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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.

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  • ThesisItemOpen Access
    Susceptibility of Tetranychus okinawanus Ehara (Prostigmata: Tetranychidae) infesting ornamental plants to novel acaricides
    (Department of Agricultural Entomology, College of Agriculture, Vellanikkara, 2021) Sreshma, M; KAU; Haseena, Bhaskar
    Spider mites of the family Tetranychidae are well-known agricultural and horticultural pests that feed on a wide variety of plants, including vegetables, fruit trees, and ornamentals. Many traditional insecticides and acaricides have been used to manage mite pests for several decades. The widespread usage of acaricides around the world has facilitated development of resistance in different mite species, making mite management challenging. As a result, many novel acaricides with distinct chemical structures and modes of action have been developed and marketed for mite control. However, after a few years of use, mite populations developed resistance to these newly introduced compounds too. The spider mite species, Tetranychus okinawanus, recently recorded on an ornamental plant Adenium in Thrissur district, for the first time in India, has now emerged as the predominant species of mite infesting ornamental plants in Kerala. Recently, several growers reported inefficacy of the commonly used novel acaricides against mite pests in many ornamental crops, suggesting that the mite populations might have developed resistance to acaricides. Hence a study was carried out to investigate the status of acaricide resistance in Tetranychus okinawanus infesting Adenium in horticultural nurseries and also to elucidate the biochemical mechanism involved in development of resistance. Purposive surveys were conducted in six commercial horticultural nurseries in Thrissur district viz., National Rose Garden, Mangadan Botanical Garden, Ayyappa Nursery, Saranamayyappa Nursery, Pooja Gardens and Nursery, and Manalur Adenium Garden and samples of spider mite infesting Adenium were collected. Mites were maintained as separate isoline cultures assigning unique accession numbers as NrAd1, MgAd2, AyAd3, SyAd4, PjAd5 and MnAd6. Morphological characterisation of the slide mounted mite specimens from the isoline cultures was carried out to confirm the species identity as T. okinawanus. Susceptibility of the six field populations to three acaricides viz., spiromesifen, fenazaquin and dicofol was evaluated in the laboratory, in comparison with the reference susceptible population maintained without exposure to any acaricides in the laboratory, following toxicological bioassay. Susceptibility studies with fenazaquin revealed that the accession NrAd1 recorded the highest LC50 value (27.85 ppm) and has developed moderate level of resistance (14.38-fold) to fenazaquin. This was followed by PjAd5 (9.70-fold), AyAd3 (4.06-fold), MnAd6 (3.78-fold), and SyAd4 (3.23-fold). The lowest resistance ratio was recorded by the accession MgAd2 (1.66). The toxicity studies of spiromesifen also recorded low to moderate levels of resistance in different populations of T. okinawanus. The accession NrAd1 recorded highest resistance ratio of 27.31 followed by PjAd5 (7.18), MnAd6 (3.94), AyAd3 (1.78), MgAd2 (1.42) and SyAd4 (1.06). However, the mite populations showed only low level of resistance to dicofol, recording resistance ratios in the range of 3.65 to 1.22. Biochemical basis of acaricide resistance in different populations of T. okinawanus was investigated by estimating the activity of detoxifying enzymes such as carboxyl-esterase, cytochrome P450 and glutathione S- transferase. Carboxyl-esterase enzyme showed an enhanced activity of 1.03 to 3.52-fold, while cytochrome P450 monooxygenases recorded 1.01 to 2.08-fold higher activity in the field collected populations, compared to the susceptible population. The level of these detoxifying enzymes was found to be higher in the accession NrAd1, which also recorded the highest resistance ratio in the study. However, the activity of glutathione S-transferase (GST) did not differ significantly among the field populations and also with susceptible population, indicating that GST is not a contributing factor in the development of resistance in T. okinawanus against spiromesifen, fenazaquin and dicofol. The study recorded development of resistance in the spider mite, T. okinawanus on Adenium to spiromesifen and fenazaquin, in the horticultural nurseries in Thrissur district, Kerala for the first time in the world. The significant role of the detoxifying enzymes, carboxyl-esterases and cytochrome P450 monooxygenases in imparting resistance in T. okinawanus to the two novel acaricides, fenazaquin and spiromesifen was also confirmed in the study. The study demands formulation of a suitable resistance management strategy in horticultural nurseries in the state for suppressing or delaying resistance development in mite populations.
