Browsing by Author "Vikraman Nair, R"

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Assessment of nitrification rate of Kerala soils and agronomic factors influencing it
(Department of Agronomy, College of Horticulture, Vellanikkara, 1989) Marykutty Zacharias; Vikraman Nair, R
The present study 'assessment of nitrification rate of Kerala soils and agronomic factors influencing it' was conducted during June 1987 to November 1988 at the College of Horticulture, Vellanikkara, Trichur. A series of laboratory incubation studies were conducted using a total of 22 soil samples including 20 samples drawn from five soil types (laterite red, alluvial, forest and black soils ) of Keralaand two from Coimbatore (red and black). The presence of Nitrosomopas was observed in 11 soil samples and that of Nitrobacters in all soil tested. The nitrification rate was high for alluvial and black soils and low for the red laterite soils.
Assessment of nitrification rates of soils and screening of plant materials for nitrification inhibition properties
(Department of Agronomy, College of Horticulture, Vellanikkara, 1993) Rekha, C; Vikraman Nair, R
The present study ‘assessment of nitrification rates of soils and screening of plant materials for nitrification inhibition properties’ was conducted during January 1993 to August 1993 at the College of Horticulture, Vellanikkara, Trichur. The three soil types, laterite, alluvial and forest were used for nitrification rate assessment. The two soil types, laterite and alluvial were taken from different locations of variable crop association. A total of 13 samples were assessed. One soil sample with the maximum rate of nitrification from these were taken for screening of plant materials for nitrification inhibition properties. Fourteen different locally available plant materials were chosen for screening using N-Serve and neem cake as the standard inhibitors for comparison. Nitrification rate in nearly all the soil was low and there was no appreciable conversion of NH4 from to NO3. A distinct crop associated influence on nitrification rate was absent in the soils studied. The only exception was the alluvial sample with banana as the associated crop and this soil was hence chosen for screening of plant materials. N-Serve was found to be the most effective nitrification inhibitor. Among the plant materials tested, cashew shell was the only material which showed a distinct advantage over other materials including neem cake. Highest mean values in plant height and number of leaves at different growth stages and dry matter production, N content and N uptake were observed in the treatment receiving cashew shell. Other useful materials identified were tobacco waste, calotropis leaf, neem leaf and castor cake.
Biomass productivity and influence of intercrops in a pre-bearing coconut-casuarina agroforestry system
(Department of Agronomy, College of Horticulture, Vellanikkara, 1990) Usha, T; Vikraman Nair, R
An experiment was conducted in the pre-bearing coconut gardens of Agricultural Research Station, Mannuthy during the period from May 1987 to May 1988 to assess the biomass productivity of different intercrops grown in coconut - casuarina alleys and their effect on the growth of tree components and on the micro-meteorological parameters. The different cropping systems tried in coconut casuarina alleys were tapioca + groundnut, amorphophallus - horsegram, fodder maize + cowpea - fodder cowpea, guinea- grass' (throughout), fodder cowpea - sesamum, groundnut blackgram, modan paddy - sesamum- and control (without any intercrops). The experiment was laid out in randomised block design in plots of size 7.5 x 7.5 m and replicated thrice. The plant height of all the crops excepting thatof fodder cowpea and sesamum showed an increase when grown I; in coconut - casuarina alleys. The yields of tapioca,', groundnut (grown mixed with tapioca), amorpho phallus, blackgram and paddy were rather low in coconut - casuarina alleys compared to sole crop yields. Fairly high fodder yields of maize (mixed with cowpea) and guineagrasswere obtained when grown in coconut - casuarina alleys. Regarding the total biomass production of different cropping systems, amorphophallus - horsegram cropping system recorded the highest and groundnut - blackgram cropping system yielded the lowest. The soil physical properties like bulk density, particle density, maximum water holding capacity were not influenced by the different cropping systems. It was seen that most of the cropping systems except that involving guineagrass left the soil richer with respect to organic carbon content and most of the primary and secondary nutrients. The cropping system which recorded fairly high gross income, net income and benefit-cost ratios were amorphophallus - horsegram, fodder maize + cowpea - fodder cowpea and groundnut - blackgram. The different component crops grown in the alleys had no adverse effect on coconut or casuarina. Casuarina which was intercropped with coconut was found to be capable of generating a fuel wood yield of 10-11 t/ha/annum.
