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Healthy Fruit 2011 Vol. 19:12

Jun 21, 2011

Current (through June 20) degree day (DD) Accumulations

Location: UMass Cold Spring Orchard (CSO), Belchertown, MA

Base 43: 1198

Base 50: 737

Significant upcoming orchard insect events based on degree days (Base 43):

Obliquebanded leafroller summer larvae hatch: 1038-1460

Apple maggot 1st catch: 1230-1632

Peachtree borer 1st flight catch: 789-1353

Oriental fruit moth 2nd flight begins: 1281-1491

Redbanded leafroller 2nd flight begins: 1244-1576

Orchard Radar insect synopsis

Note: with each issue of Healthy Fruit we will be reprinting selected apple insect degree-day model highlights from Glen Koehler's (U. of Maine) Orchard Radar output for Belchertown, MA.

  • Codling moth (CM), 1st generation adult emergence at 95% and 1st generation egg hatch at 66%. 2nd generation 7% CM egg hatch: July 29, Friday, = target date for 1st spray where multiple sprays needed to control 2nd generation CM (if needed and allowed by pre-harvest interval).
  • 1st generation obliquebanded leafroller (OBLR) flight begins around: June 5, Sunday. Early egg hatch and optimum date for initial application of B.t., Delegate, Proclaim, Intrepid, Rimon, Altacor, Belt, pyrethroid or other insecticide effective against OBLR (with follow-up applications as needed) : June 21, Tuesday. Where waiting to sample late instar OBLR larvae to determine need for treatment is an option, or to check on results from earlier sprays: Optimum sample date for late instar summer generation OBLR larvae: July 1, Friday. If first OBLR late instar larvae sample is below threshold, date for confirmation follow-up: July 4, Monday.
  • Oriental fruit moth (OFM) 2nd generation OFM flight begins around: June 27, Monday. 2nd generation - first treatment date, if needed: July 4, Monday.
  • 2nd redbanded leafroller (RBLR) flight begins around June 28, Tuesday. Peak catch and approximate start of egg hatch: July 11.
  • Spotted Tentiform Leafminer (STLM): 2nd STLM flight begins around: June 12, Sunday. Rough guess of when 2nd generation sap-feeding mines begin showing: July 2, Saturday. Optimum sample date for 2nd generation STLM sapfeeding mines is July 10, Sunday. Second optimized sample date for 2nd generation sapfeeding mines, if needed: July 16, Saturday.
  • Rough guess of date first apple maggot flies (AMF) are caught on traps is: Tuesday, June 28.

Orchard Radar preliminary McIntosh harvest date forecast

Harvest date estimates are based on temperature observations from the first 30 days after Full bloom.

  • Date to apply ReTain to delay first harvest for apples which without treatment would be ready for storage harvest on September 5 is Monday, August 8. Begin measuring actual McIntosh starch-iodine index no later than Wednesday, August 24.
  • The Michigan formula estimates that non-spur McIntosh will reach starch index 4.0 and start the optimum harvest window for long term storage on Monday, September 5.
  • Using the Hudson Valley NY formula, McIntosh maturity is forecast to reach starch index 6.0 in
    Belchertown MA on Wednesday, September 21.

Upcoming meetings

June 29, 2011: UMass Cold Spring Orchard Manager applicant 'meet and greet' 9-10 AM, UMass Cold Spring Orchard, 391 Sabin St., Belchertown, MA.

July 13, 2011: TREE FRUIT TWILIGHT MEETING Poverty Lane Orchards, 98 Poverty Lane, Lebanon, NH. 5 PM. Sponsored by U. of New Hampshire Cooperative Extension and New Hampshire Fruit Growers' Association. 2 pesticide re-certification credits. Contact Heather Bryant (603-787-6944) for more information.

July 18, 2011: Massachusetts Fruit Growers' Association Summer Meeting, Parlee Farms, Tyngsoboro, MA

August 3, 2011: Lake Ontario Summer Fruit Tour, Presented by Cornell Cooperative Extension, Cornell University, & the New York State Agricultural Experiment Station.

The way I see it

Enough of the rain. Has made picking conditions and disease control on cherries and strawberries an issue. But note that we do not have the 24c SLN supplemental label for Indar.Does anyone think we need one for next year?) Otherwise, it is really pretty quiet but there will be lots of catch-up work to do when it dries out. (Young tree training, mowing, hand-thinning and summer-pruning of peaches and apples, etc., etc.) Note that you should be reading and digesting the the Orchard Radar insect synopsis for heads-up conditions on potential insect activity.

If you can take the time next week, we are having a 'meet and greet' for two applicants for Manager of UMass Cold Spring Orchard next Wednesday (June 29) from 9-10 AM at the Orchard in Belchertown (391 Sabin St.). Joe Sincuk, current Manager, is retiring July 1 after a long career at UMass -- thanks Joe! The applicants will introduce themselves and you can ask questions and complete a short evaluation. Your input will be valuable in helping to select the next Manager of UMass Cold Spring Orchard.

