Browsing by Author "Achuthan Nair, M"

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Now showing 1 - 14 of 14
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    Crop-tree inventory of the home gardens of Southern Kerala
    (Kerala Agricultural University, 1999) Jacob John; Achuthan Nair, M
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    Effect of preceding fodder crops and fallow on productivity mechanics in first crop season rice
    (Kerala Agricultural University, 1999) Meera V Menon; Achuthan Nair, M; Potty, N N
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    Effect of summer cropping and fallowing on the productivity of rice lands
    (Kerala Agricultural University, 1999) Meera V Menon; Achuthan Nair, M; Potty, N N
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    Litter decomposition and nutrient dynamics of selected multipurpose trees in homesteads
    (Department of Agronomy, College of Agriculture, Vellayani, 2001) Sheeba Rebecca Isaac; Achuthan Nair, M
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    Nutrient cycling and soil productivity studies of homestead agroforestry systems of Southern Kerala
    (Department of Agronomy, College of Agriculture, Vellayani, 1997) Joise Abraham; Achuthan Nair, M
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    Nutrient management in snake gourd gnder partial shade
    (Department of Agronomy, College of Agriculture, Vellayani, 1989) Abdul Haris, A; Achuthan Nair, M
    A field experiment was conducted at the College of Agriculture, Vellayani during March – July, 1988 to study the influence of three levels of 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, nutrient content and uptake of major nutrients in snake gourd cv. TA -19, under partially shaded condition of coconut garden. The experiment was laid out in a 33 + 1 partially confounded factorial experiment in RBD with two replications, confounding NP2 K and NP2 K2 in replication I and II respectively. Higher levels of nitrogen had profound positive influence on growth characters like number of days taken for opening of the first female flower and its node of emergence, inter nodal length and total dry matter production. Higher levels of phosphorus had significant positive effect on the days taken for opening of the first female flower. Yield attributes like fruit set and harvest index were not significantly influenced by the major nutrients. However, control recorded a significantly lower fruit set than the treatments. Nitrogen and phosphorus levels significantly increased the male to female flower ratio. The yield increased linearly with respect to nitrogen levels. Phosphorus and potassium did not show any significant influence on yield beyond their lowest levels. Fruit weight increased significantly with higher levels of nitrogen. Fruit length and girth and the number of fruits per plant showed an increasing trend with varying levels of nitrogen, phosphorus and potassium but were not significant. However, in all the cases, the control plots recorded significantly lower values for these parameters. The levels of nitrogen had significant positive influence on the protein content of fruit. The nitrogen, phosphorus and potassium contents in fruits and plants were significantly and positively influenced by their respective levels. The uptake of nitrogen, phosphorus and potassium by fruits and whole plants were also significantly increased by their respective levels. In addition, nitrogen levels significantly influenced the uptake of phosphorus and potassium by whole plants and vice versa.
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    Performance of some fodder legumes in rice fallows
    (Kerala Agricultural University, 1993) Meera V Menon; Achuthan Nair, M
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    Potential and prospects of fodder legumes in rice fallows
    (Department of Agronomy, College of Horticulture,Vellanikara, 1987) Meera Menon, V; Achuthan Nair, M
    An experiment was conducted in the Agricultural Research Station , Mannuthy during third crop season of 1985-’86 and first crop season of 1986-’87 to evaluate the relative performance of fodder legumes in rice fallows and their residual effect on the succeeding crop of rice under graded levels of N. The experiment, replicated thrice, was laid out in a split plot design with seven treatments – six fodder legumes (sannhemp, soya bean, rice bean, velvet bean, cowpea and black gram and a fallow- as main plot treatments and two N levels (52.5 and 70 kg/ha) applied to kharif rice as sub-plot treatments. The results revealed that sannhemp gave a fodder yield of 21 t/ha in rice fallows which was significantly superior to all other treatments. An increase in soil organic carbon, total and available N was also noticed. Soil organic carbon and total N was highest in the cowpea cropped plot. Available N in the soil was highest in the velvet bean cropped plot and the fallow plot recorded the lowest values. Increased rice grain yield was recorded after legumes compared to fallow and the highest grain yield was recorded after velvet bean followed by that after sannhemp cowpea and black gram. Application of N at the recommended dose of 70 kg/ha produced superior yields compared to N at 52.5 kg/ha. Rice crop succeeding fodder legumes with 75% N produced grain yield comparable to that after fallow receiving 100% N. The net income and returns per rupee invested were highest after the sannhemp-rice sequence followed by the cowpea-rice sequence. The results proved that 25% N could be saved in the case of rice after legumes. The study also showed the superiority of sannhemp and cowpea in fodder yield and residual effect in the succeeding rice crop.
