Pre-harvest regulated deficit irrigation management effects on post-harvest quality and condition of V. corymbosum fruits cv. Brigitta

•Post-harvest fruit condition does not seem to be affected by water treatments.•Mild deficit treatment can achieve equivalent fruit quality as control plants.•Mild deficit treatment can produce similar antioxidant capacity as control fruits.•Severe water deficit enhances oxidative damage and lowers antioxidant capacity.

Blueberries are highly sensitive to water stress, especially during fruit development when fruit yields and post-harvest quality can be affected. Regulated deficit irrigation (RDI) can increase fruit quality of many fruit crops without reducing yield. However, the influence of pre-harvest RDI on postharvest quality of blueberry has not been studied. Our aim was to evaluate the post-harvest quality of V. corymbosum fruits cv. Brigitta grown under pre-harvest RDI. Two locations were used for this research: (1) Colbún, Maule Region, Chile (35° 41′ 12.99″ LS; 71° 25′ 8.75″ LW) during the 2013-14 and 2014-15 seasons using six-year-old plants, and (2) South Haven, Michigan, USA (42° 21′ 16.26″ LN; 86° 12′ 48.88″ LW), during the 2014 season, on twenty-six-year-old bushes. Plants were subjected to three irrigation treatments that replaced 50, 75 or 100% (control) of actual evapotranspiration (ETa). Fruits were harvested at >90 full color and stored for 30 and 60d at 0-2 °C + 3d at 18-20 °C. Water treatments had no effect on the proportion of sound, dehydrated or decayed berries after storage. However, fruit quality was affected, with mild water deficit (75% ETa) producing similar fruit quality, i.e., firmness, titratable acidity, soluble solids and antioxidant activity as fully irrigated plants (100% ETa), and lower oxidative stress than 50% ETa treatment at 60 + 3d, but with lesser weight loss. Blueberries are considerably sensitive to water stress, with 50% treatment showing the highest lipid peroxidation and lowest antioxidant activity (ORAC) for both 30 + 3d and 60 + 3d, as well as by decreasing fruit quality (high SS and low TA). We have shown that applying 25% less water to highbush blueberries does not reduce fruit quality or levels of antioxidants.