Irrigation Scheduling for ‘Sovereign Coronation’ Table Grapes Based on Evapotranspiration Calculations and Crop Coefficients

Abstract

Several irrigation treatments were evaluated on 'Sovereign Coronation' (Vitis labruscana) table grapes at two vineyard sites in Ontario, Canada in 2003 to 2005 to assess the usefulness of the Food and Agriculture Organization of the United Nations Penman-Monteith equation for predicting vine irrigation needs. Data (relative humidity, wind speed, solar radiation, and temperature) for calculating reference evapotranspiration (ET o ) were downloaded from the Ontario Weather Network. The five irrigation treatments were nonirrigated control plus four based on combinations of one of two ET o values [100% (ET100) or 150% (ET150)] and two crop coefficients [Kc (fixed at 0.75 or 0.5-0.8 based upon increasing canopy volume)] used to calculate the required irrigation water volume. Transpiration (Ts), leaf water potential (c), and soil moisture data were collected in all three seasons. Yield components data were collected and berries were analyzed for soluble solids, pH, titratable acidity (TA), anthocyanins, methyl anthranilate (MA), and total volatile esters (TVE). Irrigation typically increased Ts rate and soil moisture; the nonirrigated treatment showed consistently lower Ts and soil moisture over the three seasons. Irrigation also increased leaf c, which was lower throughout the three seasons for nonirrigated vines. Irrigation additionally increased yield and its various components (clusters per vine, cluster weight, and berries per cluster) in 2005. Berry weights were higher for irrigated treatments at both sites, and were consistently the main variable leading to yield increases. Soluble solids was highest for the K c = 0.75 treatments. pH, TA, anthocyanins, and phenols were highest in nonirrigated treatments in 2003 and 2004, but were highest in irrigated treatments in 2005. MA and TVE were highest in the ET150 treatments. The use of irrigation was effective in reducing water stress and for improving yield and fruit composition of 'Sovereign Coronation' table grapes in the Niagara region of Ontario. The ET150 treatments were particularly beneficial. Soil and vine water status measurements indicated that irrigation was required for Summer 2003 and 2005 due to dry conditions.

Using Grapevine Water Status Measurements for Irrigation Scheduling of Table Grapes - A Review

“…Consequently, daily fertigation increased cane mass compared to grapevines that were fertigated weekly . Irrigation increased Y L in Sovereign Coronation grapevines compared to no irrigation (Reynolds et al, 2009). As expected, the higher water constraints in the non-irrigated grapevines reduced cane mass at pruning compared to the irrigated grapevines.…”

“…The optimum Ψ S for berry colour was between -0.8 MPa and -1.0 MPa. (Myburgh, 1996;Williams & Ayars, 2005;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 et al, 2012;Gálvez et al, 2014;Mabrouk, 2014;Conesa et al, 2015;Conesa et al, 2018;Al-Fadheel et al, 2018). These studies have shown that vegetative growth, yield components, juice characteristics and fruit quality can be related to water constraints in table grapes.…”

“…Water constraints, i.e. low levels of water potential, can restrict berry development, thereby reducing berry size (Myburgh, 1996;Reynolds et al, 2009;Williams et al, 2010b;Mabrouk, 2014;Conesa et al, 2015;Al-Fadheel et al, 2018). In particular, smaller berries are primarily caused by early season water deficits (Myburgh & Howell 2007a and references therein).…”

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

“…This is probably due to table grapes being harvested at relatively low TSS for export. Yet, this does not rule out the possibility that irrigation induced water constraints have no effect on TSS in table grapes (Selles et al, 2004;El-Ansary & Okamoto, 2007;Tangolar et al, 2007;Reynolds et al, 2009). Inconsistent juice TSS responses to water deficits were also reported for a number of table grape cultivars (Permanhani et al, 2016 and references therein).…”

“…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.…”