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Healthy Fruit 2010 Vol. 18:4

Apr 27, 2010

Current (through April 26) degree day (DD) Accumulations

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

  • Base 43: 346
  • Base 50: 168

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

  • Redbanded leafroller first flight peak: 231-367
  • Spotted tentiform leafminer 1st flight peak: 263-387
  • Spotted tentiform leafminer sap-feeders present: 343-601
  • Lesser appleworm 1st catch: 260-538
  • Oriental fruit moth 1st flight peak: 348-542
  • McIntosh at bloom: 349-419

Current bud stages

Location McIntosh apple -- bloom + Pear -- early petal fall PF-14 Jersey peach -- early petal fall Regina cherry -- bloom
McIntosh apple Pear Jersey peach Regina cherry

Orchard Radar synopsis

  • 1st Lesser Apple Worm (LAW) flight begins around: April 25. Peak trap catch: May 4, Tuesday.
  • 1st generation Oriental Fruit Moth (OFM) flight starts: April 15, Thursday. 1st generation - 55% egg hatch and first treatment date, if needed: May 23, Sunday
  • 1st Red Banded Leaf Roller (RBLR) flight began around April 5, Monday. Peak trap catch and approximate start of egg hatch: April 19, Monday.
  • Increased risk of Plum Curculio damage as McIntosh and similar cultivars increase fruit size:
    May 9, Sunday
  • Sptted Tentiform Leafminer (STLM): 1st generation sapfeeding mines start showing: May 7, Friday. Optimum sample date is around Monday, May 10, when a larger portion of the mines are visible.
  • 1st generation White Apple Leafhopper (WAL) found on apple foliage: May 1, Saturday
  • Sunday, May 1 McIntosh 95% petal fall

The way I see it

Thinking about this week's HF, I though "oh, we are in bloom, relatively quiet period?" But the more I thought about it, the more I realized there is a LOT about to happen! It looks like tonight (Wednesday) might be a frosty night, however, at least here in Belchertown it is predicted to only go down to 30. If the wind calms and sky clears, cold pockets could be in the upper 20's. Frost and/or freeze injury starts at about 29 F. so we will keep our fingers crossed. Petal fall on McIntosh should be this weekend. Let's see, thinning (I am not going there until next week), Apogee for growth control, plum curculio, leafminer, etc., etc. Oh yea, and fireblight? At least the scab pressure has not been too high based on the relatively dry conditions. We will see how that pans out. JC

Apogee for apple growth control

If you have not already began applications of Apogee at bloom for growth control, you better do it now ASAP. (No later than petal fall.) At last week's Twilight Meeting in Belchertown, Dr. Duane Greene suggested that multiple, low rates of Apogee (2 to 3 oz. per 100 gallons) beginning at bloom to petal fall are effective at controlling growth (particularly in Cortland) and will not hinder your thinning efforts as much as higher rates of Apogee will. Otherwise, and for more application details, see the fact sheet 'F-127R Apogee - A New Growth Retardant for Apples.' One other note, is that normally we do not recommend the tank mixing of calcium foliar sprays with Apogee, however, Syss-Cal (Agro-K, and available from UAP) apparently is OK to tank mix with Apogee. There are some benefits to getting on a foliar calcium spray beginnnig at bloom to petal fall. JC

Fire blight weather on the horizon?

One good thing about the early bloom, is the fact it has been relatively cool, and thus the fire blight threat has been low to non-existent. In fact, Dr. Dan Cooley says "the cold temps zero the fire blight clock." But, it will start ticking again as soon as it warms up, and my hunch tells me that the risk will increase by next Sunday (May 2) based on the weather forecast. I will get out an alert if that happens, but you should be prepped with some streptomycin on hand and be prepared to spray should you be in bloom to petal fall, weather conditions warrant, and you have had fire blight in the past. JC

Massachusetts airports on NEWA

Through a cooperative effort with the New York State IPM Program, and the Northeast Regional Climate Center, Massachusetts airport locations have been added to the NEWA (Network for Environmental and Weather Applications) website ( Pests forecasts, typically based on temperature, precipitation, and relative humidity are available for various crops (fruit and vegetable). For apples, available forecasts include: codling moth, Oriental fruit moth, obliquebanded leafroller, plum curculio, spotted tentiform leafminer, apple maggot, apple scab, and fire blight. For example, here is what the fire blight forecast for Chicopee Falls (Westover ARB) looks like as of 04/28/10 9:00:

Blossom Blight Summary

I urge you to look at the NEWA website and give us your feedback. This is the future of IPM information delivery! JC

Pest watch

  • plum curculio are likely kicking around and fruit will be susceptible to damage as it increases in size. Cherries will be hit first -- a petal fall spray of Guthion will take care of that. Carbaryl (Sevin XLR @ 1 per 100 gallons) when used as a petal fall spray for thinning apples wil control curculio for awhile.
  • tarnished plant bug can cause considerable injury on peaches and nectarines beginning at shuck split, particularly where orchards are weedy and/or surrounded by weedy fields, hedgerows, and woodlots. Pyrethroid insecticides (Warrior, etc.) are excellent for plant bugs but hard on beneficial insects. There are 'softer' alternatives such as Provado and Beleaf which are rated good for plant bug control.
  • if spotted tentiform leafminer is a perpetual problem in your apples, you should consider a petal fall insecticide to get started on controlling the early generation of this pest. Ideally, you should scout for the presence of sap-feeding mines on expanded leaves shortly after petal fall to determine the need for treatment. If so, there are many insecticide options for controlling leafminer, among the best being: Agri-Mek, Actara, Assail, Calypso, Clutch, Voliam-Flexi, and Leverage. Note that all these (except Agri-Mek) control plum curculio too.

Useful links

UMass Extension Fruit Program

UMass Cold Spring Orchard

Scaffolds Fruit Journal

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