Vers une meilleure maitrise du laiteron des champs en Hauts-de-France.

Perennial sow-thistle (Sonchus arvensis L., SONAR) is a perennial weed able to multiply through its seeds and roots, where it stores energy in order to regrow once its aerial system has been destroyed. This weed is very frequent in the organic cropping systems including open-field vegetable in the Hautsde-France region, where tillage can contribute to its spreading by breaking up its root system. As part of the VivLéBio2 project, this study aims to synthesize knowledge on perennial sow-thistle in terms of biology nd herbicide-free management levers, from literature, local expertise and experiments. Strategies involving repeated stubble ploughing with various tillage tools and weed-suppressive crops were tested in field experiments. The tested strategies significantly reduced sow-thistle density when conditions were favourable, especially when a disc tool was used.