Herbicide-resistant weeds are becoming a major problem in the Midwest, and
strategies must be adopted to delay further selection, Strategies of rotati
ng and tank-mixing herbicides with different modes of actions should be eff
ective, but adoption may be limited and certain limitations may exist. Ther
efore, integrating nonchemical practices that indirectly lower selection pr
essure or restrict the growth of resistant populations is desirable. Approp
riate integration of mechanical weeding, crop rotation, increased crop comp
etition, and decision aids may further delay the development of resistance.
Understanding the effect of these practices on weed population dynamics is
required to more accurately predict their contributions toward resistance
management. This knowledge will aid in justifying the adoption of improved
management systems.