Difference between revisions of "Team:Bordeaux/Problem"
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<h6 align= "justify"> A bit of History </h6> | <h6 align= "justify"> A bit of History </h6> | ||
− | <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> ( | + | <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 caused considerable damage. However, the lack of copper 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;"> In particular, the Aquitaine region is menaced due to it's favorable (?) climate and the economic importance of the wine industry. Thus, 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. Thus, 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> | ||
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<p align="justify" style="text-indent: 3vw;"> 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. </p> | <p align="justify" style="text-indent: 3vw;"> 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. </p> | ||
− | <p align="left"> <b> | + | <p align="left"> <b>Literature Cited: </b> </p> |
+ | <p align="left"> [1] <i>Plasmopara viticola</i>: a review of knowledge on downy mildew of grapevine and effective disease management. <i> Phytopathol. Mediterr. (2011) 50, 3-44 </i></p> | ||
+ | <p align="left"> [2] Bouillies bleues et vignes bleues. 7e année d'expériences. <i> Progres Agricole et Viticole. (1923) 40, 380-382 (2011) 50, 3-44 </p> | ||
+ | <p align="left"> [3] Les leçons du mildiou en 1930 <i> Progres Agricole et Viticole (1931) 95, 187-188 </p> | ||
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<h6 align="justify"> Infection Mode of Downy Mildew</h6> | <h6 align="justify"> Infection Mode of Downy Mildew</h6> | ||
− | <p align="justify" style="text-indent: 3vw;"> Downy mildew requires | + | <p align="justify" style="text-indent: 3vw;"> Downy mildew requires a warm, moist, and humid environment to reproduce and infect the plant. </p> |
<p align="justify"> In winter, <i> Plasmopara viticola </i> is present on dead leaves on the ground as oospores. They are inactive and do not produce any symptoms. When rain falls during spring, these eggs grow and release zoospores when the temperature exceeds 11 degrees. The zoospores will be able to spread and infect the plant's upper tissues through rainwater's splashes. </p> | <p align="justify"> In winter, <i> Plasmopara viticola </i> is present on dead leaves on the ground as oospores. They are inactive and do not produce any symptoms. When rain falls during spring, these eggs grow and release zoospores when the temperature exceeds 11 degrees. The zoospores will be able to spread and infect the plant's upper tissues through rainwater's splashes. </p> | ||
<p align="justify">The primary contamination begins by the emission of a filament through the stomatal area where the parasite begins to develop sinkers from which is formed the mycelial network. These sinkers help to feed <i>Plasmopara viticola </i> by stealing the plant's nutrients, which creates discolored and yellowish areas on the it's leaves called “oil stains”. After, on leaves bottom, conidiophores and conidia are formed. These symptoms cause damages to the leaves’ tissues and affect the plant’s photosynthetic ability, which slows down the maturity of the plant.</p> | <p align="justify">The primary contamination begins by the emission of a filament through the stomatal area where the parasite begins to develop sinkers from which is formed the mycelial network. These sinkers help to feed <i>Plasmopara viticola </i> by stealing the plant's nutrients, which creates discolored and yellowish areas on the it's leaves called “oil stains”. After, on leaves bottom, conidiophores and conidia are formed. These symptoms cause damages to the leaves’ tissues and affect the plant’s photosynthetic ability, which slows down the maturity of the plant.</p> |
Revision as of 23:55, 31 July 2015