Phytophthora root rot, caused primarily by the oomycete Phytophthora cinnamomi, is a soilborne disease affecting blueberry.
Phytophthora disease is a plant pathogen that spreads to trees and plants by contaminating their roots. This disease is easily transmitted from plant to plant; it spreads by water irrigation, gardening tools, and human activity.
This fungus-like organism has an extremely wide host range and infects a large number of tree and shrub species including other ericaceous plants (such as rhododendron and madrone) and many conifers. The leaves of blueberry plants appear drought stressed. Trees or plants often wilt and die rapidly with the first warm weather of the season. Leaves may turn dull green, yellow, or in some cases red or purplish.
Wet, poorly-drained soil is one of the principal contributors to the growth and spread of this disease. Blueberry roots are shallow and like a lot of moisture, but when blueberry roots are too wet for too long, this disease organism can move in. Wilting and apparent nutrient deficiency symptoms on infected plants indicate the roots are not working correctly.
The pathogen kills plants by growing from the roots up through the root crown and into the lower trunk, where it kills the inner bark and causes a browning of the outer layer of sapwood.
Phytophthora root rot in blueberry plant
