Productivity and fruit quality of Aroma apples as affected by tree density in single row, double row and triple row planting systems in a northern climate [trunk girth]

aroma calidad color colour couleur crop yield espacement espaciamiento flaveur flavour fruits frutas line planting malus malus pumila noruega norway peso plant population plantation en lignes poids portainjertos porte greffe quality rendement des cultures rendimiento de cultivos rootstocks spacing weight