Net carbon exchange in grapevine canopies responds rapidly to timing and extent of regulated deficit irrigation

Abstract

Whole-canopy net CO 2 exchange (NCE C ) was measured near key stages of fruit development in grapevines (Vitis vinifera L. cv. Cabernet Sauvignon) that were managed under three approaches to regulated deficit irrigation (RDI): (1) standard practice (RDI S ), or weekly replacement of 60-70% of estimated evapotranspiration for well watered grapevines; (2) early additional deficit (RDI E ), or one-half of RDI S applied between fruit set and the onset of ripening (veraison), followed by RDI S ; and (3) RDI S followed by late additional deficit (RDI L ), or one-half of RDI S applied between veraison and harvest. Summed between fruit set and harvest, nearly 40% less irrigation was applied to RDI E vines and~20% less to RDI L vines than to those continuously under RDI S . After~5 weeks of additional deficit, NCE C in RDI E vines was 43-46% less per day than in RDI S vines. After RDI L vines had been under additional water deficit for~3 weeks, NCE C was 33% less per day than in RDI S vines. Instantaneous rates of NCE C responded rapidly to irrigation delivery and elapsed time between irrigation sets. Concurrent single-leaf measurements (NCE L ) reflected the relative differences in NCE C between irrigation treatments, and were linearly associated with NCE C (r 2 = 0.61). Despite halving the water applied under commercial RDI, mid-day stomatal conductance values in RDI E and RDI L of~50-125 mmol m -2 s -1 indicated that the additional deficit imposed only moderate water stress. There was no effect of additional deficit on yield or berry maturity.

Comparison of whole-canopy water use efficiency and vine performance of cv. Sangiovese (Vitis vinifera L.) vines subjected to a post-veraison water deficit

“…In fact, seasonal canopy WUE of the two treatments provide a very clear-cut picture suggesting that as the water shortage became more severe, canopy WUE markedly decreased. Other studies offering the single-leaf vs. whole-canopy WUE comparison performed in potted (Poni et al, 2009) and field grown vines (Merli et al, 2015;Poni et al, 2014a,b;Tarara et al, 2011) confirmed that, at the canopy level, no gain in WUE was seen under drought.…”

Improving water use efficiency of vineyards in semi-arid regions. A review

“…One of these strategies as discussed before is regulated deficit irrigation, which has been explored to control vegetative growth (Edwards and Clingeleffer 2013; Greven et al 2005;Intrigliolo and Castel 2010;Santesteban et al 2011;Tarara et al 2011;Terry and Kurtural 2011). This technique improves vigor by reducing water application and yield per unit water supply (Acevedo-Opazo et al 2010;Edwards and Clingeleffer 2013;Myburgh 2003;Tarara et al 2011).…”

“…A recent study performed in different cultivars of grapevine confirmed previous results by showing that there is no consistent correlation between parameters measured at leaf and whole canopy levels . The possible causes of this lack of correlation, explained in detail in different reviews Medrano et al 2012;Schultz and Stoll 2010;Tarara et al 2011;Tomás et al 2014a) are associated to the complexity of the canopy structure, and two physiological mechanisms, leaf night transpiration and plant respiration.…”

“…4 Relation between total water applied (rainfall from April to September + irrigation) and yield and crop water use efficiency. Data are collected from Acevedo-Opazo et al 2010;Bassinger and Hellman 2007;Bindon et al 2008;Chaves et al 2007;De la Hera et al 2007;Edwards and Clingeleffer 2013;Girona et al 2006;Greven et al 2005;Intrigliolo and Castel 2010;dos Santos et al 2007;Romero et al 2010;Santos et al 2005;Tarara et al 2011. Circles full irrigation, squares partial root zone drying, triangles deficit irrigation, diamonds regulated deficit irrigation.…”

Editorial: Root systems for dry environments

“…Partial rootzone drying and regulated deficit irrigation were studied in field-grown almond trees by Egea et al (2011) and grapevines by Tarara et al (2011). These studies show the benefits of deficit irrigation techniques in reducing the amount of water used and maximising plant productivity.…”