[Avoid barren brome grass, soft brome grass and silky bent-grass in the grass seed crop [Agrostis spica venti]]

agrostis aradura bromus cultivos de invierno culture d'hiver danemark denmark dinamarca escarda gramineas graminee grasses hordeum vulgare labour lutte physique malezas mauvaise herbe physical control ploughing production de semences rotation culturale rotational cropping seed production weed control weeds winter crops