No competitive advantage was conferred to 3751IR corn, other than tolerance to imidazolinone. The mutation of the ALS in 3751IR has not significantly affected the physiology of the plant, as demonstrated by the normal levels of valine, leucine and isoleucine. It is therefore not expected that 3751IR would possess traits that would render it invasive of unmanaged habitats. The resulting progeny could acquire the herbicide tolerance gene. Progeny from self-pollination will also be imidazolinone tolerant.
Heterozygous progeny express herbicide tolerance, although at a lower level than homozygotes.
Imidazolinone tolerant corn volunteers will thus appear in subsequent crops. Corn volunteers are commonly found in soybean fields when soybeans are cultivated in the year following corn. Corn volunteers are usually at an immature growth stage at soybean harvest time resulting in problems during harvest operations. While these volunteers could be managed by mechanical means and other available herbicides, the present use of imidazolinone herbicides in soybeans may be compromised. In general terms, growers must be made aware that imidazolinone tolerant corn volunteers will not be controlled in subsequent crops when imidazolinones are used as the sole weed control tool.