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  • ThesisItemOpen Access
    Standardisation of spacing and nutrient levels for fodder rice bean [Vigna umbellata (Thunb.)].
    (Department of Agronomy, College of Agriculture, Vellayani, 2018) Ajmal Fayique, C; KAU; Usha C, Thomas
    The study entitled “Standardization of spacing and nutrient levels for fodder rice bean [Vigna umbellata (Thunb.)]” was conducted at College of Agriculture, Vellayani, Kerala during Kharif 2017 to standardize the spacing and nutrient requirement of fodder rice bean and to study its impact on growth, yield and quality of the crop. The experiment was laid out in Randomised Block Design (33 confounded factorial) with three replications.The treatments consisted of three spacings (s1 - 30 cm x 10 cm, s2 - 30 cm x 20 cm and s3 - 30 cm x 30 cm), three levels of nitrogen (n0 - 0 kg ha-1, n1 - 20 kg ha-1 and n2 - 30 kg ha-1) and three levels of phosphorous (p0 - 0 kg P2O5 ha-1, p1 - 20 kg P2O5 ha-1 and p2 - 40 kg P2O5 ha-1) . FYM @ 5 t ha-1 and K2O @ 30 kg ha-1 were applied uniformly to all treatments as basal. The treatment s1 resulted in the highest plant height at 30 DAS and leaf: stem ratio at harvest. Application of N @ 20 kg ha-1 registered the highest plant height and was on par with 30 kg N (n2) while leaf stem ratio was the highest at n2. Levels of P had no significant impact on growth characters. The treatment combination s2n2p1 produced the tallest plants (173.17 cm) at harvest and treatments s1n0p1 and s1n2p2 recorded the highest leaf: stem ratio (0.82) but were on par with s1n0p0, s2n0p0, s n0p2, s1n1p0, s2n0p2 and s3n0p1. At 30 DAS, s1 produced the highest LAI (2.27) while at harvest, s2 was found superior. The highest NAR was observed at s1 and was on par with s3. Closer spacing (s1) enhanced the CGR at 30 DAS and harvest. Application of 30 kg N ha-1 (n2) enhanced LAI at both stages. At 30 DAS and at harvest, higher NAR were observed at n1 and n2. At 30 DAS, n2 and p1 registered the highest chlorophyll contents. The treatment s1 n2 p1 (30 cm x 10 cm spacing + 30 kg N ha-1 + 20 kg P2O5 ha-1) resulted in the highest LAI, CGR and chlorophyll content at 30 DAS. Spacing and N levels had significant impact on green fodder yield (GFY) and dry fodder yield (DFY). The highest GFY (12.95 t ha-1) and DFY (2.59 t ha-1) were produced at s1 (30 cm x 10 cm) and was on par with s2. The highest GFY (13.66 t ha-1) and DFY (2.73 t ha-1) were produced at n2 (30 kg N ha-1) and was on par with n1. The S x N x P interaction s1 n2 p1 (30 cm x 10 cm + 30 kg N ha-1 + 20 kg P2O5 ha-1) recorded highest GFY (17.29 t ha-1) and DFY (3.46 t ha-1). The different spacing had no impact on crude protein (CP) but the lowest crude fibre (CF) was observed at s1. Application of 30 kg N ha-1 (n2) resulted in the highest CP content and the lowest CF content was estimated at 0 kg N ha-1. Among P levels, p2 recorded the highest CP (17.69%) and was on par with p1. The lowest CF (16.43 %) was observed at s2n0p1 (30 cm x 20 cm spacing + 20 kg P205 ha-1) and was on par with s1n0p0, s1n0p1, s1n2p0, s2n0p0, s2n0p2, s3n0p0 and s3n0p1. No variation in N uptake was observed due to treatments. Uptake of P varied with N levels only and n1 and n2 recorded the highest P uptake. Spacing and P levels influenced K uptake by the crop and the highest uptake was observed at s1 and p2 but p2 was on par with p1. The three factor interaction s1n2p1 registered the highest P and K uptake. However, it was on par with s1n1p2, s1n1p0, s2n1p1 and s3n0p2 in P uptake and with s1n2p2 in K uptake. Increasing N levels increased pH and EC of soil after the experiment. Soil available N after the experiment was the highest at s3 (on par with s2) and n2 (on par with n1). At wider spacing, application of N enhanced the availability of N in the soil after the experiment. Available P in the soil varied with S x P interaction but all treatment combinations were on par except s2p0 and s3p2. The highest soil available K was observed at n0 among N levels and at p1 among P levels. The interactions S x N, S x P and N x P significantly influenced available K in the soil. Economic analysis revealed the highest net income (₹ 35762) and BC ratio (3.22) at s1n2p1 (30 cm x 10 cm spacing + 30 kg N ha-1 + 20 kg P2O5 ha-1). From the study, it can be concluded that fodder rice bean can be profitably cultivated at a spacing of 30 cm x 10 cm with application of 30 kg N ha -1 in two splits at 15 and 30 DAS and basal application of 20 kg P2O5 ha-1, 5 t ha-1 of FYM and 30 kg K2O ha-1.
