1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Response of bhindi (abelmoschus esculentus L. moench) to fertigation and foliar nutrition in red loam soil of Kasaragod(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Padannakkad, 2018) Ashwini, B N; Binitha, N KItem Tillage and water saving techniques for black gram in rice fallows(Department of Agronomy, College of Horticulture, Vellanikkara, 2017) Aisha Mol, P B; Latha, AItem Hydraulics of KAU drip irrigation system(Department of Land and Water Resources and Conservation Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1988) Susan Cherian, K; George, T PIrrigation advancements within the last decade has been astounding. Drip irrigation is one of the latest innovations for applying water to the field and it represents a definite advancement in irrigation technology. An attempt was made to study the hydraulics of microtube emitters of 1-3 mm size, Black polyethylene tube of 1" was used as main line. In the main line, three laterals of 1/2 diameter were connected. Discharge measurements were taken at different pressure heads.The total energy drop (H) in a microtube emitter is the summation of friction loss (Hf) and minor loss (Hm). There was no empirical equation available for calculating the friction drop from a microtube of size less than 4 mm. With the help of a computer, analysis was made to establish the relationships between pressure head H, length L, diameter D and discharge Q. The empirical equations obtained are 1. Combind flow condition H = 0.01402 Q1.23938/D3.54926 L0.86030 2. Turbulent flow condition H = 0.00764 Q1.82655/D4.61537 L0.77823 3. Flow in transition region H = 0.00817 Q1.56882/D3.83531 L0.83541 4. Laminar flow condition H = 0.00796 Q1.23461/D3.59105 L0.98712 Where Q = discharge, 1/hr L = length of tube, cm D = diameter of tube, mm The minor losses, viz. exit, entry, losses due to fittings and sudden contration can be expressed as a function of velocity head. The minor loss was significant because of the smaller size and short length of the microtube. The numerical solution for minor loss coefficient K was obtained in order to make the power of L unity in the estimating equations for head loss due to friction. The equations obtained are 1. Combind flow Hm = 2.34 V2/2g 2. Turbulent flow Hm = 2.14 V2/2g 3. Flow in transition region Hm = 3.18 V2/2g 4. Laminar flow Hm = 0.84 V2/2g Where V = Velocity, m/s G = acceleration due to gravity, m/s2 The empirical equations for friction drop were developed for different flow condition by fitting multiple log linear regression equations. The equations obtained are 1. Combined flow Hf = 0.00737 Q1.18905/D3.58352 L 2. Turbulent flow Hf = 0.00359 Q1.74866/D4.80544 L 3. Flow in transition region Hf = 0.00397 Q1.46302/D3.74436 L 4. Laminar flow Hf = 0.00743 Q1.22546/D3.58420 Similar to Blasius and general equations, the following equations were developed for friction factor in turbulent and laminar regions. f = 0.248/Re0.25 and f = 67.2/Re where f = friction factor Re = Reynolds number The KAU drip system has an additional component ‘Distributor’. Experiments were conducted to study the effect of distributor on flow rate. It was observed that the discharge rate was higher from the system with distributor than that of microtube having the same length. The frictional losses and the combined loss of minor and distributor for different flow conditions were estimated. Few combinations which satisfy the requirements of discharge, length and pressure head were selected for the design purpose of KAU drip irrigation system. The effect of clogging on discharge rate was studies and it was found that clogging was higher in 1 mm tube than the 2 mm and 3 mm tubes. Experiments were conducted to estimate friction loss in laterals. Hazen – Williams equation was found suitable for turbulent region and not for laminar and transition region. By adopting drip system we can bring more area under cultivation by maximum utilisation of available water. By combining improved agronomic practices along with an efficient drip irrigation system, it is possible to bring about a substantial progress in the farm front.Item Comparative evaluation of naturally ventilated polyhouse and rainshelter on the performance of tomato(Department of Land and Water Resources and Conservation Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2017) Pooja, B G; Abdul Hakkim, V MA study was conducted in the Instructional Farm of KCAET, Tavanur, Kerala, during the period from December 2016 to April 2017 to compare the performance of tomato grown under polyhouse and rainshelter cultivation. Tomato variety Akshaya, released by KAU, was used for the study. Drip irrigation system using venturi assembly was used for fertilizer application. The variation of weather parameters such as maximum and minimum temperature, relative humidity and soil temperature during the crop growth period was studied. Mean monthly values of temperature, relative humidity and soil temperature inside the polyhouse was higher than that in rainshelter throughout the growth period. The maximum temperature (36.4 0C) was recorded inside the naturally ventilated polyhouse during the month April and minimum temperature (22.3 0C) was observed in the rainshelter during month of January. The maximum relative humidity (83.82 per cent) was observed in the month of December in the polyhouse and the minimum relative humidity (70.2 per cent) was observed in the month of April in the rainshelter in the morning. The maximum soil temperature (37.8 0C) was observed under the polyhouse in the month of March at the morning and minimum soil temperature (25 0C) was observed