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ThesisItem Open Access Foliar diagnosis, yield and quality of pepper (Piper nigrum L.) in relation to nitrogen, phosphorus and potassium(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 1982) Sushama, P K; KAU; Jose, A IPepper vines of variety, Panniyoor-1, of the NPK fertilizer trial maintained at the Pepper Research Station, Panniyoor, Canncanore District were selected for the collection of tissue samples under the present study during 1979-81. The experiment was laid out in a 33 factorial design in a randomized block design, confounding the effect of NP2K2 totally. In order to standardize the best leaf position for foliar diagnosis, the mature leaves of fruit bearing laterals were numbered from the youngest to the oldest, taking the youngest fully matured leaf as the first and they were collected separately. The most suitable season for the collection of leaf intended for foliar diagnosis was also standardized by drawing samples of first mature leaf at different stages of growth of the vine. The suitability of different types of stem of the plant such a runner shoot, top shoot, fruit bearing lateral and hanging shoot for tissue analysis was also examined. For studying the variations in the oleoresin content of berry as influenced by fertilizer nutrients, the berries were sampled at different stages of maturity. The first mature leaf better reflected variation in the levels of application of nitrogen to the vine. As the phosphorus and potassium contents of the first mature leaf established significant positive correlation with yield of pepper, it is recommended as an index for foliar diagnosis in pepper in relation to nitrogen, phosphorus and potassium status of the vine. The period just prior to flushing is the most suitable season for the collection of leaf samples intended for foliar diagnosis. During this period, the first mature leaf is sensitive to application for different levels of nitrogen and its potassium content established significant positive correlation with yield. For assessing the phosphorus status of the vine, the runner shoot appeared to be a better tissue as its phosphorus content established a high degree of correlation with yield. As compared to other types of stem, the highest content of potassium was found in the fruit bearing laterals. The periods of maturity significantly influenced the phosphorus, potassium and oleoresin contents of the berry. Their contents increased from four to six months after flowering and then decreased. The graded doses of nitrogen, phosphorus and potassium and their interaction failed to influence the percentage of oleoresin content of pepper.ThesisItem Open Access Characterisation of soil organic matter in different soil types of Kerala(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 1982) Usha, P B; KAU; Jose, A ILarge number of surface soils representing the different districts of the state were analysed in order to work out precise relationships between organic carbon, total nitrogen and available nitrogen in these soils. The soils were categorized into different groups based on soil texture and content of organic matter. Relationships between different soil properties applicable to the different categories of soil were then examined. Fractionation of soil organic matter was carried out in a limited number of soils. Also the distribution of elemental components of soil organic matter was studied in soils selected for the fractionation of organic matter. Observations on the general characteristics of soil revealed that the content of organic carbon, total nitrogen and available nitrogen showed an increasing trend with increase in acidity of soil. In general more organic carbon was seen in fine textured soils. The total and available nitrogen content of soil increased with increase in content of organic matter. The content of available nitrogen showed significant and positive correlation with total nitrogen. Since the C/N ratio increased with increase in content of organic carbon it was necessary to predict the total and available nitrogen content of soil based on precise regression equations rather than depending on a conversion factor. On an average 10.82 per cent of the nitrogen in soil was extracted as available nitrogen. The C/aN ratio was positively and significantly correlated with organic carbon and total nitrogen while it was negatively correlated with available nitrogen. On an average the percentage of humic acid, fulvic acid and humin in soil organic matter were 28.28, 36.51 and 35.21 respectively. Of the 28.28 per cent humic acid, 9.60 per cent (of organic matter) was represented by hymatomelanic acid and the remaining 18.68 per cent by the insoluble fraction of humic acid. Humic acid was found to be significantly and positively correlated with total organic carbon, total nitrogen, clay and fulvic acid. Of the total fulvic acid 12.35 per cent (of organic matter) was represented by beta humus and the remaining