The peach tree is relatively short with slender and and supple branches. This usually occurs in the spring. Generally, initiation of leaf galls occurs around “bud break” or as new leaves begins to unfold in the spring. Affected trees ordinarily show little injury, although foliage of young trees is sometimes completely deformed. Infected leaves pucker, thicken, curl and often turn red. We have illustrated 12 of the most curious and colourful galls to look for. Galls on trees are caused by insects laying eggs inside or feeding on the branches of leaves of trees and other plants. Peach tree diseases can be caused by fungus, bacteria or virus. Crown gall is readily recognized by wartlike swellings, or galls, on tree roots and crown. This tiny wasp gall maker causes trees to produce large numbers of woody galls up to 2 inches in diameter around the stems of pin and willow oak trees. After a couple of years of reasonably good crops, the peaches become infested with myriad diseases and insect pests. If not controlled, it can cause serious damage to orchard trees. Forms galls which disrupt normal water and nutrient uptake Results in altered host physiology (reduced root and shoot growth, leaf chlorosis, low fruit yield, poor fruit quality, and tree decline or death) Can result in crown gall as well . Jay W. Pscheidt, 2016. The shape of the gall is determined by the chemicals used by each species of gall-maker. The manzanita leafgall aphid feeds on the leaves of kinnikinnick and other manzanita species (Arctostaphylos spp. Peach leaf curl, also known as curly leaf, curly blight or leaf blister, has been recognized as a common disease since the early 1800s. In my experience, it is easy to grow a peach tree in Atlanta but very difficult to regularly harvest any fruit. Jay W. Pscheidt, 2007. Figure 6. Because this fungal infection causes tumorous swellings on leaves, it is often referred to as a gall. peach leaf curl. pear leaf blister mites fuchsia gall mite spruce spider mite. The distorted, reddened foliage that it causes is easily seen in spring. Localized die-back is often associated with high infestation levels. Otherwise, they may not be able to stimulate the plant to produce the tissue which forms the gall. How to Identify Crown Gall After a plant has been infected, the first signs of a gall may appear within two to four weeks during the growing season: swollen tissue that looks like warts, or light-colored, round galls of about 1/10 inch. Leaf galls may be folded, partially podded, or the entire leaf may form a pod (Thompson, et al., 1998). The peach leaf curl fungus, Taphrina deformans, can infect peach leaves, flowers, and fruit. On ornamental trees this condition can be unsightly. Found on the twigs of spruce trees, often Norway spruce. Unsightly peach leaf curl caused by the parasitic fungus Taphrina deformans, a member of the fungal Division Eumycota, class Ascomycetes. Crown gall Agrobacterium tumefaciens: Phony disease = phony peach Xylella fastidiosa: Fungal diseases Fungal diseases; Alternaria rot Alternaria alternata Alternaria spp. Once the fungus is in full swing there’s no way to stop it. I don’t want to use any product harmful to the insects and biodiversity in my fruit and vegie growing. Your best course of action is to treat the tree with fungicide before the next growing season. Peach leaf curl is one of the most serious and common peach tree diseases. OSU Extension Plant Pathology Slide Collection, 1976. Meloidogyne spp. Peach leaf curl, caused by T. deformans, affects peaches, nectarines, and almonds and can cause agricultural losses. Gall midge maggots drop from the galls to pupate in the soil in a thin, silken cocoon.