Staple has been applied as an over-the-top postemerge herbicide to cotton (Gossypium hirsutum) in eleven replicated small plot tests since 1992 and six large acreage plots since 1994 in the Southern Rolling Plains of Texas. It has effectively controlled entireleaf morningglory (Ipomoea hederacea), tall morningglory (Ipomoea purpurea) red morningglory (Ipomoea coccinea), devilsclaw (Proboscidea louisianica) redroot pigweed (Amaranthus retroflexus), and palmer amaranth (Amaranthus palmeri) when applied to young unstressed plants that are growing under favorable environmental conditions.

Broadleaf weed control was lower in plots where Staple was applied to plants developing under unfavorable growing conditions. This reduction in weed control usually results in additional expense to producers because alternate control practices have to be used. In most of the tests, Staple had to be applied at a minimum rate of 1.5 ounces active ingredient (a.i.) to control weeds for a period of time long enough to keep the late developing weed populations from interfering with cotton harvest.

These tests indicate that effective weed control depends on the age of the weeds, the amount of stress encountered during development, the amount of soil moisture available for plant development, and the environmental conditions at the time of application.