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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

Análisis de la trazabilidad en las exportaciones de palta fresca de las empresas exportadoras con Certificación Orgánica de la región Lima a Países bajos en el periodo del 2013 al 2019

Carranza Guzmán, Teófilo Juan Alberto, Delgado Villena, Jorge Edilberto 30 September 2020 (has links)
El sector agroexportador en el Perú, se caracteriza por estar en constante crecimiento durante varios años consecutivos y uno de los productos que destaca es la palta y por lo cual en el presente estudio se analiza la trazabilidad en las exportaciones de palta fresca de las empresas exportadoras con Certificación Orgánica de la región Lima a Países bajos en el periodo del 2013 al 2019. Este estudio, se basó en una metodología cuantitativa a través de la recopilación de datos secundarios de CBS Netherlands, Ministerio de Agricultura del Perú, FAOstats, AdexData Trade, Euromonitor y el Banco Mundial, también, la interpretación de entrevistas realizadas a expertos para consolidar la información en el periodo base mencionado anteriormente. Por ello, se evalúa la interacción entre las exportaciones de palta de la región de lima con el precio internacional, la certificación orgánica y la demanda en el país de destino, la cual fue analizada en 42 periodos bimestrales para mayor exactitud. El precio internacional de la palta en el país de destino tiende a incrementar las exportaciones, es por ello que se relaciona la interacción de dichas variables, dando como resultado un 93.1% de relación, además de la relación directamente proporcional y lo confirmado por los expertos, respecto al precio internacional que toma en destino la palta orgánica. Los resultados concluyen en la existencia de relación entre el precio y la demanda para el aumento de las exportaciones de la palta orgánica hacia Países Bajos. Asimismo, se recomienda un mejor manejo de prioridades por parte del estado para colocar a disponibilidad estrategias y alianzas de libre comercio para el apoyo del aumento de la producción orgánica, debido a que es un sector que tiene las tendencias al crecimiento y debe ser aprovechada más aun por los productores orgánicos. / The agro-export sector in Peru is characterized by being in constant growth for several consecutive years and one of the products that stands out is avocado and for this reason, the present study analyzes the traceability of fresh avocado exports from exporting companies with Organic Certification from the Lima region to the Netherlands in the period from 2013 to 2019. This study was based on a quantitative methodology through the collection of secondary data from CBS Netherlands, Ministry of Agriculture of Peru, FAOstats, AdexData Trade, Euromonitor and the World Bank, Also, the interpretation of interviews conducted with experts to consolidate the information in the base period mentioned above. Therefore, the interaction between avocado exports from the lima region with international price, organic certification and demand in the destination country is evaluated, which was analyzed in 42 bimonthly periods for greater accuracy. The international price of avocado in the country of destination modified to exports, is why the interaction of the variable variables is related, resulting in a 93.1% relationship, in addition to the directly proportional relationship and confirmed by the experts, regarding the international price that the organic avocado takes at destination. The results conclude in the existence of the relationship between price and demand for the increase in exports of organic palm to the Netherlands. Likewise, a better management of the needs by the state is recommended to place an availability of strategies and free trade alliances to support the increase in organic production, since it is a sector that has growth trends and should be exploited even more by organic producers. / Tesis
162

Evaluation of cold storage potential and shelf-life of new 'hass' type avocado selections

