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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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ThesisItem Open Access Gender Differentiated Dimensions in Agriculture and Identifying its Factors Governing Impact on Tribal Farm Women - A Study in Assam(2022) Bora, Pallabi; Mishra, P.The present study was carried out in Jorhat, Morigaon, Baksa and Dhemaji districts of Assam with the objectives to assess the gender division of agricultural activities and to explore gender differentiated dimensions in agriculture along with its impact factors. A multistage random sampling method was followed to select the final respondents of 320 that comprises equal number of women and men respondents of a particular household. Two agricultural components namely paddy and piggery were included in the study. Appropriate statistical tools viz. frequency, percentage, mean, Z- test, multiple regression, path analysis were employed to analyse the data. The findings revealed that majority of the farm women and men belonged to young age group with less considerable level of education. More than ninety percent had male headed household and nuclear family (70.625) with medium sized family (53.75%) in between 4 to 6 members. Both had good number of years of farming experience but had low training exposure, poor extension contact and less social participation. Majority (66.25%) of them were small holding farmers utilizing 1 to 2 ha of land under paddy (71.25%) and had small pig size of less than 3 number. Most (58.12%) of them had rice and other allied agricultural activities as the main occupation. Average annual family income was Rs. 1.72 lakh and individual average income of women and men was Rs. 0.39 and Rs. 1.33 respectively. Both women and men had a medium level of knowledge and medium risk bearing ability. A medium overall level of participation was found in agriculture by women (55.62%) and men (58.12%) with mean scores of 54.57 and 67.99 in women and men respectively. Majority (40.63%) of the farm women had low decision making power in agriculture, while men (49.37%) had a high decision making power. The overall extent of access and control was found to be medium (48.75%) to low (33.13%) in women whereas, in men, a medium (47.50%) to high (30.62%) level was found. Most of the women had low (41.87%) income control (37.50) and forty five percent men had high to medium (29.38) income Comparatively the workload of women in triple role was more than men as women spent on an average of 15.75 hr. /day while spend 11.88 hr. /day. Both women (64.38%) and men (51.88%) had medium level of perception towards agriculture. A two sample Z- test showed that there were significant differences between women and men in all the four gender differentiated dimensions of agriculture. Among the seven impact factors, only education and family were positively significant with the likelihood of resources‟ access control and control pattern in usage of income at 0.001 level of probability. Three factors viz. personality, family and education were found to be positively significant with the likelihood of production decision making pattern at 0.001 level of probability. The coefficient of multiple determination (R2) values (0.619), (0.709), (0.688) stated that these factors jointly contributed 61.90 percent, 70.90 percent and 68.80 percent towards variation in production decision, resources‟ access control and control over usage of income respectively. Path analysis was performed using SPPS Amos version 26.0 to detect direct and indirect effects of the three dependent variables (Resource access control, Income usage and production decisions) and three independent variables (Personality, Family and Education). Path models revealed significant direct effects between Education and Family with all the dependent variables, i.e., Resource access control, Income usage and production decisions. However, direct effects of individual decision have been observed only with Production decisions. The co-variances among and between the independent variables were significant and showed significant indirect effects.ThesisItem Open Access Effect of different electrical conductances and vertical hydroponics systems on growth, yield and quality traits of strawberry (Fragaria x ananassa Duch.) with special reference to post-harvest shelf life under Assam condition.