Location: Soil Management ResearchTitle: Spring-sown oilseeds provide pollinators with abundant floral resources
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/5/2014
Publication Date: N/A
Technical Abstract: The Northern Great Plains (NGP) is the most important region in the USA for the production of honey and transient honey bee colonies. However, floral resources to support such colonies between May and October are limited. This limitation affects subsequent over-winter survival when the colonies are employed in California, Texas, and other southern states. Diverse, summer-flowering oilseed crops that are adapted to NGP may provide more and better nutrition to these colonies than the limited floral resources currently available. We examined flowering times and pollinator visitations of eight spring-sown crops: borage, calendula, camelina, canola, crambe, cuphea, echium, and flax. Sowing dates were varied (May, June and July) to explore effects on anthesis as well as seed yield. Early-sown camelina and canola could flower abundantly as soon as June. Late-sown calendula could flower throughout October. Volunteer canola (from August-harvested plants) flowered and attracted pollinators until early November. Pollinators were numerous, often 60 per minute of observation, on all crops except crambe and flax, which attracted few insects during anthesis. Flowers of borage and echium were especially attractive to pollinators. Honey bees often represented half of the observed pollinators. Native pollinators tended to be more common, proportionally, on calendula, camelina, and crambe, but all oilseed species attracted a wide diversity of insects. Seed yields tended to be highest for early-sowings. Thus, a balance must be sought by growers between early sowing coupled to high seed yields and adaptive sowing that extends anthesis and supports pollinators.