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ThesisItem Open Access Development of F1 hybrids of indeterminate tomato (Solanum lycopersicum L.) for protected cultivation(Department of Olericulture, College of Agriculture, Vellayani, 2015) Lekshmi, S L; KAU; Celine, V AThe present investigation entitled “Development of F1 hybrids of indeterminate tomato (Solanum lycopersicum L.) for protected cultivation” was conducted at the Department of Olericulture, College of Agriculture, Vellayani, from 2013 to 2015 with the objectives of identifying superior varieties and developing F1 hybrids of indeterminate tomato suited for protected cultivation. The study consisted of two experiments conducted in the naturally ventilated polyhouse of size 50 m x 20 m located at the Instructional Farm, Vellayani. In the first part of the first experiment, 40 tomato genotypes were evaluated for two consecutive years in an RBD with three replications. As the second part, 12 commercial hybrids were evaluated. The second experiment consisted of a 9 x 9 half diallel analysis laid out in an RBD with three replications. Analysis of variance showed significant differences between the genotypes for all the characters for two crops. Pooled analysis revealed that, LE 1 recorded the highest yield (2443.43 g) and fruit weight (108.13 g) followed by LE 7. LE 53 had maximum number of fruits per plant (65.00). In the present study, genotypes had wide variation for quality parameters. Fruits of LE 14 recorded highest TSS with a mean of 5.74 ºBrix. LE 7 had maximum ascorbic acid (30.13 mg/100g) and lycopene content (13.09 mg/100g). Beta carotene value was maximum in LE 16 (184.15 mg/100g). There was minimum incidence of pests, diseases and physiological disorders under protected conditions. Among the 12 hybrids evaluated, INDAM 9802 was the highest yielder (1444.40 g) followed by F1 T 30 (1412.22 g). F1 T 30 recorded maximum fruits per plant (35.66) which was on par with F1 Queen (35.55). Genetic parameters like phenotypic and genotypic coefficients of variation, heritability and genetic advance were studied to assess the genetic variability among the genotypes. High heritability coupled with high genetic advance were observed for characters like truss per plant, fruits per truss, fruit weight, fruits per plant, yield per plant and yield per plot. Path analysis revealed highest positive direct effect for fruit weight (0.3956), truss per plant (0.3558) and fruits per plant (0.3381). Based on D2 analysis the 40 genotypes were grouped into eight clusters. Cluster I was the largest with twenty four genotypes followed by cluster II with ten genotypes. Diallel analysis was carried out using nine parents selected based on genetic divergence and per se performance. The parents were crossed in a diallel fashion excluding reciprocals to obtain 36 F1 hybrids. The study revealed that P5 x P9 had the highest yield (3114.03 g) which was on par with P6 x P8 (3074.37 g) and P1 x P5 (3077.58 g). P1 x P5 had the maximum fruits per plant (103.93). The magnitude of relative heterosis, heterobeltiosis and standard heterosis varied considerably. For yield, relative heterosis ranged from -32.40 to 92.72, heterobeltiosis from -47.14 to 89.54 and standard heterosis from 2.91 to 160.95. The σ2gca and σ2sca ratio indicated that non-additive gene action was predominant for all traits. Among the nine parents, P9 (LE 1), P5 (LE 20) P1 (LE 2), and P2 (LE 7) were superior for yield and yield attributes. The estimates of sca effects indicated that P5 x P9 (LE 20 x LE 1), P6 x P8 (LE 39 x LE 38) and P1 x P5 (LE 2 x LE 20) were the most promising hybrids for protected cultivation. The present study revealed that the genotypes LE 1 and LE 7 and the hybrids INDAM 9802 and F1 T 30 were superior for yield and yield attributes under protection. Based on the mean performance, standard heterosis and sca effects the three potential crosses viz., P5 x P9, P6 x P8 and P1 x P5 could be adjudged as suitable indeterminate tomato hybrids for protected cultivation.ThesisItem Open Access Biochemical and molecular studies on post-harvest physiological deterioration of cassava (Manihot esculenta crantz)(Department of plant physiology, College of agriculture,Vellayani, 2015) Saravanan, R; KAU; Roy StephenThe project entitled “Biochemical and molecular studies on post-harvest physiological deterioration of cassava (Manihot esculenta Crantz)” was conducted at the Dept of Plant Physiology, College of Agriculture, Vellayani and at ICAR-CTCRI, Thiruvananthapuram during 2013 to 2015. The main objective of the work was to analyse the physiological biochemical and molecular mechanisms associated with post harvest physiological deterioration (PPD) and develop methods to delay the PPD in cassava. The initial screening of the cassava genotypes for their performance of PPD was done with 61 different genotypes including some released varieties. Significant differences were observed for PPD development and shelf-life of harvested roots. Cassava genotypes such as IMS2-8, 9S-172, 11S-53, IRS 2-10 and 9S-286 started showing the visible discolouration in the parenchyma tissue earlier (less than 3 days of storage). Genotypes such as 9S-7, 9S-98, 11S-31, 11S-86, 11S-14, CE63-3, CI43-2, CR43-2, CR54-A5, CR59-8R, Sree Athulya and Kalpaka showed low PPD scores and better shelf-life. Tissue imprinting for peroxidase enzyme showed that there was a remarkable increase in peroxidase activity in the root tissues with increasing PPD symptoms. There was no correlation between the root morphological traits and PPD severity. Carotene and starch content of root did not influence the PPD in the genotypes studied. Chemotypic profile of roots with PPD symptoms was used to classify the genotypes based on PPD. To develop an objective screening tool, Near Infrared Spectroscopy (NIRS) was utilized to analyse root samples for PPD. Principal component analysis (PCA) and chemometric tools clearly grouped the different PPD category in root tissues. Various stains such as saffranin, aniline blue, erythrocin, fast green and phloroglucinol stained the tissue specifically at vascular tissues and other cell components and were not suitable for detecting PPD. Storage techniques such as storing the