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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 I
Pepper 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.
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 I
Large 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.
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 Abraham
An 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)
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 S
Soils 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.
Open Access
Effect of potassium nutrition on the yield and quality of cassava
(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1983) Gopalakrishnan Nair, P; KAU; Aiyer, R S
Investigations were carried out as the College of Agriculture, Vellayani to find out the optimum dose and time of application of potassium to conserve in relation to yield and quality. For this purpose a seed culture experiment with nutrient solutions at varying duration of it application and a microplot field experiment with different levels of E were conducted during 1977-80. Before conducting the field experiment, two crops of cassavawere taken in the same plot without applying potassium and thus bringing down the available K to a low level.
Open Access
Foliar diagnosis, yield and quality of turmeric(Curcuma longa L.) in relation to nitrogen, phosphorus and potassium
(Department of Soil Science and Agricultural Chemistry,College of Horticulture, Vellanikkara, 1981) Saifudeen, N; KAU; Jose, A I
A field experiment was carried out at the Instructional Farm of the College of Horticulture, Vellanikkara during 1979-80 to study the effect of graded doses of nitrogen, phosphorus and potassium on the growth, nutrient uptake, yield and quality of turmeric and also to develop suitable foliar diagnosis techniques in relation to these nutrient elements. The treatments comprised of three levels each of nitrogen (0, 20 and 40 kg N/ha), phosphorus (0, 20 and 40 kg P2O5/ha) and potassium (0, 40 and 80 kg K2O/ha). The experiment was laid out in a 33 factorial experiment in randomized block design, confounding the effect of interaction NP2K2 totally. Results revealed that among the morphological characters studied, the number of tillers per clump responded to the increasing levels of nitrogen whereas number of leaves per tiller decreased with increasing levels of nitrogen. The height of tiller was not influenced by any of the fertilizer treatment. The fresh and dry weights of rhizome and total dry matter yield remained unaffected by the levels of nitrogen and phosphorus. The total dry matter production was influenced by the levels of potassium and NK interaction. Maximum production of dry matter took place at K1 level which was superior to those at K0 and K2 levels. Levels of nitrogen, phosphorus and potassium and their interaction failed to influence the yield of turmeric at harvest. The uptake of nitrogen, phosphorus and potassium was not found influenced by the levels of nitrogen and phosphorus employed. But levels of potassium significantly influenced the uptake of these nutrient elements, the K1 level being superior to K2 and K0. There was a continuous increase in the number of tillers per clump, number of leaves per tiller and height of tiller with advancing period of growth. A period of pronounced and active vegetative growth was observed during the period between 120th and 150th day. Fresh and dry weights of rhizome increased with increasing age of the crop and attained maximum at harvest. Uptake of nitrogen, phosphorus and potassium steadily progressed with advancing age of the crop. Maximum uptake of nitrogen and phosphorus took place during the period from 120th day to 150th day whereas the uptake of potassium was maximum during 180th day to 210th day after planting. The contents of nitrogen, phosphorus and potassium were highest in the top most leaf and continuously decreased with increasing number of the leaf position when the leaves are numbered from top to bottom of the tiller. In consideration of the stability of the nutrient level with leaf positions and correlation with uptake of nutrients, the third leaf appeared to be the best suited for foliar diagnosis of nitrogen, phosphorus and potassium status of the crop. The period between 90th to 120th day after planting was recommended as optimum period for the detection and amendment of the nutrient status of the crop. The graded doses of nitrogen, phosphorus and potassium and their interaction failed to influence the percentage of oleoresin content of turmeric.
Open Access
Foliar diagnosis in coconut (Cocos nucifera, Linn.) in relation to nitrogen, phosphorus and potassium
(Department of soil science and agricultural chemistry, College of Horticulture, Vellanikkara, 1981) Gopi, C S; KAU; Jose, A I
A study was undertaken to standardise the foliar diagnostic technique in coconut palm in relation to nitrogen, phosphorus and potassium, making use of the experimental palms of a permanent NPK trial maintained at the Coconut Research Station, Balaramapuram, Trivandrum District. The palms of this experiment received applications of nitrogen, phosphorus and potassium in three levels each viz., 0, 340 and 680 g nitrogen per palm per year, 0, 225 and 450 g P2O5 per palm per year and 0, 450 and 900 g k2O per palm per year. For the standardization of tissue for foliar diagnosis, samples of leaf lamina and mid-rib were drawn separately from all the leaves of the experimental palms. Attempts were also made to establish critical levels of nitrogen, phosphorus and potassium in the leaf and also to work out regression models to predict yield based on the tissue content of these nutrients. Observations revealed that the number of leaves retained by the palm was mainly a function of potassium applied. The number of leaves retained by the palm significantly correlated with the yield(r = 0.93**). The potassium content of lamina of the 2nd leaf can be predicted from the number of leaves retained, making use of the regression equation, Y = 5.32 + 8.95 x where x is the potassium per cent of leaf lamina and Y is the number of leaves retained. The number of leaves retained was also found to be significantly correlated with yield (r = 0.708**). The percentage of nitrogen in the leaf lamina increased with increasing age of leaf till leaf number 6 and thereafter steadily declined. The phosphorus and potassium contents of the leaf were