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Assam Agricultural University, Jorhat
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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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ThesisItem Open Access ORGANIC AMENDMENTS AND MULCHING FOR GROWTH, FLOWERING, YIELD, SEED PRODUCTION AND POST HARVEST LIFE IN CHINA ASTER(2022) Konwar, Binita; Talukdar, Madhumita ChoudharyThe investigation was conducted at Dhemaji during 2019-20 and 2020- 21, to study the effect of Organic amendments and mulching for growth, flowering, yield, seed production and post harvest life in China aster consisting of 36 treatments and 3 replications. Post-harvest quality of flowers was further studied for long distance transport in four different packaging material and three harvesting stages. The vegetative characters in pooled data were highly influenced by the nutrient treatment N4 (Microbial consortium (Bio fertilizers) + Rock Phosphate @ 5 g/m2 + Vermicompost @ 3.0 t/ha) where the highest plant height 60.00 cm , 205.68 number of leaves, 8.25 number of branches and 3313.39 cm2 leaf area. Similarly the mulching M2 (Silver lined plastic mulching) and its interaction with N4 i.e., N4M2 recorded the highest values for these traits. The minimum days for full bloom was recorded in the nutrient treatment N4 with 107.65 days, the mulching treatment M2 with 112.16 days and their interaction (N4M2) with 104.36 days. The nutrient treatment N4 recorded the highest number of flowers of 52.58, blooming period of 45.31 days, self life of 13.77 days and vase life of 11.15 days. The red plastic mulching (M3) was found to record higher values in terms of flower characters though at par with M2. The interaction treatment N4M2 recorded the highest number of flowers per plant (54.23) while N4M3 recorded at par performance with N4M2 showing maximum blooming period of 48.87 days, self life of 14.08 days and vase life of 11.73 days in pooled data. The physiological parameters were highly influenced by the nutrient treatments with N4 recording the highest chlorophyll content of 3.24 mg g-1, anthocyanin content of 309.02 mg 100g-1, NAR of 0.92 and RLWC of 93.21%. The mulching treatment M3 recorded highest values in terms of the above physiological parameters. The highest seed yield was observed in the treatment N4 (8.10 g/plant and 13.49 q/ha), M2 (7.52 g/plant and 12.53 q/ha) and the interaction N4M2 (8.45 g/plant and 14.09 q/ha). The germination percentage and seedling vigour showed a decreasing trend with increase in time from harvest when stored in room temperature. 6 The soil characters in the pooled analysis were found to be highest in terms of Organic carbon, pH, enzymes and microbial biomass carbon with the application of Enriched compost @3.0 t/ha (N8). In the post harvest study after transportation, packaging with high density polyethylene and flowers harvested at the full bloom stage recorded the lowest PLW (45.00%), wilting (71.85%), rotting (22.29%) and highest vase life (7.39 days) on the 5th day in the pooled data. The B:C ratio was found highest in the treatment N4M2 (4.57 and 5.54) followed by N4M3 (4.05 and 5.09) and N8M2(3.74 and 4.74) for flower and seed characters, respectively.ThesisItem Open Access Canopy and Micronutrient Management of Thailand ber (Ziziphus mauritiana Lamk.)(2022) Sarma, Bhaskarjyoti; Kotoky, UtpalThe present experiment on “Canopy and micronutrient management of Thailand ber (Ziziphus mauritiana Lamk.)” was carried out for two successive years during 2020- 21 and 2021-22 in the farmer‟s field at Pundibari village, Dompara, Bongaigaon with the objective to standardize the pruning height and to find out optimum doses of boron and zinc. The experiment was laid out in factorial Randomized Block Design with 3 factors viz. variety, pruning height and micronutrient sprays with three replications and the data of individual years were subjected to pooled analysis. The varieties V1 (Round green type) and V2 (Roundish ovate reddish type) were pruned at height P1 (50 cm from ground level) and P2 (75 cm from ground level). A total of nine micronutrients treatment were given i.e. N0 (control), N1 (Borax 