Eur.J.Hortic.Sci. 80 (3) 97-102 | DOI: 10.17660/eJHS.2015/80.3.1|
ISSN 1611-4426 print and 1611-4434 online | © ISHS 2015 | European Journal of Horticultural Science | Original article
A preharvest treatment of ethephon and methyl jasmonate affects mechanical harvesting performance and composition of 'Verdejo' grapes and wines
L. Uzquiza1, R. González1, M.R. González1, M.W. Fidelibus2 and P. Martín1
1 Departamento de Producción Vegetal y Recursos Forestales, Universidad de Valladolid, Palencia, Spain
2 Department of Viticulture and Enology, University of California, Davis, USA
Previously we showed that the combined application of ethephon and methyl jasmonate to grapes (Vitis vinifera L.) may decrease fruit detachment force and promote the formation of an abscission layer between the pedicels and berries, without causing pre-harvest yield losses or defoliation (Uzquiza et al., 2013). Theoretically, such effects could help minimize the physical damage to berries and the volume of must released during mechanical harvesting which could, in turn, reduce the opportunity for undesirable oxida-tive processes to occur before the product comes into the winery. The aim of this work was to study the effects of this treatment on mechanical harvesting performance, and on must and wine quality. The experiments were conducted in 2011 and 2013, in a ‘Verdejo’ vineyard located in ‘Rueda’ Appellation d’Origine area (North-Central Spain). In a completely randomized factorial design different treatments were compared, combining the application of abscission agents (ethephon 1,000 mg∙L-1 plus methyl jasmonate 8,960 mg∙L-1 sprayed on the clusters 10 days before harvesting, versus untreated controls), and type of harvest (manual picking and mechanical at differ-ent shaking frequencies, 400 and 425 shakes·min-1). The preharvest treat-ment did not significantly affect product losses during mechanical harvesting at 400 shakes·min-1 but, at 425 shakes·min-1, total losses in treated vines were 4.2% higher than in untreated. The percentage of free must in the harvested mass was lower in treated vines (20.6%) than in controls (23.2%) when shaking frequency was higher. The abscission agents tended to reduce potassium content in the must and increased hydroxycinnamic acid and total polyphenol contents, but they did not affect colour intensity or oxidative stability of wines.
abscission, oxidation, plant growth regulators, polyphenol, Vitis vinifera L.
Significance of this study
What is already known on this subject?
What are the new findings?
The combined application of ethephon and methyl jasmonate to grapes some days before harvest may decrease fruit detachment force and promote the formation of dry stem scars in the abscission zone, without causing significant preharvest yield losses or defoliation.
What is the expected impact on horticulture?
For the first time, the effects of abscission agents on mechanical harvesting of grapes have been evaluated. Treatment of ethephon plus methyl jasmonate reduced the release of must, reduced potassium content in the product and increased total polyphenol content.
Preharvest treatments of ethephon plus methyl jasmonate could help to minimize the physical damage to mechanically harvested wine grapes and contribute to enhance the quality of musts and wines.
- Allen, T., Herbst-Johnstone, M., Girault, M., Butler, P., Logan, G., Jouanneau, S., Nicolau, L., and Kilmartin, P. (2011). Influence of grape-harvesting steps on varietal thiol aromas in Sauvignon blanc wines. J. Agric. Food Chem. 59, 10641–10650. https://doi.org/10.1021/jf2018676.
- Arfelli, G., Sartini, E., Bordini, F., Caprara, C., and Pezzi, F. (2010). Mechanical har-vesting optimization and postharvest treatments to improve wine quality. J. Int. Sci. Vigne Vin. 44, 101–115.
- Ballinger, W.E., and Nesbitt, W.B. (1982). Postharvest decay of muscadine grapes (‘Carlos’) in relation to storage temperature, time and stem condition. Am. J. Enol. Vitic. 33, 173–175.
- Caprara, C., and Pezzi, F. (2011). Measuring the stresses transmitted during mechanical grape harvesting. Biosyst. Eng. 110, 97–105. https://doi.org/10.1016/j.biosystemseng.2011.07.003.
- Catania, P., Vallone, M., and Pipitone, F. (2009). Analysis of the main factors influencing the quality of wine from mechanically harvested grapes. J. Ag. Eng.- Riv. di Ing. Agr. 4, 27–30.
- Darias-Martín, J.J., Rodríguez, O., Díaz, E., and Lamuela-Raventós, R.M. (2000). Effect of skin contact on the antioxidant phenolics in white wine. Food Chem. 71, 483–487. https://doi.org/10.1016/S0308-8146(00)00177-1.
- Fidelibus, M.W., Cathline, K.A., and Burns, J.K. (2007). Potential abscission agents for raisin table and wine grapes. HortScience 42, 1626–1630.
- Fidelibus, M.W., and Cathline, K.A. (2010). Dose and time dependent effects of methyl jasmonate on abscission of grapes. Acta Hort. 884, 725-728. https://doi.org/10.17660/ActaHortic.2010.884.98.
