Why is coverage important when using a contact type herbicide?

Coverage is crucial when using a contact type herbicide because it ensures that the herbicide is able to effectively reach and interact with the target pest. Contact herbicides work by directly killing the pest upon contact; hence, the efficacy of the treatment depends on sufficient and even distribution across the target area.

When considering the importance of coverage, sufficient quantity is vital because if the herbicide does not coat the target adequately, it may not deliver enough active ingredient to achieve control. Additionally, small amounts of herbicide may simply not be enough to have a lethal effect on the pest, reinforcing the need for thorough coverage.

Moreover, contact herbicides do not translocate within the plant, meaning they cannot spread beyond where they initially land. If there are gaps in coverage, not only is there the risk that some pests may survive, but also because the herbicide doesn't move within the plant, those pests may not be effectively targeted. This comprehensive understanding of the need for good coverage ties all the aspects together, thereby validating the conclusion that all of these factors collectively underline the vital role of coverage when applying contact herbicides.