level IPM blocks. T. pyri were released on the center tree in
each block in mid-May 1997.

Mean no. per leaf '

Sample time

Tree size Sample site

First-level 1PM Third-level IPM

Late July

Mid-August

Large

Medium

Small

Large

Medium

Small

Early September Large

Medium

Small

Center tree

0.00 b

0.34 a

Center row, outer trees

0.01 b

0.01b

Outer row, center trees

0.00 b

Center tree

0.03 b

0.54 a

Center row, outer trees

0.00 b

Outer row, center trees

0.00 b

Center tree

0.00 b

0.68 a

Center row, outer trees

0.00 b

0.09 b

Outer row, center trees

0.00 b

Center tree

0.00 b

0.62 a

Center row, outer trees

0.00 b

0.01b

Outer row, center trees

0.00 b

0.01b

Center tree

0.00 b

1.13 a

Center row, outer trees

0.00 b

Outer row, center trees

0.00 b

Center tree

0.00 b

0.97 a

Center row, outer trees

0.00 b

Outer row, center trees

0.00 b

Center tree

0.00 b

0.87 a

Center row, outer trees

0.07 b

0.01 b

Outer row, center trees

0.01b

0.00 b

Center tree

0.00 b

0.67 a

Center row, outer trees

0.00 b

0.01b

Outer row, center trees

0.00 b

Center tree

0.00 b

0.55 a

Center row, outer trees

0.00 b

Outer row, center trees

0.00 b

0.01b

* For each size of tree at each time of sampling, numbers followed by a different letter are
significantly different at odds of 19:1.

Fruit Notes, Volume 62 (Number 4), Fall, 1997

Table 2. Abundance of T. pyri, A. fallacis, and European red mites (ERM) on leaves sampled in July,
August, and September in 1997 from first-level and third-level IPM blocks.

Mean num

ber per leaf*

pyri

A. fallacis

ERM

1^' level

S'^'' level

1"' level

S-^d level

1«' level

3^d level

Sample time

Tree size

IPM

Late July

Large

0.00 b

0.12 a

0.04 a

3.6 a

7.2 a

Medium

0.01b

0.18 a

0.08 a

0.10 a

3.3 a

4.9 a

Small

0.00 b

0.26 a

0.05 a

0.07 a

8.8 a

5.7 a

Mid-August

Large

0.00 b

0.21a

0.06 a

0.15 a

9.9 a

9.0 a

Medium

0.00 b

0.38 a

0.43 a

0.36 a

9.6 a

2.6 a

Small

0.00 b

0.33 a

0.11a

0.24 a

4.0 a

10.4 a

Early September

Large

0.01b

0.21a

0.15 a

0.17 a

2.9 a

1.3 a

Medium

0.00 b

0.26 a

0.15 a

0.17 a

1.0 a

3.3 a

Small

0.00 b

0.26 a

0.09 a

0.13 a

1.4 a

4.5 a

* Each value represents the average number of individuals found on 55 leaves per block per sampling
date (25 leaves from the center tree and a total of 30 leaves from four other trees in the blocks, all of
which were four trees removed from the center tree). For each tree size at each time of sampling,
numbers followed by a different letter are significantly different at odds of 19:1.

pyri. The fact that they were not used in third-
level blocks undoubtedly aided in establishment
of T. pyri. None of the acaricides used in either
first-level or third-level blocks is known to
affect T. pyri substantially. As hoped, none of
the third-level blocks received any Manzate,
Dithane, Mancozeb, or Penncozeb as fungicides,
whereas first-level IPM blocks received
substantial amounts of these materials up to
mid-June. Third-level IPM blocks did,
however, receive some Polyram before bloom
and a small amount after bloom. Some data
indicate that Polyram is just as harmful to T.
pyri as the other four aforementioned EBDC
fungicides, which are especially harmful when
applied during or after bloom. In general, the
profile of fungicides applied in third-leve) IPM

blocks was quite (although not completely)
conducive to establishment of T. pyri.

Conclusions

The data presented here show convincingly
that T. pyri became established on trees in
which they were released: the centermost trees
in third-level IPM blocks of small, medium, and
large trees. Growers participating in this
experiment cooperated with its aims by not
applying harmful insecticides or acaricides and
by minimizing use of fungicides harmful to T.
pyri in the blocks in which T. pyri were
released. Interestingly, even more than three
months after release, T. /?>//■/ failed to move (in
detectable numbers) even as far as four trees

Fruit Notes, Volume 62 (Number 4), Fall, 1997

Table 3. Types and dosage equivalents of insecticides, acaricides, and fungicides applied per
block in first-level and third-level IPM blocks in 1997.

Material

Before bloom

1^^ level S-^"* level

Bloom through
mid-June

Insecticide

Acaricide

Fungicide

Asana

Dimethoate

Gution

Imidan

Lorsban

Provado

Sevin

Oil

Savey

Silwet

Agrimek

Pyramite

Omite

Benlate/Topsin

Nova/Rubigan

Manzate*

Polyram

Syllit

Captec

0.06

0.08

0.04

0.20

3.10

0.12
1.10

3.20

0.12
1.00

1.25
0.50
0.13

1.25
0.38
0.13

0.08

0.13
0.42
1.75
0.21
0.01

0.13
1.54

0.46
0.60

0.61

0.34

1.28

0.72

1.05

0.28

0.16

0.01

0.73

1.7

After mid-June

1^<- level 3'''' level 1" level 3"^ level

1.00
0.13
0.26

0.06

0.16

0.06

0.67

1.2

0.15

0.13

0.17

0.55

0.26

0.04

0.13

1.15

0.88

* Includes also Dithane, Mancozeb, and Penncozeb.

away downrow or crossrow, regardless of
whether blocks were comprised of small,
medium-size or large trees. We saw no
evidence of suppression of European red mites
by released T. pyri in any trees (except one) in
which T. pyri were released. In the lone
exception (a block of small trees), the foliage of
the release tree remained dark green throughout
summer, whereas the foliage of all other trees
in the block was decidedly bronzed by mid-July.
For 1998 and 1999, we plan to sample the same
trees sampled in each block in 1997. We expect
that by 1999, T. pyri will have spread to all
parts of each third-level IPM block and will

have provided effective biocontrol of European
red mites in such blocks, particularly in blocks
of small trees.

Acknowledgments

We are grateful to the eight growers
participating in this experiment and who made
special effort to apply pesticide selectively to
third-level IPM blocks: Bill Broderick, Dave
Chandler, Dave Cheney, Dana Clark, Dave
Shearer, Joe Sincuk, Tim Smith, and Mo
Tougas. This work was supported by state/
federal IPM

Fruit Notes, Volume 62 (Number 4), Fall, 1997

An Update on the 1991 Mcintosh
Strain/Rootstock Trial

Wesley R. Autio

Department of Plant & Soil Sciences, University of Massachusetts

As apple growers plan for future plantings, differences and those caused by rootstocks

it is important to understand how different were additive. Secondarily, tree size and yield

rootstocks and scions will perform. Much performance were studied. Because of some

rootstock research in recent years has studied surprising results, the tree size and yield

the interaction of scion and rootstock to allow performance from the Massachusetts half of

for better choice of combinations for commer- the trial are reported here,
cial orchards.

In 1991, a pair of plantings was established Materials & Methods
(one at the University of Massachusetts

Horticultural Research Center in Belchertown In the summer of 1988, scions of Pioneer

and one at the University of Maine Highmoor Mac (a Mcintosh seedling), Marshall Mcintosh,

Farm in Monmouth) to study effects of a Chic-A-Dee Mcintosh, and Rogers Red Mcln-

combination of Mcintosh strains plus one tosh were budded onto Mark, M. 7 EMLA, M. 27

Mcintosh seedling and four rootstocks. The EMLA, and M.26 EMLA rootstocks at the

original intent of this trial was to determine if University of Maine Highmoor Farm. Trees

differences in ripening caused by strain were allowed to growth through the following

Table 2. Yield efficiency and fruit weight in 1997of three strains of Mcintosh anc

one Mcintosh

seedhng on four rootstocks

planted in 1991.'

Yield efficiency (kg/cm^ trunk cross

sectional area)

Fruit
weight

Cumulative

Rootstock/Cultivar

1997

(1993-97)

(g)

Mark

0.77 b

2.60 a

157 a

M.7 HMLA

0.35 c

1.19 c

157 a

M.27 EMLA

1.04 a

2.81 a

146 a

M.26 EMLA

0.63 b

2.21 b

1 56 a

Pioneer Mac

0.74 a

2.48 a

145 c

Marshall Mcintosh

0.70 a

1.84 b

151 be

Chic-A-Dee Mcintosh

0.76 a

2.40 a

161 a

Rogers Red Mcintosh

0.59 a

2.09 ab

157 ab

' Overall rootstock means

within columns or

overall cultivar

means

within

columns are

significantly different at odds of 19:1 if not foil

owed by the same

letter.

14 Fruit Notes, Volume 62 (Number 4), Fall, 1997

Tabic 1. Trunk

cross-sectional

area and yield in 1997 of three strains of Mcintosh and one

Mcintosh seedlir

g on four rootstocks planted in 1991.'

Pioneer

Marshall Chic-A-Dee Rogers Red

Rootstock

Mac

Mcintosh Mcintosh Mcintosh

Average

Trunk cross-sectional area (cm^)

Mark

30.4 c

30.7 b 26.3 b 37.2 a

31.2c

M.7 EMLA

72.8 a

49.3 a 46.7 a 47.8 a

54.2 a

M.27 EMLA

10,9 d

9,8 c 7.2 c 7.9 b

9.0 d

M.26 EMLA

41. 8b

54.3 a 29.1b 37.0 a

40.6 b

Average

39.0 a

36.0 a 27.3 b 32.4 ab
Yield per tree (kg, 1997)

Mark

23 b

26 a 1 8 a 20 a

22 ab

M.7 EMLA

24 ab

14b 19a 18a

19b

M.27 EMLA

10c

9b 8b 9b

M.26 EMLA

32 a

31a 20 a 12 ab

24 a

Average

23 a

20 ab 16 be 15 c
Cumulative yield per tree (kg, 1993-97)

Mark

91 a

76 a 59 a 84 a

77 a

M.7 EMLA

93 a

44 b 67 a 59 b

66 b

M.27 EMLA

32 b

20 c 23 b 24 c

25 c

M.26 EMLA

106 a

93 a 70 a 65 b

83 a

Average

80 a

58 b 55 b 58 b

' Rootstock means within co

umns or overall cultivar means are significantly different at odds of

19:1 if not followed by the

same

letter.

two seasons in the nursery. In April of 1991,
seven replications of all combinations were
planted at the University of Massachusetts
Horticultural Research Center. Yield and tree
size were assessed each year.

Results & Discussion

Overall tree size at the end of the seventh
growing season followed expected patterns,

with trees on M.7 EMLA the largest, and those
on M.27 EMLA the smallest (Table 1). Further,
Pioneer Mac and Marshall trees were
significantly larger than Chic-A-Dee trees, and
Rogers trees were intermediate. Interestingly,
the relative differences among the four
rootstocks were not similar across the
cultivars. With Marshall Mcintosh, trees on
M.7 EMLA were smaller than expected and
similar to those on M.26 EMLA (Figure 1).

Fruit Notes, Volume 62 (Number 4), Fall, 1997

c
O

o
a>

o
o

C
3

100
90
80
70
60
50
40
30
20
10

Pioneer

Marshall

Mark
M.7 EMLA

M.27 EMLA
M.26 EMLA

Chic-A-Dee

Rogers

Figure 1. Trunk cross-sectional area in 1997 of three strains of
Mcintosh and one Mcintosh seedHng on four rootstocks. Within
cultivar, means without the same letter are significantly different
at odds of 19:1.

140

120

M 100

0)
01

4)
'>.

Pioneer

Marshall

Chic-A-Dee

Rogers

Figure 2. Cumulative yield per tree (1993-97) of three strains of
Mcintosh and one Mcintosh seedling on four rootstocks. Within
cultivar, means without the same letter are significantly different
at odds of 19:1.

Fruit Notes, Volume 62 (Number 4), Fall, 1997

Cumulative yield generally was as ex-
pected, with trees on M.26 EMLA producing
the most fruit and those on M.27 EMLA the
least. Pioneer Mac produced significantly more
fruit than Chic-A-Dee or Rogers, and Marshall
was intermediate; however, the relative
differences among the rootstocks varied with
cultivar. Cumulative yield of M.7 EMLA and
M.26 EMLA were similar for Pioneer Mac,
Chic-A-Dee, and Rogers, but Marshall/M.26
EMLA yielded more than double Marshall/M.7
EMLA (Figure 2). Rootstock effects on yield
efficiency followed consistent trends among
cultivars. Cumulatively, M.27 and Mark
produced the most efficient trees, followed by
M.26 EMLA, and M.7 EMLA produced the least
efficient trees (Table 2). Cumulatively, Pioneer
Mac and Chic-A-Dee were significantly more

efficient than Marshall, with Rogers interme-
diate (Table 2).

Rootstock did not affect fruit weight in
1997, but Chic-A-Dee resulted in significantly
larger fruit than Marshall or Pioneer Mac
(Table 2).

Tliese results lead to an interesting
question: Why does Marshall Mcintosh
respond poorly to M.7 EMLA? One possibility
is that M.7 EMLA is sensitive to a virus present
in Marshall. Marshall is not a virus-fruit
strain of Mcintosh. It may explain some of the
variable results with Marshall Mcintosh in
recent years, particularly reduced leaf quality,
tree growth, and fruit size. If considering
semi dwarf Mcintosh trees for future plantings,
likely it is best to avoid the combination of
Marshall and M.7 EMLA.

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Fruit Notes, Volume 62 (Number 4), Fall, 1997

Comparison of Ladd Traps, Red Spheres,
and Yellow Panels for Capturing
Apple Maggot Flies in Commercial
Apple Orchards

Juan Rull and Ronald Prokopy

Department of Entomology, University of Massachusetts

In a recent study in commercial apple
orchards, it was found that sticky red spheres
baited with butyl hexanoate caught four times
more apple maggot flies (AMF) than unbaited
red spheres. However, not everyone agrees
that baited red spheres are the best AMF trap.
For example, studies carried out in the western
U.S. seem to place sticky Ladd traps as being
equal or superior to sticky red spheres. Ladd
traps consist of a square yellow panel with a red

sphere m the center. The yellow panel is
believed to attract immature AMF whereas the
red sphere is believed to attract mature AMF.
Trap position is critical for effectiveness. We
speculated that Ladd traps in poor position
could have been more effective than red sphere
traps in poor position in studies favoring Ladd
traps as being superior. Finally, some of the
studies on Ladd traps were not performed in
commercial orchards, where incoming AMF

Table 1. Number of apple

maggot flies cau

Lght by different traps

in s

L commercial orchard

in Massachus

etts from late July

to early September,

1997.

Position in

Early (wk)

Late (w

Trap type

tree

Total*

Overall

Red sphere

Optimal

48a

47a

95a

Red Sphere

Poor

33a

65a

98a

Ladd

Optimal

35a

65a

100a

Ladd

Poor

12b

19b

31b

Yellow Panel

Optimal

18b

14b

32b

Yellow Panel

Poor

10b

* Numbers followed by a different letter arc

; significantly different at (

adds of 19:1.

Fruit Notes, Volume 62 (Number 4), Fail, 1997

populations are primarily composed of mature
flies. To clarify conclusions on trap type
effectiveness for AMF, we conducted the
following experiment during the summer of
1997.

Materials & Methods

In nine rows of apple trees in a commercial
orchard in Massachusetts, the first six trees in
each row (i.e. trees nearest adjacent woods)
were selected for use. In the first row, the first
tree contained a red sphere (8 cm in diameter)
placed in optimal position (surrounded by as
much foliage and fruit as possible at a distance
of 3-6 inches), in the mid-portion of the tree
canopy. The second tree contained a red sphere
in poor position (few leaves and no fruit
nearby). The third and fourth trees contained a
Ladd trap (9 cm diameter red sphere centered
on a 9x1 1-inch yellow panel) in optimal and
poor position, respectively. The fifth and sixth
trees contained a yellow panel (9x1 1-inch
rectangle) in optimal and poor position,
respectively. For every succeeding row, trap
positions were rotated so that each trap type
appeared in each within-row tree position three
times.

In every row, poor position was

standardized for all traps, either low and out;
high and out; or close to the trunk, high or low.
A vial containing butyl hexanoate was placed 4
to 6 inches away from every trap. Traps were
serviced every week for six weeks, during
which flies were removed and counted and
sticky was replenished if needed. The
experiment was conducted from late July to
early September.

Results

Overall, red spheres in both optimal and
poor positions and Ladd traps in optimal
position caught similar numbers of flies and
three times more flies than Ladd traps in poor
position or yellow panels in either positions
(Table 1). During the first three weeks, red
spheres in optimal position caught numerically
more flies than red spheres in poor position and

Ladd traps in optimal position; the difference,
however, was not significant. During the last
three weeks, as fruit reached maturity, red
spheres in optimal position caught numerically
fewer flies than red spheres in poor position
and Ladd traps in optimal position; again
however, the difference was not significant.
Across all six weeks Ladd traps in poor position
and yellow panels in either position caught
significantly fewer flies than red spheres in
either position and Ladd traps in optimal
position.

Conclusions

From late July to mid-August, red spheres
in optimal position caught 35-40% more AMF
than red spheres in poor position or Ladd traps
in optimal position. The proximity of foliage
and fruit to red spheres in optimal position
probably facilitated more frequent opportunity
for AMF to encounter such spheres. This could
explain the numerical difference in capture
between red spheres in optimal position versus
red spheres in poor position. Yellow panels
were comparatively unattractive irrespective
of panel position. Ladd traps in poor position
caught numbers of AMF similar to those on
yellow panels. Apparently, in poor position, the
red sphere component of a Ladd trap is not
perceived as fruit by foraging AMF.

By mid-August, the Paulared apples on the
trapped trees had turned red and visually
competed with red spheres in optimal position.
At times, red sphere traps in optimal position
were difficult for us to find in the trees. At that
point, red spheres in poor position (placed
farther away from competing fruit) and Ladd
traps in optimal position began to capture more
AMF than red spheres in optimal position.
Ladd traps in optimal position might have
enhanced the contrast of a red sphere against
background by furnishing a yellow panel or
background rather than red fruit. The effect
could not be reproduced by Ladd traps in poor
position.

Efficiency of red spheres for trapping AMF
seems to decrease when fruit reaches a size and
color similar to the spheres. This factor

Fruit Notes, Volume 62 (Number 4), Fall, 1997

deserves more attention. Trap positioning may Acknowledgments

need to be adjusted toward harvest. We plan to

conduct studies on the effect of fruit density on

trap efficiency, an interfering factor that could

affect management practices especially when

early maturing cultivars of red apples are

involved.

We are grateful to Wayne Rice for allowing us
to use his orchard. We thank Stephen Lavallee,
Susan Nixson and Amy Wiebe for technical
assistance. This work was funded by USDA
CSRS NRI Grant 95-37313-1890.

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Fruit Notes, Volume 62 (Number 4), Fall, 1997

Can We Predict Flyspeck Development?

James C. Hall, Michael Frank, Arthur F. Tuttle, and Daniel R. Cooley
Department of Microbiology, University of Massachusetts

Flyspeck, caused by Schizothyrium pomi
and sooty blotch, caused by a group of fungi
including Peltaster fructicola, Leptodontium
elatius, and Geastrumia polystigmatis are two
common summer diseases of apple in New
England. Recently, summer diseases have
become more problematic due at least in part to
the decreased use of fungicides such as
mancozeb and captan, attributable to
increased label restrictions, cost cutting, and
the implementation of IPM programs
(Rosenberger, Proc. New England Fruit
Meetings \02:b\-bl, 1997). In July and August,
growers are limited to a few fungicide
applications, generally using captan with or
without a benzimidazol. Growers could more
effectively control sooty blotch and flyspeck
within the confines of an IPM program if they
were able to time their sprays better so as to
correspond to infection and the eventual
appearance of these diseases. Specifically, a
more economical and effective application of
fungicides could be accomplished if growers
were able to predict the appearance of flyspeck
disease and sooty blotch. It would then be

possible to replace a preventative spray
program with one or more eradicant sprays
timed to thwart the appearance of these
diseases.

In North Carolina, Brown and Sutton
{Plant Disease 79:1165-1168) have developed a
model for the prediction of sooty blotch and
flyspeck disease symptoms on apples. The
model is based on leaf wetness data collected at
three different sites in North Carolina from
1987 through 1994, coupled with known
biological information about the fungi involved.
From these data, the researchers concluded
that the best estimate of flyspeck and sooty
blotch symptom occurrence was based on the
cumulative hours of leaf wetness during
periods of at least four hours duration,
beginning from the first rainfall at least 10
days after petal fall. Brown and Sutton chose to
include periods of at least four hours because
they had previously demonstrated that the
pathogens required about four to five hours of
constant wetting in order to germinate (Plant
Disease 77:451-455). Under these conditions,
the researchers found that flyspeck and sooty

Table 1 .

Leaf

wetness accumulation from 10 days after petal fall until the first

symptoms of

sooty blotch or

flyspeck. Table derived from Brown and Sutton (Plant Disease 79: 1 165-1 168).

Symptoms observed Accumulated wetting |

Year

Petal fall date

Beginning date

(hrs)

1987

27-Apr

5-May

15-Jun

265

1988

28-Apr

1 1-May

26-Jul

304

1989

26-Apr

9-May

23-Jun

276

1990

25- Apr

6-May

16-Jul

289

1991

25-Apr

6-May

4-Jun

267

1992

1-May

13-May

15-Jun

310

1993

7-May

17-May

6-Jul

209

1994

29-Apr

14-May

21-Jun

242

Fruit Notes, Volume 62 (Number 4), Fall, 1997

blotch symptoms occurred after an average of
270 hours of accumulated leaf wetting. They
believe this that information is useful for
timing eradicant (benzimidazole) fungicide
spraying. An admitted limitation of this model
is the questionable relevance it has for regions
outside the southeastern United States. Sooty
blotch and flyspeck disease pressure are
extremely high in the Southeast. Weather
there is particularly favorable for these
diseases. Therefore, the model might fail to
predict accurately the onset of sooty blotch and
flyspeck symptoms for several reasons: 1)
summer temperatures and relative humidities
in New England are usually lower than in
North Carolina; 2) the precision and accuracy
of different leaf wetness sensors can vary
considerably; and 3) infection of apple trees
with the fungi causing flyspeck occurs about
one month later in New England than in North
Carolina. However, the existance of an
empirical model predicting flyspeck and sooty
blotch diseases anywhere raises the possibility
of constructing such a model in New England.
While noting the limitations and possible
sources of error, Brown and Sutton's model is
still a good starting place. Additionally, one
only needs hourly leaf wetness data available

over the course of at least one year in order to
use their model. These leaf wetness data are
readily available from records taken from
hygrothermographs or Campbell computerized
weather stations located in several Massachu-
setts orchards. Thus, beginning with leaf
wetness data collected from nine different
orchards in 1995 and 1996, we tested Brown
and Sutton's model for the prediction of
flyspeck and sooty blotch.

Table 1 from Brown and Sutton's article
shows wetness data collected from 1987
through 1994. Symptom occurrence ranged
from late June through early July, with a mean
wetness duration of 270 hours between the
beginning date and symptom occurrence. Note
that Brown and Sutton began counting wetness
hours starting from the first significant
wetness period at least 10 days after petal fall.
Thus, their starting date ranged from early to
mid May.

In contrast, Table 2 shows data collected
from Massachusetts orchards during 1995 and
1996. Using Brown and Sutton's criteria, the
mean leaf wetness accumulation of four hours
or greater from 10 days after petal fall to
symptom occurrence was 366 hours (standard
deviation = 120 hours; the larger the standard

Table 2.

Leaf wetness accumulation from 10 days

after petal

fall to the first symptoms

of flyspeck in

Massachusetts.

