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16. Fine-tune Your Weed Control Program To Reduce Rates

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There are two basic ways to approach the ultimate goal of cutting back on herbicides: Cut back on total chemical use by targeting the treatments in various ways; or reduce the application rate. Many herbicide labels give a range of recommended application rates, so try to get by with the lower rate.

If weeds are small and your treatment is early, you can sometimes cut back to the lowest recommended herbicide rate. Reduced rates work best if applied early, when weeds are 1 to 3 inches high, 14 to 21 days after planting. Some producers have had success cutting rates below the recommended rates, but be aware that you may assume liability if herbicides do not adequately control weeds.

herbicide label A less risky way to reduce herbicide application rates is to select some of the more recent products that recommend extremely low rates. Instead of requiring rates that range from 1 to 2 pounds per acre, the improved chemistry of many new pesticides makes them effective when applied at rates as low as 1 ounce per acre or even 1/8 ounce per acre.
herbicide application Many of the newer herbicides are postemergence products, which means you may be able to use them in specific problem areas, rather than treat the entire field. The result: less total product applied, less risk to groundwater, and reduced costs.
Adjuvants Adjuvants improve the performance of postemergence herbicides, so using certain adjuvants could make it possible to reduce rates. It all depends on the adjuvant used, the weed species and size, and climatic conditions.
Split application Split applications may be more effective than single-pass applications, allowing you to reduce rates. Split applications also make it easier to control early emerging and late emerging weeds. However, extra trips over the field cost time, fuel, and equipment wear.
herbicides When you use herbicides in combination, you often can cut back to 30 or 50 percent of the rate that is required when the herbicides are used alone. Using herbicides in combination usually will not reduce your total load of herbicides. But it does make it possible to reduce the rate of a problem herbicide. If you want to reduce the rate of atrazine, for instance, use it in combination with another herbicide.
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