There has been renewed interest in using fluridone herbicide to aid in control of glyphosate-resistant Palmer amaranth (Amaranthus palmeri S. Watson) in cotton (Gossypium hirsutum L.). Section 18 Emergency Use Exemptions for fluridone in cotton have been granted recently in several states and the manufacturer is pursuing federal registration. Fluridone has long persistence in soil, leading to questions about rotational crop response. Field experiments were conducted in North Carolina to evaluate the potential for fluridone to carry over to corn (Zea mays L.), peanut (Arachis hypogaea L.), grain sorghum [Sorghum bicolor (L.) Moench.], and soybean [Glycine max (L.) Merr.] grown in rotation with fluridone-treated cotton. Fluridone at 0, 280, 420, 560, 840, and 1120 g ai ha-1 was applied preemergence to cotton and rotational crops were planted the following spring. The fluridone rates were well above proposed use rates. Only minor visible injury to cotton was observed and cotton yield was unaffected by fluridone. Fluridone also caused only minor visible injury to rotational crops and did not affect stands, early season height, or yield of rotational crops.
