The Effect of Elicitors and Canopy Management in the Chemical Composition of Vitis vinifera Red Varieties in Warm and Hot Areas in Spain

Abstract

Canopy management practices in vineyards, such as sprawling systems and shoot trimming, can change the accumulation of metabolites in grapes. The use of elicitors of biological origin on grapevines of Vitis vinifera red grape varieties may also modulate the chemical composition of the berries. These modifications are often observed in the accumulation of phenolic compounds, including pigments. Both technical approaches are alternatives involved in minimizing the effects of global climate change in warm areas. The increase of temperature related to climate change accelerates the accumulation of sugars, but produces unbalanced grapes. This work establishes the use of button sensors to monitor the climate changes occurring at grape cluster level. Together with climate monitoring, conventional instrumental analytical techniques are used to follow up the chemical composition and the phenolic fraction of grapes in four different production areas in Spain. The effect of either treatment seems variable and to be affected by external factors besides the treatment itself and the climate conditions. While there is a fine effect that correlates with the use of elicitors in varieties like Merlot and Tempranillo, there is minimal improvement observed in Tintilla de Rota. The total phenolic index increases were between 2.3% and 11.8% in the first two parcels. The same happened with the vineyard’s canopy management systems, with increased pigment accumulation and the total phenolic index rising (37.7% to 68.7%) after applying intense shoot trimming, or a variation in sugar concentrations when using sprawl conduction. This study aims to provide viticulturists and oenologists in particular, and farmers in general, with data on the field regarding the use of alternative sustainable practices in the cultivation of grapes. The techniques used involved 100% natural products without adjuvants. The benefits obtained from applying some of these practices would be to produce technically mature grapes despite climate changes, and the elaboration of more balanced wines.

Training System and Methyl Jasmonate Application: A Tool to Improve Major Polyphenol Consumed by the Brazilian Population in Grape Juice

“…Basic Enological Analysis. The total soluble solids (TSS), pH, total acidity (TA), and volatile acidity of the juices were measured using WineScan, as described by Gutieŕrez et al 16 Sample Preparation. For the juice analysis, all of the samples were analyzed in a randomized sequence to prevent bias (https:// www.random.org/sequences/).…”

Cluster microclimate, canopy management and its influence on the berry (size and composition) quality

“…The chromatographic procedure that was followed is a modification of a previously reported method described (Gutiérrez et al, 2021) on the eluents' gradient. HPLC-DAD was an Agilent Technologies series 1200 (Agilent Technologies, Palo Alto, CA, USA) chromatograph with a column RP Kinetex C18 (100 mm x 4.6 mm; 2.6 µm) (Phenomenex, Torrance, CA, USA).…”

“…and do not rise to an embolic process due to high temperature reached by the canopy, unlike the VSP. Sugar accumulation depends on the environmental conditions and therefore, the grapevine microclimate and when the conditions are less extreme, a minimal modification of the canopy should lead to a slowdown in sugar accumulation (Gutiérrez et al, 2021).…”

“…Therefore, when the sun position changes, some leaves are first shaded and then others, so the sun exposure time of the leaves decreases. It has been demonstrated that the use of this technique is an alternative to supporting the sugar accumulation in grapes without affecting the phenolic compounds (Gutiérrez et al, 2021).…”

“…Sprawl systems are non-positioned systems where vegetation is in multidirectional directions. Therefore, as sun position changes along the day, some leaves are first shaded and then others, so the sun leaf exposure decreases (Gutiérrez et al, 2021).The study was conducted in D.O. Uclés vineyards (lat.…”