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Fruit Notes

Prepared by the Department of Plant & Soil Sciences.

University of Massachusetts Cooperative Extension,

United States Department of Agriculture, and Massachusetts Counties Cooperating.

Editors: Wesley R. Autio and William J. Bramlage

ISSN 0427-6906

LI'l

JAN 19 SO
UNIV. OF MASS.

BIOLOGY

Volume 55, Number 1
WINTER ISSUE, 1990

Table of Contents

The Brock Apple
Root Pruning of Apple Trees

Three Years of the Massachusetts Second-stage Apple

IPM Pilot Project: Blocks Receiving Apple

Maggot Fly Interception Traps

Three Years of the Massachusetts Second-stage Apple

IPM PilotProject: Blocks Receiving

Perimeter Row Sprays

Evaluation of Releases of Amblyseius fallacis
Predatory Mites on Apple Trees

Development of a Program for Grower and Consultant Education
and Certification in Integrated Pest Management

Effects of the Loss of EBDC Fungicides on IPM Programs in New England
Factors Affecting EBDC Fungicide Residues in Apple Fruit
Massachusetts Apple IPM Program: Observations in 1989

Fruit Notes

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Fruit Notes

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All chemical uses suggested in this publication are contingent upon continued registration. These chemicals should be
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The Brock Apple

James R. Schupp

Highmoor Farm, University of Maine

Brock is a high quality dessert apple of the Jona-
gold type that is worthy of trial by New England
growers. Although not widely known, it has been a
popular gourmet apple in localized parts of Maine,
Ohio, and Oregon.

Origin

Brock resulted from a cross of Golden Delicious
and Mcintosh made at Highmoor Farm (Monmouth,
ME) in 1933 and was first designated as Me. 7-492.
After a long period of observation and tests, Russ
Bailey, the plant breeder at the University of Maine,
released it for public trial in 1966. The selection was
named Brock after Heniy Brock, an apple grower from
Alfred, ME who tested 7-492 in cooperation with the
University. The fruit of 7-492 became veiy popular
with consumers in the Alfred area who referred to it as
"Brock's apple."

Description

The Brock tree is vigorous and similar in appear-
ance to Golden Deli-
cious with a wider leaf
blade and redder bark.
Brock is productive
and crops annually if
chemically thinned.
The fruit ripen in early
October, with Deli-
cious, under Maine
conditions. The fruit
are uniformly large,
rounded conic, and
somewhat angular.
The stem is of medium
length and thickness
and the fruit hang well
prior to picking. The
skin is 30 to 90%
blushed with bright
red over a light yellow
ground color, with
prominent white len-
ticels (see Figure 1).

The flesh is
creamed-colored, firm,
crisp, juicy, and sub-
acid to sweet. The fla-

vor is very good, and in taste tests at the University of
Maine in the 1950's and 1960's, Brock was ranked as
good as or better than the cultivars to which it was
compared: Delicious, Golden Delicious, Northern Spy,
Mcintosh, Macoun, and Idared. More recently, Brock
has received rankings as high as or higher than Golden
Delicious and others in taste tests in Oregon (see
GoodFruit Grower May 1, 1989. pp. 44-45).

The core of Brock is unusually small, a desirable
feature for culinary use. Samples of Brock from
Highmoor Farm on October 4, 1989, yielded the follow-
ing characteristics: 7.6 ounces weight, 3.25 inches
diameter, 15.7 pounds flesh firmness, and 13.5% sol-
uble solids.

In summary, Brock is a high-quality, dessert-type,
blushed, golden apple that has been a successful addi-
tion to the limited markets in which it has been tried.
Growers interested in a Jonagold-class apple with
superior storability should test it on a trial basis. Trees
of Brock are available from a few nurseries and scion
wood for budding or grafting is available from
Highmoor Farm.

Fruit Notes, Winter, 1990

Root Pruning of Apple Trees

James R. Schupp

Highmoor Farm, University of Maine

In 1989, the public furor over Alar™ effectively
eliminated the use of that chemical by apple growers.
This left a substantial number of growers looking for
alternatives to Alar as a means of reducing tree growth,
reducing preharvest drop, and improving fruit color
and fruit quality. Mechanical root pruning is one
option that some growers considered.

Root pruning has been studied in some detail at the
Ohio Agricultural Research and Development Center
since 1982, and at the University of Maine since 1988.
The results of these research efforts are summarized
here and are used to make the recommendations that
follow.

Effects on Bearing Trees

Table 1 contains a list of the effects of root pruning.
To summarize, root pruning of bearing apple trees
reduces the total growth of the tree. This growth
suppression is season-long, thus pruning time is re-
duced. Fruit set is not affected, so the net effect is a
smaller tree with just as many apples. Fruit size is
reduced, while fruit color, firmness, and sugar content
are increased. Preharvest drop is reduced.

Effects on Non-Bearing Trees

The effects reported above are for bearing trees. If
the trees have little or no crop, either from frost damage
or because of alternate bearing, the effects will be much
less dramatic. For example, in one of our studies in
Ohio, root pruning reduced vegetative growth in bear-
ing trees by over 40%, while the reduction in growth in
non-bearing trees was only 14%. Studies with young,
potted trees showed that such trees needed root prun-
ing twice in one season to achieve season-long reduc-
tions in growth, even when the pruning was quite
severe. Pruning the roots of non-bearing trees in the
orchard more than once in a single season has not been
tried and the possible benefits, as well as the possible
problems, are not known.

When and How?

All these effects are dependent on timing. The best
time to root prune is from bloom until two weeks later.
Pruning too late will increase preharvest drop instead
of reducing it and will not reduce the growth of the tree
in that season.

Root pruning is done with a sharpened subsoiling
blade mounted on a tool bar such that it extends out
beyond the right rear tire of the tractor. The 3-point
hitch, attachment pins, and tool bar should be heavy-
duty. A chain or cable extending to the front axle lends
stability to the offset blade. Tractors in the 40 to 50
horsepower class have proven satisfactory, however
the blade cuttingthrough the soil has a tendency to pull
the tractor into the tree row, particularly the first
season the treatment is applied, and especially if the
cutting depth is greater than 12 inches. Our studies
have shown that pruningto a 12-inch depth is adequate
to produce the desired effect, but if a grower wants to
prune deeper, or if the going is tough even at a 12-inch
depth, the steering problem can be corrected by: a)
running two tractors in tandem; or b) pruning the roots
once at a shallow setting, then going back through the
original cut a second time to the final depth. Root
pruning in heavy sod is much more difficult than in a
herbicide strip and almost always will require a second
pass to finish the job.

In order to take effect, root pruning must be done
on both sides of the row, to a depth of 12 inches. The
amount of vegetative growth control can be adjusted
somewhat by adjusting the distance from the cuts to
the trunk. Root pruning of overly vigorous Melrose/
M.26 trees at 24 or 32 inches from the trunk produced
dramatic reductions in growth. In Maine, I have ob-
tained satisfactory results on Mclntosh/MM.lll trees
pruned on 2 sides at 40 inches from the trunk and to a
depth of 12 inches.

What Can Go Wrong?

In addition to the problems of the blade pulling the
tractor into the tree row and the difficulty in root
pruning through thick sod, there are some things that
can go wrong. Low, hanging limbs get scraped up
badly, and if they are large, they will present an effec-
tive barrier to progress down the row. Long overhang-
ing limbs that stick out into the drive row can make the
tractor driver feel as persecuted by apple trees as was
Dorothy in The Wizard ofOz.

If there are large roots just under the surface,
occasionally one will catch on the blade instead of
cutting cleanly. When this happens the root will be
pulled off the tree and often a good chunk of the bark on
the trunk will be stripped away with it. Dave Ferree

Fruit Notes, Winter, 1990

Table 1. Effects of root pruning on apple tree growth and yield.

Parameter

Increased

Decreased

No change

Trunk growth

Shoot length

Shoot number

Spur/shoot ratio

Shoot leaf size

Spur quality

Pruning time

Canopy light penetration

Return bloom

Fruit set

Fruit yield (no. of fruit)

Fruit size

Preharvest drop

Fruit color & quality

Tree yield efficiency

•Increased return bloom from root

pruning has been reported widely, but has

not been noted in studies conducted by the author.

and I first observed this occurrence in an orchard with
sandy soil. Apparently the sand yielded to the pulling
effect when cutting thick roots, because out of the
several hundred that we root pruned that day, we
damaged two trees in this way. Large rocks directly in
the path of the blade must be negotiated over or
around, much as is the case when planting trees with a
tree planter.

Should You Root Prune?

Growers get paid better for growing big apples
than smaller apples. Not only does a box of big apples
command a higher price, but it does not contain as
many fruit. To a researcher who has worked on root
pruning as long as I have, this system of financial
reward seems dreadfully unfair; nevertheless, it is a
reality. On the other hand, if the big apple cannot make
grade because it cannot meet the minimum standard
for color or if it loses its firmness and storability hang-
ing on the tree while its owner waits for color, or if it
falls to the ground before it can be picked, then root
pruning might have a place. The savings in pruning
time can be significant; in my research plots, root-

pruned trees took 12
minutes each while
trees that were not root-
pruned required 20
minutes each for dor-
mant pruning. Re-
duced pruning time,
improved fruit color
and quality, and re-
duced preharvest drop
are the benefits. The
reduced fruit size is the
cost. The economics of
each situation need to
be considered carefully.
Often, apple grow-
ers have three kinds of
trees on their land:
blocks of large trees on
seedling rootstocks,
blocks of mature, semi-
dwarf trees, and blocks
of more recently
planted small trees.
The small trees are
coming into production,
the seedling trees are scheduled for removal, and the
semi-dwarf trees will have to remain for another 10
years to provide some cash flow and pay the bills. If the
fruit qualify and preharvest drop in part of the semi-
dwarf blocks are unacceptable and the trees are too
vigorous, then the costs and benefits of root pruning
should be weighed. If the tree spacing is too close and
hard, containment pruning is necessary, then root
pruning may be a real boon. On the other hand, if tree
vigor is moderate and a little summer pruning is all
that it takes to get red apples, then root pruning is un-
necessary.

If an apple grower has blocks of trees with exces-
sive tree size and vigor and can afford to replace them
right now with dwarf trees, then root pruning is a step
backward.

Root pruning is a highly effective method of con-
trolling tree growth and improving fruit quality. Be-
fore root pruning acres of apples, talk things over with
your local fruit specialists and researchers. If it is
possible, take the long-term solution-replant with
trees on the appropriate size-controlling rootstocks at
the appropriate spacing.

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Fruit Notes, Winter, 1990

Three Years of the Massachusetts
Second-stage Apple IPM Pilot Project:
Blocks Receiving Apple Maggot Fly
Interception Traps

Ronald J. Prokopy, Margaret Christie, Katharine Rankin, and
Cheryl Donovan

Department of Entomology, University of Massachusetts

One year ago in Fruit Notes [54(l):l-5], we re-
ported our results of the first two years (1987, 1988) of
our second-stage apple IPM pilot project in Massachu-
setts commercial orchards. Second-stage IPM employs
behavioral, ecological, and biological approaches to
pest management as a substitute for all insecticide and
miticide treatments after the last spray against plum
curculio in early June. The intent of second-stage IPM
practices is not only to provide an environmentally
safe, cost-effective approach to controlling summer
pests that directly attack apple fruit (apple maggot,
codling moth, summer leafrollers) but also to alleviate
insecticide and miticide toxicity to beneficial predators
and parasites of important foliar pests such as mites,
aphids, leafminers, and leafhoppers. Allowing more
natural enemies of foliar pests to flourish reduces the
need for pesticide treatment against foliar pests and
thereby lessens the rate (currently high) at which these
pests are developing resistance to pesticides. To em-
phasize further this latter goal, a major facet of second-
stage IPM is use, during April, May, and June, of
pesticides leastlikely to be harmful to beneficial preda-
tors and parasites.

From a veiy real and timely, practical point of view,
under current strong public pressure to reduce pesti-
cide use on apples, perhaps one of our best hopes for
minimizing the risk of there being detectable pesticide
residues on apples at harvest lies in implementing the
philosophy and practices of second-stage IPM. This
philosophy of no insecticide or miticide spray on apples
after early June should be highly appealing to environ-
mentalists, legislators, public health officials, and con-
sumers. The big question is: can high quality fruit be
produced economically year after year under this phi-
losophy?

Over the 3 years of our pilot project (1987-1989),
we have compared 2 different non-pesticidal ap-
proaches to implementing second-stage IPM philoso-

phy. The essential difference between the two lies in
the techniques used for intercepting apple maggot flies
(a key summer pest) before flies can penetrate the
orchard interior during their movement toward or-
chards from abandoned host trees hundreds of yards
away. The techniques are: (1) placing synthetic-apple-
odor-baited sticky red sphere traps every 10 yards
(1987) or every 5yards (1988, 1989) on perimeter apple
trees and (2) spraying perimeter (border row) apple
trees every 3 weeks from late June through August.
For both approaches, we aimed to control codling
moths and summer leafrollers by removing (in May,
1987) all abandoned apple trees within 100 yards of the
orchard block perimeter to preclude immigration of
fruit-seeking female moths. Each approach has been
carried out over the 3-year pilot period in 6 commercial
orchard blocks, averaging 2 to 3 acres each. Each test
block has been matched with a nearby block of compa-
rable size that was treated during June, July, and
August under first-stage IPM practices.

