Fertilization is one of the factors that can influence in the yield and quality of the fruits, however, there are few researches in that area fruit in the south of Brazil in order to guide the moment of its recommendation. The research aim was to evaluate nitrogen and potassium fertilization in the plum yield (Prunus salicina), cv. 'Reubennel'. The experiment was established in a five years old commercial orchard in Araucaria County Parana. The experiment design was a split-plot in a randomized complete block with three replications. Main plot treatments were potassium rates (55 and 110 kg of K2O ha-1 ano-1), and subplot treatments were the nitrogen rates (40, 80, 120, 160 and 200 kg of N ha-1 ano-1), that were applied during three years. The year factor was analyzed as split-split plot. The analyzed variables were yield, fruit number before the thinning and during harvesting, and fruit weight and caliber. The result indicated a high productive potential of the orchard used, with a mean yield of 38.7 tons ha-1 ano-1 in the three years evaluated. However, there was no difference in the treatments or interaction effects of the treatments on any evaluated parameters which could be associated to the chemical and physics characteristics of the soil and plant management (trims and thinning). Year factor influenced yield, caliber, and fruit number. Regardless of the treatments Plum yield was direct and inverse related with fruit number and fruit size, respectively. Low N and K rates were able to obtain high yield during three years.
Plum; Prunus salicina; fertilization; nitrogen; potassium
