Clover inclusion may increase the sustainability of certain low-maintenance turfgrasses. However, selective weed control within mixed turfgrass–clover swards proves problematic because of clover susceptibility to herbicides. Research was conducted to identify common turf herbicides that are tolerated by three Trifolium species, including white clover, ball clover, and small hop clover, within low-maintenance turfgrass. Leaf and flower density, as well as plant height, were measured 4 wk after treatment as indicators of clover response to 14 herbicides. The three Trifolium spp. were moderately tolerant of bentazon (< 35% decrease in leaf density, height, or flowering). Simazine was well tolerated by white clover (< 5% decrease in all response variables), yet moderate injury to ball clover and small hop clover was observed (> 32% decrease in leaf density and > 27% decrease in flower density). Pronamide was well tolerated by white and ball clovers, with no effect on measured response variables; however, pronamide decreased small hop clover height and flower density (38 and 42%, respectively). Imazethapyr and imazamox were moderately well tolerated by white clover and small hop clover (< 39% decrease by all response variables), yet ball clover may be more susceptible to these herbicides than was anticipated based on previously reported tolerance. The herbicides 2,4-DB, halosulfuron, and metribuzin were well tolerated by white clover, with no effect on measured response variables; however, results suggest ball and small hop clovers were less tolerant. Clopyralid, 2,4-D, glyphosate, imazaquin, metsulfuron-methyl, and nicosulfuron resulted in varying degrees of injury across clover species and response variables, but, in general, these herbicides may not be viable options when attempting to maintain any of the three clover species tested. Further research is needed to quantify long-term effects of herbicide application on sward composition and clover succession.
Nomenclature: 2,4-D; 2,4-DB; bentazon; clopyralid; glyphosate; halosulfuron; imazaquin; imazethapyr; imazamox; metribuzin; nicosulfuron; pronamide; simazine; metsulfuron-methyl; ball clover, Trifolium nigrescens Viv., small hop clover, Trifolium dubium Sibth. TRFDU, white clover, Trifolium repens L. TRFRE.
La inclusión de Trifolium podría incrementar la sostenibilidad de varios céspedes de bajo mantenimiento. Sin embargo, el control selectivo de malezas en mezclas de céspedes con Trifolium es problemático debido a la susceptibilidad de Trifolium a muchos herbicidas. Se realizó una investigación para identificar herbicidas comunes para céspedes que son tolerados por tres especies de Trifolium, incluyendo Trifolium repens, Trifolium nigrescens, y Trifolium dubium, en céspedes de bajo mantenimiento. La densidad de hojas y flores, al igual que la altura de planta, fueron medidas 4 semanas después del tratamiento, como indicadores de la respuesta de Trifolium a 14 herbicidas. Los tres Trifolium spp. fueron moderadamente tolerantes a bentazon (< 35% de disminución en densidad de hojas, altura, o floración). T. repens también toleró simazine (< 5% disminución en todas las variables de respuesta), aunque se observó un daño moderado en T. nigrescens y T. dubium (> 32% disminución en densidad de hojas y > 27% disminución en densidad de flores). Pronamide fue tolerado por T. repens y T. nigres