Here, we report results of the technique using
apple maggot fly interception traps. In a companion
article, we report results of the technique using pe-
rimeter row sprays.

Apple Maggot

Data in Table 1 show that each year, very large
numbers of apple maggot flies were captured on the
interception traps in the second-stage IPM blocks
(range of 2,054 to 3,180 flies per block per year). In our
judgement, this level represents an enormous amount
of potential maggot fly pressure on the crop. Even so,
a 3-year average of only 46% more flies was captured on
nonbaited monitoring traps at the interior of second-
stage compared with first-stage blocks. This reveals
the power of the traps in preventing fly immigration
into the block interior.

Fruit Notes, Winter, 1990

Table 1

Average number of apple maggot flies captured per

block

Year

Block

Perimeter-row
interception traps*

Interior
monitoring traps**

1987
1988
1989

Second-stage

First-stage

Second-stage

First-stage

Second-stage

First-stage

2,054
3,021
3,191

123
84
117
105
112
52

*Apple-odor-baited interception traps placed every 10 yards (1987) or every 5 yards

(1988, 1989) on perimeter apple trees.

**Four non-baited traps on interior apple trees.

Data in Table 2 reveal the average amount of fruit
injury caused by all insect pests active after mid-June.
Over the 3 years, apple maggot injury decreased from
1.4 to 0.5 to 0.3% in the second-stage blocks. The
average of 0.4% maggot injury over 1988 and 1989 in
these blocks was comparable with the average of 0.2%
maggot injury in the first-stage IPM blocks. These data
show that the interception trap approach is very little
different from insecticide sprays in ability to provide a
commercially acceptable very high level of maggot- free
fruit (0.5% or less maggot injury).

Codling Moth

Data in Table 2 also show that the method of
removing all apple trees within 100 yards of the or-
chard perimeter was as effective as a standard first-
stage program in preventing codling moth injury to
fruit. Apparently, sprays against plum curculio in late

May and early June pro-
vide excellent control of
any first-generation cod-
ling moth eggs that might
have been laid, while the
distance of 100 or more
yards from the orchard
perimeter is too great to
be overcome by potential
second-generation cod-
ling moth immigrants in
July and August. We are
initiating a field test to
determine whether re-
moving all apple trees
within 50 yards of the
orchard perimeter

achieves the same high

level of codling moth disruption as removing all apple

trees within 100 yards.

Leafrollers and Lesser Appleworm

In our judgement, the greatest potential threat to
future success of second-stage IPM practices lies in
buildup of summer leafrollers and lesser appleworms.
These pests have begun to build up substantial toler-
ance to several types of insecticides in recent years in
New York and apparently also in a few Massachusetts
orchards. Hence, the problem of increasing fruit dam-
age from leafrollers and lesser appleworms seems to be
a general one in the Northeast.

As shown in Table 2, in 1989 combined leafroller
and lesser appleworm damage in second-stage IPM
blocks averaged slightly greater than in first-stage
blocks (1.7 versus 1.1%). These pests have a much
broader host range and may be more mobile than

Table 2.

Average percent fruit

injury by insect

pests active after mid-J

une.***

Other

All

Year

Block

AMF

RBLR

LAW

other

Total

1987

Second-stage

1.4

0.0

0.1

0.0

1.5

First-stage

0.7

0.0

—

0.1

0.8

1988

Second-stage

0.5

0.0

0.1

—

0.0

0.6

First-stage

0.2

0.0

0.2

—

0.0

0.4

1989

Second-stage

0.3

0.0

0.1

1.2

0.4

0.2

2.2

First-stage

0.2

0.1

0.2

0.6

0.3

0.0

1.4

*500 on-

tree fruit sampled per

block during July, August,

and September.

**AMF

= apple maggot; CM

= codling moth

RBLR =

red banded leafroller;

other LR =

= other unidentified

leafrollers; LAW = lesser appl

sworm.

Fruit Notes, Winter, 1990

Table 3. Trap captures and larval injury in blocks receiving mass application of sex pheromone
to disrupt mating of red banded leafroller and lesser appleworm moths in 1989.

Total no. males

captured in

% Larval injury

Pest

Orchard

Block

pheromone traps*

to fruit at harvest**

Red banded

Pheromone trtd***

0.0

leafroller

Grower sprayed

471

0.5

Red banded

Pheromone trtd***

1.0

leafroller

Grower sprayed

268

2.5

Lesser

Pheromone trtd***

0.5

appleworm

Grower sprayed

123

0.5

Lesser

Pheromone trtd***

5.5

appleworm

Grower sprayed

530

4.5

*Total-season captures of males in 5 monitoring traps per block.

**Based on 200 fruit sampled per block at harvest. Most sampled fruit were doubles (stems

closely opposing one another).

* * *Treated with 400 pheromone dispensers per acre on April 20 and August 1 (for red banded),

or on May 19 and August 2 (for appleworm).

codling moths, so that it might be necessaiy to remove
a wide variety of plants over long distances from the
orchard perimeter to preclude immigration of larvae
(blowing in on threads of silk that they spin) or of
females. Even then, this approach may not succeed
because of the ability of several of these pests to tolerate
pesticides used against plum curculio. Thus, unlike the
situation with codling moth, early-season leafrollers
and lesser appleworms may not be completely elimi-
nated from the orchard interior by early season pesti-
cides directed against plum curculio.

The best future hope for managing leafrollers and
lesser appleworms under second-stage IPM principles
may lie in one of two practices: (1) application of
Dipel™ (bacteria that produce compounds toxic to
lepidoptera) or Dimilin™ (an insect growth regulator)
at the time when first-generation larvae are active
(early May to early June) or (2) application of synthetic
sex pheromone to disrupt mating and deposition of
fertile eggs. In collaboration with Bicontrol LTD of
Queensland, Australia, in 1989 we evaluated season-
long use of mating disruption pheromone against red
banded leafrollers and lesser appleworms in 3 commer-
cial orchard blocks not sprayed with insecticide after
early June. Compared to nearby first-stage IPM
blocks, there was a very strong reduction in captures of
male moths in pheromone traps in the pheromone-
treated blocks (Table 3). This result illustrates the
power of mass application of pheromone to prevent

mate-seeking males from locating sources of female
pheromone released in the traps. Presumably the
males are similarly prevented from finding living fe-
males in the orchard. However, there was only a
moderate reduction of red banded leafroller fruit injury
and no reduction of lesser appleworm injury in the
pheromone-treated blocks (Table 3). Failure to obtain
good control of larvae in the pheromone-treated blocks
may have been due to immigration of fertile females or
larvae (blowing in on silken threads). More in-depth
orchard research is needed before a mating-disruption
approach to control these pests becomes feasible.

Foliar Pests and Their Natural Enemies

Data in Table 4 show that in all years where
sampled, predatory mites, aphid predators, and
leafminer parasitoids were more abundant in second-
stage than in first-stage IPM blocks. On the other
hand, averaged over the 3 years, pest mites, apple
aphids, and leafminers were no more abundant in
second-stage than in first-stage blocks, despite no pes-
ticide treatments against these pests after early June in
the second-stage blocks. Similarly, woolly apple aphids
and potato leafhoppers were essentially no more evi-
dent in second-stage than first-stage blocks across the
3 years. In 1987 and 1988, white apple leafhoppers
were considerably more abundant in second-stage
than first-stage blocks. In 1989, use of endosulfan in

Fruit Notes, Winter, 1990

Table 4.

Average percent

leaves

(or term

inals) harboring foliai

pests or beneficial natural enemies.*

.**

Ratio of

Year

Block

ERMor
TSM AF

pest to

predatory

mites

WAA WAL

ABLM
ABLM PAR

GAA GAAP

1987

Second-stage

4.0

3.2

3:1

2 9

First-stage

1.5

2.3

4:1

2 5

1988

Second-stage

1.3

1.2

5:1

3 27

11 35

14 6.7

First-stage

1.1

0.1

9:1

4 18

11 23

16 3.7

1989

Second-stage

3.0

0.3

6:1

3 2

5 49

32 30.7

First-stage

2.3

0.1

10:1

3 1

6 35

35 27.8

*400 leaves (or terminals) sampled per block during July, August, and September.

**ERM = European red mites; TSM = two spotted mites; AF = predatory Amblyscius fallacis; YM = predatory
yellow mites; WAA = woolly apple aphid; WAL = white apple lcafhopper; PL = potato leafhopper;ABLM = apple
blotch leafmincr; ABLM PAR = percent parasitized leafmines of second generation; GAA = green apple aphid;
GAAP = green apple aphid predators (cccidomyiids and syrphids).

late May or early June against leafhoppers in problem
blocks provided good control and alleviated this poten-
tial problem.

Pesticide Use Patterns

Data in Table 5 show the average number of insec-
ticide and miticide treatments per block from April to
early June and from early June onward. On average,
each block type received 1.4 sprays of oil, 3.9 sprays of
insecticide, and 0.2 sprays of miticide from April to
early June. Thereafter, the second-stage blocks re-
ceived no insecticide or miticide, while the first-stage
blocks received an average of 2.8 insecticide and 1.5
miticide sprays. Overall, second-stage blocks received

only 58% as many insecticide sprays and 12% as many
miticide sprays as first-stage blocks. Compared with
non-IPM apple pest management practices of the mid-
1970's, second-stage blocks received only 37% as many
insecticide sprays and 10% as many miticide sprays
(exclusive of oil).

Cost Analysis

Estimated costs per acre of first-stage versus sec-
ond-stage IPM practices employing apple maggot
interception traps are given in Table 6. Average annual
per acre costs over the 3 years were nearly identical for
both practices: $190 versus $186, respectively. Thus,
even under the labor-intensive practice of stickying,

Table 5.

Average number of insecticide ;

ind miticide treatments pe

r block.

Pre-bloom

Insecticide

Miticide

April to

Early June

April to

Early June

Year

Block

oil

early June

onward

early June

onward

1987

Second-stage

0.8

4.5

0.7

0.0

First-stage

0.8

4.3

2.2

0.7

1.6

1987

Second-stage

1.5

3.5

First-stage

1.5

3.5

3.1

1.7

1989

Second-stage

2.0

3.8

First-stage

2.0

3.8

3.2

1.2

Fruit Notes, Winter, 1990

Table 6. Partial analysis of estimated cost (dollars) per acre per year of first-stage
versus second-stage IPM practices for insect and mite control (averaged over all 3
years).

First-stage

Second-stage

Control method

IPM

Pre-bloom oil*

$19

Insecticide*:

April to early June

$77

$78

Early June onward

$57

Miticide*:

April to early June

Early June onward

$32

Cutting down abandonee

apple trees**

Purchase, emplacement,

periodic

cleaning, and removal of

apple

maggot traps***

$82

Total

$190

$186

*Materials plus application costs.

**Pro-ratcd over 10 years.

***Includes initial cost of $80 (pro-rated over 10 years at $8/year) for purchase of

traps, $2/year for tangletrap, $10/year for purchase of vials and attractive odor

(both new each year), and $62/year for 10 hours of labor required to sticky-coat,

emplace, clean (3 times), and remove the traps.

emplacing, and cleaning the apple maggot traps, sec-
ond-stage IPM was no more expensive than first-stage
IPM. Replacement of sticky spheres by pesticide-
treated spheres should lower the cost of future second-
stage IPM application dramatically.

Conclusions

Overall, we are extremely encouraged by the re-
sults of 3 years of implementation of second-stage IPM
practices involving use of interception traps against
apple maggot flies in the 6 commercial apple orchard
test blocks. Fruit injury by apple maggot and codling
moth has stabilized at a veiy low level. Beneficial
predators and parasitoids have begun to flourish and to
provide good control of major foliar pests (although,
leafhoppers may be an exception). Fruit quality at
harvest, as evidenced by our systematic sampling of
injury levels and asjudgedby cooperating growers, has
been excellent. Second-stage blocks received only a bit
more than half as many insecticide sprays and a tenth
as many miticide sprays as first-stage blocks. Second-
stage practices were no more expensive than first-stage
practices, even under the labor-intensive effort associ-
ated with using sticky apple maggot traps.

