To investigate the cause(s) of copper deficiency in Wheat in Southern Wimmera region of Victoria.

• Grain yield and micronutrient of YEBS for Cu were measured. In 1984 grain yield response to applied copper was 0146 t ha-1 for wheat grown on the Yellow Duplex soils and 1.32 t ha for the Deep Sand site.
• The Red Duplex and Non-Friable Clay soils were not Cu deficient.
• In 1985 responses on yellow duplex soils (important cropping soils in region) were much smaller: attributed to fact it was a drier year than 1984 (no waterlogging).
• In 1984, leaf Cu concentration was initially sufficient but fell below the critical minimum after the onset of waterlogging and remained low until the soil dried out.

• 21 field trials across Southern Wimmera.
• At 18 trials the treatments included 2 kg ha of copper spray-applied to soil and incorporated at sowing; foliar applied copper (75 g Cu/ha) at late tillering; and 150 g Cu/ha at booting; a nil treatment.
• The other 3 trials investigated correction of previously diagnosed Cu deficiency.
• One of the most responsive sites in 1984 was reinvestigated in 1985 using similar treatments on an area which had not previously received copper.