Browsing by Author "Rajendran, P"

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Differential response of rice cultivators to potash application in the rice soil of Onattukara
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1996) Shaji, K V; Rajendran, P
It is known that there exists varietal differences in tolerance to nutrient deficiency conditions among rice cultivars. The sandy soils of Onattukara region is inherently deficient in K which resulted in a higher POP recommendation for rice in terms of K application. So to exploit the varietal differences of rice in deficiency tolerance of K, a field experiment was undertaken to screen 48 rice cultivars belonging to tall indicas and dwarf high yielding groups of varying growth durations. The experiment was laid in 384 microplots in "Group Balanced. Block in Split Plot Design" with four K levels and two replications. The various growth and yield attributes and yield were studied with a view to locate varieties which could produce similar yields even at lower levels of K. The results indicated that in general the varietal influences on most of the growth characters in all the four groups were profound. Moreover positive and significant effect of K doses were observed. However LAI showed no variation with differing levels of K. Differential response of varieties to varying K doses as manifested by root spread was considerable only in medium duration varieties while an appreciable difference was noticed in the root spread in all the groups. Root length, thin root-thick root ratio and root CEC appeared to be varietal characters which increased with increasing levels of K. The plant nitrogen content at varying levels of K was more of a varietal character. On the contrary, long duration varieties exhibited significant variation in P content with differing K levels at all critical stages of crop growth. Both K levels and genetic variability of the varieties were equally important in deciding the K content in plants and the response to added K was of a higher magnitude. All but long duration varieties responded positively and significantly to K in terms of productive tiller formation and generally tall indicas produced relatively longer panicles than dwarf varieties. Higher levels of K also led to the production of heavier grains. Yield increases over control was comparatively higher in tall short duration varieties than. any other varieties for higher levels of K. Differential response of K was highly pronounced in tall short duration varieties with Ptb23, Ptb29, Cul 7005-6-1, Cul 7004-3-1, and Cul 7006-2-1 giving comparable yields at 22.5 kg K20 ha-1 as that of the POP recommendation. However as this experiment was done in microplots the final recommendation of varieties tolerant to K deficiency could be done only after extensive studies in large plots and in farmers' fields during various seasons.
Distribution, characterization and dynamics of soil enzymes in selected soils of kerala
(Department of Soil Science and Agricultural Chemistry,College of Agriculture, Vellayani, 2000) Aparna, B; Rajendran, P
Effect of growth regulators and certain formulations on bunch development in banana var. palayankodan
(Department of Pomology & Floriculture and Landscaping, College of Horticulture, Vellanikkara, 1983) Rajendran, P; Aravindakshan, M
The yield of banana in Kerala remains very low inspite of the adoption of proper manuring and other management practices. Investigations have indicated that the main barrier to the increased production in banana is the lack of sufficient leaf area at the active phase of growth of the plants. The present experiment was conducted with the banana cultivar ‘Palayankodan’ under sparsely irrigated conditions with a view to increase the plant growth and ultimate yield by the use of growth regulators and commercially available formulations. The growth regulators viz., 2-4-D and NAA and the commercially available formulation namely ‘Navras Banana Special’ were tried at four different concentrations as given below:- 2,4-D - 5,10,15 and 20 ppm NAA - 20, 30,40 and 50 ppm ‘Navras’ - 0.25, 0.50,0.75 and 1.00 per cent The various chemicals at different concentrations were applied as two foliar sprays at three and four months after planting. A third spray was also given on the bunches immediately after the female phase of flower opening. On an overall analysis, 2,4-D at 20 ppm and ‘Navras’ at 0.50 per cent were found to be more effective in promoting the vegetative growth of plants. With respect to flowering and duration of the crop, the growth regulators alone had significant effects when compared to the commercial preparation ‘Navras’. The effectiveness also depended on the concentrations of the growth regulators. Thus 2,4-D at 20 ppm induced early shooting of plants by about 12 days whereas NAA at 50 ppm caused substantial delay in shooting. The chemicals at their various concentrations were not effective in influencing the bunch maturity, thus indicating that the applied chemicals caused the earliness or delay observed, through their influencedon the vegetative growth only. Consequent to the application of 2,4-D at 20 ppm the crop duration was advanced by 22 days. Contrary to this, NAA at 50 ppm delayed the duration of the crop. The treatments with 2,4-D at 5 to 20 ppm, NAA at 40 and 50 ppm and ‘Navras’ at 1.00 per cent were found to advance the ripening of fruits. The best quality fruits in terms of TSS and total sugars were obtained by the application of 2,4-D at 20 ppm. Among the concentrations of ‘Navras Banana Special’, o.5 per cent gave the best results with respect to the growth and yield of