  • ThesisItemOpen Access
    Vegetative propagation of promising jackfruit (Artocarpus heterophyllus Lam.) types
    (Department of Pomology and Floriculture, College of Agriculture,Padannakkad, 2018) Ashok Madala, KAU; Rajagopalan, A
    The investigation on ‘Vegetative propagation of promising jackfruit (Artocarpus heterophyllus Lam.) types’ was conducted at the College of Agriculture, Padannakkad, Kasaragod during the period 2017 - 18 to evaluate the success of epicotyl and softwood grafting in promising types of jackfruit and to examine the variation among jackfruit types with respect to grafting methods. The experiment comprised of five promising types of jackfruits viz., V1 - Varikka - early bearing (KJ 186), V2 - Gumless (KJ 397), V3 - Seedless (KJ 180), V4 - Cluster (KJ 182) and V5 - Muttam varikka (KJ 231) and two method of grafting i.e., M1 - epicotyl grafting and M2 - softwood grafting. The experiment was laid out in factorial CRD with three replications. The different jackfruit types showed significant influence for all the parameters studied except number of branches. Type V2 resulted in earliest sprouting (26.50 days) and maximum sprouting percentage of grafts (41.91 per cent) while type V3 recorded maximum survival percentage (66.94 per cent) and shoot length (8.13 cm). Maximum shoot girth (1.50 cm), number of nodes (7.50), number of leaves (7), length of leaf (12.34 cm) and breadth of leaf (5.64 cm) were observed in type V4. On the other hand, the maximum days to sprouting (30.33 days), minimum sprouting percentage (28.77 per cent), minimum shoot length (6.43 cm) and minimum number of leaves (5.17) were recorded in type V5 while type V1 showed minimum survival percentage (38.89 per cent), shoot girth (1.15 cm), leaf length (8.41 cm) and breadth of leaf (4.22 cm). Among the methods of grafting, the results on percentage of sprouting and survival as well as number of branches were not significant while all other parameters showed significant effects. Epicotyl grafts resulted in early sprouting of buds (26.00 days) and maximum shoot length (7.36 cm) whereas maximum shoot girth (1.36 cm), number of nodes (6.13), number of leaves (6.33), length of leaf (11.16 cm) and breadth of leaf (5.29 cm) were observed in softwood grafts. The interaction of varieties and methods of grafting were significant in most of the characters recorded. Interaction V2 x M1 was found better in early sprouting (24.33 days) and V2 x M2 resulted in maximum sprouting percentage (46.90 per cent) while V3 x M1 gave maximum survival of grafts (86.67 per cent). Hence, for the mass multiplication of Seedless type epicotyl grafting could be adopted and for other types like early bearing varikka, Gumless and cluster, softwood grafting could be practiced.
