School of Agricultural, Earth and Environmental Sciences

Dr Maliata Athon Wanga with his newly-bred, drought-tolerant elite sorghum varieties.

Designing Namibia’s Drought-Tolerant Sorghum

Dr Maliata Athon Wanga, an Agricultural Scientific Officer with Namibia’s Ministry of Agriculture, Water and Land Reform (MAWLR), has completed his PhD in Crop Science through UKZN’s African Centre for Crop Improvement (ACCI) using mutation breeding techniques to develop drought-tolerant sorghum varieties.

‘Sorghum is an important crop for food, feed and bioenergy feedstock in the world’s dry regions, such as Namibia, and there is a need to develop and deploy climate-smart varieties that can grow in water-limited agro-ecologies to improve production and productivity to enhance food security in the country,’ said Wanga.

‘There is often poor yields of the crop in sub-Saharan African countries including Namibia, where there has not been a sorghum breeding programme and only two relatively old and low-yielding sorghum varieties are widely grown. Studies in crops adapted to environmental conditions are the key strategy to improve farmers’ income, especially in rural areas,’ he said.

Supervised by ACCI Deputy Director and South African Sugarcane Research Institute Chair of Crop Science Professor Hussein Shimelis, Wanga set out to improve sorghum production and productivity in Namibia using climate-smart new-generation varieties preferred by farmers and markets.

His research began with a participatory rural appraisal in six sorghum-growing constituencies to establish the current state of sorghum production in northern Namibia, and document constraints and trait preferences in new varieties to guide drought-tolerance breeding. He then established the effective dose rate of gamma radiation and ethyl methanesulfonate mutagenesis to induce mutation in sorghum seed to develop drought-tolerant and best-performing types.

Wanga evaluated 20 newly-bred and elite sorghum lines created via gamma radiation using field data and diagnostic simple sequence repeat (SSR) markers, leading to the selection of 10 newly-developed mutant lines which were subjected to genotype by environment interaction analysis and determined to be the most stable varieties for release and commercialisation in Namibia.

Wanga received hands-on training from ACCI which assisted him in undertaking innovative and independent research, including in his role at the Directorate of Agricultural Research and Development (DARD) in the MAWLR. The skills and knowledge he gained from the ACCI training have been useful in his position as a National Counterpart for the joint Food and Agricultural Organisation (FAO)/International Atomic Energy Agency (IAEA) supported via the Technical Cooperation Programmes (TCP) coordinating research activities. The programme aims to develop mutant varieties for major staple crops, and soil, water and nutrition-saving practices.

Wanga has a Bachelor of Technology degree in Agricultural Management from the Polytechnic of Namibia and a Master of Agricultural Science qualification from the Kindai University in Japan. He was inspired to study plant breeding by various short courses and fellowship training he attended supported by DARD and the FAO/IAEA, some of which were facilitated by Shimelis.

Encouraged by his encounters with Shimelis and the plant breeding skills and knowledge evident in UKZN alumni working in Namibia, Wanga chose to enrol for the ACCI’s programme because of the contributions this would make to his expertise.

Despite the challenges brought about by the COVID-19 pandemic, which restricted travel and therefore Wanga’s data collection, he received support from his supervisor, the ACCI and UKZN, DARD/MAWLR, Crop Research and Production, crop research stations, the Directorate of Agricultural Production, Extension and Engineering Services, the IAEA, and his family and friends that enabled him to conclude his study.

He said he felt capacitated in plant breeding skills and knowledge after completing his PhD and looked forward to contributing to improved research in plant breeding in Namibia by establishing a modern plant breeding programme in the country.

Wanga thanked Shimelis for the training, supervision and mentorship he provided as well as DARD/MAWLR for the training opportunity and study leave and the FAO/IAEA for the fellowship support and research funding.

He said he was also grateful to the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) and his fellowship supervisor, Dr Ashok Kumar for hosting him as a research fellow at ICRISAT in Hyderabad in India. He thanked his supportive family for their understanding and encouragement during his PhD studies and the COVID-19 period, and also the ACCI and UKZN for their overall support.

Words: Christine Cuénod

Photographs: Supplied and Abhi Indrarajan