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ThesisItem Open Access Crop establishment methods and weed management on productivity of cowpea [Vigna unguiculata (L.)Walp.](Department of Agronomy, College of Agriculture,Vellanikkara, 2022-04-27) Ayisha Jezla, P; Anitha,S; KAUCowpea is an important pulse crop grown throughout India and Kerala as a grain and vegetable crop. Weeds possess severe problem in the early growth stages of cowpea due to wider spacing and low initial growth and resulted in yield reduction. Hence the crop requires to be kept weed free particularly during the initial 6-8 weeks, ie the critical period of competition. The present study was carried out with the objective to enhance the productivity of cowpea grown under different crop establishment methods by adopting proper weed management measures. Field experiment was conducted from October to December 2020 at the Department of Agronomy, College of Agriculture, Vellanikkara. The experiment was laid out with factorial RBD with two factors replicated thrice. Factor A with two methods of establishments such as broadcasting and line sowing. Factor B with six weed management practices such as hand weeding @ 20 and 40 DAS , imazethapyr + imazamox, 40 g/ha @ 15-20 DAS , imazethapyr + imazamox, 40 g/ha @15- 20 DAS fb hand weeding @ 40 DAS, imazethapyr, 40 g/ha @ 15- 20 DAS, imazethapyr, 40 g/ha @15- 20 DAS fb hand weeding @ 40 DAS and unweeded control. Cowpea variety PGCP-6 was used as test crop. Results revealed that methods of crop establishment had significant effect on weed density, growth parameters and yield attributes of cowpea. Line sowing resulted in 39% and 31% reduction in weed count and weed dry weight. Weed control efficiency and yield was 14% and 3% higher compared to broadcasting. The lowest weed count, weed dry weight and higher weed control efficiency was recorded in hand weeding at 20 and 40 DAS. The lowest weed index was observed in imazethapyr + imazamox, 40 g/ha @15- 20 DAS fb hand weeding @ 40 DAS Application of imazethapyr + imazamox, 40 g/ha @15- 20 DAS fb hand weeding at 40 DAS resulted in taller plants. At 30 DAS higher LAI was noted in imazethapyr, 40 g/ha @15- 20 DAS fb hand weeding @ 40 DAS. Imazethapyr, 40 g/ha @15- 20 DAS recorded higher LAI at 40 DAS.The highest dry matter production was recorded in imazethapyr, 40 g/ha @15- 20 DAS fb hand weeding @ 40 DAS. Application of imazethapyr + imazamox, 40 g/ha @15- 20 DAS fb hand weeding imazethapyr, 40 g/h registered significantly higher number of pods per plant and pod weight. Number of seeds per pod and 100 grain weight was higher in imazethapyr, 40 g/ha @15- 20 DAS fb hand weeding @ 40 DAS. The highest yield was recorded from plots where two hand weeding were conducted (937.67 kg/ha), followed by imazethapyr + imazamox, 40 g/ha @15- 20 DAS fb hand weeding (877.30 kg/ha). Line sown cowpea received two hand weeding recorded higher yield (923.67 kg/ha) compared to other treatment combinations. Adoption of weed management practices resulted in 70 % higher yield in cowpea. Nitrogen uptake by crop was higher in imazethapyr 40 g/ha @ 15- 20 DAS fb hand weeding @ 40 DAS, which was on par with hand weeding twice. Broadcasted plot, where two hand weeding were conducted recorded higher N uptake by crop. Higher P uptake was noticed in hand weeding @ 20 and 40 DAS. Higher soil N availability was observed in imazethapyr + imazamox 40 g/ha @ 15- 20 DAS and P availability was higher in imazethapyr + imazamox, 40 g/ha @ 15- 20 DAS fb hand weeding @ 40 DAS. Among crop establishment methods higher net return and B:C ratio was observed in broadcast sowing compared with line sown cowpea. The highest net return (Rs. 102861) and B:C ratio (2.45) was registered in imazethapyr + imazamox @ 40 g/ha @ 15- 20 DAS fb hand weeding @ 40 DAS. Results of the study indicated that application of imazethapyr + imazamox, 40 g/ha @ 15- 20 DAS fb hand weeding @ 40 DAS can be recommended as a cost effective weed management practice for broadcasted and line sown cowpea.ThesisItem Open Access Novel strains of Metarhizium anisopliae sorokin.