Loading...
Kerala Agricultural University, Thrissur
The history of agricultural education in Kerala can be traced back to the year 1896 when a scheme was evolved in the erstwhile Travancore State to train a few young men in scientific agriculture at the Demonstration Farm, Karamana, Thiruvananthapuram, presently, the Cropping Systems Research Centre under Kerala Agricultural University. Agriculture was introduced as an optional subject in the middle school classes in the State in 1922 when an Agricultural Middle School was started at Aluva, Ernakulam District. The popularity and usefulness of this school led to the starting of similar institutions at Kottarakkara and Konni in 1928 and 1931 respectively.
Agriculture was later introduced as an optional subject for Intermediate Course in 1953. In 1955, the erstwhile Government of Travancore-Cochin started the Agricultural College and Research Institute at Vellayani, Thiruvananthapuram and the College of Veterinary and Animal Sciences at Mannuthy, Thrissur for imparting higher education in agricultural and veterinary sciences, respectively. These institutions were brought under the direct administrative control of the Department of Agriculture and the Department of Animal Husbandry, respectively. With the formation of Kerala State in 1956, these two colleges were affiliated to the University of Kerala. The post-graduate programmes leading to M.Sc. (Ag), M.V.Sc. and Ph.D. degrees were started in 1961, 1962 and 1965 respectively.
On the recommendation of the Second National Education Commission (1964-66) headed by Dr. D.S. Kothari, the then Chairman of the University Grants Commission, one Agricultural University in each State was established. The State Agricultural Universities (SAUs) were established in India as an integral part of the National Agricultural Research System to give the much needed impetus to Agriculture Education and Research in the Country. As a result the Kerala Agricultural University (KAU) was established on 24th February 1971 by virtue of the Act 33 of 1971 and started functioning on 1st February 1972. The Kerala Agricultural University is the 15th in the series of the SAUs.
In accordance with the provisions of KAU Act of 1971, the Agricultural College and Research Institute at Vellayani, and the College of Veterinary and Animal Sciences, Mannuthy, were brought under the Kerala Agricultural University. In addition, twenty one agricultural and animal husbandry research stations were also transferred to the KAU for taking up research and extension programmes on various crops, animals, birds, etc.
During 2011, Kerala Agricultural University was trifurcated into Kerala Veterinary and Animal Sciences University (KVASU), Kerala University of Fisheries and Ocean Studies (KUFOS) and Kerala Agricultural University (KAU).
Now the University has seven colleges (four Agriculture, one Agricultural Engineering, one Forestry, one Co-operation Banking & Management), six RARSs, seven KVKs, 15 Research Stations and 16 Research and Extension Units under the faculties of Agriculture, Agricultural Engineering and Forestry. In addition, one Academy on Climate Change Adaptation and one Institute of Agricultural Technology offering M.Sc. (Integrated) Climate Change Adaptation and Diploma in Agricultural Sciences respectively are also functioning in Kerala Agricultural University.
Browse
22 results
Search Results
ThesisItem Open Access Novel bioformulations of entomopathogenic fungi and their efficacy aganist banana weevils(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2018) Remya, S; KAU; Reji Rani, O PThe study entitled ‘Novel bioformulations of entomopathogenic fungi and their efficacy against banana weevils’ was carried out at Dept. of Agrl. Entomology, College of Agriculture, Vellayani during 2016-2018, with the objective to develop novel formulations of entomopathogenic fungi, Metarhizium anisopliae (Metch.) Sorokin, Beauveria bassiana (Bals.) Vuillemin and to evaluate their efficacy in managing banana weevils. It was intended to develop capsule and gel formulations. Experiment to standardize a coating material for developing capsules revealed that Hard Gelatin Transparent (HGT), Hard Gelatin Coloured (HGC) and Hydroxy Propyl Methyl Cellulose (HPMC), were equally stable under ambient conditions of storage (26 -33°C and RH 60-80%). On testing their ability to disintegrate under field conditions, it was noted that chitosan filled HGT capsules easily disintegrated at 20% soil moisture after 36 h and after 24 h at 30 % soil moisture. It took 144 h for all capsules to disintegrate in sheath or leaf axil and 24 h in bore holes. Talc and chitosan were superior, in maintaining storage stability as well as degradability. A trial conducted to determine the moisture content of capsules, revealed that 10 % was the ideal moisture level content of the ingredient, to maintain storage stability as well as viability of the formulation. Viability noticed after three months was 2.29 × 107 cfu mL-1 and 2.27 × 107 cfu mL-1 in chitosan based capsules of M. anisopliae and B. bassiana and 2.10 × 107 cfu mL-1 and 0.76 × 107 cfu mL-1 in talc based capsules. Therefore, capsules were developed with HGT coating, with chitosan / talc as carrier at 10 % moisture content. Shelf life studies revealed that chitosan was the best carrier material compared to talc in retaining viability of Metarhizium capsules, with a mean cfu of 2.51 × 107 mL-1 and 1.77× 107 mL-1. During a period of three months of storage, there was no decline in the number of viable colonies, cfu ranging from 1.72 × 107 mL-1 to 2.79 × 107 mL-1. . Storage