(2022) SAROJ, NANHE LAL; Barua, Pritam CoomarAn experiment was carried out in a naturally ventilated playhouse located in Experimental Farm, Department of Horticulture, Assam Agricultural University, Jorhat during the year 2019-20 and 2020-21 to study the effect of different electrical conductances and vertical hydroponics systems most suitable for the strawberry crop. The strawberry crop was subjected to EC levels viz. L1 (1.8 dS/m) and L2 (2.5 dS/m) in three different vertical hydroponics systems viz. T1 (A-Type), T2 (Column-Type), and T3 (Shelf-Type) to study their effect. The experiment was laid out in a factorial completely randomized block design with three treatments, six replications, and two EC levels, and data of individual years were subjected to the pooled analysis. Among the three vertical hydroponics systems (T1 A-Type) and EC (L1 1.8 dS/m) were found to be the best for vegetative and yield contributing characters along with other studies of quality parameters. The significant effect of vertical hydroponics system (T1 A-Type) and EC (L1 1.8 dS/m) was observed in plant height (20.90 cm) and (21.19cm), number of leaves per plant (15.24) and (14.97), number of shoots per plant (5.78) and (5.63), days to bloom (23.79 days) and (23.76 days), number of flowers produced per plant (16.46) and (17.08), leaf area (112.33cm2) and (115.75 cm2), plant spread (24.15 cm) and (23.06cm), days to harvest from fruit set (22.42 days) and (22.64 days), root length (18.15 cm) and (17.05cm), root volume (34.03cc) and (33.19cc) and dry root(2.44g) and (2.46g) weight compared to other vertical hydroponics system and EC levels. The yield attributing characters in terms of yield (357.88g./plant) and (316.91g./plant), fruit weight (25.61g) and (24.03g), number of fruits per plant (13.92) and (12.97), number of fruits per system (295.00) and (247.08), the weight of fruit per system in T3 (5.84 kg) and (5.84 kg), fruit length (6.96cm) and (5.88cm), fruit girth (10.35cm) and (9.89cm) and fruit volume (10.56cc) and (9.74cc) were found significantly higher in vertical hydroponics system (T1 A-Type) and EC (L1 1.8 dS/m). The type of structure, EC solutions, and interaction significantly affected quality parameters. The quality parameters viz., reducing sugars (5.18%) and (4.94%), non-reducing sugars (1.93%) and (1.87%), T.S.S. (7.70 0Brix) and (7.320Brix), total sugars (7.11%) and (6.81%), anthocyanin (29.51 mg/100g) and (27.76 mg/100g), titratable acidity (0.62%) and (0.68%), ascorbic acid (34.99mg/100 g) and (33.48 mg/100 g), moisture (92.00 %) and (91.74%), PLW (9.64%) and (9.69%), decay (9.48 %) and (9.47%), ash content (0.72%) and (0.71%), potassium (2.93mg /100g) and (2.91 mg /100g) and phosphorus (1.25 mg /100g) and (1.25 mg /100g), NAR (1.35mg cm-2 day-1) and (1.34mg cm-2 day-1) and B:C ratio (2.45) was found highest in T1, L1 and T1xL1. Among the three vertical hydroponic systems, significant differences in growth parameters were observed primarily due to differences in Net Assimilation Rate (NAR) availability. A higher NAR availability led to a higher rate of photosynthesis, better growth, and better quality of the fruits of the plants in the vertical hydroponic system (A-type). Therefore, some modifications such as A-shape or V-shape designs are suggested in the vertical hydroponics system to improve NAR availability in the column type and Shelf-type. Among both E.C levels, the effect of EC 1.8 was found to be the best for vegetative and yield contributing characters along with quality parameters of strawberries. The fresh strawberry fruits of cv. ‘Winter Dawn’ were plucked at approximately 3/4th maturity stage and packed in different readily available perforated packaging films viz., low-density polyethylene (P1), high-density polyethylene (P2), polypropylene (P3), polyvinyl chloride (P4), polyolefin films(P5), butter paper(P6) and