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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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20214
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Subject: Crop Physiology × End date: 2021 × Start date: 2021 × Type: Thesis ×
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    ThesisItemOpen Access
    RESPONSE OF SOME BANANA GERMPLASM TO NATURAL COLD TEMPERATURE REGIME IN ASSAM
    (2021) Kalita, Jiliksweta; Kalita, Prakash
    Banana (Musa spp.) is one of the most important commercial fruit crops especially in the tropics and has high consumer demand worldwide. It contains good amount of health benefitting anti-oxidants, minerals and vitamins. Banana is a tropical fruit crop which belongs to the family ‘Musaceae’. It is a mesophytic plant and it’s cultivation is mostly confined between 30N and 30S of the equator with a mean temperature of 27C to 35C. Banana ranks first in production and third in area among fruit crops in India. India is the largest producer of banana in the world with a productivity of 35.8 metric tonnes/ha. Assam has a productivity of 13.9 t/ha (Hazarika et al., 2020). The lower productivity of banana in Assam may be attributed to certain abiotic stresses like moisture deficit, low temperature etc. The banana plant is susceptible to cold and frost if the temperature drops below 15C during the winter months of November and December (Simmon, 1959) and the situation in Assam also resemble this. When fruiting occurs in winter there will be slow development of bunches and the fruit may never fill well enough to become marketable because of the insufficient leaf surface and slow leaf activities (Lomas, 1970). The major effects of cold stress include growth reduction, leaf wilting, chlorosis, inhibition of photosynthetic performance, changes in membrane integrity and loss of cell compartmentation (Bo et al., 2017), impairment of enzymatic activity (Cheng and Song, 2006) and over-accumulation of reactive oxygen species (ROS) which ultimately may cause plant death (Suzuki et al., 2012). Keeping these facts in view, a study was conducted at the Experimental Farm, Department of Horticulture, Assam Agricultural University, Jorhat during the year 2020-2021. Twenty germplasm of banana viz., Sutijahaji(G1),Agnisagar(G2) Grand Naine (G3), Bogimanohar (G4),Amrit Sagar (G5),Digjowa (G6),Chenichampa(G7),Banria (G8),Barjahaji (G9), GobinTulsi (G10), Doodhsagar (G11), Balhakual (G12), Assamese Malbhog (G13), Simolu Manohar (G14), Jatikal (G15), Athiya (G16), Kachkal (G17), Bhimkal (G18), Honda (G19) and Savari (G20)were taken as test material to evaluate their response towards naturally occurring low temperature in Assam. Banana suckers of uniform size arising from the main crop during the month of February were used to grow the ratoon crop. Data on various morpho-physiological parameters were recorded in the months of August, December, January and February when the crop attained the age of 6th, 10th, 11th and 12th month. Low temperature progressively reduced the values of relative leaf water content, chlorophyll content (a,b, total), number of functional leaves, leaf area, stomatal conductance, transpiration rate, photosynthetic rate, quantum efficiency of PSII, days taken for leaf senescense etc. as compared to the August sampling while the lipid peroxidase activity ,intercellularCO2 concentration and days taken for leaf emergence was increased under low temperature. The germplasm Barjahaji (G9) showed higher values with respect to all parameters except lipid peroxidation, intercellularCO2 concentration and days taken for leaf emergence. As compared to August sampling, during winter months the reduction in values of various parameters was comparatively low in the germplasm Barjahaji (G9), Bhimkal (G18), Ahtiya(G16), Simolumanohar (G14) and Bogimanohar (G4). These germplasm were found to be superior in our study in terms of RLWC, Chlorophyll ‘a’, Chlorophyll ‘b’, total chlorophyll, number of functional leaves, leaf area, stomatal conductance, transpiration rate, photosynthetic rate, quantum efficiency of PSII, days taken for leaf senescense, number of hands per bunch, number of fingers per hand, weight of finger, and bunch weight. On the other handthese germplasm showed lower values of lipid peroxidation, intercellular CO2 concentration and days taken for leaf emergence during the winter months (December, January and February). During February, germplasm Barjahaji(G9),Bhimkal(G18),Athiya(G16)showed better recovery in RLWC by 2.62%, 5.11% and 2.63%, respectively, in photosynthetic rate by 7.71%, 7.56% and 2.84% , respectively and in quantum efficiency of PSII by 23.00%, 20.83% and 20.65%, respectively. The germplasm Bogimanohar (G4) also showed recovery in quantum efficiency of PSII by 19.60%. In the present study, the germplasm Barjahaji (G9) (17.68kg Bunch-1) was found to be thehighest yielder followed by Bhimkal (G18) (17.23kg Bunch-1) and Bogimanohar (G4) (17.18kg Bunch-1) whereas, the germplasm Chenichampa (G7) (11.27kgBunch-1) was found to be the lowest performer in this regard.Barjahaji ,Bhimkal and Bogimanohar registered 56.87%, 52.88% and 52.44% higher yield , respectively, over Chenichampa. From the correlation study, it was found that the banana yield was positively and significantly correlated with the parameters viz., number of fingers per hand (r= 0.4405), number of hands per bunch (r= 0.3536) weight of finger (r= 0.7348), number of functional leaves (r= 0.3685), and leaf area (r= 0.3299). From physiological point of view the germplasm Barjahaji(G9), Bhimkal (G18), Ahtiya(G16),Simolumanohar (G14) and Bogimanohar (G4) were found to be tolerant against low temperature as these germplasm have exhibited better values of physiological traits that are known to contribute positively towards growth and development and in majority of the cases towards yield.
