Browsing by Author "Rajagopal, V."
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Item 25 Years of the JPC: An appraisal(2007-02-08) Rajagopal, V.Item 41st COCOTECH meeting and Coconut Festival at Santo Island, Vanuatu(2004) Rajagopal, V.Item Abnormal Stomatal Opening in Coconut Palms Affected with Root (Wilt) Disease(1986-09) Rajagopal, V.; Patil, K.D.; Sumathy Kutty Amma, B.Rajagopal, V., Patil, K. D. and Sumathykuttyamma, B. 1986. Abnormal stomatal opening in coconut palms affected with root (wilt) disease.—J. exp. Bot. 37: 1398-1405. Studies on the stomatal regulation in the root (wilt) affected coconut palms (Cocos nucifera L.) revealed that the diseased palms had low stomatal resistance compared to the healthy palms, irrespective of their age. The same trend was observed whether the determinations were made at different times of the day (6-18 h) or under irrigated and unirrigated conditions or in different seasons (dry and wet). Thus, the stomatal regulation was significantly impaired in the diseased palms resulting in excessive water loss compared to the healthy palms. Results are discussed with the available literature on other similar disease caused by fungi, bacteria and mycoplasma-like organisms in different plants.Item Abnormal Stomatal Opening in Coconut Palms Affected with Root (Wilt) Disease(2007-02-08) Rajagopal, V.; Patil, K.D.; Sumathy Kutty Amma, B.Studies on the stomatal regulation in the root (wilt) affected coconut palms (Cocos nucifera L.) revealed that the diseased palms had low stomatal resistance compared to the healthy palms, irrespective of their age. The same trend was observed whether the determinations were made at different times of the day(6 18 h) or under irrigated and unirrigated conditions or in different seasons (dry and wet). Thus, the stomatal regulation was significantly impaired in the diseased palms resulting in excessive water loss compared to the healthy palms. Results arc discussed with the available literature on other similar disease caused by Fungi, bacteria and mycoplasma-like organisms in different plants.Item Adaptive mechanism of coconut palms in the changing environment conditions for higher production(2007-02-08) Rajagopal, V.; Kasturi Bai, K.V.; Naresh Kumar, S.Item ADB-Funded Project Meeting at Davao, Philippines(2003) Rajagopal, V.Item ADB-IFAD funded project workshop at Vietnam(2002) Rajagopal, V.Item Age-dependent changes in in vivo nitrate reductase activity in black pepper (Piper nigrum L.)(2007-02-08) Raju, K.; Rajagopal, V.Nitrate reductase activity (NRA) was studied in the leaves and berries of black pepper during growth and development. The mature leaves from the runner shoots showed higher NRA per leaf than the young leaves, though the latter showed higher activity on unit weight basis. The enzyme activity in the flag leaf opposite to the spikes bearing the berries and in the berry, during its development was investigated. NRA in the berry increased with the time of development while that in the flag leaf declined. The activity in the leaves of runner shoots was found to be high during the day time and negligible during the night.Item Agricultural management in coastal agro-ecosystem problems and prospects(2004) Rajagopal, V.; Krishnakumar, V.Item Arecanut(CPCRI, 2004) Balasimha, D.; Rajagopal, V.Item Arecanut(2004) Balasimha, D.; Rajagopal, V.Item Assay of enzymes in coconut cultivars and hybrids under non-stress and stress conditions(2007-02-08) Kasturi Bai, K.V.; Rajagopal, V.; Chempakam, B.; Prabha, C.D.Coconut palms of three tall varieties (West Coast Tall (WCT), Philippines Ordinary (PO) and Andaman Ordinary (AO), two dwarf varieties (Malayan Yellow Dwarf (MYD) and Gangabondam (GB)) and three hybrids (WCT x Chowghat Orange Dwarf (COD), COD xWCTand WCT x WCT) were assayed for the activities of stress sensitive enzymes viz., acid phosphatase (APH), L-aspartate : 2 Oxoglutarate amino transferase (AOAT), Superoxide dismutase (SOD), Peroxidase (POD) and Polyphenol Oxidase (PPO) during the two distinct stages viz., non-stress (September / October) and Stress (February / March) of 1989 and 1990. In general, there was stress-induced increase or decrease in the activity of enzymes among the cultivars/hybrids, based on which they were ranked. The cultivar/hybrid with higher activities of SOD and POD and lower activities of PPO, APH and AOAT could be designated as drought tolerant. Accordingly, the order of tolerance was found to be WCT x WCT > WCT > PO = WCT x COfr > AO > GB = COD x WCT > MYD.Item Assessment of diversity in coconut varieties for drought responsive physiological traits(Journal of Plantation Crops, 2006-08) Kasturi Bai, K.V.; Rajagopal, V.; Arunachalam, V.Item Avenues to improve productivity potential under drought condition- a case study on coconut(2007-02-08) Rajagopal, V.; Naresh Kumar, S.Item Biochemical composition of vascular sap from the inflorescence of apparently healthy and root (wilt) diseased coconut palms(1989) Chempakam, B.; Rajagopal, V.Vascular sap was collected from the inflorescences of apparently healthy and root (wilt) diseased coconut palms under aseptic conditions. The pH of the sap ranged from 6.8 to 7.5. Osmotic concentration was lower in the sap from the root (wilt) affected palms (540-620 m moles/kg) while apparently healthy palms showed higher values (790-850 m moles/kg). Direct analysis of the sap for the biochemical constituents, viz. sugars, protein, free amino acids, lipids and sterols showed discernible difference between the healthy and diseased palms. The major amino acids, sugars and organic acids were detected in the sap based on chromato-graphic studies. The possibility of utilising this data in preparing the media for culturing mycoplasma like organisms is discussedItem Breeding for drought tolerance in coconut: Status and potentials(2007-07-19) Rajagopal, V.; Kasturi Bai, K.V.; Kumar, N.Item Characterisation of drought tolerance in coconut(1993) Rajagopal, V.; Shivashankar, S.; Kasturi Bai, K.V.Coconut palms experience moisture stress of different magnitudes depending upon the extent of dry spell. Investigations on drought tolerance centred around the morphological observations on leaf and inflorescence characters, the physiological parameters like stomatal regulation and water potential components and biochemical aspects such as epicuticular wax and assay of certain sensitive enzymes. Out of the 23 genotypes screened, ten were found to possess desirable traits to withstand moisture stress. These included high stomatal resistance with low transpiration rate, high leaf water potential, high leaf-wax content, and relatively stable enzyme activities during moisture stress. Based on the above features, the released hybrids like LO x GB, LO x COD, WCT x COD are classified as drought tolerant. A rapid screening method has been developed to evaluate a large number of samples.Item Chlorophyll flourescence transients with response to leaf water status in coconut(2006-12) Kasturi Bai, K.V.; Rajagopal, V.; Naresh Kumar, S.Item Coconut(Naya Udyog, Kolkata., 2006-01) Rajagopal, V.; Parthasarathy, V.A.; Naresh Kumar, S.; Reddy, D.V.S.; Rohini IyerItem Coconut(2007-02-08) Ramadasan, A.; Rajagopal, V.