INVESTIGATING THE EFFECT OF ARBUSCULAR MYCORRHIZA GLOMUS Sp. AS A BIOFERTILIZER ON LETTUCE PRODUCTION

Arbuscular mycorrhiza used recently as biopesticide has shown beneficial effectson plant growth. An experiment was conducted in West Bekaa in 2016 in order toinvestigate the effect of a commercial biostimulant (MYCOSAT) containing 5Glomus species on the production of two lettuce varieties: Romaine and Iceberg.Plant growth and nutritional quality were compared between mycorrhizal plants(mycorrhizal Romaine: MR and mycorrhizal Iceberg: MI) and non-mycorrhizalplants (non-mycorrhizal Romaine: NMR and non-mycorrhizal Iceberg: NMI).Measurements were done on root and leaf parameters and results showed asignificant positive effect of mycorrhizal inoculation on plant growth. Best resultswere obtained for root parameters as well as leaf area and leaf weight inmycorrhizal plants of both varieties compared to non-mycorrhizal plants. Animprovement was found in root length, root diameter, number of secondary rootsand root weight by 81%, 81%, 61% and 60% for MR plants and of 80%, 88%, 84%and 94% in MR and MI in comparison to NMR and NMI. Leaf number was onlyenhanced in MI plants. The improved crop performance was associated with anameliorated nutritional status with higher percentages of N, P, and K in leaves andwas correlated to a stronger root development in mycorrhizal plants due to theaction of arbuscular mycorrhiza. Finally, the application of the biostimulantMYCOSAT could provide a biological tool for improvement of growth and qualityof lettuce grown in clay soils of West-Bekaa.