STUDIES ON ANTHRACNOSE OF BEAN IN EGYPT

Abstract

The results indicated that Colletotrichum / indemuthianum (Sacc & Magn.) Briosi & Cav. is the causal agent of bean anthracnose disease in Egypt.It was demonstrated that Glucose neopeptone agar was the best medium and bean pods agar was the best leguminous extract for both fungal growth and sporulation. Bronco, Contender and Morgan cvs were resistant to the mentioned pathogen, while, Giza 3, Giza 6, kentuky, Montana, Narina and Novax were susceptible. Host range study proved. that Snap bean is the most susceptible leguminous host to C /indemuthianum, it followed by Cowpea, which is considered moderately susceptible. Mung bean, Lentil, Egyptian clover and Soybean were moderately resistant while no disease symptoms occurred on Faba bean, Egyptian lupine, Fenugreek, Chickpea and Peanut. Effect of bean seed infection with Clindemuthianum gained severe infection with both pre­ and post emergence damping-off to the susceptible cultivar Narina. It was demonstrated that the viability of the infected bean leaves increased during dry conditions and decreased under wet ones. It was also indicated that the highest percentage of the causal agent recovery occurred in sandy-clay soil (1:1) under dry conditions at depth of 0 and 5 em of the soil surface. It was obvious that chemical induces increased resistance against bean anthracnose disease. Data indicated that salicylic acid 5% was the best chemical (non-fungicide) inducer .Related chemical analysis demonstrated that the high percentage of total sugar and chlorophyll pigments was found in salicylic acid treatment followed by phenol and calcium chloride, respectively. It was clear that Benlate was the most efficient fungicide against pre- and post emergence damping-off .Results stated that Radomyl plus, followed by Rovral and Bravo , were the most effective fungicide against bean anthracnose. Results reported the use of disease forecast and early warning system for the first time in Egypt and allover the Arabian and African country, Egy-Anthra was reported as a first computer program for bean anthracnose disease allover the world. During 1998 and 1999 bean growing seasons Egy-Anthra announce four early warning massages, forecasting the best time to apply fungicides for better disease control.