Leaf Curl

Wherever peaches and nectarines go, Peach Leaf Curl seems to follow. Peach leaf Curl, caused by the fungus Taphrina deformans, is a disease that causes the thickened, distorted leaves so common on peach and nectarine trees in spring.

Fungal spores over-winter in the bark crevices and on the buds. As spring approaches and the buds start to swell the spores on the leaf buds start to germinate and infect the immature leaves. Infected leaves eventually turn brown and drop. The disease generally won’t kill a mature tree but it will reduce your crop significantly and it is very unsightly.

There is no treatment post-infection. So how do we control this disease?

The most common and effective way is to use a protectant fungicide (they are mostly copper or sulfur-based, easily available and most are allowed in organic systems). The two critical aspects to controlling this disease are timing and coverage. Inadequacy in either one of these components will lead to incomplete control. In areas where Peach Leaf Curl is a big problem, two sprays are recommended. The first in autumn at 85% leaf fall and the second in late winter after the buds start to swell but before bud-break.If Peach Leaf Curl is only a minor problem in your area, then the autumn spray may be omitted. Ensure the tree gets thoroughly sprayed as any spores not contacted by the fungicide may go on to infect leaves in early spring.