harvested roots in de-aerated bags, wax coating and burying the roots under the soil were employed with selected cassava varieties like Sree Athulya, Sree Jaya, Vellayani Hrashwa, Kalpaka and Sree Padmanabha to delay PPD. Wax coating was suitable to reduce PPD for few weeks. Effect of different storage temperature on PPD was studied for five cassava varieties. Root respiratory flux was higher in roots stored at ambient conditions compared to high (40o C) or low temperature (4o C) storage. There were significant positive correlation between root respiratory flux at 3 and 9 days of storage to the CAT and POX activities studied in different cassava varieties. Roots were treated with various food preservatives at two different concentrations (0.5 and 1%). There was a weak, but significant reduction in symptom development in butylated hydroxy touline – (BHT, at 0.5 and 1% level) treated roots compared to other treatments. Nearly three folds increase in total phenol content was noticed in BHT and butylated hydroxy anisole (BHA) treated roots. The plant hormones related to wound response such as Salicylic acid and jasmonic acid were used to study the PPD response in roots under storage. The roots did not show marked influence to hormone application. Significant genetic variation was observed for PPD. The low PPD type genotypes such as 9S-7, 9S-98, 11S-31, 11S-86, 11S-14, CE63-3, CI43-2, CR43-2, CR54-A5, Sree Athulya and Kalpaka can be utilized for breeding programmes. High temperature storage of cassava at 40 oC resulted in reduced respiratory rate and increased antioxidant scavenging enzyme activity and also reduced the PPD. Differentiation of cassava roots at the metabolites level corresponding to visual symptoms and chemotypic profile of PPD and NIR spectroscopy offer a rapid screening tools. Among the different storage treatments, wax coating with antiseptic pre-treatment is most suitable and economical for increasing shelf-life of roots. Food preservatives like BHT and BHA have a significant, albeit marginal influence on PPD symptom development in cassava.ThesisItem Open Access Exploring the health potential of honey and development of a value added nutraceutical drink(Department of Home Science, College of Agriculture, Vellayani, 2015) Krishnasree, V; KAU; Mary, Ukkuru PThe present investigation entitled “Exploring the health potential of honey and development of a value added nutraceutical drink” was carried out to analyze the quality of different bee honeys in the raw as well as processed form available in Kerala and to develop a nutraceutical drink utilizing the Apis cerana bee honey, major bee honey in Kerala with an idea of value addition. The major bee honeys included in the study were Apis cerana indica, Apis mellifera, Apis dorsata, Apis florae and Trigona iridipennis. The physicochemical parameters, nutrient analysis and health promoting functions of the honeys were analyzed. The moisture content of the honeys ranged from 10.03% to 19.79% with lowest being in raw Apis dorsata honey and highest in raw Trigona iridipennis honey. The electrical conductivity of the honeys ranged from 0.26 to 0.26 mS/cm among raw honeys and from 0.13 to 0.34 mS/cm among processed honeys. Significant difference (p < 0.025) was observed in the electrical conductivity of raw honeys. The ash content of the honeys was found to be 0.16% to 1.07% among the raw honeys and from 0.06 to 0.16% among the processed honeys. Significant reduction of ash content was noticed in Apis dorsata honey. The reducing sugars percentage among the raw honeys ranged from 33.03% to 67.6% and from 54.34% to 62.9%. The raw Apis florea honey varied significantly from all the other honeys in the reducing sugars. Significant difference (p < 0.025) was also noted among the processed Apis mellifera and Apis dorsata honeys. The sucrose content among the honeys varies from 5.31% to 19.73% and significant difference was observed among the raw Apis cerana and Apis dorsata honeys at p < 0.025 level. The fructose glucose ratio among the raw honeys ranged from 1.05 to 1.66 and from 1.15 to 1.71 among the processed honeys. The free acidity of the honeys ranged from 0.15% to 0.68% and all the honeys were significantly different (p < 0.025) in acidity. The pH of the honeys ranged from 3.49 to 4.45 and all the honeys under the study varied significantly (p < 0.025). The specific gravity of the raw honeys ranged from 1.28 to 1.40 which varied significantly at p < 0.025 level, while there was no significant difference among the processed Apis cerana, Apis dorsata and Apis mellifera honeys. The major quality criteria utilized to analyze the extent of processing did to the raw honey was estimated in terms of the amount of hydroxymethyl furfural content and diastase activity. The hydroxymethyl furfural content of the raw honeys ranged from 3.4 to 30.01mg and from 6.36 to 51.87mg among the processed honeys. Significant increase in the HMF content was noticed among the processed honeys. The diastase activity of the raw honeys ranged from 36.7 to 57.5 DN and from 27.32 to 54.26 DN among the processed honeys. Significant difference in the diastase activity among the raw and processed honeys at p < 0.025 level and also between the raw and processed form (at 1%) of each honey was observed. Physico chemical parameters of honeys studied was compared with the cutoff limits as quality criteria set by European Union (EU) council. Moisture and electrical conductivity were within the limits as specified by EU, while slight elevation was noticed in honeys viz., Apis mellifera and Apis florea in their ash content, sucrose content and acidity. Hydroxymethyl furfural content and diastase activity of the honeys were within the levels of EU directive. The colour intensity of the honeys were determined in terms of the chromatic components and revealed that Apis florea, raw Apis Trigona, processed Apis mellifera, raw and processed Apis dorsata honeys had lower luminance values exhibiting amber colour while all the other honeys had lighter colour showing the prominence of other tones in them. With regards to the ‘a’ and ‘b’ values all the honeys were having reddish tone and yellowish chroma. Visco elastic properties of the honeys depicted that raw and