Huisache (Acacia farnesciana) is a major brush problem in South Texas. Although herbicide individual plant leaf sprays provide very high plant-kill levels (greater than 76%), the same herbicides have not proven reliable when applied as broadcast treatments, either ground or aerial. A fairly specific set of biotic and abiotic indicators are available for broadcast treatments of honey mesquite (Prosopis glandulosa). However, similar indicators are not available for huisache. During 2013-2014, aerial and ground broadcast herbicide treatments were applied to 7 sites. Soil temperature and soil moisture were measured at a depth of 12 inches at the time of herbicide application. Plant-mortality was measured at one and two years post treatment. For aerial sites, plant mortality was stratified by height (above and below 7 feet tall). Across all aerial treatments, plant mortality was significantly greater (p=0.000158 and p=0.000198) for plants under 7 feet tall during 2013 and 2014, respectively. For 2013 sites, there was a linear relationship (r2=0.99, p=0.025) between soil moisture and two-year plant mortality. Across all ground broadcast treatments, 2013 plant mortality was significantly greater (p=0.0208) than 2014. Soil moisture at application was 8 versus 2 (0 to 10 scale) for 2013 and 2014, respectively.
Oral presentation and poster titles, abstracts, and authors from the Society for Range Management (SRM) Annual Meetings and Tradeshows, from 2013 forward.