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

作者：Tarara Julie M^*; Pena Jorge E Perez; Keller Markus; Schreiner R Paul; Smithyman Russell P

来源：Functional Plant Biology, 2011, 38(5): 386-400.

DOI：10.1071/FP10221

• Cabernet Sauvignon
• carbon assimilation
• CO2 fixation
• drought
• photosynthesis
• Vitis vinifera
• water stress

Whole-canopy net CO2 exchange (NCEC) 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 (RDIS), or weekly replacement of 60-70% of estimated evapotranspiration for well watered grapevines; (2) early additional deficit (RDIE), or one-half of RDIS applied between fruit set and the onset of ripening (veraison), followed by RDIS; and (3) RDIS followed by late additional deficit (RDIL), or one-half of RDIS applied between veraison and harvest. Summed between fruit set and harvest, nearly 40% less irrigation was applied to RDIE vines and similar to 20% less to RDIL vines than to those continuously under RDIS. After similar to 5 weeks of additional deficit, NCEC in RDIE vines was 43-46% less per day than in RDIS vines. After RDIL vines had been under additional water deficit for similar to 3 weeks, NCEC was similar to 33% less per day than in RDIS vines. Instantaneous rates of NCEC responded rapidly to irrigation delivery and elapsed time between irrigation sets. Concurrent single-leaf measurements (NCEL) reflected the relative differences in NCEC between irrigation treatments, and were linearly associated with NCEC (r(2) = 0.61). Despite halving the water applied under commercial RDI, mid-day stomatal conductance values in RDIE and RDIL of similar to 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.

• 出版日期2011