Browsing by Author "Raghavan Pillai, G"

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Agronomic evaluation of biofarming techniques for forage production in coconut gardens
(Department of Agronomy, College of Agriculture, Vellayani, 1996) Sansamma George; Raghavan Pillai, G
Two field experiments were conducted at the Instructional Farm, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala State to study the potential of biofarming techniques for forage production in coconut gardens. The study was carried out for a period of two years from September 1993 to August 1995. The influence of the different nutrient management techniques on uptake of nutrients, quality of produce and physico-chemical properties of soil was also investigated. In experiment no.1. the influence of two nitrogen fixing organisms., viz. Azospirillum and Azotobacter and the role of Vesicular Arbuscular Mycorrhiza (VAM) in improving the growth and production of guinea grass and congosignal was studied under inoculation alone and also in combination with chemical fertilizers. The nitrogen fixers were tested under varying levels of fertilizer nitrogen and for VAM the level of phosphorus varied between treatments. The prospects for vermicompost use for guinea grass production was examined under experiment no. 2. It was also envisaged to compare the impact of integrated use of manures and fertilizers with the continuous use of chemical fertilizers alone. Results of experiment no.1 revealed that Azospirillum inoculation alone and in combination with fertilizers had significant positive influence on guinea grass production. Azotobacter inoculation showed only limited effects on growth and yield of the forage grass during the first year but the effect was significant during the second year. The results indicated that 25 per cent of the recommended nitrogen could be saved through the use of either of the biofertilizers. VAM inoculation when combined with full dose of recommended fertilizer nitrogen and potassium, showed significant superiority over the POP treatment at 0, 25 and 50 per cent phosphorus doses while the 75 percent P dose gave comparable yields. The quality parameters of the forage recorded values on par or superior to that of the recommended fertilizer treatment. The use of biofertilizers improved the net income and benefit : cost ratio from guinea grass cultivation. The inoculation treatments were found to have a favourable influence on the physical and chemical properties of the soil. Integrated use of the nitrogen fixing organisms with chemical fertilizers was found effective for Congosignal cultivation. Pooled analysis studies indicated that when inoculated with either Azospirillum or Azotobacter, 50 per cent of the recommended fertilizer nitrogen was adequate for yields. VAM inoculation alone elicited significant yield increase over the absolute control. Combind doses of VAM with chemical fertilizers at all levels of applied phosphorus responded more or less similar to the recommended fertilizer treatment. This indicated the possibility of completely substituting the need for fertilizer phosphorus in VAM inoculated congosignal. The VAM effect in promoting growth and yield of the forage was found to decline in the presence of applied phosphorus. The data on economics also favoured the use of biofertilizers. Experiment no. 2 revealed that guinea grass responded well to integrated use of manures and fertilizers. As per pooled analysis vermicompost @ 5 t ha-1 or Farm yard manure @ 10 t ha-1 when combind with 75 per cent of the recommended NPK were comparable with the 100 per cent NPK treatment. Application of the organic manures improved the quality of the produce. The physic-chemical properties of the soil was also favourably influenced by the integrated use of manures and fertilizers. The economic analysis of the data emphasised the need for reducing the reliance on purchased inputs. Coconut yield was found favourably influenced by intercropping of the fodder grasses.
Crop weather modelling in rice (oryza sativa.L.)
