Impact of irrigation with saline water and drought on floral quality, vegetative growth and yield of olive trees (Olea europaea L.) in an arid climate

The Mediterranean region's agriculture is predicted to be severely impacted negatively by climate change. In the primary production region of southern Tunisia (34°43’N, 10°41’E) in olive orchard submitted to different treatments: Rain-fed, drip irrigation with saline water (FI) : EC = 7.5 dS/m at 100% of crop evapotranspiration (ETc), alternate irrigation (PRD) with saline water at 50% of ETc and switched every 30 days, regular deficit irrigation (RDI) with saline water at 50% of ETc, drip irrigation with tap water (TW) : EC=2.46 dS/m at 100% of crop evapotranspiration (ETc), with predicted temperature increases, the effects of climate change and salinity on the floral performance of olive trees were assessed from 2015 to 2017 and the vegetative growth and yield were evaluated over the period. As results, while conserving water in comparison to FI and TW, PRD produced high values for internodes length (1.68 cm) in 2016 and an annual shoot elongation (2.5 cm) in 2015. When comparing flowering (RF) and fruit-setting (RS) rates, olive trees under PRD outperformed those under RDI and FI with (RF=67.52% and RS=7.81%) in 2015. For olive trees exposed to RDI, PRD, and FI, the fruits per unit length were statistically similar in 2015. The use of the PRD technique (50% ETc) yielded good results with an average of 2.96(kg/m3) in our study both quantitatively and qualitatively.