Hazards from Soil Applied Herbicides to Crops Grown in Rotation (October 30, 2013)

Herbicides that have residual soil activity are very useful in the low deserts, where weed seeds continue to germinate with each irrigation year-round. These herbicides can also be hazardous, however, when sensitive crops are planted into soil where they are still active. Determining the potential for crop injury from herbicides used on previous crops can be difficult. Injury potential is related to several interrelated factors such as soil type, irrigation practices, tillage, environmental conditions, organic matter and other conditions. Injury can vary from field to field, year to year and even be variable within the same field. Rotational crop restrictions on product labels must often cover many diverse conditions and geographic regions and are frequently much longer than needed. This link will give you a chart that contains the crop interval for the major crops and herbicides used in the deserts as well as the usual soil persistence for each product.

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To contact Barry Tickes go btickes@ag.arizona.edu.