processed Apis cerana, Apis mellifera, Apis dorsata and Trigona had viscous property with high loss modulus (G'') values and Apis florea honey exhibited slight elastic property with high storage modulus (G') value. Apart from the physico chemical characteristics the microbial contamination of the honeys were also analyzed with aim to analyze the quality of the honey. The microbial analysis indicated that none of the honeys analyzed were infested with pathogenic coliforms. The sensory evaluation of the raw and processed honeys revealed that raw Apis dorsata was highly acceptable (7.35) and processed Apis dorsata was least acceptable (1.05). The most acceptable colour was for raw Apis mellifera honey (6.50) and texture for processed Apis cerana honey (5.95). Significant difference (at 5%) was noted in the sensory parameters among all the honeys analyzed. The free choice profiling technique was utilized to know the distinctive character of each sensory attribute exhibited by the honeys. The presence of amber colour was noted in Apis florea, raw Apis mellifera, raw Trigona and processed Trigona. Fruity aroma was detected in raw and processed Apis cerana, while medicinal aroma was prominent in Apis florea and all other honeys had floral aroma with an exemption to processed Apis dorsata which yielded a fermented aroma. The nutrients in the honeys were analyzed and the energy content of the honeys ranged from 328 to 353kcal and carbohydrate content from 80.25g to 88g per 100g of the honey sample. The protein content of the honeys was negligible and the major amino acid proline was detected only in raw and processed Apis dorsata (4.5mg each) and Trigona iridipennis (8mg and 3mg) honeys. The vitamin C was found to be negligible in the honeys, while vitamin A and E were not detected. With respect to the mineral content potassium was detected at higher levels among all the honeys, which ranged from 30.5 to 52mg/100g among the raw honeys and from 28 to 47.5mg /100g among the processed honeys. The iron content was noted to be from 0.54 to 1.4mg/100g among the raw honeys and from 0.24 to 1.3mg/100g among the processed honeys, while the calcium, sodium and phosphorous were also recorded to be very less. The trace elements analyzed were zinc (0.04 to 5mg/100g), copper (0.002 to 0.13mg/100g) and manganese (0.001 to 0.35mg/100g) and it was noticed that all the level of three elements were in traces in all the honeys analyzed, but they are involved in umpteen biochemical functions in the body as metalloenzymes. Hence the presence of trace elements even in marginal levels might exert therapeutic properties to the honeys. The health promoting functions of the honeys were analyzed which includes the phytochemical profiling, antioxidant activity, antidiabetic activity and antimicrobial activity. The phytochemicals analyzed were polyphenols, flavonoids and flavonols. Among the raw honeys polyphenols were high in Apis dorsata (1168mg/kg) and low in Apis mellifera (905.25mg/kg); flavonoids were high in Apis dorsata (545.75mg/kg) and low in Apis cerana (185mg/kg) and flavonols were high in Trigona iridipennis honey (17.6mg/kg) and low in Apis mellifera (4.64mg/kg) and Apis florea (4.6mg/kg) honeys. Significant difference was noticed among all the honeys analyzed with respect to the phytochemicals and significant reduction in the phytochemicals was also observed on processing among all the honeys. The total antioxidant activity of the honeys was found to be highest in raw and processed Trigona (99.22%, 93.73% at 500µg/ml) honey followed by Apis cerana (97.04% at 500µg/ml) honey among the raw honeys and Apis mellifera (93.4% at 500µg/ml) among the processed honeys respectively, while moderate level of activity was noted in raw and processed Apis dorsata with 73.64% and 64.84% of antioxidant activity at at 500µg/ml. The DPPH radical scavenging activity was found to be highest in raw and processed Trigona honey (97.21%, 92.56% at 500µg/ml) followed by raw Apis cerana (95.55% at 500µg/ml) and processed Apis mellifera (88.18% at 500µg/ml) honeys, whereas comparatively lesser scavenging activity was viewed in processed Apis dorsata honey (48.17% at 500µg/ml). Average scavenging activities were noted in raw Apis dorsata and Apis florea. Significant differences (p < 0.025) in the radical scavenging activity were observed among all the raw honeys analyzed. On contrary to the above discussed antioxidant activities, non linearity was observed among the honeys in the nitric oxide scavenging activity. The highest nitric oxide scavenging activity was observed in raw Apis mellifera (77.19% at 500µg/ml) followed by Apis dorsata (68.22% at 500µg/ml) and Apis florea (65.35% at 500µg/ml) honeys. The antidiabetic activity determined in terms of alpha amylase inhibition capacity showed highest inhibition in raw and processed Trigona (77.61% and 64.84% at 500µg/ml) honeys followed by raw Apis dorsata (44.34% at 500µg/ml) honey. Average enzyme inhibition was observed among raw Apis mellifera (41.32% at 500µg/ml) and Apis florea (41.30% at 500µg/ml) honeys correspondingly. Higher rate of alpha glucosidase was also observed among the honeys ranged from 76.14% to 80.46% among the raw honeys and from 69.17% to 78.29% among the processed honeys. Significant (at 5%) reduction in the percentage inhibition was noticed in processed honeys. The glycemic index (≤ 67) and glycemic load (≤ 13.54) of the honeys revealed that all the honeys belong to intermediate GI foods category. The antimicrobial activity of the honeys analyzed revealed that raw honeys had higher antimicrobial activity than the processed form with highest in raw Trigona followed by Apis mellifera and Apis cerana honeys. From the elaborative analysis on the health promoting function of the bee honeys it could be concluded that raw honeys have higher health boosting properties when compared to the processed honeys. The screening index in terms of the therapeutic potencies showed that Trigona iridipennis honey had the highest therapeutic potency followed by Apis mellifera honey, while comparatively moderate potency was observed in Apis dorsata and Apis cerana honeys. A value added nutraceutical drink was developed utilizing the Apis cerana bee honey, the most abundantly