Evaluations of Prodiamine and Methazole for Container Ornamental Weed Control

Abstract

<jats:p>Six prodiamine treatments, three applied alone and three applied in combination with methazole, were compared with oxyfluorfen/oryzalin, oxadiazon, and controls (weeded and non-weeded) on ornamental and weed species. Ornamentals included green liriope, Asiatic jasmine, serissa, gardenia, `Needlepoint' holly, Japanese yew, `Prostrata' juniper, and `Carror' azalea. Weeds grown in separate containers were goosegrass, crabgrass, pigweed, and prostrate spurge. At 13 days after treatment (DAT), oxadiazon and oxyfluorfen/oryzalin caused some contact burn on liriope, and the injury persisted until the 81 DAT rating. Methazole/prodiamine treatments caused chlorosis on gardenia leaf tips, with plants recovering by 61 DAT. These combinations also resulted in slight injury to azalea at the first rating, but the injury disappeared by the second rating. Control of goosegrass, crabgrass, and pigweed was good to excellent with all chemical treatments. Control of spurge using oxadiazon and oxyfluorfen/oryzalin decreased at 81 and 100 DAT.</jats:p>