under refrigeration had better retention of viability (2.63 × 107 cfu mL-1) than at room temperature (1.64× 107 cfu mL-1). In Beauveria capsules, the viability did not differ in both chitosan and talc based capsules. Here also, the number of viable colonies did not decline statistically, till three months of storage, with mean cfu values ranging from 1.85 × 107 mL-1 to 2.36 × 107 mL-1. In general, shelf life of capsules could be extended by two months when chitosan was used as the carrier material. Low temperature storage could also improve the shelf life by two months. Shelf life studies of gel formulations indicated that both Metarhizium and Beauveria gels exhibited high viability in chitosan at room temperature and under refrigeration. The mean number of viable colonies observed was 2.39 × 106 cfu mL-1 in chitosan based gels of Metarhizium and 2.17 × 106 cfu mL-1 in Beauveria gels. The number of viable colonies of Metarhizium and Beauveria observed throughout the experimental period did not vary significantly over three months of storage. The mean number of cfu being 2.26 × 107 mL-1 on the 15th day and 1.41 x 106 mL-1 on the 90th day . It was also inferred that chitosan when used for formulating gels could extend the shelf life of both organisms by one month. Pathogenicity test disclosed the affinity of M. anisopliae to rhizome weevil and B. bassiana to pseudostem weevil. Pot culture studies to evaluate chitosan and talc based capsules of B. bassiana revealed that both the capsules of Beauveria were effective as chlorpyriphos 20 EC 0.05% for pseudostem weevil, in prophylactic and curative methods. The damage index (DI) was one each and reduction in pest population was 91.67 % in prophylactic control and 91.67-100 % in curative control. Metarhizium capsules reduced the damage caused by rhizome significantly, but the reduction in pest population was only to the tune of 47-55 % in prophylactic and 50- 58 % in curative control. Chitosan based gel of Metarhizium tested against rhizome weevil, reduced the damage significantly (DI 46.67 and 30, in prophylactic and curative methods). The pest population was reduced by 61.11 % in prophylactic and 36.11 % in curative methods. The study could standardize the protocol for capsule and gel formulations of entomopathogenic fungi, retaining the viability and infectivity upto three months of storage. It is concluded that placement of Beauveria capsules in leaf axils prophylactically and curatively can effectively control pseudostem weevil and Metarhizium capsules and gels placed in the rhizosphere could manage the rhizome weevil moderately.ThesisItem Open Access Mass trapping of cowpea pod borer maruca vitrata (F.) (lepidoptera; pyralidae) using sex pheromones(Department of Agricultural Entomology, College of Agriculture, Padannakkad, 2018) Eurekha Savadatti; Sreekumar, K MA study was conducted know the efficacy of synthetic sex pheromone of legume pod borer Maruca vitrata (F.) (Lepidoptera: Pyralidae) at College of Agriculture, Padannakkad. Also investigated the female calling and mating behaviour of the adult moths of M. vitrata. Response of commercial lure to male moths of the test insect was studied in Electroantennogram at NBAIR, Bangalore. The commercial synthetic pheromone lure of legume pod borer M.vitrata from M/s Pest control India (P) Limited, Bangalore was tested and found that it failed to attract not even a single moth. Subsequently, the mating behaviour of the moth was undertaken in detail to investigate whether pheromones are involved in the mating process of the insect. 30 per cent of moths emerged during photophase (6am-5pm) out of which male moths constituted 36.25% and female moths constituted 23.75%. During scotophase (6pm-5am), 69.68% moths emerged, out of which 63.12% was males and 76.25% was females. The emergence found to peak at 5th and 9th hour of scotophase. During calling period female extrudes its pheromone gland beyond the abdominal tip. Female calling behaviour of one to eight day old moths was observed throughout the scotophase. A single calling peak was observed in all aged moths at 6 th hour of scotophase except for three old day moths, which showed additional peaks of calling at fifth, eighth and 9th hour of scotophase. For three-day-old moths, 43.5% was the mean percent of calling at 6th hour of scotophase. The mating behaviour of 1-8 day old M.vitrata moths involving 15 pairs throughout the scotophase showed maximum mating percentage of 26.2 % and 16.6 % for 3 day old and 2 day old moths respectively. Electroantennogram study conducted to know the response of 3-day-old male moths to synthetic lure obtained from PCI, Bangalore showed that response to the stimulus was 0.05mv only, which was the same for the solvent hexane and the air. 75 This showed that there was no distinct physiological response for synthetic pheromone lure. For further confirmation, GC-MS analysis was done and the compound E, E-10, 12-Hexadecadienal was identified at a retention time of 16.42 min. This is the major pheromonally active compound identified in previous studies. In GC- EAD analysis, the response of M.vitrata male moths to E, E-10, 12-Hexadecadienal was checked by matching EAD and FID peaks but without any response. So, the exact reason for the absence of response to commercial synthetic lure is to be elucidated in future studies for developing an effective commercial pheromone for the legume spotted pod borer M. vitrata.ThesisItem Open Access Insecticide mixtures for the management of pest complex in cowpea(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2018) Banka