https://doi.org/10.37229/fsa.fjas.2026.10.02

A field experiment was conducted at the field station of the Department of Horticulture and Landscape Design, College of Agriculture and Forestry, University of Mosul, during the 2025–2026 growing season. The experiment was designed according to a split-split plot arrangement within a Randomized Complete Block Design (RCBD) with three factors, three replicates, and ten plants per replicate. It aimed to evaluate the physiological and productive response of borage plants (Borago officinalis L.) to mineral fertilization with NPK, treatment with the Bio Health preparation, and spraying with amino acids, as well as to study the effect of binary and triple interactions among them on improving vegetative and root growth, flowering, yield, and some chemical traits of the plant. The results clearly showed that the plant's response did not depend on the effect of any single factor alone, but rather was the outcome of functional integration among mineral nutrition, biostimulants, and amino acids - a matter directly reflected in improving the plant's physiological performance and increasing its productive efficiency. Mineral fertilization with NPK improved most of the studied traits compared to the control, particularly at the 100 kg·ha^-1 level, which increased plant height, number of branches, leaf area, and number of leaves, reaching (96.46 cm, 21.68 branch·plant^-1, 608.94 cm²·plant^-1, and 89.00 leaf·plant^-1), respectively. This was also reflected in improved number of flowers, flowering duration, and dry weight of the flower cluster, which increased to (3026.11 flower·plant^-1, 74.02 days, 5.21 g), respectively. Furthermore, at the NPK level of 150 kg·ha^-1, root growth was enhanced, with increased root length and dry weight, reaching (82.57 cm and 13.82 g), respectively. Total yield increased to 481.75 kg·ha^-1, in addition to raising the concentration of estimated nutrients in the leaves - most importantly nitrogen, phosphorus, and potassium, whose average values reached approximately (2.63%, 0.31%, and 0.67%), respectively. The results also showed that using Bio Health at 3 kg·ha^-1 improved most growth and production indicators, confirming the effectiveness of this preparation as a biostimulant that raises the plant's metabolic activity, improves root-zone characteristics, increases nutrient availability, and stimulates fine-root formation, leading to increased absorption efficiency and improved photosynthesis. This was reflected in increased plant biomass and improved flowering traits: number of flowers reached 2448.59 flower·plant^-1, flowering duration increased to 64.03 days, and dry flower weight increased to 4.82 g. In addition, 100-seed weight and total yield increased to (1.91 g and 437.97 kg·ha^-1), respectively. The study also proved that spraying with amino acids produced a distinct physiological response, manifested in a clear increase in vegetative and root growth indicators and improved flowering, productive, and chemical traits. This is attributed to the direct role of amino acids in the biosynthesis of proteins, enzymes, and plant hormones, particularly at 2.5 ml·L^-1, at which stem diameter, leaf area, number of leaves, number of flowers, flowering duration, and total yield increased, reaching (9.73 mm, 492.73 cm²·plant^-1, 84.33 leaf·plant^-1, 2204.78 flower·plant^-1, and 452.30 kg·ha^-1). The binary and triple interactions showed that integration between mineral fertilization, Bio Health, and amino acids was more effective than any single factor alone, with some interaction treatments achieving the highest averages in most studied traits - whether related to vegetative growth, the root system, flowering, yield, or chemical traits. These results indicate a synergistic effect among the treatments: improved nutrient availability, increased absorption efficiency, and activation of vital processes within the plant raised nutrient-use efficiency and improved the distribution of photosynthates among the plant's organs, ultimately increasing production and improving its quality. Finally, the results obtained represent an important scientific contribution to the field of borage nutrition, clarifying the physiological mechanisms explaining the plant's response to the interaction between mineral fertilization, biostimulants, and amino acids. They provide scientific evidence that integrated fertilization management is not limited to increasing growth and production, but also contributes to improving the plant's physiological efficiency and its ability to exploit nutritional resources more effectively - opening the way for future studies evaluating the effect of these treatments on oil quality and active compounds in borage seeds, as well as their response under different environmental stress conditions, thereby supporting the development of more efficient and sustainable fertilization programs for medicinal and aromatic plants.