During 2008, IR-4 completed 97 trials on EXC3898 (mesotrione + prodiamine + s-metolachlor). The data contained in this report was generated to register uses of EXC3898 on and around ornamental horticulture plants with over-the-top applications. The mesotrione rates were 2.1, 4.2 and 6.3 pounds active ingredient per acre (lb ai per A) as the 1X, 2X and 3X rates. EXC3898 had been applied to 39 plant genera or species. Of these, five exhibited no or minimal transient injury after application at all three rates. Twenty crops exhibited significant phytotoxicity at even the lowest rate: Buddleia davidii, Dianthus gratianopolitanus, Echinacea purpurea, Hydrangea quercifolia, Ilex sp., Lagerstroemia indica, Liriope sp. , Ophiopogon sp., Phlox paniculata, Phlox subulata, Picea sp., Pseudotsuga menziesii , Rosa sp., Salvia sylvestris, Spiraea sp., Taxus sp., Thuja occidentalis, Veronica sp., Viburnum sp., and Vinca sp.