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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 Hydroponic systems for growth, development and quality flower production(AAU, Jorhat, 2017-07) Sarmah, Ruby; Bora, SunilAn investigation was carried out at Department of Horticulture, Assam Agricultural University, Jorhat during the year 2016 to 2017 to find out the best hydroponic system, EC of hydroponic nutrient solution and growing media for quality flower production in Tuberose, Gladiolus and Marigold. The experiment was laid out in two factor completely randomized design with 15 treatment combinations and with three replications comprising of five different levels of hydroponic systems viz. S1 (NFT or Nutrient Film technique), S2 (Water culture system) , S3 ( Aggregate or drip system with coco peat ), S4 (Aggregate or drip system with sand ), S5 (Aggregate or drip system with sawdust) and three different levels of hydroponic nutrient solution concentration viz. N1 (EC 1.0 dS/m), N2 (EC 1.5 dS/m), N3 (EC 2.0 dS/m) and one control (soil and water). Statistical analysis of the data revealed that most of the growth, flowering, root, bulb characters and physiological parameters were significantly influenced due to differences in systems of cultivation, media and nutrient concentrations (EC). Among the various levels of hydroponic systems, S2 (water culture) has shown the best results for most of the growth characters including root, bulb characters and physiological parameters in Tuberose. While, S1 (NFT) was significantly superior in most of the flower characters. The nutrient treatment N3 (EC 2.0 dS/m) has significantly improved all growth parameters except leaf length and plant height which were best in N1 (EC 1.0 dS/m). N3 treatment (EC 2.0 dS/m) was found to be the best in terms of flower and bulb characters including physiological parameters under study. However, the results of root characters were significantly superior in N1 (EC 1.0 dS/m). Hence, S1N3 (NFT + EC 2.0 dS/m) was found to be the best for Tuberose in terms of growth and flowering. In case of Gladiolus, most of the growth characters were found to be significantly superior in S2 (water culture). This treatment was also found to be effective in terms of root, corm and physiological parameters under study. In Gladiolus, a remarkable growth, flowering and corm production was observed in the nutrient treatment N2 (EC 1.5 dS/m). It can be concluded that, the treatment combination S2N3 (water culture + EC 2.0 dS/m) was the most suitable treatment for Gladiolus. In case of marigold, experimental data revealed that the growth and flower characters have shown significant superiority in S1 (NFT). Whereas, S2 (water culture) has shown the best results in root and physiological characters. Among the nutrient treatments, N2 (EC 1.5 dS/m) has shown the best response in marigold in most of the growth characters. Early emergence of bud and flower was noticed in N3 (EC 2.0 dS/m), whereas other flower characters were found to be significantly better in N2 (EC 1.5 dS/m). The root characters of marigold were expressed at its best in N1 (EC 1.0 dS/m) whereas, the physiological characters were found to be significantly improved in N3 (EC 2.0 dS/m). Thus, from the floriculture perspective conclusion can be drawn that treatment combination of S2N2 (NFT + EC 1.5 dS/m) is optimum for quality flower production of marigold. The experimental findings also deduced that for all crops under experiment, S3 (coco-peat) and S4 (sand) are the best media. However, S5 (sawdust) has shown the inferior result among media under study and it was at par with control in most of the observations. The statistical analysis of control vs. rest was shown to be highly significant in most of the observations under study. Thus, it can be concluded that different hydroponic systems, potting media along with their combinations among them exert effect on overall growth, flowering, root, bulb & other physiological parameters in different flowering crops.ThesisItem Open Access CHARACTERIZATION AND EVALUATION OF SOME TURMERIC ( Curcuma longa L.) GENOTYPES OF NORTH EASTERN REGION OF INDIA(AAU, Jorhat, 2017-07) LUIRAM, SoLEI; Barua, P. C.A field experiment was conducted at Horticulture Experimental Farm, AAU, Jorhat, Assam for two consecutive years (2015 & 2016) to characterize and evaluate the performance of thirty one (31) turmeric (Curcuma longa L.) genotypes of north eastern region of India along with two check varieties. The experimental materials were collected from farmer’s field of all the