Weed seed bank dynamics under herbicide tolerant crops

Successfully marketed herbicide tolerant crops (HTCs) are associated with herbicides that lack residual activity and the promotion of reduced tillage. As a consequence of these associations, consistently excellent weed control will be necessary to stabilize or reduce weed seed banks. For excellent weed control to occur in HTCs, application timing of associated herbicides will be the single most critical factor. The threshold for application timing will be simpler and more easily determined for weeds that emerge early and quickly. Weeds with protracted emergence periods, or those that simply emerge late, will be more difficult to control. Increases in seed bank densities may be expected for these latter species under HTC management.