Toxicity evaluation of three nematicides (with or without ammonium sulphate) on root-knot nematodes attacking tomato

Three systemic nematicides at two treatment levels, with or without extra ammonical fertilization, were evaluated against root-knot nematodes attacking tomato. Addition of ammonium sulphate to temik at 2 and 4 kg a.i./ha, carbofuran at 2 kg a.i./ha and miral at 2 kg a.i./ha resulted in improved yields of tomato fruit. Addition of ammonium sulphate to carbofuran, and miral at 4 kg a.i./ha led to a depression in yield of tomato. All treatments were superior to the control oxcept miral applied at 4 kg a.i./ha + ammonium sulphate. The results of the galling indices show that all treatments were superior to the control. Treatments involving carbofuran 4 kg a.i. + ammonium sulphate, miral alone at 2 and 4 kg a.i./ha, miral at 4 kg a.i./ha + ammonium sulphate were significantly superior to the control (P = 0.05). Residues of miral in fruits were negligible and addition of ammonium sulphate did not affect the amount of residues detected significantly (P = 0.05). Residues of miral in soil samples, however, did show some discrepancies and were high in some of the samples.