We believe, however,
that there are 3 key areas to
be addressed before we can
recommend confidently
second-stage IPM practices
for widespread use. The
first is development of a
substitute for sticky (which
is too messy to handle on a
large scale) as the agent
controlling apple maggot
flies alighting on apple-
odor-baited red sphere
traps. Our progress in
developing such a substi-
tute (pesticide treated
spheres) will be reported in
a separate Fruit Notes ar-
ticle. The second is mainte-
nance of summer leaf-
rollers and lesser apple-
worms at a low level in sec-
ond-stage IPM orchards.
For this purpose, we need
further work on the poten-
tial value of using Dipel or
Dimilin in early season
sprays, and on employing
mating disruption phero-
mone. The third is picking up all drops shortly after
harvest. If drops were not removed before decay set in,
larvae of apple maggot, lesser appleworm, codling
moth and some leafrollers would have the opportunity
to remain and develop to overwintering maturity.
There would be within-orchard buildup of these pests,
threatening next year's crop. This buildup would
negate the value of attempting to manage these pests
by preventing their immigration into the orchard. The
loss of Alar™ and the consequent greater number of
apple drops makes this job more difficult.

If the EPA would approve general use of an odor-
baited, pesticide-treated-sphere system of controlling
apple maggot flies, if apple drops were faithfully picked
up shortly after harvest, and if we could contain dam-
age by summer leafrollers and lesser appleworms at a
low level, then growers should be able to employ sec-
ond-stage IPM practices with high confidence. Grow-
ers and the public alike would benefit from a healthier
orchard environment.

Acknowledgements

We thank the Massachusetts Society for the Pro-
motion of Agriculture, the Northeast Regional Project
on Integrated Management of Apple Pests (NE-156),

Fruit Notes, Winter, 1990

and the joint federal/state apple IPM project for sup-
porting our work on second-stage apple IPM in 1989.
We also thank Kathleen Leahy, Dave Stanley, and

Patti Powers for their assistance in sampling orchards,
and Roy Van Drieschefor determining leafminer para-
site levels.

«f* *% *f# *% *3a

rj» #J» #J% «J* »J%

Three Years of the Massachusetts
Second-stage Apple IPM Pilot Project:
Blocks Receiving Perimeter Row Sprays

Margaret Christie, Cheryl Donovan, Katharine Rankin, and
Ronald Prokopy

Department of Entomology, University of Massachusetts

In the preceding article, we describe the rationale
and principles of second-stage apple IPM strategy and
tactics. We outline in that article two approaches to
achieving the second-stage IPM goal of greatly reduc-
ing or eliminating use of insecticide and miticide after
May. One principal distinction between the two ap-
proaches lies in the tactic used for managing apple
maggot flies: use of traps on perimeter apple trees to
intercept immigrating apple maggot flies before they
can penetrate the orchard interior versus spraying of
perimeter-row apple trees eveiy 3 weeks from June
through August to prevent flies from penetrating the
orchard. Here, we present a summary of 3 years of
implementation of the latter approach in 6 commercial
orchard test blocks.

Methods Used

The second-stage IPM test blocks averaged 2 acres
in size and were compared with adjacent blocks of
similar varietal composition and size, treated under
first-stage IPM practices. Each year, both types of
blocks were sprayed in essentially identical fashion
from April to early June. Thereafter, the first-stage
blocks received pesticide throughout the block when
pest monitoring information indicated a need for such,
while the second-stage blocks usually received insecti-
cide every 3 weeks on both sides of all perimeter apple
trees but no insecticide (or miticide) on the block
interior. In addition, all apple trees within 100 yards of

the perimeter of each second-stage orchard block were
removed in May of 1987 to discourage immigration of
codling moths and summer leafrollers.

Results

Data in Table 1 show levels of pest captures on
monitoring traps and levels of pest injury to fruit. Over
the 3 years, 74% more apple maggot flies were captured
on nonbaited monitoring traps at the interior of sec-
ond-stage than first-stage blocks. This represents a
greater capture-level difference between first- and
second-stage blocks than where apple maggot intercep-
tion traps were employed on perimeter- row apple trees
(see preceding article). This result suggests that the
interception trap approach may be more effective than
the perimeter-row spray approach for intercepting
apple maggot flies.

Apple maggot damage averaged about the same in
perimeter- row-sprayed and first-stage IPM blocks over
1987 and 1988, but in 1989 it was considerably greater
in the perimeter-row-sprayed blocks (1.2 versus 0.1%).
No codling moth or lesser appleworm injury to fruit
was found in any block in any year. Leafrollers caused
very little fruit damage in either type of block in 1987
and 1988 (0.1% or less) but in 1989 damage climbed to
0.3% in first-stage blocks (versus 0.1% in second-stage
blocks). All other insects remained at a very low level
throughout the study (0.2% damage or less).

Data in Table 2 show levels of foliar pest mites and

Fruit Notes, Winter, 1990

Table 1

Average percent fruit injury bj

' insect

pests active after mid-June.*-**

Avg. percent of fruit injured by

insect

pests

Avg. number of
ami? „« :„+„..:„„

active after mid-June

monitoring

Other

All

Year

Block

traps

AMF

RBLR

LR LAW

other

Total

1987

Second Stage

104

0.6

0.1

0.2

0.9

First Stage

0.8

0.1

1.0

1988

Second Stage

101

0.3

0.1

0.0

0.4

First Stage

0.2

0.0

0.2

1989

Second Stage

1.2

0.0

0.3

0.1

1.6

First Stage

0.1

0.0

0.1

0.0

0.2

*500 on

-tree fruit sampled per block during July, August, and September.

**AMF

= apple maggot;

CM = codling moth; RBLR =

red banded leafroller; other LR

= other

unidentified leafrollers; LAW = lesser appleworm.

Table 2.Average percent leaves (or terminals) harboring foliar pests or beneficial natural enemies.*'

Year

Block

ERM

TSM

AF YM

Ratio of

pest to

predatory

mites

WAA WAL PL ABLM GAM GAAP

1987
1988
1989

Second-stage

First-stage

Second-stage

First-stage

Second-stage

First-stage

24
16
12
10
24
23

1.2
0.3
0.3
0.5
3.6
2.5

0.1
0.0
0.1
0.1
0.1
0.0

19:1
48:1
30:1
17:1
7:1
9:1

5
5
5
5
10
8

8
6
1

9
10
2
2
1
1

5
4
4
6
6
6

31
23
59
55

*400 leaves (or terminals) sampled per block during June, July, August, and September.
"ERA = European red mites; TSM = two spotted mites; AF = predatory Amblyseius fallacis; YM = preda-
tory yellow mites; WAA = woolly apple aphids; WAL = white apple leafhopper; PL = potato leafhopper;
ABLM = apple blotch leafminer; GAA = green apple aphid; GAAP = green apple aphid predators:
cecidomyiids and syrphids.

their principal natural enemies. Each year pest mites
averaged greater in abundance in second-stage than
first-stage IPM blocks. The difference was substantial
in 1987 (50% greater pest mites in second stage blocks)
but narrowed to only 4% greater in 1989. Predatory
Amblyseius fallacis mites averaged greater in second-
stage than first stage blocks in 1987 and 1989 but the
reverse was true in 1988. Predatory yellow mites were
very few in number in any block in any year. The
overall ratio of pest to predatory mites was unfavorable

for effective biological control in either type of block in
1987 and 1988 (never more favorable than 17 to 1) but
was favorable for moderately effective biological con-
trol in both types of blocks in 1989 (7 or 9 to 1).

Data in Table 2 also show levels of other foliar pests
and natural enemies. There was very little or no
difference between block types in any year in popula-
tion levels of woolly apple aphids, white apple leafhop-
pers, potato leafhoppers, or apple blotch leafminers.
Likewise, there were no consistent or appreciable dif-

Fruit Notes, Winter, 1990

Table 3. Average number of insecticide and miticide treatments per block.

Insecticide

Miticide

Year

Block

Pre-bloom April to Early June April to Early June
oil early June onward early June onward

1987

1988

1989

Second stage
First stage

1.2
1.3

Second stage
First stage

1.7
1.7

Second stage
First stage

1.7
1.7

3.8
4.0

3.2
3.2

3.8
3.8

3.0*

2.5

2.7*

3.2

2.8*

3.3

1.3*
2.7

0.8*
2.0

0.3*
1.3

•Treatments applied only to perimeter apple trees - not to block interior.

ferences between blocks in levels of apple aphids or
aphid predators.

With respect to frequency of insecticide and miti-
cide use, from April to early June, on average over the
3years, both first- and second-stage blocks received 1.5
oil sprays, 3.6 insecticide sprays, and miticide sprays
(Table 3). Thereafter until harvest, first-stage blocks
received on average 3.0 insecticide sprays and 2.0 miti-
cide sprays. Second-stage blocks received (on perime-
ter trees only) an average of 2.8 insecticide and 0.8
miticide sprays (Table 3). Average annual per acre
costs of oil, insecticide, and miticide treatments over
the 3 years were about $194 for the first-stage blocks,
versus about $110 for the second-stage blocks. When
determining cost of treating second-stage blocks from
early June onward, we estimated perimeter trees as
comprising about 25% of an assumed rectangular 2-
acre block of M.7 trees (225 trees per block).

Conclusions

In conclusion, we generally are pleased with the
results of this perimeter-row spraying approach to
achieving the second-stage apple IPM aim of keeping
the interior of apple orchard blocks free of insecticide
and miticide sprays after early June. Fruit injury by
codling moths, lesser appleworms, and leafrollers was
absent or in low amount. Foliar pests such as leafhop-
pers, aphids, and leafminers were essentially no more
abundant in second-stage than first-stage blocks.
Annual insect and mite control cost only about 60% as
much in second-stage as in first-stage blocks.

We are somewhat cautious, however, with respect

to long-term effective control of apple maggot and
mites using this approach. In 1989, apple maggot
injury was considerably more pronounced than in 1987
or 1988 in second-stage blocks or than in any year in
first-stage blocks. In contrast, apple maggot injury
progressively declined from year to year under the
second-stage IPM approach of using odor-baited visual
traps on perimeter apple trees to capture maggot flies
(see preceding article). The reason for the sharply
increased average level of maggot injury in 1989 in
perimeter-sprayed blocks is unclear, but could reflect
greater buildup of apple maggot flies within orchards
as a consequence of greater fruit drop in the absence of
Alar™. If so, then a perimeter-row spray approach to
controlling apple maggot maybe reliable only in blocks
where drops of early- and mid-ripening cultivars are
picked up at harvest to prevent maggots maturing in
them. With regard to mites, in no year did the average
ratio of pest mites to predator mites in perimeter-
sprayed second-stage blocks reach as low as 5 to 1,
which is considered favorable for effective biological
suppression of pest mites. The ratio always exceeded 7
to 1 and was never as favorable as in second-stage
blocks receiving apple maggot traps rather than sum-
mer insecticide treatment on perimeter apple trees
(see preceding article). Perhaps a substantial propor-
tion of predatory mites is immigrating on wind into
orchards from plants surrounding the orchard and
perhaps these predators are affected by pesticide treat-
ment of border rows.

As a final word, we now believe that we can recom-
mend with reasonable confidence the value of a pe-
rimeter-row spray approach as a transitional step

Fruit Notes, Winter, 1990

aimed at managing apple insect and mite pests without Ackowledgements
use of insecticide and miticide after early June. Even
so, we believe that this aim will be more fully achieved
at eventual lower cost by adopting the second-stage
IPM practices set forth in the preceding article.

We thank the Massachusetts Society for the Promotion
of Agriculture and the Joint federal/state apple IPM
project for supporting our work on second-stage apple
IPM in 1989. We also thank Kathleen Leahy, Dave
Stanley, and Patti Powers for their assistance in sam-
pling orchards.

*Ta %?* fcf.» a.% %f#
*4» +%* rj> cj% 0fm

Evaluation of Releases of Amblyseius fallacis
Predatory Mites on Apple Trees

Ronald J. Prokopy and Margaret Christie

Department of Entomology, University of Massachusetts

David Stanley
Biokon Insectaries

One of the major aims of apple IPM is to promote
predatory mites as a substitute for chemical miticides
to control European red mites and two-spotted spider
mites. We envision 2 major methods of promoting
predatory mites: (1) using second-stage IPM practices
of non-use after early June of any pesticide even
slightly harmful to predatoiy mites (this includes vir-
tually all insecticides and miticides currently labelled
for orchard use, and some fungicides, especially beno-
myl and mancozeb) or (2) release into orchards of
laboratory-cultured predatoiy mites that have been
selected to resist major types of insecticides, such as
organophosphate and carbamate compounds. The
first option may be the less expensive one, but resident
or immigrating predatoiy mites could still be adversely
affected by early-season pesticide use. Here, we report
on 2 years of experiments in commercial orchards
evaluating the second option.

Methods Used

In 1988, we selected 2 experimental blocks (each
about 1 acre) in each of 6 commercial orchards. One
block (the first-stage IPM block) was treated normally
by the grower, using the first-stage IPM practice of
applying pesticide when pest monitoring information

indicated the need to do so. The second block (the
second-stage IPM block) was treated identically to the
first-stage block through early June. Thereafter, each
second stage block received only a border row spray ap-
plication of insecticide on perimeter apple trees every
three weeks until harvest. No insecticide or miticide
was applied to the second-stage block interior after
early June. For essentially all blocks, only Imidan™ or
Guthion™ as insecticide was applied after early June.
This protocol was followed in both 1988 and 1989.

