FABI congratulates Phrasia Mapfumo on the successful completion of her PhD. Phrasia presented her Prestige seminar “In-field climatic factors contributing to sunflower development and health across planting dates” to a packed FABI auditorium on 20 November, while many family members, friends and colleagues also joined online. Phrasia is Dr Nicky Creux’s first PhD student to fulfil all requirements for the completion of her degree. She was co-supervised by Prof. Emma Archer, Dr Dirk Swanevelder and Dr Markus Wilken. The internal examiner for her thesis was Prof. Jacquie van der Waals and the external examiners were Prof. Yalçın Kaya from the University of Turkey and Dr Vladimir Miklic the Head of the Sunflower Department at the Serbian Institute of Field and Vegetable Crops.

Phrasia joined Dr Nicky Creux’s Crop Floral Biology and Environments research group in 2020 just before the COVID-19 lockdown was implemented. Introducing Phrasia before her Prestige Seminar, Dr Creux said that Phrasia had “squeezed every drop of information from that planting date trial” and pushed through her PhD by sheer willpower. Her findings included the first report of the Bidens mottle virus in South Africa and only the second such report on sunflowers in the world. It was a large planting date trial at two locations that required a lot of hard work and long hours. She said that Phrasia’s was always the most beautiful sunflower field with no weeds and healthy-looking plants over the two-year  period. She will now continue her research in the group as a postdoctoral Fellow.

Sunflower is the third most produced crop globally and understanding the impact of climate change on this important crop is imperative as abiotic stress impacts its development and yield. Phrasia’s PhD project investigated the impact of in-field climatic factors on sunflower growth, yield, and health across planting dates. The results highlight sunflower's capacity to maintain stable yields by adapting to adverse conditions and suggests sunflower as a model for improving drought and temperature resilience in other sensitive crops. Through disease surveys and molecular techniques, this study is the first to report the viral pathogen BiMoV on sunflower in South Africa and to explore its impact on yield. The study also provided critical insights into the climatic factors driving Sclerotinia head rot, a major sunflower disease impacting South African sunflower production.