Hydrophobic Seed Coating
Faculty Mentor: Dr. Matthew Madsen, Plant and Wildlife Sciences
The western rangelands are the wide open spaces of American history. They are increasingly used as a recreational resource by millions of visitors each year. Rangelands produce tangible products such as forage, wildlife habitat, water, minerals, energy, plant and animal gene pools, recreational opportunities, and some wood products. There has been a history of rangeland degradation in the U.S. Because of this degradation, native plant species are not as dominant as they once were. Invasive plant species, such as cheat grass, have integrated into the precious rangeland system. These invasive species out compete and take over native plants. The overall goal of this study was to provide an advantage for native grass species over these invasive species. This was to be achieved by delaying imbibition and germination of the seedlings. This insures their survival through the winter and leads to their germination in the spring.
Treatments – There were 13 treatments in the study. Hydrophobic coatings were each administered at 6 different rates. The coatings were made of Ethocel. Some contained fungicide as well. Psuedoroegneria spicata (‘Wahluke’ bluebunch wheatgrass) seeds were coated with this hydrophobic coating the previous summer.
A randomized block design was created for two sites. These were BYU Spanish Fork farm and the greenhouse at BYU Provo. Each contained 10 blocks. There were 130 plots at each site. This was made up of 13 treatments in 10 blocks. The plots were in 3.5 meter long rows each 25 centimeters apart. Each row was labeled using a metal tag and nail.
Planting -Each row was planted using a push cone seeder. For each treatment within a block, 2 seed bags were buried 1.5 centimeters deep. The seeds bags contained 25 seeds each. These seed bags were dug up at the end of January. They were counted for germination immediately after being pulled up from the ground. In June 2017, the seeds planted in the rows will be counted.
The results from the greenhouse at BYU were not expected. It was hypothesized that a seed with a higher rate of ethocel would germinate less. At the greenhouse there seemed to be no real correlation between germination rates and the rate of the coatings. The results of the study at the Spanish Fork farm were more in line with the original hypothesis. The seeds coated with rate 6 germinated the least amount and seeds coated with rate 1 germinated the most. The control group out germinated all of the coated seeds.
Further research will be necessary in order to improve the hydrophobic coatings, especially in low-elevation areas.
The hydrophobic coating showed some benefit at Spanish Fork but not in Provo. Overall the coatings broke down too early as a result of an early hard freeze followed by a warm period in the middle of December that allowed the seeds to germinate. A next step to be taken in this experiment is to add plasticizers into the coating so it can withstand freeze-thaw events early in the winter period.
While it is necessary to do more research, the results from the Spanish Fork site conclude are promising. The hydrophobic coated seeds did in fact work to delay germination. This is a huge benefit in rangeland restoration. If native grasses can be given an advantage over the invasive grasses, restoration rates will boom. This will be a much more cost-effective method for restoration efforts and will provide desired results.