On stems and fruits the water-soaked areas may also become covered with crusty white exudate. As fruits mature, brown lesions form in the flesh and continue as streaks down to the seed. Is infrequent and is caused by the seed-borne bacterium Pseudomonas syringae pv. Warm, wet weather may cause stem and leaf spots in mid-season. Anthracnose Anthracnose is common and is caused by the seed-borne fungus Colletotrichum orbiculare.
Most cucurbits are susceptible.
Most commercial cucumber varieties have some resistance. Depending on weather, leaf and fruit spotting may occur on young plants, especially in late plantings. Infects young tissue and begins on a leaf vein as small yellowish circular spots. Very young leaves may be distorted. They remain circular and the center frequently drops out leaving a shot-hole appearance.