Wireworm control with cover crops and companion plants

Wireworms are among the most important pests in potato cultivation. Feeding on potato tubers can severely reduce their quality. Currently, there is no regularly approved, effective plant protection product that can be used against wireworms in potatoes. Wireworms are not limited to potatoes as a food source; as generalists, they feed on a variety of plant species. This can be exploited for plant protection measures.

At FiBL, we investigate this approach on three levels to increase flexibility in application and reduce risk:

• Undersowing cereal in potatoes: In addition to the expected benefits of erosion control, soil revitalization, and improved load-bearing capacity, we analyse the effectiveness of oats and winter barley as cost-efficient trap crops for wireworms.
• Companion plants: We examine the effect of flowering companion plants, such as buckwheat and faba beans, on functional biodiversity above ground, i.e., vegetation and soil-dwelling generalist arthropod predators, which are natural enemies of Colorado potato beetles. We also consider their potential as trap crops for wireworms.
• Winter cover crops: Due to their long lifecycle, wireworms can be found in the soil year-round. Since wireworms hardly move horizontally, the choice of cultivated plants may influence their food intake. We are testing whether using specifically selected plants as a winter cover crop preceding potatoes can disrupt wireworm development, reduce survival rates, and ultimately limit damage to potatoes by serving as an insufficient food source.
   

• Federal Office for Agriculture (FOAG), Switzerland

• Federal Office for Agriculture (FOAG) – Research, training and innovation

• RAGT Semences, France

• Gelencsér Tobias (Department of Soil Sciences)

• Lucas-Barbosa Dani (Department of Crop Sciences; Department of Crop Sciences)
• Lustenberger Adrian (Department of Soil Sciences)
• Reinbacher Lara (Department of Crop Sciences; Department of Crop Sciences)

Project manager

• Cultivation Technique Arable Crops (Department of Soil Sciences, FiBL Switzerland)
• Plant Protection: Phytopathology & Entomology (Department of Crop Sciences, FiBL Switzerland)
• Soil fertility & Climate (Department of Soil Sciences, FiBL Switzerland)
• Vegetables & Garden Crops (Department of Crop Sciences, FiBL Switzerland)