Studies in crop physiology - Effect of nitrogen, phosphorus and potassium deficiencies on respiration rate of sugarcane leaves

Abstract

The paper narrates the results of an experimental enquiry on respiration rate of sugarcane leaves of different stages of development under four conditions of nutrition, viz., complete nutrition, nitrogen deficiency, phosphorus deficiency and potassium deficiency. The experiments were conducted at maturity stage on five varieties of sugarcane, e.g., Co 453, Co 421, POJ 2878, Co 205 and Rheora grown in sand in pots. Co 205 and Rheora show high leaf respiration as compared with Co 453 and POJ 2878, having significantly lower respiration rates. No differences in leaf respiration upto the third or fourth leaf stage are noted; beyond this the greater the stage of leaf development, the lower is the respiration of leaves. Nutritional conditions bring about considerable changes in respiration of leaves. Thus nitrogen deficiency shows normal leaf respiration at maturity as compared with either phosphorus or potassium deficiency, each of which exhibit supernormality in respiration. Variations in respiration rate under these conditions appear to be determined by changes in chemical composition of leaves, particularly nitrogen and carbohydrate fractions. Observed differences in respiration are discussed in the light of such changes. © 1951 Indian Academy of Sciences.