Producción y caracterización físico-química de granada cultivada bajo riego deficitario

Résumé

The use of sustained deficit irrigation (SDI) strategies is an interesting approach for reducing water intake from fruit crops in areas with high water scarcity. This may allow important water savings without compromising yield and commercial quality. Due to the limited information available on this topic, this study examines the physico-chemical characterization of pomegranate ‘Mollar de Elche’ cultivated in the Mediterranean area (Murcia’s Region). Trees were exposed to three irrigation systems: control: watered over crop requirements (potential evapotranspiration –ET0-) during the whole cultivation period (120% ET0) (Julian days –JD- 283); SDI16d: watered as control until JD 267 + irrigation suppression during 16 days (JD 267-283), and SDI26d: watered as control up to JD 257 + irrigation withdrawal for 26 days (JD 257-283). Fruits harvested from 12 trees, 4 trees by treatment, were analyzed. On average, there were no differences between treatments in yield (around 60 ± 4 kg/tree). However, SDI16d and SDI26d presented a significant amount of fruits with cracking when compared to control (36%, 51% and 12% respectively) and smaller size, due to lower equatorial and polar diameters. The pH, titratable acidity and soluble solids content were lower in pomegranates coming from SDI than for control, but no differences were observed for the maturity index. Related to color, fruits from SDI16d and SDI26d had a deeper red color, being those coming from SDI 26d significantly redder those from the control. No differences in fruit firmness were detected. As conclusions, SDI allowed to obtain fruits with overall good quality without affecting the global yield. However, the net yield was lower due to the higher incidence of fruit cracking. Further studies are necessary to optimize length and stage at which deficit irrigation is applied, avoiding its negative effects.