CRANBERRY TISSUE NUTRIENT LEVELS AS IMPACTED BY 3 LEVELS OF NITROGEN-FERTILIZER AND THEIR RELATIONSHIP TO FRUIT YIELD AND QUALITY

Five different cranberry (Vaccinium macrocarpon Ait.) cultivars were fertilized with either 0, 22, or 44 kg N ha/yr. After three consecutive years of these treatments, plant tissue samples were taken and analyzed for the elements, nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), manganese (Mn), boron (B), iron (Fe), copper (Cu), and zinc (Zn). These were compared to N dose and to fruit quality and quantity parameters. Across all cultivars, tissue N, P, and K levels increased with increasing N dose, whereas Fe tended to decrease with increasing N dose. Only the element Mn showed no relationship to N dose for any cultivar. Tissue N concentration was generally unrelated to fruit yield. However, fruit rot (both field and storage) was strongly related to tissue N. Average berry weight was related to the tissue concentration of a number of elements, This research suggests that tissue nutrient concentration may be useful in predicting rot and fruit size potential in cranberries.