Current tendencies are to automatically look to another herbicide to provide supplemental weed control when initial treatments fail to meet expectations. Although this strategy may be appropriate in many cases, economically it may be better to consider mechanical weed management practices. These strategies must be used in a timely fashion for maximum efficacy, not unlike supplemental herbicide application. Rotary hoeing and cultivation are effective techniques for weed management and have significant economic benefits when compared with the cost of herbicides. However, it is important to consider that mechanical strategies also require management skills for optimum weed management and these skills may be different than those used with herbicide treatments.
Primary tillage is the first consideration and probably the most important factor.
Many producers do not accept that mechanical weed management is important in no-tillage production systems. In fact, mechanical strategies are extremely effective and highly desirable strategies in these production systems. One of the major changes that occurs when tillage is eliminated is a relatively rapid change in weed populations. These shallow-emerging weeds respond readily to mechanical management tactics. Also, when plant residue levels increase on the soil surface, variability in soil temperature and moisture increases resulting in extended germination periods for weeds.