- Gallegos, J.I., González, R., González, M.R., and Martín, P. (2006). Changes in composition and colour development of ‘Tempranillo’ grapes during ripening induced by ethephon treatments at veraison. Acta Hort. 727, 505-512. https://doi.org/10.17660/ActaHortic.2006.727.62.
- Gonzalez-Herranz, R., Cathline, K.A., Fidelibus, M.W., and Burns, J.K. (2009). Potential of methyl jasmonate as a harvest aid for ‘Thompson Seedless’ grapes: Concentra-tion and time needed for consistent berry loosening. HortScience 44, 1330–1333.
- Guerzoni, M.E., Zironi, R., Intrieri, C., and Magnanini, E. (1981). Stabilization of white wine by early hyperoxidation of must. Food Technol. Aust. 33, 444–446.
- Kou, L., Luo, Y., Wu, D., and Liu, X. (2007). Effects on mild heat treatment on mi-crobiological growth and product quality of packaged fresh cut table grapes. J. Food Sci. 72, 567–573. https://doi.org/10.1111/j.1750-3841.2007.00503.x.
- Malladi, A., Vashisth, T., and Johnson, L.K. (2012). Ethephon and methyl jasmonate affect fruit detachment in rabbiteye and southern highbush blueberry. HortScience 47, 1745–1749.
- Meyer, J. (1969). Effect of fruit cane severance of grapevines on must and wine yield and composition. Am. J. Enol. Vitic. 20, 108–117.
- Nagel, C.W., and Graber, W.R. (1988). Effect of must oxidation on quality of white wines. Am. J. Enol. Vitic. 39, 1–4.
- Noble, A.C., Ough, C.S., and Kasimatis, A.N. (1975). Effects of leaf content and mechanical harvest on wine “quality”. Am. J. Enol. Vitic. 26, 158–163.
- Oliveira, C.M., Ferreira, A.C.S., De Freitas, V., and Silva, A.M.S. (2011). Oxidation mechanisms occurring in wines. Food Res. Int. 44, 1115–1126. https://doi.org/10.1016/j.foodres.2011.03.050.
- Ough, C.S. (1969). Substances extracted during skin contact with white must. I. General wine composition and quality changes with contact time. Am. J. Enol. Vitic. 20, 93–100.
- Pezzi, F., and Caprara, C. (2009). Mechanical grape harvesting: investigation of the transmission of vibrations. Biosys. Eng. 103, 281–286. https://doi.org/10.1016/j.biosystemseng.2009.04.002.
- Ribereau-Gayon, P., and Glories, Y. (1987). Phenolics in grape and wines. In Proc. 6th Australian Wine Industry Technical Conference, T. Lee, ed. (Adelaide: Australian Industrial Publishers), pp. 247–256.
- Robards, K., Prenzler, P.D., Tucker, G., Swatsitang, P., and Glover, W. (1999). Phenolic compounds and their role in oxidative processes in fruits. Food Chem. 66, 401–436. https://doi.org/10.1016/S0308-8146(99)00093-X.
- Ruiz-García, Y., Romero-Cascales, I., Gil-Muñoz, R., Fernández-Fernández, J.I., López-Roca, J.M., and Gómez-Plaza, E. (2012). Improving grape phenolic content and wine chromatic characteristics through the use of two different elicitors: methyl jasmonate versus benzothiadiazole. J. Agric. Food Chem. 60, 1283–1290. https://doi.org/10.1021/jf204028d.
- Singleton, V.L., Zaya, J., Trouslade, E., and Salgues, M. (1984). Caftaric acid in grapes and conversion to a reaction product during processing. Vitis 23, 113–120.
- Uzquiza, L., González, R., González, M.R., and Martín, P. (2013). Potential of combined ethephon and methyl jasmonate treatments for improving mechanical harvesting of wine grapes. Europ. J. Hort. Sci. 78, 169–175.
- Uzquiza, L., González, R., González, M.R., and Martín, P. (2014a). Aplicaciones de etefón y metil jasmonato para facilitar el desprendimiento del fruto en vides cv. Sauvignon blanc. In Proc. 7th Congreso Ibérico de Agroingeniería y Ciencias Hortícolas: Innovar y producir para el futuro, F. Ayuga, A. Masaguer, I. Mariscal, M. Villarroel, M. Ruiz-Altisent, F. Riquelme and E.C. Correa Hernando, eds. (Madrid), pp. 115–120.
- Uzquiza, L., Martin, P., Sievert, J.R., Arpaia, M.L., and Fidelibus, M.W. (2014b). Methyl jasmonate and 1-aminocyclopropane-1-carboxylic acid interact to promote grape berry abscission. Am. J. Enol. Vitic. 65, 504–509. https://doi.org/10.5344/ajev.2014.14038.
Received: 12 November 2014 | Revised: 4 February 2015 | Accepted: 7 February 2015 | Published: 17 June 2015 | Available online: 17 June 2015