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ThesisItem Open Access Production potential of two fodder grasses under different management practices(Department of Agronomy, College of Agriculture, Vellayani, 1986) Raghavan Pillai, G; KAU; Madhavan Nair, K PThesisItem Open Access Time of application of pre-emergence herbicides in dry-sown rice(Department of Agronomy, College of Horticulture, Vellanikkara, 1989) Suja, G; KAU; Abraham, C TThesisItem Open Access Spatial arrangement and nutrient management for maize- fodder cowpea intercropping in rice fallows(Department of Agronomy, College of Agriculture Vellayani, Trivandrum, 1989) Geetha Kumari, S; KAU; Mohamed Kunju, UAn investigation was carried out during the summer season of l987-88 in the instructional farm attached to the College of Agriculture Vellayani to determine the best crop arrangement for a grain maize fodder cowpea inter cropping in summer rice fallows under different fertility levels • The different crop arrangements. tried were pure crop of maize at normal row arrangement, maize at normal row arrangement, + one, row of cowpea in between the maize pure crop of maize at paired row arrangement two rows of cowpea in the interpair spaces maize at paired rows of cowpea.ThesisItem Open Access Effect of NPK on seed progeny and air layers in cashew ( Anacardium occidentale L. )(Department of agronomy, College of Agriculture Vellayani , Trivandrum, 1985) Harishu Kumar, P; KAU; Sreedharan, CAn experiment was conducted to assess the "Ef f e c t of NPK fertilisers on seed orogeny and air layers in cashew at Cashew Seed Farm, Shanmtigodu under Central Plantation Crops Research Institute , Regional Station, f i t c a l 574 24 3, during 1982-84. fhe treatments consisted of test ing three le v e ls each of d,? and K on seed . rogen/ i.,d ai r layers Ln cashcv/. r ’ne study revc ile 1 t h . t d i f f e r en t grov.'th oar meter 7 i. e . , he L'jl'it, can>py rolLus, surf ice area, le a f area n ; : ; v/erc influenced by increasing le v e ls of I:PR. f ■ r t i I i. s e r s . [' r/ ii chlorophyl l , to I; il v.ug ir , le.it v; .ter f-,■ n* , in-: sp e c i f ic le if w ight v;ere influenced by » b ,n v/11 i I e n i t rci' p n 11 one i n c i i iset i , , ., ii c * * . I', i r 1 y i'ii s r: u I: i- c ’ i I i r r - • * * in f l o w e r i n g , numbt l r, f ft mi. t e, _ .m ,lg ,■ I ; -I -,l puilr-h t'< t-i.l il 'hoots WC IX ; i ? V i . r ‘ I i I -■ 1 nr r r 1.0,1 b y f.f r » i I i d L >n . t’rmt j;un ii r‘ rc rn> r ri o nl; inrl acc' u b i ^ ici-1 c o n t e n t , ] Lc if ion . /c r | , 7 0 1 1 0 ' J W l ! " l p l Mut v Jupic an 1 IglTt wctr drrrc ir.ecl due to d M M, ion w,lH. V ipol ic .Llon ( ivour* rl nut md P i p d i ' - 1 , 4-r d W- i n ( k c - T l u 1 n - Leaf N v;as increased by NPIC. Lear ? was increased by p and K appl icat ion v/hile i t was reduced by N appl icat ion. Leaf K was reduced by H appl icat ion while i t was increased by ? and K appl icat ion. N appl ication resul ted in an Increase in le a f C i, where as P and K reduced i t . M and K reduced le a f Mg while P had no e f f e c t . M increased lui f Zn while P reduced the same. K had no e f f e c t . Cr i t ical levels in Ic if for M and ? are f ixed at 2.09% and 0.14% respectively. hoot CSC was increased by UP.' f e r t i 1 is ition . .1 application reduc’d organic carbon and P ‘./hale- i t i.nere -Scd ^>oil M, h and oH. P appl ication increased o i l d, K and pH. ‘V. ipol icat ion incr*. ia«_ , roi l H, h and oH wher>- as i c r c r\ v c c r: o i l P • rj ind P f spons r, r*. curvul in«. ar while not as i u ■ esnonrs v m Jincir. rhc od.imuni of U and P r , pc-j/trr ,./y ai re no-. c t ivt 1 y . M ixvv.um income W L. 1. ' - * * r t ' l i - r r l In lie 1 IV- r r . rThesisItem Open Access Response of modern varities of rice to nitrogen in kole lands(Department of Agronomy, College of Horticulture, Vellanikkara, 1987) Premkumar, J; KAU; Sreedharan, CAn experiment was carried out in Kole lands during the Kole season of 1985 (December-January to March-April) to ascertain and compare the nutritional requirement of short duration rice