1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Organic nano NPK fomulations for enhanching soil health and productivity(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2019) Nibin, P M; Ushakumari, KItem Optimizing propagation techniques in neelayamari (Indigofera tinctoria L.)(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 2019) Mekha Mariam, Abraham; Krishnakumary, KIndia is acknowledged as one of the world’s richest treasure trove of medicinal plants. Neelayamari (Indigofera tinctoria L.) commonly known as ‘Indian indigo’, is a commercially grown leguminous plant of medicinal importance. The extract of the leaves is reported to have remarkable effect on hair growth and in preventing juvenile greying of hair. Due to the presence of many worthy phytochemicals, the crop is being documented in ‘Ashtangahridaya’ and is being cultivated by several pharmaceutical entrepreneurs, both in public and private sector. Like most of the medicinal plants, the cheapest method of propagation of this crop is through seeds. However, poor germination and vigour of seeds is a major problem in Neelayamari. In addition, heavy loss in seed yield occurs due to the splitting of pods at maturity. The study ‘Optimizing propagation techniques in Neelayamari (Indigofera tinctoria L.)’ was conducted in the Department of Plantation crops and Spices, with the objectives of standardizing the physiological maturity stage in Indigofera tinctoria L. for seed harvest, presowing seed treatments to enhance seed quality and longevity and vegetative propagation technique in Indigofera tinctoria L. through stem cuttings. In order to assess the stage of attainment of physiological maturity for seed harvest in Neelayamari, flowers were tagged on the day of anthesis and the pods were harvested at five days interval from 30 days of anthesis up to the pod splitting stage (63 days after anthesis). It was observed that the values of pod, seed and seedling characters increased up to 45 days after anthesis to reach their highest and thereafter declined till the pod splitting stage (63 days after anthesis). Germination and vigour indices at 45 days after anthesis were 73.80 per cent, 485 and 294 respectively and those at the pod splitting stage were found to be 31.33 per cent, 132 and 65 respectively. Hence, it was inferred that the seeds of Neelayamari reached physiological maturity stage by 45 days after anthesis. The seeds harvested at physiological maturity were dried to 8 per cent moisture content and subjected to various seed treatments before being packed in 700 gauge polyethylene bags. Untreated seeds served as the control. The seeds were stored under ambient conditions upto six months. The scarification treatments included treatment with Conc. H2SO4 for 5, 10 and 15 minutes, mechanical scarification with sand, hot water treatment at 80oC for 20 minutes and 60oC for 30 minutes and hydration for 24 hours. The quality parameters of the stored seeds were recorded at monthly intervals during the storage period and were put for germination test in sterilized sand media. Results pointed out that most of the seed treatments were effective in enhancing germination. High initial germination was recorded in mechanically scarified (95.83 %) and hydrated seeds (93.27%), while the untreated seeds showed a germination of 74.33 per cent. Vigour index I (703 and 698 respectively) and II (430 and 428 respectively) were also the highest in these treatments. Seed treatment with sulphuric acid, however, proved to be detrimental. Seed treatment also helped in extending the viability of the seeds. Mechanically scarified and hydrated seeds retained their germination above 60 per cent for six months during storage (65.67% and 63.67% respectively), while, in untreated seeds, germination reached 61.33 per cent at four months of storage and declined to 44.34 per cent by six months of storage. Seeds treated with sulphuric acid never attained the germination of sixty per cent throughout the storage period and those treated with sulphuric acid for 15 minutes failed to germinate at sixth month of storage. EC was found to be the lowest in hydrated seeds (0.0011 dSm-1) and mechanically scarified seeds (0.0012 dSm-1). The results thus indicated that mechanical scarification of seeds or hydropriming for 24 h can not only improve seed germination and seed quality but also prolong the longevity of the seeds. It was also noticed that all the seed quality parameters declined along the storage period. Attempt to assess the possibility of vegetative propagation in Neelayamari was carried out using hardwood, semi-hardwood and softwood cuttings, exposed to varying doses of IBA (250 ppm, 500 ppm, 750 ppm, 1000 ppm, 1500 ppm, 2000 ppm and 2500 ppm) and charcoal slurry dip. The cuttings were planted in polythene bags and were maintained in a mist chamber. Initially, the experiment was conducted during summer season and only the softwood cuttings treated with 2000 (8.89%) and 1500 ppm IBA (5.53%) survived after 60 days of planting, while all