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    Rhizobium inoculation and nutrient levels on nodulation and seedling growth in nitrogen fixing tree species
    (Kerala Agricultural University, 1996) Ragini, R; Achuthan Nair, M
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    Rhizobium inoculation and nutrient levels on nodulation and seedling growth in tree legumes
    (Department of Agronomy, College of Agriculture, Vellayani, 1992) Ragini, R; Achuthan Nair, M
    An investigation entitled Rhizobium inoculation and nutrient levels on nodulation and seedling growth in tree legumes was carried out at College of Agriculture, Vellayani during August 1990 to July 1991. The investigation was carried out as three separate experiments. The main objective of Experiment I was to determine the effect of different scarification methods on the germination of some commonly grown and newly introduced legumes, the objective of Experiment II was to screen out the best among the native and exotic isolates of Rhizobium with different levels of phosphorus on the nodulation and seedling growth and the objective of Experiment III was to study the effect of Rhizobium inoculation, and nutrient levels on nodulation and seedling growth of tree legumes. The experiment (s) were carried out in a completely randomized design with five, three and four replications each for Experiments l, ll and lll respectively. Hot water treatment for three minutes was found to be effective for enhancing the germination in Acacia mangium, Paraserianthes falcataria and Sesbania grandiflora. Treatment with Con.Hcl for one minute recorded highest germination per cent in Cassia fistula. Germination percentage of 98.27 was recorded with Con.HNO3 treatment for 10 inutes. In Acaci’s Acacia Catechu and Cassia javanica maximum germination was obtained with Con.H2 SO4 treatment for five minutes, while that for one minute resulted in highest germination in Albizia moluccana. Exotic isolates, TAL 1868 and TAL 45 wire proved to be the best among the rhizobial isolates for Acacia and Albizia sp. Respectively with respect to growth and nodulation characterstics as compared to the local strains. Plant height, shoot dry weight and root dry weight were significantly influenced by phosphorus application. Nodule number per plant had increased from 0.67 to 1.33 in Acacia Arabica. Nitrogen application along with inoculation significantly influenced growth characters such as plant height, shoot dry weight and root dry weight. Maximum plant height was recorded due to application of nitrogen upto 20 kg ha-1 in Acacia Arabica and Acacia Catechu. Nitrogen application upto 20 kg ha-1resulted in highest shoot dry weight and root dry weight in both Acacia Catechu and Paraserianthes falcataria. Application of nitrogen did not increase nodule number per plant in all the tree species. However, nodule dry weight per plant increased with application of nitrogen up to 20 kg ha-1. Phosphorus application up to 50 kg ha-1 produced maximum shoot and root dry weights in Acacia catechu. Application of Phosphorus at 25 kg ha-1 resulted in maximum root dry weight in Acacia Arabica and Acacia catechu. Phosphorus application up to 25 kg ha-1 resulted in maximum number of nodules per plant in Acacia Arabica and acacia catechu. Highest nodules dry weight per plant was recorded with phosphorus application up to 25 kg ha-1 in Acacia catechu and Paraserianthes falcataria. Nitrogen application upto 20 kg ha -1 resulted in an increase in plant nitrogen content and reduction thereafter. Phosphorus application upto 25 kg ha -1. Resulted in an increase nitrogen content of plants and a reduction was noticed beyond 25 kg ha-1. Nitrogen application had significant influence on phosphorus content of plants in A Arabica and P. falcataria. Phosphorus application at 50 kg ha-1 gave highest phosphorus content in A. Arabica and A. catechu. It can be concluded that nitrogen and phosphorus application along with Rhizobium inoculation using specific strains is essential for better growth and nodulation of leguminous tree species.
