[Cereal crops. Results of the research performed in 1997 [in Belgium]. Scientific report]

abonos nitrogenados belgique belgium control de enfermedades cultivation cultivo cultivos de invierno cultivos de primavera cultural methods culture d'hiver culture de printemps disease control ensayos de variedades farmyard manure fertilisation fertilizer application fongicide fumier fungicidas fungicides hordeum vulgare mode de culture nitrogen fertilizers pratique culturale secale cereale spring crops triticum variety trials winter crops