(Ascomycota:sordariomycetes) with enhanced abiotic stress tolerance(Department of agricultural entomology, college of agriculture, Vellanikkara, 2023-08-02) Sreelakshmi, U K.; KAU; Deepthy, K BNovel strains of Metarhizium anisopliae Sorokin. (Ascomycota: Sordariomycetes) with enhanced abiotic stress tolerance Abstract The green muscardine fungus, Metarhizium anisopliae Sorokin is widely used in the management of various crop pests. However the efficacy of M. anisopliae in the field is often inconsistent, mainly due to the environmental stresses such as temperature extremes, drought, UV radiation, etc. To circumvent these hurdles, the present study was undertaken to develop novel strains of M. anisopliae with enhanced environmental stress tolerance. The Metarhizium isolates, EKM2, CKD, and M4 were collected from the repository maintained at the Department of Agricultural Entomology and were screened for their temperature and drought tolerance. The isolate EKM2 recorded the highest mycelial weight (6.221g), while the isolate M4 recorded the least mycelial weight (0.328 g) and the least sporulation at the highest temperature of 380C. The screening for drought tolerance was conducted at various levels of Polyethylene glycol (PEG) concentrations in which the isolate CKD has shown higher biomass (2.172 g) with higher sporulation, while isolate M4 recorded the lowest mycelial weight (1.336 g) at the maximum PEG concentration of 39 per cent. The three selected isolates of M. anisopliae (CKD, EKM2 and M4) were subjected to further experiments. The Metarhizium isolates (CKD, EKM2 and M4) selected from the preliminary screening were continuously subjected to temperature stress treatments starting from 35oC to 42oC. At the highest temperature of 41oC, the isolate, EKM2 recorded the highest mycelial weight (1.336 g), number of colonies (18.667103 cfu/ml), number of spores (0.783 X 10 7 /ml), spore size (3.470 µm) and mycelial thickness (3.07 µm). At the same temperature, the isolate, M4 recorded the lowest mycelial weight (0.63g), number of colonies (3 cfu/ml), number of spores (0.217 X 10 7 /ml), spore size (1.637 µm), and mycelial thickness (2.65 µm). Hence EKM2 has been identified as the thermo-tolerant isolate and M4 as the susceptible one. The thermo-tolerant isolate EKM2 was grown continuously for 6 successive generations at the same temperature level of 41oC in order to stabilize the stress tolerance. The Metarhizium isolates (CKD, EKM2, and M4) selected from the preliminary drought screening experiment were also continuously subjected to drought-inducing treatments at PEG concentrations starting from 25 to 40 per cent. At the highest level of PEG concentration (40 %), the isolate CKD showed higher mycelial weight (3.365 g), spore count (0.323X 107 /ml)), number of colonies (4 X 103 colonies/ ml), spore size (3.15 µm), and mycelial thickness (2.723µm). The isolate, M4 recorded the lowest mycelial weight (0.808g), number of colonies (2 cfu/ml), spore count (0.243 spores/ml), spore size (4.493 µm), and mycelial thickness (2.543 µm) at the same PEG concentration. Hence isolate CKD is identified as drought tolerant and M4 as susceptible. The drought-tolerant isolate, CKD was grown continuously for 6 successive generations at the same PEG concentration level of 40 per cent in order to stabilize the stress tolerance. The selected tolerant isolates were evaluated against wax moth larva (Galleria mellonella) to identify their biocontrol efficacy. Isolate EKM2 has shown cent per cent mortality at the dosage of 108 and 109 spores/ml on the 9th day after treatment. At the highest dosage of 1x 109 spores/ ml, the isolate CKD recorded a lower LT50 (5.099 days) value, and isolate M4 recorded the highest LT50 (6.124 days) value. The isolates EKM2 and CKD were found to be more virulent while M4 was less virulent. The thermo-tolerant isolate, EKM2 recorded a total protein content of 0.354 mg/ml, and the drought-tolerant isolate (CKD) recorded a total protein content of 0.373 mg/ml. The thermo-tolerant isolate EKM2 has shown a trehalose content of 1.954 mg/min/g tissue weight which was significantly higher compared to the control (1.074 mg/min/g tissue weight). The trehalose content in the drought-tolerant isolate CKD (1.970 mg/min/g) was also higher when compared to the control (1.224 mg/min/g). The catalase activity ranged between 0.237 EU/min/mg proteins in the control to 0.386 EU/min/mg protein in the thermo-tolerant isolate EKM2, while the catalase activity of the drought-tolerant isolate, CKD was 0.384 c protein which was higher when compared to its control (0.240 EU/min/mg protein). The thermo-tolerant isolate recorded a peroxidase activity of 0.0230 EU/min/g tissue and that of droughttolerant isolate CKD was 0.0236 EU/min/g tissue weight. The protease activity of thermo-tolerant isolate CKD was 0.490 EU/min/mg protein and that of the droughttolerant isolate was 0.621 EU/min/mg protein. At 25 minutes of reaction, the thermo-tolerant and drought-tolerant isolates have shown higher lipase activity (10.000 µmol fatty acid/ml and 11.00 µmol fatty acid/ml respectively) when compared to their respective controls. On the 5th day, both the thermo-tolerant and drought- tolerant isolates recorded significantly higher chitinase activity (1.140 µg of N- acetyl glucose amine/min/ml of broth and 3.062 µg of N- acetyl glucose amine/min/ml of broth respectively) than their controls. The temperature induction had