Parthenocarpy in Rabbiteye Blueberry (Vaccinium ashei)

Under greenhouse conditions, some rabbiteye blueberry cultivars set fruit that develops to maturity without pollination. Since self-fruitfulness (or lack of) is a critical issue for rabbiteye, we undertook a 3-year study of the propensity of 48 rabbiteye cultivars to set fruit under greenhouse conditions. We measured fruiting interval, fruit set, ripening interval, and fruit size, and also monitored temperature conditions during the study with the goal of not only documenting the performance of different cultivars, but also understanding as much as possible about the conditions leading to parthenocarpy. Several cultivars stood out as having distinct expressions of parthenocarpy. The cultivars, ‘Early May’, ‘Ira’, ‘Suwanee’, and ‘Owen’ had virtually no fruit-set without pollination. Several modern cultivars, ‘Pearl River’, ‘Bonita’, ‘Alapaha’, ‘Ochlockonee’, ‘Columbus’, ‘Powderblue’, and ‘Premier’ had variable set across years, but relatively large seedless fruit at maturity (10–12 mm). In contrast, ‘Chaucer’, a modern Florida cultivar, was unique in its exceptionally high fruit-set without pollination, but it produced relatively small fruit, averaging approximately 7 mm. To evaluate greenhouse data in relation to field performance, we compared parameters of field-grown fruit (size, weight, seed/pulp ratios) to determine if cultivars with stronger parthenocarpic tendencies under greenhouse conditions also exhibit a lesser need for pollination under field conditions to achieve fruit development.