ALTERNARIA LEAF SPOT DISEASE CONTROL ON FABA BEAN IN EGYPT

Abstract

Faba bean (Vicia fab ae) is considered the most important legume crop in Egypt. The varietal reaction of 16 different cultivars against Aggressive isolate of Alternaria alternata causing Alternaria leaf spot disease revealed that Wadi-l cultivar was the most susceptible cv while the other tested cultivars were varied in their susceptibility. The cultivars i.e Giza 429, Giza 3, Maser 1 and Sakha 1 were the most susceptible ones while Giza 2, Nobaria 2, Sakha 2 and Nobaria 1 were the most resistant ones. On the other hand the rest cultivars were moderate susceptible. In disease control trials using the biocides (Bio-ARC 6% and Bio-Zeid 2.5%) Bacillus sub tilis, Trichoderma harzianum, Bacillus megaterium, Trichoderma alb um, Bacillus lechniforms and Ulva algae compared with chemical fungicide (Tridex 80% WP), significantly affected the causal pathogen in vitro, greenhouse, and under field conditions. Bio-Zeid product followed by the B. sub tilis and Bio.ARC; respectively produced the best results and significant reduction of pathogen growth or infection severity. B. lechniform, T. harzianum and Ulva lactuca were the less bio-agent against the pathogen. At the same time, period progress after using the tested antagonistic materials increased disease severity. Accordingly, disease severity was more aggressive after 7 days.