Browsing by Author "Sampath Kumar, S.N."
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Item 'Anabe roga' of arecanut(Areca catechu L.)(2007-02-08) Prakasam, N.; Saraswathy, N.; Sampath Kumar, S.N.Item Collectotrichum Blight of Cinnamon(1983) Sampath Kumar, S.N.Item Diseases of arecanut(Malhotra Publishing House, 2007-02-08) Sampath Kumar, S.N.; Saraswathy, N.Item Epidemiology of bacterial leaf stripe disease of arecanut palm (Areca catechu L.) caused by Xanthomonas campestris pv arecae - II. Influence of management practices on the disease incidence(2007-02-08) Sampath Kumar, S.N.Bacterial leaf stripe of arecanut caused by X. campestris pv. arecae is a serious % disease found affecting arecanut palms in the inland plains of Karnataka. For ensuring infection by the pathogen temperature, humidity and nutrients seem to have an important role. Certain specific cultural practices adopted in plantations were also found to be congenial for disease development and spread. Frequent irrigations (once in 5 to 10 days interval) was found to aggravate the disease. Higher levels of nitrogen and green matter were found to favour disease development. Phosphorus and potash did not seem to have any influence. Intercropping with banana was found to enhance disease intensity.Item Epidemiology of bacterial leaf stripe disease of arecanut palm (Areca catechu L.) caused by Xanthomonas campestris pv arecae - II. Influence of management practices on the disease incidence(1982) Sampath Kumar, S.N.Bacterial leaf stripe of arecanut caused by X. campestris pv. arecae is a serious % disease found affecting arecanut palms in the inland plains of Karnataka. For ensuring infection by the pathogen temperature, humidity and nutrients seem to have an important role. Certain specific cultural practices adopted in plantations were also found to be congenial for disease development and spread. Frequent irrigations (once in 5 to 10 days interval) was found to aggravate the disease. Higher levels of nitrogen and green matter were found to favour disease development. Phosphorus and potash did not seem to have any influence. Intercropping with banana was found to enhance disease intensity.Item Epidemiology of bacterial leaf stripe disease of arecanut palm (Areca catechu L.) caused by Xanthomonas campestris pv arecae – I. Effect of age of palm and age of the leaf on disease manifestation(2007-02-08) Sampath Kumar, S.N.Bacterial leaf stripe disease infection on arecanut palms caused by Xanthomonas campestris pv arecae showed variation not only with the age of the palm, but also with age of the leaves. Palms of younger age groups from 3 to 5 years showed a pattern of high degree of susceptibility to the disease indicated by rapid rate of lesion expansion as also the total lesion length recorded. Palms beyond 5 years age showed reduced susceptibility indicated by decreased lesion length. The lesion length decreased gradually with age and comparatively less in higher age groups. The leaf susceptibility character also showed a similar trend. Leaves that are of similar type and physiological age but produced at different periods in the life of the palm behaved differently to infection by the pathogen.Item Ganoderma disease of arecanut palm-isolation, pathogenicity and control(2007-02) Sampath Kumar, S.N.; Nambiar, K.K.N.Foot rot or Anabe disease caused by Ganoderma spp. is widespread in arecanut plantations in Karnataka causing often serious damage. Annual loss of 4.71% palms has been estimated due to this disease. The fungus could be isolated from freshly affected stem piece/sporophotes using Waksmans agar medium. Sporophore or bracket formation was noticed when the cultures grown on sand-maize medium were kept for more than 2.5 to 3 months. Disease symptoms appeared within 8-9 months from the time of inoculation in healthy arecanut palms. The fungus could be reisolated from the affected portions, thus proving pathogenicity of Ganoderma on arecanut. Disease spread is through root-to-root contact and is more in irregularly planted or closely spaced arecanut gardens as compared to wider spaced gardens. It is necessary to isolate the diseased palm by digging trenches around. Field trials have indicated that drenching the base of the palm with Captan/Bavistin at 0.3% concentration was effective in preventing the spread of the disease to the neighbouring palms.Item Ginger rot by Fusarium solani(2007-02) Sampath Kumar, S.N.Item Incidence of Acanthopsyche (Pteroma) Plagzophleps on Arecanut(1989) Sampath Kumar, S.N.Item Phenols and oxidase in the roots of healthy and Anabe affected arecanut palms(2007-02) Koti Reddy, M.; Saraswathy, N.; Sampath Kumar, S.N.Item Relationship Among Ganoderma Species Affecting Arecanut And Coconut Palms(1993) Sampath Kumar, S.N.; Nambiar, K.K.N.Though Ganoderma lucidum Leys (Karst) was reported to cause Anabe disease in coconut and arecanut palms, other species like G. boninense and G. applanatum are also known to affect these palms. The studies indicated that both G. lucidum and G. applanatum could cause infection in coconut and arecanut palms and both are cross inoculable. The gel diffusion tests also indicate a fairly high degree of affinity among these two species. Ganoderma species affecting arecanut and coconut palms in the maidan areas of Karnataka are inter-related pathotypes.Item Research Note- Collectotrighum blight of Cinnamon(1983) Sampath Kumar, S.N.Item A Study on Toxin Produced by Xanthomonas Campestris Pv. Arecae Incitant of Bacterial Leaf Stripe of Arecanut(1984) Sampath Kumar, S.N.Xanthomonas campestris pv arecae causal agent of Bacterial leaf stripe disease of arecanut produced 2 g/l of extracellur toxic polysaccharide, a dilute (0.2 per cent) aqueous solution of which induced chlorosis and localised water soaking in younger leaves of arecanut. The toxin also wilted cut tomato shoots when dipped in a 0.2 per cent solution and hence is a non-specific toxin. The toxin is a heteropolymer made of glucose, mannose and glucuronic acid.Item Uniformity Trials: Optimum Size And Shape Of Plots And Blocks In Experiment With Ginger(1984) George, M.V.; Sannamarappa, M.; Bhagavan, S.; Sampath Kumar, S.N.Fairfield Smith’s equation with standard notations Y=ax-g and its generalisation in the form y=ac-g1r-g2 were fitted to the uniformity trial data on ginger conducted at Hirehalli during 1976-77 and 1977-78 where Y is the CV for the plot size x with r rows and c columns, taking the ultimate unit as (i) one row of 5 plants and (ii) number of plants in 1m x 1m bed. Row-wise heterogeneity was higher than column-wise heterogeneity showing thereby that formation of plots with more rows will give more homogeneous blocks for experiments. The cost of experimentation per treatment to estimate the means at 5 per cent CV was worked out under different price situations. Plot size consisting of 3-4 rows of one column m the case of ultimate unit of plants in 1m x 1m bed, and plot size of 6 rows of one column in the case of ultimate unit of one row of 5 plants each, were found to be optimum.Item Yield performance of Arecanut (Areca catechu L.) varieties in maidan region of Karnataka(2002) Anuradha Sane; Ananda, K.S.; Sampath Kumar, S.N.; Sannamarappa, S.; Ramanujam, B.