Sowing wildflowers into potato crops could reduce aphid-carried viruses and offer an alternative to declining access to insecticides for growers, according to Scottish Agronomy. In Scotland, trials are being carried out to discover the effectiveness of growing flower strips in tramlines and headlands to promote natural predator populations to reduce pests as part of an Integrated Pest Management (IPM) strategy.
Eric Anderson, senior agronomist and potato specialist at Scottish Agronomy, is leading the trials with Scottish Agronomy potato member Jim Reid on Milton of Mathers Farm. Jim is the current AHDB Strategic Potato (SPoT) farm host and, with AHDB, Eric, and Colin Herron and Colin Ross from McCain Potatoes, is looking at different sustainable measures as part of the four-year SPoT farm project.
Jim, who grows 80 hectares of seed potatoes, said: “The trade for Scottish seed potatoes is reliant on an excellent reputation for virus health, and with the pressures of reduced access to insecticides, whether through regulation or greater resistance in aphids. It is more important than ever to look at how we can use biology and targeted chemistry to keep disease at a minimum. There is a lack of a holistic approach to IPM which integrates both the traditional and modern tools. Through these trials we are exploring the roles biology, ecology and evolution play and how we can rethink aphid and potyvirus control on a commercial scale.”
Inspired by research at Rothamsted into integrating wildflowers into carrot fields and by the work of Matthias Tschumi in Switzerland on the complementary benefits for potatoes, Eric has identified species such as cornflower, common vetch and yarrow as highly effective in attracting natural enemies of aphids. These are low growing plants that measure the same height as the potato crops.
At Milton of Mathers, 3m-wide strips of this mix have been drilled between the tramlines, creating floral food resources and a refuge habitat attractive to hoverflies, lacewings and ladybirds. Eric adds:
“This will create corridors closer to the crop, increasing biodiversity in a move away from a monoculture system with its high reliance of chemical controls and creating greater impact as the predators are closer to the pests. We are still refining, to assess whether the species sown and sowing dates have an impact on the value of the strips and whether it supports the types of natural enemies needed to control potato pests and to deliver them to the crop when needed.”
Source: Scottish Agronomy. Read the full article here