  • ThesisItemOpen Access
    Microbial diversity in hive-stored pollen of indian honey bee, Apis cerana indica (Fabricius)
    (Department of Agricultural Entomology, College of Agriculture, Vellanikkara, 2021) Abhishek, V; KAU; Mani Chellappan
    Honey bees are eusocial flying insects. Among all insects that pollinate, honeybees are considered to be one of the crucial pollinators. Honey bees represent only a small fraction of the roughly 20,000 known species of bees. Honey bees obtain all of their nutritional requirements from a diverse combination of pollen and nectar. Pollen grains referred to as 'bee bread' or 'bee meat' are the natural sources of proteins, vitamins, fats, lipids and minerals, of which proteins are very much essential for building the body tissues of the bees, especially during the early embryonic growth. Worker bees of Apis cerana indica help in the fermentation of pollen which releases additional nutrients that are used in the production of antibiotics and fatty acids which inhibit spoilage. Pollen analysis of samples provides the information regarding the plants preferred by bees for nectar, as the pollen grains dispersed are mostly collected by bees along with nectar. Honey has two sources of contamination, primary one being the hive stored pollen. Thus, it is very essential to study the microbial diversity of pollen, which may lead to spoilage of pollen and nectar. The present investigation on “Microbial diversity in hive-stored pollen of Indian honey bee, Apis cerana indica (Fabricius)” was conducted at Department of Agricultural Entomology, College of Agriculture, Vellanikkara, Kerala Agricultural University during 2020-2021 in order to study the diversity of hive-stored pollen and associated microbes in A. cerana indica (Fabricius) colonies. Purposive surveys were conducted in six locations at Palakkad and Wayanad district viz., Mannarkkad, Nellipuzha, Nottaamala, Kenichira, Kayakunnu and Cheengode. Hive stored pollen collected were maintained in refrigerated conditions after assigning unique accession numbers as PKD-1, PKD-2, PKD-3, WYD-1, WYD2, WYD-3. Microbial diversity, microbial load of hive stored pollen, identification and characterization of pollen with respect to its nature, size, shape, aperture, exine pattern along with physicochemical properties viz., moisture content, water activity, pH, ash content, total acidity and protein content were studied. Palynological identification plays a crucial role in beekeeping industry. Pollen aids as a food supplement to honeybees for their growth and development. It assists in the identification of geographical and botanical origin of pollen. A total of 21 plants were recorded as pollen sources by bees from the study area (six locations) of two districts. Ten pollen types were identified based on its nature, size, shape, aperture, exine pattern using PalDAT software. Identified plant species were Sphagneticola trilobata (Asteraceae), Caesalpinia pulcherrima (Fabaceae), Zinnia elegans (Asteraceae), Ocimum sanctum (Lamiaceae), Clitoria ternatea (Fabaceae), Biophytum sensitivum (Oxalidaceae), Bauhinia acuminata (Fabaceae), Mimosa pudica (Fabaceae), Tecoma stans (Bignoniaceae), Portulaca grandiflora (Portulacaceae). Characterization of pollen revealed that ten plant species belonging to seven families serve as pollen sources in respective survey locations. Physicochemical properties of hive stored pollen of A. cerana indica collected from six locations were investigated by estimating the moisture content, water activity, pH values, ash content, total acidity and protein content. Moisture content varied from 15.29-15.38 (g/100g). Water activity varied from 0.73 to 0.74 (aw) and the pH varied between 3.77 and 3.83. Ash content varied from 1.87-2.01 (g/100g). Total acidity varied from 9.64-10.13 (mmol/g). Protein content varied from 3.46-3.69 (%). Parameters like moisture content, water activity, protein content were more in the Wayanad sample, it may be because of high humidity and temperature variations. Parameters like pH, total acidity and ash content were more in Palakkad sample, which infers that mineral content might be more. Microbial diversity of hive stored pollen of Apis cerana indica collected from six locations was investigated by identifying the microbes through their morphological, cultural, molecular characterization. Other parameters like microbial diversity, microbial load, microbial load to pollen grain ratio, microbial population were also observed. In total, four bacteria and three fungal species were identified. However, colonies of actinomycetes and yeast were not obtained. Out of four bacteria, B2, B3, B4 – gram positive while B1- gram negative. The shape of all bacterial isolates was rod with change in their colony colour.16s rRNA sequencing of bacterial isolates revealed that B1 as Pseudomonas aeruginosa, B2 as Bacillus megaterium, B3 as Bacillus aryabhattai and B4 as Bacillus megaterium respectively. Out of the three fungi, colony colour of T1 colony colour was green, W1 colony colour was white and A1 colony colour was orange. All isolates have flat elevation with an entire margin. ITS sequencing of fungal isolates revealed that T1 as Trichoderma reesei, W1 as Westerdykella multispora and A1 as Neurospora crassa. Microbial diversity was more in sample collected Wayanad with two fungal and two bacterial colonies whereas, one fungal and two bacterial colonies in sample collected from Palakkad. Microbial load was more in samples from Wayanad (6.6x104 cfu/g) when compared with Palakkad sample (3.3x104 cfu/g). Comparison of microbial load to pollen grain ratio revealed that Wayanad sample recorded highest with 6.6x104 cfu/g to Palakkad sample with 3.3x104 cfu/g. Bacterial and fungal populations were observed more in Wayanad sample when compared to Palakkad sample. The study recorded the pollen sources of different localities in and around the Palakkad and Wayanad districts of Kerala. Moisture content plays a significant role which might be the reason for high microbial diversity and microbial load in Wayanad. The present study demands the investigations of other physicochemical properties like EC, starch content, amino acid composition, microbial spores present in pollen which could be useful for the food preservation industry or potentially hazardous in due course of time.
