PG Thesis
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Item Herbicidal management of stem hemiparasite Dendrophthoe spp. in mango orchards(Department of Agronomy, College of Agriculture, Vellanikkara, 2025) Revathi, C; Prameela, PDendrophthoe falcata (Loranthus), a stem hemiparasite of the Loranthaceae family, is a problematic weed in tree crops, including mango. Manual removal of this parasitic weed is the common practice, often involving cutting the infested tree branches. However, it is labour- intensive, often ineffective, and requires repeated intervention due to persistent sub-epidermal haustoria. Even herbicidal sprays for selective control are not available, and use of conventional spraying methods often results in toxicity to the host. Recent technologies such as air-assisted and electrostatic sprayers offer low-volume and target-specific applications with improved canopy penetration and more efficacy. Under this background a study entitled “Herbicidal management of stem hemi-parasite Dendrophthoe spp. in mango orchards” was carried out at the College of Agriculture, Vellanikkara, Thrissur, from October 2024 to September 2025 with the objectives, to assess the efficacy of various herbicides against Dendrophthoe spp. and to evaluate sprayers that can enhance the application efficiency of herbicides for effective management of loranthus. The experiment was carried out on 20-25-year-old mango trees in College Orchard that had been infested with Dendrophthoe falcata for 8-10 years. Treatments were 2,4-D Na salt 80% WP (5 g/L), 2,4-D amine 58% SL (10 mL/L), 2,4-D Na salt (5 g/L) + CuSO₄ (20 g/L), glufosinate ammonium 13.5% SL (10 mL/L), metribuzin 70% WP (5 g/L), ethrel 39% SL (25 mL/L), and metsulfuron methyl 20% WP (0.4 g/L) as targeted foliar sprays. Basal banding (padding) of 2,4-D Na salt (2%) and metribuzin (2%) was also included along with manual removal and unsprayed check. Phytotoxicity symptoms on the parasite and host were observed. In loranthus, changes in biochemical and physiological parameters, nutrient content of leaves, and regrowth up to one year after treatment were assessed. Four types of sprayers, i.e., battery-powered hydraulic, air-assisted, electrostatic, and air compression sprayers, were evaluated by comparing deposition efficiency, weed control efficacy, spray volume requirement, and cost of weed control in order to identify the most efficient technology for targeted herbicide delivery to loranthus clusters. Among the herbicides, though ethrel induced the fastest response through leaf abscission of parasitic weed by two days after spraying (DAS), total control was not obtained and regrowth started by 40 DAS. In metsulfuron methyl sprayed treatments regrowth started by 60 days, while metribuzin sprayed loranthus showed regrowth by 40 days. Foliar application of 2,4-D Na salt and 2,4-D amine provided the most effective and prolonged suppression without any regrowth even up to one year, which indicated complete drying of the parasite without any adverse effect on the host. Manual removal failed to suppress regrowth beyond 3 months. Herbicidal sprays markedly impaired leaf metabolism too. A drastic reduction in total soluble sugars (from 15.26 to 7.63 mg/g), protein (2.28 to 1.79 mg/g), relative leaf water content (50 to 11%), membrane stability (56 to 26%), and chlorophyll (1.64 to 0.92 mg/g) was observed. The NPK content in loranthus leaves also showed a sharp decline. These effects were linked to oxidative stress, disrupted carbohydrate translocation, and accelerated chlorophyll degradation. In contrast, padding with 2,4-D Na salt and metribuzin maintained higher physiological and biochemical values, indicating localized action with minimal systemic translocation and hence ineffectiveness. Significant variation was observed in droplet deposition efficiency among sprayer types, with electrostatic sprayers having the highest deposition (30.5 μL/cm²), followed by air- assisted (12.63 μL/cm²), battery-powered hydraulic (10.0 μL/cm²), and air-compression sprayers (7.23 μL/cm²). Advanced spraying technologies, particularly electrostatic and air- assisted sprayers, reduced spray volume requirement to nearly one-tenth of that used by conventional sprayers. Interestingly, a comparison between droplet deposition rate and weed control efficiency of battery-powered hydraulic and electrostatic sprayers revealed an inverse relationship, wherein higher deposition did not lead to enhanced herbicidal activity. This discrepancy is attributable to the parameters such as spray volume, droplet size, and lethal dose necessary for effective herbicide performance, ensuring adequate wetting, absorption, and translocation to facilitate metabolic action within the host-parasite system. It can be concluded that targeted foliar application of 2,4-D Na salt (80% WP) @5 g/L or 2,4-D amine (58% SL) @10 mL/L, using battery-powered hydraulic sprayer, is an effective method to manage Dendrophthoe infestation in mango orchardsItem Supply chain management in mango: A critical analysis(Department of Agricultural Extension, College of Agriculture ,Vellayani, 2023) Prathiksha, I.; Gopika SomanathThe study entitled ‘Supply Chain Management in Mango: A Critical Analysis’ was conducted in Palakkad district of Kerala and Krishnagiri district of Tamil Nadu during the year 2021-2022 among the actors identified in the supply chain. The objectives of the research were identification of the existing supply chains and the supply chain management activities related to mango in Kerala and Tamil Nadu; comparative assessment of the performance effectiveness of supply chains in the selected districts and formulation of extension strategies based on the constraints identified, to strengthen the performance of the supply chains. Five respondents of each mango supply chain actor namely input suppliers, farmers, wholesalers, processors, retailers, logistic partners and consumers and officials who work on the mango supply chain from each of the four panchayats were