Clove Seed Sprouting and Bulb Growth in Garlic (Allium sativum L.) in Response to Varying Temperature

Garlic (Allium sativum L), one of the oldest cultivated crops, is the most widely used Allium species belonging to the family Amaryllidaceae. It is consumed in both fresh and dried forms as an important ingredient for flavouring various vegetarian and non-vegetarian dishes. In addition, garlic has several medicinal values such as anticancer, antibacterial, and antifungal agents, etc. In this study, the effects of varying temperature on clove seed sprouting, vegetative growth and bulb development of garlic were investigated. High temperature above 23°C enhanced vegetative growth (shoot height, pseudo stem diameter, and number of leaves) during the initial growth of garlic plants, suggesting that the high temperature affects positively on the growth of the aerial part of garlic. However, bulb development and growth during the intermediate or final growth of garlic plants was best in the temperature ranges of 17-23°C. Furthermore, the bulb quality at harvest was significantly high in temperature below 20°C, whereas generally low in high temperature, especially at temperatures over 30°C. Cross section of garlic bulbs showed that cloves were formed normally in the temperature ranges of 14-17°C, while, in the temperature below 14°C or above 17°C, secondary growth of cloves was induced.