  • ThesisItemOpen Access
    Insecticide resistance management in Rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae)
    (Department of Agricultural Entomology, College of Agriculture, Vellayani, 2021) Neethu, P; KAU; Thania Sara Varghese
    The research work entitled "Insecticide resistance management in rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae)" was done at College of Agriculture, Vellayani during 2019 to 2021.The objectives of the study were to assess the resistance levels in rice weevil, biochemical basis of resistance and screening of new molecules for the management of S. oryzae. Different sample populations of S. oryzae were collected from the three godowns of Food Corporation of India (FCI) viz., Kollam, Valiyathura, and Thikkodi, as well as a susceptible lab culture of S. oryzae maintained without pesticide exposure, was obtained from the Division of Entomology, Indian Agricultural Research Institute (IARI). Resistance levels of the commonly used insecticides in FCI viz., malathion and deltamethrin were evaluated in the three populations collected from Kollam, Valiyathura and Thikkodi by film method of bioassay and compared it with the susceptible lab population from IARI. Kollam population showed highest resistance to both malathion and deltamethrin with resistance ratios of 14.94 and 9.03 followed by Valiyathura with resistance ratios of 11.39 and 7.79, respectively. Thikkodi population showed the least resistance to malathion and deltamethrin, with resistance ratios of 8.74 and 5.48, respectively. Malathion resistance was higher in all the three populations than the deltamethrin resistance. The most resistant population selected from the previous experiment i.e., the Kollam population was further assayed for its biochemical basis along with the susceptible IARI lab culture. The Kollam population was found significantly higher in total protein (6 mg ml-1 ) and activity of detoxifying enzymes viz., carboxylesterases (0.65 µmol min-1 mg protein-1 ), glutathioneS-transferases (0.41 µmol min-1 mg protein-1 ) and cytochrome P450 (0.74 p mol min-1mg protein-1 ) than the lab sample. The sample population collected from Kollam was again screened for their susceptibility to new generation insecticides like fipronil, indoxacarb and chlorantraniliprole by film method of bioassay. Fipronil was found to be more toxic with LC50 value of 5.86 ppm followed by indoxacarb (90.57 ppm) and chlorantraniliprole (4041.43 ppm). Fipronil and indoxacarb were 619.8- and 40.13-fold toxic to resistant population of S. oryzae with respect to malathion. The newer insecticides in the previous experiment along with malathion and deltamethrin were further screened simulating the conditions of FCI godown. The insecticides were sprayed on jute bags containing 1 kg of rice grains and 50 adult beetles of Kollam population of S. oryzae. The dosages of newer insecticides were taken 10 times more the LC50 value obtained in the laboratory bioassay and FCI recommended dosage was taken for malathion and deltamethrin. Fipronil 5% SC @ 0.006% recorded significantly higher mortality of 86.5 and 89.5 per cent at 24 and 48 h of treatment followed by indoxacarb 14.5% SC @ 0.09% and chlorantraniliprole 18.5% SC @ 4.04%. The persistence of the most effective insecticide fipronil along with malathion and deltamethrin on rice grains were further studied by recording the residue levels at different time intervals after spraying. Dosages were same as the previous experiment. Insecticides were sprayed on jute bags containing rice grains and residues were analysed at 0 (2 h after spray), 1, 3, 5, 7,10, 15, 20 and 30days intervals using the methods validated prior to residue estimation. Fipronil residues were below the limit of quantification at 2 h after spraying. The residues of deltamethrin and malathion persisted up to 3 and 5 days after spraying with a half-life of 2.48 and 2.71 days, respectively. From the present study it is revealed that S. oryzae collected from Kollam, Valiyathura and Thikkodi were resistant to the commonly used insecticides viz., malathion and deltamethrin and it is confirmed here by the presence of higher levels of detoxifying enzymes in the resistant population. Further screening of newer insecticide molecules against the resistant population of S. oryzae suggested that fipronil 5% SC @ 0.006% is highly effective and less persistent on grains when compared to malathion and deltamethrin.
