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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Sunflower Improvement Research » Research » Publications at this Location » Publication #423120
Research Project: Sunflower Yield, Crop Quality, and Interactions with Biotic and Abiotic Stressors

Location: Sunflower Improvement Research

Title: Aerodynamic properties of silflower seed (Silphium integrifolium): Effects of moisture content and seed morphology

Author
item JAMMEH, PA TAMBA - North Dakota State University
item Hulke, Brent
item Prasifka, Jarrad
item SUN, XIN - North Dakota State University
item MONONO, EWUMBUA - North Dakota State University

Submitted to: Journal of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/11/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Development of new oilseed crops that provide added value to farmers may have some barriers to adoption. For one such crop, silflower, the seeds are difficult to separate from chaff in harvesting equipment, including combines. However, improvement of seed characteristics by plant breeding could improve harvestability. This work used an air column apparatus to measure the terminal velocity and other related measures of two types of silflower seeds at various moisture contents. The results indicated that seeds without papery wings showed the best promise for improved seed separation in combines. This apparatus can also be used in future studies to further optimize breeding for harvestability.

Technical Abstract: Silflower (Silphium integrifolium), a perennial wildflower native to the central United States, is a potential sustainable oilseed crop due to its drought tolerance and deep root systems. Growing this species at scale requires a better understanding of aerodynamic properties of the seed, which are crucial for handling and processing during and after harvesting. This study investigates the effects of moisture content (ranging from 10% to 15% d.b.) on the terminal velocity, drag coefficient, and Reynolds number of two Silphium seed accessions: CP-16 (with wing-like features) and SP-16 (without winglets). A custom-built vertical column unit was constructed and used for the experiment. The results showed that terminal velocity increased linearly with moisture content for both accessions (SP-16: 4.78-6.43 m/s; CP-16: 2.39-3.16 m/s). The winged morphology of CP-16 contributed to lower terminal velocities, demonstrating advantages in natural dispersal but potential challenges in mechanical processing. Drag coefficients showed complex interaction with moisture content, decreasing for CP-16 but varying inconsistently for SP-16. The Reynolds numbers increased with moisture for both accessions, indicating changes in flow dynamics. Analysis of variance confirmed significant effects of moisture content and accession type on aerodynamic properties (p < 0.0001). The findings have implications for breeding programs aimed at optimizing seed traits for mechanical harvesting and processing. The wingless SP-16 seeds, with their higher terminal velocity and bulk density, may process more efficiently with standard combines and threshers. These insights are pivotal for advancing silflower research programs.