Impact of Spraying Some Chemical Substances on Controlling Sunburn of Balady Mandarin Fruits

Document Type : Original Article


Citrus Research Dep., Horticulture Research Institute, Agricultural Research Center, Giza, Egypt.


Sunburn is one of the most important problems that may affect the growth, productivity and quality of Balady mandarin trees.
This study was conducted to determine the effects of two kaolin clay products i.e. Screen Duo ® (applied once or twice) and Surround ® (3 and 6%) used as anti-sunburn treatment on controlling sunburn of Balady mandarin fruits Citrus reticulata.
Data indicated that percentage of injured fruits were decreased by treatments in comparison with control in both seasons of study. The percentage of injured fruits in Surround ® 6 and 3 % treatments were 11.66 and 14.02% in first season and 9.33 and 15.5% in the second one, respectively, while those treated with Screen Duo ® once and twice, possessed 19.6 and 14.9 % in the first season and 20.5 and 16.3 % in the second one compared with control treatment that gained 31.68 and 32.6 % in the first and second seasons, respectively. Surround ® 6% treatment caused significant increase in fruits weight and volume.
The treatments did not affect fruits juice TSS, acidity and TSS/acidity ratio, except Surround ® 6% treatment, which caused significant increase in both TSS and acidity and significant decrease in TSS/acidity ratio in comparison with injured fruits. In the present study, the economic gain was estimated in term of assumed percentage of increase per fadan value in comparison with the control, where the estimated percentage of increase ranged between 11.6-20.66 in first season and 12.6-21.33 in the second one.