  • ThesisItemOpen Access
    Field tolerance of chilli varieties against sucking pest complex
    (Department of Agricultural Entomology, College of Agriculture, Vellayani, 2022) Haritha, N K; KAU; Vijayasree, V
    The study on the “Field tolerance of chilli varieties against sucking pest complex”was conducted at Department of Agricultural Entomology, College of Agriculture, Vellayani during 2019-2021 with the objective to evaluate chilli genotypes for field tolerance to sucking pest complex viz; Aphis gossypii Glover, Polyphagotarsonemus latus Banks and Scirtothrips dorsalis Hood. A total of 30 genotypes were screened for the field tolerance to the sucking pests, including indigenous genotypes of Kerala, KAU released varieties and accessions from NBPGR. The mean population count of A. gossypii, P. latus and S. dorsalis on 20, 35, 50 and 65 days after transplanting was recorded and significantly lower mean number of A. gossypii was recorded in L3 (2.83 leaf-1), L9 (4.61 leaf-1) and L14 (5.75 leaf-1). The population of P. latus was observed least in the genotype L5 with a mean number of 1.47 mites leaf-1 which was followed by L14 (2.36 leaf-1) and L3 (2.49 leaf-1). The minimum incidence of S. dorsalis was recorded in the genotype L5 which showed a mean population of 2.25 thrips leaf-1 and it was followed by L14 (3.94 leaf-1) and L3 (4.03 leaf-1). The genotype L11 was found most susceptible with the highest number of A. gossypii (23.72 leaf-1), P. latus (6.30 leaf-1) and S. dorsalis (6.75 leaf-1). The damage assessment was done by observing the leaf damage caused by mites and thrips. When the mean leaf damage was recorded on 20, 35, 50 and 65 days after transplanting, P. latus showed least preference to the genotype L5 with a per cent leaf damage of 14.92 and this was followed by L14 (16.92) and L3 (20.92). The minimum damage by S. dorsalis was observed in the genotype L5 with a leaf damage of 15.08 per cent and was followed by L3 and L14 with a leaf damage of 18.33 and 21.08 per cent respectively. The genotype L11 was severely damaged by P. latus and S. dorsalis with a per cent leaf damage of 76.33 and 74.08 respectively. The Per cent Leaf Curl Index (PLI) was calculated based on the leaf damage, for grouping the chilli genotypes into resistant, moderately resistant, susceptible and highly susceptible categories. Based on the mean PLI due to damage by P. latus the genotypes, L5 and L14 were grouped under moderately resistant category. The genotypes L5 and L3 were grouped as moderately resistant based on mean PLI due to damage by S. dorsalis. The genotypes L11, L4, CF1 and IC284628 were coming under the highly susceptible category due to infestation of P. latus and S. dorsalis. Principal Component Analysis (PCA) was carried out based on the mean population of A. gossypii, P. latus and S. dorsalis to find out the tolerant and susceptible genotypes against the sucking pest complex. The genotypes L5, L3 and L14 were found as the tolerant and L11 as the susceptible genotype for which the analysis of morphological traits, biochemicals and nutrients were carried out. Different morphological traits like plant height, total number of leaves plant-1 and leaf area were highest in L3. The number of branches plant-1 and trichome density was highest in L5 and the length-width ratio of leaves in the genotype L14. However, all these morphological characters were found lowest in the genotype L11. Analysis of biochemicals revealed that the total phenol content and capsaicin content was highest in the genotype L5 (0.290 mg g-1 and 0.016mg g-1 respectively) and lowest in the genotype L11. Total protein and total sugar were highest in L11 (6.169 mg g-1 and 0.216 mg g-1 respectively) and lowest in L14. Total nitrogen and total phosphorus were highest in L11 (0.18% and 0.63% respectively) and lowest in L3. Total potassium was highest in L14 (1.08%) and lowest in L11 (0.46%). Correlation studies were done to find out the relationship between the different traits in chilli genotypes and infestation of A. gossypii, P. latus and S. dorsalis. Among the morphological characters, plant height and leaf area had a significant negative correlation with the population of A. gossypii while number of branches plant-1 had a significant negative correlation with the incidence of all the three sucking pests. The total protein and total sugar had a significant positive correlation with the population of A. gossypii, whereas total phenol had a significant negative correlation with the incidence of P. latus and S. dorsalis. Total nitrogen had a significant positive correlation with the population of A. gossypii whereas total phosphorus had a significant positive correlation with the population of S. dorsalis. Based on the mean population of A. gossypii, P. latus and S. dorsalis and the leaf damage caused by them, the genotypes L5, L3 and L14 were observed as the tolerant whereas the L11 was found as the susceptible genotype to these sucking pest complex.
  • ThesisItemOpen Access
    Quantification and characterization of Indian honey bee (Apis cerana indica Fab.) Venom
    (Department of Agricultural Entomology, College of Agriculture, Vellayani, 2022) Alen, Joy; KAU; Amritha, V S
    The research work entitled “Quantification and characterization of Indian honey bee (Apiscerana indica Fab.) venom” was carried out at College of Agriculture, Vellayani during the year 2019 to 2021. The objective of the study was quantification and characterization of Indian honey bee venom during different seasons. Hives of uniform bee strength maintained in the apiary of AICRP on Honey Bees & Pollinators were selected to identify the peak hour of the day at which maximum bee venom can be collected from a hive using a bee venom collector. Venom was collected from hives at different hours starting from 6 am to 6 pm for three days. The optimum duration at which maximum venom can be collected from the hive with minimum damage to the bees were also assessed. Venom was collected for three different durations viz., 30 minutes, 40 minutes and 60 minutes and the quantity of venom collected and mortality was recorded. Seasonal variation was assessed by collecting venom