If you have ever seen emerging peach leaves that are puckered,
swollen, distorted and reddish-green color, you have seen peach leaf
curl. Uncontrolled, this disease can severely weaken trees due to
untimely leaf drop when leaves unfurl in the spring. Fortunately, peach
leaf curl is not that difficult to control if the spray is applied early
enough. However, by the time you see symptoms, it is much too late. As a
matter of fact, fungicides are ineffective if applied after buds begin
to swell. Don’t spray when temperatures are below 40 degrees or will
fall below freezing before the spray dries. Usually we can wait until
March to spray but an extended warm period in February that encourages
early bud swell may require spraying in late February.
Though peach leaf curl can be controlled by a single fungicide
application either in the fall after leaf drop, it is more commonly
controlled in the spring. There are several fungicides labeled for this
disease including Bordeaux, liquid lime sulfur, and chlorothalonil
(Ortho Garden Disease Control, Fertilome Broad Spectrum Fungicide,
GardenTech Fungicide Disease Control, Gordon’s Multipurpose Fungicide,
and Daconil). Thoroughly cover the entire tree during application. Note
that it is much easier to achieve good spray coverage if the tree is
pruned before spraying. (Ward Upham)