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    ThesisItemOpen Access
    Nitrogen acquisition under elevated CO2 and temperature in rice (Oryza sativa L.)
    (AAU, Jorhat, 2021) Doulboruah, Pronamee; Das, Ranjan
    A field experiment was conducted at stress physiology laboratory, AAU, Jorhat during kharif season of 2020-2021 to study the “Nitrogen acquisition under elevated CO2 and temperature in rice (Oryza sativa L.). The experiment was carried out in controlled environment under CO2 temperature gradient tunnel (CTGT), to understand the differential response of rice to higher level of CO2 i.e. CTGT-I at ambient CO2 395 ppm & temperature, CTGT-II at elevated CO2 (550±20ppm) + temp. of 4 0 C > ambient and CTGT-III at elevated CO2 (750±20ppm) + temp. of 6 0 C > ambient with four different level of N treatment viz. N0 (zero N), N1 (75% recommended dose), N2 (100% of recommended dose), N3 (125%of recommended dose). The experiment was laid out in two factorial completely randomized block design (FCRD) with 10 replications. The popular rice cultivar of Assam, Luit, was collected from research station of Agricultural University. This experiment was conducted on pot which was sown on 8th Aug 2020 and harvested between 28th Nov to 2nd Dec 2020. In the experiment under elevated CO2 and temperature there was a significance difference of crop growth parameters where highest value were recorded at CTGT-II with N3. In phenological data highest value was recorded at CTGT-III with N3. All biochemical and anatomical parameters also exhibit better result in CTGT-II with N3 as compared to CTGT-I. Membrane related phenomenon i.e. MSI was recorded as high at CTGT-II with N3. But there was a negative trend in H2O2 and lipid peroxidation where highest value was recorded at CTGT-III with N0. Similar result also found in water relation parameters and all physiological parameters. Chlorophyll florescence related phenomenon shows highest result in CTGT-II at N3. Likewise, yield attributing parameters gave highest value in CTGT-II with N3. Results shows that application of N significantly increased various morphological growth parameters as well as yield parameters in rice under elevated CO2 condition (at 550±20 ppm with 40 c temperature) under CTGT-II as compared to CTGT-I and CTGT-III. High temperature has a deleterious effect on plant growth and some related processes viz. physiological and biochemical activities because an effect on C: N ratio. Therefore, supplementation of N may play a pivotal role in amelioration of some deteriorative process like lipid peroxidation content and MDA content of leaves thereby reduced yield by affecting yield attributing parameters. Results indicated that higher doses of N under elevated CO2 and temperature invariably maintained not only the C:N ratio but also improved the physiological response positively. But at lower level of N in plant showed poor plant growth as well as metabolic de-arrangement because of low photo synthetic rate, nitrate reductase activity, chlorophyll loss and depression membrane stability index. Therefore, modification of agriculture and nutrient management technologies for future environments is important criteria for sustainable management of rice ecosystem.
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    ThesisItemOpen Access
    EFFECT OF SEED BIOPRIMING WITH INDIGENOUS FUNGAL ISOLATES ON GROWTH AND YIELD OF OKRA (Abelmoschus esculentus L.)
