Differential bentazon response in cowpea (Vigna unguiculata)

The U. S. Plant Introduction Collection of cowpea germplasm and a collection of cowpea cultivars were evaluated for bentazon tolerance in the field. Most accessions were intermediate in bentazon tolerance; however, several highly tolerant and highly susceptible accessions were identified. Tolerant and susceptible selections from the field experiment were evaluated in greenhouse experiments. The most susceptible selections were killed or severely injured by bentazon at 2 kg ae ha-1; the most tolerant selections were not severely injured by bentazon at 16 kg ha-1.