Sicklepod (Senna obtusifolia)
Sicklepod shrub showing leaf detail
Sicklepod is declared a Class B (growth and spread to be controlled) and Class C (not to be introduced to the Northern Territory) weed in accordance with the NT Weeds Management Act 2001.
Sicklepod is an annual or perennial woody shrub that grows to about 2m in height. Its alternate leaves are divided into two or three opposite pairs of round-ended leaflets. These leaflets are 2 to 3cm long and 1.5 to 2cm wide. Flowers are small, yellow and have five petals. They are produced in pairs in the upper leaf joints. The seed pods are long, slender, round in cross section. They are approximately 12cm long and 4mm across, and there are slight indentations between the seeds.
Sicklepod is thought to be native to Tropical America, and has spread through Africa, Asia and Northern Australia. In the Northern Territory it is widespread in the Darwin, Victoria River and Gulf regions. Sicklepod prefers well drained, fertile soils, but can invade pastures and other disturbed areas such as fencelines, roadsides, waste areas and drainage channels.
Sicklepod has the capacity to grow into dense, vigorous mono-specific stands and can smother most pasture species. Infestations can produce up to 10,000 seeds per square metre. Sicklepod has the ability to become a serious pest in both horticultural and grain crops. Sicklepod is unpalatable to livestock, but can be spread through animals consuming the seed and passing through their droppings.
Sicklepod is a difficult plant to control, especially when it becomes a large, dense infestation. Repeated slashing or cultivation, in conjunction with chemical application can control sicklepod. Slashing alone will not be effective, as under most conditions, it will not kill the plant, rather it may encourage it to regenerate.
Sicklepod flower