Petal fall

Beginning

Symptoms

Accumulated

Year

Site

date

observed

Data source

wetting (hrs)

1995

Broderick

25-May

4-Jun

8-Aug

Hygrothermograph

258

1995

HRC

24-May

3-Jun

7-Aug

Hygrothermograph

348

1995

Clark

28-May

7-Jun

17-Aug

Hygrothermograph

264

1996

HRC

26-May

5-Jun

24-Jul

Hygrothermograph

236

1996

Lincoln

27-May

6-Jun

29-Jul

Hygrothermograph

295

1996

Tuitle

26-May

5-Jun

31-Jul

Hygrothermograph

331

1996

Simeone

26-May

6-Jun

30-Jul

Campbell

484

1996

Sholan

26-May

5-Jun

14-Aug

Campbell

586

1996

HRC

26-May

5-Jun

24-Jul

Campbell

275

1996

Rice

23-May

5-Jun

2-Aug

Campbell

422

1996

S. Deerfield

26-May

5-Jun

1-Aug

Campbell

522

Fruit Notes, Volume 62 (Number 4). Fall, 1997

deviation the more variable the sample was).
The mean for the 1995-1996 hygrothermograph
data alone was much closer to Brown and
Sutton, however, with a mean of 289 hours
(standard deviation = 44 hours). Thus, using
data most favorable to the Brown and Sutton
model, approximately 19 more hours of wetting
occurred in Massachusetts, on average, than in
North Carolina before flyspeck and sooty blotch
symptoms occur. These measurements

support the idea that the Brown and Sutton
model may indeed be useful for disease
prediction in Massachusetts. The Campbell
data, however, do not provide as much
support. In addition, note that the significant
events of petal fall, beginning of wetness
measurement, and symptom occurrence
happened later in Massachusetts than in North
Carolina.

Judging from the differences between the
two data sets as well as the previously noted
regional differences between New England and
the Southeast, it is reasonable to conclude that
other factors besides leaf wetness are
responsible for the onset of flyspeck and sooty
blotch in New England. This certainly could
account for the rather large variability in the

New England data. A regression analysis of
other weather measurements like temperature
and relative humidity with disease onset may
suggest some additional factors. This will be
the focus of future research. It is also
important to note that there is a disparity
between the Campbell weather station wetness
data and the hygrothermograph wetness data,
and it cannot be ruled out that the measuring
instruments themselves may be a source of
error. There is no easy solution to this problem,
and it may be that different empirical wetness-
hour estimations may have to be made for use
with different wetness sensors, or an easily
accessible, standard weather station will have
to be used.

In conclusion, it is believed that an
empirical model predicting flyspeck disease
and sooty blotch of apple based upon the Brown
and Sutton model should be created for use by
New England apple growers. Such a model
would be useful to Massachusetts growers for
timing eradicant fungicide spraying for these
diseases in a more timely and efficient manner,
and may also provide researchers with further
insight into the ecology of the pathogens
involved.

•^ vL» vL» vL« vL*
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Fruit Notes, Volume 62 (Number 4), Fall, 1997

Fruit Notes

University of Massachusetts

Department of Plant & Soil Sciences

205 Bowditch Hall

Amherst, MA 01003

Nonprofit Organization
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Fruit Notes

Prepared by the Department of Plant & Soil Sciences.

UMass Extension, U. S. Department of Agriculture, and Massachusetts Count ies Coope rating.

BIOLOGICAL

Editors: Wesley R. Autio and William J. Bramlage

MAY 2 9 1998
SCIENCES LIBRARV

CO
CO

-c CD
iNJ JO

-^ >

Volume 63, Number 1
WINTER ISSUE, 1998

Table of Contents

Rootstock and Scion Interact
to Affect Apple Tree Performance

Plum Curculio Responses to Host Fruit and Conspecific Odors

Evaluation of Unbaited Pyramid Traps for
Monitoring Plum Curculio in Commercial Apple Orchards

Eyes on Plum Curculio: Watching Them Behave

Toward Traps Alternative to Black Pyramids
for Capturing Plum Curculios

Fruit Notes

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Fruit Notes

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205 Bowditch Hall
University of Massachusetts
Amherst, MA 01003

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These chemicals should be used in accordance with federal and stale laws and regulations.
Growers are urged to be lamiliar with all current stale regulations. Where trade names are used
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University of Massachusetts makes no warranty or guarantee of any kind, expressed or implied,
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UMass Extension offers equal opportunity in profirams and employment.

Rootstock and Scion Interact to Affect
Apple Tree Performance

Wesley R. Autio, J. LaMar Anderson, John A. Barden,
Gerald R. Brown, Paul A. Domoto, David C. Ferree, Alvan Gaus,
Richard A. Hayden, Frank Morrison, Charles A. MuUins,
Curt R. Rom, James R. Schupp, and Loren D. Tukey
NC-140 1990 CultivarlRootstock Trial Cooperators

For about 20 years, the NC-140 Regional
Research Committee has been stud3dng the
effects of rootstock on the performance of
various tree-fruit crops. The first and second
cooperative plantings of NC-140 included
Delicious apple on a variety of rootstocks from
subdwarf to vigorous. Much useful information
was generated from these trials, particularly
because of the rigorous, systematic evaluation
of performance and the large number of sites
and conditions that trees were exposed to. A
total of 25 to 30 sites were included, ranging
from Mexico and the southern United States to
several Canadian provinces.

Delicious was the cultivar of choice for
these early plantings, because it was important
for all growing regions; however, little
information was generated on how rootstocks
may affect different cultivars. In fact, no large-
scale trial had looked at the interaction of
rootstock and scion in a systematic way.
Therefore, planning began in 1987 to establish
such a trial.

Trees for the 1990 NC-140 Cultivar/
Rootstock Trial were propagated by Stark Bro's
Nurseries during the winter of 1989 and were
grown in Selma, CA during the 1989 growing
season. Trees were dug in the fall and shipped
to cooperative sites (see tables for a list of
locations) in the late winter and early spring of
1990. Each site included six replications of four
cultivars (Smoothee Golden Delicious, Nicobel
Jonagold, Empire, and Law Rome) on five
rootstocks (M.9 EMLA, B.9, Mark, 0.3, and
M.26 EMLA). The four cultivars were chosen

with different growth habits, ranging from the
basitonic (spur-type) Empire to the acrotonic
(tip-bearing) Rome. The rootstocks were the
most promising from the first two NC-140
cooperative trials.

Trees were individually staked and man-
aged as slender spindles with a standard
protocol. Pest management, irrigation, and
fertilization were per local recommendations.
Yield and tree size were measured annually.
Data reported here are through the seventh
growing season (1996).

Using trunk cross-sectional area as a
measure of tree size (Table 1), it is clear that
rootstock affected trees size differently,
depending on cultivar. M.26 EMLA, however,
resulted in the largest tree, regardless of
cultivar. Golden Delicious and Empire trees on
M.9 EMLA were significantly smaller than
those on 0.3, but Rome trees on the two
rootstock were similar in size, and Jonagold
trees on M.9 EMLA were signficantly larger
than those on 0.3. Jonagold, Empire, and
Rome trees on B.9 were similar in size to those
on Mark, however. Golden Delicious trees on
B.9 were larger than comparable trees on
Mark. The cultivars also differed overall.
Specifically, Jonagold trees were the largest
and Empire trees were the smallest. Site
differences were very dramatic. Trees in
Wichata, Kansas were the largest, and those in
Maine were the smallest, less than 1/3 of the
size of the Kansas trees. Massachusetts trees
were not significantly larger than those in
Maine.

Fruit Notes, Volume 63 (Number 1), Winter, 1998

Table 1 Trunk cross-sectional

area at the end c

f the 1996 growing

season.

Trunk cross-sectionai

area (

cm-^)

Golden

Rootstock

Delicious

Jonagold

Empire

Rome Average

M.9EMLA

49.7 c

59.8 b

45.5 c

54.7 b 52.8 b

B.9

35.3 d

34.7 d

32.1 d

32.4 c 33.6 c

Mark

30.0 e

31.6 d

28.3 d

30.1c 30.0 d

0.3

57.4 b

51.7 c

51.2 b

55.6 b 54.0 b

M.26 EMLA

67.8 a

74.9 a

64.1 a

64.8 a 68.0 a

Average

48.5 ab

50.6 a

44.3 c

47.4 b

Trunk cross-

sectional

Site

area (cm^)

Arkansas

42.2 ef

Colorado

34.1 g

Iowa

42.0 ef

Indiana

45.5 def

Kansas-Manhattan

68.5 b

Kansas-Wichita

89.3 a

Kentucky

49.6 cd

Massachusetts

30.8 gh

Maine

28.1 h

Ohio

46.5 de

Pennsylvania

30.9 gh

Tennessee

39.7 f

Utah

53.4 c

Virginia

66.9 b

Rootstock means

within columns, average rootstock means, average cultivar means, or

average site means are significantly different at

odds of 19:1

if not followed by the same |

letter.

The effects of rootstock on cumulative yield
per tree also varied with cultivar (Table 2). The
general trends were similar to those with tree
size, with trees on 0.3 and M.26 EMLA yielding
the most, those on B.9 and Mark yielding the
least, and trees on M.9 EMLA yielding
intermediately. Over all rootsotcks, Rome
trees produced the highest yield, and Empire
trees produced the lowest. Regarding the
effects of site, trees in Virginia and Ohio

produced the highest yields, and those in
Arkansas produced the lowest.

More important than yield per tree, the
effects of rootstock on cumulative yield
efficiency (relating yield to tree size) varied
with cultivar (Table 3). The most efficient
Golden Delicious, Jonagold, and Empire trees
were on B.9 and Mark, and the least efficient
were on M.26 EMLA. Trees on M.9 EMLA and
0.3 were intermediate. Rome trees on B.9 were

Fruit Notes, VoUimc 63 (Number 1), Winter, 1998

Table 2. Cumulative yield per tree (1992-96) at the end of the 1996 growing season.

Rootstock

Golden
Delicious

M.9EMLA

B.9

Mark

0.3

M.26 EMLA

Average

Site

74 b
69 be
61 c
94 a
89 a

78 b

Arkansas

Colorado

Iowa

Indiana

Kansas-Manhattan

Kansas-Wichita

Kentucky

Massachusetts

Maine

Ohio

Pennsylvania

Tennessee

Utah

Virginia

Cumulative yield (kg/tree, 1992-96)

Jonagold

Empire

74 b
60 c
54 c
81 ab
85 a

71c

71 b
53 c
43 d
83 a
77 ab

66 d

Cumulative

yield (kg/tree

1992-96)

21 1

32 h

33 h

48 fg
139 b
126 c
80 d
86 d
54 f

149 a

49 gh
35 h
65 e

150 a

Rome

96 a
79 b
62 c
102 a
95 a

87 a

Average

80 b
65 c
55 d
90 a

87 a

Rootstock means within columns, average rootstock means, average cultivar means, or
average site means are significantly different at odds of 19:1 if not followed by the same
letter.

the most efficient, those on M.26 EMLA were
the least efficient, and those on Mark, M.9
EMLA, and 0.3 were intermediate. Rome
trees, overall, were the most yield efficient, and
Jonagold trees were the least efficient. Ohio
and Massachusetts produced the most yield-
efficient trees, and Arkansas produced the
least efficient.

This study, which will continue through the
tenth growing season, has demonstrated

variation in the effects of rootstock with
different cultivars. To date, however, the
importance of the variation is minimal. Tlie
reduced size of Jonagold trees on 0.3 is an
important deviation ft-om the response with
other cultivars. The tree is smaller than
expected, but it is as yield efficient as it should
be. Unless this observation is a reflection of
some level of incompatibility between scion and
rootstock, the only change that a grower needs

Fruit Notes, Volume 63 (Number 1), Wmter, 199H

Table 3. Cumulative yield efficiency (1992-96) at the end of the 1996 growing season.

Cumulative yield efficiency (kg/cm^ trunk cross-sectional area, 1992-96)

Rootstock

Golden
Delicious Jonagold Empire

Ror

Average

M.9 EMLA

1.61 b

1.37 be 1.61b

1.74 b

1.59 c

B.9

1.97 a

1.91a 1.91a

2.37 a

2.05 a

Mark

2.09 a

1.80 a 1.88 a

1.95 b

1.93 b

0.3

1.71b

1.48 b 1.72 ab

1.83 b

1.69 c

M.26 EMLA

1.35 c

1.19 c 1.16 c

1.51c

1.30 d

Average

1.75 b

1.55 c 1.65 be

1.89 a

Cumulative yield

efficiency (kg/cm^

Site

1992-96)

Arkansas

0.51 h

Colorado

1.01 fg

Iowa

0.90 gh

Indiana

1.13 ef

Kansas-Manhattan

2.34 c

Kansas-Wichita

1.78 d

Kentucky

1.85 d

Massachusetts

2.94 b

Maine

1.96 d

Ohio

3.48 a

Pennsylvania

1.32 e

Tennessee

1.04 fg

Utah

1.32 e

Virginia

2.37 c

Rootstock means withi

n columns,

average

rootstock means, average cultivar means, or

average site means are

sign

ificantly di

fferent at odds of 19:1 if not followed by the same |

letter.

to make to use this combination is adjustment ated with Mark. In this study, rootstock did not

of planting distances.

Tlie rootstock that stands out in this trial is
B.9. It performed similarly well with all scions.
Yield efficiency was as high or higher than
Mark, without many of the problems associ-

affect fruit size, but in other trials, B.9 has
resulted in larger-than-average fruit. It
certainly is a rootstock worthy of significant
grower trial, and it is available commercially in
significant quantities.

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Fruit Notes, Volume 6.^ (Number 1), Wimcr, 1998

Plum Curculio Responses to Host Fruit
and Conspecific Odors

Tracy Leskey, Amy Wiebe, Susan Nixson, and Ronald Prokopy
Department of Entomology, University of Massachusetts

Many species of weevils are attracted to host
plant odors and use them in host finding. Fur-
ther, many species of weevils produce aggrega-
tion and/or sex pheromones. Plum curculios
(PCs) have been shown to be attracted to host
fruit odors in the laboratory over short distances
and in the field at distances up to 3 yards. Fur-
ther, a male-produced aggregation pheromone,
grandisoic acid, was recently identified in PCs
by Eller and Bartelt of Illinois.

At present, a reliable monitoring system for
detecting adult PC entry into orchards from
overwintering sites does not exist. However, if
attractive odors such as those from host fruit
and/or pheromones were employed in conjunc-
tion with a trap that was also visually attrac-
tive to adult PCs, then a reliable monitoring
device could be created as has been done for
other species of weevils.

In the 1996 and 1997 Winter issues of Fruit
Notes, we reported on results of laboratory
Petri-dish bioassays that addressed responses
of adult PCs to odors emitted from Mcintosh
apple trees. Here, we present results from bio-
assays conducted in large Plexiglas arenas de-
signed to assess PC attraction not only to fruit
odors but also to odors emitted by other PCs.

Materials and Methods

Large clear Plexiglas arenas with dimen-
sions of 24x24x12 inches with Plexiglas lids
were used as still-air arenas for the following
experiments. Materials to be tested as emit-
ting potentially attractive odors were placed in
small cotton bags hung in the upper corners (one
per corner) of each box. Originally, we tried
testing PCs with cotton bags placed in lower
corners of arenas, but found that because of the
natural tendency of PCs to crawl upwards,
hanging the bags in upper corners was a more
effective means of testing PCs.

Either ten male or ten female PCs starved
for 24 hours and chilled 30 minutes prior to test-
ing were released into the center of a box at the
beginning of darkness. Numbers of PCs that
crawled to within one-half inch of an odor source
held within a cotton bag were recorded after 1
hour. Each experiment was repeated three
more times, each time rotating the position of
cotton bags containing odor sources.

Treatments tested as potentially emitting
attractive odors included five freshly picked
wild plums, five wild plums plus five male or
female PCs, five male or female PCs alone, five

Table 1. Numbers of male PCs moving to within 1/2 inch
treatment after 1 hour. Experiment 1.*

or onto cloth bags of each

Arena

Treatments

One

Five males
O.Ob

Five males + five plums
3.3 a

Five plums
3.0 a

Control
O.Ob

Two

Five females
0.0 c

Five females + five plums
6.0 a

Five plums
1.0 b

Con trol
0.0 c

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

Fruit Notes, Volume 6,3 (Number 1), Winter, 1998

Table 2. Numbers of male PCs moving to within 1/2 inch or onto
treatment after 1 hour. Experiment 2.*

cloth bags of each

Arena

Treatments

One

Fiue punctured plums Five plums
3.5 a 1.8 ab

Control
O.Ob

Two

Five females + five plums Five males + five plums
3.8 a 1.0 b

Control
O.Ob

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

wild plums alone, and five punctured plums.
Punctured plums were used to simulate plums
that had been fed upon by PCs because we
wanted to learn if plums that had been punc-
tured released odors that may be attractive to
PCs. Each plum was punctured twice, one punc-
ture made one hour before and one puncture
made immediately before an experiment. An
empty cotton bag served as the control in each
experiment.

Results presented reflect the mean number
of PCs captured for each treatment over the four
replications.

Results

Male Responses. In experiment 1 (Table
1), we used two arenas to test male response to
the following treatments. In arena one, treat-
ments included males, males plus wild plums,
and wild plums placed in a small cotton bag,
with an empty cotton bag serving as the con-
trol. Here, males responded in significantly
greater numbers to cotton bags containing
plums alone or males plus plums compared to

males alone or the empty bag. Treatments
tested in arena two included females, females
plus plums, plums, and a control. In this case,
males were attracted to females plus plums in
significantly greater numbers than to any other
treatment.

In experiment 2 (Table 2), in arena 1 we then
evaluated male responses to punctured plums
compared to plums without punctures with two
empty cotton bags serving as controls. Here,
we wanted to learn if males were responding to
odor emitted by punctures made in plums by
feeding PCs. We saw no difference in response
of males to punctured plums compared to plums
not punctured, although there was a numeri-
cally greater response to the former. In arena
two, we compared male responses to females
plus plums, males plus plums and to two empty
bags serving once again as controls. Signifi-
cantly more males responded to females plus
plums than to any other treatment, indicating
that males may be responding to a female-pro-
duced odor.

Female Responses. In experiment 3
(Table 3), we repeated treatments for female

Table 3. Numbers of female PCs moving to within 1/2 inch or onto cloth bags of each
treatment after 1 hour. Experiment 3.*

Arena

Treatments

One

Five males Five males + five plums Five plums
OOb 2.8 a 1.3 ab

Con trol
O.Ob

Two

Five females Five females + five plums Five plums Control

O.Ob 1.0 ab 2.8 a O.Ob

* Means within rows not followed by the same letter are significantly diffcn>nt at
odds of 19:1.

Fruit Notes, Volume 6.^ (Numhcr 1), Winter, 1998

Table 4

Numbers of female PCs moving to within 1/2 inch or or

to cloth b

ags

of each

treatment after 1 hour. Experimen

t4.*

Arena

Treatments

Five punctured plums

Five plums

Control

One

2.3 ab

2.5 a

O.Ob

Five females + five plums

Five males + five plums

Control

Two

1.5 a

2.3 a

0.0 a

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

responders that we tested with male respond-
ers in experiment 1. In arena one, female re-
sponders were attracted to males plus plums
in significantly greater numbers than to males
alone or the control bag, with intermediate at-
traction to plums alone. In arena two, signifi-
cantly more females were attracted to plums
alone than to controls, with intermediate at-
traction to females plus plums.

In experiment 4 (Table 4), we repeated the
same treatments with female responders that
we had tested with male responders in experi-
ment 2. In arena one, females responded in
nearly equal numbers to punctured plums and
plums that had not been punctured. In arena
two, numerically more females were attracted
to males plus plums compared to females plus
plums or to control.

Conclusions

Both sexes were attracted to odors emitted by
freshly picked wild plums. Perhaps the most
important result from these experiments is an
indication of the existence of a female-produced
sex pheromone, as evidenced by the strong at-
traction of male PCs to the treatment that in-
cluded females plus wild plums. Further, this
putative female-produced pheromone may have
been synergized or enhanced in attractivity to
males by the presence of wild plum odor. Al-
though we cannot rule out the possibility of
sounds made by PCs as influencing these re-
sults, we could smell a unique odor in arenas
that included treatments containing females
plus plums. We plan to use this bioassay sys-
tem extensively in 1998 to confirm these pre-
liminary findings and in tests aimed at identi-
fying the chemical nature of these attractive
compounds.

We conclude that the Plexiglas arena bioas-
say system is an effective way to test PC at-
traction to host fruit odors as well as odors
emitted by other PCs at distances of approxi-
mately 16 inches under still-air conditions.

Acknowledgments

This work was supported by Hatch funds
and by the New England Tree Fruit Growers
Research Committee.

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•^ ^j^ •^ •^ r^

Fruit Notes, Volume 63 (Number 1), Winter, 1998

Evaluation of Unbaited PyramidTraps for
Monitoring Plum Curculio in Commercial
Apple Orchards

Ronald Prokopy, Michael Marsello, Tracy Leskey, and Starker Wright
Department of Entomology, University of Massachusetts

In the 1997 Winter issue of Fruit Notes, we
reported on a 1996 study evaluating unbaited
black pyramid traps as devices for capturing
plum curculio adults and predicting need and
timing of insecticide sprays against plum
curculio based on trap captures. That study,
conducted in a small commercial apple orchard
in Conway, showed that even though black p5Ta-
mid traps in optimum positions (next to apple
tree trunks) captured reasonable numbers of
plum curculios, there was no correlation be-
tween periods of substantial capture and peri-
ods of substantial damage by curculios to fruit.
In other words, trap captures were poor predic-
tors of when insecticides should be applied
against curculio in that orchard in 1996. Black
pyramid traps, intended to mimic tree trunks,
are currently receiving much attention as po-
tential monitoring devices for plum curculio in
peach orchards in the South.

Here, we report on a study in which black
pyramid traps were evaluated at three positions
in eight large commercial orchards in Massa-
chusetts in 1997.

Materials and Methods

Pyramid traps were the same as used in
1996 and were a modification of traps designed
for monitoring pecan weevils in the South.
Three traps were placed in each of six blocks of
apple trees in each of eight commercial orchards.
All blocks contained 49 trees (seven rows of
seven trees each) of mixed cultivars of fruit-
bearing age. Of the six blocks per orchard, there
were two blocks each of trees on M.9, M.26, and
M.7 rootstock, giving rise to what we term here

as small, medium, and large trees, respectively.
For each block, one trap was placed within 30
cm of the tree trunk (termed trunk trap) of a
perimeter tree, one mid-way between the
canopy of a perimeter tree and the first inte-
rior tree (termed inter-tree trap), and one at the
margin of the nearest woods (termed border
trap). The ground beneath and between orchard
trees was either free of b vegetation or vegeta-
tion was mowed to prevent obscuring of traps.
Traps were deployed during bloom and were
examined for captured plum curculio adults ev-
ery 3-4 days thereafter for 4-5 weeks. At each
trap examination, beginning at petal fall, 15
fruit per tree of each of the seven perimeter trees
were examined for presence of plum curculio
oviposition scars (total of 105 fruit per block per
sampling date). Scarred fruit were allowed to
remain on the tree. All blocks received either
two or three grower-applied sprays of Guthion
or Imidan, beginning at petal fall and 8-11 days
later(second spray), as well as 16-20 days (third
spray) thereafter. Growers applied sprays ac-
cording to their own estimation of need, with-
out access to our data for making application
decisions. To protect against insecticide, a plas-
tic bag was used to envelope each trap com-
pletely just before spraying and was removed
immediately thereafter. This was done because
in a preliminary test, only about 40% as many
curculios (0.8 vs. 1.9 per trap, a significant dif-
ference) were captured by traps sprayed with
Imidan as by unsprayed traps.

