What condition is known to weaken turf the most?

Scalping is the practice of cutting the grass too short, which can severely weaken turf. When turf is scalped, it removes a significant amount of leaf material, which is vital for photosynthesis. This loss of leaf area impairs the grass's ability to absorb sunlight and produce the energy it needs to grow. Additionally, scalping exposes the soil underneath, making it more susceptible to environmental stresses such as heat and drought, which can further weaken the grass.

The process also disrupts the root system, as cutting too close can damage the grass's ability to anchor itself in the soil. As a result, roots can become vulnerable to diseases and pests, leading to an overall decline in turf health. Keeping grass at the optimal cutting height is essential for maintaining robust growth and resilience against various stressors.

Understanding this, it becomes clear why scalping is considered the condition that weakens turf the most among the options provided.