

Came across this interesting specimen alongside a trail in Myakka River State Park. If I knew then what I know now about the Tropical Soda Apple (Solanum viarum), I would’ve happily yanked that nasty weed right out of the ground!
This spiny plant, native to Brazil and Argentina, was first documented in Florida in 1988. Since then it has infested over a million acres in the state and spread to other southern states. Due to its rapid growth and landscape dominance, TSA was added to the Florida Noxious Weed List in 1994 and the Federal Noxious list the following year.
Ready for some fun math? Each plant is capable of producing 200 (or more) fruit per year and each fruit contains about 400 seeds. That’s 80,000 seeds that are happily dispersed by hungry wildlife. (Cautionary note: though wildlife seems to enjoy the ripe fruit it contains solasodine, which is poisonous to humans.)
Now, back to the math, with an estimated 75% germination rate that’s 60,000 new plants a year. Here’s the mind-boggling part, by that second year; 60,000 x 200 fruits x 400 seeds = 4.8 billion seeds!
From my years of experience fighting Buffelgrass (a noxious weed out west) I know that battles like this require multiple modes of attack. It’s easy to see why manual removal is not an adequate measure.
There are several herbicides that have proven effective and the USDA has authorized use of the Tropical Soda Apple Leaf Beetle (Gratiana boliviana) as a biological pest control. Currently, there is also a natural, biological herbicide being developed for control TSA though it is not yet available for public.
Next time I see one of these out on the trail, regardless of all the spines, I’m pulling it up!

















































