Water use of an intermediate and a mature avocado orchard

The scarce water resources in South Africa are vulnerable to the increasing pressure of a changing climate. The recent drought experienced in South Africa (2014-2017) has negatively affected the fruit industry, highlighting the need to optimise water use efficiency (WUE) as well as accurately estimate water use. With avocado production in South Africa being export-oriented and dependant on irrigation, proper water management is vital to minimising water use, while maintaining fruit yield and quality. Data were collected in two commercial 'Hass' on 'Dusa' orchards, one a 4-year-old intermediate bearing orchard and the other, a 10-year-old full bearing orchard. Actual orchard evapotranspiration (ETa) defined as water use for this study was measured continuously using the eddy covariance method and a monthly crop coefficient was estimated. Measurements began in May and September 2017 for the intermediate and mature bearing orchards, respectively. Additional measurements included soil water content, predawn, and midday stem water potential and orchard microclimate. Daily average water use (ETa) for the measurement period was 2.8 and 3.5 mm day^‑1 for the intermediate and mature orchards, respectively.