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 f ertilized with either 0, 22, or 44 kg N ha/yr. After three consecutive years of these treatments, plant tissue samples were taken and analyz ed for the elements, nitrogen (N), phosphorus (P), potassium (K), calc ium (Ca), magnesium (Mg), manganese (Mn), boron (B), iron (Fe), copper (Cu), and zinc (Zn). These were compared to N dose and to fruit quali ty and quantity parameters. Across all cultivars, tissue N, P, and K l evels 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 unrelate d to fruit yield. However, fruit rot (both field and storage) was stro ngly related to tissue N. Average berry weight was related to the tiss ue concentration of a number of elements, This research suggests that tissue nutrient concentration may be useful in predicting rot and frui t size potential in cranberries.