diseases caused by microorganisms in plants
Organisms that cause infectious disease include fungi, oomycetes, bacteria, viruses, viroids, virus-like organisms, phytoplasmas, protozoa, nematodes and parasitic plants.Not included are ectoparasites like insects, mites, vertebrate, or other pests that affect plant health by consumption of plant tissues.ost bacteria that are associated with plants are actually saprotrophic, and do no harm to the plant itself. However, a small number, around 100 known species, are able to cause disease. Bacterial diseases are much more prevalent in sub-tropical and tropical regions of the world.