  • ThesisItemOpen Access
    Evaluation of miRNA prediction tools and in silico analysis of micro and long non coding RNAs in sweet potato
    (Department of Plant Biotechnology, College of Agriculture, Vellayani, 2018) Aswathy, M B; KAU; Sreekumar, J
    The study entitled “Evaluation of miRNA prediction tools and in silico analysis of micro and long non coding RNAs in sweet potato (Ipomoea batatas L.)” was conducted at the ICAR-CTCRI, Sreekariyam. The objectives of the study is to compare different miRNA and target prediction tools and in silico analysis of the miRNAs and lncRNAs in sweet potato. The plant miRNA identification tools: NOVOMIR and miRPlant and miRNA-target prediction tools: psRNATarget and miRanda were compared. NOVOMIR and psRNATarget were found to be a better tool in miRNA identification and target prediction. MicroRNAs (miRNA) are 18-22nt small, endogenous non coding RNA that has prominent role in many biological processes. In the present study, we report the computational prediction of miRNAs and targets from expressed sequence tags (ESTs) of sweet potato. We predicted 13 novel potential miRNAs and 81 potential target genes and functionally characterized by BLASTX and BLAST2GO. The predicted target genes were credited with their role in signalling cascades, metabolism, and defence and stress responses. Another candidate that has more importance in the genome regulation is lncRNAs. lncRNAs are greater than 200 nucleotide length ncRNA candidate that holds functions at RNA level itself. RNAplonc is a plant long non coding RNA identification tool which uses 16 feature selection methods to predict long non coding RNA molecules. The present study which predicts 9215 lncRNAs and 8665 protein coding genes by RNAplonc in sweet potato for the first time using available ESTs sequences. Since there is a lack of lncRNA functional annotation tool, the functional analysis of predicted lncRNAs is quiet difficult. From the predicted miRNAs and lncRNAs two miRNAs and two lncRNAs were randomly selected for experimental validation by real time quantitative PCR using three different sweet potato varieties Sree Kanaka, ST13 and Khanjakad available at ICAR-CTCRI and compared the target gene’s expression in each variety. Validation results prove that both the miRNAs and lncRNAs shows their importance in crop improvement.
  • ThesisItemOpen Access
    Effect of heat stress on the expression patterns of different growth related genes in Malabari goats
    (Academy of Climate Change Education and Research, Vellanikkara, 2018) Angel Sunny, P; KAU; Bagath, M
    The impact of heat stress on growth performance of goats has been established fairly based on changes associated with phenotypic traits. However, not many reports are available on the genotypic traits which get altered on exposure to heat stress in livestock. Therefore, the study is an attempt to elucidate the molecular mechanisms governing growth performance during heat stress in goats. The primary objective of the study was to establish the influence of heat stress on the expression patterns of different growth related genes in Malabari goats. The study was conducted for a period of 45 days in twelve Malabari goats randomly allocated into two groups: MC (n=6; Malabari control) and MHS (n=6; Malabari Heat stress). Goats were stall-fed with a diet composed of 60% roughage and 40% concentrate. All animals had access to adlibitum feed and water and they were fed and watered individually. The MC goats were placed in the shaded pens while MHS goats were exposed to heat stress in outside environment between 10.00 h to 16.00 h. At the end of study period, all 12 animals were slaughtered and their liver tissues were collected for gene expression and histopathological studies. The temperature-humidity-index (THI) inside the shed (74.9) proved that the animals were not stressed while in the outside environment (86.5) the animals were extremely distressed. The hepatic growth hormone (GH), growth hormone receptor (GHR), insulin-like growth factor-1 (IGF-1), leptin (LEP) and leptin receptor (LEPR) gene expression patterns were significantly (P<0.05) lower in heat stress group as compared to the control group animals. In addition, negative correlation (P<0.05) was also established between THI and all the growth related gene expression in the study. The hepatic histopathological section showed more fatty and degenerative changes (P<0.05) in hepatocytes in MHS group as compared to MC group. The study offers the first thorough insight into the expression patterns of different growth related genes during heat stress exposure in goats. Further, the study established GH, GHR, IGF-1, LEP, LEPR genes to be the ideal markers to reflect growth potential in Malabari goats. The findings from this study provide some crucial initial information on how different growth relatedgenes are expressed when Malabari goats are subjected to heat stress. This information might be of high value in assessing the growth performance of goats and may provide useful information pertaining to nutrient supplementation to the heat stressed goats.