varieties and pre – release culture 10-1-1. The treatments consisted of factorial combination of 3 varieties ( Jyothi, Culture 10-1-1 and Triveni) and 5 levels of nitrogen (50,70,90,110 and 130kg N ha-1) in Randomised Block Design, replicated thrice. It was found that the pre-release Culture 10-1-1 had significantly higher plant height, tiller number, leaf area index, dry matter production, number of panicles per m2 and thousand grain weight over other varieties. Triveni recorded the highest filled grains per panicle and weight per panicle. There was no variation in grain yield among the cultivars tested. Culture 10-1-1 registered the highest straw yield and nutrient uptake. Culture 10-1-1 also recorded the highest net income over the varieties tested. Application of nitrogen increased the vegetative characters and yield attributes of rice viz., plant height, tiller production, number of panicles per m2, panicle length, panicle weight, filled grains per panicle and thousand grain weight. The highest grain yield and net income was obtained by Jyothi at 110 kg N ha-1 and that for culture 10-1-1 and Triveni at 90 kg N ha-1. Straw yield and dry matter production were increased upto 110 kg N ha-1. The uptake of nutrients were also influenced positively by nitrogen fertilization. The per day production of Jyothi, culture 10-1-1 and Triveni was found to be 42.65, 51.63 and 49.88 kg, respectively at 90 kg N ha-1. The present investigation revealed that the optimum level of nitrogen fertilization to be 103.74, 97.48 and 93.07 kg ha-1 for Jyothi, Culture 10-1-1 and Triveni, respectively. It was also observed that the field duration of culture 10-1-1 was only 77 days compared to that of 79 and 91 days of Triveni and Jyothi respectively. Benefit cost ratio was highest for Culture 10-1-1 thus indicating the scope of popularizing this cultivar as a short duration variety in Kole land.ThesisItem Open Access Phosphorus management in a rice based cropping system(Department of Agronomy, College of Agriculture, Vellayani, 1989) Annamma, George; KAU; Sasidhar, V KIn order to standardize an appropriate phosphorus management practice in a rice based cropping system involving rice-rice-cowpea/sesamum, field experiments were carried out in the rice fields of the Instructional Farm, College of Agriculture, Vellayani from June 1984 to September 1986. The experiment was laid out in a randomized block design with three replications. There were eight treatments. The treatments comprised of (1) continuous phosphorus application to all the three crops in the system (2) phosphorus application to the first and second crops of rice (3) phosphorus application to the first crop of rice and third crop of cowpea/sesamum (4) phosphorus application to the first crop of rice only (5) phosphorus application to the second crop of rice and third crop of cowpea/sesamum (6) phosphorus application to the second crop of rice only (7) phosphorus application to the third crop of cowpea/sesamum only (8) control plot with no addition of phosphorus to any of the crops in the system. The salient findings of the experiment are as follows: Phosphorus application had no significant influence on grain and straw yield of first crop of rice. But available nitrogen, available and total phosphorus and available potassium of the soil were increased with phosphorus application. Direct, residual and cumulative effects of phosphorus had no significant influence on grain and straw yield of second crop of rice. Phosphorus uptake could not show any variation due to the different treatments. Available and total phosphorus content of the soil were highest under cumulative phosphorus treatment. All the growth and yield attributes of third crop of cowpea and sesamum were increased by the direct and cumulative effects of phosphorus. Grain yield of cowpea was significantly increased by the direct application of phosphorus. Eventhough not significant the highest sesamum yield was accorded by the direct and cumulative application of phosphorus. Phosphorus uptake in all the growth stages of the crop was highest in direct phosphorus