The presented study determined the effects of nano-NPK and biofertilizer EMG-1 on the growth and oil traits and active compounds of Linum usitatissimum L. The experiment ensued in a randomized complete block design with a split-plot arrangement, two factors, and three replications. It transpired in 2022 at the Alsada City, Babel, Iraq. The first factor was foliar application of nano-NPK fertilizer with four concentrations (0.0, 0.7, 0.10, and 0.15 ml L^-1). The second factor was biofertilization of EMG-1 (0.0, 5, 10, and 15 ml L^-1), mixed with soil with a 1-cm incision made near the rhizosphere area. The results indicated a positive role of nano-NPK and biofertilization EMG-1 in improving growth and oil yield traits in flax (L. usitatissimum). The application of nano-NPK (0.15 ml L-¹) and biofertilization EMG-1 (15 ml L^-1) showed a significant increase in the flax’s plant height, fruit branches, oil yield, oil percentage, and linolenic and oleic acids.

Keywords: Flax (Linum usitatissimum L.), Nano-NPK, EMG-1, growth and oil traits, linolenic acid, oleic acid

Key findings: The results indicated the positive role of nano-NPK (0.15 ml L^-1) and biofertilization EMG-1 (15 ml L^-1) in enhancing the flax’s plant height, fruit branches, oil yield and percentage, and linolenic and oleic acids.