Alright, so you know how you get sick sometimes like when you catch a cold? Plants can also get sick and this is called plant disease. But just like with people, not all plants will get sick unless they are exposed to a harmful thing called a pathogen.
A pathogen can be a virus, bacteria, or fungus that enters the plant and causes it to get sick. Just like when you catch a cold from someone else, the pathogen can spread to other plants and make them sick too. This spreading of disease is called epidemiology.
Scientists study plant disease epidemiology to learn more about how these pathogens spread and how to stop them from spreading. They look at different factors like the weather, the type of pathogen, and how the plants are growing. This helps them come up with ways to prevent or treat plant diseases.
Just like how you try to wash your hands and cover your mouth when you cough to prevent getting sick, farmers and plant doctors use different methods to prevent plant diseases. Some methods include using healthy seeds, spraying plants with special chemicals, or even breeding plants that are resistant to disease.
So that is plant disease epidemiology in a nutshell. Scientists study how plant diseases spread, and come up with ways to stop and prevent them.