late blight

Plant Pathol.
a disease of plants, esp. potatoes, celery, etc., characterized by spotting, blighting, and withering or decay of the entire plant, caused by any of several fungi, as Phytophthora infestans or Septoria apii.
[1900-05]

* * *

      disease of potato and tomato plants that is caused by the fungus Phytophthora infestans. The disease occurs in humid regions with temperature ranges of between 40° and 80° F (4° and 29° C); hot, dry weather checks its spread. Potato or tomato vines that are infected may rot within two weeks. The Irish potato famines of the mid-19th century were caused by late blight. The disease destroyed more than half of the tomato crop in the eastern United States in 1946, leading to the establishment of a blight-forecasting service in 1947.

      When plants have become infected, lesions (round or irregularly shaped areas that range in colour from dark green to purplish black and resemble frost injury) appear on the leaves, petioles, and stems. A whitish growth of spore-producing structures may appear at the margin of the lesions on the underleaf surfaces. Potato tubers develop rot up to 15 millimetres (0.6 inch) deep. Secondary fungi and bacteria (Erwinia species) often invade potato tubers and produce rotting that results in great losses during storage, transit, and marketing.

      The Phytophthora fungus survives in stored tubers, dump piles, field plants, and greenhouse tomatoes. Sporangia are airborne to nearby plants, in which infection may occur within a few hours. At temperatures below 59° F (15° C) sporangia germinate by producing zoospores that encyst and later form a germ tube. Above that temperature most sporangia produce a germ tube directly. Foliage blighting and a new crop of sporangia are produced within four to six days after infection. The cycle is repeated as long as cool, moist weather prevails.

* * *


Universalium. 2010.

Look at other dictionaries:

  • late blight — noun blight in which symptoms appear late in the growing season especially a disease of solanaceous plants caused by the fungus Phytophthora infestans • Hypernyms: ↑blight • Hyponyms: ↑celery blight * * * noun : a blight of plants in which… …   Useful english dictionary

  • late blight — noun Date: 1900 a disease of solanaceous plants (as the potato and tomato) that is caused by a fungus (Phytophthora infestans) and is characterized by decay of stems, leaves, and in the potato also of tubers …   New Collegiate Dictionary

  • late blight — /leɪt ˈblaɪt/ (say layt bluyt) noun a serious disease of potatoes caused by the fungus Phytophthora infestans …   Australian English dictionary

  • Blight — refers to a specific symptom affecting plants in response to infection by a pathogenic organism. It is simply a rapid and complete chlorosis, browning, then death of plant tissues such as leaves, branches, twigs, or floral organs. [Agrios, George …   Wikipedia

  • blight — blightingly, adv. /bluyt/, n. 1. Plant Pathol. a. the rapid and extensive discoloration, wilting, and death of plant tissues. b. a disease so characterized. 2. any cause of impairment, destruction, ruin, or frustration: Extravagance was the… …   Universalium

  • Blight — This interesting surname is often confused with the surname Bligh and Blythe . It is not clear why this should be so. Blight derives from the Olde English pre 6th century baptismal or given name Blitha , which means Merry or Gentle , and as such… …   Surnames reference

  • early blight — noun : any of several blights of plants in which symptoms appear early in the season: as a. : a leaf spot especially of the potato and tomato that is caused by a fungus (Alternaria solani) compare late blight b. : a leaf spot of celery caused by… …   Useful english dictionary

  • celery blight — noun a fungous leaf spot disease of the celery plant • Hypernyms: ↑late blight * * * noun : early blight, late blight, or bacterial blight of celery or a combination of these …   Useful english dictionary

  • irish blight — noun Usage: usually capitalized I : late blight …   Useful english dictionary

  • Great French Wine Blight — The Great French Wine Blight was a severe blight of the mid 19th century that destroyed many of the vineyards in France and laid to waste the wine industry. It was caused by an aphid (the actual genus of the aphid is still debated, although it is …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.