available honey in Kerala. The drink was formulated by working out different proportions of honey in combination with aloe vera gel. The bitterness of the aloe gel was removed by trying out different pre treatment combinations. The physico chemical characteristics of the drink revealed that the drink is mildly acidic in nature with 61% moisture, total soluble solids (35°Brix), acidity (0.34%) and pH (4.88). The total and reducing sugars of the nutraceutical drink were 29.69% and 18.62% respectively. The fructose to glucose ratio of the nutraceutical drink was observed to be 0.99. The drink was found to have high therapeutic potency with 1060 (mg gallic acid/kg drink) of polyphenols, 60 (mg quercitin/Kg drink) of flavonoids and 5 (mg catechin/Kg drink) of flavonols respectively. Remarkable in vitro total antioxidant capapcity (72.1µgAAE/mg at 500µg/ml), DPPH radical scavenging activity (58.4% at 500µg/ml) and alpha amylase inhibition capacity (43% at 500µg/ml) with a medium glycemic index of 65 was also determined. Even though, the drink exhibited a slight increase in the acidity and TSS on storage the drink was noticed to be free from microbial proliferation and was acceptable till the end of the storage period, indicating its fitness for consumption even after two months of storage. The cost of the drink was found to be Rs 22.00 per 200ml and yield ratio was 1.49. The clinical efficacy of the drink was determined through a supplementation study which inferred that the platelet count increased significantly (at 5%) in the subjects from 2.56± 0.02 lakh/cumm to 3.05 ± 0.04 lakh/cumm. The supplementation had resulted in improved haemoglobin levels of the respondents from 10.83±0.06 gm% prior the study to 12.01± 0.02gm% at the end of the study. Significant improvement was also recorded in the hematological indices viz., WBC (from 7310± 114.3 to 8330 ± 43.7 cells/cumm), RBC (from 4.16 ± 0.05 to4.48±0.03 millions/ cumm), MCV (88.06 fL to 92.36 fL) and PCV (36.24±0.54% to 39.78± 0.42%) under the study. Encouraging results were also obtained from the total antioxidant capacity of the serum of the subjects under investigation. Findings of the present study strongly recommend that bee honeys are indeed the elixir of life with admissible physico chemical characteristics and superior health promoting functions. Among the honeys analyzed the raw honeys (Apis cerana, Apis mellifera, Apis dorsata, Apis florea and Trigona iridipennis) were found to be better in terms of quality as well as therapeutic potency when compared with the processed honeys. Among the raw honeys Trigona iridipennis honey was found to the best in medicinal value. In vitro and in vivo studies prove the efficacy of the developed drink to be a novel option in the market of nutraceuticals with superior health boosting properties and being natural by all means.ThesisItem Open Access Performance analysis and combining ability studies in anthurium cultivars(Department of Pomology and Floriculture, College of Agriculture, Vellayani, 2015) Sheena, A; KAU; Sabina George, TThe investigation on “Performance analysis and combining ability studies in anthurium cultivars” was conducted at Department of Pomology and Floriculture, College of Agriculture, Vellayani during 2010 - 2013. The objectives were to evaluate introduced cultivars of anthurium for growth, flowering and floral attributes, to assess their compatibility with cultivars having breeding potential and to produce novel anthurium cultivars through inter-varietal hybridization. The study was conducted in two experiments and the results and salient findings are abstracted here. In experiment I, performance evaluation of nine introduced anthurium cultivars for growth and cut flower production was carried out. The cultivars exhibited differential responses in vegetative and floral characters. With respect to morphological characters the cultivars Marijke and Paradise had greater vegetative vigour, higher yields, larger spathes and greater vase life. Salmon Queen, Mozaik Fresh, Hillary, Cynthia and Elizabeth were moderate in vegetative vigour. Red Amour and Anastasia were short statured, lower in vegetative vigour and low yielders with smaller spathes. Variability studies indicated that phenotypic coefficient of variation was slightly higher than genotypic coefficient of variation for most of the characters indicating the greater influence of environment. Genotypic correlation coefficients were higher than phenotypic correlation coefficients for most of the characters. In experiment II, twenty one anthurium cultivars including the introduced ones were evaluated for their floral characters and from these, eight cultivars namely Paradise, Marijke, Mozaik Fresh, Lady Jane Pink, Orange Glory, Dragon’s Tongue, Lima White and Agnihotri Red were selected as parents for further hybridization. Significant differences in floral characters were noticed among the cultivars. The cultivars exhibited variations in the qualitative characters of spathe colour, texture, spadix colour and type and colour of the young leaf and petiole. Anthocyanin content of the spathe showed a gradation with variation in the intensity of spathe colour. Vase life of the cultivars ranged from 6.33 to 20.50 days. Peak pollen emergence was observed from October to January and absence of pollen was found from March to May. Combining ability analysis was carried out for 11 traits in which eight traits exhibited higher dominance variance and three traits had higher additive variance which indicated involvement of both additive and non-additive gene action in the inheritance of characters and suggested the importance of selection as well as hybridization for improvement of these characters. Marijke and Mozaik Fresh were good general combiners with respect to the characters number of fruits per spadix, percentage of fruit set, number of seeds and percentage of seed germination, Orange Glory and Dragon’s Tongue for days to seed maturity, days to seed germination, seedling survival and days from emergence to maturity of leaves and Paradise for percentage of fruit set, days for germination and leaf area. In vitro seed germination study revealed that surface sterilization with sodium hypochlorite 2 % for 15 minutes