up-regulated heat shock proteins of 25 kDa and 35 kDa in heat-induced isolate EKM2. The isolate also expressed heat shock proteins in the range of 100 kDa molecular weight. Drought tolerant isolate (CKD) on the other hand did not show the presence of any heat shock protein when compared to the control. The study could develop isolates of M. anisopliae which are tolerant to temperature and drought stress, with high virulence as well as higher biochemical activityThesisItem Open Access Genetic diversity analysis of rambutan (Nephelium lappaceum L.) accessions using molecular markers(Department of fruit science, College of agriculture ,Vellayani, 2023-09-12) Gazel, M Gaddafi; KAU; Anu, G KrishnanRambutan (Nephelium lappaceum L.) holds great potential in Kerala being a tropical region. It belongs to the Sapindaceae family, which consists of numerous trees and shrubs, comprising over 125 genera and more than 1000 species that are found across the tropics and warm regions. These plants are adaptable to various soil types, ranging from heavy soils in low-lying areas to hilly soils in upland regions. The origin of rambutan can be traced back to Southeast Asia, specifically Indonesia and Malaysia. Rambutan cultivation is rapidly expanding along India's western coast, particularly in the districts of Pathanamthitta, Kottayam, and Thrissur of Kerala. Even though morphological characterization and diversity studies of the collections from various localities in Kerala have been carried out, the genetic diversity analysis using molecular markers has not yet been conducted. Hence, the current research titled "Genetic diversity analysis of rambutan (Nephelium lappaceum L.) accessions using molecular markers" was conducted at the Regional Agricultural Research Station Kumarakom and at the Department of Fruit Science, College of Vellayani between 2020 and 2022. The main objective of this study was to assess the diversity of twenty rambutan accessions using SSR and ISSR molecular markers collected from the districts of Kottayam, Pathanamthitta, and Thrissur. DNA isolation was performed using the CTAB method (Doyle and Doyle,1987) with minor modifications. A pre-washing with sorbitol buffer was done to improve the DNA quality. The DNA samples showed UV absorbance ratios (A260/A280) between 1.80 and 1.95 indicating their purity. The initial primer screening was conducted with thirty ISSR and sixteen SSR primers. Based on their ability to yield reproducible and distinct banding patterns, eleven ISSR and five SSR primers were selected for subsequent analysis. The ISSR primers used in the study exhibited a polymorphism percentage ranging from 55.56% (ISSR 10 ) to 100% (ISSR-1 and UBC 828), with an average value of 79.44%. On the other hand, the selected SSR primers displayed a 100% polymorphism percentage. The Polymorphic Information Content (PIC) values ranged from 0.12 (UBC-819) to 0.41 (ISSR-23) for ISSR markers and from 0.60 (NlaSSR 7) to 0.72 (NlaSSR 23) for SSR markers. PIC is an indication of the informativeness of the primers. The Marker index (MI) which measures the utility of the primers ranged between 0.36 (UBC 819) to 2.88 (UBC 825) for ISSR markers and it varied between 1.80(NlaSSR 7) to 2.88 (NlaSSR 23) for SSR markers. The diversity analysis of rambutan accessions was performed using the NTSYS-Pc software. In the UPGMA (Unweighted Pair Group Method with Arithmetic Mean) cluster analysis based on ISSR data, the rambutan accessions were divided into two distinct clusters at a similarity coefficient of 0.61 with 10 accessions in each cluster. The Col.03 and Col.53 were found to be closely related with a similarity of 71%. In the SSR data-based cluster analysis, the rambutan accessions were divided into two major clusters at a similarity coefficient of 0.70. Cluster I comprised a total of eight rambutan accessions and Cluster II included the remaining twelve genotypes. The highest similarity of 67% was observed between Col.87 and Col.97, Col. 81 and Col.86, Col.04 and Col.52, and Col.48 and Col.15. In the combined SSR-ISSR cluster analysis, at a similarity coefficient of 0.62, the rambutan accessions were divided into two clusters, showing a similar dendrogram pattern as observed in the ISSR data-based dendrogram. The Principal Coordinate Analysis (PCoA) also revealed a similar pattern of distribution of the accessions as recorded in cluster analysis.The results of the present study revealed that the accessions studied had genetic diversity ranging from 61% to 70% under different marker systems. The accessions from the same area have shown a closer genetic distance, suggesting that dispersal from related parents may have occurred. In future crop improvement programmes for this exotic crop, existing germplasm from different locations