Effectiveness of Chemical and Mechanical Management on Gypsophila Paniculata L. in Conservation Reserve Program, Rangeland, Pasture, and Hayland Acres

Abstract

Gypsophila paniculata L., commonly known as baby’s breath, is a highly adaptive, perennial plant introduced to North America for ornamental purposes as early as 1887. While still used extensively in the floral industry, G. paniculata has high reproductive and dispersal potential, is considered a naturalized garden escape, and is listed as a noxious weed in some states and Canadian provinces. The invasion of G. paniculata in rangeland, pasture, Conservation Reserve Program (CRP) acres, and haylands throughout northeastern Montana has adverse ecological and economic implications. Precipitation events and the increase in CRP acres are believed to have advanced the spread of G. paniculata. This study investigates herbicide and mowing options in perennial acres north of Peerless, Montana, near the Canadian-U.S. border, using a split plot randomized complete block design with three replicates. Three different herbicides applied in the fall, spring, or fall and spring, and a non-sprayed control were applied for a total of 10 treatments. The herbicides tested included imazethapyr (Pursuit®); dicamba (Opti-DGA™); and metsulfuron methyl (Omni® Brand MSM 60 DF). The split plot included non-mowed or mowed to simulate dryland haying operations utilized by producers in the region. Herbicide treatments containing the active ingredient metsulfuron methyl significantly reduced the density of G. paniculata at the end of the study, strongly indicating that active ingredient is more important than timing. Mowing had no effect on density of G. paniculata and did not interact with herbicide treatment. Perennial grass cover was not affected by herbicide treatment. Perennial grass cover did not differ among herbicide treatments, indicating that there was no collateral damage of grass associated with herbicide applications. Based on the results of this study, I recommend the spring application of metsulfuron methyl used in this study to reduce the density of G. paniculata in rangeland, pasture, CRP acres, and haylands. I do not recommend mowing or haying as standalone treatments for G. paniculata, as mowing does not affect the density of G. paniculata. Furthermore, if admissible for the site, mowing or haying operations should take place before the flowering stage to effectively inhibit seed production.