Bacillus spp. isolates for the control of Meloidogyne incognita in common bean

Abstract

The objective of this work was to evaluate the effect of Bacillus spp. isolates on the control of Meloidogyne incognita in greenhouse and field experiments. In the greenhouse, isolates 57 ( Bacillus sp.), 63 ( Bacillus amyloliquefaciens ), SF 194 ( Bacillus sp.), SF 203 ( Bacillus amyloliquefaciens ), and a mixture containing the four isolates were applied to the soil surface (2 L ha -1 , 1×10 9 cfu mL -1 ), infested with 5,000 eggs of M. incognita . Sixty days after planting, the mass of the bean roots and the number of galls and eggs were evaluated. In a field natu­rally infested with M. incognita , the effects of isolates 57, 63, and a mixture containing both of them were observed after application to the soil surface (2 L ha -1 ), with or without seed treatment with the isolates (2 mL kg -1 ). Produc­tion, thousand-grain weight, reproductive factor, and number of eggs were evaluated at 90 days after planting. In the greenhouse, the application of the isolates did not influence neither root biomass, nor the number of galls and eggs. In the field, the application of isolates 57, 63, and the mixture 57 + 63 on the soil surface and in seed treat­ment did not increase total production and thousand-grain weight, nor did it reduce the nematode multiplication in the soil and in the roots of the plants. Thus, Bacillus spp. isolates 57, 63, SF 194, and SF 203 have no potential to formulate bionematicides for the control of M. incognita in common bean.