The presence of black spots on the leaves of a pear tree indicates a problem. A number of issues can cause a pear to develop black spots, and a weak, unhealthy pear tree is less likely to put out a healthy crop of fruit. Treat the pear tree to restore its health.
Fabraea leaf spot is a fungal disease that causes purple or black spots to appear on the leaves of pear trees. These are fungal spore spots that spread the disease throughout the tree. As the fungus matures, the black spot spreads to the entire leaf, eventually causing defoliation of the pear tree, which leads to stunted growth, inedible fruit and a weak season for the tree. Leaf spot is a serious problem for pear trees.
Treating Fabraea Leaf Spot
Treat fabraea leaf spot with fungicides and cultural controls. Spray the pear tree with a fungicide in early and middle summer to control the presence of fungal spores on the tree. Use fungicides according to the manufacturer directions to keep the pear tree healthy. Remove any fallen leaves from the area around the pear tree to prevent them from hosting the fungal spores and causing further infections of the pear tree.
Fire blight is a bacterial disease that affects pear trees and other ornamental or fruit trees, especially during warm, wet weather. Fire blight visibly affects leaves. Black spots followed by eventual leaf loss and dieback of the tree indicate fire blight. Streptomycin and terramycin treatments exist for fire blight, and cultural controls help slow the spread of the disease. Keep the ground free of standing water, prune the pear tree and remove affected leaves.
Pear Tree Care
Treat and prevent black spots on the leaves of a pear tree through basic gardening care. Prune the pear tree in early spring to remove dead or weak branches that can become hosts for fungal and bacterial diseases. Remove any branches affected by dieback if leaves do exhibit black spots to prevent the disease from spreading. Pick up fallen leaves and fruit so they don't attract further fungal problems to the pear tree.