of the state and molecular analysis employing more markers can be exploited. Identification of markers associated with economically important trails will be useful for marker assisted breeding programmes. The current study on genetic diversity using molecular markers is the first of its type in Kerala and hence can be considered as a basic information for future related works.ThesisItem Open Access Performance of red gram (Cajanus cajan (L.) Millsp.) intercropping systems in lowlands(Department of Agronomy, College of Agriculture,Vellayani, 2023-02-20) Gibi Mariam ,Thomas.; Jacob, John; KAUThe study entitled “Performance of red gram (Cajanus cajan (L.) Millsp.) intercropping systems in lowlands” was undertaken at College of Agriculture, Vellayani during 2020-2022. The main objective was to evaluate different red gram based intercropping systems in the summer fallow of double cropped lowland rice field in terms of weed dynamics, biological efficiency and economics. The field experiment was carried out at Integrated Farming System Research Station (IFSRS), Karamana from January to June 2022 in Randomized Block Design with 10 treatments and three replications. The treatments comprised of T1: red gram + bush cowpea (1:2), T2: red gram + green gram (1:2), T3: red gram + fodder cowpea (1:2), T4: red gram + finger millet (1:2), T5: sole crop of red gram, T6: sole crop of bush cowpea, T7: sole crop of green gram, T8: sole crop of fodder cowpea, T9: sole crop of finger millet and T10: fallow. Red gram (var. PRG 176) was raised as the main crop and bush cowpea (var. PGCP-6), green gram (CO-6), fodder cowpea (var. Aiswarya) and finger millet (var. VR 847) were raised as intercrops. Red gram was raised as per the recommendation of Regional Agricultural Research Station, Palem, Telengana and the intercrops as per KAU Package of Practice Recommendations (KAU, 2016). The results indicated that intercropping in red gram had significant influence on the growth and yield of both main crop and intercrops. Growth attributes of red gram, viz., plant height, number of branches per plant, leaf area per plant and leaf area index (LAI) showed significant variation with the intercropping systems. The treatment T5 resulted in taller plants at 30 and 60 Days after sowing (DAS), highest number of branches at 60 and 90 DAS and highest leaf area and LAI at 30, 60 and 120 DAS. Number of pods per plant (110.43), grain yield (1430 kg ha-1 ), haulm yield (5639 kg ha1 ), of red gram were also found to be highest in T5. Growth and yield attributes of intercrops were significantly reduced under intercropping systems. Sole crops of bush cowpea (T6) and green gram (T7) produced highest leaf area, LAI, number of pods, grain yield and haulm yield compared to its intercropping system. The highest plant height, number of branches, leaf area, LAI, L:S ratio, green fodder yield and dry fodder yield were recorded in the treatment T8 (sole crop of fodder cowpea). Similarly, finger millet when raised as sole crop (T9) registered highest number of tillers m-2 , productive tillers m-2 , grain yield and stover yield. Intercropping with red gram profoundly reduced the weed count, dry matter production (DMP), and NPK removal by weeds. The treatment T8 (sole crop of fodder cowpea) and T1 (red gram + bush cowpea) recorded the lowest weed count at 30 and 60 DAS, respectively. Higher DMP was recorded in T10 (fallow) and lowest in T1 (red gram + bush cowpea). The lowest N removal by weeds was observed in T1 at 30 DAS (1.36 kg ha-1 ) and 60 DAS (5.24 kg ha-1 ), respectively. The treatments T2 at 30 DAS (0.66 kg ha-1 ) and T1 at 60 DAS (2.05 kg ha-1 ) resulted in the lowest P removal by weeds. The treatment T1 recorded the lowest K removal at 30 DAS (0.94 kg ha-1 ) and 60 DAS (1.55 kg ha-1 ), respectively. In general, intercropping system exhibited more weed smothering efficiency than sole cropping. Higher values were obtained for T1 at 30 DAS (40.86 %) and 60 DAS (58.93 %), respectively. All crops were analyzed for N, P and K uptake and highest value was recorded in sole crop of both main crop and intercrops. Analysis of soil sample after harvest recorded that all parameters except available P and K were not significantly influenced by different treatments. The highest P and K content were observed in T8 (76.03 kg ha-1 ) and T3 (150 kg ha-1 ) respectively. The dehydrogenase enzyme activity was recorded highest in treatment T1 (red gram + bush cowpea) with the value of 356.37 μg TPF g-1 soil d-1 . Analysis of competitive indices of intercropping system revealed that the land equivalent ratio (LER), monetary advantage index (MAI) and red gram equivalent yield (REY) were the highest in T1. The highest relative crowding coefficient (Kri) and positive aggressivity value of red