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Open Access
Anatomy and utilization of two cane species of Kerala
(College of Forestry, Vellanikkara, 1988) Mohan, Varghese; KAU; Bhat, K M
Variation in certain anatomical and physical properties has been investigated and compared in two rattan species, viz. Calamus thwaitesii and C. travancoricus, the former representing the larger diameter and the latter possessing small-diameter canes of kerala. Five stems possing more or less similar number of internodes have been sampled in each of two species. There were significant differences between the two species in certain physical properties such as length and diameter of internode, stem “wood” density and initial moisture content although volumetric shrinkage did not differ appreciably. Similarly, quantitative data for anatomical properties such as corted percentage, number of vascular bundles per unit area, vascular bundle diameter, xylem and phloem percentage, metaxylem vessel element and fibre dimensions were markedly different between the two species while the fibre percentage had almost similar values. With the exceptions of internode size and fibre width, the mean physical and anatomical properties in each species showed definite patterns of longitudinal variation, which could be best explained using quadratic regression models. However, patterns of longitudinal variation were different between the species in volumetric shrinkage, number of vascular bundles per mm2, vascular bundle diameter, phloem percentage, metaxylem vessel element and fibre length. The most important useful features in distinguishing between the two species are internode length, stem diameter, epidermal cell and its lumen shape, diameter and frequency of vascular bundles as well as the diameter of wide metaxylem vessels. The most important determining factors of “wood” density are fibre percentage, fibre wall thickness and lumen width as well as the diameter of metaxylem vessels although features like the size and number of vascular bundles per unit area also influences this property. Volumetric shrinkage and moisture content are inversely related to the density of “wood”. With higher density owing to more thick walled fibres and narrower wide metaxylem vessels, basal portion of the stem is harder and heavier than top portion.
Open Access
Yield and its components in groundnut under partial shade in coconut garden
(Department of Plant Breeding, College of Agriculture, Vellayani, 1988) Rajasree, M R; KAU; Gopimony, R
A study on the parameters of variability, heritability and genetic advance and correlation of pod yield with other components were undertaken in thirtyone varieties of groundnut to select genotypes having good yield and adaptability under partially shaded conditions of coconut gardens. The study was conducted during kharif 1987 at the Department of Plant Breeding, College of Agriculture, Vellayani, by raising the varieties in a randomised block design with four replications. Analysis of variance revealed significant differences among varieties for the characters like plant height, first date of flowering , flowering duration, pod yield per plant on fresh weight basis, pod number per plant, mature to immature pod ratio, pod yield per plot on fresh and dry weight basis, 100 pod weight, 100 kernel weight, shelling percentage, halum yield per plant and per plot on fresh and dry weight basis, harvest index, photosynthetic efficiency at reproductive phase, leaf area index at reproductive phase and Cercospora leaf spot disease score. Analysis of variance for chlorophyll-a, b and total pigments revealed that there was no significant difference among the varieties with respect to chlorophyll pigment content. Analysis of variance for shade intensity measured in each plot during vegetative and reproductive phase indicated the presence of uniform shade in the experimental field. High genotypic and phenotypic coefficients of variation, heritability and genetic advance were observed for hundred pod weight and mature to immature pod ratio, suggesting the reliability of these characters during the selection programme for the improvement of this crop. Correlation analysis of dry pod yield per plot with twentyfour characters revealed that fresh pod yield per plot, fresh and dry pod yield per plant, pod number per plant, halum yield per plot on fresh and dry weight basis, harvest index and photosynthetic efficiency during reproductive phase showed relatively high genotypic correlation with dry pod yield per plot. The study indicated that for selecting an ideal plant type of groundnut for partially shaded conditions we have to look for the tallest, earliest flowering and vegetatively maximum vigorous individual plant.
