Relationship between Selenium and Sulfur Assimilation and Resultant Interaction on Quality Parameters in Onion

Abstract

The relationship between selenium (Se) and sulfur (S) uptake and their interaction on the pungency and quercetin contents of onion was investigated in a sand culture trial under polyhouse conditions. The results indicated that application of Se with increasing rates produced an antagonistic effect on S assimilation. An amount of 20 kg Se ha^–1 drastically reduced the S content in onion bulbs. Further, the pungency and quercetin concentration also declined. Foliar application of Se at 1.0 ppm resulted in production of bulbs with lower levels of pungency and quercetin. Though Se is essential from a health point, its application up to 10 kg ha^–1 was sufficient for enriching onions without much effect on the other essential bulb quality parameters.

Keywords:

• Onion
• pungency
• pyruvic acid
• quercetin
• selenium
• sulfur

Acknowledgment

The authors express gratitude to the Indian Council of Agricultural Research (ICAR, New Delhi) for the approval of an AP-Cess fund project for this important study.