Browsing by Author "Amma, B.S.K."

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    Carbonic anhydrase, biologically active zinc and carbon fixation in coconut palm
    (2007-02-08) Dwivedi, R.S.; Chacko Mathew; Michael, K.J.; Amma, B.S.K.; Ray, P.K.; Sunny Ninan
    Activity of carbonic anhydrase in the first fully opened leaf (FFL) of erect canopied palms (EC) was higher than that of spherical canopied palms (SC) but the reverse was true in case of middle leaves (ML). The carbon fixation rate of FFL and ML of SC palms did not differ significantly but in EC palms CO2 assimilation of former leaf was higher than latter one. However the C02 assimilation rate in FFL of EC palms did not differ markedly with FFL and ML of SC palms. But C02 fixation in ML of SC palms was significantly higher than that of EC palms. This is correlated with EDTA-zinc (biologically active zinc) but not with total zinc, since in all types of palms the total zinc ranged from 24-28ppm. Also the nut yield in SC palms was found to exceed by 1.2-2.5 times over that in EC palms. Irrespective of canopy structure, the root (wilt) dieseased palms also showed the same trend as that of EC palms. The correlation coefficient values of biologically active zinc, total zinc and carbonic anhydrase was found to be 0.94, 0.66 and 0.78, respectively, with CO2 assimilation rate; and 0.90, 0.56 and 0.76, respectively, with nut yield. This reveals that it is not the total zinc but it is carbonic anhydrase activity and the biologically active zinc which play an important role in regulating CO2 fixation and nut yield of coconut.
  • Thumbnail Image
    Item
    Certain closely associated morphological symptoms of root (wilt) disease of coconut (Cocos nucifera)
    (2007-02-08) Snehi Dwivedi, R.; Chacko Mathew; Ray, P.K.; Amma, B.S.K.; Sunny Ninan
    The morphological symptoms of root (wilt) diseased coconut palms are manifested by softening and whitening of leaflets of the spindle with necrotic spots followed by rotting. Interveinal yellowing in the leaves of the middle whorl was an additional symptom. These symptoms are important in the early diagnosis of the disease in field-grown palms.
  • Thumbnail Image
    Item
    Diagnosis
    (2007-02-08) Sasikala, M.; Amma, B.S.K.; Rajagopal, V.
  • Thumbnail Image
    Item
    In Vivo Nitrate Reductase Activity In The Leaves Of Apparently Healthy And Root (Wilt) Affected Coconut Palms
    (2007) Rajagopal, V.; Patil, K.D.; Amma, B.S.K.
    The 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.