Final answer:
Pesticide applications can fail due to incorrect pest identification, incorrect product choice, improper timing, and adverse weather conditions. Overuse can lead to environmental issues and human health problems. Pesticide resistance can render treatments ineffective over time.
Step-by-step explanation:
The factors that can cause pesticide applications to fail include incorrect pest identification, choosing the wrong pesticide product, improper timing of application, and adverse weather conditions. Incorrect pest identification can lead to using a pesticide that does not effectively target the pest, thus leading to a failure in controlling the pest population. Moreover, applying pesticides without proper timing may not coincide with the most vulnerable stage of the pest's life cycle, rendering the application ineffective. Weather conditions, such as rain or wind, can dilute or disperse pesticides before they can have an impact.
Overusing pesticides, as often seen in developing countries, can lead to environmental and human health costs such as soil degradation and chronic health issues among agricultural workers. Additionally, constant exposure to high levels of pesticides can lead to pesticide resistance within pest populations, making the chemicals ineffective over time. It is crucial to implement ecologically based control measures and view pesticides as a last resort to minimize environmental disruption.