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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.
1

Measuring the effectiveness of research and development on avocado, Persea Americana Mill, in South Africa

De Graaf, Johan 05 May 2011 (has links)
No research method has yet been identified to best measure South African avocado R&D effectiveness. The research question was which criteria were best in measuring R&D effectiveness and what was the level of satisfaction with these criteria.
2

Measuring the effectiveness of research and development on avocado, Persea Americana Mill, in South Africa

De Graaf, Johan 05 May 2011 (has links)
No research method has yet been identified to best measure South African avocado R&D effectiveness. The research question was which criteria were best in measuring R&D effectiveness and what was the level of satisfaction with these criteria.
3

'Hass' avocado fruit quality : the role of fruit minerals and rootstocks /

Marques, José Roberto. January 2002 (has links) (PDF)
Thesis (Ph. D.)--University of Queensland, 2002. / Includes bibliographical references.
4

The effect of avocado consumer preferences and behaviour on the global commercialization of new avocado horticultural intellectual property

Bekker, Theo Frederik 20 August 2012 (has links)
The study’s aim was to determine how consumers relate to specific factors that affect the way in which fruit is marketed in supermarkets. This might have an influence on effective commercialization of new intellectual property in the global avocado industry.
5

The effect of avocado consumer preferences and behaviour on the global commercialization of new avocado horticultural intellectual property

Bekker, Theo Frederik 20 August 2012 (has links)
The study’s aim was to determine how consumers relate to specific factors that affect the way in which fruit is marketed in supermarkets. This might have an influence on effective commercialization of new intellectual property in the global avocado industry.
6

Aspekte van sommige ultrastrukturele en fisiologiese veranderinge van avokadovrugte (Persea americana Mill, kultivar Fuerte) gedurende koelopberging en rypwording

Koster, Susanna Aletta 05 February 2014 (has links)
M.Sc. (Botany) / Refer to full text
7

Determinants of competitiveness among smallholder avacado farmers in Vhembe District of Limpopo Province, South Africa

Masikhwa, Humbulani January 2018 (has links)
Thesis (MSc. (Agricultural Economics)) -- University of Limpopo, 2018 / The avocado industry is a major industry in South Africa and this can be seen by its economic contribution. Limpopo Province is one of the major avocado producing areas in South Africa, and avocado production within the province ranges from smallholder to commercial production. Smallholder avocado producers within the province have a significant role to play, especially if their full potential is unleashed. For smallholder farmers to play such a role they need to be competitive. The concept of competitiveness can be defined as the ability of an industry or firm to compete successfully in order to achieve sustainable growth while earning at least the opportunity cost on resources employed. The main aim of this study was to analyse the determinants of competitiveness of smallholder avocado farmers in the Vhembe District of the Limpopo Province based on the Porter’s Diamond model framework in order to assess the level of competitiveness of farmers and to establish how the farmers can be assisted to reach their full potential. The study was conducted in the Vhembe District Municipality and a sample of 60 farmers was interviewed. SPSS (SPSS 26.0) was used to analyse the data. Three analytical techniques were used in the analysis for this study. Firstly, factor analysis was used to reduce and group the number of variables associated with competitiveness of the farmers. Secondly, profitability analysis through enterprise budgeting was used to categorise the farmers into two groups; competitive and noncompetitive. Thirdly, Logistic regression was used to establish the socio-economic and Porter’s Diamond model determinants that could be linked to the competitiveness of the farmers. From the factor analysis, 5 factors were extracted, namely; “chance”, “government, related and supporting industries”, “factor conditions”, “firm strategy structure and rivalry” and “demand conditions”. From the profitability analysis the farmers were grouped into competitive and non-competitive categories with 22 farmers classified as being competitive and 38 farmers as being non-competitive. From the results of logistic regression, 7 out of 12 hypothesised variables were found to be statistically significant, these were; age of farmer, number of trees planted, related and supporting industries, firm strategy structure and rivalry, chance, demand conditions and factor conditions. Chance was the only variable with a statistically significant v negative influence on the competitiveness of the farmers, this was because factors that were tested for their influence on the competitiveness of the farmers are among others: Crime, HIV/AIDS, fires, frost and floods. Based on the research findings, several policy suggestions were made, these include; mentorship and encouragement of youth participation in farming, provision of agricultural land, capacity building for farmers, government support and stakeholder mobilization, specialized extension service and formation of cooperatives as well as encouraging commercialization.
8

