Bacterial Spike Blight

Also known as Gummosis
Rathayibacter tritici (Carlson and Vidaver 1982) Zgurskaya et al. 1993
Clavibacter iranicus (Carlson and Vidaver 1982) Davis et al. 1984

  1. Symptoms: A yellow exudate on the spikes is indicative of bacterial spike blight. When dry, the exudate is white. Often the spikes and necks will emerge as a distorted, sticky mass (see picture).The early leaves may also be wrinkled or twisted. This bacteria is associated with the nematode Anguina tritici in some regions.
  2. Development: The bacteria persists in organic material in the soil. It attacks wheat when it comes in contact with the plant apex within the leaf whorl, and this transmission is often facilitated by the nematode Anguina tritici.
  3. Hosts/Distribution: Wheat is the only cultivated host, though some wild grasses are susceptible to attack. The disease is frequently reported in the Asian Subcontinent.
  4. Importance: Bacterial spike blight is not economically important.

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