GROWTH AND YIELD OF HIGHBUSH BLUEBERRY BLUECROP CV. (VACCINIUM CORYMBOSUM L.) IN RELATION TO THE LEVEL OF NITROGEN FERTILIZATION
The winter of 1986/87 was very severe. The lowest temperature in the field dropped to - 37,4°C. The most severe frost damages of the bushes were observed on plots fertilized with 150 kg N/ha, whereas, the bushes on control plots were the least affected. Results so far obtained indicate that the optimal nitrogen dose for highbush blueberry plants grown in soil with a low content of organic matter is about 50–100 kg N/ha. An increased N supply resulted in a lower yield and decreased frost resistance.