Final diagnosis

Elsinoe ampelina (Anthracnose)

On this vine, it is difficult to distinguish several young grape leaves affected by <i> <b> Elsinoë ampelina </b> </i>.

The lesions caused by <i> <b> Elsinoë ampelina </b> </i> gradually spread. The blade is more or less deformed in the parts affected by the numerous spots.

By necrosis and drying, the spots lighten in their center. <i> <b> Elsinoë ampelina </b> </i>

Detail of young lesions on vine leaves. <i> <b> Elsinoë ampelina </b> </i>

Moist, dark brown lesions on grape leaf. <i> <b> Elsinoë ampelina </b> </i>

n spots several millimeters in diameter mar the blade of this vine leaf. Note that they are more or less angular and arranged along the ribs. <i> <b> Elsinoë ampelina </b> </i>

Appearance of reddish-brown spots of anthracnose observed on the underside of the leaf blade. <i> <b> Elsinoë ampelina </b> </i>

Necrotic leaf tissue eventually tears, decomposes, and sometimes drops, giving the blade a riddled appearance. <i> <b> Elsinoë ampelina </b> </i>

On this young leaf, the lesions quickly spread and converged. In the end, a large proportion of the blade is damaged and has taken on a reddish-brown tint. <i> <b> Elsinoe ampelina </b> </i>

Be careful not to confuse on certain grape varieties the leaf spots of anthracnose (left leaf) with those of mildew (right leaf) <i> <b> Elsinoë ampelina </b> </i>.

The spots are rather extensive, sometimes confluent, and begin to split. <i> <b> Elsinoë ampelina </b> </i>

Affected inflorescences turn more or less partially brown. <i> <b> Elsinoë ampelina </b> </i>

The tip of this young shoot is almost completely altered. Young leaves with tender tissue are completely necrotic, while numerous canker lesions, sometimes confluent, cover the herbaceous stem. <b><i>Elsinoë ampelina</b></i>

Young lesions on herbaceous branch, rather moist and elliptical in shape. <i> <b> Elsinoë ampelina </b> </i>

More advanced canker lesions on a vine branch. Their center was necrotic, thinned, and the superficial tissues cracked longitudinally. <i> <b> Elsinoë ampelina </b> </i>

Three zoospores germinated near the sporangium from which they were formed and then released. (view with a scanning microscope) <i><b> Plasmopara viticola </i> </b>

Cankerous and confluent changes at the base of a twig. This is sometimes deeply altered making it more brittle. Note the presence of lesions on the branch formed last year. <i> <b> Elsinoë ampelina </b> </i>

This extensive lesion at the base of this twig, caused by <i> <b> Elsinoë ampelina </b> </i>, should not be confused with excoriose damage.

Several canker lesions dot this old vine wood. <i> <b> Elsinoë ampelina </b> </i>

Appearance of old lesions present on the woods formed last year. It is in particular on the latter that sclerotia are found from which the primary inoculum is formed. <i> <b> Elsinoë ampelina </b> </i>

Detail of circular lesions on grape berries. Lighter in center, they are reddish brown to black at the periphery. <i> <b> Elsinoë ampelina </b> </i>

Many berries of this cluster are affected by dark circular spots, sometimes confluent, caused by <i> <b> Elsinoë ampelina </b> </i> responsible for anthracnose on vines.

On this cluster, some berries are completely damaged. We can measure the destructive potential of <i> <b> Elsinoë ampelina </b> </i> on vines.

Appearance of different stages of development of lesions induced by <i> <b> Elsinoë ampelina </b> </i> parasitism.

Some berries affected early are completely spoiled and shriveled. <i> <b> Elsinoë ampelina </b> </i>

The altered pellucule of these berries affected by <i> <b> Elsinoë ampelina </b> </i> locally suberized, which could subsequently lead to their bursting.

Spore pads formed on these two lesions observed on a vine branch. <i> <b> Elsinoë ampelina </b> </i>

Spore pads, acervules, begin to form on this young vine branch vine lesion. <i> <b> Elsinoë ampelina </b> </i>

Appearance of several young acervuli of <i> <b> Elsinoë ampelina </b> </i> observed under an optical microscope.

Young conidiophores emerging from the cuticle of the broken leaf (two young acervules). <i> <b> Elsinoë ampelina </b> </i>

Concentration of conidiophores at the end of which they begin to form conidia (mature acervule). <i> <b> Elsinoë ampelina </b> </i>

$Hyaline conidia are cylindrical-ovoid in shape, are rather short, measure 3-7.5 x 2-5 microns, and exhibit one to two refractive points. <i> <b> Elsinoë ampelina </b> </i>$

Formation des conidies de la forme anamorphe d'<i><b>Elsinoë ampelina</b></i> (anthracnose)

Appearance of the subcuticular mycelium consisting of short and torular articles. <i> <b> Elsinoë ampelina </b> </i>

Anthracnose lesions on herbaceous tendrils, of humid and elliptical shape. <i> <b> Elsinoë ampelina </b> </i>

Appearance on nutrient medium in Petri dish of colonies of <b> <i> Elsinoë ampelina </i> </b>, agent of anthracnose in grapevine.