courses in the United States apply PGRs ( Shaddox et al. 2023a ). Imazapic is an acetolactate synthase inhibiting herbicide used for pre- and postemergence control of grassy and broadleaf weeds in various systems, including maize, rangeland, pasture, and
-of-way. Fig. 1. Hollow pecan kernels following soil application of imazapic within the root zone of pecan trees. Imazapic is a popular postemergence herbicide used in peanut fields early in the growing season to control various broadleaf weeds, grasses, and
that it is an unnecessary expense. The selective herbicide imazapic, for example, can enhance the establishment of tolerant wildflower species ( Beran et al., 1999 ), but effects can vary by site and species ( Frances, 2008 ) as well as by weather
Native wildflowers are important components of grassland communities and low-maintenance wildflower seed mixtures. Weed interference limits successful establishment of native wildflowers from seed. Experiments were conducted to determine the influence of the imidazolinone herbicides imazethapyr, imazapic, and imazaquin on the establishment of blackeyed susan (Rudbeckia hirta L.), upright prairieconeflower [Ratibida columnifera (Nutt) Woot. and Standl.], spiked liatris [Liatris spicata (L.) Willd.], blanket flower (Gaillardia aristata Pursh.), purple coneflower [Echinacea purpurea (L.) Moench.], and spotted beebalm (Monarda punctata L.). Wildflower response to the herbicide treatments was variable and appeared to be influenced by the level of weed interference. Establishment of the native wildflowers after application of imazethapyr or imazapic at 70 g·ha-1 a.i. was generally improved at sites with greater weed interference. Emergence and density of wildflowers was often reduced by imazapic in sites with low weed interference. Flower density during the second growing season was usually either improved or not reduced by either imazethapyr or imazapic. Based on these findings, imazethapyr and imazapic can reduce weed interference and improve the establishment of some native wildflowers in areas with high weed infestations. Chemical names used: (±) -2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-methyl-3-pyridinecarboxylic acid (imazapic); 2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-quinolinecarboxylic acid (imazaquin); 2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-ethyl-3-pyridinecarboxylic acid (imazethapyr).
-applied Imazapic Inhibits Pecan Production A persistent problem was identified in pecan orchards throughout southern Georgia in which pecan trees growing in rows immediately adjacent to peanut fields developed hollow pecans. In-shell nut size and appearance was
Grassland legume establishment with imazethapyr and imazapic Agron. J. 91 592 596 Beran, D.D. Masters, R.A. Gaussoin, R.E. Rivas-Pantoja, F. 2000 Establishment of big bluestem and Illinois bundleflower
and herbicides: glyphosate (1.12 L a.i./ha; Chemical Products Technologies, LLC, Cartersville, GA), imazapic (70.6 g a.i./ha; Makhteshim Agan of North America, Inc., Raleigh, NC), and clethodim (0.15 L a.i./ha; Valent U.S.A. Corp., Walnut Creek, CA