Luigi Sansone

Comparing Kaolin and Pinolene to Improve Sustainable Grapevine Production during Drought.

Viticulture is widely practiced in dry regions, where the grapevine is greatly exposed to water stress. Optimizing plant water use efficiency (WUE) without affecting crop yield, grape and wine quality is crucial to limiting use of water for irrigation and to significantly improving viticulture sustainability. This study examines the use in vineyards of particle film technology (engineered kaolin) and compares it to a film-forming antitranspirant (pinolene), traditionally used to limit leaf water loss, and to an untreated control. The trial was carried out under field conditions over three growing seasons, during which moderate to very severe plant water stress (down to -1.9 MPa) was measured through stem water potential. Leaf stomatal conductance (gs) and photosynthesis rate (An) were measured during the seasons and used to compute intrinsic WUE (WUEi, defined as An/gs ratio). Leaf temperature was also recorded and compared between treatments. Bunch quantity, bunch and berry weight, sugar accumulation, anthocyanin and flavonoid contents were measured. Finally, microvinifications were performed and resultant wines subjected to sensory evaluation.Results showed that the use of kaolin increased grapevine intrinsic WUE (+18% on average as compared to unsprayed vines) without affecting berry and bunch weight and quantity, or sugar level. Anthocyanin content increased (+35%) in kaolin treatment, and the wine was judged more attractive (p-value <0.05) and slightly more appreciated (p-value < 0.1) than control. Pinolene did not increase WUEi, limiting An more than gs; grapes with this treatment contained lower sugar and anthocyanin content than control, and the obtained wine was the least appreciated. This study demonstrates that particle film technology can improve vine WUEi and wine quality at the same time, while traditional antitranspirants were not as effective for these purposes. This positive effect can be used in interaction with other already-demonstrated uses of particle film technology, such as pest control and sunburn reduction, in order to achieve more sustainable vineyard management.

Geochemical characterization of elements in Vitis vinifera cv. Negroamaro grape berries grown under different soil managements

The present geochemical study concerns the impact of viticultural practices in the chemical composition of the grape cultivar “Negroamaro” in Apulia, a southern Italian region renowned for its quality wine. Three types of soil management (SM), two cover cropping with different mixtures, and a soil tillage were considered. For each SM, the vines were irrigated according to two irrigation levels. Chemical composition of soil and of berries of Vitis vinifera cultivar “Negroamaro” were analyzed by X-ray fluorescence, inductively coupled plasma-mass spectrometry and multivariate statistics (linear discrimination analysis). In detail, we investigated major and trace elements behavior in the soil according to irrigation levels, the related index of bioaccumulation (BA) and the relationship between trace element concentration and soil management in “Negroamaro” grapes. The results indicate that soil management affects the mobility of major and trace elements. A specific assimilation of these elements in grapes from vines grown under different soil management was confirmed by BA. Multivariate statistics allowed to associate the vines to the type of soil management. This geochemical characterization of elements could be useful to develop fingerprints of vines of the cultivar “Negroamaro” according to soil management and geographical origin.

Chemical elements as fingerprints of geographical origin in cultivars of Vitis vinifera L. raised on the same SO4 rootstock

The uptake of major and trace elements in grapevine (Vitis vinifera L.) can be influenced by soil, climate, geographic origin, and rootstock type. Rootstocks were mainly selected to resist phylloxera and for specific tolerance to lime, mineral uptake, drought, and salinity. The relationship among concentrations of major, trace, and rare earth elements was studied in soil and leaves from two Italian grapevine cultivars, “Cabernet Sauvignon” and “Corvina,” employed to produce renowned controlled designation of origin (DOC) wines. The cultivars were raised on the same rootstock SO4 in two different areas of the Veneto Region (Northern Italy). The elements were studied by X-ray fluorescence and inductively coupled plasma mass spectrometry, and data were elaborated by non-parametric tests and multivariate linear discrimination analysis. The related index of bioaccumulation was calculated to define the specific assimilation of the elements from soil to leaves. A statistically significant correspondence between soil and leaf samples was observed for Mg, Sm, V, and Zr. The results allowed to discriminate soil and leaf samples of the two cultivars according to geographical provenance, possibly providing geochemical markers (fingerprints) useful against fraudulent use of DOC wine labels.