This study aimed to evaluate the effect of natural products on the expression of resistance to Meloidogyne incognita in organically produced tomato plants. The inducers Rocksil, Chitosan, Neemseto and Biopirol were applied at 5, 10 and 15 days as independent treatments before the pathogen inoculation by means of leaf spraying, using two levels for each inducer. The nematode inoculation was performed at 30 days after planting, using 5000 eggs/plant. Evaluating the number of eggs and the reproduction factor, at 30 days after inoculation, all treatments statistically differed from the control, preventing an increase in the initial population of the pathogen. Of the natural inducers, Rocksil showed the best results for controlling the root-knot nematode in all application times and at all levels. However, plants treated with the product had low shoot weights, suggesting that there was a fitness cost of resistance. Considering the reproduction factor, there were not statistical differences when the level and the application time were compared among natural inducers, except for Chitosan applied at 5 days before the nematode inoculation and Neemseto applied at 15 days before the nematode inoculation.
resistance induction; natural inducers; Meloidogyne incognita
