Doctoral Degrees (Horticulture)
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Browsing Doctoral Degrees (Horticulture) by browse.metadata.advisor "Fawole, Olaniyi Amos"
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- ItemQuantity and quality losses of 'Crimson Seedless' grape and 'Packham's Triumph' pear along the supply chain and associated impacts(Stellenbosch : Stellenbosch University, 2022-04) Blanckenberg, Anelle; Opara, Umezuruike Linus; Fawole, Olaniyi Amos; Stellenbosch University. Faculty of AgriSciences. Dept. of Horticulture.ENGLISH ABSTRACT: Postharvest loss and waste (often referred to as wastage) is a global problem affecting all produce along the supply chain from farm to plate. These losses not only decrease food supply but also mean that huge amounts of the resources and effort used in the production of horticultural crops are squandered. From an economic perspective, addressing postharvest losses is not only helpful to producers aiming to sell more, but also to consumers who could save money as the available food becomes more affordable. To date, there is little scientific data available on the incidence and magnitude of postharvest losses of fruit and other food crops in South Africa. The aims of this study were to assess postharvest losses in quantity and quality of ‘Crimson Seedless’ table grape and ‘Packham’s Triumph’ pear along the supply chain and quantify the associated economic, environmental and resource impacts in order to inform mitigating actions. The base measurement for table grape losses occurred in the packhouses of four farms in the Western Cape during the commercial harvest. The highest quantity (%) of physical losses in the supply chain was found to occur at this level when compared to the cold storage (2 or 4 weeks at -0.3°C ± 0.7°C and 81.3% ± 4.1% RH), retail (10 days at 5.4°C ± 0.6°C and 83.7% ± 2.9% RH) and consumer/home (ambient) storage (25.1 ± 1.3°C and 46.6 ± 6.0% RH) stages. There were large differences between the 2017 and 2018 seasons, with the 2018 season’s losses being half that of the first. The main reason for losses at the packhouse level was mechanical damage (7.1% in 2017 and 3.09% in 2018) due to rough handling of crates and could be improved by making workers more aware of the necessity to handle crates with care. Harvest timing is also essential, as delayed harvesting reduces shelf life and increases postharvest losses, as evidenced by this research. The farm that sustained the highest losses in 2017 (23.3%) harvested later than was optimal, and therefore, the bunches stayed on the vines too long. In 2018 the harvest occurred two weeks earlier than in 2017, and the grapes were in better condition leading to fewer losses on farm level (5.85%). Among all supply chain scenarios, the main quality problem was rachis and stem browning at temperatures higher than -0.5ºC. This caused berries to drop faster and bunches to look less fresh, as well as causing bunches to weigh less when sold. While 500 g and 1 kg punnets are routinely kept at around 5ºC at the retail level, during peak season 4.5–10 kg cartons are often stacked on the floor under ambient conditions. Therefore, the table grapes would have a maximum shelf life of seven days before the stems have browned and too many berries per bunch are decayed to sell. Therefore, it is advisable to keep cartons at -0.5ºC and high RH and only place bunches in punnets in 5ºC display fridges as the stock sells. The base measurement for losses of pear occurred in the orchard of two farms in the Western Cape during commercial harvest. It was found that 18% of the harvest on the one farm and 19% of the harvest on the other, did not reach the minimum quality standards. The main reasons were deformed fruit and too small size. The only decay, among all supply chain scenarios, occurred when pears were kept under ambient conditions (25.1 ± 1.3°C, 46.6 ± 6.0% RH) where 3.3% were decayed after seven days and 6.6% after 10 days. The majority of physical losses were due to weight loss with a 3.9%, 3.6 and 3.7% decrease in weight for supply chain Scenario B (to local retail markets), supply chain Scenario C (to export retail markets) and supply chain Scenario D (simulated ‘abusive’ treatment of fruit within the export chain) respectively. . Of the data gaps in the existing knowledge on global food loss and waste, the largest gap is the lack of available data on postharvest losses, retail and household level (shelf-life) food waste data. Therefore, this study contributed to the advancement of new knowledge by generating primary data on postharvest quantity and quality losses along the supply chain to manage the food loss and waste problem better.