The spores of the fungus can enter the tree through these wounds and establish an infection. Once inside the tree, O. novo-ulmi grows in the water-conducting vessels of the tree, blocking the flow of water and nutrients, which eventually leads to wilting, yellowing of leaves, and tree death. The fungus also produces toxic compounds that further contribute to the damage to the tree's vascular system and overall health.
The spores of the fungus can enter the tree through these openings and start an infection. Following this, O. novo-ulmi grows in the water-carrying tissues of the tree, blocking the flow of water and nutrients, which ultimately causes leaf wilting, discoloration, and tree death. The fungus also produces toxic substances that further compromise the tree's vascular system and overall health.