Conservação refrigerada de abacate ‘Hass’ e ‘Fuerte’ submetidos à atmosferas modificadas ativas

Russo, Viviane Citadini [UNESP] 08 August 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:24:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-08-08Bitstream added on 2014-06-13T20:52:21Z : No. of bitstreams: 1 russo_vc_me_botfca.pdf: 369746 bytes, checksum: 0a8225daa88d162d6b78d8e5b5e4f7a3 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / O presente trabalho teve como objetivo avaliar a conservação refrigerada de frutos de abacates ‘Hass’ e ‘Fuerte’ submetidos à aplicação de atmosfera modificada ativa. Os frutos foram selecionados visando à homogeneização do lote quanto à ausência de injúrias e lavados com água e detergente no intuito de remover resíduos da colheita e microrganismos aderidos à superfície. A higienização dos abacates foi realizada com uma solução de hipoclorito de sódio a 1%, por aproximadamente 20 minutos antes da montagem do experimento. Os frutos das duas variedades foram acondicionados em embalagem de nylon+polietileno e submetidos a injeção de mistura de gases constituindo os tratamentos: I - mistura gasosa do ambiente (0,03% de CO2 e 21,0% de O2); II - 5,0% de CO2 e 4,0% de O2; III - 6,0% de CO2 e 4,0% de O2; IV - 7,0% de CO2 e 4,0% de O2 e V - 8,0% de CO2 e 4,0% de O2. Os frutos foram armazenados em câmara frigorífica a uma temperatura de 10ºC±1 e umidade relativa de 90±5% e avaliados durante 25 dias, sendo as análises realizadas a cada 5 dias. As análises realizadas foram perda de massa, atividade respiratória, potencial hidrogeniônico (pH), firmeza, acidez titulável (AT), sólidos solúveis (SS) e atividade das enzimas Pectinametilesterase (PME) e Poligalacturonase (PG). Os resultados foram submetidos à análise de variância e as médias foram comparadas pelo teste Scott-Knott ao nível de 1 ou 5% de probabilidade, conforme a característica avaliada. Nas condições em que os experimentos foram realizados, pode-se concluir que as concentrações de 5,0% e 8,0% de CO2 apresentaram os melhores resultados pós colheita dos abacates ‘Hass’ e ‘Fuerte’ frigorificado / This study aimed to evaluate the cold storage of fruit avocado ‘Hass’ and ‘Fuerte’ submitted to the application of active modified atmosphere. The fruits were selected aiming at the homogenization lot about the lack of injuries and washed with water and detergent in order to remove crop residues and microorganisms adhered to the surface. The cleaning of the avocados was performed with a solution of sodium hypochlorite 1% for about 20 minutes before assembling the experiment. The two varieties of fruits were packed in polyethylene + nylon and injected with mixture of gases constituting the treatments: I - the environment gas mixture (0,03% de CO2 e 21,0% de O2); II - 5,0% CO2 and 4,0% O2; III - 6,0% CO2 and 4,0% O2; IV - 7,0% CO2 and 4,0% O2 and V - 8,0% CO2 and 4,0% O2. The fruits were stored in cold chamber at a temperature of 10±1°C and relative humidity of 90±5% and evaluated for 25 days, with analyses performed every 5 days. The analyses were weight loss, respiratory activity, hydrogen potential (pH), firmness, titratable acidity (TA), soluble solids (SS), and activity of Pectinmethylesterase (SMEs) and Polygalacturonase (PG). The results were subjected to analysis of variance and the means are compared by the Scott-Knott test at 1 or 5 % probability, according to the trait. Under conditions in which the experiments were performed, one can conclude that concentrations of 5,0% and 8,0% CO2 yielded better post-harvest avocados ‘Hass’ and ‘Fuerte’ refrigerated
9