In 1988, we released in July approximately 500
adults of the predatory mite Amblyseius fallacis under
each of 7 trees per block in both first-stage and second-
stage blocks in all 6 orchards. In 1989, we tripled the
number of A fallacis released in July to reach a level of
about 1 500 per each of 7 trees per block in both types of
blocks. However, they were released on tree foliage
rather than on the ground (as done in 1988), and were
released in only 4 of the 6 orchards. The predators
originated from a strain in Geneva, New York that has
been determined to be resistant to most organo-
phosphates, and possibly also to some carbamate insec-
ticides. The predators were cage-reared on two-spot-
ted mites cultured on bean leaves. Predators were
harvested by removing infested leaves from the cages.
Then a rough count of adult predators was made, after

Fruit Notes, Winter, 1990

which predators and the bean leaves were mixed with
cool, damp bran as a spreading medium. The mixture
was gently but thoroughly turned by hand before deliv-
ery to orchards where it was applied under or upon the
canopy of apple trees. Releases were timed to coincide
with the time when 20 to 40% of the leaves in the first-
stage and second-stage blocks were infested with pest
European red mites or two-spotted mites. We rea-
soned that releasing predators in a block with too few
pest mites (less than about 20% of leaves infested)
might stimulate the predators to leave the block and
search elsewhere for more abundant prey. If pest mites
were allowed to build beyond about 40% of leaves
infested, released predators might not be able to pro-
vide effective suppres-
sion. Foliage was
sampled for presence of
pest and predatory
mites in June (before
predators were re-
leased), in July (shortly
after predators were
released), and again
once each in August
and September. In an
attempt to control the
possibility that A falla-
cis appearing in the
aforementioned first-
and second-stage IPM
blocks might have been
progeny of resident A
fallacis (present before
the releases occurred)
or were natural immi-
grants from outside the
blocks, we compared
the numbers of A falla-
cis on leaves in these 6
orchards with those on
leaves in 6 similarly
treated and similarly
sampled first- and sec-
ond-stage IPM blocks
in 6 other orchards
where A fallacis were
not released.

Results

In the 2 orchards
where predators were
released in 1988 but
not in 1989, no native
A fallacis were seen in

June before A fallacis were released. After release, the
average ratio of pest mite to A fallacis frequency on
leaves in 1988 was 5 to 1 both in second-stage and first-
stage blocks (Table 1). A ratio of 5 to 1 is generally
considered to indicate a high probability of effective
biological mite control, while a ratio of 10 to 1 is
indicative of only moderate probability of such control.
In no block in any orchard in either year were predators
other than A fallacis (such as yellow mites) sufficiently
abundant to have affected the ratio of pest mites to A
fallacis. In 1989, there were extremely few pest mites
in either type of block in these 2 orchards until Septem-
ber, well after danger of damage by mites had passed.
Interestingly, there were extremely few or no A

Table 1.

Results in 2 orchards where A fallacis predators were released in July

of 1988 but not in 1989.

Percent of sampled

leaves with*

Tt j.' £ j.

Ratio of pest

Time of

ERM or

mites to

Year

sampling

Block type

TSM

A fallacis

1988

June

Second-stage

0.0

15:0

First-stage

0.0

11:0

July

Second-stage

3.3

12:1

First-stage

2.6

15:1

August

Second-stage

9.5

2:1

First-stage

5.2

4:1

September

Second-stage

1.4

2:1

First-stage

4.8

2:1

Avg. for

July, Aug.,

Second-stage

4.7

5:1

and Sept.

First-stage

4.2

5:1

1989

June

Second-stage

0.0

0:0

First-stage

0.0

0:0

July

Second-stage

0.0

1:0

First-stage

0.0

0:0

August

Second-stage

0.0

1:0

First-stage

1.5

3:1

September

Second-stage

0.0

38:0

First-stage

0.0

10:0

Avg. for

July, Aug.,

Second-stage

0.0

13:0

and Sept.

First-stage

0.5

10:1

*On each sampling date,

in 1988 we sampled 10 leaves

per tree on 14 trees per

block (7 under which A fallacis were released and 7 adjacent trees) and in 1989

10 leaves per tree on 10 trees per block. ERM

= European red mites; TSM = two-

spotted mites; AF = A fallacis.

Fruit Notes, Winter, 1990

Table 2.:

Results in 4 orchards where A fallacis predators were released

in July of 1988

and agai

l in July of 1989.

Percent of sampled

leaves with*

Ratio of pest

Time of

ERM or

mites to

Year

sampling

Block type

TSM

A fallacis

1988

June

Second-stage

0.0

42:0

First-stage

0.0

15:0

July

Second-stage

5.3

6:1

First-stage

5.1

6:1

August

Second-stage

1.8

9:1

First-stage

2.4

8:1

September

Second-stage

0.5

18:1

First-stage

0.0

12:0

Avg. for

July, Aug.,

Second-stage

2.5

8:1

and Sept.

First-stage

2.5

9:1

1989

June

Second-stage

0.0

32:0

First-stage

0.0

29:0

July

Second-stage

4.8

14:1

First-stage

3.0

18:1

August

Second-stage

15.3

3:1

First-stage

11.4

3:1

September

Second-stage

13.6

2:1

First-stage

11.5

1:1

Avg. for

July, Aug.,

Second-stage

11.2

4:1

and Sept.

First-stage

8.6

4:1

*0n each sampling date, we

sampled 10 leaves

per tree on 14 trees per

block (7 under

which A

fallacis were released and 7 adjacent trees) in

both 1988 and 1989. See

footnote

in Table 1 for explanation of ERM, TSM, AF.

fallacis predators found in these orchards in 1989. The
near total absence of pest mites in June, July, and
August may have stimulated the A fallacis to leave the
blocks and search elsewhere for prey. A fallacis do not
remain long on foliage harboring few potential prey.
The results in these 2 orchards suggest that A fallacis
eventually provided good suppression of pest mites in
both the second-stage and the first-stage control blocks
in 1988 and that a high level of suppression occurred
through August of 1989. The near absence of A fallacis
in our samples of September, 1989 in these 2 orchards
makes us wonder, however, if enough A fallacis will be
on hand in 1990 to provide effective suppression of pest
mites.

In the 4 orchards where predators were released in

both 1988 and
1989, again no
native A fallacis
were found in
June 1988, before
A fallacis were
released. After
release, the aver-
age ratio of pest
mite to A fallacis
frequency on
leaves in 1988 was
8 to 1 in the sec-
ond-stage blocks
versus9tolinthe
first-stage blocks
(Table 2). This
result suggests
that a moderate
level of biological
control was

reached. By late
June of 1989,
however, pest
mites had reached
average frequen-
cies of 32 and 29%
of leaves infested
in the second-
stage and first-
stage blocks, re-
spectively (Table
2). These fre-
quencies are only
slightly less than
the tolerable level
of pest mite popu-
lations on apple
trees in late June.
No A fallacis were found in any of the blocks in these
4 orchards in June. Conceivably, in these orchards,
early-season use in 1989 of pesticides to which the
released predators were not tolerant may have contrib-
uted to their lack of appearance in detectable numbers.
After release of veiy large numbers of A fallacis in July
of 1989 in these orchards, the average ratio of pest mite
to A fallacis frequency on leaves was 4 to 1 in both the
second-stage and first-stage blocks. These ratios sug-
gest that a high level of biological pest mite control
occurred in these 4 orchards. It will be most interesting
to see whether the high numbers of A fallacis present
in these 4 orchards in September of 1989 carry over to
provide effective biocontrol of pest mites in 1990.
It would be wrong to conclude from the foregoing

Fruit Notes, Winter, 1990

results that the observed
patterns of pest mite and
A fallacis abundance
were entirely the prod-
uct of A fallacis that we
had released. These pat-
terns may have been af-
fected in a substantial
way by natural popula-
tions of resident or
immigrating A fallacis.
Results from the second-
stage and first-stage IPM
blocks in the 6 orchards
where predators were
not released (Table 3)
suggest that resident or
immigrant A fallacis in
these blocks provided
little pest mite suppres-
sion in 1988 (average
ratios of pest mite to A
fallacis frequencies after
June were 38:1 and 18:1,
respectively) but pro-
vided good suppression
in 1989 (average ratios of
pest mite to A fallacis
frequencies after June
were 5:1 and 6:1, respec-
tively). Thus, the 1988
ratios in these blocks
where predators were
not released were con-
siderably less favorable
for biological control
than the 1988 ratios in
blocks where A fallacis
were released (Tables 1

and 2). On the other hand, in 1989 there was little dif-
ference in prey to predator ratio between blocks where
predators were or were not released in 1989.

Table 4 provides information on possible move-
mentof A fallacis from trees under orupon which they
were released, to trees immediately adjacent where
predators had not been released. For this purpose, we
combined data across both block types and across all
orchards where releases occurred that year. The
combined data for 1988 and 1989 indicate that about
2.2 times more A fallacis were present on the release
trees than on adjacent non-release trees in July, 1.4
times more in August, and 1.3 times more in Septem-
ber. This suggests that released A fallacis may have
moved in substantial numbers to neighboring trees a

Table 3.

Results in 6 orchards where no A fallacis predators were

released in

1988 or

1989.

Percent of

sampled

leaves with*

atio of pest

Time of

ERMor

mites to

Year

sampling

Block type

TSM

AF A fallacis

1988

June

Second-stage

6:0

First-stage

1:0

July

Second-stage

0.2

50:1

First-stage

6:0

August

Second-stage

0.7

29:1

First-stage

0.5

26:1

September

Second-stage

0.2

60:1

First-stage

1.7

12:1

Avg. for

July, Aug.,

Second-stage

0.4

38:1

and Sept.

First-stage

0.7

18:1

1989

June

Second-stage

0.0

25:0

First-stage

0.0

27:0

July

Second-stage

2.5

10:1

First-stage

3.3

6:1

August

Second-stage

5.2

3:1

First-stage

2.5

6:1

September

Second-stage

6.8

4:1

First-stage

4.3

7:1

Avg. for

July, Aug.,

Second-stage

4.8

5:1

and Sept.

First-stage

3.4

6:1

*One each of the 3 sampling dates each year, we sampled ]

L0 leaves

per tree on

10 trees

per block. See footnote in Table 1 for

explanation

ofERM

, TSM, AF.

month or so after release. However, this suggestion is
based on the questionable assumption that the major-
ity of A fallacis observed were ones that had been
released (or their progeny) and were not of wild origin.

Conclusions

Can any firm conclusions be drawn from our find-
ings to date? Unfortunately, the answer is no. There is
simply no way to be certain that all or even some of the
A fallacis we observed on sampled apple leaves origi-
nated from releases of A fallacis and were not of wild
origin. Our conclusions, therefore, are highly tentative
and are based on the assumption that the majority of A
fallacis were in fact of released origin.

Fruit Notes, Winter, 1990

Table 4

. Presence of released A fallacis on trees under or upon

which they were

released

versus i

adjacent trees where none had been released.

Percent of sampled leaves

per orchard with

Predators

A fallacis

Number
of

Number
of trees

released
under these

Time of

ERMor

Year

sampling

orchards

per orchard

trees

TSM

1988

July

YES

5.5

3.1

August

YES

4.5

3.1

September

YES

1.4

1.1

1989

July

YES

5.9

2.0

August

YES

15.7

11.1

September

YES

15.1

11.3

It appeared that there were few if any detectable
differences in the outcome of releases of A fallacis in
second-stage versus first-stage IPM blocks. It appears
that the released A fallacis, selected before release to
be resistant to organophosphate insecticides, may have
been able to withstand such pesticide treatments after
early June in the grower control blocks. We must
caution, however, that such resistance could eventu-
ally break down through introgression of genes from
wild-population A fallacis in cases where such popula-
tions are still susceptible to organophosphates.

It was clear that releasing about 500 A fallacis
adults on every fourth tree in a block (as was done in
1988 in all blocks) does not guarantee effective biologi-
cal control of pest mites either that year or the following
year. In 2 orchards, effective biological control did
occur (Table 1). In 4 orchards, moderate to relatively
little biological control occurred (Table 2). The pros-
pect for effective biocontrol within the same year of
release improved considerably when about 1500 A
fallacis adults per every fourth tree were released, as
was done in 1989. Still, we must wait to see if this very
high level of release will result in year-long suppression

of pest mites in 1990 and thereafter.

