Influence of nitrogen on grain grade index and some yield related physiological characteristics in rice (Oryzu sativa L.)

Abstract

Investsgatiosis were carried out to study the effects of varying nitrogen (N) levels on certain physiological c parameters and yield characteristics of rice with special emphasis on grain grade index. Three short duration rice varieties viz., ADT 36, DR. 50 and Co 37 were selected and N was applied at five levels viz., 0,50, 100,150 and 200 kg ha'1 along with 50 kg P and 50 kg K ha'1. Experimental results revealed that higher dose of N increased the total chlorophyll content, soluble protein and nitrate reductase activity in all the three varieties in vegetative, flowering and harvest stages. Although increased N application had significant effect on grain yield, there was a negative relationship between grain grade index and N. The comparison of varieties exhibited the superiority Co.37 in all the physiological and biochemical parameters studied, and in the grain yield.