Kanda, Kishore Reddy; KAU; Ambily PaulA study on “Insecticide mixtures for the management of pest complex in cowpea” was undertaken in College of Agriculture, Vellayani and in the farmers field at Kalliyoor during 2016 to 2018. The main objectives were to evaluate the efficacy of insecticide mixtures having component molecules of different mode of action against pests of cowpea and to study the dissipation pattern of mixtures in cowpea pods. Major pests documented in the experimental field were sucking pests viz., pod bug, Riptortus pedestris Fabricius, cowpea aphid, Aphis craccivora Koch, spotted pod borer, Maruca vitrata Fabricius, and leaf eating caterpillar, Spodoptera litura Fabricius. Experiment was laid out in RBD to study the efficacy of insecticide mixtures viz., chlorantraniliprole 8.8 % + thiamethoxam 17.5 % SC @ 150 g a.i ha-1, lambda cyhalothrin 4.6 % + chlorantraniliprole 9.3 % ZC @ 30 g a.i ha-1, thiamethoxam 12.6 % + lambda cyhalothrin 9.5 % ZC @ 27.5 g a.i ha-1, beta cyfluthrin 8.49 % + imidacloprid 19.81 % SC 15.75+36.7 g a.i ha-1, flubendiamide 19.92 % + thiacloprid 19.92 % SC @ 48+48 g a.i ha-1, chlorantraniliprole 18.5 % SC +thiamethoxam 25 % WG (hand mixed) @ 1:1 @ 0.30 mL L-1 along with standard checks chlorantraniliprole 18.5 % SC @ 30 g a.i ha-1 and thiamethoxam 25 % WG @ 0.30 g L-1 against cowpea pests (Cowpea variety- Vellayani Jyothika). The results of the study revealed that chlorantraniliprole 8.8 % + thiamethoxam 17.5 % SC @ 150 g a.i ha-1 was found effective in managing the population of pod bug, R. pedestris, followed by followed by followed by followed by followed by thiamethoxam 12.6 % + lambda cyhalothrin 9.5 % ZC @ 27.5 g a.i ha-1 and beta cyfluthrin 8.49 % + imidacloprid 19.81 % SC @ 15.75+36.7 g a.i ha-1. Less incidence of bug was found in effective treatments after 7 days of spraying. More or less similar result was obtained in the management of cowpea aphid, A. craccivora. Less number of aphid was observed in the plants treated with chlorantraniliprole 8.8 % + thiamethoxam 17.5 % SC @ 150 g a.i ha-1, thiamethoxam 12.6 % + lambda cyhalothrin 9.5 % ZC @ 27.5 g a.i ha-1, chlorantraniliprole 18.5 % SC + thiamethoxam 25 % WG (hand mixed) @ 1:1 @ 0.30 mL L-1 and thiamethoxam 25 % WG @ 30 g a.i ha-1 against 211.67 aphids plant-1 in control after 15 days of spraying. Significantly higher reduction in leaf damage by S. litura was recorded in plants treated with lambda cyhalothrin 4.6 % + chlorantraniliprole 9.3 % ZC @ 30 g a.i ha-1 (25.03) which was on par with thiamethoxam 12.6 % + lambda cyhalothrin 9.5 % ZC @ 27.5 g a.i ha-1 (26.46) and chlorantraniliprole 8.8 % + thiamethoxam 17.5 % SC @ 150 g a.i ha-1 (30.20) 10 days after spraying. Whereas, in the management of cowpea pod borer, M. vitrata, less incidence of larvae was found in lambda cyhalothrin 4.6 % + chlorantraniliprole 9.3 % ZC @ 30 g a.i ha-1 and chlorantraniliprole 8.8 % + thiamethoxam 17.5 % SC @ 150 g a.i ha-1 treated plants after 5 days of spraying against 6.67 larvae in control. Dissipation of residues of these effective insecticide mixtures were studied by analysing the pods collected at 0, 1, 3, 5, 7, 10 and 15 days after treatment and the result showed that both the single insecticides in chlorantraniliprole 8.8 % + thiamethoxam 17.5 % SC were dissipated within ten days with half-lives of 5.34 and 3.01 respectively and in lambda cyhalothrin 4.6 % + chlorantraniliprole 9.3 % ZC, lambda cyhalothrin dissipated in five days and chlorantraniliprole dissipated in seven days with half-lives of 5.58 and 13.67 days respectively. The infestation of sucking pests, borers and leaf feeders simultaneously occur in cowpea especially in pod bearing stage. The results of the study revealed that spraying chlorantraniliprole 8.8 % + thiamethoxam 17.5 % SC @ 150 g a.i ha-1, thiamethoxam 12.6 % + lambda cyhalothrin 9.5 % ZC @ 27.5 g a.i ha-1 and lambda cyhalothrin 4.6 % + chlorantraniliprole 9.3 % ZC @ 30 g a.i ha-1 could effectively manage pest complex in cowpea with minimal or no risk to the consumers.ThesisItem Open Access Eco-friendly management of major pests of yard long bean, vigna unguiculata subsp. sesquipedalis (L.) Verdcourt.(Department of Agricultural Entomology, College of Agriculture, Padannakkad, 2018) Vineetha, V; KAU; Ramesha, BThe study entitled ′′Eco-friendly management of major pests of yard long bean, Vigna unguiculata subsp. sesquipedalis (L.) Verdcourt′′ was carried out in the Instructional farm of College of Agriculture, Padannakkad, Kasaragod during two seasons viz., kharif (May to August) and rabi (September to December) in the year 2016. The vegetable cowpea variety ‘Lola’ released by KAU was selected for the study. The study was undertaken with an intention to find out the efficacy of different microbial agents, neem based and biorational insecticides. The experimental design was RBD with 9 treatments and three replications. The treatments included; T1- Beauveria bassiana (liquid formulation @ 107 spores/ml of water), T2- Metarhizium anisopliae (liquid formulation @ 107 spores/ml of water), T3- Lecanicillium lecanii (liquid formulation @ 107 spores/ml of water), T4- Bt formulation 2× 108 cfu/ml @ 1 ml/l of water, T5- Neem based insecticide (Azadirachtin 1 per cent @ 5 ml/l of water), T6- Neem oil emulsion 5 per cent (50 ml/l of water), T7- Spinosad 45 SC @ 0.4 ml/l of water, T8- Malathion 50 EC @ 2ml/l of water (standard check), T9- Absolute control. All the treatments were imposed at fortnightly intervals just after the initial attack of pest was seen and observations were recorded at weekly intervals corresponding to standard weeks. The