On-farm management of citrus in drought – a statistical analysis
Prolonged drought in eastern Australia during the period from 2006 to 2011 led to a dramatic reduction in water allocations for irrigation, including those committed to irrigation of permanent horticultural plantings of fruit trees and vines. A major project was established to monitor on-farm management of permanent horticultural plantings under drought conditions, and identify strategies which might facilitate survival and recovery of plantings over the course of the drought. Monitoring sites were established in citrus, almond, avocado and wine-grape plantings, across the Riverland region of South Australia, and the Sunraysia region along the border of Victoria and New South Wales. A total of 146 citrus sites were identified, on 22 separate properties. Detailed information was collected for each site about planting material, irrigation hardware and drought management strategies employed. In addition, the owners of the properties provided detailed data on irrigation applications over 5 irrigation seasons, and yield data for those 5 seasons. Regression analysis was carried out on square root of yield and on irrigation water use index for each irrigation season, and for the average of all 5 seasons, to identify management factors which promoted or compromised yield during drought (2007/08 to 2009/10) and recovery (2010/11 and 2011/12). Only sites with good quality data for all 5 seasons were included in the analysis (54 sites). Results of the regression identified that the key significant factors influencing yield were related to matching water applied (irrigation plus rainfall) with crop water demand, either by decreasing demand or increasing supply. Planting material also contributed to the resilience of citrus in the face of drought.
Skewes, M.A., Dyson, C. and McCarthy, M.G. (2016). On-farm management of citrus in drought – a statistical analysis. Acta Hortic. 1112, 209-216
yield, irrigation water use index, wetted area, canopy area, cultivar, rootstock