Hi Fruit Growers,
Wet weather that started either Sunday or Monday, depending on your location, certainly triggered a primary apple scab infection period. If your trees were not well protected with a fungicide going into this rainy period, apply a systemic fungicide – one with ‘kickback’ – as soon as possible. See the attached chart from Dan Cooley from UMass for how many hours fungicides kickback.
There may be a few remaining overwintering apple scab spores, but certainly the bulk of primary infection season is now over. You always want to keep some fungicide on your trees so reapply a fungicide soon.
Many areas of Rhode Island received more than two inches of rain in the last couple of days. If your trees received more than two inches of rain it is probably a good idea to reapply an insecticide to protect against any plum curculio that may still migrate into orchards.
Over the next week I hope to visit many orchards looking for fire blight strikes. Hopefully I won’t find any!