[Density of vine plantation and its economic and physiological implications. Results of a study on the Loureiro variety of grape in its formation phase [Portugal]]

analyse statistique conduite de la plante cosecha espacement espaciamiento essai facteur de production harvesting main d'oeuvre mano de obra manpower plant training poda portugal production factors pruebas pruning rendement rendimiento spacing statistical analysis taille trials variedades varieties vignoble vineyards vitis vinifera yields