Last updated 6/9/99 |
Table of Contents
Clark Throssell and Dan Weisenberger
Our objective was to show the historical performance of commonly used postemergence herbicides to control crabgrass.
The level of crabgrass control provided by a given postemergence herbicide varies from year to year. Why this variability in crabgrass control occurs is not completely known. It is important for professional turf managers to recognize that crabgrass control provided by a postemergence herbicide will vary from year to year and site to site.
Commonly used postemergence herbicides were applied to Kentucky bluegrass turf after crabgrass plants were growing. Percent cover by crabgrass was determined by visual rating in mid to late Aug each year.
- The crabgrass population varied widely from year to year as indicated by the percent cover by crabgrass in the untreated check (Table 1). The exact reasons for this are not known.
- Acceptable postemergence control of crabgrass can be difficult to achieve.
- Postemergence herbicides for crabgrass control are most effective when applied to young crabgrass plants.
Table 1. Crabgrass cover following treatment with postemergence herbicides from 1994-1998. |
||||||
% Crabgrass covera |
||||||
| Herbicide | Rate lbs ai/A |
1994 | 1995 | 1996 | 1997 | 1998 |
| MSMA 6L | 2.0 | 38.3 | 73.3 | -- | 6.7 | 10.0 |
| MSMA 6Lb | 2.0 | |||||
| Acclaim 1EC | 0.18 | 21.7 | 66.0 | -- | 20.0 | -- |
| Acclaim 1EC | 0.25 | 26.7 | 23.3 | -- | -- | -- |
| Dimension 1EC | 0.5 | 15.0 | 28.3 | 16.7 | 11.7 | -- |
| Check | -- | 78.3 | 97.0 | 90.0 | 36.7 | 25.0 |
| . | ||||||
| avisual rating of percent of plot covered by crabgrass. bSequential application made 4 weeks after initial application. |
||||||
Table of Contents
Send corrections, suggestions, and comments to biehlj@purdue.edu