2019 ASHS Annual Conference

Hot pepper is a typical warm crop that can retard growth under low temperature and light intensity conditions, and reduced production can be occurred. Recently, there are frequent phenomena that are extreme weather in low temperatures and light intensity in springtime after hot pepper transplanting in open field or a greenhouse. This research objective was to evaluate the effects of low temperature and light intensity on the growth and yield of hot pepper. The treatments were set to two levels of air temperature (ventilation set points 20 and 15^oC, respectively) and three levels of light intensity (at zero, 30 and 60% shading ratio), respectively, in the plastic tunnel house, and the transplanting data was made approximately one week ahead of the conventional practice at the end of April and early May. After seven days of low temperature and light intensity treatments, we measured the plant height, length to branch, leaf area, fresh and dry weight of hot pepper, and compared the growth and yield of hot pepper about four months after its application. There was no difference between the plant height, length to branch, and leaf area of seven days after the low temperature and light treatments (initial stage), however the photosynthetic rate was reduced by low air temperature and light intensity (data not shown). After four months treatments, the plant height of hot pepper with control showed 175.4 cm/plant which was the greatest among all the tested treatments, while the fresh and dry weight was the highest 2206.9 and 580.9g/plant, respectively, at 30% shading and low temperature treatment conditions. In addition, the total fresh and dry weight of hot pepper with 30% shading and low air temperature treatments were greatest. The effect of early cold and low light treatments was almost extinguished on hot pepper’s growth and yield. Results indicated that the early growth after transplanting can affect by light shading ratio and hot pepper growth might be cope with extreme weather throughout the proper cultural practices during growing period.