We are past apple blossom time here on the island; past plum, cherry, pear and peach blossoms too, and the trees have all set fruit. With the warmer nights and continued good rainfall comes new growth and rapid development, and the first signs of insect damage.
There are many good sites on the web for information on fruit tree pests. Every variety, no matter how modern and resistant, has its own weakness manifested in an insect, blight, rust, virus, spoor or mildew. Full time orchardists have a repertoire of traps and sprays in defense of (nearly) perfect product and I admire that. I should know more about traps, for instance, and plan to do the research for 2011 – I like passive defense. Unfortunately, I don’t have the time or opportunity to be a specialist. I have to be at work five days a week, far from my trees, and often miss the first signs of mildew, or leaf curl, only to come home one day and the top third of the Clapp pear’s foliage is deformed by mites. It can be discouraging.
Then I discovered Surround CP (cue the music for the dishwashing detergent commercial). I use it on all the fruit trees plus roses and vegetable crops. Although it is promoted as an insecticide I find it also inhibits the spread of rust and mildew. From the Fedco website:
Forms a particle film which coats the surface of leaves and fruits, creating a barrier which acts as a broad-spectrum crop protectant, reducing damage from various insects, mites and disease-carrying pests. Recommended for controlling European apple sawfly, plum curculio, Japanese beetles, leafhoppers, CPB, thrips and other maleficial insects on fruit crops and field crops, effective against cucumber beetles on cucurbits. 95% kaolin clay, Surround’s layer of white particles creates an unfamiliar environment for the attacking insects, prevents them from recognizing their target, and, if they land, the particles rub off on them causing irritation and excessive grooming. The white surface also reflects sunlight, preventing sunburn and heat damage.
Notice that this product is 95% clay (most of the other material is food grade wax) and about $40.00 for 25 pounds. I have 20 trees and often grow food crops around and beneath the foliage so an inert material that is inexpensive (compared to most pesticides) is a good thing. I begin spraying just after petal fall and build up a good coating with two or three applications over a two week period and then one or two more over the course of the season depending on rainfall amounts. Surround does not wash off readily but it will strip off faster over a rainy summer. It has a helpful secondary effect of turning the foliage ghostly white after a fresh application making it easy to see where you’ve been and areas you’ve missed!
Which begs the question – is it visible on everything else? Yes, but it comes off the plastic chair and marble paving stones much faster than it does from foliage!