Deficit irrigation and reflective mulch effects on peach quality and storage performance

Abstract

The effect of deficit irrigation and reflective mulch underneath the tree canopy on quality at harvest and during cold storage of ‘Royal Glory’ peaches (Prunus persica L.) was studied for two consecutive growing seasons. Four treatments were applied: 1) control, irrigation at 100% of crop evapotranspiration (ETc); 2) deficit irrigation (DI), irrigation at 75% of ETc in the last 3 weeks before harvest and 50% of ETc postharvest; 3) reflective mulch Extenday™ underneath the tree canopy; 4) the combined treatment of reflective mulch and deficit irrigation. Quality was assessed in fruit from the upper (sun-exposed) and lower (shaded) tree canopy at harvest and after 2, 4, and 6 weeks at 2°C plus 1 day of shelf life at 20°C. The quality parameters measured were fruit mass, skin color, flesh firmness and specific conductivity, juice acidity and soluble solids content (SSC), percent dry matter (DM) and total phenolic content in the edible part. Incidence and severity of chilling injury (CI) symptoms were also evaluated. Furthermore, tree fruit productivity and solar radiation (UV and PAR) above and underneath the tree canopy were measured. During cold storage, skin color changed slightly, fruit softened and the specific conductivity, SSC, acidity and percent dry matter decreased, while total phenolic content and CI symptoms increased. Reflective mulch application improved light availability and fruit quality, especially in the lower tree canopy. Peaches grown under DI had similar fruit quality and CI symptoms as control fruit, but decreased yield and fruit size. Peaches from the reflective mulch treatment were more mature at harvest than the fruit from other treatments, and reported better quality (especially the lower canopy fruit), and similar storage performance compared to control fruit. The fruit from the combined treatment behaved like the separate DI or reflective mulch treatments. © 2022 International Society for Horticultural Science. All rights reserved.