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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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20231
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Subject: Agricultural Entomology × Author: Begum, Asma ×
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    ThesisItemOpen Access
    Biosynthesis and utilization of plant based silver nanoparticles (AgNPs) against red spider mite, Oligonychus coffeae
    (2023) Begum, Asma; Kalita, Surajit
    The present investigation on biosynthesis of silver-nanoparticles synthesized from Phlogocanthus thyrsiflorus leaf extract was carried out at Department of Plant Pathology, Assam Agricultural University (AAU), Jorhat and their bioefficacy against Oligonychus coffeae was carried out at Department of Entomology, AAU, Jorhat during 2021-2023. Characterization of the biosynthesized AgNPs through UV-Vis spectrophotometer in wavelength range of 250-600 nm revealed a peak at 417 nm, which confirmed the formation of silver nanoparticles. Dynamic Light Scattering (DLS) analysis (Z-average of 45.31 nm and polydispersity Index, PDI of 0.286) and Zeta potential (Charge: -22.5 mV) analysis were conducted to characterize the dispersion pattern of the nanoparticles. The size of the AgNPs was calculated to be around 5 nm through TEM analysis with relatively uniform circular and spherical morphology. The Electron Diffraction pattern (ED) showed polycrystalline nature of the AgNPs. SEM analysis also confirmed circular and spherical morphology of the AgNPs with a slight agglomeration, while SEM-EDX revealed the composition of the matrix to be 51.73% oxygen (O), 5.66% Carbon (C), 16.75% sodium-(Na) and 25.86% silver (Ag). FT-IR spectrograph showed strong peaks at ranges of 400-4000 per cm that confirms presence of different functional groups viz., O-H, C-H and C꞊C. The bioefficacy of AgNPs against O. coffeae at different concentration viz., 100 ppm, 150 ppm, 200 ppm, 250 ppm and 300 ppm and dosage viz., 0.1, 0.5, 1.0, 2.5, 5.0, and 10.0 ml/lit of water as compared with the standard checks viz., azadirachtin 10000 ppm @ 3.0 ml/lit of water and 3.0% P. thyrsiflorus crude extract solution @ 3.0 ml/lit of water in terms of adult mortality, ovicidal and antiovipositional toxicity at different time interval viz., 6, 12, 24, 48, 72 and 96 hours after treatment (HAT) revealed the highest of 100.0% adult mortality of O. coffeae at 200 ppm and 250 ppm at the dosage of 10.0 ml/lit and at 300 ppm at a dosage of 5.0 ml/lit. The lowest LC50 value of 0.10% for adults of O. coffeae was recorded at 200 ppm after 96 hours of treatment. The highest ovicidal activity against O. coffeae was recorded at 300 ppm concentration @ 10.0 ml/lit causing the lowest egg hatching (40.13%). The lowest LC50 value (1.63%) in terms of ovicidal effect against O. coffeae was recorded at 300 ppm of the AgNPs. The highest hatching reduction of 54.13% was recorded at 300 ppm concentration of AgNPs @ 10.0 ml/lit against O. coffeae. At 300 ppm concentration, AgNPs recorded the lowest fecundity of O. coffeae recording only 2.57 Nos. of eggs laid per female per day. The present experimentation confirmed the effectiveness of biosynthesized AgNPs as an acaricidal, ovicidal and antiovipositional agent for the management of O. coffeae, showing promise for utilization as a component of integrated tea pest management strategy.