recorded the lowest incidence of contamination and highest survival percentage. Highest germination per cent and earlier leaf development were seen in full MS media without growth regulators. Seed germination in vitro and its further multiplication could reduce the time taken to develop new hybrids in large numbers. The hybrid plants in the field are in flowering, near flowering and pre flowering stages. Vegetative and floral characters of the 35 hybrids that flowered when compared with their parents, revealed variations in the parameters studied. Ten hybrids found promising based on qualitative evaluation of spathe and spadix characters in the present study can be further assessed for flower yield and cut flower attributes and selected for cultivation.ThesisItem Open Access Entomopathogenic fungi for the management of insect pests in rice ecosystem(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2015) Malini, Nilamudeen; KAU; Sudharma, KThe study entitled “Entomopathogenic fungi for the management of insect pests in rice ecosystem” was carried out during 2011 - 2014 at College of Agriculture, Vellayani. The objectives were to isolate and identify indigenous strains of entomopathogenic fungi, to evaluate the fungal pathogens viz., Beauveria bassiana (Balsamo) Vuillemin, Metarhizium anisopliae Metschnikoff (Sorokin) and indigenous fungi against insect pests of rice, to fix their effective dose, to assess the compatibility of the fungal pathogens with new generation pesticides and to develop pesticide tolerant strains of the fungi. Six new isolates of entomopathogenic fungi viz., Aspergillus flavus Link. (Af-m1), B. bassiana (Bb-m2, Bb-m3, Bb-m4 and Bb-m5) and one isolate of M. anisopliae (Ma-m1) were collected and identified on the basis of morphological and molecular characters. The accession numbers obtained for the isolates from National Center for Biotechnology Information (NCBI) were KP 739825, KP 739828, KP 739829, KP 739830, KP 739831 and KP 739826, respectively. The pathogenicity of fungal isolates viz., B. bassiana (Bb 5), M. anisopliae (Ma 4) from NBAIR, B. bassiana (Bb 21) from Department of Microbiology, College of Agriculture, Vellayani and the six new isolates A. flavus (Af-m1), B. bassiana (Bb-m2, Bb-m3, Bb-m4 and Bb-m5) and M. anisopliae (Ma-m1) were evaluated against Cnaphalocrocis medinalis Guen. and Leptocorisa acuta (Thunb). All isolates were pathogenic to larvae of C. medinalis, nymphs and adults of L. acuta. The isolates B. bassiana (Bb 5) and M. anisopliae (Ma 4) were found superior among the fungi evaluated. The bioassay of the potent fungal pathogens viz., B. bassiana (Bb 5, Bb 21), M. anisopliae (Ma 4) and A. flavus (Af-m1) was conducted against C. medinalis larvae and nymphs and adults of L. acuta and field doses were fixed on the basis of LC90 values. Spore concentration dependent mortality of the insects was seen. The LC90 values were 3.50 x 108, 3.40 x 108, 2.25 x 108 and 3.37 x 108 spores ml-1 for B. bassiana (Bb 5, Bb 21), M. anisopliae (Ma 4) and A. flavus (Af-m1) against C. medinalis larvae, 3.92 x 108, 7.55 x 108, 2.96 x 108 and 3.46 x 108 spores ml-1 against L. acuta nymphs and 4.23 x 1010, 4.11 x 1010, 2.85 x 1010 and 8.72 x 1010 spores ml-1 against L. acuta adults. Two field trials carried out at Cropping System Research Centre, Karamana during November 2012 to March 2013 (Puncha) and June 2013 to October 2013 (Virippu) to assess the efficacy of entomopathogens revealed that B. bassiana (Bb 5) @ 1010 spores ml-1 was the best treatment, on the basis of pest population and reduction in damage of pests, population of natural enemies and benefit-cost ratio. This was followed by M. anisopliae (Ma 4) @ 1010 spores ml-1, talc based formulation of Bb 5 @ 20 g l-1, talc based formulation of M. anisopliae (Ma 4) @ 20 g l-1, talc based formulation of Bb 21 @ 20 g l-1 and A. flavus @ 1010 spores ml-1. Among the insecticides evaluated, chlorantraniliprole @ 30 g a.i ha-1 was the best. Assessment of the compatibility of fungal pathogens with insecticides on the basis of the effect of insecticides on the growth, spore count, germination and bioefficacy revealed that, B. bassiana (Bb5 and Bb 21), M. anisopliae (Ma 4) and A. flavus (Af-m1) were compatible with acephate (0.075, 0.150, 0.225 per cent), chlorantraniliprole (0.004, 0.006 and 0.008 per cent) and thiamethoxam (0.003, 0.005 and 0.008 per cent). Investigations on pesticide tolerance of entomopathogens showed that, B. bassiana (Bb 5) and M. anisopliae (Ma 4) tolerated 4.0, 8.0 and 8.0 times higher the field dose of acephate, chlorantraniliprole and thiamethoxam, respectively. The growth, spore count and the bioefficacy of selected cultures (fungi gown initially in media containing highest tolerable dose of insecticide and further grown in poisoned media for 10 passages), relaxed cultures (fungi gown initially in media containing highest tolerable dose of insecticide and further grown in unpoisoned media for 10 passages) and untreated cultures (fungi grown only in unpoisoned media) of B. bassiana (Bb 5) / M. anisopliae (Ma 4) differed significantly. On culturing of the selected, relaxed and untreated cultures of the fungi after 10 passages, in still higher dose of the insecticides i.e., 4.5x, 8.5x and 8.5x times higher the field dose of acephate, chlorantraniliprole and thiamethoxam, respectively, only the selected cultures tolerated the higher doses. Molecular characterisation of the selected, relaxed and untreated cultures of B. bassiana (Bb 5) / M. anisopliae (Ma 4), which were continuously grown for 10 passages in poisoned / unpoisoned media, respectively showed no molecular variations, except a minor polymorphism of 1.61 per cent exhibited in B. bassiana (Bb 5). To conclude, the six new indigenous fungi isolated are pathogenic to C. medinalis and L. acuta. B. bassiana (Bb 5) and M. anisopliae (Ma 4) @ 1010 spores ml-1 are effective and economical for the management of C. medinalis and L. acuta besides being safe to natural enemies. As these fungi are compatible with acephate @ 750 g a.i ha-1, chlorantraniliprole @ 30 g a.i ha-1 and thiamethoxam @ 25 g a.i ha-1, and as they tolerated higher doses of insecticides, without undergoing any genetic variation they are suitable for