Why it matters
Soilborne diseases are a major hidden threat to summer grain crops in South Africa. These diseases often damage roots without showing obvious signs above ground, making them difficult to detect until it’s too late. For black commercial farmers, who often work on limited land, this can lead to serious yield losses and threaten the long-term viability of their operations.
This project aims to reduce the impact of soilborne diseases through better management practices like seed treatment, crop rotation and cover crops. By improving root health, the project helps farmers protect yields and build more resilient, productive grain systems.
Research approach
The project uses a combination of field surveys, lab work and greenhouse trials. Key activities include:
- Identifying the soilborne fungi and oomycetes affecting maize, soybean and sunflower crops
- Testing how well different seed treatments work in soils collected from 12 farms across six provinces (Eastern Cape, Free State, Gauteng, KwaZulu-Natal, Mpumalanga and North West provinces)
- Comparing results in pasteurised (pathogen-free) and non-pasteurised soil to isolate the impact of diseases
- Measuring plant survival, growth and root rot severity under different treatments
- Analysing which pathogens affect rotation and cover crops to build an integrated management strategy
The greenhouse bioassays, using seeds supplied by the farmers, help test real-world effectiveness of seed treatments and highlight seed quality issues.
Research impact to farmers
The project has already shown that:
- Effective seed treatment matters. In many cases, treated seed planted in pathogen-infested soils resulted in healthier plants, better survival and stronger root systems
- Soil health is key. Plants grown in pasteurised soil consistently performed better, reinforcing the need to manage soilborne pathogens
- Seed quality cannot be overlooked. Some farmer-supplied seed showed poor performance even in pathogen-free conditions, highlighting the need for quality control
These findings support a practical, integrated strategy to reduce disease, improve yield stability and build resilience, particularly for black commercial farmers who cannot afford high losses.
Collaborators and Research Leads
Principal Investigator Prof Sandra C. Lamprecht – ARC Plant Health and Protection
Collaborating Institutions ARC – Grain Crops Institute (ARC-GCI) Westerdijk Fungal Biodiversity Institute (The Netherlands) Farmers in Eastern Cape, Free State, Gauteng, KwaZulu-Natal, Mpumalanga and North West
Students and Technicians
Ilka Adendorff – MSc Agric Plant Pathology (Graduated 2024)
- Thabo Phasoana – Technician
- Esihle Gcanga – Technician
- Saudiqah Williams – Technician
- Jane Lottering – Technician
- Xolisa Xhwitha – Technician
- Refilwe Disetlhe – Technician