Leaf diseases of fruit trees are very common and can either be from fungal or bacterial infections or are a symptom of a nutrient deficiency or surplus. Peach leaf curl is a common disease also known as peach blight, curly leaf, curly blight and leaf blister. The disease causes distortion of the leaves and cankers. It occasionally affects the new twig growth and buds. Leaves are thicker than normal, speckled or blushed red, lighter in colour and eventually become grey and powdery as the fungus matures. Early signs appear in spring and good management and control must be timed to occur prior to symptom eruption.
Spray the tree in fall to prevent the fungus from ruining the foliage of the peach tree. It is important to spray before leaf bud. Use a preparation of copper or lime-sulphur and mix it according to the package directions for dilution. Load the mix into the hose end sprayer and apply to all surfaces of the tree.
Minimise stress when the tree already has the disease. Apply extra fertiliser in an easy to use manner such as manure. Spread 2 inches of manure around the drip line of the tree but within 2 inches of the trunk. This slowly adds extra nutrients to the soil.
Lay a drip line for slow irrigation of the peach tree. Extra water helps minimise the loss of vigour and strain the tree is under. The drip line delivers a slow, steady supply of moisture that is easy for the tree to uptake before evaporation or runoff can steal the water.
Remove half the fruit in severely affected trees. The tree is not be able to gather enough solar energy to feed the fruit when the leaves are diseased. To prevent the loss of all the crop, reduce it so there is less fruit to support.
Clean up dropped and infected leaves. This keeps the fungus from spreading as the tree grows new leaves. In warm winter climates, the fungus could overwinter in the debris under the peach trees and cause the infection to reactivate even more quickly. Rake up and destroy dead plant material.