integration with these insecticides, the best chemical suggested for integration is chlorantraniliprole @ 30 g a.i ha-1 as it is safe to natural enemiesThesisItem Open Access Specifications of an integrated information system for micro level planning in agriculture: a user-centered analysis(Department of agricultural extension, College of horticulture, Vellanikkara, 2015) Sulaja, O R; KAU; Jiju P AlexMicro level planning is a dynamic process which involves planning at the grassroots level taking into consideration the individual, family and category of the community. Considering the diversity of crops and the geographical and socio- economic characteristics of agriculture, micro level planning has been suggested as the best way to plan agricultural development projects. Kerala has evolved a robust mechanism for micro level planning through democratic decentralization. Micro level planning is highly information intensive and it requires information flow from different hierarchical levels. This study appraised the current status of micro level planning in agriculture in Kerala with respect to use of databases and information. The study tried to characterize the legacy databases and types of information used for this purpose, with focus on availability and completeness of data. Along side, the study attempted to evolve a typology of information and development databases required for micro level planning. Specifications regarding the content and hierarchy of an ‘Integrated Information System for Micro Level Planning in Agriculture’ was also formulated. The study employed an ex-post facto design to suit the objectives. Sample included 132 respondents, with 66 officers of the Department of Agriculture working with the Grama Panchayat, Block Panchayat and District Panchayat selected and 66 People’s Representatives who were Chairmen of the working groups on agriculture at the rate of one from each local body. In order to find out the legacy databases available at the local level, details of various registers kept in Krishi Bhavans and Grama Panchayaths were compiled and classified. Krishi Bhavans maintained 140 registers under six major categories and Grama Panchayats were found to maintain171 registers under 23 categories. The registers were classified based on practical use, nature of data entry, mandatory nature and based on purpose. Registers were again categorized based on the frequency of updating, number of data fields, completeness, subsectors of agriculture and adequacy. The data support provided by legacy registers for different stages of micro level planning viz., resource appraisal, planning, beneficiary selection, implementation, monitoring, evaluation and follow up was also explored. Analysis of the socio economic and psychological profile of respondents and their perception on efficacy of micro level planning was also attempted. Comparison of the perception on efficacy of micro level planning, which included four dimensions such as planning, participation, implementation and impact, showed that ‘planning’ was perceived as the most important dimension by Extension Personnel and ‘participation’ was perceived as the most important by People’s Representatives. Analysis of the perception on efficacy of legacy databases which included four dimensions viz., completeness, adequacy, reliability and updatability showed that ‘reliability’ was perceived as the most important dimension by both Extension Personnel and People’s Representatives. Perception on the proposed Integrated Information System for Micro Level Planning in Agriculture was studied under four dimensions viz., comprehensiveness, usability, updatability and spatial and temporal orientation. Both the groups perceived ‘usability’ as the most important dimension. Scores on the awareness of stakeholders on rural databases and information systems showed that 75 per cent of the respondents were in medium category. The information items required for micro level planning were identified and grouped into 16 categories viz. land, water, soil, climate, demographic characteristics, socio-economic characteristics, crops, technology, infrastructure, mechanization, institutions, market, government policies, government programmes for agricultural development, project monitoring and existing perspective plans. The overall information requirement of stakeholders in micro level planning showed that information on government policies was the most needed and valuable data, followed by data on government programmes and data on project monitoring. The different stakeholder institutions involved in micro level planning mechanism were identified and the data support provided by them was explored. Soil Survey Department, Land Use Board and Village Office were found to provide pertinent data for micro level planning. With regards to constraints, Extension Personnel and People’s Representatives identified lack of proper mechanisms for regular updation of data as the most severe constraint. The study also proposed a conceptual model for an Integrated Information System for Micro Level Planning in Agriculture.ThesisItem Open Access Modeling carbon dynamics in teak plantations of Kerala(Department of tree physiology and breeding, College of forestry, Vellanikkara, 2015) Manjunatha, M; KAU; Santhoshkumar, A VThe study on “Modeling carbon dynamics in teak (Tectona grandis Linn. F) plantations of Kerala” was carried out in teak plantations of Kerala Forest Department during 2011-2015. The study attempted to estimate the carbon stocks in teak plantations and model the soil carbon using ‘Century’ soil carbon modelling tool. The modelling tool was used to analyze the soil carbon under different scenarios. The study also developed of a system dynamic model for carbon prediction for teak plantations. Teak plantations were divided into five strata based on age (0-5, 6-10, 11-20, 21-30 and >30 years). Thirty samples were selected at random for each stratum. Quadrants of 50 m x 50 m size were established in each sample for vegetation analysis. Fifty samples among the 150 samples so selected were used for the validation of the developed model. Ten plantations each from each age class (50 samples) were selected at random for soil studies. Pits of 1m x 1m