Abstract
Yields of southern highbush blueberries (Vaccinium corymbosum) in north Florida and southeast Georgia were reduced by up to 50% in many fields in 2003 due to poor pollination and fruit set on varieties such as 'Millennia', 'Star', and 'Southern Belle'. Mean daily relative humidity during the flowering period (15 Febrary to 15 March), as recorded at the Alachua station of the Florida Automated Weather Network (FAWN), indicated that 25 of the 29 days of the pollination season in 2003 had above-average relative humidity, and only 4 had below-average relative humidity. Average values for this comparison were based on data from the same FAWN station for the past 4 years. It is hypothesized that poor pollen shed and reduced bee flight due to rain and high humidity were responsible for the poor fruit set. Despite poor pollination and yield reductions on most varieties, some varieties and test selections had excellent fruit set. Small plantings had better fruit set than large plantings, suggesting that bee activity during the few days of good pollination weather was enough to pollinate small numbers of flowers but not large numbers.
