Which of the following statements is true regarding pesticide coverage?

The statement regarding leaf residue indicates effective application is true because visible residue on plant surfaces can be an important indicator that the pesticide has been applied correctly and is likely to be effective. When a pesticide forms a visible residue, it suggests that the product has adhered to the plant surfaces, which is crucial for its efficacy.

Effective pesticide application typically relies on the product remaining on the target area long enough for absorption or contact with pests. Leaf residue signifies that the product is present where it needs to be, increasing the likelihood of achieving the desired pest control outcome.

In contrast, the other statements lack accuracy for determining effective pesticide coverage. For example, a cloudy mixture does not guarantee adequate coverage; it could also indicate issues with mixing or formulation. Visibility of the pesticide does not inherently denote effectiveness, as some products work effectively even when not visibly present on the leaf surface. Lastly, evaluating pesticide coverage should always be done regardless of weather conditions, as dry conditions can influence the application and performance of the pesticide used.