Development of a novel herbicide, metazosulfuron.

Metazosulfuron is a novel sulfonylurea herbicide discovered and developed by Nissan Chemical Industries, Ltd., which exhibits excellent herbicidal activity against Echinochloa spp., annual and perennial weeds including sulfonylurea resistant biotypes in paddy fields at 60-120 g a.i./ha with good crop safety to rice. In addition, it has favorable toxicological, ecotoxicological and environmental profile. Metazosulfuron (trade name; Altair®) was registered and launched in Japan in 2013, and has been also introduced in Korea and China as of 2016. This paper describes a history of discovery, syntheses, herbicidal characteristics and crop safety of metazosulfuron.