Published online by Cambridge University Press: 12 June 2017
A mixture of bermudagrass with creeping bentgrass on golf greens results in a poor putting surface. An experiment was conducted to determine the frequency of herbicides applied alone or with flurprimidol on growth suppression of three bermudagrass cultivars and on tolerance of creeping bentgrass. Ethofumesate plus flurprimidol applied initially in mid-March or early April at 1.7 + 0.8 kg ha−1 and followed by four applications of 0.4 + 0.2 kg ha−1 beginning 6 wk later and then at 3-wk intervals, effectively suppressed bermudagrass growth throughout the growing season regardless of cultivar. Creeping bentgrass treated with ethofumesate plus flurprimidol at 1.7 + 0.8 kg ai ha−1 caused > 30% injury for 3 to 4 wk following application in 2 of 3 yr, but the turfgrass fully recovered. Injury was < 30% when ethofumesate plus flurprimidol was applied as repeated applications at 0.4 + 0.2 kg ha−1. Siduron plus flurprimidol applied initially in March or April at 54 + 0.8 kg ai ha−1 and followed by four additional applications at 14 + 0.2 kg ha−1 did not effectively suppress bermudagrass growth. Results with siduron alone at 54 kg ha−1 in March or April and repeated at monthly intervals at the same rate throughout the summer were similar to that obtained with siduron plus flurprimidol. Fenoxaprop applied at 0.07 kg ai ha−1 in early April and repeated at monthly intervals through August at the same rate effectively suppressed growth of common bermudagrass but did not suppress growth of Tifway or Tifgreen bermudagrasses. Creeping bentgrass was severely injured following fenoxaprop treatments.