By Aaron Hager, Extension Weed Scientist

Almost all post-emergence soybean herbicides have a pre-harvest interval or a soybean developmental stage beyond which applications cannot be made specified on their respective label.

Labels of some products may indicate both a developmental stage (before soybean bloom, for example) and a pre-harvest interval.

Pre-harvest intervals indicate the amount of time that must elapse between the herbicide application and crop harvest.  Failure to observe the pre-harvest interval may result in herbicide residue levels in the crop in excess of established limits.

Table 1 contains information regarding pre-harvest intervals for a number of post-emergence soybean herbicides.