Researchers have proved that the variation of soil and plant attributes in small areas of the same vineyard leads to different characteristics in grapes and wines produced on site The finding is the result of a study conducted in a winery in the countryside of São Paulo, Brazil, where methodology and equipment were used in association with precision agriculture. The scientists assessed two years of grape production in a double pruning system. In the standard vineyard cycle, grapes are harvested once a year, in the summer. These procedures allowed the selective harvesting of ‘Syrah' grapes and the obtention of fine winter wines with distinctive characteristics. The results may help winegrowers to make decisions on agricultural practices, obtain distinguished products of interest, and contribute to higher quality in Brazilian wine. Fine winter wine production has placed the Brazilian states of Bahia, Goiás, Minas Gerais, Mato Grosso and São Paulo as the country's new viticultural frontier. On the wine route in São Paulo's countryside, at an altitude of over 700 meters, a vineyard is reaping the results of the implementation of precision viticulture. The finding by Brazilian researchers that the variation of soil and plant attributes happens even in small areas of a vineyard allowed the selective harvesting of 'Syrah' grapes and the obtaining of fine winter wines with distinctive characteristics. The spacial and temporal variability in small vineyards was proven in a study that was conducted by Embrapa Instrumentation (São Carlos, SP) in the winery Terras Altas (Ribeirão Preto, SP), in partnership with the São Paulo State University (Unesp) School of Agriculture (FCA) in Botucatu, SP, and the Núcleo Tecnológico Epamig Uva e Vinho (Epamig Grapes and Wine Technological Center), in Caldas, Minas Gerais. The on-farm research (model that allows research directly within the rural property, following the cycle of cultivation of the wine grapevines) assessed two years of grape production - 2020 and 2021 - in a double pruning system. In this system, the vines are first pruned in August to induce the vegetative cycle, and then again between January and March to induce the production cycle and harvest grapes in the local winter. "It is unprecedented work in our production conditions. And it complements the double pruning production technique, improved by Epamig researchers", the Terras Altas winery director, agricultural engineer Ricardo Baldo, says. Grapes and wines with different characteristics In two years, winter 'Syrah' wines displayed some distinct characteristics due to the two delimited management zones, called Z1 and Z2, and in accordance with the two adopted rootstocks: 'Paulsen 1103' and 'IAC 572'. In both grape production cycles, the number of clusters, total mass per plant and average mass of clusters, soluble solids, potential of hydrogen (pH), anthocyanins (plant pigments responsible for the wine's color) and phenolic compounds (which impact astringency, color, flavor and aroma) in the seeds were higher in Z2. Phenolic compounds in the skins were higher in Z1. The wines made from the 'Paulsen 1103' rootstock showed higher volatile acidity in the two management zones in 2020, while 'IAC 572' gave the wines higher pH and anthocyanin content, and antioxidant power in Z2. In 2021, the wines from Z1 had higher alcohol and sugar content, higher pH and shade. Wines made from Z2 grapes had higher anthocyanins concentration, higher total polyphenols – substances that influence the taste and color of wine and are beneficial to health – rates and higher intensity. "This information is strategic for precision viticulture and for vineyard management, as it allows winegrowers to make decisions regarding the distinguished conduct of agricultural practices used in the cultivation of grapes. One of them is selective harvesting", says Embrapa's researcher Luís Henrique Bassoi. According to him, the implementation of this practice can lead to wines with different characteristics of interest to the winery. "The research's results have a direct impact on the quality of wine and can undoubtedly contribute to increasing the quality of Brazilian products", Baldo adds. The research advised by Bassoi was conducted by the agricultural engineer Larissa Godarelli Farinassi (pictured on the right), from FCA Unesp, to obtain her PhD in Irrigation and Drainage. She studied the spatial variability in irrigated vineyards' influence on the quality of grapes and winter 'Syrah' wine. "We used the studies' results in our vineyards. The selective harvesting of certain areas of the vineyards has already become true. The quality gains are already observed in the field and will be in our consumers' cups", Baldo says. Precision viticulture Precision viticulture is the implementation of procedures and the use of equipment and sensors for the practice of precision agriculture (PA) in wine grape production systems. This form of management of the grape production area allows to characterize the spatial and temporal variability of the soil and the plant, in addition to helping in the execution of agricultural practices in a distinguished way in the vineyard. In the specific case of the research at the Terras Altas winery, the double pruning system was implemented, so the harvest of grapes for winemaking took place during the winter. According to Bassoi, the next steps of the research include analyses of spatial and temporal variability between vineyards. Proven hypothesis The researchers started from the hypothesis that the variability of soil and vine attributes in the same vineyard could lead