Stemphylium leaf spot disease of Vicia faba is a recently recorded disease in Egypt. A survey of this disease through broad bean" growing cultivated areas, revealed its wide distribution all over the country. Symptoms of the disease are characterised by the appearance of brownish black necrotic irregular lesions, mostly covering the leaflet surface within 7-10 days. Several isolates of Stemphylium sp. were either isolated from spotted broad bean leaves or from other hosts. All S. botryosum isolates proved to be pathogenic an3 produced typical
symptoms on broad bean plants. One isolate,-identified as S. vesoarium Wallroth was the least pathogenic on this host. The disease developed, on inoculated plants at temperatures ranging from 12-27°C with an optimum of 20-27°C. Disease severity progressively increased with the increase of spore density in the inoculum.
The fungus was able to attack some other hosts such as soybean, clover, lupines, tomato, flax and maize. Peanuts, beans, lentils, chickpea and cotton were not attacked by this fungus. |
