What aspect of plant health does Phytophthora Root Rot most severely impact?

Phytophthora Root Rot primarily affects root health, which is critical for a plant's overall vitality. This disease, caused by the Phytophthora fungus, leads to the decay of the roots, impairing the plant’s ability to absorb water and nutrients. As the roots deteriorate, the plant becomes stressed, which can indirectly affect other aspects such as leaf production, flower formation, and stem strength. However, the initial and most severe impact is on the root system itself, disrupting fundamental functions required for growth and development. A compromised root system can ultimately lead to reduced growth, leaf drop, and a decline in flowering, but the root health is the first and most critical factor that Phytophthora Root Rot damages.