The in vitro nematicidal efficiency of fermentation liquid of marine-derived Acremonium sp. BH0531 on root-knot nematode was determined. The effects of potting experimental conditions on the index and decreasing rate of nematodes and microorganism amount in soli were analyzed. The results showed that when the fermentation liquid was concentrate 1 time,the corrected death rate of the root-knot nematode was up to 96.2%,and the decreasing rate of nematodes was 71.21%. The fermentation liquid had promoting effe...