WSU Tree Fruit Research & Extension Center

Tree Fruit Market Diseases

Saturday, February 16, 2019

WSU-TFREC/Postharvest Information Network/Tree Fruit Market Diseases/pearphyto

Phytophihora cactorum (Leb. & Cohn) Schroet.

Phytophthora rot of pears is a minor disease. On the market it occasionally occurs in low-grade fruits.

Infection occurs on windfalls or on low-hanging fruits that touch the ground or are splattered with infested soil. The rot develops as a firm, brown to black spot. Discoloration of diseased flesh varies with fruit variety, ranging from clear and watersoaked in Clairgeau, brown with watersoaked margin in Anjou (top photo) to brown in Kieffer. In most varieties the flesh is light brown, with the vascular bundles and strands more deeply discolored. Infections progress slowly in cold storage but develop fairly rapidly at ripening temperatures (see Apples, Phytophthora Rot).

Phytophthora rot  on pear
Phytophthora rot on pear

Phytophthora rot on pear
Phytophthora rot on pear

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