plants. When the concentration was increased further, there was a decrease in the performance of the plants. The optimum doze of ‘Narvas Banana Special’ was worked out to 0.534 per cent. The correlations worked out from the data collected revealed that the vegetative and bunch characters such as girth of psuedostem, number of functional leaves, total leaf area, length of bunch, number of hands and fingers per bunch, number of fingers per hand and weight of hand, length, girth and weight of fingers amply contributed to the overall yield in the form of bunch weight. The yield increase observed in the present study due to the application of 2,4-D at 20 ppm was by 88 per cent and that for ‘Navras’ at 0.5 per cent was by 96 per cent. The benefit/cost ratio worked out for these treatments did not differ and hence application of 2,4-D (20 ppm) and ‘Navras Banana Special’ (0.5 per cent) were equally good for increasing the yield. The present investigations were conducted under sparsely irrigated conditions where, irrigation was given just for the maintence of the crop. Further investigations with rainfed and irrigated ‘Palayankodan’ bananas may be of particular interest.
Effect of vermicompost on the electro-chemical properties and nutritional characteristics of variable charge soils
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1997) Bijulal, B L; Rajendran, P
The study entitled "Effect of vermicompost on the electrochemical properties and nutritional characteristics of variable charge soils" has been carried out during 1994-95 which comprised of two experiments, viz., an incubation study and a pot culture experiment. The incubation experiment was carried out at the laboratory attached to the Department of Soil Science and Agrl. Chemistry, College of Agriculture, Vellayani which was intended to study the effect of vermicompost (VC) in comparison with two other organic manures, viz., FYM and ordinary compost, on the electro-chemical properties and nutritional characteristics of a low activity clay soil taken from Vellayani. The pot culture experiment was conducted using the same soil used for the incubation study, to compare the agronomic effectiveness of various organic manures including vermicompost using cowpea as a test crop. Both the experiments were laid out in Completely Randomized Design. The incubation experiment was conducted with nine treatments consisting of various organic manures with and without rock phosphate. Periodical sampling and analyses of soil incubated with various treatment materials were done at 30 days' interval to study the comparative effect of treatments on the electo-chemical properties and nutritional characteristics of the soil. The pot culture experiment was conducted with eleven treatments containing different organic manures with and without chemical fertilizers, to study the comparative effect of different treatments on crop growth using cowpea. Observations on various biometric and yield parameters have been recorded and analyses of plant samples were done at three stages of growth of the plant, viz., 20 DAS, maximum flowering and at harvest. The nutrient status of the soil after the experiment was also analysed. From the incubation experiment it was made clear that the effect of various organic manures differed significantly in influencing the electro-chemical and nutritional properties of variable charge soils. In general, vermicompost maintained its superiority over other organic manures, especially in the presence of chemical fertilizers, in influencing various soil properties. The effects were statistically significant in the order vermicompost > FYM> ordinary compost. From the experiment it was proved that lower doses of vermicompost could be equated with higher doses of FYM and ordinary compost. Vermicompost established its superiority over other organic manures by influencing many of the soil properties favourably. The major effects were the reduction in P-fixation and increased P solubility in presence of vermicompost. The increased mineralisation of other major and secondary nutrients in the presence of VC caused an enhancement in the availability of these nutrients on an equivalent weight basis. A substantial increase in base status and pH, caused by vermicompost improved the overall plant nutrient status and soil environment compared to other organic manures. The organic matter fractions and other colloidal fractions were found to be favourably influenced by vermicompost. Organic colloids, being the most active and reactive phase of the soil, its contribution towards the total base exchange capacity and cation protection was more pronounced in the case of vermicompost. Biometric observations at critical stages of growth of the crop and yield parameters recorded when analysed statistically have proved the superiority of VC over other organic amendments studied. Vermicompost application in combination with chemical fertilizers was proved to be the best among treatments tested. Lower doses of VC (10 t ha-1) with lime and fertilizers was equally effective as higher doses (20 t ha-1) of other organic manures studied. Analysis of plant samples at critical stages of growth also revealed the same effect. Soil analysis data after the pot experiment has further established the superiority of VC over other treatments. This is indicative of the ability of VC to sustain a higher level of soil fertility for a sufficiently longer period of time. However, the present study being an experiment under controlled conditions, further research involving detailed field experimentation with selected crops is needed for drawing final conclusions.