    (AAU, Jorhat, 2021) Bhuyan, Rijuleena; Das, Kaushik
    A series of experiments were conducted during the year 2021 in the Department of Crop Physiology, AAU, Jorhat to evaluate the effect of seed biopriming by indigenous fungal isolates on germination, growth and yield of okra. Three different fungal strains viz., Trichoderma harzianum, Metarhizium anisopliae and Verticillium lecanii, isolated and prepared from indigenous sources were selected for the research programme. In the first experiment, which was conducted under laboratory condition, okra seeds were bioprimed with these fungal isolates with four different concentrations (0.30%, 0.50%, 0.70% and 0.90%) separately. Additional two separate sets, one with hydroprimed seeds and another with unprimed control, were also kept for comparison. Seed germination and early seedling growth of the tested crop in terms of germination percentage, germination index, root and shoot lengths, fresh and dry weights and vigour index of the seedlings were found to be increased by all the priming treatments. Among the different treatments, 0.50% T. harzianum, 0.70% M. anisopliae and 0.70% V. lecanii exhibited better promotive results compared to the other treatments. The second experiment, which was also a laboratory trial, was carried out to evaluate the combined effects of the different indigenous fungal biopriming agents. Among the different treatment combinations, T. harzianum (0.50%) + M. anisopliae (0.70%) showed the most promotive results in respect to germination and early seedling growth of okra. Third experiment was conducted in pots under shed-house to evaluate the combined effect of T. harzianum, M. anisopliae and V. lecanii as biopriming agents on morphophysiology, growth and yield of okra. For comparison other two sets were also kept, one with hydropriming treatment, and one as unprimed control. All the recorded growth and morphophysiological parameters such as plant height, leaf number, leaf area, root volume, shoot and root dry weights were increased by all the treatments. Plant water relation of the crop in terms of relative leaf water content (RLWC) was found to be positively affected by the applied seed priming treatments. Leaf chlorophyll content of the tested crop was also increased by the seed priming treatments. However, no such effect was observed on the leaf proline content of the crop. Yield and all the recorded yield attributing characters such as days to first flower initiation, fresh and dry weights of pod, fresh and dry weights of the seeds were positively affected by the applied treatments. All the fungal biopriming agents exhibited better results compared to the hydropriming treatment. Among the different bioprimning treatments, T. harzianum (0.50%) + M. anisopliae (0.70%) showed the most promotive results in respect to growth and yield enhancement in okra.
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    ThesisItemOpen Access
    EFFECTS OF COCONUT MILK AND KINETIN ON WHEAT (TRITICUM AESTIVUM L.) UNDER PHYSIOLOGICAL DROUGHT CONDITION
    (AAU, Jorhat, 2021) Dutta, Alankrita; Bharali, Bhagawan
    Wheat (Triticum aestivum L.) is a major contributor of country’s food bowl; it is the staple crop of the world and second most important crop in India. Water stress is the most significant environmental stress in agriculture worldwide and improving yield under drought has become a major goal among scientists. All phases of plant growth are not equally vulnerable to water deficit. So, a laboratory experiment and a pot culture were accomplished in the Crop Physiology department of AAU, Jorhat (November 2019-March 2020), to study the effects of coconut milk (CM) and kinetin on wheat (Var-SKU-1) during physiological drought condition. The experiment consisted of 7 treatments viz. T0: Control, T1: 10%coconut milk, T2: 30%coconut milk, T3: 50%coconut milk, T4: 10ppm Kinetin, T5: 30ppm Kinetin, T6: 50ppm Kinetin, laid in CDR design with 3 replications. In the laboratory experiment, 30%CM showed the best results in germination (87%), and seed vigour index (771.2). During the pot experiment, 10ppm Kinetin showed the best results comprising of the parameters viz., leaf area at ear emergence stage (16.580 cm2/plant), tiller number per plant(8.067), effective tillers per plant (3.565), RLWC in maximum tillering stage(48.070 %), RLWC at ear emergence stage (59.857 %), SLW at maximum tillering stage(3.01 gcm-1), SLW ear emergence stage(2.909g/cm), plant height at harvest(85.857 cm), root dry weight at harvest(19.13g/plant), shoot dry weight at harvest(19.33g/plant), total chlorophyll content at maximum tillering stage(1.377 mg g -1 fw of leaf), total chlorophyll content ear emergence stage(3.477 mg g -1 fw of leaf), total carbohydrate content in grains at harvest(118.11 mg g-1 dw), total nitrogen content in grains(118.11 mg g-1 dw), nitrate reductase (NR) activity at maximum tillering stage(20.19 nmol NO2 g-1 fw of leaf hr-1), nitrate reductase (NR) activity ear emergence stage(21.97 nmol NO2 g-1 fw of leaf hr-1), proline content at ear emergence stage (30.19mg g -1 fr.wt), no of seeds per spike at harvest(31.177), length of spike(10.27cm), spike weight (1.922 g), test weight(27.967g), economic yield (0.999g/plant), biological yield(12.32g/plant), harvest Index(8.807%). 30% CM showed best results in case of leaf area at maximum tillering stage (14.154 cm2/plant) and proline content at maximum tillering stage (30.05 mg g -1 fr.wt). Moreover, 10ppm Kinetin (23) and 30% CM (4) exhibited the highest response sores among the treatments in the pot experiment.