gram indicated the dominance and competitive nature of red gram over intercrops. Treatment T1 (red gram + bush cowpea) produced highest net income (₹ 138611 ha-1 ) and the highest B:C ratio (3.13) was recorded in T2 (red gram + green gram) intercropping system. From the present study it can be concluded that the systems involving bush cowpea and green gram in additive series (1:2) were more suitable for intercropping with red gram in the summer fallow of double cropped lowland rice field. It was identified as the best intercropping system considering the weed smothering efficiency, red gram equivalent yield, land equivalent ratio, monetary advantage index, net income and benefit: cost ratio.ThesisItem Open Access Irrigation water: assessing the economic efficiency and its pricing in banana(Department of agricultural economics, college of agriculture, Vellanikkara, 2023-07-24) Midhuna,Sivanandan; KAU; Hema, MWater has distinct properties that influence both its allocation and use as a valuable resource in agriculture. Irrigation is a critical component of agricultural production. According to the UNESCO World Water Development Report (2022), India is the world's top groundwater extractor. About 80 per cent of all withdrawals are made in the agricultural sector, and India has a low irrigation efficiency of 38 per cent when compared to developed nations (GoI, 2018). When water, the elixir of life, is becoming scarce due to over exploitation, increasing or at least maintaining its efficient use is imperative. In order to achieve effective and equitable use, the Fourth Principle of the Dublin Declarations of 1992 defines water as an economic good. It encourages the conservation and protection of water resources. With the adoption of the Fourth Dublin Principle, there was a historic shift in the focus on the economic aspects of water use in general and irrigation development in particular. Numerous researchers have looked into water valuation as a tool for managing irrigation systems, reducing water consumption, and improving water allocation. Hence, evaluating irrigation water's economic effectiveness and value becomes relevant in the current scenario. It is in this context, the study was carried out with specific objectives viz., identifying the sources of irrigation, private investments for irrigation and irrigation pattern, estimating the economic efficiency of irrigation water and making an assessment of its pricing. The study was based on primary data collected from Kodakara and Chalakkudy blocks of Thrissur district owing to their maximum share of cropped area under banana and groundwater extraction in the respective blocks. 60 farmers from each blocks using pump irrigation as a source of irrigation in banana cultivation are randomly sampled to make a total of 120 sample respondents. The sources of irrigation in the study area were found to be wells, tube wells, ponds, canals, and rivers, wherein most of the farmers relied on wells for their irrigation. I The irrigation pattern of the study area included surface irrigation, drip irrigation, and sprinkler irrigation. Most farmers use surface irrigation method due to its easy management. Drip and other micro-irrigation techniques were less adopted due to their high initial investment costs and maintenance problems. The Private investment for banana farmers cultivating banana on owned and leased land was calculated by considering depreciation and miscellaneous costs. It accounted for Rs. 19,479 per hectare for owned land and Rs. 8,183 per hectare for leased farmers. The cost of cultivation for banana cultivation was worked out separately for owned and leased farmers using ABC cost concepts. The total cost of banana cultivation was found to be Rs. 4,80,877 per hectare (owned land) and Rs. 5,04,066 per hectare (leased land) with net returns of Rs. 2,61,981 and Rs. 3,22,089 per hectare, respectively. The benefit- cost ratios were found to be stable, with 1.5 (owned land) and 1.6 (leased land), respectively. The determinants of yield in banana cultivation were analyzed using the Cobb- Douglas production function. The yield of banana was regressed with different variables like the quantity of irrigation water applied, manures and fertilizers, human labour and plant protection. It was found that the quantity of irrigation water, manures and fertilizers and human labor as the major determinants of banana cultivation. The economic efficiency of irrigation water in the study area was assessed using Data Envelopment Analysis Program. The analysis showed that the technical, allocative and economic efficiencies had a mean values of 60.9, 87.1, and 53 per cent. Analysis revealed that there exists scope for increasing the efficiency of irrigation water in the study area. The average