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ThesisItem Open Access Integrated nutrient management for basmati rice(oryza sativa L) production(Department of Agronomy, College of Agriculture, Vellayani, 2007) Tulasi, T; Shalini Pillai, PA study entitled “Integrated nutrient management for basmati rice (Oryza sativa L.) production” was undertaken at the Cropping Systems Research Centre, Karmana, Thiruvananthapuram, Kerala, from September 2006 to January 2007, with the main objective of evaluating the relative efficiency of different integrated nutrient management practices on the yield and quality of basmati rice. The experiment was laid out in (4 x 2) + 2 Randomized Block Design with three replications. The treatments comprised two organic sources (M1- FYM, M2- FYM + neem cake) and four levels of inorganic substitution with organics (L1- 25 percent substitution, L2- 50 percent substitution, L3 - 75 percent substitution, L4 -100 percent substitution.) compared against two controls (absolute control, standard practice). The test variety was Pusa Basmati-1. The response of the growth characters (plant height, tiller count and LAI) was more pronounced with respect to the levels of substitution than the organic sources. Substituting the entire quantity of the standard dose of fertilizers (SDF) and 50 percent substitution of SDF with organics were more or less equally effective in boosting the vegetative growth of basmati rice. Between the two organic sources tried, the application of FYM and among the levels of substitution, 25 percent substitution recorded higher shoot biomass. The combined application of FYM + neem cake (M2) and 50 percent substitution of SDF with organics (L2) resulted in higher panicle biomass. The higher number of productive tillers, spikelets per panicle and a lower sterility percentage supported by substituting 50 percent of SDF with FYM + neem cake, reflected upon the grain yield also. This treatment combination was at par with the standard practice. Though the cooking properties were not influenced by INM, in general, the optimum cooking time was lower and the volume expansion and grain elongation ratios were higher at 50 percent substitution of SDF with organics. Integration of chemical fertilizers and organics maintained a higher crude protein and intermediate amylose content. The organoleptic test rankings were higher for 75 percent and 50 percent substitution with FYM + neem cake. Integrated nutrient management was observed to produce grains, which were as good as or even better than the market sample, with the respect to grain quality attributes studied. Application of FYM to the substitute chemical fertilizers resulted in higher uptake of nitrogen and potassium. The phosphorus uptake was maximum with 100 percent organic nutrition. The agronomic efficiency and apparent recovery efficiency of basmati rice improved significantly when 50 percent of the chemical fertilizers were applied as FYM + neem cake. This treatment was at par with the standard practice. The organic carbon, available nitrogen and available phosphorus status of the soil remained unaffected after the experiment. Application of FYM in conjunction with neem cake as a substitute for chemical fertilizers, improved the available potassium status of the soil. Considering organic sources tested, application of FYM was more remunerative than the combined application of FYM + neem cake. The effect of substitution on net income and BCR was not significant. Between the various treatment combinations including controls, the standard practice, 25 percent substitution of chemical fertilizers with FYM and 50 percent substitution fertilizers with FYM + neem cake were at par. The study indicated that the response of basmati rice to INM was at par with the standard practice. However, considering the multifaceted benefits of organics, on crop yield, quality and soil health, integrated nutrient management needs to be emphasized. Thus it could be concluded that, the treatment combination where in 50 percent of the standard dose of fertilizers was substituted with a combination of FYM and neem cake, was a better option than the application of chemical fertilizers alone for achieving higher yields and quality in basmati rice. Substituting the entire dose of chemical fertilizers with organics (L4) was found to improve the growth, yield, nitrogen use efficiency and nutrient uptake in basmati rice. The volume expansion and crude protein content were better at 100 percent organic nutrition. Thus the present study also revealed the possibility of adopting organic nutrition in basmati rice without any appreciable reduction in yield and quality.ThesisItem Open Access Efficacy of vermicompost,vermiwash and amf on quality seed production of bhindi(Department of Agronomy, College of Agriculture, Vellayani, 