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2001 - 20024
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Subject: Soil Science and Agriculture Chemistry × End date: 2002 × Start date: 2001 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Effect of major nutrients on the yield and quality of nuts in graft-raised cashew (Anacardium occidentale Linn.)
    (Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 2002) Nair Rajiv, R K; KAU; Sam, T Kurumthottical  
    An experiment was conducted to study the "Effect of major nutrients on the yield and quality of nuts in graft raised cashew" at Cashew Research Station Madakkathara Kerala. The treatments consisted of three levels each of N, P and K on eight year old cashew trees. The salient findings are abstracted below. The study revealed that increasing levels of nitrogen significantly increased the height and spread of cashew trees, while the girth was significantly increased by the interaction effects of nitrogen and potassium. The yield parameters such as number of flushes, number of leaves per flush, number of panicles and the number of nuts per panicle were significantly enhanced by the application of nitrogen at increasing levels, while the application of phosphorus at increasing levels also significantly increased the number of nuts per panicle. The yield of cashew nuts and apples were significantly increased due to the highest level of nitrogen applications. Application of potassium at the highest level also significantly increased the apple yield per tree. Weight and volume of cashew apples was significantly increased by the application of increasing levels of potassium but nitrogen application was found to significantly decrease the weight of fruits. The juice percentage was positively and significantly influenced by the application of nitrogen and potassium. Potassium applications were found to significantly increase the nut length and weight while nitrogen applications were found to reduce the nut weight. Shelling percentage of cashew nuts was enhanced by the application of nitrogen and potassium at increasing levels. The kernel weight was increased due to the application of potassium. Ascorbic acid content of cashew apples was positively influenced due to the application of increasing levels ofNPK. The Total Soluble Solids of the apple was significantly enhanced by the application of nitrogen. Applications of nitrogen alone and in combination with phosphorus were found to increase the protein content of kernels. The carbohydrate, Non-reducing sugars and reducing sugars content of kernels were significantly enhanced by the application of different levels of nitrogen. Increase in the soil major nutrient content due to the individual effects of nitrogen, phosphorus and potassium applications were also observed. The leaf phosphorus and potassium content was enhanced specifically due to the application of increasing levels of phosphorus and potassium respectively, while the nitrogen content of leaves was positively influenced by the application of nitrogen and phosphorus. The average nutrient off-take through nuts and apples was computed to be 279.43, 4l.58 and I 86.40g of nitrogen, phosphorus and potassium respectively. The average nutrient off take per tree through nuts from an average yield of 2.89 kg tree" was found to be 93.56, 2.89 and 48.85g of nitrogen, phosphorus and potassium respectively and through apples was found to be 185.87, 38.69 and 137.54g of nitrogen, phosphorus and potassium respectively from an average yield of 18.20 kg tree". In 'general, among the major nutrients applied at different levels only nitrogen had shown exceedingly high effects in sustaining the growth, yield and quality parameters. The yield and quality parameters were also seen to be affected to a certain extent by potassium applications but the response of the crop to phosphorus was seen to be exceedingly limited.
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    ThesisItemOpen Access
    Substitution of muriate of potash by common salt in banana Musa (AAA group CAVENDISH subgroup) ‘Robusta’
    (Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2001) Sunu, S; KAU; Sudharminidevi, C R
    A field experiment was conducted III the College of Agriculture, Vellayani during August 1999 to June 2000 to study the extent of substitution of K of muriate of potash by Na of common salt in banana cv. Robusta. Four treatments involving four levels of K at 25, 50, 75 and 100 per cent of recommended dose and four treatments substituting K with N a at 25, 50, 75 and 100 per cent were tried in RBD with three replications. The plant growth parameters like plant height, pseudostem girth, number of functional leaves and LAI varied significantly due to treatments at all growth stages. These parameters in the 100 per cent K and 50 per cent K plus 50 per cent Na treatments were on par at all growth stages. Chlorophyll content and RLWC showed an increase with the addition of Na along with K. Highest bunch yield was recorded in the 50 per cent K plus 50 per cent N a treatment followed by the yield in the lOO per cent K treatment. The yield attributes like length of bunch, number of hands per bunch, number of fingers per bunch, length and girth of fingers reflected similar trends. The quality of fruits as reflected in the total soluble solid content, total sugar content and acidity was as good in 50 per cent K plus 50 per cent N a treatment as in 100 per cent K treatment. With increase in the levels of substitution above 50 per cent there was reduction in total soluble solids and sugar content. Shelf life of fruits did not vary significantly due to treatments. Pulp/peel ratio in the 100 per cent K and 50 per cent K plus 50 per cent N a treatments were on par. Pulp/peel ratio decreased significantly with increase 10 substitution of K by Na above 50 per cent level. The uptake of nutrients except N a was higher at the 50 per cent K plus 50 per cent N a treatment and decreased with increase in substitution of K by Na above this level. Na uptake increased upto 75 per cent substitution of K by N a and decreased at 100 per cent substitution. The treatments did not have any influence on the soil physical and chemical p-roperties. Bunch yield was positively and significantly correlated to plant girth (2MAP), chlorophyll content and LA!. It can thus be concluded that upto fifty per cent of the K requirement of Robusta banana, grown in soils of low K status, can be replaced by Na of common salt.