data were subjected to square root transformation and analyzed using ANOVA. After three consecutive sprays of Spinosad 45 SC @ 0.4 ml/l of water at fortnightly intervals there was complete reduction of pod borer larvae during kharif and rabi season. The percentage of flowers and pods infested by pod borer larvae were also reduced completely and no infestation was noticed after three consecutive sprays of Spinosad during both seasons. Thus it was found that Spinosad 45 SC was effective in reducing the number of pod borers, percentage of flowers infested and percentage of pods infested. During kharif season, Beauveria bassiana was found to be the most effective treatment in reducing the nymphs and adults of pod bugs with minimum number of 0.56 bugs per plant followed by 0.63 bugs in T5 compared to T9 with 7.46 bugs per plant after three consecutive sprays. During rabi season, Azadirachtin 1 per cent showed no incidence of pod bugs after three sprays and Neem oil 5 per cent consistently reduced number of bugs to zero on 15 days after third spray whereas T9 exhibited maximum number of 4.26 bugs/plant. The effect of Beauveria bassiana was lowered during rabi season. It might be due to the inability of Beauveria spores to germinate and cause infection during that season because of inadequate humidity. Azadirachtin 1 per cent incessantly lowered the per cent of pods infested by pod bugs to zero even after two sprays during both seasons and leaf miner attacked leaves was also found minimum in plot treated with Azadirachtin 1 per cent (0.63 leaves/plant) compared to T9 (7.12 leaves/plant). The aphid population on shoots and per cent of aphid infestation on shoots were found to be zero after three consecutive sprays of Lecanicillium lecanii at fortnightly intervals during kharif season. Lecanicillium lecanii also lowered the aphid population on pods and caused exorbitant reduction in the percentage of infested pods during both seasons after three sprays. Though pod length is an inheriting character, maximum length of 42.30cm and 48.40cm was shown by T7 during kharif and rabi seasons respectively. During both seasons viz., kharif and rabi, the total and marketable yield was high in T7 with highest benefit – cost ratio of 1.50 and 2.26 respectively.ThesisItem Open Access Management of sucking pest complex in chilli using botanical and microbial pesticides(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2018) Priyatha Sundaran, C; KAU; Faizal, M HThe study entitled " Management of sucking pest complex in chilli using botanical and microbial pesticides " was conducted during 2016-2018, in the Department of Agricultural Entomology, College of Agriculture, Vellayani with an objective to manage the sucking pest complex of thrips (Scirtothrips dorsalis Hood), aphids (Aphis gossypii Glover) and mites (Polyphagotarsonemus latus Banks) in chilli using botanical and microbial pesticides. Laboratory evaluation of the botanical and microbial agents was done taking aphid (A. gossypii) as test insect. Cashew nut shell liquid (CNSL), a potential insecticide and a cheap by-product of cashew industry containing a mixture of phenolic compounds was evaluated as emulsions at different concentrations (0.025, 0.05, 0.075, 0.1 and 0.2 %) along with Neem Seed Kernel Extract (NSKE) emulsion 5 %, neem oil emulsion 2 % and commercial botanical pesticide oxuron 5 mL L-1. Thiamethoxam 0.015 % served as chemical check. CNSL 0.2 % and neem oil 2 % caused significantly high mortality of 64 and 58 per cent respectively at 24 hours after treatment (HAT) and was on par with chemical check thiamethoxam 0.015 %. At 48 HAT, CNSL 0.075, 0.1 and 0.2 % with per cent mortality 88.67, 86 and 92.67, respectively was found to be as effective as oxuron 5 mL L-1 and thiamethoxam 0.015 % and significantly superior over other treatments. At 72 HAT, thiamethoxam 0.015 %, oxuron 5 mL L-1, CNSL 0.2 % and CNSL 0.1 % showed 100 per cent mortality which did not vary significantly from the other treatments viz., CNSL 0.075 %, CNSL 0.05 %, CNSL 0.025 %, neem oil 2 % and NSKE 5 % with 99.33, 98.67, 98, 98 and 97.33 per cent mortality respectively. Based on the results of the laboratory evaluation, CNSL 0.2 % which was found superior at different intervals and CNSL 0.075 % the lowest effective concentration were selected for further evaluation. All the microbial agents evaluated viz., Beauveria bassiana, Metarhizium anisopliae, Lecanicillium lecanii and Lecanicillium saksenae were found to infect A. gossypii, among which L. lecanii and L. saksenae @ 107 spores mL-1 were significantly superior. L. lecanii @ 107 spores mL-1 caused in 54.5, 87.5, 100 per cent and L. saksenae @ 107 spores mL-1 55, 85.5 and 100 per cent mortality of aphids at 24, 48 and 72 HAT respectively. CNSL was found to be compatible with all microbial agents tested as per Hassan‟s classification scheme showing 60-65 per cent growth inhibition in disc diffusion assay in Potato dextrose agar plates. A pot culture experiment was carried out in chilli variety Jwalamukhi with effective botanical pesticides (CNSL 0.075 %, CNSL 0.2 %, neem oil 2 %, oxuron 5 mL L-1) selected based on laboratory evaluation along with L. lecanii @ 107 spores mL-1 and a combination treatment (CNSL 0.2 % + L. lecanii @ 107 spores mL-1) to assess the field efficiency against sucking pest complex. Thiamethoxam 0.015 % served as chemical check. Two rounds of application one each at vegetative (30 days after planting) and reproductive phase (60 days after planting) of the crop were administered. In the vegetative stage, 99.96, 88.87, 98.66, 88.94 per cent reduction