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FRUIT
NOTES

PREPARED BY
DEPARTMENT OF PLANT AND SOIL SCIENCES

COOPERATIVE EXTENSION SERVICE,
UNIVERSITY OF MASSACHUSETTS, UNITED
STATES DEPARTMENT OF AGRICULTURE AND
COUNTY EXTENSION SERVICES COOPERATING.

EDITORS
W. J. LORD AND W. J. BRAMLAGE

Volume 50 No. 1
WINTER ISSUE, 1985

Table of Contents

Fruit Notes Subscription

The Tree-Fruit Industry in the United Kingdom:
Changing to Survive

Pomological Paragraph-
Performance of I nterstem Trees

A Report on the 1984 Apple IPM Program

Pomological Paragraph—

Spur-type Trees Can Reduce Pruning Time by 60%

Reducing Winter Injury to Tree Fruits

Variables Influencing Size of Apple Trees,
and Suggested Tree Spacings

Bud Blast, Canker, and Dieback of
Young Apple Trees in Massachusetts:
A Progress Report

issued by the Cooperative Extension Service, E. Bruce MacDougall, Dean, in further-
ance of the Acts of May 8 and June 30, 1914; United States Department of Agriculture
and County Extension Services cooperating. The Cooperative Extension Service offers
equal opportunity in programs and employment.

FRUIT NOTES SUBSCRIPTION

To subscribe to FRUIT NOTES complete and mail the
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hers, please send a U.S. postal money order).

Wi 1 1 i am J . Braml age
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Make checks payable to: FRUIT NOTES ACTIVITY ACCOUNT

Send subscription form and check to: William J. Bramlage

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1985

THE TREE-FRUIT INDUSTRY IN THE UNITED KINGDOM*: CHANGING TO SURVIVE

William J. Rramlage, Department of Plant and Soil Sciences,

and

John Turnbull, National Fruit Adviser, ADAS, East Mailing Research Station,
Kent, England

To understand the forces that are producing radical changes in the tree-
fruit industry in the U.K., it is necessary to recognize England's
geographical and political position. Geographically, the industry is
located at about the same latitude as Newfoundland, which places it at the
northern edge of a climate that will support commercial production. Many
common varieties of tree fruits cannot he grown commercially in this
cl imate.

Politically, the U.K. belongs to the European Economic Community (EEC),
which allows goods to move into the U.K. duty-free from other EEC
countries. Since some of these countries, especially France and Italy,
have climates much more suitable for tree-fruit production, European fruits
can often be sold on British markets at lower prices than for those grown
in the U.K.

The U.K.'s entry into the EEC put its tree-fruit industry in jeopardy
and resulted in major changes within the industry. Pint of the story can
be seen in the industry's statistics. Over the past 1") years, total apple
acr-'age has declined 30%, pear acreage 'las declined ?.S . and cherry acreage
has declined 50%. For plums ■'he decline is even more startling if you look
back further: acreage in 198? was only 30% of that in 1957. Approximate
acreage for these crops in 1983 was: apples, fi?,400 acres; pears, 10,000
acres; plums, 8,750 acres; cherries, 3,050 acres. Peaches arp not grown
commercially in the U.K.

These figures may imply that this is a failing industry, but the U.K.
fruit industry is not dying. It is adapting to new conditions to shedding
itself of unwanted fruit or economically nonviable orchards, and adopting
new methods to increase productivity and efficiency. These changes have
been greatest for apples, which represent the strongest as well as the
biggest component of the industry. Total apple production in 1982 was
about ?? million bushels, and the ways in which apple production has
changed will be emphasized here.

Because of the EEC competition, the U.K. must produce what its market
wants and the rest of the EEC cannot produce more efficiently. For apples
and pears, this has meant concentrating production on a handful of good-
quality varieties, all of which have been grown for more than 100 years.

*The United Kingdom (U.K.) consists of England, Scotland, Wales, and
Northern Ireland, although most of the tree fruits are grown in England.

-2-

Cox's Orange Pippin (Cox) now makes up 5fi% of the U.K. dessert apple pro-
duction, while Bramley's Seedling (Bramley) represents 80% of the culinary
apple production and over 40% of the total apple production. (Note:
Bramley's are sold for processing, but there is no major apple processing
industry in the U.K. Culinary apples are ones grown specifically for
cooking and to a large extent are sold directly to the consumers).

For pears, 73% of the production in 198? consisted of a single variety.
Conference, with most of the remainder being accounted for by Doyenne du
Cornice. These three varieties -- Cox and Bramley apples and Conference
pears -- are ones sought by the U.K. market and not grown in Southern
Europe. The industry will likely concentrate still further on the produc-
tion of these varieties.

The past 10 years have seen drastic changes in the way English apples
are produced. The traditional orchard of large, widely spaced trees
growing on a carpet of grass has virtually disappeared as a viable commer-
cial entity. The framework of the trees was first drastically lowered with
a chain saw, and strips of grass under the trees were killed with her-
bicides. Later, these trees were replaced by small, staked trees planted
more intensively and often grown on bare soil. A driving force in these
changes has been the inherently low productivity of Cox trees, which makes
increased productivity per acre critical to economic sii^vival. It is esti-
mated that the average Cox orchard produces 225-250 bushels per acre (but
this includes nonbearing trees), that 500 bushels per acre are needed for
economic viability, and that '■his figure will soon rise to 750 bushels per
acre. (Most-efficient producers are already obtaining these yields).

To achieve such yields intensive production is required. It is easy to
look across the English Channel to the Dutch apple industry and try to
adopt their techniques. However, 66 to 70% of Dutch fruit farms have less
than 10 acres of trees, while 80% of the U.K. fruit farms exceed 25 acres
of trees. Thus, most English growers cannot afford the detailed attention
to tree development that is given by Dutch growers and U.K. orchards are
developing differently from better-known Dutch orchards.

The most common rootstock for English Cox apples is MM106, although M9
is being used increasingly. For Bramley, MM106 was also widely used but
its use is now declining and M26 and M9 are becoming increasingly popular.
Single-row planting at a density of about 300-400 trees per acre is most
common, with trees trained to a central leader but restricted to no more
than 10 to 15 feet (or preferably less) in height.

There is considerable interest in 3-row bed plantings, trained to the
North Holland spindle-bush system. However, there are some clear limita-
tions to its successful adoption. fl) The size of most English orchards
limits attention to development of individual trees. (2) Many orchards
are frost-susceptible, and if a crop is lost or severely reduced by frost,
the high vigor produced that year makes the growth much harder to control.

(3) Many orchards will requi ree irrigation because their soils are too
shallow and susceptible to drought. Therefore, for the forseeable future
most English orchards will probably continue to employ single-row central
leader production systems, while only the very specialized producers will
adopt the more intensive bed systems.

Most U.K. planting stock is certified virus-free, true-to-name, and
true-to-clone. It is produced under the "Plant Health Protection Scheme"
in which virus-free "nuclear stock", or mother trees, are produced at
government laboratories and provided at nominal cost to "Special Stock"
nurserymen who mass-propagate them for commercial sale. Growers can buy
different grades of trees, the grade and price representing how far removed
the trees are from the original nuclear stock. These virus-free trees are
up to 30% more productive than virus-infected stock.

Orchard restructuring was boosted in 1QR2 when the British Government
introduced its "Orchard Replant Scheme" under which growers can be sub-
sidized for orchard replanting. The plan is linked to an EEC prohibition
against expanding the area devoted to apple production, since apples are
overproduced in EEC countries. fEach year EEC countries dump under subsidy
twice as many apples as are produced in the U.K.).

Under the plan a grower can be subsidized for 22.5% of his capital
investment in a new orchard if (1) he can provide evidence that he has
first grubbed an area of equal size, (?.) he uses only certi fied-vi rus-free
trees, and (3) he plants only eligible varieties: Cox, Rramley, and
Spartan apples, and Conference and Cornice pears. (However, 25% of the
planting can be of other varieties inserted as pollenizers.) This
replanting subsidy can increase the 32.5% of the total capital investment if
the entire farm has a development plan acceptable under EEC policies. This
plan has provided a big boost to changeover of unprofitable orchards.

The appropriate soil management system for U.K. orchards has become a
matter of controversy. The standard system over the past 20 years has been
the use of herbicide strips under the trees, leaving grass alleyways. In
recent years pomologists have been advocating application of herbicides to
the entire orchard floor, and many orchardists now employ this "overall
herbicide" soil management system. Overall herbicide usage can increase
soil acidity, lower soil nitrogen level, and produce phosphorus deficiency
in apples, which increases storage losses of fruit. It can also cause soil
erosion, although this is not a serious problem in most relatively-flat
English orchards. The biggest concern is still another effect -- loss of
soil structure. Soil compaction from rain and machinery can cause soil
structure to collapse and cause a soil cap to form, which reduces water
infiltration. Failure to return fresh organic matter can deplete soil
organic matter, and reduction of the earthworm population can reduce water
infiltration. On the other hand, overall herbicide usage increases yield
10 to 20%, and the increase in fruit size is especially welcome for Cox,
which are often small. Therefore, considerable effort is being applied to
deal with the problems created by overall herbicide usage, rather than
abandoning it.

-4-

Growth regulators are less extensively used in the U.K. than in U.S.
orchards. For fruit thinning carbaryl is used almost exclusively -- when
thinning is needed. Alar* is used hardly at all because it has adverse
effects on size and storage quality of the fruit, especially Cox. In most
cases no alternative stop-drop spray is used because red color is generally
not important for English apples. There is essentially no use of Promalin*
in the U.K. but some growers are using a gibberellin mixture to improve
fruit finish of Cox. There is strong interest in potential use of the new
growth regulator PP333 (paclohutrazol ) to suppress vegetative growth as an
aid to controlling tree vigor in intensive production systems.

Integrated Pest Management (IPM) is established in the tree fruit
industry. Its emphasis is on allowing beneficial predators to build up in
orchards, and private advisers provide guidance to growers on pesticide
usage. Mildew, scab, and canker are the most serious disease problems, and
red spider and caterpillars are the most troublesome insects on apples.
Rust mite and psylla are the leading insect problems on pears. Fireblight
is an increasing worry, especially because it can build up in the hawthorn
hedges that are very common in most apple growing areas.

Calcium chloride sprays are very widely used, primarily to reduce bitter
pit of apples, and many growers also apply phosphorus sprays early in the
season to reduce the occurrence of disorders during apple storage.'

Harvesting is done with local labor. The small tree size that is main-
tained allows picking from no more than short ladders. Pickers are usually
paid a daily rate plus a bonus for picking skill.

Storage, packaging, and marketing of apples and pears is highly centra-
lized. Although some growers operate independently, most contract with
large privately owned companies to store and pack their apples and pears.
This centralization has aided the adoption of highly sophisticated storage
technology, which in turn had had an enormous impact on length of the
market season and quality of the stored fruit. Fruit analysis is used to
determine the storage potential of fruit and is widely used. The analysis
is carried out by the advisory service A.D.A.S. /M.A.F.F. , and is paid for
by the growers.

The costs of producing fruit in England were revealed in an economic
analysis conducted in 1Q8?. To establish a typical orchard of Cox on M9,
trees cost the equivalent of about $3,000 and stakes about $1,600 per acre.
Annual costs of an orchard in full production were estimated to include
$ 450 for pest control, $ 150 for pruning, $ 75 for herbicides, and $ 50
for fertilizer. In contrast, the cost of storage (including prestorage
treatments) was $?,500 per acre. Thus, it was concluded that 70% of the
annual cost of producing these fruit was incurred after the fruit left the
tree! A high packout rate is essential for financial survival.

*Irade name

-5-

Little has been said here about pear, plum, and cherry production
because these crops have not undergone the technological evolution that has
occurred during the last decade for apple production. However, mention
should be made about the decline of the stone fruit crops illustrated in
the statistics quoted earlier.

Decline has occurred for several reasons. One is EEC competition, which
places fruit from Southern Europe on the market early at competitive
prices. Plums have also been devastated by loss of demand for processed
products. (Purchases of fresh fruit and vegetables have increased greatly
in the U.K. during the past 20 years). Another problem is severe infesta-
tions from plum pox -- a virus disease -- and bacterial canker, which have
been difficult to contain. Finally, bird damage has caused severe losses;
at present, the most common control measure is use of mechanical scare
devices, which lose effectiveness quickly.

The British cherry and plum industries remain in jeopardy.
Nevertheless, there is hope that effective size-controlling rootstocks will
be found -- some promising cherry rootstocks are presently being planted --
and that growth regulators, especially PP333, will suppress tree vigor so
that intensive production methods can be employed to reduce unit costs.

The U.K. fruit industry still has its problems but there is a deter-
mination to tackle them and meet the challenge of competition from abroad.
Despite economic constraints there is increasing collaboration within the
industry, particularly in regard to research, development, and marketing.
This cooperation is helping to streamline the U.K. fruit industry, which is
essential for its longterm wellbeing.

POMOLOGICAL PARAGRAPH

Wil 1 iam J. Lord
Department of Plant and Soil Sciences

Performance of Interstem Trees . It is becoming increasingly apparent that
unless well -grown trees are obtained from the nursery and/or unless they
receive a high level of management in the grower orchard, the growth and
early productivity of interstem trees are apt to be disappointing. Also,
we are finding it difficult to maintain a strong central leader on
interstem trees without staking. Under the management that is provided in
most of our orchards, we need trees on rootstocks that will produce satis-
factory growth and yields in the absence of optimum growing conditions and
care. Thus, interstem trees are not recommended for most orchards.

A REPORT ON THE 1984 APPLE IPM PROGRAM

W.M. Coli and R.J. Prokopy, Department of Entomology
University of Massachusetts

n.R. Cooley and W.J. Manning, Department of Plant Pathology
University of Massachusetts

and

G. Morin and R.A. Spitko, New England Fruit Consultants,

Lake Pleasant, MA

Fiscal 198^ saw a continuation of the scaled down Apple IPM program,
the focus of which is grower education and electronic information transfer.
Grower interest in and support of IPM continued to be excellent. Private
sector IPM scout/consultant service continued to expand in response to
grower demand, evidence, we believe, of substantial grower commitment to an
extension IPM approach. In addition, financial contributions to continua-
tion of an apple IPM program and specialist position totalling $2,750 were
received from 5 growers, representing about 18% of the state's tree fruit
acreage. We wish to thank all contributing growers for their continued
support of IPM educational efforts.

Entomology and Plant Pathology Extension faculty and staff presented 4
IPM training sessions in each of 3 regions, bringing growers up to date on
new pest monitoring techniques and management strategies. These sessions
allowed attendees to receive pesticide applicator recertification credits,
and were well attended. Also, Ron Prokopy and Bill Coli presented two
grower training sessions in the Hudson Valley of New York, also for recerti-
fication credits.

Program staff performed weekly scouting in 7 orchard blocks in Stowe,
Sterling, Wilbraham and Ashfield. Additional orchard visits were performed
to address specific insect/mite or disease problems on request. Numerous
telephone inquiries relating to pest control were also received and
addressed .

During 1984, Susan Butkewich and Ron Prokopy evaluated fS newly labelled
or experimental pesticides for effectiveness against a range of apple or
pear insect and mite pests at the Hort. Research Center (HRC). They also
studied time of tarnished plant bug (TPB) injury initiation and the most
effective time of pesticide application against TPB. Further, they investi-
gated plum curculio responses to odor of developing fruit and potential
egglaying sites. Tom Green and Ron Prokopy analyzed apple blotch leafminer
adult behavior in time and space in nature, while Martin Aluja and Ron
Prokopy examined maggot fly responses to interacting synthetic fruit odor
and visual trap stimuli.

Acknowledgements : We wish to thank Ms. Kathleen Leahy for scouting and
data-entry assistance, and Dave Lynch, Dana Clark, Jesse and Wayne Rice,
Bill Broderick, Rich Smith, Elmer Fitzgerald Jr., Ed. Roberts Sr. and Tony
Rossi for their cooperation.

During 1984, Bill Manning and Dan Cooley monitored Venturia inaequalis
(apple scab) inoculum levels, delivered infection potential information to
growers via twice weekly pest alert messages, monitored orchards for new or
unusual disease outbreaks (e.g., blossom end rots, a canker and dieback
disease, and fungicide resistant V. inaequalis strains), and made control
recommendations for specific disease problems on request.

The V. inaequalis inoculum monitoring and pest message program involved
several people from Bill Manning's laboratory and ran from April 1 to June
15. In addition, adaptive studies of apple fungicide use were performed.
Tests included an extended kick-back fungicide, a reduced rate of a standard
fungicide (Captan) and a new, non-toxic polymer, all of which have the
potential to reduce overall fungicide use in the state.

Regional Fruit Speicialists Jim Williams and Karen Hauschild either
performed weekly scouting or collected overwintered scab-infested leaves for
laboratory assays of pathogen developmental state. Other information
collected by private sector scout/consultants was also used to develop
twice-weekly pest status messages, sent by computer from the University to
regional specialists who then sent this information to growers in newsletter
and 24 hour "code-a-phone" hotline formats. From early April through early
bloom, utilization of the "code-a-phone" increased by about 20% over 1983.
Unfortunately, technical problems caused failure of Jim Williams' machine
between May 15 and 21, and again between June 11 and July 13. Periods of
peak calling were associated with the end of primary scab season and times
when spray decisions were being made for Plum curculio, Apple maggot fly and
second generation Leafminer.

A major goal was achieved with the publication of a 41 page manual
entitled "Integrated Management of Apple Pests in Massachusetts and New
England." This bulletin was funded in part by fruit grower contributions
and by a grant from USDA. The manual contains nearly 100 color photographs
for field identification of all major insect, mite and disease pests of New
England. Also included are sections on Vertebrate pest management and
Integrated ground cover management. Copies are available for $4.00 each
from :

Bulletin Center

Cottage A

University of Massachusetts

Amherst, MA 01003

Insect/Mite pest status and harvest injury, 1984 . Table 1 contains results
oT private sector and extension IFM harvest surveys in 1984, and compares
these to statewide averages of insect harvest injury in IPM blocks for
1978-1983. Overall pest injury appears to be down in 1984 compared to the
6-year averages, in spite of substantial rainfall during the early portion
of the pest control season.

Once again, the tarnished plant bug (TPB) caused the highest percent
fruit injury detected in on-tree harvest surveys. However, 1984 TPB injury
was about half of previous amounts. Most TPB injury we observed was one or
two "dimples" in the fruit calyx, rather than more extensive "scabbing" seen

on other occasions. These findings, combined with earlier work in Mass. and
New York showing that only about 10% of on-tree TPB injury results in fruit
downgrading, indicate that fruit culling or downgrading because of TPB
injury should be of relatively little economic importance this year.

Some possible reasons for the above include: improved monitoring of
TPB activity, improved timing of TPB control sprays and/or substantial use
of pre-bloom pyrethroid sprays (87% of monitored private sector IPM blocks)
against TPB. Further, most TPB trap captures in Extension-monitored blocks
were at or before tight cluster, when most TPB injury is expected to be in
the form of aborted/abscised buds rather than fruit injury.

European apple sawfly (EAS) injury was down somewhat, on average, com-
pared to 6-year levels. This was in spite of the finding that many growers
are delaying traditional petal fall insecticide sprays until plum curculio
entry into commercial blocks. Some blocks experienced elevated EAS injury
levels, perhaps because of pre-bloom insecticides, which normally provide a
measure of EAS control, were less effective in this regard in 1984 due to
excessive rainfall and early (about tight cluster) application of pre-bloom
sprays.

San Jose scale (SJS) injury was also down in 1984. Improved monitoring
of problem blocks and increased use of chlorpyrifos (Lorsban*) for SJS
control were factors in this observed drop in injury. Diazinon continues to
provide excellent SJS control as well. Use of Penncap-M* against SJS was
down this season; only 5 permits were issued for its purchase and use. We
expect that these latter compounds will continue to have a role in SJS
control programs, particularly with regard to second generation SJS, when
Lorsban* use may not be possible (e.g. 28 day pre-harvest interval, and last
2 uses in a season may not be closer than 21 days apart).

Plum curculio (PC) injury was up in 1984, including both early-season
injury and late season feeding injury as well. Frequent rainshowers during
the period of PC migration into commercial blocks may have reduced insec-
ticide residual protection, allowing higher PC injury, especially on block
peripheries. Late season PC feeding was particularly evident where early
season control was inadequate. Some growers experimenting with Lorsban* for
PC control experienced a relatively high amount of injury, further con-
firming earlier indications that this material should not be relied upon for
PC control .

However, Lorsban* was very effective against green fruitworm (GFW)
populations, which earlier years' results indicated may be resistant to
organophosphate insecticides. The resulting improved control probably
accounts for marked decreased in GFW injury in problem blocks.

Apple maggot fly (AMF) injury was low on average once again, perhaps
due to improved monitoring and timing of control sprays. First AMF capture
on red spheres was July 7 in an apparently early developing Ashfield block.
Peak AMF captures, as in previous years, occurred in August, with substan-

*Trade name ~~~

-tial activity detected into October in some blocks. Trap captures
averaging more than 4 per trap were recorded in the above-mentioned Ashfield
block at the end of September, with 13 AMF captured in one week, on a red
sphere placed in a Golden Delicious tree. This offers further evidence of
the importance of continued AMF monitoring, and control measures where
appropriate, even after Mcintosh harvest has begun.

Table 1. Percent insect-injured fruit in on-tree surveys of 38 commercial
orchard blocks, 1984, compared to IPM orchard harvest injury
averages, 1978-1979.

19841

1978-1983

Insect Pest

% injury

Tarnished plant bi

0.95

1.78

European apple sa^^

/fly

0.27

0.40

Plum curcul io

0.56

0.49

San Jose scale

0.32

0.45

Leafrol lers

0.01

0.03

Green fruitworms

0.02

0.07

Apple Maggot fly

0.01

0.07

Other

0.03

Total injury

2.14

3,32

^Combination of two sets of data. (1) Data from 31 blocks receiving private
IPM scout/consultant services from New England Fruit consultants. Samples
consisted of 50 fruits per tree on 6-20 trees per block. (2) Data from 7
other commercial blocks collected by Extension IPM staff. Samples con-
sisted of 100 fruits per tree on 4-10 trees per block.

Mites continue to be a major pest problem for many fruit growers.
Amblyseius fal lacis mite predators were again not an important biological
control agent, having been detected too late in the season (mid-August) and
in numbers too low to have major effect. No clear reason for this phenome-
non is evident, although continued use of carbamate of pyrethroid insec-
ticides, or "burnout" fungicides, harmful to A^ fal lacis may have been a
factor in some blocks. However, A. fallacis numbers were also low in Hort.
Research Center blocks which never received large scale use of such
materials .

Another interesting observation was the presence of early (late June)
and severe two spotted mite (TSM) problems at several sites. Although no
single factor can be pointed out which completely explains this occurrence,
use of insecticides, fungicides and herbicides which are toxic to mite pre-
dators may be one answer.

Ironically, grower success in controlling European red mite (ERM) may
offer another possible explanation. ERM overwinter as eggs on tree bark,
while TSM overwinter as adults in groundcover and at the base of tree
trunks. As a result, oil sprays may adequately control early ERM outbreaks

-10-

while having little or no effect on TSM. Further Dr. Rick Weires in New
York has found that miticides differ to the extent that they provide control
of the two mite species. For example, Kelthane*, in one test, had little
effect on TSM while its effect or ERM is excellent in many cases. The net
result may be that TSM are free to expand and fill an ecological niche
vacated by the control of "resident" ERM populations.

An interesting finding was the presence of numerous TSM in the carmine
(bright red-orange) phase in the calyx of Red Delicious apples at the HRC.
The observed mites were found during the course of a harvest survey, and
were all adults (TSM overwinter as adults) and were associated with substan-
tial silken webbing. TSM in the carmine phase have been commonly observed
in Ontario and New York in the past, but this is our first observation of
such colored forms in Massachusetts. Positive identification of this insect
was confirmed by personnel at Beltsville, Maryland to eliminate the possi-
bility that these mites were the McDaniel spider mite, a pest of tree fruits
on the West Coast but not known to exist in the Northeast.

Whatever the cause of observed TSM outbreaks, mite control is clearly
not getting any easier, particularly when one considers apparent (and docu-
mented in certain areas) resistance of ERM to certain miticides. Ors.
Reissig and Weires in New York report preliminary suggestions that some
insecticide/mite interaction exist, whereby spraying of certain pesticides
may actually enhance mite population increases directly (not indirectly, as
by killing predators ) .

Experience in 1984 reinforces our belief that multiple application of
low rates of miticide early in the season (PF-2nd cover) in problem blocks,
particularly when combined with thorough oiling, may provide excellent,
season-long mite control.

Leafminers (LM) were only occasionally a problem in Massachusetts, with
most growers achieving excellent LM control using endosulfan, oxamyl , metho-
myl or pyrethroid insecticides. In one instance, for example, methomyl
applied to ?nd generation LM sap-feeding mines (<10% of mines in tissue
feeding stages) above our provisional ETL resulted in greater than 94% kill,
and completely arrested that generation.

Red visual traps for LM monitoring were again useful. Trap captures
of overwintering generation LM indicated no need to treat for LM in 5 of 6
monitored blocks. In 3 cases, grower use of pyrethroids in the remaining
orchard blocks was unnecessary. Growers are urged to rely on LM monitoring
to determine the need for treatment so as to avoid unnecessary use of
phyrethroids.

Outbreaks of other pests such as white apple leafhopper and wooly apple
aphid were noted at a few scattered sites. A noteworthy observation was
detection of noticeable amounts of fruit injury at the H.R.C., caused by
Eye-spotted budmoth (ESB), Injury from ESB normally consists of 2-3
"stings" resembling those caused by small codling moth larvae and typically
hidden under a leaf webbed with silken threads to the side of fruit. (ESB
is in the same entomological "family" as codling moth - the Olethreutidae.
However, ESB larvae are quite distinct in appearance, with a shiny dark
brown head and thoracic shield with a dull, reddish-brown body).

-11-

Disease Injury . In general, apple scab pressure was extremely high this
year. Growers who used regular contact fungicide applications, with limited
combinations of either Cyprex or Benlate had good control if they maintained
good coverage going into infection periods. Funginex plus a contact fungi-
cide applied 3 days or less after an infection period also worked very well.
Most growers applied from 7 to 10 fungicide sprays during primary scab
season, which lasted from April to June 10 (exact dates depended on the
location). Fortunately, during the prolonged rain around May 30, most areas
were past the period of maximum ascospore pressure. However, extensive scab
was evident in many commercial blocks, requiring repeated eradicant sprays
to prevent spread of secondary inoculum to fruit.

Blossom end rot incidence was higher than normal. The two organisms
associated with this year's outbreak were Sclerotinia and Botrytis , two com-
mon end-rot fungi. As usual, most infected apples had dropped by
mid-August .

This year, the first case of benomyl -resistant scab was confirmed in
Massachusetts. The grower who developed the problem had been involved in
testing the compound early in its development. He has used benomyl alone,
and benomyl combinations for over ten years.

Plans for 1985 . It appears that funding for Extension programming in
Apple IPM wil 1 be down somewhat from 1984 levels. Inspite of this, we plan
to expand Extension's monitoring program to include blocks in the Granville
area, presently not being scouted by Extension or private sector scouts
(other than some grower scouting).

As in 1984, the purpose of this and other scouting in 1985 will be to
develop the twice weekly pest status messages, rather than provide a
scouting and grower advice service as had been the case during the pilot
program phase.

Growers interested in obtaining sector IPM scouting/consulting services
are encouraged to contact the individuals listed below.

Boston IPM, Inc.

242 Cayenne St.

W. Springfield, MA 01089

413-736-8404

New England Fruit Consultants

P.O. Box J.

Lake Pleasant, MA 01347

413-367-9678

As in 1984, Extension faculty and staff will continue to provide IPM
training to update growers on insect/disease biology and in latest develop-
ments in monitoring techniques, action thresholds, and appropriate control
strategies.

-12-

In addition, orchard visits will be performed as needed or by request
to address specific problem areas. Growers who feel they have experienced
control failures due to suspected pesticide resistance (re: Mites, fruit-
worms, apple scab, leafhoppers, etc.) in 1984, are encouraged to contact
appropriate extension workers in advance of the 1985 season.

Finally, we continue to welcome grower contributions large or small, to
a continued Extension IPM effort. Such contributions will enable us to pro-
vide an ongoing IPM educational effort, despite reduced Federal funding for
Apple IPM.

POMOLOGICAL PARAGRAPH

William J. Lord
Department of Plant and Soil Sciences

Spur-type Trees Can Reduce Pruning Time by 60% . Pruning apple trees is very
time consuming and may be the second largest cash cost for producing the
crop of apples. It is known that spur-type trees require less pruning than
non-spur trees of the same cultivar and age. However, we were interested in
actually recording the difference in time required to prune mature non-spur
and spur Delicious trees at the Horticultural Research Center (HRC) in
Belchertown, MA.

Table 1. Time required to prune non-spur and spur-Delicious trees in 1980
and 1981.*

Delicious

Growth

Time

size

■ (ft.)

Time/tree to

prune(min.)

strain**

habit

Ht.

Spread

1980

1981

Gardiner

Non-spur

13.3

18.8

13.8

19.5

Richared

Non-spur

12.5

18.5

13.7

17.8

Bisbee

Spur

11.6

13.3

3.8

5.2

Sturdeespur

Spur

12.0

13.8

4.8

8.2

*Trees pruned by Richard Clark of the HRC.

**Trees planted in 1964.

In Table 1 it is obvious that the spur-type trees were much smaller
than the non-spur trees. This fact plus the presence of fewer lateral
branches and watersprouts on the spur-type trees reduced the overall pruning
time for the 2 years by 60% on these type trees in comparison to the non-
spur trees. Thus, it appears that the reduction in pruning time on spur
trees should more than compensate for higher tree numbers/acre in plantings
of spur trees in comparison to non-spur trees.

-13-

REDUCING WINTER INJURY TO TREE FRUITS

W. J. Lord, Department of Plant and Soil Sciences

Pomologists in the early 1900 's considered winter injury to roots to be
a major problem of tree fruit production in northern growing areas.
Nevertheless, root-kill of fruit trees apparently has occurred only twice in
Massachusetts during this century. Reportedly, it occurred during the
severe winter of 1903-04 and it did occur in the "open-winter" of 1978-79.
Much more frequent in Massachusetts is injury to apple tree trunks asso-
ciated with winter freezes or early-winter pruning.

Two types of damage occur to trunks of fruit trees. The first occurs
in midwinter at the time the low temperature is encountered. The tissue in
the trunk contracts unequally and the trunk simply cracks open (Southwest
injury). The second type is actual death of the cambium layer in the trunk.
In the spring xylem layer swells but the cambium has not laid down new cells
for expansion. The bark splits away from the trunk as a result. The latter
type of damage, which is generally associated with early pruning, causes
more trouble since it involves actual death of tissue.

Southwest injury on both apple and peach trees can be reduced by appli-
cation of white latex paint to the southwest side of the tree trunks
including the base of the lower scaffold limbs. Use only latex water
soluble paint. Do not use oil or lead-base paints soluble in paint thinner
or turpentine because they can injure trees. Whitewash, a mixture of lime
and water, can be substituted for white latex paint, but durability is poor
and it may not last through the winter.

A delay in vegetative maturity (the physiological stage where deciduous
fruit trees cannot be forced to resume growth if defoliated) will delay
acclimation to low winter temperatures. Factors which delay or prevent
tissue maturity and cold acclimation include high nitrogen nutrition, late
cultivation and irrigation, early defoliation, heavy cropping, not picking
fruit on trees, and early pruning (before Christmas).

Rate of decline in temperature during the Fall can affect cold
resistance even though the same minimum temperature is obtained. A slow
decrease allows acclimation to occur, whereas a rapid decrease reaches a
level too low too quickly for acclimation to occur. Optimum temperatures
for acclimation are 25° to 30° F. Keep a record of minimum and maximum tem-
peratures, beginning November 1. Delay pruning until February if there have
not been 25 days with minima of 28° F or lower by December 25. Do not prune
within 10 days following maxima of 55° F or more that occur before
Christmas.

Pruning immediately prior to a freeze greatly increases injury to the
tree. The fresh cut apparently stimulates cellular activity and/or creates
a strong sink (attraction) for growth hormones, both of which deharden the
tissue. Therefore, listen to weather forecasts and stop pruning if a severe
cold front is on its way. Prune old apple trees first and do not prune
young trees before late February. Leave for late February and March the
pruning of all trees that bore especially heavy crops, and those that were
weak or had reduced leaf surface for any reason.

.14-

VARIABLES INFLUENCING SIZE OF APPLE TREES, AND SUGGESTED TREE SPACINGS

William J. Lord, Department of Plant and Soil Sciences

Apple trees on size-controlling rootstocks (compact trees) can produce
more bushels of U.S. Extra Fancy grade fruit per acre and reach maximum pro-
duction at an earlier age than larger trees because of better exposure of
foliage and fruit to light and bearing surface and more bearing surface per
acre. Unfortunately, the increase in productive leaf surface and/or early
yields frequently are not as great as would be expected because of influen-
ces of soil and management (includes supporting leaders) on tree size and
tree spacing.

In this article we list some of the variables that influence tree size
and give examples of the effects of these variables based on measurments at
the Horticulture Research Center and grower orchards, and observations in
pruning trials (Table 1). These illustrations show why it is extremely dif-
ficult to select the correct tree spacing.

We have learned that, under our conditions, very close tree spacings
generally are not satisfactory in Massachusetts because of tree crowding
problems. In contrast, trees in many plantings on M26 have failed to fill
their allotted space, and leaf surface per acre is further reduced because
of the failure to support the leaders. The writer recognizes that it is not
possible to select perfect tree spacings because of the variables influenc-
ing tree size. Nevertheless, the guide in Table 2 may prove useful since it
represents our experience over many years.

We have allotted an 8 foot alley for orchard travel, with some excep-
tions for trees on M9 rootstock. Reducing the between-row spacing by 2 feet
will increase tree number considerably but unless smaller equipment is
available a 6 foot alley may be too restrictive for orchard operations.

"Mark", a recently released rootstock will create considerable commer-
cial interest. Our very limited data indicate that Mark may produce a tree
slightly larger than M26. For trees on Mark we tentatively suggest allowing
2 feet more spacing in the row and between rows than suggested for trees in
Table 2 on M26, M9/111 or M^/infi.

-15-

Table 1. Variables influencing apple tree size and tree spacings and examples of
the effects of these variables.

Variable or Variables Example of effect of variable

Soil 1. In an experiment with young Mcintosh trees on 10 dif-

ferent soils, tree size differs as much as 50% among
sites.

Rootstock 1. Mcintosh on M7A may be 55-75% as large as when on a

seedling tree.

Tree training l<t soil 1. Mature Red Prince Delicious trees on M26 rootstock in

one orchard averaged 15.7 feet in height and 17.2
feet in spread. In another orchard, trees of the
same cultivar and on the same rootstock averaged 8.5
feet in height and 10 feet in spread.

Cultivar 1. Mature Cortland and Golden Delicious trees on M7

prior to dormant pruning averaged 23.6 ft and 16.8 ft
in spread, respectively.

Strain 1. Mature non-spur Delicious and spur Delicious on M7

prior to dormant pruning averaged 21 feet and 15 feet
in spread, respectively.
2. Mature Macspur and Rogers Mcintosh on M7 had similar
tree spread because of variability among Macspur.
"True" Macspur had 3 feet less spread than Rogers
Mcintosh.

Strain/rootstock 1. There is less difference in tree size between a spur

and non-spur strain of the same cultivar when they
are on weaker rootstocks than when they are on
stronger rootstocks.

Pruning 1. Red Prince Delicious trees on MM106 spaced 14 feet x

22 feet began to crowd badly in their 7th growing
season. Because of the grower's willingness to do
corrective pruning, no tree removal has been
necessary through 14 growing seasons.
2. Red Prince Delicious on M26 rootstock, planted in
1972, are being maintained at 8 feet by 22 feet
spacing by corrective pruning. Trees in the same
block spaced 16 feet by 22 feet have a 17 foot
spread.

Pruning and equipment 1. Mature non-spur Delicious trees on seedling roots

spaced 18 feet by 20 feet are being maintained with
no tree removal because of corrective pruning and
smaller equipment.

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-17-

BUD BLAST, CANKER, AND DIEBACK OF YOUNG APPLE TREES
IN MASSACHUSETTS: A PROGRESS REPORT

Daniel R. Cooley, Franzine D. Smith and William J. Manning
Department of Plant Pathology

and

Robert A. Spitko
New England Fruit Consultants

During the 1981 and 1982 growing seasons, a bud blast and branch
dieback problem occurred on young apple trees in a few scattered orchards in
Massachusetts. In the 1984 season bud blast, branch and trunk cankers and
terminal dieback were wide-spread in the State and other apple-growing
regions of New England.

Symptoms of bud blast and branch and trunk cankers were first noted on
young trees in the third to tenth leaf. Petioles from the previous season's
leaves were evident on vegetative shoots. Affected trees were usually less
than 10-years-old and had made very vigorous vegetative shoot growth in
1983. Symptoms occurred on many apple varieties, but were more prevalent
and severe on Mcintosh, especially on Marshall Mcintosh.

These symptoms ^re illustrated in Figure 1. They resemble winter
injury and this was our initial diagnosis. The prolonged warm autumn of
1983, a rapid drop in temperature to -1B° F (or lower in places) during
early winter, and a February thaw contributed to the diagnosis of winter
injury.

We also noted, however, that unique aspects of some of these symptoms
resembled those caused by plant pathogens. Rud blast and canker and dieback
can be caused by plant-pathogenic bacteria, while branch and trunk cankers
and terminal dieback can be caused by bacteria and/or plant pathogenic
fungi .

Further examination of the symptoms resulted in the conclusion that two
different yet related syndromes were present. Rud blast and branch dieback
appear to be one problem, while branch and trunk cankers and terminal
dieback are probably another problem. Both are different, but share the
canker symptom and are probably both associated with winter injury. To
identify organisms associated with the problems, samples were taken from
affected trees from spring to autumn. Isolations were made in the labora-
tory and resulting bacterial and fungal colonies were identified.

In bud blast and branch canker and dieback, affected vegetative buds
are either killed or produce only small distorted leaves. Branch cankers
develop and branches may be killed back to the trunk of the tree. In
spring, bacteria can be observed in affected buds and in the cambium beneath
buds. Of the bacteria isolated, several, such as Pseudomonas syringae , may
be plant pathogens. Frequency of isolation of bacteria decreased as the
season advanced. Several potential canker fungi such as Sphaeropsis ,
Cytospora , and Cephalosporium , and some wood decay fungi such as Irpex ,
Coriolus and Schi zophyllum , increased in frequency as the season advanced.

-18-

1. Diseased tree showing bare
branches.

2. Poorly developing buds.

3. Cankered area and dead
leaves on scaffold limb.

4. Retained petioles on year
old twig.

5. Diseased cavity in bud
area of twig.

■19-

Canker and wood decay fungi can be readily isolated from dark brown or
red trunk cankers. Later in the season fruiting bodies of the wood decay
fungi are very evident. Bacteria can be isolated from these cankers only
very early in the season.

Other people have worked on canker and dieback problems in apples. A
study done by Or. George Agrios in Massachusetts during the early IQfiO's
showed that several canker fungi were associated with apple. Of these,
Cytospora , Phoma , Physalospora , Phomopsis , Gleosporium and Botryosphaeria
were found, in order of decreasing frequency. These were associated with
cankers which became much more frequent during the drought occurring at that
time, and drought stress was believed to be a large factor in the disease,
rir. Dale Bergdahl recently completed a study of trees on marginal orchard
sites in Minnesota. He found that tree mortality went from less than 10%
when the orchards were first observed to over 90% after approximately 10
years. He attributed the decline to tohe wood-decay fungi Irpex ,
Schizophyllum and Coriolus in conjunction with cold and other environmental
stresses .

Several researchers have described a bud blast and canker on deciduous
fruit trees induced by Pseudomonas syringae . The disease is not generally
reported on apples, but an incidence apparently occurred in New York in
1950. Dr. Tom Burr of New York has shown that Pseudomonas syringae often
live on the surface of apple tissue causing no apparent di sease. iTrT Chris
Goodman of South Africa reports that there is a newly observed twig blight
caused by P^ syringae observed in that country.

Scientists at the HSDA Fruit Research Laboratory in Kearneysvi 1 le, WVA,
hosted a conference on peach decline, and suggested that we might find simi-
larities between peach tree cankers and the apple disease. Roth appear to
have a cold stress component, both have bacteria associated with cankers,
particularly a Pseudomonas sp., and both have rapid colonization of cankers
by fungi. In peaches, the primary fungus is Cytospora . The success a tree
has in walling-off, or compartmentalizing, an infection also plays a large
role in determining whether a tree will recover, or continue to decline.
Proper pruning decreased the potential for extensive fungus colonization and
wood loss in peach. Researchers also reported that wound dressings and
fungicides did not significantly decrease pruning cut infections. Figure 2
illustrates the many interactions which affect the peach canker disease.

The bud symptoms we have seen resemble descriptions of Pseudomonas bud
blast, as described on stone fruits and pear. Symptoms were widespread this
spring, yet not uniform in a given area. With the realization that the evi-
dence is still speculative and circumstantial, we suggest that the problem
may have been caused by an interaction between abnormal temperature fluctu-
ations, heavy rain during spring and autumn, a bacterial organism such as
Pseudomonas , and several fungal pathogens.

To manage the problem, we are suggesting an 8-8-100 Bordeaux Mixture
applied from silver tip to green tip. Other growers fire experimenting with
a fall application made after trees have entered rest. Others are con-
sidering similar applications of copper hydroxide (Kocide)*. These

*Trade name

-20-

Figure 2. Bacterial Canker: Factors Interacting With the Disease on Peach

Healthy Tree

Pseudomonas

Cytospora

Cold Stress

Compartmentalization

runing

No Compartmentalization

Healthy Tree

Declining Tree

materials have both bactericidal and fungicidal activities, and may be use-
ful in controlling the disease, though we are not sure at the present time.
In two orchards where Bordeaux or streptomycin were used, no incidence of
cankering was found in 1984, though adjacent orchards had the problem, and
one of the orchards had a history of the problem.

Because there is potential for economic loss from this problem, we
developed an analysis that could be used to estimate losses.

Our conservative estimate, based on orchard visits, is that approxi-
mately fiO to 80% of the orchards in Massachusetts suffered from 1% to \^%
tree damage. If you limit observations to trees from 1st to l?th leaf, the
percent loss is much more substantial, with approximately 50% - 90% showing
some damage. A written survey of 19 of the larger orchards in the state
indicated that 11 had serious loss, where approximately 15% of their total
trees were affected. Of the young trees, growers estimated 10% of their
trees lost, and damage on another 20%.

Economics of growing trees indicate that, in 1980 dollars, in eastern

New York (an area similar to Massachusetts) it cost $6174 to grow an acre of

trees to 5 years of age, or $39.80 per tree. At this point, and for the
next 7 years, each tree would return approximately $9 annually.

-21-

Table 1. Estimate of tree losses due to bud blast, canker and dieback in
1984.

Orchard cost - return over 10 years

Cost per tree to produce 5 yr-old tree $39.80
Return per tree annually after 5 years 9.00

Net return after ten years $ 5.20

Cost of Tree Loss - 10 yr-old tree

Lost investment in tree - direct % 39.80

Lost income from tree - potential 45.00

Cost to replace tree X bring to production 39.8

Total loss over 10 years $124.60"

If we limit the discussion to trees between 1st and l?th leaf, we see
that the grower will make approximately $63 per tree. Hence, if a grower
loses a tree that is B years old, he has lost $39.80 already invested, a
potential of $45.00 over the next 5 years of bearing, and another $39.80
required to bring a new tree into bearing. This does not include the cost
of running equipment at less than maximum efficiency, due to the production
loss, e.g. the cost of running a storage facility at less than capacity. A
conservative estimate of the loss of a tree is $125 over ten years
(Table 1).

From our estimates it appears that 5% of the young trees were lost, and
there was damage to another 10%. If trees were grown at an average density
of 125 per acre, and the average grower devoted 20 acres to young trees, the
average loss per grower is 125 trees, plus 250 trees damaged. At a loss of
$125/tree, the cost of this epidemic alone was $15,625 per grower to replace
the trees and bring them to production. Without replacement, the average
grower would lose $10,625 in trees and potential production. If production
on the damaged trees is ciit 25%, that translates to $590 lost per year,
assuming gradual recovery at 5% per year, a $1,750 loss over 5 years.
Therefore, the grower who replaces trees would lose a total of $17,375 over
the 10 years. This assumes no further damage occurs. If just 25 orchards
suffered this level of damage, the loss over the 10 years would be $434,375
(with replacement) or $309,374 (withoiit replacement) for an average loss of
$43,000 or $31,000 per year.

Rud blast, canker, and dieback have been most prevalent and severe in
Massachusetts. The Marshall Mcintosh was also discovered in Massachusetts.
We intend to pursue the problem to determine whether the bacteria and fungi
we have isolated are pathogenic to apple and what role cold injury plays in
disease development. Whether Marshall Mcintosh is highly susceptible or not
will also be determined.

In pursuing this work we are fortunate to have the generous support of
the Massachusetts Fruit Growers Association who have contributed $1600
towards the effort.

Cooperative Extension Service
U. S. Department of Agriculture
University of Massachusetts
Amherst, MA 01003

Official Business

Penalty for Private Use. S300

POSTAGE AND FEES PAID
U.S. DEPARTMENT OF
AGRICULTURE
(AGR 101)

BULK THIRD CLASS MAIL PERMIT

FRUITpr
NOTES

PREPARED BY
DEPARTMENT OF PLANT AND SOIL SCIENCES

COOPERATIVE EXTENSION SERVICE.
UNIVERSITY OF MASSACHUSETTS, UNITED
STATES DEPARTMENT OF AGRICULTURE AND
COUNTY EXTENSION SERVICES COOPERATING.

EDITORS
W. J. LORD AND W. J. BRAMLAGE

Volume 50 No. 2
SPRING ISSUE, 1985

Table of Contents

Bill Lord Retires

A Clean Crop of Apples with Only Two Sprays

Green Fruitworm Resistance to Guthion in
Western Massachusetts

Some Comments on Apple Tree Nutrition

Suggestions for Fertilization of Peach Trees

Understanding Effects of Weather on Apples

Recommendations for Use of Calcium Sprays

Apple Cover Sprays Unaffected by the
Addition of Calcium Chloride

Effect of Calcium Chloride Addition on
Solution pH and Hydrolysis of Certain
Pesticides

Issued by the Cooperative Extension Service, E. Bruce MacDougall, Dean, in further-
ance of the Acts of May 8 and June 30, 1914: United States Department of Agriculture
and County Extension Services cooperating. The Cooperative Extension Service offers
equal opportunity in programs and employment.

BILL LORD RETIRES

Will iani J. Bramlage
Department of Plant and Soil Sciences

On January 31, 1985 Willian J. Lord retired from the University of
Massachusetts after nearly 30 years of service as an Extension Pomologist
and as Editor of Fruit Notes .

Bill was born and reared in New Hampshire. During V/orld War II he
served 16 months with the 71st Infantry Division in Europe. He was in com-
bat in France, Germany and Austria and received a Bronze Star Medal and
Combat Infantryman's Badge. After World War II he taught at the U.S. Army
schools at Friesing and Oberammergau, Germany.

After returning to civilian life. Bill received B.S. and M.S. degrees
from the University of New Hampshire. He always had an active interest in
agriculture, and for 5 years he taught high school vocational agriculture,
where his responsibilities included management of a small apple orchard.

In 1955 Bill was awarded a Ph.D. from the Pennsylvania State
University, and accepted the Extension Pomology position at the University
of Massachusetts. In this position he became deeply involved in seeking
solutions to problems of the fruit industry and carried on an extremely
active adaptive research program. During his career he authored or
coauthored 190 research and extension publications in addition to uncounted
articles contrihuted to Fruit Notes .

In 1971, the Massachusetts Honorary Extension Fraternity recognized
Bill for his contributions to the Massachusetts Extension Service. In 1974
he received the Carl S. Bittner Award from the American Society for
Horticultural Science in recognition of outstanding contributions to hor-
ticulture through innovative extension activities.

