WSU Tree Fruit Research & Extension Center

Tree Fruit Market Diseases

Saturday, September 23, 2017

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



Phialophora malorum (Kidd & Beaum.) McColloch

Side rot occurs on pears grown in the Pacific Northwest. The same organism causes a rot on apples, but on pears the oval, dark-brown to black spots seldom exceed 1 inch in diameter and never have light centers (top photo). The skin covering the spots is tender and will break with a pop under slight pressure. The rotted tissues are wet and slimy under the intact skin, but are dry and spongy if the skin has been broken. The decayed tissues separate readily from the healthy tissues, leaving a saucer-shaped cavity usually less than 1/4 inch deep (see Apples, Side Rot).

Side rot appears to be controlled by sprays used to control bull's-eye rot. Consult your State agricultural extension service or experiment station for spray schedules.

Pear side rot
Pear side rot

Pear side rot
Pear side rot

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