Esca ( Grape Measles)

Esca (Measles)

These symptoms are diagnostic of Esca (Measles):

• Leaf symptoms (Figure 7)
  

  Figure 7 – Leaves with interveinal necrosis appear in mid-summer. The margin outlining the necrosis is reddish-brown in red cultivars (Bottom; Cabernet Sauvignon, Photo by Kendra Baumgartner) or yellow in white cultivars (Top; Sauvignon blanc, Photo by Monica Cooper).

• Fruit spots (Figure 8)

Figure 8 – Fruit spots are visible on white cultivars of wine grapes (e.g., Sauvignon blanc, shown here) and table grapes (e.g., Thompson seedless). (Photo by Monica Cooper).

• Concentric rings of black spots (Figure 9)
  

  Figure 9 – Concentric rings of black spots surround the pith, which is the naturally darkened core of this cordon. (Photo by Rhonda Smith).

Main Esca Pathogens:             Phaeomoniella chlamydospora

Phaeoacremonium aleophilum (teleomorph Togninia minima)

Other Phaeoacremonium species

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