Improvement of Herbicide Use in Crop Production w. Growth Responses of Soybean (Glycine max) Cultivars to Application Time of Metribuzin Herbicide

제초제의 사용법 개발에 관한 연구 제4보 Metribuzin 사용시간에 따른 대두품종의 생육반응

The study was conducted to know the differential growth responses of soybean cultivars as affected by various application stages of Metribuzin herbicide, at the University experimental farm of Chonnam Nat'l. Univ, Kwangjoo, 1980. Experimented soybean materials were six cultivars, as Kwanggyo, Dongbuktae, Bongui, Yukwoo 3, Suweon 85, and Suweon 86., . and Laid-out application stages were five as pre-sowing, Pre-emergence, Early Post-emergence, and Late Post-emergence treatment comparing with Control. Results obtained from the study were as follows: Among experimented soybean cultivars, no significantly tolerant cultivar was shown. Highly significant differences in phytotoxicities by Metribuzin treatments were detected among various application stages, and crop tolerances were recognized bigger in order as E. Post-emg. < L. Post-emg. $\ll$ Pre-emg. < Pre-sowing $\leq$ Control. The phytotoxic symptoms of all soybean cuitivars were severely recorded in order of Leaf No. /Plant < Plant height $\ll$ Branch No. /Plant. For the cultivation of most soybean cuitivars, the use of Metribuzin in Pre-sowing or Pre-emergence were recommended, and especially it is expected to follow of more detailed study on soil-incorporation method in Pre-sowing treatment, and rather the tank-mixture system of Metribuzin with others than the mono-application system for the safe-use and enlargement of weeding-spectrum.

본 시험은 1980년도에 전남대학교 시험포장에서 수행된 것으로서, Metribuzin의 처리시기에 따른 품종반응차이를 알기 위하여 광교외의 5대두품종과 Pre-sowing 외에 4처리 시기를 공시하여 작물의 초기생육반응을 조사하여 다음의 결과를 얻었다. 1. 공시품종내에서는 약제에 대한 저항성 차이가 뚜렷하지 않았다. 2. 품종차이보다는 약제처리시기에 따른 반응차이가 헌저하였으며, 대부분 대두품종의 저항성 크기는 E. Post-emg.< L.Post-emg $\ll$re-sowing=Control의 순으로 컸다. 3. Metribuzin의 약해 Symptom은 주당엽수 < 초장 $\ll$주당분지수의 순으로 뚜렷한 감소를 보이는 특징이었다. 4. 우리나라 대두품종에 대한 Metribuzin의 사용은 Pre-sowing이나 Pre-emg.가 추천되며, 특히 Pre-sowing에 대한 토양혼화법 연구와 단제보다는 혼용처리의 이점을 찾을 필요가 있다.