Vaccinium spp. Production Patterns and Winter Hardiness in Latvia

During the years 2006-2007, 19 cranberry and blueberry enterprises in different climatic zones of Latvia were surveyed for the cultivars grown, amount of winter damage and types of cultural conditions. Sixty percent of these farms grow cranberries, while 40% grow blueberries. December and January temperatures were 6.2 to 7.6 degrees C above average, followed by a cold February. The lowest temperature minimum was observed in the eastern and central parts of Latvia at 34.9 to -43.2 degrees C, respectively. This cold resulted in extensive damage to flower buds and young shoots and in some cases the entire plant. Not only meteorological conditions influenced winter hardiness, but also techniques of production and a cultivar's genetics. The least amount of winter hardiness was observed for the cultivars 'Duke' and 'Brigitta Blue', and the most 'Polaris', 'Blueray' and 'Chippewa'. The best climatic zone for blueberries appeared to be the Riga Region of Central Latvia. Overall, conditions are more suitable for cranberry production in Latvia, with only slight winter damage observed. The most popular cranberry cultivars are 'Stevens' (30% of hectarage), 'Bergman' (17%), 'Ben Lear' (16%) and 'Early Black' (10%). The highest cranberry yields were 2.91 to 4.51 kg/m(-2).