others withered and dried off. The experiment was then repeated during rainy season and the best results were obtained in the season. Softwood cuttings treated with 2000 ppm IBA during rainy season exhibited early sprouting (7.18 days) and a field establishment of 70.67 per cent. In comparison, the semi-hardwood and hardwood cuttings exhibited very low establishment rates of 21.77 per cent and 17.90 per cent respectively. Hence, it was evident that vegetative propagation using softwood cuttings treated with 2000 ppm IBA during rainy season can be relied upon as an alternative propagation method in Neelayamari.Item Modification and evaluation of automated drip irrigation system(Department of Land & Water Resources and Conservation Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2016) Arjun Prakash, K V; Sajeena, SWater is the most valuable resource in the world and is playing a crucial role in daily activities of living beings on the earth. To meet the ever increasing demand, conservation and management of water resource is very important. Conventional methods of irrigation, like surface and subsurface flooding leads to scarcity of water, which can be reduced by adopting drip or trickle irrigation. Drip irrigation system can be controlled through different automation techniques. The present study was focused on the modification and evaluation of the existing cost effective automated drip irrigation system. In this study, calibration of capacitor type and conductive type moisture sensors were carried out in different soil types viz. black soil, coastal alluvium, forest loam, laterite soil and riverine alluvium. Field study was carried out with Hilton FI variety of salad cucumber under different irrigation and fertigation levels using solenoid valves and GSM modem technique. The automated drip irrigation system consists of two capacitor type and two conductive type soil moisture sensors, solenoid valves and water flow sensors. Total yield and crop growth parameters showed better performance under 100 per cent fertigation when compared with 70 per cent fertigation. Combination of 100per cent fertigation with 70 per cent irrigation also showed good results, whereas production was less in the case of 70 per cent fertigation with 70 per cent irrigation. The modified automated drip irrigation system is cost effective, portable, durable and can perform betterItem Varietal suitability and crop geometry of baby corn (Zea mays L.) in coconut garden(Department of Agronomy, College of Agriculture, vellayani, 2016) Dona Scaria; Rajasree, GThe experiment entitled “Varietal suitability and crop geometry of baby corn (Zea mays L.) in coconut garden” was undertaken at the Coconut Research Station, Balaramapuram, Thiruvananthapuram, during the summer season (March to May) and the Kharif season (August to October) of 2015. The main objectives of the study were to understand the feasibility of introducing baby corn as intercrop in coconut garden, to assess the effect of varieties and spacings on its growth and productivity and to work out the economics of cultivation. The field experiment was laid out in Randomised Block Design with 9 treatments replicated thrice. The treatments comprised of combinations of three varieties and three spacings. The three varieties were Rasi 4212 (V1), G 5414 (V2) and CO-6 (V3) and the three spacings were 30 cm x 20 cm (S1), 45 cm x 20 cm (S2) and 60 cm x 20 cm (S3). The variety G 5414 recorded significantly higher baby cob weight with husk of 47.01 g cob-1 and 35.74 g cob-1, cob yield with husk of 10.97 t ha-1 and 9.98 t ha-1 and marketable baby cob yield of 3.67 t ha-1 and 3.36 t ha-1 in summer and Kharif respectively. This variety took less number of days from tasseling to harvest (2.11) and recorded the highest net income of RS. 133698 ha-1 and RS. 116629 ha-1 and B:C ratio of 2.70 and 2.49 in summer and Kharif seasons respectively. The variety G 5414 was followed by CO-6 in producing higher baby cob yield with husk and marketable baby cob yield. The growth attributes viz., plant height, number of leaves and leaf area index (LAI) at 15, 30 and 45 days after emergence (DAE), dry matter content and light interception were significantly higher for the variety CO-6. Green Stover yield was significantly higher for CO-6 (19.39 t ha-1 and 17.86 t ha-1 in summer and Kharif respectively) followed by G 5414 (16.08 t ha-1 and 14.35 t ha-1 in summer and Kharif respectively). The study revealed that spacing significantly influenced the growth attributes viz., plant height, number of leaves and LAI. The row spacing of 45 cm x 20 cm recorded the highest baby cob yield with husk of 10.90 t ha-1 and 9.63 t ha-1, marketable baby cob yield of 3.49 t ha-1 and 3.24 t ha-1 along with the highest net income of RS. 125839 ha-1 and RS. 114287 ha-1 and B:C ratio of 2.69 and 2.55 in summer and Kharif respectively. Baby cob weight with husk was significantly higher at 45 cm x 20 cm and baby cob-baby com ratio was the most desirable at 30 cm x 20 cm in summer. In summer, the interaction of