Browsing by Author "Meera Bai, M"

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Cutting management in subabul
(Kerala Agricultural University, 1990) Meera Bai, M; Lakshmi, S; Raghavan Pillai, G
Geospatial analysis and soil nutrient dynamics of Ruber plantations in relation to growing environment
(Department of Agronomy, College of Agriculture, Vellayani, 2013) Shankar Meti; Meera Bai, M
Integrated nutrient management in brinjal
(Department of Agronomy, College of Agriculture, Vellayani, 1999) Rekha, S R; Meera Bai, M
An experiment was conducted at the Instructional Farm, Vellayani during. the period from July to November, 1998. The objective of the experiment was to study the combined effect of organic manures, chemical fertilizers and biofertilizers on the productivity and quality of brinjal and to assess the possibility of substitution of fertilizers by organic manures and biofertilizers. Two sources of nitrogen, three types of organic manures, one Azospirillum treatment and two control treatments were tried in the experiment. The result of the study showed that growth characters viz., plant height, number of leaves and branches and LAI were significantly increased by poultry manure application. Integrated application of organic and inorganic sources recorded significantly higher values for all the growth characters. Yield attributes like time to 50 per cent flowering was considerably lowered by the application of 100 per cent organic source and by the poultry manure treatments. Poultry manure treated plots showed maximum number of flowers and fruits leading to maximum fruit set percentage. Marketable fruit yield per ha was found to be maximum for treatments receiving organic and inorganic sources at 1: 1 ratio and for poultry manure applied plots. The same trend was noticed in keeping quality of fruits at ambient temp~r.ature. The economics of cultivation revealed that whatever be the type of organic manure used, when it is applied along with chemical source in 1: 1 ratio the net returns and benefit cost ratio were maximum.
Integrated nutrient management in chilli (Capsicum annuum L.)
(Department of Agronomy, College of Agriculture, Vellayani, 2000) Sharu, S R; Meera Bai, M
A field experiment was conducted at the Instructional Farm attached to the College of Agriculture, Vellayani during 1999-2000 to study the combined effect of chemical fertilizers and organic manures on the productivity and quality of chilli, to assess the possibility of substitution of fertilizers by organic manures and also to work out the economics of production. The treatments consisted of combined application of chemical fertilizers and organic manures viz. poultry manure, vermicompost and neemcake in various ratios of 3: 1, 1: 1, 1:3 and 0:2. The control treatment was POP recommendation of KAU (20 t ha! of FYM + 75:40:25 kg N, P205 and K20). The experiment was laid out in randomised block design. An abstract of the result is given below. Plant height, number of branches, shoot-root ratio and dry matter content differed significantly with various treatments. All these parameters were found to be increasing with increased level of chemical nitrogen. Shoot-root ratio was highest for vermicompost applied plots whereas the maximum value for all other growth parameters was produced by poultry manure treatments. All the yield parameters were significantly influenced by various treatments. Higher fruiting phase and fruit set was observed with 2 increasing chemical nitrogen level and maximum value was obtained for poultry manure treatment (3: 1). Poultry manure treatment (1: 1) gave good performance with respect to number of fruits per plant, harvesting interval and total yield. Higher levels of poultry manure along with chemical fertilizers also performed well. Length of fruit was highest for vermicompost treated plots along with chemical fertilizers (1: 1). Highest level of chemical fertilizer along with poultry manure gave good results with respect to LAI and dry matter production. RGR, CGR and NAR was highest for vermicompost applied plots. Keeping quality and ascorbic acid content was higher for poultry manure treatments. Regarding residual nutrients high soil K was registered by higher level of neemcake along with chemical fertilizer. Highest soil N was noted by highest dose of poultry manure (0:2). Poultry manure and chemical fertilizer in equal proportion obtained highest value for soil P. Highest dose of poultry manure together with chemical nitrogen gave good result for NPK content of plants. NPK uptake was also higher for poultry manure treatments. Incidence of bacterial wilt was least in dual application of chemical fertilizer and neemcake in the ratio 3: 1. The economics of cultivation revealed that poultry manure and chemical fertilizer application in equal proportion (1: 1) gave maximum net returns and benefit-cost ratio.