Retirement will not end Bill's service to the fruit industry. He has
accepted a part-time Post-Retirement appointment which will allow him to
continue some applied research and some teaching, and at the same time allow
him to spend more time in pursuit of elusive marine life. A national search
is now underway for a replacement for Bill as Extension Pomologist, who
hopefully will be on the job on September 1, 1985.

Those of us who have had the pleasure of working with Bill have gained
greatly from his dedication, knowledge, and enthusiasm. We look forward to
continued cooperation with him, even though the new role is less demanding
of him. We wish Bill and his wife, Betty, a most enjoyable well-earned
retirement.

- 2

A CLEAN CROP OF APPLES WITH ONLY TVIO SPRAYS OF PESTICIDE

Ronald J. Prokopy
Department of Entomology, University of Massachusetts

One of my major lifetime goals as a research and extension fruit ento-
mologist is to implement every method necessary to permit the growing of a
clean, high quality crop of apples without any pesticide applications what-
soever. Ten years ago we were far from achieving this goal. Today,
however, with the excellent new varieties of disease resistant apples
developed in New York and with the new and more refined methods of insect
control developed in New York, Massachusetts, and elsewhere, we are closer
to fulfilling this aim.

Before the advent of the 5-year pilot pest management program in
Massachusetts in 1978, the average commercial apple grower made 12.3 fungi-
cide, 9.8 insecticide, and 1.8 miticide applications per year (exclusive of
oil) to control orchard pests. IPM growers from 1978 to 1982 made an
average of 10. fi fungicide applications (12% less), 6.8 insecticide applica-
tions (31% less), and 1.0 miticide applications (45% less), while realizing
just as high or higher a percentage of commercially clean fruit (98-99%) as
non- IPM growers ( Fruit Notes 48(1): 10-16, 24-34)

Here, I will describe the results of pest control methods I have
employed during the past 4 years (1981-1984) in my own small young orchard
(40 bearing trees) in Conway. Annually, only 2 applications of pesticide
were made, far less than even the most determined commercial IPM grower, and
a fine crop of clean fruit was picked.

Methods. The methods employed were as follows:

a) Use of disease resistant cultivars (particularly Liberty) on M-26
rootstock with the trees staked to prevent leaning. No fungicide what-
sovever was applied. By 1984, the older trees were about 10 feet tall,
had about a 10-foot diameter canopy, and bore an average of 1 1/2
bushels of fruit per tree.

b) Application of Superior Oil (60-70 viscosity) at a rate of 4 gallons per
acre at tight cluster against overwintering red mite eggs.

c) Application of Imidan* at a rate of 6 pounds per acre at petal fall and
again 10-14 days later, primarily against the plum curcuiio. Imidan* is
a relatively safe (to humans) organophosphate compound that is only
slightly to moderately toxic to the principal predators of mites and
aphids. The petal fall spray was applied within hours after the first
eggiaying scar of a plum curcuiio was detected in the orchard. The
petal fall spray was intended also against developing larvae of the
European apple sawfly, larvae of the speckled green fruit worm, and lar-
vae of the oblique handed leafroHer. The spray 10-14 days later was
intended also against adults, eggs, and hatching larvae of the codling
moth.

*Trade name

- 3 -

rl) From early July until apple harvest, one unhaited, Tangletrap* - coated,
sticky red sphere was hung in optimal position ( Fruit Notes 47(4):
13-16) in each tree to capture and eliminate apple maggot flies. The
Tangletrap* coating was not replenished, nor were insects or debris
removed from the sphere during this time. A major advantage of this
method is that the same sphere, when cleaned and coated freshly with
Tangletrap* at the beginning of each season, can be used for many years
without loss of effectiveness.

Result s. The results (Table 1) show that for all 4 years combined, 90% of
sampipfT fruit in my orchard were clean, compared with 0% clean fruit on
nearby (within 100-200 vards) unsprayed trees. In 1^84, the first year I
used a motor-driven backpack sprayer (I used a handpump sprayer before
that), 93% of sampled fruit in my orchard were clean.

Seven insect pests were responsible for approximately 99% of all insect-
caused fruit injury on the unsprayed trees (Table 1). In descending order
of importance, these were the plum curculio (99% of fruit injured), apple
maggot (71%), codling moth (41%), green fruitworm and/or oblique-banded
leafroller (injury by the former difficult to distinguish at harvest from
the latter) (26%), European apple sawfly (11%), and tarnished plant bug
(5%). These same 7 pests were likewise responsible for about 9q% of all
insect-caused fruit injury in my orchard (Table 1). Except for the tar-
nished plant bug, all were effectively suppressed (relative to populations
on the unsprayed trees) in my orchard by the 2 Imidan* applications and the
use of t'aps ffor apple maggot). These 7 insects represent 7 of the 8 most
injuriou . fruit pests in large commercial apple orchards in Massachusetts
( Fruit NT_tes 48(3): 23-25). The only insect pest causing appreciable fruit
injury Tn~ the latter but not found in my orchard or in the nearby unsprayed
trees was San Jose scale.

Not one of the 2250 apples sampled over the 4-year period in my orchard
was culled because of disease injury. Also, at no time in my orchard did
populations of foliage-injuring spider mites, aphids, leafhoppers, or leaf-
miners exceed the economic threshold levels given in Fruit Notes 45(3):
15-18 for larger Massachusetts commercial orchards. ~"

In addition to careful timing of the petal -fall and single post-
petal -fall spray applications against the earlier-season pests, non-
pesticidal control of the major mid-and late-season insect pest, the apple
maggot, through use of visual traps is viewed as a key element to the suc-
cess of this smal 1 -orchard pest-management program. Absence of pesticide in
the orchard from mid-season onward apparently allows natural enemies of
foliar-injuring pests to build and provide effective biological suppression.
To illustrate, syrphid and cecidomyiid predators of aphids were abundant in
my orchard in July. The excellent control of apple maggot flies (less than
1% injury in my orchard vs 71% in the unsprayed trees) using visual traps
at the rate of one trap per tree (i.e., 1 trap per about 120 apples) con-
firms that dense populations of ths insect were effectively controlled in my
80-tree orchard there using unbaited red spheres at a rate of 1 per about
100 apples.

- 4

No attempt was made here to control the tarnished plant bug or European
apple sawfly using Tang1etrap*-coated white (bud- and blossom-mimicking)
visual traps that are effective for monitoring abundance of these ?. insects
in larger commercial orchards. The reason was that such traps also may cap-
ture pollinating insects (although infrequently honey bees). Destruction of
honey-bee hives by bears in my orchard in 1981 precluded further introduc-
tion of hives for pollination. Hence, I was obliged to rely for pollination
on native bees and wasps, which are susceptible to trap capture. Also, no
attempt was made to control codling moth using traps baited with synthetic
sex pheromone to capture the males, as this approach failed in my orchard in
Wisconsin in 1973.

In sum, my findings indicate that even in the face of very strong pest
pressure originating from nearby unsprayed trees, a crop of high-quality
fruit (90-93% clean) can be grown in small commercial apple orchards in
northeastern North America using disease-resistant trees in combination with
insect traps and annually no more than a single application of petroleum oil
and 2 applications of insecticide. This number of synthetic non-oil pesti-
cide applications represents only about 8 and 11%, respectively, of the
total number of synthetic pesticide (fungicide, insecticide, and miticide)
applications made annually in larger commercial non-IPM and IPM orchards in
Massachusetts, which yield 98-99% commercially 'clean' fruit.

It would be naive at the present time to hope that the pest management
methods used in my small orchard in Conway could be transferred intact to
larger commercial orchards. At least 2 major developments are necessary
before this could become a realistic possibility:

a) Greater acceptance by commercial growers of existing high-quality
disease resistant varieties such as Liberty and/or Freedom, and the
breeding and propagation of still better disease resistant cultivars
( Fruit Note s 49(2): 25-26),

b) A non-pesticidal method of controlling apple maggot flies that is
less labor intensive than hanging a red sphere trap among every
100-120 apples on a tree. Use of synthetic oviposition-deterring
pheromone against the apple maggot could be the new method we need
( Fruit Notes 42(1): 8-11). (We have been and are continuing to try
to identify the chemical composition of this pheromone).

Maybe I'll never live to see my dream fulfilled of being able to grow
apples on a large commercial scale without any pesticide, but I still would
be thrilled if, before the end of this century, commercial growers needed to
use only two pesticide sprays per year, as now seems possible in small
orchards.

5 -

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GREEN FRUITWORM RESISTANCE TO GUTHION IN WESTERN MASSACHUSETTS!

Glenn E. Morin and Roberta A. Spitko
New England Fruit Consultants
Lake Pleasant, Massachusetts

In recent years, commercial apple growers in the Shelburne area of
western Massachusetts have experienced problems controlling (jreen fruitworm
larvae (GFW] with the standard insecticide Guthion* (azinphosmethyl ) . GFW
injury to fruit at harvest increased from a previously insignificant n.01%
in 1981 to greater than 4% in 1983 in one Shelburne orchard despite the tra-
ditional application of post-bloom Guthion* treatments.

Were we witnessing the development of green fruitworm tolerance to
Guthion* or merely the cyclical appearance of a pest not well controlled by
this material? We have provided below a brief life history of GFW common to
Massachusetts, have described our attempts to identify this control problem
in one commercial orchard, and have included alternate strategies for
managing potentially resistant populations.

Life History

Green fruitworm adults appear in orchards and begin egglaying in late
March or earl/ April. Upon hatching, young larvae attack foliage and buds.
Larvae may va 'y from light to dark green with green head capsules and a pair
or pairs of lateral white stripes. Mature larvae chew holes in developing
fruits and may cause substantial injury. Larvae burrow into the soil in
late June and emerge as adults by the following April. Severely damaged
fruits abscise during the growing season. Minor damage generally appears on
fruit at harvest as large, superficial areas of light corky tissue but may be
so extensive as to expose the seed cavity.

Field Observa t ions

Increased GFW-like injury was first brought to our attention during the
1982 harvest season. Unfortunately, GFW damage is virtually indistinguish-
able from that of the oblique-banded leafroller without observations of lar-
vae at the time of initial injury. Careful monitoring the following season
was necessary to positively identify the culprit.

In 1983, we initiated a foliar monitoring program at pink when chewing
injury to terninal growth was first noted. Terminal damage increased to
more than 30% by late bloom and limited injury to fruit clusters had begun.
Insecticide treatments were warranted to prevent excessive fruit injury and
full rate Guthion* applications were made at petal fall, first cover, and
second cover at 7-day intervals. These treatments were apparently unsatis-
factory as fruit cluster damage continued to increase and live GFW larvae
(tentatively identified as Orthosia hibisci "Guenee") were detected after
each application. Injury to fruit at harvest was greater than 4%.

^We would like to express our appreciation to the Peck families of Valley
View Orchards in Shelburne, Massachusetts for their extreme level of
interest and cooperation in this investigation.

*Trade name

- 7 -

Due to these observations, insecticide tolerance was strongly
suspected. Post-bloom Gutbion* treatments had proved effective in the past
as GFW injury was rarely noted in the packhouse. In addition, GFW damage
had not increased in other major fruit growing regions of the state despite
the use of similar spray schedules. Guthion* was apparently still effective
in these areas where GFl! injury averaged less than 0.1% in 1^83.

Tolerance Study

To investigate the possibility of insecticide resistance, we collected
GFVI larvae from the Shelburne population during bloom of 1984, caged them on
abandoned apple trees, and subjected them to various rates of Guthion*.
Treatments were made at petal fall when commercial insecticides would likely
be applied. A Lorsban* (chlorpyrifos) treatment was included for evaluation
as an alternate material should Guthion* prove ineffective. Our results are
presented in Table 1.

Table 1. Results of several organophosphate insecticide treatments against
GFV/ larvae (tentatively identified as Orthosia hibisci 'Guenee')

Material and formulation Lbs/100 gal % Mortality

Guthion SOUP 0.5 30

Guthion 50WP 1.0 30

Guthion 50WP 2.0 55

Lorsban 50WP 1.0 95

Control 5

The data clearly indicate that neither the full label rate nor the
double rate Guthion* treatments proved effective against these larvae,
resulting in only 30% mortality. If relied upon for control, these treat-
ments would have allowed the survival of a residual population capable of
subs' antial fruit injury. Even the quadruple rate resulted in only 55% kill
and we repeatedly observed larvae continuing to feed on fruit and foliage
desp te the visible presence of a heavy spray residue. Lorsban* proved a
highly effective material that resulted in 95% mortality.

Summa ry

Baseri on the work presented here, we believe that insecticide tolerance
to Guthicn* (azinphosmethyl ) was involved in the GFW control failures
recently experienced by fruit growers in western Massachusetts. We recom-
mend careful monitoring of GFW larval populations on an orchard-by-orchard
basis and the use of alternate post-bloom insecticides should damage exceed
acceptable levels.

- 8

Our tolerance study indicated that Lorsban* (chlorpyrifos) would be a
viable substitute and our field trials in 1984 support these results. A
single petal fall application on the same acreage as previously discussed
provided excellent control of GFW larvae resulting in less than 0.4% injury
to ■''ruit at harvest. Thiodan* (endosulfan) also proved to be an effective
material in a similar trial and due to its relatively mild effect on benefi-
cial mite predators, it would be well suited to an integrated mite control
program.

Pesticide resistance and subsequent control failures are common pheno-
mena. Occurrences such as the one described here continue to remind us of
the need for pest monitoring programs and the selective use of pesticides in
order to lengthen the effective "lifetime" of current spray materials.

*****

SOME COMMENTS ON APPLE TREE NUTRITION

William J. Lord
Department of Plant and Soil Sciences

James T. Williams, Massachusetts Regional Fruit Specialist, reports the
'"oHowing summary of apple leaf analyses for Northeastern Massachusetts
jrchards in 1982 and 1«83.

Pet. of samples Pet. of samples

Element below optimum range above optimum range

Nitrogen 8 15

Potassium 31 6

Calcium 50

Magnesium 5 1

Boron 17

Manganese 10 10

Copper 36 3

Zinc 5 40

A grower should obtain leaf analyses to assess the status of his own
orchard, hut the table above shows that calcium, copper, potassium, and
boron were most frequently deficient in leaves, and that zinc and nitrogen
were the elements most commonly in excess.

Some general comments about apple nutrition follow.

Apple tree nutrition . The needs of apple trees for mineral elements are
smaller than those of many other crops. Nevertheless, the problems of main-
taining optimum nutrition are complex because of the concern with nutrition
of both the tree and the fruit, and because of the influence of soil manage-
ment and orchard intensification on mineral availability.

Much less N is being applied in orchards than in the past because of the
reduction or elimination of grass and weed competition by the use of her-
bicides. Furthermore, apple trees conserve N by translocating part of the
nitrogenous material in senescing (aging) flowers and leaves to adjacent
bark and wood tissue. The N becomes part of the protein fraction. The pro-
tein levels in shoot bark and wood decrease rapidly before bud-break in the
spring. This decrease is accompanied by increased levels of soluble N.
Thus, this N is available to help support growth in early spring when con-
ditions for root uptake are poor.

Potassium (K) is the most abundant nutrient in the fruit. Therefore,
the level of cropping greatly influences the demand for K. In contrast,
very small amounts of calcium (Ca) are found in the fruit and this repre-
sents a small proportion of the total uptake of this element, emphasizing
that one of the problems of Ca nutrition is that of distribution in the
tree. Fruit are often Ca-deficient when leaves have sufficient Ca. The
effects are described in a following article (pages 14 and 15).

Manganese (Mn) . In the spring, 1984 issue of Fruit Notes , it was stated
that Mn is the most frequently deficient elemerTE in apple trees. This
statement was in error! Low Mn is the most frequent foliar symptom of defi-
ciency seen in Massachusetts. However, foliar symptoms of Magnesium
deficiency have become increasingly prevalent the last 3 or 4 years.

A standard for apple tree growth . Vihile the amount of growth made by a tree
"Ts dependent on several factors, some of which cannot be controlled by the
grower, it is desirable to set up standards to strive for. The stronger
shoots of young bearing trees 5 to 10 years of age should make 15 to 20
inches of growth each season. Older trees should have many shoots which
make 8 to 10 inches of growth. Thickness of shoot growth is <'ully as impor-
tant as length. Stocky shoots are the sign of a vigorous tree while slender
shoots indicate a poor, under-nourished tree.

*****

POMOLOGICAL NOTES

V/illiam J. Lord

Plant trees early . Tree roots will grow when the soil temperature reaches
about 45oF. Thus, early planting allows the roots to become established and
to make growth before high air temperatures cause rapid growth above ground.

CHEMICAL THINNING OF EMPIRE . It is well known that trees of this variety
tend to produce only medium-size fruit. For example, fruit on young trees
in experimental plots in 1982 and 1983 averaged only 2 1/2 inche"s Tn
diameter partly because of excessive fruit set. Thus, questions have arisen
concerning chemical thinning of Empire. Based on a thinning trial in 1982
and 1983 by Dr. Duane Greene, we tentatively suggest an application of NAA
pi'js 1 lb. of sevin, 50% V/P or its equivalent.

SUGGESTIONS FOR FERTILIZATION OF PEACH TREES

William J. Lord
Department of Plant and Soil

Sciences

Tree growth is the best guide to how your fertilizer program fulfills
the needs of peach trees, if soil moisture is not a limiting factor. Since
flower buds of the peach are formed along the new shoot growth, it is essen-
tial to produce adeguate growth by use of a nitrogen (N) fertilizer. Young
peach trees should make about 18 inches of new terminal growth annually;
12-15 inches are sufficient for mature trees. Growth in excess of these
amounts may result in poor fruit color and excessive cold injury, and will
increase the amount of pruning required.

In some orchards, N is the only fertilizer required. However, leaf
analysis in conjunction with visual observations of tree growth and fruit
quality are the best criteria by which to determine required amounts of fer-
tilizers (Table 1). In Massachusetts, N needs are usually met with an
application of ammonium nitrate or a "complete fertilizer." Foliar sprays
of urea to supply N are ineffective on peach trees because the leaves do not
absorb N as efficiently as do apple leaves.

Table 1. Standards for nutrient levels in peach leaves.

Element

Nitrogen

Potassium

Calcium

Magnesium

Boron

Copper

Manganese

Zinc

Shortage^
fless than1

3.00%

1 . 25%

1 . 35%

0.25%

25 ppm

5 ppm

25 ppm

15 ppm

Optimum^

Excess^

(within)

(more than)

3.00 - 3.50%

3.70%

1.50 - 2.50%

2.50%

1.35 - 1.50%

0.35 - 0.50%

0.50%

30 - 50 ppm

60 ppm

7-10 ppm

10 ppm

90 - 110 ppm

110 ppm

25 - 50 ppm

50 ppm

^Shortage: Corrective measures needed.

^Optimum: Applications should be continued at present rate or adjusted
according to anticipated crop size.

•^Excess: Amount applied should be decreased or eliminated.

- 11 -

Some growers apply split applications of N, the first in mid-April to
early- May and the second in June, The amount applied in June is 1/3 to 1/2
of the amount applied earlier. We have no data regarding the benefit of
split applications. However, at our Horticultural Research Center, we apply
only one application and are satisfied with tree growth and yields.
Probably a good soil management program which conserves soil moisture, or
the installation of a trickle irrigation system, would be more beneficial
than a second application of N.

Potassium (K) is occasionally deficient in Massachusetts peach
orchards. Therefore, the recommendations given in Table 2 are guides for
fulfilling the N and K needs for peach trees. The K may be applied either
in the spring or fall, but N fertilizer should be applied in the spring
about 2 or 3 weeks before bloom.

Table 2. Suggested rates of fertilizer for bearing peach trees.

Approxima te amounts per tree (1bs)
Tree age (years) Ammonium nitrate Muriate of potash

or its equivalent or its equivalent

3 to 6 1/2 to 1 1 to 2

6 to ^ 1 to 1 1/2 2 to 3

9 to 12 .1 1/2 to 2 3 to 4

12 and over 2 to 4 4 to 8

Research by Drs. Dennis Abdalla and Norman Childers in 1970-72 at
Rutgers University, New Brunswick, New Jersey, showed that we should be more
concerned about calcium (Ca) nutrition of our peach trees. Fruit from trees
g-'own under greenhouse sand culture by these researchers were smaller,
greene'' and firmer and had less soluble solids (sugar content) and red blush
when the nutrient solution was low in Ca. Our apple trees and fruit in
Massachusetts are low in Ca, thus the same may be true for peaches. The
question is, how can you increase the Ca level in peach trees and fruit?
Our suggestion is to use high Ca lime when liming the orchard.

Manganese (Mn) deficiency occurs occasionally in Massachusetts peach
orchards. T'-ees with Mn deficiency have leaves with interveinal fading of
chlorophyll with the remaining area green. Leaves from peach trees showing
Mn deficiency in 1971 contained 13 ppm of this element in comparison to 97
ppm in leaves from trees showing no interveinal loss of chlorophyll.

Mn deficiency can be corrected by foliar applications of manganese
sulfate or by use of a fungicide containing Mn. If using manganese sulfate,
apply about first cover at a rate of 3 lbs per 100 gallons of water. When
using a Mn-containing fungicide apply 2 or 3 applications with timings about
petalfall and first and second covers.

- 12

Occasionally, leaf analysis indicates that trees are low or deficient
in magnesium (Mg) (Table 1). The first indication of deficiency is a light
yellowing between veins of the leaf. When Mg deficiency is severe, browning
of the yellowed areas occurs. Usually, the more basal leaves are affected
first. For long-term correction of low or deficient Mg levels, apply dolo-
mitic limestone at the rate indicated by a soil test. For a more immediate
correction of Mg deficiency, a foliar spray of magnesium sulfate (Epsom
salts) is suggested in some peach growing ar.^as. The suggested rate is 10
pounds of Epsom salts per 100 gallons of water.

Peach trees sre more sensitive to excessive applications of B than
apple trees, thus this element should be applied only in small amounts if
needed. Peach tree symptoms of excessive B are characterized by withering
and dying-back of terminal shoots during the growing season, the development
of cankers and gumming along the shoots, rough bark, prominent lenticels,
and excessive development of lateral shoots. To avoid B toxicity, Ernest G.
Christ, former Extension Specialist of Pomology at Rutgers University, is
very cautious about recommending the use of this element when fertilizing
peach trees. He states that. . . "fertilizer with 5 pounds of borax per ton
is usually OK for peaches. No additional B is ever needed or added. Also,
keep pH of soil 6 - 6.5." We suggest that peach growers in Massachusetts
follow the recommendations of Ernest Christ concerning use of B.

*****

UNDERSTANDING EFFECTS OF WEATHER ON APPLE YIELDS

Wil 1 iam J. Bramlage
Department of Plant and Soil Sciences

Year-to-year variations in fruit yield from an orchard are usually
accepted as a fact of life, but what are their underlying causes? J.E.
•Jackson and P.J.C. Hamer of the East Mailing Research Station, Kent, England
compared estimated yields of English 'Cox's Orange Pippin' apples with
weather records from 1949 to 1975 and came up with some interesting results
( Journal of Horticultural Science s 55 : 1 49 - 1 56 ) .

Over this time there was a steady increase in yield amounting to about
0.25 ton per hectare (about 7 bushels per acre). This steady increase was
attributed to technological changes in production practices, in particular
the use of better rootstocks and closer spacing of trees. This "technologi-
cal advancement" would amount to an extra yield of 180 bushels of apples per
acre in 1975 above the average yield in 1949.

In addition to this steady increase in yield, 3 weather factors were
closely related to year-to-year variations. They were: (a) relatively high
temperature in February, March, and April; (b) relatively high temperature
immediately after full bloom (typically mid-Hay); and (c) relatively cold
weather in June.

- 13

Warm weather in February, March, and April produced an earlier bloom
and lowered yield. This was not due to a greater frequency of frost damage,
as wlrm periods tended to continue on into summer. The authors suggested
that the early bloom produced by this weather either resulted in "poorer
quality of flowers" or else was associated with lessened insect activity.
In either case, poorer fruit set would result. Relatively high tempera-
tures immediately after full bloom increased yield. The authors related
this to known effects of temperatures on pollen tube growth, suggesting that
rapid pollen tube growth increased fertilization of seeds and produced
higher yields (fruit size tends to increase with seed number). Relatively
cool weather in June related to reduc ed yields. The authors suggested that
this was due to slower growth during This time of cell division and/or to
poorer fruit retention during June drop.

Together, these 4 factors (technological improvement and temperatures
during these 3 key times) accounted for 80% of the variation in estimated
yield over this time period. Using this information, "expected yield" was
calculated for each of these years and the values were very close to actual
estimated yields in all years except those in which some frost damage
occurred. Thus, it appears that the ideal weather for high yields in
England would be to have (a) a relatively late Spring, (b) relatively high
temperatures immediately after full bloom, and (c) relatively high tempera-
tures again during late June.

Dr. Alan Lakso of the New York Agricultural Experiment Station, Geneva,
NY, has examined the effects of temperature from February 1 to April 15 on
New York apple yields over a 15-year period ( The Great Lakes Fruit Grower s
News , April, 1984). He found results similar to those of Jackson and Hamer
in England .

Using the mean maximum temperature for February 1 to April 15, he found
that higher temperatures lowered yield. The relationship of weather to
yield was further improved by considering the mean temperature during the
two weeks after petal fall, in which higher temperatures increased yield.
Using just the temperatures for these two periods of the year, 80% of the
annual variation in apple yield was accounted for.

Information such as this may allow early predictions of yields and aid
growers in making management decisions about their crops.

*****

POMOLOGICAL PARAGRAPH

Rootstock mixtures . In Massachusetts Agricultural Experiment Station
Bullftin No. 418 published in 1944, J.K. Shaw stated "we are inclined to
favor Ml, M2, M4 and M7 as the semi-dwarfing rootstocks most likely to prove
valuable and it wou 1 d simpl ify matters if this list could be shortened ." In
the 1930s and 1940s, the Mailing series were the only available rootstocks.
Certainly, the chance of mixtures is much greater today because of the
numerous rootstock introductions since the 1940s.

RECOMMENDATIONS FOR USE OF CALCIUM SPRAYS

William J. Bramlage and Mack Drake
Department of Plant and Soil Sciences

Our surveys of Massachusetts orchards have shown that concentrations of
calcium (Ca) in apple fruits are more variable than those of any other
mineral, and that fruit from many orchards are Ca def icient--which makes
them more susceptible to breakdown, bitter pit, scald, and rot during and
after storage. To combat this problem, most Massachusetts apple growers
have been foliar spraying calcium chloride (CaCl?) periodically during the
growing season. Our current recommendations for use of Ca sprays in apple
orchards are described here.

Many Ca-containing compounds have been tested for use on apples and a
number of different ones are commercially available. Technical grade
(77-80%) CaCl2 is the material we recommend. We have tested a number of
different materials and found that the amount of Ca that they put into
apples is directly proportional to the concentrations of soluble Ca in the
spray solution. With the exception of the relatively insoluble material,
Ca{H2P04)2, which was ineffective in increasing fruit Ca, neither the for-
mulations of the material nor the chemical that is associated with Ca in the
material has significantly affected the final result. Technical grade CaCl2
is the most economical material for adding the needed Ca to apples.

Foliar CaCl2 sprays should begin about 3 weeks after petal-fall and be
repeated at 2-week intervals, totaling about 8 applications for the season.
The CaCl2 can be combined with pesticide sprays. Since young leaves tend to
be sensitive to CaCl2, we recommend using 6 lbs per acre in each spray until
mid-July, and then 8-10 lbs per acre until harvest. The goal should be to
apply a total of 70 to 75 lbs of CaCl2 per acre for the season. While we
recommend the above rates, we have fouhd that minor alterations of these
rates and timings have been just as effective in raising fruit Ca levels as
the recommendations so long as the same total amount of CaCl2 is applied.
In other words, if lower rates are used'j more sprays are needed. When
higher rates are used the risk of damage from Ca sprays is increased.

Ca sprays can cause damage to leaves or even fruit. With CaCl2, leaves
are much more likely to be damaged than fruit, the injury normally appearing
as browning of the leaf margins. We have sought a less phytotoxic form of
Ca but have found no material that was safer than CaCl2 when applied at an
equal soluble-Ca concentration. Tests in other areas have shown that
calcium nitrate (Ca(N03)2) is less damaging to leaves than CaCl2, but is
more likely to cause fruit injury (black spots on the lenticels). We recom-
mend the use of CaCl2 rather than Ca(N03)2 to minimize the risk of fruit
damage. While leaf injury is undesirable, we have observed no detrimental
effect to either fruit or trees when mild symptoms have developed. However,
severe damage could cause earlier fruit ripening and dropping.

- 15 -

Some growers have chosen to use Ca(N03)2 to reduce the risk of leaf
injury. We have applied Ca(N03)2 in concentrations of soluble Ca equal to
those of the recommended rates of CaCl2, and have found that equal amounts
of Ca are added to the fruit. However, the overall effects of the treat-
ments on fruit and trees have not yet been determined, and we believe that
CaCl2 is the material of choice.

To minimize risk of foliar damage from CaCl^ sprays, care must be
taken. Sprayers need to be calibrated. CaCl2 should always be mixed in a
pail of water and be added last, when the spray tank is nearly full, to
ensure thorough mixing in the tank. The spray tank must have sufficient
agitation to maintain thorough mixing during spraying. Risk of damage is
greatest on weak trees or injured foliage. We are aware of no known incom-
patibility of CaCl2 with commonly used pesticides, but since formulations
and combinations frequently change, users should be alert to any unusual
behavior of materials in the spray mixtures. Do^ not mix CaCl2 with Solubor
or Epsom salt sprays . Do not apply CaCl2 in excessively hot weather.

Foliar CaCl2 sprays may be applied as either dilute (300 gal per acre)
or lOX concentration (30 gal per acre). We have seen indications that
uptake of Ca by apples can be greater from concentrated than dilute sprays,
but other researchers have found that these methods of CaCl2 application add
equal amounts of Ca to apples. Some growers have applied CaCl2 at higher
than lOX without problems, but we have no data on their effectiveness. If
CaCl2 is applied in a dilute form and separate from pesticides, a non-ionic
wetting agent should be added, but since most pesticides include wetting
agents in their formulation the addition should not be needed when CaCl2 and
pesticides are combined.

The initial pH of commercial CaCl2 in water is about 10.3, since small
amounts of free calcium oxide form calcium hydroxide in water. There is
evidence that this high pH may reduce effectiveness of some pesticides. We
therefore, have recommended adding 2 quarts of 5% vinegar per 100 pounds of
CaCl2 to neutralize the alkalinity and bring the spray solution to about pH
6.0. The addition of vinegar will not affect uptake of Ca by the apples, or
injury to the foliage. (Please see the following articles for more infor-
mation about this pH problem.)

Use of CaCl2 as a foliar spray for apple trees is an established annual
practive in mo' t Massachusetts apple orchards. While this material can be
phytotoxic, thf risk of injury is minimized by attention to details when it
is used. The !)enefits from its use are substantial. When 70 to 75 lbs per
acre are applied, potential storage life of the fruit can be greatly
improved. However, many growers apply less than 70 lbs per acre, and poten-
tial benefit declines proportionally as less than this total is applied
during the growing season. Our recommendations are designed to obtain the
greatest benefit from CaCl2 most efficiently, while minimizing the risk of
foliar damage. Since there is no carryover of this Ca benefit, it is
necessary to apply the sprays at full dosage each year for maximum benefit.

- 16

APPLE COVER SPRAYS UNAFFECTED BY THE ADDITION OF CALCIUM CHLORIDE*

George M. Greene, Larry A. Hull, and Kenneth D. Hickey
Pennsylvania State University

From a fruit quality standpoint, it has been proven that calcium
chloride (CaCl2) can reduce corking and bitter pit and can lengthen the
storage life of apples. Research conducted under the CIPM apple subproject
hi
di
eqi

cides arid CaCl2 can be safely combined, eliminating the necessity for
making s?parate applications.

storage life of apples. Research conducted under the CIPM apple subproject
las proven that the addition of CaCl2 to pesticides sprays normally used
iuring the post-bloom period results in disease, insect, and mite control
?qual to that obtained when the pesticides are applied alone. Thus, pesti-

Apple growers the world over are plagued by low calcium physiological
disorders of fruit. These disorders can appear during the growing season or
they may develop during the postharvest storage period. CaCl2 can often
effectively reduce the level of these disorders. Therefore, recommendations
have been developed to apply various rates of CaCl2 depending on the apple
variety and disorder involved. Since CaCl2 is considered a fertilizer, EPA
approval is not required for its use. Apple growers have been tank mixing
it with the commonly used apple pesticide cover sprays to reduce the cost of
appl ication.

However, recent concerns about pesticide efficacy, including suspected
resistance, have questioned the advisability of the past tank mixing prac-
tices. First, concerns have centered around the spray solution pH.
According to the manufacturers of CaCl2 the pH of concentrations like those
commonly encountered can be as high as 10.3 and alkaline conditions may
reduce pesticide efficacy. Second, since CaCl2 is hygroscopic, concern has
been raised concerning the weatherabil ity of sprays containing CaCl2.

Extensive field experiments were conducted during 1980, 1981, and 1982
to test the efficacy of tank mixed pesticide combinations with various rates
of CaCl2. Results are given in Table 1. Details have been provided on the
pesticides investigated, the CaCl2 rates used, and the pests that have been
studied. Some of the pests were evaluated on apple leaves while others were
observed on the fruits themselves. Results have been very consistent for
all pests, pesticides, CaCl2 rates, and for all three years. Almost without
exception, the control of pests was the same regardless of whether the
pesticides were applied alone or in combination with 24, 48, or 72 pounds of
77 to 80 % CaCl2 per acre per year. Under Pennsylvania conditions, 24
Ibs/acre/year have given good control of corking and bitter pit which deve-
lop during the growing season. However, in Massachusetts, upward of 72
Ibs/acre/year are recommended to control internal breakdown of Mcintosh.

•Reprfffted wifh permission ot the authors from "Consortium tor integrated
Pest Management Success Stories," Pennsylvania State University, 1983.

Table 1. Summary of experiments conducted to determine the influence of
calcium chloride on pesticide efficacy.

Calcium chl

oride

(77-80%) ra

ites

Pests

Year

Pesticides* studied

(Ibs/acre/year)

studied**

1980

Experiment

Polyram BOW
Penncap M 2FM
Zolone 3EC

0, 24, 48

TABM
GAA

Experiment

Plictran 50W

0, 24, 4B

ERM

1981

Experiment

Polyram BOW
Penncap M 2FM
Zolone

0, 24, 48.

SB. FS,

TABM,
SJS, FR

Experiment

Plictran SOW

0, 24, 72

ERM

1982

Experiment

1***

Polyram BOW
Penncap M 2FM
Zolone 3EC
Carzol 92SP

0, 24, 72

SB, FS,

TABM,
ERM, AS

Experiment

Captan SOW
Dikar 77W
Polyram BOW
Guthion SOW
Guthion SOW +

Imidan SOW
Guthion SOW +

Penncap M 2FM
Guthion SOW +

Zolone 3EC
Guthion SOW +

Methomvl 1.8L
Penncap M 2FM +

Methomvl 1.8L

SB
FS
AS

TABM

*Tradenames shown

**TABM = tufted apple budmoth, GAA = green apple aphid, ERM = European red
mite, SB = sooty blotch, FS = fly speck, SJS = San Jose scale, FR = fruit
rots. AS = apple scab

***This experiment involved 0, 2, and 4 hours of agitation in the tank prior
to spraying, as a variable.

EFFECT OF CALCIUM CHLORIDE ADDITION ON SOLUTION pH
AND ON HYDROLYSIS OF CERTAIN PESTICIDES

William M. Col i , John M. Clark and Matt Brooks
Department of Entomology

Commercial apple grov/ers in Massachusetts typically apply an average of
6-10 insecticide and 8-12 fungicide dosage eguivalents annually to produce a
marketable crop. Up to four dosage equivalents of miticide are applied in
problen blocks and small amounts of aphicides and herbicides are used as
well, as are various plant growth regulators for fruit thinning, to promote
early ripening or delay preharvest drop.

Most growers apply CaCl2 sprays to Mcintosh apple trees, generally as
additions to their pesticide cover sprays. Technical flake CaCl2, used for
foliar application, contains 77-80% CaCl2 as well as sizable amounts of
water, and small percentages of sodium chloride and calcium hydroxide (free
lime). Many pesticide labels contain warnings about mixing pesticides
with alkaline materials. Captan, for example, is reported to have a half
life of less than one hour in pH 8.5 water at 70OF. We became interested in
what effect, if any, use of CaCl2 would have on solution pH and potentially
on hydro ''ysis of pesticides and thus on pest control.

In our earlier tests we monitored the pH of solutions containing the
equivalent of 5 lbs/A of technical or analytical grade CaCl2, with or
without the insecticide Guthion*. Concentrations tested ranged from dilute
to lOX, to simulate a variety of application conditions. It was evident
that technical grade CaCl2 at 6 and lOX resulted in a moderately to strongly
alkaline solution pH. The addition of the acidic material Guthion* reduced
the pH of analytical grade solutions below potentially troublesome levels;
however, pH of technical grade solutions remained high except at the most
dilute concentrations. Analytical grade CaCl2 had a less dramatic effect on
pH due to the presence of less Ca(0H)2 contaminant. We also showed that pH
of CaCl2 solutions tended to drop over time as the Ca(0H)2 contaminant com-
bined with CO2 in the air to form calcium carbonate, with an overall reduc-
tion in solution alkalinity. This reaction can be speeded up by bubbling
CO2 through the solution.

Here we report the results of a laboratory study to measure any effect
of solution pH on hydrolysis of certain representative pesticides. Field
rate concentrations of azinphosmethyl (Guthion*), methomyl (Lannate*), for-
metanate hydrochloride (Carzol*) and benomyl (Benlate*) were prepared in 250
ml of distilled, deionized water containing technical grade CaCl2 at 1,5,
and lOx concentrations. A control solution containing no CaCl2 and one
containing lOx CaCl2, which had been saturated for one minute with CO2 prior
to pesticide addition, were also included. Solutions were sealed and stored
at 75" F in the absence of light.

Addition of technical grade CaCl2 resulted in substantial alkaliniza-
tion of all treated solutions. Although pH of most solutions had returned
to near neutrality within 24 hours, those containing lOX CaCl2 were still
moderately alkaline even after 24 hours, as seen in Table 1. Our earlier

*lrade name

19 -

results indicating return of solution pH to less alkaline levels within 24
hours with addition of CO2 were confirmed, even in solutions which received
the highest CaCl2 rate.

Benomyl and methomyl appeared to be most affected by CaCl2 addition,
because neither of these materials contains strongly acidic components. pH
of solutions containing either azinphosmethyl or formetanate were least
affected bv CaCl2 addition. This is because azinphosmethyl is a phosphoric
acid-containing ester, which would neutralize any added base such as calcium
hydroxide, while formetanate is formulated as a freely soluble HCl salt.

As indicated by control values, azinphosmethyl does not appear to be
very susceptible to hvdrolytic dearadation over time. This material also
seems to be quite stable over a wide range of pH readings, ranging in these
tests from about pH 6 to about 9.4. It would seem safe in this case to
suggest mixing azinphosmethyl with CaCl2 in tank mixes. Formetanate also
appears to be reasonably stable over time in solution containing no CaCl2.
However, at the high pH levels resulting from addition of 5 and lOX concen-
trations of CaCl2, ma.ior loss of parent compound occurred at 6. 12 and 24
hours.

In the case of metliomyl. substantial hvdrolysis occurred over time even
in the absence of CaCl2. Here, it seems that the buffering effect of adding
some Car.l2 enhanced this pesticide's stability up to a point, although in
lOX concentrate solutions there was still substantial loss of parent com-
pound at 48 hours.

Benomyl also appeared to hydrolyse in control solutions over time with
only 26% remaining after 48 hours. Degradation was enhanced by CaCl2 addi-
tion with only about 1/3 of the parent compound and its carbendazim break-
down product (33%) remaining at 12 hours.

V/hile the demonstrated substantial loss of parent compound in some "in-
■.tances may represent a financial loss to growers, it is still unclear at
:his time that pH-induced pesticide hydrolysis would have any negative
effect on pest control, particularly since most materials are applied within
a relatively short time after mixing. However, tractor or sprayer break-
downs that delay application, or conditions of slow drying where pesticides
remain in solution for long periods of time may at least affect residues of
susceptible pesticide. Growers in the Pacific Northwest habitually buffer
alkaline spray waters, and workers in that region have reported improved
oest control from use of buffering aoents.

We hope to look at pest control in the field as the next phase of this
work. We are particularly concerned about possible degradation of benomyl
and captan, another funaicide reported in the literature to be prone to
alkaline hydrolysis, as these materials are included in postharvest dips and
drenches to which Car.l2 may be added. In this instance, however, we have
two things going for us. One is the fact that FDA regulations allow only
use of briner's grade CaCl2. which is much more pure, beino composed of 97%
CaCl2, and thus would have a less dramatic impact on solution pH. Also,
since dips and drenches are agitated during application to harvested fruit,
mixing wi :h CO2 in the air would be expected to be af a maximum with a con-
sequent drop in pH over time.

- 20 -

For now, we can recommend several actions to growers who are concerned
with possible hydrolysis of pesticides. One choice is to apply CaCl2
separately from pesticides in tank mixes. Another is to pre-mix CaCl2
slurries 24 hours prior to adding these slurries to spray tanks. This
should reduce the dramatic rise in pH. Another option would be to use a
higher grade of CaCl2 for foliar applications, although the added cost
fabout $9/100 lbs.) may make implementation of this practice improbable.
A final option is use of commercially available buffering agents which would
result in solution pH ranges favoring pesticide stability.

Table 1. Effect of CaCl2 addition on pH and pesticide degradation over 48
hours at 75'F

'/m

;er 12 hr

After

24 hr

Aft

;er 48 hr

CaCl

% pesticide

pesticide

% pesticide

addit

ion

remaining

pH 1

"■emaining

remaining

Benomyl

5.31

5.50

5.60

6.00

7.10

6.80

10.11

8.50

8.00

lOx

9.40

8.42

7.70

lOx +

C02

5.80

6.42

6.81

Methomyl

4.88

4.92

4.84

7.38

6.66

6.31

S.96

7.35

6.98

lOx

9.26

8.23

7.40

lOx +

CO9

5.32

5.65
n'nphosmethyl

6.22

5.65

109

6.78

108

6.48

5.84

7.08

7.39

6.74

lOx

9.18

8.86

8.37

lOx +

CO2

6.04

6.08
Formetanate

6.08

4.54

4.71

4.72

5.99

6.50

6.67

7.30

7.33

7.66

lOx

8.08

7.92

7.76

lOx +

CO2

5.79

5.88

105

6.12

102

FRUIT
NOTES

PREPARED BY
DEPARTMENT OF PLANT AND SOIL SCIENCES

COOPERATIVE EXTENSION SERVICE,
UNIVERSITY OF MASSACHUSETTS, UNITED
STATES DEPARTMENT OF AGRICULTURE AND
COUNTY EXTENSION SERVICES COOPERATING.

EDITORS
W. J. LORD AND W. J. BRAMLAGE

Volume 50, No. 3
SUMMER ISSUE, 1985

Table of Contents

Compatability of Selected Apple
Rootstocks with Massachusetts Soils

Predicting the Keeping Quality of
Macintosh Apples from Preharvest Mineral
Analyses of Fruit

Biological Control of Weeds

Update on the Relative Toxicity of
Orchard Pesticides to the Predator Mite
Ambiyseius fallacis

Putting Theory into Practice

The Soft Fruit Industry in England

Parking Tips for Roadside Markets

Issued by the Cooperative Extension Service, E. Bruce MacDougall, Dean, in further-
ance of the Acts of May 8 and June 30, 1914; United States Department of Agriculture
and County Extension Services cooperating. The Cooperative Extension Service offers
equal opportunity in programs and employment.

COMPATIBILITY OF SELECTED APPLE ROOTSTOCKS WITH MASSACHUSETTS SOILS
Peter L.M. Veneman, Department of Plant and Soil Sciences

Orchard Soils

A good orchard soil should be deep and well aerated, yet capable of
holding sufficient moisture to meet the water needs of fruit trees, even
during prolonged dry spells. Soils with clayey or compacted subsoils lack
large pores, which may result in a restriction of the oxygen supply to the
roots. Tree roots often tolerate some submergence during the dormant
season, but this water should have dissipated by the time growth starts in
the spring. Tree growth and fruit production otherwise tend to be poor on
such soils. Although some of these limitations can be overcome tiiy soil
modifications, such as artificial drainage or by subsoil loosening, most of
these measures are expensive and in the case of compacted subsoils effective
only for a limited time.

Prior to purchase of any trees the soil should be examined by a
qualified soil scientist to determine whether or not the soil is suitable
for growing fruit trees. Soils which have orange-reddish and grayish
mottles, or which have predominantly gray colors within 3 feet of the soil
surface most likely have problems with excessive seasonal wetness and should
be rejected as an orchard site. Gravelly and coarse sandy soils on the
other hand lack sufficient water storage capacity and are subject to drought
during prolonged dry spells.

The ideal orchard soil should have a dark, organic-rich topsoil. The
subsoil should be capable of retaining sufficient amounts of water to
sustain unlimited grov/th even during prolonged dry periods, while on the
other hand being permeable enough to rapidly conduct excess soil water.

Careful observation of the natural vegetation growing on or adjacent to
the site selected for the orchard can be helpful in determining the suitabi-
lity of the soil for fruit trees. Pitch pine and scrub oak indicate gra-
velly soil which is excessively drained and subject to drought. Red maple,
alder, and willow indicate a soil which is poorly drained and excessively
wet. Sugar maple and white ash do best on a deep fertile, well-drained soil
of good water-holding .capacity.

Matching Rootstock and Soil

Size-controlling rootstocks in general are more demanding than seedling
rootstocks in respect to drainage, depth of soil, and water holding capa-
city. Therefore, when deciding on which rootstock to use, it is very impor-
tant to know the soil type(s) of the land to be planted. The proper match
between rootstock and soil may be the difference between the success or
failure of the planting.

- 2

Experimental plantings, matching various rootstocks with representative
Massachusetts soils, are presently being conducted throughout Massachusetts
but no definite results on yield differences are available as yet. Based on
past experience we can make some general recommendations regarding the per-
formance of certain rootstocks on various Massachusetts soils.

The first step in matching the rootstocks and soil is to determine the
soil type{s) for the land to be planted. Soils information generally is
available from the U.S. Department of Agriculture - Soil Conservation Service
office in the form of soil survey reports. If no soil map is available, an
on-site inspection by a qualified soil scientist will provide the necessary
information. On-site investigations often are preferred because localized
wet or droughty spots may exist within fields that are otherwise well suited
to apple production. These less desirable areas may be too small to be
indicated on the standard scale soils map. Your local Extension Service
office can provide you with the names of qualified soil scientists within
your area.

The soil series currently recognized in Massachusetts have been grouped
in 6 soil suitability groups (Table 1). Keep in mind that these suitability
groupings are based on internal soil characteristics. External properties
such as landscape position and a drainage potential are not considered,
therefore, soils at certain locations, although placed in a favorable
grouping, may not be suitable for apple production.

Lastly, refer to the tentative guide for rootstock/soil compatibility
in Table 2 to determine which rootstocks are most suitable for your soil
conditions .

- 3

Table 1. Grouping of Massachusetts soils according to suitability for apple orchards,

Group 1. Gravelly or sandy soils with a tendency to drought.

Carver

Dukes

Enfield

Evesboro
Groton

Hinckley
Merrimack

Plymouth
Quonset

Suncook
Windsor

Group II . Gravelly or sandy soils, without the tendency to drought

Agawam
Canton
Copake

Essex
Gal estown
Gloucester

Haven

Hinesbury

Katama

Lincroft
Montauk*
Oakville

Poquonock*
Warwick

Group III

Good, deep
capacity.

Berkshi re
Brookfield
Charlton
Chatfield

soils with average to good drainage and a good waterholding

Cheshi re
Chilmark
Col rain
Dutchess

Had ley
Hartl and
Lenox
Narragansett

Ondawa

Pittsfield

Pollux

Riverhead
Unadil la
Yalesville

Group IV.

