Experiments were conducted between 2002 and 2004 at multiple locations in Florida to determine the efficacy of aminopyralid and other herbicides on tropical soda apple (TSA) control. Aminopyralid applied at rates ≥0.08 kg ai/ha consistently provided >96% TSA control up to 335 d after treatment (DAT), while applications <0.06 kg/ha were less effective as well as inconsistent. Control of TSA with aminopyralid was often not statistically different from control with triclopyr, picloram, or dicamba. However, these responses were likely due to the variability in TSA control by triclopyr, picloram, or dicamba across several locations. For example, the standard error of the mean for TSA control with picloram at 335 DAT was 8, compared to 1 for aminopyralid. Herbicides were applied in April, January, and June, but time of year did not affect the efficacy of aminopyralid. Aminopyralid possesses soil residual activity and controlled 98% of germinating seedlings at 75 DAT, compared to 0% control for triclopyr or 2,4-D dicamba. Therefore, aminopyralid controlled TSA from foliar applications and soil residual activity more consistently than any other herbicide evaluated in these experiments.
Nomenclature: Aminopyralid, 4-amino-3,6-dichloropyridine-2-carboxylic acid; tropical soda apple, Solanum viarum Dunal. #3 SOLVI.
Additional index words: Preemergence control.
Abbreviations: DAT, days after treatment; TSA, tropical soda apple.