Field performance of Vaccinium Corymbosum and V. Ashei cultivars in Northern Italy

The distribution of northern highbush blueberries (Vaccinium corymbosum L.) is mainly limited in Italy by their requirement of a soil with low pH. The rabbiteye blueberry (V. ashei Reade) is more drought- and heat-tolerant, has a lower chilling requirement and wider pH tolerance than northern highbush. To assess the behaviour of rabbiteye blueberry in Italian northern regions, in 1997 seven cultivars ('Tifblue', 'Briteblue', 'Delite', 'Climax', 'Bluebelle', 'Brightwell' and 'Baldwin') were planted in an experimental field together with several cultivars of northern highbush blueberry. The aim of the research was to study the field performance of rabbiteye blueberries in specific pedoclimatic conditions compared to northern highbush. Each year the main phenological stages and key morphological traits were recorded including measurements of the leaf, flower and fruit, the growth of the bush (bush size, number, length and diameter of basal suckers), yield per plant, average fruit weight and fruit chemical features. Comparing 4-year-old plants, the yield of both species was similar on average. The mean weight of the rabbiteye blueberry fruit was 1.84 g, showing excellent size, even at the end of the picking season (at the end of September). Comparing self- and open pollination, in all the cultivars examined, self pollinated fruit were smaller than open pollinated ones. The size of berries was related to the number of seeds, which was always much higher in open pollinated fruit. In conclusion, the first results on the culture of rabbiteye blueberries in northern Italy are positive. However, this experimental field is located in an area where it is perhaps slightly too cold at the beginning and at the end of the vegetative season for some of the V. ashei later ripening cultivars to perform best.