Finally, we must be patient. The full story of just
how effective are releases of A fallacis in apple or-
chards, compared with the alternative option of allow-
ing native A fallacis to build in the complete absence of
insecticide or miticide use after early June, may not be
known for at least a couple of more years, after contin-
ued future sampling in the 6 experimental orchards
where releases have been made and in the 6 compa-
rable orchards where no releases have been (or will be)
made. Researchers in the Netherlands believe that it
takes at least 4 years to see the full benefits of releasing
Typhlodromus pyri mite predators in Dutch orchards.
For now, we reserve full judgement and can only wait
to see what unfolds in 1990 and 1991.

Acknowledgments

We thank the Massachusetts Society for the Pro-
motion of Agriculture and federal/state agencies
granting apple IPM funds for supporting our work on
this project. Special thanks to Katharine Rankin and
Cheryl Donovan for their assistance, and Roy Van
Driesche for his helpful advice.

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Fruit Notes, Winter, 1990

Development of a Program for Grower and
Consultant Education and Certification
in Integrated Pest Management

William M. Coli and Craig S. Hollingsworth

Integrated Pest Management Program, University of Massachusetts

Recent consumer concerns over pesticides and food
safety have been reported conspicuously in local and
national media. Consumers are increasinglywary of the
food supply; they seek assurance that their food is safe.
Massachusetts growers have experienced reduced sales
from this media attention, and growers need a mecha-
nism to demonstrate to consumers that their produce is
safe.

One approach to this problem that some consumers
have taken, is to buy organically produced food. How-
ever, considerations of produce availability, quality, and
price, as well as technology and production costs, limit
the production of organic produce in the Common-
wealth. Another attempt to allay consumers' concern
over food safety has been the use of a "low spray" or
"IPM" label on produce. Such labelling has been lim-
ited, as no generally accepted standards for these catego-
ries exist.

Because adoption of IPM by commercial growers in
Massachusetts has been high, many growers have
mentioned their interest in being recognized for their
practices. Further, sponsors of pending pesticide reform
legislation are considering language that would give a
waiver of pollution liability for growers who use IPM.

In response to these developments, we submitted a
proposal to Massachusetts Department of Food and
Agriculture to develop a program of IPM education and
performance certification using resources at the Univer-
sity. Since as this proposal has received first-year fund-
ing, we believe it would be useful to inform growers,
consultants, and others of our plans at this time.

Objectives

The objectives of this project are threefold: 1) To
develop a state-wide program for the education of grow-
ers and agricultural consultants in the principles of
integrated pest management; 2) To develop guidelines
and standards to certify crops which are grown using
IPM principles; and, 3) to design and facilitate implem-
entation of a program of IPM performance certification.

Expected Results from This Project

Through educational materials and programs, it
is expected that this program will result in increased
knowledge of IPM by Massachusetts growers, and
that knowledge will result in greater adoption of IPM
techniques throughout the Commonwealth.
Through increased training and awareness, and
greater availability, more IPM-trained professional
consultants and scouts will be hired by the private
sector, further increasing the adoption on IPM and
creating jobs.

Increased use of IPM will result in reduced pesti-
cide use in the Commonwealth. Growers using IPM
certification on their produce will reap a marketing
advantage, when consumers, educated to IPM la-
belling, purchase produce that they know has been
grown using practices minimizing environmental dis-
ruption, and with minimal and safe pesticide use.

Educational Program

A project specialist will work with other Univer-
sity of Massachusetts research and Cooperative Ex-
tension staff to develop the curriculum and course
materials for an IPM short course. The short course
will be designed to teach growers, consultants, and
field personnel the basic principles and practices of an
integrated pest and crop management strategy.
Likely topics to be covered by the short course would
include: ecology of the agroecosystem; economic
thresholds; weather and disease monitoring; pest
sampling methodology; practical biological control;
cultural controls; and record keeping systems. Also
included would be topics on pesticide technology,
including: toxicology; effects of pesticides on non-
target organisms; movement of pesticides in the envi-
ronment; pesticide selection; biorational pesticides;
and sprayer calibration.

IPM short courses will be presented at Waltham
and Amherst. A test on the material will be given.
Individuals passing the test will receive a certificate of

Fruit Notes, Winter, 1990

successful completion by the University of Massachu-
setts Cooperative Extension.

Certification of Consultants

Many growers, especially those with long-estab-
lished and effective IPM programs, possess enough
knowledge to implement an IPM program. What most
lack, however, is the time to monitor their fields ade-
quately. Hence, one of the greatest limitations to
successful, large-scale IPM implementation is a lack of
trained individuals to monitor fields and make recom-
mendations.

There are currently six scout/consultants in the
state who offer IPM services for no more than 5000
acres of crops, largely apples and cranberries. Should
greater numbers of consultants become available,
growers who hire them at a rate sufficient to represent
a living wage, have a right to expect such consultants to
be well-trained and qualified, and able to be trusted
with a valuable crop. Certification of IPM consultants
would help growers make hiring decisions.

IPM Certification Standards

Produce to be marketed or labelled as "IPM-
Grown," should be grown using certain specified prac-
tices or standards. This project proposes to develop
IPM guidelines for specific crops where feasible.
Where IPM technology is insufficient to develop appro-
priate guidelines, this project will outline what infor-
mation is needed to develop IPM standards.

In order for consumers to be confident that "IPM-
Grown" labeled commodities are true-to-name, some
form of performance certification will be necessary.
While this could take the form of a state regulatory
agency making spot inspections of production practices
to insure that they conform to specified IPM standards,
other options exist, including certification by the mar-
keting division of state government, by some private
entity, or by an organized grower group. The issue of

assigning responsibility for certification inspections
will be difficult to resolve.

Time Table

This program will begin in the fall of 1989 and is
anticipated to run for 2 years. The IPM Certification
Specialist will work closely with the State IPM Coor-
dinator, other University faculty and staff, as well as

consultants and growers to carry out the project,

using the latest research-based information available

here and in other states.

Curricula for the first short courses will be devel-
oped during the Winter of 1989-90. Production of a
curriculum manual to accompany the short course will
be initiated as well. Two short courses will be pre-
sented and participants will be certified upon success-
ful completion in the Spring of 1990.

Also in the first year, compilation of a list of com-
modities grown in Massachusetts, and the data needed
for their IPM certification will be initiated. A protocol
for developing IPM certification guidelines will be
developed and guidelines for IPM production of apples,
potatoes, strawberries, and sweet corn will be com-
pleted. Avenues of performance certification, including
its legal ramifications, as well as the practicality of
using state, federal, or other agencies for certification of
performance, will be explored.

During the second year of the program, the educa-
tional component will continue as demand warrants;
two short courses will be held in the Winter. The short
course manual will be completed. Guidelines for IPM
certification of cole crops, cranberries, greenhouse
production, and turf will be completed, and guidelines
for nursery crops will be begun. Procedures for certifi-
cation of IPM performance will be developed, and the
eventual certifying agency will be assisted in imple-
menting the certification program.

If you would like more information about our plan,
please contact either author at 413-545-2283.

•.?* %i* *?• ct* *t*

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Fruit Notes, Winter, 1990

Effects of the Loss of EBDC Fungicides on
Apple IPM in New England

Daniel R. Cooley

Department of Plant Pathology, University of Massachusetts

Stephen Wood

New England Fruit Growers' Council on the Environment

John Schneider

Very fine Products, Inc., Technical Department

Over the past several years, fungicides have been
the subject of steadily increasing criticism from food
safety advocates. At the moment, they are also in the
center of EPA's limelight.

Many of the fungicides New England growers rely
on to control diseases in fruit crops are thought to have
the potential to cause various chronic, human-health
disorders. As a result, growers have cause to wonder
about the future of the fungicides they now use. Some
may soon be regulated off the market, some may be
dropped from the market by their manufacturers, and
some may be driven from the market by another explo-
sion of public emotion.

Right now, the fungicides at center stage are the
ethylene bisdithiocarbamates (EBDCs) which include
all formulations of maneb (Maneb™, Dithane M-22™,
Manzate D™, Manex™, etc.), mancozeb (Dithane M-
45™, Manzate 200™, Penncozeb™, Dikar™, etc.),
metiram (Polyram™, Zinc-metiram™, etc.) and zineb.
Anticipating a recommendation from EPA that future
use on apples be forbidden, the registrants of all EBDC
fungicides agreed to drop apples from the 1990 label.
This measure presents growers with the problem of
producing next year's crop, and possibly every crop
thereafter, without EBDC fungicides.

This paper attempts to describe the effects of the
loss of EBDC fungicides on IPM fruit growers in New
England, and more generally to explain the extent to
which successful IPM depends on the continued availa-
bility of a broad variety of similar fungicides.

Most older fungicides (registered before 1970) are
under fire for their potential to cause cancer, tumors,
reproductive disorders, or a variety of other chronic
health problems. Under the present regulatory
scheme, the EPA attempts to determine which com-
pounds with similar uses present the lowest theoretical
risk. In a given group of materials with similar uses,
the compound with the lowest risk is cleared for contin-

ued use, while the "more hazardous alternatives" are
disallowed. Certain proposed legislation is intended to
compel EPA to take this approach.

The problem with this approach, from an IPM
grower's perspective, is that it will hamper the ability
to be precise. There is no "all purpose fungicide."
While it is useful conceptually to think of benzim-
idizoles or EBDCs as apple scab fungicides, each com-
pound has specific properties which make it the most
appropriate material to use under a given set of cir-
cumstances. IPM growers make pesticide use deci-
sions that are highly specific to the exact combinations
of diseases, arthropods, stages of tree development,
and environmental conditions present in their or-
chards at given times. Growers also specifically apply
fungicides to different pails of the orchard, depending
on cultivar or tree size. Without a wide variety of
chemicals from which to choose, such precision would
be impossible. In fact, a reduction in the number of
available fungicides will limit precision rather than
lowering the volume of fungicide used. The hard fact is
that two compounds that control the same disease
virtually never have the same full range of effects.

Without EBDCs next year, New England IPM
growers will experience a painful example of this limi-
tation. Assuming for now that no EBDCs will be
available for use on apples in 1990, our toolbox for next
year will contain the following fungicides.

Bcnomyl (Benlate™)

Captan (Captcc™, Orthocide™)

Dodine (Cyprex™)

Fenarimol (Rubigan™)

Ferbam

Fixed coppers (Kocide™, COCS™)

Myclobutanil (Nova™)

Sulfur

Thiophanate-methyl (Topsin-M™)

Thiram

Triforine (Funginex™)

Fruit Notes, Winter, 1990

To a person unfamiliar with the ecology of a New
England apple orchard, this list may seem like more
than enough options. However, to an IPM grower, the
withdrawal of the EBDCs is frightening. The reasons
emerge from a closer examination of the remaining
materials.

Benomyl and thiophanate-methyl can interfere
with biological mite control by suppressing popula-
tions of Amblyseius fallacis, our most important mite
predator. Biocontrol of mites in apple trees is essential
to second-stage or biointensive IPM. Additionally, in-
tensive use of benzimidazoles may lead to earthworm
suppression.

Benzimidazoles are recommended for use only in
specific situations, such as to inhibit scab sporulation.
Exclusive use of benzimidazoles can lead to resistant
strains of Venturia inaequalis, the apple scab fungus.
Resistance already precludes use of these compounds
in some states. To extend the useful life of these
materials, and to avoid stressing mite predators, they
must be used sparingly and always in combination
with another broad-spectrum fungicide such as captan
or the EBDCs.

Captan has recently been re-registered by EPA,
but is still the target of strenuous criticism by food
safety advocates. While a very useful fungicide against
scab and black rot, it does not control mildew, and is
only marginally effective on sooty blotch and fly speck.
Specifically, in a year such as 1989, 4 captan applica-
tions would have been made for sooty blotch and fly
speck, compared to 1 or 2 applications of an appropriate
EBDC.

The gravest difficulty with an attempt to use cap-
tan as a complete alternative to EBDCs arises from
captan's incompatibility with oil or alkaline materials.
The EBDCs do not share this unfortunate characteris-
tic. When combined with oil, or even when used within
14 days of an oil application, captan can be toxic to plant
tissue (phytotoxic). Biological mite control depends on
1 or 2 oil applications in the middle of primary scab
season. Without the EBDCs, growers are faced with 3
options:

1. Damage to the tree by captan/oil combina-
tion.

2. Oil combined with no fungicide or an infe-
rior scab fungicide, resulting in primary sea-
son infections and a season-long fungicidal
battle against serious crop damage.

3. No oil before bloom resulting in an expen-
sive chemical program against phytophagous
mites, without benefit of predator mites.

No grower will choose the first option, and the other
two violate every principle of IPM and will increase

drastically the total volume of pesticide used in New
England apple production.

Dodine may not be manufactured next season. In
any case, though a potent scab eradicant, it can and has
produced resistant scab strains. Over-reliance on
dodine will shorten its useful life, and already has done
so for many growers. Dodine is not effective against
apple diseases other than scab, and would generally
have to be used in conjunction with other fungicides.

