Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 3, 2005
Publication Date: April 16, 2005
Citation: Hendrickson, J.R., Lund, C.B. 2005. Control of smooth brome and Kentucky bluegrass using fire and fire plus chemical in the northern Great Plains. Abstract. Presented at the Invasive Species Workshop on April 5-7, 2005, Bismarck, ND. Technical Abstract: Smooth bromegrass and Kentucky bluegrass are two non-native invasive grasses on rangelands in the Northern Great Plains. The responses of smooth bromegrass and Kentucky bluegrass to a spring burn and a spring burn plus a spring application of imazapic were compared on an invaded 16 ha grassland at the Northern Great Plains Research Laboratory near Mandan, North Dakota. This grassland had not been grazed or hayed for approximately 15 years prior to the study. Ten sites were identified within the grassland in 2002 based on species composition and degree of invasion. Within each site, three plots (10 x 20 m) were established and randomly assigned to one of two treatments or a control. Treatments were 1) a late-April burn or 2) a late-April burn followed by an application of imazapic (6 oz ai acre-1 when the smooth brome was 10 - 15 cm tall. Three 1/8 m quadrats were established in each plot and total number of tillers of smooth bromegrass, Kentucky bluegrass, other invaders and native grasses and forbs were counted in the fall of 2002 to determine species composition. This was repeated in July 2003. Percent smooth bromegrass increased and percent Kentucky bluegrass decreased in all treatments and controls during this time period. The burn plus imazapic significantly decreased the percent Kentucky bluegrass and significantly increased percent native grasses compared with the control. There were no significant differences in the percent native forbs or other invaders among treatments. Visual observation indicated application of imazapic following a burn reduced forage production on sites dominated by cool-season native grasses. This study is still ongoing and treatments were reapplied in 2004 and will be again in 2005.