Blight is a rapid and complete
chlorosis, browning, then death of plant
tissues such as leaves, branches, twigs, or floral organs. Accordingly, many diseases that primarily exhibit this symptom are called blights. Several notable examples are: •
Late blight of potato, caused by the
water mold Phytophthora infestans (Mont.) de Bary, the disease which led to the
Great Irish Famine • Southern corn leaf blight, caused by the
fungus Cochliobolus heterostrophus (Drechs.) Drechs,
anamorph Bipolaris maydis (Nisikado & Miyake) Shoemaker, incited a severe loss of corn in the United States in 1970. •
Chestnut blight, caused by the fungus
Cryphonectria parasitica (Murrill) Barr, has nearly completely eradicated mature
American chestnuts in North America. •
Citrus blight, caused by an unknown agent, infects all citrus
scions. •
Fire blight of pome fruits, caused by the
bacterium Erwinia amylovora (Burrill) Winslow et al., is the most severe disease of
pear and also is found in
apple and
raspberry, among others. • Bacterial leaf blight of
rice, caused by the bacterium
Xanthomonas oryzae (Uyeda & Ishiyama) Dowson. • Bacterial seedling blight of rice (
Oryza sativa), caused by pathogen
Burkholderia plantarii • Early blight of potato and tomato, caused by species of the ubiquitous fungal genus
Alternaria • Leaf blight of the grasses e.g.
Ascochyta species and
Alternaria triticina that causes blight in wheat •
Bur oak blight, caused by the fungal pathogen
Tubakia iowensis. • South American leaf blight, caused by the
ascomycete Pseudocercospora ulei, also called
Microcyclus ulei, ended the cultivation of the rubber tree (
Hevea brasiliensis) in South America. When blights have been particularly vast and consequential in their effects, they have become named historical events, such as the 19th Century
Potato Blight, also known locally from its primary consequence as the
Great famine, the
Great Famine of Ireland, and
Highland Potato Famine, and the near extinction of the
Bermuda cedar during the 1940s and 1950s in the event described as
The Blight or
The Cedar Blight. ==Gallery==