Grader Grass (Themeda quadrivalvis)
Grader grass seed head
Grader grass is declared a Class B (growth and spread to be controlled) and Class C (not to be introduced to the Northern Territory) weed in accordance with the NT Weeds Management Act 2001.
Grader grass is native to India, and was first introduced to the NT in 1967-68 as a contaminant in pasture seed. Further introductions of this weed were probably made in the same way. Grader grass is now well established on several properties in the Katherine and Darwin regions and continues to spread..
Grader grass is an annual, tufted grass which can grow to a height of 2 metres. Tufts may range in stem numbers from a few stems to up to 10 or more, each with long branched seed heads. Seed heads are made up of globular or fan shaped clusters, interspersed by leaf-life bracts. Mature grader grass stands can be golden orange or red in colour and is quite similar to the native, perennial kangaroo grass (Themeda triandra).
Grader grass is capable of invading both native and improved pastures, competing with pasture species in over-utilised or disturbed areas. Stock may graze young plants but find mature grader grass unpalatable. If grader grass becomes dominant in a pasture there is a loss of productivity, and increased fire risk.
Grader grass introduction and spread can be attributed mostly to contaminated pasture seed, and movement by wind and water.
Grader grass
