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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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Now showing 1 - 9 of 45
  • ThesisItemOpen Access
    Variation of Weed Suppressing Ability (WSA) of popular Ahu rice varieties
    (2021) Brahma, Thirangtha; Sharma, Kishore K.
    The research was carried out with ten Ahu genotypes (including two joha mutants). The objective of the study was to identify Ahu rice varieties with weed suppressing ability (WSA), determine genetic variability and determination of the component traits for weed suppressing ability. High PCV was observed for all the characters except field emergence, plant biomass at maturity, plant height at 20 DAS and 40 DAS, grains per panicle and 1000 grain weight. High GCV were observed for number of leaves at 60 DAS and maturity, leaf area, leaf angle, plant height at 60 DAS and maturity, plant biomass at 60 DAS, total plants/m2, total tillers/m2, ear bearing tillers and grain yield /m2. High heritability was observed for all the characters except number of leaves at 20 DAS. High genetic advance was observed for all the traits except panicle length and 1000 grain weight. Estimation of correlation coefficient revealed very strong positive association of grain yield with plant biomass at maturity, plant height at maturity, total plants/m2, total tillers/m2, ear bearing tillers, grains per panicle, 1000 gr. Wt. and weed suppressing ability. Moderately strong association was found with number of leaf at maturity. Negative association was observed with weed biomass at maturity, number of weeds, leaf angle and days to flowering. Strong positive association of weed suppressing ability was found with number of leaves at maturity, plant biomass at maturity, plant height at maturity, total plants/m2, ear bearing tillers and grains per panicle. Moderately strong association was found with leaf area and 1000- grain weight. Negative association was found with weed biomass, number of weeds, days to flowering and panicle length. Characters positively associated with weed suppressing ability: number of leaves at maturity, plant biomass at maturity, plant height at maturity, total plants/m2, ear bearing tillers/m2, grains per panicle, leaf area and 1000 grain weight. Characters with high heritability having positive correlation with weed suppressing ability are number of leaves, leaf area, plant biomass, plant height and total plants/ m2. From the research, it was concluded that the variety Inglongkiri exhibited the highest weed suppressing ability followed by Banglami, Meghi and Puthia.
  • ThesisItemOpen Access
    (2021) Chakrabarty, Ritika; Barua, Purna K.
    Pesticides have been in use in agriculture since decades for crop protection and production. Farmers use chemical insecticides, fungicides and herbicides to control insect pests, diseases and weeds. Extensive use of chemical pesticides is becoming hazardous to the environment and human and animal health. Biopesticides have been used as a safer alternative. However, it is also important to know the merits and demerits of using biopesticides in the long run. In this investigation the effects of a chemical systemic insecticide ‘Actara 25WG’ and a bioinsecticide ‘Bio Sona’ were assessed for seed germination and seedling growth, and on their effect on root mitosis in five varieties of onion. Experiments were conducted in pots under polyhouse for seedling growth and in the laboratory for germination and cytogenetic study. Three concentrations of Actara 25WG viz., @ 25 g/kg seed, 50 g/kg seed (recommended dose) and 75 g/kg seed were used for seed treatment and @ 200g/ha; 400g/ha (recommended dose) and 600 g/ha for soil application. Bio Sona was applied as soil and seed treatment @ 2%; 5% (recommended dose) and 8%. Negative effects of the two pesticides were observed on seed germination except for Bio Sona at 2% concentration in the variety Bhima Shakti. Actara 25WG and Bio Sona were found to have stimulatory as well as inhibitory effects on seedling height, seedling leaf length, seedling leaf diameter, number of leaves per seedling, root length of seedling, seedling fresh and dry weight depending on the pesticide, concentration and genotype of onion. Each variety showed different level of sensitivity towards the pesticides. Cytogenetic analysis revealed that mitotic index was either promoted or depressed depending on the concentrations of the pesticides and the variety. These pesticides also induced genotoxic effects on root tip cells by showing chromosomal aberrations like binucleate cells, clumps, stickiness, disturbed stage, laggards, bridges and fragments. Bio Sona showed more aberrations than Actara 25WG. There was differential response of the varieties to the pesticide treatment. High heritability, genotypic variation and genetic advance were observed for seedling dry weight and mitotic index.
  • ThesisItemOpen Access
    (2021) Medhi, Bilash Kishore; Bora, G. C.
