Production and oil quality in ‘Arbequina’ olive (Olea europaea, L.) trees under two deficit irrigation strategies

Abstract

The effect of two deficit irrigation (DI) strategies on fruit and oil production and quality in a 12-year-old ‘Arbequina’ olive orchard with 238 trees ha−1 was evaluated. The T1 treatment was a sustained DI regime (65% ETc, 2–3 irrigation events per week). The T2 treatment was a low-frequency DI (increasing stress/rewatering cycles, which consisted in withholding irrigation until fruit shrivelling and then applying a recovery irrigation providing the same amount of water that supplied in T1 for that period). As compared to full irrigation, both strategies reduced fruit production and increased the variability of fruit ripening, but favoured oil extraction. Free acidity, peroxide value, K232, K270 and sensory quality of oil were not affected by DI. Furthermore, carotenoid, chlorophyll, phenol, and oleic contents increased. The greatest phenol content and bitterness index were found in oil from T2 trees. Later harvesting caused sensory quality and tocopherol losses, although the oil synthesized in DI olives increased.