Open Access
Slow release nitrogen in cassava nutrition
(Department of Agronomy, College of Agriculture, Vellayani, 1988) Vinod, G S; KAU; Muraleedharan nair, V
An investigation was undertaken at the College of Agriculture, Vellayani during the year 1985-86 to study the effect of slow-release nitrogen sources on cassava. The variety used for the trail was Sree Visakha. The treatments consisted of four sources namely urea, neemcake coated urea, urea super granule and rubber cake coated urea each at five levels of nitrogen (50, 75, 100, 125 and 150 kg/ha). The experiment was laid out in a 4 x 5 rectangular lattice design with three replications. Application of slow release sources of nitrogen like urea super granule and neem cake coated urea enhanced the growth characters of tapioca such as plant height, number of functional leaves, number of nodes and the leaf area index. Higher levels of nitrogen gave better results in the growth characters. The highest number of tubers, maximum tuber weight and the highest tuber yield were recorded by the urea super granule application, followed by neem cake coated urea. Among the levels of nitrogen tried, the level 150 kg/ha gave the highest yield. Starch content, crude protein content and the hydrocyanic acid contents were not affected by the slow-release source of nitrogen while higher levels of nitrogen application increased the hydrocyanic acid content and the crude protein content. Urea super granule recorded the highest nitrogen uptake and potassium uptake followed by neem cake coated urea. There was no significant difference in the total nitrogen content of the soil with the use of slor-release sources of nitrogen. The treatment combination of neem coated urea tried at 150 kg N/ha resulted in the maximum net return. Though urea super granule gave the maximum yield its cost of cultivation was higher than that of the other sources. So it is more economical to use neem cake coated urea than urea super granule. So in general, the slow-release sources of nitrogn like urea super granule and neem cake coated urea resulted in a better performance than prilled urea.
Open Access
Analysis of the effectiveness of national demonstraions conducted by the Kerala agricultural university
(Department of Agricultural extension, College of Horticulture, Vellanikkara, 1988) Syamala, K S; KAU; Balakrishnan, C
With a view to study the effectiveness of the National Demonstrations on the behaviour of farmers, the present investigation was undertaken under the title “An analysis of the effectiveness of National Demonstrations Conducted by the Kerala Agricultural University”. Effectiveness was measured in terms of the farmers’ knowing about, attitude towards the adoption of the demonstrated cultivation practices of paddy and their attitude towards the National Demonstration program. The farmers’ perception about the methodology followed in the conduct of the demonstrations and the constraints experienced by the farmer-demonstrations in conducting National Demonstrations were also analysed. The study was conducted in Quilon district where the program is ongoing. The sample consisted of 46 farmer-demonstrators and 100 randomly selected neighboring farmers. Data were collected using interview schedule and suitable statistical techniques were employed in the analysis of the data. The study revealed that the farmer-demonstrators’ knowledge about, attitude towards and adoption of the demonstrated practices were significantly affected by the National Demonstration program. The farmer demonstrators’ attitude towards the program was also favourable. But the effectiveness of the program was much less among the neighboring farmers. The selected independent variables together contributed significantly in the variation in the knowledge about and attitude towards the demonstrated practices of the farmer-demonstrators, but not in their adoption and attitude towards the programme. In the case of neighbouring farmers, the contribution of the selected independent variables in the variation in their knowledge, attitude and adoption of the practices and attitude towards National Demonstration program was significant. The methodology followed in the conduct of the demonstrations was not satisfactory as perceived by the farmers. The results of the constraint analysis also pointed out that follow-up, trainings and field days were given the least attention. The results point out to the need for proper planning and improvement in every step in the conduct of the programme to reach its cherished goals.
Open Access
Comparative analysis of the cottage and factory sub sectors of the co-operative sectors in the handloom industry of Kerala
(Department of Rural Marketing Management, College of Co-operatrion and Banking, Mannuthy, 1988) Toney, Joseph; KAU; Suresh, K A
The study on ‘A Comparative Analysis of the Factory and Cottage sub sectors of the co – operative Sector in the Handloom Industry of Kerala’ has been carried out to examine the structural differences, operational costs and profit margin and working conditions of weavers under both the categories. Five industrial societies and five primary societies which constituted 20% of the working societies of Cannanore district were selected for the study. Hundred weaver members were interviewed for the purpose of the study. The primary societies were organized on a production cum sales pattern while the industrial societies were similar to the handloom factories where production was centralised. The everage membership in primary societies was considerably high. The share of female members in total membership was also found to be high among primaries. The socio economic characteristics of weavers showed that more people were associated with weaving in primary societies than industrial societies. In the case of other variables like literacy, family size, age, caste, income, marital status, occupational mobility and territorial mobility, considerable difference was not noticed. The number of average looms and active looms covered were high among primary societies. But the average production per member was found to be high among the industrial societies. The factor productivity analysis showed that both the primary and industrial societies were found to the highly labour intensive. The analysis of the cost structure revealed that raw materials and wages constituted more than 70% of total costs. The sub sectoral analysis showed that cost structure was more or less similar. The cost –volume-profit analysis reflected the negative margin safety and it was found that break-even point of sales was above the actual sales. The working conditions revealed that the average wage received by the workers in the industrial societies by the workers in the industrial societies was considerably higher. The preference for higher counts of yarn was high in industrial societies. Health problems were wide spread among the weavers. Majority of weavers felt that they were pursuing a job of low status. Eighty percent of the weavers joined co-operatives either for better remuneration or for protection against exploitation. Thus, we have found that through industrial and primary societies were basically co-operative institutions with lot of similarities, the striking structural difference was found in their production organisation.
