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Healthy Fruit 2010 Vol. 18:13

Jun 29, 2010

Current (through June 28) degree day

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

  • Base 43: 1531
  • Base 50: 983
  • Note: this will be the last degree-day report for 2010

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

  • Lesser appleworm 2nd flight begins: 1409-1951
  • Obliquebanded leafroller summer larvae hatch: 1038-1460
  • Obliquebanded leafroller 1st flight subsides: 1612-1952
  • Redbanded leafroller 2nd flight peak: 1546-1978
  • Spotted tentiform leafminer 2nd flight peak: 1360-1790
  • Spotted tentiform leafminer 2nd generation feeders present: 1378-2035
  • Codling moth 1st flight subsides: 1280-1858
  • Codling moth 2nd flight begins: 1569-2259
  • Oriental fruit moth 2nd flight peak: 1455-1935
  • Apple maggot 1st catch: 1234-1640

Orchard Radar insect synopsis (for Belchertown)

First dogwood borer (DB) egg hatch roughly: June 15. Peak hatch roughly: July 22

Codling moth (CM) development as of June 29: 2nd generation adult emergence at 1% and 1st generation egg hatch at 98%. In most orchards, insecticide targeted against plum curculio and apple maggot prevent codling moth damage. If targetted codling moth control is needed, key management date is: 2nd generation 7% CM egg hatch: July 19, Monday (= target date for first spray where multiple sprays needed to control 2nd generation CM)

Lesser apple worm (LAW): 2nd LAW flight begins around: June 27, Sunday

1st generation Obliquebanded Leafroller (OBLR) flight begins around: May 28, Friday. 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: June 23, Wednesday. If first OBLR late instar larvae sample is below threshold, date for confirmation follow-up: June 26, Saturday

2nd generation Oriental Fruit Moth (OFM) flight begins around June 19, Saturday; first treatment date, if needed: June 26, Saturday; second treatment date, if needed, July 7, Wednesday

2nd redbanded leafroller (RBLR) flight begins around June 21, Monday; peak catch and approximate start of egg hatch, June 27

Spotted tentiform leafminer (STLM): Rough guess of when 2nd generation sap-feeding mines begin showing: June 24, Thursday. Optimum first sample date for 2nd generation STLM sapfeeding mines is June 30, Wednesday. Second optimized sample date for 2nd generation STLM sapfeeding mines, if needed: July 7, Wednesday

Orchard Radar preliminary McIntosh harvest date forecasts (for Belchertown)

Date to apply ReTain to delay harvest for apples which without treatment would be ready for storage harvest on August 25 is Wednesday, July 28

Begin measuring actual McIntosh starch-iodine index no later than Wednesday, August 18

The Michigan formula estimate for standard (i.e. non-spur) McIntosh starch index 4.0 and beginning of optimum McIntosh harvest for CA storage is Wednesday, August 25. Estimate adjusted to lessen influence of unusual bloom date is Tuesday, August 31

Cornell Bulletin 221 provides formulas for different locations to estimate date when non-spur McIntosh reach starch index 6.0 and the end of optimum harvest for CA storage. Using the Hudson Valley formula, the estimated end of McIntosh CA harvest for Belchertown MA is Wednesday, September 15

The way I see it

Cherry harvest is pretty much over. Fireblight has made an appearance in a few orchards. The typical July pests potato leafhopper and Japanese beetle have arrived. I expect the first very early peaches (PF-1, PF-5) will be harvested next week. An upcoming dry spell means young trees and peaches will need to be watered, and peaches will need to be protected from brown rot as they ripen. Don't forget to make your reservation for the MFGA Summer Meeting at the UMass Orchard in Belchertown.

New England Tree Fruit Management Guide update

Thanks to Glen Koehler of the University of Maine for this update to the insecticide characteristics tables to the 2010 New England Tree Fruit Management Guide

Potato leafhopper prevalent

Potato leafhopper are here in abundance and evidence of damage -- marginal yellowing -- is pretty easy to find. It could be a banner year for leafhopper given the weather pattern. Be sure to check your young orchards and treat with an insecticide (Actara, Assail, Avaunt, Calypso, Leverage, Portal, Provado, Sevin, etc., take your pick) at the first sign of potato leafhopper. Otherwise, expect stunting of shoot growth, something you do not want with young trees.

Japanes beetle also here

Japanese beetles are also here and there are already signs of feeding on Honeycrisp foliage. I am reprinting a useful Table from the June 28, 2010 Illinois Fruit & Vegetable News with insecticide options and pre-harvest intervals for Japanese beetles. Again, don't let them get out of hand in young plantings and in peaches/nectarines. (Cherry foliage is also desirable.) We will be dealing with Japanese beetles for a month probably, so multiple insecticide sprays will be necessary where they are abundant. Here is the Table:

Pre-harvest Intervals for Japanese Beetle Fruit Insecticidesfrom the June 28, 2010 Illinois Fruit & Vegetable News

Pre-harvest intervals (days) for selected insecticides used for Japanese beetle control in fruit crops. NR = not registered. * = generally not recommended (malathion is not labeled for use in commercial apple production; most pyrethroids are not recommended for use on apples at this time because they tend to trigger outbreaks of European red mite).

Fireblight rearing it's ugly head

I have visited a few orchards with fireblight shoot strikes. Needless to say any shoot blight found should be pruned out. I tell people the important think is to get it out of the trees on a dry day. No need to sterilize pruners. Just be careful to NOT cut into obviously blighted wood. Thus, cut way back into healthy wood (leaving an 'ugly' stub) and throw the prunings in the aisle. They will dry up quickly and not be a source of further infection. In addition, any 'trauma' event -- hail, and/or high winds with rain -- should be followed up with a strep application (within 12 hours) in orchards where there has been significant shoot blight.

Useful links

UMass Extension Fruit Program

UMass Cold Spring Orchard

Scaffolds Fruit Journal

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