eight north eastern states of India. The experiment was laid out in Randomized Block Design with 3 replications. The individual plot size was 1.5m x 1.5 m with plant to plant spacing of 30 cm x 30 cm accommodating 25 plants per plot. In the present study, all the growth parameters at different growth stages showed significant variations due to genotypes. The effect of year was found significant for leaf length at 105 DAP, leaf width at 75, 105 and 135 DAP, number of leaves per hill and number of leaves per main shoot at 75 DAP, number of leaves per tiller at 75, 105 and 135 DAP, number of tillers per hill and plant height at all the growth stages. However, the effects of interaction between the genotypes and year were significant for number of leaves per tiller at 75 DAP, number of tillers per hill in all the growth stages and plant height at 165 DAP. Significant variations in both the fresh and dry rhizome yield per hectare were observed among the different genotypes evaluated. The maximum fresh rhizome yield was recorded in the genotype TMN-2. While the minimum was recorded in the genotype TAS-14. However, the dry rhizome yield was found highest in the genotypes TPR-2 while the lowest dry rhizome yield was recorded in TNL-1. Significantly high variation was noticed for dry recovery and harvest index showing the highest in the genotype TPR-2 and Check-2 variety respectively and the lowest was recorded both in the genotypes TAS-6. The high significant variations in the curcumin and oleoresin content among the different genotypes studied were observed due to genotypes. The highest curcumin content was recorded in the check-2 variety and the lowest curcumin content was observed in the genotype TAS-3 (1.72 %). The oleoresin content in the present study ranges from 7.63 % to 17.52 %. The correlation study showed that the plant height, leaf length and leaf width at 105, 135 and 165 DAP, length of mother and primary rhizome, finger rhizome per plant, weight of mother, primary and secondary rhizome, LAI at 135 DAP and LAD were found significant and positively correlated with rhizome yield of turmeric. Thus, these characters maybe considered very important factors in selecting the genotypes for increasing the yield of turmeric in any improvement programmes. Summarizing the PCV, GCV, heritability and genetic advance characters, it could be concluded that the genotypes giving higher values of these characters might be given more emphasis and hence better selection process for further crop improvement programme. Thus, the result of the present study demonstrates that there existed wide variability among different turmeric genotypes of north eastern region of India indicating high potential for effective crop improvement through breeding as the genotypes in this region are good sources of genes for many desirable traits. The promising genotypes, viz. TMN-1, TMN-2, TNL-2, TNL-4, TML-1, TPR-1, TPR-2, TAP-2, TSK-1, TAS-4, check-2 variety and TAS-10 gave high fresh rhizome TML-3, TPR-2, TAP-2, TAS-5, TAS-6, TAS-7, TAS-8, check-2 variety and TAS-14 variety gave appreciable yield per hectare in the range from 306.11q/ha to 413.89 q/ha whereas, the genotypes TML-1, TML-2, amount of curcumin contents in the range between 5.11 % to 6.51 % which were encouraging and thus suitable for commercial production of turmeric in the north eastern region of India.ThesisItem Open Access MORPHOLOGICAL CHARACTERIZATION, PHENOTYPIC STABILITY ANALYSIS AND VALUE ADDITION IN MARIGOLD(AAU, Jorhat, 2017-10) Mahanta, Sangita; Talukdar, Madhumita ChoudhuryThe experiments were conducted during 2015-17 in six environments created by planting at different dates and spacings and involving 12 varieties to assess morphological characters, genetic variation, genetic diversity, genotype-environment interaction, phenotypic stability of marigold flowers and their value addition. The morphological traits contributed largely to variability in leaf colour, leaflet margin, stem colour, visibility of disc floret, flower colour, flower shape and petal edge. Significant differences were observed among the varieties for quantitative characters. The performance of the variety Seracole exhibited maximum for quantitative traits, viz., branches/plant (79.80), leaves/plant (256.13), flowers/plant (111.47), self life (17.66 days), loose flower life (4.93 days) and, yield (574.20g/plant, 2.41 kg/ m2 and 199.52 q/ha).The variety Seracole exhibited highest carotenoid content (290.50 μg/g). The estimates of genotypic and phenotypic coefficients of variation and heritability revealed high