Final diagnosis


Stemphylium spp. (stemphyliose)

Several small brown spots dot the leaflets of this tomato leaf. <i> <b> Stemphylium solani </b> </i> (stemphyliosis)
The spots are small, brownish and dull, and the center gradually lightens to a beige tint. <i> <b> Stemphylium solani </b> </i> (stemphyliosis)
Small, slightly angular spots (2 to 10 mm in diameter) initially brown, the center of which becomes lighter (gray) and splits, chlorosis of the lamina at the periphery of the spots <b> <i> Stemphylium vesicarium </i> </b> (stemphyliosis, gray leaf spot)
Slightly angular brown spots, split in the center, chlorosis of part of the blade. <b> <i> Stemphylium vesicarium </i> </b> (stemphyliosis, gray leaf spot)
Heavily affected leaflets may turn yellow and even dry out. <i> <b> Stemphylium solani </b> </i> (stemphyliosis)
The conidiophores are quite comparable to those of the preceding species; they bear unique conidia, more brown in color, which are rounded at their ends. <b> <i> Stemphylium vesicarium </i> </b> (stemphyliosis, gray leaf spot)
A common saprophyte, <b> <i> Stemphylium botryosum </i> </b> forms verrucous conidia with rounded ends, brown and multicellular (15-24 x 24-33 µm). <b> Black mold rot </b>
<i> <b> Stemphylium vesicarium </b> </i> presents conidia with rounded ends, echinulate wall, presenting 2 to 4 constrictions. They also have a brown tint, a rectangular shape and measure 26-44 x 12-20 µm. The perfect form of the fungus, <i> Pleospora allii </i>, is formed on artificial medium in vitro. <b> Stemphyliosis (gray leaf spot) </b>
Olive-colored and with a swollen apex, these conidiophores are septate and measure 75-300 µm x 3-5.5 µm. The conidia are also pointed but they are longer than those of <i> Stemphylium solani </i>. <b> <i> Stemphylium lycopersici </i> </b> (<i> S. floridanum </i>, stemphyliosis, gray leaf spot)
Also muriform and pointed at one end, the conidia, of an olive hue, are longer (19.9-62.2 x 4.6-23 µm) and present more numerous and fairly marked constrictions. <b> <i> Stemphylium lycopersici </i> </b> (<i> S. floridanum </i>, stemphyliosis, gray leaf spot)
We can distinguish a few brown and pointed conidia in the middle of brown and partitioned conidiophores (130-200 x 4-7 µm). <b> <i> Stemphylium solani </i> </b> (stemphyliosis, gray leaf spot)
The conidia are muriform, very brown when mature, rounded at one end and pointed at the other. Their average dimensions are of the order of 48 x 22 µm. <b> <i> Stemphylium solani </i> </b> (stemphyliosis, gray leaf spot)