Symptoms
The upper leaves are the first ones turning yellowish green an subsequently yellow. Under severe deficiency, all leaves may become yellow, resulting in stunted growth.
Necrosis occurs as point-shaped spots or marginal necrosis along the leaf edge.
Reasons
Sulphur deficiency
Unlike nitrogen, sulphur deficiency appears on younger leaves first.
Leaf symptoms resemble those of N or P deficiency while the development of thin, hard and elongated stems is typical for S deficiency.