College of Agriculture, Engineering
and Science (CAES)

Dr Sinethemba Ximba who received a PhD in Plant Pathology.

Going Bananas for Academia

‘UKZN has laid a great foundation for my academic career as I have been a student here since first year,’ says PhD graduate in Plant Pathology, Dr Sinethemba Ximba.

Ximba, who was based full-time at the Agricultural Research Council (ARC) in Nelspruit as part of the organisation’s postgraduate development programme when she registered for her PhD, chose UKZN despite the distance as she had been awarded postgraduate scholarships owing to her previous hard work and received excellent encouragement from her academic supervisor, Professor Gus Gubba.

‘It is this kind of support that one needs the most to find one’s way through academia. Professor Gubba was always just a call and text away,’ she said.

Ximba’s research – which involved multiple stakeholders such as UKZN, ARC, Department of Agriculture, Land Reform and Rural Development (DALRDD), the National Research Foundation (NRF) and GreenMatter – looked at Banana bunchy top virus (BBTV), a plant-virus that has caused destruction to the banana crop in several countries globally.

The aphid-borne virus was reported for the first time in South Africa in the South Coast region in 2016, prompting the need to determine the spread of the virus in major producing regions of South Africa.

Surveys were done on the North and South Coast of KwaZulu-Natal, Mpumalanga and Limpopo. Comparative genetic relationships of the South African isolates to global isolates were also studied. In addition, a transmission study to determine if other plant species harbour the insect responsible for BBTV spread were carried out.

‘To date, the virus is only localised within the South Coast region (of KZN),’ said Ximba. ‘There are ongoing efforts to minimise the spread of this virus through spraying programmes and raising awareness within the affected communities.

‘It is important to note that the virus is only damaging to the banana crop and poses no risk to human consumption,’ she added. ‘The challenge is that infected banana plants fail to produce marketable fruit, if they even manage to produce any at all!’

Ximba said whilst plant viruses are minute, they cause significant losses in the agricultural sector. ‘This piqued my interest. There is not much awareness on newly-emerging viruses in terms of how to control them especially in rural households. For example, some plant viruses spread through infected planting material, so when a person unknowingly shares an infected plant, that’s how the virus finds its way to another field.

‘This in turn has a negative impact on society as food security is threatened when crop yield is reduced due to plant-virus infections.’

Ximba explained that having looked at control strategies to minimise loss due to the virus, her multidisciplinary study addressed one of the United Nations’s 17 Sustainable Goals, which is Zero Hunger. ‘With implementation of control strategies such as eradication and limited movement of infected planting material, this would reduce the spread of the virus, thus preventing further infections of banana plants,’ she said.

Ximba said the PhD journey helped her develop her writing and presentation skills – reflected in the peer-reviewed articles that she has managed to publish. She has presented her research at both local and international conferences and won awards as best PhD speaker, the most meaningful being a week after she buried her beloved grandmother and was busy writing up her thesis. ‘Anyone will tell you how hectic writing up a PhD gets, so this felt like one of the biggest achievements of my career, coming as it did during one of the worst stages of my PhD.’

Ximba is currently an ad-hoc lecturer in Plant Pathology based at UKZN’s Pietermaritzburg campus. In addition to publishing the rest of her PhD findings, she plans to continue her research in crop protection as a way to contribute to food security as a whole.

‘I am also an old Fellow of GreenMatter which looks at the impact of climate change, so I am hoping to do a multidisciplinary study on the effect of climate change and plant-vector distribution in South Africa,’ she said.

The wife and mother of two, who joked that “spare time” was a myth in her world, thanked Gubba as well as fellow academic, Dr Jacques Ibaba for their support and paid tribute to her family for the pivotal role they played in her success.

‘My message to everyone is that perseverance is key,’ she said. ‘The academic journey may feel long and hard but there are always structures to help within academic institutions. Just locate them.’

Words: Sally Frost

Photograph: Abhi Indrarajan