Effectiveness of Selected Microbial Strains on the Growth of Sweet Sorghum

Microbial inoculants are of great importance in agro-ecology and plants. However, the symbiotic effectiveness of strains may vary between species or within the same species. Aim of the study was to select experimental microbial strains of national origin, to know its impact on growth of sweet sorghum (Sorghum bicolor) in greenhouse and sterile soil. Five strains of arbuscular mycorrhizal fungi (AMF) and eight rhizobacteria (two of them mutagenized) were compared with non-inocu-lated plants as control. Variables measured were index of chlorophyll SPAD, plant height, stem diameter (from the middle section), fresh biomass from stem, leaf, panicle, radical, and stem su-gars content (˚Brix) of every two internodes. The results showed that in the majority of cases, mi-crobial strains exceeded the values of variables compared with control plants. The highest values of chlorophyll (41.8 SPAD), stem diameter (13.5 mm) and total fresh biomass (144.3 g), were rec