碳酸氢铵集中点投放与喷洒加地膜覆盖杀灭钉螺效果观察

TheMolluscicidal Effect of Ammonium Bicarbonate Centralized Sprinkle and Spraying With Earth Covered Black Plastic Mulch

目的观察碳酸氢铵集中点投放与喷洒加黑色塑料地膜覆盖的灭螺效果。方法选择1条环境相对独立有螺沟渠作为实验环境,分成11段,由上游向下游分设空白对照1个组,碳酸氢铵集中点投放和喷洒加黑色地膜覆盖各设100 g/m2、200 g/m2、300 g/m2、400 g/m2、500 g/m25个剂量组,空白对照组不采取任何灭螺措施。试前和试验后10、20、30、60、90、180 d调查活螺平均密度和钉螺死亡率。结果试后10～180 d,集中点投放各组土表活螺密度下降率32.71%～98.55%,优于空白对照组(P<0.05),但密度下降未到100%,说明还有活钉螺存在。喷洒各组土表活螺密度下降率95.44%～100%,优于空白对照组(P<0.05)。300 g/m2及以上剂量组覆盖10 d以上时,钉螺死亡率达100%。结论碳酸氢铵喷洒加黑色地膜覆盖消灭钉螺效果优于集中点投放加黑色地膜覆盖,300 g/m2剂量喷洒覆盖地膜,10 d就能取得很好灭螺效果。

Objective To observe the molluscicidal effect of ammonium bicarbonate centralized sprinkle and spra- ying with earth covered black plastic mulch at different dosages. Methods A ditch with Oncomelania snails was selected as the study site, and was divided into a control group and two moUuscicide groups from upper to lower places. The two moUuscicide groups were applied ammonium bicarbonate with 5 different dosages in ways of cen- tralized embarking or spraying by earth covered black plastic mulch. The molluscicidal effect was observed before and 10, 20, 30, 60, 90 and 180 days after the experiments. Results The reduced rates of snail density of cen- tralized embarking were 32. 71% -98. 55% and the other moUuscicide group was 95. 44% - 100% between 10d and 180d. There was significant difference between molluscicide group and the control group （P 〈 0. 05 ）. The mortality of the spraying group could reach up to 100% after 10d above the dosage of 300 g/m^2. Conclu- sion The molluscicidal effect of ammonium bicarbonate spraying by earth covered with black plastic mulch is superior to centralized sprinkle method. The optimal time and dosage is respectively 300g/m^2 and 10d.