Canopy spread of and light infiltration through cassava (Manihot Esculenta Crantz) canopies
(Kerala Agricultural University, 1986) Ashokan, P K; Lalitha Bai, E K; Vikraman Nair, R
Comparative performance of fodder maize varieties at graded levels of nitrogen
(Kerala Agricultural University, 1980) Nair, M S; Vikraman Nair, R
Comparative performance of soybean varieties
(Kerala Agricultural University, 1985) Pushpakumari, R; Mercy George; Vikraman Nair, R
Experiments were conducted at the College of Horticulture, Vellanikkara during the south west monsoon seasons of 1980 and 1934 10 select soybean varieties suitable for the agro-climatic conditions of Kerala. These were laid out in randomised block design with 13 varieties during 1980 and 14 during 1984. The results of the study indicated that the varieties Bragg and EC 26691 may be adjudged as the most promising based on yield performance and consistency in yield over seasons. A further superiority of the variety, Bragg is to be recognised if protein content of seeds also is taken as a criterion.
Comparative performance of Soybean(Glycine max(L.) Merrill) varities
(Department of Agronomy, College of Horticulture, Vellanikkara, 1981) Pushpakumari, R; Vikraman Nair, R
An experiment was conducted in the Instructional Farm attached to the College, of Hortuculture, Vellanikkara, during the period from June 1980 to January 1981 to select soybean varieties suitable for the agroclimatic conditions of Kerala. The experiment was laid out in randomised block design with 14 varieties and three replications. The study revealed that there was no significant varietal difference in the expression of all growth characters and most of the yield contributing factors at any of the growth stages in both the seasons. But significant varietal differences in seed yield and stover yield were observed in the two seasons. The results of the experiment revealed that the varieties Bragg, JN 2750 and EC 26691 are most promising for the south west monsoon season of Kerala. The variety Monetta gave the highest protein content of 36 per cent and Bragg, Ankur and Improved Pelican respectively recorded the highest protein yield, oil content and oil yield in the south west monsoon season. The study further revealed that soybean cannot be successfully grown during north east monsoon season of Kerala without irrigation.
Comparison of three methods of measurement of leaf area in soybean
(Kerala Agricultural University, 1979) Geetha krishnan Nair, P; Vikraman Nair, R; Sukumaran Nair, P
Decomposition dynamics of cocoa litter under humid tropical conditions
(Kerala Agricultural University, Vellanikara, 2001) Sreekala, N V; Mercy, George; Unnithan, V K G; John, P S; Vikraman Nair, R
Dissolution rate of urea and muriate of potash packed in perforated polybags
(Kerala Agricultural University, 1985) Asokan, P K; Vikraman Nair, R; Sudhakara, K
Effect of applied potassium and rhizobial inoculation on nodulation and uptake of fertilizer nutrients by soybean
(Kerala Agricultural University, 1983) Reena Grittle Pinhero; Tajuddin, E; Abdul Salam, M; Vikraman Nair, R
Effect of different levels of nitrogen and phosphorus on the uptake of nitrogen and phosphorus at various stages of growth of sunflower variety peredovik
(Kerala Agricultural University, 1976) Thomas Varghese, P; Sadanandan, N; Vikraman Nair, R
An experiment was conducted at the College of Agriculture, Vellayani to study the effect of graded doses of nitrogen and phosphorus on the uptake of nitrogen and phosphorus at three growth stages of sunflower viz 20th day after planting, flowering and harvest. The effect of nitrogen up to 90 kg/ha resulted in significant linear increase in nitrogen uptake at all the stages except on the 20th day after planting. Phosphorus at 90 kg level showed significance in enhanced nitrogen uptake at the 20th day of planting but not later. While for the phosphorus uptake, significant effect was noticed due to increased levels of application of nitrogen at all the three stages, levels of applied phosphorus did not bring about significant changes in the uptake of this nutrient Increase in uptake of these nutrients showed a linear relationship with the magnitude of growth of the plants.