Good , but
rooting.

somewhat shallow soils with hardpans or bedrock that prevent deep

Bernardston
Brimfield
Broadbrook
Hoi lis

Hoi yoke
Lyman
Marlow
Meckesville

Mel rose
Mill is
Nantucket
Nassau

Newport
Paxton
Shel burne

Stockbridge

Suffield

Wethersfield

Group V . Soils that tend to be wet for short period of time, but usually not during the

growing

season .

Acton

Buxton

Ludlow*

Podunk

Sutton

Amenia

Deerfield

Matawan

Rainbow*

Tisbury

Amostown

Eldridge

Ninigrit

Scio

Wauchaug

Belgrade

Elmwood

Peru*

Scituate*

Winooski

Birchwood*

Hero

Pittstown*

Sudbury

Woodbridge

Buckland*

Klej

Group VI . Poorly drained soils, unsuitable for tree fruits, unless artificially drained,

Adrian

Au Gres

Berryland

Biddeford

Birdsall

Brockton*

Cabot*

Carlisle

Enosburg

Fredon

Freetown

Hal sey

Ipswich

Kendal a

Leicester

Limerick

Lyons

Mansfield*

Maybid

Menlo*

Munson

Norwell*

Palms

Pawcatuck

Peacham*

Pipestone

Pompton

Raynham

Ridgebury*

Rumney

Saco

Saugatuck

Scitico

Scarboro

Stissing*

Swansea

Swanton

Walpole

Wareham

Westbrook

Whately

Whitman*

Wilbraham*

*Denotes presence of a hardpan

Table 2. An approximate guide of rootstock/soil agreement.

Rootstock

Soil suitability groups

III

Dwarf

M.9, M.9A, or virus-tested M.9

Semi -Dwarf
M.26

Interstem M.9/Alnarp 2
Interstem M.9/Seedling
Interstem M.9/M.13
Interstem M.9/MM 111
Interstem M.9/MM 106
MM 106
M.7 or M.7A

X
X
X

X
X
X
X

X
X
X
X
X
X
X
X

X
X
X
X
X
X
X

Vigorous
Alnarp 2
MM 111
Seedling

X
X
X

X X

X denotes compatibility of rootstock and soil group

PREDICTING THE KEEPING QUALITY OF MCINTOSH APPLES
FROM PREHARVEST MINERAL ANALYSES OF FRUIT

William J. Bramlage, Sarah A. Weis, and Mack Drake
Department of Plant and Soil Sciences

If the storage potential of apples could be predicted accurately at
harvest, the fruit could be stored and marketed within these potentials.
Lots of fruit with potential for long-term storage could be stored long-
term, ones whose potential is not as good could be marketed in early- to
mid-winter, and ones with little storage potential could be marketed in the
fall. In this way the grower could make maximum use of his fruit and the
consumer could benefit by purchase of better quality fruit.

During the past 30 years a large volume of research has established
that mineral compostion is related to keeping quality of apples by
influencing the onset and rate of ripening, but especially by determining
the occurrence of physiological disorders after harvest. Early research
focused primarily on bitterpit, which is caused by a deficiency of calcium
(Ca) in the fruit, but it is now recognized that many apple disorders are
influenced, if not caused, by adverse mineral compostion of the fruit.

The predictability of storage disorders from preharvest mineral
analyses was first proposed in England; methods of fruit analyses and pre-
diction from the results were then developed there. For a number of years,
a large cooperative storage (East Kent Packers, Faversham, Kent) has used
predictions from fruit mineral analyses to schedule storage withdrawals for
its Cox's Orange Pippin apples. Since value of the apples generally
increases with later marketing, growers who maintain proper mineral levels
in their fruit are rewarded by later marketing of their fruit and the
corresponding higher prices paid for them.

During the 4 years 1979 to 198?, we conducted extensive surveys to
determine (1) the effects of minerals in Massachusetts-grown Mcintosh apples
at harvest on their keeping quality; and (2) if it is possible to predict
the keeping quality of our apples from preharvest mineral analyses. Our
findings in regard to the first question have been reported earlier ( Fruit
Notes 48(4) :4-8), and can be summarized in one sentence: "...inadequate Ca
in fruit is the primary nutritional factor influencing quality of Mcintosh
apples in Massachusetts, and this factor is expressed mostly in the
occurrence of breakdown after storage." We found that many orchards were
producing Ca-deficient fruit which therefore possessed lessened potential
for long-term storage. Here we now report our findings about predictability
of keeping quality from mineral analyses.

We used 2 different approaches to prediction. First, we used a scoring
system similar to the one developed in England, which gives each sample a
"score" for its mineral composition, and this score is then used to predict
the keeping quality of the fruit. The score is based on the concentrations
of N, P, K, Ca, and Mg in the fruit 2 weeks before harvest. A preliminary
report ( Proceedings of the Massachussetts Fruit Growers Association
88:46-56) concluded that a prediction based on such a score was feasible for
our apples, but also that accuracy of the prediction was quite variable.

- 6 -

When results of all 4 years of data were assessed, it was apparent that
this approach was reasonably accurate when only low scores (which indicate
excellent storage potential) and high scores (which indicate very poor
storage potential) were considered. However, it did not provide useful
information about samples which had intermediate scores.

Our second approach was to produce equations that described the rela-
tionships between mineral composition and keeping quality in mathematical
terms. Initial indications were that this was the better approach ( Proc
MFGA, cited above). When the 4 years of data were fully evaluated, this
initial assessment was reaffirmed. The equation that we developed was a
more accurate predictor than was the scoring method we used. Furthermore,
it could be used to predict keeping quality from any mineral composition,
not from just the very high and very low ranges.

Our results showed that because Ca was the only element that was
generally affecting keeping quality of the apples, a mineral analysis was
needed only for Ca to make a prediction. The other elements in our survey--
N, P, K, and Mg--did not need to be measured for our fruit.

In a separate study we tested the value of including measures of fruit
maturity and fruit size in a predictive equation, since storage life is
reduced as apples become large and are harvested at a later maturity. This
study indicated that inclusion of a score for starch concentration in the
apple and inclusion of a measure of fruit size at harvest both could improve
the accuracy of a prediction based on Ca concentration in the fruit ? weeks
before harvest.

To be able to predict potential keeping quality of commercial lots of
apples at harvest from mineral analyses, there must be the capability for
gathering, preparing, and analyzing representative fruit samples rapidly.
Our studies are all based on sampling apples 2 weeks before harvest. If
fruit samples could be taken earlier in the growing season it would allow
more time for analysis, but research in England has shown that the earlier
fruit samples are taken, the less likely they are to represent the mineral
content at harvest. Leaf analyses cannot substitute for fruit analyses.
While they are good measures of mineral status of trees, leaf analyses are
of little value in portraying the mineral status of fruit, especially that
of Ca . Thus, use of prediction capabilities requires the ability to obtain
results from a testing laboratory in a very short period of time--within 2
weeks after taking the samples from a tree. At present no laboratory in
Massachusetts is capable of doing this.

This has presented a dilemma to us. On one hand, we know that we can

predict with acceptable accuracy how well Mcintosh will keep after harvest,

but we do not have the facility for producing the needed analyses. On the

other hand, we are working with a rather simple problem: Ca deficiency is

the basis for the prediction. Should our efforts be directed to

establishing a facility for analyzing fruit and predicting storage life, or

would it be better for us to continue to pursue methods of avoiding and

correcting Ca -deficiency? To this point we have chosen the latter course,

and have continued to try to improve preharvest and postharvest treatments

to ensure that fruit possess sufficient Ca at harvest for maximum posthar-
vest life. '^

7 -

However, fruit mineral analyses could be quite useful to a fruit grower
if for no other reason than to measure the adequacy of his Ca treatments.
It could also indicate whether or not a postharvest Ca drench is needed.

Although no fruit analysis service is available in Massachusetts, the
Analytical Laboratory in the Department of Plant and Soil Sciences of the
University of Maine is offering a commerical apple fruit testing service.
Their capacity to analyze fruit within 7. weeks is limited, but within this
limit the cost of an analysis is $l?.On per sample. For anyone interested
in this service samples should be taken 2 weeks before the projected harvest
date. A sample would consist of 20 apples, one from each of ?0 trees, and
these trees should be representative of the block which is being tested. It
is essential that the fruit he uniform in size, between 2.7 and 2.8 inches
in diameter. These fruit will be analyzed for Ca , K, P, and Mg . A problem
that will have to be resolved is how these samples can be transported to the
laboratory. We would suggest that any grower who is interested in this ser-
vice should contact Mr. Bruce Hoskins (207-581-2917) well before sampling so
that necessary arrangements can be made.

There is considerable interest among research workers in the potential
for predictions from mineral analyses. We have not encouraged establishment
of a commercial laboratory in Massachusetts because we believe that Ca defi-
ciency is correctable. However, now that fruit analyses are available
through the University of Maine laboratory, growers have the opportunity on
a limited scale to assess the mineral status of their fruit in time to make
critical decisions about the ways in which they will be treated and stored
after harvest. This may be a direction for the future.

POMOLOGICAL PARAGRAPH

Weeds are reservoirs for virus . Tomato ring spot virus (TmRSV) can cause
disease of apples, peaches, cherries, grapes, raspberries, blueberries and
strawberries. For example, TmRSV is associated with a disease known as
apple union necrosis and decline and Prunus stem-pitting disease of peach.

Studies in Pennsylvania show that 18 species of broadleaf weeds
including common chickweed, henbit, dandelion, common plantain, wild
strawberry, sorrel, red clover and oxalis were all natural hosts for TmRSV.
Further studies showed that (1) TmRSV in dandelion is correlated with Prunus
stem-pitting diseases of peach; (2) dagger nematodes that feed on the roots
of a TmRSV-infected dandelion and then on the roots of a peach tree can
transmit the virus to that peach tree; and (3) TmRSV can be carried by dan-
del ion seeds .

How do these results apply to growers in Massachusetts? TmRSV also is
of concern in Massachusetts, thus the control of dandelions to insure good
bee activity should also help eliminate a major source of the virus.

- 8

BIOLOGICAL CONTROL OF WEEDS

William J. Lord, Department of Plant X Soil Sciences

In recent years attention of weed scientists has been directed to
biological control of weeds using insects, pathogens or allelopathy.
Successful examples of weed control with insects or pathogens can be cited
and include control of cactus in Australia by a moth borer imported from
Argentina, control of St. Johnswort in western United States by leaf-eating
beetles, and use of pathogens to control northern jointvetch in rice fields
and strangler vine in citrus orchards.

Plants may release chemicals ( al lei opathics) which are harmful or bene-
ficial to other plants and to pests that affect the plant. The release of
these chemicals by either living plants or their residues is called allelo-
pathy. Studies have been directed toward the use of allelopathy. A.R.
Putnam, Department of Horticulture, Michigan State University, is
researching the use of cover crops or companion crops whose residues can
provide mulch that chemically suppresses the germination and/or growth of
weeds under fruit trees ( 12t h Ann. Rpt . , Michigan State Hort. Soc . 1982, pp.
193-196). His studies show that residues from fall -pi anted cover crops of
Tecumseh vvheat (spring or fall -killed with herbicides) and Balboa rye
( fal 1 -ki 1 led) reduced both weed density and total weed biomass during the
following growing season. In contrast, Garry oat (fall-killed by cold
weather) residue appeared to stimulate weed germination and Balboa rye resi-
due (spring-killed with herbicide) was not toxic to weeds. Other experi-
ments indicated that Bird-a-Boo sorghum or Monarch sudangrass mulch provided
weed biomass reduction of approximatl ey 90% and 85%, respectively.

The weed species encountered in both the cover crop and mulching
experiments were primarily annual s--large crabgrass, common ragweed, common
1 ambsquarters, ladysthumb, green foxtail, and mousear chickweed. Perennial
fescue species also were partially controlled.

Putnam concluded that selected cover crop residues or mulches can pro-
vide excellent suppression of a number of annual weed species but that long-
term studies must be conducted to determine effects of these cover crops or
mulches on fruit trees. A major disadvantage of mulch is that it provides a
favorable habitat for mice.

UPDATE ON THE RELATIVE TOXICITY OF ORCHARD
PESTICIDES TO THE PREDATOR MITE AMBLYSEIUS FALLACIS

Susan L. Rutkewich and Ronald J. Prokopy
Department of Entomology

In past issues of Fruit Notes we cited the relative toxicity of orchard
pesticides commonly used in Massachusetts apple orchards to the mite preda-
tor Amblyseius fallaci s in both laboratory (Vol. 43 (5): 14-18; Vol. 44
(5): 6-8) and orchard settings (Vol. 43 (4): 5-8). We have shown that
Massachusetts field populations of A. fallacis , an important predator of red
and two-spotted spider mites, are highly susceptible to field concentrations
of some pesticides such as Lannate* (methomyl), Cygon* (dimethoate) and the
synthetic pyrethroids (SPs), but can tolerate other pesticides like Guthion*
(azinphosmethyl ) , and Thiodan* (endosul fan) .

The degree of tolerance or resistance this predator possesses can vary
from region to region depending on the history of chemicals applied in each
area. Resistant strains of A_^ fallacis have been found in orchards across
the country. In Michigan, New York, New Jersey and North Carolina, several
field populations of A^. fal lac is have been screened for resistance to
various pesticides. In' particul ar , at the Pesticide Research Center and
Department of Entomology at Michigan State University, Brian Croft and others
have evaluated pennPthrin-( Ambush* , Pounce*) resistant strains of A. fal lac i s
for cross resistance to other SPs and for resistance to insecticides in
other classes, i.e., organophosphates and carbamates. Successful establish-
ment of resistant/cross resistant predator mites in the field would provide
an important tool for IPM programs across the country.

What alternatives exist for encouraging predator mite populations
today? At present the most effective strategy a grower can undertake is to
select pesticides and application time which have minimal effects on preda-
tors. Pesticides of high or moderate toxicity are not recommended in
orchards after bloom. Pesticides can be detrimental to A. f allacis if they
are applied when the predator is in the understory, i.e. diinng spring and
early summer, and later when the predator has moved up into the tree, i.e.
July through September.

Here, we present the latest compilation of the relative toxicity of
pesticides commonly used in Massachusetts apple orchards to the predatory
m1te A. fal 1 ac is . The toxicity ratings have been arranged according to each
state where the infomation was obtained. The ratings provide comparison of
the predator's susceptibility to pesticides in different geographic loca-
tions.

*Trade name

- 10 -
Table 1. Relative toxicity of commonly used pesticides to A. fallacis

Location

Material

Insecticides

chlorpyrifos 50WP
methomyl l.aEC
carbaryl SOWP
phosalone 25WP
phosalone 3EC
demeton 6EC

fenvalerate 2.4EC
pennethrin 3.2EC
dimethoate 2.67EC
dimethoate SOWP
oxamyl 30WP
diazmon 50WP
phosphamidon 8EC

amitraz

oxythioguinox 25WP
ennosulran 50WP
phosnet 50WP
azinphosmethyl 50WP
methyl paratnion 2FM
methyl parathion 2EC
methoxychlor 50WP

Acaricides

Acaralate* 2EC
formetanate 925?
dicofol 35WP
cyhexatin P^OWP
propargite 30WP
fenbutatin-oxide 50WP

Fungicides

Lime sul fur
difol atan 4EC
dinocap 25WP
benomyl 50WP
dikar 80WP

glyodin-dodine 37-22WP
glyodin 30EC
dodine 65 WP
maneb 80WP
thiram 65WP
dichlone 50WP
captan 50WP
ferbam 76 WP
maneb-zinc 80WP
Polyram 80WP

Herbic ides

ammonium sul f amate
paraquat 2EC
glyphQsate 2EC
simazme 80 WP
dal apon WP

MASS

High
High
High
High
High

High
High
High

High
High
Mod

Low
Low
Low
Low

Low

High

Mod

Low

MICH

Relative toxicity
High

High

High
High

Mod
Mod
Mod

Mod
Low
Low
Low
Low

Low

High

Low

Mod

High

High
High

Mod

Low
High

Higf-
Mod
Low
Low

High

Mod
Low

High

Mod

Mod*

Low

Mod

Low

.ow

Low

.ow

Low

.ow

-OW

—

Low

High

Low

High

High
High

Low

Low
Low

High

High
Mod

^Sterilizes predators

- 11 -

PUTTING THEORY INTO PRACTICE
William J. Bramlage, Department of Plant and Soil Sciences

During the winter of 1979, the East Mailing Research Station, Kent,
England initiated an unusual project: development of a demonstration apple
orchard that incorporates the practices believed by the East Mailing
research staff to be most desirable for successful establishment and deve-
lopment of an orchard of 'Cox Orange Pippin', England's most important
dessert apple. A detailed examination of the development of this orchard
provides a unique view of the current thinking of England's leading pomolo-
gists.

The site for this orchard is on deep, well-drained, fine sandy loam and
is surrounded by windbreaks of alder and sweet chestnut trees. In July,
1979, the site was subsoiled to a depth of 20 inches, plowed with a chisel
plow, and leveled. The rows were laid out and the strips in which the trees
were to be planted were fumigated by injecting Chloropicrin at 25 gallons
per acre under 41/?-foot wide strips of clear polyethylene. The fumiga-
tion was done because this was fornier apple orchard land with a known
replant problem caused by a buildup of soil organisms harmful to apple
roots. The polyethylene sheets were kept in place until planting to protect
soil structure.

In December, 1979, two ll/4-acre blocks were planted, one on M9 and
one on MM106 rootstock. Trees had been budded at \?. inches, and developing
branches ("feathers") were removed from the bottom ?7 inches of stem; above
this point they were pinched at U/;? inches of length and then allowed to
develop.

'Cox' on M9 were planted at 11 1/? x 8 feet, 481 trees per acre, and
ones on MMlOfi were planted at 11.5 x 17 feet, 220 trees per acre. 'Discovery'
and 'Spartan' were planted as pollenizers, alternating at every sixth tree
in a row and being staggered in adjacent rows to produce diagonal rows of
identical cultivars. Holes were dug with a tractor-mounted auger, each tree
was immediately staked with B-foot spindle stakes, and trees were carefully
tied to stakes with plastic tubing.

In late February the central leaders were headed to a vegetative bud
about 4 inches above the uppermost "feather". M9 trees produced some bloom
and were defruited shortly afterward. In June, the second, competing shoot
was removed from all trees. The following February, the central leader of
each MMin9 tree was tipped, and all competing leaders were removed. The
central leader of each M9 tree was tipped, as were 4 other leaders. In July
of this second year the more vigorous branches were tied down to encourage
fruiting, and the following winter all remaining branches were tied down.
To further suppress vegetative growth, by stimulating flower bud formation,
daminozide was applied in July, 1980 at 18 lbs. per acre, and in July, 1981
at 13 lbs. per acre.

Assistance of Mr. G.C. White of the East MalTTng Research Station in
the preparation of this article is gratefully acknowledged.

It is intended to maintain these trees at a height of about 71/2
feet, with a well-defined "fruiting table" at ? 3/4 feet. The tip of this
central leader tree will not be allowed to become dominant, by continually
cutting it back to a suitable weaker leader.

Before planting, the entire orchard floor was sprayed with a herbicide
mixture of simazine and paraquat, and follow-up spot applications of diuron
were used to kill persistent weeds. A grass alley was then established
(before planting) and remained until the start of the 1982 season, when it
became apparent that soil structure was collapsing, and at one point in 1983
the leaves on the trees wilted. To correct this problem the alleys were
again subsoil ed in August, 1983, and grassed down with perennial ryegrass in
the spring of 1984. These grassed alleyways are a temporary measure and
will be killed when soil structure and organic matter are judged to again be
satisfactory.

An overhead irrigation system was erected in the orchard. The risers
for the system are 51/2 feet high in the M9 block and 9 3/4 feet high in
the MMine block. In 1982 and 1983 this system was used to prevent frost
damage and during the dry summers of 1983 and 1984 irrigation was an impor-
tant contributor to the yields obtained from these blocks.

In 1981 it was apparent that bloom on the pollenizer trees was inade-
quate, and this problem reoccurred in 1982 and 1983. To overcome the
problem a bouquet of bloom was placed in the center of each group of 5 'Cox'
trees. These bouquets were kept in water in a plastic bag that was looped
around a nail on the stake supporting the tree. A fresh bouquet was placed
in the bag after 4 days. By 1^84 pollenizer bloom was sufficient to avoid
this task. Fach year hives of bees were placed in the orchard on the south
side near the windbreak when 10-15% of the bloom was open.

Yield from these trees was about 8 bushels per acre in 1981 (the 3rd
growing season) regardless of rootstock. In 1982 the M9 and MM106 trees
produced 172 and 176 bushels per acre, respectively. In 1983, M9 and MM106
trees yielded 334 and 290 bushels per acre. M9 and MM106 graded out 82% and
87% Class 1 fruit, repectively, in 1983. Since the average yield of 'Cox'
in England is only 225 bushels per acre, it is evident that this orchard, in
only its fourth year, is performing very well.

In 1983 the spray program cost the equivalent of $350 per acre. Almost
half of this cost was accounted for by nutritional and growth regulator
sprays. These consisted of 4 applications of a commercial gibberellin
(fiA4+7) spray used to improve fruit finish, and 5 applications of a commer-
cial phosphorus mixture, used to improve storage quality of fruit.

Management decisions for this orchard are made by a committee of East
Mailing researchers headed by the Director of the Research Station. The
industry is kept well informed of the orchard's progress, problems that are
encountered, and responses that are made to correct the problems, by an
ongoing series of articles that appear frequently in The Growe r, a commer-
cial horticulture weekly magazine. This unusual project not only allows the
growers to observe modifications that can be made when unexpected problems
arise. It is a fine example of "putting theory into practice."

- 13

THE SOFT FRUIT INDUSTRY IN ENGLAND

Wi 1 1 iam J . Rraml age
Department of Plant and Soil Sciences

The soft fruit industry in England is under continual pressure from
European countries, but the intensity of this pressure varies with relative
values of currencies. When the value of the English pound sterling is low,
imports from Europe decline, but when the pound's value is high European
soft fruit--both fresh and processed--can quickly flood the market.
Therefore, fortunes of the industry can fluctuate dramatically for reasons
completely beyond the control of the fruit growers.

Table 1 shows the estimated size of the soft fruit industry in the
United Kingdom in 1980, which is fairly typical of recent years. Most of
this production is in England except for that of raspberries, where two-
thirds of the crop is grown in Scotland. Approximately 60% of the
strawberries are grown for fresh market, and 40% for processing. In
contrast 30% of the raspberries are grown for processing and virtually all
of the blackcurrants, gooseberries, blackberries, loganberries, and currants
are processed .

Table 1. Approximate total production areas and yields of soft fruits in
the United Kingdom (England, Scotland, Wales, and Northern Ireland). 1980.

Crop

Area (acres)

Production

(tons)

Strawberries

20,000

54,400

Raspberries

10,750

21,200

Blackcurrants

10,500

18,400

Gooseberries

2,875

7,900

Blackberries

1,425

4,400

Loganberries

450

1,000

Red and white currants

425

900

These fruit are all expensive to establish and to grow. Their produc-
tion problems can be summarized as ones of obtaining good sites, using
healthy plant material, and rigorously controlling weeds, insects, and
diseases. Plant material is provided through a system similar to that
described for apples ( Fruit Notes 50(1) :l-5) .

The biggest cost, however, is in harvesting and marketing. An effi-
cient machine harvester has been developed for blackcurrants, but its cost
is quite high. The other soft fruits are predominantly hand harvested by
local labor. PYO has become very popular for soft fruits, but a good PYO
business requires careful organization and management, and provisions for
parking, toilets, and picnic areas.

- 14 -

Strawberry production for the fresh market has remained strong in
England. European imports discourage early-season production although small
volumes are produced under plastic tunnels for early local marketing. Main-
season marketing has been strengthened by establishment of cooperatives, a
move dictated by concentration of wholesale buying into fewer and larger
outlets that demand large volumes of uniform, attractive fruit. These
markets also require properly cooled fruit, and cooperative facilities can
make this feasible. Cooperative marketing is the only way small growers can
compete in this arena. PYO production of strawberries has been growing espe-
cially in holiday areas of the country. However, strawberry processing has
been declining due to both economic factors and changing eating habits of
the Engl ish people.

Cane fruits are growing in popularity for PYO sales, but very little is
otherwise marketed fresh because of the high cost of harvesting and the need
for proper cooling if volume marketing is to be attempted. The black-
currant, a fruit with which most Americans are unfamiliar, is popular in
England primarily as a processed product. Blackcurrant production is highly
concentrated since the mechanical harvesters developed for this crop are
only efficient on large acreage. Because the capital investment in har-
vesting is high, blackcurrant growers have negotiated long-term contracts
with processors. Gooseberries and currants have lost favor with consumers
in recent decades and are dwindling as commercial commodities.

The long-term prospects for the soft fruit industry in England seem to
rest with further development of fresh fruit sales. There is considerable
interest in developing new varieties and production methods to lengthen the
harvest season for these crops. Expansion of fresh fruit sales will prob-
ably be required to balance continued erosion of the processing market to
make this a stable industry.

15 -

PARKING TIPS FOR ROADSIDE MARKETS*

Ample parking is a major concern for most new farm markets (and some
old ones too!) Today's shopper likely will not stop-to-shop if there is no
safe convenient parking area. Carefully planned customer parking offers
great opportunity for building up your trade. It is very important to
understand the handling of the traffic flow into and out of the parking lot.

1. Allow a ratio of 4 square feet of parking space for each square foot of
market size. For example, a 40 x 50 ft. building (2,000 square feet)
would require approximately 8,000 square feet or nearly one-fifth acre
of land for parking .

2. Allocate one parking space (about 400 square feet) for each $100 sale.

3. Provide 15 parking spaces for each 100 cars expected daily.

All of these general rules are good, but the important consideration
must be the convenience of the customers.

Parallel parking space should be 22 feet long by 10 feet wide. Parallel
parking is awkward and wastes space, but is used sometimes to fill in odd
areas. A combination of 90 degree angle and parallel parking often makes
the best use of small or irregular lots.

Parking at 90 degrees to a curb or fence accommodates the most cars in
the lot. Minimum practical dimensions for a parking stall are 10 x 20 feet.
With 90 degree parking, two-way traffic aisles are best.

Where lots are 60 to 70 feet wide, 90 degree parking and two-way aisles
are recommended. One row of 90 degree parking, plus a two-way aisle, can be
installed in lots as narrow as 42 feet.

The smaller the angle (45 to fiO degrees) the easier it is to park,
though cars with power steering are easy to park anywhere.

For 45 degree stalls, 14 foot aisles will be satisfactory for one-way
traffic. For 60 degree stalls, 18 foot aisles are recommended to give suf-
ficient clearance for drivers backing out of the stalls.

The Eno Foundation for Highway Traffic Control suggests the following
steps in laying out a parking lot.

1. Make an accurate drawing of the area including the following:

- Outline and use abutting properties, buildings and vacant areas.

- Abutting sidewalks, streets and alleys with direction of traffic flow
on each.

*Repri"n"ted with permission from The Great Lakes Fruit Growers News 23(3): 64,
March, 1984.

- Points where access to abutting properties must be preserved. (Use of
wheel stops and guard fences can protect adjoining property and
buildings.)

- Locations of any fixed obstacles which cannot be removed.

- Setbacks required by local building ordinances or codes.

- Space needs for any required or desired screening, such as fences,
hedges, landscaping, etc.

- Location of market and any other facility the lot is intended to
serve.

2. Determine the possibilities of acquiring any small abutting property
which would give access to a second street or to an alley and permit a
better circulation pattern.

3. Consult local building codes and zoning ordinances for any possible
instructions or requirements as to a size of curb cuts, fencing or
screening, drainage, lighting, hours of operation, signs, etc.

4. Lay out the actual spaces and bays on a piece of graph paper (everything

- building, lots, etc.) to scale. This method will enable you to mini-
mize the use of the parking area.

Approaches and driveways are very important and can add much to the
appeal and safety of the market. They should be long and smooth, whenever
possible, with space for at least 2 cars (40 feet) on the de-acceleration
lane to give the motorist a chance to pull off the highway safely some
distance from the market.

The driveway into the market should be as far from intersections as
possible and be clearly marked with directional arrows to start traffic in
the right direction.

^ parking lot surface can be gravel, soil or paved. It is important to
provide proper drainage, or pot-holes, ruts, and corduroyed surfaces will
develop quickly. Drainage requirements will depend largely on the internal
soil composition. Sandy or gravelly soils need very little slope to provide
satisfactory surface drainage. Heavy clay soils need to be sloped very con-
siderably for proper runoff, but not so steep as to cause cars to run away.

Unless guided or directed, drivers do not make efficient use of the
parking spaces. You can assist them by striping or marking the parking
lot.

More farm markets are providing shopping carts because their use
increases sales. If you have an asphalt or concrete parking lot, carts can
be pushed out to the cars.

If the parking lot is dirt or gravel, provide a sizeable sidewalk where
customers can leave their bask-carts on a hard surface while the car can be
brought up to the store front for loading.

Cooperative Extension Service
U.S. Department of Agriculture
University of Massachusetts
Amherst, Massachusetts 01003

OFFICIAL BUSINESS

PENALTY FOR PRIVATE USE, $300

POSTAGE AND FEES PAID

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FRUIT
NOTES

PREPARED BY
DEPARTMENT OF PLANT AND SOIL SCIENCES

COOPERATIVE EXTENSION SERVICE,
UNIVERSITY OF MASSACHUSETTS, UNITED
STATES DEPARTMENT OF AGRICULTURE AND
COUNTY EXTENSION SERVICES COOPERATING.

EDITORS
W. J. LORD AND W. J. BRAMLAGE

Volume 50 No. 4
FALL ISSUES, 1985

Table of Contents

Fruit Notes Subscription

Orchard Mouse Control: Points to Ponder,
Items to Consider

Fate of Lead-Arsenate in Old Orchards

Host Learning Behavior of Apple Maggot Flies

Fruit Growing in Australia

A Brief Summary of Rootstocks and
Interstem Trees

Comparison of Some Fruit Characteristics
of "Mcintosh" Apples Grown on Seedling
and M7 Rootstocl<s

isued bv the Cooperative Extension Service, E. Bruce MacDougall, Dean, in further-
nce of the Acts of May 8 and June 30, 1914; United States Department of Agriculture
nd County Extension Services cooperating. The Cooperative Extension Service offers
qual opportunity in programs and employment.

FRUIT NOTES SUBSCRIPTION

Your 1985 subscription to FRUIT NOTES is completed
with this issue. To continue to receive FRUIT NOTES,
complete and mail the following form with your check for
$3.00. (Canadian subscribers, please send a U.S. postal
money order) .

Wil 1 iam J. Bramlage
Editor

Name

Mail ing Address

Town, State, Country ^Zip

Make checks payable to: FRUIT NOTES ACTIVITY ACCOUNT

Send subscription form and check to: William J. Bramlage

Department of Plant and Soil Sciences
French Hal 1

Jniversity of Massachusetts
Amherst, MA 01003

1986

ORCHARD MOUSE CONTROL: POINTS TO PONDER AND ITEMS TO CONSIDER

Edward R. Ladd, Fish and Wildlife Service
U.S. Department of the Interior, Hadley, Massachusetts

With the advent of fall and apple harvest, it also is necessary for
orchard managers to consider how they will conduct their orchard mouse
program.

As an aid to planning orchard mouse control you as a manager might
consider the following points:

- Has a check of the orchard been conducted this year to gain some idea of
mouse activity? This information added to the orchard history of known
problem areas may well indicate the need for additional or special treat-
ment. This is particularly true of those blocks or isolated trees that
have a pine mouse infestation.

Is a sufficient amount of good quality mouse bait on hand to give ade-
quate treatment of the entire orchard and to cover the special needs of
problem areas?

Is the bait application equipment in good working order and calibrated to
provide proper coverage?

- Will the manpower needed to apply bait be available and properly trained
when needed?

There are several other items that should be considered to help insure
an effective mouse orchard program.

- Timing is perhaps one of the most important parts of mouse control. Bait
application should be after harvest toward the end of October. This is
when mouse populations will be highest.

After a block has been picked give the vegetation under the trees a chance
to recover and the mice time to reestablish their runs and burrows. This
is particularly true for pine mice if hand baiting is the planned control
method.

- Check the mouse guards on the smaller trees to insure they are properly
instal led.

If vegetation in the block is heavy, consider delaying the last mowing
until after bait application. A layer of mowed vegetation can prevent
broadcast baits from getting down to ground level where it is most effec-
tive.

- Select 3 or more days of good weather for bait application.

- Consider the treatment and mowing of buffer area for those blocks of
trees adjacent to fields or other areas having meadow mice. This treat-
ment can reduce mouse migration into the treated orchard and lower the
chance of winter tree damage.

- One to 2 weeks after the bait has been applied, recheck the orchard, par-
ticularly the known trouble spots, for mouse activity. If excess,
retreat as necessary.

c -

FATE OF LEAD-ARSENATE PESTICIDES IN OLD ORCHARDS

Peter L.M. Veneman
Department of Plant and Soil Sciences

From the early part of this century until the late 1940's lead-
arsenate was used extensively as a general pesticide. This material was
applied not only in Massachusetts, but also in any state where apples were
being produced prior to the 1950s. In Oregon and Washington the acid form
of lead-arsenate was applied, while the basic form was more popular in the
Northeast. The amount of pesticide applied may be inferred from old spray
schedules, but the exact quantity probably varied from grower to grower.
Significant amounts of this pesticide still remain in the soil. Its pre-
sence may cause some complications when an orchard site is sold for develop-
ment, but even if the site remains in production there is a concern for
potential groundwater contamination as well as the possibility that some of
the residues end up in the fruit.

In 1982 we initiated a project at the university to evaluate the fate
of lead-arsenate in soils in old orchards, as well as to assess whether or
not residues end up in the apple fruit tissue. In this paper we report on
our soils studies, while the fruit quality issue will be addressed in a sub-
sequent FRUIT NOTES article.

Our initial study was concentrated at the old university orchard on the
Amherst campus. This site has been used for fruit production since the late
1800's and has received significant applications of lead-arsenate-containing
pesticides, although no accurate records exist as to exactly how much has
been applied. We sampled the surface-soil within the old variety block in a
grid-like pattern in six rows 1.5 m (5 ft) apart, at 60 cm (2 ft) intervals
within each row. The samples were analyzed for lead and arsenic content.
Figure 1 shows the spatial distribution of the lead and it is clear that the
concentrations are not uniform because prior to the use of modern power
sprayers, pesticides were applied to each tree individually with broom
sprayers. The large shaded area in Figure 1 shows a region with lead accu-
mulations in excess of 400 ug/g (360 lbs/acre). Examination of a 1952
aerial photograph confirmed that this area coincided with the spot where one
of the small rootstock variety blocks once stood. The other areas with high
accumulations of lead were low spots where the spray run-off collected. The
spatial distribution clearly indicates a potential problem when sampling
these sites. The customary "grab sample" could produce quite different
results depending on where a single sample was taken. To avoid such a
sampling bias small subsamples at a minimum of at least 20 locations
throughout the orchard should be collected, mixed in a clean bag, and then a
sub-sample of the mixture sent to a soil testing facility.

Upon closer examination of the 1952 airphotos it was determined that a
very large apple tree had stood just outside the grid sampling area. We
sampled the upper 10 cm of the surface soil of that area along a transect
across the approximate tree location. The results showed high concentra-
tions of lead and arsenic (1400 and 340 ug/g, respectively) where the
dripline must have been. Elevated levels (700-800 ug/g lead) were observed
within the periphery of the former crown, while much lower values (200-300
ug/g lead) were found outside the former dripline. It is interesting to
note that even decades after removal of the trees these patterns still
remained quite distinct.

o >100ppm • >200ppm « >300ppin -k >400ppm SCALE (m)

I " I ■ ■ I «

L2 2.4

•••• A

21 1« 17 15 13 11 9 7 S 3 1

Fig. 1 Spatial distribution of lead in ug/g (= 0.9 lbs/acre) at a site in
the former orchard at the University of Massachusetts--Amherst cam-
pus. Shaded areas indicate concentrations in excess of 400 uq/q
(360 lbs/acre). ^

Not only was the spatial distri bution well defined, but the lead and
arsenic concentrations decreased sharply with depth. Highest amounts were
evident in the organic-rich surface horizons, while in the subsoil the
values rapidly decreased to background levels. A subsequent study in ten
old, heavily contaminated orchards revealed more or less the same patterns.
The lead always was associated with the organic material in the surface
layer, some orchards having values up to 4400 ug/g (4000 lbs/acre). Arsenic
concentrations usually were ? to 4 times less than the lead concentration at
the same point, resulting in values up to 1300 ug/g (1?00 lbs/acre''. The
maximum peak of arsenic often was below the depth of highest accumulation of
lead, indicating that the arsenic may have moved within the soil profile,
although prohably not to any great extent. Since arsenic in its behavior is
related to phosphorus, i.e. it can be removed by phosphorus applications
from the exchange sites on the clay particles, it appears wise to limit
applications of phosphorus-containing fertilizers in contaminated orchards
to just what is needed for plant-uptake.

In the survey of the ten old orchards in various parts of Massachusetts
a few sites did not show any high values for either lead or arsenic. One
possible explanation may be that in some orchards it was customary to let
cows or other animals graze. Since the lead-arsenate material is virtually
insoluble, a significant portion of the residues adhered to the grass
plants and may have been removed by the grazing animals. The presence of
old orchards, therefore, does not necessarily mean that one automatically
has a contaminated site. The survey also indicated that soils with high
clay contents tended to retain arsenic better than sandier soils.

A common inquiry is, "How do I remove the lead-arsenate or at least
bring it to within acceptable limits?" Stripping the entire site of surface
soil is impractical, costly and often unnecessary. The best solution to
this type of pollution is dilution in the form of plowing, making sure that
the plow turns the soil over as much as possible. Vegetable gardening
should be discouraged or limited to non-leafy produce, depending on the
level of contamination.

POMOLOGICAL PARAGRAPH

Wil 1 iam J. Lord

Lime for Scrubbing CA Storages . Occasionally growers receive lime that is
not fresh and it fails to absorb adequately the carbon dioxide in the CA
room. It may be completely ineffective or become ineffective after only 2
or 3 months.

D'*y lime for CA rooms should be fresh, high in calcium and have a
magnesium content not over 10?^. Specification for good lime for CA rooms
would be "fresh hydrate with about ''^-1^1- calcum oxide and only 1-?% magne-
sium oxide."

If a "^0 pound bag of hydrated lime weighs more than 'i5 pounds you can
be pretty sure that it is worthless for scrubbing. Another simple test to
determine suitability for use in CA rooms is to place 3 tablespoons of the
lime into a glass and add 3 tablespoons of water while stirring with a ther-
mometer. If the temperature of the water does not increase it means that

the material is probably useless. If it goes up ^-3 degrees, it is
suitable.

- 5 -

HOST LEARNING BEHAVIOR OF APPLE MAGGOT FLIES

Ronald J. Prokopy
Department of Entomology

During the past decade, I have written numerous articles in FRUIT NOTES
about the natural history and economic importance of apple maggot flies.
The more we have studied the biology of this major apple pest, the more we
have become fascinated with its behavior. Here, I will describe briefly
the results of some of our recent experiments that demonstrate that apple
maggot flies, like humans, have an ability to learn.

In Massachusetts and elsewhere, the apple maggot fly has two principal
hosts: hawthorn fruit (the native host) and apple (first introduced to the
United States by the Pilgrims about 1620 and first colonized by apple maggot
flies about 1850). In 1981, we discovered that apple maggot flies which had
been maintained in laboratory cages without fruit since emergence (and thus
were naive) showed a high level of acceptance of hawthorn fruit for egg-
laying and a moderate level of acceptance of apples. When we went to the
same apple trees from which the pupae of these flies had been collected and
then tested flies that had been laying eggs for about a week in the apples
there, we discovered that the flies still showed a moderate level of accep-
tance of apples but failed altogether to accept any hawthorn fruit for
egglaying. This finding caused us to wonder whether the flies might be
capable of learning with respect to host fruit acceptance.

We then proceeded to "train" groups of flies in the lab by providing
them apples for several ovipositions and then testing their responses to
hawthorns. We also did the reverse: training on hawthorns and offering
apples. In all tests, most flies trained on one fruit type (termed the
familiar type) refused to oviposit in the other fruit type (termed the novel
type). The training proved reversible. That is, flies trained on apple and
rejecting hawthorn could, after three days without any fruit, be trained on
hawthorn and found to reject apple. To our surprise, we recently found that
flies that have had familiarity with one fruit type do not accept that fruit
type to any greater degree than naive flies that have never laid an egg.
Rather, the former flies simply reject a novel or unfamiliar fruit type to a
greater degree than do naive flies. It turns out that flies reject novel
chemical fruit stimuli (e.g., fruit having a rather different aroma) as well.
as novel physical fruit stimuli (e.g., fruit of a rather different size).
This appears to be the first proven case in any animal including humans that
the nature of learning can be of a type in which a familiar stimulus does
not become increasingly acceptable with experience but rather that a novel
stimulus becomes decreasingly acceptable.

How does the ability of apple maggot flies to learn to reject novel
fruit stimuli affect the flies' foraging behavior for fruit in nature?
Presently, we are attempting to gain a partial answer to this question
through experiments we are conducting in a very large field cage that con-
tains mixtures of potted apple and hawthorn trees. First, we release onto
one of the trees a single female whose previous egglaying experience is

_ «;

known. For example, the female may have, during the previous week, laid all
her eggs only in hawthorn fruit, or only in apples. Then we track by eye
all the female's movements as she forages among the mixture of trees,
recording every time she lands on and accepts or rejects an apple or
hawthorn fruit.

Our findings to date in this field cage confirm our previous laboratory
findings and suggest, in general, that apple maggot flies that have ovi-
posited in a given fruit species in nature i^or some time may have difficulty
in switching to another fruit species readily. If this is so, then females
immigrating from neighboring wild hawthorn trees into commercial apple
orchards might pose less an immediate threat to the apple crop than females
immigrating from neighboring abandoned apple trees. Whichever, the host-
learning ability of apple maggot flies is yet another intriguing dimension
of the life of this important apple pest.

POMOLOGICAL PARAGRAPH

Will iam J. Lord

Refrigerated salesrooms . Among the reasons for shopping at roadside stands
are freshness, quality and better flavor of produce. To help maintain
attributes of produce sold at roadside stands, a number of growers have
refrigerated their sales rooms to retard fruit deterioration. Temperatures
maintained in the refrigerated salesrooms vary from 40° to SOO F during the
day and from 3^"^ to ^0° F at night. The refrigerated sales areas also pro-
vide excellent display space for cider and a mass display of fruit for self-
service. Furthermore, one of the main reasons why Mcintosh apples are below
grade at roadside stands is because of broken skin. In a study conducted
years ago, we found that l^"*- of the Mcintosh apples marked U.S. Fancy at
roadside stands were below grade because of cuts and stem punctures and/or
decay had occurred in some instances. The installation of a refrigerated
sales area appears to he a realistic approach to increased sales through
product improvement and as a means of preventing fruit deterioration since
small, shallow stem punctures are allowed in U.S. Utility grade apples but
none with softening around the punctures.

- 7

FRUIT GROWING IN AUSTRALIA

Duane W. Greene
Department of Plant and Soil Sciences

[Editor's Note: Dr. Greene was on sabbatical leave from August, 1983, to
April, 1984 at the Horticulture Research Institute, Knoxfield, Victoria,
Austral ia.]

Australia is a country that is areawise approximately the same size as
the United States. It is located between 10 and 39 degrees South Latitude,
whereas the US is located between 26 and 49 degrees North Latitude. Since
it is in the southern hemisphere, its seasons are the opposite of ours.
They are in the middle of summer in January.

Australia is a country with 7 states, and usually produces a total of
about 19 million bushels of apples.

Northern Territory. The newest state, it occupies a large part of the
northern portion of Australia. Being close to the equator, it is very warm
and humid all year. No apples are grown there,

Queensland . This is also a northern state. It is known for wheat, citrus,
peanuts, a few apples and the Great Barrier Reef.

The remaining states are located all or in part in the cooler southern
portion of the continent.

New South Wales . Five to six million bushels of apples ^re produced there,
more than in any other state. The Batlow area is probably the best area in
NSW, having a relatively high elevation, and it specializes in Delicious.
Orange is another large, important production area. Sidney, with a popula-
tion of over 3 million people, is located in NSW, so growers here are closer
to the largest city in Australia.

Western Aust^'al ia . This area produces Granny Smith, primarily for export.

Victoria . Victoria, located south of NSW, produces about 4 million bushels
of apples, but has no real production centers.

Tasmania . This is the island state located south of continental Australia.
Tasmania produces about 4 million bushels of apples. Historically, it has
been a major production area, and is called the "Apple Isle".

South Australia . This state produces about 1 million bushels, with Granny
Smith as its principal variety.

- 8 -

Growing Conditions

The climate in all apple growing areas can be described as mild by our
standards. It snows ■^ery infrequently, and the severity of the season is
described not in terms of ice, snow, or subzero temperatures, but by the
number of frosts during the winter. In Victoria, frosts are infrequent, and
the usual winter lows are above 40* F. With the exception of January and
February, when temperatures can be hot, the weather can be described as
cool and very comfortable. They get 20-50 inches of rain annually, coming
mostly in the Fall, Winter, and Spring. The summers are usually hot, windy,
and dry. The weather is extremely changeable, and hail is a major problem
and constant threat. Drastic temperature changes usually accompany the
hail. I experienced a 20' F drop in temperature in 10 minutes. It can rain
at almost any time.

Australia is a "jery old continent. Its soils are basically poor.
Underlying this thin layer of soil is a rather impervious layer of clay.
Therefore, most trees are grown in nounds. This provides enough soil to
grow a tree, and raises the tree enough to avoid water that is trapped above
the clay layer. Trees are frequently planted without digging a hole; a tree
is set on top of the ground, and soil is then mounded up around the tree.

Australia is a water-poor country, having few large rivers or lakes.
Even though most growing areas receive 20-50 inches of rain each year, all
good growers irrigate, because very little rain comes during the growing
season. During the summer, temperatures are frequently high, the wind blows
constantly, and the relative humidity is very low. All these factors
encourage rapid evaporation.

There are few rivers and streams for irrigation, and ground water is
frequently salty and unsuitable for irrigation. Therefore, nearly all
growers have ponds where they collect runoff water during the winter and
spring. This is their main source of water. Most orchards are irrigated,
primarily by trickle irrigation. Generally, the tubing is run through the
lower scaffold limbs of trees, which are about ? feet off the ground. This
makes care around the tree much easier, but it also makes movement across
rows in an orchard very difficult.

Tree Growth and Development

Tree growth and development is different in Australia from what it is
here. This difference can, I believe, be attributed to the climate.
Because of the mild winters and relatively cool springs, flowers open slowly
and over a long period of time. Bloom commonly lasts 3-4 weeks, making the
timing of chemical thinning difficult. Trees in Australia do not have the
same rapid flush of growth in spring that ours do. The growth rate is
rather slow, but it occurs over a much longer time. Terminal shoot growth
occurs throughout the whole growing season, commonly extending over a 5-5
month period. Late growth in the fall and subsequent winter injury is not a
problem because of the mild climate. Because of a lack of stress during the
bloom and postbloom period, fruit set is generally excessive. Unlike on
trees here, fruit set in Australia can occur on very upright wood. This is
a big advantage, because fruit set can occur on younger trees, and limb
spreading may not be required.

- 9

Northern Spy (20?o dwarfing) is the major dwarfing rootstock used. In
Victoria, 70-80/i of the trees were budded on this rootstock. On poor sites
it was necessary to grow trees on seedling roots to insure adequate growth.
Rootstocks less vigorous than Mailing 7 have been unsuccessful because of
conditions that do not favor vegetative growth.

