Turnip weed

Rapistrum rugosum

Turnip weed can compete particularly strongly with pulse crops, but will also substantially reduce wheat yields if it is not controlled. Better adapted to hot, dry conditions than most other brassica weeds, turnip weed is widespread in New South Wales and Queensland with the potential to become more common in all cropping areas.

Description

Turnip weed grows to about 80 cm high from a rosette. Difficult to distinguish from other brassica weeds until its pods form, turnip weed is covered in short, stiff hairs and has yellow flowers.

The pods have two segments. The lower one usually contains no seeds. The upper one is round with a conical beak and usually contains a single seed.

Control

Crop choice plays a big part in turnip weed control: pulses should be avoided if possible, while a winter fallow/summer crop sequence can ease pressure. Competitive cereal crops, especially barley, are also good options.

Reduced tillage does not necessarily increase the prevalence of turnip weed.

A range of knockdown and post-emergent herbicides will control turnip weed in cereal crops. Eclipse® is an effective option for spray-topping pulse crops if the rotation requires them.

Related Pests

Indian hedge mustard

Sisymbrium orientale

Indian hedge mustard is found in the cropping areas of Western Australia, northern and western New South Wales and southern Queensland. Its seeds are included in the ‘small foreign seeds’ fraction of allowable grain contaminants.

Wild radish

Raphanus raphanistrum

Wild radish is clearly now the most damaging broadleaf weed in Australian winter cropping. For many growers in the northern wheatbelt of Western Australia, herbicide-resistant wild radish is a threat to the viability of their cereal cropping rotation. While it is not yet such a threat in other areas, wild radish is a competitive weed wherever it emerges.