Nutrient status and irrigation management affect anthocyanins in ‘Mollar de Elche’ pomegranate

Abstract

Pomegranate (Punica granatum L.) is a deciduous fruit tree native of central Asia included in the so-called group of minor fruit tree species. Although not widely grown, it has some importance in the east and southeast of Spain, where there are about 3100 ha of commercially cultivated pomegranates. In semi-arid climate areas like Spain, irrigation management is a powerful tool to influence tree water status agronomic performance and fruit composition. The present research focused on determining the effects of soil fertility level, plant nutrient status and irrigation strategies on fruit quality attributes of 'Mollar de Elche' pomegranates. The experiment monitored the concentrations of 12 nutrients in leaf samples from 15 commercial orchards. Soil fertility levels in air-dried soil samples were analyzed for texture, pH (1:2.5 water extract), electrical conductivity (saturated paste extract), organic matter, nitrogen, total and active lime, extractable phosphorous (P) (Olsen), and available cations (extractable with ammonium acetate). In addition, an experimental orchard with various deficit irrigation strategies was established. No linear correlations were found between fruit color and soil and foliar nutrient composition for pomegranates grown in the soils of this area, with high levels of Ca and Na exchangeable cations. Deficit irrigation, when applied in the summer during the main linear fruit growth period, significantly increased the total anthocyanin concentration.