ABSTRACT
Imazaquin was the first imidazolinone to be widely accepted as an herbicide for broad spectrum weed control. In 1981, field testing began in the United States (US) and Brazil. Initial results demonstrated that imazaquin could be applied preplant incorporated, preemergence, or post-emergence for the control of many difficult-to-control weed species. Soybeans exhibit excellent tolerance to imazaquin when applied either as a soil or postemergence treatment. Once absorbed, soybeans rapidly metabolize imazaquin into inactive components. Growing conditions affect the soybean plant's ability to metabolize imazaquin. The restrictions on rotational crops are dependent on the areas in which imazaquin herbicide has been applied. In the US, the areas in which imazaquin is used has been divided into two zones, the Southern use area and the Northern use area. Imazaquin plus pendimethalin combination treatment are being evaluated in Japan. The addition of imazaquin widens the application timing and weed spectrum for pendimethalin, which is registered for use in zoysiagrass.