Many trees in Australia are trained to a vase shape. This method is
characterized by many limbs coming from a point. In order to develop this
tree, extensive and severe pruning is required for 8-10 years. Because
flowering is considerably delayed, limb propping is necessary, and pruning
costs are high. Growers <ire moving away from this system. In the future,
people using this system will not be able to stay in business. The for-
mality or the effort invested to establish a central leader tree varies
considerably from grower to grower. Training aids such as limb spreaders,
clothes pins, and hop clips are used, but not as extensively as we use them.

The South Pacific is the birthplace of several innovative trellis
systems, including the Tatura trellis, the MIA trellis, the Lincoln Canopy,
and the fibro trellis. The Tatura trellis was developed for and is working
well with peaches. The MIA system is new, and is more or less an inverse
adaptation of the Tatura trellis. The Lincoln Canopy is essentially a
trellis where all fruit is grown on one plane, 5-6 feet off the ground. It
was developed specifically for the mechanical harvesting of fruit. The Ebro
system is a patented trellis. It has several layers and uses an incredible
amount of wire per acre.

In total there are no more than 1000 acres of trees in Australia and
Mew Zealand on these systems, although there are many proponents of them.
After seeing all of these systems, I see no reason to encourage anyone here
to use any of them. I think that we have the rootstocks, scions and horti-
cultural ability right now to grow as many fruit of comparable quality
without a major investment in posts, wire, and many hours of labor.

Varieties

The leading varieties grown in Australia, listed in order of impor-
tance, are Granny Smith, Jonathan, Delicious, and Golden Delicious,
However, if one looks at the new trees going into the ground, Delicious
would be the most important variety, and Granny Smith would drop to third
position. The major reason for this is the relatively high price growers
receive for Delicious and the declining price received for Granny Smith.

Australia is lagging sadly behind in the introduction of new varieties
and striins. Because of special-interest groups, it has been difficult for
Australian fruit growers to introduce new materials. The important
varieties and strains are in quarantine now. All growers want spur-type
strains of Delicious, since this is the cultivar most heavily planted, and
the only spur they have is Starkrimson.

They are also looking at new varieties. They are interested in Mutsu,
Fuji, Akane, Gala, Lady Williams, and Bonza.

Mutsu - This is a high quality apple that is now gaining in popularity
in the U.S.

Fuji - Originating in Japan, this variety has quality, but lacks adequate
color. A red strain is available, and we shall be testing this at
the Horticultural Research Center in Belchertown.

Gala - This originated in New Zealand, and is being grown quite extensively
there. It has good quality and a distinctive flavor, but the color
could be better. There is a red coloring strain of Gala available.

Lady William - A late maturing (S'-s months) red apple that has good quality.
Post harvest-wise, it is almost indestructible. Its major attribute
is that it can stay at room temperature for up to 2 weeks without
becoming soft.

An interesting, informal taste panel study was done by Colin Little, a
postharvest physiologist at the Horticultural Research Center, Knoxfield,
Victoria. He selected Mutsu and Fuji, two varieties that scientists con-
sider to be among the best new varieties, and compared them with Granny
Smith. The taste panel was a children's Sunday school class. Apples were
rated for appearance, fresh eating quality and cooked eating quality. The
results are listed below.

— % Preference —

Variety Appearance Fresh Eating Qua! ity Cooked Eating Qual i ty

Granny Smith 10 .

Fuji 100 30 30

Mutsu 60 70

When asked why all of them liked Fuji's appearance, they replied,
"Because it is red." Therefore, good red color is still a major factor in
initial sales of apples. Granny Smith is a high quality apple, especially
when grown in its country of origin, Australia. We have an apple, Mutsu,
that has both a frash and cooked quality that is competitive with Granny
Smith. I believe that all growers should raise some Mutsu, especially for
farm sales.

Cultural Practices

Soils are generally low in potassium, phosphorus, and organic matter.
A complete fertilizer is usually applied. Soil tests prior to planting and
leaf analyses in established orchards are used as guides to fertilization.
Australians were among the first growers in the world to use calcium sprays.
They consider calcium sprays to be important for long postharvest life, and
the general practice is to use 5-5 foliar sprays per year.

- 11 -

Chemical thinning is a \iery important activity for growers in
Australia, since fruit set tends to be heavy. The major problem appears to
be getting enough off, especially in the case of Delicious. Sevin is not
entirely satisfactory because of problems associated with the use of high
rates of NAA and the detrimental effects of Sevin* on mite predators.

In Victoria, Ethrel* at 100-200 ppm is used routinely at bloom, and
this is followed by an application of NAA or Sevin*. These chemical
thinning treatments are then followed by hand thinning. A concerted effort
is made to minimize the amount of hand thinning necessary, since the minimum
wage in Australia is over $7.00/hour. Tasmania has an even greater thinning
problem than Victoria. There, 400-500 ppm Ethrel* are used on Golden
Delicious, which results in rather severe vegetative growth retardation from
their Ethrel* thinning sprays. Naphthal eneacetamide is not sold in
Austral ia.

Codling moths, light brown apple moths, and mites are the major insect
pests. Codling moths and light brown apple moths are controlled with
Guthione*. Summers in Australia can be hot and dry, and mites can build up
rapidly. Several different miticides are used. There is reluctance to use
Sevin* as a chemical thinner because of the deleterious effect it has on
mite predators. Apple scab is as troublesome in Australia as it is here.
Therefore, a number of scab sprays must be applied. Apple mosaic virus is a
major problem, and while attempts are being made to clean up nursery stocic,
the problem still persists.

The Australians have no established fruit grades. Each packer
establishes his own system and grades. In general, superficial fruit
defects caused quality in the markets to be lower than what it is in the
U.S. Color was generally poor, and surface blemishes due to scab or limb
runs were more prevalent. Prices for fruit there seem quite high,
Delicious were selling for $22 - $41/box in the Sydney markets.

Pew fruit are sold on the farm. There were few roadside stands as we
know them in New England. The reason for this, I believe, is the way that
fruit and vegetables have been traditionally sold in Australia. Each town,
big or small, has a fruit and vegetable shop where only produce is sold.
Owners of these stores go to the wholesale market and purchase their fruit
and vegetables.

Future of the Industry

Fruit growing in Australia is undergoing change. There are many
growers who are poor and inefficient in both growing and marketing. In the
next 5-10 years, many will go out of business. There are also many good
growers who will remain and thrive. The climate in Australia is suited for
high production of high quality fruit. Those who learn to deal with chemi-
cal thinning properly and capitalize on the environmental advantages will do
extremely wel 1 .

*Trade n

ame

I? -

A BRIEF -SUMMARY OF ROOTSTOCKS AND INTERSTEM TREES

Wil 1 iam J. Lord •
Department of Plant and Soil Sciences

The following information cites the strong points and weak points of
rootstocks and of interstem trees currently found in Massachusetts orchards
and describes some of the newer rootstocks. The comments are based on
observations in Massachusetts and other fruit growing areas. Some of the
newer rootstocks such as M''7 and Mark are now available from nurseries.
Virus-tested rootstocks, Alnarp 2 (used as the understock for interstem
trees), the Polish Series, and the Budogovsky Series are currently being
tested in the United States.

M?7

Strong point s:

1. Very dwarfing (smaller than M°).
?. Resistant to collar rot.

3. May be useful as stempiece on interstem trees. A "^ or R inch stempiece
of M''7 grafted on MMlOf or MMlll produces a tree approximately the size
of M?F.

4. Easy to prune and harvest.
^. Relatively sucker free.

Weak points :

1. Probably less suitable than MQ for growers with small holdings and/or U-

Pick blocks.
■'. Poor anchorage because brittleness of roots thereby requires support.

3. Susceptible to fire blight where a problem. fSec.1^

4. Requires deep, well-drained soils and detailed tree management.

Because of weak points listed above, not recommended for commercial
orchards in Massachusetts. Probably best suited for home orchards.

Strong points :

1. Easy to prune and harvest.

'. Early bearing.

''. High early yields/acre particularly if trellised.

4. Valuable as stempiece on interstem trees. A 7 or R inch stempiece of M9
grafted on MMin*^ or MMlll produces a tree approximately the size of M26.

5. Well suited for trellising or training to a post.
^. Resistant to collar rot.

^Sec = secondary problem in Massachusetts

13 -

Weak points

1. Trees need support because of brittleness of roots.

2. Attractive to mice.

3. Extremely susceptible to fire blight (Sec.)^

4. Susceptible to woolly apple aphids (Sec.)^

5. Requires deep, well-drained soils and detailed tree management. There-
fore, M9 generally is not recommended in Massachusetts,

Interstem trees (M9/HM106 or M9/MM111)

Strong points :

1. Small trees - approximately the size of M26.

2. Better anchorage than trees on M9 or M27,

3. Early bearing but only if good trees are received from the nursery and
the trees grow vigorously in the orchard.

Weak points :

1. More expensive to buy.

2. Usually only available by contracting 2 years in advance.

3. It is difficult to develop strong central leaders on some varieties and
spur strains when on interstems. Thus, leader support may be necessary.

4. Suckers from rootstock particularly when the interstem is planted above
ground.

5. The interstem portion is generally M9 and mice like the bark of M9.

6. Burrknots on the M9 stempiece may be the site of insect and disease
problems.

1. Trees not as well anchored as those on MMUl or MM106.
8. Trees require detailed tree management.

M26

Strong points :

1. Smaller tree than those on M7A thus easier to prune and harvest.

2. 45 to 60% dwarfing of seedling tree.

3. Early bearing in some orchards.

4. Very productive per acre if properly spaced, trees vigorous, and leaders
supported when necessary.

5. Tolerance to low temperature.

Weak points :

1. Extremely susceptible to fire blight (Sec.)l

2. Susceptible to woolly apple aphids (Sec.)^

3. Susceptible to collar rot.

- 14 -

4. Suckers from rootstock.

5. Trees require support in many orchards.

6. Frequently tree growth is quite variable within blocks of trees.

7. It is difficult to develop strong central leaders on trees of some
varieties and spur strains. Thus, leader support may be necessary.

8. Some cultivars and spur-types on some soils may have weak growth, for
example Cortland, Macspur and Sturdeespur Delicious.

9. "^ery sensitive to "wet feet."

Because of these weaknesses, M26 is generally not recommended in
Massachusetts.

M7A

Strong points :

1. Excellent commercially proven rootstock for most varieties.

2. 55 to 75% dwarfing of seedling trees.

3. Above average resistance to collar rot.

4. Above average tolerance to drought.

Weak points :

1. Severe suckering.

2. Delicious trees on this rootstock may have poor anchorage.

3. Susceptible to woolly apple aphids (Sec.)^

MM 106

Strong points :

1. Induces early bearing.

2. Varieties productive on this rootstock.

3. Above average tolerance to drought and low temperature.

4. Good anchorage.

5. Sucker free.

5. The rootstock is woolly apple aphid resistant.
7. Excellent rootstock on well-drained soils.

Weak points :

1. Susceptible to collar rot.

2. Susceptible to Tomato Ring Spot Virus.

3. Sensitive to "wet feet."

4. Trees on MM106 tend to grow late in the fall and therefore may be
susceptible to winter injury.

5. Excessive vigor particularly on standard- type Delicious because trees
may not bear early.

5. 75 to 90% dwarfing of seedling tree.

- 15

MMlll

Strong points :

1. Reported to be more tolerant of drought than other rootstocks.

2. Rootstock is woolly apple aphid resistant.

3. Good anchorage.

4. Intermediate winter hardiness.

5. More suitable when used with spur strains or as the understock for
interstem trees.

Weak points :

1. Large trees, perhaps only 10 to 30% smaller than seedling trees; thereby
requires wider spacings than trees on M7A or MM106.

2. Late onset of fruiting.

3. Quite susceptible to collar rot.

M13

Strong points :

1. Tolerance to wet soils.

2. May prove valuable as the understock on interstem trees.

Weak points :

1. Only about \0% dwarfing.

2. Trees on M13 are in \jery short supply.

3. Early studies in Massachusetts showed that yields of Mcintosh on M13
were low or only average. Therefore, the performance of interstem trees
with M13 as the rootstock needs testing.

Virus-tested rootstocks (Based mainly on reports from other fruit growing
areas ).

Strong points :

1. Varieties on virus-tested rootstocks (EMLA) are more vigorous than those
on virus-infected rootstocks.

2. Virus free M9's probably will produce larger yields than virus-infected
trees.

3. Yield efficiency (pounds of fruit/unit of space occupied) may be higher.

4. Fruit quality may be better.

5. Virus-tested M9s, because they make stronger growth, may require less
"tender loving care" than M9s with virus.

Weak points :

1. Need further testing. (EMLA 27, EMLA 9, EMLA 26 and EMLA 27 currently
are under test at our Horticultural Research Station, Belchertown, MA.
EMLA 9 is producing slightly larger tree than M9. The trees are too
young for meaningful data comparing productiveness of trees on EMLA 9
and M9).

MAC (Michigan State Apple Clone) Series

1. The origins of this series, listed below, were seeds from open pollinated
plants of the Mailing series 1 through 15, Alnarp 2, and Robusta 5.

Name Mother parent Tree size

MAC~9"(Mark) M9 Dwarf

MAC 25 Alnarp 2 Semi-dwarf

MAC 39 Mil Dwarf

MAC 46 ' M9 Dwarf

MAC 1 MS Semi -dwarf

MAC 24 Robusta 5 Semi -dwarf

Mark and MAC 24 currently are being tested at our Horticultural
Research Center, Belchertown, MA. Mark at present appears to be well
anchored and precocious, and produces a tree similar in size to M26. MAC 24
is producing a tree larger than on 7 and suckers badly.

Pol ish (P) Series

The descriptions of these rootstocks are incomplete and are based on
reports from other fruit growing areas. All are tolerant of low mid-winter
temperatures and resistant to collar rot. They are susceptible to fire
blight and woolly aphids. Ranked in order of dwarfing, small to large, they
are as follows: P-1, 16, 22, 2, 13, 14 and 18. P-1, P-2 and P-22 appear
most promising. It is reported that P-2 produces trees similar in size to
those on M9. P-22 is more dwarfing than M9. Trees on P-1 are reported to
be similar to those on M26 in size.

Currently being tested at our Horticultural Research Center in
Belchertown are P-2 and P-22 as stempieces on KA/313* with Starkrimson the
variety. Four-year-old Starkrimson trees on P2/KA313 Are about twice as
large as those on P22/KA313. Those on M27 and P22/KA313 are similar in
size. It is obvious that root suckering is going to be troublesome when
KA313 is the understock on interstem trees.

Cooperative Regional Plantings in 1984 in many fruit growing areas in
the United States and Canada, including Massachusetts, include Starkspur
Supreme Delicious on P-1, P-2, P-16, P-18 and P-22.

Budogovsky (Bud) Series

These were introduced for their mid-winter hardiness. Bud 9 is
reported to be very resistant to collar rot and Bud 490 has some resistance.
All are very susceptible to woolly aphids and susceptible to fire blight.
Bud 9 apparently is relatively free of burrknots. Bud 9 is a dwarfing
rootstock producing trees similar in size to those on M9.

Researchers in the Netherlands reported in 1981 that trees on Bud 9
were more vigorous than those on M9, and less productive. Bud 9, Bud 490
and Bud 491 were planted in Regional Cooperative Plantings in 1984.

*Trees received from Stark Bros. Nurseries. Clonal Antonovka rootstock
selected for its resistance to phytophthora.

mS in Southern Sweden in
dard trees. Perhaps its

Ainarp 1

Selected in the nurseries of the Ainarp Garden
1^?0. It is very winter hardy but makes semi-standar u i,rcc3. rci na
greatest potential in America is as the understock of interstem trees.

Antonovka

A winter hardy Russian cultivar. The seedlings of Antonovka are quite
uniform and more winter hardy than seedlings of Malus domestic a which were
used almost exclusively as apple rootstocks in Poland until l'^20-l°30.
Antonovka is currently heavily used in Poland as rootstocks and hardy stem-
pieces. It is being tested in the United States, including Massachusetts,
as the rootstock on interstem trees.

POMOLOGICAL PARAGRAPH
William J. Lord

Soil preparation prior to planting . Frequently, hay fields and pastures ^r^
planted to fruit trees without soil preparation. Since most growers do not
irrigate or heavily mulch the trees, the lack of soil preparation often is
the cause of poor growth the year of planting. Wherever possible, it is
desirable to plant fruit trees in tilled strips, regardless of the soil
management followed later. An alternative to the tilled strips particularly
where the soil is stony is the use of herbicide strips.

Paraquat* or Roundup* can be applied in late summer in 4- to 6-foot
wide strips where the trees are to be planted. The herbicide can be applied
again in late fall or the strips rototilled. If the strips are rototilled
they can be "worked-up" again prior to planting in the spring.

On newly cleared land and soils which are low in fertility and at^ not
too stony or likely to erode badly, it is advisable to build up the soil by
seeding and plowing or disking under cover crops before planting trees.
Spring oats, buckwheat, or millet can be sown as the summer cover crop and
spring oats for the winter cover crop. This is an opportune time to apply
lime because it can be incorporated into the soil during the disking of the
cover crops. Perennial weeds such as brambles, sumac, and sprouts of hard-
wood trees may be on newly-cleared land and should he treated with an her-
bicide the season before planting.

When the trees are planted, a mixture of grass seed and oats can be
sown. During the summer, the oats can be cut and let lie or be raked around
the trees for mulch.

On a fairly level site which is not subject to serious erosion, it may
be possible to interplant with low growing crops, such as pumpkins, for
"pick-your-own" or roadside stand sales. These crops can be grown for a few
years to help defray the cost of caring for the young trees until they come
into production. The rows of the cultivated crops should not be planted so
close to the tree rows that they interfere with growth of the young trees.
Intercrops in a young orchard should be considered as a temporary enterprise
and they should be discontinued just as soon as they interfere with tree
growth and care.

•"irade name

- 1"S

COMPARISON OF SOME FRUIT CHARACTERISTICS OF 'MCINTOSH'
APPLES GROWN ON SEEDLING AND M7 ROOTSTOCKS

Sarah A. Weis, Mack Drake

and William J. Bramlage

Department of Plant and Soil Sciences

Post-storage senescent breakdown (breakdown^ of apple causes signifi-
cant fruit loss, most of which occurs after the fruit have been distributed.
It can be difficult for the grower or packer of the fruit to anticipate the
breakdown potential of a lot of fruit at the time of packing. While many
apple growers learn through experience which areas of an orchard produce ^he
fruit which keep best, it would be useful to improve methods of predicting
breakdown potential .

From \0T^ to l*^?? we conducted surveys in orchards throughout
Massachusetts to see how fruit mineral composition affected breakdown inci-
dence in Mcintosh apples. Most of the trees in those surveys were growing
either on seedling or M7 rootstocks. The most important measured contribu-
tion to breakdown incidence was calcium deficiency.

Another factor, in addition to fruit mineral concentration, which may
influence the susceptibl ity of fruit to breakdown is rootstock. Some people
may have suspected that fruit grown on trees of different rootstocks have
different storage characteristics. In any given orchard such suspected dif-
ferences may be the result of block differences in soil, exposure, eleva-
tion, etc., or they may actually be due to differences in rootstock
characteristics. In a larger study, such as we have done, differences
attributed to location can be minimized. For the comparision of mineral
concentrations and breakdown incidence between rootstocks, data from the
above surveys of Mcintosh grown on seedling or M"' rootstocks were used.

Calcium (Ca\ magnesium ^Mg), potassium 'K\ phosphorus 'P), and nitro-
gen fN^ concentrations, and size in grams/fruit, were measured two weeks
before the beginning of commerical harvest each year. Twenty-five fruit
were analyzed from each orchard block surveyed. At the beginning of com-
merical harvest two bushels of fruit were picked from each block. One
bushel was stored S months in QOC air, the other for 8 months in controlled
atmosphere (CA^ at ?o, "^"^ 0?, ^^ COp at the Horticulture Research Center
^HRC) in Belchertown, MA. Ai^ter fruit were removed from storage, they were
left at room temperature (approx. ""^o^ for a week before percent of fruit
with breakdown was assessed. In l^Bl the post-storage room temperature was
about '^Do. hence, there was much higher breakdown incidence in 1^81.

Table 1 shows results of the ^-year survey. Looking first at the ele-
ments measured, no differences between fruit from seedling and M'' trees were
found for Ca , K, P, or N. In l^R? and 1<^S3 Mg concentration of fruit from
M'' trees was lower than that from seedling trees, but, at the levels
observed, Mg concentration has not been found to influence breakdown. Fruit
size, which affects breakdown positively, was the same for seedling and M7
rootstocks. After CA storage fruit from M7 trees, did have more breakdown.
This was statistically significant at odds of IQ;! in l^"'" and 1°^? and at
odds of Q:l in 1°80. The difference was insignificant in IQ81. Although
breakdown differences after air storage were insignificant statistically,
percent breakdown was greater on fruit from M7 blocks "^ years out of ^.

- IQ

While there are certainly other considerations, such as fruit color,
size, maturity, and Ca concentration, it may be useful to include rootstock
when deciding which fruit are to be stored, particularly in CA. These sur-
veys suggest that fruit from seedling rootstocks trees have less post-
storage breakdown than fruit grown on W rootstocks, though no clue as to
the reason for this is seen.

Table 1. Comparisons of mineral concentrations, size, and post-storage
senescent breakdown of Mcintosh apples grown on seedling and M7 rootstocks,

1<^7Q 1^550 1081 1082 1083

Number of blocks

Sdlg
M7

1*=
1?

25
24

22
21

ug/g Calcium

Sdlg
M7

ISO
144

157
149

140
154

154
1=^5

142
137

ug/g Magnesium

Sdlg

M"'

?43
244

288

277

25^

270Z
?5o

28«^y
271

ug/g Potassium

Sdlg
M7

4800
ROOO

'^SOO
54nn

5^00
(^400

5200
"^200

'^lOO
6100

ug/g Phosphorus

Sdlg
M7

3SB

441
434

34?
37?

303
302

441
440

ug/g Nitrogen

Sdlg
M7

?'^30
2*^00

''''40
2210

1440
1440

1520
1520

___

Grams/fruit

Sdlg

—

105

ino

124
124

127
128

125
124

Post-air storage
breakdown (%)

Sdlg

. M7

7
10

30
28

7
8

Post-CA storage
breakdwon {%)

Sdlg

S2
11

6X
1?

18
20

—

^Seedling different from M7 at odds of 10:1
•^Seedling different from M7 at odds of oQji
'^Seedling different from M7 at odds of 0;|

Cooperative Extension Service
U.S. Department of Agriculture
University of Massachusetts
Amherst, Massachusetts 01003

OFFICIAL BUSINESS

PENALTY FOR PRIVATE USE, $300

POSTAGE AND FEES PAID

U.S. DEPARTMENT OF

AGRICULTURE

AGR 101

Third Class Bulk Rate

Fruit Notes

Prepared by: Department of Plant and Soil Sciences

Massachusetts Cooperative Extension, University of Massachusetts, United States

Department of Agriculture and Massachusetts counties cooperating.

Editors: W. R. Autio and W. J. Bramlage

Volume 51, No. 1
SPftiNGJSSUE, 1986

Table of Contents

Alar*: What is its Role in Northeastern Apple Production

Pomological Note: Pruning Highbush Blueberries

A Report on the 1985 Apple IPM Program

Spencer Revisited

Gala: A New Cultivar for New England?

Recommended Pear Cultivars for the Northeast

Pomological Note: Jonagold

Pomological Note: Apple Cultivars in West Germany

Peach Cultivars for New Jersey with Possible Adaptation

to New England

Pomological Note: A Comparison of the Times of Ripening

of Several Apple Cultivars

Nectarine Cultivars for New Jersey and Their Adaptation

to New England States

Red Raspberry Cultivars for New England

Strawberry Cultivars for New England

- 1

Editors' Notes

Dr. Wesley R. Autio has been appointed Extension Pomologist at the
University of Massachusetts. He replaces Dr. William J. Lord, who retired
in January, I985.

Wes is a native of Maine. He attended the University of Maine before
transferring to Virginia Polytechnic Institute where he received his B.S.
degree in Horticulture in 1979. He received his M.S. and Ph.D. degree in
Plant and Soil Sciences from the University of Massachusetts, completing his
studies in March, I985.

As pat of his responsibilities, Wes is assuming editorship of Fruit
Notes begirning with this issue. I shall continue to assist in this assign-
ment as I did prior to Bill Lord's retirement.

We are very pleased to have Wes serving as Extension Pomologist, and we
are sure that the fruit industry will benefit from his active involvement in
its future.

Wi 1 1 iam J. Bramlage

A * A

You may have noticed that the last issue of Fruit Notes has the wrong
index on its cover. Through a printing error, the cover of the Summer, I985
issue was re-run and attached to the Fall issue. That is why there are two
covers on this issue. So that you can correctly identify the Fall, I985
issue in your files, please remove its cover that is included with this
issue and use it to replace the incorrect cover on the Fall, I985 issue. We
greatly regret any confusion that this error may have caused.

*****

Last call! If you have not yet renewed you subscription to Fruit
Notes , please do so now. If your subscription has not been renewed, you
will not receive the Spring, 1985 issue. The subscription form is in the

Fall, 1985 issue.

A *

Issued by the Cooperative Extension Service, E. Bruce MacDougall, Dean, In furtherance of the Acts of May 8
and June 30, 1914; United States Department of Agriculture and Massachusetts counties cooperating. The Coop-
erative Extension Service offers equal opportunity in programs and employment. J3020:4/86- 100

ALAR*: WHAT IS ITS ROLE IN NORTHEASTERN APPLE PRODUCTION?

W.J, Bramlage, D.W. Greene, W.R. Autio,
F.W. Southwick and W.J. Lord
Department of Plant and Soil Sciences

The Alar* issue has dominated the thinking of the U.S. apple industry
in 'ecent months. This is an emotional as well as a crucial issue, and a
ban age of claims and counterclaims has emerged. Our attempt here is to
ana yze the role of Alar* in Northeastern apple production, to provide a
fouidation for planning future directions.

BACKGROUND

On August 28, 1985 the Environmental Protection Agency (EPA) announced
its intent to cancel registration for daminozide (Alar*). This action was
reviewed on September 26, 1985 by an independent 7-member Scientific
Advisory Panel, which concluded that while there are some questions about
the tumor-causing potential of Alar*, available scientific evidence does not
support EPA's intention to cancel its registration. New tests have been
initiated, but it will likely be years before reliable data can be evalu-
ated.

EPA's concern is with Alar* residue in edible plant tissue, and espe-
cially the presence of its breakdown product, unsymmetrical dimethyl hydra-
zine (UDMH), which may be carcinogenic. Since Alar* can break down and
release UDMH when heated, particular attention is now being directed at pro-
cessed apple products and especially apple sauce. However, even EPA in its
original statement conceded that there is no imminent concern because poten-
tial concentrations of Alar* and UDMH are so extremely small. Rather, the
concern is the impact of many years of consumption of these materials on
food products.

Uniroyal, manufacturer of Alar*, has vigorously defended its use on
food crops, especially use on apples which accounts for 75? of its total
use. On November 12, 1985, the U.S. Department of Agriculture formally
opposed EPA's proposed cancellation of food uses for Alar*. Apple industry
representatives have also been very active in pointing out EPA's underesti-
mate of economic impacts that cancellation would have. Locally, the
Northeast Regional Environmental Public Health Center has judged the EPA's
assessment of risk from use of Alar* to be invalid. Given the critical
reactions to its initial statement, EPA has been negotiating with Uniroyal
to try to find a mutjally acceptable position on Alar* until the results of
further tests become available.

However, EPA is not the only government agency with jurisdiction over
labels for chemicals. Departments of Health and Agriculture in individual
states may also restrict use of chemicals within their boundaries. There
has been an effort by the Departments of Health in twelve states to take a
unified approach to the use of Alar*, and as of this writing, no state has
taken unilateral action, although intense activity is occurring in these
agencies and no one can predict what positions they will ultimately take.

*Trademark

- 3 -

The situation is one of uncertainty. While it appears that EPA has at
least temporarily withdrawn from its proposal to cancel food use of Alar*,
intense scrutiny will be given to further data. Futhermore, actions by the
Departments of Health, either unilaterally or in unison, could occur at any
time. Such action could iiddress the general use of Alar*, or it could
involve restrictions on use of Alar*-t reated fruit for processing.
Regardless of official actions, the focus of public attention (often by
flagrantly inaccurate statements) has put a great deal of pressure on local
apple growers to restrict or to cease the use of Alar*.

WHY IS ALAR* USED?

Alar* is a plant growth regulator with a variety of effects on differ-
ent plants. On apples it is us 3d for two different purposes: (a) to
control vegetative growth and en lance flower bud formation; and (b) to
control fruit drop and delay fruit ripening.

For vegetative growth control, 1.5 pounds of Alar* per 100 gallons of
water applied at a rate of 300 gallons per acre (i.e., '♦.S pounds of Alar*
per acre) are recommended for use 10 to 12 days after petal fall. For drop
control and delay of ripening 0.75 to 1.0 pound per 100 gallons of water
applied at 300 gallons per acre (i.e., 2.25 to 3 pounds of Alar* per acre)
are recommended for use 60 to 70 days before harvest. Currently, a
tolerance of 30 ppm is permitted in apples. The lower the concentration
used and the longer the period between application and harvest, the lower
will be the residue in the fruit. Studies have shown an average of four to
six ppm in fresh apples, far below the established tolerance.

WHAT ARE ALAR'S* EFFECTS ON APPLES?

News reports have often grossly misstated the effects of Alar* on
apples. We shall attempt here to evaluate its effects on Northeastern
apples, to provide a sound basis for looking to the future.

As a suppressant of vegetative growth. Alar* has a variety of uses. It
can be used on mature trees to suppress regrowth following severe pruning.
In orchards with overcrowding of trees. Alar* can be used as a suppletrent to
pruning. In over-vigorous orchards it can be used to suppress growth until
the source of excess vigor is brought under control. It can be used to
control vegetative growth in light crop years, e.g. following frost. It can
be used to enhance flower bud formation on alternate bearing varieties.
Thus, it is a valuable management tool in established orchards. It can also
be used with great benefit on non-bearing trees to suppress vegetation and
encourage early bloom and thus bring an orchard into bearing sooner.

in suppressing vegetative growth. Alar* has some important indirect
effects. It can increase light penetration into the tree canopy, thereby
improving fruit color and quality. It also reduces the competition between
vegetation and fruit for calcium resulting in higher fruit calcium concen-
trations. This can significantly reduce bitter pit occurrence, and can
reduce development of senescent breakdown and other disorders after storage.

As a stop-drop material, Alar* has no equal. It is applied long before
harvest when it is easier to get equipment through the orchard; it does not
require a repeat application; it does not induce fruit ripening; its effec-
tiveness does not depend on weather. It is extremely effective and
reliable. In the combined stop-drop effect and delay of fruit ripening,
Alar* generally extends the harvest period for Mcintosh by two weeks.

The extended harvest season obviously allows better use of harvest
labor. Secondly, fruit continue to grow until picked, thus yields are
increased because of delayed harvest made possible by Alar--. (Alar* can
directly reduce fruit size, but the indirect effect of delayed ripening can
easily exceed the size suppression unless excessive dosages have been used.)
Lastly, delayed harvest makes possible a higher pack-out of red-colored
cultivars because fruit color is improved by cooler temperature.

Alar's* effects on fruit quality are more difficult to assess. It
suppresses production of ethylene, the initiator of fruit ripening, thereby
delaying the onset of ripening. However, once ripening begins, it probably
progresses at the same rate as if Alar* had not been used. Thus, excessive
delay in harvest of Al ar*-t reated fruit can result in harvest of fruit with
little storage potential.

There is evidence that Alar* can directly increase red color on
Mcintosh. However, our experience is that color enhancement is not a con-
sistent response to Alar* in Massachusetts. In most cases, the redder color
following Alar* application is the result of delayed harvest and exposure to
cooler weather.

By delaying ripening, Alar* can also delay fruit softening. This gives
the grower more time to pick firm-textured fruit. Nevertheless, Alar*-
treated fruit will soften normally once softening begins, so even though it
has been used, late-picked fruit can be excessively soft. Futhermore,
Alar*-treated fruit will soften normally in storage. Thus, whether or not
Alar* produces firmer fruit after storage depends on the concentration used,
the time of harvest, and storage conditions.

By delaying ripening. Alar* can also increase fruit quality aftei
storage. Very simply, the riper the fruit that are going into storage, the
poorer will be their quality after storage. Alar* gives the grower extra
time to put fruit into storage while they still are at the stage of ripeness
that is appropriate for long-term storage and good post-storage quality.
There is no direct effect of Alar* on apple quality after storage. In fact,
research in England showed that Alar* increased fruit susceptibility to low
temperature breakdown (a disorder not generally seen in the Northeast), a
problem that is so serious that Alar* cannot be used in England.

IF ALAR* IS NOT USED. . . .

Whether the decision is by choice or by edict, what are the consequen-
ces if a grower stops using Alar*? Without doubt, for Northeastern growers
the greatest impact would be the significantly shortened harvest period for
Mcintosh. There is no substitute for Alar* as a stop-drop material that
also delays ripening. Napthaleneacet ic acid (NAA) can be used for pre-

harvest drop control but it is much less effective, more difficult to apply
and it increases fruit ripening. Failure to use mid-summer Alar* applica-
tions will greatly increase the risk of pre-harvest drop, poorer color, and
storage of riper fruit that will be softer and develop more disorders during
and after st jrage.

The alternative to using Alar* is to drastically change the ways in
which large plantings of apples are grown, harvested, stored, and marketed,
n many ways the Northeastern apple industry is tailored to the use of
Uar*. Growers with small plantings of apples may not need to change their
:)peration5 significantly, but growers with large acreage will be faced with
najor managerial decisions. There is no certainty that Mcintosh can be
grown on a large scale for today's market without Alar*. Since Mcintosh
account for about two-thirds of the New England apple industry, there is no
certainty that the industry could survive without Mcintosh.

POMOLOGICAL NOTE

Pruning Highbush Blueberries

Dominic Marini
Regional Fruit and Vegetable Speicalist
Plymouth County Extension Office, Hanson, MA

Recent research in Michigan has revealed that regular, annual, moderate
pruning of highbush blueberries results in higher yields than irregular,
heavy pruning or no pruning at all. Unpruned bushes were found to be most
productive be:tween their 5th and 10th years, so the objective in pruning
should be to maintain bushes at the five to ten year level.

Canes l.irger than 1 1/2 inches in diameter are beyond their prime,
unproductive, and should be removed. Up to ^0% of such large canes can be
removed without reducing yields, whereas only up to 20^ of medium canes
(between O.'* and 0.8 inches in diameter) can be removed without yield reduc-
t ion.

The most productive bushes are those with six to 12 canes, 25^ small
canes (less than O.k inches in diameter) and 75% medium canes. Cutting
bushes completely to the ground results in all canes of the same age, which
is not desirable. Removing only the older canes does not stimulate as many
new canes as removing the same number of medium canes. It is not desirable
to stimulate too many new canes since this necessitates additional pruning
to maintain the optimum number of canes. Too many canes results in leaf
shading. Shaded leaves are not efficient and use more food than they pro-
duce.

6 -

A REPORT ON THE I985 APPLE IPM PROGRAM

William M. Col i and Ronald J. Prokopy
Department of Entomology
University of Massachusetts

and

Daniel R. Cooley
department of Plant Pathology
University of Massachusetts

Acknowlegements ; We wish to thank Bill and Henry Broderick, Dave Lynch,
Dana Clark, Jesse and Wayne Rice, Ed Roberts, Sr., and Tony Rossi for their
cooperation. We also wish to thank Glenn Morin and Robin Spitko (NEFCO),
Doug Roberts, and Clarence Boston for their scouting reports which were
included in the weekly pest messages on several occasions. Special thanks
to Sue Butkewich and to Kathleen Leahy for all-purpose technical assistance.

In 1985, the Extension Apple IPM Program continued to focus on grower
education, with emphasis on the twice-weekly pest alert messages, refining
monitoring techniques for apple pests, updates on chemical control measures
including effects on non-targets, and problems with pesticide resistance,
drift, and groundwater contamination.

Program funding was provided in part by U.S.D.A., Smith-Lever 3(d) Pest
Management, by the Massachusetts Department of Food and Agriculture, and by
contributions totalling $2,360 received from hO Massachusetts apple growers.
We wish to thank these and other growers for their continued support of and
interest in IPM.

University Extension Entomology (Prokopy, Col i , Leahy) and Plant
Pathology (Cooley) staff and Northeastern Regional Fruit Agent James
Williams monitored weather, arthropods, and pathogens affecting tf-ee fruit
in Massachusetts on a weekly or twice weekly basis, at six locations in the
state: Wilbraham, Granville, Ashfield, Sterling, Stow, and Belchertown. In
addition, at various times during the season, private scout/consultants (New
England Fruit Consultants, Boston IPM, and Doug Roberts) supplied us with
pest information gained from their own observations. All information was
used to write twice-weekly pest alert messages (from April 12 to August 27)
which were available to all the state's growers through Regional Agent
Newsletters and 2k hour recorded phone messages. In I985, usage of the
recorded phone message system was approximately at the previous year's
levels, although a precise tally of calls made is not possible due to equip-
ment malfunctions on two occasions in the western region.

Staff gave a total of 3k Extension talks throughout the year, many of
which provided growers with pesticide certification training credits. Over
60 orchard site visits were also made, assessing pest problems faced by
small and large commerical orchardists. Many telephone inquires were
received and responded to during the year. In addition, 5 Fr uit Notes
articles, 3 talks published in the Proceedings of the New England Fruit
Meetings , and I8 scientific journal articles (in press or in print) were
written, as was the 24-page Annual March Message , co-authored this year for
the first time with Dr. Rick Weires of the Hudson Valley Lab.

A survey of Massachusetts grower knowledge and the adoption of 1PM was
administered to a statistically valid sample of Massachusetts commercial
fruit growers under the direction of Kathleen Leahy. This survey was pat-
terned after a National IPM Impact survey, coordinated by Virginia
Polytechnic Institute, which is presently nearing completion. The results
of the Massachusetts survey are being analyzed and will be reported in a
later issue of Fruit Notes .

Research and adaptive studies performed in support of the Apple IPM
Program in 1985 included: trials of fungicides, insecticides, and miticides
which are, or ultimately may be, a component of commercial spray programs;
evaluation of pesticide effects on mite predators; evaluation of disease-
reristant apple cultivars; measurement of drift from ground spraying of
orchards (in cooperation with Dr. John Clark, Dept. of Entomology); evalua-
tion of the efficacy of a Canadian-manufactured, non-sticky, pheromone trap
(in cooperation with entomologists from Mew York, Ontario and Quebec); study
of responses of plum curcul io to odor and visual clues (the second year of
study); analysis of optimum timing of pesticide application against tar-
nished plant bug (tlie sixth year of study); continued studies of apple
blotch leafminer behavior and monitoring; continued analysis of apple maggot
fly orientation to visual and odor cues in traps; and statewide survey of
the impact of problem pyrethroid sprays on spider mite predators.

Insect/Mite Pest Status and Harvest Injury, 1985 »

Table 1 contains results of extension IPM harvest surveys performed in
1985, and compares these to statewide averages of insect harvest injury sur-
veys performed by extension and private-sector scouts from 1978-1984.

Table 1. Percent insect- i njured fruit in on-tree surveys of 12 commercial
orchard blocks, 1985, compared to orchard harvest injury averages.

Percent

injury

Insect pest

1985

1978-1984

Tarnished plant bu

2.26

1.67

European apple savv

ffly

0.52

0.38

Plum curcul io

0.34

0.53

San Jose scale

0.43

0.78

Leaf rol lers

0.03

Green fruitworms

0.03

0.09

Apple maggot fly

0.03

0.07

Other

0.01

TOTAL INJURY 3. 61 3-56

Data collected by sampling 100 fruit per tree (Low in, low out and top of
tree canopy) on 6-12 trees per block.

8 -

Tarnished plant bug . Once again, TPB dimples and cat-facing repre-
sented the largest single amount of on-tree insect injury in commercial
orchards in Massachusetts. This year's average injury is up compared to
that of the previous 7 years (Table l). Cumulative TPB captured on white
visual traps were very high early in the growing season, ranging from
2.5/trap to 6.2/trap at late tight cluster ('4/26) in extension-monitored,
commercial blocl<s. At the Horticultural Research Center (Belchertown) cumu-
lative captures in the unsprayed block were 3.1/trap at tight cluster
(^/23) . Captures above 2.4/trap at tight cluster exceed the economic
threshold level (ETL), and indicate the need for an insecticide pre-bloom.
Very few captures were recorded after early pink so tnat optimal timing o'
TPB sprays was at tight cluster in 1985- Delays in af plication may account
for the higher than average TPB injury seen this year.

Plum Curcul io . Relative to tree development, PC A/ere "early" in I985,
with the first adult detected on Orchard Hill on May I (late pink to early
bloom on Mcintosh). PC appeared in commercial orcha ds during bloom e'en
though fruit were too small to allow egglaying. Egglaying occurred ove a
relatively short period of time, beginning at petal fall. Additional PC
activity was seen in late June-early July with block edges and known hot
spots sustaining some injury at that time. Overall, however, PC injury was
lower than average.

A jple Maggot Fly . In I985, AMF trap caputures in comnercial blocks
were comparable to those in the previous years, with peak fly activity
coming, as usual, in August in Dr. Prokopy's unsprayed block in Conway, MA.
In extension-monitored, commercial blocks, trap captures continued to har-
vest, with peak captures in September rather than in August. This could be
ascribed to lessened pesticide pressure, allowing greater fly survival, but
captures in the unsprayed block also increased noticeably in September.

Apple Leafminers . Most growers v/ere able to control LM quite well in
1985, using pyrethroids or carbamate insecticides. However, two aspects of
the future of control programs for LM were discussed at the annual October
meeting of Northeastern US and Canadian tree fruit researchers. One area of
apparent consensus was that pyrethroids, even if just used pre-bloom, are
resulting in earlier and more severe mite outbreaks, which many growers are
having difficulty controlling due to miticide resistance. The other was the
finding by Canadian entomologist Dr. Dave Pree that LM, long known to be
resistant to organophosphate and pyrethroid insecticides, have also deve-
loped a measure of resistance to the carbamate insecticide methomyl
(Lannate^, Nudrin"), even when this pesticide had been applied only once pei
season for three years. However, we have no indication that such resistance
has developed in Massachusetts as yet.

Red visual traps for LM monitoring and spray decision-making continued
to show great promise in tests performed by Extension and by New England
Fruit Consultants. In all of the five Extension blocks, traps indicated
whether or not sprays were required for LM (three "yes", two "no"). Traps
positioned close to the ground and adjacent to tree trunks caught greater
numbers of overwintering generation moths than traps at head height, con-
firming earlier work of Tom Green. Beginning the week of May 13» head

- 9 -

height, traps began to catch greater numbers than low position traps, as
moths took more flights frcffl the groundcover into the tree canopy, and
egglaying began in earnest. We believe that low position traps will prove
especially useful in determining early moth flight for growers who plan to
use the multiple Thiodan^ aaplication program. High position traps may
offer the better measure of tgglaying activity and be useful in deciding to
use other pre- or post-bloom controls.

Aphids . Wooly apple aphids could frequently be found in leaf axils of
terminal growth at numerous sites in I985. Whether this observation has
anything to do witi reductions in aphid predators due to pyrethroid use is
as yet unclear. In most cases, infestations were subeconomic and did not
require special sprays. Severe leaf curling from Rosy Apple Aphid was seen
on Red Delicious in one Middlesex County orchard, pointing out the need to
be vigilant in guarding against outbreaks of this pest which is a serious
pest in other fruit-growing regions but only occasionally so in
Massachusetts commercial blocks.

White Apple Leafhopper . WAL is another indirect pest which can, and
did, reach outbreak levels at several sites in 1985> especially in
September. In at least two blocks, defoliation from WAL leaf feeding was
severe, as was the amount of WAL honeydew on fruit. Growers are reminded
that W^L are resistant to organophosphate insecticides (e.g., Axinphos-
methyl, Phosmet), so that such m^iterials cannot be expected to provide
acceptable control.

Pi sease S i tuat ion . This year was quiet in comparison to the disease
situation in the 1584 season. There were only two to four major apple scab
infection periods during primary season, depending on the region of the
state. Generally, primary ascospores were aval lable in significant amounts
from April 20 to May 25, plus or minus a week, depending on region.
However, rainfall luring this period was light, and when rain fell it was
often too cold foi an infection period to occur. The most significant
infection periods uere between May 17-19> when a large number of ascospores
were available. As a result, in unsprayed trees at our Belchertown test
site, we had only 11% leaf scab and k.2% fruit scab (compared to near 100?
levels in other years).

The cankering problem (See Fruit Notes 50(1):17-21) had decreased
significantly in Massachusetts with the exception of the Granville area.
Apparently, weather and Bordeaux or KocideTl applications combined to alle-
viate the major diuback seen in 198'*. Roberta Spitko of New England Fruit
Consultants successfully isolated Erwin ia amy lovora , the fire blight orga-
nism, from oozing fruit in cankered Marshall Mcintosh trees. This is signi-
ficant because it indicates that a perennial canker and dieback observed on
Marshall Mcintosh for a number of years is not necessarily related to the
1984 outbreak, and is not necessarily a new apple disease. At this point,
we feel the 1984 outbreak was primarily a cold-stress phenomenon, while the
Marshall Mcintosh situation is probably related to fireblight.

Virus-like symptoms causing rough bark on young (7 to 10 year old)
trees were apparent in a few orchards. Of these orchards, all but one had

only a few trees showing rough bark. However, in one, an entire bIocl< of
Macouns showed the problem, in which outer layers of barl< flake and scale
from the tree, exposing the cambium. We tentatively have indentified the
disease as blister bark, as described by Dr. Lee Parish. if so, the disease
is not believed to be economically significant.

Sclerotinia -caused blossom end rot continued to be a problem in a few
orchards. We have yet to assess economic impact of the problem (visual
estimates of up to 20^ fruit infection in June have been made).

New or Unusual Outbreaks

Walnut Husk Fly ( Rhagolet i s suavi s [LeowJ), a relative of the Apple
Maggot fly, caused substantial injury tc peaches in £ Granville block and
flies were also seen on peaches in Wilbraham although no injury was found.
In Granville, injury (deposition of numerous eggs at e;)ch oviposition site)
was associated wi h extensive burrowing through peach flesh. Such infesta-
tions are extreme y rare, although a similar situation was described in New
York State in 1969 by R.W. Dean. A Fruit Notes article in a subsequent
issue will provide more information on this occurrence and discuss the
possibility of this event occuring again.

Mealybug . Sooty mold growth in the calyx of apple; was seen at several
sites, injury that New York Stete entomologists have [)reviously identified
as being caused by the Comstock Mealybug (CMB). This insect is a common
inhabitant of apple orchards, but is normally held below economic threshold
levels by predators. Recent pesticide use patterns, including the use of
pyrethroids, have been implicated in outbreaks.

Tree Crickets . (Genus Oecanthus ) . Slits in one-year-old peach wood
which contained numerous eggs of Tree Crickets were seen while pruning a
block of peaches in Wilbraham tiis past spring. This injury occurred last
summer and was readily removed djring pruning. Injury is similar to that of
periodic cicada, a cyclical pest which has been increasingly evident this
year in orchards in Pennsylvania.

Plans for 1986 .

Once again, the fate of USCA IPM money is uncertain at this time, with
the budget-balancing Gramm-Rudman amendment likely to result in £t^ least a
10^ across-the-boerd cut in the USDA budget, and presumably in IPM funds as
well. The State Department of Food and Agriuclture IPM money will once
again be available. However, this will be reduced by at least 10% because
of deduction for overhead mandated by University policy.

Present I986 plans call for a continued apple IPM program similar to
that in I985. In addition, we hope to impirove grower calibration skills and
the frequency of sprayer calibration. Beginning with the March Fruit grower
meetings, IPM staff and private sector equipment dealers will present
sessions on the theory and practice of calibration. At a later date,
regional fruit agents will hold workshops in advance of the growing season
at which actual dynamic calibration of different model sprayers will be
demonstrated. We also shall attempt to evaluate the utility of releasing
the predator mite Amblyseius fal laci s in orchards. This predator is being

11 -

reared by a New ^lersey Dept. of Agriculture lab and may ultimately be
available for purchase from private sector insectaries. Much information is
needed concerning the ability of th !se lab-reared predators to survive in
sprayed orchards, optimal release "ates and timing, release techniques,
etc., before it will be possible to augment our biological mite control
agents on a large scale.