Ferbam is at best moderately effective against
scab and has no post-infection activity, so it must be
used as a protectant. While it is fairly effective against
rust and summer diseases, ferbam leaves a heavy,
black, visible residue for some time, which tends to
discourage consumers.

Fixed coppers are useful in their place, which is a
single early-season application. Used after this time,
copper will damage leaves and russet fruit.

Fenarimol, myclobutanil, and triforine . or ergos-
terol biosynthesis inhibitors (EBIs), are a relatively
new class of fungicides. Though highly effective against
scab and (except Funginex) mildew, they do not con-
trol other diseases and are expensive. Moreover, they
are poor protectants, and their extremely specific mode
of action suggest the possibility that they may induce
pathogen resistance. Reports from Europe reinforce
this suggestion. To prevent this development, and to
provide for protectant activity, New England patholo-
gists have recommended that EBIs be used with a
broad-spectrum fungicide. EBDCs have been the fun-
gicide of choice, because they are compatible with oil.
Captan is the second choice, but will present the oil
phytotoxicity problems discussed earlier. Without the
EBDCs, the EBIs may be of marginal utility in New
England.

Thiram has about the same range of activity as
captan but is considerably less effective. Many growers
consider that its chief value is as a deer repellent.

Sulfur, while a favorite of organic growers, is
barely effective against scab, is toxic to mite predators,
and can be phytotoxic. To control scab, growers would
normally apply much more sulfur than they would any
other fungicide. This application leads to concerns
about soil acidification.

If EBDCs were available, they would be described
as follows:

EBDCs are highly effective against scab and
summer diseases, but are useless against powdery
mildew. Use at full rates late in the growing season can
result in visible residues at harvest. Like captan,
EBDCs have virtually no potential to produce patho-
gen resistance. The compatibility of EBDCs with oil
makes them the mainstay of most New England IPM
disease-management programs. Their use incombina-

Fruit Notes, Winter, 1990

tion with EBIs allows at least 10-day intervals between
fungicide applications, which is at least 3 days longer
than with any other fungicide. This program substan-
tially reduces the overall fungicide load in an orchard.

It should be obvious why IPM growers, consult-
ants, and researchers are distressed at the loss, at least
temporarily of EBDCs. Without the EBDCs, we can
confidently predict that overall fungicide use will in-
crease in New England in 1990. Miticide use will also
increase. The irony of the situation appears even more
acute when we consider that the most important IPM
use of EBDCs occurs before bloom, before fruit forma-
tion, and therefore before any possibility of residue
being deposited on the harvested crop. A related article
in this issue indicates that EBDC residue is probably
not a problem when applications are made early in the
season.

For these reasons, regaining some apple uses for
the EBDCs is most desirable. The EBDC fungicides
provide several specific and important management
options in apple IPM. Specifically, they can be used
with oil, allowing mite biocontrol. They also allow the
EBIs to be used in so-called "extended interval" pro-
grams, which reduce the amount of fungicide per sea-
son. They allow extended intervals during the sum-
mer. In reality, the only effective, broad-spectrum
fungicide left for apples is captan, in spite of its limi-
tations.

We hope that two points have emerged from this
work:

1. Present regulatory efforts to reduce risks from
fungicides aim at the identification and elimination of
"bad actors," or the individual compounds that appear
likeliest to endanger human health. This narrow
approach will frustrate real-world efforts to reduce

fungicide use, because it limits growers' ability to ex-
ploit the subtle but important differences between
similar compounds. When the benefits of a compound
are considered, its value in reducing the use of other
compounds and the overall ecological effect of such re-
ductions should be part of the consideration. Con-
versely, how the removal of compounds may increase
the overall use of similar fungicides, or even other
pesticides, should be considered. Regulators must look
more closely at how the use of each compound relates
to the use of all pesticides. The effect of the loss of the
EBDCs on New England apple IPM sharpens these
points painfully.

2. Growers and researchers must put themselves in a
better position to inform regulators about the various
compounds that come under regulatory scrutiny. The
apple industry must perform a use-pattern survey
similar to the preliminary study also presented in this
issue, but covering the complete range of compounds
and apple ecosystems. Such a study, combined with
data on residue, disease damage, and arthropod dam-
age, would greatly expand our own knowledge of our
chemical use, while enabling us to provide EPA with
the sort of information the agency needs to regulate
wisely.

We growers and agricultural researchers can, by
studying our own work, contribute sound information
to the regulatory process. If we do, we are likely to be
able to retain the use of some valuable tools. We might
yet defend our use of EBDCs successfully, if we are
quick and willing to accept or even propose stricter
limitations on their use. We must stop reacting after
the rules are written and start helping to write the
rules.

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Fruit Notes, Winter, 1990

Factors Affecting EBDC Fungicide
Residues in Apple Fruit

Daniel R. Cooley

Department of Plant Pathology, University of Massachusetts

Stephen Wood

New England Fruit Growers' Council on the Environment

John Schneider

Very fine Products, Inc., Technical Department

Apple growers, researchers, and food processors
are deeply concerned with the prohlems presented hy
the loss of EBDC fungicides. In general, these concerns
may he summarized by saying that the loss of the
EBDCs as an option will compel growers to use more
pesticides in their apple pest management programs
(see "Effects of the Loss of EBDC Fungicides on Apple
IPM in New England" in this issue). Here we examine
the results of a use pattern/residue survey done in
1988 in cooperation with a number of New England
apple growers.

The survey was intended as a preliminary study of
how use of the EBDCs and captan (and at that time,

daminozide) might affect residues in apple fruit. Sev-
eral growers throughout New England were contacted
by the New England Fruit Growers Council on the En-
vironment and asked to sample blocks and send infor-
mation about those blocks to us. The growers were
instructed to sample randomly throughout a given
block. Samples were obtained from 28 blocks. The
unwashed, raw samples were sent to the Veryfine
Technical Laboratory, where they were assigned an ID
number. Each block sample was split into two groups,
bagged in plastic, and boxed. Half of each sample was
then sent to the National Food Processors Laboratoiy
in Washington, D.C. for captan/EBDC residue analy-

Number of
Applications

No residue detected

Residue detected

I I I I

nil i inn i i I ii |i ri 1 1 1 ti

in i nim i i in lines si

9 1113
Orchard Block

15 17 19 21 23 25 27

Figure 1. The number of EBDC applications made for the 1988 season, compared with the EBDC residue
on apple samples. Where detectable, the amount of residue increases from left to right; blocks which had
no detected residues are represented in the white background, and blocks with a detected residue are in
the shaded background.

Fruit Notes, Winter, 1990

ses. (The other half was retained at Veryfine for
daminozide residue analysis as part of the overall
study.)

Amounts and dates of pesticide application were
obtained from growers, as well as information on vari-
ous tree and block characteristics. Data analysis was
done at the University of Massachusetts. The key
factors we examined were the number of applications,
the interval between the last application and harvest,
the amount of EBDC formulation applied per acre over
the season, the number of applications made and the
amount of fungicide applied after the last significant
rain of the season in July, and the amount of captan ap-
plied relative to the amount of EBDCs.

Of the 28 blocks tested, 10 had EBDC residues
which were detected. Of these, 1 had received 4 appli-
cations of an EBDC, 1 had received 6 applications, and
the rest had received 7 or more. Of the blocks with non-
detected residues, all had received 8 or less EBDC
applications over the season (Figure 1). Thus, we esti-
mated a "break-point," or point where residues built
up sufficiently to be detected in 9 of 10 cases, at 6
applications. The EBDC residues and the numbers of
applications for the season were well related ( r = 0.69;
the correlation coefficient, r, is a statistic which ranges
between -land + l.indicatingthe degree of correlation,
with meaning no correlation and + 1 or -1 meaning
perfect correlation).

We next examined the effect that the total amount

of EBDC fungicides applied over the season had on the
measured residue (Figure 2). Of course, the total
amount of fungicide applied over a season increased as
the number of applications per season increased (r =
0.95). As would be expected, the more fungicide ap-
plied, the more residue detected (r = 0.66). The
apparent "break point" was at about 15 pounds/acre/
season.

One might also expect that the number of days
between the last EBDC application and harvest would
affect residues. While there was a moderate correla-
tion, the relationship was not as strong (r = -0.33) as
that observed with some of the other factors (Figure 3).

We also considered that significant rain which
occurred in July may have removed residue approxi-
mately 60 to 70 days before harvest. During the 10 days
prior to July 23, over 8 inches of rain fell in many areas.
Therefore we examined the number of applications
and the pounds of EBDC applied after the July 23 rain.
Of the 13 blocks which received applications of EBDC
after July 23, 8 blocks had detected residue, and 5 did
not (Figure 4). All blocks that received 2 applications
after July 23 had detected residues, indicating that late
applications were related to residue (r = 0.64). The
pounds per acre applied after July 23 were more closely
related (r = 0.78), and more fungicide was applied after
July 23 in 8 of the 10 blocks with detected residues than
in the blocks with no detected residues (Figure 5).

We also examined the amounts of captan relative

Lbs./Acre Applied
Over the Season
60

No residue detected

."■ Residue detGcted;H: :

:.:.•. .■*.-, ^^_ w-:a- : •>^-»- ::■•;:■;■ y.'.'s'-y-

^m " '.:'::■"•" ^M : ' ^1

^ ■ -.-■■.-.-..-. ...-.v-;.v. : .> ^^ .-..■. .v.:. :./..:•:■■-> ^H ■•--■•:-:• ^B

I ■::■';:■' ^H -^^ ^^ ^B •*•*•_• j ^H

III! ill lli

9 11 13 15
Orchard Block

17 19 21 23 25 27

Figure 2. The pounds of EBDC fungicide used per acre for the 1988 season, compared with the EBDC
residue on apple samples. Where detectable, the amount of residue increases from left to right; blocks
which had no detected residues are represented in the white background, and blocks with a detected
residue are in the shaded background.

Fruit Notes, Winter, 1990

Days from Last EBDC
Application to Harvest

100

n mm

ii 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ? 1 i i 1 1 1 1 n

1 3 5 7 9 1 1 13 15 17 1 9 21 23 25 27

Orchard Block

Figure 3. The number of days between the last EBDC application and harvest, compared with the EBDC
residue on apple samples. Where detectable, the amount of residue increases from left to right; blocks
which had no detected residues are represented in the white background, and blocks with a detected
residue are in the shaded background.

Applications
After July 23

2
1.8
1.6

1.4
1.2

1
0.8
0.6
0.4
0.2

No residue detected

-*— i — i — i — i — i — i— i — t — t- t t t

7 9 1 1 13 1 5 1 7 1 9 21 23 25 27
Orchard Block

Figure 4. The number of applications of EBDC fungicide made after the last major rain of the season (July
23), compared with the EBDC residue on apple samples. Where detectable, the amount of residue
increases from left to right; blocks which had no detected residues are represented in the white background,
and blocks with a detected residue are in the shaded background.

Fruit Notes, Winter, 1990

Lbs./Acre
After 7/23

6
5

4
3
2

■■■■i n r

sidue detected

"•~-yyv j y. j **',''. '.'•'* 's/ys. «*•> :«•>?■:

No residue detected

•'.'". flW '

'■:'-...■'■.: : ■■Vii:]:fif-::K : :-}y\:f: : ■ ■ I ■

i ™™™aim» ||m| | |

fl ■ 1 : m ■ ■

!!!

■
1 1 1
1 II

|i P
1 1 1

: II

;:!.;;:■! II

1 — t t

— i — i— — i — •— i — i — • — i — ♦— ♦

1 1

15 17 19 21 23 25 27

3 5 7 9 1113
Orchard Block

Figure 5. The number of pounds of EBDC fungicide applied after the last major rain of the season (July
23), compared with the EBDC residue on apple samples. Where detectable, the amount of residue increases
from left to right; blocks which had no detected residues are represented in the white background, and
blocks with a detected residue are in the shaded background.

Number of
Applications
1 4

1 2
1
8
6
4
2

Captan

EBDC

No residue detected

•>x-" J ic.)o.»»»x

X Residue detected i

:■::<>•.-:■.■

17 19 21 23 25 27

I llll I II II III 1 1

1 1 1 1 1 1 1 llll I II llljiilftl

llll III llll I II Mill llll

3 5 7 9 1113 15

Orchard Block
Figure 6. The number of captan and EBDC fungicide applications over the 1988 season, compared with
the EBDC residue on apple samples. Where detectable, the amount of residue increases from left to right;
blocks which had no detected residues are represented in the white background, and blocks with a
detected residue are in the shaded background.

Fruit Notes, Winter, 1990

Lbs./Acre
per Year
60

50
40
30
20
1

Captan

EBDC

No residue detected

[

"Residue detected 1

nrnrmiiiiiiiin sniniE i

9 11 13
Orchard Block

15 17 19 21 23 25 27

Figure 7. The pounds of captan and EBDC fungicide applied over the 1988 season compared, with the
EBDC residue on apple samples. Where detectable, the amount of residue increases from left to right;
blocks which had no detected residues are represented in the white background, and blocks with a
detected residue are in the shaded background.

