Drip irrigation for winter wine grape production

Wine consumption is part of the history of several nations around the world, where the practice is a tradition. Countries such as Italy, France and Spain stand out in production, representing around 45% of world wine production in 2021, according to the OIV (International Organization of Vine and Wine). However, the “new world" countries stand out in the production and quality of the wines produced. According to data from IBGE 2022, Brazil has a cultivated area of ​​75 thousand hectares, with 46% of this total in Rio Grande do Sul, but regions such as São Paulo and Vale do São Francisco also stand out, both with 9% of cultivated area.

Brazil has a unique wine industry in the world, with wine production under three different macro conditions, in which it presents different qualities and typicities, which can be characterized as:

1) Traditional viticulture with a viticultural cycle, with one pruning and one harvest per year.

2) Tropical viticulture with two cycles, with two prunings and two harvests per year, in any period.

3) Winter viticulture with two cycles, two prunings and one harvest per year.

The Brazilian winegrower, with these cultivation options, combined with the genetic improvement of varieties and, mainly, localized irrigation, makes production possible at different times of the year.

Localized irrigation in vine cultivation has the benefit of providing water and nutrients to the plant at key moments of cultivation, such as budding, flowering and berry growth. These are phases in which the plant demands many elements such as nitrogen, calcium, magnesium, boron and water to complete its cycle.

And if the region goes through a period of drought (summer) in these phases mentioned above and the property does not have a localized irrigation system, cultivation tends to reduce berry size and bunch length, also affecting some qualitative characteristics such as the content of soluble solids (°Brix), essential parameters for the production of grapes for wine production and in natura.

Having a drip irrigation system means being able to manage it with a greater level of assertiveness, being able to achieve controlled water deficits from the fruit setting stage onwards. The production of grapes with this type of controlled water stress provides an increase in acidity and a decrease in pH, and a greater concentration of phenolic compounds as a result of the increase in the skin/pulp ratio.

This management can be carried out through tools such as the weather station, which will provide data on the amount of evapotranspiration (evaporation of water from the soil plus transpiration from plants) that occurred the previous day and will need to be replaced according to soil humidity. , which can be estimated through tensiometry (equipment that measures tension, being able to obtain the water content in the soil, being a method that indirectly determines soil moisture). Combined with Kc (crop coefficient, specific for each growth phase), these tools aim to provide the amount of water that the plant and soil need, according to the phenological phase.

Monitoring the water supply during cultivation and, essentially, in the grape maturation phase, is important for the synthesis and concentration of beneficial compounds, such as sugars, acidity reduction, aromatic and phenolic compounds, which are sensory characteristics of wine. (color, aromas and structure), aging capacity and color stability.

With these tools, winemaking in Brazil has a very promising path in the coming years, offering consumers wines of excellent quality, produced with cutting-edge localized irrigation technology, which makes it possible to produce more with less.

By Maxwell Soares da Silva, agronomic specialist at Netafim