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Healthy Fruit - Vol. 26, No. 15, July 17, 2018
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Healthy Fruit, Vol. 26, No. 15, July 17, 2018

Jon Clements, Author (unless otherwise noted) and Editor


Upcoming pest events

Ag-Radar Summary

Upcoming meetings

The way I see it




Hawkeye’s corner

Guest article

Facebook Me

Useful links

Thank you sponsors...

Upcoming pest events

Coming events

Degree days
(Base 43 BE)


Current accumulation, Belchertown, MA


Apple maggot 1st oviposition punctures

1605 to 2157

Baited yellow sticky or red spheres should be out to monitor; Early varieties susceptible to injury, particularly Gravenstein, Ginger Gold, and a bit later Honeycrisp

Codling moth 2nd flight start

1583 to 2230

Pheromone traps should be refreshed with pheromone and new sticky bottoms to monitor effectively for 2nd generation

Codling moth 2nd flight peak

1954 to 2684

Pheromone traps should be refreshed with pheromone and new sticky bottoms to monitor effectively for 2nd generation

Lesser appleworm 2nd flight start

1429 to 2108


Oblique-banded leafroller 1st fight subsides

1630 to 2048

Time for Altacor, Delegate or similar if indicated, to target hatching larvae, in cooler locations; scout for signs of caterpillar feeding; consider monitoring for 2nd generation

Oriental fruit moth 2nd flight subsides

2026 to 2524

Hang pheromone traps or replace pheromone to monitor flight

San Jose scale 2nd flight subsides

1998 to 2354


Ag-Radar summary

Key insect life cycle and management dates

Note: for 2018, we have ten Massachusetts orchard locations subscribed to Ag-Radar: Amherst, Belchertown (2 locations), Brookfield, Deerfield, Easthampton, Groton, Leominster, Northboro, and Westhampton. The website for looking at AgRadar for these locations is: What follows is the AgRadar summary for the Belchertown location.

Apple Maggot Fly (AMF) -- Rough guess of peak AM trap captures is: August 1, Wednesday. Estimated dates for first and peak trap capture are only general guidelines because the effect of rain on soil conditions is not included in the calculation.

Dogwood Borer (DB) -- First dogwood borer egg hatch roughly: June 22. Peak hatch roughly: July 26.

Codling Moth (CM) -- Codling moth development as of July 17: 2nd generation adult emergence at 15% and 2nd generation egg hatch at 2%. 2nd generation 7% CM egg hatch:  July 23,  Monday, = target date for first spray where multiple sprays needed to control 2nd generation CM. 2nd generation 30% CM egg hgatch: August 2, Thursday = target date where one spray needed to control 2nd generation CM.

Spotted Tentiform Leafminer (STLM) -- Second optimized sample date for 2nd generation STLM sapfeeding mines, if needed:  July 15,  Sunday. Third optimized sample date for 2nd generation STLM sapfeeding mines, if needed: July 25,  Wednesday.

White Apple Leafhopper (WAL) -- 2nd generation WAL found on apple foliage:  August 2,  Thursday.

Preliminary McIntosh Harvest Date Forecasts -- Date to apply ReTain to delay first harvest for apples which without treatment would be ready for storage harvest on September 6 is from Thursday August 9  to  August 16. Date to apply ReTain to delay maturity for 2nd, 3rd or 4th pick of those apples, without delaying start of harvest maturity, is from Thursday, August 23  to  August 30. Begin measuring actual McIntosh starch-iodine index no later than  Saturday, August 18. 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 Thursday, September 6. Using the Champlain Valley NY formula from Cornell Bulletin 221 ‘Predicting Harvest Date Windows for Apples,’ McIntosh maturity is forecast to reach starch index 6.0 in Belchertown-ColdSpring MA on Saturday,  September 15. (Yup, we are already talking about harvest.)

Upcoming meetings

INTERNATIONAL FRUIT TREE ASSOCIATION Summer Tour, July 22-25, 2018, Coast Capri Hotel, Kelowna, British Columbia. For more information and to register:

The way I see it

Jon Clements

Great turnout last week at Massachusetts Fruit Growers’ Association Summer Meeting at the UMass Orchard in Belchertown, thanks to all who attended. In Horticulture below, I summarized the talks by our two guest speakers from Cornell, Poliana Francescatto and Srdjan Acimovic. We were lucky to have them here sharing their knowledge. Also on the agenda were two UMass student interns -- Cam and Lindsey -- who talked about iPiPE. Both Cam and Lyndsey had a busy week last week, and Lindsey put this slide show together that summarized their activity.