Results

We combined data for the two blocks of simi-

Fruit Notes, Volume 63 (Number 1), Winter, 1998

Table 1.

Numbers of overwintering plum

curculio adults captured

on unbaited pyramid

traps at tree-trunk,

inter-tree

or orchard-border positions and |

aercent of fruit showing ovipositional

injury by plum curculio across |

sampling

dates before, between, or after insecticide spray applications against

um curcul

10 in blocks of small,

medium-size, or large apple trees and across

eight commercial orchards studied

Massachusetts in

1997.

Adu

Its

captured

aer

Injured

No.

Sampling

saff

pling date

_ fruit per

orchard

dates per

Trunk

Inter-tree

Border

sampling

Tree size

Sampling dates

blocks

block

traps

date (%)

Small

Before first spray

1.1

0.22

0.00

Between first and second spray

2.5

0.00

0.05

0.35

Between second and third spray

2.7

0.00

0.36

After final spray

4.4

0.00

0.45

Medium

Before first spray

1.1

0.00

0.11

0.00

Between first and second spray

2.5

0.05

0.00

0.05

0.33

Between second and third spray

2.7

0.00

0.36

After final spray

4.4

0.00

0.42

Large

Before first spray

1.1

0.22

0.00

0.11

0.00

Between first and second spray

2.5

0.10

0.00

0.05

0.31

Between second and third spray

2.7

0.00

0.48

After final spray

4.4

0.03

0.00

0.90

lar tree size per orchard and segregated data
according to sampling dates before, between,
and after insecticide applications. The data
(Table 1) show that no fruit injury was detected
prior to the first insecticide application even
though some curculio captures by traps in each
position had occurred. For none of the trap po-
sitions in any block type (i.e. tree-size type) was
there a significant positive relationship between
mean number of captured adults per block and
mean number of sampled fi-uit injured per block.
This was true for sampling data between the
first and second insecticide application, between
the second and third insecticide application, and
following the last insecticide application. In
every block type, mean ft-uit injury increased
between the first and second, between the sec-
ond and third, and after the third insecticide
application. Conversely, in most cases, mean
trap captures either successively decreased
fi-om levels that were reached prior to any in-
secticide treatment or were nil throughout.

The greatest fruit injury in any of the 48
blocks was in a block of large trees in Orchard
D (a mean of 2.5% fruit injured). Not a single
plum curculio was captured by any trap in this
block. Conversely, in the two blocks receiving
the greatest trap captures (small trees in Or-

chard D and large trees in Orchard F), there
were means of only 0.24 and 0.19% injured fi*uit,
respectively. Most blocks received injury greater
than this.

Conclusions

Data from this study in eight large commer-
cial apple orchards in 1997 are in agreement
with data ft-om our 1996 study in a single small
orchard and do not support the use of captures
of plum curculio adults by unbaited black pyra-
mid traps as accurate predictors of the need to
apply insecticide against curculio. This conclu-
sion holds irrespective of the position at which
unbaited pyramid traps were placed in an or-
chard. For the future, we need either a differ-
ent type of trap or a powerful attractive odor to
enhance the value of black pyramid traps. In
succeeding articles in this issue, we describe
progress toward developing alternative types
of traps and attractive odors to incorporate into
traps.

Acknowledgments

This work was supported by grants fi-om the

Fruit Notes, Volume 63 (Number 1), Winter, 1998

USDA Northeast Regional IPM Competitive ers that participated in this study: Bill

Grants Program, State /FederallPM funds, and Broderick, Dana Clark, Dave Chandler, Dave

the New England Tree Fruit Growers Research Cheney, Dave Shearer, Joe Sincuk, Tim Smith

Committee. We are grateful to the eight grow- and Mo Tougas.

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10 Fruit Notes, Volume 63 (Number 1), Winter, 1998

Eyes On Plum Curculios:
Watching Them Behave

Ronald Prokopy and Catherine Wirth

Department of Entomology^ University of Massachusetts

Shortcomings of black pyramid traps for
monitoring plum curculios described in the pre-
ceding article have stimulated us to take a closer
look at the behavior of individual curculios in
hopes of discovering why black pjrramid traps
perform less and less satisfactorily as the
curculio season progresses. In the 1997 Winter
issue of Fruit Notes, we described some pre-
liminary studies that led us to postulate that
perhaps curculios bypass pjramid traps under
moderate and high temperature conditions, fly-
ing directly into tree canopies rather than crawl-
ing or flying onto tree trunks or trunk-mimick-
ing pyramid traps. Here, we describe two stud-
ies conducted in 1997 in which we made exten-
sive direct observation of movements of plum
curculios toward host trees and p5rramid traps
under conditions as natural as possible for typi-
cal curculio behavior, while still permitting ef-
fective observation.

Materials and Methods

Curculios to be observed were tapped from
branches of unmanaged apple trees onto a
40x40-inch white bedsheet (first study) or a
16xl6-inch white bedsheet (second study) held
taut by staples driven into a wooden frame be-
neath. Apple foliage was scattered across about
15% of the surface area of each framed cloth to
provide hiding places for fallen curculios. Plum
curculios fall frequently from limbs of host trees
(sometimes more than once per day) onto the
ground beneath in response to perceived dan-
ger or adverse weather. We reasoned that tap-
ping curculios from branches and allowing them
to fall on cloth provided with shelter effectively
mimicked natural behavior and conditions.

As soon as four or five curculios (first study)

or eight curculios (second study) accumulated
on the cloth, we quickly but gently carried the
frame and cloth to a position half-way between
the trunk and canopy edge of a nearby semi-
dwarf unmanaged apple tree (first study) or
plum tree (second study). There were no
curculio traps of any sort in the vicinity of the
apple tree. One unbaited black p3rramid trap
was placed next to the trunk and another at
the edge of the canopy of the plum tree, with
the framed cloth centered between and equi-
distant (4 feet away) from either trap. Dressed
in white cap, shirt, and shorts that hopefully
were invisible to curculios, one of us knelt down
nearby the cloth and quietly observed the pro-
portion of curculios that departed the cloth by
flight or by crawling and the proportion that
moved to hide beneath foliage or rested on the
cloth. Observation periods lasted 1 hour. They
were evenly spaced among 1-hour intervals be-
ginning at 8 AM and ending at 8 PM in the first
study, or among 1-hour intervals beginning at
2 PM and ending at 6 PM in the second study.
In both studies, observations commenced a day
or two after petal fall and extended over a 3-
week period thereafter. We recorded the direc-
tion taken by each adult upon departure from
the cloth and continued to track adult destina-
tion until it was lost fi"om sight.

Results

Of the 166 plum curculios observed beneath
the apple tree, 52 (31%) left the framed cloth by
flight and 27 (16%) by crawling. The remain-
der moved to hide beneath foliage on the cloth
(18%) or rested in place (35%). Among curculios
that flew, significantly more (54%) flew toward
the tree canopy above than flew toward inter-

Fruit Notes, Volume 63 (Number 1), Winter, 1998

Table 1. Type

and direction of movement of 166 plum

rculio adults observed on a framed

cloth beneath an apple tree during

1-hour periods evenly

distributed from 8 AM to 8 PM.

Type of

Number engaged

Movement

Curculio movement in each

movement

in movement

direction toward

direction (% of movement category)* |

Flew

Tree trunk

Tree canopy

Inter-tree space

Grass

17b

54a

25b

Crawled off

Tree trunk
All others

88a
12b

Hid

None (rested)

* For each category of movement,

numbers followed

a different letter are significantly

different at ode

Is of 19:1.

tree space (25%), the tree trunk (17%), or grass
beneath the canopy (4%) (Table 1). Among
curcuhos that crawled, significantly more (88%)
crawled toward the tree trunk than toward all
other directions combined (12%) (Table 1).

Of the 104 plum curculios observed beneath
the plum tree, 39 (38%) left the framed cloth by
flight and 19 (18%) by crawling. The remain-
der moved to hide beneath foliage on the cloth
(13%) or rested in place (31%). Among those
that flew, significantly more flew toward the tree
canopy above (36%) or toward inter-tree space
(38%) than toward the pyramid trap at the tree

trunk (15%), the pyramid trap at the canopy
edge (3%) or grass beneath the canopy (8%)
(Table 2). Among curculios that crawled, sig-
nificantly more (74%) crawled toward the pyra-
mid trap at the tree trunk than toward the pyra-
mid trap at the canopy edge (10%) or toward
other directions (16%) (Table 2).

Temperatures taken beneath each tree at
the time of observed curculio movement indi-
cated that no flight occurred at temperatures
of 67°F or less. Also, there was a significant
positive correlation between temperature and
proportion of total observed curculios that flew.

Table 2. Type and direction of movement of 104 plum curculio adults observed on a framed cloth

beneath a plum tree during 1-hour

periods evenly distributed from 2 PM to 6 PM. 1

Type of Number engaged

Movement direction

Curculio movement in each

movement in movement

toward

direction (% of movement category)*

Flew 39

Trap at tree trunk

15b

Trap at canopy edge

Tree canopy

36a

Inter-tree space

38a

Grass

Bbc

Crawled off 19

Trap at tree trunk

74a

Trap at canopy edge

10b

All others

16b

Hid 14

None (rested) 32

* For each category of movement,

numbers followed by a different letter are significantly |

different at odds of 19:1.

Fruit Notes, Volume 63 (Number 1), Winter, 1998

On the other hand, a substantial proportion of
those curcuhos observed to crawl off the cloth
(about 20%) did so at temperatures of 67°F or
less, and there was no correlation between tem-
perature and proportion of total observed
curculios that crawled off.

Conclusions

The more robust data reported here confirm
and extend the preliminary data reported in the
1997 Winter issue of Fruit Notes. Combined
data indicate that when the air temperature is
67°F or less beneath the canopy of a host tree,
the plum curculio adults that have dropped from
the tree canopy (as they normally do on a fre-
quent, even daily, basis) are reluctant or unable
to fly but are able to reenter the tree canopy by
crawling. Crawling is almost exclusively toward
the tree trunk, or if a black pyramid trap is
adjacent to the tree trunk, then toward such a
trap, which is thought to be a visual mimic of a
tree trunk. At temperatures of 68°F or greater,
curculios exhibit an increasing propensity to

reenter the tree canopy by flight. Most flights
are into the tree canopy. Only a small propor-
tion (15-17% according to our findings here) is
toward the tree trunk or a black pyramid trap
next to the tree trunk. Hence, at temperatures
of 68°F or greater, there is only a small chance
of capturing a tree-reentering curculio using a
black pyramid trap. Other data that we col-
lected in 1997 show that curculio damage to tree
fruit increases with increasing temperature. It
is therefore doubtful that any prospective
unbaited curculio traps placed in association
with the tree trunk will be able to monitor
curculio entry into or abundance in the tree
canopj/^ in a way that reflects accurately the
probability of curculio damage to fruit.

Acknowledgments

This work was supported by a grant from the
USDA Northeast Regional IPM Competitive
Grants Program and the New England Tree
Fruit Research Committee.

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Fruit Notes, Volume 63 (Number 1), Winter, 1998

Toward Traps Alternative to Black
Pyramids for Capturing Plum Curoulios

Ronald Prokopy, Bonnie Dixon, and Tracy Leskey
Department of Entomology, University of Massachusetts

In the two preceding articles, we concluded
that unbaited black pyramid traps (and prob-
ably all other unbaited traps) aimed at captur-
ing plum curculios intent on entering host trees
by crawling or flying onto tree trunks are un-
satisfactory for monitoring curculios in a way
that reflects accurately the potential for curculio
damage to fruit. In the 1997 Winter issue of
Fruit Notes, we presented results of a prelimi-
nary test in 1996 showing that sticky-coated
squares of clear Plexiglas positioned just out-
side of apple tree canopies captured about as
many plum curculio adults as black pyramid
traps next to tree trunks. Here, we report on a
1997 study further comparing these two trap
types. We also report preliminary results on a
potentially useful third trap type.

Materials and Methods

The first study was carried out in a small
block of unmanaged semi-dwarf apple trees at
Hampshire College in South Amherst. The
Plexiglas traps were designed to capture plum
curculios fl3ring toward tree canopies from over-
wintering sites or from other host trees. Each
trap was constructed of clear Plexiglas (2 feet
by 2 feet) attached
vertically on a
wooden pole posi-
tioned 2 feet away
from the edge of the
tree canopy. The
outer-facing but
not the inner-fac-
ing surface of the
Plexiglas was
coated with

Tangletrap to cap-

ture curculios flying toward the tree canopy.
Two such traps were attached to each pole, one
opposite the lowermost foliage and the other
opposite the uppermost foliage. Two poles with
traps were placed on opposite sides of each of
six trees. Two unbaited black pyramid traps
were placed on opposite sides of and immedi-
ately next to the trunks of each of six other trees.
All traps were emplaced at the beginning of
apple tree bloom (May 24) and were examined
daily thereafter for 22 days for captured
curculios. Each day, 16 fruitlets on each of the
12 trees were examined for evidence of plum
curculio damage. Each day, temperature, rela-
tive humidity, and wind speed were recorded.
The second study was carried out in two
unmanaged apple trees, one in Amherst and one
in Conway. Traps were designed to capture
plum curculios that had already arrived in tree
canopies and were searching for resources of
fruit borne on twigs or resting sites on twigs.
Each trap, constructed of cardboard, was cylin-
drical in shape (8 inches tall and either 1 or 3
inches in diameter), coated with yellow or black
latex paint, and capped with an inverted screen
funnel developed originally to capture boll wee-
vils. The yellow cylinders were intended to

Table 1. Numbers of plum curculios captured daily by traps in
unmanaged apple trees. May 24 - June 15, 1997.

Traps

Clear Plexiglas, low position 12

Clear Plexiglas, high position 12

Black pyramid traps 12_

Number of Mean number of curculios
replicates captured per trap *

10.0 a
7.6 a
9.1a

* Numbers followed by a different letter are significantly different at
odds of 19:1.

Fruit Notes, Volume 63 (Number 1), Winter, 1998

Table 2. Of plum curculios that left vials in which they were contained (i.e.
curculios that were active), proportions that arrived on vertical apple twigs
(1/2 inch diameter) or on cylindrical vertical mimics (1 or 3 inches diameter)
of either apple twigs (black) or apple foliage and fruit (yellow).

Number

Curculios that arrived on

Structure

active curculios

tested structure (% of active)*

Twigs

24 b

Yellow cylinder (1 inch)

22 b

Yellow cylinder (3 inches)

24 b

Black cylinder (1 inch)

41a

Black cylinder (3 inches)

48 a

* Numbers followed by a different letter are significantly different at odds of
19:1.

mimic foliage and fruit borne by twigs and were
similar in appearance to yellow-green plastic
traps used commercially to capture cotton boll
weevils. The black cylinders were intended to
mimic twigs themselves. Each cylinder was po-
sitioned vertically on a branch over an upright
clipped twig, used as support. For each trial,
we collected curculios (by branch tapping) from
nearby trees, placed ten in a vial, and attached
the vial in horizontal position to a branch about
9 inches from a cylinder. The curculios could
crawl or fly directly from the vial opening to-
ward the cylinder. Of the curculios that left
vials, we recorded proportions that arrived on
a cylinder during a 30-minute trial period.

Results

There were no significant differences in
numbers of curculios captured per trap among
sticky-coated Plexiglas traps in low position,
sticky-coated Plexiglas traps in high position,
and black pyramid traps (Table 1). These re-
sults confirm and are remarkably similar to
those of the 1996 study reported in the 1997
Winter issue of Fruit Notes. Importantly, we
found here that increases in captures by sticky
Plexiglas traps but not by black pyramid traps
were significantly positively correlated with
increases in fruit damage caused by plum
curculios the following day. Also, captures by

sticky Plexiglas traps as well as fruit damage
were significantly positively correlated with
temperature, with the former also significantly
negatively correlated with wind speed.

Among plum curculios that left vials in
which they were released on apple tree
branches, 22-24% arrived on upright test twigs
or on 1 -inch-diameter or 3-inch-diameter up-
right yellow cylinders (Table 2). Significantly
greater proportions (41-48%) arrived on upright
black cylinders (Table 2). All observed curculios
arrived on twigs and cylinders by crawling.
None arrived by flight.

Conclusions

The findings reported here, though still pre-
liminary, encourage us to believe that improved
variants of the sticky Plexiglas squares and tall
black cylinders studied here could be more suit-
able than black pyramids for monitoring
curculios, because captures by these traps bet-
ter coincide with periods of curculio damage to
fruit than captures by black pyramid traps.
Sticky Plexiglas squares placed adjacent to tree
canopies are much too cumbersome for wide-
spread use by growers, but a simplified non-
sticky version (possibly incorporating attractive
canopy-mimicking stimuli) might be an effec-
tive substitute. Similarly, an improved version
of a black twig-mimicking trap could be of con-

Fruit Notes, Volume 63 (Number 1), Winter, 1998

siderable value in monitoring within-canopy
activity of curculios. We are planning further
studies on these alternative trap types.

Acknowledgments

This work was supported by grants from the
USDA Northeast Regional IPM Competitive
Grants program and the New England Tree
Fruit Research Committee.

•X^ •^ *^T> vL* *1>*

rp» 0^ 0^ #^ 0^

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ruit Notes

Prepared by the Department of Plant & Soil Sciences.

UMass Extension. U. S. Department of Agriculture, and Massachusetts Counties Cooperating.

Editors: Wesley R. Autio and William J. Bramlage

lAi liu \\i;

BIOLOG'GAL

FEB K
FEB 2 4 1999

\'/

Volume 63, Number 2
SPRING ISSUE, 1998

Table of Contents

Residues of Azinphosmethyl on Apples
Using First- vs. Third-level IPM

Can Apple Maggot Fly Control Benefit from Sprays of Provado
Aimed at Killing Leafminers and Leafhoppers?

Tax Pointers for Farmers and Landowners in 1998

Preliminary Study of 1PM Options for Peaches:
Major Fruit-damaging Insects

Fruit Notes

Publication Information:

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

Correspondence should be sent to:

Fruit Notes

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

UMASS EXTENSION POLICY:

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

Issued hy UMass F.xtciisuiii, John (ieiber, Direiloi. in liinbcmmr ti) the lu Is oj May S and June M). 1914.
UMass Extension ntjers equal (ipjiariunity in i>iiif;iiiiiis iiiul einploymcnl

Residues of Azinphosmethyl on
Apples Using First- vs. Third-level IPM

Starker Wright and Ronald Prokopy

Department of Entomology, University of Massachusetts

Scott Carrier, Raymond Putnam, and J. Marshall Clark
Massachusetts Pesticide Analysis Laboratory

The apple maggot fly ( AMF) is a key summer pest
of apples in New England and other parts of eastern
North America. According to recent surveys, AMF
was ranked as one of the two most important insect
pests attacking apple fruit by commercial apple grow-
ers in Massachusetts [Fruit Notes 61(3)]. AMF are
active in orchards from late June through mid-Septem-
ber, with peak activity generally in early August. Most
growers are able to achieve effective control of AMF
by applying two to four insecticide sprays during July
and August.

Over the past two decades, we have attempted to
develop an alternative behavioral approach to AMF
control. This approach involves surrounding an or-
chard block with odor-baited red spheres placed about
5 yards apart on perimeter trees. Each sphere is either
coated with Tangletrap or is treated with a feeding
stimulant and an insecticide to kill alighting flies [Fruit
Notes 62(4)]. Ideally, this system of management
would allow the grower to cease insecticide applica-
tion after plum curculio season, in effect extending the
pre-harvest interval for summer insecticide use to 80
days or more. One grower-perceived advantage to be-
havioral control of AMF is reduction in use of sum-
mer insecticides and subsequent reduction in level of
insecticide residue on fruit at harvest [Fruit Notes
60(4)].

The EPA sets standards for commercially accept-
able levels of pesticide residue on marketed fruit.
Currently, the standard for azuiphosmethyl residue on
apples is 2 parts per million (2000 parts per billion).
However, the Food Quality Protection Act (FQPA) may
strongly affect tolerable levels of residue. The intent
of the FQPA is to establish tolerance levels that are
?safe,? defined as ?a reasonable certainty that no harm

will result from aggregate exposure, including all ex-
posure from diet, drinking water, and other non-occu-
pational exposures.? In order to calculate health risks
associated with exposure to pesticide residues, the
FQPA dictates that aggregate exposure be measured
by use of a ?risk cup,? meaning that all exposures (fresh
and processed foods, water, and household exposure)
are combined into the same cup. All existing toler-
ances must be re-evaluated, and organophosphate in-
secticides (such as azinphosmethyl) are included in the
first round of review, slated for completion in August
of 1 999. Tolerance levels are based on residues present
on fruit at harvest.

Our aim here was to determine the amount of
azinphosmethyl on fniit at harvest in blocks of apple
trees that received azinphosmethyl for AMF control
versus blocks that received only odor-baited red spheres
for AMF control.

Materials & Methods

In 1997, we began a pilot third-level IPM project
in order to determine the influence of apple tree archi-
tecture and planting density on biologically-based pest
management and fruit quality. In each of eight com-
mercial orchards, we identified and flagged six blocks
of trees: two each of high, medium, and low tree den-
sity. One block of each density was managed under
first-level IPM practices that involved application of
two to four sprays of insecticide from early July to
harvest. The other block was managed under third-
level practices that involved surrounding the block with
odor-baited red spheres. For purposes here, fruit were
sampled only from the medium-density trees, which,
at -240 trees/acre, represent the majority of apple trees

Fruit Notes, Volume 63 (Number 2), Spring, 1998

rablu I. A/inphosiiiclhyl ihsccIickIl- appliciilions. a/.inpliosiiKiliyl icsidiics and AMI' in|iiry on luiil al
liarvcsl 111 blocks iiianaL'cd under liisl Il-vl-I vcislis ihird-lcvcl II'M in live eoinnicieial apple oreliards

Orchard

Dales ol

azinphosmcthyl

applieations

Dt)sage

equivalcnl per

application''

A/Jnphosnielhyl
residue at harvest (pph)

AMF injury
(%)

First

Level

IPM

Blocks

Mean

Third

Level

IPM

Blocks

Mean

May

June

July

August

May

June

July

August

May

June

July

August

June

August

May

June
June
June
July
August
August

20
30
21
11
30

1,5

1.0

0.25

0.67

0.67
1.3
0.7

0.67
1 .0
1.0
0.5
1.0
1.0
1.0
1.0
1.0
0.5

0.25
LO
1.3

0.67
1.3
1.0

0.67

4.37

May

1.5

June

1.0

May

0.67

June

0.67

June

1.3

May

1,0

June

1.0

June

0.5

May

0.25

June

1.0

June

1.0

May

1.0

June

1.3

June

0.67

June

1.3

2.83

N/D''

239

N/D"

159

N/D"

N/D''

N/D"

0.0

0.2

2.0

0.0

N/D'

0.4

One dosage equivalent = 8 o/.. formulated a/inphosniethyl per 100 gallons water.

Applications in May and June were made against plum curculio,
' ppb: parts per billion.
'' N/D: not detected (detection limit = 40 ppb).

Fruit Notes, Volmne 63 (Number 2), Spring, 1998

in Massachusetts. Of the eight medium-density third-
level IPM blocks and the eight companion first-level
blocks, five pairs were selected for sampling here. Se-
lection was based on the fact that azinphosmethyl was
the insecticide applied against AMF in all five first-
level blocks.

Within one week of harvest, ten mid-sized Mcin-
tosh fruit were selected randomly from each block,
bagged, and placed within 6 hours in a deep-freeze at
?20"C until the analyses were performed. Fruit forti-
fied with known levels of azinphosmethyl showed that
there is no significant breakdown of residues while in
storage. From each experimental block, three samples
were analyzed, each sample consisting of three fruit.
For analysis details, see the note at the end of the text.