  • ThesisItemOpen Access
    Evaluation of CMS based rice hybrids developed from rice varieties of Kerala identified as restorers
    (Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2018) Nayana Jyothibas, KAU; Jayalekshmy, V G
    The present study entitled “Evaluation of CMS based rice hybrids developed from rice varieties of Kerala identified as restorers” was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 2016-2018, with an objective to evaluate CMS based rice hybrids developed from rice varieties of Kerala as restorers, for heterosis for yield and grain quality. The study was conducted in two experiments i.e., 1) Hybrid seed production 2) Evaluation of hybrids. The first experiment, on hybrid seed production was undertaken in College of Agriculture, Vellayani during May to August, 2017 (Virippu, 2017). Two CMS lines viz., CRMS31A and CRMS32A were crossed with nine restorers. Restorers were sown in three staggers, 10 days before the sowing date of CMS lines, at the sowing date of CMS lines and 10 days after the sowing date of CMS lines. Synchronized flowering dates of the CMS and restorer lines were recorded. CRMS31A was crossed with Remya, Jayathy, Swarnaprabha, Kanakom and Neeraja. CRMS32A was crossed with Annapoorna, Aiswarya, Mattatriveni and Kanakom. Six crosses i.e., CRMS31A x Jayathi (H1), CRMS31A x Kanakom (H2), CRMS31A x Remya (H3), CRMS32A x Annapoorna (H4), CRMS32A x Kanakom (H5), CRMS32A x Mattatriveni (H6) that had given more than 1500 viable seeds were carried forward for hybrid evaluation. Date of sowing of the restorers and maintainers for getting synchronization in flowering to undertake hybridization was standardized in this experiment. In the second experiment, hybrids along with the better parent and checks were evaluated in a Randomized Block Design (RBD) with three replications during October 2017 to February 2018 (Mundakan) in IFSRS (Integrated Farming System Research Station), Karamana. Observations on 12 yield contributing traits and 8 grain quality traits were recorded in the hybrids. Genetic parameters calculated from these observations showed that the GCV and PCV values for the characters studied did not vary greatly indicating low influence of the environment in these characters. The mean performance of hybrids showed that the yield plot -1 was the highest for H5 (CRMS32A x Kanakom) followed by H3 (CRMS31A x Remya), H1 (CRMS31A x Jayathi), H2 (CRMS31A x Kanakom) and H4 (CRMS32A x Annapoorna). The hybrid H5 (CRMS32A x Kanakom) showed the highest mean values for plant height, number of filled grains panicle-1, length breadth ratio of grain and grain yield (g) plant-1. Pollen fertility of the hybrid H3 (CRMS31A x Remya) was superior to the standard check. This shows that the variety Remya is a complete restorer for male sterile cytoplasm CRMS31A. Hybrid H5 also showed pollen fertility on par with the check showing that the variety Kanakom is restorer for CRMS32A. The other hybrids H4 (CRMS32A x Annapoorna) and H6 (CRMS32A x Mattatriveni) had pollen fertility per cent around 50. So the male parents Annapoorna and Mattatriveni for CRMS32A can be considered as only partial restorers. The low level of pollen fertility was the reason for low yield of hybrids H4 (CRMS32A x Annapoorna) and H6 (CRMS32A x Mattatriveni) despite high number of productive tillers. Five out of six hybrids were red kernelled. It was found that the hybrids inherited the kernel colour from the male parents. The kernel length by breadth ratio of all the hybrids was significantly higher than that of Uma. The hybrids had a medium to slender grain shape (kernel length by breadth ratio 2.1 to 3 and above). This may be the reason behind the phenomenon of curling noted in cooked rice in all the rice hybrids studied. Standard heterosis for yield plot-1of the hybrids calculated over the standard check variety Uma was the highest for H5 (CRMS32A x Kanakom) followed by H3 (CRMS31A x Remya) and H1 (CRMS31A x Jayathi). Heterobeltiosis for yield calculated over the better parent was maximum for H1 (CRMS31A x Jayathi) followed by H5 (CRMS32A x Kanakom). Amylose content of most of the hybrids fell into intermediate category along with that of the check variety Uma, showing the hard and non sticky nature of the cooked rice of the hybrids. Cooking time for hybrids was less compared to that of Uma (29 minutes). This evaluation of hybrids could identify two promising hybrids for Kerala H5 (CRMS32A x Kanakom) and H3 (CRMS31A x Remya) which could give a yield advantage of 17.91% and 16.37% over the popular rice variety Uma. These two hybrids had long slender grain shape with red kernel colour. The amylose content of these two hybrids was also intermediate and low. These hybrids had a lower cooking time and good head rice recovery. Hence the hybrids can be recommended for Kerala after trials over locations and seasons. A better seed production technique has to be standardized before commercial release.
