Role of Sulphur in Onion Production

Sulphur is an important component of enzymes and other proteins, and is required for chlorophyll formation. It has a marked effect on the pungency of the onion through increasing the pyruvic acid content of the bulb – a key quality characteristic.

Sulphur effect at growth stages

Stage Sulfur effect
Pre-Planting Encourage plant growth
Bulb Fill Depending upon the desired pungency of the onion
See more on Onion Growth Stages.

General Guidelines for Sulfur Application

Most sulphur uptake occurs in late season during bulb growth. Sulphur helps to improve the crop's utilization of nitrogen. Plants with a high sulphur content have greater tolerance to pest and disease attack. Sulphur has also been linked to increasing skin strength and color.

Sulphur Deficiencies in Onion

Leaf production is affected and the plant produces fewer leaves. Younger leaves are uniformly yellow in color.