Evaluation of a Spray-On Product for Improving Red Color and Decreasing Sunburn Damage of ‘Red Chief Delicious’ Apples

Abstract

Sunburn is a severe type of solar radiation damage that causes meaningful economic losses in several vegetables and fruits, including apples. In this study, we examined the efficacy of a new product, Parasol, for protecting apples (cv. ‘Red Chief Delicious’) against sunburn. Specifically, we examined the effect of Parasol spraying on fruit quality attributes, including fruit color, flesh firmness, soluble solids and acidity at harvest and after a 5-month period of storage. Spraying apple trees with Parasol resulted in better red fruit coloration and reduced sunburn symptoms. Parasol (2.5 and 5 L/t) treatments resulted in an increase of fruit flesh firmness compared to the control, for both years. Fruit weight, soluble solids concentration and acidity did not differ significantly between treatments. Hue values showed that apples from the control treatment had significantly less red color than the Parasol treatments. The intensity of the red color decreased in the following order: Parasol (5 L/t)> Parasol (2.5 L/t)> Control. From our results it is concluded that Parasol protects apples from sunburn injury, increases red coloration and fruit firmness and therefore their commercial value.