Host Range of Alternaria alternata f. sp. cucurbitae Causing Leaf Spot of Cucumber

Sixty-two cultivated and weed species in 16 botanical families were artificially inoculated or exposed to natural infection in greenhouse experiments. Of these, 27 species of Cucurbitaceae were found to be susceptible to a forma specialis of Alternaria alternata that attacks cucumber. To differentiate this A. alternata pathotype from others, it is proposed that it be designated Alternaria alternata f. sp. cucurbitae