(Department of Agronomy, College of Agriculture, Vellayani, 2002) Sajitha Rani, T; Raghavan Pillai, G
Rice is intimately involved in the culture as well as in the food ways and economy of Indians especially Keralites. The demand of rice is expected to increase by 70 per cent over the next 30 years, primarily due to rapid population growth and by 20 1 O. the rice production has to be increased from the current level on. 7lakh tonnes to 21 lakh tonnes. To achieve this objective, the strategy should be to increase the total production. This can be accomplished by increasing the acreage under rice and by enhancing the productivity per unit area. Climate plays an important role in rice production. Rice is vulnerable to change in weather' and its cultivation continues to be a risky enterprise under unfavourable environment, despite advances made in rice production technologies. Within any season, long days and humid conditions with adequate rains or water supply help towards satisfactory vegetative growth of the rice plant while bright weather and short days with a diminishing supply of water favour the flowering phase, Cloudiness which leads to low light, extreme temperatures, variation in rainfall, and high relative humidity affect growth, yield attributes and productivity. To some extend rice has genetic potentiality to tolerate the adverse weather conditions and hence an appropriate cultivar may enable the farmer to avoid or lessen the problems from climatic stresses. Two field experiments were conducted at College of Agriculture, Vellayani during 1998' -1999 and at RARS, Pattambi during 1999-2000 to assess the performance offour high yielding rice varieties namely Kanchana, Jyothi, Matta T riveni, Kairali and one local variety Ptb-10 in three dates of planting in each season viz.,. 1 sI, l S" and 30th of June ,October and January, to find out the best varieties and best dates of planting in each season. It was also aimed to develop the best fitting crop weather model using step wise regression. In all seasons at both locations earlier dates of transplanting resulted in higher TDMP. more number of days to reach 50 per cent flowering and physiological maturity. higher grain yield and straw yield and higher harvest index. The nutrient uptake was also higher for earlier transplanting. The earlier transplanting also escaped from the severity of pests and diseases. Kanchana, Kairali and Jyothi registered similar values for number of days taken to 50 per cent flowering, physiological maturity and number of filled grains per panicle during all seasons at Vellayani. In all se~ons the nitrogen, phosphorus and potassium uptake by straw and grain were lower for local variety. Kanchana consistently out yielded other varieties followed by Kairali and the local variety Ptb-l 0 registered the lowest grain yield. At Pattambi also during all seasons number of days taken to 50 per cent flowering and physiological maturity were similar for Kanchana, Kairali and Jyothi. In all seasons the nitrogen, phosphorus and potassium uptake by straw and grain were lower for local variety. Highest grain yield was registered by Kanchana followed by Kairali in all seasons except third season where it was on par with Kairali. The lowest grain yield was registered by local variety. At both locations, all the high yielding varieties registered lower rice bug attack than local variety. Kairali and Kanchana were found resistant to sheath blight and gall midge At both locations similar trend in growth and yield attributes, nutrient uptake and pest' and disease incidence were observed in all the seasons. Result of this investigation revealed that early transplanting of rice and cultivation of high yielding varieties Kanchana would increase the productivity per unit area. Yield prediction equation with weather variables will act as a tool for improving the productivity of rice. Grain yield data for a period of twenty five years (1960-1985) from a permanent manurial experiment at Regional Agricultural Research Station, Pattambi was subjected to con-elation " analysis to develop the best fitting crop weather model using step wise regression. In virippu season 72 per cent of the variation in yield was attributed to climatological parameters viz., evaporation, maximum temperature, minimum temperature, number of rainy days, evening relative humidity and sunshine hours. In mundakan season 46 per cent of variation in yield was accounted for the climatological parameters viz., evaporation, maximum temperature and sunshine hours
Crude protein and crude fibre content of fodder grasses as influenced by legume intercropping and phosphorus application
(Kerala Agricultural University, 1982) Chandini, S; Raghavan Pillai, G; Sreedharan, C
Cutting management in subabul
(Kerala Agricultural University, 1990) Meera Bai, M; Lakshmi, S; Raghavan Pillai, G
Effect of nitrogen and lime on the yield attributes and yield of dinanath grass (Pennisetum pedicallatum Trin.)
