Tips To Ward Off Olive Trunk Diseases

New research by a recent Ph.D. graduate of Stellenbosch University (SU), has shed light on what olive tree farmers can do to curb olive trunk diseases in their orchards.

- Engela Duvenage

Among these tips are to prune trees when humidity levels are low, to apply wound protection within the first week after pruning, and to remove shredded branches from orchards.

The research was done by Dr Meagan van Dyk of the Strand, as part of her Ph.D. in Plant Pathology. Her research was funded by the Agricultural Research Council’s (ARC) Infruitec-Nietvoorbij, the National Research Foundation and the Department of Trade and Industry’s THRIP programme in collaboration with the SA Olive Industry Association.

She was based at the ARC’s InfruitecNietvoorbij campus in Stellenbosch while completing her four-year research project under the supervision of Prof Francois Halleen of ARC InfruitecNietvoorbij, Prof Lizel Mostert of the SU Department of Plant Pathology, and Dr Chris Spies of ARC Plant Health and Protection.

Olive production in South Africa

“The olive industry in South Africa produces an excellent quality olive oil. However, the Olive Sector Development Plan of the Department of Trade and Industry identified low production and the lack of local research as weaknesses of the olive industry in South Africa.

“The effective management of pests and diseases, including olive trunk diseases, forms an integral part in improving the lifespan and yield of olive trees, and increasing olive production in especially the Western Cape,” says Prof Halleen who is also an extraordinary associate professor in the SU Department of Plant Pathology.

Prof Halleen says that trunk diseases typically take a long time to develop. It starts with the dieback of shoots and then spreads to the rest of the tree. He reckons that good harvests can still be taken off trees that farmers have managed well.