YIELD RESPONSE AND BIOLOGICAL-CONTROL OF MELOIDOGYNE-INCOGNITA ON LETTUCE AND TOMATO WITH RHIZOBACTERIA

Three out of 15 bacterial strains preselected for antagonistic activit y in different pathosystems showed biocontrol activity towards Meloido gyne incognita on lettuce and tomato. Seed treatment with the rhizobac teria Pseudomonas sp. W34 or Bacillus cereus S18 resulted in significa nt reductions in root galling and enhanced seedling biomass. The yield response of M. incognita-infested tomato was tested in a long-term po t experiment using three antagonistic bacteria, i.e., Pseudomonas sp. W34, Bacillus cereus S18 and Bacillus subtilis VM1-32. Significant red uction in M. incognita gall index was observed within 18 weeks after i noculation with all three bacterial strains. B, cereus S18 caused a 9 % yield increase when compared with the nematode control and thereby c ompensated for the yield loss due to nematode infection. Early maturit y of fruits on M, incognita-infested tomato plants after inoculation o f B, cereus S18 was observed when compared with both the nematode and the untreated control.