Shattercane (Sorghum bicolor) biotype variation in tolerance to primisulfuron

Shattercane accessions were collected from 33 corn fields previously treated with nicosulfuron or primisulfuron. In a greenhouse study, we found no resistance to primisulfuron among the accessions. However, 15% of the accessions were more tolerant to primisulfuron than the most susceptible accessions. Shattercane survival among the 33 accessions ranged from 0 to 39% at 40 g ai/ha. While most accessions emerged uniformly, 26% of the accessions had 5 to 38% emergence after primisulfuron treatment. Delayed emergence could facilitate herbicide avoidance.