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Phomopsis twig blight on a peach tree. (Photo by Edward Sikora, Plant Pathologist, ACES)

A common sight in peach orchards this spring is Phomopsis twig blight. Wet springs favor the development of this fungal disease. Dead twigs appear as brown flags in the tree suggesting the disease is at work.

Twig lesions are often visible early in the spring. Lesions are centered on an infected bud or node of one-year-old shoots. The disease can be confused with blossom blight, though blossom blight lesions are centered on a blossom.

Phomopsis lesions are usually tan to brown in color.  The cankers are often sunken and have a zonate pattern. Lesions girdle the stem causing the blighted shoots. A small amount of gum may exude at the infection site.

Susceptibility amongst peach cultivars varies, but few are resistant to the pathogen. Fungicides are not effective for this disease. Infected twig tissue should be pruned out to reduce carryover of the pathogen into fall.

 

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