Results

In the five blocks under first-level IPM, growers
used an average of 2.4 sprays against AMF between
early July and late August, resulting in an average of
0.2% AMF injury (Table 1). Analysis revealed that
fruit treated with 2-3 sprays of azinphosmethyl con-
tained an average of 95.6 parts per billion of
azinphosmethyl residue at harvest, roughly 5% of the
current EPA tolerance.

In keeping with the principles of behaviorally-
based AMF control, no insecticides were applied to
the five third-level IPM blocks after mid-June.
Expectedly, none of the samples taken from these
blocks contained a detectable level of azinphosmethyl
residue, even though these blocks received an average
of 2.8 applications of azinphosmethyl against plum
curculio in May and June (Table I ). Blocks managed
under third-level practices received slightly more in-
jury by AMF (0.4%) than did first-level blocks.

Conclusions

This study has shown that the amount of
azinphosmethyl residue present on apples at harvest
in 1997 in test blocks managed under first-level IPM
practices averaged far less (about 95% less) than the
amount of residue allowed by current EPA regulations.
This study also showed that no detectable residues of
azinphosmethyl were found on apples at harvest in test
blocks managed under third-level IPM practices.

Although it may seem logical that no insecticide
treatment during July and August (as under third-level
1PM) ought to result m no insecticide residue on frait

at harvest, such would not necessarily be the case if
insecticide applied against plum curculio were to be
present on harvested fruit. All ten blocks in this study
received two to four sprays of azinphosmethyl from
mid-May to late June against plum curculio. Our data
from fruit samples taken in third-level IPM blocks
clearly show that treatments of azinphosmethyl applied
in May and June did not result in detectable levels of
azinphosmethyl on harvested fruit (Table I). This in-
formation could be important to EPA consideration of
continued allowable use of azinphosmethyl against
plum curculio.

Even though our findings here indicate that use of
third-level IPM practices results in no detectable resi-
dues of azinphosmethyl on fruit at harvest and pro-
vides acceptable commercial-level control of AMF,
more work is needed to refine third-level IPM prac-
tices so that they will become as economical and reli-
able as first-level IPM practices.

Acknowledgments

This work was supported by state/federal IPM
funds and USDA SEA CSREES Grant # 97-34365-
5043. We are grateful to the eight growers that par-
ticipated in this study: Bill Broderick, David Chan-
dler, David Cheney, Dana Clark, David Shearer, Joe
Sincuk, Tim Smith, and Mo Tougas.

Note: Whole fruit were blended with water and sub-
mitted to extraction with ethyl acetate, then reduced
using a sample concentrator, leaving a concentrate of
residual material. Azinphosmethyl residues from ex-
tracted apples were analyzed using a Varian model 3400
GC gas chromatograph (Varian Associates, Sunnyvale,
CA) equipped with a nitrogen phosphorous detector
(NPD). The capillary column was a fused silica DB-5
liquid phase, 0.53 mm i.d. X 1 5 m, 0.25mm film thick-
ness (J & W Scientific). A deactivated cyclodouble-
gooseneck injection port liner (Restek, Bellefonte, PA)
was used for splitless injections. Operating conditions
were as follows: injection volume, 1.0 ml; injection
port temperature, 250"C; detector temperature, 300"C;
column temperature, 1 75"C for 0.5 min, ramped at
20'C/min to 250"C and held for 12 min. The carrier
gas was helium at a rate of 8 ml min '. Detector gas
flow rates were: nitrogen, 25 ml min'; oxygen, 175
ml min ': hydrogen, 2.5 ml min ' (Kadenczki et al., J.
Assoc. Off. Anal. Chem. 75, No.l, 53-61).

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Fruit Notes, Volume 63 (Number 2), Spring, 1998

Can Apple Maggot Fly Control Benefit
from Sprays of Provado Aimed at
Killing Leafminers and Leafhoppers?

Xing Ping Hu, Andrew Kaknes, and Ronald Prokopy
Department of Entomology, University of Massachusetts

The insecticide Provado (containing imidacloprid
as the active ingredient) was synthesized by Japanese
Chemists in 1985. In 1995, it was labeled for use on
apple in the United States. One of its greatest perceived
advantages is its high toxicity to several major apple
pests but comparative lack of toxicity to beneficial
predators and parasitoids. Indeed, Provado has proven
very effective against leafminers, leafhoppers, and
aphids in apple orchards of Massachusetts and other
states [Fruit Notes 60(4)]. Provado may be used ef-
fectively when applied against either first-generation
leafminers and leafhoppers at petal fall in May, or
against second-generation leafminers and leafhoppers
in late June. Application in late June conceivably also

could provide control of early-invading populations of
apple maggot flies. One reason for believing this might
be so stems from recent tests of Provado applied, to-
gether with latex paint, on red spheres aimed at killing
alighting apple maggot flies. Results of these tests
showed high toxicity of Provado against the flies even
at very low doses [Fruit Notes 62 (4)] . Here, we evalu-
ated effects of Provado against apple maggot flies when
applied to the foliage and fruit of apple trees.

Materials & Methods

Provado was provided by Bayer Corporation (Kan-
sas City, MO). Flies used in bioassays were obtained

o
E

40
35
30
25
20
15
10

5 i

— •— Flies caged immediately following spray
-•— Flies caged 24 hours after spray
-•— Flies caged on insprayed leaves

2 3 4 5

Days of exposure to sprayed foliage and fruit

Figure 1 . Mortality of apple maggot flies caged on apple trees sprayed with Provado (0.03% a.i.).

Fruit Notes, Volume 63 (Number 2), Spring, 1998

3
C

D Flies caged immediately following spray

■ Flies caged 24 hours after spray

■ Flies caged on unsprayed leaves

Oviposition puncture

Eggs laid

Egg load

Figure 2. Mean number of oviposition punctures, eggs laid, and egg load per female among
apple maggot Hies that survived exposure to Provado during 7 days in field cages

from pupae collected from unsprayed apple drops. Five
apple trees were selected from an abandoned orchard
near Amherst, Massachusetts. Branches of four trees
were sprayed to runoff at a dose of 0.03% a.i. of
Provado, the rate labeled for controlling sucking in-
sects in apple orchards. The fifth tree was not sprayed
and used as a control. For each tree, four branches
were selected for caging flies, using 30x50-cm cloth
screen net. Two fruit were allowed to remain on each
branch. Four leaves on each branch received an aque-
ous slurry of a mixture of 8% sugar and 10% bird drop-
pings to serve as a food supply for flies. Two cages
per tree received 20 flies (10 males and 10 females)
immediately following spray application. The other
two cages received like numbers of flies 24 hours later.
Mortality counts were made daily for 7 days. To
determine possible effects on fly reproduction, apples
and surviving flies from each cage were brought back
to the laboratory on the 7"' day. Apples were exam-
ined to detemiine the effects of Provado on fly ovipo-
sition behavior by counting the number of oviposition
punctures and number of eggs laid. Female flies were
dissected to determine effects of Provado on egg load
by counting the number of mature eggs in fly ovaries.

Results

Our results indicate that application of Provado to
apple tree foliage and fruit neither effectively reduced
fly survival (Figure 1 ) or fly reproductive ability (Fig-

ure 2). Less than 20% of flies caged immediately after
spray application were killed over the 7-day test pe-
riod, too low to provide effective control. Mortality
was even lower (8%) for flies released into cages 24
hours after spraying. This was essentially no greater
than the 5% mortality of flies in the control cages. The
results suggest a rapid decline of Provado activity on
leaf and fruit surfaces after application.

Figure 2 shows that fly oviposition behavior was
only slightly reduced for flies exposed to sprayed com-
pared with unsprayed leaves and fniit. Groups of flies
exposed to foliage and fruit immediately after spray-
ing with Provado made an average of 16 ovipositional
punctures and laid an average of 14 eggs over 7 days,
compared with 1 9 ovipositional punctures and 1 7 eggs
laid by tlies expo.sed to foliage and fruit 24 hours after
spraying, and 21 ovipositional punctures and 19 eggs
laid by control flies. The egg load per female remained
at essentially the same level for all the treatments.
These results suggest that Provado applied to apple
foliage and fruit had minimal effects of fly oviposi-
tion.

Conclusions

Even though Provado has proven excellent in pro-
viding season-long control of .sucking in.sect pests on
apple trees, and even though our laboratory tests
showed high toxicity of Provado to apple maggot flies,
the results generated here indicate that Provado ap-

Fruit Notes, Volume 63 (Number 2), Spring, 1998

plied to apple tree foliage and fruit has little or no ef-
fect on apple maggot fly mortality and oviposition.
There may be two reasons for the ineffectiveness of
Provado spray on tree foliage and fruit against apple
maggot flies. First, Provado is a systemic insecticide,
and is quickly absorbed by foliage (and perhaps also
fmit) once sprayed. Thus, it kills pests that suck sap
from the interior of foliage but does not remain on plant
surfaces long enough to kill pests, such as apple mag-
got flies, that do not suck plant sap. Second, Provado
on exterior surfaces of plants is subject to rapid degra-
dation by sunlight. Nevertheless, when applied to-
gether with latex paint to red spheres, Provado, even
at very low doses, has provided excellent control of
apple maggot flies alighting on treated spheres for up

to three months after initial application. Thus far, it
has proven more effective than any other insecticide
that we have evaluated for this purpose.

Acknowledgements

We thank Richard H. Ackerman from Bayer Cor-
poration for providing us with samples of imidacloprid
and John Clark and David Ferro from our department
for helpful suggestions. This work was supported by
funds from USDA Cooperative Agreement 58-3620-
104, the Northeast Regional IPM Competitive Grants
programs and the Washington State Tree Fruit Research
Commission.

«t« «t« %f# %% ftl^
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Fruit Notes, Volume 63 (Number 2), Spring, 1998

Tax Pointers for Farmers and
Landowners in 1998

P. Geoffrey Allen

Department of Resource Economics, University of Massachusetts

Tax advice given below is intended as general
advice and is believed to be correct. It does not
substitute for a detailed review of the circumstances of
an individual taxpayer by a professional tax
practitioner. For more details, you and your tax
adviser may wish to consult the sources referenced in
the square brackets [thusj (see footnote). Taxpayers
filing returns other than for calendar year 1998 may
face different rules than those described here .

New Legislation

Life seems to be getting ever more complicated.

• On January 1 , 1 998, many of the provisions of the
Taxpayer Relief Act of 1997 "TRA97" (Public
Law 105-34) became effective.

• On July 22, 1998, the IRS Restructuring and
Reform Act/ Taxpayer Bill of Rights 3
"RRA98"(H.R. 2676) was enacted mto law (P.L.
105-206), and many of its provisions became
effective on that date. While mostly concerned
with internal operations of the IRS, changes in
laws governing collection of taxes and "innocent
spouse" provisions will affect some taxpayers.
The Act also makes technical corrections to
TRA97 that affect treatment of some capital gains
and losses and sale of a principal residence.

• Finally, as the last act of the 105"" Congress, the
Omnibus Appropriations Act for FY99 "OAA99"
(H.R. 4328) was enacted into law on October 21,
1998 as P.L. 105-277. It contains several
retroactive tax provisions of specific interest to
farmers. They are discussed below.

Income Averaging for Farmers
Made Permanent [IRC §1301]

TRA97 introduced income averaging for farmers
for 1998-2000. OAA99 made the averaging provisions

permanent.

Use income averaging if you had a successful year
in 1 998 and less profit in prior years. The idea is to shift
some of your income from the high marginal tax rate
you would otherwise face in 1998 to the rate it would
have been taxed in earlier years. Schedule J of Form
1040 is used for calculations.

Step 1 . Calculate the tax on your taxable income (farm
and non-farm) in 1998. If the last dollar of income is in
a higher tax bracket than the last dollar of taxable
income in any of the three prior years then income
averaging will reduce your 1998 taxes.

Step 2. Elect the amount of farm income to be
averaged. Only farm income can be averaged.
However, if your family has high taxable income in
1998 because of both farm and non-farm income, you
can average the farm income part. Farm income
includes gains from the sale of assets (except land)
used in the farming business for a "substantial period"
(not defined). Sales of machinery and breeding
livestock reported on Form 4797 would be eligible.
Elect as much of the current year's eligible farm
income as you want to distribute over the three prior
years. The principle is to get income after averaging
approximately level across the years. The more
detailed operational rule is explained after the
example.

Step 3. Divide the elected amount of income into three
equal parts and add each part to your taxable income
(farm and non-farm) in each of the three prior years.
Subtract the elected amount from 1998 income.

Step 4. Using the income levels from step 3, figure the
tax for each year using the tax table for that year and
add the tax amounts together.

Step 5. Add the actual taxes paid in the three prior
years to the 1 998 taxes from step 1 .

Step 6. Compare the total from step 4 with the total

Fruit Notes, Volume 63 (Number 2), Spring, 1998

Irom step 5 H the total from step 4 is smaller then
income averaging will be advantageous.

Example: Andy Farmer, who is married, filing
jointly, has both farm and non-farm income for the last
four years as shown in Table I . Net losses are within
parentheses. If Andy does not elect income averaging
then the family income tax liability for 1998 will be
$32,346. [. 1 5 X $42,350 + .28 x ($ 1 02,300 - $42,350)
+ .31 x ($132,000 - $102,300)]. Andy can elect to

Table 1

Taxable income

and tax before

averaging.

Year

Taxable
income

Tax on

unaveraged

income

Income
reported on
Schedule F

Livestock and

machinery
gains reported
on Form 4797

1995
1996
1997
1998

$6,000

$8,000

$11,000

$132,000

$900

$1,200

$1,650

$32,346

$(14,000)

$(10,000)

$(8,500)

$114,000

$4,000
$1,500
$2,000
$3,000

Total

tax 1995-98

$36,096

average up to $ 1 1 7,000 of 1 998 income (the total of the

Schedule F and Form 4797 amounts). If he elects to

average $90,000, then $30,000 is added to the taxable

income of 1995, 1996 and 1997. Results of averaging

are shown in Table 2.

Note that if Andy elects

to income average in

1999 the amounts in

Table 2 become the

initial taxable incomes.

The saving from

averaging is $12,546 [=

$36,096 - $23,550]. The

1998 tax liability is

$19,800 [$23,550 -$900

-$1,200 -$1,650]. Note:

the tax is figured at 15%

of taxable income. U.se

of tax tables will give

slightly different answers

($4 more m each case).

The operational rule is to increase the amount of
the election as long as the average marginal tax rate
over the three prior years is as low or lower after
averaging than the marginal rate on the income
remaining in 1998. In the example, the last dollar of
taxable income before averaging (Table 1 ) in each of
the prior years is taxed at 15%, against the marginal
rate for 1998 of 31 %. Therefore, moving $3 from 1998
to the prior years reduces the tax rate on that income

from 31% to 15%. After
averaging (Table 2) the
marginal rates are 15%
throughout.

If the election was

increased by more than

$600 (to over $90,600)

this would bring 1997

taxable income over

$41,200, increasing the

marginal rate of tax in

1997 to 28%. Now the

average marginal tax

rate of the three prior

years (15% -i- 15% -f-

28%)/3 = 19.3%> exceeds

the marginal rate for

1 998, which has dropped

to 15%.

Caution: If you are subject to alternative minimum

tax in the year for which averaging is elected ( 1 998 in

the example) then income averaging will be of no

benefit.

Table 2.

Taxable income

and tax after averaging.

Year

Taxable income

Lndof IS'/r taxable
income bracket

Tax on averaged
income

1995
IW6
l'W7
1998

$36,000
$38,000
$4 1 ,000
$42,000

$39,000
$40,100

$41,200
$42,350

$5,400
$5,700
$6, 1 50
$6,300

Total lax 1995-98

$23,550

Fruit Notes, Volume 63 (Number 2), Spring, 199cS

Averaging Does Not Alter
Self-employment Tax [IRC §1301]

Andy's self-employment tax in 1998 in the
example above would be $11,535. [92.35% of
$114,000 = $105,279. The first $68,400 is taxed at
15.3% = $10,465. The balance. $105,279 - $68,400 =
$36,879 IS taxed at 2.9% = $1070.] Income averaging
does not change the self-employment tax amount.

Conservation Reserve Payments Are
Rent Not Farm Income, Are Not Subject to
Self-employment Tax, and Are Reportable on
Schedule E [Wuebker vs Commissioner, 1 10
T.C. No. 31 (June 23, 1998); IRC §1402]

For several years the IRS has taken the position
that Conservation Reserve Program (CRP) payments
to materially participating farmers are subject to
self-employment tax. (If you do not fall under the
material participation rules, see below, you were not
and still are not subject to SE tax on CRP payments.) .
The Tax Court in the Wuebker case determined that
CRP payments are rent; however, CRP agreements
prevent the land from being used for agricultural
production. Therefore, the language in IRC § 1402 that
called for the payment of SE tax on rent by a materially
participating farmer does not apply. The IRS may
appeal the Court's decision.

Note: There are reasons why you might not wish to
treat CRP payments as rent. Some estate tax benefits
might be lost. For example, to get the favorable
valuation as farmland rather than fair market value (in
highest and best use), the deceased owner must have
materially participated in using the land for farming
purposes. In this situation, you would want to report
the CRP payments on Schedule F and pay SE tax on
them. If taking this position, filing the disclosure form,
Form 8275, is probably wise, relying on the past IRS
position and its likely appeal of the Wuebker decision.
[IRC § 1402(a)(1)]

Material Participation

There are two sets of material participation rules.
A taxpayer who is materially participating for the
purposes of self-employment tax may or may not be
materially participating for the puqjo.ses of passive

activity loss rules. The reverse is true: a taxpayer who
materially participates for the purposes of passive
activity loss rules may not be materially participating
for the purposes of self-employment tax.

The Farmer's Tax Guide (IRS Publication 225)
lists the tests of material participation of a farm-
landlord to determine whether or not self-employment
tax must be paid. You are materially participating if
you have an arrangement with your tenant and you
meet one of the following tests:

Test No. 1 . You do any three of the following: ( 1 ) pay
or stand good (e.g. sign for materials bought on credit)
for at least half the direct costs of producing the crop;
(2) furnish at least half the tools, equipment, and
livestock used in producing the crop; (3) consult with
your tenant; and (4) inspect the production activities
periodically.

Test No. 2. You regularly and frequently make, or take
an important part in making, management decisions
substantially contributing to or affecting the success of
the enterprise.

Test No. 3. You work 1 00 hours or more spread over a
period of 5 weeks or more in activities connected with
crop production. (Note: these numbers do not appear in
either the tax code or the regulations.)

Test No. 4. You do things which, considered in their
total effect, show that you are materially and
significantly involved in the production of the farm
commodities.

If you pass the test for material participation you file
Schedule F and are subject to self-employment tax on
the income. [I.R.C. §1402. Treas. Reg. §1. 1402(a)-
4(b)(6) gives six examples]

Capital Gains Changes

TRA97 set up three rate groups of assets:

1 . 28%. Short-term gains and losses, assets held not
more than 1 2 months; all collectibles (coins, paintings,
stamps, wine, etc.); long-term capital loss carryovers.
(Note: Excess depreciation (above straight-line
amounts) recaptured from the sale of § 1 250 property
(basically, buildings) is ordinary income, does not
appear on Schedule D.)

2. 25% Long-term gains (no losses in this group) from

Fruit Notes, Volume 63 (Number 2), Spring, 1998

sale of buildings and improvements that result from
straight-line depreciation (generally, the rest of the
depreciation you have taken), limited by net §1231
gain [Technical correction in RRA98 to IRC
§l(h)(7)(B)]. Section 1231 property is those durable
assets used in a trade or business (not in inventory, not
supplies).

3. 20% All other long term gains and losses, including
the gain over purchase price from selling a building.

The 1997 Act also set complicated holding
periods. RRA98 has simplified matters in several
areas.

1. Sales on or after January 1, 1998, of assets held more
than 12 months qualify for long term capital gains.

2. The amount of gain at the 25% rate is limited to the
net §1231 gain. [IRC § 1(h)(7)(b)] Generally, this
change only becomes a concern during a year when
you sell some property for less than you paid for it.
Example: In 1998, Bruce Bullock sells a piece of land
for $80,000 that he had purchased for $100,000. He
also sold a building for $80,000 that he purchased for
$70,000. He had taken $40,000 of straight line
depreciation on the building. He had no unrecaptured
§1231 losses from prior years. Bruce also sold some
mutual fund shares for a gain of $20,000. The basis of
the building is $30,000 ($70,000 - $40,000).
Therefore, in 1998 Bruce has:

Gain on building
Loss on land
Net §1231 gain

$50,000
(20.000)
$30,000

On the building alone, Bruce has $40,000 of gain taxed
at 25% (the straight-line depreciation) and $10,000 of
gain taxed at 20%. (Refer to the rate groups listed
above.) However, because of the loss on sale of his
land, the amount of gain subject to the 25% rate is only
$30,000. Note that the gain on sale of the mutual funds
offsets the loss on the sale of the land and normally
these would be netted out, since they are in the same
(20%) rate group, to give a net gain of zero for that
group. But the limitation described in the example is
done first.

3. Netting of gains and losses. Form 4979 and the
worksheet on page .seven of the instructions for
Schedule D together perform the desired calculations.
If you have losses in the 28% or 20% rate group and a

gain from selling depreciable property (25% group)
the worksheet will reduce the recapture amount you

enter on line 25 of Schedule D. Details of the netting
are as follows:

( 1 ) Within each group, net out the gains and losses for
that group.

(2) Short term losses first reduce short-temi gains, if
any.

(3) Any residue from (2) is applied first to reduce long-
term gains at the 28% rate, then to reduce gains at the
25% rate then to reduce gains at the 20% rate.

(4) A net loss from the 28% group (including long-
term loss carryovers) is applied first to reduce gains at
the 257o rate , then to reduce gains at the 20% rate.

(5) A net loss from the 20% group is applied first to
reduce gains in the 28% rate, then to reduce gains at the
25% rate.

Order of computing tax on gains. For taxpayers in
the 15% bracket, the capital gains rate will be less than
the amounts given in the rate groups above. Schedule
D does a masterful job of figuring out the amounts
subject to the various rates of tax. It performs
computations by taking income in the following order:
ordinary income, taxed at 1 5%; gains in the 25% class
, taxed at 15%; gains in the 28% class, taxed at 15%;
and gains in the 20% class, taxed at the reduced rate of
1 0%. Once the 15% bracket has been used up, the rate
of the asset group is applied to the capital gains.

Sale of Farm and Principal Residence

TRA97 and corrections in RRA98 permit much or
all of the capital gain on the sale of your principal
residence ($250,000 if single, $500,000 if married
filing jointly) to be excluded from income if you meet
ownership and occupancy requirements (generally, to
have owned and occupied the house in two out of the
last five years). [IRC §121] Instead of the single
lifetime exclusion available previously, you can now
use the exclusion every time you .sell your home.
Farmers, therefore, have an even bigger incentive to
declare their house a principal residence and not part of
the farm. To get the exclusion you must show that
your hou.se is residential not agricultural. For
example, use the area around it to graze horses used for
plea.sure by your children; maintain the area around it

Fruit Notes, Volume 63 (Number 2), Spring, 1998

as a garden giving scenic enjoyment; report mortgage
interest and property taxes on Schedule A rather than
on Schedule F; retain the house and some land for
some period of time after the sale of the farm.

Net Operating Losses on the Farming
Business Now Carried Back Five Years [IRC

§172(b)(l)(G)]

RRA98 added a five-year carryback for the net
operating loss that would result if only income and
deductions attributable to farming businesses were
taken into account (i.e., "farming losses", reduced by
the amount of profit, if any, from other businesses).
[IRC § 172(b)(1)(G)] "Farming business" means the
trade or business of farming, including operating a
nursery or sod farm and raising or harvesting fruit trees
and ornamental trees. [IRC §263A(e)(4)]

If you want to make use of the net operating loss
provisions to lower your taxes, the five-year carryback
is now the default. If you want to use the regular net
operating loss provisions you must elect to do so. Such
election must be made by the due date (including
extensions) for filing the return for the year with the
loss. Once made, the election is irrevocable. [IRC
§172(b)(3)]

Regular net operating loss provisions have also
changed. In 1 998 and future years losses can be carried
back two years (instead of three) and carried forward
20 years (instead of 1 5). [TRA97; IRC § 1 72(b)( 1 )( A)] .
Farmers in "Presidentially declared disaster areas" can
use a three year carryback for disasters but not for
"fanning losses" (i.e. not for losses incurred in the
ordinary business), so this is of little use to most
farmers. If you want to use these regular provisions
you can elect to use only the carryforward provision.
The same conditions apply to this election. You must
make the election before the due date to file your return
(including extensions) and once made the election is
irrevocable.

