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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 

Publication Information: 

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



The costs of subscriptions to Fruit Notes are $4.00 for United States 
addresses and $6.00 for foreign addresses. Each one-year subscrip- 
tion begins January 1 and ends December 31. Some back issues are 
available for $1.00 (United States addresses) and $1.50 (foreign 
addresses). Payments must be in United States currency and should 
be made to the University of Massachusetts. 



Correspondence should be sent to: 

Fruit Notes 

Department of Plant & Soil Sciences 

205 Bowditch Hall 

University of Massachusetts 

Amherst, MA 01003 



COOPERATIVE EXTENSION POLICY: 

All chemical uses suggested in this publication are contingent upon continued registration. These chemicals should be 
used in accordance with federal and stale 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, 
concerningthe 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 ofMassachuselts Cooperative Extension offers equal opportunity in programs 
and employment. 



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 




X 




Shoot length 




X 




Shoot number 




X 




Spur/shoot ratio 


X 






Shoot leaf size 




X 




Spur quality 


X 






Pruning time 




X 




Canopy light penetration 


X 






Return bloom 


X* 






Fruit set 






X 


Fruit yield (no. of fruit) 






X 


Fruit size 




X 




Preharvest drop 




X 




Fruit color & quality 


X 






Tree yield efficiency 


X 






•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. 



»$» •{» «.% *}* »S* 
*j* »j» «j» »f» «y» 



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 


CM 


RBLR 


LR 


LAW 


other 


Total 


1987 


Second-stage 


1.4 


0.0 


0.1 








0.0 


1.5 




First-stage 


0.7 


0.0 


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 


A 


Pheromone trtd*** 


28 


0.0 


leafroller 




Grower sprayed 


471 


0.5 


Red banded 


B 


Pheromone trtd*** 


4 


1.0 


leafroller 




Grower sprayed 


268 


2.5 


Lesser 


C 


Pheromone trtd*** 


10 


0.5 


appleworm 




Grower sprayed 


123 


0.5 


Lesser 


B 


Pheromone trtd*** 


35 


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 


YM 


pest to 

predatory 

mites 


WAA WAL 


PL 


ABLM 
ABLM PAR 


GAA GAAP 


1987 


Second-stage 


20 


4.0 


3.2 


3:1 


2 9 


17 


10 


.. 




First-stage 


13 


1.5 


2.3 


4:1 


2 5 


10 


14 


.. 


1988 


Second-stage 


12 


1.3 


1.2 


5:1 


3 27 


3 


11 35 


14 6.7 




First-stage 


11 


1.1 


0.1 


9:1 


4 18 


2 


11 23 


16 3.7 


1989 


Second-stage 


22 


3.0 


0.3 


6:1 


3 2 


5 


5 49 


32 30.7 




First-stage 


24 


2.3 


0.1 


10:1 


3 1 


4 


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 


IPM 


Pre-bloom oil* 




$19 


$19 


Insecticide*: 








April to early June 




$77 


$78 


Early June onward 




$57 


$0 


Miticide*: 








April to early June 




$5 


$5 


Early June onward 




$32 


$0 


Cutting down abandonee 


apple trees** 


$0 


$2 


Purchase, emplacement, 


periodic 






cleaning, and removal of 


apple 






maggot traps*** 




$0 


$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), 



8 



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 


CM 


RBLR 


LR LAW 


other 


Total 


1987 


Second Stage 


104 


0.6 





0.1 


. 


0.2 


0.9 




First Stage 


63 


0.8 





0.1 


- 


0.1 


1.0 


1988 


Second Stage 


101 


0.3 





0.1 


- 


0.0 


0.4 




First Stage 


53 


0.2 





0.0 


- 


0.0 


0.2 


1989 


Second Stage 


54 


1.2 





0.0 


0.3 


0.1 


1.6 




First Stage 


33 


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 




1 

8 
6 
1 

1 



9 
10 
2 
2 
1 
1 



5 
4 
4 
6 
6 
6 



31 
23 
59 
55 



11 

8 

47 

50 



*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- 



10 



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 



11 



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 



12 



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 


AF 


A fallacis 


1988 


June 


Second-stage 


15 


0.0 


15:0 






First-stage 


11 


0.0 


11:0 




July 


Second-stage 


40 


3.3 


12:1 






First-stage 


38 


2.6 


15:1 




August 


Second-stage 


21 


9.5 


2:1 






First-stage 


20 


5.2 


4:1 




September 


Second-stage 


3 


1.4 


2:1 






First-stage 


7 


4.8 


2:1 




Avg. for 












July, Aug., 


Second-stage 


21 


4.7 


5:1 




and Sept. 


First-stage 


22 


4.2 


5:1 


1989 


June 


Second-stage 





0.0 


0:0 






First-stage 





0.0 


0:0 




July 


Second-stage 


1 


0.0 


1:0 






First-stage 





0.0 


0:0 




August 


Second-stage 


1 


0.0 


1:0 






First-stage 


4 


1.5 


3:1 




September 


Second-stage 


38 


0.0 


38:0 






First-stage 


10 


0.0 


10:0 




Avg. for 












July, Aug., 


Second-stage 


13 


0.0 


13:0 




and Sept. 