2005) Nishana H; Sajitharani TAn experiment was conducted at College of Agriculture, Vellayani during June to September of 2004 to evaluate the efficacy of vermicompost, vermiwash and AMF on quality seed production in bhindi. The experiment was laid out in split plot design with two replications. The main treatments were aquatic weed vermicompost, banana pseudostem vermicompost and farmyard manure along with vermiwash through soil application, foliar application, soil + foliar application and control treatment as water spray. The subplot treatments consisted of AMF application and without AMF application. Taller plants were observed in banana pseudostem vermicompost and aquatic weed vermicompost treated plots. Significantly higher number of leaves with high leaf area index and dry matter production was noticed in aquatic weed vermicompost compared to other organic manures. Days for 50 per cent flowering was found maximum for farmyard manure. Aquatic weed vermicompost also showed better root characteristics along with yield attributes such as number of flowers plant-1, number of fruits plant-1, fruit yield plant-1, total fruit yield ha-1, number of seeds fruit-1 & seed yield ha–1 with better seed quality parameters like seed viability, seeding vigour and germination percentage. Among the modes of vermiwash application, soil + foliar application of vermiwash was found better in showing superior trends in plant height, number of leaves, leaf area index, dry matter production, number of flowers and fruits plant-1, fruit yield plant-1, total fruit yield and seed yield ha–1 with better seed quality i.e., seedling vigour and germination percentage. AMF application also showed maximum plant height, leaf area index, dry matter production, root length, root - shoot ratio, fruit yield plant-1, total fruit yield, weight of seeds fruit-1 and seed yield ha–1. Higher BC ratio was found in aquatic weed vermicompost, soil + foliar application of vermiwash and in AMF. So aquatic weed vermicompost along with soil + foliar application of vermiwash and AMF is ideal for quality seed production in bhindi.ThesisItem Open Access Identification of drought tolerant cocoa types(Department of Agronomy, College of Horticulture, Vellanikkara, 2005) Binimol, B; KAU; George Thomas, CExperiments were conducted at the college of Horticulture, Vellanikkara to investigate the drought tolerant characteristics of the most promising cocoa varieties and accessions. The investigation involved a two-stage screening of cocoa seedlings and budlings and monitoring of their field grown plants. As the first step, a preliminary screening was done on six month old seedlings and budlings of ten cocoa cultivars released from Kerala Agricultural University and twenty promising accessions. A secondary screening of cocoa cultivars/accessions selected from the preliminary screening was then conducted. Simultaneously, field monitoring of cocoa trees of the varieties selected from the primary screening was also done. From the preliminary screening, seven apparently tolerant varieties were selected for secondary screening in both seedlings and budlings based on higher RWC and DWF, lower percentage of dried leaves and longer duration of life under during moisture stress. Three apparently sensitive verities were also selected based on opposite values of the above characters. Varieties identified in the preliminary screening were subjected to a secondary screening under three moisture regimes of no irrigation , watering once in five days (life saving irrigation), and regular watering. Observations on physiological parameters such as relative leaf water content, dry weight fraction, leaf drying percentage, number of days taken for complete drying, stomatal conductance, transpiration rate, leaf water potential, chlorophyll ‘a’, ‘b’ and total chlorophyll, chlorophyll stability index, leaf area per seedling, membrane stability, relative injury; growth characters like plant height, collar girth, number of leaves and total biomass; biochemical characters such as proline content and nitrate reductase activity were recorded. After conducting a cluster analysis, the varieties with high RWC, DWF, total chlorophyll content, leaf water potential and proline content; low stomatal conductance, transpiration rate and leaf area during water stress were rated as drought tolerant and with opposite characters as drought sensitive. Based on these, in seedlings; the varieties M 13.12, GII 19.5 and GVI 55 were ranked as moisture stress tolerant and GVI 61, GV 50 and GI 4.8 as sensitive under no irrigation. In budlings, the varieties GI 4.8 and GII 19.5 were selected as drought tolerant and GIII 4.1, GVI 51 and GII 12.3 as drought sensitive under no irrigation Important characters were also monitored in 16-year old clonal trees of the seedlings/budlings of