S18 - Session P4 - Weed management in French apple cider orchard with automated and autonomous mowers

Authors: Jean Le Maguet *, Bernard Benet, Nathalie Corroyer, Bruno Corroyer, Matthieu Benoit, Alice Denis, Gaël Lebon, Jean-Charles Cardon

French apple cider orchards soil are essentially covered by grass, with a narrow strip remaining on the planting row. The ground on the tree line must stay clean for permitting mechanical fruits harvesting. In conventional orchards, growers mainly use herbicides to control weeds on the tree line. Weeds reduce indeed substantially tree productivity by their competition for soil nutrients and water. However, the development of orchards managed in organic farming and the willingness to use less herbicides involve to find other way to manage weeds.In organic agriculture, growers use mechanicals tools or mowing to maintain a good sate of the row. Those methods cost lot of time for grower in comparison with herbicide applications. The research project Innorob is carried out by the French Institut for Cider Production to study the development of autonomous mowing as an alternative to herbicides use and mechanical techniques. This project, funded for 3 years with EAFRD from the Normandy region, proposes to help the cider production in the search for new solutions to maintain the grassy cover of orchards. A network of experimental plots was established since 2021 in Normandy in the north-west of France to study different models of autonomous lawnmower. First results revealed that orchard configuration is the main barrier to an efficient mowing by autonomous robots. Tree density (around 900 trees per hectare) and unevenness of the ground are not yet supported by machines currently on the market. Other models of autonomous lawnmower will be tested. As well, discussions are being held with manufacturers to improve machine capacity based on orchard characteristics.