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  • ThesisItemOpen Access
    Evaluation of the toxicity of O,O-diethyl-thiono phosphoric acid O (quinoxalyl (2) ester (sandoz insecticide-6538)to insect pests
    (Division of entomology ,Agricultural college and research institute ,Vellayani., 1970) Gopinathan Nair, P; KAU; Nair, M R G K
  • ThesisItemOpen Access
    Control of nematode parasites of brinjal with insecticide and nematicide granules
    (Division of entomology ,Agricultural college and research institute ,Vellayani., 1970) Vergis, P C; KAU; Mohas Das, N
  • ThesisItemOpen Access
    Studies on the parasitic nematodes associated with vegetables in kerala
    (Division of entomology ,Agricultural college and research institute ,Vellayani., 1968) Ramakrishnan Nair, N; KAU; Mohan Das, N
  • ThesisItemOpen Access
    Management of banana pseudostem weevil odoiporus longicollis oliv.using entomopathogenic fungi
    (Department of Agricultural Entomology, College of Agriculture, Vellayani, 2005) Sahi Beegum, M K; KAU; Anitha, N
    Investigation on “Management of banana pseudostem weevil, Odoiporus longicollis Oliv. using entomopathogenic fungi” was carried out in the Department of Agricultural Entomology, College of Agriculture, Vellayani. The study was conducted to screen four entomopathogenic fungi, to evaluate their biocontrol potential and to standardize the effective dose and method of application for the management of the banana pseudostem weevil. Four entomopathogenic fungi viz., Metarhizium anisopliae, Beauveria bassiana, Paecilomyces lilacinus and Nomuraea rileyi were tested against O. longicollis. Among them M. anisopliae and B. bassiana were found to infect O. longicollis grubs. Susceptibility of different stages of grubs to fungal infection was tested by using first, second, third, fourth and fifth instar grubs of O. longicollis and the results revealed that first and second instar grubs were more susceptible to fungal infection. Determination of effective dose of fungi against second instar grubs of O. longicollis was carried out by spraying the grubs with different concentrations of M. anisopliae and B. bassiana. The LC50 values of M. anisopliae and B. bassiana were 3.9 x 106 spores ml-1 and 1.6 x 105 spores ml-1 respectively. Evaluation of six naturally available solid media viz., rice bran, wheat bran, guinea grass, gingelly oil cake, coir pith, and neem cake were carried out for mass multiplication of M. anisopliae and B. bassiana. The results revealed that both rice bran and wheat bran were suitable for the mass multiplication of these fungi. The spore production was 9.26 x 106 spores ml-1 and 8.71 x 106 spores ml-1 respectively for M. anisopliae on first week after inoculation. For B. bassiana, the spore count was 503.42 x 106 spores ml-1 and 320.32 x 106 spores ml-1 respectively on first week after inoculation. Among the liquid media tried, coconut water and rice bran extract produced maximum mycelial growth and sporulation of fungi. For M. anisopliae the spore count was 7.77 x 107 spores ml-1 and 0.49 x 107 spores ml-1 respectively. B. bassiana recorded 440.03 x 106 spores ml-1 and 232.26 x 106 spores ml-1 respectively. M. anisopliae and B. bassiana grown in rice bran and wheat bran recorded maximum virulence on two weeks after storage and decreased thereafter. However, coconut water and rice bran extract showed maximum virulence on first week after storage and then found decreasing. Studies conducted to evaluate the compatibility of fungi with NeemAzal 0.4 per cent, chlorpyriphos 0.03 per cent, copper oxychloride 0.4 per cent and mancozeb 0.3 per cent revealed that all the pesticides tested inhibited the growth of M. anisopliae and B. bassiana. But the per cent inhibition was least in the case of NeemAzal 0.4 per cent. Field experiments were conducted with M. anisopliae and B. bassiana with chlorpyriphos (0.03 per cent) and NeemAzal (0.4 per cent) as checks. The plants were artificially infested with known number of grubs. Two experiments were conducted, one with prophylactic treatments and the other with curative treatments. Three application methods viz., leaf axil filling of spore suspension of M. anisopliae and B. bassiana, leaf axil filling of fungi in rice bran and stem injection of spore suspension were tested. Among these treatments leaf axil filling of B. bassiana spore suspension at 1.8 x 107 ml-1 as prophylactic treatment was most effective which gave 52.42 per cent mortality of grubs.