0.4%), N2 (Borax 0.5%), N3 (ZnSO4 0.4%), N4 (ZnSO4 0.5%), N5 (Borax 0.4% + ZnSO4 0.4%), N6 (Borax 0.4% + ZnSO4 0.5%), N7 (Borax 0.5% + ZnSO4 0.4%) and N8 (Borax 0.5% + ZnSO4 0.5%). The plant height was not influenced by any of the treatments. The variety V1 (Round green type) recorded the earliest flowering (121.25 days), heavier fruits (35.49 g) leading to higher yield per plant (31.17 kg) although the variety V2 (Roundish ovate reddish type) exhibited better fruit quality, viz., the highest TSS (15.00 oBrix), total sugar (15.14%), reducing sugar (8.08%), carotenoid (0.33 μg/g), vitamin C content (68.49 mg/100 g) and DPPH scavenging ability (9.96%). Pruning at 75 cm above ground level (P2) resulted in more number of primary branches (8.28) leading to more fruits (148.90/branch) and better quality fruits in terms of size, TSS, total sugar, reducing sugar, carotenoid content and the lowest titratable acidity. Among the micronutrient sprays, borax 0.5 per cent along with zinc sulphate 0.5 per cent (N8) was most effective with respect to fruit retention (56.65%), more fruits per branch (146.90) and better quality fruits. The N8 treatment favourably influenced the TSS, total and reducing sugars, titratable acidity and total leaf chlorophyll content. The interaction of three factors revealed that V1P2N3 was better for number of primary branches, while V2P1N4 recorded the highest DPPH scavenging ability (10.05%). Although V2P2N8 (Roundish ovate reddish type variety, pruning at 75 cm from ground level, Borax 0.5% + ZnSO4 0.5% spray) registered the maximum number of fruits (181.24/branch), the highest fruit yield (85.18 t/ha) was obtained in the treatment V1P2N8 (Round green type variety, pruning at 75 cm from ground level, Borax 0.5% + ZnSO4 0.5% spray) owing to differences in fruit size. The treatment combination V2P2N8 was registered to be better in vitamin C content (70.28 mg/100 g) and other quality parameters along with total leaf chlorophyll content (4.32 mg/g FW). Computation of production economics revealed the B:C ratio to be the highest in V2P2N8 (7.36), followed by V2P2N7 (7.08).ThesisItem Open Access INTEGRATED NUTRIENT MANAGEMENT IN MANGO (Mangifera indica L.) CV. AMRAPALI(AAU, Jorhat, 2021) Mehta, Ritika; Gogoi, BornaliAn experiment entitled “Integrated nutrient management in mango (Mangifera indica) cv. Amrapali” was conducted during 2019-2021 at Experimental Farm, Department of Horticulture, Assam Agriculture University, Jorhat-13 with the objective to determine the effect of Integrated Nutrient Management (INM) on flowering, yield and biochemical constituents of mango and to determine the economics of cultivation. The experiment was laid out in Randomized Block Design with eight number of treatments which were replicated three times. The treatments are T0 : Absolute control, T1 : RDF (730 g N : 180 g P : 680 g K) + FYM plant-1, T2 : 75% RDF + FYM + Vermicompost (3 kg) + Azotobacter + PSB plant-1, T3: 50% RDF + FYM + Vermicompost (5 kg) + Azotobacter + PSB plant-1, T4: 75% RDF + FYM + Vermicompost (3 kg) +Azotobacter + PSB + Rock phosphate (100g) plant-1, T5: 50% RDF + FYM + Vermicompost (5 kg) + Azotobacter + PSB + Rock phosphate (200 g) plant-1, T6: 75% RDF + FYM + Enriched compost (3 kg) + Azotobacter + PSB plant-1, T7: 50% RDF + FYM + Enriched compost (5 kg) + Azotobacter + PSB plant-1. Azotobacter and PSB were applied 5 g each per kg of the compost and FYM was applied 20 kg per plant in every treatment from T1 to T7. Field data was taken for the two years i.e., 2019-2020 and 2020-2021 and the biochemical parameters were evaluated only during the year 2019-2020. During the first year of experiment, Days to 50% inflorescence emergence and Days to 50% flowering, were found to be non-significant. However, integrated application of nutrients had significant difference among each other during the second year of experiment. Pooled analysis over the two years revealed that the minimum days to 50% inflorescence emergence (133.58), minimum days to 50% flowering (143.24), maximum length of panicle (27.74 cm), number of rachis per branch (26.72), percentage of fruit set (33.34), fruit size (10.24 cm), yield per plant (14.60 kg) and pulp-peel ratio (6.31) were observed in T4. Percentage of fruit drop was also found to be lowest in treatment T4. Quality parameters like TSS (22.09º Brix), reducing sugar (4.94%), non-reducing sugar (12.15%) was found to be highest in T4. β carotene content was found to be maximum in treatment T2 which was statistically at par with treatment T4. Titratable acidity and crude fibre were found to be non-significant among the treatments. Results revealed that maximum available nitrogen (286.28 kg/ha), phosphorus (48.55 kg/ha), potassium (183.66 kg/ha) and organic carbon (0.99%) was found in treatment T4. pH among the treatments was observed to be non-significant. The net return and B:C ratio were found to be highest in treatment T4 followed by treatment T2. Thus, in a broader view, treatment T4 was better towards improving the flowering, yield and biochemical constituents of mango which is followed by treatment T2. Hence, considering the above points and based on results of experiment, treatment T4 [75% RDF + FYM (20 kg) + Vermicompost (3 kg) + Azotobacter (15 g) + PSB (15 g) + Rock phosphate (100 g) plant-1] is considered best for recommendation which is followed by treatment T2 [75% RDF + FYM (20 kg) + Vermicompost (3 kg) + Azotobacter (15 g) + PSB (15 g)] plant-1.ThesisItem Open Access Integrated nutrient management in lettuce (Lactuca sativa L.)(AAU, Jorhat, 2021) NATH, KANGKANA; Sarma, IraA field experiment was conducted at the Experimental Farm, Department of Horticulture, Assam Agricultural University, Jorhat during the year 2019-20 and 2020-21 to study the effect of integrated nutrient management on growth, yield and quality of lettuce. The experiment was laid out in a randomized block design (RBD) with eight treatments replicated thrice. The treatments were T1: Control, T2: 40:20:40 Kg NPK ha-1, T3: 40:20:40 Kg NPK ha-1+ FYM 2t ha-1, T4: 40:20:40 Kg NPK ha-1 +FYM 2t ha-1 + PSB, T5: FYM 3t ha-1+ PSB, T6: 40:20:40 Kg NPK ha-1 +VC 1t ha-1, T7: 40:20:40 Kg NPK ha-1 + VC 1t ha-1 +PSB and T8: VC 2t ha-1 + PSB. Observations of the growth parameters were taken at 30 days after planting (DAP), 45 days after planting (DAP) and at harvest. Analysis of variance during 2019-20, 2020-21 and across the years revealed significant mean square due to treatment for all the characters under study. The characters studied were plant height, leaves per plant, leaf length, leaf breadth, leaf canopy spread, leaf area, fresh weight, dry weight, days to marketable maturity, yield per plot and yield per hectare.The pooled analysis across 2019-20 and 2020-21 revealed that the treatment T7 recorded maximum plant height (14.25cm, 19.17cm and 26.92cm) and maximum leaves per plant (10.00, 17.17 and 29.17) at 30 DAP, 45 DAP and at harvest, respectively. The leaves per plant in the treatment T4 (9.88) at 30 DAP was statistically at par with treatment T7. Maximum leaf length (16.33cm, 22.67cm and 27.64cm) and leaf breadth (16.08cm, 22.17cm and 27.67cm) were exhibited by the treatment T7 at all the three growth stages. Leaf length in the treatments T4 (16.00cm) and T6 (15.48cm) were statistically at par with treatment T7 at 30 DAP. Maximum leaf canopy spread (12.6cm, 21.33cm and 29.75cm) and maximum leaf area (198.95cm², 347.29cm² and 543.33cm²) were observed in the treatment T7 at 30 DAP, 45 DAP and at harvest, respectively. Maximum fresh weight of leaves (206.33g) as well as dry weight of leaves per plant (13.85g) were exhibited by the treatment T7 whereas, minimum of these were recorded by the treatment T1. The highest yield (27.5 t/ha) was exhibited by the treatment T7. Minimum number of days to reach the marketable maturity was observed in the treatments T4 and T7 with values 53 days whereas maximum number of days (63 days) for the same character was observed in the treatment T1. The highest moisture content (96.28 %) was observed in the treatment T6. The integrated application of organic, inorganic and biofertilizers influenced the nutritional content of lettuce significantly. The ascorbic acid content (3.76mg/100g), calcium content (20.67mg/100g), non-reducing sugar content (3.98 %) and chlorophyll content (3.77mg/100g) were recorded maximum in treatment T7 whereas the maximum iron content (1.50 mg/100g) was observed in the treatment T5.The highest nitrogen (0.23%) and the crude protein content (1.44%) were observed in both the treatments T6 and T7. Maximum reducing sugar content was observed in T4. The highest net return (Rs. 192703.00) was obtained in the treatment T7 with benefit cost ratio 2.34. However, the highest benefit cost ratio was exhibited by the treatment T4 (2.58) with a net return of Rs. 189703.00 due to high cost of production in T7.ThesisItem Open Access GROWTH, FLOWERING AND CORM PRODUCTION OF GLADIOLUS (Gladiolus grandiflorus L.) AS INFLUENCED BY NITROGEN AND PHOSPHORUS(AAU, Jorhat, 2021) Kachari, Polashi; Bora, SunilAn experiment entitled “Growth, flowering and corm production of gladiolus (Gladiolus grandiflorus L.) as influenced by nitrogen and phosphorus” was carried out in the Experimental Farm, Department of Horticulture, Assam Agricultural University, Jorhat during 2019-2020. The treatments referred to four levels of nitrogen viz., 0, 5, 10 and 15 g/m2, four levels of phosphorus viz., 0, 3, 6 and 9 g/m2 and a constant dose of potassium viz., 6 g/m2. Hence, there were sixteen (4×4) combinations of various treatments of nitrogen and phosphorus and one additional treatment i.e. RDF (NPK::1:2:2 @ 56 g/m2) and each treatment was replicated three times in a Factorial Randomized Block Design. The mean performance of growth and yield parameters revealed that nitrogen level N3 (N 15 g/m2) recorded the maximum values for most of the growth as well as yield attributing characters viz. plant height (144.47 cm), number of leaves (8.14), breadth of leaves (5.35 cm), number of spikes per plant (1.78), length of spike (104.18 cm), flower diameter (10.36 cm), highest self-life (16.00 days) and vase life (11.33 days) and highest fresh weight of spike (90.93 g). In case of corm parameters, N3 (N 15 g/m2) also recorded maximum number of corms (1.87) and cormels (29.90) and highest weight (91.03 g) of corm. In respect of phosphorus levels, P3 (P2O5 9 g/m2) recorded the highest pant height (137.26 cm), number of leaves (7.82), breadth of leaves (4.92 cm), maximum number of spikes per plant (1.70), highest length of spike (100.35 cm), flower diameter (10.22 cm), self-life (15.39 days) and vase life (10.83 days), fresh weight of spike (84.62) and maximum weight of corm (84.28 g). Interaction between nitrogen and phosphorus showed that, N3P3 (N:P2O5 @ 15:9 g/m2) was superior in respect of the key parameters like plant height (147.24 cm), number of leaves (9.21), number of florets per spike (18.27), length of spike (107.52 cm), fresh weight of spike (97.46 g), self-life (16.80 days) and vase life (11.86 days) of spike and weight of corm (102.24 g) and cormels (13.65 g). From economic point of view, combination of N3P3 (N:P2O5 @ 15:9 g/m2) recorded the highest B:C ratio of 3.15 against the lowest B:C ratio of 1.52 in control treatment. Hence considering the best values in respect of vegetative, floral, corm characteristics and benefit-cost ratio, the treatment combination of nitrogen at 15 g/m2, phosphorus at 9 g/m2 and potassium at 6 g/m2 (Urea, SSP and MOP @ 32.6 g, 56.25 g and 10 g/m2) could be considered as the best treatment and can be effectively applied for commercial cultivation of gladiolus under Assam (Jorhat) conditions.ThesisItem Open Access High Density Orcharding of Guava (Psidium guajava L) cv. Lalit for Assam(2022) Borah, Anjan; Kotoky, U.The present research work entitled, ―High Density Orcharding of Guava (Psidium guajava L) cv. Lalit for Assam‖ was conducted at the Experimental Farm of Horticultural Research Station, Assam Agricultural University, Kahikuchi, Guwahati during the year 2017–2020 to standardize the planting density and to determine the ideal NPK levels for high-density planting system in Guava for Assam conditions. The experiment was laid out in Factorial Randomised Block Design (RBD) with 3 replications and two factors comprising of four planting densities i.e. S1 (4444 plants ha-1), S2 (5000 plants ha-1), S3 (6666 plants ha-1), S4 (10000 plants ha-1) and three fertiliser levels viz., F1 (50:25:15 g NPK plant-1 for first year and 110:55:45 g NPK plant-1 for second year), F2 (60:35:25 g NPK plant-1 for