Efficacy of aryloxyphenoxypropionate herbicides tank-mixed with triclopyr for selective bermudagrass control in zoysiagrass fairways

Bermudagrass (Cynodon dactylon (L.) Pers.) is a difficult weed to control in Zoysia spp. fairways. Aryloxyphenoxypropionate (AOPP) herbicides, commonly referred to as graminicides, have been used in various turfgrass settings for controlling bermudagrass contamination; however, applications of these materials can injure zoysiagrass. Research has indicated that zoysiagrass injury can be reduced when multiple AOPP herbicides are tank-mixed with triclopyr, a synthetic auxin. Experiments evaluated the efficacy and safening of several AOPP herbicides when tank-mixed with triclopyr for bermudagrass control in several Zoysia spp. fairways. Experiments were also conducted to determine the response of bermudagrass and Zoysia spp. to varying application intervals and different rates of fluazifop applied alone or tank-mixed with triclopyr. The tolerance of seeded 'Zenith' zoysiagrass (Z. japonica Steud.) to various timings and rates of fluazifop, triclopyr, and fluazifop plus triclopyr was also assessed.