A field experiment was conducted during winter season of 2021 at a research station of college of agricultural engineering sciences, university of Baghdad to determine the response of active fertility percentage and seed yield and its components of faba bean (Vicia faba L. cv. Aguadulce) to distance between plants and spraying of nano and traditional boron. A Randomized Complete Block Design according to split-plots arrangement was used at three replicates. The main plots were three distances between plants (25, 35 and 45 cm), while the sub plots including spraying of distilled water only (control treatment), spraying of boron at a 100 mg L-1 and spraying of nano boron at two concentrations (10 and 15 mg L-1). The results showed that the 25 cm distance between plants was significantly superiority and gave a highest mean of seed yield (4.968 ton ha-1), whereas the 45 cm distance between plants was significantly superiority and gave highest means of number of branches (10.83 branch plant-1), number of flowers (400.4 flower plant-1), number of pods (28.36 pod plant-1), active fertility percentage (7.10%) and umber of seeds (6.66 seed pod-1). The spraying of nano boron at a 10 mg L-1 was significantly superior and gave the highest means of number of pods (26.91 pod plant-1), active fertility percentage (7.01%), number of seeds (6.23 seed pod-1) and seed yield (4.334 ton ha-1), while the spraying of nano boron at a 15 mg L-1 was significantly superior and gave the highest means of number of branches (9.83 branch plant-1) and number of flowers (400.0 flower plant-1). The interaction between two factors had significant effect on the most studied traits.
