Extractos vegetales para el manejo sostenible de Meloidogyne incognita en el cultivo de tomate (Solanum lycopersicum L.) en Ecuador

Abstract

Rook-knot nematodes (Meloidogyne spp.) represent a serious threat to agriculture, causing yield losses in economically important crops worldwide. Several studies have shown that it is possible to control their populations sustainably, reducing costs and minimizing negative impacts on the environment and human health. In this context, the present study aimed to evaluate the efficacy of plant extracts under laboratory, greenhouse, and field conditions. Thirty plant species were analyzed at different concentrations (50, 75 and 90 %), using leaves, roots, stems, flowers, fruits, and seeds, selecting the most effective ones for subsequent tests. Extracts from noni, chaya, green tomato, cabbage, black nightshade, horsetail, among others, showed high efficacy in immobilizing juveniles of M. incognita, reaching 100 % mortality in vitro. The greatest nematicidal activity was recorded with foliar extracts (43 %). In greenhouse conditions, extracts of noni (fruit), chaya (leaves), black nightshade, and horsetail, particularly at a dose of 10 mL per plant, demonstrated high effectiveness in reducing nematode populations. In field trials, the strongest effect was achieved with horsetail extracts applied at transplanting, at doses of 200 and 400 L/ha, which were the most effective combinations to reduce nematode densities in roots and soil. It is concluded that extracts derived from the families Rubiaceae, Euphorbiaceae, Solanaceae, and Equisetaceae possess strong nematicidal potential and can be incorporated into the integrated management of these parasites.