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13-580: 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: On leaf tissue, symptoms of blight are the initial appearance of lesions which rapidly engulf surrounding tissue. However, leaf spots may, in advanced stages, expand to kill entire areas of leaf tissue and thus exhibit blight symptoms. Blights are often named after their causative agent. For example, Colletotrichum blight

26-550: Is a needed component in the production of chlorophyll. Chlorosis is typically caused when leaves do not have enough nutrients to synthesise all the chlorophyll they need. It can be brought about by a combination of factors including: However, the exact conditions vary from plant type to plant type. For example, Azaleas grow best in acidic soil and rice is unharmed by waterlogged soil. Like many other plants, grape vines are susceptible to chlorosis, and symptoms of iron deficiency tend to be common on soils rich in limestone . In

39-457: Is almost exclusively grown in the wine region of Baden under the name Gutedel . In France it is mostly grown in the Loire region , where it is blended with Sauvignon blanc to produce a wine called "Pouilly-sur-Loire". Californian and Australian growers know this variety under the names Chasselas Doré and Golden Chasselas . Michel Chapoutier has stated that he is looking for land for

52-538: Is mostly vinified to be a full, dry and fruity white wine. It is also suitable as a table grape , grown widely for this purpose in Turkey and Hungary . Genetic analyses made in 2009 in a laboratory of the University of Dieppe showed that Chasselas is a grape variety originating in western Switzerland. Its name was first mentioned in the 16th century. In 1940, Chasselas was crossed with Silvaner to produce

65-548: Is named after the fungus Colletotrichum capsici , and Phytophthora blight is named after the water mold Phytophthora parasitica . 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

78-488: Is necessary for the viticulturalist to balance the need for chlorosis resistance against other viticultural needs. This is illustrated by one of the most common lime-resistant rootstocks, 41 B, which is a hybrid between V. vinifera cultivar Chasselas and V. berlandieri , which generally has a sufficient, but not extremely high, Phylloxera resistance. Specific nutrient deficiencies (often aggravated by high soil pH ) may be corrected by supplemental feedings of iron , in

91-451: The cause of its chlorophyll insufficiency is treated and this may lead to a plant disease called rusts , although some chlorotic plants, such as the albino Arabidopsis thaliana mutant ppi2 , are viable if supplied with exogenous sucrose . The word chlorosis is derived from the Greek khloros meaning "greenish-yellow", "pale green", "pale", "pallid", or "fresh". In viticulture ,

104-565: The form of a chelate or sulphate , magnesium or nitrogen compounds in various combinations. If the soil is too acidic, applying lime can raise the pH to the proper range, making more nutrients available to the plant. Likewise, sulfur can be used to lower soil pH if it is too alkaline. Chasselas Chasselas or Chasselas blanc is a wine grape variety grown mainly in Switzerland , France , Germany , Portugal , Hungary , Romania , New Zealand , Croatia and Chile . Chasselas

117-555: The lime-rich soils that were common in France's vineyards, in particular many of those that produced wines of top quality. Many grafted vines in lime-rich vineyards therefore showed signs of iron deficiency, and in France this specific form of chlorosis was termed chlorose calcaire. The problem was largely overcome by the selection of lime-resistant American vines as basis for hybrid vines used for rootstock material. However, since such rootstocks may be less than optimal in other respects, it

130-679: The most common symptom of poor nutrition in grapevines is the yellowing of grape leaves caused by chlorosis and the subsequent loss of chlorophyll. This is often seen in vineyard soils that are high in limestone such as the Italian wine region of Barolo in the Piedmont , the Spanish wine region of Rioja and the French wine regions of Champagne and Burgundy . In these soils the grapevine often struggles to pull sufficient levels of iron which

143-531: The near extinction of the Bermuda cedar during the 1940s and 1950s in the event described as The Blight or The Cedar Blight . Chlorosis In botany , chlorosis is a condition in which leaves produce insufficient chlorophyll . As chlorophyll is responsible for the green color of leaves, chlorotic leaves are pale, yellow, or yellow-white. The affected plant has little or no ability to manufacture carbohydrates through photosynthesis and may die unless

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156-469: The wake of The Great French Wine Blight , when European Vitis vinifera were affected by Phylloxera , chlorosis became a greater problem in viticulture . To deal with the Phylloxera blight, V. vinifera was grafted onto rootstock based on American species of the genus Vitis , such as Vitis riparia , Vitis rupestris , and Vitis berlandieri . However, many of these were less adapted to

169-585: The white grape variety Nobling . Chasselas is widely grown in Switzerland, where it has several regional synonym names, the main one being Fendant in the canton of Valais . It is considered an ideal pairing for raclette or fondue . Chasselas is also known as Perlan in the Mandement district of Geneva. In 2009, it was Switzerland's second-most planted grape variety at 4,013 hectares (9,920 acres). In Germany, with 1,123 hectares (2,770 acres), it

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