Commercial Bumble Bees as Vectors of the Microbial Antagonist Clonostachys rosea for Management of Botrytis Blight in Wild Blueberry (Vaccinium angustifolium)

Abstract

Greenhouse and laboratory experiments in 2011 determined that Clonostachys rosea can effectively prevent Botrytis cinerea infection in Vaccinium angustifolium blossoms. In vitro testing demonstrated that C. rosea germination was not significantly affected by the presence of Switch®, but was by either Pristine® or Maestro®. Field experiments completed during the summer of 2010 and 2011 indicated that the dispenser designs tested had no significant effects on Bombus impatiens foraging behaviours, aside from hive-activity. There was also no difference in the quantity of C. rosea applied by each to bees, the distribution of product in the field, or for blossoms exposed to bees from each dispenser to resist infection by B. cinerea. However, B. cinerea prevalence in blossoms from both treatments was significantly different from the control, with infection reduced by 10-20%. Technical issues with dispensers currently appear to be the limiting factor for application within commercial wild blueberry production.