The unneighbourly habits of a weed

Dr Aik-Hock Cheam headed team which gained international award for weed research.

An award-winning collaborative research effort led by Agriculture WA weed research officer Aik-Hock Cheam has thrown new light on the allelopathic impact goosefoot (Chenopodium pumilio) has on crops and pastures in Western Australia.

Allelopathy is any direct or indirect harmful effect of one plant on another through chem-ical compounds released into the environment.

The work, which was jointly supported by the GRDC and Agriculture WA, was judged overall winner of the Best Research Paper award at the 16th Conference of the Asian-Pacific Weed Science Society at Kuala Lumpur last year.

Goosefoot is a major summer weed in the Western Australian wheat belt and is found across southern Australia. Because it can grow until the time of crop sowing, goosefoot has caused serious establishment problems to crops and pastures by releasing allelochemicals into the soil. Some legumes, including lupins and pastures, are very susceptible.

The researchers have identified several chemicals capable of inhibiting germination and crop or pasture seedling growth. They also learned that the most serious damage occurs following dry summers and autumns, particularly in first opportunity planting. The toxic effects are mitigated by early control followed by adequate rainfall.

Dr Cheam said early control should be at the seedling stage, to avoid problems.

The research collaborators include Siew Lee, John Pearce and Brad Rayner (Agriculture WA), Lionel Martin (Muresk Institute of Agriculture) and Neil Rothnie, Wayne Best and Dave Harris (Chemistry Centre of Western Australia).

Program 3.15.03

Contact: Dr Aik-Hock Cheam 08 9368 3241