Effect of biofertilizers and organic phosphorus amendments on growth and essential oil of marjoram (Majorana hortensis L.)

The effect of bacterial inoculation (biofertilization) and application of faba bean straw and sheep manure considered by the authors to be organic phosphorus sources to marjoram plants that cultivated in field experiment of Atomic Energy Authority, Inshas, Egypt was studied. Faba bean straw and sheep manure were added at rate of 1500 kg P/ ha of both residues. Residues were incorporated into the soil one month prior to marjoram cultivation. Marjoram (root cutting) was inoculated with either B. polymixa and/ or Bradyrhizobium sp. .The results showed that, growth parameter of marjoram plants were positively affected by bacterial inoculation as well as organic phosphorus sources at three cuts. The herb and oil yield were the highest in case of the combination between sheep manure and B. polymixa at the 2nd cut than in control. Nutrient uptake of marjoram plants positively responded to bacterial inoculation and the concerned organic phosphorus sources. The chemical composition of marjoram essential oil did not change due to the bacterial inoculation or applied residues, but the percentages of certain constituents were affected.