quantity of irrigation water currently used in the study area was 2.4x103 per hectare for 1373 plants per hectare, which was compared with the study results carried out in Agricultural Research Station, Chalakudy, to determine whether irrigation water is being overused or underused. The study was conducted during 2009- II 2014 on system intensification for better water productivity in banana (Nendran) (ARS Chalakudy, 2021). The study results showed that irrigating crops at 100 per cent irrigation (10 mm CPE- Cumulative Potential Evaporation), i.e., 20 liters of water per plant per day, is required for the banana to increase the bunch yield per plant significantly. The study found that the water required was 1.3 x 103 m3 per hectare (1373 plants/ha). On comparing it with the results of the present study, an overuse of 1.1 x 103 m3 per hectare was found in the study area. It is mainly attributed to the surface irrigation method followed in the study area. The marginal pricing of irrigation water under the study area was analyzed using the Cobb-Douglas production function, and the marginal value was found to be Rs. 22.31 per m3. The ratio of MVP to MFC for the quantity of water applied was also found to be 0.8, which indicated the overutilization of the irrigation water applied. Thus, the farmers in the study area are currently overutilizing the irrigation water, and the mean economic efficiency of the farm was only 53 per cent, wherein improvement can be made by promoting the use of micro-irrigation technologies such as drip instead of surface irrigation. Also, promotion of extension and awareness activities relating to water harvesting, irrigation scheduling, water management, and crop alignment for farmers and grass root level field functionaries has to be carried out to enhance the irrigation efficiency of the farms in the study area.ThesisItem Open Access Preservation of coconut wood using inorganic nanoparticles(Department of forest products and utilization , college of forestry,Vellanikkara, 2023-12-22) Sidhartha, T N; KAU; Vishnu, RCoconut is a vital crop of Kerala, potential substitute for conventional timber. However, it is susceptible to termites, red palm weevils, bark weevils, shot hole or bark borers, and other pathogens. Traditional wood preservatives like Chromated Copper Arsenate and Chromated Copper Borate pose environmental risks. To address these challenges, researchers are exploring the concept of nanotechnology as a potential solution for wood protection. Nanoparticle has high efficiency to maintain wood natural color, and controlled release of active ingredients at a low concentration, making them a priority for future wood protection applications. As there is limited research on coconut's durability, degradability, and biocide properties of nanoparticles study has been conducted to understand the same. The copper and zinc nanoparticle was prepared by chemical reduction and precipitation method respectively. Medium and high density coconut wood was impregnated with this nanoparticles at 1%, 2.5% and 5% concentration. Two method of impregnation was carried out i.e., coating with fixative and pressure without fixative. Later, these samples were undergone chemical retention test, leaching test, subterranean termite test, weatherability test and water absorption test according to various standards of ASTM and AWPA. Nested anova was carried out to know the significant difference among various factors and their levels. Chemical reduction and precipitation method of copper and zinc nanoparticle preparation yielded 65.06% and 70.15% respectively. The SEM image of copper and zinc nanoparticles confirmed to have irregular cuboidal and flake shape with average size of 173.66 nm and 105.44 nm respectively. The presence of copper and zinc in the nanoparticles was verified by EDX analysis. The presence of the corresponding nanoparticles' metal-hydroxyl and metal-oxide groups was verified by the FTIR spectrum. XRD analysis shows that most of the copper in copper nanoparticles is present as copper oxide and cuprous oxide whereas, zinc nanoparticles as zinc oxide. The chemical retention of both pressure and coating treatment had significantly varied among various density, and nanoparticle concentrations. Among density, medium density had shown higher retention than high density. Concentration of 5% zinc and 5% xxix copper treated to medium density had shown greater retention among various nanoparticle concentration. The chemical leaching test showed that high leaching of nanoparticles occurred during initial stage. Pressure treated coconut wood with nanoparticles statistically varied between various density, nanoparticle and its concentration. High density had shown low leaching compared to medium density. Among