Browsing by Author "Das, N M"
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Item Acrocercops zygonoma meyrick as a pest of Mango in Kerala(Kerala Agricultural University, Vellanikara, 1968) Remamony, K S; Das, N M; Nair, M R G KItem Bioassay of insecticide residues on crops-I Persistence of endrin residues on paddy(Kerala Agricultural University, Vellanikara, 1969) Asaf Ali, K; Das, N M; Nair, M R G KItem Chemical 'control of the red spider mite, Tetranychus telarius L. (Tetranychidae)(Kerala Agricultural University, 1972) Saradamma, K; Dale, D; Das, N MItem Comparative efficacy of different formulations of ethyl parathion(Kerala Agricultural University, 1973) Sasidharan Pillai, K; Saradarnma, K; Das, N MItem Contact toxicity of different insecticides to third and fifth instar nymphs of brown plant hopper Nilaparvata lugens stal (Delphacidae : Homoptera)(Kerala Agricultural University, 1981) Baby P Skaria; Das, N MThe relative efficacy of 1 2 contact insecticides to the third and fifth instar nymphs of the brown plant-hopper Nilaparvata lugens was assessed in the laboratory by assessing their LC 50 values. These chemicals were found to be equally effective against both the stages of the pest. Insecticides found most effective were carbaryl, monocrotophos, quinalphos, fenthion, phosalone, fenitrothion and dichlorvos. On relative cost basis these may be ranked ascarbaryl, monocrotophos dichlorvos, phosolone, fenthion, fenitrothion and quinalphos, against third instar nymphs and carbaryl, monocrotophos, quinalphos, fenitrothton, fenthion, phosalone and dichlorvos against fifth instar nymphs.Item Control of the insect pests affecting cowpea Vigna Sinensis(Kerala Agricultural University, 1977) Das, N M; Susamma Mathai; Christudas, S PIn a field experiment conducted in the red soil of Agricultural College Farm, Vellayani applying thimet, disulfotan, rnephosfolan and carbofuron granules at three different levels, applied at the' time of sowing, disulfoton at 1 kgai/ha was found an effective and economic method for controlling pea aphid upto 5 weeks after sowing. In another field experiment it was observed that spraying of different insecticides commencing from the time of flowering along with one application of disulfotan granules at the rate of 1 kg ai/ha at the time of sowing reduced the incidence of pea aphid and pod borers and increased the yield significantly. On a benefit cost ratio basis the effective insecticides could be ranked as follows: f enithion >f enitrothion > monocrotophos > carbaryl > phosalone > quinalphos.Item Deterioration of insecticides on glass and on leaf surface(Kerala Agricultural University, 1972) George Koshy; Das, N M; Nair, M R G KItem Effect of nutrition on the susceptibility of Tribolium castaneum herbst to the toxicity of different insecticides(Kerala Agricultural University, 1972) Omana, M M; Das, N M; Nair, M R G KItem Effect of rice varieties on the extent of leaf consumption by caterpillars of Cnaphalorocis medinalis(Kerala Agricultural University, 1974) Das, N M; Nair, M R G KItem Effect of seed treatment with systemic insecticides on the germination of paddy and the growth of seedlings(Kerala Agricultural University, 1972) Das, N M; Chandrika, SItem Effect of water level in rice fields on the population build up of the brown plant hopper, Nilaparvata lugens and on the incidence of hopper burn(Kerala Agricultural University, 1977) Das, N M; Thomas, M JItem Effect of weathering on persistence of insecticide residues on glass surfaces(Kerala Agricultural University, 1981) George Koshy; Das, N M; Nair, M R G KItem Field and laboratory evaluation of insecticide sprays against the rice leaf-roller Cnaphalocroos Medinalis guenee(Kerala Agricultural University, 1976) Das, N M; Nair, M R G KTwenty four insecticides were evaluated against the caterpillars of Cnaphalocrocis medinalis Guenee in the laboratory using a new laboratory technique of spraying them within leaf folds under a Potter's Tower and in field experiment in which the per cent reduction of larval population caused by spraying was assessed. The results of the two experiments showed strict correspondence. Ethyl parathion, carbaryl, carbophenothion, dimethoate, fenthion fenitrothion and leptophos were found very effective against C. medinalis larvae while phosphamidon, phorate, formothion, methyl demeton, quinalphos, monocrotophos, thiometon and acephate, were moderately effective.Item Granulosis virus of the rice leaf roller, Cnaphalocrocis medinalis guenee (Pyraustidae, Lepidoptera)(Kerala Agricultural University, 1971) Abraham, Jacob; Das, N M; Thomas, M JItem New record of Coccinella arcuata Fabricius (Coleoptera: Cocclnellidae) as a predator of Nilaparvata lugens stal in Kerala(Kerala Agricultural University, 1973) Abraham, C C; Kunjamma P Mathew; Das, N MItem Occurrence of Nilaparvatha lugens (Stal.) (Delphacidae: Homoftera) as a serious pest of paddy in Kerala(Kerala Agricultural University, 1972) Das, N M; Mammen, K V; Christudas, S PItem On control of the melon fly Dacus cucurbitae Coquillett with some newer synthetic insecticides applied as cover sprays(Kerala Agricultural University, Vellanikara, 1968) Das, N M; Remamony, K S; Nair, M R G KItem Persistence of some systemic insecticides in cowpea when applied as granules in different soil types of Kerala(Kerala Agricultural University, 1975) Das, N M; Dale, D; Sasidharan Pillai, KA pot trial was conducted to study the persistent toxicity of phorate, car. bofuran, mephosfolan and disulfoton to the pea aphid, Aphis craccivota on cowpea grown in sandy, laterite, red, forest and black soils treated with the above insecticides as granule. The persistent toxicity was highest in plants treated with disulfoton in all types of soils. Mephosfolan was next best in sandy, red and forest soils whereas carbofuran was next to disulfoton in laterite and black soils. The yields obtained from treated plants were significantly higher than those of corresponding controls. But there was no direct correlation between the persistent toxicity of insecticides and the yield. The yield factor appears to be influenced by the impact of the insecticide on some soil factors favouring plant growth.Item Persistent toxicity of some systemic insecticides sprayed on coconut palms to the adults of Trichospilus pupivora(Kerala Agricultural University, 1972) Chandrika, S; Das, N MItem Records of hymenopterous parasites of the rice leaf folder Cnaphalacrocismedinalis guen. in Kerala(Kerala Agricultural University, 1973) Kunjamma P. Mathew; Das, N M