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    ThesisItemOpen Access
    Methods to increase the efficiency of rajphos (jamarkhotra rockphosphate) in the black soils of Palakkad district for rice
    (Department of Soil Science and Agriculture, College of Agriculture, Vellayani, 2002) Vyas, N G; KAU; Surendran Nair, C
    There has been considerable interest in studying the efficiency of rockphosphate for direct application to the soil in the rice farming situations of Kerala, particularly tapping the iron - to - magnet type of relationship between rockphosphate and acid soils. However no work has been done in the neutral to alkaline soils of Kerala located in the Chittoor Taluk of Palakkad District to utilize the potential of rockphosphate. These soils are inherently poor In phosphorus and the situation 1S furthur complicated by the high P fixation capacity. Problems of fixation of soluble P can be alleviated to some extent by the use of less soluble forms like rockphosphate in conjunction with acid forming amendments like iron pyrites. sulphuric acid and P solubilising micro organisms. A study was undertaken to investigate the effect of direct application of rockphosphate in combination with amendments for rice in the Department of Soil Science and Agricultural Chemistry at the College of Agriculture, Vellayani. There were two experiments, an incubation study to investigate the relative efficacy of various amendments in releasing soluble P from rockphosphate and a pot culture experiment to study the comparative efficiency of rock phosphate with amendments. Incubation experiment shows an Increase In P fractions like saloid-P, occluded-P, reductant-P, Fe-P, AI-P and Ca-P upto 45 days which decreased subsequently with the advancement of time. The values stabilized towards the last observation at around 90 days of incubation which was higher than the initial starting values. Rock phosphate acidulated with sulphuric acid and amended with pyrite at all levels of P addition increased P fractions. Inoculation of phosphobacterin was also effective though the release of P was slightly lower than treatment with chemical amendments. In the pot culture experiment growth and yield character of crop were significantly influenced by treatments receiving rockphosphate amended with direct acidulation and pyrite application at all levels. Rajphos @ 45 kg ha' with 50 per cent acidulation was found to be on par with the treatment receiving Rajphos @ 30 kg ha" with 50 per cent acidulation. Rajphos treated with acid perform equally well as SSP and the results were comparable. The grain and straw yield and uptake of pi ant nutrients were significantly superior for treatment consisting of acidulated rockphosphate. Chemical amendment like iron pyrite and microbial inoculation with phosphobacterin was also found to be efficient but the effect was not significant statistically.
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    ThesisItemOpen Access
    Yield maximization in banana cv. Nendran through systematic approach of fertilizer use in the red loam soils of Vellayani
    (Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2002) Prakashmani, N; KAU; Sumam Susan, Vargheese
    In order to achieve maximum yield with minimum fertilizer and to develop an economically viable fertilizer recommendation in banana cv. Nendran, a 'systematic approach' in fertilizer use was experimented in red loam soils of Vellayani, Kerala. The initial nutrient status of soil and the data already generated by Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani (Susan, 2000) on sorption capacity of soil were utilized to formulate the optimum treatment for greenhouse nutrient survey study using sorghum as the indicator crop. The design of the experiment was CRD with fourteen treatments and three replications. The nutrient elements N, K, Ca and Mg were found to be deficient in the soil through this study. The treatments of the field trial were also generated from the results of greenhouse nutrient survey study. The nutrient elements which were found deficient were added in the field trial in different combinations. The treatments composed of four levels of each of fertilizer N (60, 120, 180, 240 g plant"), K20 (80, 160, 240, 320 g plant."), Ca (0, 190, 380, 570 g plant-I) and a single level of Mg (120 g plant-I). These treatments were compared with the control and POP recommendations. The design of the experiment was RBD and there were two replications of thirteen treatments. The treatments T 4 which was the optimum treatment, T 5 with maximum N applied and T 8 with maximum K applied, showed higher values along with POP in growth as well as yield characters of the crop. The marked effects of these treatments than the others indicate the significance of 'systematic approach' studies in banana. The cost of fertilizer nutrients highly influenced the value-cost ratio. The optimum treatment T 4, though gave higher yields, showed lower value- cost ratio due to the high cost of Ca fertilizer lime. Though 'systematic approach of fertilizer use' could be followed satisfactorily, the crop requirement also be taken into consideration in the case of heavy nutrient exhausting crops like banana. The insignificant effect of Ca on growth and yield of banana was also proved through this study.