without packaging as a control(P7). Fruits were wrapped in each packet to create a passive modified atmospheric condition. All the film-packed fruits were then stored in refrigerated and ambient storage temperature (i.e., 6℃ + 65-71% RH and 22-27℃ + 70-76% RH). The various quality attributes viz., physiological loss in weight, decay %, T.S.S., titratable acidity, ascorbic acid, total sugars, reducing sugars, anthocyanin, and sensory attributes of fruits were estimated in refrigerated (S1) and ambient (S2) storage conditions (viz., 3- and 1-days intervals) during the entire storage period. Under (S1) and (S2) storage conditions the result inferred that the PLW (P1S1 3.13 and P1S2 5.66%), Decay (P1S1 8.57 and P1S2 13.37%), TSS (P1S1 6.90and P1S2 6.92°Brix), titratable acidity (P1S1 0.55 and P1S2 0.70%), ascorbic acid (P1S1 23.08and P1S2 18.41mg/100g), total sugars (P1S1 4.77and P1S2 4.75%), reducing sugars (P1S1 3.78 and P1S2 3.80%), anthocyanin (P1S1 48.45 mg/100g and P1S2 53.47 mg/100g) and Organoleptic rating (P1S16.14 and P1S2 7.56) were found to decrease with the prolongation of storage periods. No significant variation was recorded for different packaging materials and EC, except for PLW, Decay, and ascorbic acid in fruits packed with P1. The organoleptic rating of strawberry fruits was found best in fruits packed with P1(S1 6.14and S2 7.56) packaging films. In the future, these experimental results may prove very useful for the storage of strawberry fruits for a certain period with better quality.ThesisItem Open Access PERFORMANCE OF GLADIOLUS (Gladiolus grandiflorus L.) AT DIFFERENT LEVELS OF FERTILIZERS AND SPACING USING MARIGOLD (Tagetes patula) AS AN INTER-CROP(2022) Borah, Karishma; Bora, SunilThe investigation was conducted in the Experimental farm of Department of Horticulture, Assam Agricultural University, Jorhat during 2018-19 and 2019-20, to study the effect of varied levels of spacing and Nitrogenous fertilizer doses in intercropping of French marigold with Gladiolus on growth, yield and quality attributes of the crops and determine the suitable spacing and fertilizer for the system. Postharvest quality of gladiolus spikes produced in the system was further evaluated in the Laboratory of Department of Horticulture, AAU, Jorhat during both the years. The first experiment was replicated three times in 3 factorial RBD with 12 treatments having 3 spacing levels (40cm×20cm, 50cm×20cm, 60cm×20cm), 3 Nitrogenous doses (130 + 220 + 200 kg NPK/ha, 160 + 220 + 200 kg NPK/ha, 190 + 220 + 200 kg NPK/ha), which were compared with 3 controls (Sole Gladiolus, Sole Marigold and Gladiolus + Marigold intercropping with RDF and Recommended Fertilizer). Laboratory experiment laid out in CRD with 3 replications and 10 treatments viz. Distilled water, Sucrose 4%), NaOCl 100 ppm, 8-HQC 200 ppm, Al2(SO4)3 300 ppm, CoSO4 400 ppm, Sucrose 4% + Al2(SO4)3 300 ppm, Sucrose 4% + 8-HQC 200 ppm, Sucrose 4% + CoSO4 400 ppm and Sucrose 4% + NaOCl 100 ppm. Field experiment revealed that growth, floral, yield and quality traits recorded significant variation in intercropping of both crops. In gladiolus, maximum sprouts per plant (2.43), plant height (140.79 cm) and leaves per plant (7.07) recorded with 190 + 220 + 200 kg NPK/ha (F3). Spacing of 60cm×20cm (S3) recorded highest plant height (141.12 cm) and leaves per plant (7.32). Sprouts per plant was superior (2.13) in 50cm×20cm spacing, which is at par with 60cm×20cm spacing. The treatment effect having maximum sprouts per plants (2.52) was attained in T9 (S2F3) and maximum plant height (144.17 days) and leaves per plant (7.42) were revealed in T12 (S3F3). Flowering attributes including days to emergence of gladiolus spike (79.20 days), bud initiation (87.19 days) and opening of first floret (94.72 days) was recorded minimum in spacing S3 (60cm × 20cm). 