Effects of Sunscreen, Kaolin Application, Fruit Thinning and Supplementary Irrigation on the Aril Browning Disorder of Pomegranate cv. Malase Torshe Saveh

Aril color whitening or browning (AB) in pomegranate fruit is a physiological disorder that critically decrease fruit quality and market acceptability. To find the effects of cun screen, kaolin application, fruit thinning, supplementary irrigation and fertilizer on decreasing aril browning disorder of the pomegranate (Punica granatum L. cv. ‘Malase Torshe Saveh’), an experiment was carried out in Saveh using a complete randomized block design with three replications. Treatments were 1) 3% kaolin application at 40 days after full bloom (DAFB), 2) fruit thinning at 40 DAFB, 3) supplementary irrigation at 80 DAFB, 4) fruit thinning with kaolin application, 5) supplementary irrigation combination with fruit thinning and kaolin application, 6) control with conventional management, 7) Animal manure application with foliar spray of the potassium sulfate and Nitrate calcium, 8) sunscreen combination with kaolin application and supplementary irrigation. The experiment was carried out in 2014 and 2015 in a commercial pomegranate orchard, in Saveh, Iran. The physicochemical properties of the pomegranate fruits were measured. Results showed that the kaolin application had no significant effect on the aril browning disorder, but the sunscreen treatment combined with supplementary irrigation and kaolin application reduced the aril browning index (24%) and increased the abundance of non-affected fruit (%96), conversely the fruit thinning increased aril browning index (69%) and reduced the abundance of non-affected fruits. Moreover, the supplementary irrigation had positive effect toameliorate the aril browning disorder, but the aril browning was also influenced by high temperature, low relative humidity and water quality. Overhead sunscreen, increase soil organic matter, foliar application of potassium and calcium during the growing season and irrigation with fewer intervals can ameliorate the pomegranate aril browning disorder and improve the fruit quality.