A study on green cover management in vineyards with special consideration of field bindweed ( <i>Convolvulus arvensis</i> )

Abstract Vineyard green cover management, within the vine row, in interrows and also in the surrounding areas significantly affects vigor, yield performance and health of vines. The current study compares relatively new devices on the market for under-vine care based on the use of high voltage electricity (Zasso) and high-pressure water jets (Grasskiller) with mechanical management methods and a glyphosate-free chemical treatment. In terms of overall coverage, the mechanical devices inter-vine blade (Clemens, Wittlich, Germany) and Tournesol (Pellenc, Frankreich) gave the best results, followed by electrical application, in terms of vegetation height, all treatments were comparably effective. The study also recorded the effect of the measures against field bindweed ( Convolvulus arvensis ), which is a difficult-to-control vineyard weed, but also a crucial source of Stolbur Phytoplasma ‘ Candidatus Phytoplasma solani’. All under-vine treatments favoured field bindweed density, compared to the untreated control, with weed control using a high-pressure water jet performing worst. Overall, the experiments revealed no decisive advantages of electric weeding or high-pressure jets compared to conventional mechanical methods. The present study also included trials to reduce field bindweed density in vineyard interrows by means of seeded cover crop and cereal straw mulch, and around vineyards and along roadsides by largely reducing tillage (leaving the green cover long). In summary, the trials showed that competition and shading by other plant species was the most effective way of reducing field bindweed density. In order to keep the stolbur infection pressure on the vines as low as possible, it is therefore advisable to manage the green cover so that the field bindweed is shaded as much as possible. At the same time, however, competition between the vine and the greening, e.g., during dry periods, must be kept in mind.