Gummy stem blight

Gummy Stem Blight affects many cucurbits including watermelon, cantaloupe, cucumber, pumpkin, and some squash. Some symptoms are common of all Gummy Stem Blight infections while other symptoms can vary depending on the specific host the pathogen has infected. Hosts can become infected at any time in their life. When the pathogen is present in a young seedling, the cotyledons will sprout appearing dark and drenched. When older plants become infected, their leaves may appear water soaked and begin to develop dark tan lesions. The leaves begin to turn brown at the margins and necrosis progresses towards the base of the leaf.

Cankers, which may or may not have black spots, may appear in the epidermal cortical tissue and on the stems of infected plants. Black spots, if visible, are pycnidia and/or perithecia. Black rot is a common symptom on the fruit of Gummy Stem Blight infected cucurbits. Lesions formed on the fruit; start as water soaked spots that expand and exude gummy ooze. As the spots grow they develop fruiting bodies which turn the spots black. Fruit can also rot internally, with the only symptoms being shriveling and discoloration of centrally located tissue. Fruit rot can occur while in the field or after fruit has been harvested.