Tropical Soda Apple
Domestic Programs Pest Evaluation. Arthur E. Miller, USDA-APHIS-PPQ, AERO, Raleigh, NC. September 17, 2003
Scientific name: Solanum viarum Dumal (Solanaceae)
Physical Description: TSA is a perennial in mild climates. Mature plants grow up to 6 feet tall and wide. The fig-shaped leaves, stems, petioles, and pedicles are armed with thorn-like, straight prickles up to 3/4 inch long. Flowers have five white recurved petals; immature fruit are mottled whitish and dark green like a watermelon; and mature fruits are smooth, round, yellow and 3/4 to 1 1/2 inches in diameter with about 400 seeds.
Origin and North American Distribution: TSA is native to South America. It was found in Glades County, Florida in 1988 and has been called The Plant from Hell! Florida is generally infested. TSA infests pastures and other land in AL, GA, MS, NC, SC and TN.
Quarantines: TSA was placed on the Florida Noxious Weed List in 1994 and is regulated by a few other states. It was added to the Federal Noxious Weed List in 1995.
Dispersal: TSA is spread primarily by movement of livestock and wild animals that feed on the mature fruit. Viable seeds pass through the animal and are defecated. Seeds can also be spread with contaminated manure, hay, seed, and sod from infested areas. High risk destinations are pastures, stockyards, slaughter houses, truck washes, fairgrounds,and sodded highways.
Cultural Control: Pastures with dense stands of TSA or environmentally sensitive areas may be mowed to a three-inch height stubble to keep them from producing fruit and seed. Mowing must be repeated when plants reach the flowering stage 50 to 60 days after the mowing or after a hard freeze. In dairy situations, plants may have to be dug. All plants with fruit collected should be incinerated or buried. Standard practices prevent TSA from growing in cotton fields.
Chemical Control: On pastures and non-crop land, TSA can be controlled by application of labeled pasture, hayfield, or non-crop herbicides such as Grazon P+D, Remedy, Roundup, Velpar, Banvel, and Weedmaster. The best time to treat is when TSA plants are 6 to 12 inches tall and prior to fruiting. Repeated spot treatments are needed because seeds are viable for several years.
Biological Control: A few of the insects and diseases that have been researched show promise as bioherbicides or long term biological control in heavily infested areas.
Economic Impact: TSA can become a major weed problem in pastures and parks. It is a threat to the vegetable industry as a competitive weed and alternate host of vegetable crop pathogens including cucumber mosaic virus, gemini virus, tomato mosaic virus, and tomato mottle virus.
Environmental Impact: TSA has the potential to infest large parts of fields, forests, and natural areas in the Southeast, making them nearly impenetrable to domestic animals, large wildlife, and man. Once TSA is established in an area, wildlife will continue to spread the weed.
Benefits of Control: Control protects the environment, increases the value of pastures and other land, and reduces further spread of the weed.
|Bargeron, C.T., D.J. Moorhead, G.K. Douce, R.C. Reardon & A.E. Miller |
(Tech. Coordinators). 2003. Invasive Plants of the Eastern U.S.:
Identification and Control. USDA Forest Service - Forest Health
Technology Enterprise Team. Morgantown, WV USA. FHTET-2003-08.