The diagnosis of sulphur deficiency in wheat

Abstract

In a glasshouse experiment with wheat (Triticum aestivum L.), changes in the concentrations of total sulphur, sulphate sulphur, amide nitrogen, and total nitrogen/total sulphur ratio with age, plant part, and nitrogen and sulphur supply, were studied. This was done so that more reliable methods can be devised for the assessment of the sulphur status of this species.

Each of the indices studied was strongly related to the current and subsequent sulphur status of the wheat plant. Amide nitrogen provided the greatest relative change in values between sulphur-deficient and sulphur-adequate plants, and on that basis was the most sensitive index. However, each of these indices had shortcomings which could preclude its general acceptance as a useful indicator of sulphur status.

The most promising index of sulphur status was shown to be the proportion of total sulphur held as sulphate. This criterion was unaffected by nitrogen supply or plant age. The data suggest that wheat plants containing more than one-tenth of their sulphur as sulphate are adequately supplied with sulphur.