genetic variation for most of the characters. High heritability with moderategenetic advance exhibited by leaves/plant, branches/plant, leaf length, fresh weight of flower, flowers/plant and yield/plant indicated that along with additive gene effect non additive effects like dominance and epistasis might have played a role in the expression of these characters.Based on D2 values, all the 12 marigold varieties were grouped into two clusters. Cluster I consisted of 11 varieties, viz. Pusa Narangi Gainda, Pusa Basanti Gainda, Pusa Arpita, Hajo Orange, Mumbai Orange, Hajo Yellow, Sunrise Orange, Hawaii Orange, Calcutta Orange, Calcutta Yellow, Yellow Babuda; while cluster II consisted of only Seracole. Inter-cluster distance was greater than intra-cluster distance which indicated wider genetic diversity among the varieties of the two clusters. There was significant genotype-environment (GE) interaction for all the growth and flower characters, except plant height and number of ray florets. Both linear and non-linear components contributed towards GE interaction except disc floret, for which only linear component contributed. The varieties, viz. Seracole, Pusa Narangi Gainda, Pusa Basanti Gainda exhibited average stability for flower yield/ha. Pusa Narangi Gainda and Pusa Basanti Gainda showed average stability for plant height and earliness to days to bud visibility. Among the various drying methods tested, cabinet drying gave the highest carotenoid content (337.64μg/g) compared to the other methods. The basal diet, supplemented with fresh and dried marigold petals @12 mg carotenoid/kg diet recorded highest carotenoid content 38.82 μg/g and 39.86 μg/g respectively, and respective colour score 10.73 and 10.8 of egg yolk. The carotenoid content was highest in the first month with LDPE packaging materials of 400 gauge (270.47 μg/g), 300 gauge (269.64 μg/g) and 200 gauge (266.94 μg/g) which decreased with advancement of storage period. The outcome of the present investigation could be considered as a basic work for this region which could provide guidance and basic information to the researchers for further value addition to marigold flowers, particularly for incorporationin poultry diet.ThesisItem Open Access MORPHOLOGICAL AND BIOCHEMICAL CHARACTERIZATION OF BHUT JOLOKIA (Capsicum chinense Jacq.)(AAU, Jorhat, 2015) Sentimenla; Narzary, B. D.An experiment was conducted during the year 2012-13 and 2013-14 in the Experimental Farm, Department of Horticulture, College of Agriculture, Assam Agricultural University, Jorhat on eleven Bhut jolokia (Capsicum chinense Jacq.) genotypes for morphological and biochemical characterization. Observations were recorded for morphologic traits, growth characters, yield and yield attributing traits, biochemical characters and colour parameters. Characterization of the genotypes was done based on 11 morphological characters following the descriptors developed by the International Plant Genetic Resources Institute for the genus Capsicum, IPGRI (1995).The genotypes were characterized by the 11 morphological characters, of which only 4 characters showed polymorphism. Significant variation was revealed among the genotypes for all the growth and yield and yield attributing characters except for 1000 seed weight. The highest fruit yield per plant with the highest number of flowers per cluster, minimum days to emergence of flower bud, highest number of fruits per plant and maximum days to harvest maturity was produced by G9 compared to other genotypes. Among the other genotypes G1, G6 and G10 were found promising for fruit yield. All the genotypes showed significant variation with regard to the biochemical characters except moisture content. Genotypes G1 showed the highest content for potassium, iron, capsaicin, moisture and DPPH scavenging activity. It was observed that the crude protein, beta-carotene and oleoresin content were highest in G3 compared to the other genotypes. G6 gave the highest value for ascorbic acid and phosphorus content compared to the other genotypes under study. From the colour value estimation it was found that genotype G3 exhibited the highest ‘L’ and ‘a’ value while G4 showed the highest value for ‘b’ and hue compared to the other genotypes and the highest value for Chroma was recorded in G9. From the study of genetic parameters in this population of genotypes, it was observed that fruit yield per plant showed the highest genotypic variation, heritability and genetic advance. The other characters found to be effective selection criteria were plant height, number of leaves