Cover crops against herbicide-resistant invasive weeds.
A field experiment was conducted to evaluate the effects of several cover crops against a serious invasive weed, Conyza albida. The particular species is characterized by a wide dispersal, an enormous seed production and a high trend for glyphosate-resistance development. In the present study, four different cover crops were tested, namely Lolium multiflorum, L. perenne, Festuca arundinacea and Trifolium repens. The experiment was performed as a randomized complete design and several measurements on soil coverage and weed growth and density were taken. Soil coverage was faster and higher for L. multiflorum, followed by F. arundinacea and T. repens. On the contrary, canopy development for the perennial L. perenne was 62-72% lower than the other cover crops. This rapid and high canopy development especially of L. multiflorum and T. repens resulted to the significant reduction of C. albida density (lower by 87 and 83%, respectively) and also to weeds' growth suppression (plant height reduction up to 50%). Consequently, the specific species could be certainly used, solely or in mixtures of cover crops for the effective management of invasive and herbicide-resistant weeds.