New technology in basil production with high essential oil yield and quality

•Shaded basil plants achieved higher essential oil yield and antioxidant activity.•The main constituents in the oil were linalool, eugenol, 1,8-cineole and epi-α-cadinol.•The highest degree of 2,2- diphenyl-1-picrylhydrazyl radicals’ neutralization is for 30 min incubation.•Plants from blue nets have the highest eugenol content and antioxidant activity.•New technology based on direct sowing, high density, succesive harvest and shading. Light modification by colour shade net manipulation plays an important role in the synthesis of bioactive compounds and has been shown to affect quantity and quality of essential oils in basil. In the present study, basil was grown in the soil under net-house cover by pearl and red nets (50% shade index), or in unshaded condition (open field-control). Sweet basil (Ocumum basilicum L. cv. ‘Genovese’) were used to determine whether different times of harvest could improve yield, chemical composition of essential oils and antioxidant activity under light stress conditions. The lowest accumulation of essential oils was observed in the second harvest from unshaded, control plants (1.02 mL/100 g) while the highest oil accumulation was achieved in first harvest from red nets (3.23 mL/100 g). The main constituents found in the oil were linalool (46.7–53.9%), eugenol (9.7–20.9%), 1,8-cineole (8.7–15.3%), epi-α-cadinol (3.3–4.5%) and α-trans-bergamotene (2.2–3.4%). Light manipulation by color shade nets also increased antioxidant activity. Plants grown under blue shade nets from the second harvest are characterized by the highest eugenol content (20.9%) and highest antioxidant activity (efficient concentration - EC50, 0.003 mg mL−1). Direct sowing, high plant density, colour shade nets and successive harvests represents a new technology in basil production with high essential oil yield and quality.