x 1 m were dug in each sample plot and soils were collected at 0-20, 20-40, 40-60 and 60-100 cm depths. The total litter was collected from each plot at an interval of three months to estimate diurnal litter fall. Soil C, N, S was estimated along with the N, P, K and lignin of litter. Biomass of the study site was estimated using allometric equations. Secondary data on weather parameters were collected from appropriate sources. Significant differences were not observed among the different age classes and soil depths in case of sand and silt content of soil. However, clay content varied between the different age classes and soil depths. Although water holding capacity did not vary among the plantations of different age class in the surface layer (0-20 cm), it varied among the age classes at 20-40 cm. The bulk density did not differ between age classes, while it was higher in deeper layer of the soil (1.1 to 1.36 g/cm3). Soil pH was moderately acidic (5.1 to 6.0). The soil N varied from 0.07 to 0.34 % in plantations, while the values ranged from 0.43 to 1.23 % in natural forests. Nitrogen content was highest in the surface and decreased with the depth in both teak plantation and natural forest. The mean values of available P in the teak plantations and natural forest varied from 1.0 to 4.81 g/kg and 3.16 to 4.82 g/kg respectively. Significant differences in soil C was noticed between plantation and natural forest. While the soil C did not vary between various age classes, it was higher in surface layers compared to deeper layers. Simulation by CENTURY model in teak plantation indicated decline in total SOC up to 50 per cent by 30th year from the initial value of 6168 g C m-2. There after SOC pool declined at a slower rate till 45 years and reached 2702 g C m-2 by 80 years. There was rapid decrease in active carbon pool in teak plantations from 6.25 g C m-2 to 2.88 g C m-2 initially (up to 3rd year) and slow increase to 10.17 g C m-2 by 9th year. By the end of 80th year, the active pool almost doubled to 12 g C m-2. Slow carbon pool in teak plantations reduced from 3700 g C m-2 to 1224 g C m-2 by 22 years and reached 920 g C m-2 at an age of 80 years. Passive carbon pools in teak plantations more or less remained stable (2150.84 to 1912 g C m-2). Analysis indicated that the model was able to predict the values with high efficiency (0.922) and accuracy (R² = 0.9156) Fire reduced total SOC in teak plantation. The study found a 20 per cent decline in the total SOC by the 22nd year of plantation establishment. The SOC reached at 2343 g C m-2 at the age of 30 year of teak plantation compared to 2702 g C m-2 in a normal plantation. Teak plantation converted to natural forest resulted in an increase of SOC pools by 163 g C m-2 compared to that of the teak plantation. Conversion of teak plantation to agroforestry system resulted in marginal decline of 156 g C m-2 in SOC by 30 years. The SOC in teak plantation converted to ginger cultivation declined by 39 per cent at 30 years after ginger cultivation. Conversion of teak plantation to agriculture (pulses and tuber) resulted in significant reduction all the carbon pools. The SOC declined to 43 per cent at 30 years. A system dynamic model of soil carbon dynamics was developed using STELLA software. It was observed that the model was able to predict the total SOC with high precision (ME=0.69). The present study indicated that modelling is suitable for studying C dynamics in soils under teak plantations. Present results highlight the potential of using these tools for reliable evaluation the carbon sequestration potential of management interventions at plantation as well as landscape level.ThesisItem Open Access Investigations on the efficacy of biochar from tender coconut husk for enhanced crop production(Department of soil science and agricultural chemistry, College of agriculture, Vellayani, 2015) Mariya Dainy, M S; KAU; Usha, P BAn investigation was carried out at College of Agriculture, Vellayani to characterize biochar from tender coconut husk and to assess its effects on soil properties, growth and yield of yard long bean (Vigna unguiculata subsp. sesquipedalis). The experiment consisted of production and characterization of biochar, laboratory experiments on nutrient sorption- desorption studies, carbon dioxide emission studies and a field experiment. Biochar was produced from tender coconut husk by the process of pyrolysis and it was crushed, sieved and the 2 mm sieved samples were used for further studies. The produced biochar had an alkaline pH (9.13), high CEC (15.26 cmol kg-1) and C: N ratio (68.86). Electrical Conductivity, total C, N, P, K, Ca, Mg and S contents in the prepared biochar were 1.73 dS m-1, 72.3 per cent, 1.05 per cent, 0.38 per cent, 2.27 per cent, 0.40 per cent, 0.20 per cent and 0.27 per cent respectively. The produced biochar recorded very high water holding capacity (226 per cent), low bulk density (0.14 Mg m-3) and high Brunauer Emmett Teller surface area (157.93 m² g-1) A laboratory experiment was conducted to study the desorption and sorption of nutrients like N, P, K, Ca, Mg, S, Fe, Mn, Zn and Cu using biochar. 32.35 per cent NH4+, 75.65 per cent PO42-, 45.14 per cent K+, 46.00 per cent Ca2+, 23.45 per cent Mg2+, 74.38 per cent SO42-, 36.80 per cent Fe2+, 30.20 per cent Mn2+, 26.75 per cent Zn2+ and 26.72 per cent Cu2+ were found to be desorbed from biochar after 7 rinses using de-ionized water in 1:100 ratio. The highest per cent of nutrient desorbed was P (75.65 per cent), followed by S (74.38 per cent) and the lowest per cent of nutrients desorbed were Zn (26.75 per cent) and Cu (26.72 per cent) within 72 hours. Sorption experiments were performed using rinsed biochar at different concentrations of nutrients and at different time intervals in 1:100 ratio. The results of the study indicated that biochar could sorb 100 per cent NH4+, 90.70 per cent PO42-, 92.00 per cent K+, 87.00 per cent Ca2+, 86.15 per cent Mg2+ and 91.82 per cent SO42- when it was equilibrated with 100ppm solutions within 24hours. For micronutrients, when 50 mg l-1 Fe2+, Mn2+, Zn2+ and Cu2+ solutions were given, biochar could sorb 99.67 per cent, 100 per cent, 99.12 per cent and 99.12 per cent respectively. Biochar from tender