Comparison of Herbicidal Action between Pyrazosulfuron - ethyl and Imazaquin

Pyrazosulfuron - ethyl과 Imazaquin의 살초작용 비교

To know whether pyrazosulfuron-ethyl(PYR) and imazaquin(IMA), known as a acetolactate synthase(ALS) inhibitors, have a same herbicidal action pattern in rice(Oryza sativa) or barnyardgrass (Echinochloa crus-galli), an inhibition pattern and a response characteristics in combination with dymron or butachlor were investigated. In contrast to the phytotoxicity of rice treated with IMA, the one treated with PYR was completely tended to be recovered after 25 days after treatment. Safening effect of dymron against PYR was effectively developed to transplanted-rice, while such an effect was not shown in combination with IMA. In combination with PYR and butachlor, antagonistic effect was observed in both simultaneous or sequential treatment on bamyardgrass, however, additive effect was rather shown in combination with IMA and its activity was dominantly dependent on the first applied compound. $I_{50}$ of PYR and IMA on the ALS extracted from barnyardgrass was $4{\times}10^{-7}$M and $2.8{\times}10^{-6})$M, respectively. Butachlor did not affect their activities on ALS in vitro. These results suggest that PYR and IMA might have a different action each other in the pathway to a final herbicidal activity even though their primary action site is ALS.

Sulfonylurea계 제초제 pyrazoslulfuron-ethyl과 imidazolinone계 제초제 imazaquin을 대상으로 약해발생양상, dymron에 의한 약해경감효과, butachlor와의 상호작용성, ALS에 대한 혼합작용 등을 조사한 결과는 다음과 같다. 1. 제초제에 의한 벼(동진)의 생장저해증상은 pyrazosulfuron-ehtyl 처리구에서 시간이 경과되면서 회복되었지만 imazaquin 처리구에서는 회복되지 않았다. 2. 높은 농도의 pyrazosulfuron-ehtyl에 의한 벼의 약해는 dymron 혼합처리에 의하여 크게 감소되었지만, IMA에 대해서는 약해경감효과가 나타나지 않았다. 3. 혼합처리에 의한 강피의 생장억제효과는 동시 또는 체계처리 모두 동일한 경향으로 pyrazosulfuron-ehtyl과 butachlor은 길항적이었지만 imazaquin과 butachlor은 상가적이었다. 4. Pyrazosulfuron-ehtyl과 imazaquin의 ALS 효소활성 50% 저해농도는 각각 $4{\times}10^{-7}$M, $2.8{\times}10^{-6})$M 이었고 혼합처리할 경우 butachlor은 두 제초제의 ALS 저해작용에 영향을 주지 않았다. 이상의 결과를 보면 pyrazosulfuron-ethyl과 imazaquin이 공통적으로 ALS를 저해하지만 살초기작은 서로 다른 것으로 생각되었다.