Citrullus lanatus, a new host of Bipolaris spicifera in Morocco

Abstract

Bipolaris spicifera was isolated from necrotic leaves of field-grown watermelon plants from the Taroudant area of southern Morocco. The pathogenicity of this fungus was tested on the leaves of two cultivars of watermelon (Peacock 124 and Mabrouka) widely cultivated in this area. The infection coefficients (incidence × severity index) of the cv. Mabrouka and Peacock 124 after inoculation with B. spicifera conidial suspensions were 53.3 and 22.4 respectively. Calculated disease development rates were greater for cv. Peacock 124 than for cv. Mabrouka. Conidium production of B. spicifera on inoculated leaves was very abundant on the two cultivars, and the fungus was re-isolated from lesions on inoculated plants. This is the first record of B. spicifera on watermelon in Morocco.