In this section:
Leaf Curl
Cause
Fungus Taphrina deformans
Affected
Affects mainly peaches and nectarines, and occasionally apricots.
Symptoms
Infected leaves become thickened, curled and grossly deformed. As the disease progresses, the leaf gradually changes colour to a lighter green that often has red to purple tints. The leaf eventually turns brown, withers and drops prematurely. In most seasons healthy leaves develop later in the season.
Infected shoots are stunted and often killed. New shoots may then sprout from below these dead twigs.
Infected fruit are rare, but they develop blister-like areas that are raised and distorted with red to purple tints similar to those found on the leaves.
Conditions favouring
Young trees are most susceptible, but all can be affected. The leaf curl fungus survives in the plant in infected leaf buds and invades young leaves and shoots during moist weather in early spring.
Control
Leaf curl can normally be prevented by a single spray of copper oxychloride at the early budswell stage. The timing is critical. Once the buds burst, the spray is less effective. In very wet seasons and when disease has been severe, two or even three sprays at seven day intervals will be needed.
Several other chemicals are registered for its control.
