Greyish brown, globular or slightly flattened, 2-6 mm diameter, beaked, dimpled and usually one seeded. Remain attached to stem by a fine stalk that is 5-8 mm long. Doesn't release seed at maturity. Valves hard, 1 nerved, network pattern on the surface.
Seeds:
Yellow brown, spherical, 2-6 mm diameter. Tip pointed. Surface hairless, ridged and with a network pattern. Base has stalk remnant.
Roots:
Well developed taproot.
Key Characters:
Ball shaped pods.
Biology:
Life cycle:
Annual. Germinates autumn to winter. Forms a basal rosette of leaves over winter. Flowers late-winter to spring. Dies in summer.
Physiology:
Reproduction:
By seed.
Flowering times:
October to November in SA.
Seed Biology and Germination:
Vegetative Propagules:
None.
Hybrids:
Allelopathy:
Population Dynamics and Dispersal:
Spread by seed and as a contaminant of agricultural produce and seeds.
Origin and History:
Central Europe. Mediterranean. South west Asia
Distribution:
SA, VIC.
Habitats:
Climate:
Temperate.
Soil:
Plant Associations:
Significance:
Beneficial:
Detrimental:
Weed of crops.
Toxicity:
Not recorded as toxic.
Legislation:
None.
Management and Control:
Thresholds:
Eradication strategies:
Most of the Brassicaceae weeds have dormant seeds that continue to germinate throughout the season and for several years. They often mature and set seed very quickly. Manual removal is effective but must be done at least every 8-10 weeks. Once pods are formed, seed will often mature even if the plant has been uprooted. Soil disturbance often leads to a flush of seedlings.
Many are somewhat unpalatable, so grazing only offers partial control. They often flourish in undergrazed, sunny areas.
In bushland situations, fairly selective control can be achieved with 100 mL spray oil plus 0.1 g Eclipse® or 0.5 g Logran® in 10 L water. 5 mL Brodal® is often added to this mix to provide residual control of seedlings. Spray the plants until just wet from the seedling stage up to pod formation.
Isolated plants should be removed manually and burnt if flowering or seeding and a 10 m buffer area sprayed with 10 mL Brodal® in 10 L water.
500 mL/ha of glyphosate(450g/L) can be used at flowering to reduce the seed set of most species on roadsides without causing significant damage to most native plants.
Wick application with 1 part glyphosate(450g/L) in 2 parts water or overall spraying with 100 mL glyphosate(450g/L) in 10 L water provides reasonable control of most species though Wild Radish tends to regrow.
Herbicide resistance:
Biological Control:
Related plants:
None.
Plants of similar appearance:
White Ball Mustard (Calepina irregularis) has a longer point on the tip of the fruit.
References:
Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P384, 387. Diagram of pod.
Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne).
Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #877.1
Moerkerk, M.R. and Barnett, A.G. (1998). More Crop Weeds. R.G. and F.J. Richardson, Melbourne. P72. Diagrams. Photos.
Muenschner p 2526.
Acknowledgments:
Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.