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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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Subject: Plant Breeding × Author: Mazumder, Priyanku × End date: 2019 × Start date: 2019 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    EVALUATION OF A FEW BOTANICALS AND BIOAGENTS IN SEED TRANSMISSION OF BROWN SPOT OF RICE CAUSED BY BIPOLARIS ORYZAE
    (AAU, Jorhat, 2019-07) Mazumder, Priyanku; Medhi, T.
    Brown spot of rice caused by Bipolaris oryzae Subr. and Jain (syn. Helminthosporium oryzae Breda de Haan) is an important disease of rice which has been reported to occur in all the rice growing countries of the world. In India, it is known to occur in all the rice growing states including Assam causing loss of 5-53.33 percent annually. Considering its widespread significance, an experiment was conducted to study the effect of a few botanicals and bioagents in seed transimission of the disease. The location of B. oryzae in the rice seed and its transmission from seed to seedling were studied. Each part of infected seed including embryo, endosperm, lemma, palea, sterile lemma and rachilla, was found to be infected by B. oryzae. The highest level of infection was found in endosperm (78.50 percent) followed by rachilla (68.50 percent). Lowest infection was found in embryo (32.50 percent).Transmission studies from the infected seed to the seedling using test tube agar, blotter and sand indicated that primary symptom appeared on coleoptile and roots after 7 – 14 days. However, recovery of infection percentage was greater in test tube agar and blotter than sand method. Efficacy of three botanicals viz., Turmeric (Curcuma longa), Neem (Azadirachta indica), Tulsi (Ocimum sanctum) in different concentrations (10%, 20% and 50% each in Turmeric in Neem and 20%, 30% and 50% in Tulsi) and one bioformulation, Biogreen @5%, 10% and 15% concentration was studied to reduce growth of B. oryzae in vitro and its transmission from treated seeds to seedlings. Turmeric @50% concentration was found to be most effective in reducing the colony growth of the pathogen (1.97 cm and 72.87 percent inhibition over control) followed by Turmeric 20% concentration (3.16 cm and 56.47 percent inhibition over control), Tulsi 50% and Biogreen 15% concentration (3.52 cm and 3.84 cm respectively). Turmeric 50% and Turmeric 20 % concentration were also the most effective in reducing the transmission of the pathogen from seed to seedling both in test tube agar method and sand method. These four treatments from the in vitro experiments were further studied for their effect on seed transmission of B. oryzae, Percent Disease Incidence (PDI) and seed quality parameters under pot condition. Percent Disease Incidence was found to be the lowest in the treatment Turmeric @50% during all the three observed stages (8.36, 9.58 and 18.54 percent at Tillering, Panicle Initiation and Grain filling stage respectively). At grain filling stage Turmeric @50% was followed by Tulsi @50% (19.44). However at this stage PDI observed in treatments Tulsi @50%, Turmeric @20% (22.71) and Biogreen @15% (24.59%) were at par with each other. Seed yield per plant was highest in the treatment Turmeric @50% (29.40 g) which was at par with that of Carbendazim @0.2% (28.80 g) and Turmeric 20%(28.52 g). Thousand seed weight was also highest in the treatment Turmeric @50% (22.48 g) followed by control treatment (Carbendazim @0.2%) (21.86 g). Seedling vigour and speed of germination were significantly higher in the treatment Turmeric @50% (1244.37 and 10.79 respectively) but germination percentage of the treatment Turmeric @50% (92.50%) was at par with that of treatment Turmeric @20% (89.00%) and Carbendazim @0.2% (93.50%). Mean germination time was also significantly lower in the treatment Turmeric @50% (4.74 days). Mean daily germination was found to be highest in the treatment Turmeric @50% (3.49) which is statistically at par with the treatment Turmeric @20% (3.46) and Carbendazim @0.2% (3.44). The harvested seeds from different treatments showed varying level of association by B. oryzae. Seeds in Agar plate method showed infection of 25.75 percent and 37.72 percent reduction over absolute contol in the treatment Turmeric @50% which was lowest among botanicals and bioagents. The treatment Carbendazim @0.2% was the best in all the observed parameters. However, seed yield per plant, germination percentage, mean daily germination and mean germination time were at par with those of the treatment Turmeric @50% concentration.