Survey of the extent of copper deficiency of wheat on the Western Downs, Queensland

Abstract

Thirty-five sites from the major soils on which wheat is grown on the Western Downs, Queensland, were screened for Cu deficiency by applying two foliar sprays of 2 % copper sulphate solution (0. 5 kg ha- 1 Cu) to strips within commercially planted wheat crops. Copper deficiency was not widespread. Responses in grain yield were obtained at four sites (classed as deficient), and low concentrations of Cu in grain were recorded at an additional four sites (potentially deficient). Deficient soils occurred near quartz/sandstone rock outcrops, were grey to grey-brown clays of near neutral to alkaline pH, and had natural vegetation of brigalow and belah. Red-brown earths which carry belah or poplar-box in their natural state did not respond to applied Cu.