Conservação refrigerada de abacate 'Hass' e 'Fuerte' submetidos à atmosferas modificadas ativas /

Russo, Viviane Citadini, 1983- January 2012 (has links)
Orientador: Rogério Lopes Vieites / Banca: Erica Regina Daiuto Bastos / Banca: Sergio Marques Costa / Resumo: O presente trabalho teve como objetivo avaliar a conservação refrigerada de frutos de abacates 'Hass' e 'Fuerte' submetidos à aplicação de atmosfera modificada ativa. Os frutos foram selecionados visando à homogeneização do lote quanto à ausência de injúrias e lavados com água e detergente no intuito de remover resíduos da colheita e microrganismos aderidos à superfície. A higienização dos abacates foi realizada com uma solução de hipoclorito de sódio a 1%, por aproximadamente 20 minutos antes da montagem do experimento. Os frutos das duas variedades foram acondicionados em embalagem de nylon+polietileno e submetidos a injeção de mistura de gases constituindo os tratamentos: I - mistura gasosa do ambiente (0,03% de CO2 e 21,0% de O2); II - 5,0% de CO2 e 4,0% de O2; III - 6,0% de CO2 e 4,0% de O2; IV - 7,0% de CO2 e 4,0% de O2 e V - 8,0% de CO2 e 4,0% de O2. Os frutos foram armazenados em câmara frigorífica a uma temperatura de 10ºC±1 e umidade relativa de 90±5% e avaliados durante 25 dias, sendo as análises realizadas a cada 5 dias. As análises realizadas foram perda de massa, atividade respiratória, potencial hidrogeniônico (pH), firmeza, acidez titulável (AT), sólidos solúveis (SS) e atividade das enzimas Pectinametilesterase (PME) e Poligalacturonase (PG). Os resultados foram submetidos à análise de variância e as médias foram comparadas pelo teste Scott-Knott ao nível de 1 ou 5% de probabilidade, conforme a característica avaliada. Nas condições em que os experimentos foram realizados, pode-se concluir que as concentrações de 5,0% e 8,0% de CO2 apresentaram os melhores resultados pós colheita dos abacates 'Hass' e 'Fuerte' frigorificado / Abstract: This study aimed to evaluate the cold storage of fruit avocado 'Hass' and 'Fuerte' submitted to the application of active modified atmosphere. The fruits were selected aiming at the homogenization lot about the lack of injuries and washed with water and detergent in order to remove crop residues and microorganisms adhered to the surface. The cleaning of the avocados was performed with a solution of sodium hypochlorite 1% for about 20 minutes before assembling the experiment. The two varieties of fruits were packed in polyethylene + nylon and injected with mixture of gases constituting the treatments: I - the environment gas mixture (0,03% de CO2 e 21,0% de O2); II - 5,0% CO2 and 4,0% O2; III - 6,0% CO2 and 4,0% O2; IV - 7,0% CO2 and 4,0% O2 and V - 8,0% CO2 and 4,0% O2. The fruits were stored in cold chamber at a temperature of 10±1°C and relative humidity of 90±5% and evaluated for 25 days, with analyses performed every 5 days. The analyses were weight loss, respiratory activity, hydrogen potential (pH), firmness, titratable acidity (TA), soluble solids (SS), and activity of Pectinmethylesterase (SMEs) and Polygalacturonase (PG). The results were subjected to analysis of variance and the means are compared by the Scott-Knott test at 1 or 5 % probability, according to the trait. Under conditions in which the experiments were performed, one can conclude that concentrations of 5,0% and 8,0% CO2 yielded better post-harvest avocados 'Hass' and 'Fuerte' refrigerated / Mestre
10

Effect of partial root-zone drying, storage temperature and days to ripening on post-harvest quality of 'hass' avocado fruit

