Assessing population yields and developing an agronomic cropping system for Silflower (Silphium integrifolium), a perennial oilseed crop

Abstract

Silphium integrifolium Michx. (silflower) is a perennial forb native to the central United States that is currently being domesticated as a potential oilseed crop. It has deep roots, large seeds relative to other native perennials, and can produce 9.5 Mg ha-1 of biomass (Schiffner et al., 2020). We compare seed yield of ten silflower populations, two collected from wild germplasm, one from initial domestication work at the Land Institute in Kansas, and seven populations selected at the University of Minnesota. One population, MN4, had significantly higher seed yields (593.7 kg ha-1) than the wild populations (247.8 and 255.1 kg ha-1). Additionally, we evaluate the potential of silflower in a dual-use oilseed and forage cropping system by comparing biomass collected at four dates early in the growing season to mimic mowing. Silflower has potential as a dual-use crop, but there are tradeoffs between forage and seed production.