Management of plant parasitic nematode populations by use of vermicomposts.

Commercial vermicomposts, produced from cattle manure, food and recycled paper wastes, were applied at rates of 5 t/ha, 10 t/ha and 20 t/ha, to field plots planted with tomatoes (Lycopersicon esculentum) bell peppers (Capsicum anuum grossum), strawberries (Fragaria ananasa) or grapes (Vitis vinifera). Control plots were treated with inorganic fertilizers only, and all vermicomposttreated plots were supplemented with inorganic fertilizers, to equalize levels of available N in all plots. Nematodes populations were estimated by after extraction in Baermann funnels and nematodes were identified and classified to trophic level. Populations of plant-parasitic nematodes were depressed significantly by the three vermicomposts in all four field experiments compared with those in plots treated with inorganic fertilizer. Conversely, populations of fungivorous and bacterivorous nematodes tended to increase consistently compared with those in the inorganic fertilizer-treated plots.