  • ThesisItemUnknown
    Identification of water stress tolerant amaranthus genotypes (Amaranthus tricolor L.) with high yield and quality
    (Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2018) Shahiba, A M; KAU; Beena Thomas
    The present study entitled “Identification of water stress tolerant amaranthus genotypes (Amaranthus tricolor L.) with high yield and quality” was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 2016-2018, with an objective to identify high yielding genotypes of amaranthus with good quality and tolerance to water stress. The study was conducted under two experiments. In the first experiment thirty accessions of Amaranthus tricolor L. available in the Department of Plant Breeding and Genetics and collected from other sources were evaluated for yield under field condition and morphologically described using IBPGR descriptor for the amaranthus. Madhur local (A22) recorded highest yield plant-1(125.926g) followed by Kalliyoor local (A4), Ayyanthole local (A28), Haripad local (A7), Palakkadu local (A2), Anachal local (A6), Aryanadu local (A21), Poonkulam local (A20), Kazhakkuttom local (A9) and Kannara local (A29). In the second experiment, these ten genotypes selected based on the yield were evaluated in a Randomized Block Design (RBD) with three replications during November 2017- December 2017. Water stress was imposed after 5 days of irrigation to water holding capacity to the transplanted seedlings by scheduling the irrigation at a depth of 20mm at 20mm CPE (Cumulative Pan Evaporation). Analysis of variance was calculated for all the characters under study and was found to be significant for all the genotypes evaluated. The mean performance of the genotypes for the characters were studied. The maximum yield was observed for the genotype A22 (Madhur local) followed by the genotype A9 (Kazhakkuttom local), genotype A20 (Poonkulam local) and genotype A2 (Palakkadu local) and the minimum yield was recorded for genotype A4 (Kalliyoor local). The genotype A22 (Madhur local) showed the highest mean values for stem girth, number of branches, length of leaf lamina, leaf to stem ratio, membrane integrity, relative water content, proline content of leaves, vitamin A and lowest oxalate content. The character Vitamin A content registered the highest GCV (41.22%) and PCV (41.25%). High heritability coupled with high genetic advance was observed for leaf width, number of branches, yield plant-1, protein content, fibre content and vitamin A. The yield plant-1was found to be significantly and positively correlated with leaf width, number of branches, yield plot-1, membrane integrity, proline content of leaves and vitamin A both at genotypic and phenotypic levels. Petiole length and percentage leachate were found to be negatively correlated with yield plant-1. Path analysis revealed that number of branches, yield plot-1and proline content of leaves had the maximum positive direct effect on yield plant-1. The results of the present study showed that genotype A22 (Madhur local) was superior in yield performance under water stress condition followed by the genotype A9 (Kazhakkuttom local), genotype A20 (Poonkulam local) and the genotype A2 (Palakkadu local). The genotype A22 (Madhur local) also recorded the maximum stem girth, number of branches, length of leaf lamina, leaf to stem ratio, membrane integrity, relative water content and proline content of leaves with high Vitamin A and low oxalate content. Presence of proline in the leaves might be considered as an important water stress tolerance mechanism.