maximum in the youngest leaf and declined with increasing age of leaf. Palms receiving higher levels of nitrogen and potassium retained correspondingly higher contents of nitrogen and potassium in leaf lamina. Application of different levels of phosphorus gave only marginal difference in the percentage of phosphorus in leaf lamina. The nitrogen content of leaf lamina of different leaf position was significantly correlated with yield, the highest coefficient of partial correlation of 0.777** being registered for the 10th leaf, followed by 0.699**for the 2nd leaf. The phosphorus content of leaf lamina failed to establish significant correlation with yield, irrespective of leaf positions. The coefficients of partial correlation between yield and potassium per cent of lamina of leaf positions 2, 3, and 6 were significant, the highest value of 0.663** being recorded for the second leaf. Taking the percentage of nitrogen (N) and potassium (K) in the lamina of 2nd leaf and leaf number (L) as independent variables, yield can be predicted with an accuracy of 84 per cent (R2 = 0.84**) by the regression model, Y = -14.956 + 39.215 N – 16.097 N2 + 83.873 K – 37.388 K2 -11.046 L – 0.202 L2 – 44.186 N x K + 5.529 N x L + 6.276 K x L. The yield can also be predicted with an accuracy of 72 per cent by the regression model, Y = -64.29 + 23.356 N + 1.779 L where N is the nitrogen percentage of lamina of 2nd leaf and L is the number of leaves retained. The critical values for nitrogen and potassium in the leaf lamina of 2nd leaf were found to be 3.31 per cent for nitrogen and 2.17 per cent for potassium. The pattern of distribution for nitrogen, phosphorus and potassium in the leaf mid – ribs was almost similar to the pattern of distribution of those nutrients in the leaf lamina. The coefficients of partial correlation between yield and nitrogen content of leaf mid-rib of leaf positions 6, 14, 15 and 18 were statistically significant, the highest value of 0.677** being recorded for the 14th leaf. The phosphorus content of mid-rib failed to establish significant correlation with yield. The coefficients of partial linear correlation between yield and potassium per cent of mid-ribs were significant for leaf positions 1, 2, 3, 4, 5, 6, 7 and 10, the highest value being recorded for the 4th leaf (r = 0.762**). The multiple correlation coefficient between yield and percentage of nitrogen, phosphorus and potassium was highest (R = 0.771**) for the lamina of the second leaf, among all the position and types of tissue examined and hence, this tissue is recommended as the best tissue for the foliar diagnosis of nitrogen, phosphorus and potassium.
Open Access
Increasing nitrogen use efficiency in upland soils
(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1982) Sathianathan, K M; KAU; Padmaja, P
An investigation was carried out at the College of Agriculture, Vellayani, during the year 1980-81 to study the efficacy of the use of some of the commonly available non-edible oilcakes as nitrification inhibitors to increase the nitrogen use efficiency in rainfed upland soils of Kerala. Urea was mixed with neem, mahua, maroti, rubber or karinja cakes at 5:1, 5:2 and 5:3 ratios (urea : oil -cake) to obtain a blend. The mineralisation pattern of those blends were studied along with untreated urea in an incubation study in a typical red loam upland soil kept at 60 per cent field moisture capacity to screen them for nitrification inhibitory properties. Selected blends at the most efficient ratio of mixing were tried in the field at 3 levels of nitrogen supply with cassava as the test crop. The experiment was laid out in randomised block design in factorial structure.
Open Access
Aggregate size distribution and its relationship to physical and chemical properties of some typical soils of Kerala
(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 1983) Ushakumary, K; KAU; Leela, K
The present study was undertaken to evaluate the structural indices of some typical soil groups of Kerala namely, laterite, black, red loam, riverine and coastal alluvium and to relate them to some physico-chemical properties of soils. Soil groups were selected from five extensively occurring series namely, Velappaya, Valiavallampathy, Vellayani, Ponnamattom and Beypore series covering Trichur, Palghat, Trivandrum, Ernakulam and Calicut districts, respectively. Three profiles were chosen from each series and from each profile, samples were collected at four depths viz., 0-15, 15-30, 30-45 and 45-60 cm. The experimental results revealed that the aggregates greater than 0.25 mm were found to be in appreciable amount in all the soils except for few layers in riverine and coastal alluvium. This indicated good structural status of the soils. Black soils have distinctly superior aggregation in comparison to the rest of the soils under investigation. Some of the physico-chemical properties like clay, organic matter, CEC and sesquioxide plays an important role in building soil structure in most of the soil group except riverine alluvium. This is because of the comparatively recent origin of riverine alluvium soils. The texture of the soils varied from clay to loam. The black soils were exclusively clay in texture. Riverine alluvium and coastal alluvium were found to be of clay loam and sandy clay loam in texture, respectively. An increase in finer fraction content with depth was observed. Black soils could retain more water at any given tension and were also superior in available water status. Infiltration rates were high in all soil groups except for black soil and riverine alluvium which were uniformly finer in texture. Except black soils, all other soils were acidic in reaction and have comparatively low CEC. Black soils showed highest value for CEC. Laterite and red soils were richer in sesquioxide content compared to other soil groups. Thus the results clearly indicates that black soils were relatively well aggregated as compared to other soil groups. They were also superior to other soil groups in respect of CEC and available water status, Laterite, red loam and coastal alluvium soils were highly pervious whereas black and riverine alluvium soils relatively less pervious. The former groups of soils were also very poor in respect of their available water status. The rate and stability of aggregation in these soils were more or less of similar type.

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