벼 담수직파 논 잡초방제 체계에 따른 올방개 방제 특성

Abstract

벼 담수직파 재배시 제초제 사용에 따른 잡초발생 생태를 구명하고, 합리적인 잡초방제 체계를 확립하고자 연구한 결과는 다음과 같다. 벼 종자 파종 후 12일에 설포닐우레아계 혼합제초제(azimsulfuron + carfentrazone-ethyl + pyriminobac-methyl) 처리는 피 등 일년생잡초의 방제효과는 높았으나, 올방개의 방제효과는 낮았다. 그러나, 설포닐우레아계 혼합제초제 초중기처리 후 20일에 설포닐우레아계 혼합제초제(pyrazosulfuron-ethyl + thiobencarb)의 체계처리는 올방개의 방제효과가 높고, 새로운 괴경의 형성량은 적었으나, 구 괴경의 휴면율은 높았다. 또한 설포닐우레아계 혼합제초제의 초중기처리와 파종 후 55일에 bentazone 액제의 체계처리는 올방개의 방제효과가 높고, 새로운 괴경의 형성량도 적었으며, 휴면 괴경도 적었다. This study was conducted to investigate the ecology of weed occurrence and to establish an economical paddy field weed control system for direct-seeded rice on water. The main problem weed among annual and perennial weeds was Eleocharis kuroguwai. The control effect of E. kuroguwai was low by the application of azimsulfuron + carfentrazone-ethyl + pyriminobac-methyl at the early stages of rice in directly seeded paddy fields, but most annual weeds including Echinochloa crus-galli were controlled. Also, the additional application of pyrazosulfuron-ethyl + thiobencarb GR at 20 days after first treatment or of bentazone SL at 43 days after the first treatment effectively controlled E. kuroguwai. Tuber formation of E. kuroguwai was inhibited by the additional application of pyrazosulfuron-ethyl + thiobencarb by 84%, but the dormancy rate of old tubers of E. kuroguwai under the soil was higher than that of E. kuroguwai tubers following single application of azimsulfuron + carfentrazone-ethyl + pyriminobac-methyl at the early stages of rice. Tuber formation was inhibited by the additional application of bentazone by approximately 87%, and the old tuber dormancy rate was low in the bentazone treatment. High amounts of old dormant tubers of E. kuroguwai were found in the weedy plots.