Net operating loss carryback and carryforward is
most useful when set against income subject to high
marginal tax rates. If you have low incomes and low
marginal tax rates in prior years you may wish to use
carryforward only. This is a decision that requires
careful analysis of past years' incomes and formation
of expectation about future net incomes.

Form 1045 and its associated Schedules are used
to make the complex adjustments to itemized

deductions, to figure the allocation of losses and to
calculate the amount of the tax reduction. As before,
net operating losses are allocated chronologically, that
is, to the earliest eligible year first.

Massachusetts State Taxes Get Up to Date -
Almost

After being frozen at January 1, 1988,
Massachusetts personal income tax law now follows
the Internal Revenue Code in effect on January 1,
1998. Unless they are related to deductions for
business expenses or one of the special federal tax
provisions such as Roth and Education IRAs, any
federal tax law changes that become part of the IRC as
amended and in effect after January 1, 1998, will not
be adopted by Massachusetts.

One place where farmers might be affected is with
depreciation. If you took different amounts of
depreciation on a property for federal and State
purposes, that difference will disappear on your 1998
returns. Example: The life for single purpose
agricultural or horticultural buildings placed in service
after 1989 is 10 years for federal purposes while it
would remain at the 1988 life of 7 years Massachusetts
purposes. Possibly amounts on purchased equipment
taken as expenses (§179 expensing) might have been
higher for federal than for State purposes. These
differences would cause the amount of depreciation
taken on federal returns to differ from that taken on
State returns.

Septic Credit Carryover
Extended to Five Years

The Massachusetts credit for the replacement or
repair of failed cesspools or septic systems had been
amended to extend the carryover for unused credit
from three to five years. The current annual $1,500
maximum credit and $6,000 total maximum credit
remains the same. If you claimed the credit in 1997 you
have until 2002 to carryover any unused credit.

Conversion to Roth IRA:
What Did You Miss?

If you convert from a traditional IRA to a Roth
IRA by December 31, 1998, you meet a special rule
that allows you (but does not require you) to spread the

Fruit Notes, Volume 63 (Number 2), Spring, 1998

taxable income from the conversion over the next four
years. This is not as big a deal as some advertising
implies. You lose little by converting one fourth of the
planned amount in each of the next four years. Most of
the advertising by mutual funds or brokers is (or should
be) directed at employees. Self-employed individuals
have other possibilities (SEP-IRA and SIMPLE-IRA)
that remove much of the attraction of the Roth IRA.

A contribution to a Roth IRA is income after taxes
have been paid while a contribution to a regular
(deductible) IRA is before tax income. Both types of
IRA accumulate earnings tax-free. Distributions from
a Roth IRA are tax-free, while those from a regular
IRA are taxable. The key issue appears to be whether
the tax rate on contributions will be higher, the same or
lower than the tax rate on distributions. If higher, the
Roth is an advantage. If lower, it is not.

Worksheets that do not employ any "smoke-and-
mirrors" appear to show that conversion of a regular to
a Roth IRA is advantageous, even when the tax rate
during retirement is lower. That is, removing funds
from a regular IRA, paying the tax on these funds
(which are treated as ordinary income) and depositing
the funds in a Roth IRA gives greater retirement
income than not making the conversion. The money to
pay taxes must come from somewhere, but the result

occurs even after factoring in the lost earnings on that
money.

Why does the conversion "work" even if your tax
rates fall after you retire? Because it allows you to
shelter more interest and dividend income from taxes.
If it is your goal to put a lot of money away for
retirement, as an employee you are restricted to $2,000
of earned income each year (and usually less if you
participate in another retirement plan). A Roth IRA
conversion lets you increase this. Example: You
withdraw $10,000 from a regular IRA. If you have
sufficient other income to put you in the 28% tax
bracket, the tax on this distribution is $2,800. Without
any other source of money you only have $7,200 to put
into a Roth IRA. If in retirement you are subject to a
28% percent tax rate it turns out that your after-tax
retirement income is the same whether you converted
or not. (Worse, the $2,800 is treated as a premature
withdrawal and incurs a further 10% excise tax
penalty.) But if you have other money to pay the
$2,800 tax bill, you are effectively putting that same
amount into your IRA (in addition to the $2,000 that
you could put into a new Roth IRA).

Footnotes: IRC. Internal Revenue Code; T.C.,
Court; Treas. Reg., Treasury Regulations.

Tax

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Fruit Notes, Volume 63 (Number 2), Spring, 1998

Preliminary Study of IPI\/I Options for
Peaclies: i\/lajor Fruit-damaging Insects

Karen I. Hauschild

Department of Plant & Soil Sciences, University of Massachusetts

Arthur T\ittle and Daniel R. Cooley

Department of Microbiology, University of Massachusetts

Ronald J. Prokopy

Department of Entomology, University of Massachusetts

At harvest, the most severe damage on peach fruit
is caused by true bugs (primarily insects in the group
Pentatomidae, stink bugs) and Japanese beetles. Fruit
may show scarring or fresh feeding wounds accompa-
nied by a gummy ooze. Often this injury is severe
enough that damaged fruit must be culled or, at the
very least, downgraded to processing quality. With
the greatest profitability gained from fresh-quality
peaches, growers need and want to keep insect-dam-
aged fruit at the lowest level that is economically and
environmentally feasible.

There are three species of stink bugs that are known
to attack peaches and cause cat-facing injury: the
brown stink bug (Eiischistus sennis), the dusky stink
bug [E. nisrigmus), and the green stink bug
{Acrosternum hilare). These insects are all highly
mobile, and usually remain in the orchard for only a
short period of time. Stink bugs reproduce on the trees,
laying eggs on the lower surface of peach leaves. These
eggs are easily identified; they are barrel-shaped, shiny,
and appear in clusters of about seven eggs each. After
the eggs hatch, the young nymphs move into the or-
chard groundcover. Nymphs do little feeding on
peaches. Primary damage is the result of adult feed-
ing. Numbers of brown and dusky stinkbugs are great-
est within a month of shuck fall. Green stink bug num-
bers tend to increase throughout the growing season.
The most severe damage to peach fruit occurs between
petal fall and the time when fmits are 0.5-0.75 inch in
diameter. If fruit that is damaged during this time pe-
riod fails to abscise, at maturity, it is heavily scarred or
malformed (injury commonly referred to as "catfac-
ing"). As the fruits enlarge, damage by stinkbugs is

less dramatic. Injury results in holes with gummy exu-
date or dry, corky areas just below the fruit surface.

The Japanese beetle {Popillia japonica) is a seri-
ous pest of ornamentals, grapes, and plants in the fam-
ily Roseaceae. Adult beetles chew on leaves and fruit.
Leaf damage ranges from minor tissue loss to com-
plete skeletonization. Fruit damage is restricted to the
fruit surface (surface damage), but can be extensive
and contaminated with beetle frass. Damage caused
by Japanese beetles often attracts other insects or dis-
ease organisms. Because Japanese beetles tend to
congregate, damage can occur very quickly and be-
come quite severe in a short period of time.

The objective of this study was to determine the
incidence of damaged caused by these pests under re-
duced-pesticide regimes. Brown rot incidence from
the same study was reported [Fruit Notes 62(4)] .

Materials & Methods

Until pit hardening in early June, all treatment plots
received standard calendar-based pesticide applications
every 7 to 10 days. After pit hardening occurred, four
different treatment protocols were employed. These
treatments are outlined in Table 1 . Refer to Fruit Notes
62(4) for additional information on experimental de-

Results & Discussion

For Redhaven peaches (Table 2), the incidence of
stink bug damage was twice that of Glohaven (Table
3), while the incidence of Japanese beetle damage was

Fruit Notes, Volume 63 (Number 2), Spring, 1998

Tabic 1 . Insecticide and fungicide ircalmciiis on

pcache.s

after June 10 at the

University of Massachusetts Horticultural Research Center, Bel

chertown, MA, 1996

Treatment

(rate /lOO gal. dilute spray)

Date of application

Full spray

Imidan 70WP (0.75 lbs.)

17 June; 2, 14, 25 July

Captan80WP(l lb.)

17 June, 2, 14 July

Captan 80WP (1 lb.) + Benlate 50DF (6 11. oz.)

25 July, 2 Aug.

Reduced spray

Imidan 70WP (0.75 lbs.)

2, 14 July

Captan 80WP (I lb.)

2, 14 July

Captan 80WP (1 lb.) + Benlate 50DF (6 R. oz.)

2 Aug.

Lo\^' spray

Imidan 70WP (0.75 lbs.)

2, 14 July

Captan80WP(Ilb.)

2 July

Captan 80WP (1 lb.) + Benlate 50DF (6 n. oz.)

Aug.

No spray

None

none

substantially less than that on Glohaven. These
differences most likely reflect the timing of
activity of each of these two insect pests rela-
tive to the timing of fruit development of the
two cultivars and the last insecticide spray.

The four treatment regimes resulted in
similar levels of stink bug damage on Redhaven
and Glohaven fruit(Tables 2 and 3). Because
these were 3-tree plots, with different treat-
ments applied to adjacent trees, it is possible
that spray drift could account for at least some
of the lack of effect. Timing of insecticide ap-
plications could have affected results as well.

Redhaven fruit under the reduced-spray
regime had the greatest amount of Japanese
beetle feeding, and those under the other treat-
ments were similar (Table 2). Likewise,
Glohaven fruit under the reduced-spray treat-
ment had the most damage, but for Glohaven,
the no-spray treatment had significantly less
damage (Table 3). It is unclear why these re-
sults occurred. It is likely, however, that real differ-
ences did not occur in this experiment. High mean

Table 2. Insect damage to Redhaven peaches under
different pesticide treatment schedules. Fruit were
harvested on August 15 and 21. Each treatment
included three trees in each of three replications. For
assessment, 100 peaches were harvested from each
tree. '-

Stink bug

Japanese beetle

Trcalmcnt

damage (%)

IhiII s|ii"ay

28 a

Reduced spi

31 a

Low spray

29 a

No spray

22 a

'Means within columns not followed by the same
letter are significant at odds of 15:1.

values were likely the result of very localized infesta-
tions of Japanese beetles.

Fruit Notes, Volume 63 (Number 2), Spring, 1998

Tabic 3. Insect damiige Id Glohavcn peaches under
differenl pesticide Ireatmenl schedules Fruil were
harvested on September 3. Each treatment included
three trees in each of lour replications. For
assessment, 100 peaches were harvested from each
tree. '

Treatment

Slink hug
damage (%)

Japanese beetle
damage (%)

Full spray
Reduced spray
Low spray
No spray

9a
12a
12a
12a

23 b

31 a

16 be

^Means within columns not followed by the same
letter are significant at odds of 15:1.

Clearly Ihiscxpcriincnl shuuld be repeated,
perhaps with closer attention paid to timing of
insecticides. Weekly scouting of plots would
help to determine more accurately when each
insect pest is present, and whether timing of
insecticide applications coincides with the tim-
ing required for fungicide applications. Closer
attention to pest status would also help to ex-
plain how these pests enter and move within
the orchard.

It is obvious from this data, however, that
both stink bugs and Japanese beetles can have
a substantial effect on fruit quality at harvest.
Better timing of insecticide treatments and al-
ternative pesticides or methods of control could
impact results in another year.

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Fruit Notes, Volume 63 (Number 2), Spring, 1998

Fruit Notes

University of Massachusetts

Department of Plant & Soil Sciences

205 Bowditch Hall

Amherst, MA 01003

Nonprofit Organization
U.S. Postage Paid

Permit No. 2
Amherst, IMA 01002

SERIAL SECTION

UNIV OF MASSACHUSETTS LIBRARY

AMHERST MA 01003

Account No. 2-22914

vJorr

Fruit Notes

Prepared by the Department of Plant & Soil Sciences.

UMass Extension, U. S. Department of Agriculture, and Massachusetts Counties Cooperating.

Editors: Wesley R. Autio and William J. Bramlage

blume 63, Number 3
SUMMER ISSUE, 1998

Table of Contents

An Easy and Reliable Procedure for Predicting Scald and
DPA Requirement for New England Delicious Apples

Commercial-orchard Trial of Unbaited Traps
for Monitoring Plum Curculio: 1998 Results

Comparison of Six Different Types of Unbaited Traps
for Monitoring Plum Curculios in Orchards

Two Odor Compounds Hold Promise for Increasing
Trap Effectiveness for Plum Curculio

Fruit Notes

Publication Information:

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

The costs of subscriptions to Fruit Notes are $ 1 0.00 for United States
addresses and $ 1 2.00 for foreign addresses. Each one-year subscription
begins January 1 and ends December 3 1 . Some back issues are available
for $3.00 (United States addresses) and $3.50 (foreign addresses). Pay-
ments must be in United States currency and should be made to the
University of Massachusetts.

Correspondence should be sent to:

Fruit Notes

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

UMASS EXTENSION POLICY:

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

Issued hv UMiiss Extension, Jclin (ierhcr. Direclor, in liirllwranie oj the acts of M(iy S tutd June ^0. 1 914.
Utvtass Extension t'ffers equal njifun lunilv in piiii^itiiiis and eiiiplnynietit

An Easy and Reliable Procedure for
Predicting Scald and DPA Requirement
for New England Delicious Apples

Sarah A. Weis, William J. Bramlage, and William J. Lord
Department of Plant and Soil Sciences, University of Massachusetts

The processes which control scald susceptibility
and development have been, and are being, studied by
many researchers. While the exact causes of scald are
not known, it has been observed that a) within a
cultivar, late harvested fruit scalds less than early
harvested fruit, b) other things being equal, the riper
the fruit at harvest, the less they will scald, c) scald
susceptibility varies from year to year among fruit,
even from a given tree, and d) year to year variation is
(at least partly) a function of weather. Cool, sunny
weather favors scald reduction, while hot weather may
increase scald susceptibility.

We have been studying the effects of weather on
scald variability, both at the University of Massachu-
setts Horticultural Research Center (HRC) and at other
New England locations in relation to effects recorded
at various locations world-wide. Here we will report
on recent findings from the New England studies. Our
sites were in Ashfield, Belchertown (HRC), Shelbume,
Warren, and Wilbraham, MA, Storrs, CT, Putney, VT,
Durham, NH, and Monmouth ME. First, it must be
recognized that many of the factors purported to
influence scald are related to one another. For
example, as the harvest season progresses, the fruit
ripen, temperature falls, and the days become shorter.
However, these factors relate somewhat differently to
one another in different years, and in different
locations. Our hope was that if we collected data for
many years at the HRC, we could identify some of the
specific factors influencing scald susceptibility, and
then develop a workable general relationship of
preharvest factors to scald susceptibility.

The factors we have concentrated on are the
following: 1) preharvest cool temperature as the
number of days the apples are subjected to sub-50"F
weather between August 1" and harvest; 2) a
qualitative measure (sunny, partly cloudy, cloudy) of

light to which fruit are subjected during the week prior
to harvest; 3) fruit maturity at harvest as measured by
a starch/iodine test, and 4) harvest date. Because we
have been working primarily with Delicious, which
are not harvested before late September, we did not
experience enough hot (over 80"F) weather near
harvest to evaluate that factor, even though we know it
could be important. We also have not included a light
factor in the reported equations because light measures
were only available for the HRC.

Development of Prediction Equations

Between 1988 and 1993, we harvested 213 one-
bushel samples of Delicious from HRC, stored them
20-25 weeks in 32"F air, and then removed the fruit to
room temperature for a week before rating them for
scald. Scald rating consisted of examining each apple
in a box and recording the percent of apples developing
scald in that box. A sample was considered very scald-
susceptible if more than 60% of fruit in the box
developed scald, and was considered scald-resistant if
fewer than 20% of the fruit developed scald. It should
be noted that any sign of scald was recorded, and some
fruit in this latter category would not have been
downgraded. The following equations, reported in
Fruit Notes 61(4) were generated:

Equation 1: If [8.36 - 0.320(harvest date as
number of days after 8/31) + 0.0546(number of
preharvest days < 50"F) - 0.0550(harvest starch
score)] > 0, then fruit are very scald-susceptible.

Equation 2: If [-11.8 + 0.414(harvest date as
number of days after 8/31) - 0.0298(number of
preharvest days < 50"F) - 0.708(harvest starch
score)] > 0, then fruit are very scald-resistant.

Fruit Notes, Volume 63 (Number 3), Summer, 1998

If a sample fits neither of these categories, it is
considered to be of intermediate scald susceptibility.
Please note: There was a typographic error in one
equation in Fruit Notes 61(4). Those that we present
here are the correct equations.

The numbers you get from these calculations are
called Indices. These Indices were tested in 1995,
1996, and 1997 a) for their ability to accurately place
samples in the correct scald category and b) to see if
they could be used as guides for application of the
scald inhibitor, diphenylamine (DPA). We also are
interested in relating the scald potential of controlled
atmosphere (CA)-stored fruit to the scald Indices. In
1 996 and 1 997, we stored fruit from the HRC in C A, as
well as in air storage. Scald symptoms on the CA fruit
were roughly parallel to symptoms on air stored fruit,
but affected a significantly higher percent of the fruit.
It is possible that this is because CA fruit were stored
for 28 to 29 weeks, while air-stored fruit were kept for
25 weeks. In CA, the specific atmosphere should
influence scald potential. Our storage atmosphere was
2.8% 0„ <2% CO,. Lower oxygen concentrations
ought to reduce scald, but we do not yet have adequate

data to address specific questions regarding use of the
scald Indices to determine DPA requirements for CA-
stored fruit.

Ability of Equations to Predict Scald

Figure 1 shows how well the 1995, 1996. and 1997
samples fit the equations developed using the pre- 1 995
data. These samples included fruit from Storrs, CT,
Putney, VT, Durham, NH, and Monmouth, ME, as
well as the MA locations shown in Figure 2. In each
category, observed scald was only slightly different
from predicted scald, indicating successful application
of the equations to estimate scald potential at the time
of fruit harvest.

Very Scald-susceptible Fruit

Figure 2 shows the most scald susceptible samples
from Massachusetts, which were those from the first
harvest at each location. In all locations and years
scald did develop on more than 60% of these fruit.
However, responses to DPA varied by location. The

n Fruit Predicted to Scald ■ Observed as Predicted

80%

■S 60%

E
<o

,2 40%

o 20%

> 60%

<60% <20%

Number of Fruit Expected to Scald

>20%

Figure 1. Summary of results of scald forecasts: 237 samples, 9 orchards in Five states, 1995, 1996, 1997. Fruit
developing any scald-like.

Fruit Notes, Volume 63 (Number 3), Summer, 1998

100

nj
u
(/)

< c

3 to

a>
a.

DNo DP A DSOO ppm DP A 11000 ppm DP A 12000 ppm DP A

Figure 2. Effects of DPA when more than 60% of fruit were predicted to scald. Percent of fruit showing any
scald-like symptoms.

highly scald susceptible fruit from the Warren MA site
responded to 500 or 1000 ppm DPA to a much greater
degree than did the corresponding fruit from other
sites. (The only statistical comparison which could be
made was with HRC and there the difference was
significant at odds of 1:100). Yet overall, 2000 ppm
DPA would have to be recommended for confidence
that scald would be controlled in these highly scald
susceptible fruit. Note that all the fruit samples
represented in Figure 2 were harvested before 24
September, and Delicious are not normally harvested
that early in New England. Results for samples
harvested during the commercial harvest period will
be represented below in Figure 3 and Tables 1 and 2.

Intermediately Scald-susceptible Fruit

When we moved on to consideration of the next
category of fniit, those of intermediate scald-

susceptibility, we began looking closely at scald
severity, as well as whether any scald-like symptoms
were evident. Most of the samples of "very scald-
susceptible" and "intermediately scald-susceptible"
included fruit displaying scald of varying degrees of
severity. Scald would clearly render some of the fruit
unsaleable in the fresh market. Other fruit, however,
displayed scald, or scald-like symptoms, which would
not be noticeable to the casual observer, and would not
likely downgrade the fruit. The "very scald-
susceptible" fruit tended to have enough severe scald
that there was no question but that 2000 ppm DPA was
needed if the fruit were to be stored for 25 weeks. In
the fruit of intermediate scald susceptibility (or less),
there often were few fruit with severe scald. In some
cases we had difficulty determining if a given apple
did or did not have scald. Therefore, we used a rating
system which separated fruit showing any discolora-
tion that might possibly be scald, from fruit with more

Fruit Notes, Volume 63 (Number 3), Summer, 1998

D No DP A, Any Scald
DSOO ppm DP A, Any Scald

I No DP A, Distinct Scald
1500 ppm DP A, Distinct Scald

HRC 1996 HRC 1997 Warren 1996 Warren 1997 Shelb. 1997

Figure 3. Effects of 500 ppm DPA when 20-60% of fruit were predicted to scald (Intermediate category).

D Any Scald from Storage D Any Scald after 1 Week ■"Distinct Scald" after 1 Week

Figure 4. Development of scald on 'Delicious' apples during one week at room temperature. All DPA
treatments are included, and vary by year and location. These data do not relate to treatment; only to develop-
ment of scald at room temperature.

Fruit Notes, Volume 63 (Number 3), Summer, 1998

Table 1. Percent of fruit on which any scald-hkc symptoms occurred when fewer than 20% ol fruit had been
predicted to scald.

Percent of fruit with any scaid-hke symptoms if
index is:

Location

Harvest year

Number of
samples

0-1

1-3

HRC

1995

1996

1997

Ashfield

1996

12>'

Wilbraham

1995

Warren

1996

1997

Shelbume

1997

Storrs, CT

1995

Putney, VT

1996

34"

Durham, NH

1996

Monmouth, ME

1996

Overall

130

' A "-" indicates that

no samples fell into this

category.

" Sample consists of

Dniy one box.

distinct external browning which would clearly reduce
the grade of the fruit. In Figure 3, the term "distinct
scald" is used. This scald was not always severely
disfiguring, but it always was clearly noticeable. The
term, "Any Scald" is used in Figure 3 (and Figure 4) to
denote fruit which showed any scald-like external
browning. We did observe differences in the
appearance of scald on fruit from different sites. Scald
on the HRC Redspur in particular was difficult to rate,
because the early harvested fruit tended to have a
brownish cast which was not necessarily scald, but did
not occur when the higher concentrations of DPA were
used; this brownish cast did not appear on fruit from
the latest harvests. In contrast, the Sturdeespur from
Warren showed scald very clearly if it was present at
all. The appearance of scald was also variable among
the different striped strains of Delicious we harvested
in Ashfield in 1996. In fruit from some trees, the scald
stood out, while in fruit from others, scald blended

with the fruits' coloring, making it less noticeable.

Figure 3 shows the effects of 500 ppm DPA on
fruit predicted to be of intermediate scald susceptibil-
ity. These fruit all were harvested from September 30
to October 3, when commercial Delicious harvest is
expected to begin. From to 3% of the 500 ppm DPA-
treated fruit shown in Figure 3 clearly displayed scald.
It should be noted for those who find 3% scald too
much, that the 1996 HRC Delicious, which show 3%
scald in Figure 3, also showed 3% scald following
storage when 2000 ppm DPA was applied. Overall,
500 ppm DPA provided adequate .scald control; use of
1 000 to 2000 ppm DPA was not any more beneficial
and constituted overu.se of the chemical on these
intermediately susceptible fruit.

