Sunburn is a major problem on early maturing mandarins such as 'Miho Wase' Satsuma. Currently, optimal irrigation during critical periods and shade nets are the only measures to reduce losses due to sunburn. Previous work using particle film technology (kaolin) on citrus to reduce sunburn was very effective, but the formulation used resulted in insect repercussions. The objective of the study was to determine if products such as Screen TM, Vapor Gard, Silicon and Raynox TM can reduce tree canopy temperature and thereby reduce sunburn on 'Miho Wase' Satsuma mandarins. All treatments were applied three times between December 2009 and January 2010. Screen TM reduced the sunburn incidence (fruit per tree) by 50%, possibly due to reductions in leaf temperature by 2.53C and fruit temperature by 1.73C, without a negative effect on fruit quality. Screen TM increased the sugar content of fruit. Vapor Gard increased fruit temperature, reduced the sugar content of the fruit, and increased sunburn incidence by 16%. Raynox TM, Silicon, and the combination of Screen TM and Vapor Gard had no effect on sunburn incidence.
