UMass Healthy Fruit

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Volume 9 -- 2001

Healthy Fruit is written by Jon Clements, Ron Prokopy, Dan Cooley, Arthur Tuttle, Gerald Lafleur, Wes Autio, Bill Coli, Duane Greene, Bill Bramlage, and Sarah Weis and is presented with the cooperation of New England Fruit Consultants and Polaris Orchard Management. Publication is funded in part by the UMass Extension Agroecology Program, grower subscriptions, and the University of Massachusetts IPM Program. A text version can be e-mailed to you if you contact Doreen York. Please cite this source if reprinting information.

Issue 16 - July 24, 2001
Hudson Valley Orchard Tour

The Area Fruit Program of Cornell University has arranged a summer tour of Hudson Valley Orchards and the Hudson Valley Lab in Highland on August 8, 2001. Orchards to be visited include Dressel's Orchard in New Paltz and Crist Brothers Orchard in Marlborough. Cornell on-farm field experiments involving spray drift, Honeycrisp thinning, and fall urea application will be featured as part of the orchard tours. At the Hudson Valley Lab, Apogee experiments and Lab personnel will discuss more Honeycrisp research – including a planting of 50 Honeycrisp ‘strains'. Lunch will also be served at the lab, however, is limited to the first 50 registrants. For more information or to register call 518-885-8995 and ask for Nancy. Or e-mail Kevin Iungerman, kai3@cornell.edu.

Leaf Analysis Time

NOW is the ideal time to collect leaf samples for foliar nutrient analysis. Blocks of apples, pears, peaches, and cherries should be sampled every 3-4 years to get a good handle on the nutritional needs of your orchard. Benefits of leaf analysis include: optimize yields; protect environment from excess fertilization; aid in diagnosis of nutrient deficiency; and save money! Enclosed is a ‘Plant Tissue Analysis Questionnaire' and form with directions for submitting your sample(s) to the UMass Soil and Plant Tissue Testing Laboratory. (You can also get the form at www.umass.edu/plsoils/soiltest/services1.htm.) The cost is $15 per sample, which includes nitrogen (recommended). Remember, leaf analysis is an important part of an integrated fruit production program!

Quality Loss Sign-up Set

According to the Fruit Growers News (www.fruitgrowersnews.com), "the USDA has announced that farmers can sign up for the Quality Loss Program (QLP) beginning Aug. 13." Sign up also begins for a separate quality loss program that will provide up to $38 million for apple and potato growers. "The programs help farmers who lost income due to weather-related disasters that caused loss of crop quality, including apple growers who suffered at least a 20% loss in the quality of their crop in 1999 or 2000," according to the Fruit Growers News. You should contact your local USDA Service Center of Farm Services Agency office for details of the program and to sign-up.

Apple Maggot

All monitored orchards have experienced at least a few captures of apple maggot flies on unbaited or odor-baited sticky red spheres. Since early July, there has been a consistent weekly trend of about 3 times more captures of AMF on traps this year compared with last year. As of today, about half of monitored orchards have reached the treatment threshold of 2 AMF per unbaited sphere. All early-ripening cultivars (except Paula Red) and other cultivars such as Gala and Fuji are especially attractive to AMF. Traps placed on these cultivars will give a very good indication of the state of the AMF population in your orchard.

The weather during early July (warm and thunderstorms) favored AMF emergence from damp soil. The relative dryness of the past couple of weeks has slowed adult emergence. As soon as we get another soaking rain, we can expect another flush of flies entering orchards within a week or so after the rain.
An application of azinphosmethyl or phosmet, each at one-half or even one-third of recommended rate, has given excellent AMF control in the past, with residual effectiveness lasting 2-3 weeks depending on amount of rainfall.
The bottom line on AMF is that AMF are considerably more numerous than last year and that susceptible cultivars should be protected, especially over the next 3-4 weeks.

Armyworms

More than at any time in the past decade or two, armyworms have become quite a topic of discussion in many Massachusetts towns during the past month. They are unable to overwinter in Massachusetts but fly up from the South in early summer, laying eggs on favored host plants. Larvae eat a variety of grasses, including corn and grains. Normally they don't attack non-grasses, but under stress of hunger, may do so. Fortunately, they rarely get stressed enough to feed on the fruit tree foliage. Larvae are dark green with white stripes and feed predominately at night. They are prone to hide during the day, partly to avoid predation by birds. Many orchards have experienced substantial consumption of orchard floor grasses by armyworms during the past few weeks, but most larvae have now pupated and the main period of damage is nearing an end. Damage by second-generated larvae should be much less than by the first generation due to pupal mortality and a more spread-out emergence pattern.

Woolly Aphids

Woolly aphids are building into potentially damaging numbers in about a third of monitored orchards. The honeydew they secrete, upon which sooty mold fungus grows, can raise havoc with pickers hands (which become very sticky) and with fruit quality (black fungal growth on harvested fruit is pretty ugly). The best way to handle woolly aphids is to treat with Thiodan. Even a half rate will do the job. But treatment needs to occur at least 21 days before harvest.

Mites

Lately, with the warmer and dryer weather, neither red mites nor two-spotted mites are making much of an appearance in most orchards. Even so, bronzed or off-color leaf foliage is conspicuous on some trees in some orchards. In some cases, the cause is apple rust mites, which are too small to be seen readily without 20-fold magnification. In other cases, the cause is voles, whose feeding results in gradual decline of tree vigor. Voles were very abundant in Massachusetts orchards this past winter.

Leafhoppers

Our monitoring indicates that neither rose leafhoppers nor white apple leafhoppers nor potato leafhoppers are particularly abundant in Massachusetts orchards this summer. In fact, all 3 species appear to be comparatively lower in abundance than in recent years, particularly potato leafhopper.

Leafminers

Most leafminers of the current second generation are now in the tissue-feeding stage, though some, remain as sap feeders. It's now too late for application of an insecticide that can be counted on to give control of second-generation miners.