SPENCER REVISITED

Wesley R, Autio

Department of Plant and Soil Sciences

Univeristy of Massachusetts

The Spencer ajple was recommended strongly at one time for trial in
Massachusetts but never gained a great deal of popularity. It is a large,
high quality apple with white, crisp flesh which ripens slightly later than
Baldwin, It has a red blush ove - 50 to 80 percent of the fruit surface.
Spencer originated as a cross of hiclntosh and Golden Delicious made in 1929
at the Summerland Researcli Station in British Columbia. The first trial
plantings were established in 19^1 and 19^*2 (1), and they found Spencer
fruit to be of very high quality and to store better than Mcintosh.
However, it was no; released immediately, because data from some locations
suggested that it had a tendency to develop excessive breakdown and core
'lush during storace (1). It finally was named and released in 1959 at the
•equest of Professor O.C. Roberts of the University of Massachusetts.

The first planting in Massachusetts (1950) was on Orchard Hill at the
Amherst campus of the University. Fruit from this planting were very high
quality and did not experience excessive breakdown or core flush during
storage. Professor Weeks considered it to be a late winter apple (2).

A planting of Spencer trees was established in 196^ at the
Horticultural Research Center in Belchertown, MA. Fruit from these trees
develop considerable amounts of breakdown during long-term air storage in
most years, but early in the storage season the fruit are very high quality
for eating and cook ng. Some Massachusetts growers have had reasonable suc-
cess with Spencer ii- their CA storages.

Regardless of the storage potential, the high quality and nice
appearance of Spencer fruit suggest that it could be an excellent apple at
farm stands and roadside markets for sale in the fall. It is certainly
worthy of trial .

References Cited ;

1. Fisher, D.V. 1959. The Spencer apple. Fruit Var. Hort. Dig. 14:15-16,

2. Weeks, W.D, I960. Performance of the Spencer apples in Massachusetts,

Fruit Var. Hort. Dig. 15:l6.

- 12 -

GALA: A NEW CULTIVAR FOR NEW ENGLAND?

Duane W. Greene and Wesley R. Autio

Department of Plant & Soil Sciences

Univeristy of Massachusetts

Gala is a new apple cultivar that was recently introduced from New
Zealand. This cultivar is being planted extensively in the United States
and elsewhere in the world. The purpose of this article is to update a pre-
vious report ( Fruit Notes '49{2):l8. igS't) and to present preliminary infor-
mation on the suitability of Gala for culture under New England conditions.

Gala was introduced in New Zealand in 1962 by Dr. Donald McKenzie. It
was the result of a cross between Kidd's Orange and Golden Delicious. We
planted Gala/M26 in 1978 at the Horticultural Research Center. The fruit is
smooth round conic with a red strip over a golden yellow ground color. We
have noted no russeting tendencies similar to Golden Delicious. The flesh
is firm, yellow, juicy, and more dense than other apple cultivars. The
distinctive spicy flavor, the attractive color, and the firm crisp flesh
make Gala an apple that is distinctive and easily identifiable.

Our experience at the Horticultural Research Center confirms other
reports that it is both precocious and productive. The first commercial
crop was produced 3 years after planting and in the fourth year production
was up to 3.3 bu/tree (Table 1). If these trees were planted at a spacing
of 12/22, as we currently recommend (175 trees/ acre), the yield during this
fourth year would have been over 500 bu/acre. Trees have continued to be
productive so that in their 7th leaf over 8 bu/tree or 1300 bu/acre were
harvested. They have shown no sign of biennial bearing. Preharvest drop
has not been a problem so that the use of daminozide as a stop-drop would
not be necessary.

Table 1. Yield of Gala/M26 planted at the Horticultural Research
Center in 1978.

1981 1982 1983 198i» 1985 Total
Yield/tree (bu)* 0.^4 3-3 2.7 ^.3 8.4 19. 1
Yield/. ere (bu) 66 S'fS 4^5 710 I386 3152

*Based on 12 X 22 planting distance (l65 trees/acre)

- 13 -

The development of red color has be'n good (Table 2). It compares
quite favorably with Mcintosh harvested on Sept. 6 (Table 3). The bright
yellow ground color is attractive and contrasts well with the pink-red
color. Gala was harvested at several times during September and early
October. The optimum harvest, we believe, was September 17> although at
least one additional harvest would have been necessary to get poorly colored
fruit. Flesh firmness dropped the longer fruit were allowed to hang on the
tree, but the reduction was not as great as with Mcintosh. Fruit harvested
on October k were still quite firm and very crisp although fruit acid level
seemed quite low.

Table 2. Fruit characteristics of Gala when harvested at different
times during the harvest season at the Horticultural
Research Center.

Fruit Harvest Date

characteristics Sept. 17 Sept. 25 Oct. 4

Red color {%) 60 66 69

Soluble sol ids {%) 11. '4 121 12.2

Flesh firmness (lb) I6.5 15.1 1^.5

Weight (g) 173 178 I88

Table 3. Fruit characteristics of Mclntosh/M26 planted at the
Horticultural Research Center in 1976.

Fruit , Harvest date

characteristic Sept. I6

Red color {%) 63

Soluble sol ids {%) 11.6

Flesh firmness ( lb) 15-8

Fruit weight (g) 160

Sept.

12,

1i»,

184

- 1^

It has been suggested that the size of Gala may be small, however, the
fruit harvested at the Horticultural Research Center have had good size. On
September 17 fruit weight was 173 g and this corresponds to fruit that is
approximately 3 inches in diameter. We have seen no tendency for fruit size
to decline although our trees are still relatively young.

We have followed the onset of the ethylene climacteric and find that
Gala, unlike other cultivars, displayed what appeared to be a degree of
ethylene insens i t ivi ty • It did not initiate the ethylene climacteric until
internal ethylene levels increased to near 3 ppm whereas Mcintosh and other
cultivars initiated the climacteric when ethylene levels were below 1 ppm.
This could be one reason why Gala appears to store very well and not suffer
from preharvest drop. We have observed some shriveling in storage similar
to that observed for one of its parents, Golden Delicious. Storage in
polyethylene-lined containers may be necessary to minimize shriveling.

There are several red coloring sports of Gala that have been described
by Dr. McKenzie. Royal Gala and Imperial Gala are scarlet red and heavily
striped. Regal Gala has a solid scarlet blush. According to Dr. McKenzie
Regal Gala develops the best color, however, even small amounts of shade
significantly reduce the red intensity. Only those willing to prune trees
for good light penetration should attempt to grow Regal Gala.

Gala and its red sports are pat -nt pr:)tected. Currently, Stark Bros.
Nursery, Louisiana, MO holds patent rights to Gala and Royjil Gala. Under a
special licensing agreement with Statk Bro,., Van Well Nursery, Wenatchee,
WA and Carlton Nursery, Parker, WA a' so se!l Gala and Roye 1 Gala. Hi'ltop
Nursery, Hartford, Ml has patent rights on Regal Gala and Imperial Gala.

We in New England are able to grow the best Mcintosh in the United
States. Since Gala ripens at about the same time as Mcintosh or perhaps
slightly earlier, we may also be the best place in the United States to grow
Gala because of our coloring weather. Gala has also developed high customer
acceptance. We feel that Gala is an exceptional apple that is worth
planting in Massachusetts.

POMOLOGICAL NOTE

Jonagol d

Loren D. Tukey
Department of Horticulture
Pennsylvania State University

Jonagold is a good yieldinc, apple cultivar of excellent eating quality
which is attracting much attention across Europe. The tree has strong wide
crotches and is spreading. It crops mainly on spurs. It has handled and
produced well on the Dutch slender spindle training system with M9. Yields
of over 1000 boxes/acre ('♦2 lb units) have been reported. Because of its

vigor (triploid), Jonagold can be grown on M27, especially on vigorous apple
soils, but fruits are slightly small in size. The cultivar was introduced
in 1968 by the N.Y. State Agr. Exp. Station in Geneva, and is a cross of
Golden Delicious and Jonathan. The fruit is golden-yellow in color with red
striping or a solid blush, under good sunlight conditions. Improved red
color clones have been reported from Japan and England. Jonagold is similar
to Jonathan in flavor, ripens with Golden Delicious, has a long storage
life, and has excellent processing quality. The cultivar should do well in
Pennsylvania, based on trials at Rock Springs. (Reprinted from Penn. State
Horticultural News, Vol. 3'4 , No. h.)

POMOLOGICAL NOTE

Apple Cultivars in West Germany

Loren D. Tukey
Department of Horticulture
Pennsylvania State University

Preference for certain apple cultivars in West Germany was shown in a
survey made by the Wonnegau Fruit Growing Society at a fruit exhibition in
Worms. The event was held to introduce newer apple cultivars and to promote
those baing grown in the Wonnegau area. Visitors were given a choice of 11
apple cultivars to purchase, and were encouraged to try one unknown to them.
Sales and comments were tabulated. Those in the well-known group were
Geheimrat Oldenburg, Red Boskoop, Cox Orange, Gold Parmane and Golden
Delicious. The newer cultivars consisted of Jonagold, Gloster, Mutsu,
Idared, Melrose and Granny Smith. Jonagold was the most popular, accounting
for 25% of sales, and tasters asked where they could be purchased. Next in
sales was Cox's Orange (15^), followed by Idared (12)^ and Melrose (10^).
In terms of price, sales were affected only slightly. Red apples were pre-
ferred to green/yellow ones. The lack of general appeal for Granny Smith
(3^) was attributed to the age of the buyer. Based on the survey, this
cultivar is "of the young people", roughly 25 years old and under, and was
liked especially by girls and young ladies, according to G. Steinborn, State
Teaching and Research Institute at Oppenheim. (Reprinted from Penn. State
Horticultural News, Vol. 3^, No. '♦.)

RECOMMENDED PEAR CULTIVARS FOR THE NORTHEAST

Francis C. Del lamano

Cooperative Extension Association of Oswego County

Mexico, New York

To make a profit when growing pears it is necessary to produce high
yields (500 + bu/acre) of large fruit (preferably greater than 2 1/2 inches
in diameter bit 2 3/8 inches at a minimum). Unfortunately, nearly 10 years
is usually required to obtain .3 profitable crop, but the use of dwarfing
rootstocks an good cultural practices can reduce this period to 7 years.
The following are brief descriptions of the pear cultivars which can be
grown profitably in the Northeast.

BARTLETT is the most widely planted and best known variety for Fresh con-
sumption and canning. Adequate, early pollination and good cultural prac-
tices are necessary to obtain good yield and size. If the trees are in good
vigor they may not respond well to thinning with NAA. If harvested at l8 to
21 lbs firmness and cooled quickly, fruit will store well. By delaying har-
vest a week and beginning to pick at 16 lbs., size and yield will be
increased by at least 10^; howev;r, shelf life will be reduced.

BOSC is a good variety which is increasing in importance, because increased
knowledge of Bosc culture has resulted in the ability to produce fruit 2 1/2
inches and larger. Generally, t:he Northeast can produce high quality Bosc
fruit with prices varying from 30 to 100? higher than Bartletts. If you are
purchasing Bosc trees, select only those which are virus-free. Because of
sensitivity to cold winter temperatures (southwest trunk injury) trunks
should be painted with white latex paint. Good fertility must be main-
tained, particularly for potassium, because Bosc trees are sensitive to low
potassium levels. Thinning is accomplished easily with NAA, and hand
thinning is seldom needed. Fruit should be harvested at approximately the
same time as Mcintosh apples. \ields can exceed those of Bartlett by 2S+%-
(Note: Bosc is not the best pollinator for Bartlett, since it blooms during
the last half of Bartlett bloom in most years.)

CLAPP pears are harvested 2 to 3 weeks prior to Bartletts, and it is a good
variety for its season. The tree is winter hardy, productive, and a good
pollinator. Fruit which are 2 1/2 inches or larger are obtained easily with
adequate thinning. Fire blight is a problem with Clapp trees, and the fruit
decays internally prior to softening.

SECKEL is a small, sweet pear harvested just prior to Mcintosh apples.
Because of low prices from 1950 to 1975 pear growers moved away from Seckel,
but the demand presently exceeds the supply and now the prices are good.
Thinning chemicals do not work on Seckel, so it is difficult to produce
fruit larger than 1 3/k inches.

SPARTLETT trees produce fruit which are 50% larger than Bartletts. They can
develop a red cheek and have a nice appearance but are not as high quality
as Bartlett. The trees have poor crotch angles and weak wood which can
break with a crop load. Fruit set is generally poor but can be improved
with daminozide (Alar^),

- 17 -

FLEMISH BEAUTY pears are large and sweet with a red cheek. They are har-
vested about 1 week after Bartletts. Trees are vigorous, very winter hardy,
and must be thinned with NAA to get adequate size. Flemish Beauty is an old
variety which lost popularity because of susceptibility to pear scab and may
be difficult to sell because it is unknown. Only trees free of stoney pit
virus should be planted. (Note: Flemish Beauty is an excellent pollinator
for Bartlett. )

ANJOU is a large, green, winter pear which is harvested in early October.
Trees are late comirg into bearing but are quite productive. Chemical
thinning is necessary to obtain adequate fruit size. Spring frosts can harm
fruit finish, and Captan sprays can burn the leaves. Fruit must be stored
after harvest to initiate the development of good flavor and ripening.

AURORA was introduced by the New York Agricultural Experiment Station in
Geneva. It is harvested near the end of Bartlett harvest and is a good
quality pear for the roadside market. Chemical thinning is necessary for
the development of adequate size.

HIGHLAND is another introduction from the New York AgricultJral Experiment
Station, Geneva. It is a russeted pear which resembles Bosc.

JUNO (Butirra Precoce de Morettini) was introduced from Italy and is similar
to Barlett in shape but is harvested 3 weeks earlier. I was impressed with
its quality in California and at the Agricultural Experiment Station in
Geneva. Fruit are large with good flavor, and the trees appear to be pro-
ductive. More will be known about this variety in the next few years.

RED PEARS are bringing big money in West Coast wholesale markets and Eastern
retail markets. Many trees are being planted in the West. Is the demand
sufficient to handle a lot of new plantings? Only time with tell.
Generally, red varieties are less vigorous and productive than their green
relat i ves.

PEACH CULTIVARS FOR NEW JERSEY
WITH POSSIBLE ADAPTATION TO NEW ENGLAND STATES

Jerome L. Frecon
Glouster County Agricultural Agent

Cooperative Extension Service
Cook College - Rutgers University

The 1982 Fruit Tree Census for New Jersey lists Rio Oso Gem, Loring,
Redhaven, Cresthaven and Jerseyqueen cultivars in order of importance in the
state's fruit industry. Tree varietal trends will not change drastically in
the immediate future. Each cultivar has weaknesses and strengths. Rio Osa
Gem is large, generally attractive, firm, yellow-fleshed, freestone, and
most importantly, it matures late (September 1 to 10). The tree is weak.

18 -

crops erratically, and produces a significant percentage of fruit with a
rough, raised suture. The fruit and foliage are susceptible to bacterial
spot, a problem on trees grown in our South Jersey sandy soils.

Loring and Jerseyqueen are both large, attractive, firm, yellow-fleshed
peaches. Both are strong vigorous trees. Jerseyqueen i: susceptible to
bacterial spot and matures late (August 2h to September }) . Loring is
tolerant to bacterial spot and matures mid season (August 10 to 20). Both
cultivars crop unreliably because of the fluctuating temperatures we
experience in mid winter and early spring.

Cresthaven is a near-perfect peach. jf thinned early, it will attain
excellent size. The fruit have short stem^ and a round shape, making it
occasionally prone to softening and injury around the stem. The tree is an
excellent cropper but somewhat weak and shor lived.

Most fruit growers are familiar with Redhaven. It has the
strengths and weaknesses in Ne / Jersey that it has in New England.

same

Now that you know what wf grow and tolerate in New Jersey, you can see
we need much improvement in )ur peach cultivars. Thousands of cultivars
have been field-tested in New Jersey in the past 200 years. Sixty cultivars
have been introduced by the New Jersey Agricultural Experiment Station since
the establishment of its peach breeding program in 191^. Our primary objec-
tive today is to develop and evaluate large, high quality, attractive, later
maturing, new, firm, yellow-fleshed peach cultivars. Tree vigor, and most
importantly winter hardiness, and bacterial spot resistance, are primary
objectives. Encore"^ (NJ260 cultivar) is a late maturing cultivar (September
1 to 10) which best exemplifies these standards. Jerseydown (NJ2^6 culti-
var) and Jerseyglo (NJ2^^ cultivar) are other recent selections with
outstanding characteristics. The following yellow fleshed cultivars are
recommended to New Jersey growers as the best available in their respective
seasons of maturity.

SEASON OF MATURITY

CULTIVAR

July 1 to 10
July 10 to 20

CANDOR

GARNET BEAUTY, EARLIGLo"^
(Roxborough Cultivar), EARL I
REDHAVEN

July 20 to 25

July 2": to August 5

August 1 to August 10
August 10 to August 20
August 20 to August 27

JERSEYDAWN, HARBELLE

REDHAVEN, HARKEN, HARBRITE,
LATE SUNHAVEN (Slaybaugh
Special cultivar)

NEWHAVEN, NORMAN

LORING, REDKIST

BLAKE, BISCOE, CRESTHAVEN

- 19 -

August Ik to September 3
September 1 to September 10

JERSEYQUEEN, JERSEYGLO

encore"^ (NJ260 cultivar),
AUTUMNGLO, RIO OSO GEM

I would plant Late Sunhaven, Loring, Blake, and Jerseyqueen with
caution in most New England states because they do not crop reliably in New
Jersey. Encore" (NJ260 cultivar), Auturrnglo and Rio Oso Gem may mature
too late in most New England states.

We have tested over 300 cultivars in the past 10 years and currently
have 110 under test in replicated field plots. The following cultivars are
suggested for commerical planting but are not placed on the recommended list
either be ause they have not been tested long enough or have some weal<ness
that woul. limit listing them as a recommended cultivar:

SEASON OF RIPENING
July 1 to 10 (Candor season)
July 10 to 20 (Garnet Beauty season)
July 20 to 25 (Jerseydawn season)

July 25 to August 5 (Redhaven season)

August 1 to August 10 (Norman season)

August 10 to August 20 (Loring season)
August 20 to August 27 (Cresthaven season)

August 2^ to Sept. 3 ^Jerseyqueen season)
September 1 to September 10

CULTIVAR

SPRINGOLD, CORRELL, DERBY

PEKIN

SENTINEL, SURECROP,
FLAVORCREST

EARLY LORING, HARVESTER
VELVET, JIM WILSON

JIM DANDEE'^ (Friday cultivar)
TOPAZ

SUNCREST, JAYAVEN, BEEKMAN

FIRERED, EARLIRIO, EARLY RIO
OSO GEM

MARGLOW

SWEET SUE, MARLAND, TYLER

1 would plant Sentinel, Early Loring, Harvester, Jim Wilson, Topaz,
Suncrest, Beekman, Earlirio, Earl i Rio Osa Gem, and Sweet Sue with caution
in New England because they have not been reliable croppers in New Jersey.
Marland, Sweet Sue, and Tyler may mature too late in most New England
States.

- 20

Most white fleshed peach cultivars lack good flesh firmness for whole-
sale distribution in New Jersey. The best white fleshed peach we have
evaluated is Summer Pearl^. The following white fleshed cultivars are
suggested for local market planting:

EARLY WHITE GIANT (Garnet Beauty season)

RARITAN ROSE (Jerseydawn season)

EDEN (Redhaven season)

REDROSE (Loring season)

SUMMER PEARL^ (NJ 252 cultivar) (Cresthaven season)

WHITE HALE OR MONEYDEW HALE (Jerseyqueen season)

LATEROSE (Rio C sa Gem season)

Most of the pe.ich cultivars recomme ided and suggested lave very accep-
table flavor. A few of our most flavo ful cultivars are Brighton (Garnet
Beauty season), Topaz (Norman season), Sunhigh (Loring season), Summer
Pearl^and Madison (Cresthaven season), and Laterose (Rio Oso Gem season).

Reliance (Norman season), Enroy (Loring season), and Madisoi
(Cresthaven season) would be three peaches to try in areas where some peac i
cultivars cannot be cropped successfully because of low winter temperatures.
It is important to remember that the wood and bark of some peach trees will
be injured by low temperatures but still have a full crop of fruit buds.

Detailed descriptions of many of these peach cultivars are contained in
Bulletin FS095--New Jersey Peach & Nectarine Var let ies--avai 1 able by writing
to me.

POMOLOGICAL NOTE

A Comparison of the Time of Ripening of Several Apple Cultivars

Wesley R. Aut 'o

Department of Plant and Soil Sciences

University of Massa :husetts

During the course of apple ripening the concentration of ethylene gas
in the core Increases many thousand fold. Monitoring the ethylene concen-
tration allows comparison of the time of ripening of different cultivars.
In 1985 fruit were harvested periodically from seven apple cultivars at the
Horticultural Research Center, Belchertown, MA. Ethylene data suggested
that at the Research Center Gala, Cortland, Redspur Delicious, Baldwin,
Spencer, and Mutsu fruit should be harvested on approximately September 17>
m, 19, October 5, 9, and 14, respectively. The actual dates of optimum
harvest would vary from orchard to orchard, but the relative times should be
simi lar.

21 -

NECTARINE CULTIVARS FOR NEW JERSEY
AND THEIR ADAPTATION TO NEW ENGLAND STATES

Jerome L. Frecon
Gloucester County Agricultural Agent
Cooperative Extension Service
Cook College - Rutgers University

Nectarines are fuzzless peaches. Commercially adapted cultivars are
genetically similar to peach cultivars except for their lack of pubescence
(fuzz). There are good and poor cultivars of both nectarines and peaches.

Nectarines may be more difficult to grow for some because of their lack
of fuzz. The control of brown rot, and the elimination of insect stings,
and avoidance of mechanical injury are more difficult and generally more
costly than for peaches. Nectarines may be more difficult to market
because: (1) the California tree iruit industry has brainwashed retailers
and brokers into believing they are unique and can only be grown in
California; (2) growers on the East Coast have been growing inferior culti-
vars for years and equate these with all nectarines; (3) no outlets are
available for second grade fruit; {h) growers pick the fruit before it is
mature which has hurt the establishment of new markets.

Nectarines have promise for E.istern markets because: (l) they do not
have fuzz and some consumers will not buy peaches because of it; (2) they
are more attractive than peaches because the best cultivars have solid
scarlet-red overcolor and high gloss; (3) the California tree fruit industry
has established good markets for nectarines which are open to Eastern culti-
vars that will have more red color, more maturity, and better flavor; (4)
these nectarines can be distributed in Eastern markets at a lower distribu-
tion cost.

The following list of cultivars are recommended for areas that can grow
Redhaven, Loring, and Cresthaven peaches, three of our top cultivars in New
Jersey .

SUMMER BEAUT: Firm me 1 1 i ng--ye 1 low flesh, freestone, SS% to 90^ scarlet red
skin color, medium-large size (2 1/2" to 2 3/'*")- Ovate, good quality, very
attractive, susceptible to brown rot. The tree is a reliable cropper
(slightly less than Redhaven), semi-vigorous, and susceptible to bacterial
spot. Ripens in early August {k weeks ahead of Elberta).

SUNGLO: Firm mel t ing--yel low flesh, freestone, 75% to 80% orange to scarlet
red skin color, medium-large size (2 1/2" up). Globose to ovate, very good
quality, very attractive, but susceptible to brown rot. The tree is a
reliable cropper (but less than Redhaven), semi-vigorous, and susceptible to
bacterial spot. Ripens in mid-August (3 weeks ahead of Elberta).

FLAVORTOP: Firm mel t ing--yel low flesh, freestone, 80? to 90% scarlet red
skin color, medium-large size (2 1/2" up). Globose to ovate, very good
quality, very attractive, but susceptible to brown rot. The tree is not a
reliable cropper (equal to Loring) is vigorous and suscpetible to bacterial
spot. Ripens in mid-August (2 weeks ahead of Elberta).

REDGOLD: Firm mel t ing--yel low flesh, freestone, 80% to 90% scarlet red skin
color, medium-large size (2 1/2" and up). Globose to ovate, good quality,
very attractive, susceptible to brown rot. The tree is a reliable cropper

- 22

(slightly less than Redhaven) vigorous, and very susceptible to bacterial
spot. Ripens in late August (1 week ahead of Elberta).

The following nectarines are suggested for trial planting in areas
that can grow Redhaven, Loring, and Cresthaven, three of our top cultivars
in New Jersey.

FANTASIA: Firm mel t ing--yel low flesh, freestone, 80^ scarlet red skin
color, large size (2 3/^" up). Globose to ovate, good quality, very attrac-
tive, susceptible to brown rot. The tree is a reliable cropper (slightly
less than Redhaven), vigorous, and very susceptible to bacterial spot.
Ripens in late August (1 week ahead of Elberta).

CRIMSON GOLD: Firm mel t ing--yel low flesh, semi-freestone, 90^ crimson red
skin color. Small to medium size (2" to 2 1/^4") . Globose, good quality,
attractive, and susceptible to brown rot. The tree is a reliable cropper
(slightly less than Redhaven), vigorous, and susceptible to bacterial spot.
Ripens in early to mid-July (6 weeks ahead of Elberta).

JUNEGLO: Firm mel t ing--yel low flesh, semi-freestone, 30% scarlet red skin
color, small to medium size (2" to 2 I/**")/ Globose, v( ry good quality,
very attractive, and susceptible to brown rot. The trie is a reliable
cropper (slightly less than Redhaven), vigorous, and su'ceptible to bac-
terial spot. Ripens in mid-July (6 weeks ahead of Elberta). Similar to
Crimson Gold.

HARKO: Semi-firm melting — yellow flesh, semi-freestone, 80% to 30% scarlet
red skin color, small to medium size (2" to 2 1/^"). Globose, good quality,
attractive, and tolerant to brown rot. The tree is a reliable cropper, and
is susceptible to bacterial spot. Ripens late July (5 weeks ahead of
Elberta). Not as attractive or firm as Crimson Gold or Juneglo.

EARLIBLAZE: Semi-firm mel t ing--yel low flesh, freestone, 8S% to 95% scarlet
red skin color, medium size (2 1/'*" to 2 1/2"). Globose, excellent quality,
very attractive, and susceptible to bacterial spot and brown rot. The tree
is an erratic cropper. Ripens in early August {k weeks ahead of Elberta).
Not as firm as Crimson Gold or Juneglo.

HARDIRFD: Semi-firm mel t ing--yel low flesh, freestone, 70% to 80% crimson to
scarlel red skin color, medium size (2 1/8" to 2 1/4"). Globose, very good
qualit\, attractive, and tolerant to brown rot. The tree is a reliable
cropper, (equivalent to or better than Redhaven), very vigorous, and
tolerart to bacterial spot. Ripens in early August Ct weeks ahead of
Elbertc). Not as firm as Red Diamond or Summer Beaut.

RED Diy,MOND: Firm mel t ing--yel low flesh, freestone, 100% scarlet red skin
color, medium large size (2 1/2" to 2 3/4") • Globose to ovate, excellent
quality, very attractive, and susceptible to brown rot. Very similar in
appearance to Moon Grand. The tree needs to be tested further to determine
cropping capability. It is susceptible to bacterial spot. Ripens ir early
August {k weeks ahead of Elberta).

FAIRLANE: Fi rm-mel t ing--yel low flesh, freestone, 70% to 80% crinson to
scarlet red skin color, large size (2 1/2" to 2 3/4"). Ovate, good qaality,
slightly astringent, moderately attractive, and susceptible to brown rot and
bacterial spot. The tree is an erratic cropper. Ripens in early to mid-
September (2 weeks after Elberta). Not as much color as earlier cultivars
and probably too late for New England.

RED RASPBERRY CULTIVARS FOR NEW ENGLAND

David T. Handley
Extension Vegetable and Small Fruit Specialist
University of Maine

Red raspberry production is currently increasing in New England, pri-
marily for the retail and "picl<-your-own" markets. There are however,
severe limits regarding the number of cultivars which can characteristically
withstand the extreme winter temperatures, and produce a good crop during
the relatively short growing season. Only those cultivars described as
hardy or very hardy should be considered for the Northeast. Careful atten-
tion to site selection and cultural practices can further reduce winter
damage.

Plant several cultivars to provide variety and stretch out the harvest
season. If planting everbearing types (those which bear twice in one
season), note the average harvest date of the second crop. Cultivars such
as Heritage may bear too late for some areas and succumb to frost.

The table below describes cultivars generally acceptable for the New
England region. This is no guarantee that any of these cultivars could sur-
vive every winter, however. It is more than likely that some winter damage
will be experienced every year. Select cultivars according to hardiness,
ripening time, and fruit quality. Always evaluate new cultivars in small
test plantings for several seasons, as performance can vary according to
site, soil type, and production practices.

RED RASPBERRY CULTIVARS RECOffCNDED FOR TRIAL IN NEW ENGLAND
OBSERVED AND/OR DOCUMENTED CULTIVAR CHARACTERISTICS

Winter

Sucker

Harvest

Fruit

Drupelet

Cultivar

hardiness

growth

Thorns

vason

size

cohesion

Flavor

SUrtCR BEARING

Latham

V. hardy

Vigorous

Few

Mid. -late

Large

Cruifcly

Fair

Taylor

Hardy

Vigorous

Moderate

Late

Large

Good

Excel lent

Newburgh

Hardy

Moderate

Midseason

Large

Fair

Hilton

Hardy

Vigorous

Moderate

Midseason

V. Large

Excel lent

Good

Madawaska

Hard/

Moderate

Early

fted. large

Cruibly

Fair

Bo/ne

V. hardy

Vigorous

Man/

Early

Mediim

Good

Nwa

V. hardy

Vigorous

Few

Midseason

Mediun

Good

Festival

V. hardy

Moderate

Few

Mi dseason

Mediun

Good

Prestige

V. hard/

Low

Moderate

Early

Large

Crunrbly

Fair

Reveille

V. hardy

Vigorous

Moderate

Early

Large

Good

r<yTd

Titan (new)

Hardy

Low

Fav

Midseason

V. large

Excel lent

good

EVERBEARING

(2nd harvest)

August Red

Hardy

Moderate

Many

Late Aug.

Mediun

r<rri

Good

Fall Red

Hard/

Vigorous

MDderate

Mid Sept.

Med. large

Good

Excel lent

Amity (new)

Vigorous

Few

Mid. Sept.

Mediiri

Good

Excel lent

Heritage

Hardy

Vigorous

Moderate

Late Sept.

Med, large

Excel lent

Excellent

- 2A -

STRAWBERRY CULTIVARS FOR NEW ENGLAND

David T. Handley

Extension Vegetable and Small Fruit Specialist

University of Maine

The selection of strawberry cultivars available to small fruit growers
has been greatly increased in recent years by introductions from both new
and established breeding programs. Although many of these entries have
characteristics desirable to growers, such as large, glossy fruit and high
yields, further considerations are necessary prior to placing an order.
Ripening season is one such factor. Early berries tend to bring the highest
price, but the plants are also more susceptible to frost damage and may not
have good yields or fruit quality. Midseason berries supply the bulk of the
market, but there is a great deal of variation in quality and growth habit
among these cultivars. Late season fruit can be of high quality but tend to
meet a slow market.

Disease resistance should always be a primary consideration in cultivar
selection. In New England, red stele ( Phytophthora f ragar iae ) , a root rot
fungus, is prevalent in many soils, especially the heavier types. Plant
resistance is the only means available to combat this disease. Cultivars
resistant to red stele should therefore have priority when ordering straw-
berry plants. Planting exclusively non-resistant cultivars could result in
total crop failure, especially during a wet year.

The cultivars described below are considered acceptable for production
in New England. Individual cultivars may perform differently according to
soil type, fertilization, or renovation practices. Always have several
cultivars to stretch out the season and insure against serious disease and
frost problems. Evaluate the performance of new cultivars in small test
plantings prior to placing large orders. Do no forget your customers along
the way. A certain berry may seem to have everything going for it, but if
the customers do not like it, it will not bring profits.

Strawberry Cultivar Notes

Early Season

EARLIGLOW: An early berry of high quality. Fruit are firm with excellent
flavor and color. Yields may be low in the Northeast. Fruit size tends to
decrease as the season progresses. Plants are vigorous runner producers and
resistant to red stele and Vert ic i 1 1 ium wilt.

VEESTAR: A popular Canadian introduction. Plants are very productive, and
fruit have good flavor but tend to be soft. Plants are vigorous, but have
no known resistance to red stele or Vert ic i 1 1 ium.

SUNRISE: Fruit are large, red-orange and tend to be soft. Plants are
vigorous and yield well, with some resistance to red stele and Vert ic i 1 1 ium.

REDCOAT: Very popular Canadian cultivar. Large, attractive fruit are
somewhat soft and difficult to "hull." Plants are quite vigorous but
susceptible to red stele and Vert ici 1 1 ium.

- 25 -

DARROW: Released by the USDA in 197'«. Berries are large with good color,
but may be rough and tend to split. Plants are large, but shy runner pro-
ducers with resistance to red stele and Vert ic i 1 I ium.

Early-Midseason

HONEOYE: A New York release which may be early in some areas. Plants are
high yielding with large, very attractive fruit with firm flesh, but it
received low scores in taste tests. Plants are vigorous and produce many
runners and are not known to be resistant to red stele or Vert ic i 1 1 ium.

RARITAN: Fruit are attractive, firm, and excellently flavored. Plants are
fairly vigorous but very susceptible to red stele and Verticillium Wilt.

GILBERT: A new release from Wisconsin for trial only . Plants produce
nicely colored fruit of large size which holds well during the season.
Plants are vigorous and produce runners freely, but are susceptible to red
stele.

LESTER: A new release by the USDA for trial . Fruit are large and firm with
good color and flavor. Plants are vigorous and moderate runner producers
with resistance to red stele and Verticillium Wilt.

ANNAPOLIS: A new cultivar from Nova Scotia for trial . Fruit are large with
good flavor and color, but are somewhat soft. Plants are very vigorous,
free-running, and resistant to red stele.

CORNWALLiS: New cultivar for trial from Nova Scotia (Earl iglow x Kent).
Plants are very productive and fruit have good flavor and color. Plants are
vigorous and produce runners freely and are resistant to red stele.

Hidseason

CATSKILL: A popular variety for many years. Fruit have good flavor and are
large, light red, rough, and very soft. Plants are vigorous, produce many
runners, and are resistant to Verticillium but not red stele.

SURECROP: Fruit are large firm and of fair quality. Plants have moderate
vigor, and are resistant to red stele and Verticillium wilt.

MIDWAY: Fruit are large and firm with good flavor and color. Plants have
high yields, are vigorous, and are resistant to red stele and Verticillium
Wilt.

GUARDIAN: Berries are rough, and sometimes hollow with fair flavor. Plants
produce runners well and are resistant to red stele and Verticillium.

REDCHIEF: Fruit are glossy, attractive, and have firm texture, with good
flavor. Plants have good production and vigor, but prefer heavier soils.
They are resistant to red stele and Verticillium.

SCOTT: A recent release from the USDA. Fruit are large and light-colored,
but their flavor is only fair. Plants are vigorous runner producers and are
resistant to red stele and Verticillium.

- 26 -

JEWELL: A new release from New York for trial . Fruit are glossy, and
attractive with firm texture. Plants are of moderate vigor and runner pro-
duction with no resistance to red stele or Vert ici 1 1 ium.

Mid-Late Season

ALLSTAR: A new cultivar for trial from the USDA. Berries are large and
attractive with mild flavor. The plants are vigorous and produce runners
freely and are resistant to red stele and Vert ici 1 1 ium.

SPARKLE: Fruit have excellent flavor but are somewhat soft. Fruit size
tends to decrease as the season progresses. Plants are vigorous and copious
runner producers with some resistance to red stele.

KENT: New cultivar from Nova Scotia for trial . Plants are high yielding
with large, attractive, well-flavored fruit. Plants are vigorous and good
runner producers with no known resistance to red stele or Vert ic i 1 1 ium.

MICMAC: A Nova Scotia introduction. Berries are large, bright red, and
firm. Plants produce good yields, are vigorous, and produce many runners.
They have no known resistance to red stele or Vert ic i 1 1 ium. .

Late Season

CANOGA: A New York release. Fruit are firm, dark red, and large. Plants
are vigorous and good runner producers with no known resistance to red stele
or Vert ici 1 1 ium.

VESPER: Fruit are large and dark red with good flavor. Plants are not very
vigorous and are shy runner producers with no resistantce to red stele or
Vert ic i 1 1 ium.

BOUNTY: Fruit are good flavored and uniform. Plants show good vigor and
runner production with no resistance to red stele or Vert ic i ' 1 ium.

BLOMIDON: A ne^ introduction from Nova Scotia for trial . Fruit are large
with good flavor and firmness. Plants are high yielding ve y vigorous, and
produce many runners, but have no resistance to red stele.

FRUIT
NOTES

PREPARED BY
DEPARTMENT OF PLANT AND SOIL SCIENCES

MASSACHUSETTS COOPERATIVE EXTENSION,

UNIVERSITY OF MASSACHUSETTS, UNITED

STATES DEPARTMENT OF AGRICULTURE AND

MASSACHUSETTS COUNTIES COOPERATING

EDITORS
W. R, AUTIO AND W. J. BRAMLAGE

Volume 51 No. 2
SPRING ISSUE, 1986

Table of Contents

Scoring: An Old but Useful Technique

Pomological Paragraphs: Chemical Control
of Vetch, Determining the Need to Thin

Synthetic Pyrethroids: Benefits Versus
Biological Costs in Fruit Management

Is Chemical Peach Thinning on the Horizon?

A Telephone Survey of Extension IPM
Program Impacts on Commercial Apple
Growers in Massachusetts

Large Crabgrass — A Problem Weed

The 1985 Alar i'i' Survey,

Pollination of Blueberries, Strawberries,
and Blackberries

Issued bv the Cooperative Extension Service, E Bruce MacDougall, Dean,
in furtherance of the Acts of May 8 and June 30, 1914, University of Mas-
sachusetts, United Stales Department of Agriculture and Massachusetts
counties cooperating. The Cooperative Extension Service offers equal op-
portunity in programs and employment

SCORING: AN OLD BUT USEFUL TECHNIQUE

Duane W. Greene and William J. Lord
Department of Plant and Soil Sciences
University of Massachusetts

The inflationary spiral has forced apple growers to plant trees more
intensively to increase production per acre and per man-hour. We have
available to us rootstocks that when matched properly with soil, good horti-
cultural techniques, and scion vigor, can result in a highly productive and
efficient orchard. However, frequently an error in spacing, poor pruning
practices, or frost can result in a situation where trees have filled their
allotted space, and yet they remain vigorous and unproductive. Heavy,
dormant pruning intended to restrict tree spread can reduce flower bud
formation, fruit set, and fruit quality because of excessive shading from
vigorous regrowth. Appropriate corrective dormant pruning can reduce but
not eliminate this problem. Frequently, Alar" use has been recommended in
conjunction with corrective dormant pruning to help control growth and over-
come the problem.

The purpose of this article is to reacquaint readers with the practice
of scoring and present our research results which show that scoring may be
an effective tool for controlling tree growth and encouraging flower bud
formation and fruit set.

Scoring is a practice used in Europe for many years to restrict vegeta-
tive growth and to encourage flower bud formation. Fitzgerald mentioned
scoring as an effective technique for this purpose in 1762 when he presented
a paper to the Royal Society of London titled '*Exper iments on checking too
luxuriant growth of fruit trees, tending to dispose them to produce fruit".
The questions ar-i: What is scoring, and is there a place in the modern
orchard for scoring?

Scoring involves cutting through the bark to the cambium completely
around the trunk or branch of a tree (Fig. 1). This procedure will tempo-
rarily stop the movement of carbohydrates through the phloem to the roots,
reducing their growth and thereby restricting vegetative growth and
encouraging flower bud formation. Ringing, which involves the removal of a
ring of bark from the trunk or branches (Fig. 1), will ierve the same pur-
pose but is not recommended since it iJiay severely damage or kill a tree
depending upon the width of the band of bark removed and the time required
for cambium to replace the bark removed. Once a bridge is restored, car-
bohydrate movement can resume.

Scoring can be done with a number of instruments. We recommend using a
sharp linoleum knife, because the shape and size of the handle will allow
the pressure necessary to cut all the way through the bark. Care rather
than experience is important in scoring. Careless scoring may cause separa-
tion of the bark and damage to the tree. A sharp knife or other instrument
may also be used as long as the cut is made deeply enough and the severed
pieces of bark touch.

ade Mark

- 2

Scoring
Recommended

Ringing

Not

Recommended

Fig. 1. Diagramatic illustration of trees that have been either scored
(left) or ringed (right).

Scoring is done on young trees which are large enough to bear but have
failed to produce a crop and/or are excessively vigorous and are crowded for
space. Thus, scoring certainly does have a place in the modern orchard.
Scoring has an added advantage over chemical methods of tree control because
it can increase fruit set the year that it is done as well as reduce ter-
minal growth and increase flowering the following year. Scoring is normally
done in the spring shortly after bloom. Although precise timing is not cri-
tical, we recommend scoring when the terminal growth of shoots is about '4
inches long. Only one score or cut per tree is necessary and recommended.
Since no bark is removed, covering the wound with protectants such as
grafting compound or tape is not necessary. Scoring a tree once may be all
that is required, but scoring in subsequent years may be useful and
necessary, especially if trees are large and extremely vigorous. We empha-
size that scoring weak trees could severely retard growth for several years.

It has been noted that bloom and fruit set on scored trees can be
reduced the second year following scoring. Most of the reduction is due to
the inhibitory effects of fruit on flower bud formation. Scoring does not
counteract the effects of fruit on flowering. However, it can reduce growth
thus converting unproductive vegetative growth into growth where flower buds
can form.

Research Results with Scoring . Several methods to control growth and
maintain productivity in a block of very vigorous Red Prince De I ic ious/MMl 06
spaced '♦.2 x 6.3 m were applied annually for 3 years commencing in 1978
(Table 1): 1. light dormant pruning; 2. Corrective dormant pruning (CDP);
3. CDP + 1500 ppm AlarTl; A. CDP + scoring. Scoring had no influence
on either growth or fruit quality the first year. Scoring in subsequent
years reduced growth on CDP trees while increasing yield to a level com-
parable to that of lightly pruned trees (Table 2.). Alar" did not do this.

2
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- ^4 -

Table 2. Effects of corrective dormant pruning (COP), scoring, and Alar"

on fruit size and yield of vigorous Red Prince Del ic ious/MMl 06.

Fruit weight (g) Yield (kg/tree)

Treatment IsW 1979 1980 1978 1979 TpO

Light dormant pruning l88ab^ 192b l80a 80a l66a l66ab

Corrective dormant 206a 212a l85a 8'4a 76c 156b
pruning (CDP)

CDP + 1500 ppm 178b ^'♦c l63b 92a 100b lAOb
dam inoz ide

CDP + scoring 200a l89bc l6lb 100a 13'*a l86a

^Means within a column not followed by the same letter are significantly
different at the 5^ level.

Another 3-year experiment was initiated in a block of 6-year-old
Cort1and/M7 trees that had not yet filled their allotted space. These trees
were scored once 2 weeks after bloom in 1978 and nothing else was done the 2
subsequent years. Scoring reduced trunk circumference increase all three
years and terminal growth the first two years (Table 3). Undoubtedly, one
of the reasons why scoring so effectively restricted growth on these
Cortland trees was that they were smaller than the Delicious, and reserve
food storage in the roots was limiting.

Table 3. Effects of scoring on terminal growth and trunk circumference
increase on Cortland/M7 apples scored only in 1978.

Terminal

1 grow

(cm)

Trunk
1978

rcum. increas
1979

e (cm)

Treatment

1978

1979

1980

Control
Score

33a2
28b

29a
l8b

32a
28b

3.9a
2,0b

'4.2a
2.8b

3.9a
3.1b

^Means within a column not followed by the same letter are significantly
different at the S% level.

These experiments illustrate that scoring is an effective method for
controlling growth in vigorous trees. It not only controlled growth but
also increased flowering and cropping on heavily-pruned trees, thus con-
verting unproductive vegetative growth into fruitful wood during the time
the trees were being maintained in their allotted space. Scoring is a tech-
nique that you should consider if it was necessary to prune certain blocks
this past winter more heavily than they should have been pruned.

*****

POMOLOGICAL PARAGRAPHS

Wi I I iam J . Lord

Department of Plant and Soil Sciences

University of Massachusetts

Chemical Control of Vetch . Paraquat pi us simazine is the most commonly
used herbicide combination in Massachusetts. One of the "escape" weeds from
continuous use of this combination is common vetch, an alternate host of
plant bug, a very troublesome insect under our conditions. Studies in
Ontario indicate that terbacil rather than simazine would be the better
choice in orchards where common vetch is a problem.

Determining the need to thin . Probably the most dependable means of
determining the need for chemical thinning of Mcintosh 10 to 1^ days after
bloom is by calculating the number of fruits set per TOO blossoming clusters
by actual count on several trees. This means that the number of blossom
clusters on at least 2 limbs of 5 to 6 trees must be counted and recorded in
each block. The number of fruits developing on the same limbs must be
determined 10 to 1^ days after petal fall. If one finds (by dividing the
number of apples by the number of blossom clusters) an average set in excess
of 50 to 60 fruits per 100 blossoming clusters on trees that have a reason-
ably heavy bloom, some thinning of Mcintosh may be necessary. A final set
of 25 to 35 fruits per 100 blossoming clusters seems to be about right for
heavy to moderate blooming Mcintosh. If 50 or less fruits are left 10 to ^^
days after petal fall, one may expect reductions in set during the June drop
period to be sufficient so that chemical thinning will not be necessary.
When in doubt, omit the spray or use NAAm at 25 ppm or carbaryl . We have
never seen these materials seriously overthin Mcintosh.

*****

- 6

SYNTHETIC PYRETHROIDS: BENEFITS VERSUS BIOLOGICAL
COSTS IN FRUIT MANAGEMENT

Ronald J. Prokopy and William M. Col i
Department of Entomology
University of Masachusetts

and

Glenn E. Morin and Robin Spitko
New England Fruit Consultants

Synthetic pyrethorids (SP's) were first registered for use against
insects in commercial apple orchards in I983. SP's include such materials
as Pydrin" ( fenval erate) , Ambush^ or Pounce^ (permethr i n, ) and Pay-Off
( f 1 ucythr inate) . We now have 3 years of experience with commercial use of
SP's in Massachusetts. Here, we outline what we feel are some of the poten-
tial benefits of using SP's for pest control and some of the biological
costs that call into question the value of using SP's.

Benef i t s. Per ounce of active ingredient, SP's are far less toxic to
humans than any other class of insecticides currently used in orchards.
Moreover, the recommended dosage of active SP ingredient per acre is much
less than that for other sorts of insecticides. Together, these 2 facts
argue in favor of SP's as potentially being of real positive value in an
orchard spray program.

The primary use of SP's on apples has been as a single pre-bloom appli-
cation against tarnished plant bug and leafminer adults. In some orchards,
SP's have also been used at petal fall against plant bug and leafminer
adults as well as against plum curcu! io and green fruitworm.

How effective have SP's been against their primary targets, plant bugs
and leafminers? A compilation of results of tests conducted in
Massachusetts, New York, and Maine from 198l to 1985 shows that single
application of SP at the optimum time (tight cluster to early pink) usually
reduces plant bug injury to fruit by about 70%. A similarly timed spray of
Guthion" or Imidan" usually reduces plant bug injury by about 50%. Several
exceptions to this general pattern have occurred, however, resulting in only
20-30% reductions in plant bug injury through SP application. These tests
have also shown that a tight cluster or early pink spray of SP usually pro-
vides season-long control of leafminer adults. Again, however, there have
been exceptions, particularly where leafminer adult emergence has occurred
over a prolonged period, beyond the duration of SP effectiveness.