Otherwise, it’s just kind of hot, and many orchard chores are caught up. Remember to avoid spraying when it gets too hot (above 85 F. is a good cut-off point), keep mowing and irrigating when and where necessary. Unfortunately we have seen some sunburn/heat injury on apple fruit (pictured below) which most likely occurred back around the first of July when both temperature (mid-upper 90’s) and sunlight intensity combined to produce the sunburn injury on exposed apples. If you want to read more about sunburn, and fruit surface temperature considerations, see this article at Washington State University: and this experimental calculator for modeling apple fruit skin temperature. (See screen snapshot below, and note that sunburn is likely to occur if the fruit surface temperature rises above 115 degrees F.) Most growers are not prepared to deal with sunburn, however, there are various spray-on products -- Raynox (Valent) comes to mind -- which definitely help the situation (if it occurs again). Good luck…

Calculated for 1-July, 2018 at the UMass Orchard in Belchertown, MA

Sunburn/heat injury to yellow skin apples, 9-July 2018


Jaime Pinero

Insecticides against apple maggot fly (AMF)

High adult AMF activity has been reported in commercial orchards throughout Massachusetts that have received rainfall over the past couple of weeks. Effective AMF control relies on timely and thorough application of insecticides BEFORE females lay eggs inside the fruit. Below are some notes on insecticides that are listed in the New England Tree Fruit Management Guide for AMF control

The timing of sprays against AMF usually coincides with codling moth control applications, and as a result a single insecticide spray can often be used to manage both of these pests. It is important to remember that while some of the newer chemistries (Altacor®, Delegate®) provide effective management of codling moth, they will only provide AMF suppression in low pressure orchards.

Delegate® is not listed in the New England Tree Fruit Management Guide against AMF. However, when applied at low rates for lepidopteran control, Delegate will suppress AMF. Since sugars have a phagostimulant effect on AMF, then the addition of sugar at 2 lbs. per 100 gallons of water is likely to increase the efficacy of Delegate®, particularly if AMF populations are low.

The neonicotinoids Belay® and Assail® have limited lethal action on adult AMF but provide strong curative activity on eggs and larvae.


Looking for organic management options? Research has shown that one of the most effective OMRI-listed treatments is the combination of Surround® WP (kaolin clay) tank-mixed with pyrethrins (Pyganic® EC 1.4/5.0). When used separately, Surround and Pyganic are only moderately effective, but when applied together their efficacy increases. Applications of 25-50 lbs of Surround per 100-200 gallons per acre form a white "particle film" barrier on treated surfaces. Thorough coverage must be maintained by multiple applications, usually every 7-10 days, for effective control. Modes of action of Surround include repellency and deterrence to egg-laying. Also, remember that AMF are attracted to the red color of ripening apples, so a white apple is less visually attractive to them.

Always follow the pesticide label directions. Remember, the label is the law.


Do you have any suggestions for articles on arthropod IPM? Please let me know!      

Contact info:; (413) 545-1031 (campus office); (808) 756-2019 (cell).


Ed. note. This morning I was asked the question “So what’s the deal with sooty blotch/fly speck (SBFS)? NEWA says High risk, consultant somewhat dismissive, Penn State says fungicide should be done every 14 days. Five weeks since we last sprayed, should we be concerned?” I think the short answer is yes. NEWA says High because we are clearly in a time period when with high humidity, especially accompanied by rainfall, will cause SBFS to gain a foothold on fruit and ultimately result in symptoms. Thus, fungicide coverage is necessary. (Maybe the consultant was saying, “What, are you brain dead? Of course you need to be worried about SBFS now!”) The every 14 day fungicide spray schedule is a rule of thumb, if heavy rain occurs, fungicides may wash off and not be effective, re-spraying is necessary after 1.5 to 2 inches of rain depending on fungicide. So again,  the answer is YES, you should be concerned! Cornell has a nice Fact Sheet on SBFS here. Recommended fungicides might include Topsin, Sovran, Flint, one of them combined with Captan. More here in the New England Tree Fruit Management Guide.


Jon Clements

For those of you who missed the MFGA Summer Meeting last week in Belchertown, and for those of you who need a refresher, here are some of the take-home messages presented by Srdjan Acimovic and Poliana Francescatto during their talks which were “New Rules for Apple Scab and Fire Blight” and “Bud Flower Formation on Apples” respectively.

Srdjan Acimovic - “New Rules for apple scab and fire blight”

Poliana Francescatto - “Bud Flower Formation on Apples”

Hawkeye’s corner (notes from the field)

Liz Garofalo

Harbingers of sorrow…

While brown marmorated stink bug (BMSB) trap captures remain low across Massachusetts, populations can be seen building in known hot spots.

BMSB adults in an unsprayed crabapple at UMass. This hotspot was ID’d last fall.  We now have a trap placed in the espaliered (also unsprayed) apple “block” next to these trees.

Adult BMSB feeding on crabapple.

Later instar BMSB nymph also feeding on crabapple.  

Not to be outdone by BMSB as most obnoxious invasive insect pest, gypsy moth is still moving around (although not feeding thank goodness!).

Flightless female gypsy moth caught in the act of egg laying in the forested edge next to the orchard (Cold Spring Research Orchard).

Don’t forget to check out Ag-Radar’s Honey Bee Activity Chart!

Guest article

No Guest Article this week...

Facebook Me

Useful links

UMass Fruit Advisor:

Scaffolds Fruit Journal:

Network for Environment and Weather Applications (NEWA):

Follow me on Twitter ( and Facebook (

Acimovic Lab at Hudson Valley

Peter Jentsch's Blog

The next Healthy Fruit will be published on or about July 31, 2018. In the meantime, feel free to contact any of the UMass Fruit Team if you have any fruit-related production questions.

Thank you sponsors…

Orchard Equipment and Supply Company, Inc. Conway, Massachusetts

Nourse Farms