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Assam Agricultural University, Jorhat

Assam Agricultural University is the first institution of its kind in the whole of North-Eastern Region of India. The main goal of this institution is to produce globally competitive human resources in farm sectorand to carry out research in both conventional and frontier areas for production optimization as well as to disseminate the generated technologies as public good for benefitting the food growers/produces and traders involved in the sector while emphasizing on sustainability, equity and overall food security at household level. Genesis of AAU - The embryo of the agricultural research in the state of Assam was formed as early as 1897 with the establishment of the Upper Shillong Experimental Farm (now in Meghalaya) just after about a decade of creation of the agricultural department in 1882. However, the seeds of agricultural research in today’s Assam were sown in the dawn of the twentieth century with the establishment of two Rice Experimental Stations, one at Karimganj in Barak valley in 1913 and the other at Titabor in Brahmaputra valley in 1923. Subsequent to these research stations, a number of research stations were established to conduct research on important crops, more specifically, jute, pulses, oilseeds etc. The Assam Agricultural University was established on April 1, 1969 under The Assam Agricultural University Act, 1968’ with the mandate of imparting farm education, conduct research in agriculture and allied sciences and to effectively disseminate technologies so generated. Before establishment of the University, there were altogether 17 research schemes/projects in the state under the Department of Agriculture. By July 1973, all the research projects and 10 experimental farms were transferred by the Government of Assam to the AAU which already inherited the College of Agriculture and its farm at Barbheta, Jorhat and College of Veterinary Sciences at Khanapara, Guwahati. Subsequently, College of Community Science at Jorhat (1969), College of Fisheries at Raha (1988), Biswanath College of Agriculture at Biswanath Chariali (1988) and Lakhimpur College of Veterinary Science at Joyhing, North Lakhimpur (1988) were established. Presently, the University has three more colleges under its jurisdiction, viz., Sarat Chandra Singha College of Agriculture, Chapar, College of Horticulture, Nalbari & College of Sericulture, Titabar. Similarly, few more regional research stations at Shillongani, Diphu, Gossaigaon, Lakhimpur; and commodity research stations at Kahikuchi, Buralikson, Tinsukia, Kharua, Burnihat and Mandira were added to generate location and crop specific agricultural production packages.

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20223
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Subject: Entomology × End date: 2022 × Start date: 2022 ×
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    ThesisItemOpen Access
    DIVERSITY, HABITAT OF MAJOR MONKEY SPECIES AND THEIR CROP LOSS ASSESSMENT IN AGRO-ECOSYSTEM
    (2022) Chakraborty, Debjyoti; Borah, R. K.
    The study on “Diversity, habitat of major monkey species and their crop loss assessment in agro-ecosystem” was conducted at Upper Brahmaputra Valley Zone (Golaghat), Hills zone (Karbi anlong) and North Bank Plain Zone (North Lakhimpur) of Assam in the year 2019-21. Population status, habit, habitat, food and feeding behavior of prevalent monkey species were calculated from the Jorhat district in different cropping seasons and the damage caused by the macaques in rice and homestead gardens were calculated. The various population distribution, group size and composition was calculated through transact method in all the locations of the zones comprising all the crop season. During the survey period, the highest number of Rhesus monkeys among all the three locations was recorded at Kakoti gaon of Golaghat district (UBVZ) with 306 monkeys while Sarthe Rongphar gaon, Karbi anlong (Hills zone) recorded the lowest macaque population of 48. During 2019, a total of 151 individuals were encountered in five groups. The largest group (36 individuals) was recorded in Meleng and the smallest group (20 individuals) in Gondhia Gaon. Furthermore, five groups of 159 individuals were found in 2020. Meleng had the largest group of 49 individuals while Madhupur had the smallest (15 individuals). The average overall adult sex ratio of male: to female was 1:2.33 (1 male to 2.33 female) in 2019. On the contrary, proportions of sexes in Rhesus macaques were found to be one male to three females during 2020. During the behavior study period (January 2020-November 2021), scan sampling yielded a total of 9545 scan records. In this study it was found that 24.87% of their total annual time spends on feeding purposes, followed by movement (21.35%), resting (20.09%), grooming (17.72%), playing (14.30%) and calling (1.65%). There were found to be significant differences in time spent in feeding, movement, resting and social activities among the age-sex group. The adult male was found to be spent more time feeding (21.73%) than resting (18.26%) while adult females spent more time resting (25.17%) than feeding (21.80%). Feeding is a major activity and runs throughout the year, but there was found to be variation in feeding during different months of the year i.e. total feeding was not equal in all the months of the year. It was found to be maximum in April 2021 (8.80%), May 2021 (8.47%), March 2021 (8.38%); minimum were in December 2020 (5.35%), October 2020 (5.52%) and November 2021(5.73%). Feeding was found to be highest in April and lowest in December. In this study, 27 plant species representing 13 genera belonging to 19 families were exploited by the study group as natural food. In light of this questionnaire survey, the majority of the respondents (92%) agreed that the damage to crops caused by monkeys was severe. Potato was the most raided crop (30%), paddy (27%), maize (20%), vegetables (18%) and fruits (5%), respectively. Crop raiding was reported by 92 percent of respondents, although the level of crop-raiding was discovered to be different in different places. Crop raiding was found to be highest in Kakoti Gaon (78%), followed by Guwal gaon, which had the least crop raiding (22%).
