February Pest of the Month: Weeds

There are many species of weeds that colonise production nurseries including broadleaf weeds, grasses, sedges and liverworts. Weeds reduce the rate of crop growth, crop saleability and spread pests down the supply chain. Weed management is most effectively achieved by using a combination of cultural, physical and chemical strategies to prevent weeds from establishing.

Preventing weeds from flowering and seeding is the single most important strategy for weed control. Do not rely solely on herbicides to manage weed populations, even if the cost of preemergence herbicides may be relatively low.

Research has shown that hand weeding on a fortnightly basis has a massive impact on weed pressure, reducing overall weed growth by about 70% and reducing labour costs by half over a 6 month period, compared to hand weeding every 8 weeks.

For a great deal of information on the management of weeds and herbicide resistance refer to the weed management plan and a complimentary webinar. The nursery paper on weed management has an excellent summary including herbicides registered for use in production nurseries. There is also a management plan on liverworts available. Finally, various species have brief descriptions on the Pest ID tool.