I have 2 peach trees in my back yard, and I have used 2 fungicides (Captan and wettable sulfur) to prevent “scurge,” a black scurge which invovlved the skin of the peaches. Is there anything “organic” that you have to prevent the “scurge”? Thank you very much, Bob
Answer: Bob, thank you for your inquiry about the problem with your peach trees. Since I am not personally familiar with the diseases of peach trees, I did a little research without finding anything labeled as “black scurge.” I’m going to assume you’re dealing with the common problems of peach trees, Leaf Curl or Brown Rot, both of which affect the fruit as well as the leaf.
Leaf Curl is a common fungal infection that occurs in the spring on peach and nectarine trees. Symptoms are leaves becoming distorted in the early spring, turning to a purplish color and then becoming gray and powder-covered, then they drop off. The fruit will have reddish color with brown soft spots turning to rot.
The spore overwinters on the bark and bud and will be worse with cool, wet springs after a mild winter. To control the spread of it you need to spray with a fungicide, making sure to completely cover the tree, early in the spring before the leaves appear. Be sure to remove and destroy any affected leaves or fruit at the end of the season to help control the spread of the disease.
Brown Rot is also a fungal condition that affects the stone or seed of the fruit, causing the fruit to be covered with brown soft circles, before it shrivels and develops a fuzzy coating of the fungus. The fungus overwinters on old mummified fruit that is left on the tree over the winter. Make sure to remove and destroy any fruit left.
The organic method of control would be to remove by hand any fruit that begins to show signs during the growing season, not allowing any rotting fruit to remain on or near the tree. Harvest fruits as soon as they turn to all yellow and avoid bruising. Allow them to ripen off the tree. In the late winter or early spring, thin the tree to provide more air circulation, which is essential to reduce wetness that encourages brown rot.
If this does not sound like your problems, please send more details or contact your county Extension office with samples so they can assist in the proper diagnosis.