고추 유묘의 생장, 광합성, 호흡 및 양수분흡수에 미치는 온도 및 주야변온의 영향을 구명하기 위하여 환경조절이 가능한 생장상내에서 실험을 수행한바 얻어진 결과는 다음과 같다. 1. 고추육묘시 적온으로 생각되는 $25^{circ}C$에 비하여 온도가 12$^{circ}C$로 저하함에 따라 수분 및 N, P, K 양분흡수에 현저한 감소를 보였으며, 5$^{circ}C$에는 양수분의 흡수가 거의 이루어지지 않았다. 2. 엽의 광합성은 5$^{circ}C$에서 $25^{circ}C$까지는 점차적으로 증가되다가 $25^{circ}C$에서 최대광합성을 보였으며, 엽과 근의 호흡은 온도가 증가할수록 계속 증가하였다. 3. 지하부 건물중이 가장 높은 적정 주야온도조합은 주간 3$0^{circ}C$와 야간 $25^{circ}C$로 나타났고, 주/야 온도 25/$25^{circ}C$, 30/15$^{circ}C$, 25/15$^{circ}C$, 15/$25^{circ}C$, 10/$25^{circ}C$ 간에는 큰 차이가 있었으며, 야간온도 5$^{circ}C$에서는 주간온도에 관계없이 지상부 건물중 증가가 거의 없었다.
The effect of day and night temperature on the seedlings growth as well as physiological responses of red pepper seedlings to temperature, such as uptake of water and nutrients, rates of photosynthesis and respiration of leaf and root were also investigated in growth cabinet. The results obtained were as follows ; 1. As the temperature dropped down to 12$^{circ}C$, the uptake of water and nutrients, nitrate, phosphorus and potassium were decreased drastically. At 5$^{circ}C$ there was virtually no uptake of water and nutrients. 2. Photosynthetic activity in the leaves of red pepper seedlings was increased gradually from 5$^{circ}C$ to $25^{circ}C$ and observed the highest photosynthetic activity at $25^{circ}C$, but respiratory activity of leaf increased up to 3$0^{circ}C$ and the same trend was observed in root respiratory activity. 3. Optimal combination of day and night temperature for shoot dry weight which is the decisive criterion of good seedlings of red pepper was found to be $25^{circ}C$ at nighttime and 3$0^{circ}C$ at daytime and then day/night temperature showed in the order of 25/25, 30/15, 15/25, 10/$25^{circ}C$. No increment of shoot dry weight at 5$^{circ}C$ in nighttime temperature observed regardless of daytime temperature.