  • ThesisItemOpen Access
    Weed management in upland rice (Oryza sativa L.) intercropped in coconut
    (Department of Agronomy, College of Agriculture, Vellayani, 2018) Ravikiran; KAU; Elizebeth Syriac, K
    The investigation entitled “Weed management in upland rice (Oryza sativa L.) intercropped in coconut” was undertaken during the period, 2017 - 2018 at College of Agriculture, Vellayani, Thiruvananthapuram to standardise an eco-friendly and economic weed management strategy for upland rice intercropped in coconut. The field experiment was carried out at Coconut Research Station, Balaramapuram, Thiruvananthapuram district during the period from June to October 2017. The variety used was Prathyasa (MO-21) released from Rice Research Station, Moncompu. The experiment was laid out in randomized block design (factorial) with sixteen treatment combinations and three replications. The treatments consisted of two stale seedbed methods viz., stale seedbed with mechanical removal of weeds (s1) and no stale seedbed (s2) and eight weed management methods i.e., penoxsulam @ 20 g ha-1 at 10-15 days after sowing (DAS) fb hand weeding (HW) at 35-40 DAS (m1), penoxsulam @ 25 g ha-1 at 10-15 DAS fb HW at 35-40 DAS (m2), penoxsulam @ 30 g ha-1 at 10-15 DAS fb HW at 35-40 DAS (m3), penoxsulam @ 20 g ha-1 at 10-15 DAS fb metsulfuron methyl + chlorimuron ethyl (MM+CE) @ 4 g ha-1 at 35-40 DAS (m4), penoxsulam @ 25 g ha-1 at 10-15 DAS fb MM+CE @ 4 g ha-1 at 35-40 DAS (m5), penoxsulam @ 30 g ha-1 at 10-15 DAS fb MM+CE @ 4 g ha-1 at 35-40 DAS (m6), HW twice at 15 and 35 DAS (m7) and weedy check (m8). Study of the weed flora of experimental area indicated the dominance of broad leaved weeds (eight spp.) followed by grasses (six spp.) and sedges (two spp.). Stale seedbed method (s1) recorded significantly lower weed density at all stages of observations (15, 30 and 60 DAS), weed dry weight at 15 and 30 DAS and higher weed control efficiency (WCE) at 30 and 60 DAS compared to no stale seedbed. Among the weed management methods, at 60 DAS, all the penoxsulam doses i.e., 20, 25 and 30 g ha-1 at 10-15 DAS fb either HW at 35-40 DAS or MM+CE at 35-40 DAS (m 6, m4, m3, m5, m1 and m2) were on par in their effect on total weed dry weight and WCE. Stale seedbed method (s1) registered significantly higher plant height at 60 DAS, number of tillers m-2 at 30 DAS and at harvest, dry matter production at harvest and LAI at 60 DAS compared to no stale seedbed (s2). Penoxsulam at different doses fb HW treatments (m 1, m2 and m3) recorded higher plant height at 30 and 60 DAS and at harvest, number of tillers m-2 at 30 DAS, DMP at harvest and LAI at 30 DAS. None of the herbicide treated plots showed any phytotoxicity symptom on rice crop. The yield attributes viz., number of spikelets panicle-1, per cent filled grains and thousand grain weight were significantly higher for stale seedbed, compared to no stale seedbed (s2). Weed management methods also significantly improved yield attributes viz., panilces m-2, spikelets panicles-1, per cent filled grains and thousand grain weight compared to weedy check treatment. Penoxsulam @ 25 g ha-1 at 10-15 DAS fb HW at 35-40 DAS (m2) registered the highest values for per cent filled grains and thousand grain weight. Stale seedbed method (s1) recorded significantly higher grain yield, straw yield and lower weed index compared to no stale seedbed method (s 2). Though penoxsulam @ 25 g ha-1 at 10-15 DAS fb HW at 35-40 DAS (m2) registered the highest grain yield (3.23 t ha-1), it was on par with the other penoxsulam fb HW treatments viz., m1 and m3. None of the s x m interactions were found statistically significant. Regarding weed index also m2 registered the lowest value and it was significantly superior to all other weed management methods. Higher net income (₹ 27, 848/-) and B:C ratio (1.48) were obtained with stale seedbed method (s1), compared to no stale