Morphological, cultural and physiological characters of Fusarium solani causing wilt of cluster bean

Abstract

Cluster bean [Cyamopsis tetragonoloba (L.) Taub.], commonly called guar is an important legume crop belongs to family Fabaceae. It is cultivated mainly in the rainy season and major producing states in India are Rajasthan, Haryana, Gujarat, Maharashtra and to a limited extent in Uttar Pradesh and Madhya Pradesh. Cluster bean is a highly commercial, industrial and medicinally important leguminous crop due to presence of glactomannan gum in endosperm of seeds. The crop is known to suffer from many diseases which are responsible for its inferior quality and poor yield resulting in severe economic losses to the country as it is an important cash crop with a great potential for foreign exchange. In recent years Fusarium wilt of cluster bean has assumed a serious problem and causing considerable yield losses. Although wilt diseases has assumed importance in Maharashtra, no systematic work has been carried out so for the disease may appear in an epidemic form in future and may threaten the cultivation of cluster bean. Present studies were undertaken with objectives viz., isolation, identification, symptomatology, pathogenicity test, morphological, cultural and physiological characteristics of wilt disease. In cultural studies, it was observed that the test pathogen Fusarium solani shows maximum radial growth on Richard’s media and good sporulation was recorded on Richard’s, PDA and V8 juice agar media. In physiological studies, it was observed that the maximum growth and sporulation of Fusarium solani ranged from 25 °C to 30 °C and grew well from pH levels 6.5 to 7.