Root and Stem Rot of Cucumber Caused by Fusarium oxysporum f. sp. radicis-cucumerinum f. sp. nov. Demetrios J. Vakalounakis, National Agricultural Research Foundation, Plant Protection Institute, P.O. Box 1802, Heraklio, Crete, Greece. Plant Dis 80:313. Accepted for publication 15 November 1995. Copyright 1996 The American Phytopathological Society. DOI: 10.1094/PD-80-0313.

Root and stem rot of cucumber (Cucumis sativus) caused by a new Fusarium oxysporum forma specialis is reported for the first time. Of 18 cultivated species from six different botanical families that were artificially inoculated, two species of Cucurbitaceae—melon (C. melo) and sponge gourd (Luffa aegyptiaca)—showed root and stem rot similar to that caused by isolates of F. oxysporum that attack cucumber. Optimum temperature for disease development was close to 17°C. Disease symptoms and pathogenicity tests confirm that a new forma specialis of F. oxysporum is the incitant of the disease. The author proposes to name this forma specialis as F. oxysporum f. sp. radicis-cucumerinum f. sp. nov