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ThesisItem Open Access Mechanical control of the floating type aquatic weed salvinia wolesta (African payal)(Department of Agricultural Engineering, College of Horticulture, Vellanikkara, 1981) Sankaranarayanan, M R; KAU; Jose, SamuelSalvlnia molesta, locally known as ’African Payal‘ is a noxious floating type aquatic weed of common occurance, particularly in the State of Kerala in India* The infestation is the heaviest in the Kuttanadu region and in the Kole lands of Trichur District of the State, where alone more than 50,000 hectares of inland water surface is under the grip of this weed. In the present project, the possibilities of mechanical control of the Salvinia weed were investigated* The study concentrated on the development and evaluation of a prototype Salvinia harvesting Machine which utilised a novel design concept of fluidising the mass by means of a centrifugal* ejector pump combination* The machine consisted of two 5 H.P portable pumpsets as the prime mover and an ejector system mounted on a floating platform. The machine pump out the weed-water mixture into a floating filtering unit at zero lift from which the water was drained by gravity, the material was automatically loaded into a country boat. The results of tests conducted indicated that the 10 H.Pmachine was capable of pumping the Salvinia weed at an average rate of 16 T/hr at zero lift conditions. The proportion of the weed pumped was of the order of 15 % by weight of the secondary flow when pump¬ing water alone. The special features of this equipment were that it could utilise conventional Irrigation punpsets as the prime mover and that it did not allow the weed materials to be drawn into and clog the primary pump. The machine was also capable of being operated as a self propelled unit. In this project, certain accessory units such as a gather¬ing arm, a floating fence and an automatic filtering unit were also successfully developed and evaluated* In addition to load¬ing the material into a country boat, a disposal technique of pumping the weed materials into a field fermentation pond, which avoided any immediate transportation costs for the harvested material, was also investigated. It was found that the bulk density of Salvinia was of the order of 400 kg/n3. It was also found that the spread density value of the weed, depending on the stage of growth and degree of packing, could vary from 8 T/ha to 32 T/ha. A representative value for the spread density, under the still water condition at Kuttanadu, was found to toe of the order of 16 T/ht. This meant that the prototype Salvinia Harvesting Machine would be capable of clearing the weed from a hectare in 10 working hours* The estimated cost of such an operation amounted to Rs.280/- per hectare which compared favourably with the reported costs of Rs.900/- to Rs.2700/- per hectare for manual collection and disposal of the weed. It is considered that the present work is a signi¬ficant contribution to solving the problem of African Payal infestation in Kerala State.ThesisItem Open Access Hydraulics of border strip irrigation on level or nearly levely rice fields(Department of Agricultural Engineering, College of Horticulture, Vellanikkara, 1983) Visalakshi, K P; KAU; George, T PIn Kerala, more than seventy per cent of the double cropped rice fields lie fallow during summer months. Rice cannot be grown during this season because of the limited availability of water and the very low water use efficiency that can be attained during this season. The development of a technology for efficient use of limited water available during summer is necessary to make use of these rice fallows for cultivating crops other than rice. As most of the area is under paddy during first and second crop seasons, the level of the land cannot be disturbed. But now, there is no any satisfactory method of irrigation suitable for irrigating nearly level rice fallows. The objective of this project was to study the hydraulics of border strip irrigation in nearly level lands and to recommend suitable specifications. The experiment was done at the Agronomic Research Station, Chalakudy during 1981-82. It consisted of five replications of four treatments. The treatments were two widths of 4m and 6m combined with two discharge rates of 2 1/sec/m and 4 1/sec/m, the length of strip in all cases being 45m. The surface gradient was 0.03815 per cent in the direction of natural slope. Altogether seven irrigations were given at an interval of seven days. Blackgram seeds were dibbled in the field after the first irrigation and cultural practices as recommended in the package of practices were followed. The time of advance of waterfront, the depth of flow and the time of recession of tail water were observed at every 5m length for each strip. The