Abstract:
In this research project we compared the keeping quality of fruits harvested in plots fertilized during the last three years with 0, 13, 27, 40 and 54 lbs of nitrogen/acre. The nitrogen treatments were applied on small plots of 10 X 13 feet and split into four applications during bloom. The treatments were replicated two times per site in each of one organic and three conventional sites. The nitrogen fertilization had an effect on the keeping quality in both conventional and organic sites, with the best keeping quality obtained with a nitrogen fertilization of 0 or 13 lbs/acre (10% cumulative defects after 12 weeks). The worst keeping quality was obtained with a nitrogen fertilization of 54 lbs/acre (10% cumulative defects after 6 weeks). Most of the differences in keeping quality between treatments were related to fruit rot. As expected, the total percent weight of fruits smaller than 13/32 inches decreased and the number of white fruits increased as the amount of nitrogen fertilization increased. The highest average yield in the conventional sites was obtained in plots treated with 54 lbs of nitrogen/acre (43195 lbs/acre). It was closely followed by the plots treated with 27 and 40 lbs of nitrogen/acre (40 954 lbs/acre 35 876 lbs/acre respectively). Considering the keeping quality and the yield, the best nitrogen fertilization for fresh fruits in Quebec, based on this trial, seems to be between 27 and 40 lbs/acre, which confirms the standard recommendation in fresh fruit fertilization