Herbicide Study: Developing an Effective Chemical

Develop an effective herbicide protocol for the treatment of regrowing yaupon holly, following an initial mechanical treatment, for larger scale projects that cannot be accomplished with Individual Plant Treatment (IPT). Specific protocols goals are to-

1. Maximize yaupon holly mortality and/or suppression,
2. Minimize impacts on non-target herbaceous species (native grasses and forbs) and,
3. Minimize impacts on overstory trees.

The following four herbicide mixes which are considered effective for yaupon control in the post oak savannah ecoregion will be tested.

1. 1Triclopyr 3 (amine) mixed with a Non-Ionic Surfactant (NIS) + water. Applied at the highest recommended rate per acre.
2. 2riclopyr 3 + MSM (Metsulfuron-methyl) mixed with a Non-Ionic Surfactant (NIS) + water. Applied at the highest recommended rate per acre.
3. Triclopyr 4 (ester) mixed with MSO (Methylated seed oil) + water. Applied at the highest recommended rate per acre.
4. Invora mixed MSO-OS (with Methylated seed oil-organo silicate) + water. Applied at 36 oz per acre.

We mulched a 21.25-acre area at the Cedar Hill Nature Preserve. This area was carved out of undisturbed forest with a dense understory of mature yaupon. The area is laid out with 60 ¼-acre plots with buffer zones and access paths.