Application of Colored Nets to Prevent Sunburn and Increase Pomegranate Fruit Quality

A prevalent problem in pomegranate fruit (Punica granatum L.) is sunburn which reduces fruit quality. This study aimed to reduce the severity of sunburn during the growth of pomegranate fruit by covering them with colored netted bags. Kaolin (5%) as a traditional treatment to reduce sunburn was used to compare the efficiency of noble and traditional techniques. The netted bags were either white, green, yellow, gray or blue. The experiment was carried out on a commercial cultivar (‘Rabab-e-Neyriz’) over a period of two successive years. The colors of the netted bags affected the anthocyanin content of arils at harvest time. They also reduced sunburn damage. Fruit of the control group were damaged notably by sunburn (32.26%), compared to those covered with blue and white netted bags (0%). The highest amount of ascorbic acid and the minimum amount of anthocyanin were recorded in fruit covered with blue netted bags. The lowest degree of aril whitening (i.e. the discoloration of arils) was observed when fruit were covered with white bags. Covering the fruits with gray netted bags caused the highest antioxidant activity and the highest total phenolic content in the arils. Overall, covering fruit with netted bags is recommended to prevent sun burn and to increase fruit quality.