per plant, number of fruits per plant and number of seeds per fruit. From Path analysis it was found that the number of primary branches and fruit width exerted positive direct effects and were positively correlated with fruit yield per plant. Thus by considering both genetic parameters and character relationships number of leaves per plant, days to emergence of flower bud, fruit width, number of primary branches per plant, number of fruit per plant and harvest duration could be further exploited for crop improvement to develop suitable plant type. Thus considerable variation observed among the genotypes for various yield attributes suggested good scope for developing high yielding varieties through selection and hybridization. Moreover identification and characterization of bhut jolokia genotypes is essential for protection of plant varieties and for maintenance breeding, seed production and certification.ThesisItem Open Access GENETIC DIVERSITY IN IVY GOURD [Coccinia grandis (L.) Voigt.] GENOTYPES OF NORTH EASTERN REGION BASED ON MORPHOLOGICAL AND RAPD MARKERS(AAU, Jorhat, 2014) Saikia, Jumi; Borbora Phookan, DeepaAn experiment was conducted to study the genetic diversity in ivy gourd [Coccinia grandis (L.) Voigt.] genotypes collected from different parts of Assam and other North Eastern States (Arunachal Pradesh, Tripura and Nagaland) during the summer seasons of 2013 and 2014. The experiment was laid out in Randomized Block Design with three replications at the Experimental Farm, Department of Horticulture, Assam Agricultural University, Jorhat. Morphological characterization of 22 genotypes revealed significant variation among the genotypes. The mean performance of genotypes for quantitative traits revealed that the genotype IG-23 recorded maximum for fruit characters viz., fruit length (8.50 cm), fruit weight (33.62 g) and fruit yield per plant (8.66 kg). Whereas IG-22 exhibited the highest number of primary branches (7.35), fruit width (3.03 cm) and number of fruits per plant (391.83). Promising genotypes were IG-10, IG-18, IG-22 and IG-23. Genetic variability in terms of PCV and GCV were high for yield per plant (27.56% and 23.87%, respectively). High heritability in broad sense combined with high genetic advance was recorded for number of fruits per plant (94.39%, 38.57%) followed by fruit weight (93.36%, 32.61%) which were indicative of preponderance of additive and additive x additive type of gene interaction. The correlation analysis revealed that yield per plant had significant positive correlation with number of primary branches, fruit length, number of fruits per plant and fruit weight. From the path coefficient analysis, it was observed that number of fruits per plant had the highest positive direct effect (1.1928) on yield. Number of primary branches had the highest positive indirect effect on yield via number of fruits per plant (1.1491). The residual effect was 0.1097 which was within a reasonable limit indicating that the characters included in path coefficient analysis were adequate in explaining the variation in ivy gourd. Genetic diversity using Mahalanobis’s D2 statistic grouped the genotypes into 6 clusters following the method suggested by Tocher. Among the 6 clusters the intra-cluster distance varied from 0.00 to 3.48 and maximum inter-cluster distance was observed between cluster IV and cluster V (7.83). Cluster IV showed desirable values for number of primary branches (6.66), peduncle length (2.27 cm), fruit length (7.10 cm), number of fruits per plant (302.83), fruit weight (28.92 g) and yield per plant (7.55 kg). The most important characters contributing towards divergence were fruit weight (37.23% contribution) followed by number of fruits per plant (30.30%). D2 analysis revealed that the pattern of distribution of genotypes from different locations into different cluster was random. At molecular level, 25 random decamer primers generated a total of 124 amplification products of which 52 bands were polymorphic. Total polymorphism was 41.94%. The extent of polymorphism was higher with RAPD primers such as OPB-08 (83.33%), OPC-01 (71.43%) and OPD-05 (66.66%). The dendrogram showed that UPGMA cluster analysis grouped the genotypes into 4 major clusters. In cluster I, only one genotype i.e. IG-14 was included which was out grouped from the rest of the genotypes. A fairly wide range of Jaccard’s similarity coefficient (0.10 to 1.09) was observed which indicated high level of genetic diversity. Among the nutritional traits, highest protein content (1.41 g/100 g) as well as iron (2.75 