Foliar Spray with Selenium to Mitigate the Impact of Water Stress on Chemical, Enzymatic, and Hormonal Parameters of Garlic Allium sativum L.

Abstract

The current research explored the beneficial role of selenium (Se) in alleviating the negative impacts of water stress on the chemical, enzymatic, and hormonal parameters of garlic plants via manipulating chemo-physiological mechanisms. A field experiment was executed at the research station of the Faculty of Agriculture, University of Kufa, Iraq in September 2022 using a randomized complete block design with three replicates based on a strip-plot system. Three water levels (100%, 80%, and 60%) were set up in the whole plots while foliar application of selenium (Se) with three concentrations (0, 10, and 20) mg.L-1 were assigned to the subplots. Our findings revealed a significant increase in the leaf content of free proline acid, sulfur, and ABA, as well as an increase in the activity of the antioxidant enzymes SOD and CAT when reducing irrigation levels from (100% to 60%) of the water requirement. While there was a significant decline in the plant hormones GA3 and IAA content in garlic leaves @ (60%) level of irrigation. The plants treated with foliar selenium @ (20 mg.L-1) enhanced most of the studied characteristics of garlic plants grown at different water levels. Moreover’ the full water requirement in combination with foliar Se @ (20 mg.L-1) provided the highest values of GA3 and IAA which were both comparable to the interaction treatment of water level @ (80%) and foliar Se @ (20 mg.L-1).