How does Verticillium wilt infect the roots?

Verticillium wilt is a soil-borne fungal disease that primarily infects plants through their roots. When the fungus is present in the soil, it can enter the plant's root system as the roots absorb water and nutrients. Specifically, the infection spreads upward from the roots into the sapwood, which is part of the plant's vascular system responsible for transporting water and nutrients to the leaves and other parts of the plant.

Once the fungus establishes itself in the roots, it can move through the sapwood, leading to blockages in water transport and causing symptoms such as wilting, leaf yellowing, and ultimately, plant decline. This upwards movement through the sapwood is critical for the disease's progression, setting it apart from other options. Understanding this pathway is essential for effective management and control strategies in agricultural practices.