Effects of blueberry red ringspot virus on yield and fruit maturation in southern highbush blueberry

Abstract

Blueberry red ringspot virus (BRRV) has become prevalent in southern highbush blueberry in the southeastern United States but information about the yield effects associated with the disease is limited and conflicting. A 3-year study was conducted on mature, container-grown plants of ‘Star’ and ‘Jewel’ blueberry that were either systemically infected or not infected with BRRV to determine the effect of the disease on flower bud numbers and fruit yield and on advances or delays in fruit ripening. On Star, flower bud counts were lower for BRRV-positive plants (P = 0.0137 in one year and P = 0.1085 in another) but no such effect was observed for Jewel. When fruit were harvested over time during the ripening period in the spring, no consistent yield or berry weight reductions were observed due to BRRV infection for either cultivar. On Star, fruit maturity tended to be slightly advanced in BRRV-positive plants in all years. Specifically, the weight of unripe fruit remaining after the last harvest was consistently lower for BRRV-positive plants than for BRRVnegative plants, suggesting that BRRV infection in Star may lead to a shorter fruit ripening period. No such effect on fruit ripening was observed for Jewel. It is concluded that—for the cultivars examined in this study—BRRV causes a relatively benign infection with no negative yield implications.