Many different kinds of organisms can cause plant disease, including:

  • bacteria
  • fungi
  • viruses
  • nematodes
  • parasitic plants

An organism that causes plant disease is called a plant pathogen. Plant pathogens are considered plant pests. Plant pathogens spread in various ways, including by insects, water, soil, air, people and other animals.

A goal of the Minnesota Department of Agriculture is to protect Minnesota’s terrestrial plants from plant pathogens. We do this through inspections and testing of nursery stock, seed, including seed potatoes, and by keeping new invasive pathogens out of the state.