It’s time to consider treating peach trees
It's still a little early to be thinking of picking ripe peaches off trees, but it isn't too early to consider control of peach leaf curl, especially considering the relatively warm weather we have had. Leaf curl is a springtime disease of peaches and nectarines that can result in severe defoliation, weakened trees and reduced fruit quality, set and yield.
This last year we had a lot of calls about Peach Leaf Curl. The disease is most noticeable on the peach leaves about a month after full bloom. Developing leaves become distorted and have a reddish-green color. They will eventually drop off the tree. Infection is limited to early spring; it does not progress through the summer. Nevertheless, it does cause early defoliation which may weaken the tree and reduce the size and quality of the fruit. The fungus that causes leaf curl survives the winter in bark crevices and bud scales. In early spring the fungus infects the leaf buds as they swell.
Leaf curl can easily be controlled by a single fungicide application in early spring before buds begin to swell. If you did not apply a fungicide application last fall, think about getting a spray on early this spring. Be sure to get the application on before the buds begin to swell.
Several fungicides, including copper hydroxide, Bordeaux mixture, liquid HIM sulfur, ferbam (Carbarnate), ziram, and chlorothalonil (Bravo and others) are very effective in controlling leaf curl. Make sure to thoroughly cover the bark and trunk of the trees during application.
A similar disease called plum pocket may develop on American and sand hill plums. It results in the formation of distorted, light green bladder-shaped fruit. If you are growing wild plum species for jellies or jams, I suggest you also make a dormant fungicide application to these trees as well. Asian and European plums are not susceptible to the local strain of plum pocket and do not require fungicide treatment.