黑色塑料地膜覆盖灭螺近期效果观察

Short-term Effect of Snail Control by Earth Covered with Black Plastic Mulch

目的观察有螺排灌沟使用黑色塑料地膜结合氯硝柳胺不同用量一次性喷洒与未覆盖近期灭螺效果。方法选择1条有螺排灌沟,分12段,覆盖6段分设氯硝柳胺0、2、4、6、8、10g/m2组。未覆盖6段分设空白对照,氯硝柳胺2、4、6、8、10g/m2组,试前各组按系统抽样法每组调查7框,捕获框内全部土表钉螺观察。调查后各组按设计用药量每m2加水1000ml配制喷洒,各组覆盖黑色塑料地膜。试后12个组1、2、3、5、7、10d按试前调查方法捕获钉螺观察,同时每天8、10、12、16、18时测环境气温覆盖与未覆盖土表、土内3cm、6cm、15cm处温度。结果覆盖组10:00-16:00土表温度最高,晴天维持在40oC62oC之间,土层内315cm深处均在22oC36oC之间,在盖膜10d内,无药组累计钉螺死亡率44.55%,,密度下降72.90%,加药各组死亡率为64.79%85.59%,密度下降率84.83%95.24%,未覆盖各组死亡率58.03%83.81%,密度下降率59.96%90.17%。结论黑色塑料地膜灭螺近期效果,喷药各组均比不喷药组钉螺死亡率和活螺平均密度下降率高,同时高于对应未覆盖各组,该方法省时、省工、操作简便,灭螺效果好,易检查考核,适合多种有螺环境灭螺,宜继续研究和推广应用。

Objective To observe the short-term effect of covering the irrigationl and drainage ditch with or without the black plastic mulch, and combined with one-time spraying different concentrations of Luomiecide for snail control. Method 12 sections of ditch were selected as pilot sites. 6 sections were covered with blach plastic mulch and the other 6 sections without mulch. Besides, different concentrations of Luomiecide i. e. 0,2,4,6,8,10g^2/m^2 were sprayed on all sections. Snail survey was made before experimeat and 1,2,3,4, 5,7,10 days after experiment. Air temperature and soil temperature in different depth （ 3,6,15 cm） were measured everyday. Result The ditch covered with mulch, the temperature of the earth was maximum at 10 to 16 o＇clock i. e. 40 -62℃ in sunny day, 22 -36 ℃ at 3 - 15 cm under the surface of the earth. In 10 days, the snail mortality rate was 44.55% and the snail density declined 72. 90% in the non-spraying drug group. However in the spraying drug groups, the snail mortality rate was 64.79% -85.59%, and the density declined 84.83% -95.24%. In groups without mulch, the two indices were 58.03% -83.81% and 59.96% -90.17%. Conclusion The spraying drug groups are higher than the non-spraying group in the mortality rate and the rate of the decline of density, and all the groups mentioned above are higher than without mulch groups in the two indices. This method is simple and efficient, and it should be studied and promoted continuously.