Final diagnosis


Plasmopara viticola (Downy mildew)

Foliar tasks appearing in early infection <b><i>Plasmopara viticola</i></b> are translucent, oily appearance. Foliar tasks Appearing early in infection Plasmopara viticola are translucent, oily appearance. That is why we speak of Commonly "oil spots". Downy mildew
<i> <b> Plasmopara viticola </b> </i>: upper surface of a leaf affected by downy mildew.
The leaf spots caused by <b> <i> Plasmopara viticola </i> </b>, which are initially oily, take on a necrotic brown color.
Leaf spots caused by <i> <b> Plasmopara viticola </b> </i> turn yellow and then become necrotic as the disease progresses.
The leaf spot Caused by <i><b>Plasmopara viticola</b></i> are all oily yellow translucent first And Then Quickly, as is the case is this sheet. Downy mildew
Large chlorotic leaf spots induced by <i> <b> Plasmopara viticola </b> </i>.
Large anthocyanin leaf spots induced by <i> <b> Plasmopara viticola </b> </i> on certain grape varieties.
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The "oil spots" observable at the start of <b> <i> Plasmopara viticola </i> </b> infection on leaves subsequently spread and turn yellow to necrotic. Downy mildiew
Mosaic mildew on upper surface of vine leaf: numerous small chlorotic lesions, often delimited by veins, appear on the leaf blade. <i> <b> Plasmopara viticola </b> </i> (Mildew)
Mosaic mildew on the underside of a vine leaf: the numerous and small lesions often delimited by the veins are covered with a whitish sporulation. <i> <b> Plasmopara viticola </b> </i> (Mildew)
Mosaic mildew beginning on a vine leaf. We can distinguish numerous small chlorotic lesions, often delimited by veins, appearing on the leaf blade. <i> Plasmopara viticola </i> (<b> Mildew </b>)
Detail of the first spots of mosaic mildew on a vine leaf: the lesions gradually necrotize. <b> <i> Plasmopara viticola </i> </b> (Mildew)
Facies of leaf mildew observed on certain grape varieties. <b> <i> Plasmopara viticola </i> </b>
End-stage mosaic mildew. <b> <i> Plasmopara viticola </i> </b> (Mildew)
The "mosaic mildew" facies on a vine leaf is made up of small polygonal spots. First chlorotic, they quickly become necrotic as is the case in this photo. <i> <b> Plasmopara viticola </b> </i>
This type of symptom, called "mosaic mildew", caused by <b> <i> Plasmopara viticola </i> </b> on a vine leaf, is here at an advanced stage: the disparate spots join together and become necrotic.
<b> <i> Plasmopara viticola </i> </b>: underside of a leaf affected by downy mildew.
On the underside of the leaves, the presence of <b> <i> Plasmopara viticola </i> </b> is manifested by the appearance of a white down on the back of the "oil spots" observable on the upper side. Downy mildiew
<b><i>Plasmopara viticola</i></b> (Mildew)
Sporulation generalized on the underside of the leaf blade. <b> <i> Plasmopara viticola </i> </b> (downy mildew)
Generalized attack of mildew on vine foliage. Many leaves are more or less completely necrotic and withered. <b> <i> Plasmopara viticola </i> </b>
The vines attacked by <i> <b> Plasmopara viticola </b> </i> (on the left) are desiccated and defoliated compared to the healthy vines (on the right).
These inflorescences were attacked by <i> <b> Plasmopara viticola </b> </i> which is starting to fruit on the surface.
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The fruiting bodies of <b> <i> Plasmopara viticola </i> </b> on this cluster are the cause of the "<b> gray burp </b>" symptom. (mildew)
<b> <i> Plasmopara viticola </i> </b>: symptom of "gray burp" on immature berries. The mildew agent sporulated heavily on the latter once colonized.
