Root Rot of Melon Caused by Nodulisporium melonis in Japan

Collapse of melon with brown-rotted and corky roots occurred in Shizuoka Prefecture, Japan in 1975. This disease was named root rot of melon by Sato et al. in 1976. Nodulisporium melonis Watanabe & Sato (1995) was predominantly isolated from rotted root tissues together with five other fungus genera. In inoculation tests, N. melonis was pathogenic to melon seedlings, but other fungal isolates were not pathogenic. Melon and five other cucurbitaceous crops tested were diseased by growing in the artificially infested soil with N. melonis, but healthy in uninfested soils. This fungus was not pathogenic to wax gourd, and other 18 crops inoculated.