Efficacy of watershed development programmes in Kerala : a gender perspective
(Department of Agricultural Extension, College of Horticulture, Vellanikkara, 2012) Roshin Varghese; Rajendran, P
Watershed development programmes were taken up under different programmes launched by GOI. As a prelude to these, a number of programmes were implemented viz. DPAP, DDP and IWDP etc with a common objective to conserve the soil and water resources for sustainable management. In 2008 GOI formulated common guidelines for watershed development projects in order to have a unified perspective by all ministries. There is a need to know the perspective about the watershed development programme, the beneficiaries’ knowledge level etc. So far no attempt has been made to such aspects. Hence the study was designed with the following objectives, to explore the gender issues involved in watershed development programmes in Kerala, to find out the dimensions of watershed development programme at various levels of formulation and implementation and the constraints from a gender perspective and to access the training needs of women stakeholders in watershed development programme. The study also intends to suggest various measures for effective gender mainstreaming in watershed development programmes in Kerala. The study was taken up in two panchayaths of Akathethara of Thrissur and Wadakkanchery of Palakkad. Random sampling procedure was adopted to select 15 each from male, female and the implementing officers to form a total sample size of 90 from both panchayath. A pretested interview schedule, observations technique as well as group discussion method were the tools used for the data collection. The knowledge level of women stakeholders was very high. There is no differences in the knowledge level of men and women. There exists no relationship between the knowledge level and the characteristics of respondents. The training needs of women and men were one and the same. There exist a negative relationship between the education and training need of the stakeholders. Regarding the dimensions perceived by the beneficiaries under the planning phase by the Wadakkanchery and Akthethara panchayath were one and the same except two dimensions additionally perceived in the Akathethara and the same was perceived by men also. Under the implementation stage also the same trend was observed in two panchayaths. Men and women perceived the same dimensions consistently. Under the withdrawal and follow up phase the perception by men and women as well as panchayaths were one and the same. The linkage study indicates the Wadakkanchery panchayath perceived soil conservation office as most essential institution where as Akathethara perceived the same as least essential. The horizontal integration results revealed that “grama sabha” and “watershed committee” having a direct linkage with the “soil conservation office” and “krishi bhavan” at Wadakkanchery. The Akathethara panchayath showed a direct and close linkage with the “krishibhavan”. The institutions like the "PHC”, “watershed development team” and the “veterinary” shows a direct linkage but less involvement, the least involvement with the research station. The following gender issues were explored viz. “The role of women in decision making are less”, “Women have no title deed of property”, “Women involvement in WDP is proxy”, “Wage differences” and “Work drudgery is more among women” The following suggestions are made out of results and experiences of researcher. The need base training should be imparted to the stakeholders. The youngsters must be encouraged to participate and should be given preference for including in the groups and committee. Vertical and horizontal linkages must be strengthened so as to ensure the participation of the institutions. Watershed development programmmes will be more effective and a successful programme if it is implemented effectively with a wholistic approach.
