Effect of the Combined Treatment of Endomycorrhizal Inoculum and Trichoderma Harzianum on the Growth of Argan Plants

The present study aimed to assess the combined effect of Trichoderma harzianum and a composite endomycorrhizal inoculum on the growth of argan seedlings in nurseries. The dual application of T. harzianum and endomycorrhizal inoculum results in the increase of all growth parameters. Indeed, fresh weight average of aerial and root parts were in the order of (3.43 g) et (6.16 g) respectively, seedling height of 28.75 cm, twigs number 2.16 and stem diameter of 0.77 cm in plants derived from seeds treated with T. harzianum and endomycorrhizal inoculum. Comparatively, the control plants recorded 1.03 g, 1.5 g, 9.33, as mean values of fresh weight of aerial parts, roots parts and argan plants height respectively. Furthermore, the result showed that T. harzianum was recovered from the root of argan plants obtained after seed treatment with the combination of T. harzianum and endomycorrhizal inoculum. The presence of T. harzianum did not avoid the endomycorrhizal structures formation, the proliferation and the sporulation of spore of endomycorrhizal inoculum initially used for inoculation of argan seeds. In this context, an intensity and mycorrhization frequency of 59.9%, 93.33% have been respectively registered. Hence, after eight months of co-inoculation with both T. harzianum and endomycorrhizal inoculum of argan seeds, the analysis of rhizospheric soil of argan plants imparted the existence of 17 endomycorrhizal fungal species which belong to five genus Glomus, Acaulospora, Scutellospora, Entrophospora et Gigaspora.