*Agronomic Operation and Maintenance of Field Irrigation Systems DOI: http://dx.doi.org/10.5772/intechopen.84997*

*Irrigation - Water Productivity and Operation, Sustainability and Climate Change*

*Irrigation scheduling for Chardonnay and Merlot plots, November 15–December 31, 2018.*

concordance for daily calculated ET and actual water depth applied.

difference between both cultivars accounts for 340 m3

Between these dates, differences in water depth applied, as compared to calculated ETp, are 3.79% for Merlot and 0.21% for Chardonnay; however, the

the whole season (data not shown), the calculated ETp difference between both

/hectare, equivalent to 19.7%, due to differences in the onset

/hectare. Considering

A 15.1% difference on ETp between plots 1 and 6 accounts for climatic evaporative water differences between both plots. Three years before the implementation of the irrigation scheduling platform at this vineyard, both plots were irrigated with identical water depths and timings; as a result, significant differences in grape yield, average berry size, and wine organoleptic characteristics were obtained. These differences are almost nil for the last two vintages. Also, annual water and energy savings, due to the adoption of irrigation scheduling, account for 34.7%. Similar data for plots 2 and 5 (cultivars Merlot and Chardonnay, respectively) are presented in **Figure 4**. Irrigation scheduling procedures follow a consistent

**20**

cultivars is 1.216 m3

**Figure 4.**

of each phenology dates, which significantly modify its respective Kc = f(t) functions. An irrigation scheduling strategy adequate for Merlot, applied into Chardonnay, will result in overirrigation, excessive canopy vigor, and poor wine organoleptic characteristics, as well as unnecessary water end energy costs in this last plot.

At the same vineyard, a different situation regarding irrigation scheduling was detected; **Figure 5** presents data for plots 3 and 4 (cultivars Syrah and Sauvignon blanc, respectively). Irrigation scheduling between December 1, 2018 and January 18, 2019 consisted on a daily 8 h unique irrigation event, regardless of actual ETp, with no irrigation taking place in December 25.

For the Syrah plot, on the average between these dates, no differences between calculated ETp and actually applied water depth are detected, but if each day is considered separately, overirrigation took place during 20 days, and during 19 days, the plot was underirrigated. This time span includes the berry veraison

**Figure 5.**

*Irrigation scheduling for Syrah and Sauvignon blanc plots, December 1, 2018–January 18, 2019.*

to maturity stage; this irrigation strategy produced 14.6% larger than targeted average berry size (data not shown) and possibly, with expected negative effects on wine organoleptic indicators. In the Sauvignon blanc plot, overirrigation took place throughout these dates, except for December 25 and 26; for this cultivar, the phenology stage corresponds to berry final maturity, which was delayed by 10 days (harvesting date was January 31, ); also, 18–20% of the berries cracked due to excessive irrigation and *Botrytis cinerea* affected a significant number of grape clusters.
