Changes in biochemical metabolites and growth of garlic by evapotranspiration-based irrigation regime

Growing garlic, the main ingredient of Korean kimchi, is becoming increasingly difficult due to climate change, especially frequent droughts and rising temperatures. In this study, an irrigation method based on evapotranspiration was investigated to address the inefficient water use of conventional irrigation methods. To find out the effect of this method on drought resistance of two garlic varieties (‘Namdo’ and ‘Hongsan’), hormone adaptation through the abscisic acid metabolites (ABAs), which regulate the water stress response of plants, was analyzed. The ‘Namdo’ showed remarkable adaptability in Penman-Monteith (PM)-based irrigation, with a 205 % increase in phaseic acid levels compared to the conventional method. The PM-based irrigation method kept garlic in optimal moisture conditions while reducing water consumption by 34 %. This improved water efficiency and hormone adaptation were achieved without impeding the synthesis of useful compounds, such as allicin and other organosulfur metabolites, which determine the nutritional and medicinal value of garlic. Evapotranspiration-based irrigation succeeded in optimizing water use while maintaining the quality of garlic crops in drought conditions. This approach could be useful for areas experiencing water scarcity, and it has the potential to be applied to other high-value crops with similar physiological responses to water stress.