BIOLOGY OF TROPICAL SODA APPLE (SOLANUM-VIARUM) AN INTRODUCED WEED INFLORIDA

Understanding the biology of tropical soda apple (TSA) is necessary to develop effective control strategies. Tropical soda apple seedling em ergence, growth, and regeneration from roots were evaluated. Plant gro wth (height, leaf number, flowering) was monitored over 110 d in a gre enhouse experiment. Emerged seedlings required 83 d to reach a height of 40 cm and 108 d to flower. Total nonstructural carbohydrate concent rations in TSA root and stem fractions, monitored monthly for 1 yr, we re highest in December (35%-root, 18%-stem). Seedling emergence as aff ected by planting depth (0, 1, 2, 4, 8 cm) and regeneration from root segments (7.5, 15 cm long) placed on the soil surface and 5 and 10 cm deep were studied in separate greenhouse experiments. Seedling emergen ce was lowest (P < 0.05) for seed placed on the soil surface (6.9%) an d at a depth of 8 cm (19.4%) with the highest level of TSA emergence p redicted at 63% for seed planted 3.6 cm deep. Regeneration from roots was higher (P < 0.05) for the 15-cm root segments than for the 7.5-cm segments while depth of root segment placement did not affect regenera tion. Weed control strategies should involve cultural and chemical pra ctices that affect both roots and seeds.