Biofortifying drought-tolerant rice: enhancing growth and nutritional quality with foliar iron and zinc applications in Eastern India

Abstract

Micronutrient deficiencies in staple food crops pose a significant global health concern, especially in regions prone to drought. Agronomic biofortification offers a promising solution by enhancing the content of essential micronutrients. This study aims to identify efficient rice varieties for iron (Fe) and zinc (Zn) biofortification through foliar applications. A field experiment was carried out during kharif season in 2019 and 2020 with four drought-tolerant rice varieties (Swarna Shreya, Swarna Shakti Dhan, Sahbhagi Dhan, and DRR Dhan 42) were assessed under four foliar applications of Fe and Zn (control, 1% of Fe, 1% of Zn and combined 1% of Fe + 1% of Zn) at Indian Council of Agricultural Research-Research Complex for Eastern Region (ICAR-RCER), Patna. The highest grain yield of 5.65 t/ha was attained with the main plot treatment, Swarna Shreya variety, and in the subplot treatment, Fe + Zn foliar application resulted in a yield of 5.50 t/ha. The combined foliar application of Fe + Zn demonstrates the highest chlorophyll content and starch synthesis. Foliar application of combined Fe and Zn increased paddy grain Fe and Zn concentration by up to 30 and 16%, respectively, compared to the control. This finding is important for addressing micronutrient deficiencies in regions where rice is a dietary staple. Thus, Swarna Shreya, in combination with iron and zinc foliar application is a promising option for enhancing yield and fortifying grains in rainfed areas of eastern India.