  • ThesisItemOpen Access
    Studies on the rice swarming caterpillar , Spodoptera mauritia boisduval in Kerala
    (Division of entomology ,Agricultural college and research institute ,Vellayani., 1967) Thomas, B; KAU; M R G K Nair
  • ThesisItemOpen Access
    Studies on the effect of plant nutrient on insect infestation on Abelmoschus esculentus monech
    (Division of entomology ,Agricultural college and research institute ,Vellayani.Trivandrum, 1967) Viswanath, B N; KAU; M R G K Nair
  • ThesisItemOpen Access
    Studies on the toxtcity of insecticide to residues on brinjal to Epilachna vigintioctopunctata fabricius
    (Division of entomology, Agricultural college and research institute, Vellayani, Trivandrum., 1965) Kunjamma Mathew, P; KAU; M R G K Nair
  • ThesisItemOpen Access
    Studies on the effect of refrigeration on the deveolopment of Trichospilus pupivora ferriere (Eulophidae)
    (Division of entomology ,Agricultural college and research institute ,Vellayani., 1964) Narayanan, N J; KAU; Gopalakrishnan Nair, M R
  • ThesisItemOpen Access
    Chemodynamics of Carbofuran in Cucumber
    (Department of Entomology, College of Agriculture,Vellayani, 1993) Anil Abraham, KAU; Naseema Beevi, S
    A field experiment was conducted to study the chemodynamics of carbofuran in cucumber plants when applied as granule in the soil. The insecticide was applied at two doses of 0.5 and 1.5 kg ai/ha at three occasions viz. sowing, vining and flowering stage of the crop. The residues of carbofuran and its metabolites were estimated from the vines, leaves and fruits at different intervals after the insecticidal treatment using gas chromatographic technique. Distribution of the residues in the various portions of fruit and the effect of different periods of storage on the degradation of residues were also studied in detail. A safe waiting period was also arrived so as to avoid residue hazards in consumption of the fruits. The results indicated that absorption and metabolism of carbofuran in the plant begins soon after its application in the soil. Pure carbofuran and the metabolites, 3-OH carbofuran and 3-keto carbofuran were detected in the vines, leaves and fruit samples at 1,3,7,14,21 and 28 days after treatment. When the different portions of the plant were analysed, the highest level of residues was detected at different occasions. Thus in the vines the peak level of residues was seen on the first day after treatment where as in the leaves and fruits it was on the third seventh day respectively. A gradual decline was noticed thereafter and the residues reached almost non – detectable by 28th day after treatment in all parts of the plant. The effect of peeling on residues was studied in a separate experiment and the results indicated that peeling of fruits could reduce the residues considerably. Distibution of carbofuran residues in different fruit portions was studied and the results indicated that maximum accumulation of the residues took place in the top portions of the fruit followed by middle and basal portions. Comparing the carbofuran residues in the flesh and placenta of cucumber fruits when treated at the flowering stage of the crop it was observed that maximum accumulation of residues of carbofuran took place in the flesh portion when compared with the placenta of the fruit (inner core and seeds). Effect of storing the fruits on the degradation of carbofuran residues showed that metabolism and degradation of the chemical continued even after harvest, during the process of storage. For safe consumption of fruits following carbofuran treatment at the flowering stage a waiting period of 25 and 26 days have to be given when applied @ 0.5 and 1.5 kg ai/ha respectively.