Over the course of a year, two plots on the lawn were studied, each approximately 969 square feet in size. In the first plot, a notched hand spade was used in January to uproot 95 privet seedlings, exhuming the entire canopy and root structure. Predominant plants in this plot (listed in approximate order of abundance) included: Little bluestem, Rescuegrass, Carolina dichondra, Mouse-ear chickweed, Mallow, Dandelion, Buckhorn plaintain, Henbit, and Pale seed plaintain.
In the second plot seedlings were chemically treated by hand spraying with glyphosate solution. Predominant plants in this plot (listed in approximate order of abundance) included: Rescuegrass Bluestem, Henbit, Mouse-ear chickweed, Carolina dichondra, Dandelion, Sticktight buttercup, Ragweed, and Wild onion. A fourth, control category of 26 seedlings was not chemically treated.
Established a week later, the chemical plot had 104 seedlings, including 26 in each of four categories: (1) control, not sprayed; (2) sprayed with 1% glyphosate; (3) sprayed with 3% glyphosate; and (4) sprayed with 5% glyphosate. Plants were sprayed once, on January 26, 2019, with approximately .4 fluid ounces of fine mist, enough to saturate the exposed canopy and stem.
Plant survival was assessed periodically, and the study concluded at the end of January this year. For various observation dates, a one-way chi-square was used to evaluate differences in observed versus expected numbers of plants surviving among: (a) all four categories (control and three chemical treatments); and (b) the three treatments. Tests for significance used a probability (p) level of 0.01.
Results & Conclusion
None of the mechanically-removed plants returned, whereas the chemically-treated plants died off at varying times (Table 3). Initial mortality in sprayed plants was observed after 2.6 months. However, no significant difference in survivability among all four categories occurred until 4.3 months; at that time, fewer than half of the seedlings were alive in each of the sprayed treatments. Significant differences in survivability among all four categories persisted over the remainder of the study (Table 3). After 9.2 months until the end of the study, all sprayed plants died while 20 control plants survived. No significant difference in survivability was observed between the three sprayed categories during the study.