Metribuzin Tolerance of Early-Maturing Soybean Genotypes

Metribuzin is an alternative herbicide to control glyphosate-resistant common ragweed (Ambrosia artemisiifolia L.) in soybean (Glycine max L. Merr). Metribuzin has potential to injure soybean. A screening technique to grow soybean genotypes in hydroponic solution was developed to determine differences in tolerance and sensitivity. Twenty-two named and experimental genotypes from the North Dakota State University breeding program were screened for visual injury rating, root and shoot weight, and plant height. Metribuzin ? genotype interaction was significant for visual injury rating and shoot weight in both greenhouse experiments. Two tolerant and two sensitive genotypes were screened in the field for tolerance at three rates of metribuzin on soils with pH greater than 7.5. Although some genotypes were more sensitive to metribuzin in the greenhouse, none of the genotypes were sensitive to metribuzin in the field