(Kerala Agricultural University, 1980) Abraham, C T; Raghavan Pillai, G; Sreedharan, C
Effect of phosphorus and lime on the growth attributes and yield Stylosanthes gracilis Swartz
(Kerala Agricultural University, 1980) Mariyappan, H; Chandrasekharan, P; Raghavan Pillai, G
A field experiment conducted to study the effect of graded doses of phosphorus (0,40, 80, 120 and 160 kg/ha ) on the growth attributes, green and dry matter yields of Stylosanthes gracilis Swartz with two levels of lime [0 and 500 kg/ha] in the red loam soils of the Instructional farm, College of Agriculture. Vellayani has shown that growth attribuies like plant height, number of leaves, number of branches and leaf/stem ratio were not influenced by the application of graded doses of phosphorus except lime which increased the leaf number significantly. Phosphorus at the rate of 120 kg/ha recorded the maximum green matteryteld and dry matter production. Although lime level at 500 kg/ha failed to produce significant increase in green matter and dry matter yields, a positive trend was noticed by lime application.
Effect of phosphorus, lime and cutting interval on green fodder yield, nodulation and protein enrichment of Stylosanthes gracilis and nitrogen in soil
(Kerala Agricultural University, 1987) Mariyappan, H; Chandrasekharan, P; Raghavan Pillai, G
An experiment was conducted at the Instructional Farm, College of Agriculture, Vellayani, Kerala during 1977-78 to study the effect of phosphorus levels, lime and cutting intervals on green fodder yield, protein enrichment and nodulation of Stylosanthes gracilis and nitrogen build up in the soil. The treatments constituted five levels of phosphorus viz., 0,40, 80, 120 and 160 kg P205/ha, two levels of lime viz., 0 and 500 kg CaO/ha and two intervals of cutting viz., 30 days and 45 days. The green fodder yield, protein content and protein yield were found to increase progressively upto 120 kg P205/ha. The combination of phosphorus and lime had significant influence in increasing the green fodder yield and protein content. Cutting interval of 45 days recorded more green fodder yield and the combination of 120 kg phosphorus per hectare with 30 days interval of cutting recorded the maximum protein content. Nodule number and weight were found to increase progressively upto 120kg P205/ha. but lime and cutting interval had no significant influence. An increase of 7.3% of total nitrogen content of soil with increase in the levels of phosphorus was observed. Phosphorus and lime together contributed for the increase in the available nitrogen.
Fodder production potential of five cultivars of bajra (Pennisetum Typhoides.Stapf) in coconut garden lands of Kerala
(Kerala Agricultural University, 1981) Raghavan Pillai, G; Purushothaman Nair, N; Sreedharan, C
Fodder production potential of grass legume mixtures as influenced by phosphorus levels
(Kerala Agricultural University, 1985) Chandini, S; Raghavan Pillai, G; Sreedharan, C
Fodder production potential of sweet potato (Ipomoea Batatas)
(Kerala Agricultural University, 1980) Raghavan Pillai, G; Kamalam Joseph; Sreedharan, C
Forage and seed production of signal grass (Brachiaria decumbens Stapf.) under different management practices
(Department of Agronomy, College of Agriculture, Vellayani, 1999) Sonia, V K; Raghavan Pillai, G
A field experiment was conducted in the Instructional Farm, College of Agriculture, Vellayani to assess the forage and seed production potential of signal grass under open conditions. The effect of varying levels of nitrogen, potassium and cutting management on the yield and quality of fodder and on the seed production potential of the grass were studied. The investigation was carried out for a period of one year from July 1998 to July 1999. The results revealed that nitrogen applied at the rate of 200 kg ha! improved the growth parameters like plant height, tiller number per hill and leaf number per hill. Potassium showed no significant response on growth parameters. The green fodder and dry fodder yields were favourably enhanced by nitrogen application. Nitrogen had a favourable effect on the number of days to attain 50 per cent flowering. Other yield attributes like number of seeds per panicle, seed yield and thousand seed weight were favourably . influenced by all the main treatment effects viz., nitrogen, potassium and cutting management. 