Plant Disease Management Handbook

A swelling or blistering on leaves and other plant parts under conditions of high moisture and restricted transpiration (see also edema).

a swollen, flattened portion of a fungal hyphae that adheres to the surface of a plant, providing anchorage for penetration into the tissue.

A subdivision of a plant-pathogenic bacterial species defined by host range; pathovar for bacteria is equivalent to forma specialis for fungi.

To grow together into one body or spot.

The microenvironment in the soil, immediately around roots.

A swelling or blistering on leaves and other plant parts under conditions of high moisture and restricted transpiration (see also oedema).

A necrotic condition in which tissue is usually bleached and has the appearance of having been exposed to high temperatures.

Native to a particular place; pertaining to a low and steady level of natural disease occurrence.

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.

A chemical substance produced in one part of an organism and transported in minute quantities to induce a growth response in another part, such as auxins, cytokinins, and gibberellins. Some fungicides induce a growth-regulation response when applied to plants.