A simple, labor-efficient screening procedure was developed for identifying metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one] tolerant southernpea [Vigna unguiculata (L.) Walp.] germplasm in the greenhouse. Of 1241 southernpea plant introduction (PI) accessions screened, two (PI 293569 and PI 427221) tolerated metribuzin. In additional greenhouse experiments, the two selected southernpea accessions were slightly more tolerant than the susceptible cultivar ‘Lady’ or the moderately tolerant cultivar ‘Big Boy’. However, several accessions from related Vigna species tolerated 1.5 ppmw metribuzin, twice the concentration that killed the southernpea selections.
