Tuesday, August 12, 2008

Observations from Belchertown

Some late-summer observations at the UMass Cold Spring Orchard in Belchertown:
  • Flyspeck on Zestar! I expect summer diseases -- sooty blotch and flyspeck, fruit rots, etc. -- to be problematic this year with the wet weather we have had. Continuous fungicide coverage has been necessary to prevent these summer diseases.
  • Frog-eye leafspot -- a classic symptom of black rot fungus, another disease that loves a wet summer. Mostly a non-issue unless it infects fruit as most season-long fungicide programs keep it at bay. Cultivar susceptibility seems to vary widely, this on Zestar! But Honeycrisp (see below) and Cortland seem to be particularly susceptible. (Among others I suppose.)
  • Cherry leaf spot -- this one snuck up on me. Here, in a cherry orchard planted in 2001, I have not had much of a problem yet. But I suspect inoculum build-up and a wet summer have combined to cause a problem. Should I have maintained fungicide sprays after harvest? Of course. Did I? Noooo...not a good thing as it can lead to premature defolation which can pre-dispose trees to winter injury.
  • Turkeys (feathered types) love Honeycrisp -- need I say more? But I am not happy, they have managed to pretty well destroy the fruit at (their) 'peck-level,' these on 3rd leaf Honeycrisp in a tall-spindle planting with relatively low branches. I figure each fruit is worth about a half-dollar at retail. That makes them a serious pest in my book, far worse than the fruit I have lost to plum curculio or apple maggot. Arghh...
  • More black rot on Honeycrisp? -- I am wondering if this is black rot moving in where the infamous Honeycrisp 'Yellows' has presumably made the foliar tissue susceptible to infection? I don't know, but I don't like it. Honeycrisp does maintain 'mummies' which I think continue to Honeycrisp's susceptibility to black rot. (Also see my web gallery of Honeycrisp disorders.) Honeycrisp is the apple we 'love to hate.'
  • On a brighter note -- I am a bit enamored by the appearance of these 'Snappy Mac' from Stark Brothers Nursery. Supposedly a limb sport of Rogers McIntosh from the lower Champlain Valley of New York, they color much earlier and better than Rogers. Who says we can't grow good colored Macs in Massachusetts?
  • OBLR damage -- a little oblique-banded leafroller damage to Honeycrisp, this apple was a 'double,' which OBLR seem to prefer. An emerging insect pest. Many, and rather complicated, control options.
  • Active scab in August? -- yup, more wet-weather woes. These trees did not have a real strong fungicide program. Fruit is not particularly susceptible when it starts to color, but I would still include Captan and/or Pristine in a summer fungicide program to slow or halt it's spread. (Three weeks of dry weather would help too.)
Are we having fun yet?