Control of Summer Annual Grasses during Seeded Zoysiagrass Establishment with Various Timings and Rates of Fluazifop, Triclopyr, and Fluazifop plus Triclopyr

Abstract Summer annual grasses such as goosegrass and smooth crabgrass can hinder seeded zoysiagrass establishment. The herbicide fluazifop controls various grassy weed species but can injure mature and seedling zoysiagrass. Research has indicated that fluazifop applications can be safened on mature zoysiagrass cultivars with the addition of triclopyr. Based on these observations, research was conducted to evaluate weed control and tolerance of seeded ‘Zenith’ zoysiagrass to fluazifop (0.11 or 0.21 kg ai ha−1), triclopyr (1.12 kg ae ha−1), or fluazifop plus triclopyr (0.11 or 0.21 kg ha−1 plus 1.12 kg ha−1) applied at seeding, 14, or 28 d after emergence (DAE). All herbicide treatments applied at seeding did not hinder zoysiagrass germination but did not reduce goosegrass populations. Fluazifop alone (0.11 and 0.21 kg ha−1) applied at 14 and 28 DAE injured zoysiagrass seedlings but was reduced with the addition of triclopyr. At the end of the growing season, the greatest zoysiagrass cover was achieved by ...