Development of fungicides controlling Cercospora, Ramularia leaf spot, powdery mildew and rust in sugar beet [in France]

agricultural warning services avertissement agricole beta vulgaris carbohydrate content cercospora beticola contenido de carbohidratos crop yield erysiphe betae field experimentation fongicide france francia fungicidas fungicides monitoring plant protection protection des plantes ramularia beticola rendement des cultures rendimiento de cultivos teneur en glucides uromyces vigilancia