Browsing by Author "Gopinathan Pillai, N."
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Item Distribution and intensity of root (wilt) disease of coconut in Kerala(2007-02-08) Gopinathan Pillai, N.; Lal, S.B.; Shanta, P.A survey conducted recently to study the distribution and intensity of "wilt" disease ofcoconut in Kerala revealed its incidence along with leaf rot disease in six districts: Trivandrum. Quiion, Alleppey, Kottayam, Ernakulam, and Trichur. In the north, the disease occurred upto Ala, Varan-darappally, and Kalloor of Trichur District, in the south, palms in Ncmum,Ottassekharamangalam, and Maranelloor were infected. Earlier reports of the disense were confined to gardens between Quiion and Vamannpuram in the south and Ochenthuruthy and Malayatoor in the north. Sporadic occurrence of this disease was also noticed in Kulasckharam and Vallom villages of Tamil Nadu. The spread was faster, more conspicuous, and rampant in sandy, sandy loam, and clayey soils and on the banks of rivers and canals. Intensity of disease was higher in sandy, sandy loam, and clayey soils than in laterite soils. Over 2-5 lakhs hectares of coconut plantations in Kerala are estimated to be affected by this disease.Item Distribution and retention of oxytetracycline hydrochloride injected into coconut palms affected by root (wilt) disease(2007-02-08) Chowdappa, P.; Gopinathan Pillai, N.; Gunasekaran, M.; Solomon, J.J.Oxytetracycline-HCI (OTC) was administered by pressure injector into the trunks of root (wilt) diseased coconut palms. Uptake, translocation and persistence of OTC in various parts of the palms were monitored by microbiological assay of buffer extracts of fresh tissue samples using Bacillus cereus subsp. mycoides (ATCC 6462). Presence of OTC in the foliage was detected within 24 h after administration. The highest concentration was noticed after 5-6 days. Maximum detectable levels in the range of 3-11 Pg/g fresh weight were found in the leaf No. 11. Lower concentrations in the range of 1.0-5 Pg/g fresh weight were detected in the leaf No. 1, 6 and 31 after a week of injection. With the onset of senescence, OTC gets redistributed from older leaves to the most actively transpiring leaves. Very little OTC activity was detected in roots, inflorescence, and spear leaf. Detectable levels of OTC was observed for more than 12 weeks in the foliage.Item Epidemiology of coconut root (wilt) disease(1980-12) Gopinathan Pillai, N.; Sasikala, M.; Mathen, K.Coconut root (wilt) disease of Kerala (S. India) is a debilitating disease of uncertain etiology. Out of 7,40,000 ha of coconut planatation, 2,50,000 ha are affected by this malady causing an annual loss of about 340 million nuts. Associations of fungi, bacteria, nematodes, and a transmissible virus-like pathogen with the disease have been reported. Observations recorded for seven years in 10 coconut gardens, each of approximately one ha in extent with very low percentage of disease incidence revealed indiscriminate spread in sandy, sandy-loam, and alluvial soils. The percentage of infection increased from 2.3 to 18.2 with 2-5 palms contracting infection every year. The spread of the disease was slower in laterite soils, with only one palm developing the disease in two years. The spread was erratic and irregular irrespective of soil conditions and occurred in jumps/leaps. The rate of spread was 1-4 km from the nearest source of infection. The pattern of spatial distribution or galaxial outbreak of the disease is suggestive of the involvement of aerial vector(s).Item Epidemiology of coconut root (wilt) disease(2007-02-08) Gopinathan Pillai, N.; Sasikala, M.; Mathen, K.Coconut root (wilt) disease of Kerala (S. India) is a debilitating disease of uncertain etiology. Out of 7,40,000 ha of coconut planatation, 2,50,000 ha are affected by this malady causing an annual loss of about 340 million nuts. Associations of fungi, bacteria, nematodes, and a transmissible virus-like pathogen with the disease have been reported. Observations recorded for seven years in 10 coconut gardens, each of approximately one ha in extent with very low percentage of disease incidence revealed indiscriminate spread in sandy, sandy-loam, and alluvial soils. The percentage of infection increased from 2.3 to 18.2 with 2-5 palms contracting infection every year. The spread of the disease was slower in laterite soils, with only one palm developing the disease in two years. The spread was erratic and irregular irrespective of soil conditions and occurred in jumps/leaps. The rate of spread was 1-4 km from the nearest source of infection. The pattern of spatial distribution or galaxial outbreak of the disease is suggestive of the involvement of aerial vector(s).Item Impact of root (wilt) disease on the yield of young coconut palms(2007-02) Jacob Mathew; Gopinathan Pillai, N.; Kamalakshi Amma, P.G.; Robert Cecil, S.When young West Coast Tall palms under regular fertiliser management contracted the disease during the pre-bearing period, the onset of bearing was found to be delayed. While about 90 per cent of the healthy palms flowered by the end of the eighth year, it was only around 70 per cent in palms which contracted disease during the pre-bearing stage. About 18 per cent of these diseased palms did not flower even up to the thirteenth year. Decline in yield was faster in palms which became diseased in later years. In general, about 45 per cent decline in yield was observed in diseased palms, during the course of 10 years, compared to the yield of healthy palms, while in palms which were diseased during the initial years, this loss was to the extent of 68 per cent. In Dwarf x Tall palms though the occurrence of disease was at a slower rate the increase in the disease index was higher compared to that in WCT palms. The diseased Dwarf x Tall palms, in general were giving about 60 per cent lower yields, compared to the healthy palms.Item A mosaic disease of snake gourd(Trichosanthes anguina Linn.)