Effects of planting density and nitrogen fertilizer level on the occurrence of hollow heart and internal brown spot of processing potato tubers

abonos nitrogenados application rates crop yield dose d'application espacement espaciamiento functional disorders manchas morbidite morbidity morbosidad nitrogen fertilizers procesamiento processing rendement des cultures rendimiento de cultivos solanum tuberosum spacing spots traitement trastornos funcionales trouble fonctionnel tubercule tubers