in thrips population over control was observed in treatments with CNSL 0.2 % + L. lecanii @ 107 spores mL-1, L. lecanii @ 107 spores mL-1, CNSL 0.075 % and CNSL 0.2 % respectively at 3 DAT. The mite population was found to be least in the treatments CNSL 0.2 % (0.32 mites leaf-1 at 5 DAT) and CNSL 0.075 % (0.53 and 0.35 mites leaf-1 on 3 and 5 DAT) which did not vary significantly with the combination of CNSL 0.2 % + L. lecanii @ 107 spores mL-1 with 0.42 and 0.29 mites leaf-1 on 3 and 5 DAT respectively. The population of mites was significantly lower (0.15 leaf-1) in chemical check than all other treatments at seven days after treatment followed by CNSL 0.2% and L. lecanii @ 107 spores mL-1 recording mite population of 0.34 and 0.43 leaf-1 respectively. CNSL 0.2 %, L. lecanii @ 107 spores mL-1 and the combination treatment were found to be superior in managing chilli thrips and as effective as chemical check thiamethoxam 0.015 % in the reproductive phase. These treatments recorded low population (1.27, 1.23 and 1.23 thrips leaf-1 respectively) at 14 DAT as against 4.5 thrips leaf-1 in control. The mites were controlled effectively by both CNSL 0.2 % and CNSL 0.075 % upto 3 DAT. The botanical CNSL 0.2 % gave control upto 7 DAT with 1.07 mites leaf-1 as against 3.1 mites leaf-1 in control. Neem oil 2 % and oxuron 5 mL L-1 were found to be the next effective treatments against chilli mites. Reduced leaf curl, on par with chemical check was observed in treatments CNSL 0.075 %, CNSL 0.2%, combination of CNSL 0.2 % + L. lecanii @ 107 spores mL-1 and neem oil 2 % as evidenced by lesser value of leaf curl index, an indicator of damage by sucking pest complex (1, 1.33, 1.33 and 1.33 respectively), at 70 days after planting. The corresponding index in the control during the same period was 3.0. L. lecanii @ 107 spores mL-1 was also found to reduce the leaf curl index (1.67) though inferior to the above treatments. CNSL at the higher concentration of 0.2 % though found effective in managing the population of thrips and mites, did not show improved plant growth characters indicating possible growth retarding effect as evidenced by inferior growth attributes in comparison with chemical check. Significantly low plant height (23.2 cm), number of leaves (45.33), shoot fresh weight (13.25 g plant-1) and shoot dry weight (1.05 g plant-1) were observed in comparison to chemical check. L. lecanii @ 107 spores mL-1 and CNSL 0.075 % treated plants showed better growth characters than those treated with CNSL 0.2 %. The results of the study indicated the suitability of CNSL 0.2 %, CNSL 0.075 % and the combination treatment of CNSL 0.2 % + L. lecanii @ 107 spores mL-1 in sucking pest complex management. Thus considering the effectiveness in managing the sucking pests and their effect on plant growth attributes, CNSL 0.075 % and L. lecanii @ 107 spores mL-1 are better choices for eco-friendly management of sucking pest complex of chilli.ThesisItem Open Access Impact of new generation granular insecticides on beneficial fauna of paddy ecosystem(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2018) Niranjan, H P; KAU; Suja, GThe research on “Impact of new generation granular insecticides on beneficial fauna of paddy ecosystem” was carried out at College of Agriculture, Vellayani during 2016-18 to study the effect of newly recommended granular insecticides on the non-target organisms viz., parasitoids, predators and soil fauna of paddy ecosystem at recommended and double the recommended doses. The field experiment was done at Integrated Farming System Research Station (IFSRS), Karamana. Soil and water samples were tested to estimate residues and the degradation studies of the granular insecticides were also conducted. A field experiment was conducted with the rice variety Uma. The treatments were chlorantraniliprole 0.4 G at 10 and 20 kg ha-1, fipronil 0.3 G at 10 and 20 kg ha-1 and cartap hydrochloride 4 G at 25 and 50 kg ha-1. Major pests viz., stem borer, leaf roller and rice bug were recorded during the study. Among natural enemies major predators like damselflies, dragonflies, ground beetles, coccinellids and spiders were recorded and parasitoids of the order hymenoptera were observed. Soil fauna like ground beetles, water scavenger, ants, snails, spiders, nematodes and earthworms were recorded. Results revealed that, among the new generation granular insecticides fipronil 0.3 G at both 10 kg ha-1 and 20 kg ha-1 was found to be effective and superior to other treatments in reducing the damage (2.33 and 2.79 per cent of dead hearts at 75 days and 5.63 and 4.07 per cent of white ear heads at 90 days after transplanting [DAT] respectively) and population of adult stem borer (0.67 and 0.33 at 75 DAT respectively). Leaf roller damage (2.00 and 1.85 per cent at 75 DAT respectively) and its population (0.00 and 0.00 at 75 DAT respectively) were reduced significantly with chlorantraniliprole 0.4 G at both recommended and double the recommended dose. Cartap hydrochloride 4 G at 25 kg ha-1 effectively reduced the rice bug population (10.63 and 6.33 at 75 and 90 DAT) among the recommended insecticides. Among the new generation granular insecticides fipronil 0.3 G at 20 kg ha-1 followed by the recommended dose of 10 kg ha -1 was found to be toxic to natural enemies (predators of 10.33 and 13.33 at 75 days and parasitoids of 1.34 and 1.67 at 75 DAT) and soil fauna at all stages of the crop. Chlorantraniliprole 0.4 G at recommended dose of 10 kg ha -1 (21.67 of predators and 2.00 of parasitoids at 75 DAT) followed by double the recommended dose of 20 kg ha -1 (19.67 