2 Nitrogen exerted significant influence on leaf area index in the later harvests. Maximum leaf area index was noticed in the second harvest stage. The treatment with highest level of nitrogen alone influenced seed germination significantly. Application of nitrogen as well as potassium reduced the nitrogen content of the fodder. Potassium application resulted in a significant increase in potassium content of forage. Incremental levels of nitrogen reduced the crude fibre content. Potassium application resulted in a decreasing trend in crude protein content. The calcium and magnesium contents increased by potassium application alone. Incremental levels of applied potassium exerted a reducing effect on calcium and magnesium content of fodder. The K : (Ca+Mg) ratio of the fodder increased with increase in levels of applied potassium. The available nitrogen status of the soil was improved by nitrogen application. The available potassium status of the soil declined with increase in applied nitrogen while higher potassium levels substantially enhanced the available K status of soil. Considering the economics of fodder cultivation, highest B:C ratio was realised for the treatment which received the highest dose of nitrogen and potassium . . '
Herbage production of leguminous crops in summer rice fallows
(Department of Agronomy, College of Agriculture, Vellayani, 1994) Rajasree, G; Raghavan Pillai, G
An Investigation was carried out at Cropping Systems Research Centre, Karamana, Thiruvananthapuram to study the fodder production potential of four legumes (cowpea variety CO -5, cowpea variety C-152, cowpea variety Karnataka local and Sesbania rostrata) under three levels of lime (0,125 and 250 kg per hectare) and three levels of phosphorus (0, 30 and 60 kg P2 O5 per hectare) in summer rice fallow. To study the residual effect, a bulk crop of paddy was raised in the first crop season retaining the same layout. The trial was laid out as a split – plot experiment in RBD with three replications. Application for lime increased the growth attributes like plant height, number of leaves, LAI and number of branches, in all fodder legumes. Various growth parameters were increased due to the application of phosphorus. Combined application of lime and phosphorus improved the growth parameters through the indirect effect of increased availability of nutrients. Combined application of higher levels of lime and phosphorus decreased the nodulation in Sesbania rostrata. Combined application of 125 kg lime and 60 kg P2 O5 improved the crude protein content. Application of 250 kg lime increased the plant phosphorus content which however decreased with increasing levels of application of phosphorus. Combined application of 125 kg lime and 60 kg P2 O5 resulted in more plant potassium content. Increase in lime levels from O to 125 kg increased calcium content of legumes. Combined application of 125 kg lime and 30 kg P2 O5 produced more magnesium cont3ent in plant than 250 kg lime and 60 kg P2O5 treatment combination. Available nitrogen content in soil after the experiment increased with the combined application of 250 kg lime and 30 kg P2O5. Combined application of moderate levels of lime and phosphorus resulted in more available phosphorus and potassium contents. Available calcium content of soil increased with increasing level of lime, but magnesium content of soil was found to decrease with the application of 250 kg lime. Sesbania rostrata and cowpea variety CO – 5 produced taller plants, while Sesbania rostrata followed by cowpea variety C – 152 recorded more number of leaves and LAI. Sesbania rostrata also recorded maximum number of branches, but was poor in nodulation where the combined application of 250 kg lime and 60 kg P2O5 declined the stem nodulation. Green fodder yield was maximum in cowpea variety C-152, while dry fodder production was maximum in Sesbania rostrata. Sesbania rostrata recorded highest crude protein, phosphorus, calcium and magnesium contents where as CO-5 had maximum plant potassium content. Available soil potassium content was lowest under cowpea variety CO-5. Uptake of nutrients were maximum in Sesbania rostrata and minimum in Karnataka local. The trial also indicated the suitability of Sesbania rostrata as a fodder crop on account of its higher dry matter production and nutrient content. Cowpea variety C-152 was found to be more economic as a fodder crop under summer rice fallow conditions.
Influence of nitrogen and lime on the k/(Ca + Mg) ratio of dinanath grass (Pennisetum pedicellatum Trin.)