at the peak hour and optimum duration on all the three seasons viz, brood rearing (September - December), honey flow (January - April) and dearth (May-August). The brood parameters and foraging activity of the hives were also assessed at weekly intervals for a period of one month in order to determine whether the bee venom collection has any impact on these parameters. The venom collected during the three seasons were subjected to characterisation and the proportion of components present in the venom were analysed. Control hives were maintained and the data were subjected to ANOVA and paired t test analysis. Observations on the venom collection at hourly intervals of a day revealed that maximum quantity of venom was collected at 2 pm to 3 pm (52.00 mg per hive) and least venom was collected at 7 am to 8 am. Statistical analysis of the data on optimum duration for venom collection showed that highest quantity of venom was collected at 60 minutes duration (55.34 mg per hive), but the mean mortality was high (5.20 bees per hive). Venom collected at 40 minutes and 30 minutes were 34.14 mg and 25.12 mg per hive which were on par. The optimum duration for placing the bee venom collector was selected as 30 minutes considering the low mortality of bees (0.80 per hive) as compared to 40 minutes (2.00 per hive). Significant variation was not observed in the brood parameters as well as in the foraging activity of the venom collected and control hives. Studies on the seasonal variation in bee venom collected revealed that maximum quantity of venom was collected at honey flow season (55.16 mg per high) followed by dearth season (41.00 mg) and brood rearing season (25.12 mg). Maximum mortality was also recorded at honey flow season followed by dearth season and brood rearing season. Brood parameters as well as the foraging activity of the bees did not vary significantly among the seasons. The quantity of bee venom collected had a non-significant positive correlation with temperature and negative correlation with humidity. The characterisation of bee venom samples collected during the three seasons were carried out at SAIF, IIT Bombay by HR LC-MS (High Resolution Liquid Chromatography-Mass Spectrometry) with database (Plant extract Impurity Profiling and Metabolite Identification). Melittin and apamin were identified as the major components, with melittin showing maximum abundance on all the three seasons. No significant difference was recorded in the abundance of both melittin and apamin among the three seasons. Thus, in the present study, highest quantity of bee venom was collected at 2 pm to 3 pm (52.00 mg per hive) and the optimum duration for collection was 30 minutes, considering the bee mortality factors. Studies on the seasonal variation revealed that significantly high bee venom was collected during the honey flow season (55.16 mg per hive), while no significant variation was observed in the brood parameters among the seasons. Characterisation of the bee venom revealed that melittin and apamin were the major components, of which melittin was 8.5 times abundant than that of apamin with no significant variation among the seasons.
  • ThesisItemEmbargo
    Bacillus spp. for seed biopriming to enhance growth in transplants of Solanaceous vegetable crops.
    (Department of Agricultural Microbiology, College of Agriculture , Vellayani, 2022) Safa, Biju; KAU; Anith, K N
    The experimental work entitled “Bacillus spp. for seed biopriming to enhance growth in transplants of solanaceous vegetable crops” was done at Department of Agricultural Microbiology, College of Agriculture, Vellayani, Thiruvananthapuram during academic year 2019-21. Objective of study was to assess the effectiveness of biopriming with spore forming bacilli for plant growth promotion in transplants of solanaceous vegetable crops such as tomato, brinjal and chilli. In vitro as well as in vivo experiments were conducted in this study. In vitro studies included characterization of the bioagents viz, B. pumilus VLY17, B. amyloliquefaciens VLY24 and B. velezensis PCSE10 for plant growth promoting parameters. IAA production was assessed in presence and absence of tryptophan and it was found that B. pumilus VLY17 produced maximum IAA (23.344μgmL1 ) in presence of tryptophan whereas in the absence of tryptophan, B. amyloliquefaciens VLY24 produced maximum IAA (15.072 μgmL-1 ). Ammonia production was observed in B. amyloliquefaciens VLY24 and B. velezensis PCSE10. Direct and indirect antagonism against Pythium sp. was done by dual culture plate assay and agar well diffusion assay respectively. All three bioagents showed inhibitory effects. In agar well diffusion assay, unmeasurable inhibitory zone was observed in case of B. velezensis PCSE10. Roll towel technique was performed to assess seedling vigour of tomato, brinjal and chilli seeds bioprimed with bacterial bioagents and their consortium against hydroprimed and untreated control. In tomato, maximum seedling vigour was observed in seeds treated with B. pumilus VLY17 (556.75). In brinjal, B. amyloliquefaciens VLY24 treated seeds showed maximum vigour (860.5) followed by consortium treatment (828). In chilli, consortial treatment (970) followed by B. pumilus VLY17 (951.25) treatment showed maximum vigour index. In vivo studies were done by raising treated seeds of tomato, brinjal and chilli in protrays. In tomato, three of the treatments showed superior results in growth promotion viz, consortium treatment followed by B. pumilus VLY17 and B. amyloliquefaciens VLY24. In brinjal, B. velezensis PCSE10 showed best results in majority of plant growth promoting traits. In chilli, B. pumilus VLY17 and B. amyloliquefaciens VLY24 showed superior results. Root colonization studies were also done and all the three bioagents were found to be effective root colonizers in all the three crops studied. Results of this study lead to the conclusion that the three endospore formers are highly effective as biopriming agents for enhancing plant growth promotion and development in solanaceous vegetable crops under nursery conditions.
  • ThesisItemOpen Access
    Documentation and management of pests of jasmine, Jasminum spp.