mg/100 g) were recorded in IG-22. Ascorbic acid (27.05 mg/100 g) and carotene (189 g/100 g) were found to be highest in IG-18. IG-23 recorded the highest crude fibre content (1.97%) and total ash content (6.78%).ThesisItem Open Access Morpho-biochemical characterization of Garcinia species of Assam(AAU, Jorhat, 2015) Gogoi, Bornali; Dr. R. P. DasAn investigation was conducted during the period of 2012-14 to study the morpho-biochemical characterization of Garcinia species of Assam viz., Garcinia pedunculata Roxb, Garcinia cowa Roxb, Garcinia lanceaefolia Roxb and Garcinia xanthochymus Hook.f. The morphological parameters of plant, floral biology and biochemical composition of fruits were studied in healthy, bearing trees of uniform age from five locations of Jorhat district viz., Bahek gaon (L1), Charaibahi (L2), Atila gaon (L3), Chotai (L4) and Borbheta (L5). The five districts of Assam i.e. Dibrugarh, Sivsagar, Jorhat, Golaghat and Nagaon were selected purposively for ethno-botanical survey of the selected species. The ethno-botanical study revealed that majority of people uses the fruits of all the four species for different purposes than the seed, leaf and bark. However, most of the people from the five districts used these Garcinia plant as a source of medicine and for some social customs. Non significant difference was found in plant height of each species. However, plant height of G. pedunculata is highest (22.40 m) among the four species in which flowering occurs twice in a year i.e. once at last week of October to first week of November and another at last week of April to first week of May. Whereas in other species flowering occurred only once in a year. Duration of flowering was almost same in all the species and the maximum (52 days) was observed in G. xanthochymus and the minimum (42 days) was recorded in G. lanceaefolia. Anthesis took place early in the morning in all the species and the time period was from 1.00 A.M. to 6.00 A.M. Wide variations were observed in fruit weight and volume. The G. pedunculata exhibited highest (620.80 g) fruit weight whereas G. lanceaefolia exhibited lowest (22.51 g) fruit weight. In respect of number of seeds per fruit G. pedunculata had 9.35 numbers of seed whereas G. xanthochymus showed 2.50 numbers of seed. The moisture content was found to be highest (92.91%) in G. cowa and ascorbic acid content ranges from 35.37mg/100 g to 88.92 mg/100g and the highest was found in G. pedunculata and the lowest in G. lanceaefolia respectively. The total phenol content was highest (3.68%) in G.xanthochymus the lowest (1.89%) was recorded in G.cowa whereas total ash content was found highest (2.18%) in G. lanceaefolia. Reducing sugar content of all the four species were found to be in a lower range and no significant difference was observed among the locations of each species in terms of total carbohydrate and energy value. Total carbohydrate ranges from 50.75 per cent to 57.90 per cent and energy value ranges from 224.57Kcal/100 g to 245.49 Kcal/100 g, respectively. On the other hand total antioxidant activity was recorded to be highest in G. xanthochymus (9.45%) and the lowest (5.22%) was recorded in G. lanceaefolia. However, HCA content was highest in G. cowa (1.48%). Karyotype study revealed that chromosome number of G. pedunculata, G. cowa and G. lanceaefolia was found to be 2n=48 whereas G. xanthochymus had 2n=72 numbers of chromosome. The biochemical analysis of the present study will help to enrich diet formulations and nutraceuticals. The karyotype analysis and morphological study gives a scope for genetic assessment and breeding due to the presence of variability in different characters.ThesisItem Open Access SHELF LIFE ENHANCEMENT OF KEW PINEAPPLE AND KHASI MANDARIN USING BIOTIC POLYMER, MICROBIAL ANTAGONIST AND UV RADIATION(2014) Mili, Jyoti Prashad; Borthakur, P. K.Studies were carried out at Department of Horticulture, Assam Agricultural University during the period 2012-2014 with an objective to study the effect of biotic polymer, microbial antagonist and UV radiation on shelf-life of Khasi mandarin and Kew pineapple fruits and to study the economics of using the treatments. The study revealed that decay of fruits was mainly caused by Penicillium digitatum, P. niger, P. chryogenum and Aspergillus niger on Khasi mandarin and Penicillium sp., Aspergillus niger, Fusarium subglutinas, Nigrospora sp. on Kew pineapple. The decay percentage, PLW, pH, TSS, acidity and peroxidase enzyme activity of Khasi mandarin and Kew pineapple fruits increased with increase in the period of