Open Access
Antibiotic producing and antagonistic microorganisms in the forest soils of Kerala
(Department of Plant Pathology, College of Horticulture, Vellanikkara, 1988) Vinod, P B; KAU; Sukumara Varma, A
The antibiotic producing and antagonistic fungi, actinomycetes and bacteria in the evergreen forest soils of Ladysmith forest of Thariyode in Wynad, and Cheriyakanom forest of Thekkadi in Idukki districts of Kerala State were studied. The phanerogamic flore around the sites of soil sample collection in both localities were identified. The total microbial population was studied in relation to the depth of soil. The microbial population was maximum in the top layer and decreased with increase in depth of soil. The total microbial population was higher in Idukki and in both districts, population of bacteria was maximum followed by actinomycetes and fungi. A diversified group of fungi consisting, Mucor, Syncephalastrum, Trichoderma, Microascus, Cunningphamella, Absidia, Aspergillus, Penicillium, Talaromyces, Paecelomyces and Fusarium was present. Three types of actinomycetes viz. Streptomyces sp. with straight sporophores, flexuous sporophores and fascicled sporophores were present while four types of bacteria viz., B. subtilis. Bacillus sp. identical to B. subtilis, Bacillus sp. with small cell and fast growth in NA and Bacillus sp. with small cell and slow growth in NA were present. Antagonistic properties of the isolated were studied with the test organisms Pythium myriotylum, Phytophthora palmivora and Rhizoctonia soleni. Mucor sp. and Cunninchamella elegans showed intermingling and overgrowth with all the test organisms while Absidia corymbefera, Syncephalastrum racemosum, Aspergillus meleus, A. tarreus, Microascus cinereus and Fusarium oxysporum showed this character with P. myriotylum and P. palmivora. Intermingling and overgrowth character was observed in Paecelomyces lilacinus with P. palmivora and R. solani whereas A. versicolor and three species of streptomyces showed this character only with P. palmivora. Mutual inhibition on contact was exhibited by Talaromyces wortmannii with all the three test organisms, while A. versicolor and Streptomyces spp. with flexuous sporophores and fascicled sporophores showed this character with P. myriotylum and R. solani. This character was observed in case of A. corymbefera, S. racemosum, A. meleus, M. cinereus, F. oxysporum and Streptomyces sp. with straigtht sporophores, with R. solani while P. lilacinus showed this with P. myrootylum. Mutual inhibition at a distance was shown by Penicillium citrinum, P. simplicissimum, B. subtilis and the other three Bacillus spp. when tested with P. palmivora and R. solani, but A. terreus showed this reaction only with R. solani. Inhibition at a distance and disintegration of test organism was shown by A. niger with P. myriotylum and R. solani while P. citrinum and P. simplicissimum showed this character only with P. myriotylum. All the three spp. of Trichoderma showed die – back and disintegration of all the three test organisms, while A. niger showed this character only with P. palmivora and A. sydowii showed this character with R. solani only. streptomyces sp. with straight sporophores, B. subtilis and the other three Bacillus spp. showed this character with P. myriotylum alone. Inhibitory properties of antagonists using cell free culture filtrates were estimated and found that A. niger inhibited 100 per cent growth of all the three test organisms while P. citrinum, P. simpliciccimum and B. subtilis showed 100 per cent inhibition of P. myriotylum and a range of 67-87 per cent in case of P. palmovora and R. solani. A. terreus did not inhibit P. myriotylum and P. palmivora, but inhibites 78 per cent of R. solani. All the three Trichoderma spp. moderately inhibited all the three test organisms (13-26 per cent) while A. sydowii showed 20 per cent inhibition of R. solani only. Antibiotic property of the antagonists was determined and P. citrinum exhibited maximum, equivalent to 325 ppm tetracycline followed by Streptomyces with straight sporophores having 250 ppm. T. longibracheatum, P. simplicissimum and A. versicolor recovered antibiotic property equivalent to 150 ppm tetracycline hydrochloride while the other isolates had < 100 ppm equivalence of tetracycline hydrochloride.
