Red Seal Landscape Horticulturist Practice Exam

What role does good air circulation play in plant health?

1. Increases humidity levels

2. Prevents disease development

3. Promotes soil erosion

4. Enhances growth rate

The correct answer is: Prevents disease development

Good air circulation is crucial for plant health primarily because it helps to prevent disease development. When air circulates freely around plants, it reduces the humidity levels in the immediate environment, particularly on leaf surfaces. This is vital because many plant pathogens thrive in high humidity conditions; they require moisture for spore germination and growth. By keeping the air moving, the moisture on leaves evaporates more quickly, thus lowering the likelihood of fungal infections and other moisture-related diseases developing. While increased humidity levels can benefit certain plants, excessive humidity often leads to problems. Promoting soil erosion does not relate to air circulation, as erosion primarily involves water movement and soil degradation. Lastly, while good air circulation can contribute to better overall plant health and potentially enhance growth rates indirectly, the primary benefit regarding plant resistance to diseases is what makes preventing disease development the most relevant answer in this context.