Silphium integrifolium is a perennial plant in the sunflower family native to the Great Plains and other parts of North America.
The Land Institute is domesticating silphium, which has the potential to be at least as productive as the oilseed sunflower in favorable environments.
Why Perennial Oilseeds?
- During the dust bowl years, American botanist John Weaver noted how well silphium survived in Nebraska under extreme drought. Silphium’s long, strong roots penetrate very heavy clay soil that challenges many other species. Therefore, silphium has the ability access groundwater (when present) at depths upwards of 4-6 feet thereby eliminating the need for frequent irrigation. Silphium is much more resilient to short-term droughts (from weeks to a couple of years) than annual crops.
- Silphium also provides good habitat for earthworms, hoverflies (pollinators and aphid-eaters), native bees, Monarch butterflies, and honeybees.
- Because it does not spread and uses water and nutrients at different depths, Silphium is a strong candidate for intercropping systems and is expected to provide soil protection and carbon sequestration.
In 2001, David Van Tassel began collecting wild silphium seed. By 2003, he had integrated silphium integrifolium into his research with several other perennial oilseeds. Silphium’s surprisingly good performance during drought in 2013 drove a shift in focus to this deep rooted species.
Below are the short and long term goals for perennial oilseeds, bred by an international network of breeders in different climates, latitudes, and soil types around the world.
- Long-term, the goal is for perennial silphium to partially replace annual oilseed crops such as sunflower, canola and soy. It may also become commercially viable in drought-prone environments that lack access to irrigation water, and in regions outside the range of native silphium pests and diseases (for instance, in parts of Argentina). We anticipate that silphium, by 2025, may be able to achieve yields high enough for commercial production (particularly in the gourmet or environmentally labelled markets of edible vegetable oil). Our long-term vision, the displacement of oilseed sunflower and canola in North America, may require another decade or two of intensive plant breeding.
- Our near-term goal is to learn how to harvest efficiently and keep plants healthy through improved plant nutrition and pest control. This includes breeding for rust-resistance, improving understanding of insect pests, collecting new wild germplasm, and making hybrids between silphium species and ecotypes. Day-to-day activities include:
- Advancing our silphium populations through the breeding cycle. Every cycle is a big chance to bring together genes we need and to break up associations between useful genes and unhelpful ones.
- Identifying key indicators on how this species responds to new situations. New experiments are usually needed to confirm such observations.
- Identifying how to germinate seeds more quickly. Doing so will speed up future research.
- Continue working with a growing group of collaborators. We supply collaborators with seeds and data so that the work can continue in multiple states and countries, and so that young scientists have a chance to become passionate about domestication and plant breeding.
Makaneyyat Project Ramallah, Palestine
Museo Paleontológico Egidio Feruglio (MEF) Trelew, Argentina
Universidad de la Republica Montevideo, Uruguay
University of Bonn, Germany
Kansas State University, Manhattan, Kansas
Northwest Research and Extension Colby, Kansas
Red River Valley Agricultural Research Center, USDA-ARS Fargo, north Dakota
Saint Louis University and Missouri Botanical Garden St. Louis, Missouri
University of Colorado, Boulder, Colorado
University of Manitoba, Canada
University of Minnesota, St. Paul, Minnesota
University of Vermont, Burlington, Vermonnt
University of Wisconsin, Madison, Wisconsin
USDA Soil Erosion Lab Fayetteville, Arkansas
Join us by supporting this work with a donation to The Land Institute!
The Land Institute’s Perennial Oilseeds research technician, Sydney Schiffner, walks us through a day in…
Related Scientific Publications
Balancing Forage Production, Seed Yield, and Pest Management in the Perennial Sunflower Silphium integrifolium (Asteraceae)
Abstract The perennial sunflower Silphium integrifolium Michx. (Asteraceae), also known as silflower, is a prospective dual-purpose forage plus grain crop. Pre-flowering biomass harvest for animal feed and the subsequent delay…
Assessment of the biogeographical variation of seed size and seed oil traits in wild Silphium integrifolium Michx. genotypes
Silphium spp. have garnered interest in Europe as a bioenergy crop and in North America as a perennial oilseed crop. However, very little has been done at this early stage of…