Final diagnosis


Cercospora spp.

Many more or less marked yellow spots are clearly visible on the leaflets of the lower leaves of this tomato plant. <i>Pseudocercospora fuligena</i> (cercospora leaf spot)
On this tomato leaflet, the Sigatoka spots are rather discreet. their outline is ill-defined, and their tint is brownish-yellow. <i>Pseudocercospora fuligena</i>
The underside of this tomato leaf blade reveals rather dense black spore spots. <i>Pseudocercospora fuligena</i> (cercospora leaf spot)
Detail of the black sporiferous down forming under the leaf blade of tomato leaflets. <i>Pseudocercospora fuligena</i> (cercospora leaf spot)
Sur cette foliole de tomate, les taches de cercosporiose sont plus évoluées et bien marquées. elles sont plutôt délimitées par les nervures et révèlent une teinte jaune sale. <i>Pseudocercospora fuligena</i>
En retournant le limbe on peut observer un duvet sporifère noire plus ou moins dense à l'emplacement de chaque tache. <i>Pseudocercospora fuligena</i> (cercosporiose)
Piment-Plante
Classic Sigatoka spots on pepper leaves. The lesions have a grayish center, a darker peripheral border, and present concentric patterns. <i>Cercospora</i> sp.
Brownish leaf spots located on the blade and on the periphery. brownish in color, there are discreet concentric patterns. <i>Cercospora</i> sp.
Detail of the concentric patterns forming inside Sigatoka spots on pepper leaves. <i>Cercospora</i> sp.
On this eggplant leaf, the brown lesions are rather delimited by the veins. Their center has disappeared giving the blade a riddled appearance. <i>Cercospora</i> sp. (cercospora)
On this chlorotic eggplant leaf, there are small brown lesions with a lighter center. <i>Cercospora</i> sp.
Detail of young necrotic spots on the underside of an eggplant leaf. <i>Cercospora</i> sp.
Salades
Strong attack of Sigatoka on lettuce: many lower leaves are now necrotic and dried out. <b><i>Cercospora longissima</i></b>
Young Sigatoka spots on the upper side of the leaf blade of a lettuce; initially moist, they quickly turn brown and a central area remains clear. <b><i>Cercospora longissima</i></b>
Sigatoka spots on the upper side of the leaf blade of a lettuce; note their lighter center, and concentric patterns. <b><i>Cercospora longissima</i></b> (<i>cercospora</i> leaf spot)
Appearance of slightly evolved Sigatoka spots visible on the underside of the leaf blade; notice their clear center. <b><i>Cercospora longissima</i></b>
Detail of cankered, beigeish to brown longitudinal lesions on the midrib of this lettuce leaf. <b><i>Cercospora longissima</i></b>
The spots show a brownish tint; they are also surrounded by a faint yellow halo and concentric patterns are visible on some. <i>Cercospora brassicae</i> (cercospora leaf spot)
By magnifying a little more, we can distinguish a discreet blackish down. <i>Cercospora brassicae</i> (cercospora leaf spot)
Many spots have more or less developed on the lower leaves of this cabbage stalk. They eventually turn yellow and become necrotic. <i>Cercospora brassicae</i> (cercospora leaf spot)
On some spots on cabbage the tissues in the center eventually break down and fall off, giving the leaves a partially riddled appearance. <i>Cercospora brassicae</i> (cercospora leaf spot)
Okra
Young lesions on okra leaf observed by transparency on the underside of the leaf blade. <i>Cercospora</i> sp.
Okra leaf showing different stages of development of lesions on the upper surface of the leaf blade: moist and dark, then chlorotic and finally necrotic and reddish brown. <i>Cercospora</i> sp.
The leaf spots are now rather evolved. the center becomes lighter, while the blade curls slightly. <i>Cercospora</i> sp. (cercospora)
Sigatoka spots on okra leaf studied on the underside of the leaf blade. Note the presence of a blackish mould. <i>Cercospora</i> sp.
