Setaria glauca, annual grass weeds, belongs to Setaria. Usually its stem is purplish red and flat like Barnyard grass. So many people take it as Barnyard grass with red stem. But the biggest difference between them is the connection part of the leaf and the leaf sheath. Setaria glauca has cilia-like ligule, but all kinds of the barnyard grass don’t have. Its main spike usually is shorter and smaller than green bristlegrass.
Control strategy:
For Setaria glauca in broad-leaf crops, can use sulfonyolurea herbicides like Quizalofop-p-ethyl, Haloxyfop-P-methyl, Clethodim, etc.;
In Maize field, it’s better to use Nicosulfuron+Atrazine(with safner) or Topramezone+Atrazine(not has good effect for Crab grass), no suggest to use Mesotrione herbicides because the green bristlegrass has natural resistance to the Mesotrione.
It’s difficult to control the Setaria glauca in the upland direct-seeding rice. Metamifop with some Cyhalofop-butyl works.
Bispyribac-sodium has good result for Barnyard grass and Paspalum distichum L., but doesn’t have satisfied result for Setaria glauca.
Cyhalofop-butyl with Fenoxaprop-P-ethyl has good result, but should apply after 4-5 leaves of the rice. At the same time, pay attention to increase Fenoxaprop-P-ethyl’s usage following with the rice age.