Mycosphaerella melonis, is an ascomycete fungal plant pathogen that causes gummy stem blight on the family Cucurbitaceae (the family of gourds and melons), which includes cantaloupe, cucumber, muskmelon and watermelon plants.

Eventually all infected vines will become necrotic and occasionally the plant dies due to wilting and defoliation.

[6] Some regions report the presence of small pseudothecia as black specks inside the cankers.

[7] Gummy stem blight can be confused with anthracnose, which is caused by a fungal plant pathogen called Colletotrichum lagenarium.

[3] Ideal ascospore dispersal occurs after nightly rainfall and dew periods.

[2] D. bryoniae can also be found in temperate regions, especially where winter squash and pumpkins are grown.

[9] The pathogen requires an entry site on the plant in order to infect so areas that also experience issues with pests are at higher risk.

In vitro, D. bryoniae does not form pycnidia without UV-light but if cultured in the presence of UV light and darkness, conidia/pycnidiospores produce mycelium rapidly.

[10] The standard management practice for D. bryoniae is to use pesticide treated/pathogen-free seeds and to rotate crops on a 2-year cycle to reduce inoculum prevalence.

[2] Proper irrigation and ventilation can be utilized to prevent water buildup on leaves.

[12] Currently cultural practices and fungicides work well in greenhouses and in the field only if D. bryoniae is diagnosed in the early stages of disease development.

[4] Molecular tools such as polymerase chain reaction (PCR), PCR-enzyme-linked immunosorbent assay and magnetic-capture hybridization multiplex real-time PCR are used to diagnose D. bryoniae in the early stages disease development, although these molecular tools may only be useful for specific isolates of D.