Importance of growth hormones and temperature for physiological regulation of dormancy and sprouting in onions

ABSTRACT

Onion is one of the most cultivated crops, and its production is increasing worldwide. Proper handling and storage will add huge benefits to the supply of onion to meet the demand of consumers. For storage, it is important to understand onion physiology from the day it was harvested from the field until it reaches the market. This review summarizes the scientific literature related to the physiology of the onion bulb with respect to growth regulators, temperature, and chemical controls. The biochemical changes that occur during dormancy break and sprouting have been discussed in detail. The three main environmental factors that can influence onions during storage are temperature, humidity, and composition of the atmosphere in the storage area. Among these factors, temperature plays a paramount role in the physiology of onion during pre- and postharvest storage. Particular emphasis was given to plant growth hormones (endogenous and exogenous) and their consequent effects with respect to dormancy, sprouting, and biochemical changes that occur in onions.

KEYWORDS:

• Dormancy
• onion
• plant growth regulators
• sprouting
• storage
• temperature

Acknowledgments

This paper was supported by the KU Research Professor Program of Konkuk University, 2015, Konkuk University, Seoul, Republic of Korea.