In October 2020, EPA approved five-year registrations
In October 2020, EPA approved five-year registrations (until 2025) for dicamba products including XtendiMax (Bayer), Engenia (BASF) and Tavium (Syngenta) for over-the-top use in Xtend and XtendFlex soybeans. These new dicamba product registrations included national cutoff dates (June 30 in most cases) and mandatory use of additional volatility reduction agents (VRAs) in the tank.
Problem: ISU Extension field agronomists and commercial agronomists in several areas of the state have reported a high percentage of non-dicamba resistant soybean showing symptoms characteristic of dicamba, and in many fields the injury is fence row to fence row. This is the type of injury we have seen in previous years in Iowa and other adjacent states. Weed scientists in the Delta region used the term ‘atmospheric loading’. Atmospheric loading refers to so much dicamba moving into the atmosphere that it is difficult, if not impossible, to identify the specific source or application that resulted in an injury to a field. More information on dicamba volatility can be found in this article.