Impact of colored plastic mulch on grape quality of Vitis vinifera L. c.v. Muscat grown in La Mancha region

The aim of this research was to study the effect on grape aroma composition of plastic mulching of different colours, white and black, as alternative to controlled-growth cover on vineyard of Muscat grape as agronomic innovation, in order to mitigate the adverse effects that climate change has in La Mancha region. Free and bound volatile compounds were isolated by SPE and then, analysed and quantified by GC-MS. A total of 95 aroma compounds were identified and quantified, 45 of them in the free aroma fraction and 50 in the glycosidically bound fraction. The terpene compounds were the quantitative and qualitative major group independently of the type of mulching used. Nevertheless, the colour of mulching affects the concentration of aroma compounds of must. The must from grapes cultivated using white mulching exhibited the highest concentration of free and glycosidically bound aroma compounds while the must from grapes grown using black mulching exhibited the lowest of free and bound terpene compounds. Free benzene compounds showed low concentration when the grapes were cultivated under controlled-growth cover. Mulching is an alternative measure that could be adopted by growers on La Mancha region to reduce the effects of climate change and permit the quality preservation of La Mancha Muscat grape variety. • This is the first study of the influence of plastic mulching on the quality of grapes. • Black mulching on grapevines leads to lower values of nitrogen and higher phenolic concentration. • White mulching produced grapes with the highest concentration of free volatile compounds.