(Kerala Agricultural University, 1980) Abraham, C T; Sreedharan, C; Raghavan Pillai, G
Nutrient removal by rice crop and weeds
(Kerala Agricultural University, 1987) Lakshmi, S; Nair, K P M; Raghavan Pillai, G; Muraleedharan Nair, V
Nutrient- growth regulator interaction in snakegourd (Trichosathes anguina L.) under drip irrigation system
(Department of Agronomy, College of Agriculture, Vellayani, 1998) Elizabeth K Syriak; Raghavan Pillai, G
Two field experiments were conducted at the Instructional Farm, College of Agriculture, Vellayani, Thiruvananthapuram, to study the effect of varying levels of nitrogen (n), ethephon (g) and drip irrigation frequency (i) on the productivity of snakegourd. The influence of the treatments on the size, quality and shelf life of the produce and also on the physico-chemical properties of soil was investigated. The trials were conducted during the summer seasons (December to April) of 1994-'95 and 1995-'96. The experiments were laid out in 4 2x2 + 2 asymmetrical confounded factorial design with two replications and each replication included two blocks. Combinations of four levels each of N (35, 70, 105 and 140 kg ha'), ethephon (0, 50, 100 and 200 ppm) and two frequencies of drip irrigation (5 mm CPE and 10 mm CPE) constituted the treatments along with two controls (nogoiI and llogoi2) in each block. The highest order interaction NOI was confounded in both the replications. Results of the field experiments revealed that during both the years of experimentation, nitrogen, ethephon and irrigation frequency exerted significant positive influence on the fruit yield of snakegourd. During both the years, the higher levels of nitrogen (105 and 140 kg N ha') were found to be significantly superior to the lower levels (70 and 35 kg N ha'). Pooled analysis of the yield data also revealed a similar trend. Growth characters like internodal length, number of leaves plant" and dry matter production showed significant enhancement due to N application. The positive significant effect of N was manifested in the yield attributes viz., number of fruits plant" and average fruit weight. Significant increase in the WUE of the crop due to N application was also observed. The content and uptake of major nutrients also increased substantially due to applied N. Nitrogen improved the quality of fruits, significantly, in terms of crude protein, total sugars, reducing sugars and ascorbic acid content. However, the shelf life was adversely affected by it. The highest net profit and B:C ratio were recorded by 105 kg N ha' (Rs. 74,636/- and 2.37, respectively) compared to the other levels of N. Considerable improvement in the physico-chemical properties of soil due to applied N was also noticed. The results of the field experiments also indicated significant yield . increase in snakegourd due to ethephon application. The higher levels of ethephon ie., 100 and 200 ppm, were found to be significantly superior to the lower levels in this regard. Growth and yield attributes as well as quality of fruits were favourably influenced by ethephon. Through its indirect positive effect on fruit yield, the higher levels of ethephon improved the WUE of the crop significantly over its lower levels. The economic analysis also revealed the positive effect of ethephon on the net profit and B:C ratio and the highest values were registered by 200 ppm ethephon (Rs. 71,194/- and 2.31, respectively). With respect to irrigation frequency, il (irrigation at 5 mm CPE) registered significantly higher fruit yield compared to i2 (irrigation at 10 mm CPE): Growth characters and also the quality of fruits exhibited a similar trend. More frequent irrigation treatment (i.) exerted its positive significant effect on yield attributes viz., number of fruits plant:' and mean weight and girth of fruits. The physical optima for N at il were worked out to be 100 and 115 kg ha" during the first and second year, respectively. Economic analysis also revealed the favourable effect of frequent drip irrigation, with il registering substantially higher net profit and B:C ratio (Rs. 70,038/- and 2.28, respectively) compared to i2 (Rs. 61,615/- and 2.14, respecti vel y) .. A perusal of the data on fruit yield and economics of the treatment combinations elicited the favourable effect of n3g4il which registered the highest fruit yield, net profit and RC ratio (31.06 t ha", Rs. 1,04,271/- and 3.04, respectively) and hence this combination could be adjudged as the best one for snakegourd cultivation.