Phosphorus nutrioperiodism in rubber
(Department of Agronomy, College of Agriculture, Vellayani, 2004) Jessy, M D; Meera Bai, M
Mature rubber tree does not respond to application of phosphorus fertilizers consistently. In majority of the earlier fertilizer experiments on mature rubber, there was no response to application of phosphorus fertilizers, in terms of growth and yield. Trees continued to maintain leaf P status without application of P even when the soil P status was low. An experiment was initiated at the Rubber Research Institute of India, Kottayam in 1997 in an area planted in 1984 to study the response of mature rubber to phosphorus application. From planting to till the commencement of the experiment all trees were given uniform quantities of nutrients. Treatments were imposed from 1998 onwards. Detailed investigation was carried out in this experiment during 2002-2004 to explore the possibility of reducing the present dose of P fertilizer (30 kg P2O5 ha-1 year-1) for mature rubber. Phosphorus was applied at five levels (0,10,20,30 and 40 kg P2O5 ha–1 year¬1). Nitrogen and potassium were applied @ 30 kg ha-1 year¬1 at uniform rates. None of the growth characters studied, viz., girth, girth increment, length of tapping panel and bark thickness were influenced by the application of P. The yield and dry rubber content were also not influenced by levels of applied P. Trees which did not receive any P fertilizer continued to maintain leaf P status at comparable levels with that of the P applied treatments. Magnesium content of the leaves was generally higher in the P applied treatments after fertilizer application. Content of other nutrients (N, K, Ca, Fe, Mn, Zn and Cu) in the leaves was not affected by the different treatments. The accumulation of P and other nutrients in the dry matter was not influenced by application of P. The content of P and other nutrients (N, K, Ca, Mg, Fe, Mn, Zn and Cu) in the latex and their annual removal were not influenced by the levels of applied P. The quantity of litter added and the litter nutrient content were also not affected by the different treatments. Removal of P through latex was slightly less than addition through litter. Before defoliation the litter P content was comparatively less in the treatment which did not receive any P fertilizer indicating high P utilization efficiency of trees. Application of P did not influence the content of different P fractions (saloid P, Fe-P, Al-P, Ca-P, reductant P, occluded P and organic P) in soil. Organic P constituted more than 50 per cent of the total P in the soil. Total P content was significantly higher in the treatments which received higher levels of P. Soil available P status was higher in P applied treatments. In most cases, a decline in micronutrient content was observed in the treatments which received higher levels of P. More than 85 per cent of the roots were colonised by arbuscular mycorrhizal fungi (AMF), but no relation was observed between the levels of applied P and root colonization. Population of phosphorus solubilizing bacteria (PSB) in the rhizosphere was suppressed after application of P whereas the population of other microorganisms (total bacteria, phosphofungi, total fungi and actinomycetes) was not influenced. The trees which were not supplied with P improved their P acquisition by several processes. Secretion of acid phosphatase, an enzyme which hydrolyzes organic P, was found to be higher from the roots of trees which did not receive P fertilizers. Soil phosphatase activity was also higher in the rhizosphere of trees which did not receive any P fertilizer. Activities of phosphoenol pyruvate carboxylase (PEPC) and malate dehydrogenase (MDH), enzymes involved in the biosynthesis of organic acids were higher in the roots of trees which were not supplied with P fertilizers indicating the possibility of more exudation of organic anions and H+ from these trees. Rhizosphere pH was generally lower in the treatment which did not receive P fertilizers. Compared with non-rhizosphere soil pH, rhizosphere pH was comparatively higher in most cases. Roots of mature rubber trees explored a large area of soil (89.38 m2). More than 60 per cent of the fine roots explored the surface 10 cm layer indicating that the trees have a high P acquisition efficiency. A spatial difference in fine root production and distribution was observed between treatments. Trees which were not supplied with P produced more fine roots than trees supplied with P. Root hair production was also higher in the control trees. All these adaptations contributed to a high P acquisition efficiency of rubber trees which were supplied with P during active growing phase. The results of the present study indicate the self sustainability of phosphorus cycle in a well managed mature rubber plantation which was fertilized during the active growing phase of the plant suggesting the possibility of skipping P application in trees of that age group. This situation is likely to continue during the later phase also, however if a need is indicated through leaf P status, application of P can be resumed.
Sustainable nutritional practices for bittergourd-amaranthus intercropping system
(Department of Agronomy, College of Agriculture, Vellayani, 2003) Renu C Nair; Meera Bai, M
A field experiment was conducted at the Instructional Farm, College of Agriculture, Vellayani during 2001-2002 to identify sustainable nutritional practices for enhancing the yield, quality and income from bittergourd and to assess the economics of intercropping amaranthus in bittergourd. The experiment consisted of seven nutrient sources and two cropping systems and was laid out in factorial RBD with three replications. The various nutrient sources as well as cropping system exerted significant influence on growth parameters and yield attributing characters of bittergourd. Application of 50 per cent N as poultry manure + 50 per cent N as chemical fertilizer significantly increased the growth, yield attributes and the total yield. Bittergourd grown as pure crop showed increase in growth parameters, yield attributes and yield. The nutrient sources influenced the quality characters of bittergourd. Keeping quality was higher for vermicornpost treatment while ascorbic acid content and iron content were higher for the integrated application of poultry manure and chemical fertilizer. Highest value for NPK content of plants and NPK uptake was obtained when chemical sources of nitrogen was substituted with poultry manure in I: 1 ratio. The soil physical properties were improved significantly by the application of organic manures alone. Soil available nitrogen and potassium were higher for the treatment in which 100 per cent N was applied as vermicompost. The depth of root penetration was not affected by intercropping in bittergourd and amaranthus. The root spread was more in amaranthus when grown as an intercrop compared to sole cropping. The nutrient release pattern of organic manures had shown that there is a progressive increase in the availability of Nand P20S till the 90th day and for available K20 there was a progressive increase upto 60th day and thereafter decreased. Among the three organic manures, poultry manure showed higher availability of the three nutrients. The economics of cultivation revealed that application of 50 per cent N as poultry manure + 50 per cent N as chemical fertilizer gave the maximum net returns and benefit-cost ratio. The net returns and B:C ratio were higher under bittergourd-amaranthus intercropping system compared to sole crop of bittergourd.