Electro-chemical properties of selected oxisols and ultisols of Kerala with special reference to charge characteristics and surface mineralogy
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1992) Rajendran, P; Subramonia Iyer, R
A study has been conducted in seven selected profiles of Oxisols and Ultisols representing the important pedological units with a wide geographical distribution in the state to have a deeper insight in to the electro-chemical behaviour of these soils. A multipronged approach to the studies made are highlighted to enable a clear understanding of the achievements as against the major objectives and approaches made. A laboratory study with thirty six samples from seven profiles representing six Ultisols and one Oxisol has been carried out. Path coefficient analysis of important thirteen charge contributing factors against two parameters for measurement of charge and the inter-relationship of 15 soil characters show that organic matter5, clay %, R2 O3%, Alo% and Feo% are the major factors that control the surface charge behaviour of the soils. The factors studied explained only 55% and 48% of the variability of cation exchange and anion exchange respectively. Study of the distribution of the electric charges in the surface and sub- surface horizons of the soils was made by the means of potentiometric titrations and by measurement of adsorption of ions in the presence of varying concentration of electrolytes. The titration curves at different ionic strengths crossed at the common point intersection the zero-point of charge (zpc). Thus the electro-chemical behaviour of these soils was found to be similar to that exhibited by many metallic oxides in which the surface potential of reversible double layer is determined solely by the activity of potential determining ions, H+ and OH- in the bulk of the solution. The zpc for the surface horizons was found to be lower than the sub-surface and sub- surface horizons in all the soils studied. Soil to soil variation in zcp between surface and sub-surface horizons were more or less the same for all samples. Thus zcp can not be recommended as a taxonomic tool in soil classification to distinguish Oxisols from Ultisols. From known values of surface area and zpc of these soils, the values for net electric charge was calculated by the application of the Gouy- Chapman model of double layer and was found to obey the theory only at a critical electrolyte concentration. As the soils were found to be similar to that of constant potential systems, the charge distribution varied substan\tially with PH and electrolyte concentration. Direct measurement of adsorption of ions from solutions of KC1 NaCl and CaCl2 showed that the nature and valence of index cations also influenced the magnitude of the negative charges on the soils particles. On the basis of the influence of PHJ, electrolyte concentration and the valence of the counter-ions on the electric charges of the soils most of the conventional methods of ion-exchanged determinations using buffered electrolytes at high concentrations appears to be inappropriate for tropical soils. In a study for the evaluation of ion-exchange measurements it was found that the compulsive exchange methods is most suitable for the combined estimation of CEC and AEC. The traditional ammonium acetate method was found to give over estimations of CEC and thus very high values. Calcium chloride, 0.002 M was found to be equally effective but owing to the simplicity of the procedure, the former appeared better. The compulsive exchange method is free from the inherent defects of neutral normal ammonium acetate and hence would seem well suited for the Oxisols and Ultisols of Kerala. Although sesquioxidic components in combination with organic matter apparently dominate the charge properties of these soils, there was evidence from the titration curves to shows the presence of small amounts of clay minerals with permanent negative charge. This was confirmed by different methods and was found in good agreement with the estimated theoretical results. However under field conditions the expression of this constituent was minimum and the variable charge components such as Fe, al oxides certainly control the electro-chemical characteristics. In a separate experiment to find out the contribution of organic matter and sesquioxides towards exchanges properties of soils, it was observed that bout 64% of the negative sites and 8% of the positive was contributed from organic matter. Sesquioxides explained only 11% of the variablility in CECX and 22% of the variability in AEC. The combined effect of organic matter and R2O3 removal was highly significant with respect to CEC and AEC in all the soils studied. Mineralogical investigation revealed the presence of kaolinite as the dominant clay mineral. Appreciable amounts of smectities, quartz and gibbsite was also identified. The presence of smectities was not reflected in the CEC of any of the samples. Scanning electron micrographs did not give much information other than the presence of a thick coating of iron and amorphous materials over clay aggregates. The specific surface measured by ethylence glycol retention method invariably showed higher values than the determined values obtained for negative adsorption data. The specific surface determined closely followed the organic matter content of the samples inspite of the vertical increase in clay content with in profiles.
