Weeds likely are emerging with corn in many fields due to the lack of a preemergence herbicide. Whether this was planned or due to weather constraints, it is critical to control weeds early in order to protect yields. The term critical period is used to define how long weeds can be allowed to compete with the crop before yields are impacted. To obtain maximum yields, weeds must be controlled before the critical period is reached. The difficulty in relying on total post programs is the variability in the critical period, making it impossible to predict the optimum time for postemergence herbicide application.
Iowa State University
Hartzler, Robert G., "Timeliness Critical to Protect Corn Yields" (2008). Integrated Crop Management News. 923.
The Iowa State University Digital Repository provides access to Integrated Crop Management News for historical purposes only. Users are hereby notified that the content may be inaccurate, out of date, incomplete and/or may not meet the needs and requirements of the user. Users should make their own assessment of the information and whether it is suitable for their intended purpose. For current information on integrated crop management from Iowa State University Extension and Outreach, please visit https://crops.extension.iastate.edu/.