Francesca Petracca

Climate change in the internal areas of the Mediterranean region is causing a decrease in the frequency of rains and an increase in temperatures, leading to dryer and warmer seasons. These conditions, which will become more and more intense in the coming decades, are already affecting viticulture (e.g. photoinhibition, leaf and berry sunburn) influencing the growth and physiology of vines together with the yield and quality of grapes. The sustainability of vine cultivation in these areas is increasingly at risk, thus, the definition of sustainable cultivation techniques is pivotal to stabilize production and maintain high quality standards of the grapes.The aim of this work is to evaluate the effects of the application of basalt dust on the leaf surface of Vitis vinifera L. subsp. vinifera ‘Falanghina’ grapevine, grown under two different water availability levels over two years characterized by different climatic conditions. The experiment was conducted between 2021 and 2022 in a commercial vineyard of La Guardiense farm at Guardia Sanframondi (Benevento, southern Italy), in the Sannio wine district. The treatment blocks set, localized after geo-physical analysis of the soil, were the following: DI (distribution of basalt dusts and irrigated; Dust-Irrigated), DR (distribution of basalt dusts and rainfed; Dust-Rainfed), NDI (without basalt dusts and irrigated; No Dust-Irrigated), and NDR (without basalt dusts and rainfed; No Dust-Rainfed). The basalt dusts were distributed during the productive-vegetative cycle of the vine (from April to September) and the irrigation was managed according to weather conditions and soil water availability. During the two years of trials, the vegetative growth was monitored through biometric measures, the eco-physiological characteristics through leaf gas-exchanges, chlorophyll “a” fluorescence emission and leaf water potential, during the four main phenological phases: flowering, fruit set, veraison and maturation. Eco-physiological traits were also linked to leaf functional anatomical traits (e. g. lamina thickness, localization of phenolics, stomatal size and frequency) to detect mechanisms for acclimation. After the measurement of fertility, the grapes from each plot were harvested and micro-vinified. The musts and wines were chemically characterized to understand the oenological potential of each one. The analysis of the data from the two seasons 2021 and 2022 allowed us to unravel the effect of inter-annual climatic variability on the potential for photoprotection of the dust distribution. Gained information is useful to evaluate whether the use of basalt dust can be considered a tool for mitigating water stress and rationalizing irrigation protocols.

Climate is a determinant driver for grapevine geographical distribution, influencing yield and berry quality. The current environmental changes are intensifying the need to improve the knowledge of the soil–plant–atmosphere system in the vineyard, to properly manage cultivation factors and to increase berry yield and quality. Since most of the berry growth and ripening phases occur during the driest period in the Mediterranean area, increasing environmental constraints are expected to impose more and more limitations on grapevine productivity and finally on wine quality. The aim of this study was to evaluate whether different pedoclimatic conditions in four proximally located vineyards of the Campania Region in Southern Italy determine differences in crop yield and must quality of Vitis vinifera L. subsp. vinifera “Falanghina”. This study was conducted over three growing seasons, by monitoring vine growth and characterizing yield and must quality. The overall results showed differences in yield and berry quality characteristics for the four vineyards, with the field CA (Calvese) and GR (Grottole) showing pedoclimatic conditions limiting growth and yield compared to SL (Santa Lucia) and AC (Acquefredde).

In the inland of Southern Italy, climate change puts viticulture at risk of sustainability. Cultivar-specific cultivation techniques, also designed to suit peculiar pedoclimatic conditions of the vineyard, are needed to stabilize the productivity of vines, increase the grape quality, and improve the use efficiency of resources. Currently, the Italian legislation requires that vineyards are cultivated as rainfed to achieve quality and/or geographical indication labels. However, climate forecast models indicate that in the next decades there will be an increase in severity and duration of drought events that will affect the growth and productivity of vines beyond a threshold level making rainfed vineyards unsustainable.The aim of this study was to verify whether foliar applications of basalt dust can mitigate the negative effects of drought stress in a vineyard of Falanghina grapevine in Southern Italy. The vineyard is in an inland area of Campania Region, at the premises of the La Guardiense farm, in Guardia Sanframondi, Benevento. A pedological survey, supported by a geophysical campaign, was performed to detect the soil spatial variability of the area and to identify the four subplots where the following treatments were imposed: 1) rainfed with the application of basalt powder on the leaf surface during the vine vegetative-productive cycle (i.e. from April to September); 2) rainfed,without distribution of basalt powder; 3) irrigated, with basalt powder; 4) irrigated, without basalt powder. The irrigation plan was defined weekly, applying a model considering precipitation and evapotranspiration, to reintegrate the water losses by transpiration. The growth and the ecophysiological traits of vines were monitored in the main phenological phases by measuring morphological parameters, fertility, leaf gas-exchanges, chlorophyll a fluorescence emission, leaf water potentials, and leaf anatomical characteristics, while the meteorological data and soil water content were collected through weather stations and time-domain reflectometry (TDR) technique. The production of each experimental plot was evaluated in terms of chemical characterization of musts and wines in order to assess the oenological potential. Specific attention was paid to the setup of protocols for ecophysiological measurements to avoid bias and evidence the occurrence of possible photoprotection mechanisms. Results of the first year of experiments indicated the occurrence of interaction between the two main factors in a year particularly dry. The repetition of the experiments in the next years will allow us to unravel both the interference with climatic variability and the long-term effects due to the combination of factors.