Recently, the interest in methyl jasmonate (MeJ) has increased in viticulture due to its effects on the synthesis of phenolic secondary metabolites in grapes, especially of anthocyanins, flavonols, and stilbenes derivatives, naturally occurring or synthesized, in berries in response to MeJ application to grapevines. These metabolites help to define sensory characteristics of wines by contributing to their color, flavor and mouthfeel properties, and to derive potential beneficial health effects due to their consumption. This review offers an overview of the importance of these phenolic compounds in grape and wine quality, in association with the MeJ supplementation to grapevines, and also considers their natural biosynthesis in grapes. On the other hand, this review describes the adaptation mechanisms induced after the grapevine elicitation. In addition, this report addresses the effects of MeJ over other aspects of Vitis immunity and its association with phenolic compounds and summarizes the recently published reports about the effects of exogenous MeJ applications to grapevines on grape and wine quality.

Hyper-arid regions are characterized by extreme conditions for growing and lack of water (<100 mm annual rainfall average), where desertification renders human activities almost impossible. In addition to the use of irrigation, different viticultural strategies should be taken into account to face the adverse effects of these conditions in which rootstocks may play a crucial role. This research aim was to evaluate the effects of the rootstock on yield, vigor, and petiole nutrient content in Syrah grapevines growing under hyper-arid conditions during five seasons and compare them to ungrafted ones. St. George induced lower yield than 1103 Paulsen. Salt Creek induced higher plant growth vigor and Cu petiole content than ungrafted vines in Syrah, which was correlated to P petiole content. However, Salt Creek and St. George rootstocks induced an excess of vigor in Syrah according to Ravaz Index. Rootstocks with V. berlandieri genetic background should be used in Syrah growing under hyper-arid conditions to maintain adequate levels of plant vigor and to avoid deficiencies or toxicity of macro and micronutrients.

Certain grape (Vitis vinifera L.) varieties overseen for decades by the Chilean wine industry have emerged as the 'Carignan'. 'País' has not had this resurgence and its production is sold for a price below the national average, negatively affecting the economy of small producers of the Maule Valley (Chile). The aim was to study the grape phenolic composition of 'Carignan' grapevines grafted onto 'País' rootstock according to climate and soil conditions. Sites were located in Valdivia (Val), Loncomilla (Lon), Melozal (Mel), and Huerta de Maule (Hdm) situated in Maule Valley. Phenolic compounds in grapes were analyzed by HPLC. The results showed that soil and climate conditions affected the accumulation of soluble solids, weight of 100 berries and most of the anthocyanins, flavonols and flavanols. Total anthocyanins content in grapes varied from 1393.05 to 1856.03 mg kg-1 (Val and Mel sites, respectively), while total flavonols content ranged from 124.17 to 218.93 mg kg-1 (Val and Lon, respectively). Total flavanols concentration varied from 86.85 to 158.13 mg kg-1 (Lon and Val), while total content of hydroxycinnamic acids varied from 23.91 to 34.84 mg kg-1 (Mel and Hdm). Location conditioned grape flavonoid composition of 'Carignan' grapevines grafted onto 'País'. The use of an ancient variety as a rootstock ('País') on a variety with a great oenological potential ('Carignan'), could be a viticultural tool to improve the income of the small wine-growers of the Maule Valley, without affecting phenolic composition in grapes.

A trial was conducted during the 2005-2006 season in order to determine the effects of different leaf-to-fruit ratios on yield components and fruit composition in four Vitis vinifera L. cultivars. The treatments consisted of selecting shoots of four lengths (>1.3 m, 1.3-0.8 m, 0.8-0.4 m, and <0.4 m) with two crop levels (1-2 clusters/shoot), which allowed defining eight ratios. Berry composition and yield components were measured. The treatments affected the accumulation of soluble solids in "Sauvignon blanc", "Cabernet Sauvignon", and "Syrah", delaying it as the ratio decreased. All yield components were affected in "Sauvignon blanc", while bunch weight and the number of berries per bunch were altered without a clear trend. None of the yield components were affected in "Cabernet Sauvignon", while the lowest ratio presented the lowest number of berries per bunch in "Syrah". Total polyphenol index (TPI) was affected in "Carmenère" without a clear trend. A highly significant correlation was found between shoot length and leaf area in all studied cultivars. As the ratio increased, the shoot lignification increased in "Sauvignon blanc". However, studies must be conducted during more seasons to establish better conclusions about the effects of leaf-to-fruit ratios on yield and fruit composition.

(1) Background: Degradation of soils and erosion have been described for most of the soils presented along the Maule Valley. Organic and integrated management promotes agroecosystem health, improving soil biological activity. Due to this, the aim of this research was to study the effect of organic, integrated, and conventional management on the productive, oenological and soil variables of a vineyard cultivated under semiarid conditions during 5 consecutive seasons; (2) Methods: Yield, grape and wine oenological, and soil physicochemical parameters were evaluated. Bioclimatic indices were calculated in the studied seasons; (3) Results: Conventional management allowed to improve yield and the number of bunches per vine compared to organic management. However, this latter enhanced mineral nitrogen and potassium content in soil. Based on bioclimatic indices, heat accumulation improved number of bunches per plant and most of the soil physicochemical parameters; (4) Conclusions: Organic management improved the accumulation of some microelements in soils at the expense of yield. Organic matter decreased along the study was carried out. Season was the conditioning factor of the variability of most of the studied parameters, while the interaction between season and type of management affected soluble solids, probable alcohol and pH in grapes, and total polyphenol index and pH in wines.