The South African avocado industry is increasing efforts to prevent the spread of avocado sunblotch viroid (ASBVd), a plant pathogen that poses a serious risk to fruit quality and orchard productivity. The disease, caused by a small RNA molecule, results in fruit blemishes, stem streaking, and leaf deformities. Although it seldom kills trees, ASBVd reduces marketable yields and can affect profitability.
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Transmission occurs through infected propagation material, pollen, seed, or contaminated tools, and there is currently no known cure. As a result, prevention and strict biosecurity practices remain the only effective means of control.
Industry organisations such as the South African Avocado Growers' Association (SAAGA) and the Avocado Nurserymen's Association (ANA) have implemented sanitation and testing standards aimed at limiting the spread of the disease. These include mandatory testing of all seed and graftwood sources at least once every three years, as well as rigorous hygiene procedures in nurseries and orchards.
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According to nursery managers, consistent monitoring and clean plant management are essential. Frequent testing, maintaining physical separation between trees, and sourcing seed from isolated, disease-free orchards have been shown to reduce the likelihood of infection. Some nurseries employ measures such as root-zone barriers and separation ditches between tree groups to further limit the chance of cross-contamination.
Seed sourcing is also carefully managed, with nurseries obtaining avocado seeds from verified local and international suppliers. Dedicated seed orchards located near Nelspruit and surrounded by non-avocado crops are used to minimise pollen transfer by bees.
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Growers are encouraged to source plants from accredited nurseries, implement strict pruning and sanitation protocols, and test propagation material regularly to maintain ASBVd-free status. These measures are seen as essential to safeguarding the country's expanding avocado industry and preserving access to key export markets.
© Du Roi Halls NurseryFor more information:
Du Roi Halls Nursery
Tel: +27 13 004 0462
Email: [email protected]
www.duroihalls.co.za
