Whitetail News Vol 30.1

Page 44

The WEED DOCTOR

By W. Carroll Johnson, III, PhD.,, Weed Scientist and Agronomist

Site Preparation Weed Control:

The Starting Point, Not an Afterthought

S

ome weeds are not effectively controlled in food plots, and there is nothing in my bag of tricks to help. Herbicides for forages are limited, and multi-species forage blends complicate use. That might sound like a position of weakness coming from a career weed scientist, but it is undeniable. Knowing our weed-control limitations, successful management begins before forage seeds are planted. Additionally, new food plot locations are often in remote sites or where hunters have no prior experience, creating a Pandora’s box of weedy unknowns. Preparing the site for a food plot requires a proactive plan and intensive effort. Site preparation weed control begins at that time, weeks or months before planting. This is an essential step in the successful shortterm and long-term management of troublesome weeds in food plots.

New food plot sites can be along old logging roads, ramps or any grown-up clearing large enough for a food plot. Regardless of the recent land use, there will be a proliferation of competitive plants in those areas, including briars, blackberry, vines, trumpet creeper and dozens of species of deciduous tree saplings sprouting from old rootstock. There are also the typical perennial competitors, such as common bermudagrass, quackgrass, johnsongrass, broomsedge and nutsedges.

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Figure 1. Greenbriar is an example of a perennial weed that commonly infests new food plot sites. The perennating rootstock (that is, bulbs) defies control efforts. Tillage to chop the rootstock and systemic non-selective herbicides are synergistic in controlling perennial weeds such as greenbriar.

Mowing and Tillage Mowing, which includes heavy-duty mulching using tracked vehicles, is a logical first step. Mowing or mulching rough areas will not kill saplings or any other perennial weed. However, mowing weakens perennial weeds, which greatly improves future weed-control efforts. Mowing enhances tillage by shredding the tops of tall plants improving the function of any tillage implement. Mowing also stimulates succulent regrowth, which is often more susceptible to herbicide uptake than older, tough foliage. This is an essential step for successful herbicide performance. Initial tillage of rough non-improved sites is difficult and must be carefully conducted to prevent damage to equipment. This is a case where large (heavy-duty) disk harrows are the preferred choice. Harrow size refers to diameter of harrow blades and robustness of the www.whitetailinstitute.com