Dothiorella cane blight

Dothiorella sarmentorum is a fungal pathogen primarily known for causing serious wood-related diseases in grapevines. It acts as a primary agent in the complex of fungi that trigger vine decline and dieback, affecting the structural integrity of the plant's permanent wood.

While grapevines are the most economically significant host, this fungus also affects various fruit trees and woody perennials. It is a wound-invading pathogen, meaning it establishes infection primarily through physical injuries caused by frost, pruning shears, or insect activity, eventually colonizing the xylem and phloem tissues.

The disease progresses through internal tissue colonization, leading to visible external symptoms. Key diagnostic signs include:

• Dark, sunken necrotic lesions on the vine bark.
• Internal wood discoloration, appearing as brown or black streaking in cross-sections.
• Foliar chlorosis followed by rapid wilting during peak summer temperatures.
• Stunted growth and eventual necrosis of affected cordons or entire trunks.

Environmental conditions characterized by moderate temperatures and high humidity are ideal for the development and dispersal of spores. The pathogen survives in infected wood remnants and produces conidia that are disseminated through rain splashes and wind currents, making management difficult during wet seasons.

Controlling this pathogen relies heavily on cultural practices and strict hygiene. Removing and burning symptomatic wood is crucial to reduce inoculum pressure. Growers are advised to disinfect pruning equipment regularly to prevent cross-contamination and to apply protective wound sealants to prevent the pathogen from entering fresh cuts during the dormant pruning season.