Induced Resistance Against Fusarium Wilt of Chickpea by Nonpathogenic Races of Fusarium oxysporum f. sp. ciceris and Nonpathogenic Isolates of F oxysporum. A. Hervas, Research Associate; Departamento de Proteccion de Cultivos, Instituto de Agricultura Sostenible, Consejo Superior de Investigaciones Cientificas (CSIC), Apartado 3048, 14080 Cordoba, Spain. J. L. Trapero-Casas, Research Assistant, and R. M. Jimenez-Diaz, Professor, Departamento de Proteccion de Cultivos, Instituto de Agricultura Sostenible, Consejo Superior de Investigaciones Cientificas (CSIC), Apartado 3048, 14080 Cordoba, Spain. PLANT DIS. 79:1110. Accepted for publication 10 June 1995. Copyright 1995 The American Phytopalhological Society. DOI: 10.1094/PD-79-1110.

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. a. 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.