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Healthy Fruit 2011 Vol. 19:11

Jun 7, 2011

Current (through June 6) degree day (DD) Accumulations

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

Base 43: 872

Base 50: 562

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

Codling moth 1st flight peak: 574-1008

Black cherry fruit fly 1st catch: 702-934

Obliquebanded leafoller pupae present: 601-821

Obliquebanded leafoller 1st catch: 815-979

Obliquebanded leafroller 1st flight peak: 843-1139

Redbanded leafroller 1st flight subsides: 579-893

European red mite summer eggs hatch: 737-923

Peachtree borer 1st flight catch: 789-1353

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. Access the full Orchard Radar output.

  • Codling moth (CM), 1st generation, first sustained trap catch biofix date: May 16, Monday. 1st generation adult emergence at 63% and 1st generation egg hatch at 9%. 1st generation 20% CM hatch = June 9, Thursday = target day where one spray needed to control 1st generation CM.
  • 1st generation obliquebanded leafroller (OBLR) flight begins around: June 6, Monday. 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.
  • Spotted Tentiform Leafminer (STLM): 2nd STLM flight begins around: June 11, Saturday. Rough guess of when 2nd generation sap-feeding mines begin showing: July 2, Saturday.

Upcoming meetings

June 14, 15, 16, 2011: Tree fruit twilight meetings.

Tuesday, June 14, Kosinski Farms, 420 Russellville Rd., Westfield, MA

Wednesday, June 15, Red Apple Farm, 455 Highland Ave., Phillipston, MA

Thursday, June 16, TBA

  • Tree fruit twilight meetings start promptly at 5:30 PM.
  • Pesticide recertification credit(s) will be offered.
  • There will be a $25 meeting admission charged at the door. ($20 for Massachusetts and Rhode Island Fruit Growers' Association FULL members.)
  • A light meal or snack is typically served at all meetings.
  • For more information, call Jon Clements: 413-478-7219.

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

The way I see it

It's fairly quiet as we await final drop of thinned apple fruitlets to see how the potential apple crop is shaking out. My overall impression is it is a little variable, and will be on the ligher side (after several heavy years) when everything is said and done. I have not heard any reports of serious damage (hail or otherwise) to orchards, which is very fortunate given the severe weather we experienced last week.

I will say the sweet cherry crop is on the lighter side as plenty of fruit are sloughing off because of the extended period of cloudy weather following bloom. (Likely affecting apple fruit set too.) Brown rot has been a problem this year too -- expect it to be a problem on stone fruit throughout harvest unless it gets real dry or very adequate fungicide coverage is maintained.

Apple scab lesions are being increasingly observed. You are not out of the woods yet if you see any scab lesions in your orchard. (Go out and look!) See comments on apple scab and other diseases below in Dean Polk's guest article. There are also some occassional fire blight strikes showing up -- I suspect where strep was not applied because infection conditions were marginal during late bloom.

Plum curculio season is largely over in most MA orchards as long as you still have some insecticide residue out there. According to Glen Koehler's Orchard Radar, however, "PC egglaying begins to naturally decline around Friday, June 14" in Belchertown. Make of that what you will, but I would say the potential for scattered and likely minor injury exists for a couple more weeks. (One more PC spray?)

Horticulturally (is that a word?) you should be thinking about:

  • hand thinning apples (when June drop is done) and peaches beginning ASAP. Return bloom (apple) and fruit size (peach) will be positively affected by early thinning.
  • late apple fruit thinning applications with 'Ethrel' if fruit set is still heavy in certain varieties, See: F-129R Late-season "Rescue" Thinning with Ethephon
  • training branches of 1st leaf trees to just below horizontal using clothespins (for good crotch angles), rubber bands, wire hooks, string, etc. 1st leaf tall spindle orchards must have remaining feathers bent down to below horizontal to be successful. See: Training Techniques for Young Apple Trees
  • beginning calcium sprays to apple. See: F-119R Foliar Calcium Sprays for Apples
  • turning on irrigation during periods of dry weather (like now), don't underestimate the water needs of trees (particularly young ones)