In sum, a single, properly timed pre-bloom application of SP offers a
method safe to humans for achieving reasonable season-long control of both
plant bugs and leafminers in many situations, though effective control is
not guaranteed. There is no other single type of material that is as effec-
tive against both plant bugs and leafminers as a SP.

- 7 -

3 iol og ical Costs . There exist numerous reports in the literature that
season-long use of SP's results in large buildups of spider mites on apples.
Does even a single pre-bloom application of SP have any effect on mite popu-
lations? To help answer this question, in 1985 we collected data in 3^*
Massachusetts orchards, some of which had never used a SP and others of
which used a single pre-bloom SP (usually Pounce^) for 1 or 2 years. All the
orchards had used a pre-bloom oil spray.

No. of No. of dosage equivalents-
SP h i story orc h ards of miticide used in 1985

None used 9 1 .20

1 year (198^4 or 1985) 12 2.03

2 years (I98A, I985) ^ 3.l8
2 years (1983, 1984) 7 2.71

*One dosage equivalent equals actual amount of pesticide used divided by the
amount currently recommended in the Pest Control Guide. Generally, miti-
cide was applied only when mites reached moderate population levels (5 or
more per leaf ) .

These data indicate that, compared with orchards where a SP had never
been used, 70^ more miticide was applied in orchards where SP's were used
once (198^ or 1985), 166? more miticide where SP's were used both in 1984
and 1985, and 126^ more miticide where SP's were used in 1983 and 1934 but
not in 1985. Data of this sort are merely non-experimental, correlation-
type data. They cannot be taken to imply that SP usage caused mite buildup
without additional data from actual experiments.

Very recently, Bostonian and Belanger (1) published a series of tests
where they made a single petal Fall application (recommended field rate) of
several types of SP's to apple trees in Quebec and measured the actual
amount of SP remaining after several weeks as well as the residual toxicity
to Amb 1 yse i us fa 1 lac i s , the major predator of spider mites in Massachusetts
and Quebec. Bostonian and Belanger found that 6 weeks after the single
treatment at pink, \2% of the original amount of permethrin and 1 8^ of the
original amount of fenvalerate still remained on the foliage. When they
confined A. fallacis predators on such foliage (6 weeks after treatment),
62% of the predators on permethrin leaves and 85% of those on fenvalerate
leaves died after 1 day, while only 6% of predators on unsprayed leaves
di ed.

These findings of Bostonian and Belanger on the very long residual life
of SP's and the very high toxicity to mite predators probably constitute, in
our opinion, strong experimental evidence that SP application was the cause
of greater miticide use in 1985 in orchards in Massachusetts that had used
SP's for one or more years.

The effects of SP's on A. fa 1 laci s in orchards are probably even more
devastating than Bostonian and Belanger's data reveal. On several occasions
we have measured spray droplet distribution on apple tree foliage and on the
ground cover beneath trees. At pink, massive numbers of spray droplets from

- 8

a mist blower (1x or 6x) accumulate on the ground cover beneath sprayed
trees. That is precisely the place where A^ fa 1 lac i s begins to move up into
the trees. It seems almost certain, therefore, that the initial high toxi-
city of SP ' s to A^ fal lac i s in the ground cover and the tree foliage poses
an insurmountable barrier to effective predator suppression of spider mites.

Besides the devastating effects of SP ' s on mite predators, SP's may
promote apple pest buildup yet in other ways. For example, Frank Hall in
Ohio (pers. commun.) has found that SP's stimulate spider mite dispersal,
leading to colonization of trees that were previously free of mites. Also,
data from Weires in New York (pers. commun.) implicate use of SP's in the
buildup of woolly apple aphids, rosy apple aphids, and mealybugs. In addi-
tion, several researchers believe (though there is no proof) that SP's
biochemically alter the physiology of the apple tree in a way that pranotes
greater and more rapid spider mite reproduction. We must also recognize
that the more often spider mite populations rise above damaging levels, the
more miticide is necessary to control them, and hence the more rapidly mite
resistance to miticides will develop. The end result is an upward spiral of
the cost of mite control over the long term.

Finally, recent data from Ontario (McKay, pers. commun.) confirm that
leafminer adults develop at least partial resistance to SP's after only 1 SP
application per year for 5 consecutive years. This very rapid rate of
resistance development may be due in large part to pre-adapta t ion on the
part of leafminers to detoxify SP's. It turns out that SP's are detoxi'^ied
primarily in the same way as DDT and its relatives. Extensive exposure of
leafminers and other pests to ODT-like materials in apple orchards in the
1950's and 1960's may very well have given such pests a big head-start in
ability to rapidly detoxify SP's. The more frequent the application of SP's
in any one year, and the more consecutive years they are used, the greater
the likelihood of rapid resistance development, as in Ontario.

Cone 1 us ion . We have tried to present the evidence in favor of, as well
as against, the use of SP's for pre-bloom control of plant bugs and leaf-
miners. We hope each grower will weigh the evidence and make a decision
that best fits his overall operation. In our opinion, use of SP's pre-bloom
against plant bugs and leafminers can save money in the short run, but is
very likely to be more costly (in terms of greater need for miticides and
aphicides) in the long run. Under no cirumstances do we believe it advi-
sable to use SP's after bloom. Such use would only promote more rapid
development of leaf miner resistance and cause additional harm to mite and
aphid predators.

Reference

1. Bostonian, N.J. and A. Belanger. 1985. The toxicity of three
pyrethroids to Amblysei us fa 1 lac i s . Agricul. Ecosyst. Environ.
T4:2'43-250.

*****

- 9 -

IS CHEMICAL PEACH THINNING ON THE HORIZON?

Wes 1 ey R. Aut io
Department of Plant & Soil Sciences
University of Massachusetts

To obtain fruit of adequate size and quality peaches must be thinned.
Presently, most thinning is done by hand or by knocking fruit off with
sticks, rubber hoses, or bats. Because of the labor intensive nature of
this operation much research has been devoted to finding chemicals which
when sprayed on the tree can thin peach fruit. Several compounds have been
tested and found to have undesirable properties, but recent work in Virginia
has given some promising results.

A study in I98A by Byers, et al. (1) showed that reduction of photo-
synthesis of peach trees approximately at the time of "June drop" thinned
young fruit. They, first of all, showed this effect with simple shading,
but they also demonstrated a similar effect with a photosyn thes i s- i nh i b i t i ng
chemical, terbacil (Sinbar^). A second study (2) compared several other
photosynthes i s- i nhi b i t i ng chemicals and found that terbacil was the only one
which had potential as a peach fruit thinner.

The results of the second study (2) showing the effect of terbacil on
peach trees is presented in Table 1. These were 20- to 25-year-old
'Madison' trees, and treatments were applied about 1 month after bloom. The
1000 ppm terbacil treatment removed about 1S% of the fruit and resulted in

Table 1. The effect of terbacil treatments on peach thinning (from 2).

Number of fruit per limb Fruit size
Treatment Pretreatment Post treatment at harvest

Untreated 95 a^ 76 a 2.03 c

Hand-thinned 2.21 a

1000 ppm terbacil 86 a 23 b 2.21 a

2000 ppm terbacil 68 a 16 b l.\k b

^Means within a column not followed by the same letter are significantly
different at the 5% level.

fruit of comparable size to the hand-thinned treatment. These treatments

did not damage fruit, but some leaf damage did occur. The authors indicated

that the levels used in this study were too high, and less than 500 ppm ter-
bacil likely would be effective.

10 -

In an experiment with Cresthaven peaches (1) fruit quality at harvest
was assessed after a 1000 ppm terbacil treatment and compared to nonthinned
and hand-thinned treatments. Table 2 shows these data. The only signifi-

Table 2. The effect of terbacil on fruit quality (from l).

Soluble

Red

Ground

F i rmnes'S

sol ids

color

Treatment

(lb)

{%)

i%)

(0 - 5)

Untreated

66 a^

7.8 b

63 a

3.7 a

Hand-th i nned

hh a

10.3 a

65 a

A. 3 a

1000 ppm terbaci 1

80 a

10.9 a

61 a

3. A a

^Means within a column not followed by the same letter are significantly
different at the S% level.

cant differences were for soluble solids, where hand-thinned and terbaci 1-
treated fruit had more total soluble solids than nontreated fruit.

The results From these studies are very preliminary, and much more
research needs to be done before these treatments can be recommended.
However, it does appear that there is some possibility that chemical
thinning of peaches is feasible.

References

Byers, R.E., C.G. Lyons, Jr., T.B. Del Valle, J. A. Barden, and R.W.
Young. I98A. Peach fruit abscission by shading and photosynthet ic
inhibition. HortScience 19:6^9-651.

Del Valle, T.B.G., J. A. Barden, and R.E. Byers. I985. Thinning of
peaches by temporary inhibition of photosynthesis with terbacil.
J. Amer. Soc. Hort. Sci. 110:804-807.

*****

1 1

A TELEPHONE SURVEY OF EXTENSION IPM PROGRAM IMPACTS
ON COMMERCIAL APPLE GROWERS IN MASSACHUSETTS

Kathleen Leahy, Wiilliam M. Col i , and Ronald J. Prokopy
Department of Entomology
University of Massachusetts

History a nd Devel opment of the Survey

in 198^, USDA, as part of an ongoing process of program evaluation,
chose the Virginia Polytechnic Institute and State University (VPl) to
design and help states administer a national IPM program impact survey.
Several important agricultural commodities were chosen, including cotton,
peanuts, and apples, among others. Although Massachusetts was not chosen to
be a participant in the study. Dr. Edwin Rajotte and later Dr. Richard
Kazmierczak, survey project leaders at VPl, indicated a willingness to
supply non-par t i: i pa t i ng states with the appropriate professionally-designed
survey instrument, as well as lielp in sample selection and with later analy-
sis of data .

Consequently, we received a draft questionnaire which was intended to
be given to apple growers in New York State, a particpant in the national
study. After review by several tree fruit specialists at the University of
Massachusetts, a draft which was more appropriate to our conditions was
developed and approved by VPl.

Methods and Materials

Our sample of Massachusetts apple growers was obtained from a list com-
piled by the 3 regional fruit extension agents, and included most or all of
the larger operations in the state, and gave adequate representation from
smaller ones as well. An extensive sample was needed so that we could
accurately represent the total apple-growing population. Although the ori-
ginal ragional agent tree fruit mailing lists contained over 200 names, a
number of the growers said they were "too small" to be included, leading to
a revised estimate of 176 growers with 3 acres or more in the state.

We drew a random sample from tiie list of Massachusetts apple growers
arranged in Zip-Code order. This was designed to l) eliminate bias in the
sample and 2) allow us to break the list down into the three major fruit-
growing regions of the state. These randomly selected growers received
letters informing them of the survey and its purpose and requesting their
par t Ic i pat ion .

Interviews were conducted on the telephone and lasted about one half
hour eacli on an average, slightly more than had been expected. Growers
often had a great many comments to make about the questionnaire or the
program. An effort was made to record these comments in addition to survey
responses, which we coded directly onto Opscan forms during the interview.
In all, 88 growers answered the survey--half of our estimate of the total
number of growers in Massachusetts with 3 acres or more, and a number which

- 12

is sufficient for a statistical analysis to be accurate. The Opscan forms
were read at VP I and sent back to us on computer tape. Statistical analyses
were done on the University Cyber 175 using SPSS (Statistical Package for
the Social Sciences). The data presented here represent a first-level
anal ys i s--that is, no attempt has been made to correlate data (e.g., pesti-
cide use vs IPM adoption). We hope to present a further analysis in a
future article.

Grower Demographics

Respondents ranged in age from 18 to over 80. The median age group was
'40-i»9, with a fairly normal d i s t r i but ion--that is, there were no big jumps
or dips in size among the population groups. Thirty-eight percent of
respondents were over 50, which perhaps reflects the fact that farmers don't
retire at age 65- A large proportion (32?) of the respondents said they had
been farming for over 30 years. Quite a few growers wanted to give the same
response to "age" and "number of years farming." Ninety-three percent of
the respondents were male. The majority of apple growers in the state are
college-educated. Over 50'^ had finished college or done post-graduate work.
Seventy-nine percent had at least attended college.

Orchard Size

Orchards ranged approximately from 3 to 300 acres. (There was no lower
limit set as such, but growers with less than 3 acres tended to feel that
the survey questions addressed issues that were not relevant to them.) The
median orchard size was in the 21-^40 acre range. Seventy percent of respon-
dents fell in the same ranges for "acres farmed" and "acres of apples
farmed," indicating that most apple growers are not diversified but tend to
concentrate on one crop.

Over 50? of growers earned more than 25? of their income on the farm--
h3% earned over 75?. The correlation between orchard size and percent
income was rather scattered, but most growers with more than 20 acres were
getting most of their income from the farm.

Fifty-one percent have size-controlling rootstock on more than 50? of
their acreage. Many said they planned to have more as more young trees are
planted.

Seventy-six percent sell more than 75? of their crop fresh. Many said
they sell only a small percentage (less than 5?) for processing. Much of
the processing seemed to mean cider production (although we collected no
data on this).

Familiarity wi t h and Use of Integrated Pest Management

Most of the state's growers (32?) had at least heard of integrated pest
management, and 90? knew of the Massachusetts IPM program. Respondents who
said they were familiar with IPM were asked to rate a series of "selling
points" of the program with respect to their importance to the respondent.
Initially the scale was from 1 (very important) to k (not important), but
when a number of growers said they did not feel that a selling point per-

- 13 -

tained to what they knew of 1PM, a category 5 (disagree) was added.
Although this category was little used (only 9 respondents disagreed with 5
of the points), it gives an indication that tlie growers were really consi-
dering their answers to these points, not just giving the expected response.

Results are given in Table 1. The mean response is obtained by adding
the numerical response (I-**) and dividing the number answering each
question. A mean of from 1.0 to 2.5 indicates a positive overall response;
2.5 to k.O would be negative. In this survey, all the selling points fell
in the positive range.

Table 1. On a scale of 1 to '«; 1 = very important, '4 = not important (5 =
disagree), please rate the following "selling points" of IPM. Points
are ranked by the mean of the responses. Since "very important" = 1,
the lower the mean, the more positive the response.

'Selling point" Mean response

.^5

.^8

.'♦9

.71

.73

.75

.81

.21

Reduces damage to the environment

Involves the safe use of pesticides

increases farm profits by decreasing pesticide use

Has a more positive image with neighbors/consumers

Gives an unbiased opinion of pest problems

Involves the use of natural enemies

Controls yield and quality loss

Frees you to use management skills elsewhere

It is clear that reducing environmental damage, using pesticides
safely, and increasing profits are the most commonly cited reasons for
adopting IPM. The next four points are not quite so important. The last
was closest to being a negative response. Many growers said they felt that
1PM took more time, an accurate comment based on requirements for scouting,
training, weather monitoring, sprayer calibration, etc. It is interesting
to note that, in general, respondents did not feel that "public relations"
played an important part in their adoption of IPM. Many pointed out that
the public knows very little about pesticide use or about the program. Some
suggested that we should publicize it more, although a few thought Chat
publicity would not be useful, or could even be counterproductive.

Use of IPM-related Practices

Most growers said they scout their acreage regularly. Fifty-four per-
cent of respondents said they scout more than 50^ of their acreage weekly.
Twelve percent said they do not scout regularly. The questions on scouting
did not directly address the issue of use of traps, etc., which were covered
under "methods most frequently used," so that it is possible that some
growers' definition of scouting may not be as intensive as others. Of the
growers who do scout, 86% said they scouted their acreage themselves, or
assigned an employee to scout. Only 7% used private scouts, possibly a

u -

reflection of the relatively small size of most orchards in Massachusetts,
and k% relied on monitoring by IPM personnel. Only one grower said he
relied on a pesticide fleidman For his scouting.

Over half (5'*.'*%) of the growers said they based their spray decisions
primarily on information obtained through scouting, almost exactly the same
number (5^.1%) who said they scouted their acreage weekly. Another 1 8%
relied on information obtained through the county agent, and ]h% relied on
the calendar. The ]2% who stated "other" all said they did not want to
choose one method, but used some ccnnbination of methods.

Table 2. How frequently do you use the following? {% each response)

Frequently Sometimes Never

Pest Alert message/Agents' newsletter
Recommendations from UMass Extension
Code-A-Phone message
Sticky spheres for apple maggot fly
Alternate row spraying
Pheromone traps
Leaf wetness machine
Perimeter-only sprays

82.6

1^.0

3. A

71.3

25.3

3.'*

30.2

29.1

^40. 7

31.3

2k. k

'♦'♦.2

7.2

k}.k

kS.k

1^.(4

20.5

65.1

11.9

6.0

82.1

27.0

73.0

Growers say they are using Extension material, since over 95% used the
Pest Alert messages sent via the regional agents' newsletter and UMass
Extension recommendations. Nearly 60% of respondents said they used the
county-based Code-A-Phone message system. Over 50% used sticky spheres, and
a similar number used alternate row spraying as a routine practice. About
2/3 of growers said they never jsed pheromone traps. Over 82% said they
never used a leaf wetness machine.

Sixty-five percent of the growers said they calibrate their sprayers at
least once per season. It was difficult to tell how many did a detailed
calibration. Some said that they check to see how much of a tank they have
left after spraying a given area and base their "calibration" on that infor-
mation. Surprisingly, 19% of respondents calibrate their sprayer less than
once per season. However, this is offset somewhat by the 22% who calibrate
twice per season, and the 13% who calibrate m ore than twice per season.
Most growers use a high-volume sprayer primarily, fewer use a low-volume,
and some used both. A few of the smallest growers surveyed use backpack-
type sprayers.

When asked about whether they had changed spray practices in the last
ten years, 52% of those who responded said they sprayed less now. Thirty-
six percent said they sprayed about the same, although many of these spe-
cified that they felt they were using pesticides more intelligently as a

- 15 -

result of the I PM program. Overall, the average number of insecticides
applied per season was 8.9: miticides, 1.9; fungicides, 11.9; and herbicides
0.9. We are presently analyzing data from a survey of actual grower spray
records from 1983 to the present to determine if the data in the I PM impact
survey are accurate. There is reason to believe, for example, that pesti-
cide use by growers who employ private I PM scout/consultants is much lower
than the state averages which survey respondents gave, clearly an "impact"
of IPM. The impact survey did not address the issue of Dosage Equ i val ents ,
a measure of actual rates of pesticide used. Since I PM growers may use less
than the maximum label rate, study of actual spray records to look at DE ' s
applied may present a very different picture of pesticide use. These points
will also be clarified by further analyses of the survey data.

Usefulness of Pest Control Information

The format of Table 3 'S similar to that of Table 1--a mean response on
a range of 1 to A, in this case with 1 = "very useful" and ^4 = "not useful".
There was also a response of 5 = "never used." A mean score of 2.5 or less
indicated that more people gave positive ratings; higher than 2.5 indicated
a negative rating.

Table 3- Sources of pest control information.

Information source Mean response

Articles in Fruit Notes 1.33

March message 1 .50

Extension handbooks and manuals 1.66

Pest Alert message by mail 1.67

Talking to the regional Extension agent 1 .8A

Pest Alert message by Code-A-Phone ] .Sh

Pesticide dealers and salespeople 2.30

Private consultants 2.67

Neighboring farmers 2.75

Articles in trade magazines 2.98

Newspaper articles 3.58

Weekly IPM Pest Alert Messages, the New England Pest Control Guide, and the
annual March Message were the three most frequently cited sources of infor-
mation on pesticides. About equal numbers relied on regional extension
agents, University Extension personnel, and agricultural chemical fieldmen
for such information. Altnough almost 25? of respondents said they "never"
used University Extension personnel d i rect 1 y as a source of information, it
should be noted that the three most frequently cited information sources on
pesticides originate with University faculty and professional staff in
Entomology and Plant Pathology. A majority of growers said they "never"
obtained pesticide information from a neighboring farmer or an agricultural
magazine. Although the vast majority said they "never" used private con-
sultants, it should be remembered that only 7% of growers surveyed in the
study used private consultants for IPM scouting and advice.

Pest Problem s

Table 5 contains information about which pests growers perceive to be a
problem in their orchards. The definition of "prob lem"--whether it meant a
potential problem or a situation which was not being adequately control led--
was left to the respondent. Most seemed to use the latter definition. The
choices are ranked by the percent of respondents who answered "yes."

Table 5- Which pests are a problem on your farm?

Tota

West

Central

Southeast

Scabz

65%

76%

ERM

81%

Scab 62%

ERM

62%

TPB

75%

Scab

6^4%

PC 50%

60%

Scab

68%

TPB

58%

LM A6%

TPB

57%

ERM

^9%

^49%

SJS 50%

AMF

ki\%

^♦5%

ERM 50%

39%

k2%

37%

GAA A6%

AMR

3^%

35%

SJS

35%

BR 38%

SJS

3'4%

GAA

30%

AMF

28%

AMF 23%

GAA

29%

SJS

26%

GAA

22%

TPB 8%

^Scab=apple scab; ERM=European red mite; PC=plum curcul io; TPB=tarn i shed
plant bug; LM=leafminers; BR=black rot; AMF=apple maggot fly; SJS=San Jose
scale; GAA=green apple aphid.

Most growers reported Scab, ERM, PC, and TPB as problem pests.
However, the relative importance given these pests varied among regions of
the state. Three-fourths of the growers in the western part of the state
regarded plum curcul io to be a problem while less than half those in the
central section responded positively. The situation is almost exactly
reversed in the case of European red mites, the number one perceived problem
pest in central Massachusetts, but not widely regarded as a problem in the
west. The southeast, meanwhile, was apparently untroubled by tarnished
plant bug. While about the same number of growers considered leafminers to
be a problem in central (^5%) and southeastern (^46%) Mass., only about 1/3
of western Mass. growers considered it so. SJS was also perceived as rela-
tively more a problem by central and southeastern growers. We do not have
data to indicate whether these differences are a matter of grower attitudes,
or whether there is an actual difference in pest pressure among the three
regions. In either case, this unexpected result deserves further investiga-
t ion.

Cone 1 us ion

We are pleased to conclude from survey results that Massachusetts com-
mercial apple growers are highly aware of tPM, that a sizable portion have
adopted sound IPM practices, and that traditional Cooperative Extension
delivery methods are rated as very useful sources of information on pesti-
cides and pest control. We would like to express our appreciation to the
growers who participated in the survey for their time and cooperation.

*****

- 17

LARGE CRABGRASS - A PROBLEM WEED

Prasanta C. Bhowmik

Department of Plant and Soil Sciences

University of Massachusetts

Common name ; Large crabgrass or hairy crabgrass

Botanical name ; D i g i tar ia sangui nal i s (L.) Scop.

Other names ; Hairy crabgrass, purple crabgrass, crow foot, Polish millet,
pigeon grass, and finger grass.

Crabgrass is a problem weed in lawns, field crops, vegetables, and
turfgrasses. Orchard areas are no exception. Crabgrass belongs to the
genus P i g i tar i a . The word digitaria is derived from the Latin word 'digi-
tus' meaning finger. The flower spikes (Fig. 1) or seedheads of crabgrass
diverge from a single point like the fingers of a hand. The name
'crabgrass' is given to the grass because of the crablike branching habit of
its prostrate stems.

S imi 1 ar spec i es

The two closely related species of crabgrass in the United States are
large or hairy crabgrass ( Digitaria sangu inal is ) and small or smooth
crabgrass ( Digitaria i schaemum ).

Origin

Crabgrass was grown in Switzerland by the Stone Age lake dwellers. As
early as 2700 B.C., a form of crabgrass known as foxtail millet was grown in
China and considered an important food source. Prehistoric man grew
crabgrass in India, utilizing it in porridge and bread.

Crabgrass was introduced into the U.S. in iS'tS by the U.S. Patent
Office. At that time the Patent Office (then doing work of the future
Department of Agriculture) elected to introduce crabgrass to American far-
mers to help alleviate the acute need for good forage which resulted from
the importation of thousands of domestic animals. It was soon forgotten to
promote the new introduction.

In the late 19th Century, a wave of immigrants from Europe arrived on
America's shores. With them came the real invasion of crabgrass. Most
immigrants brought along crop seeds. The essential grain to many of them
was "manna grits", a variety of crabgrass and a form of millet native to
central Europe.

Crabgrass thrived in its new home, producing bountiful crops, but it
was soon abandoned in favor of corn and wheat. Features which made crab-
grass a valued crop now made it a tenacious weed. Large crabgrass is
considered as a problem weed in 56 countries and 33 different crops in the
wor 1 d .

► Seedhead

Figure 1. Large Crabgrass

D'jscr i pt ion

The leaf sheaths oF large crabgrass seedlings are tinged purple and are
covered witH long stiff hairs. The ligule is membranous, flat at the top,
and smooth (Fig. la). A ligule is a thin membrane or row of hairs at the
top of the junction of the leaf sheath and the leaf blade. Large crabgrass
3nd small crabgrass are the only species of the grass family which have a
membranous ligule. Auricles are absent. Auricles are the appendages pro-
jecting around the stem from both sides of the collar. The first leaf is
only about twice as long as it is wide. It is tinged light purple and has a
white strip running down the center. Both sides have silky, shiny hair.

Biol ogy

Large crabgrass, a summer annual, is a member of the grass family. It
is purplish or green and has very hairy leaves and sheaths. Leaves are 6 to
8 mm wide and 5 to 15 cm long. The stems are spreading and much branched.
Roots develop at nodes on the prostrate stems (Fig. 1).

Large crabgrass reproduces by tillers and seeds. This weed has a pro-
lific tillering or branching habit. Just a few plants can spread rapidly
and cover considerable area. A single plant is capable of producing 150 to
700 tillers and 150,000 seeds. Plants can produce seeds at mowing heights
as low as 6 mm. If top growth is mowed, two or three seed crops may form in
a single growing season.

Seeds germinate best from mid-spring to late summer. Large crabgrass
seeds are dormant for a short time after they shed. Large crabgrass con-
tinues to grow until mid-summer when days become shorter. Vegetative
growth slows down and plants enter their reproductive stage. Purplish seed
heads form until frost kills the plants. Plants that emerge early in the
season and have a long period of vegetative growth are much larger and more
competitive than plants that germinate late in the season.

Large crabgrass is a serious weed of cultivated crops, lawns, nur-
series, orchards, and pastures. Once established, large crabgrass tolerates
both high temperatures and dry weather conditions.

Cont r ol of Crabg r ass

The basic principle of a large crabgrass control program is to prevent
rei nf estat ion by seed. Controlling seed production for several years will
help reduce the viable seed supply.

Large crabgrass can not be controlled in one growing season because of
the great number of viable seeds that accumulate in the soil from years of
infestation. A good weed management program in a fruit orchard is one that
consists of both cultural and chemical methods of weed control. Satisfac-
tory control requires several years of conscientious adherence to a good
control program.

20 -

Cultural Control

Mechanical control methods include mowing, disking, and cultivating.
Mowing is very effective in controlling large crabgrass because of its
annual growth habit. However, this method must be repeated to control late
germinating crabgrass and other weeds.

Chemical Control

A good weed management system includes both knock-down herbicides and
residual herbicides. The knock-down herbicides include PARAQUAT CL^
(paraquat) and ROUNDUP" (g 1 yphosa te) . Paraquat is a contact type herbicide.
It- requires uniform application for best results. On the other hand,
glyphosate is a systemic or translocated type herbicide. It can provide
effective control of perennial weeds under orchard situations. Do not apply
to trees less than two-years old. Prehavest interval is 14 days. Do not
allow spray to drift to green foliage, green bark, or suckers.

The residual herbicides are those that provide weed control over a
period of time. These include DOWPON M^ (dalapon), KARMEX^ (diuron),
PRINCEP^ (simazine), CASORON^^ (d i ch loben i 1 ) , and SINBAR^ (terbacil). The
purpose of combining knock-down herbicides and residual herbicides is to
provide season-long control of annual weeds (grass and broadleaf species)
and perennial weeds.

For more information regarding rates of herbicide application, com-
binations of herbicides, and specific comments on safety and precautions,
consult the latest edition of New England Chemical Weed Control for tree
f ru its.

*****

THE 1985 ALAr"^ SURVEY

Wes ley R. Aut io

Department of Plant and Soil Sciences

University of Massachusetts

As many of you know I conducted a survey of Massachusetts apple growers

as to their use of Alar". The questionnaire was sent to all of the people

on the tree fruit mailing lists of the regional fruit agents. It included
the following questions:

1. Total acreage in apples?

2. Acreage of bearing apples?

3. Total acreage of Mcintosh?
'♦. Acreage of bearing Mcintosh?

5. Percent bearing Mcintosh receiving Alar^

6. Percent of other cultivars receiving Alar^

7. How would the loss of Alar"^ affect you?

Eighty-five responses were received, representing 5^3^ acres of apple
production (68^ of the Massachusetts apple acreage). Table 1 shows the num-
bers of acres of trees fitting into the various categories. it is important

Table 1. 1985 Alar^-use survey results.

Catagory

Acreage

Percentage

Total acreage of apples

Mc 1 ntosh

Bearing trees
Mc 1 ntosh
Other cul t i vars

Alar^^-treated
Mc I ntosh
Other cultivars

5^31

3^471

hhhO
2877
1563

3157

2376

781

68? of Massachusetts total

(>h% of survey

82? of survey

65? of bearing, 53? of survey

35? of bearing, 29? of survey

71? of bearing, 58? of survey

83? of bearing Mcintosh

50? of other bearing cultivars

to note that 6^4? of our total acreage is in Mcintosh, and 53? of all the
trees in Massachusetts are bear i ng Mc I ntosh , Eighty-three percent oF all
bearing Mcintosh trees received Alar^ in 1985, representing 75? of the total
Alar"^ use in Massachusetts. With that in mind the answers to the last
question were not at all surprising.

Most people stated that large quantities of fruit would be lost to
drop, and there would be an overall loss of fruit quality without the use of
Alar". However, in addition many growers felt that the loss of Alar- would
severely jeopardize their business, and several suggested that they would go
out of business altogether if they could not use Alar".

The use of Alar" in Massachusetts obviously is extensive, and if Alar"
was not available many changes would have to occur in the way that we grow
apples. These changes include alterations in cultivars, cultural practices,
and storage conditions. Later Fru i t Notes articles will discuss some of
the practices which may partly replace the use of Alar".

*****

POLLINATION OF BLUEBERRIES, STRAWBERRIES AND BLACKBERRIES

James N. Moore
Department oF Horticulture and Forestry
University of Arkansas, Fayetteville, AR

Knowledge of the pollination requirements of fruit crops is essential
to fruit producers, since the potential magnitude of the crop is determined
by the extent of successful pollination and fertilization of the flowers at
the time of bloom. An understanding of the mechanisms of pollination of his
fruit crops enables a fruit grower to provide those conditions which lead to
satisfactory fruit set.

B 1 ueber r ies

At the outset, we can make two definite statements concerning pollina-
tion of blueberries: 1) insect pollination is obligatory and 2) bees are
the principal pollinators.

The necessity of insect pollination of blueberries is determined by the
morphology of the flower. The blueberry flower has all the characteristics
of an entomoph i lous (insect attracting) flower. These characteristics are:

1. Corolla of the flower in shape of a tube, opening only at tip
(prevents wind pollination).

2. Pistil of flower extends well beyond anthers, and stigma flanged to
inside, preventing unaided self-pollination.

3. Nectary glands produced at base of ovary to attract insects.
h. Fragrance produced to attract insects.

5. Pollen heavy, clumping, not readily wind-borne.

Thus, the construction of the flower effectively suppresses both wind
pollination and unaided self-pollination. However, as insects enter the
corolla tube seeking the nectar at the base of the ovary, their bodies
collect pollen as they rub on the anthers and deposit pollen on the exposed
stigmas of flowers subsequently visited.

Numerous research studies using various types of caging have shown that
bees are the principal effective pollinators of the blueberry. Most repor-
ters state that both honeybees and bumblebees are effective pollinators, but
in many blueberry producing areas, native bee populations are considered
inadequate for complete pollinations, and honey-bee colonies are introduced
into the fields.

- 23 -

Inadequate poIUnation of blueberries may be expressed in two ways.
Flowers receiving no pollination will abscise without fruit set. Flowers
partially pollinated may set but produce small fruits. The blueberry nor-
mally contains up to 85 seeds, and seed number and fruit size have been
shown to be highly correlated. Thus, any reduction in seed set will likely
result in production of smaller fruit.

Studies of the effect of cross- vs self-pollination of the highbush
blueberry have not all been in agreement, but most careful studies show that
pollination with pollen of a different cultivar results in slightly
increased fruit size and sometimes earlier ripening fruit. Most studies of
the rabbiteye blueberry agree that cross-pollination is important and that
two or more cultivars should always be planted together.

Blueberry cultivars appear to differ in attractiveness to bees. Two
cultivars identified as "unattractive" are 'Coville' and 'Earliblue', and
these require more honeybee colonies per acre for adequate pollination.
Attractiveness of cultivars to bees seems to be conditioned by nectar volume
and nectar sugar content.

Blueberries are generally not a preferred Pood source For honeybees.
Blueberries are a very poor source of pollen. Consequently, bees may
overfly blueberries to forage on other plant species nearby. A major
problem in Arkansas fields is the presence of dandelions during the blue-
berry bloom period. Bees may be seen foraging on dandelions rather than
blueberries. Since bees tend to continue foraging on a plant species that
they start on, we recommend that bee colonies not be placed in blueberry
fields until the blueberries have some open blossoms. Do not withhold bees
past 25 percent open bloom, however, or reduced set will result. Pistil
receptivity lasts only 5 to 8 days.

I consider the bumblebees to be more effective pollinators for blue-
berries than the honeybees. They are less intimidated by adverse weather and
bumblebees can be seen foraging in blueberry plantings on cold, windy days
(common in Arkansas during blueberry bloom) when honeybees remain in their
hives. Unfortunately, however, bumblebee pollination is not reliable due to
population fluctuations. Modern agricultural practices have greatly reduced
bumblebee (and other native bee) populations in many areas, and the only
recourse to ensure adequate pollination is to place honeybee colonies in the
fields.

Generally, a set of 80 percent of the blossoms is needed to yield an
excellent crop of blueberries. To achieve this goal, recommendations for
introducing honeybees into blueberry plantings have been made by most blue-
berry producing states. The numbers of colonies recommended per acre vary
among states and are associated with the extent of native bees. Michigan,
for example, with 12,000 acres of blueberries, recommends up to 5 colonies
per acre. In Arkansas, with our less concentrated acreage and still
available native bees, we recommend 1 to 2 colonies per acre. A rule of
thumb developed in Michigan is that i f 4 to 8 bees are observed per bush
when temperatures during bloom are in the 70s and 80s (degrees F), pollina-
tion will be adequate.

- 2'»

The inescapable conclusion to blueberry pollination is that blueberries
must be pollinated by bees, and in most areas native bee populations are
insufficient to provide adequate pollination.

St rawber r i es

Most modern strawberry cultivars produce hermaphroditic Flowers, and
the arrangement of the flower parts (pistils surrounded by taller stamens)
encourages self-pollination. However, a characteristic common to many
cultivars is that primary flowers often lack well developed stamens and may
not be well pollinated. Research conducted in Arkansas has shown that
strawberries benefit greatly from insect pollination, and that bees are
important pollinators.

Experiments conducted over a period of four years showed that excluding
insects by covering strawberry plots with l8 mesh screen wire during bloom
resulted in yield reductions of an average of 50 percent and fruit size
reduction of up to 31 percent. Furthermore, a high percentage of fruits
produced on caged plants were badly malformed, exhibiting evidence of
incomplete pollination.

Most strawberry growers do not provide bee colonies to their fields.
However, most strawberry plantings are small and apparently attract adequate
numbers of native bees. For large plantings, or plantings located near
large plantings of other bee-attracting crops, growers should consider
providing additional bees in order to achieve maximum yields oF good quality
berr ies.

Blackberries

Many species and some cultivars of blackberries are self-unfruitful and
must be cross-pollinated for Fruit set to occur. Most erect, thorny culti-
vars grown in Arkansas are fully self-fertile and require no other pollina-
tor.

There is little information on pollinating agents for blackberries.
Both honeybees and bumblebees readily forage on blackberry flowers. Wind
may also be an important pollinating mechanism, since the pollen is produced
in abundance, and the flower is so constructed that wind-borne pollen may
readily reach the pistils in the Field.

Experiments conducted in Arkansas compared blackberry Fruit set under
three conditions. Plants in bloom were placed in a greenhouse in which both
wind and insect pollination was excluded, other plants were placed in a
field and caged to prevent bee, but not wind, pollination, and other plants
were uncaged in the field. The lowest percent fruit set and smallest berry
size was produced by the greenhouse-grown plants. Good fruit set and normal
fruit size was produced by both groups of field-grown plants. The conclu-
sion was that insect pollination was not essential for greater yields. No
doubt, under natural conditions, bees are also effective in distributing
pollen in blackberry Fields.

25 -

CONCLUSIONS

Research has shown that bees are i ndi spens ib le for blueberry pollina-
tion, highly desirable for strawberry pollination, and contribute (with
wind) to blacl<berry pollination. The importance of bees as pollinators can-
not be overemphasized and should not be taken for granted. Growers should
do all in their power to conserve native populations of bees. Steps in con-
servation should include care in not destroying nesting areas and not using
toxic pesticides when bees are active in the field. Fruit growers should
monitor native bee populations, and if inadequate for pollination, provide
colonies of honeybees to ensure complete pollination of their fruit crops.

Reprinted from The Ohio Fruit Journal, Spring 1985.

Fruit Notes

Prepared by: Department of Plant and Soil Sciences

Massachusetts Cooperative Extension, University of Massachusetts, United States
Department of Agriculture and Massachusetts counties cooperating.

Editors: W. R. Autio and W. J. Bramlage

Volume 51, No. 3
SUMMER ISSUE, 1986

Table of Contents

The Walnut Husk Fly: A "New" Pest of Peaches

in Massachusetts

Pomological Note: Thermometers

Stone Fruit Weed Control

Boom Sprayer Calibration and Use

Polological Paragraph: Harvesting Empires
from Interstem Trees

Rules and Regulations on Pesticide Residues

Pomological Paragraph: Disinfect Cull Bins

Benlate^ Residues on Red Delicious

Herbicide Selection for Small Fruits

Results of a Telephone Survey of Extension IPM Program

Impacts on Commercial Apple Growers

in Massachusetts: Part II

THE WALNUT HUSK FLY: A "NEW" PEST OF PEACHES IN MASSACHUSETTS

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

Department of Entomology

University of Massachusetts

Peaches are grown by many commercial orchard! sts in Massachusetts, and
typically are marketed directly to consumers at on-farm stands. While the
total size of the state's peach crop is quite small, compared to states to
our south, the retail price of this fruit certainly justifies the effort of
growing it, especially because peaches are the first tree fruit crop to
ripen and find its way onto local shelves in any quantity.

Under our conditions, winter and spring temperatures are the major fac-
tors limiting peach production inasmuch as most growers usually have little
difficulty controlling the major peach pests: brown rot, catfacing plant
bugs, plum curculio, green peach aphids, and borers.

Consequently, we reacted with great interest when we received a call in
early September from a commercial grower in Granville, Massachsetts, who
reported observing an unknown fruit fly, active and causing substantial
injury to his peaches. In addition, another grower in the Wilbraham area
reported sighting similar flies active in his peach block during harvest,
although no fruit injury was observed.

Adult specimens sent to us were identified as the walnut husk fly
(WHF), Rhagol et i s suavi s Loew, a Tephritid fly related to the apple maggot
(AMF), R^ pomonel la , and the blueberry maggot, R_^ mendax . WHF had been
reported to cause injury to peaches at two unrelated sites in New York State
in 1968 (2).

The intent of this article is to provide information about the fly's
life history and general appearance, a description of injury to peach, and
available monitoring and control options. We conclude with a discussion of
the potential of this fly to become a serious pest of peaches.

LIFE HISTORY AND. DESCRIPTION

In New York (3), WHF is reported to emerge from pupae in the soil about
July 15, somewhat after first emergence of apple maggot adults. Adult
females (Fig. 1) are about 4 mm in length, and are slightly larger than
males. The adult fly is a tawny brown color with a yellow spot on the back.
The wings have three prominent dark bands, one of which extends around the
wing tip to form a "V" shape. Like AMF, there is only one generation per
year. Adult WHF emergence continues until about mid August. Unlike its
relatives, R_^ suavi s is reported to utilize as its normal hosts black,
Persian, and Japanese walnuts, and butternuts. Eggs are initially white,
somewhat curved, and measure about 0.9 nim x 0.3 mm. On wild hosts,
egglaying occurs during August, and the nearly transparent to cream-white
larvae feed within the husk (exocarp) of the nut and emerge from husks from
about September 1 to November 1. Pupae resemble grains of wheat. Pupation
occurs in soil at depths of from 1/2 to 1 1/2 inches, with emergence of most

2 -

adults the following year. Although we are not certain if this is so in
Massachusetts, a percentage of WHF pupae may remain in the soil until one or
two years later, as is the case with R_^ pomgnel la and R^ mendax, and with
another member of the walnut husk fly complex, R_^ juglandi s Cresson (l).

WALNUT HUSK FLY

Diptera: Tephritidae

(after Calif. Ext. Serv. Cir. 87)

Figure 1 . Walnut husk fly. From R.E. Berry. 1978. Insects and mites of
economic importance in the Northwest. O.S.U. Book Stores, Corvallis, OR.

INJURY TO PEACH

In Granville, injured peaches were found on 15-year-old trees (cv.
Jersey Queen) in a 3 acre block surrounded on all sides by thick forest,
with oak, pignut hickory, and shagbark hickory predominating. Several
mature hickory trees were seen, but the nut crop was low to nil.

Although Jersey Queen peaches are moderately hairy, WHF injury was
relatively easily seen and appeared similar to egglaying punctures caused by
apple maggot fly on apples. Often, a 2 mm area around the oviposition site

- 3

appeared slightly depressed and retained a green color even when the
remainder of peach skin background color had become reddish. in a few
instances a rather large droplet of clear gummy ooze exuded from the punc-
ture as well, which we took to indicate an active larva burrowing within the
fruit. Over time, a small, circular black spot developed where the female
fly had punctured the fruit. Injured fruit were seen with multiple punc-
tures in some cases, while others were only punctured once. Spots were
similar to small lesions of Peach Scab and positive identification required
removing the skin to look for eggs and/or burrows beneath.

A cluster of numerous eggs could be seen easily with a 10X hand lens
and already-hatched eggs appeared shriveled. We were unable to retrieve any
larvae, although extensive brownish burrows were evident. Such trails dif-
ferred from those of AMF, with the majority confined to an area beneath the
puncture within 1 cm (0.^ in.) of the surface and rarely larger than 2 cm
(0.8 in.) in diameter. Between 75^ and 100^ of fruit were infested,
necessitating substantial culling of the most severely attacked fruit and
marketing the rest as "orchard run" at a reduced price.

No larvae were successfully reared to pupation due to rapid rotting of
infested fruit when held at room temperature, although WHF are reportedly
able to reach pupation on this host (2).

MONITORING AND CONTROL

Presently, we do not know what monitoring techniques work best for WHF
nor whether monitoring is even necessary in most years. We anticipate,
however, that yellow sticky boards or green sticky spheres (k) may be effec-
tive monitoring devices. We hope to look into this question in 1986.

Prior to our visit to the Granville orchard, the grower had applied a
single carbaryl treatment, and a careful check of remaining fruit and trees
revealed no adult flies. Other registered insecticides applied against
usual peach pests likely also will control WHF, although overlap of fly
activity with peach harvest would clearly limit choices to materials with
short pre-harvest interval requirements.

CONCLUSION

It is our belief that the walnut husk fly injury we observed was simi-
lar to the 1968 New York report mentioned earlier, when the crop of native
nuts was also found to be very small. We have no reason to believe that
resistance to insecticides played a role in our I985 infestation, so we
conclude that the absence of native hosts caused mated females to emigrate
to adjacent peach blocks in search of oviposition sites. Due to the like-
lihood of poor WHF larval survival in rapidly rotting peach flesh, and from
what is known of Tephritid host selection behavior, it would seem very un-
likely that WHF would switch preferred hosts and become a "new" pest of
peach. Nonetheless, in years when native hosts produce few nuts, or should
clearcut logging remove native hosts adjacent to peach blocks, growers
should, at the very least, be aware of the possibility of fruit injury and
monitor flies using either visual traps or direct observation of adult acti-
vity.

- k

REFERENCES

1. Boyce, A.M. 1929- The Walnut Husk Fly ( Rhagoletis jug land is Cresson).

J. Econ. Entomol . 22:861-66.

2. Dean, R.W. 1968. Infestation of peaches by Rhagolet i s suavi s . J.

Econ. Entomol. 62(^) :9i»0-'4l

3. Gambrell, F.E. 1931. The fruit flies of New York. J. Econ. Entomol.

2't(l):226-32.

4. Riedl, H., and R. Hislop. 1985- Visual attraction of the walnut husk

fly to colored rectangles and spheres. Environ. Entomol.
14:810-14.

JL ^ JU Jt. J^

POMOLOGICAL NOTE

Thermometers

Wi 1 1 iam J. Lord

Department of Plant and Soil Sciences

University of Massachusetts

Some storage operators foolishly use uncal ibrated thermometers to set
their thermostat(s) . It is not at all unusual for thermometers to be inac-
curate by 1 or 2 degrees. Consequently, rooms are sometimes run at 30° or
34° instead of a desired 32°F. Occasionally, thermometers are highly inac-
curate. We know of a storage operator who set the thermostat in a CA
Mcintosh room with a thermometer that was reading 7° low. He loaded the
room at 39° (the thermometer read 32°) and operated the room all winter at
43° (the thermometer read 36°). The fruit was a complete loss.

Don't entrust your valuable, stored apple crop to an uncal ibrated,
"cheap" thermometer with 2° subdivisions on the scale. Remember that all
thermometers except primary reference thermometers should be calibrated with
a primary reference thermometer or by placing the thermometer into a con-
tainer of melting ice and ice water, which will be 32°. All thermometers
should be checked for corrections of reading at the beginning of each
storage season.

Sources of thermometers:

Orchard Equipment and Supply, Co,
P.O. Box 540
Conway, MA 01341

Rodeo Products Co., Inc.
P.O. Box 944
Columbus, NE 68601

Fred Reeve, Inc.
132 Sound Ave.
Riverhead, NY II9OI

A.M. Leonard, Inc.

P.O. Box 816

Piqua, OH 45356-08l6

- 5 -

STONE FRUIT WEED CONTROL

Bradley A. Majek

Assistant Specialist in Weed Control

Rutgers Research and Development Center, Bridgeton, NJ

A good orchard floor management program eliminates and prevents the
reestabi i shment of undesirable vegetation. Weeds compete with fruit trees
for water, nutrients and light, serve as alternate hosts for diseases and
harmful insects, harbor rodents, and impede harvest. Herbicides used to
control weeds must have a good margin of crop safety to minimize the risk to
the tree.

Weeds can be classified by life cycle. Annual weeds live less than one
year. Summer annuals germinate in the spring or early summer, grow, flower,
produce seed, and die in the fall. Winter annuals germinate in late summer
or in the fall, grow vegetatively through the fall, overwinter, flower, pro-
duce seed, and die in the spring. Biennial weeds live more than one year
but less than two years, produce seed, and die. Perennial weeds live more
than two years. They often reproduce vegetatively as well as by seed and
are much more difficult to control. Consider summer annuals, winter annuals
and biennials, and perennial weeds separately when planning a control
program.

Weed control in a newly planted orchard should be planned to provide a
maximum margin of crop safety. Established biennial and perennial weeds
should be controlled by tillage and/or herbicides prior to planting. After
planting, use a combination of napropamide (Devrinol^) OR oryzalin (Surf Ian")
OR pendimethal in (Prowl'^) for annual grass control PLUS oxyfluorfen (Goal")
for control of broadleaf weeds. Apply in early spring after 1 to 2 inches
of rainfall or irrigation has settled the soil around roots of the newly
planted trees, but before weeds germinate or tree buds break. Do not
cultivate or mechanically incorporate Goal"^ into the soil or effectiveness
will be reduced or eliminated.

