We are often asked “What is the worst weed in this area?” Whilst this can depend on many factors, more often than not the answer is this weed, Tropical Soda Apple - Solanum viarum.
Native to parts of South America, it was first discovered as a weed in Florida in 1987. By 1995 it had infested an area larger than the entire Hastings LGA! Locally, it was first discovered nearby in the Macleay valley in 2010 and has since spread to areas throughout the north coast, tablelands and southern Queensland.
Tropical Soda Apple spreads aggressively in pastures and riparian areas, and from there invades forests, roadsides and recreational areas. It is mainly spread by cattle and deer who are attracted to the fruit, but can also spread via water and birds. The movement of cattle around the region without adhering to recommended 6-day quarantine periods is the main cause of spread of Tropical Soda Apple. Once established, the sharp prickles on this plant prevent the movement of people and livestock through infested areas leading to the rapid loss of productive land.
Tropical Soda Apple is a prickly shrub 1-2m high. 1cm long spines on stems and both sides of the leaves are present from seedling stage. Palm sized and shaped leaves are light green in colour with a dense covering of short hairs. The small white flowers develop green, mottled fruit the size of a golf ball, which mature to yellow. They fruit heavily with each fruit producing hundreds of seeds similar to tomato seeds.
Tropical Soda Apple is the subject of a Control Order in NSW, which means all suspected infestations must be reported to Council’s Biosecurity Officer. Confirmed infestations must be continuously suppressed and destroyed, and cattle (if present) may not be moved from the property without strictly quarantining them in a weed-free holding paddock for 6 days. Recently purchased cattle should also be held for 6 days before releasing them into paddocks.
There are also many other weeds and native plants in the Solanum genus that may be found, therefore it is very important to report plants and receive confirmation from the Biosecurity Officer. Find out more about Tropical Soda Apple on WeedWise: NSW WeedWise