The Effective Pollination Period in Rabbiteye Blueberry

Abstract

Rabbiteye blueberries (Vaccinium ashei Reade) often exhibit poor fruit set under commercial field conditions. Problems of low fruit set have been attributed to short periods of flower receptivity in different fruit crops. This study seeks to establish the effective pollination period (EPP, defined as the number of days during which pollination is effective to produce a fruit) in rabbiteye blueberry. The cultivars Brightwell and Tifblue were chosen due to their known difference in fruit set and field performance. Flowers were hand pollinated 0, 2, 4, 6, and 8 days after anthesis (DAA) using self- and cross-pollen. Fruit set, seeds per berry, berry weight and days to ripening were recorded. Fruit set showed a polynomial trend across flower ages. `Brightwell' was highly receptive from the day of anthesis, whereas, `Tifblue' receptivity was low until 2 DAA. `Brightwell' and `Tifblue' flowers produced adequate fruit set (≥50%) over a period of 7 and 5 days, respectively. In `Tifblue', fruit set was limited by the low receptivity of newly opened flowers. The difference in EPP helps to explain the performance of these cultivars in the field. The rate of ripening increased with flower age in both cultivars. The number of seeds per berry was affected by flower age only in `Tifblue'. The effect of flower age on berry weight depended on the cultivar and the pollen source.