School of Agricultural, Earth and Environmental Sciences

Cum laude Master’s in Horticulture graduate Mr Siphokuhle Mbuyisa is congratulated by his aunt, Ms Thandazile Ntimbane (left) and mother, Ms Fundile Makwakwa.

Reducing Use of Agrochemicals Motivates Cum Laude Master’s Graduate

Mr Siphokuhle Mbuyisa attained a cum laude Master’s in Horticultural Science degree for investigating how plant extracts could enhance the growth, development, yield and post-harvest quality and shelf-life of potatoes.

The study was motivated by Mbuyisa’s recognition of the detrimental effects of agrochemicals on human and environmental health.

Applying extracts of Ascophyllum nodosum (a common seaweed), aloe vera leaf, garlic bulb and moringa, Mbuyisa found that the application of plant extracts as post-harvest treatments significantly influenced the post-harvest quality and shelf-life of potato tubers, variously reducing physiological mass loss during storage, increasing mineral composition and total soluble solids, while retaining vitamin C, total carbohydrate, protein, phenolic and flavonoid concentration as well as antioxidant activity during storage.

His results suggest that natural plant extracts are an appealing alternative to hazardous chemicals used to preserve and prolong potato tubers’ post-harvest quality and shelf-life without compromising consumers’ health.

Mbuyisa is originally from Shemula Gata in the Jozini municipality in northern KwaZulu-Natal, where he grew up in challenging circumstances. Watching his mother cultivate subsistence crops to help her family survive sparked a passion for agricultural studies in Mbuyisa, and he chose to study at UKZN as he viewed it as a place where his passion could be transformed into reality.

Supported financially by his aunt when he enrolled as he did not have a residence facility, Mbuyisa later received funding from the National Student Financial Aid Scheme (NSFAS) to continue his studies.

The experience of studying at UKZN has been positive, exposing him to people from different provinces and countries who have shaped his personal and academic development. Mbuyisa said he learned a lot from the six years he spent in the School of Agricultural, Earth and Environmental Sciences, where he could work as a student demonstrator and grow his skills and confidence as a scientist and researcher.

During the fourth year of his BScAgric degree, Mbuyisa was intrigued by the application of moringa leaf extracts. He decided to deepen his knowledge of plant extracts during his postgraduate studies.

Completing his master’s was challenging – Mbuyisa began without funding and relied on friends for accommodation. His supervisor, Professor Isa Bertling, recognised Mbuyisa’s potential and worked tirelessly and patiently to support him, including sourcing funding for his registration fees.

Disputes with NSFAS have left Mbuyisa owing fees that he cannot cover, and he appealed to the University’s Student Funding office to improve the funding solutions available to students or he would join legions of graduates who leave university with no certificate to show for their work.

Believing he can contribute to society through his research, Mbuyisa wants to pursue his PhD studies if he can source funding. Given the lack of suitable disposal sites for organic waste, he hopes to focus on the effect of light and the use of organic landfill waste to develop compost and grow crops.

Mbuyisa thanked his supervisor, Bertling, for her encouragement and for seeing something in him that no-one else did. He also thanked his co-supervisor, Dr Bonga Ngcobo, for being a friend and mentor, and his mother for being his support system and playing the role of both parents. He acknowledged his older brother for being there for him and supporting him when he had no funding, enabling him to become the first of his four siblings to progress to master’s level. His friends, Mr Sibonelo Ngubane and Mr Ayanda Shandu, also played a critical role in Mbuyisa’s success.

Words: Christine Cuenod

Photograph: Sethu Dlamini