Redhaven peach harvest onset

Based on a formula developed in Michigan, the predicted onset of Redhaven peach harvest for Belchertown, MA is August 3. This compares to a predicted date of July 28 in 2010. So, this season appears to be about a week later than last year, however, this season is much closer to 'average.'

Guest Article: HEY MAGGOT! Notes on the fly

Art Agnello and HarveyReissig, Cornell Entomology, Geneva, NY (Reprinted from Scaffolds Fruit Journal, June 20, 2011.)

It is once again the time of year when we expect the first appearance of apple maggot (AM) flies in wild apple trees and abandoned orchards, particularly in eastern N.Y.; western N.Y. could be about a week later, depending on what kind of temperatures and rainfall we get over the next week or so. Crop scouts and consultants have used traps to monitor AM populations for a long time, but this approach, useful as it is, nevertheless is not recommended in all cases. Some orchards have such high or such low AM populations that monitoring for them is not time-efficient. That is, in some blocks, sprays are necessary every season, often on a calendar basis; however, in some blocks the populations are so low that they are rarely needed at all. However, most commercial N.Y. orchards have moderate or variable pressure from this pest, so monitoring to determine when damaging numbers of them are present allows growers to apply only the number of sprays necessary to protect the fruit from infestation.

Sticky yellow panels have been in use for over 40 years, and these can be very helpful in determining when AM flies are present. These insects emerge from their hibernation sites in the soil from mid-June to early July in New York, and spend the first 7–10 days of their adult life feeding on substances such as aphid honeydew until they are sexually mature. Because honeydew is most likely to be found on foliage, and because the flies see the yellow panel as a "super leaf", they are naturally attracted to it during this early adult stage. A few of these panels hung in such an orchard can serve as an early warning device for growers if there is a likely AM emergence site nearby.

Many flies pass this period outside of the orchard, however, and then begin searching for fruit only when they are ready to mate and lay eggs. That means that growers don't always have the advantage of this advance warning, in which case the catch of a single (sexually mature) fly indicates that a spray is necessary immediately to adequately protect the fruit. This can translate into an undesirable risk if the traps are not being checked daily and are used signal an immediate response, something that's not always possible during a busy summer.

To regainthis time advantage, traps have been developed that have the form of a "super apple" — large, round, deep red, and often accompanied by the smell of a ripe apple — in an attempt to catch that first AM fly in the orchard. Because this kind of trap is so much more efficient at detecting AM flies when they are still at relatively low levels in the orchard, the traps can usually be checked twice a week to allow a 1–2-day response period (before spraying) after a catch is recorded, without incurring any risk to the fruit. Research done in Geneva over a number of years indicates that some of these traps work so well that it is possible to use a higher threshold than the old "1 fly and spray" guidelines recommended for the panel traps. Specifically, it has been found that sphere-type traps baited with a lure that emits apple volatiles attract AM flies so efficiently that an insecticide cover spray is not required until a threshold of 5 flies per trap is reached.

The recommended practice is to hang three volatile-baited sphere traps in a 10- to 15-acre orchard, on the outside row facing the most probable direction of AM migration (towards woods or abandoned apple trees, or else on the south-facing side). Then, the traps are periodically checked to get a total number of flies caught; dividing this by 3 gives the average catch per trap, and a spray is advised when the result is 5 or more. Be sure you know how to distinguish AM flies from others that will be collected by the inviting-looking sphere. There are good photos for identifying the adults on the Apple Maggot IPM Fact Sheet (No. 102GFSTF-I8).

In home apple plantings, these traps can be used to "trap out" local populations of AM flies by attracting any adult female in the tree's vicinity to the sticky surface of the red sphere before it can lay eggs in the fruit. Research done in Massachusetts suggests that this strategy can protect the fruit moderately well if one trap is used for every 100–150 apples normally produced by the tree (i.e., a maximum of three to four traps per tree in most cases), a density that makes this strategy fairly impractical on the commercial level.

A variety of traps and lures are currently available from commercial suppliers; among them: permanent sphere traps made of wood or stiff plastic, disposable sphere traps made of flexible plastic, and sphere-plus-panel ("Ladd") traps. The disposable traps are cheaper than the others, of course, but only last one season. Ladd traps are very effective at catching flies, but are harder to keep clean, and performed no better than any other sphere trap in our field tests. Brush-on stickum is available to facilitate trap setup in the orchard. Apple volatile lures are available for use in combination with any of these traps. These tools are available from a number of orchard pest monitoring suppliers, among them:

By preparing now for the apple maggot season, you can simplify the decisions required to get your apples through the summer in good shape for harvest.

Useful links

UMass Extension Fruit Program

UMass Cold Spring Orchard

Scaffolds Fruit Journal

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