Effect of graded doses of nitrogen on the growth, yield and nitrogen uptake of soyabean under rhizobium inoculated and non-inoculated conditions
(Kerala Agricultural University, 1974) Vikraman Nair, R; Tajuddin, E
Effect of methods of fermentation on temperature, acidity and quality of cocoa (Theobroma cacao L.) beans
(Kerala Agricultural University, 1981) Adomako, D; Vikraman Nair, R; Kumaran, K
The trend of variation in temperature, and pH of cocoa beans in heap and tray methods of fermentation was studied at the Cocoa Research Institute of Ghana. Heaps of sizes having 50 kg, 150kg, and 450 kg and the standard tray method of fermentation were tested and the grades of dried beans obtained from the different methods were compared. In the heaps, a higher peak temperature was reached as compared to the trays. The beans in the heaps followed regular fluctuations in temperature during fermentation while the temperature fluctuations were low in the trays. The final pH values of pulp and beans were not much affected by the method of fermentation and heap size However, the decrease in pH of cotyledons was slower in the largest heap The fermentation methods and heap sizes did not markedly affect the grade of the dried beans.
Effect of potassium and rhizobial inoculation on growth, yield and quality of soybean in the sandy clay loam soils of Kerala
(Kerala Agricultural University, 1982) Reena Grittle Pinhero; Tajuddin, E; Abdul Salam, M; Vikraman Nair, R
An experiment wasconducted at the Instructional Farm attached to the College of Horticulture, Vellanikkara to study the effect of potassium and rhizobiai inoculation on growth, yield and quality of soybean. The study revealed that applied potassium and rhizobiai culture inoculation did not significantly influence growth characters, yield components, seed yield and stoveryield. Protein content and oil content were significantly influenced by levels of potassium and inoculation. The highest oil content was recorded by 120 kg K20/ha and the highest protein content was obtained without application of potassium. Inoculation increased the protein content and decreased the oil content of seeds. Studies on residual effects of treatments during 2nd crop season revealed that there was no marked variation in seed yield.
Effect of shade and moisture regimes on the growth of cocoa seedlings
(Department of Agronomy, College of Horticulture, Vellanikkara, 1981) Gopinathan, R; Vikraman Nair, R
Effect of shade on growth, nodulation and yield of cowpea (Vigna unguiculata (L) walp)
(Kerala Agricultural University, 1987) Sansamma George; Vikraman Nair, R
Effect of shade on nutrient uptake and dry matter accumulation in Ginger
(Kerala Agricultural University, 1998) Beena Elizebeth George; Sreedevi, P; Vikraman Nair, R
Effect of shade on plant characters and net assimilation rate of ginger cultivars
(Kerala Agricultural University, 1998) Beena Elizabeth George; Sreedevi, P; Vikraman Nair, R
Effect of weather on cocoa and improvement of bean size through seasonal crop orientation
(Department of Agronomy, College of Horticulture, Vellanikkara, 1997) Prameela, K P; Vikraman Nair, R
With an objective of understanding the probable reasons for seasonal fluctuations in flowering and fruiting and also to orient the cocoa crop to a season favourable for bean size, a four year investigation was carried out at the College of Horticulture, Vellanikkara during 1993-96. The influence of weather variables on flowering was studied by correlating weekly flower production with weather parameters of previous one to twelve weeks. This was done using plants with and without fruit load. Flower production was also correlated with increase in fruit load of previous one to twelve weeks. The possible effects of soil moisture deficit and surplus on flowering was also studied. The influence of weather on fruiting was studied by correlating monthly pod yield with weather variables of previous one to seven months. The influence of fruit load on fruiting was also studied by correlating monthly pod yield with increase in fruit load of previous one to seven months. For crop orientation study two sets of plants were used, one as control and the other as treatment. The plants used as control were retained as such without disturbing pods. In the other set, defloration was done excepting during the period from April to July. The results revealed that maximum temperature and bright sunshine hours were positively correlated with flower production while rainfall, relative humidity and number of rainy days were negatively' correlated. However, summer rains had positive effect. Fruit load had negative influence on flowering. For pod production the seasonal difference was much pronounced. During monsoon season a comparatively dry condition with high temperature and low relative humidity caused high pod production after five to six months, while in a non-monsoon period production was favoured by high humidity and high rainfall. Pod load affected flower and fruit production adversely. Models were developed to predict flower and fruit production from weather variables and pod load. The crop orientation study showed that the crop could be oriented to the favourable season of October-November without affecting the total annual yield. However, during years of heavy incessant rains the practice may fail.