EFFICIENCY OF DUAL INOCULATION WITH MYCORRHIZAL FUNGI AND Azotobacter chroococcum IN STIMULATING TOMATO PLANT RESISTANCE to root-ROT DISEASE CAUSED BY Rhizoctonia solani

Abstract

The results of antagonistic activity of five isolates of Azotobaetar chroococcum showed that the isolates varied in their ability in reducing radial growth rate of R. solani . Azo.4 and Azo. 5 isolates showed significant reduction in radial growth rate ( 3.16, 3.03) cm respectively compared to control treatment ( 5.16 ) cm . Results of the effect of Azotobaetar suspension dilution on radial growth of R. solani revealed that the antagonistic activity was depend upon the isolate type and inoculum level .Azo. 4 and Azo. 5 isolates were the superior in all tested inoculum levels ( 10, 15 and 20 ) % which recorded (3.20, 3.13) cm (3.06, 3.03) cm and ( 3.0, 2.90 ) cm respectively compared to control treatment ( 5.0 ) cm. Results of greenhouse experiment showed that most treatments significantly increased tomato growth parameters ( shoot and root length ,dry and soft weight of shoot and root , no. of leaves and flowers /plant ), and decreased the percentage of infected tomato plants by R. solani ( pre and post emergency).