storage while texture value, fruit weight, moisture content, ascorbic acid and chlorophyll content decreased during storage period. Amongst all the UV treatments; UV radiation and chitosan combined treatment (T9) was found most effective in retention of shelf life. UV radiation and Pseudomonus combined treatment (T12) and Bacillus and Pseudomonus combined treatment (T8) had best result in most of the microbial antagonist treatments on Khasi mandarin and Kew pineapple fruits, respectively. Chitosan treatment had produced the best result among all the treatments and helped in retention of fruit texture and colour, had lower decay percentage, lower enzymatic activity and retained overall better fruit quality in both Khasi mandarin and Kew pineapple fruits during storage. This might be due to the properties of chitosan which not only has antimicrobial properties but also has the ability to form coating on fruit and vegetable surface, reducing the respiration rate by adjusting the permeability of carbon dioxide and oxygen. The UV radiation treatment showed less impressive results as compared to chitosan treatment. This was due to the free radicals generated from UV radiation might target cell membranes, nucleic acids, cell walls and enzymes, inducing the acceleration of senescence. The chitosan treatment was found to be the best in enhancing shelf life in both Khasi mandarin and Kew pineapple fruits during storage.ThesisItem Open Access Uni-packaging for shelf life extension of Khasi mandarin (Citrus reticulata Blanco.(AAU, 2015) Bhuyan, Namita; Baruah, P. C.A laboratory experiment was carried out in the Quality Control and PHT Laboratory, Department of Horticulture, Assam Agricultural University, Jorhat during 2012-2014, to study the effect of packaging materials, storage conditions and different altitudes on quality and storability of Khasi mandarin. The fruits were harvested at physiologically mature, i.e. colour break stage from three different altitude viz., relatively high altitude, medium altitude and low altitude. Healthy fruits were treated with 100 ppm sodium hypo chloride solution for 2 minutes. After drying the fruits in shade, fruits were uni-packed in different perforated packaging films viz., low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), polyvinyl chloride (PVC) and polyolefin films. The film-packed fruits were then stored under ambient (22-27°C and 70-75% RH), A.A.U developed semi-underground evaporative cool chamber (17-24°C and 89-90% RH) and cold storage conditions (6°C and 68-72% RH). The various physico-chemical and sensory attributes of fruits were recorded at weekly intervals during the entire storage period. Among the packaging materials, fruits packed in perforated HDPE films retained the highest sensory and nutritional quality (ascorbic acid, total carotenoid and pectin content) with slow and steadier change in the respiration rate, ethylene evaluation, PME activity, moisture content, titrable acidity and weight loss as compared to control (unpacked fruits). In all the packaged fruits under different storage conditions, the value of CCI (Citrus colour index) increased with progress of storage period. Fruit packed in perforated HDPE films under cold storage registered lower CCI value (1.66) compare to other packaging materials and storage conditions. Highest value was recorded in unpacked fruits (3.01) under cold storage condition. Higher amount of juice per cent was found in low altitude fruits but acidity and vitamin C was lower as compared to high altitude fruits. From the sensory quality study, it was observed that higher and medium altitude fruits packaged with perforated HDPE films scored the highest values on colour, texture, flavour and overall acceptability under all the storage conditions during the entire storage period. The lowest acceptability and sensory quality was registered in lower altitude fruits without packaging films. Individual Khasi mandarin fruit packed with perforated HDPE films can be successfully stored for 32 days under ambient condition, 40 days under evaporative cool chamber and 59 days under cold storage condition with highly acceptable sensory quality. The control (unpacked) fruits, on the other hand, maintained postharvest shelf life of 15, 28 and 37 days under ambient condition, evaporative cool chamber and cold storage condition, respectively. These results indicate that use of perforated HDPE films can prolong the shelf life by maintaining quality attributes and external appearance of Khasi mandarin fruits and hence extend their marketing period.
