Australian Herbicide Resistance Initiative (AHRI)

Survey zones

Survey zones

Map of south-western Western Australia showing the agronomic zones of the grain belt where survey samples were collected for herbicide resistance testing (as classified in 2003 by the Department of Agriculture and Food).

Rainfall regions represented by:

  • H (High 450 to 750 mm)
  • M (Medium 325 to 450 mm)
  • L (Low <325 mm)

Zones are signified by:

  •  1 (North)
  • 2 (North central)
  • 3 (Central)
  • 4 (South central)
  • 5 (South)



H1 H2 H3 H4 H5 M1 M2 M3 M4 M5 L1 L2 L3 L4 L5