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Subject: Agricultural Entomology × End date: 1982 × Start date: 1982 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Pathogenicity of burrowing nematode, Radopholus similis (Cobb 1893) Thorne 1949 on banana
    (Department of Entomology,College of Agriculture, Vellayani, 1982) Satyanarayana, P; KAU; John Kuriyan, K
    Pathogenicity of the burrowing nematode,Radopholus similis on banana was studied at the College of Agriculture, Vellayani with three levels of population viz. 1000', 10,000 and 1,00,000 nematodes at five different growth stages of the crop starting from 45 days after planting and with 45 days interval. I t was observed that the general growth of the plant was retarded. The reduction was directly proportional to the initial inoculum used and the period of infestation. A reduction of 36*84 per cent was seen in the yield of plants inoculated earlier with 1,00,000 nematodes and as high as 60.52 per cent reduction in weight of the roots in the plants treated with 10,000 nematodes. Nematode population was found to reach its peak during the flowering season of the plant and decreasing thereafter. The multiplication of the nematode was observed to be inversely proportional to the Initial inoculum level. Population of even 1000 nematodes at active growth stage was enough to cause severe reduction in the plants growth. It was seen that plants could withstand the damage caused by the nematode feeding at later stages Le. after 180 days after planting. So the plants should be protected from the nematodes at earlier stages. The histological changes in the roots infested by nematodes revealed that the nematodes feed on the cortical tissue causing reddish brown lesions on the roots and nematodes could not enter the stelar region of the root even under severely infested conditions
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    ThesisItemOpen Access
    Effect of synthetic pyrethroids on the pests of paddy
    (Department of Agricultural Entomology, College of Agriculture, Vellayani, 1982) Balaji, T S B; KAU; Mohan Das, N
    The relative efficacy of four synthetic pyrethroide against the important rice pests was assessed through a field experiment laid out at the Model Agronomic Research Station karamana, during 1981, taking carbaryl as standard. Against the rice gall midge Pachydiplosis oryzae cypermethrin (50 and 25 g ai/ha) and permethrin (50 g ai/ha) were found superior, The low variation in tho percentage incidence of silver shoots in plots treated with pyrothroids and carbaryl showed that the use of the former category of pesticides is not justified due to the high, cost involved.
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    ThesisItemOpen Access
    Protection of stored cowpea seeds (Vigna unguiculata (L) (Walp) from infestation by the pulse beetle Callosobruchus maculatus F. (Bruchidae : Coleoptera)
    (Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 1982) Purnamma, B; KAU; Mammen, K V
    Studies were conducted to assess the effect of different materials in protecting cowpea seeds against attack of pulse beetle, Callosobruchus maculatus in storage for a period of six months. Rhizome bits of sweet flag, neem kernal powder, activated charcoal powder, carbaryl 5% dust, etrimphos 2% dust were directly mixed with seeds