Fruit With Low Scald Susceptibility

The second equation presented earlier in this

Fruit Notes, Volume 63 (Number 3), Summer, 1998

Tabic 2. Percent ol

Iruit on which dislinc

t scald ;

>vmpl()ins

occurred when

lower than

207,

ol Iruii had been

predicted to

scald.

'erceni

ol Iruit

with distinct

seal

ll ll IIH

ex is:

mbcr

Location

Harvest date

implcs

0-1

1-3

HRC

10/8/96
10/15/96
10/2/97
10/9/97
10/14/97

Ashfield

10/3/96
10/14/96

5
5

Warren

9/30/96
10/7/96
10/6/97
10/16/97

2
8
5
5

Shelburne

10/8/97
10/15/97

5
5

Overall

' A "-" indicates that

no samples fell

into this category.

report identifies fmit of low scald susceptibility. This
categoi^ should represent fnait with little or no need
for DPA treatment. Identifying these fruit is of
particular interest because 1 ) scald control treatment is
expensive and inconvenient to apply, and 2) the
materials used are not acceptable to an increasing
number of markets. Clearly, if 20% of fruit in a lot
develop scald, this is unacceptable. However, when
we attempted to generate equations for forecasting
small amounts, for example, less than 10% .scald, we
were unsuccessful; there was simply too much
variation in scald development in the vicinity of 10%.
We therefore developed the equation to predict under
20% scald because it produced consistent results. If
the Index for the "scald resistant" equation (Equation
2) is greater than zero for a given day, location, and
starch score, then fewer than 207c of fruit harvested on
that day will be predicted to scald after 25 weeks of
storage. In addition, the higher the Index, the greater
the likelihood that fewerthan 207p of fmit will scald. It
also follows that the higher the Index, the less scald
one would expect. Tables I and 2 show how many fruit

developed any scald-like browning (Table 1) and how
many developed "distinct scald" (Table 2). As the
Index increased, the amount of scald did indeed
decrease. There was some variability among orchards
and years, but the trend was there. What this means is
that an individual could base scald control measures on
personal experience about how much scald had
developed on fmit from this site in previous years, and
on how much risk the grower was willing to accept,
using the tables shown below as a guide. If the Index
for Equation 2 is greater than zero, low susceptibility
exists. As the number becomes increasingly greater
than zero, the risk of scald becomes progressively
smaller.

A Simple Procedure for Using (he
Prediction Equations

The equations presented earlier in this article can
be intimidating. However, they can be rearranged to
produce an easy-to-use system for tracking scald
susceptibility during the harvest .season.

Fruit Notes, Vokime 63 (Number 3), Summer, 1998

Equation 1 ; Ti

) idenlify highly scald-sustcplihic Iruil (more than 60% likely to scald):

8.36

In Seplember:[day ol month] x 0.320, or
In Oclober:[30 + day of month] x 0.320

(Number of times (overnights) the
temperature was below 50"F] x 0.0546

[Starch Score (measured on harvest
date) of representative fruit] x 0.0550

= INDEX

If greater than 0, then more than 60%
of fruit likely to scald

Equation 2: To identify scald resistant fruit (fewer than 20% likely to scald):

-11.8

In September: [day of month] x 0.414, or
In October:[30 + day of month] x 0.414

[Number of times (overnights) the
temperature was below 50"F] x 0.0298

[Starch Score (measured on harvest
date) of representative fruit] x 0.708

= INDEX

If greater than 0, then fewer than 20%
of fruit likely to scald

Example: Delicious were harvested on October 1, the
temperature had gone below 50"F on 7 nights since
August 1, and the starch score at harvest was 2.2.

Using Equal ion I :

8.36 - 3 1 (0.320) + 7(0.0546) - 2.2(0.0550) = Index I

so. Index 1 =-1.30

Since the Index is less than zero, less than 60% of the
fruit are predicted to scald after storage if no DPA is
applied.

Using Equation 2:

-1 1.8 + 31(0.414) - 7(0.0298) - 2.2(0.708) = Index 2

so. Index 2 = -0.73

Since this Index also is less than zero, then more than
20% of fruit are predicted to scald. Therefore, if these
fruit are stored in air at 32"F for 20-25 weeks, between
20% and 60% of the fruit can be expected to scald if no
DPA is applied. This scald can be controlled by
application of 500 ppm DPA, as seen in Figure 3.

Fruit Notes, Volume 63 (Number 3), Summer, 1998

Post-Storage Scald Development

One of the concerns about scald is that while it
may not appear on fruit on removal from storage or
when packed, it may appear later, before fruit are
consumed. We had not intended to address this issue,
but we would like to report here that we did not see a
great deal of scald developing during the week the fruit
were kept at room temperature. In 1996 and 1997, we
inspected some of the fruit at the time of removal from
storage, as well as after 7 days at room temperature.
Figure 4 shows that on air-stored Delicious, this post-
storage increase in scald was not significant. Note that
sometimes more scald was discernible at removal from
storage than after a week at room temperature. This is
an indication of the difficulty we sometimes had in
determining if fruit discoloration was or was not scald.
It should be made clear that not all cultivars are like
Delicious in this regard. For example, we have
observed repeatedly that Cortland may show little or
no sign of scald at removal from storage, but after 7
days at room temperature, much scald is present.

Conclusions

We conclude from this research that forecasting
scald susceptibility on air-stored New England
Delicious is feasible, and we believe that use of these
prediction models can lead to more efficient use of
DPA. Results of 3 years of tests of the models
developed from 6 previous years' data indicate that
using a calendar, a min-max thermometer, and a starch
test for maturity, one can use these equations to
effectively predict high, intermediate, or low scald
susceptibility of Delicious apples harvested at a given

site on a given day anywhere in New England.
Furthermore, the equations predict the need for DPA:
highly susceptible fruit require 2000 ppm, intermedi-
ately susceptible fruit require only 500 ppm, and low-
susceptibility fruit, particularly those with an Index
greater than 1 in Equation 2, have no need for DPA
treatment. We offer a system for determining which
fruit need 2000 ppm DPA, which will be protected by
500 ppm, and which may be stored without DPA
treatment, and with a minimum of concern for post-
storage scald development on air-stored fruit. As
demonstrated by the data in Tables 1 and 2, it is
possible to choose an Index higher than zero in
Equation 2 as a demarcation between groups of fruit
which receive 500 ppm DPA and those which receive
none. This can be especially useful if experience has
shown that the fruit from particular trees are especially
scald susceptible, and allows flexibility in determining
at what point to stop applying DPA.

Acknowledgments

The authors would like to thank the following
people for their assistance in selection and provision of
fruit and preharvest information for developing and
testing scald prediction models: Dana Clark, Evan
Darrow, David Kollas, William G. Lord, Wayne Rice,
James Schupp, Joe Sincuk, Tim Smith, and Mark and
Bob Tuttle. Technical assistance by Irene Clark and
Laura Lee Jones is much appreciated. We would also
like to thank the Massachusetts Fruit Growers'
Association, the New England Tree Fruit Growers
Research Committee, and the Washington Tree Fruit
Research Commission for their financial support of
this research.

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Fruit Notes, Volume 63 (Number 3), Summer, 1998

Commercial-orchard Trial of Unbaited
Traps for Monitoring Plum Curculio:
1998 Results

Starker Wright, Stephen Lavallee, and Ronald Prokopy
Department of Entomology, University of Massachusetts

For the past 3 years, we have performed field and
laboratory studies aimed at developing an effective trap
for monitoring plum curculio (PC) in commercial or-
chards. Our goal in trap development is to establish a
system whereby growers can predict the need for and
timing of sprays.

In 1996, we evaluated unbaited black pyramid traps
in small orchard blocks in Belchertown, MA, Conway,

MA, and South Deerfield, MA. Our principal finding
in this study was that unbaited pyramid traps are inef-
fective in warm weather. When the temperature rises
above 20"C (when most PC injury occurs), PCs enter
trees largely by flying directly into the tree canopy,
bypassing the tree trunks and trunk-associated pyra-
mid traps.

In 1 997, black pyramid traps were evaluated at three

(a)

(b)

48 inches

12 inches

24 inches

3 inches

Figure 1 . Trap designs used in the 1 998 field (rial: (a) unbaited trunk-mimicking pyramid trap, placed adjacent to
the tree trunk and (b) unbaited tvvig-mimicking cylinder trap, positioned wiihiii ihe tree canopy and kept m a
vertical position by a clipped upright twig.

Fruit Notes, Volume 63 (Number 3), Summer, 1998

Tabic 1 Relationship between numbers of plum curculio adults captured by unbaited pyramid and twig-mimic
traps and percent fruit showing injury by plum curculio across all 16 replicates of each tree size treatment m
commercial orchards in 1998.

Number of adults captured
per sampling period

Tree size

Sampling period

Pyramid

Twig mimic

Cumulative fruit
injury (%)

Small

Before I'' spray

0.10

0.05

0.1

Between 1 "* and 2"'' spray

0.06

0.09

1.0

Between 2"^ and 3"* spray

0.03

0.02

2.2

After y' spray

0.00

3.5

Medium

Before 1 " spray

0.14

0.10

0.1

Between i " and 2"'' spray

0.18

0.00

0.4

Between 2"^ and 3"* spray

0.02

0.00

0.7

After 3"* spray

0.00

0.5

Large

Before 1 " spray

0.19

0.00

0.1

Between T and 2"'' spray

0.12

0.09

0.6

Between 2"'' and 3"" spray

0.00

0.7

After 3"' spray

0.00

0.8

positions in 48 blocks of trees in commercial orchards.
In each block, one trap was placed immediately adja-
cent to the tiTjnk of a perimeter tree, one trap was
placed at the midway point between the perimeter tree
and the first interior tree, and one trap was placed at
the margin of the nearest woods. Data from this study
extended our 1996 findings. Irrespective of trap posi-
tion, captures of PC in unbaited pyramid traps did not
reflect accurately the need for or proper timing of in-
secticide spray. A second (preliminary) study was
conducted m 1 997 intended to develop a trap to moni-
tor PC abundance and activity within tree canopies.
From this work, we developed a twig-mnnicking black
cylinder trap as an alternative to trunk-mimicking black
pyramid traps.

In 1998, we repeated and expanded our trial of
trap types in the same 48 commercial orchard blocks
used in 1997. We compared the performance of black
pyramid trunk traps with black cylinder canopy traps
as indicators of the potential for PC injury.

Materials & Methods

As in 1997, traps were placed in six blocks of trees
in each of eight commercial orchards. All blocks con-
tained 49 trees (seven rows of seven trees each) of
mixed cultivars. Of the six blocks in each orchard, two
were considered high tree density (M.9 rootstock), two
medium tree density (M.26 rootstock), and two low
tree density (M.7 rootstock).

Prior to bloom, we placed two unbaited black pyra-
mid traps in each of the 48 blocks, each trap adjacent
to the trunk of a perimeter tree (the most effective
postion for traps of this type). We also placed two
unbaited black hollow cylindrical (3 inches diameter x
12 inches height) twig-mimic traps in perimeter trees
of each block, kept in a vertical position within the
canopy by a clipped twig (Figure I ). In early May
1998, when all traps were placed, we knew of no at-
tractive odor which could be used in conjunction with
these traps (sec study of odors attractive to PC, this

Fruit Notes, Volume 63 (Number 3), Summer, 1998

Prior to 1st 1st to 2nd 2ncl to 3rd

Insecticide Application

After 3rd

D Pyramid
□ Cylinder
■ % Injury

Figure 2. Captures of plum curculios per trap for two unbailed trap types and percent fruit injured by plum curculio
before the first insecticide application, between the first and second applications, between the second and third

issue).

Evei7 3-4 days from petal fall until five weeks af-
terward (the peiiod of fruit susceptibility to PC injury),
we examined 15 fruit on each of the seven perimeter
trees of each block. The number of PC egglaying scars
was recorded, and scarred fruit were allowed to re-
main on the tree. At each sample date, captures of PC
were recorded for each trap, and all captured PCs were
removed from traps and returned to the laboratory. All
blocks were treated according to the growers' stan-
dard orchard management practices, receiving two to
three applications of Guthion or Imidan at 9- to 14-day
intervals beginning at petal fall.

Results

We combined data for the two blocks of each plant-
ing density for each orchard and categorized fmit in-
jury and trap capture data according to spray interval.
The data (Table 1, Figure 2) show that PC egglaying
injury was very light in all blocks prior to the first in-
secticide application. Injury to fruit increa.sed sharply
between the first and second spray, and increased fur-
ther between the second and third spray. Interestingly,
PC damage to fruit subsided in most blocks after the

third spray, but in a few blocks of high density trees,
there was a flurry of PC egglaying activity in mid-June,
after the final spray.

Captures of PCs by unbaited black pyramid traps
were greatest prior to the first insecticide application,
decreased moderately between the first and second
spray, and decreased substantially after the second
spray (Table I, Figure 2). In fact, in several blocks
which continued to accumulate substantial PC damage
after the second insecticide application, not a single PC
was captured during this interval by unbaited pyramid
traps. A similar trend occurred for captures within the
tree canopies by unbaited black cylinder traps (Table
I , Figure 2).

Conclusions

Results of the 1998 field trial of unbaited PC traps
confirm our findings of 1 996 and 1 997. For commer-
cial use, captures of PC in unbaited trunk-mimic or twig-
mimic traps are not accurate indicators of the need for
or timing of insecticide applications. If development of
traps for other species related to PC (such as cotton
boll weevil and sugar cane weevil) can be used as a
guide, then the most effective trap for PCs should be

Fruit Notes, Volume 63 (Number 3), Sui

1998

baited with a combination of attractive pheromone and
host odor (neither of which was available at the start
of the 1998 season). For 1999, we intend to maximize
the visual attractiveness of traps, and incorporate use
of attractive odor lures.

Acknowledgments

This work was supported by State/Federal IPM
Funds, the New England Tree Fruit Growers Research
Committtee and SARE Grant #97 LNE 97-90 (USDA
96-COOP- 1-2700). We are grateful to the eight grow-
ers that participated in this study: Bill Broderick, Dana
Clark, Dave Chandler, Dave Cheney, Dave Shearer,
Joe Sincuk, Tim Smith and Mo Tougas.

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Comparison of Six Different Types of
Unbaited Traps for Monitoring Plum
Curculios in Orchards

Ronald Prokopy, Shawn Mclntire, Jonathan Black, Max Prokopy,

and Tracy Leskey

Department of Entomology, University of Massachusetts

We can conceive of at least four approaches to
monitoring entry of plum curculio (PC) adults into or-
chards and orchard trees that might be useful in pre-
dicting need and time to spray for PC control. These
approaches are: (1) monitoring flights of PCs exiting
from overwintering sites in areas bordering orchards,
(2) monitoring flights of overwintering PCs into orchard
trees, (3) monitoring PCs entering orchard trees via
climbing tree trunks, and (4) monitoring PCs present in
orchard tree canopies. In 1998, we evaluated each of
these four approaches using unbaited traps placed near
or in four small blocks of apple trees.

Materials & Methods

Two of the four blocks of trees (one at the Univer-
sity of Massachusetts Horticultural Research Center
and one in Deerfield, MA) received no insecticide to
control PC. Each of the other two blocks one at the

Horticultural Research Center and one in Conway, MA)
received two sprays of Imidan: one at petal fall and the
other two weeks later. All trees were on either M.7 or
M.26 rootstock.

To monitor exit flights of PCs from overwintering
sites, we positioned unbaited Tangletrap-coated clear
Plexiglas traps (2 feet by 2 feet), intended to represent
empty space, 6 feet from edges of foliage of woods
that bordered each block. Each of the four traps per
block was fastened vertically to a wooden pole. The
center of each trap was 3 feet above ground. The
sticky-coated side faced the woods.

To monitor flights of overwintered PCs into orchard
trees, we positioned three different types of unbaited
Tangletrap-coated traps 1 8 inches away from edges of
canopies of orchard trees and facing woods. The three
trap types were: a 2 foot by 2 foot square of clear
Plexiglas, a 2 foot by 2 foot square of plywood painted
green to mimic tree foliage, and a 1 foot by 4 foot tall

Fruit Notes, Volume 63 (Number 3), Summer, 1998

Tabic I, Numbers ol plum cuaulios captured by each type ol Irap m blocks ol unsprayed and sprayed apple
trees May I- June 19, 199X

Trap type

Number ol replicates

Unsprayed Sprayed

Number ol curculios per trap*

Unsprayed

Sprayed

Sticky clear traps at edge of woods
Sticky clear traps at edge ot apple trees
Sticky green traps at edge of apple trees
Sticky black traps at edge of apple trees
Black pyramid traps at apple tree trunks
Black cylinder traps in apple tree canopies

0.5 c

1.6 a

2.6 b

1.0 a

1.9 b

0.8 a

0.3 c

0.4 a

26.3 a

1.5 a

2.2 b

0.5 a

Numbers in the same column followed by a different letter are significantly different at odds of 19:1.

rectangle of plywood painted black to mimic a tree
trunk. Each trap was attached vertically to a wooden
pole, with trap center 3 feet above ground. The sticky-
coated side faced the woods. Each block contained
four traps of each type, arranged so that traps alter-
nated in type.

To monitor PCs entering orchard trees by climbing
tree trunks, we placed one unbaited black pyramid
trunk-mimicking trap (described in the preceding ar-
ticle) next to the trunk of each of eight perimeter apple
trees bordering woods in each block.

To monitor PCs present in orchard tree canopies,
we placed one unbaited hollow black cylinder twig-mim-
icking trap (described in the preceding article) in the
canopy of each of the eight other perimeter apple trees
(not the same trees having pyramid traps) bordering
woods in each block. The black cylinder traps were
maintained in vertical position by placing each one over
a clipped vertical branchlet about mid-way between
the edge and center of the tree canopy and at mid-
height of the canopy.

All traps were emplaced during the pink stage of
apple bud development and were monitored twice
weekly for eight weeks for captured PCs. On each
monitoring day, beginning at petal fall, 1 2 fruit on each
of 12 perimeter trees per block were examined for
evidence of PC damage. Damaged fruit were allowed
to remain on the tree.

Results

In the unsprayed blocks of apple trees, significantly
more PCs (at least 10 times more) were captured by
black pyramid traps next to apple tree trunks than by
any other type of trap (Table 1 ). Sticky clear traps and
sticky green traps at edges of apple tree canopies, along
with black cylinder traps in apple tree canopies, cap-
tured about the same number of PCs and significantly
more than the sticky clear traps at edges of the woods
or sticky black traps at edges of apple tree canopies
(Table I ). Despite the large number of PCs captured
by the pyramid traps, captures by these traps were not
useful in predicting occurrence of PC injury to fruit.
Thus, increases in captures by sticky clear traps and
sticky green traps at edges of apple tree canopies, but
not increases in captures by any other types of traps,
were positively correlated with increases in fmit dain-
age caused by PCs during the monitoring period.

In the sprayed blocks of apple trees, there were no
significant differences among any of the trap types in
numbers of PCs captured, although sticky clear traps
at edges of woods and black pyramid traps next to apple
tree trunks captured the most PCs numerically, and
sticky black traps at edges of apple tree canopies and
black cylinder traps in apple tree canopies captured
the fewest PCs numerically (Table I). Increases in
captures by any of the trap types did not correlate sig-

Fruit Notes, Volume 63 (Number 3), Summer, 1998

nificantly with increases in fruit damage caused by PCs
during the monitoring period.

Compared to captures of PCs by traps in unsprayed
blocks, captures in sprayed blocks were ( 1 ) just as great
for PCs caught by sticky clear traps at edges of woods
(this is an expected finding because orchard sprays
should not interfere with emigration of PCs from woods),
(2) fewer by an average of about 50% for PCs caught
by all three types of sticky traps (combined) at edges
of apple tree canopies, (3) fewer by about 80% for
PCs caught by black cylinder traps in apple tree cano-
pies, and (4) fewer by about 95% for PCs caught by
black pyramid traps at apple tree trunks. We do not
know why orchard sprays apparently interfered more
with captures of PCs by pyramid traps at tree trunks
than captures by cylinder traps in tree canopies.

apple tree canopies better coincided with periods of
increase in fruit injury than did periods of increase in
captures of PCs by black pyramid traps at tree trunks.
Disappointingly, in the sprayed blocks, in no case did
periods of increase in captures of PCs by any of the
trap types tested in 1 998 correlate positively with peri-
ods of increase in fruit injury.

We believe that a more user-friendly form of a
sticky trap placed at the edge of an apple tree canopy
to capture PCs flying into apple trees and/or a modi-
fied form of a cylinder trap placed in an apple tree to
capture PCs active within the canopy hold the most
promise as effective monitoring devices. We further
believe that neither of these trap types can succeed in
monitoring accurately the presence of PCs in sprayed
orchards unless they are baited with attractive odor.

Conclusions

Acknowledgments

The findings from these studies in unsprayed blocks
of apple trees in 1998 are similar to findings reported in
Fruit Notes 63(1) on studies in an unsprayed block of
apple trees in 1997. In both studies, periods of increase
in captures of PCs by sticky clear traps at edges of

This work was supported by USDA Hatch funds
and the New England Tree Fruit Growers Research
Committee. We thank Jim Hardigg for allowing us to
use his orchard for part of this work.

vl^ *X* *X* *^ *X*

0^ 0^ *Y* *X* *T*

Fruit Notes, Volume 63 (Number 3), Summer, 1998

Two Odor Compounds Hold Promise
for Increasing Trap Effectiveness for
Plum Curculio

Tracy Leskey, Max Prokopy, Anthea Yanopolous, Margaret Young, Brian Hogg,

Fidelma Boyd, and Ronald Prokopy

Department of Entomology, University of Massachusetts

Larry Phelan

Department of Entomology, Ohio State University

There has been no trap developed for plum
curculios (PCs) that successfully detects the beginning
of PC activity in orchards each spring. Traps for other
species of weevils such as the cotton boll weevil and
the sugar cane weevil use a combination of attractive
compounds present in host plant odors and weevil-pro-
duced pheromones to increase trap effectiveness. PCs
are attracted to odors produced by their host fruit over
short distances as reported in the 1 996, 1 997, and 1 998
Winter Issues of Fruit Notes. Under field conditions,
PCs are attracted to host fruit odors at distances up to
3 yards. Eller and Bartelt of Illinois found that male
PCs produce an aggregation pheromone called
grandisoic acid. Therefore, we decided to screen 18
of the 19 compounds present in plum odor that were
identified by Larry Phelan's lab at Ohio State Univer-
sity in hopes of finding attractive compounds that could
be used in combination with grandisoic acid to improve
trap performance. Compounds were tested in the labo-
ratory and in the field to identify those that were most
attractive to PCs.

Materials & Methods

A profile of volatile compounds that comprises the
odor of freshly picked plum fruit (2 weeks after bloom)
was completed in the laboratory of Larry Phelan using
a gas chromatograph and mass spectrometer. The
compounds listed in Table 1 plus phenol were identified
as comprising plum odor. All compounds were evalu-
ated as potential attractants for PCs in laboratory and
field experiments with the exception of phenol, which

is highly toxic to mammals. Compounds were tested in
the laboratory at three concentrations (1, 0.1, and
0.01%) and in the field at two concentrations (5 and
0.5%).

