Drought-induced effects on buckwheat (Fagopyrum esculentum) floral traits and honey bee visitation

Authors: MALLINGER, RACHEL - University Of Florida; Rering, Caitlin; Franco, Jose; Beck, John

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/4/2018
Publication Date: 8/20/2018
Citation: Mallinger, R.E., Rering, C.C., Franco Jr, J.G., Beck, J.J. 2018. Drought-induced effects on buckwheat (Fagopyrum esculentum) floral traits and honey bee visitation. 256th American Chemical Society National Meeting. pg.1.

Interpretive Summary: Droughts are expected to worsen in the future, potentially negatively affecting many important crops and helpful insects, like honey bees. These effects are not understood. Buckwheat plants are grown to support honey production by honey bees. In this study, buckwheat plants were grown under three watering treatments, ranging from low to very extreme drought stress. Floral scent, nectar volumes and nectar sugar content were evaluated. Then, plants from all watering treatments were simultaneously offered to honey bees for foraging. Understanding the effect of drought on nectar quality and availability and honey bee behavior will help farmers select plants that remain viable and supportive to honey production under drought conditions.

Technical Abstract: Buckwheat is commonly grown as a honey plant because of its long-flowering period, generous, stable standing nectar crop, and attractiveness to honey bees. Abiotic stressors such as drought can modify a variety of floral traits, including nectar chemistry and volume, and floral scent and density. Droughts are predicted to increase in severity and duration, thus a richer understanding of the effects of drought on plant floral traits, and subsequent effects on plant-pollinator interactions, is needed. To evaluate the effects of drought on buckwheat floral traits, plants were grown under controlled greenhouse conditions with three water regimens: well-watered, moderate drought stress, and extreme drought stress. Floral volatiles were identified and analyzed by gas chromatography mass spectrometry, while nectar volume and carbohydrate content was evaluated by liquid chromatography evaporative light scattering detection. To compare honey bee affinity between drought stressed treatments, plants from all three treatments were placed nearby an apiary, where honey bee visitations were observed. After the observation period, plants were excluded from further pollinator visitation and allowed to set seed to evaluate crop yield potential and plant fecundity.