of predators and 1.34 of parasitoids at 75 DAT) were found to be safe to natural enemies and soil fauna. The P: D ratio of chlorantraniliprole 0.4 G (10 and 20 kg ha-1) were 0.93 and 0.92 at 75 DAT respectively. Dissipation of residues of selected insecticides fipronil 0.3 G and chlorantraniliprole 0.4 G was studied by analyzing the soil and water samples collected at 0, 1, 3, 5, 7, 10, 15 and 30 days after treatment with insecticides at recommended and double the recommended doses. The results revealed that fipronil 0.3 G at both doses dissipated within two hours (0 day) after treatment in both soil and water. Residues of chlorantraniliprole 0.4 G at both doses dissipated within two hours after treatment in water and five days after treatment in soil. New generation insecticides fipronil 0.3 G (10 kg ha-1), chlorantraniliprole 0.4 G (10 kg ha-1) and cartap hydrochloride 4 G (25 kg ha-1) were found effective against stem borer, leaf roller and rice bugs respectively. The present study revealed that among all the tested insecticides chlorantraniliprole 0.4 G at 10 kg ha-1 was safe to natural enemies and soil fauna with a low P: D ratio along with suppression of the insect pests.ThesisItem Open Access Field toxicity of new generation insecticides to bee pollinators(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2018) Raeesa, P; KAU; Amritha, V SThe study entitled “Field toxicity of new generation insecticides to bee pollinators” was carried out at AICRP on Honey Bees and Pollinators, Department of Agricultural Entomology, College of Agriculture, Vellayani, during 2016-18 with the objective to evaluate the field toxicity of new generation insecticides to major pollinators namely, A. cerana indica and T. iridipennis and to assess the insecticide residues in cucumber flowers. The toxicity of new generation insecticides (at field concentration and half of the field concentration) recommended for the pest management in vegetable crops viz., thiamethoxam 25 WG, dinotefuran 20 SG, cyantraniliprole 20 SC, novaluron 10 EC, diafenthiuron 50 WP, their combinations viz., thiamethoxam (17.50 %) + chlorantraniliprole (8.8 %) 300 SC, flubendiamide (19.92 %) + thiacloprid (19.92 %) 480 SC along with a conventional insecticide (dimethoate 30 EC) to the major pollinators were evaluated in terms of bee mortality in the laboratory. From the laboratory study, two new generation insecticides with least mortality were evaluated under field conditions along with an insecticidal check (dimethoate 30 EC @ 0.5 mL L-1) and an untreated control in order to study their effect on foraging activity of major pollinators of the crop. The persistence of the insecticides was studied by assessing the residues in the flowers. Laboratory evaluation of the insecticides revealed that upto three HAT, no mortality was recorded in Indian bees, A. cerana indica and stingless bees, T. iridipennis when treated with cyantraniliprole 20 SC (1.2 mL L-1 and 0.6 mL L-1) and novaluron 10 EC (2.0 mL L-1 and 1.0 mL L-1). Mortality of Indian bees ranged from 0 to 15 per cent and that of stingless bees from 0 to 2.50 per cent at six HAT, when treated with cyantraniliprole and novaluron at their respective concentrations. At 12 HAT the mortality of Indian bees ranged from 15.56 to 44.72 per cent while that of the stingless bees ranged from 19.44 to 30.56 per cent. Thus, two insecticides, cyantraniliprole 20 SC @ 1.2 mL L-1 and novaluron 10 EC @ 2.0 mL L-1 which recorded the lowest mortality in the laboratory evaluation were selected for field evaluation. Observations on the pollinator diversity in C. melo L. flowers, prior to the insecticide treatment, revealed that majority of the pollinators belong to order Hymenoptera (63.54 %) followed by Coleoptera (27.26 %) and Lepidoptera (9.01 %). Among the hymenopterans, T. iridipennis (9.33 m-2 5 min-1) and A. cerana indica (7.67 m-2 5 min-1) were the dominant pollinators with their peak time of activity being 0800 h to 0900 h and 1000 h to 1100 h respectively. For the sufficient pollinator population, one hive of each bee species was installed near the experimental plot which resulted in the percentage increase of field population of Indian bees and stingless bees by 26.07 and 50.05 per cent. Field evaluation of insecticide toxicity was assessed in terms of bee foraging behaviour viz., relative abundance, foraging rate (no. of bees visited m-2 min.-1), foraging speed (no. of flowers visited in a single plot min-1) and the time spent by the bees on male and female flowers separately (in sec.). Significant variation in relative abundance of pollinators among the treatments was observed upto five DAS in the case of Indian bees and seven DAS in stingless bees. Lowest relative abundance was recorded for stingless bees from plots treated with dimethoate 30 EC @ 0.5 mL L-1 which ranged from 12.33 to 23.87 per cent. The foraging rate varied significantly among the treatments upto five DAS in both the bees. The stingless bees showed significant variation in the time spent on flowers upto seven DAS, while Indian bees had significant variation only upto three DAS. Though the foraging speed of Indian bees showed significant variation among the treatments upto three DAS, dimethoate 30 EC @ 0.5 mL L-1 recorded lowest foraging rate when compared to other treatments. In the case of stingless bees, significant variation in foraging speed among the treatments was observed upto one DAS with least foraging speed from the treated check. Observations on the number of returning foragers in the hive before and after application of insecticides revealed significant