异噁草松对豚草(Ambrosia artemisiifolia L.)种子萌发的抑制作用

Inhibitive effect of clomazone on seed germination of common ragweed,Ambrosia artemisiifolia L.

为明确异噁草松对豚草的防除效果和最佳使用剂量，研究了异噁草松在室内和室外对豚草种子萌发的抑制作用。将不同浓度药液处理的豚草种子进行培养，10d后取出，测定发芽率、芽长、根长、鲜重。结果表明，异嗯草松浓度与豚草种子发芽率呈抛物线关系，不同处理间存在显著差异，而相对抑制率几乎均在20％～40％之间，1．62g／hm2处理浓度的抑制率最高，为37.3％。芽长、根长和鲜重的抑制率，均随药剂浓度增大而显著提高，不同处理间差异显著。1．62g/hm2处理浓度对芽长、根长和鲜重的抑制率分别为80．5％、79．8％、74．1％，与其他更高浓度处理间无显著差异。说明异嗯草松在一定浓度范围内增大施药量．可显著提高防效：但浓度超过一定范围时．增大施药量反而会降低防效．建议田间施药量以1．62g/hm2为宜。

In order to clarify the control effect and optimum dosage of clomazone on common ragweed, the inhibitive effect of elomazone on seed germination of common ragweed, Ambrosia artemisiifolia was evaluated in laboratory and outdoor studies. Ten days after incubation, common ragweed seeds in different treatments were took out to survey the germination rate, shoot length, root length and fresh weight. The results showed that there was a parabolic relationship between elomazone dosages and germination rates, all inhibitive rates were almost between 20% and 40%, and there were significant differences among different treatments. 1.62 g/hm2 solution showed the highest inhibitive rate, which was 37.3%. The inhibitive rates of shoot length, root length and fresh weight increased significantly with the increase of clomazone dosage, and there were significant differences among different treatments in the inhibitive rates. The inhibitive rates of clomazone at 1.62 g/hm2 on shoot length, root length and fresh weight were 80.5%, 79.8% and 74.1%, respectively, which did not differ from the higher dosages. Based on the results of present experiment, it is suggested that the control effects increased significantly with the increasing dosage of clomazone in an optimum dosage range. But, the control effects decreased along with the increasing dosage when the dosage exceeds the optimum range. Thus, the optimum dosage of clomazone was 1.62 g/hm2 for field application.