BIOLOGICAL-CONTROL OF SOILBORNE ROOT INFECTING FUNGI IN TOMATO AND OKRA

In a green house experiment soil artificially infested with a pathogenic strain of Fusarium oxysporum f. sp. lycopersici suppressed the infection of Macrophomina phaseolina, F. solani and Rhizoctonia solani on tomato and okra roots. The suppressive effect of F. oxysporum increased in the presence of Trichoderma harzianum, T. koningii, Gliocladium virens, Paecilomyces lilacinus, Bradyrhizobium japonicum and Rhizobium meliloti against F. solani and M. phaseolina. F. oxysporum induced mortality in tomato plants. Root colonization by F. oxysporum increased in F. oxysporum infested soil with reduced plant growth and less infection of M. phaseolina and R solani. T. harzianum, T. koningii, G. virens, P. lilacinus, B. japonicum and R meliloti showed significant control of M. phaseolina, F. oxysporum and F. solani infection on tomato and okra both in F. oxysporum infested and uninfested natural soil, whereas T. koningii G. virens and B. japonicum increased R solani infection in F. oxysporum infested soil in tomato.