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Appearance of gray burp ending, even brown burping beginning on grape berries. <b> <i> Plasmopara viticola </i> </b> (downy mildew)
Fruiting bodies of <b> <i> Plasmopara viticola </i> </b> are still present on these berries showing a symptom of brown burping. (<b> gray rot </b>). (downy mildew)
Detail of <b> <i> Plasmopara viticola </i> </b> fruiting bodies still present on this berry showing a symptom of brown burping. (<b> gray rot </b>). (downy mildew)
Young cluster strongly affected by <i> <b> Plasmopara viticola </b> </i>. (downy mildew)
Appearance of brown burp on grape berries. <b> <i> Plasmopara viticola </i> </b> (downy mildew)
Appearance of brown burp on grape berries. <b> <i> Plasmopara viticola </i> </b> (downy mildew)
Symptom of <b> brown burp </b> on grape berries <b> <i> Plasmopara viticola </i> </b> (downy mildew)
On some berries, brown to blackish spots, depressed "in boost", can be observed. Some of them are more or less shriveled. <b> <i> Plasmopara viticola </i> </b> (Downy mildew, "<b> brown rot </b>")
Larva of <i> <b> Panonychus ulmi </b> </i> seen from below. (red spider)
The facies called "gray burp" can also be found on a tendril. <i> <b> Plasmopara viticola </b> </i>
When the climatic conditions are favorable, one can easily observe the sporulation of <i> Plasmopara viticola </i> on the surface of the contaminated organs. <b> mildew </b>
When the climatic conditions are favorable, one can easily observe the sporulation of <i> <b> Plasmopara viticola </b> </i> on the surface of the contaminated organs. <b> Downy mildew </b>
High concentration of sporangiophores on the blade of a vine leaf. <b> <i> Plasmopara viticola </i> </b>. (mildew)
Arbusculous sporangiophores of <b> <i> Plasmopara viticola </i> </b> observed with a binocular magnifying glass. (mildew)
Outline of a sporangiophore emerging from a stomata on a vine leaf. (view under a scanning microscope) <i> <b>Plasmopara viticola </i></b> (Nathalie PICHON)
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Young sporangiophore of <b> <i> Plasmopara viticola </i> </b>. outgoing observed under a light microscope. (mildew)
Appearance under a light microscope of a bushy sporangiophore of <b> <i> Plasmopara viticola </i> </b> carrying young sporangia. (mildew)
Several sterigmas located at the end of this sporangiophore are clearly visible. They carry young sporangia of <b> <i> Plasmopara viticola </i> </b>. (mildew)
Detail of the sterigmas present at the ends of the arbuscular sporangiophores and on which the sporangia are formed. (view under a scanning microscope) <i><b> Plasmopara viticola </i></b> (Nathalie PICHON)
Appearance of several ovoid to piriform sporangia of <b> <i> Plasmopara viticola </i> </b>. (mildew)
Three zoospores germinated near the sporangium from which they were formed and then released. (view with a scanning microscope) <i><b> Plasmopara viticola</b> </i>
Zoospore of <i> <b>Plasmopara viticola </i></b> having germinated on the surface of a vine leaf (seen under a scanning microscope). (Nathalie PICHON)
Several <i> Plasmopara viticola </i> oospores have recently formed on this <b> Grapevine mildew </b> leaf.
Detail of an oospore of <i> Plasmopara viticola </i> compared to two sporangia located on the left in the photo. <b> downy mildew </b>.
Detail of a young thick-walled <i> <b>Plasmopara viticola </i> </b>oospore, observed under a light microscope.
Thick-walled oospores (20-120 µm in diameter) of <i> Plasmopara viticola </i> can be observed in contaminated tissues late in the season. They are yellow in color and represent the sexual reproduction of <b> Downy mildew </b>.
On this leaf which has spent the winter on the ground, we observe the presence of a germinal filament carrying at its end a macroconidia at the origin of the primary inoculum. <b> <i> Plasmopara viticola </ i > </b> (mildew)
légende à venir
In spring, the oospores of <i> Plasmopara viticola </i> germinate, forming a germ tube ending in a piriform macroconidia (28x36 µm); the latter will produce 30 to 50 zoospores. <b> Downy mildew </b>