to different characteristics in the grapes and in the wines made from them. Thus, the spatial variability of the drip-irrigated vineyard was defined from the delimitation of two management zones. In one of them, the assessment was related to the soil attributes – apparent electrical conductivity and humidity. In the other, the assessment was focused on the plant – vegetation rates. In addition, the researchers analyzed whether the management zones differed from each other in terms of chemical and physical-hydric soil attributes, as well as regarding the productive, quantitative and qualitative aspects of the grapes and the wine composition in the production cycles that were studied. As they suspected, the spatial and temporal variability of the Terras Altas winery's vineyard, found in the two management zones, happened even in small areas of the production unit. More selective harvests Farinassi explained that the management zones also made it possible to assess differences in water-physical soil attributes. "Soil moisture values, as a result of irrigation and rainfall, were higher in Z2 at depths of 0.4 to 1.0 meters. The difference observed between management zones 1 and 2 increased in depth in both production cycles", the researcher confirms. For Ricardo Baldo, the project developed in partnership with Embrapa is very important, considering that the company's production target is fully focused on the quality of the wine. "Knowing in depth the characteristics of each vineyard and determining the areas of better yield in relation to fruit quality allows us to work with more selective harvests, which enables us to prioritize the type of grape that is more suitable for each profile of wine to be produced", the director says. Another winery where this research is carried out is Casa Verrone (Itobi, SP). According to its owner-director Márcio Vedovato Verrone, the study brought information that will support future decisions and studies in other areas. "This year, for example, it was necessary to enter the vineyard in which research work is being carried out for an early harvest. We make the best decision of which part to harvest first according to the results obtained by the research in previous years. The knowledge on the variability of the vineyard is assisting the implementation of the drip irrigation system in the winery, by defining the irrigation system sectors, to apply a varied water slide if necessary. The research also has the financial support of the Brazilian Council for Scientific and Technological Development (CNPq) and the São Paulo Research Foundation (Fapesp). Microvinification Based on the data from the management zones, the selective winter 'Syrah' grapes harvestings were carried out in July 2020 and July 2021. The grapes were sent to the Núcleo Tecnológico Epamig Uva e Vinho for microvinification – small-scale wine production process – and determination of parameters such as pH, total acidity, sugar, alkalinity, among others. For Renata Vieira da Mota, coordinator of Epamig's Program of State Research in Viticulture (Programa Estadual de Pesquisa em Vitivinicultura), precision viticulture is an important tool in research, as it contributes to detailed knowledge of the vineyard and provides information that helps explain the plant's physiological behavior. "Precision viticulture is essential when we think about the elaboration of fine wines of higher quality, because knowing the characteristics of the grapes in each plot allows the winemaker to make distinguished products from the selective harvesting of the grapes, which brings higher added value to the wine", the coordinator says. Viticultural potential According to the pedoclimatic zoning carried out by researchers from the University of São Paulo (USP), the Federal University of São Carlos (UFSCar) and the State University of Campinas (Unicamp), more than 70% of the state of São Paulo shows edaphic aptitude for vine cultivation. However, according to the study, the region's viticultural potential is most noticeable in the autumn and winter seasons, when weather conditions are favorable for the maturation of grapes. According to the Associação Nacional de Produtores de Vinho de Inverno (Brazil's National Winter Winemakers Association - Anprovin), 13 wineries adopt the double pruning technique in the state of São Paulo, thus producing winter wines in an area of 60 hectares. Jobs and income "The socio-economic impact of wineries has been increasing, especially due to projects that involve wine tourism. There are successful examples of wineries that have added spaces for visitation and to welcome tourists, which fostered business and created jobs", says Anprovin's executive manager, Matheus Cassimiro. According to him, the estimate of job generation in the field is of one employee per hectare, plus wine tourism spaces, when there are such. "This demands hiring a workforce in the service area, with training for reception to the public and even hotel management concepts. These spaces attract income not only to the wineries themselves, but also to the cities", the executive-manager says. In Brazil, according to Anprovin, the cultivation of vines for the harvest of grapes in winter takes place on 267 hectares, which makes it possible to obtain 400,000 liters and 500,000 bottles of wine per year, produced by 35 associates present in five Brazilian states – Bahia, Goiás, Minas Gerais, Mato Grosso e São Paulo. Obs: This news report (authors below) had the collaboration of the Associação Nacional de Produtores de Vinho de Inverno (Brazil's National Winter Winemakers Association - Anprovin)