Horticultural Science and TechnologyISSN:1226-8763(Print) 2465-8588(Online)원예과학기술지

Photosynthesis, growth, and clove formation were investigated in southern-type garlic (Allium sativum L.) grown under different day/night temperature regimes (11/7, 17/12, and 23/18°C) using soil-plant-atmosphere-research (SPAR) chambers to determine the optimum cultivation temperature and assess the impact of low- and high-temperature stress on garlic plants. Garlic grown at 17/12°C had the greatest height, bulb diameter and length, bulb fresh weight, and numbers of normal cloves per bulb at harvest time. Furthermore, the net photosynthetic rate (A_max) was high and the dark respiration rate (R_d) was low during the growth stage. Conversely, garlic grown at 23/18°C had enhanced secondary growth when harvested, including continuous growth of cloves of primary plants and/or the growth of bulbil buds into secondary plants. Garlic harvested from plants grown under the 11/7°C regime had small bulbs and immature cloves because vegetative growth was incomplete. In addition, garlic grown at 23/18°C and 11/7°C had low A_max and high R_d during the growth stage. These findings indicate that the 17/12°C temperature regime is favorable to the growth of garlic plants and may be better for producing optimum commercial products with bulbs and cloves of regular shape and size. Garlic grown at 23/18°C should be harvested earlier to prevent damage caused by high temperature, whereas garlic grown at 11/7°C should be harvested later to increase the growth period.