ABSTRACT 

The aim of this study was to investigate the effects of “Arbuscular mycorrhizal fungi” (AM fungi) density and different growing media on the growth, photosynthesis parameters and yield of sweet pepper under greenhouse conditions. The experiment was conducted as a factorial plan based on control randomized design (CRD ) by using three growing media, Perlite (PR) and cocopeat (Co) (PR50:Co50 V:V) (C), PR25:Co50: vermicompost (V) 25 (C+V25) and PR25:Co25: V50 (C+V50), and three levels of AM fungi inoculation (0, 1000 and 2000 spores) with three replications. Results indicated that AM fungi inoculation and mixture of vermicompost increased shoot and root fresh weights, Total Suspended Solids (TSS), fruit fresh and dry weights in the C+V50 compared to other treatments. Fruit yield increased more than 100 and 94.95% with AM-fungi inoculation with 2000 spores at C+V25 and V50 treatments, respectively. Mycorrhiza dependency decreased with high application rate of vermicompost, and vermicompost dependency was the highest in non-inoculated plants. With AM-fungi inoculations, the chlorophyll level (SPAD values) was increased in C+V25 by 100%.  Photosynthesis rate was increased in C+V25×M1 significantly compared to other treatments. Nitrogen, phosphorus, and potassium concentrations significantly increased by mycorrhiza inoculation in the high vermicompost ratio.