Syngenta Japan debuts herbicides for sulfonylurea-tolerant weeds

Syngenta Japan has announced the market launch of new one-shot herbicides with significant efficacy against the sulfonylurea-tolerant weeds that pervade Japan’s paddy fields. The herbicides contain as their active ingredient mesotrione, a chemical analog of a naturally occurring biochemicals synthesized by its Swiss parent that has been shown to act on a diversity of weeds.

The company is targeting annual sales of 700 mn yen ($8.3 mn) in the initial year and 10 bn after five years from these herbicides, with an application area of 28,000 hectares in the initial year, out of 1.6mn hectares of paddy cultivation nationwide, and 400,000 hectares after five years. The herbicides are Apirotop MX 1 kg G 75, Apirotop MX 1 kg G 51, Apirokirio MX 1 kg G 75 and Apirokirio MX 1 kg G 51.

Mestrione, registered as a pesticide in Japan on May 19, is applied in small amounts, does not have long-term persistence in soil and is highly safe, with a low environmental burden. It is a copy of an allelochemical produced by Callistemon citrinus, a bush native to Australia, that curbs weed growth by disturbing a mechanism to form carotenoids, which are related to photosynthesis. It acts in 7-10 days on sulfonylurea-resistant weeds like Scirpus juncoide, Monochoria vaginales and Monochoria korsakowii.