- The resistant levels of 29 populations of barnyardgrass(Echinochloa crus-galli) in Hunan province and in the other provinces to quinclorac were determined with agar method.
- The biotypes of quinclorac-resistant barnyardgrass in Anxiang county and in Chede county of Hunan province were negative cross-resistance to butachlor with agar method and with litter cup method.
- The method seems good but it needs to be tried out.
- MICs were determined by an agar dilution method.
- I can't claim infallibility for this method.
- Summer fallow is the best method of destroying weeds.