Nowadays competition for the available water supply, for irrigation, is
increasing. This study which carried out for two seasons aimed to investigate the
effect of vestcutar-arbuscular mycorrhizae 0IAM) and Azotobacter inoculation on
growth and essential oil production of the aromatic plant Achillea millefolium, which
has different usage as a medicinal aromatic plant. Plants were trar.splanted in sandy
soil, which maintained at 50, 75 or 100% of field capacity. In addition to the control
treatment, plants were inoculated with A. cnrcococcum and/or VAM. Field capacity
significantly affected plant growth measured parameters; plant height. herb fresh and
dry weight, flower fresh and dry weight as well as volatile oil yield. Microbial
inoculation, significantly improved plant growth as well as its volatile oil yield
compared with the control plants. The highest essential oil yield of flower tops (0.165
ml/plant) has been estimated when soil inoculated with both of the microorganism and
maintained in 50% FC. Azotobacter inoculation significantly increased N% but not po;.
of yarrow herb however, VAM Significantly increased P% of the herb. Inoculation with
both of microorganisms had a beneficial effect in plant growth especially under lower
levels of FC. Moreover inoculation with both of microorganisms had more pronounced
eHect than single inoculation.