    (Department of Agricultural Entomology, College of Agriculture ,Vellayani, 2022) Swathy, I M; KAU; Malini, Nilamudeen
    In Kerala, jasmine is mostly grown as an ornamental crop in homesteads. Recently, there is an increase in jasmine cultivation due to its high export potential. In this scenario, knowledge about the pests and defenders of jasmine and their eco-friendly management under Kerala condition is highly essential. With this backdrop, the study entitled “Documentation and management of pests of jasmine, Jasminum spp.” was carried out at Department of Agricultural Entomology, College of Agriculture, Vellayani during the period of 2019 to 2021. The objectives of the study were to document the pests infesting Jasminum spp., their damage and symptoms, natural enemies associated with the pest and to develop suitable pest management measures. The documentation conducted at three districts viz., Thiruvananthapuram, Kollam and Alappuzha recorded sixteen pests. Jasmine budworm (Hendecasis duplifascialis Hampson), jasmine leaf webworm (Nausinoe geometralis (Guenee), Nausinoe perspectata (Fabricius)), shoot webworm (Margaronia unionalis Hubner), jasmine gallery worm (Elasmopalpus jasminophagus (Hampson)), blossom midge (Contarina maculipennis Felt), lacewing bug (Corythauma ayyari Drake), flower thrips (Thrips orientalis (Bagnall)), flea beetle (Hyphasis sita (Maulik)), grasshoppers (Diabolocatantops pinguis (Stal), Neorthacris acuticeps (Bolivar)), tortoise beetle (Cassida sp.), leafhopper (Kolla ceylonica (Melichar)), jasmine bug (Antestiopsis cruciata (Fabricus), moth bug (Ricania sp.), whitefly (Dialeurodes sp.), mealy bug (unidentified) and red spider mite (Tetranychus sp.). The grasshoppers (D. pinguis, N. acuticeps) tortoise beetle (Cassida sp.) and leafhopper (K. ceylonica) were reported for the first time from Kerala as pest of jasmine. Natural enemies associated with pests of jasmine were also documented in which the spiders were prominent predators followed by praying mantis. The spiders documented were white lynx spider (Oxyopes shweta Tikader), crab spider (Camaricus sp.), pantropical jumping spider (Plexippus paykulli (Audouin)), heavy bodied jumper (Hyllus semicupreus (Simon)), two striped jumper (Telamonia dimidiata (Simon)), flower crab spider (Thomisus lobosus Tikader), grass cross spider (Argiope catenulata (Doleschall)), long jawed orb-weaver (Tetragnatha maxillosa Thorell) and banded phintella (Phintella vittata (C. L Koch)). Apart from spiders, Asian mantis (Hierodula membranacea Burmeister) and praying mantis (Odontomantis pulchra Olivier) were also documented. Spiders Camaricus sp., A. catenulate and T. maxillosa were reported for the first time from Kerala on jasmine. A consolidated documentation of spider and mantid predators from jasmine ecosystem is first of its kind from Kerala. Pupal parasitoid Brachymeria nephantidis Gahan and larval parasitoid Apanteles sp. were found parasitizing on the jasmine leaf webworm, N. geometralis and larval parasitoid Phanerotoma hendecasiella (Cameron) was found parasitizing on jasmine budworm H. duplifascialis and jasmine gallery worm E. jasminophagus. Studies on the biology of H. duplifascialis and N. geometralis were carried out under laboratory condition. H. duplifascialis had an average of 3.35 + 0.11, 11.15 + 0.08 and 5.25 + 0.10 days of egg, larval and pupal period respectively whereas N. geometralis recorded an egg, larval and pupal period of 3.35 + 0.11, 10.65 + 0.20 and 6.65 + 0.11 days respectively. The prophylactic and curative field experiments were conducted at College of Agriculture, Vellayani for evolving efficient pest management practices. It was found that the prophylactic treatments with biopesticides, oil based formulation of Metarhizium anisopliae NBAIR Ma 4 @ 10 mL L-1 and Beauveria bassiana NBAIR Bb 5 @ 10 mL L-1 caused cent per cent reduction in the population of C. ayyari at 60 days after planting. The population of H. duplifacsialis was also nil in these plots. A three and two fold increase in flower yield was recorded for M.anisopliae and B.bassiana, respectively in comparison to untreated plots. The treatments were found safe to spider predators also. Among the curative treatments, chlorantraniliprole 8.8% w/w+Thiamethoxam 17.5 % w/w SC @150g a.i ha-1 was the best with no pest incidence and also had three-fold increase in mean flower yield (8.10 g plant -1 ) compared to the untreated plots. However, it was not safe to spiders. Among the biopesticides, oil based formulation of M. anisopliae NBAIR Ma 4 @ 10 mL L-1 and B. bassiana NBAIR Bb 5 @ 10 mL L-1 caused 73 and 67 per cent reduction in the population of H. duplifascialis and 90 and 89 per cent respectively for C.ayyari. The mean flower yield in M. anisopliae NBAIR Ma 4 @ 10 mL L-1 and B. bassiana NBAIR Bb 5 @ 10 mL L-1 treated plots was 2.7 and 2.2 times higher than that in untreated plots. Both treatments were found safe to spiders. From the present study, it can be concluded that, of the sixteen pests infesting jasmine, H. duplifascialis, C. ayyari and C. maculipennis attained the status of major pests. However, considering the presence of different pests belonging to various orders on jasmine, pest surveillance is highly recommended in the scenario of area expansion. The study recorded an extensive spectrum of spiders and parasitoids which played a key role in preventing the population build-up of pests. Prophylactic sprayings of oil based formulation of M. anisopliae NBAIR Ma 4 @ 10 mL L-1 or B. bassiana NBAIR Bb 5 @ 10 mL L-1 can be recommended during the initial appearance of pests on jasmine and the same can be recommended for curative management. However, for managing severe incidence of pest, single spray of Chlorantraniliprole 8.8% w/w+ Thiamethoxam 17.5 % w/w SC @150 g a.i ha-1 can be recommended.
