Germination and Herbicide Susceptibility of Six Pigweed Species

Abstract
The germination and growth of six pigweeds (Amaranthus spp.) were studied in the germinator and greenhouse. Treatments with sulfuric acid, acetone, sodium hypochlorate, and potassium nitrate variously influenced species germination. Seedlings emerged more rapidly at 100 F than at other soil temperatures. Variation in seedling characteristics was noted. Some species were more susceptible to 4-(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline (nitralin) and 2,4-bis (isopropylamino)-6-(methylthio)-s-triazine (prometryne) than others in the greenhouse. In the field little variation in susceptibility to several preplant and preemergence herbicides was found; but there were differences when postemergence herbicides were used.