||Marestail (Conyza canadensis) is a common invasive plant of no-tillage crop systems and can potentially cause crop losses. Infestations of marestail could also have negative effects on the
establishment of native grasslands. I evaluated the effectiveness of post-emergence applications of 2,4-D amine, triclopyr, and mowing to marestail in a dormant season planting to establish native warm-season grasses (NWSG) at Key Cave National Wildlife Refuge in northwest Alabama. The entire study area, including the control plot, was treated with imazapic at 0.07 kg ai/ha (4 oz/ac) during April. Marestail control treatments (2,4-D at 0.28 kg ai/ha [16 oz/ac];
triclopyr at 0.28 kg ai/ha [16 oz/ac]) and mowing (0.46 m [18 inches] above ground surface) were applied to 2.02 ha (5 ac) treatment plots during July 2000. Five 1-m˛ plots were sampled at the time of treatment, fall 2000, and during summer and fall 2001 to determine marestail control and establishment of NWSG. ANOVA and Fisher’s Protected LSD Test were used to detect differences in total vegetative canopy cover (%), plant cover by species (%), planted NWSG
cover (%), bare ground (%), and plant species richness (species/m˛) among treatments. All treatments provided some degree of marestail control during the study. Marestail coverage was less (P = 0.0004) in the triclopyr plot than all other plots during fall 2000. During July 2001, marestail coverage was reduced (P = 0.054) in the mowing and 2,4-D amine plots. By fall 2001, marestail coverage was reduced in all plots, including the control plot, indicating that as NWSG
became established, they quickly became the dominant vegetation in the study plots. This dormant season planting established NWSG in one to two growing seasons.