Impact (topramezone) is one of three important HPPD (4-hydroxyphenyl-pyruvatedioxygenase) herbicides labeled for use in sweet corn. The other two are Callisto (mesotrione) and Laudis (tembotrione). Impact provides postemergence control of numerous broadleaf weeds and control or suppression of several annual grass weeds. Research evaluations and commercial usage have shown good safety when used on corn but label restrictions severely limit rotational crop plantings for vegetable growers. This study looks at Impact herbicide use on sweet corn and its potential for injuring subsequent crops of snap bean, cucumber, and tomato.