Effective weed management is paramount for ensuring successful crop production and sustaining agricultural productivity over time. Herbicides serve as indispensable tools in this endeavor, aiding farmers in controlling weed populations and safeguarding the health of their crops. In Oklahoma, producers have encountered challenges related to failed cotton crops and the subsequent complications arising from herbicide rotation when transitioning to sorghum. Residual herbicides remain active in the soil for an extended period after application, providing ongoing weed control by inhibiting weed seed germination or growth. They are typically used for long-term management in both pre- and post-emergence scenarios. Non-residual herbicides are fast acting and degrade quickly, affecting only the weeds present at the time of application, without providing longterm control. Non-residual herbicides are typically used for immediate control of actively growing weeds.

When cotton crops fail due to various factors such as adverse weather conditions, pest infestations or disease outbreaks, producers often face obstacles in transitioning to sorghum due to the persistence of herbicide residues in the soil. These residual herbicides, originally applied for weed control in cotton, can linger in the soil and disrupt the growth of subsequent crops like sorghum, posing significant challenges to the rotation process.

This publication provides an up-to-date listing of herbicide rotational restrictions for sorghum planted after failed cotton in Oklahoma. Using information on commonly used herbicides in cotton production and their residual effects on sorghum crops, farmers can make informed decisions to safeguard their crops against potential herbicide damage and maximize yields.

*This list is not all inclusive of herbicides that growers can potentially apply to cotton. Herbicide labels should be consulted for further information or if chemical is not present on the list.