Machipyane, Pheladi Bridgette January 2017 (has links)
Thesis (M.Sc. Agriculture (Horticultrure)) -- University of Limpopo, 2017 / The current South African ‘Hass’ type avocado cultivars are inadequate to enhance competitiveness, cultivar diversity and profitability. In an effort to ensure competitiveness and maintain sustainability, the Agricultural Research CouncilInstitute for Tropical and Subtropical Crops (ARC-ITSC) as one the South African Avocado Industry’s (SAAI) main stakeholder, has bred and selected new superior ‘Hass’ type avocado selections. However, the cold storage potential and associated physico-chemical ripening properties of these selections (‘Jalna’, ‘OA 184’ and ‘Balboa’) have not been documented. Therefore, the objective of this study was to evaluate the effect of cold storage on internal and external physico-chemical ripening variables of the new ‘Hass’ type avocado selections. New ‘Hass’ type avocado fruit maturity was evaluated using moisture content, thereafter, harvested, sorted, graded and stored under two temperature regimes (2.0°C and 5.5°C) for 28 days to simulate export conditions. The experiment was a completely randomised factorial design with three treatment factors; temperature regimes (2.0°C and 5.5°C), days to ripening and ‘Hass’ type avocado selections fruit and control (commercial ‘Hass’) replicated three times. After withdrawal from cold storage, fruit were ripened at ambient temperature and evaluated for electrical conductivity, external chilling injury, fruit water loss, skin colour change, ripening percentage, firmness, respiration rate and seed:fruit weight ratio. Results indicated that treatment factors had no significant effect on moisture content (P=0.733) and chilling injury (P=0.776). Treatment factors had a significant effect on electrical conductivity (P=0.004), skin colour parameters; eye colour (P<0.001), hue angle (P<0.001), lightness (P=0.011) and chroma (P=0.042). Selection ‘Jalna’ fruit started changing colour whilst in storage (2.0°C and 5.5°C). Furthermore, ‘Hass’ type avocado selection fruit followed a declining pattern for lightness, chroma and hue angle in agreement with commercial ‘Hass’. Moreover, results indicated that treatment factors had a significant effect (P<0.001) on respiration rate, fruit firmness, ripening percentage and seed:fruit weight ratio. Selection ‘Jalna’ and ‘OA 184’ desynchronised mesocarp softening with exocarp due to genetically non-softening exocarp. Treatment factors had no significant effect (P=0.998) on fruit water loss during ripening. Selection ‘OA 184’ fruit showed export potential due to its good storage, ripening physico-chemical and shelf-life properties. Studies on cold sterilisation would add more value on generated scientific information, as such would enable the SAAI to gain access to high paying export markets. In addition, the selections should be planted and evaluated in other avocado producing region
163

Improving fruit soluble solids content in melon (Cucumis melo L.) (reticulatus group) in the Australian production system

Long, Robert Llewellyn, bizarrealong@hotmail.com January 2005 (has links)
Total soluble solids (TSS) is a reliable indicator of melon eating quality, with a minimum standard of 10% recommended. The state of Australian melon production with respect to this quality criterion was considered within seasons, between growing districts and over seasons. It was concluded that improvement in agronomic practice and varietal selection is required to produce sweeter melons. The scientific literature addressing melon physiology and agronomy was summarised, as a background to the work that is required to improve melon production practices in Australia. The effect of source sink manipulation was assessed for commercially grown and glasshouse grown melon plants. The timing of fruit thinning, pollination scheduling, the application of a growth inhibitor and source biomass removal were assessed in relation to fruit growth and sugar accumulation. Results are interpreted against a model in which fruit rapidly increase in weight until about two weeks before harvest, with sugar accumulation continuing as fruit growth ceases. Thus treatment response is very dependant on timing of application. For example, fruit thinning at 25 days before harvest resulted in further fruit set and increased fruit weight but did not impact on fruit TSS (at 9.8%, control 9.3%), while thinning at 5 days before harvest resulted in a significant (Pless than 0.05) increase in fruit TSS (to 10.8%, control 9.3%) and no increase in fruit weight or number. A cost/ benefit analysis is presented, allowing an estimation of the increase in sale price required to sustain the implementation of fruit thinning. The effect of irrigation scheduling was also considered with respect to increasing melon yield and quality. To date, recommended practice has been to cause an irrigation deficit close to fruit harvest, with the intent of 'drying out' or 'stressing' the plant, to 'bring on' maturity and increase sugar accumulation. Irrigation trials showed that keeping plants stress-free close to harvest and during harvest, facilitated the production of sweeter fruit. The maintenance of a TSS grade standard using either batch based (destructive) sampling or (non-invasive) grading of individual fruit is discussed. On-line grading of individual fruit is possible using near infrared spectroscopy (NIR), but the applicability of the technique to melons has received little published attention. Tissue sampling strategy was optimised, in relation to the optical geometry used (in commercial operation in Australia), both in terms of the diameter and depth of sampled tissue. NIR calibration model performance was superior when based on the TSS of outer, rather than inner mesocarp tissue. However the linear relationship between outer and middle tissue TSS was strong (r2 = 0.8) in immature fruit, though less related in maturing fruit (r2 = 0.5). The effect of fruit storage (maturation/senescence) on calibration model performance was assessed. There was a negligible effect of fruit cold storage on calibration performance. Currently, the agronomist lacks a cost-effective tool to rapidly assess fruit TSS in the field. Design parameters for such a tool were established, and several optical front ends compared for rapid, though invasive, analysis. Further, for visualisation of the spatial distribution of tissue TSS within a melon fruit, a two-dimensional, or hyper-spectral NIR imaging system based on a low cost 8-bit charge coupled device (CCD) camera and filter arrangement, was designed and characterised.

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