PCs used in laboratory bioassays were collected
from unsprayed wild plum and apple trees. For all labo-
ratory tests, PCs were starved 24 hours prior to test-
ing. Tests were conducted at the beginning of dark-
ness. A 75 ul aliquot of the compound (the treatment)
was pipetted onto a small cotton wick placed next to
one of the two pipette tips that served as ports into a
Petri dish test chamber. Either 75 ul of hexane or wa-
ter (depending on the solubility of the compound) was
used as a solvent control and was pipetted onto a sec-
ond cotton square placed next to the other pipette port.
Handling of PCs was kept to a minimum. A single PC
was placed gently in the center of each Petri dish test
chamber. Each time a specific compound was tested,
12 PCs were tested singly in individual dishes and kept
together on a tray. Dishes were then moved immedi-
ately to the testing room. All bioassays lasted 2 hours,
and all compounds were tested at least four times at
each concentration ( 1 2 individual PC per tray x 4 trays
= 48 individual PCs tested per compound and concen-
tration). To measure the level of attraction to a par-
ticular compound (the treatment), we used a Response
Index (RI). The RI was calculated by subtracting the
number of PCs responding to the control (C) from the
number responding to the treatment (T), dividing this
amount by the total number of PCs tested each time,
and multiplying by one hundred. Thus RI = [(T - C) /
12] x 100. The greater the RI value, the more attrac-

Fruit Notes, Volume 63 (Number 3), Summer, 1998

Tabic I. Laboratory response indices (RIs) ol plum curculio ailulls lo individual odor compounds al three
concentrations in solvent

Compound

0. 1 %

0.01%

Bcnzaldehyde

-28

-13

Benzonitrile

-29

-10

Biphenyl

-33

-10

-4

Diphenyl methane

-6

-8

Ethyl acetate

-6

Ethyl butyrate

Ethyl isovalerate

-4

13*

24*

2-Hexenal

-21

-17

-13

2-Hexanol

-4

3-Hexanol

-2

2-Hexanone

3-Hexanone

-10

3-Hydroxy-2-butanone

-17

-6

-17

Isopropyl acetate

-13

-4

Limonene

-7

18*

Linalool

-27

-6

2-PentanoI

-2

2-PropanoI

-4

* Significantly different from zero at odds of 19 to 1 .

live was the stimulus.

Ifi the field, green boll weevil traps were placed on
the ground beneath the canopy of unsprayed apple trees
approximately one yard from the trunk at each cardi-
nal point. Compounds being tested were diluted in min-
eral oil to a 5% concentration and applied to a 3-inch
piece of cylindrical cotton wick that was wrapped in
aluminum foil and attached by a wire to a boll weevil
cone-shaped trap top. One end of the wrapped foil
cylinder was clipped to permit dissemination of odor.
For each tree, two traps were baited with an individual
compound and placed at north and south positions, and
two traps baited with mineral oil only (the control) were
placed at east and west positions. After 48 hours, the
number of PCs captured in each of the traps was
counted, traps were baited with fresh wicks, and posi-
tions of traps were rotated around the tree so that com-
pound-baited traps were in east-west positions and
control-baited traps were in north-south positions. This
procedure was repeated 12 times. A .second experi-

ment was conducted using only the most and least at-
tractive compounds at two concentrations: 5 and 0.5%.
In this experiment, procedures were nearly the same
as in the first experiment except this procedure lasted
only 24 rather than 48 hours, and was repeated only 10
times. To measure the attractiveness of a particular
compound, a Field Response Index was created by
subtracting the number of PCs responding to the con-
trol (C) from the number responding to the treatment
(T), dividing by the total number of PCs captured in the
treatment and control traps, and then multiplying by 100.
Thus, RI = 1(T - C )/ (T + O] X 100. The greater the
RI, the more attractive the compound.

Results

Laboratory Results. For compounds at 1 %, none
of the RI values were significantly (Table I). AtO. I'^f,
ethyl isovalerate jiiovided a positive and significant RI.
Other compounds did not result in significant RIs at

Fruit Notes, Volume 6.^ (Number 3), Summer, 1998

Tabic 2 I'lc'ld response indices (KIsj ol plum cuiciilio adulls lo (iilor cumpouruls :il conccnlralions ol 5 "/< . anil
().5'/f in mineral oil.

Compound

Experiment
(5%)

Expcrimcnl 2

0.5%

Benzaldchyde

Benzonitriie

Biphenyl

-27

Diphenyl methane

Ethyl acetate

Ethyl butyrate

Ethyl isovalerate

71*

2-Hexenal

2-Hexanol

-13

3-Hexanol

-67

2-Hexanone

-18

3-Hexanone

-39

3-Hydroxy-2-butanone

Isopropyl acetate

-13

Limonene

38*

Linalool

2-Pentanol

-25

2-Propanol

-31

80*

100*

Significantly different from zero at odds of 19 to 1.

0.1%. At 0.01%, ethyl isovalerate and limonene re-
sulted in positive and significant RIs, and all others re-
sulted in nonsignficant RIs.

Field Results. In the first field experiment, the
only significant RIs were recorded for 5% solutions of
ethyl isovalerate and limonene (Table 2). In a second
set of experiments testing ethyl isovalerate and limonene
(the most attractive compounds from the first field ex-
periment) and 3-hexanol (the least attractive compound
from the first field experiment), significant RIs were
recorded for 5% solutions of ethyl isovalerate and li-
monene, but not 3-hexanol at 5% or any of the three at
0.5% (Table 2).

Conclusions

Data obtained from our laboratory and field ex-

periments are in agreement. Two compounds, ethyl
isovalerate and limonene, proved significantly attrac-
tive to PCs under the test conditions described here.
For the future, we plan lo test these two attractive com-
pounds alone or in combination with male-produced
pheromone as baits for the pyramid traps described in
1997 and 1998 Winter Issues of Fruit Notes, and also
for alternative trap designs including a circle trap and a
twig-mimicking black cylinder trap to see if trap effi-
cacy is increased,

A ckn ow ledge m ents

This work was supported by USDA Hatch funds
and by the New England Tree Fruit Growers Research
Committee. We thank Jim Hardigg for allowing us to
use his orchard for part of this work.

vt* vl> *!>* vl>* vT>*
y^ *^ *^ #^ #^

Fruit Notes, Volume 63 (Number 3), Summer, 1998

Fruit Notes

University of Massachusetts

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Fruit Notes

Prepared by the Department of Plant & Soil Sciences.

UMass Extension, U. S. Department of Agriculture, and Massachusetts Counties Cooperating.

Editors: Wesley R. Autio and William J. Bramlage

iiMIW AC lAACC

u i * I V . w r iv 1 /\ o ^ .
Volume 63, Number 4

FALL ISSUE, 1998

Table of Contents

Structural Refinement of Spheres
for Controlling Apple Maggot

Evaluation of Varying Doses of Different Toxicants for
Use on Spheres to Control Apple Maggot Flies

Fate of Apple Maggot Flies Alighting on Pesticide-treated
Spheres in a Commercial Apple Orchard

Evaluation of Scab on Fruit of New Apple Cultivars

Testing Various Methods of Timing Summer Fungicides

On-farm 1PM Education: Displays and Self-guided Tours

Fruit Notes

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Fruit Notes, Volume 63 (Number 4), Fall, 1998

Structural Refinement of Spheres for
Controlling Apple Maggot

Starker Wright, Ronald Prokopy, and Xing Ping Hu
Department of Entomology, University of Massachusetts

Currently, there is no clear indication of the
extent to which organophosphate insecticides will
continue to be labeled for use in commercial apple
production. If recent state and federal decision-
making trends can be used as a guide for future
action, then we should prepare ourselves for the
possibility that the pre-harvest interval for orga-
nophosphate insecticides (particularly
azinphosmethyl) may be lengthened considerably,
possibly to 60 days or more. The purpose for do-
ing this would be to eliminate all detectable resi-
due on fruit at harvest, a principal aim of the Food
Quality Protection Act (FQPA). This same sce-
nario could well apply to permissible use patterns
of carbamate insecticides, the only other class of
labeled materials known to be at least moderately
effective against apple maggot.

For many years (as reported in Fruit Notes),
we have conducted studies aimed at development
of behavioral control of apple maggot using traps
as a substitute for insecticide applications. These
studies have led to the development of pesticide-
treated spheres as a potential alternative in com-
mercial apple production. Such spheres are in-
tended to be inexpensive, easy to use, safe to handle,
and to offer reliable control of apple maggot.

In 1997, we began an extensive comparison of
odor-baited sticky coated spheres, pesticide-treated
wooden spheres, and biodegradable pesticide-
treated spheres for direct control of apple maggot
flies (AMF) in commercial orchards. This study
was conducted in eight commercial apple orchards,
each containing four blocks of 49 trees each. In
each orchard, one block received three insecticide
sprays for AMF control, one block was surrounded
by sticky-coated wooden spheres, one block was
surrounded by pesticide-treated wooden spheres,
and one block was surrounded by biodegradable
pesticide-treated spheres. The results [Fruit Notes

62(4)] showed that pesticide-treated biodegradable
spheres performed as well as sticky spheres and
considerably better than pesticide-treated wooden
spheres on which we were unable to preserve an
effective level of feeding stimulant. None of the
three trap types provided quite the level of AMF
control as 3 insecticide sprays did. In the case of
biodegradable pesticide-treated spheres, compro-
mising factors were that some spheres cracked pre-
maturely, some were eaten by birds and/or rodents,
and some were overgrown by fungi, reducing the
number of effective spheres comprising the barrier
to fly immigration into some blocks. Despite short-
comings, our 1997 findings were encouraging, as
all sphere types performed well under high pest
pressure in commercial orchards.

Our goal for 1998 was to conduct experiments
leading to improved versions of pesticide-treated
spheres and to evaluate these for direct control of
AMF. Here we report on structural refinements of
both pesticide-treated biodegradable spheres and
pesticide-treated wooden spheres.

Materials & Methods

To maximize effectiveness and durability of bio-
degradable spheres, we addressed each of the short-
comings of such spheres experienced in 1997:

1 ) To combat premature breakdown of biodegrad-
able sphere bodies, we evaluated seven differ-
ent structural compositions. We assessed each
body type for drying ti-ne, hardness, and resis-
tance to humidity.

2) To ease deployment, we replaced the trouble-
some string hangers with wire hooks, and used
a metal disc beneath each sphere to support
the weight of the sphere body.

3) To prevent consumption of spheres by rodents,

Fruit Notes, Volume 63 (Number 4), Fall, 1998

we evaluated five different fornuilations of hot
pepper additive, whose active ingredient (cap-
saicin) is known to deter rodent feeding.

4) To reduce damage caused by birds, we evalu-
ated black spheres versus red spheres.

5) To inhibit growth of fungi on the surface and
in the body of the spheres, we incorporated
1.0% sorbic acid mto the ingredients of each
sphere body as a preservative.

In an attempt to extend the residual activity of
sucrose as the necessary feeding stimulant on pes-
ticide-treated wooden spheres, each sphere was fit-
ted with a 1.25-inch plastic dish containing 15
grams of molten sucrose, which cooled and hard-
ened after pouring. In concept, as these spheres
are exposed to rainfall, the sphere surface is re-
treated with a dilute sucrose solution from the res-
ervoir atop the sphere. If there was a constant
release of sugar to the sphere surface under condi-
tions of rainfall, then ideally each sphere would
have enough sucrose to replenish the active supply
through several inches of rainfall.

In addition to structural modifications of pes-
ticide-treated spheres, we increased the level of
imidacloprid (Merit formulation, 75 WP) from
1.5% to 2.0% active ingredient to extend late-sea-
son effectiveness of the spheres (see following ar-

ticle), l-'or all pesticidc-treated spheres, the toxi-
cant (iniKiacloprid) was applied to the spheres at
2.0% a.i. in Glidden Latex Gloss Enamel paint.
In 1998, we evaluated odor-baited sticky spheres,
modified wooden pesticide-treated spheres, and im-
proved biodegradable pesticide-treated spheres in
32 commercial orchard blocks. Blocks used in 1998
were the same blocks used in 1997; spheres were
emplaced in eight commercial orchards, each con-
taining four blocks of 49 trees. Each block receiv-
ing spheres was surrounded by 26 spheres of the
same type at a 5-meter interval, and each sphere
was baited with a vial of butyl hexanoate.

Results

In laboratory tests under conditions of artifi-
cial rainfall, the following body composition
proved the most durable for biodegradable spheres:
16% wheat flour, 16% pre-gelatinized corn flour,
5% corn starch, 20% powdered sugar, 13% granu-
lated sugar, 7% corn syrup, 8% glycerol, and 9%
water. Spheres of this composition were found to
harden very quickly and were much more resis-
tant to premature breakdown than the body style
used in 1997.

Of materials tested to deter rodent feeding, the
best product was African cayenne pepper powder,

Table 1. Control of apple maggot flies by odor-baited sticky-coated wooden spheres, wooden
pesticide-treated spheres (PTS), biodegradable pesticide-treated spheres, or three applications
of azinphosmethyl in 32 blocks of medium-size apple trees in eight commercial orchards in
1998.

Mean no

flies captured per block

Mean

Treatment

Perimeter tra

Interior monitoring
traps

injured fruit per
block*

Sticky spheres
Wooden PTS
Biodegradable PTS
Insecticide sprays (3)

1702.5

137.3
210.8
272.4
123.6

0.70
2.93
0.77
0.59

* Values here represent injury during five sampling periods (every 2 weeks from mid-July
tiirough harvest), during which 100 fruit per block were sampled on each sampling date.

Fruit Notes, Volume 63 (Number 4), Fall, 1998

mixed at 5% with sphere body ingredients. Sub-
sequent lab and field tests indicated that AMF were
completely unaffected by the pepper additive,
whereas damage to spheres by rodents was greatly
reduced or eliminated. Field assays revealed that
bird damage to biodegradable spheres was substan-
tially reduced by painting spheres black, thus mak-
ing them less visually attractive to foraging birds.
Fortunately, AMF are equally attracted to black
and red spheres. Given this early-season progress,
we were confident in the potential of biodegrad-
able pesticide-treated spheres to offer AMF con-
trol comparable to sticky-coated wooden spheres.
Data trends established in the 1997 comparison of
sphere types held true in 1998. Results for 1998
(Table 1) showed that biodegradable pesticide-
treated spheres performed about as well as sticky
spheres (0.77% and 0.70% injured fruit, respec-
tively) and nearly as well as three insecticide appli-
cations (0.59% injured fruit). As in 1997, wooden
pesticide-treated spheres released the entire sucrose
supply too quickly, and did not perform as well
(2.93% injured fruit). Unfortunately, many bio-
degradable spheres required replacement after
about a month of field exposure due to softening
and bursting of the sphere bodies.

Conclusions

Pest pressure in commercial orchards in 1998
was even higher than in 1997 (an average of 1702
AMF per block captured by the 26 sticky spheres
per block). Despite shortcomings of biodegrad-
able and wooden pesticide-treated spheres, we are
nonetheless encouraged by the 1998 results, par-

ticularly by the performance of biodegradable
spheres under very high pest pressure. With fur-
ther structural modifications and pending commer-
cial production of biodegradable sphere bodies, we
are becoming increasingly confident in recommend-
ing use of sphere traps in place of insecticide sprays
for control of AMF in commercial orchards. As
discussed m the Introduction, development of al-
ternatives for control of AMF is gaining emphasis
given the implications of FQPA implementation.

For the 1999 field season, we will again com-
pare the efficacy of sticky-coated wooden spheres,
pesticide-treated wooden spheres, and pesticide-
treated biodegradable spheres for direct control of
AMF. In 1999 field trials, pesticide-treated wooden
spheres will be augmented with a new sucrose-re-
lease mechanism, and biodegradable spheres used
in 1999 will be commercially-made prototypes,
produced by a private corporation under USDA
supervision.

Acknowledgments

This work was supported by state/federal IPM
funds, a grant from the Washington Tree Fruit Re-
search Commission, a USDA SEA CSREES grant
(# 97-34365-5043), and a SARE grant (USDA 96-
COOP-1-2700). As always, we are grateful to the
seven growers who participated in this study: Bill
Broderick, Dana Clark, Dave Chandler, Tony Lin-
coln, Wayne Rice, Dave Shearer, and Tim Smith;
and to our field technicians: Jon Black, Joel Benton,
Anthony Minalga, Stephen Lavallee, Eric
Gemborys, and Max Prokopy.

\f^ Kf^ Kf^ \r %f
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Fruit Notes, Volume 63 (Number 4). Fall. 1998

Evaluation of Varying Doses of Different
Toxicants for Use on Spheres to Control
Apple Maggot Flies

Ronald Prokopy, Starker Wright, Brad Chandler and Xingping Hu
Department of Entomology, University of Massachusetts

In the 1997 Fall issue of Fruit Notes, we re-
ported that imidacloprid was a promising alterna-
tive to dimethoate as a toxicant for application to
pesticide-treated spheres for controlling apple mag-
got flies (AMF). We also reported that imidacloprid
at 1.5% active ingredient (a.i.) in paint afforded
longer residual activity than imidacloprid at 0.5%
a.i. in paint, and that a Merit 75 WP formulation
of imidacloprid in paint was more effective than a
Provado 1.6 F formulation in paint at 0.5% a.i.,
though not at 1.5% a.i.

The unusually large numbers of AMF in some
Massachusetts commercial apple orchards in 1998
allowed early-season direct observations of the
behavior of AMF after alighting on imidacloprid-
treated spheres. These observations suggested to
us that by increasing the dose of imidacloprid on
spheres beyond the 1.5% active ingredient used
heretofore, we might be able to capitalize on con-
tact-type toxicity of imidacloprid, thus diminish-
ing the need to maintain feeding stimulant (sucrose)
on the sphere surface. Such a high-dose approach
was thought previously to be impractical, owing
to the handling risk associated with higher doses
of our originally-adopted toxicant, dimethoate.

Here, we report on 1998 studies of AMF re-
sponses to four different doses of imdacloprid in
latex paint, with and without the addition of su-
crose as feeding stimulant. We also report on AMF
responses to three new candidate toxicants:
spinosad, sugar ester, and fipronil. All three, like
imidacloprid, are considered to be comparatively
safe for handling by humans.

Materials & Methods

In our first test, we painted the inside surface
of small plastic cups with a mixture of Glidden

Red Latex Gloss Enamel paint and either 0.1, 0.5,
1.0, or 5.0% a.i. of one of the following potential
toxicants: imidacloprid (Merit 75 WP), spinosad
(SpinTor 22.8 F), sugar ester (SCO 3483, 100%),
or fipronil (Regent 80 WG). No sugar was added
to any mixture. After the mixture dried, 10 AMF
were confined in each of two cups of the same treat-
ment type for 10 minutes, following which AMF
were transferred to clean cups supplied with food
and water. Mortality was assessed after 72 hours.

For our second test, we focused on the two
toxicants that showed the most promise in the first
test: imidacloprid and fipronil. Each of these toxi-
cants was evaluated at 2, 4, 8, and 16% a.i. in
Glidden Red Latex Gloss Enamel paint (no sugar
added) applied to wooden spheres. After drying,
spheres were hung in orchard trees and returned
to the laboratory after 3, 6, 9, or 12 weeks for
evaluation of toxicity to AMF. For evaluation, 30
AMF were placed individually on a sphere of each
treatment type and allowed to remain 10 minutes,
following which AMF were transferred to small,
clean cups supplied with food and water. Mortal-
ity was assessed after 24 hours. Half of the spheres
of each treatment type received a 20% sucrose so-
lution just prior to testing. The other half received
no sucrose.

For our third test, we again focused on
imidacloprid and fipronil, but in this experiment,
we evaluated the behavior of sphere-exposed AMF
shortly after removal from spheres. Spheres were
treated with 2.0% a.i. imidacloprid or fipronil in
Glidden Red Latex Gloss Enamel paint and exposed
for 3 weeks in orchard trees. Just before testing,
all spheres received a 20% sucrose solution. For
each treatment, 32 AMF were placed individually
on a sphere and allowed to feed for up to 10 min-
utes. One hour after feeding, each fly was trans-

Fruit Notes, Volume 63 (Number 4), Fail, 1998

fcrred to a leaf nc.ir the center of the canopy of a
small non-frinting fig tree and allowed to forage
freely for 15 muiutes. The niinibcr of leaves vis-
ited was recorded. Immediately thereafter, each
fly was placed on a ripe hawthorn fruit, and pro-
pensity to lay an egg was observed.

Results

In our first test, conducted with no sugar added,
20, 80, and 100% of AMF died by contact toxic-
ity alone when confined in plastic cups treated with
0.5, 1.0, and 5.0% a.i., respectively, of imidacloprid
in paint (Table 1). None died at 0.1% a.i. of
imidacloprid. The only other toxicant causing
AMF mortality was fipronil, where 107o of AMF
died by contact toxicity alone after exposure to
5.0% a.i. of this material. Even though both
spinosad and sugar ester conceivably might be
somewhat toxic to AMF if ingested together with
sugar or when applied alone to foliage, neither
material caused any toxicity by contact alone when
mixed in latex paint.

In our second test, results showed that in the
presence of sucrose, mortality of AMF was consis-
tently high (70% or more) on spheres treated with
imidacloprid, even after 12 weeks of sphere expo-
sure to outdoor weather in orchard trees (Figure
1). Provided that sugar was present, the dose of

imidacloprid had little effect on AMF toxicity, with
2% a.i. being about as toxic as 16% a.i. at all evalu-
ation periods (3, 6, 9, and 12 weeks). In contrast,
in the absence of sucrose, toxicity of imidaclcjprid-
treated spheres to AMF did not exceed 15% at 12
weeks of orchard exposure, even at the highest dose
tested (16% a.i.). Results for fipronil roughly par-
alleled those for imidacloprid at 3, 6, and 9 weeks
of orchard exposure. However, at 12 weeks, even
in the presence of sucrose, lower doses of fipronil
(2 and 4% a.i.) yielded no more than 40% mortal-
ity of AMF. A dose of 8% fipronil was required
before toxicity approached that of 2% imidacloprid
at 12 weeks. In the absence of sucrose, toxicity
from contact with fipronil, as with imidacloprid,
was virtually nil at 12 weeks, irrespective of dose.
In our third test, results showed that only a
minority of AMF exposed to spheres treated with
2% a.i. imidacloprid and sucrose were capable of
foraging within a plant canopy after exposure, and
of those that could forage, an average of only one
leaf was visited for every three flies tested (Table
2). Moreover, only 6% of assayed AMF attempted
to oviposit in a hawthorn fruit. In contrast, al-
most all AMF exposed to spheres treated with 2%
a.i. fipronil were capable of foraging within a plant
canopy, with the average number of leaves visited
nearly equaling the number visited by AMF that
were exposed to spheres lacking pesticide. Also,

Table 1. Fate after 72 hours of apple maggot flies confined for 10 minutes in plastic cv
with insecticide in latex paint (no sugar added).

ps coated

Insecticide

Active

ingredient (a.i.) concentration

(%)*

0.1% a.i

0.5% a.i. 1.0% a.i.

5.0% a.i.

Imidacloprid (Merit 75 WP)
Fipronil (Regent 80 WG)
Spinosad (Spintor 22.8 F)
Sugar Ester (SC03483 100% a.i.)

Mortality (%)

20 80

100
10

For each dose of each insecticide, ten

flies

were confine

d in each ot two cups for 10 minutes.

Fruit Notes, Volume 63 (Number 4), Fall, 1998

I'lguic I rerCL'Ml iiiDilalilv nl .ipplc in.iggol llics cxpuscil Id wooiicn pcsliculc-lrcalcd spheres siili|ccle(l lo ^, ().
') or 12 weeks dI liekl exposure aller UealnienI w rlli varying conceiilralrons ol insectieide. I'Ires were lesled on
spheres with and without suizar added lo llic surface prror lo lestinc.

100

c 60
o

>- 40

3 weeks exposure

% active ingredient

100 '

^ 80-

? 60
o

>■ 40

^ 20

6 weeks exposure

1 ' ' ' 1

-"■'•■*■

" +'

=^^

, - - ' ^^^^

-^--rrrrr

_..

4 8
% active Ingredient

100 -
>- 80-

1 60

>. 40 ■

^ 20-

9 weeks exposure

_.--*'

- +

t I - ■ '

. "

■\ '■ ■ ■

— h

77^ ^-^^^ -^^jj

- - ^^

-— —

% active ingredient

100
>- 80

? 60

^ 40

°- 20

12 weeks exposure

.... _ . ■ ■!

