Thesis (M inst Agrar(Rural Engineering Technology))--University of Pretoria, 2005. / Includes bibliographical references (leaves 71-74)

Thesis (M.S.)--University of California. May, 1916. / Bibliography: p. 108-117.

Thesis (Ph. D.) (Horticulture)--University of Pretoria, 2004. / Yitle from opening screen (viewed March 14, 2005). Includes summary. Includes bibliographical references.

Thesis (D.Phil.(Department of Microbiology and Plant Pathology))-University of Pretoria, 2006. / Includes summary. Includes bibliographical references. Available on the Internet via the World Wide Web.

The main goal of this research was to determine the feasibility of using electron beam irradiation as an alternative disinfestation technology while preserving the overall quality of mangoes, and to verify its suitability for the preservation shelf life of blueberries. Physicochemical and sensory characteristics of the fruits were evaluated. Mangoes were irradiated at 1.0, 1.5 and 3.1 kGy using a 10MeV (10 kW) linear accelerator (LINAC) with double beam fixture. Samples were stored at 12ºC and 62.7% RH for 21 days. Blueberries packed in plastic clamshell containers were irradiated at 1.1, 1.6 and 3.2 kGy doses using the same linear accelerator with a single beam. The shelf life of the berries stored at 5ºC and 70.4% RH was evaluated for 14 days. The firmness of mangoes irradiated at 1.5 and 3.1 kGy significantly (p > 0.05) decreased during storage. There was a reduction of total sugars (8.1% and 14.1%) in samples irradiated at 1.0 kGy and 1.5 kGy, respectively. All irradiated mangoes had significantly lower (50- 70 %) ascorbic acid content throughout storage. The phenolic compounds increased in samples irradiated at 1.5 kGy (27.4%) and 3.1 kGy) (18.3%). Sensory evaluation of the fruits irradiated with 3.1 kGy showed significantly less acceptability for overall quality, color, texture and aroma. Irradiation of blueberries at 1.1 kGy had no significant (p > 0.05) effect on the fruits' physicochemical characteristics with the exception of ascorbic acid which decreased by 17% after 14 days. A significant decrease in texture (firmness) of irradiated berries was observed during storage time. Total sugars decreased in all irradiated fruits while total phenolics and tannins increased (10 -20%). Sensory attributes of samples irradiated with 1.1 kGy and 1.6 kGy were found acceptable by the panelists. The high dose-treated fruits were considered unacceptable. The results from this research suggest that a 1.5 kGy is the best treatment to maintain the quality attributes of mangoes and increase the shelf life by three days. The electron beam irradiation of packed blueberries at doses of 1.1 and 1.6 kGy ensures and enhances the quality and the shelf life of blueberries up to 14 days.

Mangifera indica L. cv. Kent trees were subjected to five irrigation treatments during the 2000/2001 growing season with the aim of assessing the effects of irrigation on tree productivity and fruit quality. Two progressively reduced irrigation treatments (75 and 50% of the amount of irrigation water applied to the control), a control (100% field capacity), a regulated deficit irrigation (RDI) treatment and a farm control were compared with each other. Fruit yield, number and mean fruit weight were not significantly influenced by the different irrigation treatments. Peel colour and storage potential were improved in the reduced irrigation treatments. The RDI treatment improved the total soluble solids concentration (TSS) of fruits but increased the occurrence of split pit. Fruit firmness was not significantly influenced by the different irrigation treatments. In the second experiment, 'Kent' trees were covered with white shade netting of four mesh densities (50, 75, 100 and 125 g m-2) on a long¬term basis, while control trees remained uncovered. During the 2000/2001 growing season, light shading (50 g m-2) increased the yield and fruit numbers above that of control trees, while, heavier shading decreased the yield and fruit number below that of the control with the most dense net (125 g m-2) having the greatest affect. Peel colour, firmness and total soluble solids (TSS) at harvest were not affected by shading while the heaviest shade (125 g m-2) reduced storage potential of the fruit. Shading improved the appearance of fruits through the reduction of split pit, sunburn and wind damage. No fruit damage caused by bacterial black spot was observed in any of the shade treatments or the control. / Dissertation (M Inst Agrar (Horticultural Science))--University of Pretoria, 2006. / Plant Production and Soil Science / unrestricted

Thesis (M.Ag.Sc.)--University of Adelaide, Dept. of Horticulture, Viticulture and Oenology, 1999. / Bibliography: leaves 69-78.

Please read the abstract in the section 00front of this document / Dissertation (Magister Institutiones Agrariae)--University of Pretoria, 2005. / Plant Production and Soil Science / unrestricted

Thesis (M. A. Agricultural Management (Horticulture)) -- University of Limpopo, 2003 / Refer to document

The market life of many fruits and vegetables can be extended through storage at low temperatures. Chilling injury (CI) is a major postharvest storage problem for tropical commodities. Storing these products at temperatures below their critical temperature may result in severe physiological disorders known as CI symptoms. Mangoes (Mangifera indica. L) are susceptible to CI when stored below 12 °C. Visual CI symptoms include uneven ripening, surface pitting, discoloration, shriveling and scalding. Research has been conducted to overcome these serious problems using various postharvest treatments such as hot water, methyl jasmonate (MJ) or diphenylamine (DPA) with some reduction of the incidence of CI symptoms in fruits and vegetables. / Experiments were performed to assess and compare the potential of the above-mentioned postharvest treatments to reduce the CI symptoms on mango cv. Kent. The obtained results indicated that MJ- and DPA-treatments gave significantly greater percentage of marketable fruits. / Experiments were also conducted with mangoes cv. Tommy Atkins treated with MJ and DPA before storing at low temperatures (1, 4, 7 and 10°C). The chemical treatments were successful at reducing CI symptoms of mangoes. Fruit decay was reduced during subsequent ripening. MJ-treated fruits had lower mass loss and higher total soluble solids (TSS) than the control treatment. The overall quality of MJ- and DPA-treated fruits was good with lower surface pitting and scalding compared with the control treatment. The best results were obtained at storage temperatures of 7 and 10°C. Both MJ and DPA postharvest treatments can reduce CI symptoms in mangoes cvs. Kent and Tommy Atkins when the mangoes are stored at below critical temperature.