Open Access
Characterization of Kerala soils into fertility classes with respect to available P and K extracted by a common extractant
(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 1988) Kamalam, P V; KAU; Jose, A I
A laboratory study was undertaken to evaluate the suitability of Mathew’s triacid extractant (0.06 N H2SO4 + 0.06 N HCI + 0.05 N oxalic acid) for the combined extraction of available P and available K in soil. The suitability of this triacid extractant was confirmed on a large number of soil samples. Precise relationships between triacid K and NH4OAc K were established. The ten fertility classes for available P and K currently followed in the soil testing laboratories are based on Bray-1 P and NH4OAc K. By making use of suitable regression equations the class intervals in terms of triacid P and triacid K values have to be formulated for the purpose of fertilizer recommendation. The use of this extractant can simplify the work in soil testing procedures thus enabling considerable savings of time and labour. A large number of soil samples was collected representing the entire state of Kerala. The available phosphorus of soil was extracted by Bray No.1 solution (1:10 soil solution ratio with an equilibration period of 5 min) and by Mathew’s triacid extractant (1:10 soil solution ratio with an equilibration period of 30 min). Phosphorus in the extract was then determined colorimetrically by the chlorostannous reduced molybdophosphoric blue colour method in HCI system. The available potassium of the soil was determined by neutral N NH4OAc with a soil solution ratio of 1:5 and an equilibration period of 5 min as well as by the triacid acid method. Potassium in the extract was determined flame photometrically. Soils were also analysed for organic carbon, pH and EC. Suitable correlation was worked out between Bray-1 P and triacid P. A linear regression equation was fitted to predict triacid P values from Bray-1 P values. Suitable relationship was also established between NH4OAc K and triacid K. The linear regression model worked out between NH4OAc K and triacid K was used to predict triacid K values from NH4OAc K. Most of the soils were acidic and non-saline. The pH showed a negative correlation with Ec and organic carbon content of soil. Soils varied in the content of organic carbon from 0.04 per cent to 4.41 per cent but in general was rich with a mean organic carbon content of 1.14 per cent. Electrical conductivity was positively correlated with organic carbon content of soil. A positive correlation was observed between organic carbon and available K. Mineralisation of organic matter contributed significantly to the increasing acidity of soil. The available P estimated by Bray-1 was found to range from 0.46 to 370.30 ppm whereas triacid P ranged from 1.73 to 462.50 ppm. The triacid extracted larger amounts of available P than the Bray-1. A significant correlation was observed between triacid P and Bray-1 P (r = 0.9575**). By fitting the regression equation y = 1.15x, where y represented triacid P and x represented Bray-1 P, the triacid P values of the ten fertility classes have been worked out. The available K as estimated by neutral N NH4OAc ranged from 10.0 to 425.0 ppm whereas triacid K ranged from 4.0 to 154.0 ppm. Triacid extracted lower amounts of available K (42.38 ppm) than the neutral N NH4OAc K (105.23 ppm). Although triacid showed less efficiency for releasing K from soil it was found to have high correlation with neutral N NH4OAc (r = 0.9235**). The linear regression equation of the form y = 0.44x was worked out where y represented triacid K and x represented NH4OAc K. This was employed to redefine the ten fertility classes in terms of triacid K values. The increase in precision obtained by the relationship between P estimated by Bray 1 and triacid as well as K estimated by neutral N NH4OAc and triacid by grouping the soils into separate textural classes was only marginal. The present study therefore confirmed the suitability of the triacid for estimation of both available P and K in the soil of Kerala. The revised class intervals for the ten fertility classes followed in the soil testing laboratories of Kerala have been formulated in terms of triacid P and triacid K values which will serve as a guide for giving fertilizer recommendations for various crops.
