Browsing by Author "Dwivedi, R.S."

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    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.
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    Efficiency of different methods of fertiliser application in coconut using radio-isotope technique
    (2007-02-08) Ray, P.K.; Dwivedi, R.S.; Sunny Ninan
    Different methods of plant injection and soil placement techniques were tried. KH232PO4 was used in this study which was simultaneously confirmed by tagged single Superphosphate fertiliser application. In plant injection technique, 32P was fed to the palms through growing root tip, cut end of root, stem injection and leaf axil application; whereas in soil placement method, the radio-active P was applied to the palms through basin, circular trenches, strips and holes made around the bole. Plant injection technique was efficient and economical than soil application method. Among plant injection methods, the application of 32P through cut-end of roots was most efficient and the radioactivity in the palm was detected after 4 hours of application. On the other hand, the radioactivity in the palm was detected after 8, 12 and 18 hours of application through stem, leaf axil and growing root tip, respectively. Out of four methods of soil application tried, the placement of radioactive P through holes gave quick recovery. The 32P activity was detected in the palm after 7, 8, 8 and 11 days, respectively, in hole, circular trench, strip and basin application methods. The 32P absorption was equally efficient in the palms, receiving irrigation daily and once in a week.
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    Rapid Biochemical Test to Detect Root (Wilt) Disease of Coconut
    (1977) Dwivedi, R.S.; Chacko Mathew; Ray, P.K.; Sumathy Kutty Amma, B.; Sunny Ninan
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    Rapid Biochemical Test to Detect Root (Wilt) Disease of Coconut
    (1977) Dwivedi, R.S.; Chacko Mathew; Ray, P.K.; Sumathy Kutty Amma, B.; Sunny Ninan