Control of Meloidogyne javanica using Pasteuria penetrans on tomato crop Second assay
Pimenta, C.A.ves Moraes; Gomes Carneiro, R.M.D.
Nematologia Brasileira 26(1): 77-91
The efficiency of Pasteuria penetrans on the control of Meloidogyne javanica was tested on tomato Santa Cruz, after a previous assay with cultivation of lettuce. The bacterium was added to the substrate of lettuce seedlings, in two concentrations, 105 and 106 endospores/g of substrate, in treatments with or without incorporation of lettuce root systems. The influence of fallow was also evaluated on the control induced by the bacterium. The experiment was conducted under greenhouse conditions. In this assay with tomato plants, P. penetrans was present in all treatments where the substrate had been treated previously. The bacterium in both concentrations led to a significant 10-fold reduction in M. javanica population in tomato. The highest concentration of the bacterium caused a decrease of the nematode population level, mainly in the treatment with the incorporation of lettuce root system. The percentage of infected second-stage juveniles (J2) and the numbers of attached endospores/J2 increased significantly with the incorporation of the lettuce roots, showing that the residual bacterium inoculum was significant in promoting the suppression. The significant numbers of bacterium-infected females, in the second experiment with tomato plants, will possibly increase the concentration of the bacterium inoculum for the next generation of M. javanica. The fallow treatments did not reduce nematode population levels satisfactorily. In addition, the nematode suppression induced by the bacterium was lower under fallow treatments.