Multi-seasonal effects of warming and elevated CO₂ on the physiology, growth and production of mature, field grown, Shiraz grapevines

Abstract

Industry concerns in Australia about the impacts of climate change have, to date, focused on the effects of warming, particularly shorter maturation periods. The effects of elevated CO 2 concentration (eCO 2 ) on C 3 plant physiology have been extensively studied and suggest that eCO 2 impacts on viticulture could affect grapevine shoot growth, fruit production and fruit composition. We previously used open top chambers (OTC) with an active heating system to study the effects of elevated air temperature (eTemp) on mature grapevines in the field. This system was augmented with the ability to elevate atmospheric CO 2 and established in a mature Shiraz vineyard in a factorial combination of eTemp and eCO 2 . Three seasons of observations on the eTemp only treatment corroborated our previous study; all aspects of phenology were advanced, but leaf function was largely unaffected. In contrast, the effects of eCO 2 on phenology were small in the first season, but increased over the subsequent two seasons. Interactive effects of the treatments on gas exchange were observed; photosynthesis rates were significantly higher in the eCO 2 +eTemp treatment, compared to eCO 2 alone, suggesting that the likely future climate will have a larger impact on viticulture than might be predicted from experiments examining only one of these factors.

The Effect of Elevated CO2 on Berry Development and Bunch Structure of Vitis vinifera L. cvs. Riesling and Cabernet Sauvignon

“…Interestingly, Bindi et al [7] demonstrated that TSS of Sangiovese was stimulated by eCO 2 during ripening, but the positive effect disappeared when grapes reached maturity. Gonçalves et al [2] also confirmed this for Touriga Franca, whereas only Edwards et al [5] indicated that eCO 2 resulted in a higher TSS accumulation for Shiraz at harvest. Berries of both cultivars reached a higher sugar concentration for both treatments at maturity in 2015 compared to the other seasons.…”

“…CO 2 enrichment increases photosynthesis and, therefore, growth and yield of perennial plants. Within grapevines, this was already shown by various authors using different CO 2 enrichment techniques such as open top chambers [2][3][4][5], Mini-FACE (Free-Air Carbon Dioxide enrichment) [6][7][8], or the recently reported VineyardFACE system [9,10]. In addition to open field studies on grapevines, CO 2…”

“…Berry development of grapevines plays an important role in the formation of fruit quality parameters that are substantial for efficient wine making and the following wine profile. According to previous work, vines exposed to eCO 2 conditions predominantly affect total soluble solid accumulation and acid degradation [2,5,7,11]. These two main components are well known to be sensitive to several abiotic factors such as soil, temperature, precipitation, or sunlight [44][45][46][47][48][49], which all count as climate-driven relevant markers.…”

“…In cv. Shiraz, Edwards et al [5] showed that eCO 2 treatment was advanced in phenological development and, therefore, in total soluble solids accumulation with an increasing effect over seasons. Acid and sugar concentrations of cv.…”

Grapevine bud fertility under conditions of elevated carbon dioxide

“…Elevated CO 2 concentration (eCO 2 ) is one of the main drivers of climate change ; however, its impact on the bud fertility of field-grown grapevines has not yet been investigated. Studies that focused on the influence of eCO 2 on grapevines, particularly in the field, have shown increased vegetative and fruit biomass under eCO 2 , due to higher rates of photosynthesis (Bindi et al, 2001 ;Moutinho-Pereira et al, 2009 ;Edwards et al, 2017 ;Wohlfahrt et al, 2018). Although eCO 2 had no effect on the number of bunches per vine, bunch and berry weight were increased (Bindi et al, 1996 ;Moutinho-Pereira et al, 2009 ;Wohlfahrt et al, 2018).…”