Open Access
Crops loss caused by root-knot nematode infesting coleus parviflours and its control
(Department of Entomology, College of Agriculture, Vellayani, 1988) Sosamma, P; KAU; Ravindran Nair, K K
Crop loss caused by the root-knot nematode infesting Coleus parviflorus and its control was studied in a pot culture experiment and a field experiment in the Department of Entomology, College of Agriculture, Vellayani, Trivandrum, during August to December, 1986. The number of leaves, shoot length, fresh shoot weight and weight of tubers obtained were less in inoculated plants than in control. The yield and growth parameters showed an negative correlation with the population of nematodes. A high positive correlation was noticed between the tuber weight and the number of leaves and shoot weight of coleus. The shoot length did not influence the tuber yield significantly. Roots showed profuse galling by the second month. Rotting of roots was observed by the third month, and at harvest, no healthy root was present in infected plants. Tubers when stored developed dark patches on the suface of galls and these spread inwards covering the whole of the internal tissues within nine days, and by the twelfth day the internal contents had turned into a dark brown watery liquid with a bad odour. The peel of the tubers did not show rotting. The nature of rot indicated the involvement of secondary organisms like bacterial and fungi. Histopathological studies showed that the nematodes were lodged in the cortex with head in the stellar region of the root. One month after inoculation, quadrangular giant cells (four in number) were observed in roots. There was cell proliferation in the stellar region of the infected roots. Alternate arrangement of the xylem and phloem was disturbed, though the central cylinder and cortex could be distinguished. Two months after inoculation the giant cells were seen larger and fewer in number. The cytoplasm of giant cells became granular and aggregated towards the head region of the nematode. Stele could not be easily distinguished from the cortex. The cortex was greatly enlarged due to hypertrophy and hyperplasia of cells. The development of medullary rays and secondary xylem noticed in the normal root could not be distinguished in infected roots. Infected roots showed numerous cavities formed by the disintegration of giant cells, egg masses and adult females by end of the fourth month. Necrosis of tissue was also observed. The xylem and phloem elements were not distinguishable. At five months after inoculation the tissues of the roots were completely rotten. In the field experiment application of nematicides one month after planting preceded by the burning of plant material in the field prior to planting was found better than the other treatments. Carbofuran @ 1 kg a.i./ha was more effective than phorate for the control of the nematode. No residue of carbofuran or phorate could be detected in tubers at harvest. The rotting of tubers obtained from different plots when kept in store indicated the inefficacy of the treatments for giving protection from the nematode and the need for a second application of the nematicide at tuber setting. Hot water treatments of the tubers prior to storage did not reduce the damage.
Open Access
Studies on exchange equilibria and its prediction on some acid soils of Kerala
(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellayani, 1988) Swarnavi, S; KAU; Pushakala, S
More than 70 per cent of the upland soils of Kerala are acidic. The acidity of the soil is primarily associated with the presence of hydrogen and aluminium in exchangeable form. The soil solution aluminium in acid soil infertility clearly establishes the agronomic significance of aluminium ion equilibria in soils. The present study, entitled “Studies on exchange equilibria and its prediction on some acid soils of Kerala” was conducted to find out(1) the effect of different concentrations of aluminium in the electrolyte solution on exchange equilibria in soils (2) the influence of different cations on the free energy and various selectivity coefficients (3) the dependence of different selectivity coefficients on potassium, calcium and magnesium saturation of soils (4) the role of organic matter on cation exchange equilibria with special reference to potassium, calcium, magnesium and aluminium. Cation exchange equilibria involving aluminium- potassium, aluminium – calcium and aluminium- magnesium were studied in three soil types, viz., Kari, laterite and redloam soils, differencing in their texture and organic matter content. The normalized exchange isotherms for different soils and cationic systems were drawn and the results were interpreted in terms of different selectivity coefficients and approximate free energy change of the exchange reactions. From the study on the effect of different electrolyte concentration of aluminium on aluminium – potassium, aluminium- calcium and aluminium – magnesium exchange, an increasing aluminium adsorption was observed with an increase in electrolyte concentration of aluminium. The adsorption of aluminium was maximum in soils with high organic matter content. The normalized exchange isotherms of aluminium for different cationic systems and soils lay above the diagonal, suggested the preferential adsorption of aluminium over other cations. Except the Gapon selectivity coefficient, all the other coefficients (KKDO, KV and KN) increased upto a certain value of base saturation and then decreased. The value of KG increased with increase in base satuation. Among the various selectivity coefficients, KN was found to be the most dependent one and KG the least dependent. The dependence followed the order KN > KV > KKDO > KG. The negative values of free energy change for different cationic systems suggested the preferential adsorption of potassium, calcium and magnesium over aluminium. Among these cations potassium was found to be adsorbed with more energy, followed by calcium, magnesium, and then by aluminium. The values of free energy change showed the following order of preference for the competing cations: K > Ca > Mg > Al. From the study it can be concluded that potassic fertilizers can be effectively used in acid soils of Kerala, because of its high retention and minimum leaching loss. Compared to potassium, calcium and magnesium were adsorbed with less bond energy and hence to maintain a higher concentration of these cations in the soil exchanger, a considerable amount of calcium and magnesium should be supplied by frequent application of lime. To evaluate correctly the response of applied potassic fertilizers and liming material in different soils, efforts should be made to relate exchange behaviour of potassium, calcium and magnesium to the nature and relative proportion of different soil clay minerals. Similarly, the extension of the predictive approach essentially meant for binary system need special attention in order to make the studies on cation exchange equilibria more realistic and field oriented.

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