Cape Town – Agriculture is one of South Africa’s strongest export pillars.
In 2024, the country shipped goods worth $110 billion, including a record $13.7 billion in agricultural products led by grapes, maize, and citrus.
More than 925 000 people work in primary agriculture, and in the Western Cape, the sector accounts for 11% of total employment.
However, a single quarantine pest can shut key markets overnight.
For fruit-producing regions, where entire towns depend on farm work, the economic consequences of infestation are enormous.
The Mediterranean fruit fly and the false codling moth target citrus and grapes that are central to the Western Cape’s rural economy.
Fruit fly damage and control costs in the province alone have previously been estimated at over $3.2 million per year, while a quarantine embargo affecting exports would be devastating.
Rising pesticide resistance and stricter residue limits in Europe and Asia have made traditional control methods increasingly difficult.
For an export sector built on quality and compliance, South Africa needs solutions that reduce pests without compromising market access.
This is where the sterile insect technique (SIT) has become a cornerstone of modern pest management.
The method is straightforward: male insects are mass-reared, sterilised using controlled doses of gamma or X-ray radiation and released into orchards.
When wild females mate with sterile males, no offspring are produced, and the pest population steadily collapses.
The technique is species-specific, does not contaminate crops, and replaces repeated chemical spraying with a biological, self-limiting approach.
South Africa operates one of the most established long-running SIT programmes in Africa.
A mass-rearing facility established in Stellenbosch in 1999 produces sterile male Mediterranean fruit flies for release across the Western Cape’s orchards and vineyards.
Early challenges, including inadequate rearing infrastructure and unstable diets or the need to import sterile pupae were gradually resolved through improved climate control, a dedicated quality-management system and the adoption of the VIENNA 8 genetic sexing strain.
Today, the programme, commercialised through SIT Africa, releases millions of sterile flies weekly over roughly 15 600 hectares in multiple production areas.
Building on that experience, South Africa has become a global leader in the use of SIT against the false codling moth, a major threat to citrus exports.
Using equipment and a gamma irradiator supplied via the IAEA, X-SIT releases millions of sterile moths each week.
Farmers in Citrusdal report dramatic improvements: infestations that once reached two damaged fruits per tree per week have, in some orchards, fallen to one per entire orchard per season.
Growers estimate that suppressing the moth has helped safeguard the livelihoods of nearly 10 000 workers.
In 2024, with proven results in the field, the Western Cape Department of Agriculture allocated R2 million in 2024 to expand X-SIT’s operations.
The current 20 400-hectare programme could grow to 40 000 hectares with sufficient funding, creating around 50 new jobs and reducing reliance on costly chemical controls.
The Citrus Growers Association notes that scaling SIT is essential for maintaining residue-free fruit, meeting strict export standards, and sustaining the province’s competitive position in global markets.
South Africa’s experience reflects a broader global shift: nuclear technologies are increasingly being used to solve practical problems in agriculture and food production.
One recent example comes from Bolivia, where a gamma-irradiation technology has been introduced to sterilise mosquitoes that spread yellow fever.
The programme is being implemented at the Nuclear Science and Technology Centre, built by Russia’s Rosatom.
The method is entirely safe for humans as it targets pest insect populations and does not affect agricultural produce.
For over half a century, SIT has been a core part of the work of the Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture.
Cases like this show that irradiation-based pest-control methods are widely used across different regions and that international technology providers are successfully transferring proven solutions to partner countries.
As SIT programmes continue to expand in South Africa, access to this kind of technological cooperation and accumulated global experience can support facility design, technical planning, and long-term scalability.
Nuclear science is not confined to power stations.
When applied to agriculture, it stabilises exports, strengthens rural economies, and protects jobs.
As climate pressures, pesticide resistance, and market standards tighten, expanding the use of SIT and ensuring long-term funding for facilities and field operations will be essential.
A technology once seen as experimental is now part of the country’s agricultural backbone, helping ensure that South African fruit reaches global markets in good condition and that the regions depending on these industries continue to thrive.
