Precision agriculture helps produce differentiated wines in SP

Researchers have proven that the variation in soil and plant attributes in small areas of the same vineyard leads to different characteristics in the grapes and wines produced there.

06.09.2022 | 09:52 (UTC -3)
Embrapa

On the São Paulo wine route, in the interior of the state, at more than 700 meters of altitude, a vineyard is reaping the results of the application of precision viticulture. The finding by Brazilian researchers that variation in soil and plant attributes occurs even in small areas of a vineyard allowed the selective harvesting of ‘Syrah’ grapes and the obtaining of fine winter wines with distinct characteristics.

Spatial and temporal variability in small vineyards was proven in research carried out by Embrapa Instrumentação (SP) at the Terras Altas winery (Ribeirão Preto, SP), in partnership with the Faculty of Agricultural Sciences (FCA) of the Universidade Estadual Paulista (Unesp), in Botucatu (SP), and the Epamig Grape and Wine Technological Center, in Caldas (MG).

Carried out using the on farm research model, which allows direct study on the agricultural property, during the vine cultivation cycle for wine, the work evaluated two years of grape production - 2020 and 2021 - in a double pruning system. In it, one pruning is carried out in August to induce the vegetative cycle and another between January and March, to induce the productive cycle and harvest grapes in winter.

“It is unprecedented work in our production conditions. And it complements the double pruning production technique, improved by Epamig researchers”, says the director of the Terras Altas winery, agronomist Ricardo Baldo.

Grapes and wines with different characteristics

In both years, the winter 'Syrah' wines presented some distinct characteristics depending on the two delimited management zones, called Z1 and Z2, and according to the two rootstocks adopted: 'Paulsen 1103' and 'IAC 572'.

In both grape production cycles, the number of bunches, total mass per plant and the average mass of bunches, soluble solids, hydrogen potential (pH), anthocyanins (plant pigments responsible for wine color) and phenolic compounds (which give astringency, color, flavor and aroma) in the seeds were greater in Z2. Phenolic compounds in the peels were higher in Z1.

Wines originating from the ‘Paulsen 1103’ rootstock showed higher volatile acidity in both management zones in 2020, while ‘IAC 572’ gave the wines higher pH values ​​and anthocyanin content, and antioxidant power in Z2.

In 2021, wines from Z1 had higher alcohol and sugar content, higher pH and tone. Wines made from Z2 grapes had a higher concentration of anthocyanins, a higher level of total polyphenols – substances that influence the flavor and color of the wine and are beneficial to health – and greater intensity.

“The information is strategic for precision viticulture and vineyard management, because from it the winegrower can make decisions regarding the differentiated conduct of agricultural practices used in grape cultivation. One of them is selective harvesting”, says Embrapa researcher Luís Henrique Bassoi.

According to him, the adoption of this practice can result in wines with different characteristics that are of interest to the winery. “The results of the research have a direct impact on the quality of the wine and can, without a doubt, contribute to increasing the quality of the national product”, reinforces Baldo. The research guided by Bassoi was conducted by agricultural engineer Larissa Godarelli Farinassi, from FCA Unesp, to obtain a doctorate in Irrigation and Drainage. She investigated the influence of spatial variability in irrigated vineyards on the quality of grapes and winter ’Syrah’ wine.

“We use the results of studies in our vineyards, selective harvesting of certain areas of the vineyards has already become a reality. The quality gains are already perceived in the field and will be in our consumer’s cup”, says Baldo.

Precision viticulture

Precision viticulture is the adoption of procedures and the use of equipment and sensors for the practice of precision agriculture (PA) in a wine grape production system.

This form of management of the grape production area allows the spatial and temporal variability of the soil and plants to be characterized, in addition to helping to carry out agricultural practices differently in the vineyard. In the specific case of research at the Terras Altas winery, the double pruning system was adopted, meaning that the harvesting of grapes for winemaking took place during the winter. According to Bassoi, the next steps of the research involve analysis 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 the wines originating from them.

