Branched broomrape (Orobanche ramosa) is a parasitic weed of broad leaved crops. It is a serious weed pest of pulses, oilseed and vegetable crops as well as weeds such as capeweed. Branched broomrape causes severe yield losses and as this species has been detected in South Australia its seed is a prohibited import for many of Australia’s key export markets.
Branched broomrape is a small (10 to 30cm tall), upright parasitic plant with blue, white or purple coloured flowers and no green coloured tissue. It attaches itself to the roots of other plants, spends about 6 weeks underground before emerging to flower and set seed for about two weeks. Parasitising causes its host to show symptoms, which include poor vigour, yellowing leaves, yield losses leading to total crop failure in heavily infested areas.
The symptoms on host plants are similar to those caused by witchweeds and other broomrapes. Symptoms could also be confused with the symptoms of drought. However, if they occur when the soil is wet the paddock should be checked for the presence of branched broomrape and other pests.
You should look for signs of the broomrape flowers, remembering they are visible for only 2 weeks. The multi-stemmed plants are short (10-30 cm), with no green pigment and have small blue, white or purple flowers. Roadsides and paddock edges should be regularly checked as herbicides kill branched broomrape in crops, making roadsides potentially a key source of infection.
Branched broomrape seeds are tiny, almost dust like, and are spread by the wind, water, livestock, and soil (e.g. on machinery) as well as contaminated seed and animal feed. They have a long soil life, so once established it is hard to eradicate. Exercise caution when visiting or buying machinery or seed from overseas, or interstate. If you have been overseas inspect paddocks and roadsides regularly for signs of branched broomrape.
It has been detected in South Australia on canola, medics, field peas and on some weeds and native plants but branched broomrape is a weed of many other pulse, oilseed and vegetable crops in other parts of the world in Asia, Africa, Europe, North America, Cuba and Chile.
Check your crop regularly for signs of branched broomrape, especially if you or your neighbours have recently been overseas or bought seed/machinery from a branched broomrape infected property.
Make sure you are familiar with common pests and diseases so you can tell if you see something different.
If you see anything unusual, call the Exotic Plant Pest Hotline on 1800 084 881.
Check your crop regularly for signs of branched broomrape, especially if you or your neighbours have recently been overseas or bought seed/machinery from a branched broomrape infected property.
Make sure you are familiar with common pests and diseases so you can tell if you see something different.
If you see anything unusual, call the Exotic Plant Pest Hotline on 1800 084 881.