The symptoms of gummy stem blight first appear as grayish green circular spots between the veins in the lobes of leaves. Spots turn a dark brown to black with age. Spread of the disease begins in the center of the plant and moves outward. Lesions develop first on the vines at the nodes and elongate into water-soaked streaks that become pale brown to gray with time. Stem tissue often cracks and a characteristic gummy ooze is exuded from the wound.
Infected vines die eventually, and entire plants die occasionally.
The disease, unlike anthracnose, does not attack fruit. Persistence And Transmission. The fungus overwinters in old cucurbit vines, in seed, or in weeds in the cucurbit family. Gummy stem blight can appear anytime during the season, but most damage occurs late in the season after the fruit is set. Plant in well-drained soil free from surface runoff water.