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

This study assessed shoot growth, bulb development, and mineral content of southern-type garlic (Allium sativum L.) in a temperature gradient tunnel (TGT), to examine effects of temperature increase. TGT temperatures in the middle and outlet were maintained at +3°C and +6°C higher, respectively, than ambient temperatures at the inlet. The germination of garlic cloves occurred at 19.2 days after sowing near the inlet, yet occurred at 23.5 and 25.0 days, respectively, in the middle and outlet. At ambient and +3°C temperatures, bulbs developed well, with clove size and shape large and uniform, resulting in a high-quality commodity with high post-harvest commercial value. In all temperatures, 7-8 cloves per bulb developed, but small secondary cloves developed from the cloves in the transverse sections of bulbs grown in the middle and outlet of the TGT. The surfaces of cloves showed a distinct purple color at ambient +3°C. In addition, at elevated temperatures, the Ca and Zn content in the cloves decreased, while the K and Fe content increased, indicating that the rising temperature affects mineral absorption of garlic. Implications of this study include possible delays to sowing time, and/or delayed harvest, as a response to climate change, to avoid irregular small-sized cloves caused by secondary growth in the bulb. The results of this study, therefore, are important to maintain the productivity and quality of garlic in the future, as it becomes necessary to mitigate impacts of elevated temperature at each stage of growth.