First-stage 


5 


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 



13 



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 


AF 


A fallacis 


1988 


June 


Second-stage 


42 


0.0 


42:0 






First-stage 


15 


0.0 


15:0 




July 


Second-stage 


31 


5.3 


6:1 






First-stage 


33 


5.1 


6:1 




August 


Second-stage 


17 


1.8 


9:1 






First-stage 


20 


2.4 


8:1 




September 


Second-stage 


9 


0.5 


18:1 






First-stage 


12 


0.0 


12:0 




Avg. for 












July, Aug., 


Second-stage 


19 


2.5 


8:1 




and Sept. 


First-stage 


22 


2.5 


9:1 


1989 


June 


Second-stage 


32 


0.0 


32:0 






First-stage 


29 


0.0 


29:0 




July 


Second-stage 


69 


4.8 


14:1 






First-stage 


55 


3.0 


18:1 




August 


Second-stage 


51 


15.3 


3:1 






First-stage 


32 


11.4 


3:1 




September 


Second-stage 


25 


13.6 


2:1 






First-stage 


8 


11.5 


1:1 




Avg. for 












July, Aug., 


Second-stage 


48 


11.2 


4:1 




and Sept. 


First-stage 


32 


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 



14 



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* 












p 


atio of pest 




x\ 




Time of 




ERMor 




mites to 


Year 


sampling 


Block type 


TSM 


AF A fallacis 


1988 


June 


Second-stage 


6 





6:0 






First-stage 


1 





1:0 




July 


Second-stage 


10 


0.2 


50:1 






First-stage 


6 





6:0 




August 


Second-stage 


20 


0.7 


29:1 






First-stage 


13 


0.5 


26:1 




September 


Second-stage 


12 


0.2 


60:1 






First-stage 


21 


1.7 


12:1 




Avg. for 












July, Aug., 


Second-stage 


11 


0.4 


38:1 




and Sept. 


First-stage 


13 


0.7 


18:1 


1989 


June 


Second-stage 


25 


0.0 


25:0 






First-stage 


27 


0.0 


27:0 




July 


Second-stage 


25 


2.5 


10:1 






First-stage 


21 


3.3 


6:1 




August 


Second-stage 


18 


5.2 


3:1 






First-stage 


16 


2.5 


6:1 




September 


Second-stage 


28 


6.8 


4:1 






First-stage 


28 


4.3 


7:1 




Avg. for 












July, Aug., 


Second-stage 


24 


4.8 


5:1 




and Sept. 


First-stage 


22 


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 



15 



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 


AF 


1988 


July 


6 


14 


YES 


32 


5.5 






6 


14 


NO 


35 


3.1 




August 


6 


14 


YES 


19 


4.5 






6 


14 


NO 


18 


3.1 




September 


6 


14 


YES 


7 


1.4 






6 


14 


NO 


9 


1.1 


1989 


July 


4 


14 


YES 


63 


5.9 






4 


14 


NO 


61 


2.0 




August 


4 


14 


YES 


38 


15.7 






4 


14 


NO 


45 


11.1 




September 


4 


14 


YES 


16 


15.1 






4 


14 


NO 


18 


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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16 



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 



17 



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. 



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18 



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 



19 



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- 



20 



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. 



»T> «{• »t» »J* %{' 
»£» «J« «J% «j» •{* 



Fruit Notes, Winter, 1990 



21 



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 



12 



1 



8 



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. 



22 



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 

50 

40 

30 

20 

1 





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 



23 



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 





1 



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. 



24 



Fruit Notes, Winter, 1990 



Lbs./Acre 
After 7/23 



6 
5 

4 
3 
2 

1 





■■■■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 — ♦— ♦ 


II 


1 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 



:■::<>•.-:■.■ 



1 



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 



25 



Lbs./Acre 
per Year 
60 



50 
40 
30 
20 
1 



Captan 



EBDC 



No residue detected 



^j 



[ 



"Residue detected 1 



i 

FT 



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 




10 



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 



26 



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. 



•!# «$# %1* %I# *% 
#2* %"* *X* r i» *$* 



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 



27 



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 



3 



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 



28 



Fruit Notes, Winter, 1990 



1.50 



1.00 



3 



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 



29 




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 



FN 



01003 



Account No. 3-20685 



l&rr, i\ 

5 

r 



Fruit Notes 



^v 



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 



j 



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: 

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



The costs of subscriptions to Fruit Notes are $5.00 for United States 
addresses and $6.00 for foreign addresses. Each one-year subscrip- 
tion begins January 1 and ends December 31. Some back issues are 
available for $1.50 (United States addresses) and $2.00 (foreign ad- 
dresses). Payments must be in United States currency and should be 
made to the University of Massachusetts. 



Correspondence should be sent to: 

Fruit Notes 

Department of Plant & Soil Sciences 

205 Bowditch Hall 

University of Massachusetts 

Amherst, MA 01003 



COOPERATIVE EXTENSION 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 ** ** 


NS 


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 


" ,,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 




♦ — • — •- 



B 



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) 



10 



e 




-« — * — *- 



200 



150 



100 



60 



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 






96 






94 








-$- Qala • papar 




92 


- Otlt • pintle 
-©■ laelntoah • 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. 



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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