[Polycrops (cabbage - tomato, cabbage - carrot) and the incidence of Plutella xylostella (L.) and their natural enemies in cabbage]

brassica oleracea crop yield cultivo intercalado culture intercalaire culture multiple daucus carota diadegma economic situation enemigos naturales ennemi naturel insecte nuisible intercropping lycopersicon esculentum monocultivo monoculture morbidite morbidity morbosidad multiple cropping natural enemies pest insects plutella xylostella rendement des cultures rendimiento de cultivos