Net Spot of Cucumbers. C. H. Blazquez, Associate Professor (Plant Pathologist), University of Florida, IFAS, Agricultural Research and Education Center, Lake Alfred 33850. Plant Dis. 67:534-536. Accepted for publication 1 November 1982. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-534.

A cucumber (Cucumis sativus) leaf disease caused by Leandria momordica not previously reported in Florida is described. The disease was first attributed to Stemphylium cucurbitacearum when it was observed in Ohio and Indiana in cucumber fields in 1915 and 1916. In Florida, the pathogen caused severe defoliation of cucumber plants in the fields during the 1974–1975 season, producing lesions that appeared first as white leaf spots with reddish margins on both surfaces of the leaf. In early stages, lesions have an angular appearance and later enlarge into round indistinct lesions. The veins and veinlets in the white center of the lesion acquire a brownish red discoloration with a ringlike form, giving the lesion a netlike appearance. The net-spot disease was first observed on cucumber leaves and later, on leaves of balsam pear (Momordica charantia), a wild cucurbit vine.