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Assessment of heat stress mitigation in tomatoes (Solanum lycopersicum L.)
Thesis (MScAgric)--Stellenbosch University, 2025.
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| Format: | Thesis |
| Language: | English |
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Stellenbosch : Stellenbosch University
2025
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| _version_ | 1867614099016253440 |
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| access_status_str | Open Access |
| author | Van Wyk, Jancke |
| author2 | Kempen, Estelle |
| author_browse | Kempen, Estelle Van Wyk, Jancke |
| author_facet | Kempen, Estelle Van Wyk, Jancke |
| author_sort | Van Wyk, Jancke |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MScAgric)--Stellenbosch University, 2025. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/132331 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:46:39.009Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2025 |
| publishDateRange | 2025 |
| publishDateSort | 2025 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/132331 Assessment of heat stress mitigation in tomatoes (Solanum lycopersicum L.) Van Wyk, Jancke Kempen, Estelle Wilson, Ida Stellenbosch University. Faculty of AgriSciences. Dept. of Agronomy. Tomatoes -- Breeding Tomatoes -- Growth Tomatoes -- Effect of heat on Crops -- Effect of global warming on Global warming Tomatoes -- Effect of stress on UCTD Thesis (MScAgric)--Stellenbosch University, 2025. van Wyk, J. 2025. Assessment of Heat Stress Mitigation in Tomatoes (Solanum lycopersicum L.). Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/df8fa0ff-4351-4e33-9536-2a82f9aa27d9 ENGLISH ABSTRACT: Global warming and intensifying heat stress threaten agricultural sustainability, productivity, and food security, particularly in horticultural crops like tomatoes (Solanum lycopersicum L.). Tomatoes are vital for human nutrition and serve as an important model species for studying abiotic stress responses of fleshy fruits. This study investigated the efficacy of a commercially available, environmentally friendly, plant-based biostimulant, hereinafter BR4, in mitigating the effects of respective chronic heat stress on tomato growth, yield, and quality. BR4 is commercially registered for enhanced yield and quality responses across 48 crops, including vegetable crops. Trials were conducted in temperature-controlled glasshouses at the Welgevallen Experimental Farm in Stellenbosch, Western Cape Province, South Africa. Tomatoes were exposed to chronic mild heat stress (day/night temperatures of 30/16 °C) or chronic intensive heat stress (day/night temperatures of 36/20 °C). Two separate trials with a two-way factorial design within a completely randomised layout were conducted for each temperature regime. The biostimulant was applied as either a foliar spray or soil drench to two tomato cultivars and compared to the control. Notably, under mild heat stress, the percentage of marketable fruit, fruit weight, and fruit firmness was greater (p < 0.05) for treated fruit, regardless of application method. These findings suggest that the application of BR4 improved crop resilience, market value, and postharvest quality under moderately elevated temperatures in specific seasons and light intensities, given observed seasonal differences. Numerous exposure responses were also cultivar-specific, highlighting the impact of genotypic variation on crop response to heat stress and biostimulant application. Under the intensive heat stress scenario, BR4 enhanced (p < 0.05) vegetative growth and physiological parameters in both trials. Fruit set was almost completely inhibited under intensive heat stress, regardless of treatment. There was no marketable fruit yield in either trial under these conditions, and compared to mild heat stress yields, up to 100% yield loss was observed. These findings underscore the significant challenges intensive heat stress poses to the critical reproductive stages of tomatoes and emphasise that extreme heat conditions, which completely alter crop physiology, cannot only be overcome by measures like biostimulants. Overall, the study demonstrated the huge potential of BR4 to enhance tomato productivity, resilience, and postharvest quality, although outcomes are conditional to commercial growing conditions and tomato genotypes. In the future, combining the use of organic, environmentally friendly biostimulants, such as BR4, with heat-tolerant crop breeding, advanced agronomic practices, and improved climate-controlled systems can potentially offer solutions for crop production as the planet continues to become warmer. This product may hold great global potential for future crop production, and further research is encouraged. AFRIKAANSE OPSOMMING: Geen opsomming beskikbaar. Masters 2025-06-04T06:49:03Z 2025-06-04T06:49:03Z 2025-03 Thesis https://scholar.sun.ac.za/handle/10019.1/132331 en Stellenbosch University xiii, 93 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Tomatoes -- Breeding Tomatoes -- Growth Tomatoes -- Effect of heat on Crops -- Effect of global warming on Global warming Tomatoes -- Effect of stress on UCTD Van Wyk, Jancke Assessment of heat stress mitigation in tomatoes (Solanum lycopersicum L.) |
| title | Assessment of heat stress mitigation in tomatoes (Solanum lycopersicum L.) |
| title_full | Assessment of heat stress mitigation in tomatoes (Solanum lycopersicum L.) |
| title_fullStr | Assessment of heat stress mitigation in tomatoes (Solanum lycopersicum L.) |
| title_full_unstemmed | Assessment of heat stress mitigation in tomatoes (Solanum lycopersicum L.) |
| title_short | Assessment of heat stress mitigation in tomatoes (Solanum lycopersicum L.) |
| title_sort | assessment of heat stress mitigation in tomatoes solanum lycopersicum l |
| topic | Tomatoes -- Breeding Tomatoes -- Growth Tomatoes -- Effect of heat on Crops -- Effect of global warming on Global warming Tomatoes -- Effect of stress on UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/132331 |
| work_keys_str_mv | AT vanwykjancke assessmentofheatstressmitigationintomatoessolanumlycopersicuml |