  • ThesisItemOpen Access
    Antifeedant and growth regulatory activity of Sphagneticola trilobata(L) Pruski on tobacco caterpiller, Spodoptera litura (Fab)(Lepidoptera: noctuidae)
    (Department of Agricultural Entomology, College of Agriculture, Vellanikkara, 2021) Rahul, Raj M; KAU; Mani, Chellappan
    One of the most important aspects of agriculture is pest management. Pesticides used in the past produced a variety of environmental problems, including ecological imbalances, soil fertility loss, and marine life degradation. Conventional pesticides have also been linked to a number of significant and detrimental effects on human and animal health, including severe malignancies, neurological diseases, hormone disruptions, and reproductive troubles. Botanical pesticides are found to be an effective alternative to conventional pesticides for pest management. Sphagneticola trilobata (L.) Pruski, is an herb included in the Asteraceae and is well known for its medicinal properties, information about its bioactivity against insects is very less. Hence, in this study we evaluated the antifeedant and growth regulatory activity of various extract of Sphagneticola trilobata against Spodoptera litura. Dried and powdered S. trilobata plant materials were sequentially extracted with hexane and methanol followed by concentrated in vacuo in a rotary evaporator at a lower temperature to obtain crude extracts of S. trilobata. Hexane extracts of aerial parts and roots were named as SP1 and SP3 and methanol extract of aerial parts and roots were named as SP2 and SP4. The yield of methanol extract of aerial parts (5.67% w/w) was higher followed by methanol extract of roots (2.32% w/w), hexane extract of aerial parts (1.96% w/w) and hexane extract of roots (1.23% w/w) The antifeedant activity of various extracts of Sphagneticola trilobata tested in nochoice leaf disc bioassay revealed that methanol extract of aerial parts of S. trilobata had the maximum antifeedant activity of 52.10 per cent at 0.1 per cent of the extract against S. litura after 24h of feeding. Compared to aerial extracts, root extracts were less active against S. litura. At lower concentrations, the antifeedant activity of all the extract were not much prominent and are not statistically significant. The antifeedant activity of all the extract increased in 48h experiment except for 0.1 per cent concentration. The decreasing order of antifeedancy of four extracts was SP2>SP1>SP4>SP3. ii Similar results were recorded in the choice method of bioassay of extracts against S. litura. Maximum antifeedant activity of 46.65 per cent was obtained for methanol extract of aerial parts (SP2) after 24h of feeding. At lowest concentrations of 0.005, 0.01 and 0.03 per cent none of the extracts exhibited significant difference in activity. Increasing concentration beyond 0.03 per cent had a significant effect on antifeedancy in the choice method. As similar to the no-choice method, reduced activity was recorded after 48h of feeding. Maximum antifeedant activity of 38.81 per cent was recorded for SP2 after 48h of feeding. Similar to the no-choice method, root extracts exhibited a low level of activity against S. litura. Insect growth regulatory activity of various extracts was evaluated by diet incorporation method against five-day old larvae of S. litura. A maximum larval weight reduction of 31.4 per cent was recorded for SP4 at 0.1 per cent of the extract. A significant increase in larval duration compared to control was recorded for SP2 extracts at higher concentrations. Similar to larval weight reduction, a dose-dependent pupal weight reduction was recorded for SP1 (29.57 per cent at 0.1 per cent of the extract). Compared to the other three extracts, pupal weight reduction was very less for SP3. Pupal duration increased to a maximum period of 13.54 days at 0.1 per cent of SP4. Observations on abnormal pupae were not significant for any of the extracts. No larval mortality could be obtained with any of the treatments. A maximum of 16.7 per cent larval pupal intermediates was recorded for SP4 at the highest dose, but it was not significantly different from other treatments. Similar to larval mortality, no pupal adult intermediates were recorded for any of the extracts. Maximum pupal mortality of 41.00 per cent was recorded at 0.1 per cent of SP1, and it was significantly different from other treatments. For all the extracts, pupal mortality was dose-dependent. Minimum adult emergence was noticed for SP1 at 0.1 per cent of the extract. GC-MS/MS and LC-MS/MS analysis of active fractions revealed that more phytochemicals are present in aerial parts than roots. The higher activity of aerial parts might be due to the presence bioactive compounds like andrographolide, artemisin, iii genistein and taxifolin. Most of the chemicals identified were derivatives of steroids, terpenoids and flavonoids. The study results indicate that methanol extract of aerial parts of S. trilobata has strong antifeedant activity against S. litura. All other extracts were relatively less active against S. litura. Insect growth regulatory activity was maximum for hexane extract of aerial parts. All the extracts adversely affected the growth and devolvement of S. litura. The absence of larval mortality indicates that all the extracts have less contact toxicity.