first year and 120:65:55 g NPK plant-1 for second year) and F3 (70:45:35 g NPK plant-1 for first year and 130:75:65 g NPK plant-1 for second year). The significant findings of the present experiment revealed that the high density planting had a substantial impact on plant growth, yield and quality of guava. The highest plant girth, canopy spread, number of branches, total number of leaves, leaf area and leaf area index were recorded in the lowest planting density (S1), while the maximum plant height was observed in the highest density (S4) during winter and rainy seasons of 2018-19 and 2019-20. The significantly higher number of flowers, fruits per branch, highest fruit set and lowest fruit drop was observed in widely spaced populations and the rainy season crop bear more flowers and fruits consistently for the two years, while fruit set percentage was recorded higher in winter season as compared to rainy season crop. The results also indicated that different levels of fertiliser had shown varied responses to vegetative and reproductive growth of plants. The fruit yield per plant increased significantly with decrease in plant population thus, maximum yield (1.74 and 1.83 kg plant-1) was obtained in the lowest density (S1) and the minimum (0.75 and 0.78 kg plant-1) at highest density (S4) respectively in the year 2018-19 and 2019-20. Further, the highest yield per hectare was obtained in planting density S2 (8.02 t ha-1) and S1 (8.15 t ha-1), while the lowest was recorded in plants under density S3 (6.04 and 6.76 t ha-1). The physical and chemical attributes of fruit were found significantly superior in lower densities during both years and the winter season crop was superior to rainy season in terms of physico-chemical characteristics of fruit. The 7 plants under the lowest population density (S1) yielded fruits with the highest length (5.79 cm and 6.17 cm), maximum weight (124.34 g and 130.21 g), highest volume (116.97 ml and 125.05 ml) and maximum pulp weight (113.39 g and 120.00 g). The lowest number of seeds (223.10 and 231.41), minimum seed weight (3.87 g and 4.37 g) and highest value of pulp:seed ratio were observed in the fruits of plants at the lowest density. The widely spaced population (S1) produced fruits with the maximum ascorbic acid, total sugars, non-reducing sugar, sugar to acid ratio, juice content and minimum acidity during both years, while the highest TSS, reducing sugar and pectin content was obtained in fruits from the plant at density S1 in 2018-19 and S2 in 2019-20. The fertiliser level also impacted the yield and quality of fruit quite significantly, the highest fruit yield per plant (1.54 and 1.64 kg per plant) and maximum yield per unit area (9.06 t ha-1 and 9.73 t ha-1) during the first and second year of investigation was obtained with the application of F3 level of fertiliser. Also, the plants nourished with the highest level of fertiliser (F3) produced fruits superior in quality irrespective of season or year. The plants under the lowest density (S1) had the highest percentage of leaf NPK, while the maximum N (1.52% and 1.61%), P (0.26% and 0.28%) and K (0.62% and 0.63%) was found in leaves of plants treated with F3 level of fertiliser. The total chlorophyll content of leaves was also varied markedly with different levels of plant density and fertiliser, the highest value of chlorophyll content (1.91 mg g-1 and 2.07 mg g-1) was noted in the lowest density (S1), while it was found maximum in the highest level of fertiliser (F3). The interaction of lower plant densities with the highest level of fertiliser produced superior results in comparison to other combinations, the S1F3 and S2F3 treatment combinations resulted in higher yield with superior quality fruits. The highest benefit to cost ratio was estimated to be 3.28 in S1F3 followed by 2.92 in the S2F3 combination. The guava plants grown at population density of 4444 plants ha-1 with the application of 70:45:35 g NPK plant-1 in the first year and 130:75:65 g NPK plant-1 in the second year exhibited optimum growth, higher yield with superior quality fruits and gave higher profitability.ThesisItem Open Access Drying of flowers using different desiccants(AAU, Jorhat, 