Orchard management week of June 15

by Terence Bradshaw

Apparently I need to go away for a week for us to get any significant moisture, and boy did we get it. The good news is that apple scab ascospores should be all released now, so if you maintained good protection during the primary infection season, You should be done by now. If you have any question about fungicide coverage, be sure to carefully inspect the orchard for lesions that could cause secondary infections during the summer. Lesions from the May 28 infection period should be visible by now. The bad news is that no matter what was last sprayed, there is likely zero fungicide residue in orchards unless they were treated recently. Sooty blotch and flyspeck (SBFS)are the main diseases of note now, and will require treatment to manage them. Dr. David Rosenberger wrote a good summary article on SBFS management in the June 23, 2014 issue of Scaffolds. Fire blight infections should be visible in orchards by now. Please let me know if you are seeing this disease in your orchard. At this point, if you have it, the primary management strategy is to cut it out.
Codling moth eggs are hatching now, and insecticides targeted at larvae should be applied as soon as possible.
Results from apple thinner applications should be evident by now, and I am hearing from many growers that there is excessive fruit in their orchards. I do not have enough experience with ‘rescue thinning’ at this point to recommend it, your best option to reduce crop load may be to hand thin. Hand thinning at this point will have little effect on return bloom. For growers who are concerned about poor blossom bud development for next year’s crop, especially on biennial-tending cultivars (Honeycrisp especially), application of a return bloom enhancer such as Fruitone or Ethrel may be considered. Specific materials, rates, and timings are found in Chapter 11 of the New England Tree Fruit Management Guide.