Effect of plant growth promoting rhizobacteria on black scurf disease of potato and their ability to promote growth

Plant growth-promoting rhizobacteria strains; B4 (Becillus cereus), B5 (Bacillus subtilis), Ml {Enterobacter cloacae) and AZ10 (Azotobacter sp.) were tested for their ability to biologically control black scurf disease in potato incited by Rhizobacterium solani (Kuhn (teleomorph Thanatephorus cucumeris (A. B. Frank) Donk). Based on their ability to control development of black scurf disease and enhancement of potato yield, the strain B5 was recorded the best in inhibiting growth of R. solani in dual culture by 94.22 per cent and enhanced per plant tuber yield by 68.98 per cent in comparison to control. The results of in vitro studies indicate effectiveness of all the four PGPR strains in controlling black scurf disease of potato and can be used as potential biocontrol agents of R, solani in field conditions.