    The present investigation entitled as “Studies on genetic variation and character association in brinjal (Solanum melongena L.)” was executed to study the variability, heritability, genetic advance, correlation coefficient, direct and indirect effects of interrelated characters and genetic diversity present among the 16 brinjal genotypes at Horticultural Experimental Farm, Assam Agricultural University, in the year 2020-2021. Analysis of variance revealed that substantial genetic variation present among the genotypes for each observed characters. High genotypic and phenotypic coefficient of variation were recorded for number of fruits per plant, fruit length, fruit girth, fruit weight and fruit yield, which indicates that the existence of broad genetic base. Hence,, it would be amenable for further selection. High heritability was estimated for fruit length, fruit girth, number of fruits per plant, number of primary branches per plant, first harvest and fruit yield. High heritability accompanied with high genetic advance was observed for fruit length, fruit girth, number of fruits per plant, fruit weight, number of primary branches per plant, first harvest and fruit yield, indicating these traits are controlled by additive genes. Hence, these characters can be improved through simple selection. Correlation coefficient revealed that fruit yield per plant had positive correlation with fruit weight, plant height and fruit girth at both phenotypic and genotypic level. Fruit yield per plant was also found to be positively correlated with fruit length, root length, root dry weight percentage and first flowering node number at genotypic level. Hence, genetic improvement of fruit yield can be obtained by direct selection of these independent component traits. Genotypic correlation also revealed that positive association among the desirable traits such as, fruit weight with plant height, Fruit weight with fruit girth, days to first flowering with days to 50% flowering, number of fruits per plant with number of primary branches per plant. Hence, selection for such positively associated characters might help the improvement of fruit yield. Path coefficient analysis revealed that characters namely, fruit length, fruit girth, number of fruits per plant, number of primary branches per plant showed maximum positive direct effects on fruit yield. So, direct selection of these characters may be effective for the further yield improvement programmes. Based on the Mahalanobis D2 statistics, 16 brinjal genotypes were grouped into 4 clusters. Cluster I consisted of maximum genotypes (7) followed by cluster II (6), cluster III (2) and cluster IV (1). Maximum intra cluster distance was obtained in cluster III (363.26) followed by cluster II (219.63) and cluster I (145.75). High degree of divergence among the genotypes within a cluster would produce a wide range of segregating material. Maximum inter cluster distance was obtained between the cluster III and cluster IV (6340.56) followed by cluster II and cluster III (4026.45), cluster I and cluster IV (2660.97), cluster I and III (1566.42) and cluster I and II (1141.38). This clustering will help the breeders to choose the diverse parents for hybridization programme, which leads to recombination of non-identical genes.
  • ThesisItemOpen Access
    (AAU, Jorhat, 2021) Devi, Ningombam Sonia; Zaman, Shazmira
    Rice, being a staple food of India, is crucial to enhance its productivity and quality. There are region-wise variations in ethnic preferences of rice. Hence, the study of these variations for quality traits present in different cultivated groups of rice from the region will help in the value addition of the crop. The present experiment was carried out to evaluate 41 rice cultivars from Manipur and Assam to access the genetic variability, correlation, path analysis and genetic divergence for yield and quality traits. The study was conducted in a Randomized Block Design with three replications. The analysis of variance on 24 yield, yield components and quality traits showed the presence of variability in the experimental material for all the characters. A high range of GCV and PCV were observed for the total number of grains per panicle, the number of filled grains per panicle, grain yield per plant, biological yield and harvest index. High heritability coupled with high genetic advance as per cent of mean was observed for most of the characters under study indicating greater transmissibility of these characters and selection can be done effectively based on these characters. Grain yield exhibited positive and significant association with days to 50 per cent flowering, days to maturity, panicle number per plant, the total number of grains per panicle, number of filled grains per panicle, 100-grain weight, spikelet fertility, biological yield, harvest index, panicle harvest index, grain breadth, kernel length, kernel breadth, kernel length after cooking and kernel breadth after cooking. Hence, these characters can be considered to set the selection criteria for increasing grain yield. Path-coefficient analysis revealed that kernel breadth after cooking exhibited the highest positive direct effect on grain yield. Based on Mahalanobis D2 statistics, the genotypes could be grouped into 12 clusters out of which cluster IV had the maximum number of genotypes followed by cluster V. Among all the characters studied, grain length exhibited maximum contribution towards divergence. Cluster X and XII showed the maximum inter-cluster distance and the maximum intra cluster distance was exhibited by cluster XII. Hybridization among the genotypes of these two clusters is presumed to produce better heterotic combinations.