the varieties selected from primary screening. Transpiration rate, stomatal conductance, leaf water potential, stomatal frequency, leaf thickness, bark thickness and soil moisture content were recorded during summer. The varieties GVI 61, M 13.12 and GI 4.8 showed drought tolerant features. The accession M13.12 (CCRP2) showed drought tolerant features in secondary screening of seedlings and field performance. The accession GVI 51, which showed sensitivity to moisture stress in seedlings (but tolerant in budlings) under secondary screening, was showing similar behavior of sensitivity in field grown plants. The study shows the possibility of exploiting drought tolerant features of cocoa varieties/accessions. However, final conclusions are difficult to be drawn as only 10 accessions were subjected to secondary screening and field monitoring, and data for only one year were collected. In the light of the promising results obtained, screening trails involving more number of varieties/accessions have to be conducted and monitored for more number of years to get consistent values.ThesisItem Open Access Integrated weed management in lowland rice(Department of Agronomy, College of Agriculture, Vellayani, 2004) Seema, V; KAU; Janardhanan Pillai, SA field experiment was conducted at Cropping Systems Research Centre (CSRC), Karamana, Thiruvananthapuram to evolve a suitable integrated weed management practice for lowland nee. The study was conducted during the viruppu season of 2003. The field experiment was laid out in randomised block design having three replication with twelve treatments. The treatments include different herbicides in combinations, herbicides + hand weeding, hand weeding twice and unweeded control. Butachlor, 2,4~D, pretilachlor, anilofos + 2,4-DEE, anilofos, ethoxysulfuron, metsulfuron methyl and chlorirnuron- ethyl were the different herbicides used in the experiment. The rice variety used for the experiment was Kanchana. The results of the study revealed that grasses, broadleaved weeds and sedges competed with the rice crop. Different weed management practices significantly influenced the intensity and distribution of weeds ... The lowest dry matter of weeds was recorded by anilofos + ethoxysulfuron followed by one hand weeding which was on par with anilofos -+ ethoxysulfuorn alone. All the weed management treatments resulted in improved yield attributes and higher grain yield compared to weedy check. The plots treated with anilofos + ethoxysulfuron followed by hand weeding at 40 DA T recorded the highest grain yield. This treatment resulted in enhanced plant height, number of productive tillers un', LAI and nutrient uptake of rice. The yield attributes and grain yield were significantly increased by this treatment. The total weed population, weed dry matter production and nutrient removal by weeds were also reduced and weed control efficiency was increased by this treatment. Unweeded control recorded the lowest gram yield. No herbicide used in this experiment resulted m residual toxicity after the cropping season. Manual weeding is expensive, laborious and time consummg. Labour non-availability at peak crop season for weeding also poses great threat. Readymix application of anilofos + 2,4-DEE (T3) resulted in highest B:C ratio of 1.41 and butachlor + 2,4-D (T,) with 1.40. Pre-emergence application of anilofos + ethoxysulfuron followed by one hand weeding at 40 DA T (T 8) was the most remunerative treatment.ThesisItem Open Access Nutrient management of guinea grass (Panicum maximum J.) under open and shaded conditions(Department of Agronomy, College of Agriculture, Vellayani, 2004) Lekshmi, P; KAU; Lakshmi, SA field experiment was conducted at the Instructional Farm, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala state to find out the nitrogen and phosphorus requirement for guinea grass (Panicum maximum J.) under zero and 50 per cent shade levels. The influence of shade levels, nitrogen and phosphorus application on growth parameters, fodder yield, quality of produce, physiological parameters, uptake of nutrients, chemical properties of soil and economics was investigated. Two levels of shade (0 and 50 per cent), three levels of nitrogen (100, 200 and 300 kg ha") and three levels of phosphorus (25, 50 and 75 kg ha") were combined to form eighteen treatment combinations. The experiment was laid out in split plot design with three replications. Results of the experiment revealed that lower levels of shade as well as higher- levels of nitrogen and phosphorus had significant positive influence on improving the fodder production potential of guinea grass. The lower levels of shade and higher doses of nitrogen and phosphorus were found to increase significantly the growth parameters namely number of tillers and leaf: stem ratio and physiological parameters like