New Winetech funded viticulture project 2021:
This study will aim to detect, identify and characterize soils that maintain specific natural suppressiveness to ring nematodes, leading to the identification of improved agricultural practices to conserve and enhance these soils.
Ring nematodes (Criconemoides xenoplax) are one of the most common and abundant nematode species in vineyards in the Western Cape. A 90% occurrence of the nematode has been recorded in vineyards in the Western Cape, with C. xenoplax being described as the key pest responsible for the damage observed on grapevines in South Africa. However, damage by ring nematodes is especially evident when vineyards are exposed to other stresses, such as poor soil conditions and water stress. Nematicides are not very effective in reducing the numbers of ring nematodes, because the nematodes occur very deep where nematicides do not reach, endorsing the need for alternative measures of control.
Evidence suggests that some level of biological control of nematodes is occurring naturally in many agricultural fields. These soils are considered suppressive to nematode damage and it is believed that they offer some degree of antagonistic activity towards plant-parasitic nematodes (PPN), most of which is related to the soil microbiome. The presence of these soils are suspected, but have been poorly documented in South Africa. Understanding the crop management practices that modulate the suppressive activity of the soil microbiome towards PPN will lead to long-lasting and cost-effective crop production. The characterization of soils that maintain specific suppressiveness against ring nematodes is also important for the establishment of agricultural practices that may conserve and enhance such soils.
If this project is successful, the development of biological control agents can be addressed in a future project. The suppressive soils identified in this project will provide valuable resources for the isolation and identification of the organisms involved in specific suppressiveness.
Researcher: Dr R Knoetze, Plant protection, ARC Infruitec-Nietvoorbij
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