More than 32 million ha of maize were planted in the United
States in 2009, of which 85%was planted to insect-resistant hybrids,
particularly ones that produce Bacillus thuringiensis (USDA-NASS,
2009). Additionally, 68% of maize in 2009 was genetically engineered
with a herbicide trait (22% herbicide alone and 46% stacked
with insecticide resistance) (USDA-ERS, 2010). Glyphosate-resistant
maize has been widely adopted, which has created a lack of control
options for volunteer maize or in situations where a failed maize
stand must be eliminated prior to replant of maize or other crops
such as soybean or cotton. Replanting with glufosinate-resistant
maize is an option. However, glyphosate-resistant genes stacked
with insect-resistant genes can bring glufosinate tolerance because
glufosinate- and insect-resistant genes are co-transformed, with
glufosinate resistance used as the selectable marker (Moellenbeck
et al., 2001). Additionally, glufosinate exhibits poor control under
cool conditions, which arecommonduring early spring (Norsworthy
et al., 2009; Steckel et al., 2006). Hence, there are limited control