Influence of Organic-Biofertilizers and Foliar Spray with Different Biostimulants on Increasing Yield and Essential Oil of sweet marjoram (Marjorana hortensis L.) Plant

Given the importance of medicinal and aromatic plants in various medical and food industries, it is important to apply the organic production methods. A field trail was performed at the research farm of Medicinal and Aromatic Plants Department, Horticulture Research Institute (HRI), Agriculture Research Center (ARC), Dokki, Giza, Egypt, throughout two consecutive growing seasons 2020/2021 and 2021/2022. Aims to investigate the effect of spraying by various biostimulants (seaweed extract, fulvic acid and humic acid at 10 ml/L.) on vegetative growth, yield, essential oil content plus several chemical compositions of marjoram plant fertilized with organic-biofertilizers. Soil health indicator was also studied by determining the biological activity of soil enzymes. The results showed that, plants fertilized with organic-biofertilizers and sprayed with the biostimulant seaweed extract recorded the highest significant values for all studied traits, followed by plants sprayed with fulvic acid extract compared to control treatment (mineral fertilizers alone). So, the application of these biostimulants could be promoted organic marjoram production, which is compatible with sustainable development goals and food security.