Pest and disease control under shade netting

As fruit-importing countries become increasingly intolerant of pest infestations and diseases posing phytosanitary risks and equally intolerant of the use of pesticides, South African fruit producers have had to revisit their pest and disease management strategies

- Magda du Toit.

Over the years, South Africa has established a reputation for supplying fruit to local and international markets. Farmers have adjusted their practices to comply with strict global phytosanitary regulations amid challenges like adverse weather conditions, water scarcity, and load-shedding, with an ongoing emphasis on year-round pest and disease control.

To reduce the risks associated with weather conditions like hail, sunburn and wind damage in certain production areas, the area under nets in South Africa is expanding rapidly.

Integrated pest management (IPM) programmes, which use a mix of chemical, biological, and cultural controls alongside habitat manipulation, have been widely adopted in the fruit industry for long-term pest management and damage prevention.

By installing nets, farmers are creating a different microclimate for their orchards, which may require an adaptation of their pest and disease control management practices, says André Labuschagne, campaign lead for potatoes and subtropical fruit at Syngenta. Failure to adapt, he warns, can result in a loss of all the benefits associated with crops under protection.

OPEN ORCHARDS VERSUS NETTED AREAS

Production in open fields allows for full sunlight exposure that can help reduce numbers of certain pests, as some insects are less active or unable to survive in intense sunlight. Open fields also allow natural predators like birds, ladybugs, spiders, and parasitoids, such as wasps, to control pests. These beneficial organisms thrive in open environments.

However, there are also some challenges associated with production in open orchards and fields. Some crops are more susceptible to pests in open fields due to lack of protection. Although weeds and other plants in the vicinity can harbour beneficial insects, they also serve as hosts for pests and compete with crops for resources.