plots. Available and total phosphorus content of the soil was highest in continuous phosphorus applied plots. There was no significant influence on grain and straw yield of first crop of rice after cowpea and sesamum in the direct, residual and cumulative effects of phosphorus. Residual phosphorus was sufficient to maintain the available nitrogen status of the soil. Available phosphorus of the soil was increased by the direct, cumulative and continuous application of phosphorus and total phosphorus by continuous application of phosphorus. Balance sheet of available phosphorus revealed that the soil phosphorus level almost maintained, where phosphorus was applied only to the third crop of cowpea or sesamum. The highest net return and benefit-cost ratio for the rice-rice-cowpea and rice-rice-sesamum system was obtained when phosphorus was applied only to the third crop in the rice fallow and the residual effect being utilized by the succeeding rice crops.ThesisItem Open Access Nutrient management in bitter gourd under partial shade(Department of Agronomy, College of Agriculture, Vellayani, 1989) Ravikrishnan, M K; KAU; Sasidhar, V KA field experiment was conducted at the College of Agriculture, Vellayani during 1988 to study the influence of three levels of each nitrogen (50, 70 and 90 kg/ha), phosphorus (15, 25 and 35 kg/ha) and potassium (25, 50 and 75 kg /ha) on growth, yield, content and uptake of major nutrients in bittergourd VK-1 (Priya) under partially shaded conditions of coconut gardens. The trial was conducted as 33 + 1 partially confounded factorial experiment in Randomised Block design with two replications. Higher levels of nitrogen had profound influence on growth characters like days for opening of first male and female flowers and their node of emergence, internodal length, length of main vine and total dry matter production. Application of phosphorus of 35 kg/ha had significant positive effect on the node of emergence of first female flower and total dry matter production. Yield attributes like sex ratio, fruits per plant and harvest index were not influenced significantly by the main and interaction effects of the major nutrients. However the control plots registered a significant reduction in values for these parameters. The fruit set was maximum at 90 kg/ha of nitrogen, 25 kg/ha of phosphorus and 25 kg/ha of potash. Application of 90 kg N/ha, 25 kg P2O5/ha and 50 kg K2O/ha recorded the maximum yield. The response of bittergourd to nitrogen levels was linear and that to phosphorus levels was quadratic. Application of potassium at 75 kg K2O/ha was found to significantly increase the fruit weight. The length and girth of the fruits were positively influenced by the application of nitrogenous fertilizer. Potassium at the rate of 75 kg K2O/ha recorded the maximum girth of fruits signifying its effect on this character. The nitrogen and phosphorus content of fruits and plants and protein content of fruits were found to be unaffected by the main effects of nitrogen, phosphorus and potash. An increase in potash level increased the potassium content of fruits and plants. Nitrogen at 90 kg/ha significantly increased the nitrogen uptake by plants and fruits and phosphorus uptake by plants as compared to other levels. Maximum potassium uptake by fruits was obtained by application of 35 kg P2O5/ha and 75 kg K2O/ha and uptake of potassium by plants was maximum at 90 kg N/ha, 35 kg P2O5/ha and 75 kg K2O/ha. The study indicated that application of 90 kg N/ha 25 kg P2O5/ha and 50 kg K2O/ha recorded the maximum yield and net returns from bittergourd cv. VK-1 (Priya) under partially shaded conditions of coconut gardens in the red loam soils of Vellayani.ThesisItem Open Access Slow release nitrogen in cassava nutrition(Department of Agronomy, College of Agriculture, Vellayani, 1988) Vinod, G S; KAU; Muraleedharan nair, VAn 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.ThesisItem Open Access Seed production in stylosanthes gracilis under varying levels of population density, nutrition, moisturiser regimes and cuttings(Department of Agronomy, College