2019 ASHS Annual Conference

Previous work on the attractiveness of annual flowers to pollinators promoted the question about how this information could be used to improve crop yields. In this study, we asked the question “Would self or wind pollinated crops produce better if pollinator-attractive flowers are planted nearby?” Ace peppers were the chosen crop because they are primarily pollinated by wind, relatively easy to grow and have minimal pest issues. Literature reviews found out that large bees (bumble, honey) were the primary insect pollinators on peppers. I selected three annual flowers in my previous study that were shown to attract honey, bumble and other native bees on some level and demonstrated continuous bloom: Showstar butter daisy, Double Click cosmos, and Orange Fudge Rudbeckia. Twelve of each variety were together as a single planting adjacent to 36 Ace bell peppers. The 18 peppers closest to the flowers were open to pollinators while the other 18 peppers were covered with exclusion fabric that prevent insect pollination. Crops were planted at three sites: the Minnesota Landscape Arboretum (Chaska MN), the University of Minnesota North Central Research and Outreach Center (Grand Rapids, MN) and the Ottertail County fairgrounds (Perham, MN). A half-sized planting was established in a raise bed in the Horticulture Display Garden (St. Paul campus) as a demonstration site for Gopher Adventures youth day camp. Complete data was only obtained and reported from Grand Rapids and the Arboretum site. Peppers were harvested when they started to ripen – a visual indication they had reached their mature size. The fruit was counted, measured and weighed to determine an average fruit weight for that harvest. Being that seed development is an indicator of good pollination, seeds were extracted from harvested fruit and weighed and an average seed count per fruit was obtained. Data for the excluded plants at Grand Rapids and the Arboretum were combined, and data for the open plants (open to pollination) for these two sites were combined. The results demonstrate pollinator interaction improves bell pepper harvest. This information supports the value of planting pollinator-attractive flowers near / adjacent to wind-pollinated or self-fertile crops.