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Pecan Tree Diseases

Native to the central and eastern parts of North America, the pecan tree is a deciduous tree that belongs to the same family as hickory and walnut trees. Though the pecan tree is a hardy one that is resilient to the adverse effects of extreme weather, the tree is a susceptible to certain diseases that can cause poor harvests and even death of the tree.

Pecan Scab

Pecan scab is a fungal disease that attacks the pecan tree with fungal material called stroma. In the right temperatures, stroma is infested with fungal spores that, in turn, spread over the tree, causing infection. Winds and rain pass the fungal spores through the air and infect surrounding trees. Pecan scab initially attacks leaves, leaving round, olive-green spots that eventually turn black. If left untreated, the disease spreads and infects the pecan nut, causing early nut drop, stick-tights and prevention of nut growth. Pecan scab can be prevented with a fungicide spray program during the early season. Additional treatments may be required during the growing season. Fungicides and they must be chosen according to your selected pecan variety, surrounding plants and animals, and harvesting time. Speak with a nursery or horticultural specialist for selection assistance.

Cotton Root Rot

Cotton root rot is a soil-borne fungal disease that causes the wilt and death of pecan trees, as well as other trees and shrubs. The wilting and death of the tree is often very rapid, and usually occurs during the summer and early fall when temperatures are quit warm. Cotton root rot attacks the tree's roots, causing browning and the appearance of white spores on the roots. As the disease spreads, it kills the roots, eliminating the pathway of nutrients and moisture to the tree. There is no way to test soil for cotton root rot fungus. Because the disease appears in microscopic variations, an experienced professional must be called in to identify the appearance of the disease. If a pecan tree dies of this disease, avoid planting new, susceptible trees and plants in the area.

Bunch Disease

Bunch disease is a mycoplasma organism that attacks the tree’s foliage and buds. The disease causes slender, willow-like shoots to grow on the pecan tree in bushy patterns. Bunch disease develops during the winter and begins to appear in late to early summer. Infected leaves usually develop much quicker than healthy ones. There is no control or prevention for bunch disease. Infected areas of the tree should be immediately pruned out. Trees that become severely infected should be removed immediately and destroyed. Avoid planting new trees or plants in the area, as the disease can be passed on through the soil.

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