New technology is continually making its mark in the cotton industry. Roundup Ready™ cotton is an exceptional value to those farmers wishing to reduce their input costs or control weeds resistant to conventional herbicide programs. As with any new advancement or technology, growers have questions about performance in field type situations. This trial compares the performance of three different varieties to timed Roundup Ultra applications ranging from in label applications at the 4 leaf stage to a past label application at the 10 leaf stage. Field conditions that growers experience vary from year to year and field to field. Growth stages in any given field may not (and most likely will not)be the same. Timing roundup applications according to label directions is a must, but in any field, there are plants that may not meet the growth stage criteria specified.

Roundup Ultra applications may be made over the top prior to the five leaf stage of growth. Up to two applications can be made prior to the five leaf stage with a minimum of two nodes of growth and ten days between applications.

The purpose of this trial was to look at the effects of late, out of label over the top applications of Roundup Ultra and its effect on yield performance.