^ — ■ — '

1-^ ^ , - - ■

+--■'"■

-..----'--+''

__...+-■" \r

.-■■'

— \

4 8

% actrve rngredlent

Imidacloprid Fipronil

+ + + + in line indiealcs that spheres were treated with 20% sucrose solution prior to testing.

Fruit Notes, Volume 6.3 (Number 4), Fall, 1998

Tnble 2. f-'ornging behavior of .ipplc maggot fly females, subsequent egglaying propensity and
percent mortality following feeding on untreated, fipronil-treated or nnidacloprid-treated red
wooden spheres. Foraging and cgglaynig behaviors were evaluated I hour after exposure to spheres.

Females tested

Sphere treatment

per

treatement

Parameter measured

(no.)

Untreated

ipronil

dacloprid

Mean feedmg time on spheres (sec.)

596

579

363

Flies capable of foraging on tree (%)

100

Mean foraging tune (sec.)

844

760

585

Mean number of leaves visited

2.3

1.6

0.3

Flies laymg an egg (%)

Mortality: 24 hours (%)

72 hours (%)

Treated spheres contained 2% active ingredient of insecticide in latex paint. All spheres were

subjected to 3 weeks field exposure and then were re-treated with 20% sucrose solution just

prior to testing.

Maximum permited feeding time = 600 seconds.

Flies were placed individually on a small, caged tree. Numbers represent mean foraging time of

flies capable of foraging. Maximum permitted canopy foragmg time = 900 seconds.

Immediately after foraging, each fly was exposed to a hawthorn fruit. Maximum permitted time

on fruit = 600 seconds.

16% of AMP that were exposed to fipronil-treated
spheres attempted to lay an egg. Together, the re-
sults of the behavior tests reflect the fact that
fipronil is a much slower-acting compound than
imidacloprid. AMF mortality following ingestion
of fipronil was only about a third the amount at
24 hours after exposure as at 72 hours afterward,
whereas with imidacloprid, mortality at 24 hours
was nearly equal to that at 72 hours (Table 2).

Conclusions

Our combined findings show that imidacloprid
performed better as an AMF toxicant on pesticide-
treated spheres than did any of three other candi-
date toxicants tested here: fipronil, spinosad and
sugar ester. Imidacloprid at 2% a.i. in Glidden

Red Latex Gloss Enamel paint gave excellent sea-
son-long ( 1 2 weeks) AMF control provided that it
was ingested with a feeding stimulant (sucrose). It
gave very poor control, as did fipronil, in the ab-
sence of sucrose, irrespective of dose used (16%
a.i. was the highest dose tested). A low dose of
imidacloprid, such as 2% a.i., not only is less ex-
pensive than a higher dose but is safer for those
handling pesticide-treated spheres. Imidacloprid
rapidly immobilized AMF that ingested it, result-
ing in very little or no subsequent foraging and
egglaying activity of exposed AMF. Because
imidacloprid seems to be an ideal toxicant for use
in conjunction with sucrose on pesticide-treated
spheres for controlling AMF, we are hopeful that
the registrant (Bayer Corporation) will see fit to
officially register its use for this purpose.

Fruit Notes, Volume 63 (Number 4), Fall, 1998

Acknowledgments

This work was supported by a grant from the
Washington Tree Fruit Research Commission and

USDA SEA CSREES grant # 97-34365-5043. We
thank Gary Puterka of the USDA Regional Fruit
lab in Kearneysville, WV for providing the sugar
ester.

^C •'k *C *C *C

Fate of Apple Maggot Flies Alighting on
Pesticide-treated Spheres in a Commercial
Apple Orchard

Xingping Hu, Eric Gemborys, Max Prokopy, and Ronald Prokopy
Department of Entomology, University of Massachusetts

As mentioned in the preceding article, unusu-
ally large numbers of apple maggot flies (AMF)
invaded certain commercial apple orchards in
Massachusetts in 1998. In most cases, invasion
was attributable to a combination of large num-
bers of AMF emerging from overwintered pupae
beneath unmanaged apple trees nearby commer-
cial orchards and to near or total absence of any
fruit on such unmanaged trees, leading to AMF
abandonment of unmanaged trees and movement
to fruiting trees in commercial orchards. We took
advantage of this situation in a cooperating orchard
and studied the fate of AMF that were observed to
alight on pesticide-treated red spheres.

Methods & Materials

Eight wooden spheres, 3 inches in diameter,
were coated with a mixture containing 2% active
ingredient of imidacloprid (Merit 75 WP), 20%
sucrose, and 78% Glidden Red Latex Gloss Enamel
paint. Four similar spheres, serving as non-toxi-

cant checks, received only the sucrose and paint.
All of the spheres were exposed outdoors for 3
weeks before testing (but no rain fell during this
period). On three sunny days (July 21, 27, and
29), each of three observers hung two pesticide-
treated and one check sphere about 2 feet apart in
an apple tree and watched each sphere continu-
ously for alighting AMF for a period of about 6
hours per day. An attempt was made to capture
each AMF after it departed or fell from a sphere.
Captured AMF were placed singly in small clean
cups, supplied with food and water, and observed
1, 24, and 72 hours later for mortality.

Results

In all, 36 AMF were observed alighting on pes-
ticide-treated spheres and 19 AMF on untreated
check spheres. Of the 36 alighting on pesticide-
treated spheres, the median duration of stay was
about 3 minutes and 25 died while still on a sphere
or within 1 hour after having fallen from a sphere.

Fruit Notes, Volume 63 (Number 4), Fall, 1998

All remaining 1 1 AMF flew from a pesticide-treated
sphere to nearby foliage. Of these, six were cap-
tured. All six died within 24 hours. The other five
AMF evaded capture. Of the 19 AMF alighting
on untreated check spheres, the median duration
of stay was about 4 minutes and none died while
on a sphere. Unfortunately, none could be cap-
tured after departing an untreated sphere, as flight
was too fast and far to permit capture.

Conclusions

Results of this study of responses of wild-popu-
lation AMF in a commercial orchard to wooden
spheres treated with imidacloprid, sucrose and la-
tex paint confirm results of a study reported in the

preceding article conducted using laboratory-main- Acknowledgments
tained AMF. Among all wild-population AMF
observed here to alight on pesticide-treated spheres,
86% (31 of 36) died within 24 hours and most
died within 1 hour. The fate of the 14% that were

not captured after alighting is unknown. Some of
these also may have died. In the preceding article,
data showed that pesticide-treated spheres com-
parable both in type (2% a.i. imidacloprid) and
field-exposure before testing (3 weeks) to those
used here yielded 75% mortality of tested AMF. It
is thus reassuring to know from this study of wild-
population AMF that we can use response patterns
of laboratory-maintained AMF placed directly on
pesticide-treated spheres as an accurate guide to
the performance of pesticide-treated spheres in
commercial orchards. It is also reassuring to know
that pesticide-treated spheres treated with 2% a.i.
imidacloprid and sucrose are highly effective
against AMF.

This work was supported by a grant from the
Washington Tree Fruit Research Commission and
a USDA SEA CSRESS grant (#97-34365-5043).

^C *C ^C ^C *C

Fruit Notes, Volume 63 (Number 4), Fall, 1998

Evaluation of Scab on Fruit of New
Apple Cultivars

Daniel R, Cooley, Arthur Tuttle, James Hall

Department of Microbiology, University of Massachusetts

Duane Greene

Department of Plant and Soil Sciences

While scab resistance has not proven to be the
most important characteristic of new apple culti-
vars, it is still useful to know how susceptible new
cultivars are to scab. A grower is probably wisest
to choose a new cultivar based on marketability
and production, but then treat it for scab ac-
cording to susceptibility to the disease.

It was difficult to control scab in 1998, and
a test block of new cultivars at the Horticul-
tural Research Center in Belchertown, MA
developed significant foliar and fruit scab over
the growing season even though fungicides
were applied. These cultivars were planted in
five replicated blocks, and we decided to evalu-
ate scab incidence to determine if there were
differences. All the trees were on M.9 root-
stock, except two that also were on Mark
(Golden Delicious and Yataka). On Septem-
ber 3, 1998, scab on the fruit was evaluated,
and incidence was calculated as a percent of
total fruit per tree.

The only cultivar in the planting that is al-
ready widely planted commercially in Massa-
chusetts is Golden Delicious. Golden Delicious
is generally reported as not very susceptible to
scab, and this evaluation supported that as-
sumption. While Golden Delicious had about
10% scab incidence, scab incidence over the
whole planting ranged from to 49%. Gala
Supreme was quite resistant to scab, with 0%
incidence. Similarly, Sansa, a Gala x Akane
cross, also had 0% scab. As might be expected,
two scab-resistant cultivars from the Purdue/
Rutgers/Illinois program, Enterprise and
Goldrush, and one from the New York pro-
gram, NY-75414-1, also did not show any

scab. Suncrisp, progeny of a Golden Delicious
cross, had very little scab (6%).

Unfortunately, two cultivars that would have
been very interesting to evaluate, Honeycrisp and
Ginger Gold, did not produce fruit in 1998.

Table 1. Evaluation of fruit scab in a variety
block (NE 183) at the Horticulture Research
Center, Belchertown, MA, September 3, 1998.

Cultivar/Rootstock

Apples wi

thscab(%)

Enterprise

Gala Supreme

Sansa

NY 75414-1

Goldrush

BC8M 15-10

Suncrisp

Golden Delicious

Golden Delicious/Mark

Shizuka

Cameo

abc

Fuji

a be

Orin

abc

Braeburn

Golden Supreme

Yataka

Arlet

Yataka/Mark

NY 429

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

Fruit Notes. Volume 63 (Number 4), Fall, 1998

Braeburn and Fuji were both quite susceptible to
apple scab.

Results of this test were similar to those in for-
mal disease analyses done in Connecticut, Michi-
gan, New York, Virginia, and West Virginia

All apple cultivars do not get scab to the same
degree. The key question, for which we do not yet
have an answer, is how much less can we spray the
less susceptible cultivars? That will have to be re-
searched.

%r ^r \r ^r ^r
*^i ^C •'k •'k •'k

Testing Various Methods of Timing
Summer Fungicides

Kathleen Leahy

Polaris Orchard Management, Colrain, Massachusetts

Thomas Clark

Clarkdale Fruit Farm, Deerfield, Massachusetts

Ezekiel Goodband

Alyson's Apple Orchard, Walpole, New Hampshire

The summer diseases, sooty blotch and flyspeck
are the cause of most of the fungicide use after
June in New England orchards. Using an improved
understanding of the biology of these diseases, and
specifically the wetness-hour model developed by
Turner Sutton and his colleagues , has allowed
growers to reduce fungicide usage in North Caro-
lina and other mid-Atlantic states. We wanted to
test this model to see whether it is viable in New
England conditions.

In a nutshell, the method developed by Brown
and Sutton in North Carolina is based on the biol-
ogy of the sooty blotch and flyspeck fungi. It al-
lows the first summer fungicide to be delayed until
200-250 hours of wetness (counting only wetting
periods of 4 hours or more) after the last scab fun-
gicide. With our relatively dry summers, we gen-
erally reach this threshold in early to mid-August.
Thus, using this method, we could, in most years,
save a couple of fungicide applications and have

greater flexibility in timing summer fungicides with
respect to insecticides and miticides/summer oils.
We also decided to try a somewhat less radical
method, based on work by David Rosenberger in
New York, showing that fungicide retention dur-
ing the summer is such that fungicides need not be
re-applied until 150 hours of wetness (no mini-
mum threshold) having occurred since the previ-
ous fungicide. This would still provide a measure
of flexibility in summer fungicide use.

Materials & Methods

The two cooperating orchards were located in
the Connecticut Valley, one in Walpole, NH and
the other in Deerfield, MA. In these orchards, the
test blocks were divided into three Vi acre plots,
and each plot was treated according to one of three
summer fungicide programs: 1) the 'standard' pro-
gram of a fungicide application every three weeks

Fruit Notes, Volume 63 (Number 4), Fall, 1998

Table 1.

The percent of fruit wi

th flyspeck in a 50-fruit sample from each

tree

evaluated

weekly from

mid July

and at harvest in

1998.

Clarkdale

Alyson's

Standard

Check

1 00- fruit sample taken

at Mcintosh harvest, 9/11/98

through June, July, and August; 2) the 'New York'
program of waiting until 150 hours of wetness had
accumulated since the most recent fungicide appli-
cation; and 3) the 'North Carolina' model of wait-
ing until 200-250 hours of wetness had accumu-
lated after the primary infection period for these
diseases.

A modified hygrothermograph unit was used
to measure the wetting periods in both orchards.
The weather units were set out prior to blossom.
The time of petal fall was noted (May 10 at
Clarkdale Orchards; May 1 1 at Alyson's Apple
Orchard) and wetness-hours were accumulated
beginning 10 days after petal fall (May 20 and May
21, respectively). Trees in both blocks are on M.7
rootstock. The Clarkdale block consisted of
Golden Delicious and Mcintosh, about 15 years
old, with rows running east-west, and the Alyson's
block was Mcintosh and Empire, about 12 years
old, with rows running north-south.

This was an unusually wet year in the North-
east. In a more typical year we would not reach
the 'North Carolina' threshold until early August,
but in 1998, we reached this threshold by early
July. Over 100 hours of wetness occurred during

a single week in June. The specific threshold dates
were: at Clarkdale Orchards, the New York thresh-
old of 150 hours from the last apple scab fungi-
cide was reached on June 22, and the North Caro-
lina threshold of 200 hours was reached on July 3.
At Alyson's Apple Orchard, the New York thresh-
old was reached on June 24, and the North Caro-
lina threshold on July 2. Because the New York
threshold at Clark's was reached at the same time
that he was planning a 'standard' spray, both the
'standard' and 'New York' plots were treated on
the same date.

The first summer fungicide applications were
made on June 22, June 22, and July 9 at Clarkdale
for the standard program, NY program, and NC
program, respectively. The first summer fungicide
applications were made on June 24, July 2, and
July 16 at Alyson's for the standard program, NY
program, and NC program, respectively.

At Alyson's, Mr. Goodband decided to test a
yet more radical approach than what we had origi-
nally proposed. The fungicide application on June
24 actually coincided with the NY threshold, and
the July 2 date was when the 200-hour NC thresh-
old was reached. The application on July 16 was

Fruit Notes, Volume 63 (Number 4), Fall, 1998

Table 2.

The

percent of Mcintosh

Lilt With fivs

pec

k m a

50-fruit

sample

from each

tree eval

lated

weekly

from mid Se

ptember throL

early

October

in 1998

Clarkdale

Alyson's

Standard

Check

—

at 336 wetness-hours from 10 days after petal fall,
and 262 wetness-hours from the previous fungi-
cide. Once the first summer fungicide was applied
in each section, that section thereafter continued
to receive a regular fungicide program.

Results

Because of the early accumulation of the thresh-
old level of leaf wetness hours, sampling (50 fruit
per section per week) began in mid-July instead of
early August as planned, but no symptoms were
seen even in check trees until mid-August. When
flyspeck symptoms began to appear (virtually all
the summer disease seen this year was flyspeck),
they appeared first in the most lightly-sprayed plots.
Despite the early wetness, there was not a signifi-
cant level of flyspeck except in the check trees un-
til mid-September.

As can be seen from Table 1, there were few
significant differences in summer disease occurrence
except between the treated and check trees, but
there was a trend toward somewhat higher disease
in the 'radical' plot at Alyson's. When Mcintosh
fruit were harvested in this plot, a random survey
of fruit showed over 40% with flyspeck, which is
not commercially acceptable. It was clear that this
'radical' option did not provide acceptable control
of flyspeck. Because of the advanced season and
the dry conditions in August, the fruit in the other
two plots were harvested before a proper survey

could be done, but it was evident that control was
satisfactory in these two plots.

At Clarkdale, there was very little difference
between treated plots (the intended check trees were
sprayed so the data were not included), and a har-
vest survey of 100 Mcintosh per plot showed no
significant difference nor any trend between treat-
ments.

Once the Mcintosh had been harvested, it be-
came evident that there were differences in flyspeck
occurrence between varieties in both orchards. This
effect had been masked by the random zigzag pat-
tern through the plot adopted when sampling fruit
in the regular weekly sessions. At Alyson's, the
Empires had much less flyspeck than the Mcin-
tosh, whereas at Clarkdale, the Golden Delicious
had much more flyspeck than the Mcintosh. These
differences were presumably not owing to varietal
susceptibility, since the literature indicates that
apple varieties are essentially identical in their sus-
ceptibility to flyspeck. We believe that the differ-
ences were owing to the more open growth habit
of Empires vs. Mcintosh at Alyson's, generating a
less favorable (lower humidity) environment for
the organism, whereas at Clarkdale the strikingly
high level of flyspeck throughout all three treat-
ments indicates that this entire row did not receive
a summer fungicide application - perhaps the last
scab fungicide on June 9.

Mite sampling in the test plots did not show
any difference in either pest or predator mite num-

Fruit Notes, Volume 63 (Number 4), Fall, 1998

bers. This was as we expected, since the first year
of reducing fungicide is unhkely to produce a dra-
matic effect on the mite population.

Discussion

In general both the New York and North Caro-
lina methods of timing fungicide applications
seemed to work very well, under unusually chal-
lenging conditions for this region. It is clear,
though, that extending the number of wetness-
hours beyond the 250 recommended by the North

Carolina model poses an unacceptable risk to the
crop. The economic savings from reduced sprays
overall were less than $10 per acre, but even this
amount could be significant, given the slim profit
margins in apple-growing at this time. The major
benefit of adopting a reduced summer fungicide
program, however, is more likely to be increased
flexibility in time management and the ability to
incorporate summer oils into the spray program
without risking phytotoxicity from fungicide/oil in-
teractions. In addition, it is possible that this prac-
tice might be helpful for beneficial organisms in
the orchard.

^L ^U ^L •^L ^L

Fruit Notes, Volume 63 (Number 4), Fall, 1998

On-farm IPM Education:
Displays and Self-guided Tours

Craig HoUingsworth, William Coli, and Ronald Prokopy
Department of Entomology, University of Massachusetts

Karen Hauschild

Department of Plant & Soil Sciences, University of Massachusetts

Returning from a 1995 international scientific
conference, two of us toured the fruit growing re-
gion of Switzerland. Among the techniques for
educating the Swiss consumer about Integrated
Fruit Production (the European version of IPM)
that we observed were self-guided tours within
vineyards. These tours consisted of signs and pic-

tures which explained a variety of agricultural tech-
niques in use in the vineyard. This spawned the
idea of educating Massachusetts apple customers
about IPM through similar orchard tours.

Apple growers were solicited to participate in
the project through announcements in extension
publications and by phone. The nineteen growers

VISUAL TRAPS attract early season pests
such as apple sawtlies and leafininers by
mimicking the attractive parts of the apple tree.
Using these traps, a farmer can detennine
whether pesticide applications are needed,
eliminating unnecessary pesticide use. and
often resulting in better quality fruit.

Sawflies are attracted to apple
blossoms, mimicked by white traps.

Leafminers are attracted to reddish
tree bark, mimicked bv red traps.

Apple sawfly adult Sawfly damufie Leafminer adult Leafminer damage

Trap for apple saw/ly Trap for leafminer adult

Figure 1. A photograph of one of the signs in the self-guided tour.

Fruit Notes, Volume 63 (Number 4), Fall, 1998

who responded provided assistance in determin-
ing the content and design of the education dis-
plays and contributed matching funds for a grant
by the Massachusetts Department of Food &c Ag-
ricuhure. It was determined that self-guided tours
would the most appropriate for pick-your-own
operations but that static sign-boards would be
more useful for farmstands and farmers markets.

Self-guided Tour

trol, biological control and pesticide use, as well
as the biology of primary apple pests. A colorful
8-x-l 0-inch sign to advertise the tour was also in-
cluded.

At each orchard,, the grower determined how
the signs were placed. Most were arranged through
part of the orchard. In some cases, a path was
marked by mowing or with plastic tape. It was
suggested that IPM tools such as insect traps and
scare-eye balloons be placed in association with
appropriate signs.

Each tour consisted of eight signs, 18 x 24
inches, on laminated paper, mounted on 0.5-inch Apple IPM Displays
plywood, covered with Plexiglas and sealed with
plastic. Figure 1 is an example of one of these
eight signs. Each sign was mounted on a 7-foot, 3-
x-5-inch pressure-treated post. The signs describe
aspects of IPM, including monitoring, cultural con-

Self-standing displays were developed and dis-
tributed to eleven Massachusetts farms for use at
farmstands and farmers markets. Figure 2 is a
photograph of one of the displays. Displays con-

NTr-C^iiTEO PEST MANAGEMENT

,.ombi;iti di(fL-(ciu in(:tt,vds of [x-u

rntrot to produce qn.ility fruit in an

n onmcntaily rwponsiblc m,li>nc'

■ [I'O fitJ'^.Tged tlirougli .1 cot'ibination

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, actices aod chemical coniroi

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Figure 2. A photograph of the self-standing display.

Fruit Notes, Volume 63 (Number 4), Fall, 1998

sisted of a three hinged panels of vinyl lattice mea-
suring 4x8 feet. For strength and stability, each
panel was framed with vinyl edging. Four lami-
nated posters describing and illustrating apple IPM
through the four seasons were hung on the frame-
work. The displays could be folded for transport
and were light enough to be carried by one person.

Evaluation

The self-guided tour was evaluated by a ques-
tionnaire mailed to participating growers. Seven
of the ten growers returned the questionnaire.

Most growers (5 of 7) arranged the signs as
tours within their orchards. Two growers placed
all the signs in one place. Five of the seven grow-
ers told their customers about the tour. No grow-
ers provided extra signs to direct their customers
to the tour. Four growers added traps and other
IPM equipment to the tour. Positive comments
from customers about the tour were received by
four of the growers. Five growers reported their
intentions to use the tour as part of their educa-
tion program for school children.

Growers reported that between 1% and 40%
of their customers took the "tour". Two growers
(with participation of 1% and 40%) rated this as
"unsatisfactory." All growers reported that the
message and information presented, presentation
and workmanship were good to excellent. The
over-all success of the project was rated good to
excellent on six farms and poor on one farm.

Both educational projects were also evaluated
by a brief customer survey. Twenty-nine custom-
ers at two farmstands with self-guided tours were
surveyed, 30 at a farmstand with an IPM display,
and 40 at two farmstands with neither educational
program.

Twenty-four percent of all customers professed
to having heard of IPM before coming to any of
the orchards. Where a self-guided tour was located.

14% of customers interviewed had taken the tour,
whereas, 60% of customers looked at available
IPM displays. When asked to describe what they
learned from a farmstand display, the most frequent
response (37%) was that IPM uses less pesticide.
Ninety-five percent (20 of 21 responses) of the re-
spondents agreed that seeing this information af-
fected their attitude about farming. Of these, 85%
said that their attitude became more positive. Three
individuals traveling together said that their atti-
tude was more negative after viewing the display.
We also evaluated the program by visiting farms
where the tours and displays were used. It was
apparent tours were less successful where custom-
ers were not adequately informed that the tours
existed, or where the start of the tour was too far
from the farmstand.

Conclusions

Public education on farms can be especially
effective in a pick-your-own setting. As customers
indicated, families pick apples, in part, as a recre-
ational activity, but once the apples are picked, they
are looking for other things to do.

These educational products were successful for
some growers, but not for others. As with most
educational or marketing products, they are tools
and must be used in an appropriate manner to pro-
duce the best results. Self-guided tours are best
placed in a convenient, conspicuous location and
promoted by the grower through welcoming
signage, talking to customers, and other methods.
Tours can become another reason for customers to
come a particular farm. In this project, press re-
leases attracted a number of customers. Static dis-
plays are much simpler for the grower to use, and
while they did not have the novelty or recreational
value of the tours, it was clear that the message
from simple signs reached a greater percentage of
customers.

*,L Kf^ ^L *.L *>?.

Fruit Notes, Volume 63 (Number 4), Fall, 1998

X X L^xi^ x^vycv^vj

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