Guest article—excerpts from Dean Polk (Rutgers University IPM)

e-mail Fruit IPM update 6/7/11


Catfacing Damage, Stinkbugs (SB) and Tarnished Plant Bugs (TPB): Catfacing insects are key pests as summer begins. Applications made to control Brown Marmorated Stink Bug (BMSB) will control all other catfacing insects. Reports from western Maryland and West Virginia indicate that alternate middle sprays of the more effective (and harsh) materials for BMSB are the way to go, but that spray intervals that are 7 or more days apart are leaving too many opportunities for fresh infestation resulting from dispersal from woods and other border areas. Evidently, under high BMSB populations, fresh insecticide needs to be continually present. Border sprays that supplement alternate middle applications are another option. In NJ we are experiencing increased damage and bug populations, but damage levels are still relatively low, and nothing like the 30-35% damage levels we are hearing about in other areas. Increased activity was found on 2 farms in Warren Co with 2-3% damaged fruit. On another farm, after 2 sprays with Thionex and Permethrin, no new fruit injury was detected. Scattered injury is present on other farms. We now know that BMSB will reproduce on wheat as well as soybeans. Growers who have these, or other grain crops should scout them as they mature, and treat if BMSB is present. If you have fruit next to these crops, and they are not yours, talk to your neighbor and consider border sprays if BMSB are present. (Ed. note: although BMSB is not a problem here in Massachusetts yet, you should get a feel for the challenge it will presents if it does show up. But, there is plenty of opportunity for other plant bugs to damage peaches during this period. I speak from experience. One or two broad-spectrum insecticides will be necessary over the next couple weeks.)

Bacterial Spot: Bacterial spot infections continue to be present in very susceptible varietes at low levels in southern counties. Fruit symptoms have been present in affected blocks for a few weeks. Copper sprays should be maintained and reapplied after heavy rains. If significant new growth occurs between a copper application and an infection period, then that new growth is not protected. The best protection is when fresh copper is applied 24 to 36 hr prior to an infection period. Mycoshield or Flame Out also may be used. These materials will provide about 3-5 days protection, and possibly 24 hours "back action" to suppress new infections.


Apple Scab and Other Diseases: Scab is present in a few orchards statewide at present. Summer diseases, including black rot and white rot are the key diseases to control at present. Combinations with Topsin and Captan have been the most economical, and give broad spectrum control. Some growers have used Indar/Captan combinations. This may be useful if low levels of scab, since in addition to scab, Indar has efficacy for sooty blotch and fly speck. Growers should bear in mind that resistance to DMI fungicides has been noted in the northeast and elsewhere. Use of Indar to "burn out" scab lesions may speed the development of resistance. Sovran is also effective on the rots as well as sooty blotch and fly speck, but is limited to 4 applications per season. Use higher rates of Sovran plus a half rate of Captan where scab is present. Growers should begin to shift away from EBDCs, which have a limit of 21 pounds/acre and a 77 day PHI. Where cost is a limiting factor, a combination of 3# Captan 50W (2# Captan 80) + 3# Ziram have provided acceptable control in past years. All the above materials and combinations are effective bitter rot materials. (Ed. note: Inspire Super is also very good in the above situation, particularly if it gets wet. Captan, otherwise, is the best choice for burning out scab when it is hot and dry.)

Codling Moth (CM): Degree day based spray timings are now past in all growing regions. If after about 7-10 days after an insecticide application, trap counts remain above 5 moths per trap, then additional sprays may be required. High counts are common in northern counties. We are seeing averages of 12-28 moths per trap, and extremely high numbers on 1 farm in Middlesex Co (66 moths per trap). Especially in high pressure areas, trees need to be well pruned, sprayers calibrated, and alternative materials used such as Altacor, Belt and Delegate. The addition of granulosis virus has also helped under high populations. Mating disruption can also, over time, help bring a population down. (Ed. note: in Massachusetts, this week is the peak timing for insecticide sprays against CM if your orchard has a history of this pest and it is not being adequately controlled by PC sprays.)

Thanks Dean! JC

Useful links

UMass Extension Fruit Program

Scaffolds Fruit Journal

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