禾谷缢管蚜侵染量及危害历期对小麦旗叶SPAD及千粒重的影响

Effect of Infection Quantity and Period of Rhopalosiphum padi on Flag SPAD and 1000-grain Weight of Wheat

禾谷缢管蚜是西南麦区的第一大害虫。在小麦抽穗期采用大田罩网接蚜方式,研究了禾谷缢管蚜不同侵染量和危害历期对旗叶SPAD和千粒重的影响。结果表明μ2头/茎的初始蚜量,从抽穗期侵染至乳熟期,旗叶SPAD值降幅较对照处理增加41.2%,千粒重降低15.8%,随着初始蚜量的增加,旗叶SPAD值和千粒重降幅增大。在起始蚜量5头/茎条件下,随着侵染时间的延长,蚜虫对旗叶危害增加,千粒重降幅增大,连续侵染14d时,千粒重降幅12.3%,侵染28～56d,千粒重降幅21.8%～48.0%。蚜虫防治时除考虑单茎蚜量外,还需考虑蚜虫繁殖速度,以确定蚜虫最佳防治时间。

Rhopalosiphum podi was the major pest in southwestern wheat region. Using field caging methods ,the effect of infection quantity and period of Rhopalosiphum padi on flag SPAD and 1000-grain weight of wheat was studied. The results showed that the infection from heading stage to milk stage with ：2 initial aphids per stem,the decreasing range of flag SPAD increased by 41.2% compared with CK, and 1000-grain weight reduced by 15.8%. With the increasing of initial aphid quantity, the decreasing range of flag SPAD and 1000-grain weight increased. In the condition of 5 initial aphids per stem ,the 1000-grain weight decreased rapidly with the infection time prolonging. Infection for 14 d, 1000-grain weight decreased by 12.3% and for 28-：26 d decreased by 21.8%-48.0%. In the practices of Rhopdosiphumpadi control ,the farmers needed to consider the numbers per stem and the reproduction speed.