Applying glyphosate (for example, Roundup) over-the-top past the 4th true leaf stage in Roundup Ready cotton can result in poor pollination and fruit shed in some environments. This fruit shed can subsequently result in excessive vegetative growth. This does not occur in every situation where glyphosate is applied over-the-top later than the label allows. This tends to be worse in late planted cotton and areas that accumulate fewer heat units since the plant does not have time to compensate for lost fruit. If getting into the field to spray glyphosate before the over-the-top window closes is a common challenge, you may want to consider planting varieties with other herbicide-tolerance technologies such as Roundup Ready Flex or Liberty Link. Check with you local cotton Extension agent to obtain performance information on varieties containing these technologies.

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