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Star of Bethlehem (Ornithogalum umbellatum)

Star of Bethlehem (Figure 1) is an increasingly on barley stubble and infect Star of Bethlehem as soon problematic weed found in areas of the Murrumbidgee as it emerges. It then produces further spores which can catchment including near Henty and Junee. Infestations spread to barley plants. The spores which survive over impact on crop growth and mechanical operations due summer on stubble cannot directly reinfect barley to the high bulb density and dense foliage. Bulb seedlings (Wallwork, Mayfield & Dillon 1992). densities are estimated to be up to 15 million bulbs per hectare (Southern Illinois University 2003) which Taxonomy reduces the total soil volume, seed to soil contact and root to soil contact of crop species. Star of Bethlehem is Star of Bethlehem belongs to the Lily family (Liliaceae) often misidentified because of a low level of awareness and the Ornithogalum genus. It is also known as cupid’s by landholders. flower, summer snowflake, starflower, snowdrop or nap- at-noon.

Legislation

Star of Bethlehem is not declared noxious in the Murrumbidgee catchment.

Origin, Introduction to Australia and Distribution

Star of Bethlehem is native to the Mediterranean region (Klingaman 2006). It was introduced into Australia as an ornamental garden plant and has since escaped to become a significant weed in many areas of Australia (Figure 2). The predominant method of spread is via mechanical activity such as tillage and movement of machinery. Photo: Cynthia Podmore

Figure 1. Star of Bethlehem.

KEY POINTS

• Correct identification is essential as Star of Bethlehem can be confused with other species but needs to be managed differently.

• Early eradication is important, as control is very difficult in established populations.

• Farm hygiene is imperative to limit the spread of the weed.

All parts of the Star of Bethlehem plant contain cardiac glycosides and are poisonous to stock and humans if ingested however the bulbs contain a higher concentration. The bulbs are more accessible to stock Photo: Cynthia Podmore following ploughing or any activity which leaves them on the soil surface. Symptoms of toxicosis include Figure 2. A Star of Bethlehem infestation near Henty, NSW. shortness of breath, nausea, salivation, vomiting, diarrhoea and swelling of the lips, tongue and throat. Biology and Ecology The toxins are still present in the plant when it has dried off. Star of Bethlehem is a perennial bulb often mistaken for onion weed (Asphodelus fistulosus) or wild garlic (Allium Star of Bethlehem is also an important weed in the vineale) however it does not have the distinctive odour survival of barley leaf rust. Spores survive over summer of these species. It prefers moist to wet habitats and is

found in a range of situations including continuous Management cropping and pasture paddocks. Identification and awareness of Star of Bethlehem, The leaves are narrow and linear, have a waxy surface, together with good farm hygiene, are important for are dark green in colour with a white mid-rib and are managing the weed due to the limited control options approximately 10-30cm long and 0.25-0.5cm wide. They available. are hollow and tend to arch over as they grow longer. As spread is predominantly via machinery, farm hygiene Shortly after emergence in autumn, stems similar in is imperative to prevent the spread of Star of Bethlehem. length to the leaves (approximately 30cm) appear and Thoroughly wash machinery when moving from areas of flowers form on the end of these stems. The flowers are known infestations and avoid the areas altogether where white, have 6 petals measuring 1.25-1.9cm in diameter possible, e.g. sow around infestations. and resemble a star. The back of the petals are marked with a distinctive green band. The flowers open in the Physical removal of bulbs is the most effective form of morning and close each night. eradication however it is only practical for small infestations. Once the infested area becomes too large Star of Bethlehem reproduces predominantly by the for physical removal, control is very difficult. Star of formation of bulbets on the parent bulb. The bulbs are Bethlehem is near impossible to control in winter crops white and 1.25-3.75cm in length with fibrous roots at the and pastures and severe infestations are likely to need a base and increase to form large clumps (Figure 3). complete crop or pasture renovation. Each bulb can produce up to 7 auxiliary bulbs (Southern Illinois University 2003). Following flowering in spring, There are no herbicides registered for the control of Star the plants die back to the bulbs which remain dormant of Bethlehem in dryland cropping systems in New South over summer. Wales. Some are registered for use in Sugar Cane in New South Wales and some are registered in Queensland for other situations however the efficacy is variable.

A small amount of research (mostly in America) has been conducted to evaluate herbicides for the control of Star of Bethlehem. The results indicate that Gramoxone® is the only herbicide to provide effective control the season following herbicide application.

References

Klingaman, G. (2006). Plant of the Week: Star of Bethlehem (Ornithogalum umbellatum), Cooperative Extension Service, Division of Agriculture, University of Arkansas.

Wallwork, H., Mayfield, A. & Dillon, T. (1992) Control of Star of Bethlehem: Farmer Report.

Southern Illinois University (2003). Star-of-Bethlehem Management with Herbicides, Southern Illinois University Weed Research Annual. Photo: Trevor Haines

Figure 3. Star of Bethlehem plants showing dense foliage and high bulb density.

Further Information: www.murrumbidgee.cma.nsw.gov.au or www.dpi.nsw.gov.au

Disclaimer

The information contained in this publication is based on knowledge and understanding at the time of writing (2008). However, because of advances in knowledge, users are reminded of the need to ensure that information upon which they rely is up to date and to check currency of the information with the appropriate officer of New South Wales Department of Primary Industries/Murrumbidgee Catchment Management Authority or the user’s independent adviser.

The product trade names in this publication are supplied on the understanding that no preference between equivalent products is intended and that the inclusion of a product name does not imply endorsement by NSW Department of Primary Industries or Murrumbidgee CMA over any equivalent product from another manufacturer.

ALWAYS READ THE LABEL Users of agricultural chemical products must always read the label and any Permit, before using the product, and strictly comply with directions on the label and the conditions of any Permit. Users are not absolved from compliance with the directions on the label or the conditions of the permit by reason of any statement made or omitted to be made in this publication.

This project has been funded through the Australian and NSW Governments’ National Action Plan for Salinity and Water Quality.