A complex chemical substance produced by one microorganism that inhibits or kills other microorganisms (e.g., streptomycin).
Excrement of an insect, usually mixed with plant debris.
The distortion, fluting, and puffing of a leaf resulting from the unequal development of its two sides.
The galls that form on peach leaves from Taphrina deformans give the disease its name Peach Leaf Curl.
Photo part of OSU Extension Plant Pathology Slide Collection
Parenchyma tissue that grows over a wound or graft and protects it against drying or other injury.
The plant on or in which a parasite lives and from which it obtains its food.
Regulation forbidding sale or shipment of plants or plant parts, usually to prevent disease, insect, nematode, or weed invasion of an area.
A sign you might see when travelling to or from different countries.
Jay W. Pscheidt, 2011.
The widespread and destructive development of a disease on many plants in a community or communities.
Degenerate bacteria that do not have cell walls. Mycoplasmas are smaller than bacteria but larger than viruses. They cause animal and human diseases.
An elongated lesion with irregular sides.
A local injury or delimited diseased area.
The chlorotic halo around each lesion is easy to see when light comes from behind this iris leaf.
Photo by Jay W. Pscheidt, 2006.