  • ThesisItemOpen Access
    (AAU, Jorhat, 2021) KAMAN, BISWAJIT; Bora, Gobin Chandra
  • ThesisItemOpen Access
    EMS and Gamma ray induced quantitative variation in black gram (Vigna mungo (L). Hepper)
    (AAU, Jorhat, 2021) Biswas, Ardita; Sarma, Akashi
    An investigation was carried out with black gram (urdbean) genotype SBC-40 to determine the effects of gamma rays (250Gy, 300Gy, 350Gy, 400Gy, 450Gy and 500Gy) and ethyl methane sulphonate (0.2%). The data was collected on seed germination and survival percentage, shoot length, root length, fresh weight, dry weight in the first generation i.e. in M1 generationThe LD50 value was recorded at 456Gy and GR50 value was recorded at 362Gy for shoot length and 372Gy for root length. The progressive reduction in germination and survival percentage with increasing doses of gamma radiation was observed in the mutagenic treatments. In M2 and M3 generations, the traits viz., days to 50% flowering, days to pod initiation, days to maturity, plant height, number of branches, number of clusters per plant, number of pods per cluster, pod length, number of seeds per plant, hundred seed weight and seed yield per plant were calculated to estimate the genetic variability, character association, path coefficient, mean performance of the genotypes among the nine treatments of black-gram genotypes for eleven quantitative characters. Analysis of genetic variance revealed moderate to high level of genetic variability among all the genotypes in majority of the characters. High to moderate PCV and GCV were recorded for the traits viz., seed yield per plant, number of clusters per plant, number of pods per plant, plant height and number of branches per plant. The high heritability along with the genetic advance as per cent of mean was recorded in 100 seed weight, clusters per plant, plant height and branches per plant and seeds per pod in M2 generation and in M3, the traits viz., branches per plant, number of clusters per plant, number of pods per plant recorded high heritability along with high genetic advance. In M2 and M3 generations, variation in leaf arrangement like pentafoliate and hexafoliate were observed in different treatments along with variation in leaf colour, leaf shape and structure.Correlation studies showed that seed yield per plant exhibited positive significant association with the traits viz., days to 50% flowering, days to pod initiation, days to maturity, clusters per plant, pod length and 100 seed weight.Path coefficient analysis identified that 100 seed weight, days to pod initiation, clusters per plant and pod length had positive direct effect and indirect effect via days to 50% flowering, seeds per pod, days to maturity and branches per plant. Hence, simultaneous selection of the above traits would be more rewarding to bring improvement in black-gram.
  • ThesisItemOpen Access
    (AAU, Jorhat, 2022) Jamir, Pursangla; Barua, Purna K.
    Green gram (Vigna radiata L. Wilczek) is an important pulse crop of India and is grown in almost all the states. India is the major producer of green gram in the world. In Assam, it is sown in two seasons, summer (February and March) and kharif (August-September). Kharif sowing generally coincides with the rainy season causing problem in seed germination and seedling establishment. Seed coating is a seed technological technique for enhancing germination and seedling establishment under a wide range of environmental conditions. The present study was carried out to study the effect of seed coating with linseed, castor and mustard oils on green gram seed quality in laboratory conditions and to evaluate the effect of seed coating with these vegetable oils on seedling establishment and crop performance in saturated soil moisture condition in the field. Each of the oils was applied @ 5 ml, 10 ml and 15 ml/kg seed by thorough mixing to impart seed coating. Mustard oil and castor oil treatments were found to improve the seed germination and vigour in the laboratory. In the field, under saturated soil conditions mustard oil and castor oil treatments enhanced field emergence percentage, seedling dry weight, plant height, pod clusters per plant, pods per plant, seeds per pod and seed yield per plant. Linseed oil @10 ml/kg and 15 ml/kg also showed promising performance for seedling dry weight, pod clusters per plant and seeds per pod. In field soil capacity soil condition, linseed and castor oil treatments significantly increased field emergence, plant height, number of branches per plant, pod clusters, seeds per pod and seed yield per plant.