nanoparticle and its concentration, zinc has shown the least leachability when compared to control. Same trend was seen in coating method. The subterranean termite test (no-choice) shown significant variation for mass loss and visual appearance among various density, and nanoparticles. While there was no significant difference seen with respect to different nanoparticle concentrations. Among density class medium was susceptible to termite attacks. Copper treated sample shown significant resistant to termite damage when compared to zinc treated sample. Statistically significant variation among density, nanoparticle and its concentration was seen in a weatherability test. High density sample was least susceptible to mass loss and greying. Zinc and copper treated sample shown excellent resistant to mass loss and greying as compared to control. Water absorption test shows a remarkable variation among density, nanoparticle and its concentration in the coconut wood treated by pressure and coating. Medium density shown greater water absorption and volume swelling percentage. Among nanoparticles, control shown more water absorption and volume swelling percentage. Hence, nanoparticles in wood preservation offer improved durability and performance due to their small size and unique properties. They offer enhanced resistance to leaching, termites, and other environmental factors, leading increased lifespan for wood-based products. However, further research is needed to ensure the safe and responsible application of nanoparticle-based wood preservation technologies, while considering cost and scalability.ThesisItem Open Access Expression profiling of E2F and CDKA during embryo culture in coconut(Cocos nucifera L.)(Department of plant biotechnology, college of agriculture, Vellanikkara, 2023-08-05) Mounika Sai, K.; KAU; Smita, NairThe study entitled “Expression profiling of E2F and CDKA genes during embryo culture in coconut (Cocos nucifera L.)” was undertaken at the Department of Plant Biotechnology, College of Agriculture, Kerala Agriculture University, Vellanikkara, Thrissur. The objective of the study was, expression profiling of the genes governing organogenic regeneration pathway at different morphogenic response stages in coconut embryo culture. This chapter provides the key insights of the study.ThesisItem Open Access Bioefficacy of Tagetes minuta L. against Teranychus truncatus ehara (Prostigmata: Tetranychidae) and Aphis craccivora koch (Hemiptera: Aphididae)(Department of Agricultural Entomology, College of Agriculture, Vellanikkara, 2023-03-25) Ashish V V.; KAU; Haseena, BhaskarThe spider mite, Tetranychus truncatus Ehara and the black cowpea aphid, Aphis craccivora Koch are two predominant sucking pests infesting several vegetable crops in Kerala. Farmers depend heavily on chemical pesticides for the management of these pests. However, due to the adverse effects of synthetic pesticides on environment and non-target organisms, there is a growing need for environmentally benign alternatives. This has generated interest in the development of biopesticides, based on botanicals. Tagetes minuta L., commonly known as Mexican marigold or wild marigold or southern cone marigold is a plant whose pesticidal properties have been well documented. The study was carried out in the Department of Agricultural Entomology, College of Agriculture, KAU, Vellanikkara during 2020-2022. The objectives of the study were to identify the bioactive fractions of T. minuta and to evaluate the bioefficacy of the solvent fractions against T. truncatus and A. craccivora. Tagetes minuta plants cultivated in the Department of Floriculture and Landscaping, were harvested at the flowering stage followed by shade drying and grinding. The powdered botanical was extracted sequentially using hexane (non-polar), chloroform (medium polar) and water (highly polar) as solvents. The hexane, chloroform and aqueous fractions of T. minuta were evaluated for their efficacy against T. truncatus and A. craccivora in the laboratory at five different concentrations viz., 0.025, 0.05, 0.1, 0.15 and 0.2 %. The ovicidal and adulticidal effects of the solvent fractions were evaluated against T. truncatus by topical application method. Considerable ovicidal action was exhibited only by hexane fraction at higher concentrations (0.1, 0.15 and 0.2 %), with cent per cent egg mortality at 0.2 %, after 120 h of treatment. However, all the three solvent fractions caused appreciable mortality of adult mites, in a concentration dependent manner. The hexane fraction at 0.2 % and 0.15 % were significantly superior, causing 91.67 and 90.00 per cent mortality, respectively, followed by 0.2 % chloroform (66.67), 0.15 and 0.10% (56.67), and 0.2 % aqueous fraction (53.33), after 120 