Patrick Marcuzzo

A two‐year study was carried out to investigate the effects of eight rootstocks belonging to different crosses within Vitis genus on the performance of cv Glera grown in Northeastern Italy. Vegetative growth, yield, vine water status, and chemical parameters of berry juice were analyzed with the aim of identifying more suitable genotypes for adapting to climate change conditions. During the two experimental years, different amounts of precipitation were recorded, with warmer and drier conditions observed in 2022; consequently, the interaction effects between rootstocks and year (RxY) were significant for most of the parameters analyzed. Overall, the Vitis berlandieri × Vitis riparia genotypes (SO4, K5BB, and 420A) showed the best agronomic performance, although suffering from dry conditions in the warmer vintage. Vitis berlandieri × Vitis rupestris genotypes (1103P in particular, but also 140Ru and 110R) exhibited the best tolerance to the water stress conditions that characterized the 2022 season, maintaining acceptable yield and quality. Finally, a wide variability in responses was observed among Vitis riparia × Vitis rupestris genotypes in the investigated area; 101‐14 showed a higher yield and number of clusters, while Schwarzmann was the least performing, with lower yield and lower acidity of the juice at harvest; moreover, the latter rootstock showed an anticipated budbreak, making it more susceptible to late frosts. This study revealed that Glera physiological and agronomic responses may vary greatly in response to the use of different rootstocks. Some genotypes showed the ability to confer to this variety a greater adaptability to high temperature and drought. These findings provide valuable insights for the selection of rootstocks capable of sustaining yield and preserving quality in the Glera variety under the projected climatic changes in the study area.

This study examined the potential use of three bacterial strains—Paraburkholderia sp. strain CRV74, Pseudomonas sp. strain CRV21, and Acinetobacter sp. strain CRV19—as biocontrol agents of Botrytis cinerea in grapevine. These strains were selected for their ability to inhibit B. cinerea growth in vitro and used in field conditions for the control of grey mould symptoms in ‘Glera’ grapes. To this end, after inoculating these microorganisms onto plants sprayed with B. cinerea spores, the final yield, the physicochemical characteristics of the must, disease incidence, and the possible influence on the expression of plant-defence proteins were evaluated. Strain CRV21 resulted as being the most effective in combating grey mould (−20% of disease incidence). Although yield was not affected, significantly different values of total soluble solids content was observed. Additionally, a significant up-regulation of the genes PR-1, PR-5, β-1,3-glucanase, and class III chitinase was observed. These findings highlight the potential application of strains with anti-botrytis activity as sustainable alternatives to chemical defence for the control of this pathogen.

In a world grappling with the severe effects induced by climate change, one of the most significant concerns affecting agriculture is the gradual decline in water quality for irrigation associated with reduced rainfalls and the consequent increase in soil salinity. This issue is particularly crucial for grapevine cultivation (Vitis vinifera L.) and the associated winemaking industry. The aroma of the resulting wines and the yield parameters can be influenced both directly by water quality and indirectly due to the effects exerted by salinity on the microbiota, which directly impacts plant health. To gain insights into this topic, our study aimed to analyse the changes induced in the microbiota of both the rhizosphere and the carposphere due to salt stress using a metabarcoding approach, focusing on Vitis vinifera cv. Glera. The control plants were irrigated with rainwater, while the treated plants were irrigated with water containing salt (NaCl). Our findings revealed significant differences in the microbiota (both fungi and bacteria) of the rhizosphere and carposphere between the two treatments. For instance, the Shannon diversity index (i.e., alpha diversity) was lower in the treated plants compared to the control not-treated ones, whilst the beta diversity did not show any differences. Several microbial phyla exhibited better resilience to this abiotic stress (e.g., Ascomycota, Saccharomycetes, Acidobacteria, Proteobacteria, Bacteroidetes), shedding light on their impact on crucial bacterial and fungal groups essential for the subsequent winemaking stages. Additionally, the salt stress negatively affected the yield parameters. This study contributes valuable insights to the viticultural community, providing a deeper understanding of the complex interplay between soil characteristics, microbial communities, and their influence on productivity.

Several researchers stated that climate change effects are arising quickly in the Mediterranean region. Temperature increasing and droughty summers are two of the most common patterns threatening sparkling wines’ grape quality. The present study investigated nitrogen nutrition to enhance acidity and preserve the aromatic compound on Vitis vinifera var. Glera for producing white sparkling wine. Half of the one-hectare vineyard placed in northeast Italy was fertigated with nitrogen during summer, while the control half received only mineral fertilization in spring as usual in the area. The trial lasted three years. The grapes’ quality was monitored and compared at harvest. The statistical analysis proved an affordable trend among treatments in which the fertigated grapes showed, on average, more free amino acids (+32%), more yeast assimilable nitrogen (+71%), more acidity (+21%), and lower total soluble solids concentration (−3%) than the control grapes. Energy storage, fruit yield, and wood mass were measured too. The study proved the nitrogen supply did not affect either fruit yield or plant vigor. Therefore, nitrogen fertigation has been confirmed to be a reasonable growing practice to preserve wine’s aroma and acidity against climate change.

In the Valpolicella area (Verona, Italy) one of the most important Italian wines is being produced: Amarone, predominately made by Vitis vinifera cv. Corvina. This wine is subjected to a specific postharvest process, namely, withering, which aims to increase alcohol content and/or high residual sugars while retaining richness in aromas and organoleptic compounds. In accordance with guidelines and strict Amarone protocol set by the Consorzio of Amarone-Valpolicella, withering must be carried out by setting the grapes in a suitable environment. In our study, the withering process was performed following the traditional methods, i.e., in open-air, natural environmental conditions, as generally performed by winegrowers, leading to a weight loss in grapes of up to 30%. Whilst the effect of different postharvest conditions is clear and studied, it is interesting to know how soil can affect both grapes and wine profile, in terms of aromas, which are of great importance for this crafted wine. For this purpose, for two study years, the influence of two different sites (with regards to the carbonates’ content) on aromas were investigated. Furthermore, microvinifications and the sensory profile of the resulting wines were analysed. Our results clearly indicated that different soils’ characteristics, particularly differences in carbonate content, had an important effect, not only on the aromatic compounds of grapes and wines, but on the sensory profile as well. This information will help winegrowers and winemakers in the process of determining site selection for future vineyards in order to obtain a final optimum Amarone wine, in terms of its aromatic composition—one that is able to respond to the market demand.

Potassium concentration in grape berries can affect acidity and pH in must and wines. Under the current warming scenario, where preserving equilibrated value for these grape parameters is increasingly challenging, K fertilization could represent a tool to manage grape composition. In this study, the effect of potassium fertilization was investigated over 4 years (2013–2016) in field-grown grapevines (Vitis vinifera cv. Glera). Four different potassium rates (0, 15, 30, 60 kg K₂O ha⁻¹ year⁻¹) were tested and agronomic responses, grape quality as well as K concentration in the berry were recorded over the four years. At harvest, yield parameters and total soluble solids were unaffected by potassium fertilization. On the contrary, the titratable acidity of the musts was increased by the higher rate of potassium (K60), and both tartaric and malic acids showed higher values when the K rate was higher. K fertilization did not affect the pH, as all the treatments displayed comparable pH values and in an optimal range for winemaking. Overall, in our experimental conditions, medium potassium inputs showed better results on Glera grape quality compared to low K rates, by promoting higher titratable acidity levels without altering the pH in musts.