EBDC
Residues

y = .036x -.121x + .07

Lbs. EBDC applied after July 23

Figure 8. EBDC residues as a function of the pounds of EBDCs
applied after July 23.

to EBDC fungicides used over the
season. In general, as the number
of EBDC applications decreased,
the number of captan applications
increased (r = -0.73) (Figure 6).
Interestingly, as the combined
number of applications for both
types of fungicide decreased, the
mix of captan and EBDC was the
most balanced. These same blocks
were also ones in which EBDC resi-
dues were not detected. (Only one
block, no. 3, had detected captan
residues.) The pounds per acre per
season of each material were less
closely related (r = -0.48), but
showed the same pattern (Figure
7). The correlation between the
pounds of captan per acre for the
season and EBDC residues was
low, but significant (r = 0.44). Not
surprisingly, the pattern suggests
that using more captan reduces the
use of EBDCs, and reduces the
EBDC residue.

If we could use some simple
standards, such as the number of
applications or the total pounds per
acre applied, to predict whether
EBDC residues would remain on

Fruit Notes, Winter, 1990

the fruit, it might be possible to label EBDCs for limited
use. Toward this end we attempted to determine
which of the factors we examined might best predict
EBDC residue in this survey. Using the number of
applications and the total pounds per acre applied for
the season, we could account for about 44% of the
change in EBDC residue . If we looked at the number
of EBDC applications after July 23 and the pounds of
EBDC applied after July 23, we could account for about
69% of the change in EBDC residue. By using a
different type of equation (quadratic) with the pounds
of EBDC applied after July 23, 84% of the change in
EBDC residues could be predicted. This was as well as
we were able to do with the data (Figure 8).

In conclusion, we see this as preliminary informa-

tion indicatingthat concern over EBDC residue may be
managed by changing application timing and amounts.
We certainly do not advocate using crop protectants
which pose a threat to public health and the environ-
ment, regardless of benefits to production. However,
we suggest that it is worthwhile to re-examine costs
and benefits in the context of actual use patterns,
particularly within IPM programs. If information like
that presented here were true for a national sample
over several years, it would indicate that limited use of
EBDC fungicides would not be a health threat. In fact,
as we have argued elsewhere, keeping specific uses for
EBDC fungicides would in fact be a net benefit for food
safety and environmental pollution, because they
would benefit apple IPM programs.

•!# «$# %1* %I# *%
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Massachusetts Apple IPM Program:
Observations in 1989

Kathleen Leahy, Ronald J. Prokopy, and William M. Coli

Department of Entomology, University of Massachusetts

Daniel R. Cooley

Department of Plant Pathology, University of Massachusetts

Our thanks to the following growers who partici-
pated in the IPM monitoring program this year: Alex
Dowse, Tony Lincoln, Tony Rossi, Don Schlicke and
Bill Rose, Steve Smedberg, Mike and Tim Smith, Mike
Smolak, and Denis Wagner.

IPM-Related Research

Spray trials done at the Horticulture Research
Center in Belchertown, and with cooperating commer-
cial growers, included tests of the insect growth regula-
tor Dimilin™, Safers Soap™, sterol inhibiting (SI)
fungicides, and delayed, reduced fungicide applica-
tions.

Two efforts were made to promote biological pest
control in orchards. First, we collected and released
200 adults, larvae, and pupae of the small black lady-
bird beetle Stethorus punctum, an important mite
predator in some parts of the Northeast, into two first-
stage IPM orchards. Second, we collaborated with Roy

van Driesche (University of Massachusetts Biocontrol
Coordinator) and Chris Maier (Connecticut Agricul-
tural Experiment Station) in culturing and releasing
several hundred adults of Testaceipes holcothorax,
which parasitizes leafminer eggs. We will monitor the
populations of these predators to determine their effec-
tiveness and their survival in our conditions.

The manufacturers of EBDC fungicides have
asked that the label for apples be suspended, in order to
allow them to develop data on dietary risk without the
hysteria which occurred regarding Alar™. As a result,
many of the most common apple fungicides now used
will not be available in 1990. We have taken two
approaches to this problem.

First, with a group of New England growers, we
developed a profile of EBDC and Captan use patterns,
and correlated these data with residues on fruit. See
the article in this issue on the results of this survey.

Second, in conjunction with David Rosenberger at
the Hudson Valley Laboratory and Wayne Wilcox at

Fruit Notes, Winter, 1990

the New York Agricultural Experiment Station at
Geneva, we have done tests toward the economic use of
the SI fungicides. This program was tested in 4 grower
blocks this year. In all 4 blocks, primary scab control
was superior to that in check blocks, with virtually no
scab present at the end of primary season in the test
blocks. The first applications were delayed, on average,
until the tight cluster stage of tree development, and
involved an average of 4 primary season sprays, com-
pared to an average of 5.5 applications in check blocks
where the SI fungicides were not used.

Diseases in 1989

With the very wet weather we had this year, dis-
ease problems were by and large more notable than
insect problems. Incidence of fruit injury is given in
Figure 1.

Fire blight . Of major concern to some growers in
Massachusetts was a severe outbreak of fire blight,
most often in orchards which previously had not had
problems with this disease. Most growers who previ-
ously experienced a fire blight problem had used a
dormant fixed copper spray, and did not have trouble
this year. The problem seemed to be primarily in the
central region of the state. The outbreak was all stem
blight, with no blossom blight. In the past, this problem
generally has occurred in conjunction with aphid or
leafhopper population development at the end of June.
This year, the first date of occurrence was mid- June to
mid-July. In two cases, large parts of entire orchards
were infected.

Scab . Scab was evident late in the season on
poorly-pruned trees, and pinpoint scab was noted on
some fruit at harvest. In most cases where a spray was
misapplied (timing or amount), there was disease

1.50--

1.00

0.50--

0.00

SCAB CALYX BLACK SOOTY OTHER

END- ROT ROT BLOTCH/

FLYSPECK

Figurel. Harvest injury in first-stage IPM blocks. Disease injury
in 1978-88 as compared to injury in 1989.

development. Primary pressure was high and lasted
about 5 to 7 days later than last year. In the majority of
orchards, however, scab control was satisfactory.

Flyspeck/sooty blotch . Not surprisingly, in view of
the very wet weather this year, flyspeck was a signifi-
cant problem in orchards which had not been ade-
quately covered with summer fungicides. Sooty blotch
was less prevalent but also present, particularly in
orchards that had used a very light summer fungicide
program. Since light summer programs were being
promoted, growers found themselves in a dilemma:
high disease pressure vs. potentially adverse public
opinion. This year had the worst overall summer
disease situation we have seen in over ten years.

Ron Prokopy observed approximately 5% flyspeck
and 60% sooty blotch on non-fungicide treated Liberty
on his farm.

Brooks spot . Possible Brooks spot was seen on the
cultivar Spencer in one block, although the field iden-
tification was not confirmed by isolation.

Summer rots . More summer rots were seen this
year than in most years, but the level was still not
economically important. Bitter rot and black rot were
the predominant rots, depending on the orchard.

Insects in 1989

Insects and mites were less of a problem in most
orchards this year than in other years, as can be seen
from the incidence of fruit injury in Figure 2.

Plant bug . Activity was very low again this spring.
As always, it was difficult to assess tarnished plant bug
damage at harvest because of similarities with other
insect damage, but on the whole it appears that virtu-
ally no downgrading occurred as a result of plant bug
damage.

Leafminer . Parasitism and other
causes of leafminer mortality were
unusually high this year (over 60% of
second-generation mines in some
monitored blocks). Due to the cool
weather, mine development was
slowed and should have caused less
tree stress. Leaf mines were observed
on pear trees in Belchertown. Al-
though signs of emergence were seen in
some mines (indicating that pear trees
are an acceptable host for this insect),
we were not successful in trapping
emerging moths to see if they were the
same species as the leafminers infest-
ing apples. The larvae were veiy simi-
lar, however.

ES 1978-88
E2S 1989

Fruit Notes, Winter, 1990

1.50

1.00

se °- 50

0.00

OTHER

Figure 2. Harvest injury in first-stage IPM blocks. Insect injury
in 1978-88 as compared to injury in 1989. TPB = tarnished plant
bug; EA = European apple sawfly; PC = plum curculio; LR =
leafrollers; AMF = apple maggot fly; GFW = green fruitworm;
CM = codling moth; SJS = San Jose scale.

Mites . Again this year, mite populations were
generally low, although there were some notable ex-
ceptions, and growers in the monitoring program used
an average of 1.25 dosage equivalents of miticide.
Predators continued to increase in many of the state's
orchards, including Amblyseius fallacis, Zetzellia mali,
Orius insidiosus, and also possibly Stethoruspunctum.
Predation was late building up this year.

Plum curculio . Curculio activity was unusually
prolonged (through early July in some orchards) but
the level of harvest injury in most first-stage blocks was
not unduly high, perhaps because growers were alert
and treated promptly. Some blocks, however, did have
unusually high levels of late-June curculio injury.

White apple leafhopper . This insect is increasingly
evident in Massachusetts orchards, and may be associ-

ated with the fire blight outbreak
mentioned above.

Green fruitworm . Damage that
appears to have been caused by green
fruitworm has been showing up in our
harvest surveys (0.6% in one 12-block
survey), although it does not seem to
be of concern to most growers, and
injury levels probably do not justify a
special application of insecticide.

Leafroller/slug . A fair amount of
surface feeding was noted at harvest in
some blocks, although much of this
feedingwas on dropped fruit. Some of
it was caused by leafroller, but slugs
also had a field day with the damp
weather, and have been seen on at-
tached fruit as well as drops.

Aphids . In most orchards, aphids
seemed to come and go very quickly
this year. Predators were abundant.
Some growers used Thiodan T M against the summer
flight of leafminers, which would have contributed to
the early demise of the aphids; also, the cool.wet
weather may not have allowed aphids to flourish at
their usual levels this year.

Tent caterpillars/gypsy moths . These caterpillars
were more common this year than they have been for
a while. Apparently another population outbreak is
predicted in the next few years. Neither insect pre-
sented much of a problem to growers except on non-
bearing young trees that were not under a full spray
program.

Thrips . Numbers of pear thrips were substantially
lower in commercial blocks than they have been in
recent years, although they still caused some reduction
in fruit set in low-spray, non-commercial orchards.

4.T.* *% C% «f« fcf>

«rj% cy» e|^ #{% r£»

Fruit Notes, Winter, 1990

Fruit Notes

University of Massachusetts

Department of Plant & Soil Sciences

205 Bowditch Hall

Amherst, MA 01003

Nonprofit Organization
U.S. Postage Paid

Permit No. 2
Amherst, MA 01 002

serial section
univ. library

01003

Account No. 3-20685

l&rr, i\

Fruit Notes

ISSN 0427-6906

Prepared by the Department of Plant & Soil Sciences.

University of Massachusetts Cooperative Extension,

United States Department of Agriculture, and Massachusetts Counties Cooperating.

Editors: Wesley R. Autio and William J. Bramlage

Volume 55, Number 2
SPRING ISSUE, 1990

B!OLOG!CAL

MAY U 3 1990

SCIENCES LIBRARY

Table of Contents

Comparison of Ripening and Fruit Quality of Gala and
Mcintosh Apples at Harvest and Following Air Storage

Pomological Note: Blueberry Cultivar Update

Commercial Potential of Red Fuji in New England

Preliminary Observations of Redmax in Massachusetts

Managing Small Fruit Crops for the Retail Market

Food for Thought

Peach Cultivars

Effectiveness of Dimilin™ Against Apple Blotch Leafminere

Evaluation of Dimilin™ Against Pear Psylla

Advancements in Second-stage Apple IPM:
Substituting for "Sticky" on Baited Red Spheres

Evaluation of Safer's™ Insecticidal Soap as a
Management Tool in Apple Orchards

Insecticidal Soap for Pear Psylla Management

Fruit Notes

Publication Information:

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

The costs of subscriptions to Fruit Notes are $5.00 for United States
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Correspondence should be sent to:

Fruit Notes

Department of Plant & Soil Sciences

205 Bowditch Hall

University of Massachusetts

Amherst, MA 01003

COOPERATIVE EXTENSION POLICY:

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

Issued by the University of Massachusetts Cooperative Extension, Robert G. Helgesen, Director, in furtherance of the acts
of May 8 and June 30, 1914. The University of Massachusetts Cooperative Extension offers equal opportunity in progwms
and employment

Comparison of Ripening and Fruit Quality of
Gala and Mcintosh Apples at Harvest and
Following Air Storage

Duane W. Greene and Wesley R. Autio

Department of Plant & Soil Sciences, University of Massachusetts

Gala is becoming one of the most popular and
widely planted apple cultivars in the world. It is a very
high quality apple with broad consumer appeal. We
have been harvesting and evalu-
ating Gala/M.26 for several years
from trees planted at the Horti-
cultural Research Center in Bel-
chertown in 1978. Descriptions
and observations have appeared
in previous Fruit Notes articles
[49(2):18; 51(1):12-14]. Since
Gala appears to be such a promis-
ing apple, we initiated a study of
ripening, fruit quality, and stor-
age potential to determine if Gala
could be a reasonable alternative
to Mcintosh for growers in Massa-
chusetts who wish to reduce their
Mcintosh acreage.

