Browsing by Author "Asha Shankar, M"

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    Efficiency of four methods of selection in brinjal improvement in relation to resistance to bacterial wilt
    (Department of Olericulture, College of Horticulture, Vellanikkara, 1984) Asha Shankar, M; Peter, K V
    Bacterial wilt caused by pseudomonas solanacearun is one of the serious problems that limits its cultivation in kerala. With the identification of SM- 6, a brinjal line from Kerala Agricultural University showing considerable degree of resistance to wilt, the prospects of brinjal cultivation has become brighter under the acidic soil conditions of kerala. Studies at the department of Olericulture, Kerala Agriculture University, indicated the presence of transgressive seggregant(s) within SM-6 which were grouped into eleven distinct types. Hence a study was undertaken at the College of Horticulture, Vellanikara to improve upon the existing eleven types for earliness and yield keeping resistance to wilt intact. Each of the eleven genetics groups were improved through four methods of selection mass, single plant, pure line and single seed descent. The selections were conducted in two consecutive cycles. The criteria for selecting elite plant types were fruits/plant and total yield/plant. Observations were recorded on earliness, Vegitative characters, Productive characters and their components. The relative efficiency of the four methods of selection to improve economic characters was critically examined. Being a cross pollinated crop mass selection and single plant selection were found superior to pure line selection and single seed descent to improve economic characters. Genetic information line genotypic co-efficient of variation, phenotypic co-efficient of variation, heritability in the broad sense, genetic advance and genetic advance as percentage of mean was estimated for the progenies developed through four method of selection. The relative efficiency of the four methods of selection was also examined in terms of improving genetic parameters of progenies. Genetic advance as percentage of mean was highest for progenies developed through single plant selection. Realised genetic gain for economic characters as compaired to the overall mean was positive for progenies developed through maas and single plant selections. The eleven genetic groups were also evaluated under each selection method for the characters under study. The genetic groups SH-6-2, SH-5-1 and SH-6-4 were promising for fruits/plant and yield/plant. The level of resistance of sm-6 to bacterial wilt was assessed under four methods of selection. Single seed descent was found effective to improve to improve the level of resistance of sm-6 to bacterial wilt. When screened under field conditions, the genetic groups sm-6-1, sm-6-4,and sm-6-9 exhibited complete plant immunity under all the four methods of selection. In both the cycles. Multi locational trials and artificial inoculation studies further confirmed the resistance of the basic population of sm-6 to bacterial wilt.
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    Impact of bioagents and soil amendments on the performance of patchouli (pogostemon patchouli pellet.)
    (Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 2004) Smilu Babu; Asha Shankar, M
    An experiment entitled "Impact ofbio agents and soil amendments on the performance of patchouli" was conducted at the Department of Plantation crops and Spices, College of Horticulture, Vellanikkara during 2002-04 to elucidate the effect of application of bioagents, soil amendments and bioregulators on growth, yield and oil quality of patchouli. The study was also aimed at refming vegetative propagation technique to generate disease free quality planting materials. The investigations were conducted in two experiments. Results of the first experiment, " Impact of bioagents on the production of quality planting materials in the nursery "revealed that bioagents had a significant influence on the growth characters of the crop in the nursery stage wherein significant differences were observed among the treatments with respect to characters such as number of leaves, number of roots, length of roots and root volume. Root characters were markedly influenced by bioagents and bioregulators. Root length and root volume were found the highest for the treatment receiving combined application of Trichoderma and Pseudomonas fluorescens at the rate of 2 g each at the time of planting. This treatment also recorded earliest sprout emergence in 6.3 days after planting the terminalcuttings in the nursery. Terminal cuttings which were treated with IBA at the rate of 1000 ppm at the time of planting came to rooting earlier in 8 days after planting in the nursery. Root number was also recorded the highest with the same treatment. The highest leaf number in 45 days old patchouli plants was recorded in nursery with the incorporation of Trichoderma at the rate of 2 g per bag. This treatment also recorded the highest sprout length of 0.45 cm. Earliness in sprouting, length of sprout and earliness in rooting were not found influenced by bioagents in nursery experiment. Plants raised in the nursery by the combined application of Trichoderma and Pseudomonas fluorescens rated the best in the nursery were selected for main field experiment. Impact of bioagents and soil amendments on growth, yield and oil quality were studied in the main field and results obtained revealed that treatments ~----.-.- .. -- involving combined application of bioagents and soil amendments significantly influenced the growth and yield parameters of the crop plant .. Plant height was the highest with the combined application of lime, neem cake, Trichoderma and Pseudomonas fluorescens along with the application of recommended doses of FYM and NPK both in main crop and regenerated crop. Compared to control, this treatment also improved vegetative characters like number of leaves and yield attributes like fresh herb yield and fresh leaf yield both in main crop and regenerated crop. Combined application of control, lime, neem cake and Pseudomonas fluorescens along with the recommended doses of FYM and NPK recorded highest number of branches and greatest plant spread. Leaf area also was found varying significantly among treatments. Application of neem cake, Trichoderma and Pseudomonas fluorescens in addition to the recommended doses of FYM and NPK recorded the highest leaf area. Dry leaf yield recorded was also the highest with the same treatment. Oil yield and oil content in the plant were found to be significantly influenced by bioagents and soil amendments. The plants treated with a combination of neem cake + Trichoderma + Pseudomonas fluorescens along with the recommended doses of FYM and NPK recorded highest values of oil yield and oil content. Physicochemical properties of the essential oil of patchouli were analysed wherein it was, observed that specific gravity of oil between 0.940 and 0.953 and refractive index was recorded between 1.5032 and 1.5150 at 31 Qc. Gas chromatographic profile of oil samples were analysed and significant variation with respect to the application of various treatments was observed. Number of components present in the oil sample varied significantly among treatments. It is observed that when the number of peaks increases, the percentage of major components in the oil decreases. Treatments receiving neem cake along with NPK and FYM recorded maximum number of components in the oil sample. It is found that neem cake can add optimum level of nutrients to the soil at a slow and steady rate which finally resulted in the increment of oil components.