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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 
Editor 



Name 



Mailing 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 Science 
French Hall 

University of Massachusetts 
Amherst, MA 01003 

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<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 



J 



i 



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. 



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, 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 



II 



III 



IV 



VI 



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 

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 

Low 

Low 



NY 



MICH 



NC 



NJ 



Relative toxicity 
High 



High 

High 
High 



High 
High 

Mod 
Mod 
Mod 

Mod 
Low 
Low 
Low 
Low 

Low 



High 

High 

Low 

Low 

Low 



Mod 



High 

High 
High 

High 
High 

Mod 

Low 
High 



Higf- 
Mod 
Low 
Low 



High 

Mod 
Low 



High 



Mod 


_ 


_ 


Mod* 


Low 


Low 


Low 


Mod 


Mod 


Low 


_ 


_ 


Low 


- 


- 


Low 


Low 


Low 


Low 


_ 




Low 


- 


_ 


Low 


.ow 


_ 


Low 


.ow 


Low 


.ow 


.ow 


_ 


-OW 




_ 


" 


— 


Low 


High 






High 


- 


- 


High 


_ 


_ 


Low 


Low 


_ 


Low 


- 


- 



High 



High 
High 



Low 



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. 



12 



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. 



16 



- 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 

U.S. DEPARTMENT OF 

AGRICULTURE 

AGR 101 

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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 

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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. 



10 



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. 

M2 

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). 



16 



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 

18 


21 

18 


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 

M7 


— 


105 

ino 


124 
124 


127 
128 


125 
124 


Post-air storage 
breakdown (%) 


Sdlg 

. M7 


7 
10 


? 

5 


30 
28 


7 
8 





Post-CA storage 
breakdwon {%) 


Sdlg 

M7 


S2 
11 


6X 
1? 


18 
20 


32 

11 


— 



^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 



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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 


ig 


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 



10 



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. 


25 


81 




12, 


.6 


1i», 


.0 


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 



15 



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. '♦.) 



16 



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. 



23 



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 


Moderate 


Midseason 


Large 


Fair 


Fair 


Hilton 


Hardy 


Vigorous 


Moderate 


Midseason 


V. Large 


Excel lent 


Good 


Madawaska 


Hard/ 


Moderate 


Moderate 


Early 


fted. large 


Cruibly 


Fair 


Bo/ne 


V. hardy 


Vigorous 


Man/ 


Early 


Mediim 


Good 


Good 


Nwa 


V. hardy 


Vigorous 


Few 


Midseason 


Mediun 


Good 


Good 


Festival 


V. hardy 


Moderate 


Few 


Mi dseason 


Mediun 


Good 


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) 


7 


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. 



1 



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. 



^r 



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. 



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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 


th 


(cm) 


Trunk 
1978 


ci 


rcum. increas 
1979 


e (cm) 


Treatment 


1978 


1979 




1980 


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 


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 


2 


.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. 



16 



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 


1 


West 


Central 


Southeast 


Scabz 


65% 


PC 


76% 


ERM 


81% 


Scab 62% 


ERM 


62% 


TPB 


75% 


Scab 


6^4% 


PC 50% 


PC 


60% 


Scab 


68% 


TPB 


58% 


LM A6% 


TPB 


57% 


ERM 


^9% 


PC 


^49% 


SJS 50% 


LM 


kn 


AMF 


ki\% 


LM 


^♦5% 


ERM 50% 


BR 


39% 


BR 


k2% 


BR 


37% 


GAA A6% 


AMR 


3^% 


LM 


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 . 



18 



► Seedhead 




Figure 1. Large Crabgrass 



19 



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? 



21 



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". 



***** 



22 



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 



8 



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 


ng 


Feet to 


( inches) 




travel 


10 




hOS 


12 




3hO 


18 




111 


20 




20i» 


30 




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. 



10 



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 



12 



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 


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 


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 


none 


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 


none 


none 


none 


none 


Singapore 




none 


none 


none 


15.0 






Sweden 




1.0 


10.0 


1.0 


5.0 


3.0 


3.0 


Taiwan 


(no info) 


none 


none 


none 








Thai land 




none 


none 


none 


20.0 


none 


none 


Trinidad- 


(no info) 














Tobago 
















UAE 


(US) 




10.0 


7.0 


7 


- 


- 


United Kingdom 




none 


0.0 


none 


? 


3.0 


10.0 


United States 




7.0 


6.0 




15.0 


7 


3.0 



^Most information supplied by USDA-FAS, I982. 

y 

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 



none 



5.0 


3.0 


- 


3.0 


none 


none 


10.0 


3.0 


none 


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- 



16 



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 . 



19 



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. 



* 



ft 



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. 



20 



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 


9- 


■16-85 


Harvested 


9' 


-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 
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 

(c) Refrigeration or processing of tree-harvested fruit to prevent 
larvae from maturing into pupae. 

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 


38 


11 


116 


15 


85 


18 


35 


21 


69 


25 


44 


28 


12 


31 


13 


Aug. k 


9 


8 


3 










2 





TOTAL 



424 









2 


2 


26 











36 


77 





2 


22 


53 


8 








13 


16 


6 





7 


19 


27 


14 


1 


5 


9 


14 


6 








3 


3 


6 








3 


2 


4 


G 








4 


2 








1 


1 


1 


1 


14 


72 


158 


150 



22 



% 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. 



10 



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. 



11 



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. 



19 



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 




% 

Fl 


Frui t di 
y speck 


i seases^ 


Cult i var 


Black rot 


Rust 


Scab 


Scab 


Freedom 


0.5 










NAW 


NA 


Imperial Mcintosh 


20 


60 


76 




10 


100 


Jonaf ree 


5 


10 







NA 


NA 


King Luscious 


25 


30 







NA 


NA 


Liberty 


5 










2 





MacFree 


15 


10 







10 





Nova Easygro 


^ 20 










5 





NY 61345-2 


10 


0.5 







2 





NY 75414-1 


5 










NA 


NA 


NY 66325-113 


5 










NA 


NA 


NY 74828-12 


10 










NA 


NA 


Prisci 1 la 


10 


6 












Redfree 


10 










NA 


NA 


Sir Prize 


40 


20 













Sweet Sixteen 


5 










NA 


NA 



^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. 



20 



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 

by 

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. 

***** 



22 



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 

Mid September 

Late September 

Late September 

Early October 

Early to mid October 

Mid October 

Mid October 

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 



OFFICIAL BUSINESS 

PENALTY FOR PRIVATE USE. S300 



BULK RATE 


POSTAGE & FEES PAID 


USDA 


PERMIT No G268 



ACME 
BOOKBINDING CO.. INC. 

JUL 1 6 1987 

100 CAMBRIDGE STREET 
CHAnlLESTOWN. MASS.