2019 ASHS Annual Conference

Washington State is one of the largest highbush blueberry producers in the United States, making this crop important to the regional economy. Blueberry growers usually rent honey bee (Apis mellifera) hives for pollination. However, fruit set and yield in western Washington can be low and this may be partially due to poor pollination in the cooler, wetter part of the state. To overcome pollination constraints, growers will apply commercial pheromones and/or attractants. Synthetic pheromones are made to mimic natural pheromones with the intent to affect honey bee behavior and increase foraging. Despite widespread commercial use, the effects of these pheromones and attractants on improving blueberry pollination are unclear. The overall objective of this project is to evaluate the effects of commercial pheromones and attractants on pollination, fruit set, and fruit quality attributes in blueberry grown in western Washington. Four different pheromone and attractant treatments plus two controls were applied to 9-m long plots in a randomized complete block design experiment using ‘Draper’ blueberry. Treatments include: 1) Bee-Scent (Scentry Biologicals, Inc., Billings, MT), 2) Pollinate Pro (Instar Nuturals LLC, Yakima, WA), 3) Honey Bee Magnet (AgBio Inc., Westminster, CO), 4) SureSet-Apex (Fusion360, Inc., Turlock, CA), 5) Water control (treated with distilled water), and 6) No-water control. Honey bee visitation, fruit set, average berry mass, seed number, firmness, and °Brix were measured in 2018. Results show that Pollinate Pro had the highest honey bee visitation rate, while the no water control and SureSet-Apex had the lowest visitation rates. However, these differences were slight and may not be biologically or economically significant for growers. Fruit collected from Pollinate Pro treated plots were less firm than fruit from the water control, Honey Bee Magnet, and SureSet-Apex treatments. No differences in fruit set, seed number per berry, °Brix, nor fruit size were observed. The experiment will be repeated in 2019, but current data suggests commercial pheromones and attractants do not increase honey bee foraging and that growers should consider other strategies to improve pollination.