Tropical Soda Apple Tia Bauer

Tropical Soda Apple: Solanum viarum Duna  A perennial shrub  native to Brazil and Argentina  Has become a weed in other areas of South America and in Africa, India, Nepal, West Indies, Honduras, and Mexico  Recently in the U.S

Preferred Habitat  primarily in pastures, ditch banks, roadsides, cattle yards, and wet areas of various fields cannot  survive standing water for extended periods of time  as a weed of nature it preserves where it displaces native plants by crowding and shading

Physical Description Tropical Soda Apple differs from other Solanum species by having the young fruits colored like mini-water melons, straight thorns, and petiolate leaves.

Life Path  Tropical soda apple reaches maturity from seed within 105 days  It is difficult to eradicate  due to rapid regeneration of shoots from an extensive root system  Flowering and fruiting time have not been established in northern climates  but it is likely to flower from June to September  One plant can produce 40,000 to 50,000 seeds  Germination rate greater than 75%.

Classification  Species: Solanum viarum Dunal – tropical soda apple  Family Solanaceae– Potato family  Kingdom: Plantae- Plants

Dispersal  means of dispersal of tropical soda apple in the U.S. is livestock and wildlife  raccoons, deer, feral hogs, and birds feeding on fruits

 Foliage (the leaves, not the fruit) is unpalatable to livestock although cattle will eat the mature fruit  Scarification of seeds by digestive systems of livestock and wildlife seems to promote seed germination… But not always…

The Problem…  Tropical soda apple is a threat to the vegetable crop industry as a competitive weed  because it is an alternate host for numerous pathogens that are diseases  Some endangered crops include:  eggplant, peppers, potatoes, tomatoes

Infections  These vegetable crop patho-gens include:  the cucumber mosaic virus,  Gemini virus,  potato leafroll virus,  potato virus Y,  tobacco etch virus,  tomato mosaic virus,  tomato mottle virus,  and the fungal pathogen, Alternaria solani

The Cattle Industry  It cost the cattle business over $11 million in 1994  Damage to croplands, forestlands, and natural habitats and the cost of control of currently infested areas is difficult to determine  has the potential to become a major problem throughout the southern U.S. and could cost farmers and the public billions of dollars annually.  Illness occurs, including brain damage visible upon autopsy Farmers and ranchers that find tropical soda apple quarantine their cattle from the area as they eliminate it.

Solutions?  Biological: Several species of Solanum are native and no biological controls for Solanum viarum are in widespread use.  Physical No physical controls are currently recommended for tropical soda apple.

Does anything work?  Chemical : Chemical controls can be effective for tropical soda apple.  Triclopyr  Also, Sprays containing aminopyralid are effective at preventing plant growth and germination for several months

Mechanical Removal  Mechanical: Hand removal is discouraged unless extreme caution is used.  Plants can regenerate from roots, so complete removal is necessary  Mowing is also an effective way to remove, even after the flowering process has begun.

Natural Enemies More than 75 species of insects were collected from tropical soda apple in the United States  2001, A strain of the tobacco mild green mosaic virus (TMGMV U2), tested in greenhouse and field trials, found to be lethal to tropical soda apple

Predatory Insect  Gratiana boliviana  native to South America  eats holes in the plant's leaves, skeletonizing and killing it

Dangerous Introduction? No,  this beetle eats exclusively tropical soda apple, so if the plant disappears in an area, the beetles will move on or die, rather than attacking native vegetation.

Should We Worry?

Sources for Images and Information  Joá-bravo  Pest Alert  Tropical Soda Apple  Center for Aquatic and Invasive Plants  Regional Soda Apple Task Force  What Kills Soda Apples  Google Images +apple&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&biw=1095&bih=770&wrapid=tljp &um=1&ie=UTF- 8&tbm=isch&source=og&sa=N&tab=wi&ei=JTCgT7_RNajx0gHB96mjAg