What can result from ineffective droplet deposition during an aerial application?

Ineffective droplet deposition during an aerial application can lead to reduced pesticide efficiency, which is why this choice is the correct answer. When pesticide droplets do not reach the intended target effectively, whether due to improper droplet size, poor distribution, or environmental factors like wind, the amount of active ingredient that actually impacts the pest is diminished. This can lead to inadequate pest control, allowing populations to survive and potentially leading to increased pest problems in the future.

In contrast, increased crop yield typically results from effective pest management rather than ineffective droplet deposition. Pest resistance can occur over time with repeated exposure to a pesticide, but it is not directly a result of poor application techniques. The option stating "none of the above" would imply that no negative consequences arise from ineffective droplet deposition, which is incorrect, as it indeed affects the efficiency of pesticide application significantly. Thus, reduced pesticide efficiency effectively captures the negative outcome of ineffective droplet deposition.