Growth and Nutrient Uptake of Red Pepper Plug Seedlings as Influenced by Various Day and Night Temperatures

This study was conducted to investigate the effects of various day and night temperatures on the growth and nutrient uptake of red-pepper plug seedlings and to obtain image data related to the growth of these seedlings.The temperature was controlled at three levels: 15°C (day, D)/10°C (night, N), 20°C (D)/15°C (N), and 25°C (D)/20°C (N), and the experiment involved 'AT Sinhotan', 'Allbokhap', and 'Callatan' peppers.After sowing in 72-cell plug trays, germinated seedlings were raised in temperature-controlled growth chambers and growth was investigated 39 and 70 days after sowing.The higher the day and night temperature, the larger or wider the plant height and leaf area of the three cultivars.At 70 days after sowing, 'AT Sinhotan' peppers in the 25°C (D)/20°C (N) were tallest with a plant height of 29.4 cm, and the 'Callatan' peppers in the 20°C (D)/15°C (N) condition were thickest with a stem diameter of 3.57 mm.The number of nodes was highest in the 'AT Sinhotan' peppers in both 20°C (D)/15°C (N) and 25°C (D)/20°C (N) treatments with eleven nodes.Fresh weight was greatest in the 25°C (D)/20°C (N) case among all cultivars, but the dry weight was not significantly different compared to that in the 20°C (D)/15°C (N) condition.Seedling compactness was greatest at 15°C (D)/10°C (N), but the plant height was less than 7 cm in this treatment, implying that it is unsuitable for transplanting, with the 20°C (D)/15°C (N) treatment judged to be suitable.The 'Allbokhap' peppers had the highest number of leaves and the largest leaf area under the 25°C (D)/20°C (N) treatment, at 15.3 and 156.5 cm 2 , respectively.The SPAD values were highest in the 'Allbokhap' and 'Callatan' peppers under the 15°C (D)/10°C (N) treatment.These results suggest that 20°C (D)/15°C (N) is suitable for shortening the seedling raising duration and reducing production costs.