by the soluble fraction of fulvic acid. Fulvic acid was positively and significantly correlated with organic carbon, total nitrogen, humic acid and clay. Humic acid and fulvic acid maintained a constant proportion irrespective of the variation in content of total organic matter. Humin was also positively and significantly correlated with organic carbon and total nitrogen. The mean phosphorus, sulphur and potassium content of organic matter were 0.051, 6.96 and 0.32 per cent respectively. The C/org.P, C/org.K, C/org.S, N/org.P, N/org.K, N/org.S, Org.P/org.K, Org.P/org.S and Org.K/org.S ratios were 1672.8, 94.1, 19.23, 205.81, 9.77, 2.91, 0.07, 0.008 and 0.0073 respectively.ThesisItem Open Access Pedologic studies on lateritic catenary sequences occuring in Kerala(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1980) Venugopal, V K; KAU; Koshy, M NThree toposequences were identified at Varkala, Poruvazhy and Kalliaserry in the midland laterite regions of Kerala using soil maps prepared by the Soil Survey Wing of the Department of Agriculture. A systematic study of these catenary sequences along transects extending from crest to valley was made. Profile pits were dug at the different physiographic positions of the transects, viz., crest, upper midslope, nearly level lower slope and valley at each of these sites are examined for their morphological features. Soil samples representing the different horizons were also collected for laboratory studies. The physicochemical charecteristics, mineral assemblage of fine sand fraction and the minerology of the clays in the profile samples were studied with a view to relating these properties to the genesis of the four diverse groups of soils formed in the transects . Patterns of similarity or otherwise between the three locations of widely different conditions and the four physiographic positions were brought out .ThesisItem Open Access Studies on the effect of varying levels of zinc on the growth and yield of rice(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1980) Krishnan Namboodiri, K; KAU; Ramasubramonian, P RA field experiment was conducted in a cultivators field at Edathua (Kuttanad) to study the effect of different levels and methods of zinc application on the growth and yield of rice (var. Jaya). Soil application of 0, 10, 20 and 30 kg zinc sulphate per hectare: foliar application of 0.25per cent and 0.5 per cent zinc sulphate, root dip in 2 per cent zinc oxide suspension , lime at 150, 300 and 600 kg CaO per hectare and their combinations were included in the treatments. The field was selected on the basis of a low content of available zinc (EDTA extractable). Observations were recorded on the growth parameters and yield characters . The chemical analysis of the plant material for N, P, K, Ca, Mg and Zn at harvest were also carried out . The different growth parameters studied, recorded a significant increase in the grain yield could be obtained by zinc application . Foliar application of 0.5 per cent zinc sulphate and soil application of 20 kg zinc sulphate per hectare recorded the maximum yield of grain. These treatment yielded more than 20 per cent grain over control and were statistically on per. There was no significant increase in the mineral contents in the plant by zinc application, except zinc and phosphorus.ThesisItem Open Access Nutritional status of soil and plant in relation to the incidence of chenthal disease of cardamom(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1983) Dileep Kumar, K N; KAU; Alice AbrahamAn investigation was carried out at the College of Agriculture, Vellayani, to study the nutritional status of soil and plant in relation to the incidence of chenthal disease in three major cultivars of cardomom viz., Vazhukka, Malabar and Mysore. Soil and plant samples for the study were collected from the cardamom plantations in the High Ranges of Idukki district of Kearala State during March, 1982 (Pre-monsoon period) and September, 1982 (Post-monsoon period)ThesisItem Open Access Release of soluble aluminum in soils under submerged conditions and its effect on rice(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1984) Alice Abraham; KAU; Koshy, M MA study has been made of the extent of aluminium toxicity in relation to other important characters in the acid Rice soils of Kerala with a view to evolving suitable ameliorative measures. The submerged wet-land rice soils of Kerala showing a pH value of less than 6.0 were found to contain appreciable amounts of exchangeable aluminium. The aluminium saturation of the total and effective CEC of these soils were also very high and above the critical limits for rice. Flooding of these soils in water resulted in a rise in pH and EC, as well as water soluble and exchangeable iron. Peak values for these parameters were obtained by 20-30 days of flooding, after which the pH remained steady while EC and iron showed a decreasing trend . Water soluble and exchangeable aluminium, on the other hand, registered