New technologies for management, monitoring, and control of spatio-temporal crop variability in precision viticulture scenarios are numerous. Remote sensing relies on sensors able to provide useful data for the improvement of management efficiency and the optimization of inputs. unmanned aerial systems (UASs) are the newest and most versatile tools, characterized by high precision and accuracy, flexibility, and low operating costs. The work aims at providing a complete overview of the application of UASs in precision viticulture, focusing on the different application purposes, the applied equipment, the potential of technologies combined with UASs for identifying vineyards’ variability. The review discusses the potential of UASs in viticulture by distinguishing five areas of application: rows segmentation and crop features detection techniques; vineyard variability monitoring; estimation of row area and volume; disease detection; vigor and prescription maps creation. Technological innovation and low purchase costs make UASs the core tools for decision support in the customary use by winegrowers. The ability of the systems to respond to the current demands for the acquisition of digital technologies in agricultural fields makes UASs a candidate to play an increasingly important role in future scenarios of viticulture application.

Of the geographical parameters in a winegrowing site, altitude is an important determinant of wine composition and quality. Grape polyphenols and volatiles comprise a large and varied group of compounds that contribute considerably to the sensory and health-promoting properties of wine. This review surveys the impacts of altitude and its related climatic characteristics on the phenolic and aroma compounds of grapes and wine through the examination of existing literature. Furthermore, this review highlights the challenge of distinguishing the effects of parameters, such as air temperature, variety, vine water status, soil and UV radiation, from the altitude effect. Overall, high-altitude growing sites can favour an increase - albeit at different intensities - in content of many chemical compounds found in grapes and wine, such as total polyphenols, total monomeric anthocyanins, catechins, quercetin derivatives and cyanidin-derived anthocyanins, trihydroxylated flavonols, carotenoids, isoamyl acetate and ethyl hexanoate. However, the altitude factor seems to be cultivar-dependent; in fact, it can exert a positive effect on the concentrations of acylated anthocyanins and of total aroma compounds in some cultivars (e.g., Ekşikara and Glera) and a negative effect on the same components in other cultivars (e.g., Merlot and Cabernet-Sauvignon). Its influence on the polyphenol content can also differ between different parts of the same cultivar; for instance, an increase in skin tannins and a decrease in seed tannins have been found to be concomitant with an increase in altitude in Syrah grapes. Moreover, at higher altitude, the effect of an increase in UV-B radiation can lead to an enhancement in colour intensity due to an increase in the synthesis of anthocyanins, flavonols and tannins. Due to their cool climate, high-elevated winegrowing regions represent favourite cultivation sites under current and future global warming.

The responses of two red grape varieties, Bovale Grande (syn. Carignan) and Cannonau (syn. Grenache), to temperature and natural UV radiation were studied in a three-years field experiment conducted in Sardinia (Italy), under Mediterranean climate conditions. Vines were covered with plastic films with different transmittances to UV radiation and compared to uncovered controls. Light intensity and spectral composition at the fruit zone were monitored and berry skin temperature was recorded from veraison. Total skin anthocyanin content (TSA) and composition indicated positive but inconsistent effects of natural UV light. Elevated temperatures induced alterations to a greater extent, decreasing TSA and increasing the degree of derivatives acylation. In Cannonau total soluble solids increases were not followed by increasing TSA as in Bovale Grande, due to both lower phenolic potential and higher sensitivity to permanence of high temperatures. Multi linear regression analysis tested the effects of different ranges of temperature as source of variation on anthocyanin accumulation patterns. To estimate the thermal time for anthocyanin accumulation, the use of normal heat hours model had benefit from the addition of predictor variables that take into account the permanence of high (>35 °C) and low (<15 °C and <17 °C) temperatures during ripening.

An early estimation of the exact number of fruits, flowers, and trees helps farmers to make better decisions on cultivation practices, plant disease prevention, and the size of harvest labor force. The current practice of yield estimation based on manual counting of fruits or flowers by workers is a time consuming and expensive process and it is not feasible for large fields. Automatic yield estimation based on robotic agriculture provides a viable solution in this regard. In a typical image classification process, the task is not only to specify the presence or absence of a given object on a specific location, while counting how many objects are present in the scene. The success of these tasks largely depends on the availability of a large amount of training samples. This paper presents a detector of bunches of one fruit, grape, based on a deep convolutional neural network trained to detect vine bunches directly on the field. Experimental results show a 91% mean Average Precision.