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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
following form with your check for $3.00 (Canadian subscri
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
% injury
Tarnished plant bi
'9
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
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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.
10
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.
14
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.
17
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
1
Polyram BOW
Penncap M 2FM
Zolone 3EC
0, 24, 48
TABM
GAA
Experiment
2
Plictran 50W
0, 24, 4B
ERM
1981
Experiment
1
Polyram BOW
Penncap M 2FM
Zolone
0, 24, 48.
72
SB. FS,
TABM,
SJS, FR
Experiment
2
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
2
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
72
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.
18
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
2
'/m
;er 12 hr
After
24 hr
Aft
;er 48 hr
CaCl
% pesticide
%
pesticide
% pesticide
addit
ion
pH
remaining
pH 1
"■emaining
pH
remaining
Benomyl
Ox
5.31
48
5.50
39
5.60
26
Ix
6.00
41
7.10
45
6.80
40
5x
10.11
42
8.50
37
8.00
37
lOx
9.40
33
8.42
25
7.70
30
lOx +
C02
5.80
55
6.42
50
6.81
54
Methomyl
Ox
4.88
89
4.92
20
4.84
30
Ix
7.38
42
6.66
62
6.31
44
5x
S.96
--
7.35
61
6.98
21
lOx
9.26
52
8.23
28
7.40
31
lOx +
CO9
5.32
87
A;
5.65
n'nphosmethyl
66
6.22
48
Ox
5.65
109
6.78
108
6.48
82
Ix
5.84
71
5.84
74
5.84
75
5x
7.08
80
7.39
59
6.74
63
lOx
9.18
63
8.86
67
8.37
73
lOx +
CO2
6.04
86
6.08
Formetanate
96
6.08
88
)x
4.54
91
4.71
88
4.72
84
ix
5.99
78
6.50
79
6.67
55
5x
7.30
57
7.33
47
7.66
22
lOx
8.08
41
7.92
14
7.76
8
lOx +
CO2
5.79
95
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