(1971-01) Gopinathan Pillai, N.Item Oil-Palm (Elaeis Guineensis Jacq.), A Natural Host of Root (Wilt) Disease Pathogen of Coconut(1970-06) Shanta, P.; Gopinathan Pillai, N.; Lal, S.B.Item Origin, Distribution and Spread(2007-02) Gopinathan Pillai, N.Item Possible Association of Tobacco Mosaic Virus with the Root (Wilt) Disease of Coconut(2007) Shanta, P.; Hariharasubramanian, V.; Gopinathan Pillai, N.Experiments to check the presence of tobacco mosaic virus have shown that very low amounts of the coconut strain of TMV could be detected when added to coconut root or leaf extract, showing that if the virus is present, infectivity tests should be adequate for testing the presence of the virus in diseased plants. It. was also possible to distinguish particles of TMV in negatively stained preparations of coconut root and leaf containing TMV. All infectivity tests and electron microscope observations carried out with diseased coconut material yielded negative results for presence of this strain of the virus.Item Remission Of Symptoms Of Root (Wilt) Disease Of Coconut Injected With Oxytetracycline - HCL(1991) Gopinathan Pillai, N.; Chowdappa, P.; Solomon, J.J.; Jacob MathewNinety root (wilt) diseased coconut palms having uniform intensities of disease were treated with 1, 2, 3 and 6 gm. active ingredient of oxytetracycline-HCL (Terramy-cin 20% soluble powder) and 3,000,000 units of Penicillin for 36 months at quarterly intervals using a pressure injection device. Terramycin treated palms showed reduction of disease index score. Untreated palms and palms injected with penicillin deteriorated. Remission of symptoms in response to injection with terramycin supports mycoplasmal etiology of the disease.Item Reproduction of Symptoms of Root (Wilt) Disease of Coconut in Potted Coconut Seedlings(1976-12) Mathen, K.; Gopinathan Pillai, N.; Mathew, A.S.; Shanta, P.Item Root (Wilt) Disease of Coconut - Current Status(1993) Solomon, J.J.; Gopinathan Pillai, N.Root (wilt) disease of coconut reported over a century ago in Kerala, South India, is a non-lethal but declining malady. The annual loss due to the disease is estimated to be about 968 million nuts. The cause of the disease remained uncertain till recently. Recent studies have conclusively ruled out involvement of biological agents, nutritional and physiological factors as disease incitant(s). Identification of a phloem bound mollicute, its insect vector and the evidences accrued in favour of the mycoplasmal etiology are discussed.Item Short Scientific Notes: Reproduction of Symptoms of Root (Wilt) Disease of Coconut in Potted Coconut Seedlings(1976-12) Mathen, K.; Gopinathan Pillai, N.; Mathew, A.S.; Shanta, P.Item A Simple Pressure Injection Device for the Application of Antibiotics on Coconut Palms(1985) Gopinathan Pillai, N.; Raju, C.A.Item Symptoms Of Disorders In Coconut Are Aids To Diagnosis And Treatment(1977) Mathen, K.; Mathew, A.S.; Gopinathan Pillai, N.Item A Terminology for the Coconut Root (Wilt) Disease(1983) Mathen, K.; Gopinathan Pillai, N.; Radha, K.Coconut root (wilt) disease has been referred to by various authors under different names. The variations in the name have created confusion among readers and reviewers to mistake the disease for other disorders in the coconut palm. A list of all such names used in the literature hitherto is given in alphabetical order. A chronological order of the variations is cited. Suitability of each name is discussed. From among the available names, coconut root (wilt) disease is chosen and recommended for use by all workers for the sake of uniformity, until such time as a new name can justifiably replace it.Item Transmission Of Coconut Root (Wilt) Disease—Reaction Of 170 Test Plants(1978) Sasikala, M.; Gopinathan Pillai, N.Experiments to study the transmission of coconut root (wilt) disease under normal environmental conditions, employing mechanical inoculation (with leaf and root extracts, partially purified preparations, root exudates and soil suspension), soil transmission, leachates and insect feeding were conducted on 22,160 plants of 170 species and cultivars belonging to 30 families. Impatients balsamina, Lycopersicon esculentum cult. San Marzano, and Physalis minima showed very low percentage of infection when mechanically inoculated with diseased leaf extracts. Plants which were earlier reported as suspects did not show any symptoms in these trials. Cowpea (Vigna sinensis Endl.) reported earlier as an indicator host also failed to show symptoms consistently.Item Virus Diseases of Intercrops in Coconut Gardens(1971-11) Gopinathan Pillai, N.