The Diagnostic Centre at the ARC-Vegetable, Industrial and Medicinal Plants(ARC-VIMP) campus at Roodeplaat, aims to assist growers with pest and disease diagnosis of vegetables, including sweet potatoes, and various other crops.. Apart from plant disease diagnostic services and consultations, we also offer several other important services, such as testing for the presence of pathogens from soil or planting media, irrigation water, propagation material or other plant material. Detection of pathogens is done either by isolations or by molecular-based species-specific detection, depending on the pathogen. Furthermore, we can identify fungi, bacteria and viruses, determine viability of biocontrol agents, evaluate chemical or biological products for their efficacy against specific plant pathogens, prepare inoculum for field trials and present training. We can also provide advice on integrated disease management strategies for addressing specific problems.

One of the most important factors in the production of agriculture produce, is the source of the propagation or planting material, e.g. cuttings. Propagation material is usually obtained from approved or certified nurseries and seed suppliers or from the grower's own cuttings or seeds saved from previous seasons. In all cases, it is important to test the propagation material for the presence of pathogens before planting. Infected propagation material can be a source of bacteria, fungi and viruses, which could be transferred from the previous season to the new season (next generation of crops) and this can reduce the yield sand quality of the agricultural produce by up to 100%. Therefore, knowing the status of the material before planting is of crucial importance, especially for crops that are solely propagated by using vegetative material, such as potato, sweet potato and cassava. Although vegetative propagated material can be a source of bacteria, fungi and viruses, viruses are mostly of more concern as the plant material can accumulate different viruses and higher virus loads over several seasons. Seed producers, nurseries or vine growers are welcome to submit samples to be tested for common pathogens before distribution, to ensure that disease free seeds and planting material are distributed to growers to prevent the spread of pathogens and production losses. 


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