A disease control practice in which soil is covered with plastic sheeting and exposed to sunlight, thereby heating the soil and inhibiting or killing soilborne plant pathogens.
An aggregate of resting spores present in soil or plant structures, such as the clusters with hundreds of spores that are produced by Spongospora subterranea (causal agent of powdery scab in potato).
Injury to aboveground plant parts (leaves, bark, flowers, and fruit) caused by excessive exposure to solar radiation. Associated with high temperatures but not necessarily lack of soil moisture.
Rhododendron sunburn resulting in chlorotic areas near the leaf midribs and some necrosis.
Plant tissues are injured when freezing temperatures precede or follow daytime warming by the sun. Can also be considered winter injury or called southwest injury.
Pertaining to a disease in which an infection leads to general spread throughout the plant body. Also, a chemical that spreads internally through a plant.
A thin-walled spore produced by rust fungi which can function as primary or secondary inoculum and are spread by wind or wind-blown rain. These spores can be repeatedly produced throughout the growing season, depending on the specific rust fungus, and are borne in yellow-, orange-, or brown-colored pustules (uredinia).
One or more races of a pathogen that are characterized by the limitation of their host range to a certain genus or genera. Also, a group of closely related plants of common origin and similar characteristics within a species (see also Cultivar).
a cylinder of meristematic cells (lateral meristem) that produces secondary phloem to the outside and secondary xylem (wood) to the inside of a branch or trunk of a woody plant.