leaf area index, CGR, RGR and NAR. , Lower levels of shade and higher doses of nitrogen and phosphorus registered maximum green fodder yield in all the five harvests. Total green fodder yield was also highest at open and at higher levels of nitrogen and phosphorus. Similar results were obtained in the case of dry fodder yield also. Quality parameters of the forage significantly improved as shade progresses. Higher levels of nitrogen and phosphorus registered higher crude protein and chlorophyll contents and lower crude fibre content. The nutrient content of plant showed a significant increase with increasing levels of shade while the nutrient uptake showed a significant increase with lower levels of shade. Application of nitrogen and phosphorus significantly increased the content and uptake of nitrogen, phosphorus and potassium. There was a significant increase In available phosphorus and a decrease in available potassium content of the soil with increase in shade levels. Application of nitrogen significantly increased the nitrogen content of the soil while reduced phosphorus and potassium content of the soil after the experiment. Phosphorus levels also significantly increased the nitrogen and phosphorus content but potassium content of the soil after the experiment showed a parabolic type of response. Lower levels of shade with higher dose of nitrogen and phosphorus registered highest net returns and benefit cost ratio. But economic yield was obtained in shade intensity upto 50 per cent.ThesisItem Open Access Evaluation of establishment methods and AMF application on growth and yield of rice(Department of Agronomy, College of Agriculture, Vellayani, 2004) Jayakiran, K; KAU; Sajitharani, TAn experiment was conducted at College of Agriculture, Vellayani during kharif season (June - September 2003) to evaluate the efficiency of different planting methods and AMF application en the establishment, growth and yield attributes of rice. The experiment was laid out in split plot design with five replications. The main treatments were seedling , throwing, machine planting and line transplanting methods. The subplot treatments consisted of AMF application and without AMF application. Maximum establishment as noticed in line planting. More root activity, plant height, leaf area index, dry matter production and tillers were observed in seedling throwing method. Days to 50 per cent flowering was minimum in machine planting. Higher number of filled grains per panicle was observed in line planting. Higher number of productive tillers, panicles m-2 and straw yield was observed in seedling throwing method. Higher grain yield was observed in seedling throwing and line planting methods. Maximum harvest index was noticed in line planting. Higher uptake was noticed in seedling throwing method. AMF inoculated plants show~d supenor trends in establishment plant height, leaf area index, drymatter production, number of productive tillers, panicles m ", filled grains panicle.", 1000 grain ,eUEbt. grain yield and straw yield. Higher gross return and net return was observed in seedling ing method. In machine planting and see~ling throwing there was high labour saving compared to line planting .. High B : C ratio, gross turn and net return were observed in AMF inoculated plants. Machine planting of seedlings raised in AMF inoculated mat nursery, at a spacing of 30 x 10 cm followed by seedling throwing of MF inoculated seedlings recorded higher B : C ratio.ThesisItem Open Access Concurrent growing of green manure crops in dry and wet seeded rice(Department of Agronomy, College of Horticulture, Vellanikkara, 2008) Anitha, S; KAU; Jose, MathewAn investigation entitled ‘Concurrent growing of green manure crops in dry and wet seeded rice’ was conducted at Agricultural Research Station, Mannuthy to develop a comprehensive technology package for the system of concurrent growing of green manure crops in direct seeded rice. The investigation consisted of four experiments viz., Experiment Ia - Concurrent growing of green manure crops in dry seeded rice, Experiment Ib - Residual effect of concurrent growing of green manure crops in dry seeded rice, Experiment IIa - Concurrent growing of daincha in wet seeded rice and Experiment IIb - Residual effect of concurrent growing of daincha in wet seeded rice. The experiment on concurrent growing of green manure crops in dry seeded rice consisted of two green manure crops (horse gram and cowpea), three methods of incorporation (Incorporation by cono weeder, desiccation by 2,4 - D spray @1.0 kg ha-1 and allowing for self decomposition) and two levels of nitrogen (100 and 75% of recommended N) and a control without green manure crops . Among the two green manure crops, cowpea was the best in supplying the required quantity of green matter with 25 per cent savings of N fertilizer