April 17, 2009
Hello Fruit Growers,
I found hatched winter moth caterpillars in Bristol and Warwick yesterday, April 16. Perhaps a few had hatched a day or two earlier, but no sooner. Apple orchards and blueberry farms in known winter moth infestation areas should apply an insecticide immediately. Warmer weather today and tomorrow could allow a large percentage of eggs to hatch. Once the larvae have entered buds, the larvae are protected from insecticide sprays until the buds open. The larvae are relatively easy to kill and can be controlled with most insecticides.

Even though we find winter moths all over Rhode Island, they have reached outbreak levels only along coastal areas of RI and MA. I know there are pockets of large populations in East Greenwich, Warwick, Bristol, and Portsmouth. In MA there are large populations in Cape Cod, Seekonk, Somerset, and probably several other areas.

Hopefully everyone’s apple trees will be protected with a fungicide before the next rainy period. We have to assume we have a large percent of mature ascospores, as they do in New York. These ascospores will be discharged during rain and can cause apple scab infections as soon as green tissue is showing.

It is probably too late to apply copper now unless it is to very young trees that haven’t budded out yet. Spraying copper to young trees is an excellent practice to protect young trees from fire blight.

These freezing temperatures have made it impossible to apply oil safely. The next few days look to be free of frost, so now would be a good time to apply your first oil application. Oil applied before tight cluster can be applied at 2 gal/100. Do not concentrate the oil – add only 2 gallons of oil to the finished product. Once we are at pink, reduce oil to 1 gallon per 100. Oil applied at pink is more effective at controlling European red mites, but it isn’t always possible to apply oil when you want! It is better to apply oil when the opportunity arises. Coverage is so important – apply as much water as possible to get the best cover possible.

I hope many of you will make it to the twilight meeting on Thursday April 23 at Outlook Farm in Natick, MA. The meeting starts at 5:30, costs $20 per farm and provides one hour of pesticide recertification credit. If you have more questions, call me at 874-2967.

Thanks for calling and the next message will be recorded Thursday, April 23rd