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2021 - 20223
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Subject: Agricultre × Start date: 2017 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    STUDIES ON NON-CHEMICAL METHODS OF MANAGEMENT OF TEA PESTS AND USE OF PLANT BASED FORMULATIONS AGAINST RED SPIDER MITE
    (2022) Hazarika, Bidisha; Saikia, Gautam Kumar
    An investigation entitled “Studies on non-chemical methods for management of tea pests and use of plant based formulations against red spider mite” was carried out in the Experimental Garden for Plantation Crops (EGPC) and Department of Entomology, Assam Agricultural University, Jorhat during 2019-2021. The study was undertaken to survey non-chemical methods of management of red spider mite used by twenty small tea growers of Dibrugarh district of Assam and to study the efficacy of plant based formulations for management of red spider mite in-vitro. It was found that 45% of the small tea growers used cow urine with Ghora neem (Melia azedarach), Karanj (Pongamia glabra) and Pothorua bihlongoni Polygonum hydropiper combinations for management of red spider mite. Moreover, they also used bhoot jolokia (Capsicum chinense), sour curd, wheat flour in small quantities.
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    ThesisItemOpen Access
    STUDIES ON NON-CHEMICAL METHODS OF MANAGEMENT OF TEA PESTS AND USE OF OIL BASED FORMULATIONS AGAINST RED SPIDER MITE
    (2022) Konwar, Joyshree; Saikia, Gautam Kumar
    An investigation entitled “Studies on non-chemical methods for management of tea pests and use of oil based formulations against red spider mite” was carried out in the Experimental Garden for Plantation Crops (EGPC) and Department of Entomology, Assam Agricultural University, Jorhat during 2019-2021. The study was undertaken to survey non-chemical methods of management of red spider mite used by twenty (20) small tea growers of Sivasagar district of Assam and to study the efficacy of oil based formulations for management of red spider mite in-vitro. It was found in the survey that 50% of the tea growers used cow urine and water with Neem (Azadirachta indica), Pothorua bihlongoni (Polygonum hydropiper) and Karanj (Pongamia pinnata) combinations for management of red spider mite. Twenty percent (20%) of the tea growers used cow urine and water alone. Oil cake, cow dung, bhoot jolokia (Capsicum chinense), garlic (Allium sativum), limestone, curd and other ingredients were also used in small quantities. Home-made mustard and sesame oil were taken for laboratory experimentation on red spider mite, Oligonychus coffeae at 0.5%, 0.75% and 1% concentration alone or in combination with cow urine. Among the oil based treatment combinations, sesame oil 1% + cow urine 5% was found to be most effective for management of red spider mite. All the treatments of sesame oil were found to be effective in reducing rate of oviposition of red spider mite which were at par with commercial neem (1:1500). Egg hatchability was found to be reduced satisfactorily when the tea leaves were sprayed with sesame oil1% and sesame oil 1% + cow urine 5% and were at par with commercial neem. Sesame oil 0.75% + cow urine 5%, sesame oil 1% and sesame oil 1% + cow urine 5% were found to be effective for mortality of nymphs of red spider mite which were at par with commercial neem. Adult mortality was found to be at par with commercial neem when sprayed with sesame oil 0.75%, sesame oil 0.75% + cow urine 5%, sesame oil 1% and sesame oil 1% + cow urine 5%. From the present study, it can be concluded that the non-chemical methods which are prevalent among the tea growers if scanned, validated and standardized scientifically would definitely help in the management of tea pests. These pest control practices serve as an alternative to overcome the ill effects of synthetic chemical pesticides. Thus, studies on oil based formulations mixed with cow urine or without cow urine showed possible incorporation and utilization in tea IPM programme.
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    ThesisItemOpen Access
    Morpho-physiological and biochemical characterization of tea [Camellia sinensis (L) O. Kuntze] germplasm maintained in the field gene bank of AAU
    (AAU, Jorhat, 2021) NARAH, BIDISHA; Bhuyan, R P
    Tea is one of the oldest non- alcoholic bevaragesin the world which require proper observation, evaluation and documentation of germplasm to develop planting material of diverse genetic background. Germplasm collection helps in discovering archetypes which help in sorting out the taxonomy of tea. Accordingly this study was made to evaluate the morpho-physiological variability and to analyse the biochemical variability of unidentified tea germplasm in field gene bank maintained in the Experimental Garden for Plantation Crops. For which thirty germplasms were selected under the study. The germplasms THT 027, THT 028, THT 040, THT 041, THT 042, THT 043, THT 044 and THT 045 were found to have multiple stems which were similar to standard China type. Moreover they possessed purple colored young shoots, leaf upper surface was found to be “rugose”, ovate type leaf and erect leaf pose which were similar with typical China type, whereas the germplasms THT 021, THT 022, THT 024, THT 026, THT 030, THT 032, THT 033, THT 034, THT 035, THT 038 , THT 039, THT 048, THT 049 and THT 050 were found to have green color young shoot, glossy leaves, lanceolate type to oblong type of leaf shape and semi-erect to horizontal leaf pose similar with typical Assam type and Cambod type. In all the germplasm stem pigmentation was found to be indiscriminate. The germplasms THT 029, THT 033, THT 040, THT 041, THT042, THT 043, THT 044 and THT 045 exhibited densely distributed pubescence which is an important character for cup quality. The germplasms THT 021, THT 022, THT 023, THT 046 and THT 047 exhibited sparsely distributed young shoot pubescence while the remaining were observed to have medium young shoot pubescence. Soil Plant Analysis Detector (SPAD) study revealed that the germplasms THT 027 (49.4), THT 040 (47.2), THT 044 (44.7) showed the high SPAD value and the lower value was found for germplasms THT 041(25.7) and THT 042(25.9). The Relative Water Content(RWC) was recorded high in the germplasms THT 029(88.5%), THT 030(88.8%), THT 031(87.6%) whereas lower RWC was found in the germplasms THT 021(77.5%), THT 049(77.6%) and THT 050(77.8%). The highest polyphenol content was found in the germplasm THT 049 and lowest was found for THT 039. Germplasm THT 021 had the highest caffeine content of 4.1 % and lowest in THT 040 of 2.0 %. Moreover in case of total flavanoid all the germplasms exhibiting China type characters possessed high flavanoid.