Research was conducted to determine environmental and cultural factors influencing triallate phytotoxicity to hard red spring wheat. Triallate injured ‘Alex’ wheat more than ‘Coteau’ but injury was not influenced by triallate application date. Wild oat control was greater when triallate was applied immediately before seeding compared to 12 d before seeding. Triallate tolerance in wheat did not relate to solid stem characteristic. Injury was highest when wheat was seeded in a 4-cm incorporated triallate layer and least when wheat was seeded below the treated layer. However, triallate injury to wheat was similar at both seeding depths within the 8-cm incorporated triallate layer. Triallate at 1.1 kg ai ha-1 reduced wheat fresh weight approximately 33% with a soil at 8 C but over 84% with a soil at 24 C.