Submitted to: HortScience
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/13/2010
Publication Date: 8/1/2010
Citation: Glenn, D.M., Cooley, N., Shellie, K., Walker, R., Clingeleffer, P. 2010. Impact of kaolin particle film and water deficit on wine grape water use efficiency and plant water relations. HortScience. 45(8):1178-1187. Interpretive Summary: In wine grape production, excessive vegetative growth reduces wine quality. We imposed two levels of deficit irrigation to control vegetative growth and examined the effect of an inert mineral reflectant on vine response. Deficit irrigation created vine water deficits, reduced vegetative growth, and reduced water use. The mineral reflectant reduced the severity of the water deficits, increased water use efficiency, and may increase the sustainability of deficit irrigation.
Technical Abstract: Water use efficiency (WUE), photosynthesis (A), transpiration (E), stomatal conductance (Gs), shaded leaf water potential (SLWP), and leaf-air temperature (DT) responses of Cabernet Sauvignon (Vitis vinifera L.) vines were measured in standard irrigation (STD), regulated deficit (RDI) and prolonged deficit (PD) irrigation treatments, each with and without a particle film (PFT). The STD received 100% evapotranspiration (ET) replacement the entire growing season. The RDI received 100% ET from budbreak until 44 days after budbreak (25-Nov) then 50% ET for 38 days followed by 100% ET the remainder of the season. The PD treatment incorporated a RDI treatment followed by an 18 day period of no irrigation. After the no irrigation interval, 100% ET was applied to the PD for the remainder of the season. During the period of PD stress both A, E, and Gs were reduced in the PD and RDI treatments compared to the STD. Four days after resumption of 100% ET in the PD treatment, the PD treatments had reduced A, E, and Gs compared to the STD and the RDI was intermediate. Sixteen days after resumption of 100% ET in the PD treatment, there were no significant differences in gas exchange. Pre-veraison SLWP indicated an irrigation by PFT treatment interaction in which the non-PFT RDI had significantly more negative SLWP compared to other treatments. After veraison, the STD non-PFT treatment maintained less negative SLWP compared to the PD and RDI non-PFT treatments. SLWP was less negative with the PFT treatments of all irrigation treatments. STD and RDI irrigation increased DT compared to PD for the non-PFT treatments. The PFT treatments increased DT and water use efficiency (measured as isotopic carbon discrimination [']) in all irrigation treatments. The addition of PFT to the deficit treatments may increase the sustainability of deficit irrigation particularly in the case of the PD treatments.