Evaluation of ‘Sun Protect’ in protecting apples (Malus × domestica Borkh.) against sunburn
T. Sotiropoulos, A. Petridis, M. Koukourikou-Petridou, S. Koundourashttps://doi.org/10.17221/200/2015-HORTSCICitation:Sotiropoulos T., Petridis A., Koukourikou-Petridou M., Koundouras S. (2016): Evaluation of ‘Sun Protect’ in protecting apples (Malus × domestica Borkh.) against sunburn. Hort. Sci. (Prague), 43: 175-180.
Sunburn is a major type of solar radiation injury that leads to significant economic losses in several fruits, including apples. Here, the efficiency of a new product, called ‘Sun Protect’, in protecting apples (cv. Granny Smith) against sunburn was tested. The effect of ‘Sun Protect’ application was further examined on fruit quality characteristics, including soluble solids, acidity, flesh firmness, total phenol content and antioxidant activity, at harvest and after a 4-month period of storage. Spraying apple trees with ‘Sun Protect’ resulted in better fruit coloration and no visual symptoms of sunburn. On the other hand, fruit quality characteristics were not affected by the treatment. After storage for four months, apples sprayed with ‘Sun Protect’ retained their intense green colour in relation to the green-yellowish appearance of the untreated ones. Results on photosynthetic parameters revealed that there was no negative effect of the treatments on gas exchange of the leaves; moreover, sprayed trees showed a higher water use efficiency in comparison to the control. Our results provide evidence that ‘Sun Protect’ protects apples from sunburn injury and increases their marketability.Keywords:
antioxidant activity; firmness; fruit colour; photosynthesis; sunburnReferences:
Benzie Iris F.F., Strain J.J. (1996): The Ferric Reducing Ability of Plasma (FRAP) as a Measure of “Antioxidant Power”: The FRAP Assay. Analytical Biochemistry, 239, 70-76 https://doi.org/10.1006/abio.1996.0292Evans R.G., van der Gulik T.W. (2011): Irrigation for microclimate control. In: Stetson L., Dedrick A. (eds): Irrigation. 6th Ed. The Irrigation Association. Falls Church, VA.: 1015–1036.Felicetti David A., Schrader Larry E. (2008): Photooxidative Sunburn of Apples: Characterization of a Third Type of Apple Sunburn. International Journal of Fruit Science, 8, 160-172 https://doi.org/10.1080/15538360802526472Felicetti David A., Schrader Larry E. (2009): Changes in pigment concentrations associated with sunburn browning of five apple cultivars. II. Phenolics. Plant Science, 176, 84-89 https://doi.org/10.1016/j.plantsci.2008.09.010Glenn D.M. (2009): Particle film mechanisms of action that reduce the effect of environmental stress in ‘Empire’ apple. Journal of the American Society of Horticultural Science, 134: 314–321.Havaux M. (2003): Chloroplast Membrane Photostability in chlP Transgenic Tobacco Plants Deficient in Tocopherols. PLANT PHYSIOLOGY, 132, 300-310 https://doi.org/10.1104/pp.102.017178Koukourikou-Petridou M., Voyatzis D., Stylianidis D., Sotiropoulos T., Therios I. (2007): Effects of some growth regulators on pre and after storage quality of Red Chief Delicious apples. European Journal of Horticultural Science, 72: 8–11.Lolicato S. (2011): Sunburn protection for fruit – a practical manual for orchardists in northern Victoria. Department of Environment and Primary Industries, Victoria, Australia.Sattler S. E. (2003): Characterization of Tocopherol Cyclases from Higher Plants and Cyanobacteria. Evolutionary Implications for Tocopherol Synthesis and Function. PLANT PHYSIOLOGY, 132, 2184-2195 https://doi.org/10.1104/pp.103.024257Schrader L., Zhang J., Sun J. (2003): ENVIRONMENTAL STRESSES THAT CAUSE SUNBURN OF APPLE. Acta Horticulturae, , 397-405 https://doi.org/10.17660/ActaHortic.2003.618.47Singleton V.L., Orthhofer R., Lamuela-Raventos R.M. (1999): Analysis of total phenols and other oxidation substrates and antioxidants by means of Folin-Ciocalteu reagent. Methods Enzymology, 299: 152–178.