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    Socio-economic characteristics of homestead farming in South Kerala
    (Kerala Agricultural University, 1999) Jacob John; Achuthan Nair, M
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    Standardisation of agro-techniques for sweet potato variety sree nandini
    (Department of Agronomy, College of Agriculture, Vellayani, 1990) Sudhadevi, K C; Achuthan Nair, M
    With a view to standardise the agro-techniques for sweet potato var. Sree Nandini, a field experiment was conducted in the wetlands of the instructional Farm of College of Agriculture, Vellayani. The main objectives of this experiment was to work out the optimum dose and time of application of potassium and depth of planting for the sweet potato var. Sree Nandini. The experiment was laid out in split plot design with four replications. The main plot treatments included 3 levels of potassium (50 kg, 75 kg and 100 kg K2O/ha) and 2 depths of planting 95 cm and 10 cm) while the subplot treatments consisted of the different time of application of potassium (full basal, half basal + half topdressing, 1/3 basal + 2/3 top – dressing and 2/3 basal + 1/3 topdressing). An abstract of the results is given below : Among the vegetative growth characters, the length of vines was found to be maximum at the highest level of potassium while the number of branches and leaf area of index were not influenced by the levels of potassium. The drymatter production and tuber bulking rate were maximum when potassium was applied at 100 kg K2o/ha. The tuber number, length of tuber, girth of tuber and tuber yield were also maximum at the highest level of potassium. Among the quality attributes, starch content was maximum at the highest level of potassium and sugar content was maximum at the lowest level while the crude protein content was not affected by the different levels of potassium. The uptake of potassium and phosphorus were maximum at 100 kg K2o/ha. The highest available nitrogen and potassium content of the soil was also obtained at this level while available phosphorus content of the soil was not affected. As regards the time of application of potassium, application of potassium in two equal splits produced the longest vines while the number of branches and LAI were not affected. The parameters like drymatter production, tuber bulking rate, length and girth of tubers, tuber yield, starch content of tubers and uptake of potassium by plants were also maximum in this treatment while the vine yield, crude protein content of tubers and uptake of nitrogen and phosphorus by plants were not influenced by the time of application of potassium. The depth of planting had no significant influence on most of the parameters investigated like number of branches, LAI, drymatter production, tuber number, tuber yield, vine yield, quality attributes of tubers and uptake of nutrients by plants. However, deeper planting increased the length of vines while the size of tubers and tuber bulking rate decreased with deeper planting. Thus, it is revealed from the present study that the application of 100 kg K2o/ha in two equal split doses – half as basal and half as topdressing in combination with a planting depth of 5 cm is more profitable for the particular variety under the agro-climatic conditions prevailing in Thiruvananthapuram district.
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    Sturcture analysis and system dynamics of agroforestry home gardens of southern Kerala
    (Department of Agronomy, College of Agriculture, Vellayani, 1997) Jacob John; Achuthan Nair, M
    A study entitled "Structure analysis and system dynamics of agroforestry home gardens of southern Kerala" was undertaken during the period from 1994 - 1997 in Thiruvananthapuram district of Kerala State. The study comprised of a detailed agroforestry systems inventory description survey of the home gardens in the district, investigations on the system dynamics of two home gardens of the district, laboratory experiments to assess the allelopathic tendencies of some commonly grown multipurpose tree species and linear programming to develop integrated homestead models. The results of the survey revealed that the size of an overwhelming number of holdings was small. The species diversity and average number of plants per home garden was considerably high. Tuber crops ranked first among the crops, followed by fruits, oilseeds, rubber, spices, vegetables, timber and fuel trees and fodder crops. The tree intensity was found to increase as the size of the holding decreased. The frequency of occurrence was highest for coconut, followed by jack, mango, moringa, guava, wild jack and tamarind and lowest for the nitrogen fixing trees. Differences between the agroecological zones of the district with respect to the predominance of crop categories and tree species were also observed. The home gardens presented a multi-tier canopy configuration. There was no specific planting pattern or arrangement. The system, as a whole, was found to be profitable. The two year long field investigation on the dynamics of home gardens revealed that the tree components contributed considerable amounts of nutrients by way of litterfall, stemflow and throughfall. Nutrient addition took place mainly through organic manures at both locations. Harvested biomass accounted for removal of large quantities of nutrients from the systems. Coconut accounted for maximum biomass production and nutrient removal at both sites. The physical, chemical and microbiological properties of the homestead soil were better than that of the control. The soil in the homestead had a lower bulk density, high water holding. capacity, porosity and moisture "Content. An enhanced soil organic carbon content, available N, P and K status were also observed in the home garden. The soil microbial population (bacteria, fungi, actinomycetes and phosphorus solubilizing bacteria) was comparatively higher in the home garden. Nutrient cycling, recycling of crop residues and addition of organic manures helped in improving and maintaining the soil physico-chemical and biological properties of the system in a sustainable manner. The presence of trees lowered the soil temperature in the homestead, whereas relative humidity was maintained at an optimum level when compared to open condition. The light intensities at the floor of all the trees studied were invariably less than that in the open. Both the home gardens were found to be profitable. The tree-crop-livestock integration was a special feature which increased income considerably. Allelopathic inhibition of germination and growth of rice was caused by leaf extracts of all the tree species. Germination of cowpea was inhibited by the leaf extracts of acacia, eucalyptus, casuarina, ailanthus, tamarind, portia and cashew. Growth of cowpea was suppressed by leaf extracts of all the tree species except jack. The powdered leaf litter of all the trees inhibited rice germination and growth. However, jack did not suppress radicle growth. Cowpea germination was inhibited by the powdered litter of all the trees except jack and mange. Cashew, casuarina and jack did not suppress plumule growth of cowpea. Radicle growth of cowpea was inhibited all tree species. The integrated model for the 0.50 ha home garden with 23 enterprises was found to generate a profit of Rs. 10354.21 with an investment of Rs. 3262.30. The coconut-based mixed fanning model developed for the 0.40 ha home garden with 35 enterprises provided a net profit of Rs. 32464.32 on investing Rs. 45000/-.