Feasibility and utilisation of improved vegetable production technologies in family farming by agricultural labourers in the Thrissur district
(Department of Agricultural Extension, College of Horticulture, Vellanikkara, 1996) Abdul Jabbar, P K; Rajendran, P
The research study entitled “Feasibility and Utilization of Improved Vegetable Production Technologies in family farming by agricultural labourers in the Thrissur district” was conducted to analyse the feasibility and utilization of vegetable production technologies in family farming by the agricultural labourers in Thrissur district in relation to their personal and socio-economic factors and to assess the constraints and consequences these of. The study area comprised of five panchayats namely, Pananchery, Puthur, Nadathara, Mattathur and Thekkumkara and a total of 100 agricultural labourers engaged in family farming were selected as respondents. Data were collected from the agricultural labourers using a pre-tested structured interview schedule. Appropriate statistical techniques like correlation analysis, regression analysis and path analysis were done to analyse the data. The perception of feasibility of technologies and extent of utilization were measured using arbitrary scale developed for the purpose. Five crops namely, brinjal, bittergourd, pumpkin, ladies finger and amaranthus were selected for the study with five selected practices under each crop. The study revealed that amaranthus received the highest feasibility score, while bittergourd and brinjal received feasibility perception scores below the average feasibility score. Foliar fertilization in amaranthus received the highest feasibility perception score. Among crop varieties, pumpkin varieties were the most preferred while bittergourd varieties got the least scores. Majority of agricultural labourers belonged to the medium category in extent of utilization and only 19 per cent were low adopters. Amaranthus production technologies received the highest utilization score while bittergourd received the lowest. Split application of fertilizer received the high utilization index in brinjal and bittergourd cultivation. The correlation analysis revealed that all independent variables except experience in vegetable cultivation were positively correlated with feasibility perception. Variables like farm size, annual income, innovativeness, economic motivation, management orientation and knowledge were significant in influencing the feasibility perception. All variables except experience in vegetable cultivation were found positively correlated with utilization of IVPT. Knowledge on IVPT exerted the largest direct effect. Information seeking behaviour, FFT-Actual, social participation and attitude towards scientific agriculture, management orientation, area under vegetables and extension orientation were found to influence significantly. Plant protection was cited to be the most preferred area where training was required, followed by improved varieties of crops harvesting and post harvest aspects and manures and fertilizers respectively. Constraints such as uneconomic holding size, inadequacy of capital, increased cost of plant protection chemicals and lack of leisure time, availability were cited as most important.Economic utilization of leisure time, enhancement of family income, generation of additional employment and promotion of family integrity were the important consequences. Lack of time to care children and other house operations and drudgery were cited to be the negative consequences.
Feasibility and utilization of improved vegetable production technologies in family farming by agricultural labourers in the Thrissur district
(Department of Agricultural Extension, College of Horticulture, Vellanikkara, 1996) Abdul Jabbar, P K; Rajendran, P
The research study entitled "Feasibility and Utilization of Improved Vegetable Production Technologies in family farming by agricultural labourers in the Thrissur district" was conducted to analyse the feasibility and utilization of vegetable production technologies in family farming by the agricultural labourers in Thrissur district in relation to their personal and socio-economic factors and to assess the constraints and consequences these of. The study area comprised of five panchayats namely, Pananchery, Puthur, Nadathara, Mattathur and Thekkumkara and a total of 100 agricultural labourers engaged in family farming were selected as respondents. Data were collected from the agricultural labourers using a pre-tested structured interview schedule. Appropriate statistical techniques like correlation analysis, regression analysis and path analysis were done to analyse the data. The perception of feasibility of technologies and extent of utilization were measured using arbitrary scale developed for the purpose. Five crops namely, brinjal, bittergourd, pumpkin, ladies finger and amaranthus were selected for the study with five selected practices under each crop. The study revealed that amaranthus received the highest feasibility scoie, while bittergourd and brinjal received feasibility perception scores below the average feasibility score. Foliar fertilization in amaranthus received the highest feasibility perception score. Among crop varieties, pumpkin varieties were the most preferred while bittergourd varieties got the least scores. Majority of agricultural labourers belonged to the medium category in extent of utilization and only 19 per cent were low adopters. Amaranthus production technologies received the highest utilization score while bittergourd received the lowest. Split application of fertilizer received the high utilization