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    ThesisItemOpen Access
    Bioformulation of entomopathogenic fungus against Helopeltis theivora Waterhouse (Hemiptera: Miridae)
    (AAU, Jorhat, 2022) Kaur, Priya; Das, Purnima
    Pathogenicity test of 5 strains or isolate of entomopathogens on adult Helopeltis theivora were carried out in the Physiology Laboratory, Department of Entomology, Assam Agricultural University, Jorhat during 2019-2021. Among the strains or isolate, Archips sp. isolate showed the best results at concentration 1x107 conidia/ml. The radial growth of Archips. sp isolatewas found to be 75.33 mm. At concentration 1x107 conidia/ml, the conidial density, germination and pathogenicity of Archips sp. isolate was 8.08x107 conidia/ml, 85.49% and 80%, respectively. Morphological characters of Archips sp. isolate were studied and its molecular characterization was carried out by using CP plant gDNA mini kit protocol and its accession no. was assigned as OM321438. While Archips sp. isolate when grown on liquid media supplemented with carbon, nitrogen and mineral sources (Glucose, Peptone and MgCl2), the medium supplemented with the mineral source- MgCl2 (0.75%) showed maximum conidial load (6.54x107 conidia/ml) and maximum germination (88.91%). Three talc-based formulations were prepared. One was prepared by using base material as harvested from PDB supplemented with 0.75% MgCl2, second with combination of all the nutrients (0.75% Glucose, 0.75% Peptone and 0.75% MgCl2) and third without nutrient. And among these formulations, all nutrients supplemented talc-based formulation showed maximum conidial density (11.52x107conidia/ml) and germination (90.06%). Also, in order to increase the virulence and efficacy of the prepared bio-formulation, two stickers- Tween-80 and Triton-X@ 0.01% and two spreader oils-coconut oil and mustard oil@ 0.025% were tested. It was found that the formulation incorporated with Tween-80@ 0.01% and coconut oil @0.025% had maximum conidial load(13.12x107 conidia/ml) and spore germination (95.49%). Three doses viz., 5, 10, 15 gm/L were tested on the adults of Helopeltis theivora. Among these doses, the dose of 15 gm/L showed the highest mortality (88%) at 9th DOT.
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    ThesisItemOpen Access
    POPULATION DYNAMICS AND CROP LOSS ASSESSMENT OF MAJOR INSECT PESTS OF CUCUMBER (Cucumis sativus)
    (2022) Balaga Mohan Ganesh; Saikia, D.K.
    Cucumber (Cucumis sativus L.2n = 14) is one of the widely cultivated summer vegetable crops from the gourd family of Cucurbitaceae which is native to India. The climatic conditions of northeast India especially Assam are highly conducive for reproduction of insects, and this region has been considered to be a biodiversity hotspot. Moreover, this region has huge potential for the production of vegetable crops especially cucurbits, but insect pests like fruit flies, pumpkin beetle and sucking pests are major limiting factors for successful cultivation of cucurbits like cucumber etc. Therefore, understanding population fluctuation in the field in relation to losses caused by insect pests are a function of their population dynamics which needs to be thoroughly studied. In view of above factors, an investigation on “Population Dynamics and Crop Loss Assessment of Major Insect Pests of Cucumber (Cucumis sativus)” was carried out at Horticultural Farm and RNA laboratory of Agricultural Biotechnology, Assam Agricultural University, Jorhat. The results showed that during 2019 -2021 summer season, the red pumpkin beetle first appeared on 24th April 2019 and 7th May 2020 with initial population of 4.51 and 2.23 beetles per plant, respectively. However, maximum beetle populations were recorded on 8thMay 2019 and 3rd July 2020 with 6.15 and 6.52 beetles per plant, respectively. Similarly, during 2019-2021, the fruit infestation by fruit fly was recorded first time on 13th June, 2019 and 26th June ,2020 with per cent fruit infestation of 10.24 per cent and 10.75 per cent, respectively. However, highest level of fruit infestation by fruit fly was observed on 25th July, 2019 and 8th August 2020 with 46.86 and 41.3 per cent fruit infestation, respectively. The data on relative abundance of different insects of cucumber during 2019-2021 revealed that the relative abundance of fruit fly species, Bactrocera dorsalis (62.27%) was the highest followed by B. tau (15.68%), B. cucurbitae (10.73%), Dacus longicornis (2.47%), Coccinella transversalis (2.45%), Aulacophora foveicollis (2.20%), Micrapsis discolor (1.56%), A. frontalis (1.16%), and Coccinella septumapunctata (1.08%). During 2019 and 2020, the Simpson-Index diversity showed highest value for fruit fly (0.97 and 0.94) followed by predacious coccinellid beetles (0.67 and 0.71) and red pumpkin beetle (0.55 and 0.64), respectively. Whereas, Shannon-Wiener index diversity (H’) during 2019 and 2020 observed highest in fruit fly (1.65 and 1.85) followed by predacious coccinellid beetles (1.15 and 1.05) and pumpkin beetle (0.68 and 0.85), respectively. The results of yield loss studies during 2019-2020 revealed that the per cent fruit infestation was highest in untreated control plot (30.73%) compared to treated plot (26.8%) with fruit yield of 1223.91 kg/ha and 2311.83 kg/ha, respectively. The yield loss in untreated plot was recorded as 1087.91 kg/ha with 47.05 per cent avoidable loss in yield. Whereas, per cent yield increase over control during 2019-2021 (summer season) was observed as 88.88 per cent. However, economic injury level (EIL) of fruit fly with respect to cucumber was determined as 15.27 and 10.40 per cent with per cent fruit loss of 0.743 and 0.745 during 2019 and 2020, respectively. The optimal phylogenetic tree of 10 fruit fly specimens collected from different locations grouped into two clusters (Cluster A and Cluster B) of two specimens out groups namely B. rubigina and D. longicornis with branch length of 0.0724. In cluster-A, highest genetic distance of 0.047 was recorded between B. rubigina and B. dorsalis. Similarly, in cluster-B the highest genetic distance of 0.0682 was recorded between D. longicornis, B.tau and B.cucurbitae collected from different locations.