Effect of seed inoculation with Bacillus subtilis and Streptomyces griseus on the growth of cereals and carrots

Abstract

The effect of Bacillus subtilis A13 and Streptomyces griseus 2-A24 on the yield of cereals and carrots was studied. The organisms, both antagonistic to Rhizoctonia solani, were applied individually to barley, oats and wheat for sowing at three sites with a known incidence of R. solani. Root disease was not effectively controlled, yet the seed treatments increased grain yield and dry matter production at one site, advanced time of heading at another site and increased tiller number at two sites. Evidence was obtained that the organisms persisted on pericarps in soil for 5 weeks after sowing. In subsequent trials application of B. subtilis and S. griseus in combination with a pellet treatment increased marketable yields of carrots by 48% and 15% respectively over controls. Addition of the organisms to seed without pelleting increased yields by 17% over controls. These results indicate a non-specific effect of B. subtilis and S. griseus, since they increased growth of plants belonging to two different families, the Gramineae and Umbelliferae, in different soils.