The response of four growth stages of Setaria glauca (L.) Beauv. (yellow foxtail), Eleusine indica (L.) Gaertn. (goosegrass), and Dactyloctenium aegyptium (L.) Richt (crowfootgrass) to dimethylarsinic acid (cacodylic acid) applied at rates of 0.25, 0.5, and 1.0 lb/A was studied.
The four growth stages for chemical treatments were generally: (a) early tillering, (b) late tillering, (c) boot, and (d) post-heading. Seed production was reduced by as much as 96% in yellow foxtail, 80% in goosegrass, and 37% in crowfootgrass. Application of the chemical at the “boot” stage was most effective although earlier applications also were effective. Inflorescences often were malformed. Other growth effects suggested a growth regulator type activity.