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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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20171
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Subject: Entomology × Author: Choudhury, Kasturi × End date: 2017 × Start date: 2017 × Type: Thesis ×
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    ThesisItemOpen Access
    MOLECULAR BASIS OF VARIETAL RESISTANCE OF BRINJAL AGAINST Leucinodes orbonalis Gunee (Lepidoptera: Pyralidae) AND ITS ECOFRIENDLY MANAGEMENT
    (AAU, Jorhat, 2017-07) Choudhury, Kasturi; Borah, R. K.
    The investigations on “Molecular basis of varietal resistance of brinjal against Leucinodes orbonalis Guenee (Lepidoptera: Pyralidae) and its eco-friendly management” were carried out at College of Agriculture, Assam Agricultural University, Jorhat during 2013-14 and 2014-15. Studies on the varietal screening of brinjal varieties revealed that the minimum shoot as well as fruit infestation on number basis recorded on variety Khorua-1 with 2.96 and 9.31 per cent, respectively. The minimum fruit infestation on weight basis was recorded on variety Brinjal long green (5.54 %). The highest infestation of shoot (17.85 %) and fruit infestation on number basis (36.52 %) and weight basis (36.08 %) noted on variety JC- 1. The remaining varieties viz., Brinjal long green , Khorua-2, White brinjal, Borbengena, Sagalihingia, Tita bengena, Pusa purple cluster and Pusa purple long registered shoot infestation ranged from 3.05 to 13.69 per cent, 9.70 to 21.81 per cent fruit infestation on number basis and 5.54 to 21.84 per cent on weight basis. The highest brinjal fruit yield was recorded on JC-1 (238.69 q/ha) followed by Pusa purple long (177.83 q/ha). The minimum fruit yield was recorded on Khorua-2 (30.69 q/ha). Varieties Brinjal long green, Khorua-1, White brinjal and Khorua-2 were designated as resistant to L. orbonalis as fruit damage recorded between 1.0 to 10.00 per cent. The fairly resistant varieties to L. orbonalis comprised of Pusa purple cluster, Borbengena and Sagalihingia which registered fruit infestation ranged from 11.0 to 20.0 per cent. Two varieties viz., Khorua-3 and Pusa purple long were categorized as tolerant (21.0 to 30.0%) fruit infestation. The varieties viz., Tita bengena and JC-1 were found susceptible to shoot and fruit borer with fruit infestation between 31.0 to 40.0 per cent. The influence of morphological and biochemical factors on the infestation by L. orbonalis revealed that the correlations of shoot diameter (r= 0.646), plant height (r=0.291), leaf thickness (r=0.314), and leaf area (r=0.137) with shoot infestation by L. orbonalis were positive but did not show any significant correlation , however the effect of trichome density (r = -0.140) exhibited negative association with shoot infestation , while length of pedicel (r=0.388), length of calyx (r =0.473) and fruit length (r =0.234) were statistically significant but did not show any significant correlation with fruit infestation. Among biochemical contents in shoots, the total phenol (r= -0.584), peroxidase (r= - 0.796) and polyphenol oxidase (r = -0.734) showed significantly negative correlation with per cent shoot infestation caused by L. orbonalis. In regards to the studies of defense response gene, the relative expression level of Ascorbate Peroxidase1 (AP1) and PR3 gene were significantly higher in resistant Khorua variety than in the susceptible JC-1 variety in response to L. orbonalis regurgitant. The relative expression of AP1 and PR-3 gene in Khorua brinjal were greater than 45 and 40 fold higher than untreated control, respectively. However, the expression of this gene was significantly lower in susceptible brinjal, JC1. Six different modules were tested against L.orbonalis in order to develop an ecofriendly management tactics against this pest. Among the different treatment modules, Module III that includes seedling root dip treatment by Imidacloprid 17.8 SL @ 0.5 ml/lit for 3 hrs + Clean cultivation at 15 days interval +Clipping of infested shoots and destruction of infested fruits +Intercrop with Coriander +Spraying with Spinosad 45 SC @ 0.1ml/lit were found to the best performer in suppressing of shoot infestation (6.04% and 6.95%) in 2013- 14 and 2014-15, respectively as well as fruit infestation on number basis (15.71%) and weight basis (17.16%) by L. orbonalis. All the treatment modules had also significantly reduced the shoot and fruit infestation as compared to untreated control. The maximum total increased in yield over untreated control was recorded in Module III (162.17 q/ha) followed by Module IV (133.91 q/ha), and Module V (95.47 q/ ha) while, minimum total increase in yield (88.18 q/ ha) over untreated control was recorded in ModuleI followed by Module II (92.92 q/ ha). The maximum net profit of Rs. 322790.00/ ha was obtained in Module III followed by Module IV (Rs. 279910.00/ ha), Module II (Rs. 218065.00/ ha) and Module I ( Rs. 205465.00 /ha) and Module V (Rs. 195125.00/ha) while, the minimum net profit of Rs. 97920.00 was obtained in control plot (Module VI). The maximum B:C ratio of 4.06 was obtained in Module III followed by Module IV (3.50), Module II (2.72) and Module I (2.40), Module V (1.82) and Module VI (1.60).