Whenever the S status of growing plants drops below the critical level required, visual symptoms of S deficiency start appearing on the plant. The appearance of such symptoms indicates a serious condition because crop yields can decrease even without the appearance of such symptoms.

<----- Tomato plant with S (L), without S (R)

Sulphur deficiency symptoms in many ways resemble those of N - that is, the leaves become pale-yellow or light-green. Unlike N, S-deficiency symptoms appear first on the younger leaves, and persist even after N application. In cotton, tobacco and citrus, some of the older leaves are affected first.

Cabbage plant without S (L), with S (R) ------>

Plants deficient in S are small and spindly with short and slender stalks, their growth is retarded, maturity in cereals is delayed, nodulation in legumes may be poor and N-fixation reduced, fruits often do not mature fully and remain light-green in color, forages contain undesirably wide N:S ratio and thus have lower nutritive value.

<----- Sorghum plant with S (L), without S (R)

When S deficiency symptoms have been confirmed, soil application through a material containing readily available S such as one in the sulphate form should be applied.

Tobacco plant without S (L), with S (R) ----->