무경운 논에서 제초제 체계처리에 따른 잔존잡초와 벼의 수량 (The Remaining Weed Species and Rice Yield by Sequential Application of Herbicide in No-Tillage Paddy Fields)

서지정보

· 발행기관 : 한국잡초학회
· 수록지 정보 : Weed&Turfgrass Science / 22권 / 3호 / 243 ~ 253페이지
· 저자명 : 국용인, 권오도

초록

본 연구는 1993～1997년까지 무경운 상태로 벼를 담수직파, 어린모 및 중묘 기계이앙한 논에서 발생한 잡초를 방제하기 위하여 파종 또는 이앙 전 20일에 glyphosate 단독처리와 glyphosate, pretilachlor 및 pyrazosulfuron + molinate를 체계처리하여 잔존잡초와 벼의 수량감소을 조사하였고, 몇 가지 제초제를 사용하여 이들 잔존잡초에 대한 방제효과를 검토하였다. 파종 또는 이앙 전 20일에 glyphosate만 처리한 후, 잔존한 잡초종수는 재배양식간 차이가 적거나 없었으며, 잔존한 전체 잡초중은 담수직파 > 어린모이앙재배 > 중묘이앙재배 순으로 많았으며 특히 잔존량이 많았던 초종은 담수직파와 어린모이앙재배에서는 사마귀풀이었고 중묘이앙재배에서는 올방개이었다. 체계처리한 무경운 재배양식별 잡초 잔존량은 glyphosate 단독처리와 동일하게 담수직파 > 어린모이앙재배 > 중묘이앙재배 순이었고 가장 많이 잔존한 잡초종은 사마귀풀, 올방개 및 나도겨풀이었다. 그러나 glyphosate 단독처리에 비해 glyphosate를 처리하고 pyrazosulfuron + molinate을 표준량을 처리한 무경운 담수직파에서는 59-84%, 어린모 기계이앙에서는 74-98% 그리고 중묘 어린모이앙재배에서는 84-86% 방제가를 보였다. 따라서 제초제 체계처리 후에도 완전 방제되지 않고 잔존한 사마귀풀과 나도겨풀의 방제법을 찾고자 수종의 제초제를 처리하였다. 벼 무경운 담수직파재배에서 사마귀풀을 방제하기 위해 사용한 토양처리제 butachlor, pretilachlor, pyrazosulfuron + pretilachlor, bensulfuron-methyl + thiobencarb 처리에서 모두 96% 이상의 방제가을 보였으나 pyrazosulfuron + molinate 처리에서만 23.5 %로 매우 낮았다. 또한, 경엽처리제 제초제 2,4-D와 bentazon는 사마귀풀의 방제에 거의 효과가 없었고 pyrimidyloxy benzoate 계통의 pyribenzoxim을 처리했을 때는 거의 완전방제가 가능하였다. 무경운 논에 발생한 나도겨풀을 방제하기 위하여 사용한 pyribenzoxim과 fenoxaprofop + bentazon의 처리에서는 방제효과가 아주 낮았다. 모든 무경운 벼재배양식의 glyphosate 단독 처리에서는 손제초구에 비해 51-87% 벼 수량감소가 되었고, 체계처리에서는 손제초구에 비해 담수직파에서 23.7%, 어린모 기계이앙재배에서 9% 감소를 보였으나 중묘 기계이앙 재배에서는 수량감소가 없었다. 따라서 무경운 벼 재배에서 수량감소를 줄이기 위해서는 중묘기계이앙 재배를 하거나 무경운재배에 문제시되는 사마귀풀, 나도겨풀 및 올방개 등의 잡초종 방제를 위한 새로운 제초제 체계처리법이 확립되어야 할 것이다.

영어초록

This study was conducted to investigate the remaining weed species after a glyphosate application at 20 days before rice seeding (DBS), transplanting (DBT) or sequential application, and a glyphosate application at 20 DBS, DBT followed by pretilachlor at 2 days after flooding followed by pyrazosulfuron + molinate at 13 days after transplanting (DAT) in three different cultivation methods of direct-seeded, and transplanted 10-day-old or 30-day-old seedlings under no-tillage conditions from 1993 to 1997, to examine the level of reduction of rice yield as affected by the remaining weed species, and to confirm the controlling effect of using various herbicides to control troublesome weeds. There was little or no difference in the number of total remaining weed species in cropping patterns of no-tillage paddies after a glyphosate application at 20 DBS or DBT. The total weight of the remaining weed species, ranked from highest to lowest, was direct-seeded > 10-day-old seedlings > 30-day-old seedlings. Especially, the highest remaining weed species was Aneilema keisak in direct-seeded and transplanted 10-day-old seedlings and Eleocharis kuroguwai Ohwi in 30-day-old seedlings during no-tillage. In sequential application, the weight of the remaining weed species by cropping patterns of rice under no-tillage, ranked from highest to lowest, was direct-seeded > 10-day-old seedlings > 30-day-old seedlings similar to the glyphosate application. The remaining weed species were mostly Aneilema keisak, Eleocharis kuroguwai Ohwi, and Leersia japonica. The controlling effects on sequential application, glyphosate application followed by pyrazosulfuron + molinate showed 59-84% in direct-seeded, 74-98% in transplanted 10-day-old seedlings, and 84-86% in 30-day-old seedlings under no-tillage compared with a glyphosate application alone. Therefore, we treated with various herbicides to find out the control methods of Leersia japonica and Aneilema keisak, which were not controlled by sequential application. Aneilema keisak in direct-seeded of no-tillage paddies was controlled by 96% by the soil application of butachlor, pretilachlor, pyrazosulfuron + pretilachlor or bensulfuron-methyl + thiobencarb at their respective recommendation rates at 20 days after rice seeding, and was controlled by 23.5% by pyrazosulfuron + molinate. Aneilema keisak was almost not controlled at all by the foliar application of 2,4-D and bentazon, but the Aneilema keisak was completely controlled by pyribenzoxim of the pyrimidyloxy benzoate family. In addition, the controlling effect of Leersia japonica in no-tillage paddy fields was lowered by pyribenzoxim and fenoxaprofop + bentazon. Rice yield in glyphosate application alone in all cropping patterns of no-tillage paddies was reduced by 51-87%, compared with hand weeding. On the other hand, rice yield in sequential application in direct-seeded, 10-day-old seedlings, and 30-day-old seedlings was reduced by 23.7%, 9%, and 0% respectively compared with hand weeding. Therefore, to prevent rice yield from being reduced in no-tillage paddy fields, we suggest the cultivation method of 30-day-old seedlings instead of direct-seeded and transplanted 10-day-old seedlings in no-tillage paddies and we have to find out new methods of sequential application for control of troublesome weeds such as Aneilema keisak, Leersia japonica, and Eleocharis kuroguwai Ohwi etc. in no-tillage rice cultivation.

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