index in brinjal and bittergourd cultivation. The correlation analysis revealed that all independent variables except experience in vegetable cultivation were positively correlated with feasibility perception. Variables like farm size, annual income, innovativeness, economic motivation, management orientation and knowledge were significant in influencing the feasibility perception. All variables except experience in vegetable cultivation were found positively correlated with utilization of IVPT. Knowledge on IVPT exerted the largest direct effect. Information seeking behaviour, FFT-Actual, social participation and attitude towards scientific agriculture, management orientation, area under vegetables and extension orientation were found to influence significantly. Plant protection was cited to be the most preferred area where training was required, followed by improved varieites of crops harvesting and post harvest aspects and manures and fertilizers respectively. Constraints such as uneconomic holding size, inadequacy of capital, increased cost of plant protection chemicals and lack of leisure time availability were cited as most important. Economic utilization of leisure time, enhancement of family income, generation of additional employment and promotion of family integrity were the important consequences. Lack of time to care children and other house operations and drudgery were cited to be the negative consequences.
Feasibility and utilization of agricultural technologies among scheduled caste farmers
(Department of Agricultural Extension, College of Horticulture, Vellanikkara, 1992) Rajendran, P; Menon, A G
A Study was conducted in Kerala State with the over-riding objective of analyzing the feasibility perception and utilization pattern of agricultural technologies by the scheduled caste farmers of the state and the constraints in and the consequences of utilization of technologies by them. The study was conducted covering all the five agro-climatic regions of the state, using probability proportionate to size random sampling procedure. Three hundred and thirty seven scheduled caste farmers from five panchayaths coming under five Blocks with the highest scheduled caste population representing each agro-climatic region were selected as the respondents. Five enterprises viz, coconut cultivation, tuber crops cultivation, banana cultivation, cattle rearing and goat rearing were selected and five specific practices for each of these enterprises were selected for assessing the utilization pattern of farmers. Feasibility of technology was analysed in terms of different attributes. Fifteen attributes viz., initial cost, availability of raw materials, availability of supplies and services, physical compatibility, efficiency profitability, availability of technology, simplicity suitability time utilization pattern, social acceptability, rapidity of returns, income generation potential, regularity of returns and viability, were selected for the study. The characteristics of the farmers such as education, family size, experience in farming, farm size, annual income, indebtedness, social participation, extension guidance, extension participation, cosmopoliteness, achievement orientation, development orientation, risk orientation, economic motivation, market orientation, self confidence, level of aspiration, rational orientation and innovativeness were selected for the study. These variables were quantified using standardized procedures. Statistical methods such as mena, percentage analysis, zero-order correlation, Kruskallwalli’s one-way analysis of variance, Kendall’s coefficient of concordance, spearman rank order correlation and stepwise regression analysis were employed for analyzing the data. The major findings of the study were: 1. Goat rearing was perceived as the most feasible enterprise while cattle rearing was perceived the least feasible enterprise by the respondents in general, 2. Agro-climatic differentiations caused variations in the perception of feasibility of the enterprises. 3. Simplicity, initial cost, physical compatibility, suitability, availability of raw materials, efficiency and availability of technology were found to be the crucial determinants of feasibility of agricultural technologies in general. 4. More than 50 percent of the respondents were distributed in the medium category with respect to the level of utilization of the selected enterprises, 5. Feasibility perception of the enterprises and its utilization by the respondents were found significantly related with respect to only coconut and cattle enterprises. 6. There was marked inter regional differences in most cases with respect to feasibility perception and utilization of practices for the five enterprises studied, 7. Lack of technical knowledge, lack of necessary supporting services and unavailability of raw materials were reported as the major constraints in the utilization of agricultural technologies in general. 8. Untimely and ineffective utilization of inputs and inclusion in the defaulters list of credit agencies were reported as the major consequences of utilization of agricultural technologies in general. 9. The characteristics of the respondents viz., extension guidance, risk orientation, self confidence, education, economic motivation, market orientation and cosmopoliteness were found to be significant in influencing and explaining the variation in the utilization of the enterprises by the scheduled caste farmers. Based on the findings of the study, a model for the effective implementation of agricultural development programmes among scheduled caste farmers in the state has been suggested.