cutoff length was chosen as 77 per cent from the upstream end. The hydraulic gradient, hydraulic resistance and velocity of flow for each irrigation were determined. The advance and recession curves were drawn. The results of the experiment revealed that a discharge rate of 2 1/sec/m is the best for irrigating nearly level borders of 4m and 6m widths. The depth of irrigation could be limited to 5 cm even in soils having high rate of infiltration. The lower discharge rate of 2 1/sec/m reduced the time of ponding at the downstream end and this minimized the wastage due to deep percolation at the downstream end. Soil erosion in the strip was minimum at this rate of discharge, and long strips upto 45m length in loamy sand could be irrigated with high degree of efficiency. As only a low rate of discharge is required to practice this method, even in areas having limited availability of water, an additional crop can be profitably raised. It is estimated that the water needed to raise one hectare of rice in summer months can be more profitably used to raise about 4 ha. of any other crop. Hence, growing rice during summer season should be discouraged and the land should be utilized to raise other remunerative crops like pulses, oilseeds and vegetables. Now the Government has decided to provide water not only for rice but also for other seasonal crops during the summer months. But now, there is no satisfactory method of irrigation for nearly level fields. Border strip method of irrigation is hardly practiced anywhere in Kerala, even though this is a very popular method in the other parts of India for raising cereals, pulses and oilseeds. However, this method is practiced there on sloping lands. Since the present study revealed that this method can be practiced efficiently on level or nearly level fields, this is best suited for the rice fallows during the dry season. Most of the paddy fields have a mild natural slope in one directions. This slope can be used to advantage by laying the strips in the direction of natural slope. This method can be recommended to the farmers for raising a crop in the rice fallows. The specifications of border strips for nearly level lands are as follows: _______________________________________ Length of border - Upto 45m Width of border - 4 – 6m Rate of flow - 2 1/sec/m Slope - should be laid in the direction of natural slope Height of bunds separating the strips - 20 cm Base width of bunds - 30 cm __ThesisItem Open Access Utilization of "salvina molesta" (African payal) for bio-gas production(Department of Agricultural Engineering, College of Horticulture, Vellanikkara, 1983) Somashekaren Nair, S; KAU; Remadevi, A NAn investigation on 'Utilization of Salvinia molesta(African Payal) for bio-gas production' was conducted in the Agricultural Engineering Department, College of Horticulture , Kerala Agricultural University, with the objective of standardizing the conditions and identifying the best generator model for optimum gas production from salvinia. From the physical and the gas production characteristic studies, salvinia was recognised as a potential raw material for bio-gas production. For the pilot plant experiments a new design was fabricated and was compared with the adaptive designs of K.V.I.C model, Bhagyalekshmi model, and horizontal type K.A.U model.ThesisItem Open Access Development of a low cost garden tractor(Department of Agricultural Engineering, College of Horticulture, Vellanikkara, 1982) Sivaswami, M; KAU; Muhammad, C PThe study was conducted with the objectives of systematic analysis of components with respect to their kinematics, dynamics and ergonomics and evaluation of traction performance and economics of low cost garden tractor. A greaves Lombardini 5.4 hp diesel engine with 1800 rpm was selected and a simple three step speed reduction system having a single stage V belt drive and double stage chain drives with a pivotted countershaft clutch have been designed. A road speed of 6.635 kmph and field speed of 3.317 kpmh were achieved by using a cone pulley arrangement with 6.00 x 12 size wheel.Correct position of various components bringe the centre of gravity of the unit with and without implement at very close to the final drive axle for easy balancingThesisItem Open Access Development of small scale equipment for extraction of cocoa butter and production of cocoa powder(Department of Agricultural Engineering, College of Horticulture, Vellanikkara, 1982) Ganeshan, V; KAU; George, T PThe primary objective of this project was to evolve a viable technology and equipment system for small scale processing of cocoa beans. The study mainly concentrated on the development of an extraction unit for the separation of butter from cocoa mass. Various equipment required for small scale processing of cocoa beans were either identified or designed.