2021) Goswami, Jutika; Langthasa, SupriyaAn experiment on “Drying of flowers using different desiccants” was conducted during 2019-2021 in the laboratory, Department of Horticulture, Biswanath College of Agriculture, AAU, Biswanath Chariali with two objectives (i) to find out the best desiccants for drying of flowers, and ii) to study the keeping quality of dried flowers. Five different flowers were selected for the experiment such as Marigold (Tagetes patula), Calendula (Calendula officinalis), Gomphrena (Gomphrena globosa), Plumeria (Plumeria alba) and Yellow Oleander (Thevetia peruviana). The experiment was laid out in factorial CRD with three replications. The treatments were T1: Control (without embedding), T2: Borax, T3: Sand, T4: Silica gel, T5: Sand + Borax (50: 50) and T6: Sand + Silica gel. Flowers were dried using two method (a) Hot air oven and (b) Microwave oven. The results of the findings revealed that quality of dry flower vary due to drying methods and desiccants used for drying. Highest moisture-loss was observed in control (drying without embedding materials) in all the flower, like Marigold (86.82%), Calendula (89.71%) and Yellow Oleander (77.81%) and Gomphrena recorded highest in Borax (69.43%), Plumeria in Silica gel (84.03%). Hot air oven showed higher moisture- loss than microwave oven. The minimum reduction in diameter was found in Silica gel, such as in Marigold (0.83cm), Calendula (0.52cm), Plumeria (0.49cm), Yellow Oleander (0.57cm) where as 0.32 cm reduction was noticed in Sand + Borax for Gomphrena. The time taken for drying was longest in sand media for both hot air oven and microwave oven. Among the desiccants control took minimum time for drying in all the flowers. The colour retention in dry flower was observed by Hunter Lab Colorimeter where ΔE* value was observed for the colour difference. Sand was found to be most effective in terms of colour retention for Marigold (3.45), Calendula (11.32), Gomphrena (20.09) and borax was found efficient for Plumeria(12.20), Yellow Oleander (12.58). In case of texture, smooth texture was found in Sand media for Calendula, Gomphrena, Plumeria and Yellow Oleander while Silica gel was effective for Marigold. In terms of general appearance, shape retention and petal shattering, silica gel was found to be superior. There was no significant change in dry flowers during storage (3 months). Thus, silica gel and sand together can be recommended for drying of flowers under hot air oven.ThesisItem Open Access Shelf life of Khasi mandarin (Citrus reticulata Blanco) fruits as influenced by plant extracts, essential oils and natural coatings(AAU, Jorhat, 2018) Muzafary, Sayed Yusuf; Borthakur, P. K.The experiment was conducted during 2017-18 in the Post-harvest laboratory of the Department of Horticulture and Department of Plant Pathology, Assam Agricultural University, Jorhat. The objective of this investigation was to study the effect of plant extracts, essential oils and natural coatings on shelf life of Khasi mandarin fruits and also to determine the physico- chemical and organoleptic changes during storage. The experiment was taken up in two parts .In the first experiment in vitro pathological study was taken up to test the effect of selected plant extracts and essential oils against Penicillium digitatum (green mold). The results of in vitro studies revealed that, out of the various plant extracts 100% inhibition of Penicillium digitatum was observed in Neem extract and cinnamon extract treatments. Similarly amongst the oils, clove oil, Thyme oil and lemongrass essential oil showed maximum inhibition (100%) of the fungi. The two of the best plant extracts and essential oils were selected for next experiment. In the second Experiment, Khasi mandarin fruits were treated with two best Plant extracts and essential oils (as obtained in the first experiment) alone or in combination with two natural coatings viz. Aloe vera gel and chitosan. After the treatment the fruits were wrapped in perforated 50 micron polyethylene bags and stored under ambient condition and various physicochemical and sensory evaluations were taken up across the storage period. The results revealed that during 20 days of