To clarify the control effect of mushroom material on root knot nematode disease, black edible mushroom, which mainly cultivated in Hengyang area, was chose as the research strains, the paper measured the control effect of production-before mushroom material and production-after mushroom material on root knot nematode (Meloidogyne incognita) disease of tomato under the condition of potted plant. The results showed that the production-before mushroom material and production-after mushroom material both had control effect and the control effect...