randomly selected, totalling the sample size 160. The independent variables in the study selected through judges rating were age, education, annual income, market perception, perception about supply chain, information seeking behaviour, alertness, problem solving skill and risk orientation and dependent variable performance effectiveness of the mango supply chain was measured using the scale developed for the study. On performing Mann-Whitney U test on independent variables among all the actors it was found that there exists a significant difference between age of the farmers in Kerala (52.4) and Tamil Nadu (63.5), education status of the farmers in Kerala (5.4) and Tamil Nadu (2.9), annual income of the wholesalers in Kerala (685000) and Tamil Nadu (285000), market perception of the wholesalers in Kerala (6.1) and Tamil Nadu (7.2) and the retailers in Kerala (5.4) and Tamil Nadu (7.5), perception about supply chain of the wholesalers in Kerala (14.0) and Tamil Nadu (14.8), alertness of the retailers in Kerala (13.2) and Tamil Nadu (12.5), problem-solving skill of the wholesalers in Kerala (8.1) and Tamil Nadu (8.9), retailers in Kerala (8.7) and Tamil Nadu (8.0) and logistics partners in Kerala (8.1) and Tamil Nadu (7.4) and risk orientation of the farmers in Kerala (17.5) and Tamil Nadu (19.1) with the P-value less than 0.05 at 0.05% level of significance, whereas other actors are relatively significant with the P-value 123 greater than 0.05 at 0.05% level of significance for all the independent variables. From the analysis of Mann-Whitney U test on the performance effectiveness of the mango supply chains in Kerala and Tamil Nadu it was found that there exist no significant differences in the performance effectiveness scores of the respondents in Kerala and Tamil Nadu with a P-value of 0.571 which is not significant at 0.05% level of significance. It was also observed that the P-values for the input suppliers (1) and processors (1) were equal, which may be attributed to the fact that the input suppliers and processors operating across the border in Tamil Nadu is depended upon by the mango supply chains operating in both the states. It was pertinent to observe that there were no input suppliers and processors for mango in Kollengode block in Kerala. On performing Principal Component Analysis for the influence of the subdimensions on the performance effectiveness scores of the supply chains it was found that the first principal component accounts to the largest percentage variance (73.25%) in the performance effectiveness scores of the respondents in Kerala and the first three principal components accounts for a cumulative variance of more than 97 percent. It was also revealed that it is the product quality ensured by the supply chains and the efficiency of the supply chains which largely influence the performance effectiveness of the mango supply chains in Kerala whereas in Tamil Nadu it was found that the first principal component accounts to the largest percentage variance (70.55%) in the performance effectiveness scores of the respondents and the first three principal components accounts for a cumulative variance of more than 97 percent. It was also revealed that it is the efficiency of the performance of the supply chains and the responsiveness of the supply chains which largely influence the performance effectiveness of the mango supply chains in Tamil Nadu. Comparative analysis of the PCA-biplots revealed that majority of the mango supply chains in Kerala (60%) were having higher flexibility, efficiency, product quality and responsiveness compared to 40% of mango supply chains in Tamil Nadu giving similar results. From the analysis of multiple regression for the influence of actors on the performance effectiveness of the mango supply chains in Kerala and Tamil Nadu it was found that the performance effectiveness scores of the seven actors viz., 124 input suppliers (0.026), farmers (0.000), wholesalers (0.044), processors (0.012), retailers (0.050), logistics partners (0.003) and consumers (0.003) were significant in influencing the performance effectiveness of the mango supply chains. It was further observed that the performance effectiveness of the farmers was found to be highly significant in influencing the performance effectiveness scores of the mango supply chains. Since the respondents of input suppliers and processors from Kerala and Tamil Nadu are same, major constraints faced by the supply chain actors in Kerala and Tamil Nadu were unavailability of good quality saplings, delay in payments, post-harvest management losses, lack of awareness about production, lack of financial support from Government, competitive pricing of the products, inadequate storage facilities, lack of communication among the actors upstream and downstream the chain and miscommunication of feedback to upstream actors in the supply chain. Suggestions to strengthen the performance effectiveness of the mango supply chains in Kerala and Tamil Nadu are assisting the farmers in choosing reliable suppliers for availing good quality inputs during peak seasons and providing useful training programme for better production. Assisting the farmers with subsidies to provide purchasers with quick payment options. Imparting knowledge to farmers and wholesalers on proper grading, standardizing, processing and careful handling of the products which can help in reducing postharvest and handling losses. The real-time data sharing of information across the actors in the supply chain can be improved with the help of social media, newspapers, APMC markets, market information sharing platforms, etc., Improvements can be brought in scientific transportation facilities like cold storage vans and providing infrastructure facilities for setting up of warehouse, processing units, cold storage units in rural areas. Pricing of products should be set after considering the market conditions that actually exist and limit pricing competitions among the retailers. Improving the large scale organised direct retailing by farmers in Agriculture Produce Market Committee markets. Increasing the supply chain visibility by ensuring technology assisted traceability of the supply chains for better communication across the actors. 