storage period maximum decay loss was observed in the control treatment. On the other hand fruits treated with Bavistin, Neem extract and combination of Aloe vera gel + Neem extract treatments, no decay loss was observed during the 20 days of storage period. As regard the number of days taken for 50% decay of fruits; it was observed that the fruits treated with Bavistin treatment took the maximum number of days for 50% decay of fruits i.e.35 days followed by Neem extract treatment (33.66 days) and combination of Aloe vera gel + Neem extract (29.33days) treatments. Though Bavistin treatment recorded higher values with respect to physic-chemical and sensory evaluation; there was no significant difference between the Bavistin treatment and Neem extract treatment and also with the combination of Aloe vera gel (1%)+ Neem extract(10%) (in some of the observations). Since plant extracts are environment friendly and do not leave any chemical residue as against use of chemical fungicides (like Bavistin), use of Neem leaf extract and combination of Aloe vera gel (0.1%) + Neem extract(10%) can be advocated for enhancing shelf life of Khasi mandarin fruits.ThesisItem Open Access Performance of Chilli (Capsicum annuum) cv. ‘Krishna Jolokia’ as influenced by organic inputs and microbial consortium(AAU, Jorhat, 2018) Shiriyappagoudar, Tejaswini; Saikia, JumiA field experiment was conducted at the Experimental Farm, Department of Horticulture, Assam Agricultural University, Jorhat during November 2016 to march 2017 to study the “Performance of Chilli (Capsicum annuum) cv. „Krishna Jolokia‟ as influenced by organic inputs and microbial consortium”. The experiment was laid out with Randomized Block Design and replicated three times. There were seven treatments consisting of T1 [RDF (120:60:60 kg ha-1 NPK + FYM @ 10 t ha-1)], T2 (Compost @ 2.5 t ha-1 + microbial consortium), T3 (Compost @ 5 t ha-1+ microbial consortium), T4 (Vermicompost @ 2.5 t ha-1 + microbial consortium), T5 (Vermicompost @ 5 t ha-1 + microbial consortium), T6 (Enriched compost @ 2.5 t ha-1) and T7 (Enriched compost @ 5 t ha-1) with an objective to study the effect of organic, and microbial consortium on growth, yield and quality of chilli as well as soil chemical and biological properties. The results revealed that growth, yield and yield attributing characters were significantly influenced by the application of different nutrient sources. T1 recorded the highest value in all the growth, yield and yield attributing characters among all the treatments. However, among the organic treatments the highest plant height (79.85 cm), number of primary branches per plant (5.6) in T3, number of secondary branches per plant (9.8) in T2 were observed. The highest number of fruits per plant (95.63), fruit length (7.98 cm), fruit girth (0.98 cm), fruit weight (1.91 g), seeds per fruit (96.68), fruit yield per plant (256.63 g) and fruit yield per hectare (12.07 t) were found in treatment T5. All the growth, yield and yield attributing parameters were significantly poor in T6 (Enriched compost @ 2.5 t ha-1). Among the quality parameters, the organic treatments recorded superior results when compared to inorganic treatments. The highest ascorbic acid content (80.90 mg 100g-1) in T5, moisture content (91.14%) in T1 and pungency (35,000 SHU) in T7 were recorded. The results of soil analysis after harvest clearly indicated that the available NPK in all the treatments improved over initial availability. The microbial population and various enzymatic activities also improved markedly over the initial value. However, soil parameter studies revealed that soil organic carbon, N, P, K, Microbial Biomass Carbon and various soil enzyme activities were found highest in T7. Economics of production showed that the highest B:C ratio of 4.60 was observed in T1 [RDF (120:60:60 kg ha-1 NPK + FYM @ 10 t ha-1)] followed by organic treatment T5 (Vermicompost @ 5 t ha-1 + microbial consortium) with 3.78. Hence, considering the positive effect on growth, yield, quality and soil health, T5 can be considered as the best for adopting at the field level to reap good economic yield with better quality, sustained soil health and high net return.