reduction of foragers upto five DAS in stingless bees and three DAS in Indian bees. Thus, the foraging activities of stingless bees were found to be more affected by the insecticide application than that of Indian bees. The study could establish that the new generation insecticides, cyantraniliprole 20 SC @ 1.2 mL L-1and novaluron 10 EC @ 2.0 mL L-1 which recorded the lowest mortality in the laboratory are safe to the pollinators in terms of their foraging behaviour when compared to the dimethoate 30 EC @ 0.5 mL L-1. Considering the safety of new generation insecticides to the dominant pollinators, they can be used for effective pest management in cucurbits, though the residues of novaluron 10 EC was detected upto 10 DAS when compared to dimethoate 30 EC (upto three DAS) on flowers of culinary melon.ThesisItem Open Access Dissipation and risk assessment of select insecticides used for pest management in cabbage and cauliflower(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2018) Anju Padmanabhan; KAU; Ambily PaulStudies on “Dissipation and risk assessment of select insecticides used for pest management in cabbage and cauliflower” was conducted in College of Agriculture, Vellayani, Cardamom Research Station, Pampadumpara and farmers field at Kalliyoor during 2015-2018. The present research work was under taken to study the dissipation of select insecticides viz., chlorantraniliprole 18.5 % SC, flubendiamide 39.35 % SC, indoxacarb14.5 % SC, emamectin benzoate 5 % SG, fipronil 5 % SC, quinalphos 25 % EC, cypermethrin 10% EC, acetamiprid 20% SP, thiamethoxam 25 % WG and dimethoate 30 % EC in cabbage and cauliflower, to assess their potential risks to human health, to determine their effect on soil microbial activity, to estimate the residues in cooked samples and to evaluate the efficacy of “Veggie Wash” to eliminate residues. Survey conducted among 25 each of farmers cultivating cabbage and cauliflower in plain (Thiruvananthapuram) and hill (Idukki) representing two agro climatic conditions revealed that pest infestation was more in hills when compared with plains. Accordingly, pesticide usage was higher in Idukki (84 % each) than in Thiruvananthapuram district (12 and 8 %) in cabbage and cauliflower respectively. Dissipation studies of insecticides having label claim for cabbage and cauliflower under CIB & RC in two agroclimatic regions of Kerala viz., Thiruvananthapuram and Idukki showed that the degradation of insecticides varied with crop and chemistry of the insecticides. Insecticides persisted more in cabbage under plain were flubendiamide (20 days) followed by acetamiprid and quinalphos (10 days each), while in hills, higher persistence was observed in flubendiamide, cypermethrin and quinalphos (10 days each). The lowest persistence was observed in fipronil (3 days) in cabbage under plains and acetamiprid (3 days) in hills. In cauliflower higher persistence was observed for flubendiamide, chlorantraniliprole and dimethoate in plains and flubendiamide, quinalphos (20 days each) and cypermethrin (15 days) treated plots in hills. The lowest persistence was observed for emamectin benzoate (3 days) in cauliflower under plains and hills. Risk assessment study was carried out in cabbage and cauliflower using selected insecticides under plains and hills by comparing the values of Theortical Maximum Residue Concentration (TMRC) and Maximum Permissible Intake (MPI). The result revealed that consumption of dimethoate and fipronil treated cabbage and cauliflower were found to be risky to the end users. However, all other insecticides are safe even on the same day of insecticide application. Effect of insecticides on soil microbial activity was studied in cabbage and cauliflower through the activity of urease, phosphatase and dehydrogenase enzymes. Lower reduction in urease activity was observed in flubendiamide, dimethoate and thiamethoxam treated plot and higher reduction was recorded in fipronil and quinalphos treated plots over control both in cabbage and cauliflower. However, lower reduction in phosphatase activity was recorded in flubendiamide, thiamethoxam and cypermethrin and higher reduction was observed in indoxacarb and fipronil treated plots over control. Lower reduction in dehydrogenase activity was recorded in cypermethrin, acetamiprid and thiamethoxam treated plots and higher reduction was recorded in indoxacarb and fipronil treated plots over contol in both cabbage and cauliflower. Study on extent of removal of insecticides through cooking from cabbage and cauliflower was conducted with insecticides which had more persistence revealed that 15 min cooking removed more residues and the highest removal was observed for quinalphos (54.79 %) in cabbage under plains and cypermethrin (66.47 %) in hills. However, in cauliflower the highest per cent removal was observed for chlorantraniliprole (44.78) in plains and cypermethrin (52.32 %) in hills. “Veggie wash” technology was evaluated in the cabbage and cauliflower after application of insecticides at recommended doses revealed that dipping of cabbage and cauliflower in one per cent “Veggie Wash” solution for 10 min. followed by water wash removed 12-40 per cent of treated insecticides while water wash alone removed 9 -35 per cent. The present study revealed that the dissipation pattern of insecticides varied with crop, agro climatic areas, and chemistry of the molecules. Risk assessment study shown that insecticides viz., fipronil and dimethoate posed risk on human health even at recommended dose. Studies on effect of insecticides on soil enzyme revealed that except fipronil and