Difference between revisions of "Team:Bordeaux/Problem"
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<p align= "justify" style="text-indent: 3vw;"> Downy Mildew was originally observed in the United States of America in 1834 and has been most abundantly found in the Northern and mid-Western areas of the United States. Shortly after, the pathogen was introduced in European countries where it played a devastating role in the yield and production of their wine. In <b>1878</b>, the <b>first cases of Downy mildew were observed in France </b> (in the region of Lyon) and also in Swizerland and Italy. While some North American species have become resistant to this parasite, European species such as <i> Vitis vinifera </i> (the grapevine used for wine) are extremely sensitive. From the beginning of the 20th century, the disease was clearly a huge problem for European viticulture. In the years in which weather conditions were favorable and sufficient control measures were not yet availabe or were not applied, serious damage was caused to viticulture in Germany, France and Switzerland. For example in 1915, 70% of the French grape crop was lost to <i> P. viticola </i> ([2],[3]). In 1930, 20 million hl of wine were lost in France. from 1907 to 1916, downy mildew was responsible for a 33% reduction in the total vine-growing area in the Baden province of Germany (Müller, 1938). During the Second World War, this disease also caused considerable damage. However, the lack of copper for pesticides contributed to this situation more than unfavourable weather conditions (Hadorn, 1942). As an example, it was reported that the normal Swiss copper requirements for agriculture in 1942 would have amounted to 1550 tons but due to the war situation, the government allocated only 690 tons, of which 300 tons were allocated for the potato crop and 320 tons were allocated for viticulture. The remaining copper was allocated for orchards, beans, tomatoes, celery and onions. [1] </p> | <p align= "justify" style="text-indent: 3vw;"> Downy Mildew was originally observed in the United States of America in 1834 and has been most abundantly found in the Northern and mid-Western areas of the United States. Shortly after, the pathogen was introduced in European countries where it played a devastating role in the yield and production of their wine. In <b>1878</b>, the <b>first cases of Downy mildew were observed in France </b> (in the region of Lyon) and also in Swizerland and Italy. While some North American species have become resistant to this parasite, European species such as <i> Vitis vinifera </i> (the grapevine used for wine) are extremely sensitive. From the beginning of the 20th century, the disease was clearly a huge problem for European viticulture. In the years in which weather conditions were favorable and sufficient control measures were not yet availabe or were not applied, serious damage was caused to viticulture in Germany, France and Switzerland. For example in 1915, 70% of the French grape crop was lost to <i> P. viticola </i> ([2],[3]). In 1930, 20 million hl of wine were lost in France. from 1907 to 1916, downy mildew was responsible for a 33% reduction in the total vine-growing area in the Baden province of Germany (Müller, 1938). During the Second World War, this disease also caused considerable damage. However, the lack of copper for pesticides contributed to this situation more than unfavourable weather conditions (Hadorn, 1942). As an example, it was reported that the normal Swiss copper requirements for agriculture in 1942 would have amounted to 1550 tons but due to the war situation, the government allocated only 690 tons, of which 300 tons were allocated for the potato crop and 320 tons were allocated for viticulture. The remaining copper was allocated for orchards, beans, tomatoes, celery and onions. [1] </p> | ||
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− | <h6 align= "justify"> Favorable conditions </h6> | + | <h6 align= "justify"> Favorable conditions in Aquitaine </h6> |
− | <p align="justify" style="text-indent: 3vw;"> Downy mildew requires a warm, moist, and humid environment to reproduce and infect the plant. Generally, a correlation exists between low rainfall during the winter-spring period and slight epidemics, although an abundance of rain during the same period does not appear to be sufficient in the absence of at least two primary infection events (Baldacci, 1947). Mature oospores germinate best if their outer walls are ruptured, possibly as a result of a light freeze and sufficient humidity. The germination of oospores requires soil temperatures of 12 to 13°C (occasionally 11°C) and moisture. Common symptoms include necrosis of the stem or shoot, discoloration, brown spotting and yellowish-green tips of the leaves and mycelium invasion of the grapes. [1] </p> | + | <p align="justify" style="text-indent: 3vw;"> Downy mildew requires a warm, moist, and humid environment to reproduce and infect the plant, which is the case in the Aquitaine region. Generally, a correlation exists between low rainfall during the winter-spring period and slight epidemics, although an abundance of rain during the same period does not appear to be sufficient in the absence of at least two primary infection events (Baldacci, 1947). Mature oospores germinate best if their outer walls are ruptured, possibly as a result of a light freeze and sufficient humidity. The germination of oospores requires soil temperatures of 12 to 13°C (occasionally 11°C) and moisture. Common symptoms include necrosis of the stem or shoot, discoloration, brown spotting and yellowish-green tips of the leaves and mycelium invasion of the grapes. [1] hus, Downy mildew has been considered the most <b> devastating disease </b> caused by a <b> filamentous pathogen </b> to affect European vineyards and this has lead vineyards to search for effective measures to protect their vines. Unfortunately, most of these mesures have a bad environmental impact and pollute the surrounding soils. </p> |
+ | <p align= "justify" style="text-indent: 3vw;"> In particular, the Aquitaine region is menaced due to it's favorable (?) climate and the economic importance of the wine industry. T </p> | ||
+ | <!-- --------------------------------------------- BIBLIO 1 ---------------------------------------------------------- --> | ||
<p class="reference" align="left"> <b>Literature Cited: </b> </p> | <p class="reference" align="left"> <b>Literature Cited: </b> </p> |
Revision as of 13:30, 3 August 2015