This is a final research report from Hort Innovation’s historical archives. Please note that as these reports may date back as far as the 1990s, the content and recommendations within them may be superseded by more recent research.

What was it all about?

Weeds were a persistent problem for many vegetable producers in Australia. The common features of vegetable cropping systems, including frequent cultivation, irrigation, and the addition of large quantities of nutritional inputs, meant that the potential for weed growth was high. Weeds had a significant impact on crop profitability, yield and quality, and crop management.

In consultation with the Australian industry the researcher sought to identify the most important weed species in Australian vegetable production and the methods used to control them at the time, gaps in knowledge of weed control, potential lessons from other industries, and the most important research, development and extension (RD&E) issues. The project involved a review of the literature, a national survey of vegetable farmers, focus groups and farm visits in major vegetable producing regions across Australia, and key informant interviews.

The most commonly reported weeds of Australian vegetable production were generally annual or biennial broadleaf species. Examples of common weeds were fat hen, stinging nettle, mallow, pigweed, and nutgrass. These could dominate because they seeded heavily, and were more difficult to control using selective herbicides. The current strategy of most farmers to control weeds in vegetable crops included a mixture of herbicides, cultivation, hand weeding, plastic mulch (where applicable), and crop rotation. Other methods may have also been used successfully.

Nearly all farmers integrated a number of control methods (‘Integrated Weed Management’, IWM), because no single technique alone would effectively manage weeds in the crop during the entire growing season. However, relatively less attention had been paid to IWM in vegetables than in broadacre cropping.

The primary output of this project was a series of recommendations for weed control RD&E, to guide future investment.