Mukovhanama, Khangwelo Jessica January 2019 (has links)
Thesis (M. Sc. (Horticulture)) -- University of Limpopo, 2019 / The South African Avocado Industry is continuously expanding with ‘Hass’ cultivar occupying the largest land and therefore, the most exported cultivar. Expansion of the industry implies an increased demand for irrigation water. However, South Africa is a water scarce country characterised by low and erratic rainfall, where fruit production relies heavily on irrigation. The agricultural sector is under an obligation to reduce water use due to the increasing demand for water by other economic sectors. Therefore, it must find efficient water use techniques to save water and ensure water availability for other economic sectors. Partial root-zone drying (PRD) is an irrigation technique which may lead to 50% reduction in water use, half of the root system is kept wet while the other half is left dry to a predetermined level of soil water depletion, the dry and the moist sides are alternated at regular intervals. During storage and transportation of fresh produce, low temperature is a post-harvest tool used to maintain quality, especially when fruit are destined for long distant export markets. This study investigated the effect of PRD and low temperature storage on post-harvest quality parameters of ‘Hass’ avocado fruit. The experiment was laid as a factorial arranged in randomised complete block design (RCBD). The treatment factors for chilling injury, electrolyte leakage and vascular browning were 2 x irrigation regimes (Full Irrigation (FI) vs. PRD) and 2 x storage temperatures (2.0 and 5.5°C). However, treatment factors for fruit weight loss, respiration rate, fruit firmness, ripening percentage and fruit skin colour were 2 x irrigation regimes (Full Irrigation (FI) vs. PRD), 2 x storage temperatures (2.0 and 5.5°C) and 4 ripening days (0, 2, 4 and 6 days). Mature ‘Hass’ avocado fruit were harvested from PRD and fully irrigated trees and thereafter fruit of each treatment were stored at 2.0 and 5.5°C for 28 days. Each treatment consisted of 6 replicates, with an exception of electrolyte leakage, whereby the experiment was replicated 4 times. After 28 days’ storage at 2.0 and 5.5°C, fruit were ripened at 21°C. The effect of PRD and low temperature storage was determined by evaluating the following physico-chemical fruit parameters during ripening: external chilling injury, electrolyte leakage, fruit weight loss, respiration rate, firmness, fruit skin colour and vascular browning. During ripening, ‘Hass’ avocado fruit stored at 2.0°C showed significantly higher incidences of external chilling injury symptoms compared with xiii 5.5°C, irrespective of irrigation treatment. Furthermore, an interaction between irrigation treatment and low storage temperature had a significant (P<0.05) effect on cell membrane electrolyte leakage. All evaluated fruit showed similar weight loss, irrespective of irrigation and storage treatment. Irrigation, storage temperature and ripening days did not have effect on respiration during ripening. Fruit reached the respiratory climacteric peak on the same day (day 2). Furthermore, there was no significant interaction effect (P˃0.05) on fruit firmness. However, PRD treated fruit showed slightly low firmness when compared with control fruit. ‘Hass’ avocado fruit harvested from PRD and fully irrigated trees and stored at 5.5°C ripened quicker compared to fruit stored at 2.0°C. There was no significant interaction effect (P˃0.05) on fruit skin lightness (L), chroma (C), hue angle (h°) and fruit eye colour due to irrigation and cold storage treatment. In general, fruit showed skin colour change from emerald green to approximately 75% coloured. Furthermore, irrigation and storage temperature did not have effect on vascular browning, however, there incidence was high on fruit stored at 2.0°C when compared with 5.5°C. The results of this study indicated that ‘Hass’ avocado fruit stored at 2.0°C was negatively affected by low temperature storage and this cold storage temperature is not recommended. PRD reduced water use during irrigation, however, its effect on post-harvest quality of ‘Hass’ avocado fruit subjected to 5.5°C must be further investigated before recommended for export markets. / Agricultural Research Council-Tropical and Subtropical Crops (ARC-TSC) and Agricultural Sector Education Training Authority (AgriSeta)

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