PARTIAL ROOTZONE DRYING OF VITIS VINIFERA CV. ‘SHIRAZ’ WINEGRAPES IN A SEMI-ARID CLIMATE

Environmental issues such as prolonged drought have triggered the need to reduce the use of irrigated water to a sustainable level.
Novel irrigation methods, like partial rootzone drying (PRD), have increased our understanding of plant physiology with respect to plant water use.
A field trial was established in Mildura, Northwest Victoria, Australia to determine whether Vitis vinifera L. cv. ‘Shiraz’ grown in semi-arid conditions were actually producing a PRD response, that being a reduction in stomatal conductance with no loss in plant water potential, and then to measure the responses with respect to yield and fruit quality attributes.
Treatments consisted of a control irrigated by two drip lines on either side of the vine row (100% control), a deficit treatment irrigated by a single drip line (50% control), and two PRD treatments alternated between single drip lines on each side of the vine row on a 2 irrigation (50% PRD²) and 14 day (50% PRD¹⁴) cycle.
There were no significant changes in leaf water potential (Ψ_L) between any irrigation treatment for measurements conducted at 1000 h and 1500 h.
However, stomatal conductance (g_s) was significantly reduced at 1500 h for the 50% PRD¹⁴ compared with the 100% control.
Yield was unaffected across all treatments despite the 50% control and PRD treatments having smaller berry weights and higher total anthocyanin levels compared to the 100% control.
Overall the controlled level of water stress did improve water use efficiency whilst being favourable on some of the grape quality attributes.

IV International Symposium on Irrigation of Horticultural Crops

Y.M. Chalmers, G. Kelly, M.P. Krstic

partial rootzone drying, winegrapes, leaf water potential, stomatal conductance, water use efficiency, fruit quality, anthocyanins

https://doi.org/10.17660/ActaHortic.2004.664.13