Variation of water potential and trunk diameter answer as sensitivity to the water availability in table grapes

Abstract

Variation in trunk diameter (TDV) has been proposed as an indicator of the water status of grape vines, with apparently contradictory results. In Vitis vinifera L. var. Crimson Seedless we evaluated the water potential (Ψ), an indicator normally used to determine the water status of grapes, and TDV, comparing two irrigation treatments which restored 100% or 50% of the ETc, to compare the sensitivity of these two indicators to a decrease in soil water. Two evaluation periods of 23 d each were used, the first during the exponential growth phase and the second in the post-veraison period, when the trunk stops growing. In both periods TDV showed coefficients of variation greater than 25%, compared to the 7-10% recorded for water potential. However, during the first measuring period (82-105 d after bud break) the TDV of the treatment with water deficit decreased by more than 30%, while water potential only decreased from 6-12%. In the second measurement period (112-155 d after bud break) in which fruit growth is predominant, the control showed TDV values 100% greater than those of the treatment with water deficit, while the differences in water potential were between 10% and 13%. These results demonstrate the sensitivity of the continuous variation of the trunk diameter and the utility of TDV as a criterion for irrigation control, taking into consideration the development stage of the vines.

Irrigation Protocols in Different Water Availability Scenarios for ‘Crimson Seedless’ Table Grapes under Mediterranean Semi-Arid Conditions

“…This reduction represents savings of more than 50% with respect to well-irrigated vines during this period, and 30% over the entire crop cycle -averaging 2054 m 3 ha −1 during the entire experimental period. This behavior differs from grapevines, with pre-veraison considered to be a non-critical period, because table grapes need more water, as they require a greater leaf area to supply photoassimilates to developing berries, allowing for large berries for fresh consumption [30,31].…”

Deficit irrigation in table grape: eco-physiological basis and potential use to save water and improve quality

“…Several parameters to assess vine's water status have been used in table grape production namely trunk diameter variation (TDV), berry growth, leaf/stem water potential and leaf temperature (Avidan et al 2005;Kopyt and Ton 2005;Gálvez et al 2014). The TDV allows an early and quantitative detection of vine's response to soil water availability during the vegetative and reproductive growth but the variation coefficients can be larger than the ones obtained for water potential (Silva-Contreras et al 2012). Besides, TDV installation is complex, it is prone to maintenance problems and provides too localized information of the vineyard, missing its spatial variability.…”

Determining a Midday Stem Water Potential Threshold for Irrigation of Table Grapes Water potential threshold

“…Consequently, management of grapevine water status to avoid water constraints in table grapes is essential to ensure optimum yield and grape quality. Predawn (Ψ PD ), as well as midday Ψ L and Ψ S are proven measures to assess the water status in table grapes (Myburgh, 1996;Myburgh, 2003;Selles et al, 2004;Williams & Ayars, 2005;Myburgh & Howell, 2006a;El-Ansary & Okamoto, 2007;Reynolds et al, 2009;Williams et al, 2010a;Williams et al, 2010b;Myburgh, 2012;Myburgh & Howell, 2012;Silva-Contreras et al, 2012;Williams, 2012;Williams et al, 2012;Howell et al, 2013;Gálvez et al, 2014;Mabrouk, 2014;Conesa et al, 2015;Zúñiga-Espinoza et al, 2015;Pinillos et al, 2016;Conesa et al, 2018;Al-Fadheel et al, 2018;Weiler et al, 2019). These studies have shown that water potential relates to important grapevine responses such as physiological processes, vegetative growth, berry size, yield and grape quality.…”