130 + 220 + 200 kg/ha NPK revealed minimum days to spike emergence (77.77 days), bud initiation (85.79 days) and opening of first floret (93.83 days). Treatment T10 (S3F1) took least days for spike emergence (76.25 days), bud initiation (84.41 days) and floret opening (92.47 days). Spikes per corm (2.20), rachis length (65.06 cm), internodal length (7.61 cm), spike length (94.17 cm) and floret diameter (12.53 cm) of spike, fresh weight (111.04 gm), dry weight (46.04gm), self life (16.16 days) and vase life (12.94 days) recorded highest in treatment T11 (S3F2). Number of florets open (5.36) and florets per spike (12.36) obtained maximum in T8 (S2F2). Treatment T3 (S1F1) attained minimum spike fresh weight (67.75 gm), dry weight (20.75 gm), self life (9.10 days) and vase life (6.98 days). T8 (S2F2) recorded maximum corm size (7.23 cm) and T11 (S3F2) recorded maximum corm weight (139.48 gm), number of corms (3.36) and number of cormels (26.24) per corm planted. Spacing 60cm×20cm (S3) and 160 + 220 + 200 kg NPK/ha (F2) recorded highest corm weight, number of corms per corm planted and number of cormels per corm planted. Physiological attributes of gladiolus viz. Total Chlorophyll content, Net Assimilation Rate, Leaf Relative Water Content and Leaf Area Duration was maximum in of 60cm×20cmand 190 + 220 + 200 kg NPK/ha. Leaf Nitrogen, Phosphorus and Potassium was attained superior in S3 (60cm×20cm) and F3 (190 + 220 + 200 kg NPK/ha). Vegetative and reproductive growth of marigold used as intercrop depicted significant results. Growth parameters of marigold was superior with NPK at 190 + 220 + 200 kg/ha and 60cm×20cm (S3).Flower characters including days to bud visibility (28.02 days), days to full bloom (43.95 days), flowers per plant (36.19), flower diameter (3.38 cm), days to 50% flowering (59.94 days), flower fresh weight (2.96 gm), self life (4.75 days) loose flower life (3.57 days) and flower yield per plant (114.93 gm) was attained in spacing S3. Days to bud visibility (26.34 days), days to full bloom (42.08 days) and days to 50% flowering (58.38 days) was observed maximum in F1 (130 + 220 + 200 kg/ha NPK) and number of flowers per plant (36.84), flower diameter (3.64 cm), fresh weight (2.81 gm), self life (4.85 days), loose flower life (3.79 days) and yield per plant (119.86 gm) was attained with in NPK supplied at 160 + 220 + 200 kg/ha NPK (F3). Evaluation of post-harvest soil analysis revealed that maximum soil organic Carbon and availability of NPK in soil was attained in broader spacing of 60cm×20cm and NPK at 190 + 220 + 200 kg/ha. Highest B:C ratio of 3.44 was attained in treatment combination T11 (S3F2). Considering performance of both crops in intercropping system, T11 was found to be prominent option for increasing yield and maximizing the economic return in the system under study. The results of the second experiment for evaluation of effect of floral preservatives on the post-harvest life of gladiolus spikes upon intercropping with marigold, the treatment T8 comprising Sucrose (4%) + 8-HQC (200 ppm) attained maximum florets open at a time (5.80 days) and total blooming period (17.62 days). The treatment T7 i.e. Sucrose (4%) + Al2(SO4)3 (300 ppm) recorded minimum days to basal floret opening (2.58 days), maximum floret size (11.81 cm), longevity of first floret (5.62 days), highest vase life (13.39 days) and vase solution uptake (101.61 ml) and lowest was obtained in treatment with T1 (distilled water). Based on the analysis, it may be suggested that gladiolus spikes grown in intercropping of marigold can be treated with Sucrose (4%) + Al2(SO4)3 (300 ppm) to maximize the post-harvest floral attributes of the spikes.ThesisItem Open Access Response of crop geometry and management practices on growth and shelf life of strawberry (Fragaria x ananassa Duch.)(2022) Datta, Himadri Shekhar; Barua, Pritam CoomarThe present study on ―Response of crop geometry and management practices on growth and shelf life of strawberry (Fragaria x ananassa Duch)‖ was conducted at the farmer‘s field in Dhankhuloi village of Jorhat district, Assam during the consecutive years 2019-20 and 2020-21 to assess the effects of varied spacing and different mulch material on growth, yield and quality parameters of strawberry. The field experiment was laid out in randomised block design (RBD) with three replications involving twenty treatments comprising of five plant spacings viz., 20 cm x 30 cm (S1), 30 cm x 30 