Thus, the spatial variability of the drip-irrigated vineyard was characterized by delimiting two management zones. In one of them, the evaluation referred to soil attributes – apparent electrical conductivity and humidity. In the other, the evaluation focused on the plant – vegetation indices.

Furthermore, the researchers assessed whether the management zones differed from each other in terms of the chemical and physical-water attributes of the soil, as well as in relation to the productive, quantitative and qualitative aspects of the grapes and the composition of the wines, in the production cycles investigated. .

As suspected, the spatial and temporal variability of the vineyard belonging to the Terras Altas winery, found in two management zones, occurred even in small areas of the production unit.

More selective harvests

Farinassi explained that the management zones also made it possible to evaluate differences in the physical-water attributes of the soil. “The soil moisture values, as a result of the irrigation carried out and the rain that occurred, were higher in Z2 at depths of 0,4 to 1,0 meter. The difference observed between management zones 1 and 2 increased in depth in both production cycles”, confirms the researcher.

For Ricardo Baldo, the project developed in partnership with Embrapa is very important, considering that the company's production focus is entirely focused on wine quality.

“Knowing in depth the characteristics of each vineyard and outlining the areas of best production in relation to the quality of the fruit makes us work with more selective harvests, favoring the type of grape most suitable for each profile of wine to be produced”, observes the director.

Another winery in which research is also carried out is Casa Verrone (Itobi, SP). According to its owner-director, Márcio Vedovato Verrone, the study provided information that will support future decisions and studies in other areas.

“This year, for example, it was necessary to enter the vineyard where the research work is being carried out for an early harvest. According to the results obtained from research in previous years, we made the best decision on which part to harvest first”.

Knowledge of the vineyard's variability is helping to install the drip irrigation system in the winery, by defining the sectors of the irrigation system, to apply a varied water depth, if necessary.

The research also has financial support from the National Council for Scientific and Technological Development (CNPq) and the São Paulo State Research Support Foundation (Fapesp).

Microvinification

Based on data from the management zones, selective winter harvests of ‘Syrah’ grapes were carried out in July 2020 and July 2021.

The grapes were sent to the Epamig Grape and Wine Technological Center, for microvinification - a small-scale wine manufacturing process - and determination of parameters such as pH, total acidity, sugar, alkalinity, among others.

For the coordinator of the State Program for Research in Viticulture at Epamig, Renata Vieira da Mota, precision viticulture is an important tool in research, as it contributes to detailed knowledge of the vineyard and provides information that helps explain the physiological behavior of the plant. .

“Precision viticulture is essential when we think about producing fine wines of better quality, as knowledge of the characteristics of the grapes in each plot allows the winemaker to create differentiated products from the selective harvesting of grapes, bringing greater added value to the wine” , assesses the coordinator.

Viticultural potential

According to pedoclimatic zoning carried out by researchers from the University of São Paulo (USP), Federal University of São Carlos (UFSCar) and State University of Campinas (Unicamp), more than 70% of the state of São Paulo has soil suitability for cultivation of the vine.

However, according to the study, the regional viticultural potential is more prominent in the autumn and winter seasons, when climatic conditions are favorable for the ripening of grapes.

According to the National Association of Winter Wine Producers (Anprovin), 13 wineries adopt the double pruning technique in the state of São Paulo, producing winter wines in an area of ​​60 hectares.

Employment and income

“The socioeconomic impact of wineries has been increasing, especially due to projects involving wine tourism. There are successful examples of wineries that have added visiting and reception spaces for tourists, promoting business and generating jobs”, says the executive manager of Anprovin, Matheus Cassimiro.

According to him, the calculation for job creation in the countryside is one employee per hectare, not counting wine tourism spaces, when there are any. “This requires hiring a workforce in the service area, with training in public reception and even hotel concepts. These spaces attract income not only for the locations themselves, but also for the municipalities”, says the executive manager.

In Brazil, according to Anprovin, vine cultivation for winter grape harvesting takes place on 267 hectares, which makes it possible to obtain 400 liters of wine per year and 500 bottles, produced by 35 associates present in five states Brazilians - Bahia, Goiás, Minas Gerais, Mato Grosso and São Paulo.

Mosaic Biosciences March 2024