indoxacarb, all other insecticides under present study have less impact on soil enzymes. Decontamination studies showed that cooking at 15 min. removed 50-60 per cent of insecticides and “Veggie Wash” removed 12-40 per cent of treated insecticides. Present study urged the need to evaluate the new insecticides carefully, by considering safety to environment and human health. The risk assessment studies of all insecticides should be done before going for field level recommendations.ThesisItem Open Access Elucidating the biochemical basis of interaction between tea mosquito bug, helopeltis antonii signoret (hemiptera:miridae) and cashew (anacardium occidentale)(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 2018) Nimisha, T; KAU; Deepthy, K BCashew is one of the important foreign exchange earning crops of India with an export value of Rs. 5,077 crores during 2016-17.Cashew production is not in tune with increase in area under its cultivation. Low productivity in cashew is mainly due to the incidence of pests and diseases. Among the insect pests, tea mosquito bug (TMB), Helopeltis antonii Signoret (Hemiptera: Miridae) is the most important. It causes 30-50 per cent yield loss and during outbreak situations even up to 100 per cent loss has been reported. Cashew varieties exhibit wide variation in response to TMB infestation. Hardly any variety has ever been recorded as resistant to TMB till date. However, a few accessions are reported to be capable of withstanding TMB infestation and hence have been grouped as less susceptible category. Understanding the basis of interaction between the bug and the cashew is a prerequisite in developing varieties resistant to TMB. The present study entitled “Elucidating the biochemical basis of interaction between tea mosquito bug, Helopeltis antonii Signoret (Hemiptera: Miridae) and cashew (Anacardium occidentale)” was undertaken at the Department of Agricultural Entomology, College of Horticulture, Vellanikkara during September 2017 to July 2018. The objective of the study was to understand the variation in secondary metabolites and defense enzymes in selected cashew varieties induced by tea mosquito bug infestation and to elucidate the secondary metabolite detoxification mechanisms in the pest. Three months old grafts of four cashew varieties viz., two from the highly susceptible category (Anagha, Madakkathara-1) and two from less susceptible category (Damodar, Raghav) were used to conduct the experiment. Female adult bug (0-24 h old) was allowed to feed on each variety for different time intervals of 6, 24, 48 and 72 h. The biochemical parameters such as protein, phenol, tannin and defense enzymes viz., polyphenol oxidase (PPO) and phenyl alanine ammonia lyase (PAL) in leaves of TMB infested and non infested cashew grafts were analysed before release (0 h) as well as at different intervals of release. Biochemical analysis of the released TMB (crude homogenate of whole insect) viz., variation in total protein, SDS PAGE profiling of TMB crude protein, detoxifying enzymes viz., carboxyl esterase, cytochrome P450, and glutathione-s-transferases (GST) were carried out before releasing on the plant and at different intervals after release. The total leaf protein was found to be highest in the less susceptible variety Damodar (0.9925 mg g-1) and the lowest in the highly susceptible Madakkathara-1 (0.6729 mg g-1). Total phenol content was highest in the less susceptible Damodar (69.834 mg g-1) and Raghav (67.207 mg g-1) and the lowest was recorded in Anagha (29.625 mg g-1). Regardless of the varieties, highest phenol content was recorded in samples taken after 72 h of TMB infestation. Tannin content was also high in the less susceptible varieties Raghav (4.420 mg g-1) and Damodar (4.276 mg g-1) while highly susceptible varieties Anagha and Madakkathara-1 recorded lower values. Irrespective of the varieties, the highest tannin content was recorded in samples before the release of TMB (6.662 mg g-1). Results of the present study revealed that, detoxifying enzyme specific activity of PPO was highest in Damodar (0.003158 EU g-1min-1) and observed lowest value in Anagha (0.001406 EU g-1min-1). Irrespective of the varieties, enzyme activity reached highest at 48 h of release (0.00367 EU g1min-1). PAL specific activity was highest in Madakkathara-1 (0.575 μg g-1 min-1) and lowest in Anagha and was on par with Raghav and Damodar. In SDS PAGE, the whole body homogenate of adult female TMB revealed presence of bands in the range of ̴ 63 kDa and 35-48 kDa in the early stage of infestation. However, as the exposure time increased, protein bands ranging from 17-75 kDa appeared. Defensive enzymes viz., carboxyl esterase and GST expressed elevated activity in TMB that fed on less susceptible Raghav (258.117 μmol min-1mg-1 protein, and 365.262 μmol min-1mg-1 protein respectively) and Damodar (208.916 μmol min-1mg-1protein, and 501.879 μmol min-1mg-1protein respectively) when compared to the highly susceptible varieties. Cytochrome P450 showed highest activity in TMB fed on Damodar (0.372 nmol min-1mg-1 protein) and it was having lowest activity in insect fed on other three varieties. The study revealed that, the secondary metabolites viz., phenol, tannin and PPO have a definite role in imparting resistance in cashew to TMB attack. These metabolites have potential use in early detection of resistance in cashew against TMB. The enhanced levels of detoxification enzymes in TMB indicate plasticity of the pest against host plant defense and chance of resistance development against synthetic insecticides.
- «
- 1 (current)
- 2
- 3
- »