  • ThesisItemOpen Access
    Antifeedant and growth regulatory activity of Sphagneticola trilobata(L) Pruski on tobacco caterpiller, Spodoptera litura (Fab)(Lepidoptera: noctuidae)
    (Department of Agricultural Entomology, College of Agriculture, Vellanikkara, 2021) Rahul Raj, M; KAU; Mani, Chellappan
    me Browse Help Sign on to: Search DSpace DSpace logo Kerala Agricultural University Digital Library 1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval) PG Thesis a Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/12249 Title: Antifeedant and growth regulatory activity of Sphagneticola trilobata(L) Pruski on tobacco caterpiller, Spodoptera litura (Fab)(Lepidoptera: noctuidae) Authors: Mani, Chellappan Rahul, Raj M Keywords: Agricultural Entomology Tobacco Spodoptera litura Lepidoptera Noctuidae Pruski Issue Date: 2021 Publisher: Department of Agricultural Entomology, College of Agriculture, Vellanikkara Abstract: One of the most important aspects of agriculture is pest management. Pesticides used in the past produced a variety of environmental problems, including ecological imbalances, soil fertility loss, and marine life degradation. Conventional pesticides have also been linked to a number of significant and detrimental effects on human and animal health, including severe malignancies, neurological diseases, hormone disruptions, and reproductive troubles. Botanical pesticides are found to be an effective alternative to conventional pesticides for pest management. Sphagneticola trilobata (L.) Pruski, is an herb included in the Asteraceae and is well known for its medicinal properties, information about its bioactivity against insects is very less. Hence, in this study we evaluated the antifeedant and growth regulatory activity of various extract of Sphagneticola trilobata against Spodoptera litura. Dried and powdered S. trilobata plant materials were sequentially extracted with hexane and methanol followed by concentrated in vacuo in a rotary evaporator at a lower temperature to obtain crude extracts of S. trilobata. Hexane extracts of aerial parts and roots were named as SP1 and SP3 and methanol extract of aerial parts and roots were named as SP2 and SP4. The yield of methanol extract of aerial parts (5.67% w/w) was higher followed by methanol extract of roots (2.32% w/w), hexane extract of aerial parts (1.96% w/w) and hexane extract of roots (1.23% w/w) The antifeedant activity of various extracts of Sphagneticola trilobata tested in nochoice leaf disc bioassay revealed that methanol extract of aerial parts of S. trilobata had the maximum antifeedant activity of 52.10 per cent at 0.1 per cent of the extract against S. litura after 24h of feeding. Compared to aerial extracts, root extracts were less active against S. litura. At lower concentrations, the antifeedant activity of all the extract were not much prominent and are not statistically significant. The antifeedant activity of all the extract increased in 48h experiment except for 0.1 per cent concentration. The decreasing order of antifeedancy of four extracts was SP2>SP1>SP4>SP3. ii Similar results were recorded in the choice method of bioassay of extracts against S. litura. Maximum antifeedant activity of 46.65 per cent was obtained for methanol extract of aerial parts (SP2) after 24h of feeding. At lowest concentrations of 0.005, 0.01 and 0.03 per cent none of the extracts exhibited significant difference in activity. Increasing concentration beyond 0.03 per cent had a significant effect on antifeedancy in the choice method. As similar to the no-choice method, reduced activity was recorded after 48h of feeding. Maximum antifeedant activity of 38.81 per cent was recorded for SP2 after 48h of feeding. Similar to the no-choice method, root extracts exhibited a low level of activity against S. litura. Insect growth regulatory activity of various extracts was evaluated by diet incorporation method against five-day old larvae of S. litura. A maximum larval weight reduction of 31.4 per cent was recorded for SP4 at 0.1 per cent of the extract. A significant increase in larval duration compared to control was recorded for SP2 extracts at higher concentrations. Similar to larval weight reduction, a dose-dependent pupal weight reduction was recorded for SP1 (29.57 per cent at 0.1 per cent of the extract). Compared to the other three extracts, pupal weight reduction was very less for SP3. Pupal duration increased to a maximum period of 13.54 days at 0.1 per cent of SP4. Observations on abnormal pupae were not significant for any of the extracts. No larval mortality could be obtained with any of the treatments. A maximum of 16.7 per cent larval pupal intermediates was recorded for SP4 at the highest dose, but it was not significantly different from other treatments. Similar to larval mortality, no pupal adult intermediates were recorded for any of the extracts. Maximum pupal mortality of 41.00 per cent was recorded at 0.1 per cent of SP1, and it was significantly different from other treatments. For all the extracts, pupal mortality was dose-dependent. Minimum adult emergence was noticed for SP1 at 0.1 per cent of the extract. GC-MS/MS and LC-MS/MS analysis of active fractions revealed that more phytochemicals are present in aerial parts than roots. The higher activity of aerial parts might be due to the presence bioactive compounds like andrographolide, artemisin, iii genistein and taxifolin. Most of the chemicals identified were derivatives of steroids, terpenoids and flavonoids. The study results indicate that methanol extract of aerial parts of S. trilobata has strong antifeedant activity against S. litura. All other extracts were relatively less active against S. litura. Insect growth regulatory activity was maximum for hexane extract of aerial parts. All the extracts adversely affected the growth and devolvement of S. litura. The absence of larval mortality indicates that all the extracts have less contact toxicity.