strain mixtures increased biomatter production and yield compared to individual strains (Nandakumar et al., 2001). Combined application of Pichia guilermondii and Bacillus mycoides (B16) reduced the infection of Botrytis cinerea by 75% on fruits in strawberry plants grown commercially under greenhouse conditions. But the individual application of either antagonist resulted in 50% reduction of strawberry fruit infection. Population of yeast increased when applied as mixture rather than single application (Guetsky et al., 2002). Delivering of talc based strain mixtures of
P. fluorescens strains (Pf1 and FP7) through seed, soil and foliar reduced sheath blight and leaf folder incidence in rice under greenhouse and field conditions. It also reduced the feeding behavior of leaffolder, reduced larval and pupal weight, and increased larval mortality. Besides, population of parasitoids and spiders also increased in PGPR treated plots (Radja Commare et al., 2002).
Table 2.Efficacy of PGPR formulations against plant disease and growth promotion.