a significantly lower content after the 6th day and the trend continued till the 30th day.ThesisItem Open Access Nature of acidity in upland and rice fallows in relation to response of pulse crop to liming(Department of Soil Science and Agricultural Chemistry,College of Agriculture, Vellayani, 1983) Sudharmai Devi, C R; KAU; Aiyer, R SSoils over vast areas of uplands and rice lands in Kerala are acidic in nature. High concentrations of Al and Mn often limit the productivity of pulses when grown in these areas. The present investigation was aimed at detecting the toxic factors causing acidity and locating suitable varieties of cowpea and blackgram suited to these soil situations. It was further programmed to find out the optimum levels of lime that would be required to arrive at a low input management programme for pulses. For this purpose a large number of soil samples were analysed. Several pulse varieties were screened in respect of their tolerance and a pot culture study was conducted to assess their productivity, the results of which are summarised and appropriate conclusions drawn. The collected soils were acidic in nature, the factors causing toxicity being high concentration of Al and Mn. The soils require large amount of lime as amendment. Cation exchange capacity of these soils is very low and to some extent contributed by Al and Mn. Screening experiments were conducted to select varieties which are tolerant to Al and Mn toxicity. As a result S-488, a cowpea variety and Velloor, a blackgram variety were selected as tolerant ones. Comparative assessment of the yielding ability of the selected varieties, with the recommended varieties New Era (cowpea) and T9 (Blackgram) revealed that they could yield as much as or even better than the recommended varieties. The recommended varieties require high doses of lime for a substantial yield whereas the selected varieties could give economic yield with practically no liming. The observations on number of pods, grain yield, haulm yield and number of nodules revealed that the two selected varieties could excel the others in these aspects Uptake studies indicated that the increased yield in the case of the selected varieties is mainly due to the enhanced uptake and fixation of N and uptake of P and K. From the results of the study, it was concluded that the cowpea variety S-488 and the blackgram variety Velloor can be cultivated successfully under acid soil conditions. They possess the ability to give economic yields with little or no liming. These results have to be tested in farmers 'fields to evolve a low input management strategy for pulse cultivation in garden lands as a vegetable in kharif season and in the rice fallows in summer season.ThesisItem Open Access Evaluation of the role of elements Ca, Mg, S and B in the nutrition of groundnut with reference to monovalent (K) to divalent (Ca + Mg) catonic ratios(Department of Soil Science and Agricultural Chemistry,College of Agriculture, Vellayani, 1984) Suresh Kumar, P; KAU; Aiyer, R SThesisItem Open Access Effect of lime and different forms of phosphorus on the growth(Department of Soil Science and Agricultural Chemistry,College of Agriculture, Vellayani, 1984) Latha, R; KAU; Koshy, M MA field experiment was conducted in the College of Agriculture, Vellayanl on a sandy clay loam soil (Alfisol) of pH 4.9 to study the effect of three levels of lime,0, 500 and 1000 kg per hectare and three levels of phosphorus, 50, 100 and 150 kg PgĀ°5 Per hectare in two different forms, on the growth, yield and chemical composition of cowpea. The field trial was laid out as a (3x7) factorial RBD with two replications. The study revealed that lime application significantly increased some of the- growth characters of cowpea. Application of lime at 1000 kg per hectare significantly increased the number of branches on the 60th day of sowing. The highest application rate of 1000 kg per hectare increased the length and dry weight of root on the 30th day, fresh weight of nodules on the 60th day and the number of leaves at all the stages of growth. Liming at 500 kg per hectare increased the yield and yield components of cowpea significantly, such as the dry weight of the pods per plot, weight of seeds per plot and the hundred seed weight. The highest grain yield of 408.3 g per plot (1418.0 kg per hectare) v/as obtained for lime applied at this rate as compared to the control (1172.0 kg per hectare). Lime application at 500 kg per hectare significantly increased the phosphorus content of the plant on the 60th day and the calcium content on the 30th day. The calcium content was Increased on the 45th day also by the highest level of lime application. Lime application at 1000 kg per hectare significantly reduced the potassium content of the plant on the 30th day. Application of lime at 500 kg per hectare significantly increased the phosphorus and calcium contents of the seed. But the magnesium content of the seed was reduced significantly by lime at both levels.