How to reduce the number of Meloidogyne paranaensis galls in tomato using earthworms?

Abstract

The objective of the present work was to determine the incidence of Meloidogyne paranaensis galls in the roots of Solanum lycopersicum, after inoculation with Amynthas spp. and Pontoscolex corethrurus. The experiment was performed in the greenhouse in a randomised block experimental design was adopted, with four treatments and five repetitions: T1. M. paranaensis; T2. M. paranaensis + Amynthas spp. T3. M. paranaensis +P. corethrurus; T4. M. paranaensis + Amynthas spp. + P. corethrurus. Initially, six adult worms of Amynthas spp. or P. corethrurus, isolated or in the same proportion (3:3), with the previously determined fresh biomass. After one week, tomato seedlings (cultivar “Rutgers”) were transplanted to the pots and inoculated with 5 mL of a suspension of M. paranaensis containing 5,000 eggs and/or juveniles per pot. Sixty-five days after inoculation, the number of remaining worms was counted after manual collection; the fresh biomass was determined by direct weighing, and the number of galls on the roots of the tomato was counted directly in a stereomicroscope. The results demonstrated a reduction in the number of galls per plant with treatments involving inoculation with worms, varying between 26,7% and 63,3%, respectively, for Amynthas spp. and P. corethrurus. Meanwhile, the combination of worms lead to a reduction of 50,0% in the incidence of galls. The results demonstrate that the use of worms in the biological control of nematodes, during tomato cultivation, has great potential that requires further investigation.