Additional herbicides are available in established, bearing orchards.
Terbacil (Sinbar^ and diuron (Karmex") used alone or in combination are
extremely effective herbicides, but use is restricted to established
orchards. The margin of crop safety observed with Sinbar" or Karmex" is
narrower than that for herbicides recommended for use in newly planted and
one-year-old orchards. Sinbar or Karmex" should not be used on loamy sand
soils or soils with less than 1^ organic matter. Consider using Devrinol^,
OR Surflan^ OR norflurazon (Sol icam^^) PLUS Goal'f' OR Princep"'^ or reduced
rates of Sinbar^ OR Karmex^ on sites with extremely coarse textured soils
low in organic matter for summer annual weed control.

For several reasons a trend has developed in many fruit growing areas
toward the application of residual herbicides later in the spring with a
postemergence contact herbicide. Growers are extremely busy in March and
April pruning, planting, fertilizing, pollinating, thinning, and spraying
for insects and diseases. Weather frequently is not favorable for spraying
herbicides. Delaying application is convenient. In addition, the marginal
crop safety of Sinbar^ and Karmex" on extremely coarse-textured soils low
in organic matter has led to the use of reduced rates. This has resulted
in reduced length of residual control. Delaying application from early
April until late May or early June can compensate for this reduced length of
control, but unfortunately results in ^ to 8 weeks of weed competition in
the spring when the trees are growing vigorously. Vigorous weed competition
in late April and May can reduce efficient utilization of annual spring fer-
tilizer applications (and water in dry years).

Residual herbicides for summer annual weed control should be applied in
late fall or early spring. Maximum effectiveness is observed when applied
in November or late March to early April. At least 1/2 to 1 inch or rain is
needed to move the spring-applied herbicides into the soil and into contact
with weed seeds as they begin to germinate. Early application and rainfall
are more critical when using some of the more recently labeled herbicides,
including Devrinol^, Surflan", and Prowl^, which inhibit germination and
seedling emergence, than when using Sinbar^, Karmex^, or Princep^ which
affect photosynthesis.

Growers who cannot efficiently apply herbicides in early spring and
growers with extremely coarse-textured low-organic-matter soils should con-
sider splitting their weed control program into 2 applications. Apply half
of the total rate of the annual grass herbicide plus an annual broadleaf
weed herbicide in November to provide weed control until early summer.
Apply the second half of the annual grass herbicide plus a different annual
broadleaf herbicide in late spring to control weeds until fall. Choose her-
bicide combinations based on weed species present or expected in each
orchard.

Winter annual, biennial, and certain perennial broadleaves, including
horseweed, camphorweed, and dandelion, can be most effectively controlled by
anplying 2,'«-D in early spring or late fall. Two formulations, Hi-Dep" by
PBI-Gordon and Envy^ by Lilly-Miller, are labeled for use with stone fruits.
2,4-D can be tank-mixed with the residual herbicides applied at that time.
Sod strips between tree rows can also be treated with ?.,k-D to control
broadleaf weeds. Use care when applying 2,4-D as a growth regulator type
herbicide, because minute amounts of drift can seriously damage many
flowers, vegetable crops and grapes. Avoid using 2,'*-D in late spring and
summer after these sensitive crops are growing.

Control hard-to-kill perennial broadleaf weeds in the orchard by spot
treating the weed with glyphosate (Roundup*^). Application timing is criti-
cal to obtain maximum translocation of the herbicides from the leaves where
it is absorbed into the extensive root systems of these weeds. The optimum
time of application depends on the weed species. Apply Roundup^ when the

- 7

weed to be controlled is in the "full bloom" to "green fruit" stages of
growth. Most applications are made too early, and result in good top kill
but allow the roots to survive and resprout. Severe injury may result if
Roundup^ contacts a fresh wound, the fol iage, or green immature bark of an
apple tree, oj- any part of a peach tree. Always carry pruning shears when
using Roundup" in an orchard. Immediate pruning of an accidentally sprayed
limb will eliminate the risk of herbicide damage to the tree.

*****

BOOM SPRAYER CALIBRATION AND USE

Elden J. Stang

Department of Horticulture

University of Wisconsin, Madison, Wl

There are many ways to properly calibrate a conventional boom-type weed

sprayer. The principles are the same whether you use a massive field

sprayer with ^0 nozzles or a simple 2 or 3 nozzle boom for undertree
spraying.

Why calibrate? According to a study by Nebraska agricultural engineers
the four most common causes of error in applications of agricultural chemi-
cals include: 1) INACCURATE SPRAYER CALIBRATION, 2) incorrect mixing, 3)
worn equipment, and '*) failure to read the label.

Do you really know how to calibrate your sprayer? If you do, fine. If
not, or if you would like to check your method, the procedure described
below, suggested by Robert Newman and L.K. Binnin, UW-Madison weed scien-
tists, is offered for your use.

The method is simple and accurate. Follow the directions carefully and
you can be assured your sprayer is correctly calibrated.

Calibration Tools You Need

1. A tape measure, 2 stakes or flags.

2. A new pressure gauge.

3. Catch bottles or containers.

h. An accurate measure, in ounces.
5 . A calculator.

- use the tape measure to measure distance accurately

- use the new pressure gauge to check the accuracy of the old one

- use the catch bottle to collect nozzle output

- measure the output accurately

- use the calculator to avoid mistakes in arithmetic

Sprayer Cal ibration Steps

1. Clean out the sprayer tank and booms.

2. Remove and clean all screens and nozzle tips.

3. Check the tips to see that they are all similar.

k. Check the pressure gauge to see that it is operating. Screw in a new
gauge to check the old one.

5. Fill the sprayer about half full with clean water. While standing,
start the pump and turn on the sprayer. Catch and measure the output
of every nozzle tip by holding the measuring cup under each nozzle tip
for 15 seconds. Output should not vary by over + 5^ among nozzles.
Replace inaccurate tips.

6. Set the pressure appropriate for the pesticide. Read the product label
for directions.

7. Select the tractor speed in MPH or the gear and RPM you intend to use
when spraying.

8. Measure off the appropriate distance based on nozzle spacing from the
table below. Measure with a tape measure and put flags or stakes at
each end.

Nozzle spaci

Feet to

( inches)

travel

hOS

3hO

111

20i»

136

ifO

102

9. Catch the output of one nozzle tip as you travel over the measured
distance. Use a running start and travel at the speed you intend to
use when spraying. Turn on the entire boom if you are broadcast
spraying, not just one or two sections.

10. Measure the spray output in ounces.

- 9

11. The number of ounces is equal to gallons per acre your sprayer is deli-
vering.

1 2 . Example ;

a. Nozzle spacing is 20 inches.

b. Measure off 20'» feet (from table).

c. Catch the output of water from one nozzle while traveling 20^4 feet.

d. The output in ounces for one nozzle is equal to gal Ions per sprayed
acre.

Suppose you collected 20 ounces. Your sprayer is delivering 20 gallons
per acre. But let's assume the herbicide label suggests at least 30 gal
water/acre. The easiest way to change sprayer output is to change travel
speed. Slow down the travel speed and collect the output from one nozzle
for 20'» feet. If you are able to slow down the travel speed enough to
collect 30 ounces then proceed to step e below. If not, change nozzle tips
for a larger opening and proceed from step a above until output is correct,
or at least 30 gal/A or as suggested by the herbicide label. When output is
correct, proceed to e.

e. The sprayer is now operating at the pressure and output suggested
on the label. Let's suppose we plan to spray glyohosate (Roundup")
herbicide as indicated on the label. Roundup" contains ^4 lbs
active ingredient per gallon of product. The label suggests appli-
cation of 1 1/2 lbs active ingredient per acre sprayed. Each quart
of Roundup" contains 1 lb of herbicide, hence to 30 gals water in
the sprayer we add 1 1/2 quarts (1 1/2 lbs a.i.) of Roundup*^ and
proceed with spraying, assuming we have only j^ acre of total area
to be sprayed. If not, we have one more step.

f. Let's remember herbicide rates are given in amount per acre
sprayed . For undertree spraying we are not spraying the entire
orchard floor.

Let's assume our undertree boom has three nozzles spaced 20 inches
apart, with an effective coverage of 60 inches (5 feet). We'll be
spraying each side of the tree row or ten feet for each row.

If the tree rows are 20 feet apart we will actually be spraying
only 1/2 acre for each acre of orchard covered. Again, suppose our
orchard includes 8 acres of trees. Since we are actually spraying
only 1/2 acre for each total acre covered in this example, we will

really be spraying ^ acres, not 8.

Our example
(in numbers)

water output/A 30 gal /A

acres to be sprayed ^ acres required

total water 120 gals water, and

from e, above

rates of herbicide 1 1/2 qt Roundups/tree
per acre sprayed X

acres 4^ acres requires

total herbicide 6 qts Roundup^

Mix the 6 quarts Roundup" in the 120 gallons of water and proceed to
spray at the speed and pressure determined earlier. The procedure is the
same for other herbicide formulations. Read the label!

Calibrate your sprayer often. Nozzle tips wear, pressure gauges fail,
pumps wear, and screens clog. Keep a record of pressure, speed, and sprayer
output for later reference.

Calibration of sprayers is one of the steps in proper use of agri-
cultural chemicals, an important step. Improper calibration wastes product
and money, pollutes, and may cause crop injury.

Take time to calibrate often and accurately.

*****

POMOLOGICAL PARAGRAPH

Wi 1 1 iam J. Lord

Department of Plant and Soil Sciences

University of Massachusetts

Harvesting Empire apples from interstem trees . While harvesting
Empires from interstem trees last fall two thoughts came in mind.
Harvesting apples from low limbs on dwarf trees is "hard" on the back.
Secondly, it is very necessary to eliminate most of the grasses and weeds
under these trees because of fruit shading. In the planting being harvested
a high percentage of the fruits on many low limbs were culls because of ina-
dequate color.

- 11

RULES AND REGULATONS ON PESTICIDE RESIDUES

Eugene M. Kupferman

Extension Horticulturist

Tree Fruit Research Center

Wenatchee, WA

The tree fruit industry has become increasingly aware of the prolifera-
tion of agencies and regulations which impact shipments of fruit, especially
to foreign ports. This article attempts to explain who these agencies are
and reports on efforts made by the fruit industry to comply with the regula-
t ions.

Definitions of Terms

The term pest ic ide res idue refers to the amount of a pesticide and
possibly breakdown remaining on or in a crop. The term tolerance describes
the minute trace level of a pesticide residue permitted on or in a crop
after harvest. If the residue exceeds the tolerance set by the appropriate
regulatory agency, then the crop may not be marketed or sold.

Regulatory Agencies

The regulatory agency which established pesticide residue tolerance on
crops within the USA is the Environmental Protection Agency (EPA). Market
surveillance is done by the Food and Drug Administration (FDA).

Some other countries to whom Washington sends apples set regulations
regarding pesticide residues and tolerances through in-country agencies and
legislation. For example, in Canada the "Canadian Food and Drugs Act and
Regulations" apply to food sold in Canada whether produced domestically or
imported. Countries including Switzerland, Finland, Sweden, Germany,
France, and the United Kingdom sometimes act somewhat independently of each
other on questions of chemical residue standards.

Many countries of the European Economic Community (EEC) follow the
recommendations of an EEC Ministerial Decision which lists a number of
pesticides and accepted residue tolerances by commodity. However, they are
not mandated to do so.

Countries are also influenced by the "Codex Al imentar ius" prepared by a
joint committee of members of the World Health Organization (WHO) and the
Food and Agricultural Organization of the United Nations (FAD). The "Codex
Alimentarius Committee on Pesticide Residues" is only an advisory body, but
it often provides the foundation for decisions made by countries, especially
those lacking sophisticated regulatory laboratories.

Export Manual Available

Chris Schlect, President of the Northwest Horticultural Council, com-
piled an excellent "Export Manual, I983" which describes the regulations for
shipments of fruit into foreign countries. The information was gathered by
USDA's Foreign Agricultural Service (FAS). An updated version of this

manual is planned for I986. To place an order for the I986 Export Manual
write to the: Northwest Horticultural Council, P.O Box 570, Yakima, WA
98907.

Residue Tolerances

Tables 1 and 2 describe the permissible residue tolerances of some che-
micals which can be used after harvest on tree fruits. This is an area of
actively changing regulations. Check with the fruit importer if any doubt
should exist about the residue tolerance allowed by a particular country.
Also, the company selling the product to the warehouse should have infor-
mation on acceptance of a chemical by other countries. Do not rely exclu-
sively on the information contained in these tables.

Table 1. Chemical Residue Tolerances for Apples^ (ppm).

Country

Benlatey MertectY TopsinV Captan Ethoxyquin DPAY

Canada

5.0

10.0

5.0

3.0

10.0

Colombia

(Codex)

Costa Rica

(US)

10.0

7.0

Finland

1.0

3.0

2.0

3.0

5.0

France

6.0

15.0

3.0

Hong Kong

(US or UK)

10.0

7.0

Kuwa i t

(UN or FAO)

Malaysia

5.0

none^

none

Mexico

7.0

10.0

7.0

New Zealand

5.0

none

5.0

10.0

3.0

10.0

Norway

(Codex)

Saudi Arabia

none

Singapore

none

15.0

Sweden

1.0

10.0

1.0

5.0

3.0

Taiwan

(no info)

none

Thai land

none

20.0

none

Trinidad-

(no info)

Tobago

UAE

(US)

10.0

7.0

United Kingdom

none

0.0

none

3.0

10.0

United States

7.0

6.0

15.0

3.0

^Most information supplied by USDA-FAS, I982.

Trade Name Common Scientific Name

Benlate = Benomyl

Mertect = Thiabendozole (TBZ)

Topsin = Thiophanate-methy 1

DPA = Dipheny lamine

none = no restrictions indicated/or accepts US standards.

- 13 -
Table 2. Chemical Residue Tolerances for Pears (ppm).

Country Benlate Captan Ethoxyquin

5.0

1.0

Canada

Co 1 omb i a

(Codex)

Costa Rica

(No info)

Finland

Hong Kong

(US or UK)

Kuwait

(UN or FAO)

Malaysia

Mexico

(US)

New Zealand

Norway

(Codex)

Saudi Arabia

Singapore

Sweden

Taiwan

(No info)

Thai land

Trin idad-

(No info)

Tobago

UAE

(US)

Uni ted Kingdom

United States

none

5.0

3.0

none

10.0

3.0

none

15.0

5.0

3.0

20.0

none

3.0
7.0 25.0 3.0

Table 3. Effective Levels of Residue (ppm).

Maximum
Minimun residue

Chemical acceptable Desired allowed (USA)

APPLES

2.5 25

1.0 7

1.5 10

3.0 10

0.5 3

PEARS

5.0 25

2.5 25

1.5 10

1.0 7

0.5 3

OPP

1.0

Benomyl

0.5

TBZ

0.8

DPA

1.0

Ethoxyqu in

0.3

Captan

2.5

OPP

1.0

TBZ

0.8

Benomyl

0.5

Ethoxyqu in

0.3

1i»

Industry Practices

The Tree Fruit Research Commission worl<ed together with the USOA-ARS
laboratory in Yakima, Oregon State University, and commercial chemical labs
to determine the levels of chemical residue found on fruit following custo-
mary postharvest commercial application techniques. These very 1 imi ted
tests have shown that in most cases the chemical residue is well below that
of even the strictest licensing countries.

In some cases, the residue found on fruit was of an insufficient quan-
tity to control the target disease or disorder. Further study indicated
that it was not a question of improperly mixing the solution, but rather a
faulty application rate. Poor nozzle configuration and plugged nozzles
resulted in insufficient chemical being applied. Full coverage is
necessary. Table 3 lists the residue levels of certain chemicals to control
diseases and disorders.

A summary of this study's findings on Benlate is included in this issue
of Fruit Notes .

(Reprinted with permission from the Postharvest Pomology Newsletter ,
November, I985, Washington State University, Cooperative Extens ion. )

*****

POMOLOGICAL PARAGRAPH

Wi I 1 iam J. Lord

Department of Plant and Soil Sciences

University of Massachusetts

Pi sinfect cul 1 bins . Fungus spores in boxes and bins can be a source
of inoculum to infect the current crop of apples when they are treated with
a scald inhibitor after harvest. A fungicide with the scald inhibitor will
reduce but not completely eliminate the hazard of rot. Therefore a 10 per-
cent chlorox spray is suggested to disinfect empty cull boxes and bins.

- 15 -

benlate"^ residues on red delicious

R. Kammereck

Consultant

and

R.D. Bartram

Tree Fruit Research Commission

Washington State

in order to prolong storage life and reduce fungus-caused decay, Red
Delicious apples are routinely treated with Benlate by some packinghouses.
This treatment is made after harvest and during the preparatory stages
preceding packaging. Most countries place strict limitations on the quan-
tity of fungicide (residue) remaining in fruit at the time of purchase by
the consumer. It is, therefore, of great interest to fruit sales organiza-
tions to have a clear understanding of the level of residue at the time of
sale.

Residue Study

The following results and conclusions were obtained from an analysis of
data derived from the chemical determination of benomyl and its metabolic
breakdown product MBC in Red Delicious apples treated commercially with the
fungicide Benlate^. This study was designed to explore the fate of benomyl
(the active ingredient of Benlate^) as influenced by 1) application condi-
tions, 2) storage time and storage facilities, and 3) treatment of fruit
prior to packaging. The chemical determinations were performed at the USOA
Yakima Agricultural Research Laboratory by Research Chemist Don George in
IBS'* and I985 on preceding year fruit samples.

During the course of the chemical extraction procedure, all benomyl was
altered to MBC and measured in the MBC form. In the following report, the
term "benomyl equivalent" stands for combined benomyl and MBC present in
whole fruit samples at time of chemical analysis, and its concentration is
expressed as milligrams per kilogram of fresh fruit (ppm). Data were sub-
jected to statistical analysis.

Benlate^ Drenches, I983

In the 1983 trial, apples were drenched with Benlate^ at commercially
recommended rates. Fruit, prior to storage, contained benomyl -equ ivalent
residues of 0.85 ppm on the average, with residue levels ranging from 0.49
to 1 .'♦2 ppm. The odds against finding apple sample lots with average resi-
due levels of greater than 0.93 Ppm were more than 1000 to 1.

During subsequent storage of these fruit under "cold room" conditions
for up to 180 days, there was no statistically significant change in the
average residue level. Similarly, storage for I8O days under "controlled
atmosphere" conditions had no effect on the average residue concentration.

BenlateT< Drenches, 1984

In 1984 when this trial was repeated under comparable procedures, the
average level of benomyl equivalent prior to storage increased to 1.41 ppm.
The reasons for the observed increase cannot be deduced from the data given,
but likely causes are differences in BenlateTl solution concentration, dura-

tion of use of drench baths, quantity of fruit treated, etc. The variation
in residue levels among treated fruit can be expressed as the 1000 to 1 odds
against detection in apple sample lots of average residue levels greater
than 1 .49 ppm.

"Cold room" storage again did not affect the benomyl residues dif-
ferently than "controlled atmosphere" storage, but there was a substantial
lowering of residue levels in both storage conditions. After 180 days the
residue concentration declined on average by 22^

Effective Control

In both years, apples involved in the drench treatment trials would
have been likely to pass inspection in all those countries imposing a 2.0
ppm tolerance on residue concentration. But the achieved benomyl level in
1983 must be considered too low for effective decay control.

Benlate"^ with Wax, 1983

Extending the "drench and store" treatment experiment to an additional
mode of fungicide application. Red Delicious apples in I983 and 198't were
treated with Benlate^ in combination with wax. in the I983 trial, stored
fruit pretreated by drenching and exhibiting a benomyl -equ ivalent level of
0.35 ppm average was sprayed prior to packaging with a Benlate^-wax mixture,
then stored for 60 days.

After waxing, the benomyl levels were raised substantially to an
average of 1.33 ppm. At this stage the variability of residue concentration
among individual fruit was such that if a random sampling of apples were done
then the odds against finding a sample lot with an average residue level of
1.^2 ppm or greater were 1000 to 1 . As was observed in the ^SB^ "drench and
store" trial (but not in the corresponding I983 trial), the benomyl levels
decreased significantly during storage at a rate of about 20% in 60 days.

Benlate"^ with Wax, 198't

This experiment was repeated in 198'* at another warehouse. Starting from
an average benomyl concentration of 0.36 ppm, spray application combined with
waxing raised the average benomyl equivalent level to 2.89 ppm. Variability
in residue concentrations among fruit was such that had a random sampling of
apples been done just after waxing, then 1 out of 10 sample lots would have
shown average benomyl equivalent levels of at least 3.0 ppm. During storage
over a period of 60 days the average level of benomyl decreased by about 19?.
This rate of loss would bring a typical fruit lot into compliance with a 2.0
ppm tolerance limitation after an estimated 105 days of storage.

Effect of Packingline Practices

A further test in 198^* sought to determine the influence of packing
line operations such as grading, sorting and washing on fungicide levels.
Grading and sorting operations had no significant effect on the residue
levels. But washing prior to waxing reduced the residues on the average by
2'*%. Waxing increased residues substantially, although the test protocol
does not mention the addition of Benlate^ to the waxing spray in this par-
ticular experiment.

17 -

Conclus ions

Drenching of Red Delicious with Benlate^ at commercially recommended
rates results in benomyl levels which are likely to be below that of 2.0
ppm. Care must be taken during drenching to ensure that adequate levels of
benomyl are appied for effective decay control.

The application of Benlate^ as part of the waxing operation on the
packingline is more difficult to control and may result in benomyl levels
above 2 .0 ppm.

Benomyl levels in treated apples are reduced by prolonged, regular or
"CA" storage, and also by washing. Precise residue levels can be determined
by having fruit tested by a qualified commercial laboratory.

(Reprinted with permission from Postharvest Pomology Newsletter , November
1985, Washington State University, Cooperative Extension) .

*****

HERBICIDE SELECTION FOR SMALL FRUITS

Dominic A. Mar in i

Regional Fruit and Vegetable Agent

Plymouth County Extension Office, Hanson, MA

When it comes to selecting herbicides to use on small fruit crops, a
number of factors have a bearing on the material to choose. Some of these
are the small fruit crop being grown, and in some cases, the variety, the
predominant weed species to be control led, whether they are annual or peren-
nial weeds, and whether the material is to be used for pre-emergence or
post-emergence control. Soil type has a bearing on the rate to be used and,
in certain cases, the degree of safety to the crop.

The following outline lists the herbicides included in the I986 New
England Chemical Weed Control Guide for Small Fruit with a brief summary of
crop uses and weeds controlled. For complete information refer to the Guide
and to the label for each material.

Chloroxuron (Tenoran")

Uses: strawberries; pre- or early post-emergence.

Weeds Controlled: most broadleaf weeds up to 2 inches, galinsoga up to 3/^

inch, weak on grasses; good in fall on chickweed and fall and winter weeds.

DCPA (Dacthal"^)

Uses: strawberries; pre-emergence, shallow, incorporate or 1 inch water
within 7 days.

Weeds controlled: crabgrass, foxtail, chickweed, lambsquarters, purslane;
does not control galinsoga, ragweed, smartweed, or mustards.

- 18 -

Dichlobenil (Casoron'^)

Uses: blueberries, raspberries; late fall or early spring.

Weeds controlled: crabgrass, most annual broad leaf weeds and grasses, many

perennials, but not deep-rooted perennials or woody plants.

Diphenamid (Enide^) pre-emergence

Uses: strawberries, raspberries; new plantings only, not within 12 months
of harvest.

Weeds Controlled: crabgrass, chickweed, foxtail, lambsquarters, pigweed,
smartweed; does not control galinsoga.

Diuron (Karmex^)

Uses: blueberries, grapes, raspberries; pre-emergence.

Weeds Controlled: crabgrass, chickweed, lambsquarters, smartweed, pigweed,

mustartd, shepherd's purse.

Fluaz ifopbuty 1 (Fusilade^)

Uses: blueberries, grapes, raspberries; post-emergence.

Weeds Controlled: annual grass seedlings or perennial grasses 6-10 inches

tall; not within 12 months of harvest.

Glyphosate (Roundup^)

Uses: grapes; post-emergence, before end of bloom.

Weeds Controlled: perennial and annual weeds including quackgrass, milkweed
and other hard to kill weeds. Useful for eradicating quackgrass and other
perennials the year before planting small fruits; brambles and Japanese
knotweed in late summer.

Napropamide (Pevrinol^)

Uses: blueberries, grapes, raspberries, strawberries; pre-emergence.
Weeds Controlled: barnyard grass, crabgrass, chickweed, may suppress galin-
soga, does not control ragweed. Must be incorporated with water or cultiva-
tion. Long lasting. Useful on strawberries in fall before mulching,
controls grains from mulch.

Oryzal in (Surf lan"^)

Uses: grapes, raspberries; pre-emergence.

Weeds Controlled: barnyard grass, crabgrass, foxtail, lambsquarters,

pigweed, purslane; does not control ragweed or wild carrot.

Paraquat (Paraquate Plus^)

Uses: blueberries, grapes, raspberries; post-emergence.

Weeds Controlled: Kills annual weeds and grasses up to 6 inches tall; kills
tops and suppresses perennials. Contact herbicide, non-selective, apply as
directed spray. Restricted use, observe safety precautions .

Sethoxydim (Poast^)

Uses: blueberries, grapes, raspberries; post-emergence.

Weeds Controlled: annual grass seedlings or perennial grasses 6-10 inches

tall. Not within 1 year of harvest.

Simazine (Princep")

Uses: blueberries, grapes, raspberries; pre-emergence.

Weeds Controlled: crabgrass, chickweed, lambsquarters, pigweed, etc.

Terbaci 1 (Sinbar^)

Uses: blueberries, strawberries; pre- or early post-emergence.
Weeds Controlled: quackgrass at highest rates, crabgrass, foxtail,
chickweed, lambsquarters, mustard, shepherd's purse, purslane, ragweed,
smartweed. Does not control sorrel. On strawberries apply immediately
after renovation or in dormant season. Not on soils with less than 2% orga-
nic matter.

2,^-D (Dow Formula hO^)

Uses: strawberries; post-emergence.

Weeds Controlled: Dandelions, plantains, and other broadleaved weeds in

established beds. Apply after picking, before renovation.

RESULTS OF A TELEPHONE SURVEY OF EXTENSION IPM PROGRAM IMPACTS
ON COMMERCIAL APPLE GROWERS IN MASSACHUSETTS: PART II

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

Department of Entomology

University of Massachusetts

Introduction

In an earlier volume of Fru i t Notes (Spring, 1986, Vol. 51, No. 2), we
reported our initial analysis of a telephone survey administered to a sample
of Massachusetts apple growers which was performed earlier in 1986. That
article explained that the survey attempted to determine what impacts the
University of Massachusetts Extension IPM Program has had on apple grower
attitudes and pest management practices. Persons interested in details of
the methods used to design the questionnaire, select a sample, or administer
and analyze the data are referred to this earlier article.

A complete analysis of survey results will be published at a later date
as part of a national impact survey of IPM programs being conducted by
various states under the leadership of Virginia Polytechnic Institute and
State University (VPI). We wish to acknowledge the substantial assistance
provided us by Drs. E. Rajotte and R. Kazmierczak of VPI.

We also wish to express our thanks to the 88 Massachusetts apple
growers who participated in the study.

Here we present the results of an analysis of survey data comparing
responses of growers grouped according to their level of adoption of IPM.
It should be noted that although sample biases were minimized to as great an
extent as possible, some may have occurred due to non-response. It is
possible that there could be differences between the respondents interviewed
and those of the sample population whom we were unable to reach. In many
cases there were no substantial differences between the two groups; if
responses are detailed in the earlier paper and not here, it is because the
overall response accurately reflected the responses of both groups. Here we
will concentrate on those questions where the differences were substantial.

IPM Versus Non-IPM Growers

Inasmuch as a goal of the survey was to determine the extent to which
the state's apple growers are using IPM, and whether there were significant
differences in practices, costs, or production between growers who used IPM
and those who did not, the first step in this analysis was to distinguish
between the two groups. We decided to follow VP I ' s lead and define IPM
growers as those who scout more than 50^ of their acreage weekly.
Conversely, those who do not scout at all and those who scout less than 50^
were considered non-IPM growers. There is no perfect criterion which would
place all growers in the proper category, and we realize that some growers
who say they "scout" are merely taking a walk through the orchard at con-
venient times, while others may scout only 25? of their acreage but use
traps, careful examination of foliage and fruit, and economic threshold
levels in their decision-making. Nonetheless, the correlation between
scouting 50 percent or more of the orchard weekly and use of other
IPM-recommended practices was quite strong, so we feel justified in having
made this choice.

The two groups were fairly evenly divided; ^6 respondents (52% of the
total) said they scouted 50? or more of their acreage weekly, while k2
respondents {^8% of the total) said they did not. (Twenty-six percent of
the non-scouting growers said they did not scout at all.) The scouting was
done in most cases by the grower, a family member, or an employee of the
farm, but scouting was also performed by private consultants, pesticide
fieldmen, and Extension personnel. Unilike the analysts at VP I , we did not
place a grower in the "non-IPM" group if scouting was performed by pesticide
fieldmen, who may not practice or support IPM.

Grower Demographics

Few large differences were seen between IPM and non-IPM grower popula-
tions. There was a tendency for IPM growers to be younger and have fewer
years experience farming than non-IPM growers; '♦I? of IPM growers were under
40 as compared with 25? of non-IPM growers, and only 26? of IPM users had
been farming for more than 30 years as compared to 38? of non-IPM growers.
The percentage of growers in both groups having finished and gone beyond
college level was nearly identical. There were no substantial variations

- 21

in overall acreage owned or farmed, or in total acres of apples farmed,
although there was a slight tendency for non-IPM growers to be "clumped" in
the middle whereas IPM growers might either be very small (i.e., less than 5
acres) or very large (i.e., over 150 acres). Responses to questions about
farm value and the gross value of the annual crop also showed little dif-
ference between the two groups; however, a greater fraction of IPM growers
(52%) than non-IPM growers {k2%) derived more than 75 percent of their
income from the farm.

Farm Practices and Pesticide Use Problems

Looking at Table 1, for example, it is clear that an iPM grower was
much more likely to use sticky spheres for apple maggot fly detection and a
leaf wetness machine for the determination of an apple scab infection
period, and somewhat more likely to use pheromone traps and alternate row

Table 1. How often do you use the following methods of pest control?

IPM Growers Non-IPM Growers

Pheromone traps 37.8* 31 .6*

Sticky spheres 65.3 ^5.0

Leaf wetness machine 24.5 10.2

Alternate row sprays 57.8 h2.]

Perimeter-only sprays 26.7 27.5

Recommendations from UMass Extension 100.0 92.7

Pest Alert on Code-A-Phone 57.7 60.9

Pest Alert message by mail 97.8 95.0

*Percentage of respondents who answered "frequently" or "sometimes".

sprays than a non-IPM grower. The two groups were about equally likely (or
unlikely) to use perimeter-only sprays, and in the other 3 categories they
were also quite similar, an indication that a sizable percentage of the
state's growers used Extension-generated pest management information. As
mentioned above, this increased use of pest management materials correlated
well with the use of scouting as an IPM criterion.

Since the philosophy and techniques of Integrated Pest Management have
often been presented at grower meetings, we next looked to see whether IPM
growers were more likely to attend these meetings. In fact, a greater per-
centage of IPM growers attended afternoon and twilight meetings (3^%) and
the annual summer meeting of the Mass. Fruit Growers' Association (7'*^)>
than non-IPM growers (82^ and 60%, respectively). About 75^ of the growers
in both groups attended the annual New England Fruit Meetings.

However, an interesting difference between the two groups occured in
their awareness of the effective use of pesticides, as illustrated in Table
2. Both groups were equally likely to calibrate at least once per season,
but IPM growers were almost 3 times more likely to calibrate their sprayer

22 -

more than once per season than non-IPM growers. (There was no substantial
difference in the type of sprayer used, except that all the growers who use
backpack-type sprayers were in the IPM category.) Further, a majority of
IPM growers were equally likely to spray less or the same compared to ten
years ago. The percentage saying they spray more often was fairly small in
both cases.

Table 2. How often do you calibrate your sprayer?

IPM growers Non-IPM Growers

Less than once per season 18.6* 19.0*

Once per season 27.9 61.9

More than once per season 53-5 19.1

Do you spray

More? 9.3 15.0

Less? 60.5 '♦2.5

The same compared to 10 years ago? 30.2 't2.5

*Percentage of respondents in each category.

Table 3 indicates that a substantial majority (72^) of IPM growers used
scouting to decide when a pesticide treatment was needed, and another 11%
used a combination of techniques ("other"). Less than half of the non-IPM
growers gave these two responses. While nearly a third of the non-IPM
growers said they used the county agent for information on when to spray, in
most cases, we believe, this means that they used the Pest Alert and
Code-A-Phone messages. Thus, while some growers may be using IPM-generated
information, they may not be making the best use of this information if they
are not backing it up with their own scouting observations. It is possible
that reliance on the Pest Alert messages may be counterproductive if growers
treat for pests mentioned in the message regardless of whether they actually
have a problem with these pests on their farm.

Table 3. How do you decide when a pesticide treatment is needed?

IPM Growers Non-IPM Growers

Neighbors are treating 0* 2. A*

Scouting determines need 71.7 36.6

By the calendar 10.9 17.1

County agent information** 6.9 31.7

Other 10.9 12.1

♦Percentage of respondents in each category,
**Pest Alert messages.

23 -

From Table ^, it is clear that the IPM growers were spending less,
applied fewer insecticides and miticides, and achieved somewhat better pro-
duction than non-iPM growers. In the survey we asl<ed only the number of
pesticide applications, so we do not have any information on dosage equiva-
lents, a measure of pesticide rates. However, the cost per application of
pesticide was also slightly lower for IPM growers, possibly indicating that
such growers were using reduced rates of pesticide.

Table h. Average pesticide cost, number of applications, and production per
acre.

1PM Grower Non-IPM Grower

Pesticide Cost per Acre $171.11* $233.^'*'

Number of Insecticdes 8.2 9.8

Number of Miticides 1.8 2.1

Number of Fungicides 12.4 }] .k

Number of Herbicides 0.9 0.9

Bushels per Acre Production 386. 2^* 377.03

*Average response in each category.

When asked to rate various "selling points" of IPM, both IPM and
non-IPM growers responded fairly positively to most of the points. As one
might expect, the IPM group were more apt to give responses of "very useful"
and "useful," but it was possible to see trends in both groups. It is espe-
cially interesting to note that the non-IPM group rated "increases farm pro-
fits" and "control yield and quality loss" relatively poorly, whereas the
IPM growers regarded them as among the strongest reasons for using
integrated pest management. Again, as we noted in the earlier paper, IPM
growers' lower rating of "free management skills for use elsewhere", pro-
bably indicates a recognition of the somewhat complex nature of the IPM
system and an awareness that the grower still has the ultimate management
responsibility for spray decisions.

Growers also were asked to rate the usefulness of a variety of sources
of pest control and pesticide information. The two groups tended to be
fairly similar in rating most categories "very useful" or "useful," with the
exception that IPM growers were twice as likely to rate scouts highly (20^
and 10^ respectively) and non IPM growers were more likely to rate agri-
chemical salespeople highly (60% for non IPM, kQt for IPM) (data not shown).
Non-IPM growers also showed a tendency to use newspapers, agricultural maga-
zines, and neighboring farmers for pest control information, whereas the
percentage of IPM growers using these sources was close to 0.

Table 5.

Zk -

Please rate the following "selling point" of IPM according to how
important they are to you.

IPM Grower

Non-IPM Grower

Safe use of pesticides 95.1-

Increase farm profits 95.0

Control crop yield and quality loss 9'*. 7

Reduce environment damage 100.0

Unbiased opinion of pest problems 86.1

Use of natural enemies for pest control 89.7

Free management skills for use elsewhere 56.7
More positive image with neighbors and consumers 83.8

^Percentage of respondents answering "very useful" or "useful".
Orchard size

86.9*

75.7

65.8

92.1

75.0

76.3

62.9

75.7

The size of the orchard turned out to be an important factor in the
average amount of pesticide used and in per acre production. In Table 6,
respondents were considered by size instead of IPM use. There was a clear
decrease in the number of insecticide and fungicide applications with
greater orchard size; miticide use was about the same for all groups; and
the increased use of herbicides was to be expected, given that smaller
growers are much more likely to mow. (This decrease in herbicide use may
partially account for the lower pesticide cost per acre experienced by small
growers.) The increased production per acre in larger orchards was also not
unexpected. But the fact that growers under 20 acres used 25^ more insec-
ticide applications than large growers was most surprising at first sight.

Table 6. Average pesticide costs, number of applications, and production
per acre by orchard size.

<20 Acres

21-60 Acre

Cost per Acre $133. i»4^

Number of Insecticides 9.7

Number of Miticides 1.7

Number of Fungicides 12. 'i

Number of Herbicides 0.6

Bushels Per Acre 275.87

$258.64*

9.2

2.1

12.3

0.9

416.96

>60 Acres

$171.11*

7.2

2.0

10.8

1.4

459.05

^Average response in each category.

There are several reasons to believe that small growers have had less
exposure to Integrated Pest Management than large growers, and that this may
be related to their increased pesticide use. For a variety of reasons,

- 25

small growers may be less likely to attend the grower meetings where IPM
training has been presented, and in fact, the percentage of such growers
attending all grower meetings was smaller than the overall average.
Moreover, the majority of orchards on the IPM pilot program (1978-1982) were
large, and all the growers on this survey who used private consultants had
orchards larger than 60 acres. In addition, there may be less incentive for
small growers to reduce pesticides costs, since their costs are already
comparatively less.

But smaller growers have a strong potential for the use of integrated
pest management in their orchards, since a grower with a few acres can often
be more flexible than a grower who manages a large acreage. For example, a
large grower may need 2 or more days to spray their entire orchard while a
small grower may accomplish this task in less than a day. As a consequence,
the use of post-infection scab sprays or insecticides based on scouting
results (eg., for plum curcul io) may be less of a problem for the smaller
grower. It should be noted here that the respondents with less than 20
acres who do scout had the lowest pesticide costs on the survey--$121 per
acre, and the lowest use of mi t ic ides--l .3 applications per season. We
would anticipate that with better use of IPM techniques this group also
could substantially reduce their use of insecticides and fungicides, reaping
both economic and environmental benefits.

Summary and Conclusions

In summary, principal reasons for adopting IPM were safe use of pesti-
cides, increases in farm profits, control of crop yield, and a more positive
image with neighbors and consumers.

Compared to non-1 PM growers, IPM practitioners tended to be somewhat
younger and with less farming experience; were more likely to use sticky
spheres, pheromone traps, leaf wetness machines, and alternate row spraying;
were 3 times more likely to calibrate their sprayer more than once per
season; reported higher per acre yields, but lower pesticide costs, and
somewhat lower numbers of insecticide and miticide applications.

We conclude that growers who adopt integrated Pest Management experi-
ence benefits in several areas, and that such benefits can more than justify
the cost of hiring a private IPM scout/consultant or alloting the time to
implement an IPM system on their own.

Issued by the Cooperative Extension Service, E. Bruce MacDougall, Dean, in
furtherance of the Acts of May 8 and June 30, 191^; United States Department
of Agriculture and Massachusetts counties cooperating. The Cooperative
Extension Service offers equal opportunity in programs and employment.

COOPERATIVE EXTENSION SERVICE

U S DEPARTMENT OF AGRICULTURE

UNIVERSITY OF MASSACHUSETTS
AMHERST MASS 01003

OFFICIAL BUSINESS

PENALTY FOR PRIVATE USE, S300

BULK RATE

POSTAGE & FEESPAID

USDA

PERMIT No G?G8

Fruit Notes

Prepared by: Department of Plant and Soil Sciences

Massachusetts Cooperative Extension, University of Massachusetts, United States

Department of Agriculture and Massachusetts counties cooperating.

Editors: W. R. Autio and W. J. Bramlage

Volume 51, No. 4
FALL ISSUE, 1986

Table of Contents

Redcort: A Superior Strain of Cortland

Picking up Apple Drops to Prevent Buildup of
Apple Maggot Flies in "Organic" Orchards

Mammal Control

Sampling Orchard Soils

Apple Replant Problems

Update on Disease-Resistant Apples

Peach Rootstocks in New Jersey

Rootstock Evaluation in Massachusetts

Cultivars of Apples for Massachusetts

REDCORT: A SUPERIOR STRAIN OF CORTLAND

Wesley R. Autio

Department of Plant and Soil Sciences

University of Massachusetts

Apple growers are always looking for strains which have superior color
to the standard strains. Redcort (sold by Hilltop Orchard and Nurseries,
Inc., Hartford, Michigan) is one such Cortland strain. It was selected as a
branch mutation on a standard Cortland tree in Marlboro, NY.

Redcort and Cortland trees on M7A rootstocks were planted in I98O at
the Horticultural Research Center, Belchertown, MA. In I985 fruit were har-
vested on September I6 and September 23 for evaluation. Measurement of the
internal ethylene concentration was used to determine differences with
respect to the time of ripening. As apples ripen the ethylene concentration
in the core rises sharply, providing a means of pinpointing the time of
ripening. Both the internal concentration at harvest and the number of days
after harvest required for the core ethylene concentration to reach 1 ppm
are reported in Table 1. As the fruit matures the number of days required
for the internal ethylene concentration to reach 1 ppm declines, so a more
mature fruit would have a higher internal concentration at harvest and would
require fewer days to reach 1 ppm. There were no differences between
Redcort and Cortland in these two measurements for the two harvests, so our
data suggest that Redcort and Cortland fruit ripen at the same time.

Table 1. Ripening of Redcort and Cortland fruit in I985.

Harvested

■16-85

Harvested

-23-85

Strain

Core
ethylene
concen.
(ppm)

Days to

1 ppm
ethylene

Core
ethylene
concen.
(ppm)

Days to
1 ppm
ethylene

Redcort
Cortland

0.02 a*
0.07 a

5.0 a

0.10 a
0.10 a

3.2 a

3.3 a

*Within columns, means not followed by the same letter are significantly
different at the S% level.

On September 23 fruit weight, diameter, firmness, and soluble solids
were also measured (Table 2), but no differences existed between the two
strains for any of these parameters. The percentage of the surface of the
fruit which was red also was assessed on September 23, and Redcort fruit
were significantly redder the Cortland fruit. Redcort fruit averaged 86%
red, whereas Cortland fruit averaged only 58^ red. Fruit from these trees
were placed in air and CA storage for evaluation of storability.

Table 2. Fruit characteristics of Redcort and Cortland fruit harvested
9-23-85.

Strain

Fruit
weight
(lbs.)

Fruit
diameter
(in.)

Fruit
f irmness
(lbs.)

Total
soluble
sol ids
{%)

Surface

red

color

{%)

Redcort
Cortland

0.53 a*
0.52 a

3.42 a
3.38 a

14.9 a
15.4 a

13.9 a
14.0 a

86 a
58 b

*Within columns, means not followed by the same letter are significantly
different at the 5% level.

When storage was terminated fruit were moved to room temperature.
After 24 hours firmness was measured, and after 7 days the incidences of
scald, senescent breakdown, bitter pit, and decay were measured. There were
no differences between Cortland and Redcort fruit after 19 weeks of air
storage (Table 3). After 17 weeks of CA storage followed by 14 weeks of air
storage (Table 4) Redcort and Cortland fruit displayed similar firmness
values and percentages of senescent breakdown, bitter pit, and decay.
However, scald was more prevalent on Cortland fruit, reflecting the fact
that scald forms more readily on the green portions of fruit.

Table 3. Characteristics of Redcort and Cortland fruit after 19 weeks of
air storage.

Strain

Flesh
f i rmness
(lbs.)

Scald

Senescent

breakdown

(^)

Bitter
pit

{%)

Decay

Redcort
Cortland

8.6 a*
8.6 a

7 a
10 a

7 a

8 a

1 a

2 a

*Within columns, means not followed by the same letter are significantly
different at the 5% level.

After one year's observation Redcort fruit appear to be similar to
Cortland fruit except for the much higher degree of coloring. The higher
coloring translates into more fruit meeting the U.S. Extra Fancy grade.

Table A. Characteristics of Redcort and Cortland fruit after 17 weeks of
CA storage followed by 14 weeks of air storage.

Strain

Flesh
firmness
(lbs.)

Scald

Senescent

breakdown

{%)

Bitter
pit

Decay

Redcort
Cortland

12.1 a*
12.0 a

73 b
95 a

6 a
13 a

k a

h a

10 a
8 a

*Within columns, means not followed by the same letter are significantly
different at the S% level.

PICKING UP APPLE DROPS TO PREVENT BUILDUP OF
APPLE MAGGOT FLIES IN "ORGANIC" ORCHARDS

Ronald J. Prokopy
Department of Entomology
University of Massachusetts

The apple maggot has been a key pest in eastern and midwestern apple
orchards ever since it expanded its host range from hawthorn (its native
host) onto apple sometime mid 19th century. Before the advent of inorganic
pesticides such as calcium arsenate and lead arsenate in the early part of
the 20th century, the only effective method of controlling the apple maggot
was to pick up dropped fruit from beneath apple trees to prevent the larvae
from forming pupae. So long as drops were picked up on a frequent schedule,
this practice precluded pupal buildup beneath orchard trees and thereby pre-
vented wi thi n-orchard fly emergence the next summer. It could not affect
immigration of flies from sources outside an orchard, however.

Nowadays, with so many effective pesticides available to control the
apple maggot, probably few, if any, commercial apple growers in eastern or
midwestern regions bother with picking up maggot- i nfested drops. The
situation is very different in California, however. In an earlier article
(Fruit Notes 49(2) : 16-18) , I gave a brief account of how the apple maggot
fly was first detected in California in August of 1983 and how it has
created a state of alarm among many apple growers there. Indeed, twice
within the past year, 1 have been called upon to file legal declarations on
various aspects of apple maggot management. One of the declarations was in
behalf of "California Organic Apple Growers" and supported a proposed
program of apple maggot control that did not involve use of pesticides. If
such a program were to prove effective, an organic apple grower would not
then be required by law to have his orchard sprayed with pesticide by the
State to control maggot. If not, then the grower would have to submit his

orchard to a series of pesticide sprays to ensure that maggot fly popula-
tions were not building up over successive years within the orchard-
There are 3 elements in the non-pest icidal program of apple maggot
control in California:

(a) Use of sticky red spheres hung in apple trees to capture the flies
and thereby prevent (or greatly reduce) egglaying (see Fruit Notes
50(2):2-5);

(b) Twice-weekly removal of drops from beneath the trees to prevent
larval exit from any infested fruit; and

No one of these elements alone is likely to completely prevent apple
maggot buildup within an orchard. Together, they ought to work as well as
frequent pesticide treatments.

A principal point of debate over the efficacy of this non-pest ic idal
approach has been the frequency with which dropped apples must be picked up
to prevent any larvae from emerging and forming pupae in the soil. Because
picking up infested drops constituted the first line of defense against the
apple maggot until earlier this century, a good deal of work was conducted
on this subject by pioneering apple maggot researchers such as J.F.
Illingworth of Cornell, W.C. O'Kane of New Hampshire, and W.H. Brittain and
C.A. Good of Nova Scotia. It is this work that gave rise to the recommen-
dation that an effective schedule of drop pickup should be twice per week.
In recent decades, however, little or no research has been carried out along
these lines. Thus, we decided to initiate 3 small experiments to determine
if the findings of the pioneering workers were still valid.

In the first test, we placed 5 wire baskets (18 x 30 inches) under each
of 3 unsprayed Early Mcintosh trees (an early-season variety) on Orchard
Hill in Amherst. The baskets were in place from June 15 (before any maggot
flies were mature) until August 8 (the date by which all but a handful of
fruit had fallen). Every 3-^ days, we collected each fruit that dropped
into the baskets and examined it carefully for presence of an exit hole made
through the fruit skin by an emerging larva. After examination, we put the
drops in wire baskets beneath non-fruiting trees and thereafter examined
them for exit holes every 3-^ days until all had completely rotted.

