Phaeomoniella

Phaeomoniella (Phaeomoniella chlamydospora) is a notorious fungal pathogen responsible for significant grapevine trunk diseases, including Esca and Petri disease. The fungus colonizes the xylem vessels, leading to vascular occlusion and the subsequent decline of the vine's physiological functions.

The primary host for this pathogen is the grapevine (Vitis vinifera). It is a major concern globally, affecting nursery stock during propagation and established vineyards, often leading to reduced yields and eventual premature death of the vines.

Common symptoms include stunted growth, interveinal chlorosis, and necrosis of the leaves, often referred to as "tiger stripes." When cutting into the wood, cross-sections reveal dark, streaky, or circular necrotic lesions, which are classic signs of vascular obstruction caused by the pathogen.

Development and spread of the fungus are heavily influenced by environmental conditions and viticultural practices. Conidia are dispersed via rainfall and wind, primarily invading the vine through pruning wounds. Humidity levels during pruning play a critical role in the severity of infection.

Preventative measures are essential, as there is no curative treatment once the vine is severely infected. Best management practices include pruning only in dry weather, sterilizing pruning equipment between vines, painting fresh wounds with protective sealants, and strictly using certified pathogen-free propagation material.