[The principle of plant varieties resistant to pests and diseases [applied to main crops in Belgium]]

belgique belgium biological properties cereal crops cultivos de cereales disease resistance enfermedades de las plantas hortalizas (plantas) humulus lupulus linum usitatissimum maladie des plantes nematodos de las plantas pest resistance plant diseases plant nematodes resistencia a la enfermedad resistencia a las plagas solanum tuberosum variedades varieties vegetable crops