Micronutrient applications to enhance olive fruit growth and extra virgin olive oil chemical and sensory attributes

• Application of foliar micronutrients treatments affect olive fruit and oil quality. • Greater fruit growth and size observed with selenium-based treatments. • The application of boron increases flavors and taste in oils. This study investigated the effects of micronutrient treatments—Selenium and Betaine (SeBe), Boron (B), Betaine (Be), and their combinations—on the growth, physicochemical attributes, and sensory qualities of ‘Nostrana di Brisighella’ olives. Treatments significantly influenced fruit size, firmness, water content, oil content, and sensory characteristics. SeBe-treated plants yielded larger fruits with higher firmness and oil content, likely due to enhanced water retention and metabolic activity. Notably, B and Be treatments positively influenced sensory attributes, with B enhancing flavor complexity and Be contributing to improved fruit sweetness and aromatic profiles. The combination of B and Be resulted in a synergistic effect, yielding olives with a balanced flavor profile and appealing sensory characteristics. These findings emphasize selenium's role in promoting fruit growth and oil accumulation while highlighting the potential of B and Be to enhance flavor and sensory appeal. This study provides insights into optimizing olive quality through target micronutrient management.