Water use dynamics of young and mature apple trees planted in South African orchards: a case study of the Golden Delicious and Cripps’ Pink cultivars
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Date
2018
Journal Title
Journal ISSN
Volume Title
Publisher
Copernicus Publications
Abstract
Apple orchards have previously been bearing 60–80 t ha-1 at most. However in recent years yield
has increased to more than 100 t ha-1. There is need to understand the water requirements of the high yielding
orchards, given that high crop loads are associated with high water use rates. The aim of this study was to
quantify the water requirements of young and mature unstressed apple orchards. We also assess the impact of
climate variables on transpiration rates. Data was collected in 4 orchards in the Western Cape Province. The
orchards comprised young non-bearing (< 3 years) and mature trees planted to the Golden Delicious and Cripps’
Pink cultivars, all under micro-sprinkler irrigation. Transpiration by the trees was measured using heat pulse
velocity sap flow sensors hourly throughout the growing season (October–June). Weather was monitored using
an automatic weather station. Tree transpiration was linearly related to the solar radiation, but the relationship
with the vapour pressure deficit (VPD) was non-linear. There were no significant differences (p>0:05) in the
sapflux density of the Golden Delicious and Cripp’s Pink cultivars. This suggests that these two cultivars have
similar water use characteristics. Mature orchards transpired between 6000 to 8000m3 ha-1 season-1 while nonbearing
orchards used between 2000 to 3000m3 ha-1 season-1.
Description
Keywords
Water use, Apple trees, South Africa, Golden Delicious, Cripp's Pink
Citation
Ntshidi, Z. et al. (2018). Water use dynamics of young and mature apple trees planted in South African orchards: a case study of the Golden Delicious and Cripps’ Pink cultivars. Proceedings of the International Association of Hydrological Sciences, 378: 79–83