Cup Plant

Silphium perfoliatum

General info

Native to the North American prairies (Centre and East of USA and Canada), S. perfoliatum has spread all around the world, being extensively grown for forage in China (Zhang et al., 2010). Of a lush foliage and yellow flowers, it is an attractive decorative plant, reason it was brought to Europe in the 18^th century (Kowalski and Kȩdzia, 2007). This species is known for its fast development, production of high annual yields, great tolerance to adverse situations, copious seeding, and straightforward cultivation in general (Zhang et al., 2010).

Part of the daisies family (Compositae/Asteraceae), S. perfoliatum can reach heights of up to 4m tall. On the base, leaves have a chordate to triangular shape, growing alternate. On the stem, coarsely toothed leaves grow opposite, are connate-perfoliate, and have a triangular to ovate shape. Yellow flowers bloom from July to September (Gansberger, et al., 2015).

Cultivation and agronomy

It prospers in riparian woods and edges, as well as abandoned farmland. S. perfoliatum can be established both from seeds (2.0-2.5 kg/ha) and seedlings (40,000 seedlings per ha), it prefers partially sunny to sunny locations, receiving a minimum 400-500mm of precipitation per season. Optimum fertilisation has been estimated to 120-90-90 NPK but it can also be grown without the application of any fertiliser, producing lower yields. Mechanical weeding during the first two years of growth is essential and afterwards advised. During the first year of growth, S. perfoliatum only develops a rosette of leaves on the ground. Harvest can begin on the second year of cultivation and should be done in summer when DM yields are about 30%, often using a maize harvester. Single and double harvests are possible, potentially increasing yields with the latter. Average mature dry matter yields are in the range of 16 t DM ha^-1, remaining in full production for 15 years.

Uses

Currently, S. perfoliatum is mainly used as feedstock in anaerobic digestion systems and as forage for cattle. Green biomass is often ensiled to maximise biogas production. Methane yields vary between 227-315 dm³ kg oDM (Haag et al., 2015; Schittenhelm et al., 2016). Alternative uses of S. perfoliatum include forage and fibre, bioremediation, production of an array of essential ingredients for the chemical, pharmaceutical, agrochemical, and food industries. S. perfoliatum promotes a rich-in-biodiversity habitat both above and below ground, supports pollinators with pollen and nectar during a long blossoming season, can contribute to soil health regulation, and carbon sequestration.

Additional Resources