inside the rainshelter in the month of February. Crop growth parameters such as plant height, inter-nodal length, number of branches, stem girth, number of leaves and time taken for flower initiation were noted during various crop growth stages for all the treatments. During all growth stages, the plant height and inter-nodal length were significantly higher inside the polyhouse than rainshelter. Stem girth of the plant was higher under rainshelter than the rainshelter. The higher numbers of leaves per plant were observed under rainshelter structure than polyhouse. Among the different treatments, early flower initiation (45 days) was observed in the polyhouse and late flower initiation (49 days) in rainshelter. Yield parameters such as number of fruits per plant and total yield per plant for each treatment were noted during various crop growth stages. Number of fruits per plant was maximum under rainshelter than naturally ventilated polyhouse at all the growing stages of the plant growth. The fruit diameters, average weight per fruit are significantly higher in polyhouse compare to rainshelter. The total yield of tomato observed from polyhouse and rainshelter were 1.31 kg/m2 and 4.15 kg/m2 respectively. Quality parameter of tomato like TSS content of tomato under the polyhouse system was found 4.56 0B and rainshelter was found 4.0 0B. Water use efficiency was observed higher under rainshelter (165.41 kg/ha.mm) than the polyhouse (52.12 kg/ ha.mm). Cost Benefit (B:C) ratio for each treatment was calculated. The maximum benefit cost ratio of 2.00 was observed in rainshelter than the 0.46 under polyhouse cultivation. From the results of the study it was evident that growing of tomato inside the rainshelter is more profitable than growing it inside naturally ventilated polyhouse.Item Fertigation and mulching studies in yard long bean (Vigna unguiculata var-sesquipedalis (L.) verdcourt)(Department of Olericulture, College of horticulture, Vellanikkara, 2014) Mahasuma Puthuppalli; Salikutty JosephThe investigations on ‘Fertigation and mulching studies in yard long bean (Vigna unguiculata var. sesquipedalis (L.) Verdcourt)’ were carried out in the Department of Olericulture, College of Horticulture, Vellanikkara during January –May 2014. The study was conducted in the yard long bean variety Vellayani Jyothika to standardize the fertigation requirement and to assess the relative efficacy of fertigation and mulching over the conventional method. The experiment was laid out in strip plot design with two replications. There was a total of 17 treatments consisting of combinations of two irrigation levels (60 and 80 per cent pan evaporation (Ep) through drip irrigation) and four fertilizer levels (75, 100 and 125 per cent recommended dose of fertilizer (RDF) and 100 per cent RDF with water soluble fertilizer) with and without mulching and a control treatment (channel irrigation once in three days with 100 per cent RDF). The study revealed that irrigation, mulching and fertilizer levels had significant effect on vine length. Scheduling of irrigation at 80 per cent Ep resulted in significantly higher vine length. At higher levels of irrigation (80 per cent Ep) yield and number of pods per plant were higher whereas, length and weight of pods, and number of seeds per pod were not influenced by the levels of irrigation. Mulching significantly influenced yield and yield attributing characters like number of pods per plant, and length and weight of pods but had no influence on number of seeds per pod and protein content of pods. Plants receiving 125 per cent RDF resulted in significantly higher yield and yield attributing characters like number of pods per plant, number of seeds per pod, length and weight of pods compared to 75 and 100 per cent RDF. Per se and interaction effects of irrigation, mulching and fertilizer were not significant with respect to days to first flowering, first fruit set, first harvest, days from flowering to harvest, number of harvests, duration of the crop and protein content. Weed growth in terms of fresh and dry weight was not influenced by levels of irrigation while mulched plots recorded significantly lower weed growth than the unmulched plots. Among the fertilizer levels, 125 per cent RDF resulted in higher weed growth. Organic carbon content, available nitrogen, available phosphorus and available potassium on 45 DAS and at final harvest were the highest in treatments receiving 125 per cent RDF whereas, the highest pH and the lowest EC were recorded in 75 per cent RDF. Interactions between levels of irrigation, mulching and fertilizer when considered together, had significant effect on vine length, all yield attributes, weed growth and all soil parameters. The vine length, yield, yield attributes like length and weight of pods and soil nutrients were the highest when irrigation was given at 80 percent Ep along with mulching and 125 per cent RDF (I1M1F3). This was statistically on par with the treatment I2M1F3 in which irrigation was limited to 60 per cent Ep. An increase of 3.4 times was there in yield in the treatments I1M1F3 and I2M1F3 over conventional channel irrigation at 3 days interval with 100 per cent RDF (control). The highest BC ratio of 1.83 was obtained for the treatments I1M1F3 and I2M1F3 (60 and 80 per cent Ep with mulching, 125 per cent RDF). Irrigation at 60 or 80 per cent Ep along with 125 per cent RDF and mulching with white on black polythene was found to be the best treatments.Item Studies on fertigation in yard long bean (Vigna unguiculata subsp. sesquipedalis (L.) Verdcourt)(Department of Agronomy, College of Agriculture, Vellayani, 2016) Elsa Giles; Sheela, K R