What specific action should be taken immediately after discovering black knot on a tree?

When black knot is discovered on a tree, the most effective immediate action is to prune and dispose of the infected parts. Black knot is a fungal disease that affects the branches of certain trees, particularly plums and cherries, leading to black, elongated galls. These galls can severely weaken the tree and hinder its growth if not addressed promptly.

Pruning the infected areas helps to remove the disease from the tree and prevents further spread of the fungus to healthy areas. It is crucial to dispose of the removed portions properly, either by burning them or placing them in sealed bags for disposal, as leaving them in the vicinity can lead to reinfection. This step is essential because it targets the source of the problem, effectively managing the disease and promoting the overall health of the tree.

In contrast, actions such as replanting nearby vegetation, applying fertilizers, or excessive watering do not directly address the infection and can potentially worsen the tree’s condition or spread the disease further. Thus, the most appropriate and immediate response is focused on the careful removal of the infected tissue.