Factors and Recovery of Herbicide Phytotoxicity on Direct-seeded Rice - 2. Phytotoxicity of Herbicide with Nutrient Condition

직파(直播) 벼의 제초제(除草劑) 약해(藥害) 요인(要因)과 회복(回復) 연구(硏究) - 2. 영양(營養) 조건(條件)에 따른 약해(藥害)

The influence of nutrients on the phytotoxicity of herbicides (bensulfuron-methyl, pyrazosulfuron-ethyl, imazosulfuron, dimepiperate, and molinate) was investigated in controlled-environment growth chamber with direct-seeded rice (Oryza sativa L. cv. Dongjin). The phytotoxicity of bensulfuron-methyl, pyrazosulfuron-ethyl, and imazosulfuron for rice was greater in nutrient culture than in no-nutrient condition. The root growth of rice applied with these herbicides was more inhibited than the shoot growth. The most severe inhibition was obtained with pyrazosulfuron-ethyl application. The growth inhibition of rice applied by dimepiperate was increased under no-nutrient culture condition. Dimepiperate suppressed more remarkably shoot growth than root. Especially the shoot elongation was much more inhibited than the others. The shoot growth inhibition in rice applied by molinate was severer than the root. The shoot growth was reduced under nutrient culture condition, while the root growth was reduced under no-nutrient culture.

담수 직파 벼에서 최근 많이 사용하고 있는 제초제들의 영양(營養) 유무(有無)에 따른 약해 반응을 검토한 결과는 다음과 같다. 1. Bensulfuron-methyl, pyrazosulfuron-ethyl 및 imazosulfuron의 처리는 경엽부(莖葉部)보다 근부(根部)의 생육을 크게 억제시켰으며 영양(營養) 조건 재배에서 무영양(無營養) 조건의 재배에서보다 생육 억제 정도가 컸다. 또한 영양(營養) 재배와 무영양(無營養) 재배에서 벼 생육 억제율(抑制率)의 차이는 pyrazosulfuronethyl의 처리에서 가장 컸다. 2. Dimepiperate의 처리는 경엽부(莖葉部) 근부(根部) 모두 무영양(無營養) 조건에서 생육 저해 정도가 컸으며, 근부(根部)보다 경엽부(莖葉部)의 생육을 크게 억제시켰으며, 특히 초장신장이 크게 억제되었다. 3. Molinate 처리는 경엽부(莖葉部)의 억제율(抑制率)이 근부(根部)보다 컸으며 경엽부(莖葉部)는 영양(營養)조건에서, 근부(根部)는 무영양(無營養) 조건에서 생육 억제율(抑制率)이 큰 경향이었다.