  • ThesisItemOpen Access
    (AAU, Jorhat, 2021) Bhattacharyya, Prastuti; Phukan, Rumjhum
    Indian mustard [Brassica juncea (L.) Czern. & Coss.] holds a notable position among the oilseed crops grown in the world and has emerged to be the second most important oilseed crop in India. However, the crop is not popular among the farmers of Assam as it does not fit well into the cropping system due to the longer duration required for its maturity. Thus, developing a mustard variety with short height, shorter duration without compromising the yield can change it into a valuable crop in Assam. The disease Alternaria blight seems to be a major issue in the area affecting the yield up to a great extent, thereby attracting attention for its consideration during the study of the yield parameters. The research was guided with a target to the analysis of variability among the parents and F1s, character interrelationship, and combining ability in the diallel cross. Ten genotypes were grown in the Rabi 2019-20 containing three Alternaria blight tolerant lines, two high yielding lines (under Assam conditions), four single zero varieties, and one genotype that was a double zero variety belonging to the Brassica napus species. Diallel crosses were made between five selected parents to produce F1 progeny including reciprocals to study the nature of gene action involved in the expression of quantitative traits which were subsequently grown in Rabi 2020-21 along with other genotypes. Some of the other crosses that were presumed to be consequential were also developed and evaluated to develop breeding materials having quality oil content with lower amounts of erucic acid with the least impairment in yield. The analysis of variance (pooled) revealed significant variation among the parents for all the characters under study indicating the presence of exploitable variation among the genotypes included in the experiment. Moderate genotypic coefficient of variation and phenotypic coefficient of variance for most of the characters and high broad-sense heritability was observed for all the traits under study. High genetic advance coupled with high heritability was observed for the characters, foot length, thousand seed weight, seed yield per plant, plant height, number of primary branches, number of secondary branches and biological yield per plant which denotes the probable preponderance of additive gene effects and selection may be effective. Since yield is polygenecally controlled and highly influenced by the environment, selection based on yield alone is not effective. From correlation analysis studies in both the years, it can be concluded that days to maturity and plant height were the major yield attributing traits which showed strong negative genotypic correlation with the character, yield per plant. The path analysis of both the years revealed that the characters, days to 50% flowering, number of secondary branches per plant, number of pods per main shoot and number of seeds per siliqua had direct positive effects on seed yield per plant. From the analysis of variance for combining ability, significant variation among the parents, among the total crosses, among F1s and among the reciprocals was inferred, which indicates the presence of genetic differences among the parental genotypes and their prepotency. Moreover, the significance of the difference between Parent vs F1s was observed for all the characters under study, which suggests the presence of heterosis, while in the case of F1 vs Reciprocal, significant variation was observed for most of the characters. This denotes the preponderance of reciprocal effect. From the evaluation of GCA in parents, the genotypes EC339000 and Pusa Mahek were found to be good combiners with high GCA for early maturity, early days to 50% flowering and low foot length, while, TM-2 for seed yield per plant. The crosses TM-2 x PM21, followed by PHR2 x PM21 depicted positive significant SCA effects for seed yield per plant and also exhibited high positive significant heterosis over better parent for the character. The banding patterns of 10 SSR gene-linked markers were studied, out of which 9 primers showed polymorphism. The PIC value was calculated which ranged from 0.190 to 0.927. Clustering was done based on Jaccard coefficient of similarity and the genotypes DLSC-1 and Pusa Mahek were found to be most similar, whereas, TM-2 and PM-22 exhibited the least similarity. The marker data generated can be utilized in further breeding programmes.
  • ThesisItemOpen Access
    (AAU, Jorhat, 2021) SAHARIA, NIHARIKA; Sarma, R N
    Soybean has attained important status in agriculture and oil economy of the country. It is a distinctive multi-purpose crop with ever increasing popularity due to various health benefits. It is imperative to estimate the nature and extent of variability among soybean genotypes to develop improved varieties suitable for varied agro-ecological situations. Moreover, there is limitation of molecular marker based diversity analysis in a precise way among the genotypes used for varietal breeding programme. The present investigation was carried out with 38 soybean genotypes during Kharif, 2020. In the field experiment, the data on qualitative traits were taken on plot basis, while data on quantitative traits on five plant basis were recorded. For molecular analysis, 24 SSR primers were used to asses fingerprint pattern for estimation of genetic relatedness. A wide range of variation was noticed for all characters. Highest GCV and PCV were recorded for the plant height, the branches per plant, the pods per plant and seed yield along with high heritability and genetic advance as per cent of mean. Per se performance revealed that different genotypes possessed different desirable yield attributes. However, genotype NRC-128, JS 22-11, ASb-9, DS 3105 and NRC-109 were the best genotypes based on per se performances for different yield components. Seed yield per plant showed positive association with the plant height, the branches per plant and the pods per plant. Path coefficient analysis identified that the pods per plants could be used as a direct or indirect selection criterion in identification for higher-yielding genotypes, along with emphasis on selecting for more branches per plants in tall plant. Among the qualitative characters, hilum colour, pubescent density and pubescent type had the maximum distinguishing potential (4 classes) indicating their importance in describing the genotypes. Euclidean distance based on qualitative characters indicated the genotype DLSb-2 and JS 22-14 to be most divergent, while that based on quantitative characters revealed the maximum divergence between the genotype NRC 128 and TS20-5. The Mahalanobis D2 value was observed to be highest between NRC-128 and NRC-109, which were placed in different clusters with maximum inter-cluster distance between them. Out of 24soybean specific SSR primers, 19 were found to be polymorphic. The number of SSR allele per locus ranged from one to three with an average of 1.4 alleles per locus. The PIC value ranged from 0.10 (Satt416) to 0.79 (Sat_172) with an average of 0.37.Jaccard’s coefficient of similarity (SSR marker based) ranged from 0.52 to 0.97 with an average value of 0.72. No concordance was found between the distance matrices of morphological and molecular markers.