of Agriculture, Vellayani, 1989) Balachandran Nair, G K; KAU; Sreedharan, CAn investigation was carried out during the period from July 1980 to March 1982 in the Instructional Farm, College of Agriculture, Vellayani to study the agronomic techniques required for maximum seed production in Brazilian lucerne (Stylosanthes gracilis). The following three separate field experiments were conducted and data collected and analysed. The first experiment entitled ‘influence of cultivars and plant population on seed production’ was laid out as a22 Factorial Experiment in R. B. D and replicated five times with the objective to find out the best cultivar of Stylosanthes gracilis for seed production along with the seed rate. The treatments consisted of combinations of two cultivars of Stylosanthes gracilis viz. Schofield and Cook, and two seed rates viz. 2.5 and 5 kg/ha. The second experiment entitled ‘nutritional requirements of Stylosanthes for seed production’ was laid out as a32 Factorial Experiment in R. B. D and replicated thrice with the treatment combinations of three levels of phosphorus viz.80, 120 and 160 kg P2 O5/ha and three levels of lime viz. no lime, 375 and 750 kg lime/ha. The objective was to assess the phosphorus and lime requirement of the crop for maximum seed yield. The third experiment entitled ‘Effect of moisture regimes and cuttings on seed production’ was conducted as a 32 Factorial Experiment in R.B. D and replicated thrice with treatment combinations of three irrigation schedules (IW/CPE ratios) viz. 0.50, 0.75 and 1.00 and three cutting schedules viz. no cutting, one cutting and two cutting. The objective was to investigate the efficiency of irrigation schedules and cuttings on seed yield. The results from the investigation revealed that the variety cook produced significantly higher seed yield of about 64 kg/ha as against 35 kg/ha obtained from the variety schofield. The seed rate of 5 kg/ha gave the higher seed yield of about 56 kg/ha as against the seed yield of about 43 kg/ha under the seed rate of 2.5 kg/ha. The seed yield attributing characters like setting percentage of seeds and number of seeds per plant were maximum for the variety cook. All the growth characters contributed to about 66 per cent of the variation in seed yield. The highest net return per hectare was obtained when the variety schofield was grown under a seed rate of 2.5 kg/ha. Application of phosphorus at 120 kg and lime at 375 kg per hectare gave maximum seed yield of about 80 kg/ha. It was also found that higher levels of phosphorus like 120 or 160 kg/ha helped to increase the setting percentage of seeds. The biometric characters such as spread of plants, number of branches and LAI were significantly influenced by the application of 120 kg phosphorus and 375 kg lime per hectare. The nutrients uptake was also enhanced by the application of phosphorus and lime at the above levels. The growth characters influenced the seed yield by 53 per cent. The economic optimum doses of phosphorus and lime for maximum seed yield were found to be 149 kg and 593 kg per hectare respectively. The highest gross and net returns were obtained from plots treated with phosphorus and lime at 120 kg and 375 kg per hectare respectively. Irrigating the crop at IW/CPE ratio 1.00 gave the maximum seed yield of 89 kg/ha. When the crop was left without cut it produced the highest seed yield of 92 kg/ha. The maximum setting percentage of seeds and leaf production were observed when the crop was irrigated at ratio 1.00 and without cut. The no cutting treatment gave maximum number of seeds per plant. The biometric charaters like height, spread, number of branches and length of branches were all found maximum in treatments where no cutting was given. Maximum water use efficiency for seed production was recorded by the lowest irrigation ratio of 0.50 and also when the crop was left without cut. About 46 per cent of the variation in seed yield was explained by the growth characters. Maximum net return per hectare was obtained when the crop was irrigated at IW/CPE ratio 1.00 and without cut.
