Control Replant Disease By Soil Treatment

Replant disease is serious for agricultural production of vegetable, fruit, grain, and so on. It is about 15000hm2 in Xi an for tomato, watermelon, melon, strawberry, cucumber, celery etc. This research is intended to use the Soil Treatment Technology that used lime nitrogen, chloropicrin, microbial fertilizer, and so on to control diseases in field. The result shows that:1. The effect of continuous cropping on strawberry both number of leaf and stem diameter is not obvious, while affect plant height, root flesh weight, flesh weight. The soil treatment technology of chloropicrin eliminated the adverse effects of strawberry growing. Technology of chloropicrin control effect on strawberry root diseases was 64.1%and 79.1% in Squaring period and full fruit-bearing stages. Fragaria were isolated from strawberry root diseases which is demonstrated to cause continuous cropping of strawberry. The texts demonstrated that the number of bacteria in the soil of strawberry root can be obviously reduced by continuous cropping of strawberry, prompting transformation of soil microorganism form bacterial type to fungus type.2. Fusarium oxysporum and Mycosphaerella melonis were the reason for blight and Didymella bryoniae in the melon of continuous cropping. Four extraction methods of using lime nitrogen, chloropicrin, bacillus EM, and actinomycete 153 increase the yield. The effect of using bacillus EM 300kg/hm2 was best, the yield is about 8560kg/hm2. The blight control effect of chloropicrin 300kg/hm2 is best, the didymella bryoniae control effect of actinomycete 153 is best. The control effect was increased with drug concentrations. The eelworm control effect of chloropicrin 300kg/hm2 and 225kg/hm2 were 59.8%and 51.5%.3. Plant height, stem diameter, yield of continuous cropping tomato were obviously increased with sun and plastic wrap, lime nitrogen, Fuqiduo.The effect of using lime nitrogen was obviously about 9.44%,30%,20.1%more than others.The meloidogyne spp control effect of using sun and plastic wrap is about 59.14%,while add lime nitrogen is about 74.73%. The control effect of using fuqiduo is lower than others,is about 51.68%.