The Buzz on Alternative Pollinators in Vegetable Crop Production

LEXINGTON, South Carolina – With honey bee colonies continuing to decline, more producers are interested in adding alternative pollinators to the mix of their vegetable crop pollination systems.

Rawl Farms, a 2,000-acre vegetable farm in Lexington, S.C., has received an $8,530 Southern Sustainable Agriculture Research & Education (SARE) Producer Grant to use bumblebees to pollinate cucumbers.

David MacFawn, one of the farm’s beekeepers and the only Master Craftsman Beekeeper in the state, said the project is two-fold: to determine how well bumblebees pollinate cucurbits; and to increase cucumber yields by increasing the number of honey bee colonies from 1.5 colonies per acre to 3 colonies per acre – a process known as forced pollination.

“Bumblebees tend to pollinate crops differently than honey bees. They will pollinate in inclement weather and they pollinate earlier in the season than honey bees. We want to see just how well they will perform,” said MacFawn. “In addition, we want to determine if we can increase yields, thereby generating more dollars, by doubling honey bee colonies per acre. Then we’ll compare the two.”

One 2-5 acre field will be pollinated with three honey bee colonies per acre (approximately 20,000 – 30,000 honey bees per colony), and one 2-5 acre field will be pollinated with four bumblebee colonies per hectare (one hectare equals 2.4711 acres). The yields from the two fields will be assessed to determine the difference between honey bee pollination and bumblebee pollination. The same cucumber variety will be planted within days of each other in early May, in anticipation of pollination. Harvest will take place the end of May to the first part of June.

The cucumbers from each plot will be counted, weighed, and graded based on current grading standards. A comparison of the mean yields and their variances from the two fields will be conducted. Based on the statistical analysis, a financial analysis looking at the yields with respect to the variable cost will be conducted to determine the payback for honey bees and for bumblebees.

The goal, said MacFawn, is to determine if using bumblebees as alternative pollinators can produce a productive crop and be economically viable for area producers.

Other participants in the 2-year study, "Cucumber Pollination with Bumblebees," include Rawl Farms President Chris Rawl, beekeeper Wesley Boomer, and Clemson Extension associate J. Powell Smith. You can review a copy of the project, No. FS11-255, on the SARE database.

Southern SARE Producer Grants, one of the organization’s seven grant opportunities, allow farmers and ranchers to explore sustainable agriculture production research projects. The program not only helps them solve on-farm problems, but also allows them to share their results with fellow farmers and ranchers who face similar issues.

Read more about Producer Grants and how to apply for them.