CO-6 at 45 cm x 20 cm recorded the highest baby cob weight with husk (56.25 g cob-1), marketable baby cob yield (4.21 t ha-1) and B:C ratio (3.16). Net income was the highest with G 5414 at 45 cm x 20 cm and was on a par with CO-6 at 45 cm x 20 cm. In Kharif, CO-6 at 45 cm x 20 cm resulted in the highest baby cob yield with husk (11.16 t ha-1), marketable baby cob yield (3.68 t ha-1), net income (RS.145237 ha-1) and B:C ratio (3.03). The variety G 5414 at 45 cm x 20 cm was on a par with the variety CO-6 at 45 cm x 20 cm with respect to baby cob yield with husk (9.91 t ha-1) and marketable baby cob yield (3.49 t ha-1). The study revealed that, among the varieties tested, the variety G 5414 was superior and among the spacings, 45 cm x 20 cm was significantly superior in both summer and Kharif seasons. The interaction effects revealed that the variety G 5414 at 45 cm x 20 cm and the variety CO-6 at 45 cm x 20 cm were equally superior in terms of yield and economics. In baby com cultivation, detasseling is an important operation which is labour intensive. The variety G 5414 exhibited 50 per cent silking prior to tasseling and hence the detasseling before first harvesting could be avoided. This variety had a better appearance and uniformity compared to CO-6. In general, the baby com yield was higher in summer season compared to Kharif season. To conclude, the result of the study indicated that baby corn can be profitably intercropped in coconut gardens in summer and Kharif seasons. The baby corn hybrid G 5414 at 45 cm x 20 cm spacing resulted in higher baby cob yield with husk, marketable baby cob yield, net income and B:C ratio during both seasons in southern Kerala. The maize variety CO-6 also performed well in coconut garden during both summer and Kharif seasons.Item Functional diversity of an evergreen forest ecosystem of Vazhachal forest division, Kerala(Department of Forest Management and Utilisation, College of Forestry, Vellanikkara, 2016) Deepakkumar, R; Gopakumar, SItem Morphology, ecology and management of monochoria vaginalis (Burm.f.) Kunth(Department of Agronomy , College of Horticulture, Vellanikkara, 2019) Athira G R; Meera V MenonItem Assessment of soil temperature and soil parameters on the population and functional efficiency of pseudomonas fluorescens in the rhizosphere of pokkali rice (Oryza sative L.)(Department of Agricultural Microbiology, College of Agriculture, Vellayani, 2018) Reshma Francis; Surendra Gopal, KPokkali is a umque variety of rice that is cultivated organically in coastal wetlands of Kerala. Pokkali fields are situated close to the sea and therefore prone to flooding and salinity. Pokkali rice has enormous potential for tolerating most of the abiotic stresses. It is the only economic crop which can be grown in waterlogged environment while tolerating salinity. The present study on “Assessment of soil temperature and soil parameters on the population and functional efficiency of Pseudomonas fluorescens in the rhizosphere of Pokkali rice (Oryza sativa L.)”, was conducted in Rice Research Station, Vyttila, under Kerala Agricultural University during 2016 to 2018. Two plots (40 m2) were used for the study. One of the plots was maintained as control (without application of Pseudomonas fluorescens) and another plot with rice was treated with P. fluorescens. P. fluorescens (KAU) was applied as seed treatment (10g kg-1) just before sowing and soil application (2.5 kg ha-1) at 1 week after dismantling. The main objectives were to study the effect of soil temperature and soil parameters on the population and functional efficiency of P. fluorescens / fluorescent Pseudomonas in Pokkali rice. The rhizosphere soils of Pokkali rice were collected at monthly interval from June, 2017 to October, 2017. The population of fluorescent Pseudomonas sp. in the rhizosphere soils of Pokkali rice were recorded at monthly interval. The population was absent before the start of the experiment in treated plot. However, the highest population 3.3x102 cfu g-l) was recorded at 90 DAS (August, 2017). However, the lowest population was recorded at 60 DAS (July, 2017). The population was not found at 30 DAS (June, 2017), 120 DAS (September, 2017) and 150 DAS (October, 2017). In the case of control plot, population of fluorescent Pseudomonas was absent before the start of experiment. At 30 DAS (June, 2017) population of fluorescent Pseudomonas was 3.3 x 102 cfu g-1. However, no fluorescent Pseudomonas were found at 60 DAS (July, 2017), 90 DAS (August, 2017), 120 DAS (September, 2017) and 150 DAS (October, 2017). Out of the six isolates (VPJU, VPJL, VPAU1, VPAU2, VPAU3 and VPAU4) of fluorescent Pseudomonas obtained, all the isolates produced IAA and ammonia with varied intensity. Three isolates (VPAU1, VPAU3 and VPAU4) produced HCN and none of the isolates showed siderophore production. The correlation studies between soil temperature, soil pH, EC and C02 evolution with population, revealed that the population of fluorescent Pseudomonas was affected by soil pH and soil EC. However, soil