and a substantial reduction in weed incidence. All the three methods of incorporation were found to be equally effective. Hence in places where there is a difficulty in self decomposition, cowpea can be effectively incorporated by conoweeder or by spraying 2, 4-D. The cowpea variety used in this study was a short duration bush type variety facilitating additional pod yield from cowpea before it was incorporated. Concurrent growing of cowpea along with dry seeded rice is a viable system as it resulted in increased productivity, profitability and sustainability dry seeded rice. In the experiment to study the residual effect of concurrent growing of green manure crops in dry seeded rice, the main plots of dry seeded rice crop during the 1st crop season were divided into two sub plots and applied 100 and 75 per cent N to the subplots. The results revealed that concurrent growing of green manure crops were effective in increasing the yield and sustaining soil fertility status compared to pure crop of rice receiving 5 t ha-1 of FYM and 100 per cent of the recommended nitrogen. But there was no savings of N fertilizer to the succeeding transplanted rice crop as the highest yield of succeeding rice was achieved only when it received 100 per cent of the recommended N. The profitability of the rice- rice cropping system was the highest with concurrent growing of cowpea in dry seeded rice. The experiment on concurrent growing of daincha in wet seeded rice consisted of two stages of incorporation of daincha (20 DAS and 30DAS), three methods of incorporation (Incorporation by cono weeder, desiccation by 2, 4 - D spray @1.0kg ha-1 and Desiccation by Chlorimuron ethyl+ met sulfuron methyl spray @ 4.0 g ha-1 met sulfuron methyl spray @ 5 g ha-1) and two levels of nitrogen (100 and 75% of recommended N) and a control without daincha. Results indicated that concurrent growing of daincha can be successfully practiced in wet seeded rice with improved productivity. Incorporation of 30 days old daincha employing any of the three methods of incorporation was equally effective in increasing the productivity and profitability of wet seeded rice. Incorporation of daincha at 30 DAS could add about 14 t ha-1 of green matter with minimum investment and resulted in 70 per cent weed suppression. Concurrent growing of daincha receiving both 100 and 75 per cent of recommended N produced significantly higher yield than pure crop of rice receiving 5 t ha-1 of FYM and 100 per cent of the recommended nitrogen. Hence there was a saving of 25 per cent N without affecting the yield. The highest yield was obtained when 100 per cent of recommended N was applied to the system. The treatments for the experiment to study the residual effect of concurrent growing of daincha in wet seeded rice were similar to that of dry seeded rice. The results showed that concurrent growing of daincha and its incorporation at 30 DAS was effective in increasing the yield of succeeding rice and sustaining soil fertility status compared to pure crop of rice receiving 5 t ha-1 of FYM and 100 per cent of the recommended nitrogen. The highest yield of succeeding rice was achieved only when it received 100 per cent of the recommended N hence there was no savings of N fertilizer to the succeeding transplanted rice crop. Concurrent growing of daincha in wet seeded rice increased the profitability of the rice- rice cropping system. Concurrent growing of green manure crops in dry and wet seeded rice is a management alternative to reduce the production cost and to increase the yield of rice and is a practical model for sustainable rice production.ThesisItem Open Access Nutrient source efficiency relations on the productivity of cowpea in summer rice fallows(Department of Agronomy, College of Horticulture, Vellanikkara, 2006) Lekha, B. Nair; KAU; Savithri, K VA field experiment was conducted in the rice fallows of Agricultural Research Station, Mannuthy, during the summer season (February – April) of 2005, to study the effect of different sources of nitrogen and phosphorus on growth, yield and quality of cowpea and to asses the possibility of reducing the quantity of fertilizers through inoculation of phosphate solubilising bacteria and foliar application of diammonium phosphate. The experiment was laid out in randomized block design with seventeen treatments and three replications. The treatments included were, different sources of nitrogen and phosphorus along with or with out phosphate solubilising bacteria inoculation and foliar application two percent diammonium phosphate twice and package of practices recommendation alone. Most of the growth characters, dry matter production, yield and yield attributes and uptake of N, P, K, Ca, Mg, and S were higher in the treatments which received nitrogen in the form of urea and phosphorus in the form