seedbed (s2). Application of penoxsulam @ 25 g ha-1 at 10-15 DAS fb HW at 35-40 DAS (m2) registered the highest net income (₹ 36,090/-) and B: C ratio (1.63). The s1m2 registered the highest net income (₹ 44,433/-) and B: C ratio (1.77), among the interactions. The results on soil microbial population revealed that population of fungi, bacteria and actinomycetes increased in all the herbicidal treatments compared to pre-treatment population. Activity of dehydrogenase enzyme also increased significantly in the herbicide applied plots implying the safety of the tested chemicals on soil health. Based on grain yield, weed index and economic analysis, integration of stale seedbed method with the broad spectrum herbicide penoxsulam @ 25 g ha-1 at 10-15 DAS fb HW at 35-40 DAS can be recommended as an eco-friendly and economic weed management practice in upland rice.
  • ThesisItemUnknown
    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 P
    The 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.
  • ThesisItemOpen Access
    Status and habitat preferences of White-rumped vulture (Gyps bengalensis ) population of Wayand wildlife sanctuary, Kerala
    (Department of Wildlife Sciences, College of Forestry, Vellanikkara, 2018) Vishnu, M; KAU; Nameer, P O
    The research work entitled "Status and habitat preferences of White-rumped Vulture (Gyps bengalensis) population of Wayanad Wildlife Sanctuary, Kerala" was studied during August 2017 to April 2018. It was carried out in four study locations viz., Kurichiat, Muthanga, Sulthan Bathery and Tholpetty. The main objective of the study was to find out the status, nesting characteristics, feeding observations and interview of various stakeholders. Three species of vultures included in the family Accipitridae were reported from the current study in Wayanad WLS viz., Gyps bengalens is, Gyps indicus, and Sarcogyps calvus. Total of 4 active nesting trees were identified from two different colonies this year. All the 4 nest were present in Haldina cardifolia. Out of the 4 nests, 3 nests belongs to Gyps bengalensis located in Kazukankolli and 1 nest belongs to Sarcogyps calvus which was the 1st report of nesting of this species in the sanctuary located in Karamukku, Kurichiyad. Apart from this, 9 nests of the previous years on 6 different tree species were also studied. Other nesting tree species were Terminalia elliptica, Lagerstroemea microcarpa, Dalbergia latifolia, Stereospermum chelenoides and Tectona grandis. Thirty species of trees were identified belonging to 17 different families from the 44 circular plots surveyed in the nesting colony of Wayanad Wildlife Sanctuary. Most of the nesting are having height between 25 m - 35 m and girth more than 300 em. Mostly height of the nests are in between 23 m - 26 m of the nesting trees. IVI of the nesting trees are comparatively higher than the other tree species got from the plots. The vegetation parameters that influence the nesting habitat of vultures are the girth of the tree, height of the tree and the tree species diversity in the area. The camera trapping has been found to be a useful technique for the population estimation of the vultures at the vulture restaurants in Wayanad. The camera trap success rate of vultures observed in Kakkappadam is 34.09%. The high success rate is because it is a dumping ground of carcass. Carcass monitored was of Elephant, Sambar Deer and Spotted deer. The most preferred feeding hours by the vultures were 7-8 hours and 12-13. hours.From the survey conducted among the veterinarians and the medical shops it was found that the harmful NSAID's such as Ketoprofen are being used to treat livestock, which could be a problem for the long-term conservation of the vultures. The use of the veterinary diclofenac was nil at Wayanad District. However, some of the medical practitioners were found using the human diclofenac for treating livestock.