Development of control methods against root-knot nematode (Meloidogyne chitwoodi Golden, O'Bannon, Santo & Finley, 1980) in potato

Root-knot nematodes are ranked first among plant-parasitic nematodes in terms of the economic damage they cause to agricultural products (Jones et al., 2013). Meloidogyne spp. has a very broad host range. The high number of species within root-knot nematodes, along with the extensive family of the potato plant, leads to significant yield losses caused by species of the Meloidogyne genus.This thesis study was conducted in 2023 in a field infested with Meloidogyne chitwoodi in Niğde, while laboratory studies were carried out in vitro in the nematology laboratory at Niğde Ömer Halisdemir University. In the field study, three conditions were examined in potato planting plots: an untreated control, surface application of fluopyram, and seedbed application of fluopyram. In the laboratory study, M. chitwoodi was inoculated into tomato seedlings, and Bacillus thuringiensis strains carrying the Cry6Aa2, Cry55Aa1, and Cry5B genes were used as biological control agents. For this purpose, different doses of Bacillus thuringiensis spores were tested in pots against root-knot nematodes at concentrations of 10% (3.7 x 108 spores/1.25 l/da), 30% (3.75 l/da), and 100% (12.5 l/da).The results of the field trials indicated that the surface application had a greater effect on yield than the seedbed application. In vitro experiments showed that Bt played a significant role in both plant growth and the suppression of nematode development, yielding promising findings for commercialization. Keywords: Biological control, Chemical control, Root-knot nematode, Bacillus thuringiensis