Les champignons du genre Trichoderma, connus depuis 1887 pour leurs propriétés antagonistes, ont été utilisés comme agents de lutte biologique contre un large spectre de phytopathogènes. Récemment, certaines études ont démontré l'aptitude des Trichoderma à stimuler la croissance de certaines plantes. Ainsi, l'effet de six souches du Trichoderma sur les paramètres de croissance et de rendement d'une culture de tomate en serre a été étudié. Les résultats montrent que toutes les souches du T. harzianum ont stimulé la croissance de la tomate, notamment les biomasses végétative et racinaire, alors que le T. viride n'a pas eu un effet significativement différent par rapport au témoin. L'effet du Trichoderma sur l'incidence des maladies foliaires a aussi été très net pour des souches de T. harzianum qui ont protégé à 100 % les feuilles de tomate. La colonisation des racines par les différentes souches du Trichoderma ne diffère pas significativement entre les souches du T. harzianum (86 à 100 %), alors qu'elle est significativement plus faible pour la souche TV₁ du T. viride. De même, les souches du Trichoderma ont pu se maintenir à un niveau très élevé dans la rhizosphère par rapport aux témoins.

The cultivation of the olive tree has several problems related to pests and diseases that can cause heavy economic losses by causing the death of trees. Fusarium solani was detected in the olive trees of Sidi Taibi’s nurseries located in the national road between Kénitra and Rabat in spring 2012 and 2013 (1 to 2% of diseased plants). Koch’s postulate was verified in the olive trees variety ‘Picholine Moraine’, inoculated with F. solani. Three months after inoculation of the plants, the extremities of the young buds began to dry out, then the drying became generalized and the roots of the inoculated plants showed rot and detached from the base of the plants. The pathogen was re-isolated from the roots, dried buds, bark and petioles of the leaves of the inoculated plants; the percentage of isolation was 100%.

The diversity of endomycorrhizal fungi in the rhizosphere of Crocus sativus has been studied at five sites in the Taliouine region (Tinfat), located in Taroudant Province (Morocco), according to the number of years of soil exploitation by Saffron cultivation. In all sites, the roots of Crocus sativus carry structures of endomycorrhizal fungi. Root mycorrhizal frequencies are very high in site 1 (93.33%); site 2 (96.67%); site 4 (90%) and in site 6 (93.33%). In these sites, the spore density is, respectively, 39, 58, 138, 99 spores / 100 g of soil. The frequency of root mycorrhization is lower at the site (76.66%) which also exhibited a spore density of 27 spores / 100 g of soil. The identification of isolated spores made it possible to note the presence of 36 species belonging to 6 genera: Glomus (15 species), Acaulospora (10 species), Scutellospora (6 species), Gigaspora (2 species), Pacispora (2 species), Entrophospora (1 species). Species such as Glomus clarum, G. etunicatum, G. aggregatum, G. intraradices, Acaulospora laevis, Scutellospora coralloidea, were present in all studied sites. The greatest richness of MA fungi was registers in the site at four successive years of exploitation by Saffron (24 species), with a Shannon diversity index H ‘= 2.82 which is the highest among all studied sites, followed by the site at six years of occupation by Saffron (21 species), with H ‘= 2.61, while the lowest number of species was recorded in sites of two, three and ten years of exploitation of sol by Saffron, with H ‘= 1.77, respectively; 2.12 and 2.44. This decrease in endomycorrhizal species richness confirms that Crocus sativus residues are probably the cause. In fact, the prolonged occupation of plots with safrana has an allelopathic effect on mycoflora and on the yield of Saffron.

Fusarium equiseti as One of the Main Fusarium Species Causing Wilt and Root Rot of Chickpeas in Morocco