The results (Table 1) show that of the ^24 dropped fruit collected over
the course of the season, only 2 (0.5%) showed a larval exit hole on the day
of drop pickup (0 to 3 or 4 days after drop), and only one additional fruit
(0.2%) showed a larval exit hole when examined 3-k days after drop pickup (3
or 4 to 7 days after drop). Each of these 3 fruit had fallen at least 2
weeks after the optimum time for fruit harvest (July 8). (Note: in this
abandoned orchard optimum harvest was about 1 month earlier than in commer-
cial orchards.) In addition to examination of drops, 25 on-tree fruit were
sampled every 3-4 days from July 8 - August h for larval exit holes. None
was found. However, one fruit that had dropped and was caught in a crotch

between tree branches was nearly rotten when found and did have larval exit
holes. Several bushels of fruit were picked up beneath these 3 trees on
July 15 and were placed over wire traps to obtain pupae. The average yield
was about 6 pupae per apple, revealing the high level of fruit infestation.

Table 1. First appearance of exit holes of apple maggot larvae in Early Mcintosh
drops.

NO. FRUIT IN WHICH A LARVAL EXIT HOLE FIRST Af REARED

AT SUCCESSIVE INTERVALS (DAYS) AFTER FRUIT DROP PICKUP*

Day of J^ 6^7 10-11 U-l'* 16-17 20-21 More Than
Drop pickup Days Days Days Days Days Days 21 Days

No.

D/-op Pickup

Drops

July 8

116

Aug. k

TOTAL

424

158

150

% FRUIT WITH
AN EXIT HOLE

0.5

0.2 3.3 17.0 37.3 35.4

5.2

1.2

*Once an exit hole was detected in a fruit, that fruit was discarded.

In the second test, carried out at the Horticultural Research Center at
Belchertown, we inserted 4 apple maggot eggs into each of 5 previously uni-
fested Mcintosh apples (a mid-season variety) during each of 4 weeks from
late July until late August. We placed a cloth bag over each fruit to catch
the fruit when it dropped. We looked at each cloth bag for drops every 3-4
days until all fruit had dropped (first drop was August 9> last drop was
October 4). Of the 80 fruit, not a single larval exit hole appeared at the
time of drop pickup nor even within the first week after drop pickup. Each
fruit did eventually produce mature larvae, however.

In the final test, we placed cloth bags on September 10 over 1121
Crataegus mol 1 i s (hawthorn) fruit heavily infested with apple maggot larvae.
The fruit are a native host of this species. Every 3-4 days until the last
fruit had fallen, new drops were examined for larval exit holes.

The results (Table 2) show that 203 fruit (18%) exhibited an exit hole
made by a larva sometime within the period between dropping and examination.

Table 2. Appearance of exit holes of apple maggot larvae in Crataegus
mo 1 1 i 5 hawthorn drops.

DATE OF W. DROPS IN WHICH A LARVAL EXIT HOLE

DROP PICKUP DROPS APPEARED ON DAY OF DROP PICKUP

NO. %_

Sept. 15 9^

19 90

23 305 38 12

27 206 Ith 21

Oct. 1 295 86 29

4 99 29 29

8 25 4 16

12 7 _2 29

TOTAL 1121 203 l8

What conclusions can be drawn from this work? By and large, our
results do indeed confirm the findings of the earlier researchers in that
picking up dropped fruit twice per week in commercial apple orchards is an
effective method of preventing entry of apple maggot larvae into the soil.
In fact, our results suggest that in nearly all situations, picking up drops
once per week should be sufficient. Only in cases where the variety is an
exceptionally early maturing one (for example. Early Mcintosh), and where
harvest of on-tree fruit is delayed well beyond the optimum for good commer-
cial quality, should it be necessary to pick up drops as often as every 3-4
days. Even then, use of sticky sphere; to capture the adults should reduce
larval infestation to such a low level that larval exit from fruit could be
delayed beyond that observed in this study. We speculate that this could be
so on the basis that the comparatively earlier exit of larvae after fruit
drop from C_^ mo 1 1 i s hawthorn trees than after fruit drop from Early
Mcintosh trees may have been in response to the more limited fruit flesh
resources of the hawthorn fruit (about 1/2 inch diameter) than the Early
Mcintosh apples (about 1 1/2 inches diameter). In other words, we postu-
late that under conditions where larval infestation is low and fruit size is
moderate or large, as ought to be the case in a commercial apple orchard in
which sticky spheres are used, larval exit from dropped fruit may occur
later than where larval infestation is high or the fruit is exceptionally
sma 1 1 .

Further research is needed to evaluate this speculation and to deter-
mine the optimum frequency of apple drop pickup under existing California
orchard conditions. For non-pesticide-using apple growers in Massachusetts,
the combination of trapping with sticky red spheres and picking up maggot-
infested drops once per week should very effectively prevent any apple
maggot buildup, though it will not prevent entry of immigrating flies from
outside the orchard.

*****

- 7 -

MAMMAL CONTROL

Wi 1 I iam G. Lord
Plant Science Department
University of New Hampshire

Deer

Deer feeding causes significant injury to many apple orchards. Injury
to young plantings can be devastating, especially if deer pressures are such
that trees sustain multiple browsings during both the dormant and growing
seasons. Injury to older, fruiting trees will consist of browse damage to
vegetative shoots (usually not serious) and flower bud and spur damage that
can result in significant, immediate, and long term crop losses.

There are several management options that can be used to alter deer
feeding patterns and minimize damage. However, many sites will require
fencing systems that exclude deer completely to prevent serious economic
injury. In locations with a history of high deer population density and
crop damage, a deer management program including fencing needs to be an
integral part of any orchard design and management plan. In many cases,
establishment of exclusionary fencing should precede orchard establishment.

Electric Fencing

The development of high-tensile, suspended electric fences charged with
low impedance energizers, coupled with their lower relative cost of cons-
truction when compared to traditional woven wire fencing systems, has
increased the use of electric fencing to control deer. Two basic electric
fence configurations are being employed--a vertical, 6- or 7-wire design and
a sloped, 7-wire design. The 6- or 7-wire vertical design has been readily
accepted by growers since it is easy to construct and maintain.

These vertical fences have been effective in controlling deer damage,
especially on small and intermediate sized acreages experiencing low to
moderate deer pressure. They do invite more deer interaction than
3-dimens ional (sloped) configurations. The lowest wire should be a maximum
of 10 inches above the ground with the remaining wires spaced at 8 to 10
inches.

Vertical electric fences may more effectively control jumping deer if
outfitted with a charged "outrigger" wire. A single, charged wire is set
38 inches outside the vertical fence at 15 inches above the ground to add a
3-dimens ional barrier effect to be a vertical fence.

The sloped, 7-wire electric fence design has been effective in
controlling high deer pressure on larger acreages. It presents deer with
both a 6-foot deep barrier and a shock upon contact. The fence slopes up
from the ground (and away from the crop) to an outside height of h feet.
Wires are spaced at 12-inch intervals.

- 8 -

The use of bipolar low impedance fence energizers is often employed to
increase effectiveness of these electric fences by providing control (shock)
when animal feet are not grounded (such as on frozen ground).

Construction and maintenance of electric fences needs to be considered
carefully. Always follow manufacturers' fence construction specifications,
paying particular attention to construction of corner and braced assemblies.
Electrify and properly ground the fence (or completed fence sections) as
soon as they are erected. it is important that deer respect the fence
barrier from their first encounter.

Control of vegetation and woody growth that may contact the fence is
required for maximum effectiveness. Fence voltage needs to be checked
monthly at the farthest point from the charger to insure that a charge of
approximately 3000 volts is being maintained. Routine tension and equipment
checks to maintain manufacturers' specifications is required.

Woven Wire Fencing

Vertical, woven wire fencing systems have been the standard control
measure recommended for the protection of large acreages experiencing high
deer pressure. Typically, these fences consist of 6" x 12" wire mesh 8 feet
high. Additional strands of barbed wire are added to the top of the fence
to extend the fence to 10 feet in height.

Woven wire fencing is highly effective if properly maintained.
However, its high relative cost and maintenance requirements limit grower
acceptance of woven wire fence.

Repel lents

A variety of repellents have been developed to deter deer feeding
pressure. While all of these have some effectiveness for short-term
control, none is effective in situations of moderate to heavy deer pressure.

Repellents are classified according to their basic mode of action.
Some that are taste repellent and some produce an odor offensive to deer.
Among those available Thiram^, a taste repellent, and a fatty acid
(Hinder^), an odor repellent, are most effective. These materials are also
effective against rabbit feeding damage when used according to manufac-
turers' instructions.

Several non-commercial, odor repellent materials will provide some deer
repel lency action under low deer pressure situations. Human hair (available
from barber shops and beauty salons) can be applied in mesh bags (1/8" mesh
or less) and hung on outer tree branches at a height of approximately 30
inches. Each bag should contain at least 2 large handfuls of hair, and bags
should be spaced at no further than 3 feet apart within the tree.

Deoderant soap bars are also being used to repel deer. Soap bars are
strung on wire and hung in trees in a distribution pattern as described for
hair bags. Leave soap bar wrappers on to reduce weathering and prolong
life.

- 9

Rabbits

Cottontail rabbits can be found throughout southern New England and
often cause serious damage to young fruit trees. Damage to young fruit
trees generally includes extensive bark removal and severe clipping of
lateral shoots.

Habitat control is an effective rabbit population control measure.
Overgrown ditches, brushy fence rows or stone walls provide excellent food
and protection from predators for rabbits. Elimination of these areas may
be all that is needed for adequate rabbit control.

Rabbit damage can be prevented by exclusion with hardware cloth (1/2
inch mesh) tree guards that extend 2 feet above the average snow depth.
Orchard perimeter fencing or 1 or 1 1/2 inch mesh wire that extends 3 feet
above the average snow depth is also effective.

Taste repellents are another effective method of reducing rabbit damage
to orchards. Repellents containing Thiram^ applied according to label
directions have been effective. Other commercial products such as Hinder"
also provide effective control.

Orchard Mice and Voles ^

Mice and voles are closely related rodents that can be distinguished
from each other on the basis of tail and ear size, among other minor
differences. In New England, mice are not a problem in orchards, but two
species of voles frequently cause serious orchard damage. These pests are
the meadow vole and the pine vole. Meadow voles range throughout New
England, but pine voles are known to be present only in southern New England
to southern Vermont, New Hampshire, and the southern tip of Maine (Kittery
area) .

Meadow voles inhabit the orchard floor, developing a network of surface
trails through the groundcover, and they feed primarily on grasses and
fleshy herbs. This species usually does most of its tree damage during the
winter when herbage is less abundant, but damage is possible any time of the
year. They chew away areas of bark and cambium that can be reached from the
ground or from higher positions in or on snow cover. In some soils they
will burrow, and sometimes are responsible for trunk girdling several inches
below the ground surface.

'Information presented in this section taken in part from:

- 1985 New England Apple Spray Guide - Cooperative Extension Services of
New England

- Management of Orchard Mice by Alan Eaton, Pest Management Fact Sheet #8,
Cooperative Extension Service, University of New Hampshire - 1985.

Pine voles travel either in surface trails, or in burrows at depths up
to 3 feet or more, depending somewhat on soil conditions. In solid grass
sods they may be almost total ly subterranean, but where the ground cover
contains a high percentage of broadleaf herbs, surface pine vole trails may
be numerous. During the cold months, their activity is pretty much limited
to the underground burrows. When herbage is abundant, pine voles put away
caches in the tunnel system for later use. They feed upon bark and cambium
primarily below the soil line, and chew off small roots up to about pencil
diameter.

Commercial apple cultivars and their seedlings, as well as the
available rootstocks, are very susceptible to vole feeding. A selection of
Mai us sublobata has been found to be quite resistant, however. The selec-
tion was named "Novole" and has been introduced as an apple root and trunk
stock for areas with severe vole problems. As a rootstock, "Novole" pro-
duces a large, vigorous tree. Use of a dwarfing interstem is suggested for
tree size control .

Identification of Pest Species

It is important to determine whether pine voles are present, because
some of the management practices used for meadow vole are not effective
against pine vole. Identification of the species may require trapping. Use
snap traps baited with breakfast rolled oats, or peanut butter, or a 50:50
mix of these two. Fresh apple pieces are also a good bait. Place traps
across active runs, including those that lead into underground burrows, if
present. Cover the trap with an apple box, or similar cover to exclude
birds and cats, and to aid in locating the trap trees in the orchard. Set
enough traps to be sure of catching 5-10 voles, from various locations in
the orchard. Check the traps after only one or two days. Tail length is
useful for identification. The pine vole tail is very short; about the same
length as the hind foot (not leg!), measuring 2>/k inch or less. The meadow
vole tail is about twice the length of its hind feet reaching 1 1/2 - 1 3/^
inch on adults. Both species have chunky bodies, small beady eyes, and
their ears are small and almost concealed in fur. Fur color is dark brown
or gray-brown. If you catch a long-tailed specimen, it is likely to be a
white-footed mouse ( Peromyscus ) . The Peromyscus ' tail is well over 2 inches
long, and all underparts of this mouse are covered with white fur. It is
reported to eat bark of young trees occasionally, but is generally con-
sidered a non-pest species in orchards. Your traps may also catch a shrew,
which is a beneficial small mammal, or a mole. Shrews can be identified by
their long pointed snout and needle-pointed front teeth. Voles have chisel-
shaped front teeth. Moles differ from all others in their front feet, which
are very large, with prominent digging claws.

Orchard Floor Management

Prevention of vole population build-ups offers the most practical
method of reducing tree injury.

1. Mow orchard floor sod frequently during the growing season. On
soils where erosion is not a problem, clean cultivate young
orchards.

2. Maintain a vegetation-free area within at least 3 feet of tree
trunks. The use of herbicides may be necessary to accomplish
thi s.

3. Eliminate brush and thick vegetative cover around orchard peri-
meters.

k. Completely remove all fruit drops from the orchard.

Tree Guards

Maintenance of proper tree guards is the most effective measure for
preventing tree girdling by meadow voles, unless snow depth exceeds guard
height. Voles tunnel through snow to any depth. Trunk guards do not pre-
vent underground damage by pine voles.

Galvanized hardware cloth is one of the best materials for tree guards.
One-quarter-inch mesh in 24-inch width is preferred. The cloth is cut large
enough to completely encircle the tree and allow enough room for 10 or more
years of growth. The cloth is formed into a cylinder and the cut ends are
used to fasten it together so that no gaps are left for the mice to gain
entry. Two or 3 short pieces of wire may be necessary to secure the ends.
The guards are embedded at least 2 inches into the soil to prevent the
rodents from burrowing underneath. An annual check of guards is recom-
mended, preferably before the ground freezes. Hardware cloth is difficult
to work with, and installation is time-consuming.

Several rigid, perforated polyethylene or plastic mesh products are
being promoted for use as tree guards. Each is used in a way similar to
that of galvanized hardware cloth to form a cylinder which is buried in the
ground and is of large enough diameter to give free circulation to air and
to allow for growth. They are easier to handle than wire guards, but some
may be broken down by ultraviolet light and may have a limited life.

Wrap-around plastic guards are readily available, cheap and easy to
install but are not recommended unless they are removed each spring and put
on again in the fall. Various borers seem to prefer trees with wrap-around
plastic or paper guards, and with their use the bark remains tender and har-
dens off slowly. The plastic may become brittle when weathered, and these
guards are difficult to keep in place on trees with uneven trunks or swollen
graft unions.

Paper wrap-around guards are not recommended. They must be tied off
with string which can girdle the tree unless it is removed in the spring.
Very high populations of bark borers have been found in trees protected with
this material. The treated paper also weathers quickly, and the protected
bark remains tender and hardens off slowly.

Rodent ic ides

Poison baits are of two types: zinc phosphide and anti-coagulant.
Just one or two fresh grains or pellets of zinc phosphide baits can quickly
kill the vole that eats them, but it may take several days of feeding on

- 12 -

anti-coagulant baits to kill voles. Owing to the catching habit of pine
voles, poison baits that are taken by the species may not be consumed until
much later, or not at all. Zinc phosphide breaks down slowly in moist air,
and it loses its toxicity rather quickly if the bait becomes wet. To pre-
serve toxicity of unused zinc phosphide baits, place opened package within a
plastic bag and seal tightly.

Rodenticide Techniques

Broadcast applications of baits can be effective against meadow voles.
However, they are usually not effective against pine vole. Bait should be
directed into live ground cover where meadow voles forage, rather than into
herbicide-treated strips. Most product labels limit treatments to the
postharvest dormant period. The presence of dropped apples can make baiting
ineffective, however, as farm apples are a preferred food for voles. All
sound drops should be removed before bait is broadcast. If the weather is
wet and dark during the first few days after bait is broadcast, the baiting
effort will have been wasted. Wet weather and dark days discourage vole
activity, and wet bait loses potency and palatabi 1 i ty . Try to bait just
before a mild, fair-weather period of several days.

Baiting in Artificial Trails . Mechanical trai 1 -bui Ider baiting
machines construct trails beneath the soil surface, and supply baits at
regular intervals for meadow or pine voles that enter those trails.
According to the U.S. Fish and Wildlife Service, who can furnish plans to
construct the device, this technique can be effective against both pine and
meadow voles. Sod cover and reasonably moist soil is required at the time
the machine is pulled through the orchard. Generally, one trail is made
along each side of tree rows, beyond the wheel tracks, beneath the drip
line of the trees, in sod. Trails should be cut 2-4 inches deep, with bait
placed at ^4-5 foot intervals.

Hand-bai ting . Hand-baiting implies selective placement of baits where
vole activity is most likely, or where active trails or burrows are located.
Teaspoon quantities of bait are placed, at the rate of 2-3 lbs. per acre.
To greatly speed bait placement, bait stations such as asphalt roofing
shingles or split tires should be distributed beneath the trees in sodded
areas well in advance of baiting time. Over a period of weeks or months,
voles develop trails under these bait stations; trails that can be quickly
baited after harvest.

Orchard Floor Sprays . Liquid Rozol" (chlorphacinone) is an anti-
coagulant formulated for spray application. Effectiveness depends on
thoroughly wetting and penetrating the ground cover. Before application,
the ground cover should be dry and mowed short enough for maximum spray
penetration. Voles are killed after repeated exposure to residues on the
ground and cover crop. It will not be effective when there is no surface-
feeding activity.

13 -

Estimating Vole Activity

Vole activity can be estimated by placement of apples in runways, or
tunnel entrances. Place whole, firm apples, with a thin slice removed, at
regular intervals throughout the orchard where activity is suspected. After
2k hours, lool< for small teeth marl<s in the apples. if such a check indi-
cates voles are present 2-3 weeks following a baiting, a second treatment
may be needed.

Re-Treatment with Baits

Where some voles have survived a rodenticide treatment after being
sickened, acceptance of the same bait a second time within a few weeks will
be poor. This seems to be a problem more with zinc phosphide baits than
with anticoagulants. There are two ways of minimizing this problem: 1) Do
everything possible to favor nearly complete control with the first treat-
ment. 2) If a second treatment is needed, use a different bait. If zinc
phosphide was used in the earlier treatment, use an ant i -coagulant for the
fol low- up.

Orchard Borders

in the brushy areas immediately adjacent to a vole- infested orchard,
one can generally find a relatively high population of the same species that
is present in the orchard. If these border areas are not baited they will
be a source of rei nfestat ion to treated orchard.

Caut ion

Rodenticide baits may be attractive to domestic pets, birds, and other
nontarget wildlife. Exposed bait, and especially exposed piled bait,
increases the chances on nontarget injury. As with all pesticides, use good
judgment and take reasonable precautions to avoid problems.

SAMPLING ORCHARD SOILS

Wi 1 1 iam J. Lord

Department of Plant and Soil Sciences

University of Massachusetts

Soil tests can be a useful tool to aid in the determination of lime
needs in orchards. Although it is felt that leaf analysis is a more effec-
tive guide for the determini nat ion of the nutritional status of orchards,
soil tests are still useful, particularly for the determination of lime
requ i rements.

The value of soil tests will depend upon several factors but what we
are primarily concerned with in this article is how well the soil samples
represent the area being sampled. Without a standardized sampling procedure
and careful adherence to this procedure, the value of the soil sample may be
negl igible.

- 14

When to Sample

Soil samples may be taken any time when the soil is not frozen. The
results of soil samples taken after harvest, however, are useful for deter-
mining the amount of lime to apply in late fall or winter, the usual time
1 ime is appi led.

Method of Taking Soil Samples

1. If there are two or more distinct soil types within the orchard block
being sampled, each should be sampled separately. The same is true if
portions of the block have received different lime and fertilizer treat-
ments.

2. Sample each soil type as follows:

a. Scrape away the mulch and grass from the area to be sampled under
the trees. Sample about half way between the trunk and the dripline
where the soil is apt to be most acid because of fertilization.

b. Take the soil sample with an auger to the full depth of the surface
soil as shown by the change of color.

c. In place of an auger, a spade may be used. Care should be taken to
take a slice of uniform thickness, top to bottom. First expose the
surface soil to its full depth, then cut off a slice about an inch
thick. Break or cut the side of the slice to produce a column one
inch thick and about two inches wide and as deep as the surface soil
depth.

d. Take one boring or soil slice under each 10th to 15th tree in a
block. After obtaining five such borings or soil slices, place them
in a clean container such as a pail and mix thoroughly. From this
composite sample remove about 1 cup of soil for the test. If the
soil is wet and soggy, place it on wax paper and let it air dry.
Place the composite soil sample in a clean container (such as an ice
cream container) or a plastic bag.

e. Repeat the process described in 2.d. until the whole orchard block
has been sampled.

f. Label each container with the date, owner of farm, and orchard name
or number.

g. In many instances a subsoil sample should be taken. To do this
enlarge the hole from which the surface soil sample was taken and
bore or dig into the subsoil. The sampling procedure is the same as
that for the surface soi 1 .

h. Send the samples, along with $5 per sample, to the Soil Testing
Laboratory, Suburban Experiment Station, 2^0 Beaver Street, Waltham,
MA 02254.

- 15

APPLE REPLANT PROBLEMS

Joseph F. Costante
Plant and Soil Sciences Department
University of Vermont

Difficulties in establishing apple trees on old orchard sites could
pose a risi< to tree growth and seriously affect crop performance. The
living orchard soil contains billions of soil microorganisms in every hand-
ful. Some of these rhizosphere organisms can cause disease problems to
roots, especially within the top 1^ inches of soil. Seventy to eighty per-
cent of a soil's metabolic activity is generated by organsims like nemato-
des, bacteria, fungi, and act i nomycetes. Apple replant disease (ARD) refers
to poor growth of apple trees on old orchard soils caused, in large part, by
harmful rhizosphere organisms. ARD is a major problem of apples in New
England and will likely increase as orchard sites are replanted over and
over. The level of severity depends on such factors as orchard age, pre-
vious host crops, soil type, and extent of damage on old tree roots.

Any losses incurred in tree replacement due to replant failure presents
a serious obstacle to growers. In view of the escalating cost of fruit pro-
duction, and the limited supply of suitable sites for orcharding in New
England, these replant difficulties and their control are being given
increased attention.

Symptoms of Replant Injury

Numerous factors, other than soil microorganisms, contribute to diff-
culties in replanting apple trees. These include poor, injured and diseased
planting stock, improper planting, irregular cultural practices, unbalanced
soil nutrition, poor drainage, impaired soil structure, and allelopathic
effects.

The above-ground symptoms of injury from root-feeding nematodes and
rhizosphere organisms are generally those which result from partial destruc-
tion of the root system. These include stunting, foliage wilting and
yellowing, and, in extreme cases, death of the tree. Some parasitic nema-
todes and rhizosphere organisms may cause swollen and distorted roots while
others cause dark colored lesions, killing large numbers of unsuberized
feeder roots. Trees may remain severely stunted for years or during their
entire life. Although the majority of apple trees usually experience
improved growth with age, they rarely become as productive as healthy trees
on sites with low populations of parasitic nematodes.

It appears that there are a number of different replant problems and
that many organisms are involved. Causal organisms will vary among each
orchard's habitat and even between trees. Many failures in replanting trees
have been attributed to drought, cold, or winter injury. Usually trees suf-
fering from ARD are much more susceptible to drought and cold injury than
are similar trees with uninjured roots.

16 -

Agents Causing Destruction of Feeder Roots

Researcti has shown that ARD problems in New England orchards are caused
by at least two biological agents. The first organism is the lesion nema-
tode, Praty lenchus penetrans , and the second is on incompletely identified
root rhizosphere organi sm(s) . Although this causal organism(s) has not been
completely identified, findings indicate that root-pathogenic fungi will
destroy unsuberized roots and cause replant problems. Fusar ium spp.,
Pythium spp., Phyt ophthora spp., Thielaviops is spp., and Rhizoctonia solani
are five of the fungi implicated.

Important Parasitic Nematodes

The microscopic roundworms that live in soil or water are l<nown as
nematodes. Most are free-living and pose no disease problems, whereas
others are parasites of apple roots. Some species of nematodes inadver-
tently introduce pathogenic root invading microorganisms into the plants
while feeding. in other instances, the nematodes themselves cause the
disease, disrupting the flow of water and nutrients in the vascular system.
This can result in root-knot or deprivation of the above-ground parts, ulti-
mately causing stunting.

Root-Lesion Nematodes ( Praty lench us spp.) Lesion nematodes are con-
sidered the most damaging nematode pathogens and are probably present in all
New England apple orchards. They are endoparas i tes which live and feed
inside feeder root tissues, migrating through soil to go from root to root.
P. penetrans is the most economically important species causing critical
damage to roots of newly planted trees. Recent data from Vermont show that
the les ion-nematode affects all major rootstocks (M.9, M.26, M.7, MM106,
MM111 and seedling) growing in light and heavy soils. Generally, most
orchard tree roots have a low number of P_^ penetrans nematodes and cause
little or no damage. Injury occurs when population levels drastically
increase into the hundreds (per gram of root tissue). Some of the factors
affecting nematode populations are previous crop, soil type and condition,
health of host, winter climate, and unexplained variation.

Dagger Nematodes ( Xiph i nema spp.) The dagger nematodes are ectopara-
sites which feed from the root surface. The most commonly found orchard
species is X. amer icanum which causes reduced growth and necrosis of feeder
roots. This nematode transmits tomato ringspot virus resulting in apple
union necrosis.

Less important ectoparasite nematodes which have been reported to
contribute to ARD problems in New England include Pin nematodes
( Paraty lanchus spp.). Lance nematodes ( Hoplolaimus spp.), and Ring nematodes
( Cr iconemoides spp.).

Assessment of Replant Problems

Certain procedures should be followed prior to replanting an orchard

site to gain insight into soil-based problems and to correct them as quickly

as possible. The key to success is a program of sound horticultural prac-
tices.

- 17

1. Collect appropriate soil and feeder root samples from old orchard
at the time of removal (refer to section "Resources Available" for
obtaining information on ARD sampling, rating and testing).

2. Evaluate the condition of feeder root samples for damage or necro-
sis (black or brown rotted areas).

3. Forward samples and root condition report to Nematode Diagnostic
Laboratory. Roots will be assayed for parasitic nematode levels
and soil will be assayed for parastiic nematodes, an ARD seedling
stunting determination, pH, organic matter, P,K, and Mg levels.

Corrective Practices

Based on results of ARD and soil nutritional assays the following may
be recommended:

1. Biocide fumigation of row strips the fall prior to planting.

2. Liming to raise soil pH.

3. Addition of organic matter to row strips.

k. Cover-cropping with sudan grass, perennial rye grass or creeping
red fescue (for reducing potential root-lesion nematode problems).

5. Applications of post-plant nematicides to individual trees or rows.

6. Addition of other nutrients before or at the time of planting.

7. Cleaning-up dandelion weeds if dagger nematodes pose a problem.
Additional pre-plant practices which may be necessary are:

1. Subsoiling to break-up hardpan.

2. Drainage by tiling and/or ditching.

3. Soi 1 level i ng.

Since the first four years are considered the most important in combating
ARD, the following are critical for initial success on all sites:

1. Use of only top quality nursery stock.

2. Establishment of irrigation program during the non-bearing years.

3. Maintenance of an ideal tree nutrition status (monitor levels in
fol iage and soi 1 s) .

k. Control of weeds within tree rows.

5- Maintaining an organic matter level of 6^ (top 12 inches of soil).

6. Monitoring and controlling nematodes when necessary.

- 18 -

It has been demonstrated that protecting feeder roots of apple trees
will result in increased growth, yield, and returns. The ARD diagnostic
service and integrated control program mentioned are the only sound
approaches available to growers at this time. Experiments are being con-
ducted to find control measures to substitute for the chemical soil treat-
ments. A better solution to these problems would result in economic
benefits to growers and the industry alike.

Resources Available

1. For parasitic nematode and replant chemical control practices refer
to the annual New England Apple Pest Control Guide.

2. For ARD sampling information, nematode and ARD testing contact:

Nematode Diagnostic and Orchard Management Service
Hills Bui Iding, Rm. 206
University of Vermont
Burlington, VT 05^05-0082
(802) 656-0477

* * ->

I UPDATE ON DISEASE-RESISTANT APPLES

' William J. Manning and Daniel R. Cooley

Department of Plant Pathology
University of Massachusetts

The first disease-resistant apple trees at the Horticultural Research
Center in Belchertown were planted in 1978. Since that time, we have added
other new cultivars and numbered accessions as they have become available.
Descriptions and performances for some cultivars have been published in pre-
vious FRUIT NOTES issues (Vol. hS, No. 1; Vol. ^9, No. 2). Our purpose here
is to bring you up-to-date on the current contents of the collection and to
make you aware of plans to evaluate a new block of disease-resistant apple
trees to be established in a commercial orchard.

There are now }k cultivars or numbered accessions in the collection at
Belchertown (Table 1). All of them are immune or highly resistant to apple
scab ( Ventur ia inaequal is ), but vary in their degree of resistance to black
rot ( Physalospora obtusa ) , cedar-apple rust ( Gymnosporang i u rn jun iper i -
viginianae ) , and powdery mildew ( Podosphaera leucotr icha) . Their reactions
are compared to those of the disease-susceptible cultivar, Imperial
Mcintosh.

Foliar and fruit evaluations were made on September 10, 1985-
One-hundred leaves were evaluated per tree for percent incidence of black
rot, rust, and scab (Table 2). Foliar black rot was especially evident on
Imperial Mcintosh, King Luscious, MacFree, Nova Easygro, and Sir Prize.
Rust was evident on Imperial Mcintosh, King Luscious, and Sir Prize. Scab
was evident only on Imperial Mcintosh. These findings were consistent with
previous results.

Table 1. Disease-resistant apples at the Horticultural Research Center,
Belchertown, MA.

Cul t i var

Year Planted

Source

Imperial Mcintosh

Liberty

MacFree

Nova Easygro

NY 613^5-2

Pr i sc i 1 la

Sir Pr ize

King Luscious

Jonaf ree

Redf ree

Freedom

Sweet Sixteen

NY ys^i^^-i

NY 66325-113
NY 7^828-12

1978
1978
1978
1978
1978
1978
1978
1983
1983
1983
1984
1984
1985
1985
1985

Kel ly Bros.
Geneva Program
Canadian program
Canadian program
Geneva program
PRI program^
PRI program
Bountiful Ridge
PRI program
PRI program
Geneva program
Univ. Minnesota
Geneva program
Geneva program
Geneva program

-Purdue, Rutgers, Illinois cooperative program

Table 2. Performance of disease-resistant apple trees in 1985.^

% Fol

iar diseasesY

Frui t di
y speck

i seases^

Cult i var

Black rot

Rust

Scab

Freedom

0.5

NAW

Imperial Mcintosh

100

Jonaf ree

King Luscious

Liberty

MacFree

Nova Easygro

^ 20

NY 61345-2

0.5

NY 75414-1

NY 66325-113

NY 74828-12

Prisci 1 la

Redfree

Sir Prize

Sweet Sixteen

^Evaluations made on 10 September 1985.
^100 leaves evaluated/tree.

^Percent of available fruit (variable for cultivars and accessions because

of tree age) .
^NA = Not applicable, no fruit.

During the 1985 season, the grass in the block was longer than usual.
For the first time we noted a low incidence of fly specl< ( Zygophiala
jamaicensi s ) on Imperial Mcintosh, Liberty, MacFree, and NY 613^5-2. While
not a serious problem, flyspeck infections can reduce grade. Better manage-
ment of grass heights will help to eliminate this problem.

Evaluation of disease-resistant apple trees allows us to see how they
perform under Massachusetts conditions. We now are ready, however, to
establish a block of di sease-res i-stant trees in a commercial orchard. This
will be done in the spring of 1986 in western Massachusetts with a
cooperating grower and through the Regional Extension Agent, Karen
Hauschild. As the trees grow and bear, they will be evaluated for perfor-
mance by a plant pathologist, entomologist, and pomologist. The grower will
also make critical evaluation as will other growers who see them at educa-
tional meetings held at the orchard. The test block will consist of 16
trees each of Rogers Mcintosh, Liberty, Freedom, Redfree, PRI Coop No. 23,
NY 7^*828-12, and NY 75^'i^-^, for a total of 112 trees all on M7A.

Developing disease-resistant apple cultivars is a long and tedious pro-
cedure. The cultivars that are emerging are, however, improving all the
time. The two NY numbered accessions planned for the commercial orchard
trial were selected because they have many of the characteristics of
Mcintosh, yet are immune to scab and highly resistant to other apple
diseases. Better cultivars and insect management strategies aimed at
reducing sprays will result in quality apples available for direct sale to
consumers with the assurance that only a very few insecticide applications
were made. Ron Prokopy, University of Massachusetts Department of
Entomology, has demonstrated that he can use as few as two insecticide
sprays on his disease resistant apples and still produce a crop of nearly
blemish-free apples (Fruit Notes 50(2):2-5).

All of the trees in the Disease Resistance Block will be labelled by
name. Please feel free to examine them when you visit the Horticultural
Research Center. For additional information on disease-resistant apple
trees, please contact Dr. William J. Manning in the Department of Plant
Pathology.

Acknowl edgements ; We thank Tony Rossi and others at the Horticultural
Research Center for maintaining the block and applying insecticides.
Special thanks go to the Horticultural Research Center Trust Fund for
purchasing trees of 5 of the 7 apple cultivars to be used in the commercial
orchard planting and to Hilltop Nurseries for donating Redfree and PRI Coop
Trees.

This activity is also supported by the University of Massachusetts
Cooperative Extension Service.

- 21 -

PEACH ROOTSTOCKS IN NEW JERSEY

Jerome L. Frecon
Cooperative Extension Service
Cook Col iege--Rutgers University

We recommend that growers have peach and nectarine varieties budded on
Lovel 1 and Halford seedling rootstocks for future peach plantings. We also
recommend that the seedlings used in the production of these rootstocks be
from seed collected in self-pollinated seed orchards. Seeds produced in
cross-pollinated orchards may have great variability and result in short-
lived trees. We also encourage growers to purchase trees on virus-certified
seedl ings.

Some growers have been planting peach trees on seedlings of Tennessee
Natural and Bailey. We do not have enough research information in New
Jersery or the Eastern United States to make a recommendation on their per-
formance. Bailey, which is being tested in our NC-140 planting at the
Rutgers Fruit Research and Development Center in Cream Ridge, New Jersey,
was found in Iowa and has been planted by some growers in the Midwest and
Canada. It is reported to impart cold hardiness and vigor to the scion
variety by Midwestern and Canadian growers and researchers.

Tennessee Natural is a broad name given to seeds collected from wild
peach trees in the mountains of Tennessee and Kentucky. Seeds are not
available from these sources. Some growers and nurserymen feel these old
time trees are longer lived and hardier than today's trees. In the past 20
years some selections of Tennessee Natural were made, virus indexed and
established at the Interregional Fruit Repository at Prosser, Washington.
Some nurserymen have collected scionwood from these selections, budded seed
trees and established seed orchards for tree propagation.

Based on the current short tree life of peach orchards in New Jersey,
growers probably have little to lose by trying a test planting of trees on
these stocks. Lovel 1 and Halford originated in California and can be
improved upon for tree hardiness.

The dwarfing rootstock, Citation, has been tested in Gloucester County
since 1982. It reduces tree size over S0% on peaches and nectarines in
comparison to Lovel l-rooted trees. It imparts early defoliation in the
fall. Trees appear to be stressed and are suffering from slow decline on
our loamy sand soils.

We have numerous plantings of self-rooted peach trees and experimental
plantings up to 5 years of age. Self-rooted trees are equal in performance
to trees on Lovel I and Halford. Jerseyqueen on its own roots has been more
precocious and productive than on Lovel I seedling. Jefferson has been 30%
reduced in size on its own roots than on Lovel 1. Much more testing needs to
be done.

*****

ROOTSTOCK EVALUATION IN MASSACHUSETTS

(Editors note: Massachusetts is involved in a multistate apple
rootstock evaluation project (NC-140). Two groups of rootstocks are being
evaluated at the Horticultural Research Center in Belchertown, Massachusetts
along with approximately 30 other locations in the U.S. and Canada. The
first group was planted in I98O and the second was planted in 1984. The
descriptions presented here were supplied by Dr. David Ferree, Ohio State
University, and a later Frui t Notes article will discuss observations in
Massachusetts. )

Rootstocks in I98O NC-TtO Planting

1. Ottawa 3 - Originated as a cross of Robin x M.9. (Robin is a hardy
crabapple). It produces trees of M.9 size or slightly larger, but better
anchored than M.9. It is reported to be resistant to crown rot, but
susceptible to fireblight and to wooly aphids. Suckering is rare.

2. EMLA 7 - This is the original M.7 with known viruses removed. According
to early reports, it produces a tree only slightly larger than the
original M.7, which would be 50 to 60^ the size of standard.

3. EMLA 9 - In providing this stock with EMLA virus status, apparently a
sub-clone was selected and trees on the EMLA 9 may be 25-50^ larger than
the original M.9. It is reported to result in less russet on Golden
Delicious and have greater productive efficiency than M.9.

4. EMLA 26 - Early reports indicate only a slightly larger tree than the
original M.26.

5. EMLA 27 - This stock has not been widely tested, but produces a tree
smaller than M.9 (15-20^ the size of standard), is very precocious, not
well anchored, and generally free of root suckers. Originally it was
produced from a cross of M.13 x M.9. Northern Spy and Granny Smith have
shown some incompatibility (broken off union) with EMLA 27. Compared to
M.9, M.27 is similarly resistant to crown rot and susceptible to fire
blight and wooly aphid. Its hardiness is unknown.

6. M.9 - This rootstock produces trees 20-35% the size of standard trees,
is very precocious and fruitful, and poorly anchored with a tendency to
sucker. It has a long history in both the U.S. and Europe and is used
as the standard in this trial.

7. MAC 9 (MARK) - Introduced in I98O by Michigan State University. Dr.
Robert Carlson selected it as an open-pollinated seedling of M.9. It
produces trees about the same size as M.9 or slightly larger, is very
precocious and fruitful, and is non-suckering.

- 23 -

8. MAC 2k - Another selection in the Michigan Apple Clone series (Female
parent was Robusta 5). Trees on this rootstock are vigorous in the
MM. Ill or Standard size class. It has a shallow spreading rootsystem
and is well anchored. It has not been widely tested.

9. OAR 1 - An Oregon planting of Gravenstein on seedling rootstocks made
in 19^3 had many trees blown over by a severe storm in 1962. Among the
survivors was a conspicuously dwarfed tree that was very productive.
Suckers of this tree were propagated by Dr. Melvin Westwood of Oregon
State. This stock has not been widely tested.

Apple Rootstocks in 1984 NC-140 Planting

1. Bud 491 - One of the hardy Budagovsky rootstock series produced at the
Michurin College of Horticulture in Russia. B. 491 produces trees
smaller than M.9, is very winter hardy, and propagates well.

2. B.9 - One of the Budagovsky series (Red-leafed Paradise) with dwarfing
potential similar to that of M.9. New York tests indicate suscep-
tibility to fire blight, wooly aphids, and brittle roots. It is much
hardier than M.9 and has greater resistance to crown rot.

3. MAC 1 - One of the Michigan Apple Clone series originated by Dr. Robert
Carlson from an open-pollinated planting of the Mailing rootstocks
(Female parent Ml). Trees on this stock are approximately M.7 size,
but do not sucker and are well anchored.

4. MAC 39 - One of the Michigan Apple Clone series producing trees smaller
than M.9 and very precocious. Trees on this stock are not well
anchored.

5. P.I - One of the Polish series produced at the Research Institute of
Pomology and Floriculture at Sk ierni ewicz . This series was produced
from a cross of Antonovka. P.l produces trees similar in size and pro-
ductivity to M.9, but are easier to propagate and have greater winter
hardi ness.

6. P. 11 - Another of the hardy Polish series producing trees smaller than
M.9 with s imi lar propagat ion characteristics.

7. Domestic Seedling - The full size standard in this trial. Seedling
stocks generally produce large vigorous trees with late-bearing ten-
dency, but good soil adaptability and anchorage.

8. CG 10 - The Cornell-Geneva (CG) series of rootstocks was originated by
Karl Brase CG-10 (M.8 open pollinated) produces trees slightly larger
than M.9 with good anchorage and some tendency to sucker. It has
moderate resistance to collar rot and fire blight.

9. CG 24 - Its parentage was open-pollinated M.8, and it produces trees
approximately M.26 size.

- 2k -

10. M.4 - One of the original Mailing series producing trees similar in
size, precocity, and suckering to trees on M.7. One of the major
problems of M.^ is that roots tend to develop mainly on one side,
making anchorage questionable. There is renewed interest in this stock
because of its resistance to collar rot.

11. EMLA 7 - One of the semi-dwarfing standards in this trial.

12. EMLA 26 - One of the dwarfing standards in the trial.

13. B. 'tSO - Another of the Budgovsky series producing trees similar in
size to MM. 106. It induces early production, burr knots rarely occur,
and it is easy to propagate from hardwood cuttings. It is crown rot
resistant and moderately susceptible to fire blight and susceptible to
wooly aphid.

1A. P. 2 - One of the hardy Polish series producing trees larger than M.9
and smaller than MM. 106 with productive efficiency good, but slightly
lower than that of M.9. It has good resistance to crown rot.

15. P. 16 - One of the Polish series producing trees of M.9 size with similar
winter hardiness and productive efficiency but with superior propaga-
tion characteristics.

16. P.l8 - One of the Polish series that resulted from a cross of M.4 x
Antonovka and produces a tree size similar to that of MM. 106. It shows
less susceptibility to fireblight than the other P series rootstocks,
combined with good resistance to crown rot.

17. Own Rooted - These stocks were produced through tissue culture by
Oregon Rootstock and Stark Brothers Nursery so that we could test tree
performance and size of Starkspur Supreme Delicious without a geneti-
cally different rootstock.

18. C.6 - Originated as a dwarfing interstem by Stark's from open polli-
nated M.S. It reportedly produces trees the size of M.26 and is very
susceptible to fire blight.

19. Antonovka 313 - From the Adams Nursery in Washington State as selec-
tions from open-pollinated Antonovka from Poland, This selection
appears resistant to crown rot.

20. 0.3 - Originated as a cross of Robin x M.9. (Robin is a hardy
crab-apple.) It produces trees of M.9 size or slightly larger, but
they are better anchored than M.9 trees. It is reported to be
resistant to crown rot, but susceptible to fire blight and to wooly
aphids. Suckering is rare.

21. AL 800 - Produced from suckers of a dwarfed Duchess tree on seedling
rootstock in the Arnold Lynd orchard in Ohio. The original tree did
not show winter injury symptoms after the 1936 freeze or the collar rot
experienced by trees on MM.IO6 in surrounding blocks. This rootstock
has not been tested and demonstrates difficulty in propagation by con-
ventional methods.

*****

- 25 -

CULTIVARS OF APPLES FOR MASSACHUSETTS

James F. Anderson
Department of Plant and Soil Sciences
University of Massachussetts

Cultivar

Recommended for

Harvesting season

Vista Bel la

Jerseymac

Paulared

Akane

Jonamac

Gala

Mel ntosh

Macoun

Empire

Cortland

Del ic ious

Golden Del icious

Idared

Spencer

Mutsu

C
T
C
T
T
T
C
C
C
C
C
C

c
c
c

Late July to early August

Mid to late August

Late August to early September

Early September

Early to mid September

Mid September

Late September

Early October

Early to mid October

Mid October

T = Trial

C = Commercial

Cultivars so marked are not necessarily equally adapted to
al 1 parts of the state.

Cultivar Notes

VISTA BELLA: The fruits are of medium size, firm, have a bright, smooth
finish, medium red color, and very good quality for an apple of this season.
Susceptible to watercore. The tree is large, vigorous, and productive.

JERSEYMAC: An attractive Mcintosh type. The fruit is above medium in size,
with a bright red color over about 8Q% of the surface. The texture is
medium in firmness and the quality good. The tree bears early and is pro-
ductive. Thinning may be necessary to maintain size and annual production.

PAULARED: Ripening in late August, the fruits are medium to large in size,
roundi ng-oblate in shape, and have excellent color and finish. The fruit
colors very early and is often picked before optimum size and quality are
reached. The trees are annual and productive.

AKANE: The fruits are medium in size, attractive with a bright red color,
but may show some russet. The flavor and keeping qualities are very good.
The trees in our plantings have been less than moderate in production.

JONAMAC: A Mel ntosh-type apple, ripening about a week before Mcintosh. The
fruits are of meidum size, firm, crisp, and have very good quality. The
fruit develop a good red blush color. The tree is medium in vigor and
appears to be productive. Merits trial by growers operating farm markets or
servicing retail stores.

- 26 -

GALA: This introduction from New Zealand has looked very promising in our
trials. The fruit ripens in mid-September, is medium to large in size, and
round-conic in shape. The flesh is yellow, crisp, and very good in flavor.
The skin is smooth, and its golden-yellow color is overlaid with about 80%
red. The trees have been annual and productive. Gala merits trial by those
growers operating farm markets or servicing retail stores. Red strains are
aval lable.

MCINTOSH: Remains the major cultivar for Massachusetts. The fruit is

attractive, has excellent quality, but bruises easily. The tree is

vigorous, hardy, and productive. Red strains such as Marshall, Imperial,
Rogers, or Summerland are preferred. Spur types are available.

MACOUN: The fruit has excellent quality and an attractive red color. The
tree tends to develop a poor structure, and thinning is required to maintain
fruit size and annual bearing. Macoun is an excellent cultivar for the farm
market.

EMPIRE: A very attractive apple with full red color, medium size, very good
dessert quality, and good storage life. The tree is annual and productive.
The flowers of Empire are susceptible to frost.

CORTLAND: The fruit is large, very good in quality and excellent for
salads, as the flesh does not discolor. Cortland fruit are very susceptible
to storage scald. The tree is hardy, productive, and annual. Redcort, a
recently introduced red strain of Cortland, merits trial. The fruits of
Redcort develop a dark red color that covers most of the fruit. (See
article on p. 1 this issue).

DELICIOUS: Produces fruit of excellent quality but susceptible to watercore
and internal breakdown. Tree is of medium vigor, often biennial, and may
require thinning. A good pollinizer, Redchief, Starkrimson, and
Sturdeespur are good spur types. imperial and Early Red One are among the
better non-spur types.

GOLDEN DELICIOUS: The fruit is of excellent quality and attractive when
well grown. The fruit is susceptible to russeting. Tree is of medium
vigor, biennial and requires thinning to maintain fruit size, color, and
quality. Russet-free strains such as Smoothee are recommended.

IDARED: An attractive bright red winter apple of good quality and size.
Suitable for both dessert and processing. The tree is small, annual, and
productive.

SPENCER: The fruit is attractive, bright red, and has very good quality
suitable for both dessert and pie. The tree is hardy, annual, and produc-
tive. Spencer is most useful for the farm market.

MUTSU: A Golden Delicious type that is less susceptible to fruit russeting
and storage shrivel. The tree is vigorous and productive. Mutsu is a
triploid and its pollen is not viable. The fruit is susceptible to blister
spot.

*****

3982' 061

COOPERATIVF EXTENSION SERVICE

U S DEPARTMENT OF AGRICULTURE

UNIVERSITY OF MASSACHUSETTS
AMHERST MASS 01003

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PENALTY FOR PRIVATE USE. S300

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