Blight

The browned fruit has blight.

Blight refers to way plants wither when infected. It is usually caused by fungi, or viruses, or sometimes by bacteria.

Blight is a rapid and complete chlorosis,[1] browning, then death of plant tissues such as leaves, branches, twigs, or flowers.[2] Various diseases which cause the symptom are known as blights. Several notable examples are:

  • Late blight of potato, caused by the water mould Phytophthora infestans, the disease which led to the Irish potato famine
  • Southern corn leaf blight, caused by the fungus Cochliobolus heterostrophus. This caused a severe loss of corn in the United States in 1970.[3]
  • Chestnut blight, caused by the fungus Cryphonectria parasitica has nearly eradicated mature American chestnuts in North America.
  • Bacterial leaf blight of rice is caused by the bacterium Xanthomonas oryzae.[4]
  • Early blight of potato and tomato, caused by species of the common fungal genus Alternaria.
  • Leaf blight of grasses. On leaf tissue, symptoms of blight are the initial appearance of lesions which rapidly engulf surrounding tissue.

References

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  1. ↑ yellowing due to loss of chlorophyll
  2. ↑ Agrios, George N. 2005 Plant pathology. 5th ed, Burlington, MA: Elsevier Academic Press.
  3. ↑ Partridge J.E. Southern Corn Leaf Blight. 2003. 8 August 2006. http://nu-distance.unl.edu/homer/disease/agron/corn/CoSCLB.html Archived 2010-07-23 at the Wayback Machine
  4. ↑ Oda M. Sekizawa Y. and Watanabe T. 1966. Phenazines as disinfectants against bacterial leaf blight of the rice plant. Applied Microbiology 14(3):365-367.