Identification of molecular markers for developing breeding strategies in rose
(Centre for Plant Biotechnology and Molecular Biology, College of Horticulture, Vellanikkara, 2007) Cinu Sebastian; Rajendran, P
Rose, one of the most important flowering ornamentals is a favourite for landscaping and an important commercial cut flower. Breeders are always looking for new and novel varieties to meet the ever increasing demand of consumers. However, many years are required to develop a new variety through conventional methods. Many desirable roses are female sterile and hence pose a real limitation to breeding. Developing a molecular marker that can readily identify a female parent can go a long way to avoid unproductive hybrids. Premature abortion of developing embryos resulting in few or no viable seeds is another major set back. The present investigation entitled ‘Identification of molecular markers for developing breeding strategies in rose’ was held out at this context at the Centre of Plant Biotechnology and Molecular Biology (CPBMB) with the aim of determining a molecular marker and attempting embryo rescue of rose. Fifty rose varieties were selected based on morphological characters viz., seed setting ability. Variations in foliar characters of plants were recorded. Genomic DNA extraction from tender leaves of rose plants using Roger and Bendich’s method (1994) with slight modification was found to be the best. Out of fifty-one primers screened four primers belonging to OPAA 2 , C 4, C 15 and C19 were identified as the best. Molecular characterization by RAPD assay generated a total of 331 amplification products. Some bands were specific or prominent to the group. The clustering of sterile and fertile varieties mostly into two separate clusters indicated their similarity at the genetic level. Further studies have to be conducted by increasing the number of primers used, for identification of fertility status of more varieties. In view of the problems faced by breeders regarding unproductive hybrids, an attempt was made for embryo rescue. Surface sterilization of hips with 0.1 per cent mercuric chloride was standardized. The pollen fertility was assessed by acetocarmine staining and mean fertility was observed to be 74.6 per cent. The poor response of germination observed for achenes was due to both physical and chemical restriction on the embryo. Effect of media type and combination of growth regulators were assessed. A high germination rate was observed in cultures incubated for two weeks in dark and subsequently transferred to light. Inoculation media with BA and IAA and subculturing media with BA and NAA combined with low salt concentration (half MS) was found to give maximum response. Further trials can lead to the identification of a definite protocol for regeneration.
Imprints 25 years of KVK Palakkad
(Kerala Agricultural University, Vellanikkara, 2004) KAU; Rajendran, P
Modelling of carbofuran movement and sorption in soils with varying physico-chemical properties
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1994) Moossa, P P; Rajendran, P
An experiment was conducted at the College of Agriculture, Vellayani, during 1992 – 93 for modelling carbofuran movement and sorption in soils with varying physic – chemical properties. Undisturbed vertical and horizontal soil columns were used for the study. Five major locations of the state cropped to banana were selected for the study viz. Malappuram (Ultisol), Chengannur (Inceptisol), Kayamkulam (Entisol), Nedumangad (Mollisol) and Kuttanad (Entisol). The soils exhibited wide variation in the major physico – chemical properties such as texture, water holding capacity, bluk density, particle density, hydraulic conductivity, CEC, AEC and organic matter. The mineralogy of the clay samples had revealed the occurrence of Kaolinite, quartz and smetite as major minerals in these soils. Distribution of carbofuran in the vertical soil columns showed high concentration of carbofuran at lower depths in the first observation for the Inceptisol of Chengannur and the Entisol of Kayamkulam. While in the 6th observation, the Ultisol of Malappuram, Entisol of Kuttanad and the Mollisol of Nedumangad showed higher concentrations in the lower layers due to higher adsorption. Horizontal distribution of carbofuran was very low though significant differences were observed between soils. Maximum horizontal distribution was observed in the Entisol of Kuttanad and the least for the Entisol of Kayamkulam. Regression equation of soil properties on carbofuran content indicated significant influence for organic