125 The major extension strategies suggested are providing training on the use of mobile applications and software of the improved agricultural technologies for input suppliers. Sensitising the farmers on direct marketing of their produce through APMC markets which reduces the intervention of middlemen thereby increasing the profit. Conducting workshops to familiarize the wholesalers with the real-time data sharing tools to ensure better co-ordination in the supply chain. Awareness on the importance of cold storage facilities, capacity building programmes for the managers of the processing units and demonstrations on the improved technologies in value addition in mango. Empowering the retailers on the use of ICT based applications and platforms for improved communication within the supply chain. Capacity building programmes to facilitate computerised documentation for the logistics partners. Awareness regarding consumer rights, quality produce, pricing of products. Sensitization on their role in providing feedback on the supply of the produce by the consumers and creating awareness on traceability of the products.Item Impact of seed deterioration on seedling vigour in mango (Mangifera indica L.)(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2002) Anila, P; Girija, TItem Protoplast isolation, culture and regeneration in Mango (Mangifera indica L.)(Department of Horticulture, College of Agriculture, Vellayani, 2000) Ullas Mony; Rajmohan, KAttempts were made to standardise techniques for isolation, culture and regeneration of protoplasts in mango, during 1998-1999 at the Plant Molecular Biology and Biotechnology Centre, College of Agriculture, Vellayani. Efforts were made to standardise the source of explant, optimum concentration, temperature and duration of incubation and osmolarity of the enzyme mixture. Callus induced from nucellus of immature fruits was found to be the best plant material for protoplast isolation. The cell wall digesting enzymes Cellulase 'Onozuka' R-I0 and Macerozyme R-lO at l.0 and 0.5 per cent respectively at a pH of 5.8 yielded the highest number of protoplasts (101 protoplasts per " field). The optimum time of incubation was found to be eight hours. Pre- plasmolysis of the callus was found to be not beneficial. Treatment without pre-plasmolysis and with 9.0 per cent osmolarity recorded the highest yield. Incubation temperature of 28.0 "c was found to be optimum for the best yield of protoplasts. Cell wall formation and microcalli development from the protoplast was observed when Murashige and Skoog medium with half strength of major salts, supplemented with BAP 3.0 mg r', NAA 0.1 mg r ' along with sucrose or glucose 90.0 g r ' was used. Combinations of osmoticums like sucrose 70.0 g r', mannitol 10.0 g r' and glucose 10.0 g r' as !. well as sucrose 70.0 g r', mannitol 10.0 g r' and inositol 10.0 g r' were found to be ideal for cell wall formation and micro calli development.Item Quality analysis and product development of selected mango cultivars(Department of Home Science, College of Agriculture, Vellayani, 1997) Byni Elizabeth Oomen; Nandini, P VThe present study entitled 'Quality analysis and product development of selected mango cultivars' is a comprehensive study carried out with an objective to evaluate the quality of different varieties of mango based on physical characteristics, chemical composition and organoleptic qualities so as to identify the most suitable mango variety for the preparation of mango pulp based products. Twenty dessert varieties of mango including local and improved types were selected for the study. Among these, 9 were Kerala Agricultural University recommended varieties and the remaining 11 were local varieties. A detailed study on the different quality parameters of mango such as physical characteristics, chemical and nutritional composition and organoleptic qualities was envisaged. Cluster analysis was carried for the mango varieties based on then chemical and nutritional characteristics and based on the D2 values the varieties of similar characters were grouped together. The superior variety was selected for the product development among the twenty mango varieties taken for study. The variety Neelum obtained the highest score. The mango juice from the superior variety Neelum was then used for the preparation of mango Ready-To-Serve beverage. FPO specified tests were administered on the product to evaluate its suitability. The nutritional composition. organoleptic and shelf-life qualities of the product prepared was also analysed. The product was stored for a period of 1 month and the chemical analysis was carried out at weekly intervals and compared, with the fresh product. The chemical composition and organoleptic qualities of the RTS beverage remained unaltered during the first and second weeks of storage. Slight variations in the chemical composition and organoleptic qualities were seen during the end of the third and fourth weeks of storage. Sensory evaluation of the RTS beverage after four weeks of storage at ambient temperature showed that the overall acceptability declined for all the attributes. Microbial and fermentation tests were conducted during weekly intervals. Colonies of Pencillium was detected in the RTS beverage after four weeks of storage. Also the fermentation test were found to be positive. Thus the product was found to be shelf stable for a period of one month. From the above observations and findings it is clear that, it is possible to develop and organoleptically and nutritionally adequate pulp based product using the mango variety Neelum. Processing of Neelum mango fruits particularly during the seasonal glut could go a long way in reducing post- harvest losses and also in improving the employment potential of the local people.