temperature and C02 evolution did not affect the population of fluorescent Pseudomonas. The functional efficiency of the fluorescent Pseudomonas were correlated with soil temperature, soil pH, EC and C02 evolution It was found that soil temperature, soil pH, EC and C02 evolution did not affect the functional efficiency of fluorescent Pseudomonas. All the six isolates obtained m the study were identified and confirmed through 168 rDNA sequencing. The isolates VPAJU, VPAU1 and VPAU2 were identified as Pseudomonas sp. and VPAJL, VPAU3 and VPAU4 isolates were found to be Pseudomonas aeruginosa. The present studies indicated that the inoculated P.fluorescens did not survive in Pokkali fields. The population of fluorescent Pseudomonas showed negative correlation with soil pH and EC. However, soil temperature and C02 evolution did not had any effect on population. The functional efficiency of fluorescent Pseudomonas was not affected by soil temperature, soil pH, EC and C02 evolution. However, further studies on influence of soil edaphic factors and weather variables on host plant and P. fluorescens needs to be studied and develop a suitable PGPR for Pokkali rice.Item Effect of agrochemicals on biological activity in lateritic soil(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 2018) Nisha Paul; Durga Devi, K MIn modern agriculture, agrochemicals are frequently used to boost crop production. The use of pesticides is indispensable in various crops and cropping systems, particularly under tropical climatic condition. However erratic application of these chemicals may affect soil health, which in turn change the population and composition of soil microflora and soil fertility. The land use type also play a significant role in controlling the microbial community. Hence, the present study was undertaken at College of Horticulture, Vellanikkara during 2017-2018 so as to determine the impact of three agrochemicals viz. oxyfluorfen, copper oxychloride and chlorpyriphos on the population of soil microflora and dehydrogenase enzyme activity in lateritic soil collected from two land use types. Representative soil samples were collected from two land use types viz., land under cultivated grass, Agronomy farm, College of Horticulture, Vellanikkara (LUT 1) and cocoa plantation, Cocoa Research Center, KAU, Vellanikkara (LUT 2) during August, 2017. The soil samples were analyzed to assess physical, chemical and biological characteristics before starting experiment and the data revealed that soil collected from LUT 2 was more conducive for microbial growth and dehydrogenase activity. Pot culture experiment with cowpea (variety: Bhagyalakshmi) was conducted during March to June, 2018 with fourteen treatments (3 agrochemicals at 2 different doses under each land use types + 2 controls, one each for two land use types) and three replications. Agrochemicals viz., oxyflourfen (OXY) at 0.15 and 0.30 kg ha-1 (herbicide), copper oxychloride (COC) at 0.75 and 1.50 kg ha-1 (fungicide) and chlorpyriphos (CHL) at 0.30 and 0.60 kg ha-1 (insecticide) were selected for the study. Soil samples were analyzed at four intervals viz., 7, 30, 60 and 90 days after agrochemical spraying (DAS) to evaluate the effect of agrochemicals on chemical and biological characteristics of soil. The chemical characteristics of soil viz., pH, electrical conductivity, organic carbon, available N, P, K, Ca, Mg, S and micro nutrients like Fe, Mn, Cu, and Zn followed a decreasing trend towards the harvest in all the treatments under both the land use types. The effect of agrochemical application on chemical characteristics and nutrient availability of the soil was at lower magnitude compared to their influence on biological activity of the soil. The biological characteristics of soil viz. dehydrogenase activity and microbial population (fungi, bacteria and actinomycetes) were higher in soil samples collected from LUT 2 (cocoa plantation) at all the sampling intervals. Soil samples from both the land use types registered reduction in biological activity due to agrochemical application, which was higher at 7 DAS than the other sampling intervals. The extent of reduction in biological activity after application of agrochemicals was comparatively higher in LUT 1 (land under cultivated grass). Higher doses of the pesticides showed greater decline compared to their lower doses. Biological activity increased from 7 to 60 DAS and the extent of reduction with respect to control also became lower. At 90 DAS, a declining trend in the dehydrogenase activity and microbial population (except fungi) was noticed. The adverse effect of agrochemicals on dehydrogenase activity and bacterial population at 7 DAS followed the order: CHL > COC > OXY and OXY > CHL > COC respectively. However at 90 DAS, oxyflourfen exerted minimum adverse effect on soil bacteria. The study revealed that dehydrogenase activity is highly correlated with the population of soil microflora, especially soil bacteria. The adverse effect of agrochemicals on fungal population