Description: TSA is an herbaceous perennial, with simple, alternate, lobed and velvety leaves. The plant is 3 to 7 ft tall depending upon growing conditions and about 3.5 ft in diameter. The leaves measure about 20 cm.by 15cm. Thorns up to 20 mm. long with a yellowish cast and terminal hooks are found on the main stem and branches. The thorns extend onto the main and secondary veins of the leaves. Flowers are white with yellow stamens and reflexed petals like other members of the Nightshade family (e.g. eggplant, etc). They are borne on the stems beneath the leaves. Young fruit are pale green with a network of darker lines and splotches much like a watermelon's skin. The mature fruit is yellow and 2-3 cm in size. TSA is extremely prolific. A single plant may produce from 125 to 400 fruit per plant. As many as 90000 seeds with a germination rate thought to be in excess of 75% are produced per season.
Habitat: TSA was introduced to this country through Glades Co., FL, where it was first found in 1987. The plant is a native of South America, where it is primarily a plant of pastureland and range. In mild winter areas TSA is capable of overwintering, and in Florida it can continue to bear fruit the entire year. .
Life Cycle: Dispersal of the plant's seeds is accomplished through the fecal materials of domesticated, feral, and wild animals. The transportation of cattle and hay from infested areas can spread the pest quickly to uninfested areas. It is also possible that improperly composted cow manure could harbor viable seeds.
Damage: If unchecked, TSA can form dense thickets that replace forage areas and render land unusable. Cattle will avoid heavily infested areas, even if the area is located in much needed shade from the hot sun. This increases heat stress on the animal and lowers production.
When TSA is located near other Nightshade family crops (tomatos, potatos, and eggplants) the problem is a bit different. TSA is an alternate host for tomato mottle disease, tomato mosaic virus, potato virus Y and several other diseases which can threaten commercial field crops. The whitefly has been implicated as a vector for the tomato mottled virus.
The Colorado Potato Beetle finds TSA quite attractive. This beetle was implicated in a situation in Florida that required insecticide application to eggplant in a commercial grower's fields. A buildup of the beetle in nearby pasturelands that had become infested with TSA apparently spread to the grower's fields. Tomato and potato growers also share this risk should a similar situation arise near their crops.
Control: Mowing the plants (or uprooting a single plant) helps, but the application of herbicides such as Roundup (Monsanto) or Remedy (Dow Elanco), coupled with removal by mowing is a better course of action. Keeping the plant from producing seed is the most important control factor.
Interesting Facts: Although TSA has not been found in Virginia to date, it has been transported outside of FL. In Tennessee it has been reported in 4 counties, one of which is not far from the western North Carolina border. Other states in the south (Mississippi, Alabama, Arkansas, South Carolina and North Carolina) have reported infestations of varying degrees of seriousness. One county in Pennsylvania has recently reported finding TSA.
One study has branded this exotic pest:" THE PLANT from HELL".
Tropical Soda Apple Photographs
If you have questions or comments about this page, or notice errors, please send us an e-mail message at idlab@vt.edu. Be sure to include your location (State) and mailing address. Or, you can contact my office at: Insect Identification Lab, Department of Entomology, Virginia Tech, Blacksburg, VA 24061-0319. Please let us know how you heard about this World Wide Web page.