Appearance of Sigatoka spots on the underside of an okra leaf. The central tissues are now well necrosed and the sporulation has partly disappeared. <i>Cercospora</i> sp.
Cucurbitacees
A few Sigatoka spots are clearly visible on this watermelon leaf. Note their well-marked yellow halo. <i>Cercospora citrullina</i>
More extensive Sigatoka lesions on watermelon leaf. <i>Cercospora citrullina</i>
The central tissues of this Sigatoka spot on a watermelon leaf have lightened and degraded. There are also some discrete concentric patterns more on the periphery of the alteration. <i>Cercospora citrullina</i>
A few well-defined Sigatoka spots are visible on more or less chlorotic sorossi leaves (<i>Momordica charantia</i>). They show concentric brown patterns. (<i>Cercospora citrullina</i>)
Sigatoka spots on sorossi fruits. (<i>Momordica charantia</i>). In their zone of influence, the extremity of the fruit, the latter has strongly yellowed. (<i>Cercospora citrullina</i>)
Microscopie1.jpg
Several conidiophores emerging from a stomata and conidia are present on this leaf portion observed under a light microscope. <i>Pseudocercospora fuligena</i> (cercospora leaf spot)
Detail of conidiophores emerging from a stomata present on this portion of leaf observed under a light microscope. A few young septate conidia are forming. <i>Pseudocercospora fuligena</i> (cercospora leaf spot)
Appearance of a bunch of tortuous conidiophores of <i>Pseudocercospora fuligena</i>. (cercospora)
Appearance of several subhyaline conidia of <i>Pseudocercospora fuligena</i>, these are almost filiform and have transverse septa. (cercospora)
Tortuous conidiophores and young conidia of .<i>Cercospora</i> sp.
Detail of a young conidium forming at the tip of a melanized conidiophore. Note the presence of a few transverse septa at the base of the spore. <i>Cercospora</i> sp.
This elongated, slightly arched spore of <i>Cercospora</i> sp. has five clearly visible partitions.
Aspect under the light microscope of a cluster of conidiophore of <i>Cercospora</i> sp. There are also some elongated and septate conidia.
Light microscope detail of the elongated, septate conidia of a <i>Cercospora</i> sp. observed on eggplant leaf.
Several unbranched and erect conidiophores of <b> <i> Cercospora longissima </i> </b> (Sigatoka, "<i> cercospora </i> leaf spot") are visible on the epidermis of this leaf. Initially hyaline, they gradually turn brown.
Several unbranched and erect conidiophores of <b><i>Cercospora longissima</i></b> are visible on the epidermis of this leaf. Initially hyaline, they gradually turn brown.
In addition to the unbranched and erect conidiophores located on the right of the photo, we can also distinguish under the light microscope filiform and septate conidia on the left. <b><i>Cercospora longissima</i></b>
The conidia formed at the end of the conidiophores are hyaline and cylindrical. They show from 1 to 18 partitions and measure from 11 to 170 µm in length. <b> <i> Cercospora longissima </i> </b> (Sigatoka, "<i> cercospora </i> leaf spot")
Detail of a young conidium forming at the tip of a melanized conidiophore. Note the presence of a few transverse septa at the base of the spore. <i>Cercospora longissima</i> (cercospora leaf spot)
Several clusters of conidiophores and a few conidia are visible under the light microscope on this okra leaf. <i>Cercospora</i> sp.
The conidiophores of <i>Cercospora abelmoschi</i> have a pale to olive brown hue, (cercospora leaf spot)
Conidia of <i>Cercospora abelmoschi</i>, note that it is smooth, rather cylindrical and slightly curved (25-95 × 2.5-7 μm) (cercospora leaf spot)
Detail of conidiophores produced <i>Cercospora citrulina</i>. They are septate, brown, more or less curved, measuring from 50 to 300 micrometers. and clearer at their end.
The conidia of <i>Cercospora citrulina</i> are solitary, hyaline; straight to slightly curved, with 1 to 16 septa; their length varies from 20 to 270 micrometers.