Location: Great Basin Rangelands ResearchTitle: Seed moisture content and forage kochia (brassia prostrata) seed viability
Submitted to: Society for Range Management
Publication Type: Abstract Only
Publication Acceptance Date: 1/5/2022
Publication Date: 2/22/2022
Citation: Harmon, D.N., Clements, D.D. 2022. Seed moisture content and forage kochia (brassia prostrata) seed viability. Society for Range Management. 75:82.
Technical Abstract: One of the most profound plant community changes in the Great Basin is the conversion of big sagebrush (Artimesia tridentata) communities to cheatgrass (Bromus tectorum) dominance. Increasing wildfire threats due to cheatgrass fine fuels consumes sagebrush habitat every year. A valuable tool to both create fire breaks and mitigate lost shrub resources is forage kochia (Bassia prostrata). Two releases are widely used in the Great Basin, ‘Immigrant’ (Bassia prostrata spp. virescens) and ‘Snowstrom’ (spp. grisea). The earlier released, ‘Immigrant’ (1984) can have highly varying short lasting seed viability. The more recent ‘Snowstorm’ (2012) has larger seeds and reports of more consistent seed viability. We were interested what role, if any, seed moisture content plays in predicting seed viability. Proper seed moisture content is known to be important for seed storage. We designed an experiment using three sources of both cultivars and stored them at three temperatures (0C, 20C and “shed” storage) for two years and measured seed moisture content and germination. Looking at all data points (all sources, both cultivars, all storage temperatures) seed moisture was a poor predictor of seed viability (R2 = 0.2294). Analyzing cultivars separately, seed stored at 0C had higher germination rates (‘Immigrant’ 25%, ‘Snowstorm’ 52%) than 20C or “shed” storage (‘Immigrant’ 5%, ‘Snowstorm’ 17%) and was correlated with higher seed moisture (> 6% vs. < 5% moisture). Interestingly, when analyzing among seed sources within each storage temperature, we observed the opposite, higher seed moisture correlated with lower germination for ‘Snowstorm’ forage kochia (0C storage: R2 = 0.9935, 20C storage: R2 = 0.9732, “shed” storage: R2 = 0.9732). No correlation was found with ‘Immigrant’ among seed sources (R2 < 0.4). These results indicate that proper seed moisture (6-7.5%) plays a role in maintaining seed viability but is a poor predictor of viability between seed sources.