of rock phosphate. The influence of rock phosphate was more when it was applied along with phosphate solubilising bacteria inoculation. Foliar application of two percent diammonium phosphate at pre flowering and flowering stages increased the growth characters and drymatter production but showed a reduction in yield and yield attributes of cowpea. The protein content of grain and Bhusa was not significantly influenced by various sources of nitrogen and phosphorus, phosphate solubilising bacteria inoculation and foliar spray of two percent diammonium phosophate. None of the treatments could bring about much impact on soil nutrient status. However, complete basal application of nitrogen and phosphorus showed a slightly higher content of N, P, K, Ca, Mg and S over their 50 percent application. Moreover, application of nitrogen as ammonium sulphate resulted in a slightly higher content of sulphur in the soil compared to application of urea. Among the various treatments, considering the growth and yield of cowpea as well as economics, basal application of 50 percent nitrogen as urea and 50 percent phosphorus as rock phosphate along with phosphate solubilising bacteria inoculation and subsequent foliar spray of two percent diammonium phosphate at pre flowering and flowering stages was found to be the best.ThesisItem Open Access Impact of long term integrated nutrient supply system on soil health and rice productivity(Department of Agronomy, College of Agriculture, Vellayani, 2007) Raji S, Prasad; KAU; Babu Mathew, TA field experiment was carried out in both kharif and rabi seasons during 2004-2005 at Cropping System Research station, Karamana to find out the effect of long term integrated nutrient supply system on soil health and productivity of rice ( Oryza sativa L) –rice sequential cropping system. The experiment was laid out in RBD with 12 treatments in 4 replications and treatments in kharif and rabi together form one set of treatment. The treatments included control , 50% ,75% and 100% levels of RDF in kharif and rabi and 50% or 25% substitution of recommended dose of nitrogen in kharif substituted by organic manure viz. FYM , crop residues and green manure. The treatments exerted profound influence in majority of growth characters and yield attributes. Application of 25% or 50% substitution of RDF through organic manure along with 75% or 100% RDF in rabi through chemicals produced remarkable influence in growth and yield attributes. In grain and straw yield of rabi and kharif , the highest values were given by those treatments which supplied either 50% or 25% of RDF through FYM or crop residues in kharif and 100% or 75% of RDF through inorganic fertilizers in rabi .Since these treatments were on par with each other, the best treatment is that which supply 25% RDF through organic manure in kharif and 75% of RDF through inorganic fertilizers in rabi since25% of the chemical fertilizers are saved there. The highest NPK contents in grain and straw in both kharif and rabi were recorded and mostly in those treatments with 50% or 25% of RDF through organic manures in kharif along with 100% or 75% of RDF through in organics in rabi The highest NPK uptake in all the crop stages in both kharif and rabi were also higher observed in plots those receive 50% or 25% of RDF through organic manures in kharif along with 100% or 75% of RDF through in organics in rabi The soil available P and K values did not vary remarkably in both Kharif and rabi .However soil available nitrogen in soil varied profoundly before and after rabi seasons and the maximum available nitrogen was observed before rabi in those plots which supply 25% RDF through crop residues in kharif and 100% RDF through chemical fertilizers in rabi and 50% RDF through green manure in kharif and 100% RDF through chemical fertilizers in rabi. The physical properties like bulk density and water holding capacity were also significantly influenced by the treatments before and after the experiment in which lower bulk density values were exhibited by organics applied plots in kharif and they also showed significantly higher water holding capacity compared to those treatments which were supplied with organic matter in kharif . Soil chemical properties like organic carbon and CEC remarkably improved in organic manure applied plots along with inorganics in rabi. The population count studies of bacteria, fungi, and actinomycetes revealed the positive influence of the collective application of organic matter and inorganic fertilizers on soil biological properties and its subsequent influence on soil health when compared with control. As per the economic analysis of the cultivation the maximum benefit cost ratio was exhibited by the treatment which received 25% of RDF in kharif through crop residues and 75% of RDF through in organics in rabi .