can be ranked as: COC > OXY > CHL at both 7 and 90 DAS. The percentage inhibition of actinomycetes population at 7 as well as 90 days after agrochemical application was in the order: OXY > COC > CHL. Cowpea yield was not affected by the agrochemical application and land use types. However higher doses of all the agrochemicals under study reduced the number of root nodules in cowpea.Item Quality assessment of organic manures and their effect on okra(Department of Agronomy, College of Horticulture, Vellanikkara, 2018) Santhiya, K; Usha, K EItem Chemistry and transformations of calcium and magnesium in tropical acid soils of kerala(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Thrissur, 2017) Bhindhu, P S; Sureshkumar, PCalcium and magnesium are indispensible as secondary nutrients for plant growth. Availability of these nutrients to plants depends on the form and quantity present in soil. Soils of the tropics normally pose the problem of acidity due to high rainfall and leaching of bases causing widespread deficiency of these nutrients. The study aims at characterization of soil samples from 23 agro ecological units of Kerala with respect to supplying power, chemistry, dynamics, transformations and availability indices of calcium and magnesium and also to optimize the level of calcium and magnesium for rice nutrition in lateritic soils. Sixty four representative soil samples from 23 agro ecological units under five agro ecological zones of the state were collected and characterised for physico-chemical properties. Among these soils, ninety two per cent were acidic in reaction, of which sixty three per cent were strongly to very strongly acidic (4.5-5.5). Lowlands of Kuttanad, Pokkali and Kaipad were extremely to ultra acidic. Twenty seven per cent of samples were deficient (< 300 mg kg-1) in available calcium, while sixty seven per cent samples were deficient in available magnesium (< 120 mg kg-1). Deficiency was negligible in soils from Attapady hills (AEU 18 and 19), Palakkad central and eastern plains (AEU 22 and 23) and the lowlands of Kuttanad, Pokkali, and Kaipad (AEU 4, 5 and 7). The availability of calcium and magnesium increased with pH, cation exchange capacity and decreased with increase in exchangeable aluminium. Forty one soil samples from different agro ecological units were subjected to sequential fractionation. The mean per cent contribution of different fractions to total calcium was in the order exchangeable > mineral > acid soluble > water soluble > organic complexed, whereas in the case of magnesium, it was observed as mineral > acid soluble > exchangeable > water soluble > organic-complexed. Exchangeable calcium and water soluble magnesium were the sole forms contributing directly to the available pool. The quantity-intensity relationship of calcium and magnesium in twenty- three soils belonging to different AEUs of Kerala were studied at 25oC and 40oC. Potential buffering capacity or the supplying power of soil had significant positive correlation with CEC and exchangeable cations in soil. The adsorption data of both calcium and magnesium at 25oC and 40oC were best explained by Tempkin adsorption isotherm indicating that the affinity for adsorption decreases linearly with degree of saturation. The change in free energy of adsorption for calcium and magnesium was negative in all the soils studied signifying the spontaneous nature of adsorption. The change in enthalpy (ΔH0) was negative in most of the soils indicating the process to be exothermic. The close correlation of enthalpy change with change in entropy proved that as the enthalpy change becomes more negative, stronger is the bond and more orderly is the adsorption. The incubation experiment conducted to study the effect of organic matter on the adsorption of calcium and magnesium revealed a positive influence of organic matter on availability of calcium and magnesium. The addition of organic matter improved the supplying power with respect to calcium and magnesium either through mineralization or formation of stable soluble complexes especially at higher pH. Two field experiments to optimize the level of calcium and magnesium nutrition for rice in low land of north central laterites (Pattambi) revealed the clear role of calcium and magnesium in improving the yield and yield attributing characters of the crop. Application of dolomite as per ΔpH was found to be effective in increasing the yield and maintaining optimum level of calcium as well as magnesium in soil. Application of lime was not found to influence the in situ soil pH. The response of crop to magnesium showed yield improvement to the tune of 1.18 t ha-1 by application of magnesium sulphate @ 120 kg ha-1. Residual effect of dolomite had significant influence on the yield of rice whereas no residual effect of applied magnesium sulphate was evident. The correlation studies and path analysis clearly indicated that plant absorption of calcium mainly takes place from exchangeable fraction and that of magnesium from water soluble fraction.