cm (S2), 30 cm x 40 cm (S3), 40 cm x 40 cm (S4), 40 cm x 60 cm (S5) and four different mulch applications viz., paddy straw (M1), red mulch (M2), silver black mulch (M3) and no mulch (M4). After crop harvest, a laboratory experiment was carried out with five treatments involving dipping of freshly harvested berries in Hexanal with varying strengths viz., 1% Hexanal for 2.5 minutes (V1), 1% Hexanal for 5 minutes (V2), 2% Hexanal for 2.5 minutes (V3) and 2% Hexanal for 5 minutes (V4). Undipped berries were considered for control treatment (V5). Both hexanal treated and berries under control treatment were stored at ambient temperature for evaluation of shelf life. The study revealed that the spacing had a substantial impact on crop growth, yield and quality of strawberry. The pooled data revealed that the highest number of leaves per plant (44.55), leaf area (86.77 cm2), number of flowers per plant (38.69), root volume (23.62 cc), minimum days from first flower opening to fruit setting (6.30 days) and days required for initiation of first ripening (63.61 days) were recorded in the widest spacing S5 (40 cm x 60 cm) while minimum days to appearance of first flower (37.85 days) was documented in closest spacing S1 (20 cm x 30 cm). The plants under wider spacing S4 (40 cm x 40 cm) yielded fruits with the highest fruit weight (17.96 g) and number of fruits per plant (32.31). The fruit yield per plant increased significantly with increase in plant spacing and registered maximum of 644.31 g per plant in S4. However, the highest marketable yield (11.80 t ha-1) was obtained in S1. The physical and chemical attributes of fruits were found to be superior in S5 viz., the maximum total sugar (6.31%), reducing sugar (5.59%) and ascorbic acid (78.65 mg 100 g-1) including minimum post harvest disease incidence (27.42%) during both the years of study. The vegetative and reproductive growth of plants varied with the type of mulch used. Highest number of leaves per plant (53.67), leaf area (100.75 cm2), number 6 of flowers per plant (48.73) along with the minimum days required for appearance of the first flower (34.69 days), days from first flower opening to fruit setting (5.31 days) and days required for initiation of first ripening (53.59 days) were recorded with application of silver black mulch (M3). The maximum number of fruits per plant (42.11), fruit weight (22.40 g), fruit yield per plant (945.87 g) and marketable fruit yield (18.98 t ha-1) was obtained with application of silver black mulch (M3). Similarly, treatment M3 produced fruits of superior quality recording the maximum TSS (12.75° Brix), total sugar (6.38%), reducing sugar (5.61%) and ascorbic acid (85.81 mg 100g-1) including minimum post harvest disease incidence of 21.37%. The interaction effect of spacing and mulch revealed that maximum fruit weight (23.12 g), total number of fruits per plant (50.49), fruit yield per plant (1167.91 g), total sugar (6.49%) and reducing sugar (5.72%) was recorded with the treatment combination T15 (40 cm x 40 cm spacing with silver black mulch).The highest marketable yield (22.75 t ha-1) was obtained in T3 (20 cm x 30 cm with silver black mulch). However, the treatment combination T15 yielded highest benefit: cost ratio (3.07). Dipping of fruits in 2% Hexanal for 2.5 minutes (V3) was found to be the most efficacious treatment for prolonging shelf life of strawberry. Maximum fruit firmness (5.88 N mm-1) and shelf life (5.90 days) was obtained in treatment V3, thereby extending the marketing period of the fruit. Based on yield, quality and economics, the treatment combination T15 (40 cm x 40 cm spacing with silver black mulch) was found to be the most viable economic proposition for strawberry in Jorhat condition of Assam. Additionally, dipping the berries in 2% Hexanal for two and half minutes extended the shelf life of strawberry. Thus, the research investigation highlighted the fact that crop geometry and management practices govern yield parameters and shelf life of the high valued crop, strawberry.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 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.
