Safener sulfonylurea herbicides

Iodosulfuron-methyl-sodium was the first safened sulfonylurea herbicide on the market [17, 18] when introduced in 1999 and has been commercialized by Bayer CropScience for use both in cereals and maize. A safener such as mefen-pyr-diethyl (cf Fig. 2.2.2) is a chemical that, when applied to crop plants, reduces the injury caused by herbicides to an acceptable level. A safener ideally does not... 

Mesosulfuron-methyl (AE F130060) (Table 2.2.11) [19] was the second safened sulfonylurea herbicide for cereal crops to be commercialized. This compound was introduced in 2001 and has been commercialized by Bayer CropScience [20, 21]. Its strength is broad-spectrum post-emergence grass weed control. Mesosulfuron-methyl, at a dose rate of 4.5-15 g-a.i. ha , reliably controls 24 different grass weed species from 12 different families. Among the commercially... 

Foramsulfuron (AE FI30360) [48] is a postemergence sulfonylurea herbicide for the control of major grass species and certain broadleaf weeds in maize (Table 2.2.21). It is applied with the safener isoxadifen-ethyl (AE F122006) (Fig. 2.2.7) and in some products in combination with small quantities iodosulfuron-methyl-sodium [49]. 

Uptake studies were also carried out with the recently developed combinations of the safener mefenpyr-diethyl with the sulfonylurea herbicides mesosulfuron-methyl and iodosulfuron-methyl-sodium, which are used for selective postemergence weed control in wheat crop. In both combinations the safener had no influence on herbicide uptake [29]. 

As already mentioned, it is a major advantage of mefenpyr-diethyl to act as a safener also in combination with sulfonylurea herbicides in cereal species. Combinations have been developed with the sulfonylureas iodosulfuron-methyl-sodium and mesosulfuron-methyl. 

This compound was recently developed as a safener for the sulfonylurea herbicide foramsulfuron in maize. Metabolism studies revealed that isoxadifen-ethyl also acts by enhancement of foramsulfuron metabolism in maize, while it does not influence the rate of metabolism of this herbicide in susceptible weed species [17, 18]. 

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