h of treatment. The efficacy of the solvent fractions (0.025, 0.05, 0.1, 0.15 and 0.2 %) against A. craccivora was evaluated in the laboratory on cowpea seedlings grown in paper cups. Though the highest reduction in aphid count after 120 h of treatment was recorded in hexane fraction at 0.2 % (90.00 per cent), chloroform (86.67) and aqueous fraction (85.00) also recorded reduction in aphid count on par with it, at the same concentration. Qualitative phytochemical analysis of the hexane and chloroform fractions was carried out by GC-MS/MS to identify the major bio- active constituents. The two compounds, 4-o-methylphorbol 12, 13- didecanoate and milbemycin b were found in both the fractions, while 4α-phorbol 12,13-didecanoate was found in hexane fraction only. The best concentrations of the three botanical fractions of T. minuta were tested for efficacy against T. truncatus on potted plants of amaranthus along with neem oil emulsion (2%) and horticultural mineral oil (2.5%). After 14 days of treatment, the hexane fraction recorded the highest reduction in mite population (88.78 %) followed by chloroform and aqueous fractions which were on par with each other (77.97 and 76.96 %, respectively). Hexane fraction was superior to neem oil emulsion, while chloroform and aqueous fractions were found to be on par with neem oil emulsion (76.44), which is a widely recommended botanical preparation for mite pest management in different crops. The best concentrations of the three solvent fractions of T. minuta identified in the laboratory study were evaluated against A. craccivora on cowpea, in a pot culture experiment. By 10th day of treatment, the field efficacy of hexane fraction (78.95 % reduction) was comparable with that of neem oil emulsion (87.59 %), while chloroform (72.43 %) and aqueous fractions (68.20 %) were comparable with azadirachtin 1 EC (67.97 %). The results of the study indicate that Mexican marigold possess excellent acaricidal and insecticidal properties and that the plant can be explored further, for utilization in the management of spider mites as well as aphids.ThesisItem Open Access Mild storage invigoration with nanoparticles in chilli (Capsicum annuum L.)(Department of seed science and technology, College of Agriculture,Vellanikkara, 2023-11-17) Gagana, G; Dijee ,Bastian; KAUThe entitled "Mid storage seed invigoration with nanoparticles in chilli (Capsicum annuum L.)" was carried out in the Department of Seed Science and Technology, College of Agriculture, Kerala Agricultural University, Vellanikkara, Thrissur during the year 2022-2023. The study aimed to assess the effect of nanoparticles on crop performance, seed yield, quality and longevity when administered as midterm storage treatment. The initial quality assessment of the six-month-old seeds was carried out at the beginning of the experiment. Seeds exhibited an initial germination of 67.37%, with seedling shoot and root length with value of 4.68 cm and 6.81 cm, respectively and seedling dry weight of 24.1mg. The vigour index-I and II were calculated as 774 and 1595 respectively. The electrical conductivity of the seed leachate and initial moisture content were 192.33 μS cm-1 and 7.53 % respectively, and the seed microflora was observed to be 47.15per cent (blotter method) and 53.30 % (agar plate method). The seeds were imposed with different treatments of nano zinc oxide (300, 400, 500, 600, and 700mg of nano ZnO) and 500 mg nanosized custard leaf powder per kilogram of seed. The six treatments along with untreated control formed the basis of the study. The quality parameters of treated seeds were studied and significant variation was noticed among treatments. Seeds treated with 700 mg of nano zinc oxide per kilogram of seed recorded significantly higher seed germination (73.31%) and enhanced seedling vigor indices (945, 1771). Mid storage treatment could enhance the germination and vigour of seeds. The treatments along with control (seven treatments) were raised in a randomized block design with three replications. Observations on growth and yield parameters were recorded at appropriate growth stages in the tagged plants. While all nanoparticles treated seeds performed better than control (untreated seeds) treatments. Seed treatment with nano ZnO @ 700 mg kg-1 of seed (T6) performed superior for plant height (80.40 cm), days to 50% flowering, (82.67 days), fruit length (5.55 cm), 100 seed weight (g). Treatment with nano ZnO @ 600 mg kg-1 of seed (T5) was effective in improving branches per plant (5.80), fruits per plant (112.57), fruit weight at maturity (2.31g), fruit yield per plant (478.73g), seeds per fruit (61.50), seed yield per plant (25.76g) and 100 seed weight (0.433g). Significant effects were recorded when seeds were treated with nano