Rajagopal, V.Patil, K.D.Amma, B.S.K.2014-09-022014-09-022007Placrosym VIhttp://hdl.handle.net/123456789/5292The in vivo nitrate reductase activity (NRA) was studied in apparently healthy and root (wilt) diseased coconut palms. The enzyme activity was more in the leaves of the middle whorl, followed by those of the outer whorl, than either in the spindle leaf or the first fully open leaf. In all the leaves studied, the diseased palms had higher activity than in the apparently healthy palms. The enzyme activity was influenced by the light intensity. Irrespective of the palm condition the NRA was higher at high light intensity (1250 to 1400µE m-2s-1) than that at low light intensity (250 to 500/iE tn-s1). Again, the activity of enzyme in apparently healthy palms was less than that in the diseased palms. With increase in the level of nitrogen application there was increase in NRA both in apparently healthy and diseased palms, the latter recording relatively high activity. The response of palms to simulated stress indicated that the enzyme was adversely affected in both the palms. The study thus revealed disturbed nitrogen metabolism caused by the root (wilt) disease.enArticle