EFECTO DE LA FERTILIZACIÓN NITROGENADA SOBRE RENDIMIENTO Y CALIDAD DE FRUTA EN FRAMBUESO (Rubus idaeus L.) BAJO DOS PROGRAMAS DE FERTIRRIGACIÓN

The aim of the study was to present the effect of nitrogen fertilization on the yield and the fruit quality in raspberries (Rubus idaeus L.) cv. Heritage, submitted to drip irrigation. The field experiment was carried out on a silt loam soil (Typic Melanoxerands) during the growing season 2002-2003 in an second-year old orchard. Urea fertilizer was applied with the irrigation under two fertigation programs: permanent (doses fractioned 43 times) and single (doses applied at the beginning of growing season). The nitrogen rate applied in both systems was 0, 25, 50 and 100 kg ha-1. The single fertigation with 100 kg ha-1 rate was the best treatment in yield and volume of exportable fruit, while the permanent fertigation with the same rate presented the highest fruit weight and diameter, as the smaller incidence of dropping and white drupelets. A clear response to the permanent fertigation is not presented, but with the increasing of the nitrogen rate is observed a positive effect in the majority of the evaluated parameters.