Abstract

Native plants offer numerous ecological benefits and opportunities for both rangeland restoration and urban landscaping, making their integration essential for building sustainable ecosystems. They enhance soil health, promote pollinator activity, increase microbial diversity, and support both wildlife and livestock, all of which contribute to overall ecosystem resilience. A promising strategy to improve the use of native plants is the application of seed enhancement technologies, which can optimize seed germination, improve seedling establishment, and enhance overall plant success in challenging environments. These post-harvest seed treatments incorporate materials that improve seed performance, often through coatings composed of binders, fillers, and active ingredients. This thesis examines how seed enhancement technologies can improve native plant restoration in rangelands and facilitate their integration into urban landscapes. Specifically, we focused on the development of seed enhancements for winterfat (Krascheninnikovia lanata), Wyoming Indian paintbrush (Castilleja linariifolia), and Rocky Mountain penstemon (Penstemon strictus). Chapter 1 investigates the application of a hydrophobic polymer seed coating to winterfat to regulate germination timing by delaying fall-planted seeds until spring germination. We developed and tested three hydrophobic coatings and compared their effectiveness to a hydrophilic coating (Blank, which served as the control) using one-year-old seeds (collected fall 2022) and recently harvested seeds (collected fall 2023). Seeds were planted in fall 2023 in Utah and Nevada and evaluated the following spring, early summer, and late summer. The effectiveness of the hydrophobic coatings varied by site. In Utah, favorable conditions allowed the hydrophobic coatings to delay germination and potentially improve seedling establishment (P < 0.0001). However, environmental conditions in Nevada led to low seed germination, and the hydrophobic coatings had minimal effect. Seed population had the greatest influence on seedling emergence and survival, with recently harvested seeds having significantly higher success than one-year-old seeds (P < 0.0001). Chapter 2 examines a seed conglomerate of Wyoming Indian paintbrush and Rocky Mountain penstemon to improve Indian paintbrush establishment success. These forb species are often excluded from seed mixes due to their small size, and Indian paintbrush, as a hemiparasitic plant, requires a host to thrive. To address these challenges, we grouped the two species into a conglomerate and compared their performance to untreated (control) and agglomerated seeds, where single species were clustered together. In a greenhouse study, both the agglomerate and conglomerate treatments resulted in the emergence of both species, whereas only penstemon emerged in the control. Overall, the agglomerate treatment yielded the highest emergence compared to the conglomerate and control (P = 0.0008 and P < 0.0001). Microscope analysis of treated groups confirmed the development and attachment of haustoria, the specialized structures enabling parasitic connections. These results indicate that seed conglomeration and agglomeration can improve Indian paintbrush establishment, and that these seed enhancement techniques may be applicable to a wide range of other small-seeded forbs.

Degree

MS

College and Department

Life Sciences; Plant and Wildlife Sciences

Rights

https://lib.byu.edu/about/copyright/

Date Submitted

2025-04-22

Document Type

Thesis

Handle

http://hdl.lib.byu.edu/1877/etd13631

Keywords

hydrophobic, Rocky Mountain penstemon, seed coatings, seed conglomerate, winterfat, Wyoming Indian paintbrush

Language

english

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