Weed Science Commons^™

Roly Poly And Its Management, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Roly poly, also known as prickly saltwort or tumbleweed (Salsola australis), is a native species found throughout Australia. The dead plants can break off at ground level, forming the ‘tumbleweeds’ seen in movies.

Like most summer weeds, roly poly uses soil moisture and nutrients that would otherwise be available to the following crop. The time taken to clear uncontrolled plants can delay seeding.

Livestock will graze the young plants; however, they will not eat the mature plants and are injured by the prickly leaves.

Windmill Grass And Its Management, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Windmill grass is a native species and the tenth most common summer weed species in the Western Australian (WA) grainbelt. It hosts pests and diseases and utilises stored soil moisture that would otherwise be available to the following crop.

Capeweed And Its Management, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Capeweed (Arctotheca calendula) is a prostrate, stemless, sprawling annual herb that germinates during autumn and winter. In Western Australia (WA), competition from 7 to 90 capeweed plants per square metre in a wheat crop can reduce crop yield by 28 to 44% and net return by 25 to 76%.

Diamondback Moth And Its Management In Canola And Crop Weeds, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Diamondback moth larvae are a serious pest of canola, brassicas, and forage crops, and are difficult to control. The pest breeds up on summer weeds and volunteer canola plants. If there are abundant early rains and mild winters, diamondback moth larvae pose a risk to canola crops.

Spray-Topping Pastures, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Spray-topping or pasture topping is the application of a sub-lethal rate of herbicide when grasses are coming into head and flowering.

The aim is to reduce the production of viable seed and the seedling population in the following year. The grass is not killed by the herbicide application.

Spray-topping is normally carried out in preparation for the following season's cropping program.

Are You Planting Resistant Weeds With Your Crop Seed?, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Key messages

• West Australian (WA) grain growers have significant weed seed contamination in their crop seed.

• WA growers are sowing herbicide resistant weed seed into their cropping paddocks.

• Crop hygiene (harvest, seeding, transporting) is important to minimise spread of weeds.

Harvest is well underway throughout the WA grainbelt, and growers will be harvesting grain and collecting seed for next year’s crop.

However, this crop seed can be contaminated with weed seeds and, if seed cleaning operations are only partially effective, this weed seed may be sown into paddocks with crop seed in the following season.

Button Grass And Its Management, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Button grass (Dactyloctenium radulans) is a native species found throughout Australia. It is a common summer weed species that depletes soil moisture and nutrients, reducing the yield potential of the subsequent crop. It also acts as a green bridge for crop pests and disease.

The rapid emergence and growth of button grass after rainfall makes it important for the Australian plague locust.

It can be a valuable pasture species in arid areas, although overgrazing of button grass can result in toxicity for sheep and cattle.

Barley Grass And Its Management In Crops, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Barley grass is a common name for Hordeum glaucum and H. leporinum. Barley grass is a major crop weeds species because the seed is readily dispersed, it is renowned for rapidly germinating in autumn, and post-emergent herbicide control options are limited. It can also act as an alternate host for cereal diseases and can develop resistance to herbicides.

The rapid germination of the species after rainfall gives barley grass the potential to act as a green bridge for cereal root rot diseases

Wild Oat And Its Management In Crops, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Wild oats (Avena fatua and A. ludoviciana) represent a large cost to cropping; they are highly competitive and when left uncontrolled, can reduce wheat yields by up to 80%.

The greatest yield loss occurs when wild oat plants emerge at the same time as the crop.

Brome Grass And Its Management In Crops, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Brome grass (Bromus spp.) is one of the most competitive grass weeds in wheat. Over the last 10 years, brome grass has increased in importance to a greater extent than any other weed species in Australia.

Recent changes in crop production systems, increased conservation tillage, a lack of available selective herbicides, and a decline in system diversity have seen an increase in the importance of this weed in Western Australia (WA).

Seed is the main source of brome grass infestation and, as few seeds remain dormant, the most important aspect of management is to reduce its seed bank.

Annual Ryegrass And Its Management In Crops, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Annual ryegrass (Lolium rigidum) is one of the most serious and costly weeds of annual winter cropping systems in southern Australia. It is highly competitive and can compete with a crop as early as the 2-leaf stage.

Annual ryegrass is a winter to spring growing weed that can emerge from late autumn to early spring. The number of emergence flushes and the density of plants that emerge are related to initial seedbank levels and the frequency and amount of rainfall.

Herbicides, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Herbicides play a vital role in integrated weed management programs. Knowledge of the mechanisms and activity of herbicides will improve the impact and sustainability of herbicides as a weed management tactic. This fact sheet is a guide to the types of herbicides available and when and how they should be used.

Herbicide Application, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Herbicides can be applied by a variety of means, including boom sprayers, aerial spraying, misters, blanket wipers, rope wick applicators, weed seekers and back-pack sprayers. This fact sheet reviews the different methods, including nozzles and calibration of equipment, used to apply herbicides.