EXTRATO DE Tagetes erecta NO CONTROLE DE Meloidogyne enterolobii NA CULTURA DA BERINJELA

Abstract

Parasitism by nematodes of the genus Meloidogyne represents one of the main obstacles in agriculture, causing high losses. The species M. enterolobii has the potential to cause great losses in vegetable crops in several regions of the country. Due to the presence of nematicidal substances in their chemical composition, plants of the genus Tagetes, popularly known as marigold, deserve attention in the control of phytonematodes. Thus, the present study aimed to study the effect of the aqueous extract of the aerial part of T. erecta in the control of M. enterolobii in eggplant. The test was conducted in a greenhouse with different concentrations of aqueous extracts of marigold flowers and leaves: Control 1 - without inoculation (T1); Control 2 - inoculated (T2); 5 mL (T3); 10 mL (T4); 20 mL (T5) and 50 mL (T6) per liter of soil. The extracts were applied to the soil of a pot containing an eggplant plant at 7 and 21 days after nematode inoculation. A completely randomized design was used, with 6 treatments and 6 replicates, totaling 36 experimental units. 5,000 nematode eggs were inoculated into the eggplant seedlings and, 60 days after inoculation, the following variables were evaluated: plant height, fresh and dry mass, and nematode reproduction: gall index, number of eggs and reproduction factor. The treatment with 50 mL (T6) had the highest value for shoot dry matter (13.3 g). The treatments with T. erecta extracts significantly reduced nematode reproduction. The percentage of egg reduction (PRO) was proportional to the extract concentration, reaching 54% at T6. The results indicate a dose-dependent effect of T. erecta extract, with greater efficacy in reducing the reproduction of M. enterolobii in the treatment with 50 mL. The results demonstrate that the addition of T. erecta extract increased the vegetative development of eggplant and significantly reduced the reproduction of M. enterolobii.