MIXTURES OF OLIVE POMACE WITH DIFFERENT NITROGEN-SOURCES FOR THE CONTROL OF MELOIDOGYNE SPP ON TOMATO

The efficacy of mixtures of dry olive (Olea europea) pomace with biure t, guanidine, and melamine for control of root-knot nematodes (Meloido gyne spp.) on tomato (Lycopersicon esculentum) was studied in greenhou se experiments. Olive pomace (OF) applied pre-plant at 10 g/kg soil wa s phytotoxic. Mixtures of OP (10 g/kg soil) with biuret or guanidine a t 200-300 mg/kg soil reduced or eliminated the phytotoxic effect, cont rolled root-knot nematodes, and increased soil esterase activity indic ative of microbial activity. The addition of biuret or guanidine witho ut OP to soil at rates <300 mg/kg soil did not control root-knot nemat odes. Melamine applied at 100-400 mg/kg soil was phytotoxic as were mi xtures of melamine with OF. Treatment of OP with anhydrous ammonia inc reased N content of the material. In another greenhouse experiment, NH 3-treated OP added to soil was not phytotoxic to tomato, suppressed ro ot-knot nematodes, and increased soil esterase activity. Greenhouse an d microplot experiments with OP plus chicken litter demonstrated the e fficacy of these combination amendments to control root-knot nematodes and increase tomato yields in Meloidogyne-infested soil.