RI Apple IPM Newsletter – July 7, 2011

Hi Fruit Growers,

I finally made it to some orchards yesterday! I’m happy to report that the orchards I scouted looked good! This hot, dry weather has been ideal for limiting scab. I don’t say halting scab because even after all this hot weather and applications of captan, I can find what looks like live spores on leaf lesions. If your trees have apple scab, keep them protected with captan! Don’t let the fungicide coverage run out – respray every 14 days or after 2 inches of rain.

If your trees are scab-free, you still need to protect with a fungicide against summer diseases of flyspeck, sooty blotch and fruit rots. I’ll repeat what I said last month about summer fungicide sprays: New York is recommending not spraying Captan alone since it is not extremely effective against fly speck and sooty blotch. We are limited to using no more than 4 pounds of Topsin M per acre per season. So, if you feel you need to improve your fly speck/sooty blotch control, you can add one of the Phosphite fungicides to Captan. Several Phosphite fungicides are labeled for apples: Fosphite, Fungi-Phite, Prophyt, Phorcephite, and Phostrol. There are probably others too.

The strobies (Sovran, Flint, Pristine) control summer diseases well, but they are expensive and you are limited to a total of 4 applications per year. If you are using strobies, it is probably best to use one for your final spray for the season.

Regardless of the fungicide, you need to reapply after 2-2.5 inches of rain. Check Orchard Radar to see when you need to reapply fungicides to control flyspeck and sooty blotch. Topsin M and the strobies will give some kick back and control flyspeck and sooty blotch – which means these fungicides can be applied after an unprotected wet period. Orchard Radar will tell you when you need to spray by to get effective control. From the Apple IPM website choose the July-August Orchard Radar for either Greenville or Newport County http://web.uri.edu/ipm/ From here, select ‘flyspeck’ and then choose what kind of fungicide you sprayed last: Group A (Topsin M or a strobie) or Group B (captan or Ziram). Then select the month of July. It’s not as complicated as it looks (or sounds!) It’s worth your effort and you can always call me if you need assistance!

For insects (and mites): We should be thinking about apple maggot flies. Mid-July is generally when we start being concerned. Over the next couple of weeks I expect apple trees to be sprayed with either half rates of Imidan or full rates of Avaunt, Assail or Calypso. I haven’t set up any apple maggot traps but, a RI grower did set up traps in early maturing trees and we checked them yesterday. There were no apple maggot flies. Has anyone else set up traps? I’ll come by and check them if you let me know!

I found white apple leafhopper in one orchard and rose leafhopper in another. If you see nymphs now, they are rose leafhoppers. If you see adults flying and white, stippling damage on fruit cluster leaves, these are white apple leafhoppers. White apple leafhoppers have two generations. These adults will lay eggs, which won’t hatch until early August. Rose leafhoppers will stay active in apple trees from late June through September. So nymphs present now will develop into adults and these adults will lay eggs, which quickly hatch. Both species can be present as adults in September, which is when they are really a nuisance to pickers. Leafhoppers can not be controlled with Imidan. To control leafhoppers use low rates of Sevin, Provado or Thionex. The New England Pest Management Guide says use .25-.75 pt Sevin XLR per 100 gallons. Assail, Calypso or Avaunt applied to control apple maggot will also control leafhoppers.

I did find one orchard with high numbers of European red mites. The threshold for red mites in July is 5 mites per leaf. It’s much better for your crop to control mite problems before foliage turns a bronze color (bronzing). This time of year the choice of miticides is large. Refer to the pest management guide page 156 and use a miticide that you haven’t used for at least one year.

I’m sure you’ve noticed Japanese beetles are out! Japanese beetles are especially pesky on Honeycrisp and peaches and other stone fruit. They usually don’t bother other apple varieties too badly. If you need to spray, use Assail, Calypso or Sevin.

The Massachusetts fruit growers summer meeting is Monday, July 18. Look at Parlee Farm’s website. It sounds like a great farm to visit. http://parleefarms.com/
Here is information from Jon Clements:
Annual Summer Meeting
Massachusetts Fruit Growers Association, Inc. in cooperation with University of Massachusetts Amherst Extension

Monday, July 18, 2011
Parlee Farms (parleefarms.com)
95 Farwell Rd., Tyngsboro, MA

10:00 AM Orchard Tour of Parlee Farms including apple, cherry,
blueberry and ‘Advanced’ and ‘Extension Team’ IPM

12:00 PM Catered LUNCH by Bianco Catering (www.biancocatering.com)

1:00 PM Welcome, introductions, and brief remarks Mark Parlee
President, Massachusetts Fruit Growers’ Association

1:15 PM ‘Squirt and Pray: Growth Regulator Use in Tree Fruit’ Win
Cowgill, Rutgers Cooperative Extension

1:45 PM ‘Bad &Ugly: Experience with Brown Marmorated Stink Bug in New
Jersey’? Win Cowgill, Rutgers Cooperative Extension

2:15 PM ‘Pre-harvest Drop Control of Apple: What to Look For This
Year’ Duane Greene, UMass Amherst

2:30 PM Pesticide re-certification credits and adjourn

Registration for this meeting will be $50 per person ($40 per person
for full members of the Massachusetts or Rhode Island Fruit Growers’
Associations). Includes the tour, educational program, pesticide
recertification credits, and catered hot LUNCH.

?To ensure availability of meal, please pre-register by returning this
form (attached), with a check made out to M.F.G.A. for $50 ($40
MFGA/RIFGA) per person. Or go to http://www.massfruitgrowers.org and
pay by credit card.
We must receive pre-registrations by Monday, July 11
Heather