Thursday, August 11, 2016
Georgia Ballroom (Sheraton Hotel Atlanta)
Pepper (Capsicum annuum L.), belonging to the Solanaceae family, is an economically important crop in Korea and cultivated widely as a spice crop. Pepper plants have originated in South America and spread in a wide range of warm, subtropical and tropical regions throughout the world. During the growing season, various climatic and soil factors, including air temperature, light intensity, and precipitation, and soil conditions, have impacts on the growth and development of pepper plants. Particularly, the temperature is one of most major environmental factors impacting on processes such as flowering, fruit set, and fruit growth. In this study, we investigated the impact of temperature stress on the vegetative growth, fruit development, and the fruit quality of the plants. The temperature ranges of 20-25°C was optimum for the vegetative growth and fruit development of plants. On the other hand, the high temperature (30°C) reduced generally the fruit development such as the fruit-set and fruit growth, although enhanced the vegetative growth. The low temperature (15°C) caused the short shoot height, and the small number of main branches (nodes), whileas resulted in the elongate fruits, and the long green fruit period. Under conditions of optimum temperature (20-25°C) and high temperature (30°C), the fruit development was advanced by 15 and 20 days, respectively, compared to that of the plants at low temperature (15°C). Furthermore, the fruit color change was significantly advanced in the optimum temperature (20-25°C) and high temperature (30°C). However, high temperature (30°C) not only reduced the number of total fruits, but also increased the number of short or malformed fruits. Total free sugar contents of red-ripe fruits were significantly higher in the optimum temperature (20-25°C), while capsaicinoid contents of red-ripe fruits increased with the rise of temperature in the range of 15 to 30°C.