July 2, 2008
Summer meeting July 17 at Belchertown! http://www.massfruitgrowers.org/2008/summermeeting.html
There is not too much to report this week. Pests to watch out for include mites, leafhoppers and aphids. European red mites and two spotted mites are building. The threshold for July is 5 mites per leaf. Miticide choices include Nexter, Acramite, Kanemite and Zeal.
Leafhoppers found in orchards now may be white apple leafhoppers, rose leafhoppers or potato leafhoppers. If the oldest foliage has white stippling, the leafhopper damage is most likely white apple leafhopper. If you are finding leafhoppers now with little or no damage on the oldest foliage, then you probably have rose leafhopper that has migrated into the orchard. Leafhoppers are primarily just a nuisance pest, so unless they are really bothersome, you can often ignore them. The rose leafhopper will continue to migrate into the orchard and the white apple leafhopper will disappear until the middle of August, so I guess the best thing to do is ignore the leafhoppers for now and then spray in August if necessary.
Potato leafhoppers feed on the outer most foliage – on the terminals. Potato leafhoppers cause the terminal leaves to cup and turn yellow. Potato leafhopper feeding also stunts the terminal growth. This is not a problem unless the trees are young and you want a lot of terminal growth. So, if your trees are young, control potato leafhopper with Imidan. White apple leafhopper and rose leafhopper are resistant to Imidan. To control these two leafhoppers, spray with Thiodan, Provado or Sevin.
Surprisingly I have found very few apple aphids this year – and in all orchards where I found aphids there have been plenty of predators.
I have not set up any apple maggot traps this year, but one of your fellow growers did. I checked these traps on Wednesday and there were no apple maggot flies. I don’t think we need to spray for apple maggot fly until the middle of July.
Last Tuesday, June 24, several orchards suffered hail damage. There was more hail Wednesday, July 2. Ugh!
Next message will be recorded Tuesday, July 8. 949-1456.