P and K nutrition of guinea and congosignal grasses grown in coconut gardens
(Kerala Agricultural University, 1993) Meerabai, M; Lakshmi, S; Raghavan Pillai, G
Two separate experiments on P and K nutrition of guinea and congosignal grass were conducted in the Instructional Farm, College of Agriculture, Trivandrum to find out the P and K requirements of these two grasses when grown in coconut gardens. It was found that 30 kg P2Os/ha and 90 kg KjO/ha as basal dose are sufficient to produce economic fodder yield.
Performance of fodder legumes under lime and phosphorus nutrition in summer rice fallows
(Kerala Agricultural University, Vellanikara, 2001) Rajasree, G.; Raghavan Pillai, G
Production potential of two fodder grasses under different management practices
(Department of Agronomy, College of Agriculture, Vellayani, 1986) Raghavan Pillai, G; Madhavan Nair, K P
Seed production of gamba grass under varying levels of nitrogen phosohrus and pottassium
(Department of Agronomy, College of Agriculture, Vellayani, 1995) Vineetha, L J; Raghavan Pillai, G
An experiment was conducted in the college of Agriculture, Vellayani during the period from July 1993 to January 1994 with the object of finding out the effect of nitrogen, phosphorus and potassium on seed production of gamba grass (Andropogon gayanus kunth). The experiment was laid out in partially confounded factorial design with two replications and three blocks in each replication. The experimental treatments consisted of twenty seven combinations of three levels each of nitrogen (75, 150 and 225 kg/ha) phosphorus (50,75 and 100 kg/ha) and potassium (50, 75 and 100 kg/ha). Increase in nitrogen levels results in increased plant height, number of tillers, number of leaves, fresh fodder yield and dry fodder yield. Phosphorus and potassium did not have any significant effect on these parameters, except dry fodder yield which was significantly reduced by potassium levels. Nitrogen content in the fodder was not influenced by either nitrogen or phosphorus or potassium. Phosphorus content in the fodder was increased by phosphorus application and potassium content was increased by potassium application. Uptake of nitrogen was higher at higher levels of nitrogen while phoshorus and potassium did not have any influence. Uptake of phosphorus was increased by nitrogen and phosphorus while potassium caused a reduction in phosphorus uptake. Potassium uptake was significantly increased due to nitrogen application. Crude fibre content in the fodder was found to decrease with an increase in the levels of NPK nutrients. Nitrogen caused a significant increase in the number of panicles per plant, but reduced the number of seeds per panicle significantly. Seed viability, seed germination and number of kernals /500 seeds were significantly increased by the levels of phosphorus while nitrogen and potassium showed no significant effect. Seed purity, seed moisture and 1000 seed weight were not influenced by none of the treatments. Maximum seed yield was recorded at the highest level of nitrogen, but neither nitrogen, nor phosphorus, nor potassium had any significant effect. Nitrogen content of the soil was found to increase with nitrogen fertilization and phosphorus content by phosphorus fertilization. Potassium status was increased by nitrogen and potassium.
Shade tolerance of guinea grass var. Mackuenii under different levels of potassium
(Department of Agronomy, College of Agriculture, Vellayani, 1982) Mullakoya, P; Raghavan Pillai, G
An investigation was carried out in the Instructional Farm attached to the College of Agriculture, Vellayani, during 1981-82 with the objective to assess the production potential of guinea grass var. Mackuenii under varying intensities of shade. It was also aimed to assess the potassium requirement was laid out in a 4 x 4 factorial randomised block design with 3 replications. The results of the study are summarised below: (1) Height of grass was positively influenced by both shade intensities and potash levels. (2) Leaf area of grass was increased with increase in shade intensities and potash levels. (3) Tiller production was adversely affected by shade, while potash application increased tiller number of grasses.