matter and clay content. Path coefficient analysis of soil properties revealed significant direct positive effect for organic matter and significant direct negative effect for clay content. Indirect negative effects expressed through pH, clay content, Bulk density and AEC with respect to organic matter was not strong enough to counteract the direct positive effect. Similarly the indirect positive effect contributed by clay through organic matter, CEC and sesquioxide was also not sufficient to overcome the direct negative effect. Concentration of carbofuran in the leachate showed highest values for the Inceptisol of Chengannur followed by the Entisol of Kayamkulam, both having low CEC, organic matter and clay content. The Ultisol of Malappuram with high organic matter, CEC and clay had given the lowest value for carbofuran in the leachate. Persistence of carbofuran of was maximum in the Mollisol of Nedumangad with high organic matter, clay content and CEC. Persistence was poor in the Inceptisol of Chengannur and the Entisol of Kayamkulam which are low in organic matter, clay content and CEC. Persistence was poor in the Inceptisol of Chengannur and the entisol of Kayamkulam which are low in organic matter, clay content and CEC. The only transformation product identified was 3 – keto carbofuran observed in the surface soil of Ultisol of Malappuram and Mollisol of Nedumanged in the last observation made at 80 days after application.
Scaling up of good extension practices in rice production systems
(Kerala Agricultural University, Vellanikkara, 2004) Rajendran, P; KAU
Study of factors affecting the adoption of selected agricultural practices
(Department of Agricultural Extension, College of Agriculture, Vellayani, 1978) Rajendran, P; Menon, A G G
Rice is the staple food of the people of Kerala. But Kerala is deficient in its rice production by about 50 per cent. All most all the cultivable area has already been brought under the plough. Therefore, the scope for increasing the area under rice is rather limited. The fact that more than 50 per cent of the cropped area is devoted for perinnial cash crops further limits the scope for expansion of area under rice. Besides 60 per cent of the holdings are less than 1 acre in extent . Therefore, the only possibility to increase rice production is to increase the gross area under rice by resorting to scientific cultivation practices. A number of development programmes particularly focused on rice production have been introduced and implemented in the state. Improved technology required for stepping up rice production was also diffused with great vigour and enthusiasm.
Surface charge characteristics and phosphorus availability in selected oxisoils and ultisoils of Kerala
(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1993) Sreekala, S; Rajendran, P
To meet the goal of increased food production in areas dominated by LAC soils, it is essential to alleviate specific physical and chemical soil related constraints. A major constraint identified in the Oxisols and Ultisols is the widespread deficiency of phosphorus and moderate to high P – fixation coupled with low nutrient holding capacity. The use of low grade silicates and lime suggested as a low input strategy for sound phosphorus management in these soils is tested in the present study. In addition to this objective the by – product effect of the application of phosphate and silicate in excercising cation protection by enhancement of CEC is also tested in these selected soils. The results of the studies are summarised and appropriate conclusions drawn. The electro – chemical properties of the two soils studied clearly showed that the inorganic components of the soils are of variable charge type. The results of the incubation experiment proved the beneficial effect of silicate application in enhancing the available ‘P’ status. Adsorption studies of phosphate and silicate showed that the Kandiustult of Kottarakkara exhibited extremely high adsorption capacity for ‘P’ indicating a higher ‘P’ fixing capacity than the Haplustox of Pachalloor. The column study conducted revealed that it is possible to increase the retention of cations by applying phosphate and silicate as soil amendments. Neubauer’s experiment conducted to determine the effect of silicate lime and phosphate application on ‘P’ availability, did not show any significant result. However, the trend was indicative of the beneficial effect of silicate application in increasing the phosphate release from the soil. This aspect of the study needs further elaboration through field experiments.