Effects of Planting Dates on Dry Matter Production and Ecological Characteristics of Soybeans(Glycine max. (L.) Merr.) in Southern Region of Korea

남부지역 콩 파종기에 따른 품종간 건물생산 및 생태적 특성

The object of this study was to investigate the differences in dry matter production, physiological characteristic and grain yield of soybean (Glycine max (L.) Merr.) as affected by planting dates in southern region of Korea. This experiment was conducted using four planting dates and four varieties over 3 years (1982-1984). The different responses of soybean varieties to different temperature and daylength, days from planting to flowering were ranged from 43 to 55 days when planted on May 10 long daylength and low temperature condition. Flowering duration was ranged from 12 to 27 days and 9 to 13 days for the plantings made on May 10 and July 9, respectively. Therefore, it was the shortest under the short daylength and high tempera-ture condition. It also appeared that the later planting caused the lower dry matter weight and leaf area index which resulted in lower grain yield. But grain yield was not directly correlated with the unbalance of Xink/Source Ratio and the lodging from excessive vegatative growth. The grain yield was the highest in May 30 and the lowest in July 9 planting: it was ranged from 2.26 to 2.55 t/ha in the former and 0.85 to 1.20 t/ha in the latter, respectively. The increase in yield was depended on the increase in the number of pods per plant, the number of seeds per pod and the seed weight. The distribution ratio of dry matter to leaves was the hightest at the sixth trifoliolate leaf stage and gradually declined thereafter in all planting dates, and it also appeared that the later planting, the lower the ratio of dry matter to leaves.

본시험은 남부지역에 있어서 파종기 이동이 콩의 건물생산능력 및 생리, 생태적특성에 미치는 영향을 파악하여 적정 파종 한계기를 제시하고자 ＇82년∼＇84년도 3개년에 걸쳐 시험을 실시하였던바 다음과 같은 결과를 얻었다. 1. 만파할수록 개화일수, 성숙기 개화기간 등은 크게 단축되었고 품종가 차이도 인정되었으며 엽후는 만파에 의하여 두꺼워지는 반면, 엽면적은 감소하였고, CGR은 활엽기를 전후하여 뚜렷한 차이를 보였는데 7월 9일 파종기는 타 파종기의 50% 내외의 작물생자율을 나타내었다. 2 건물중은 만파할수록 현저히 감소되었으나 100 입중을 제외한 다른 수량구성요소는 5월 10일과 5월 30일간에 비슷한 경향을 나타냈다. 3. 10a당 수량은 5월 10일 파종구 225kg, 5월 30일 239kg, 6월 19일 188kg, 7월 9일은 101kg으로 5월 30일 파종구의 수량이 가장 높았으며 품종간에는 단엽콩이 파종기 이동에 의한 수량변이폭이 가장 작았다.