Induced Resistance Against Fusarium Wilt of Chickpea by Nonpathogenic Races ofFusarium oxysporumf. sp.cicerisand Nonpathogenic Isolates ofF oxysporum

Germinated seeds of chickpea cultivars JG 62 and ICCV 4 were inoculated with a conidial suspension of nonpathogenic races 0 and 1 of Fusarium oxysporum f. sp. ciceris or isolates of F. oxysporum (inducers), then challenged by root dip in a conidial suspension of F. o. f. sp. ciceris race 5. Prior inoculation with the inducers significantly reduced disease incidence and severity caused by race 5. However, the extent of protection decreased when the inoculum concentration of the challenger was close to that of the inducing agent, and it varied with the nature of inducing agent and genotype of the host. Also, resistance induced by race 0 in JG 62 was annulled when more than 3 days elapsed between inoculations with the nonpathogen and the challenger.