Atrazine application flexibility

One of the reasons the triazines are so important in corn and other crops around the world is their application flexibility and their ability to mix with other herbicides for broad-spectrum weed control. Figure 1.6 demonstrates the relative importance of atrazine in com compared to other herbicides. 

The benefits of the triazines in multiple cropping systems range from their application flexibility, effective weed control, soil residual activity, and crop selectivity to their important role in resistance management and conservation tillage. The triazines also have made a major impact on agricultural sustainability and crop yields, as evidenced by the use of atrazine, especially in com. 

Atrazine is widely used in corn production due to its efficacy, application flexibility, low cost, and crop safety. Its efficacy ratings for some common weed species are listed in Table 34.1a. Table 34.1b presents estimates of the infestation of these important weeds in Illinois and of the potential yield loss that would occur if these weed species were uncontrolled. These data indicate that atrazine provides significant levels of control for most of the important weed species that are widely distributed and those that would cause significant com yield loss if left uncontrolled. 

The economics of mixtures and dual applications are very important to farmers. The treatment cost would include the cost of the ALS herbicide plus the cost of the nonALS product. Depending on the nonALS herbicide partner, treatment costs per acre could increase by 24% to 98%. These additional costs could be prohibitive to the grower, and the use of the ALS herbicides on the infested acres could decline significantly. Atrazine is the preferred nonALS herbicide alternative because it has preemergence and postemergence flexibility, does not have the shortcomings of other nonALS-alternatives, and is very economical. 

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