How can sanitation aid in reducing the spread of late blight and fire blight?

Sanitation is a crucial practice in managing plant diseases like late blight and fire blight. The option that highlights the importance of removing and destroying cull piles is particularly relevant. Cull piles can consist of diseased plant material, which serves as a reservoir for pathogens. If left untreated, these discarded materials can harbor spores and bacteria that can easily infect healthy plants in the vicinity.

By actively managing these infected or diseased materials, the risk of pathogen spread is significantly reduced. This is because sanitizing the environment limits the availability of sources that could reinoculate plants. Proper sanitation practices also include cleaning tools and equipment that may have come into contact with infected plants to avoid transferring pathogens to new locations.

This method is contrasted by other options that either do not directly address disease control through sanitation, such as chemical applications or irrigation changes, or that do so indirectly, like promoting healthy plant growth. While healthy plants are more resilient to diseases, sanitation specifically focuses on minimizing the immediate risk posed by existing pathogens in the environment.