Abstract: A field experiment was conducted to observe the VA mycorrhizal colonization and subsequent growth and yield of EM (Effective Microorganisms) treated and non-treated sunflower plants, at two growth stages viz., 40 and 70 days after sowing (DAS). In 40-day old plants, EM supported mycorrhizal association, which resulted in a parallel increase in number and biomass of leaves as well as stem length while stem biomass remained almost unaffected. Root growth was, however, slightly suppressed by EM application at this growth stage. EM failed to induce any remarkable change in extent of mycorrhizal infection 70 DAS. However, the arbuscular infection was enhanced by EM application that resulted in a parallel increase in vegetative and reproductive growth of the plant.