Bioactivity of Certain Formulations of Abamectin Against Root-Knot Nematodes (Meloidogyne incognita) In Vitro and In Vivo.

The root-knot nematode, Meloidogyne incognita, poses a significant challenge to tomato cultivation, necessitating the development of effective and sustainable management strategies. This study investigated the nematocidal efficacy of various abamectin formulations, micro emulsion (ME), suspension concentrate (SC), and emulsifiable concentrate (EC), alongside two oxamyl formulations: suspension liquid (SL) and emulsifiable concentrate (EC) under both laboratory and greenhouse conditions. All three abamectin formulations demonstrated considerable toxicity against M. incognita across all tested concentrations. Notably, the microemulsion formulation, Romectin 5% ME, emerged as the most potent among the abamectin products. A significant reduction in LC50 values for abamectin (ME) was observed over time, decreasing from 42.39 µg/ml at 24 hours to 14.21 µg/ml after 96 hours. Both oxamyl formulations proved less toxic than abamectin formulations particularly when compared to its ME formulation. The toxicity index of abamectin (ME) was markedly higher, ranging from 217% to 338.77% when compared to oxamyl SL during the same experimental periods. Furthermore, abamectin(ME) displayed lower LT50 (18.5 hours) and LT90 (42.7 hours) values, underscoring its superior toxicity and rapid action as a nematicide. The overall nematicidal effect of abamectin intensified with prolonged exposure, indicating enhanced efficacy in both laboratory and greenhouse environments. In greenhouse trials, the ME formulation significantly mitigated gall formation, reproduction factor(Rf) and final population Followed by SC formulation. These Results suggest that both the microemulsion (ME) and suspension concentrate (SC) formulations of abamectin warrant serious consideration for integration into sustainable nematode management programs.