ABSTRACT
Two field trials were conducted during the two successive seasons (1997/98 and 1998/99) to evaluate the effect of dual inoculation with diazotrophs (Azotobacter chroococcum or Azospirillum brasilense) combined with either Bacillus megatherium var. phosphaticum or (VAM) Glomus mosseae in the presence of half dose of inorganic N-fertilizer on growth, chemical constituents, yield and volatile oil content of coriander plants. The results revealed that dual inoculation of coriander seeds with non-symbiotic N2-fixers and phosphate solubilizers increased the available phosphorus content of the soil. This increase was accompanied by the highest values of phosphate dissolving bacteria densities and mycorrhizal root infection percentage. Combined inoculation of Azotobacter chroococcum and Glomus mosseae increased values of nitrogenase activity and ammoniacal and nitrate nitrogen contents of coriander plant rhizosphere. Inoculation with Azotobacter or Azospirillum combined with Glomus mosseae gave significant increases in vegetative growth, total carbohydrates, photosynthetic characteristics, essential oil, seed parameters, nitrogen, phosphorus and potassium contents of coriander plants. Volatile oil constituents were determined with GLC analysis. It was found that linalool was the major constituent in the oil of coriander seeds. Maximum values of linalool were obtained in treatments inoculated with Azotobacter or Azospirillum in the presence of Glomus mosseae.

Key words :-
Coriandrum sativum , Azotobacter, Azospirillum ,Glomus , vegetative growth and volatile oils.