coconut husk is a good sorber and slow releaser of nutrients. An incubation study was carried out to estimate and study the pattern of carbon dioxide emission by the application of biochar into soil and it was compared with that of common organic amendments viz. FYM and vermicompost. The experiment consisted of 7 treatments with 3 replications and the study revealed that the cumulative amount of carbon dioxide emitted was highest for FYM @ 2 per cent (1014.05 mg CO2 100 g-1) and biochar @ 2 per cent registered an emission of 87.17 mg CO2 100 g-1 after 6months of incubation. There observed 91.40 per cent reduction in CO2 emission when soil was incubated with biochar @ 2 per cent compared to 2 per cent FYM. A field experiment was carried out with biochar and other commonly used organic manures at different doses using yard long bean variety Vellayani Jyothika as the test crop during January 2013 to April 2013, at the Instructional farm, College of Agriculture, Vellayani. Yield (1358 g plant-1) and yield attributes like pod length (54.50 cm), pod girth (3.90 cm), number of pods per plant (51), nutrient uptake and B: C ratio were significantly superior for the treatment T8 which received biochar @ 20 t ha-1 with 2 per cent PGPR and NPK as per POP. Physical properties chemical properties of the soil were significantly improved by the application of biochar @ 30 t ha-1. Biochar application reduced the bulk density, increased water holding capacity, water stable aggregates, pH, Cation Exchange Capacity, organic carbon status and nutrient availability. From the investigations, it can be concluded that application of biochar @ 20 t ha-1 along with 2 per cent PGPR and NPK as per POP which resulted in the yield of 1358 g plant-1 (20.12 t ha-1) can be considered as the economically viable and the best treatment. Biochar from tender coconut husk can be used as a good soil amendment which can improve soil health and enhance crop production.ThesisItem Open Access Efficacy of ligno-phenolic compost in the suppression of soil borne plant pathogens(Department of plant pathology, College of horticulture, Vellanikkara, 2015) Gleena Mary, C F; KAU; Sally K, MathewThe study on the “Efficacy of ligno-phenolic compost in the suppression of soil borne plant pathogens” was carried out at College of Horticulture, Vellanikkara during 2011 -2014. The major objectives were to develop a microbial consortium for rapid composting of lignintannin rich agrowastes and also to study the effect of these composts on the management of leaf blight of amaranth and bacterial wilt of tomato. Sample of soils and partially degraded substrates were collected from 15 sources of 34 locations. Among them, ayurvedic wastes yielded maximum population of cellulose and lignin degraders whereas, tannin degraders were more in the samples of teak plantation. A total of 378 microbial degraders were isolated which included 125 cellulose, 133 lignin and 120 tannin degraders. Actinomycetes were the predominant degraders of cellulose and fungi were dominant among both lignin and tannin with majority belonged to Aspergillus spp. and Penicilium spp. In vitro evaluation of degraders on respective selective media showed diffusion zones more than 4cm by 31 cellulose, 39 lignin and 33 tannin degraders. Fungi were the most efficient degraders of cellulose, lignin and tannin. Thirty five degraders found effective on their respective selective media showed ability to degrade all the three chemical components. In vitro decomposition of 33 degraders on respective host substrates recorded lowest maturity periods of 40 and 43 days for the degraders isolated from ayurvedic waste and coir pith. The degraders, ALF-26, CLF-13, CCB-8, ECF-2, ECA-8, TLF-8, CaLF-5 and ATY-1were most effective on their respective host substrates and also on other tested lignintannin rich substrates in vivo. All the 22 selected degraders were found mutually compatible. Based on the ability to degrade all the three chemical components, early maturity of composting, type and species of organisms and mutual compatibility, 10 degraders viz. Trichoderma harzianum, Paecilomyces variotii, Penicillium oxalicum, P. chrysogenum, Talaromyces sp., Streptomyces albus, S. niveus, Arthrobacter sp. and Massilia sp.were selected for the formulation of microbial consortium. Screening of selected consortium under in vitro and in vivo condition showed early maturity of 35 and 43 days in mixed substrate followed by coir pith with 35 and 45 days. In large scale composting of various agrowastes with microbial consortium, cow dung slurry and the combination of both, the minimum maturity period was observed with microbial consortium as compared to other treatments recording 30, 35, 40 and 55 days for mixed substrate, coir pith, ayurvedic waste and leaf litters respectively. Composting with microbial consortium resulted in drastic reduction of C:N ratio of the composts with 47 -81 per cent reduction from the initial and the lowest in ayurvedic compost (10.4:1) .Composts treated with microbial consortium recorded neutral to alkaline pH and high contents of N, P and K with maximum N and P in ayurvedic and K in coir pith compost. Traces of lead detected in all compost samples were below the permissible limits. Composting with consortium showed reduction in cellulose, lignin and tannin contents with maximum reduction in ayurvedic (49.38 %), coir pith (49.02%) and leaf litter composts (98.95%) respectively. The degraders of the consortium were thermophilic and recorded extra cellular enzyme activities of cellulase, lignin peroxidase, polyphenol oxidase, amylase, catalase, protease and xylanase. The selected degraders showed antagonism against six major soil borne pathogens viz. Pythium sp., Phytophthora sp., Rhizoctonia sp., Fusarium sp., Sclerotium sp. and Ralstonia solanacearum and T. harzianum was the most effective one. In the field evaluation of various composts in the management of bacterial wilt of tomato and leaf blight of amaranth, application of ayurvedic compost was effective in reducing both diseases. In addition, coir pith and leaf litter composts also reduced bacterial wilt incidence and mixture compost in case of leaf blight.
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