Functions of S :- Visual symptoms :- Predisposing factors:- Corrective measures :- Sulphur is taken up by the plant roots in the form of a divalent anion SO4-2 at relatively low rates. Reduction of sulphur is necessary for the incorporation into proteins, amino acids and coenzymes. Under conditions of sulphur deficiency, protein synthesis is inhibited or proteins of low sulphur content are synthesized. Sulphur is a structural constituent of several co-enzymes and prosthetic groups such as ferridoxin, biotin and thiamin phosphate and sulphur deficiency impairs the synthesis of these compounds. Sulphur requirement for optimal growth varies between 0.2 and 0.5% of the dry weight of the plants. Under conditions of sulphur deficiency, inhibition of protein synthesis is correlated with an accumulation of soluble organic nitrogen and nitrate. The sulfate content was extremely low in deficient plants and hence sulfate sulphur content rather than total sulphur is more sensitive indicator of sulphur nutritional status of the plant. Sulphur deficiency results in chlorosis and it is uniform among old and young leaves unlike nitrogen deficiency induced chlorosis. Sulphur deficiency results in light green colour of the plant as a whole, though there is tendency for the young leaves to be lighter than the older ones. High Rainfall reduces sulphur availability in soils as it is readily leaches from the soil Sulphur deficiency seldom occurs under normal tobacco cultivation as sulfate containing potassium fertilizers, single super phosphate, ammonium sulphate are liberally used.

Back