Field trials were conducted to assess the efficacy of biological agents on the control of root lesion nematodes in banana in comparison with the nematicide carbofuran. The bio-agents were Pseudomonas fluorescens, Trichoderma viride, Glomus fasciculatum, Bacillus subtilis and Paecilomyces lilacinus. Application of P. fluorescens at 20 g/plant gave the greatest bunch length (95 cm), bunch weight (24 kg), number of hands per bunch (10) and number of fingers per bunch (176). The increases in yield parameters ranged from 59 to 110%. Pseudomonas fluorescens was also the most effective to control nematodes until harvest as the populations of Radopholus similis, Pratylenchus coffeae and Helicotylenchus multicinctus were reduced by 48.7, 46.3 and 44.3%, respectively. Soil application of T. viride or carbofuran were the next best treatments followed by the application of G. fasciculatum, B. subtilis and P. lilacinus. The lowest bunch weight (15 kg) was obtained from the control plants. Carbofuran was the most effective to control nematodes until three months after planting, but its efficacy thereafter was reduced and remained at a level similar to that of P. fluorescens. Root colonization by P. fluorescens, T. viride, G. fasciculatum, and B. subtilis was 105 × 108cfu/g, 60 × 106 cfu/g, 44% and 58 × 108 cells/g of root.
