온도ㆍ토양수분 포텐셜 및 삼투처리가 옥수수와 대두의 발아 및 묘신장에 미치는 영향

Effect of Temperature, Soil Water Potential and Osmoconditioning on Germination and Seedling Elongation of Corn and Soybeans

옥수수품종 (Dekalb XL 72B)과 대두품종 ( Willi -ams)의 발아와 묘신장을 두 온도, 세 토양수분 포텐셜 및 네 polyethylene glycol(PEG) 8,000 수준에서 측정하였다. 각 품종의 20처리종자를 0.2% Thiram에 처리하여 가비중 1.20으로 압축된 살균사양토에 2.0cm 깊이로 파종 분할구배치법 사반복으로 실시하였다. 1. PEG로 한 삼투처리는 고온에서나 저토양수분포텐셜 조건에서 효과가 거의 없었다. 2. 대두는 옥수수보다 높은 묘수분함량을 보였고 두 작물 모두 토양수분 포텐셜과 온도가 증가할수록 수분흡수가 증가되었다. 3. 옥수수의 묘장이 35$^{\circ}C$에서는 대두보다 길었으나 15$^{\circ}C$에서는 짧았다. 4. 옥수수의 건물중은 35$^{\circ}C$에서 감소되었고 대두의 건물중은 토양수분 포텐셜이 증가할수록 감소되었다.

Germination and seedling elongation of maize (Dekalb XL 72B), and soybeans (Williams) were measured at two temperatures (15 and 35$^{\circ}C$), three soil water potentials (-1.50, -0.5, and -0.05 MPa), and four polyethy-lene glycol 8000 (PEG) levels (0, 20, 30, and 50 percent). Twenty conditioned seeds of each cultivar were treated with 0.2% thiram and planted 2 cm deep in sterilized Mexico silt loam soil which was subsequently compacted to a bulk density of 1.20 g/㎤. Seedling moisture content, dry weight, and length were measured for each treatment combination. Osmoconditioning with PEG showed little effect at high temperature or low soil water potential conditions. Soybeans had higher seedling moisture content than corn and both crops in-creased moisture uptake as soil water potential and temperature increased. Seedling length of corn was longer than soybeans at 35$^{\circ}C$ but shorter at 15$^{\circ}C$. Seedling dry weight of corn decreased at 35$^{\circ}C$ and that of soybeans decreased as soil water potential increased.