Too often, growers mix pesticides at higher rates than recommended on the label in hopes of better control or a more lasting effect. This is a dangerous approach and can pose unwarranted hazards not only to applicators, but also to the plants being treated. Recommended rates are based on the amounts needed for control. If reasonable control is not achieved at these rates, there is likely some fault in the choice of pesticide, in timing treatments or in the application method. Applications in excess of the recommended rates contribute unnecessarily to environmental contamination without increasing the level of control. Generally, repeated applications at intervals of 7, 10 or 14 days are required to protect new growth that has developed since the last spray or to replace spray residues that are no longer effective because of weathering and chemical breakdown.