Fruit used in this investiga-
tion were collected in 1988 from
Kidd's D-8 Gala/M.26 planted in
1978 and Rogers Mclntosh/M.26
planted in 1976 at the University
of Massachusetts Horticultural
Research Center in Belchertown,
MA. The Mcintosh trees received
750 ppm of daminozide on July
18, 1988.

Fruit Quality and Ripening

Ten fruit per tree were col-
lected randomly from 3 Gala and 3
Mcintosh trees at weekly inter-
vals starting on August 24 and
continuing through October 19.
Fruit collection was made from
the interior and exterior portions
of all quadrants of each tree. On
each date fruit were evaluated for
percent and intensity of red color,

flesh firmness, soluble solids, titratable acidity, fruit
weight, and internal ethylene.

When the initial harvest was made on August 24,

Table 1. Effects of time of harvest and lengths of storage period on fruit
quality of Gala and Mcintosh apples.

Flesh Soluble
firmness solids
Treatment (lbs) (%)

Titratable

acidity

(meq/100 ml)

Harvest date (mean of both cultivars)

Sept. 15 13.5 10.8
Sept. 22 12.6 11.0
Sept. 29 12.5 11.6

6.4
6.3
6.5

Significance ** **

Evaluation date (mean of both cultivars)

Harvest 15.6 11.1
Oct. 25 12.8 11.3
Nov. 22 11.6 11.1
Dec. 14 11.5 11.0

7.9
6.5
6.1
5.1

Significance •• **

«*

Cultivar (mean of all harvest and evaluation dates)

Gala 14.6 11.7
Mcintosh 11.1 10.6

4.3
8.5

Significance •• *

•

Storage (mean of all harvest and evaluation dates)

Paper 12.9 11.2
Plastic 12.8 11.1

6.5
6.4

Significance NS **

" ,,NS Numbers within column and treatment grouping are signifi-
cantly different at odds of 99 to 1, 19 to 1, or not significantly different,
respectively.

Fruit Notes, Spring, 1990

100
80
60
40
20

Red color (%)

Oak
Mcintosh

100
80
60
40
20

U.S. Extra

♦ — • — •-

8/17 8/31 0/14 0/28 10/12 10/26 8/17 8/31 0/14 0/28 10/12 10/28

24
22

20
18
16
14

Flesh firmness (lbs)

12 1 —
8/17

16
14
13
12
11
10

Soluble solids (%)

8/31 0/14 0/28 10/12 10/26 8/17 8/31 0/14 0/28 10/12 10/26

Titratable acidity (meq/100ml)

-« — * — *-

200

150

100

nternal ethylene (ppm)

8/17 8/31 0/14 0/28 10/12 10/26 8/17 8/31 0/14 0/28 10/12 10/26

Figure 1. Changes in fruit quality parameters and characteristics of Gala and Mcintosh prior to, during
and after the normal harvest period: August 24 through October 19. A, red color, B, U.S. Extra Fancy;
C, flesh firmness; D, soluble solids; E, titratable acidity; F, internal ethylene.

Fruit Notes, Spring, 1990

Mcintosh had more red color than Gala (Figure 1).
Both cultivars continued to develop red color on succes-
sive harvest dates. Although Gala appeared to reach
the maximum red color of 80% in early October, Mcin-
tosh continued to develop red color to the last harvest
on October 19, when nearly 100% of the fruit surface
was judged to be red. The U. S. Extra Fancy grade was
denned for both cultivars as requiring 50% or more red
color, typical for the cultivar (although an official color
requirement has not yet been established for Gala).
Mcintosh developed typical red color earlier and
reached nearly 100% U. S. Extra Fancy before Gala.
However, by September 28, fruit from both cultivars
were nearly 100% U. S. Extra Fancy.

Gala fruit were firmer than Mcintosh on all har-
vest dates. Both cultivars had similar soluble solids
(sugar) levels when sampling was started, but Gala
accumulated sugars faster and ultimately had a signifi-
cantly higher sugar content. Titratable acidity of Mcin-
tosh was nearly twice as high as that of Gala on all
harvest dates. Acid content of fruit declined slightly
but not significantly for both cultivars over the 8-week
sampling period. Fruit internal ethylene concentra-
tions remained very low in all fruit on all harvest dates
through September 14, when increasing numbers of
Mcintosh fruit began producing large amounts of eth-
ylene. After September 14, Gala fruit produced ethyl-
ene but considerably less of it than did Mcintosh. The
pattern and rate of ethylene production in Mcintosh is
typical of many apple cultivars. The
rise in ethylene locates the exact time
of ripening and indicates a period
when harvest is appropriate. Since
Gala did not display this typical signal
of ripening it is not possible to com-
pare the time of ripening of Gala and
Mcintosh. However, based upon the
other quality parameters measured, it
appears that the time of ripening of
these cultivars is quite similar.

Storage and Taste Panel
Evaluation

of 10 apples each were placed in air storage at 32°F.
Fruit in the fourth bag, whether lined on not lined with
plastic, were evaluated at harvest for flesh firmness,
red color, soluble solids, and titratable acidity. A group
of apples from each harvest date that was stored in a
paper bag or in a plastic-lined paper bag was removed
from storage on October 25, November 22, and Decem-
ber 14 and flesh firmness, soluble solids, and titratable
acidity were determined. Fruit were peeled, sliced, and
subjected to a taste panel evaluation of between 24 and
32 individuals. Each taste panelist was asked on each
date to evaluate crispness, sweetness, acidity, and
overall rank of fruit from each of the 3 harvest dates
using a descriptive scoring test.

Gala fruit were firmer, had higher soluble solids,
and had lower titratable acidity than Mcintosh when
all harvest dates and all storage periods were consid-
ered (Table 1). With progressive harvest dates, soluble
solids increased, flesh firmness decreased, and ti-
tratable acidity remained unchanged for both culti-
vars. Flesh firmness dropped rapidly after harvest, but
the rate of loss slowed considerably in storage.

Gala was preferred to Mcintosh in taste tests when
all harvest dates and storage periods were considered.
Taste panelists rated Gala crisper, sweeter, and less
acid. The later the harvest date, the more the fruit were
preferred by taste panelists. The longer fruit were kept
in storage, the less taste panelists liked them.

Eighty fruit per tree were har-
vested from all quadrants of 3 Gala
and 3 Mcintosh trees on September
15, 22, and 29. On each datefruitwere
separated into 8 uniform groups of 10
apples each. Four of the groups were
placed in paper bags, and 4 were
placed in similar paper bags that were
lined with plastic. Three paper bags of
10 apples each and 3 plastic-lined bags

Per&ent^of initial weight

100
98

-$- Qala • papar

O Uelnloah • plaalle

90
9i

9 10/7 11/4 12/2 12/30 1/27 2/24

Figure 2. Weight loss of Gala and Mcintosh fruit in air storage
at 32°F in either paper bags or plastic-lined paper bags.

Fruit Notes, Spring, 1990

Water Loss in Storage

Uniform samples of approximately 3000 g each
were selected from each cultivar. Half of the samples
were kept in paper bags while the other half were
placed in plastic-lined paper bags. All samples were
weighed and then placed in air storage at 32°F. Bags
were weighed every 2 weeks until February 28, 1989.
Fruit were examined at each weighing date to deter-
mine if any shriveling had occurred.

Fruit stored in plastic-lined paper bags lost consid-
erably less weight than those in paper bags (Figure 2).
Gala stored in paper bags lost more weight in storage
than Mcintosh and they lost it more rapidly. If placed
in plastic-lined paper bags, fruit of both cultivars lost a
comparable amount of weight.

Golden Delicious, one of the parents of Gala, com-
monly are stored in boxes lined with plastic. It appears

that Gala will benefit similarly from storage in plastic
since weight loss and shriveling can be reduced. In
previous years shriveling was noted in October in the
storage but not until December in this investigation.
The summer of 1988 was the hottest in 50 years in
Massachusetts. Perhaps fruit developed a thicker cu-
ticle and less permeable wax under these stressful
conditions, which might have helped reduce water loss.

Conclusions

There was a strong preference for Gala by taste
panelists. Gala does not exhibit excessive preharvest
drop, and it is precocious and productive. We conclude
that Gala is a very promising new cultivar that appears
to be a viable alternative for growers who wish to
replace Mcintosh or to plant a cultivar that has a broad
customer appeal.

iSm iSm *J# •{« %£#
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Pomological Note:
Blueberry Cultivar Update

Dominic A. Marini

Cooperative Extension, University of Massachusetts

Dr. James Hancock, Michigan State University,
presented a talk on blueberry cultivars at the New
England Small Fruit and Vegetable Convention, No-
vember, 1989. Here I will outline some of his major
points.

Dr. Hancock discussed cultivars from a number of
different aspects. For flavor, Darrow, Patriot, and
Spartan are preferred in Michigan. Bluecrop, Patriot,
Darrow, and Spartan are of the largest size. Bluetta,
Bluejay, Patriot, and Spartan are the highest yielding
early cultivars, while Bluecrop, Blueray, and North-
land are the heaviest yielding mid-season cultivars.
Elliot is very late and very high yielding. Darrow,
Elliot, and Lateblue have the most resistance to
mummy berry, while Bluecrop, Bluejay, Coville, Jer-
sey, and Spartan have moderate resistance. Suscep-

tible cultivars include Berkeley, Blueray, Bluetta, and
Collins. Blueray, Lateblue, Northland, and Patriot are
very winter hardy, while Bluejay, Bluecrop, Collins,
and Jersey are hardy. Bluetta, Berkeley, and Coville
are the least winter hardy. Spartan blooms early and
thus is more likely to be injured by frost. The bloom
season of other cultivars is directly related to the time
of harvest

On the basis of these characteristics Dr. Hancock
recommends the following cultivars:
Early season - Bluejay, Spartan, and Patriot (blooms
very early and could be hurt by frost);
Mid-season -- Blueray, Bluecrop, and Rubel;
Late season - Jersey and Elliot (may be too late in
cold areas).

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Fruit Notes, Spring, 1990

Commercial Potential of Red Fuji in
New England

Duane W. Greene and Wesley R. Autio

Department of Plant and Soil Sciences, University of Massachusetts

The apple cultivar that is in greatest demand for
planting in the United States is Fuji, including its red
coloring sports. Interest and popularity of Fuji has
preceded an appropriate and thorough evaluation of its
commercial potential. Our first evaluation of Fuji was
presented in Fruit Notes 54(1):10. It is the purpose of
this article is to give an update of our experience
growing and evaluating fruit of a strain of Red Fuji.

We obtained our Red Fuji from the New York
Agricultural Experiment Station in Geneva, and we
believe that it is the Akifu #1 strain. We began
propagating it 4 years ago and have harvested fruit
from these trees for the past 2 years at the University of
Massachusetts Horticultural Research Center in Bel-
chertown.

Tree Characteristics

Fuji is a vigorous, nonspur tree (Table 1). It is a
diploid that blooms mid- to late-season. Fuji is preco-
cious, but it also shows signs of biennial bearing that
starts at an early age. It has a spreading growth habit
with good crotch angles. After 4 years Fuji/M.9 is at
least 30% larger than adjacent Marshall Mclntosh/M.9
planted at the same time.

Table 1. Fuji fruit and tree characteristics.

Fruit characteristics

Tree characteristics

Firm

Very vigorous

Crisp

Spreading

Very sweet

Good crotch angles

Slightly aromatic

Precocious

Pink-red color

Biennial

Subacid

Diploid

Medium size

Good flavor

Slightly rough skin

Exeptional storability

Ripens before Rome

Fruit Characteristics

Fuji fruit are firm, crisp, very sweet, subacid, and
slightly aromatic (Table 1). Fruit are round to oblate,
medium in size, with a roughened skin. The standard
strain of Fuji has a pinkish red blush over a yellowish-
green ground color. The red coloring strains have
much more red that ranges from a cherry red to a
darker burgundy maroon. The fruit has good flavor
which improves after a period of storage.

The most notable characteristic of Fuji appears to
be its unequaled storage potential. There is no other
cultivar that we can grow in the Northeast that main-
tains condition and high quality in storage like Fuji.

In 1988, we harvested Red Fuji on October 24,
when flesh firmness averaged 18.5 lbs (Table 2). After
22 weeks in regular storage, flesh firmness averaged
16.5 lbs. It was noted that firmness could be catego-
rized according to fruit ground color. Fruit that had
green or green/ye


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