CGA 163935 was evaluated for its growth regulating effect on common bermudagrass for two years and ‘Tifway’ bermudagrass for four years. The vegetative growth of mowed common bermudagrass was suppressed for 5 wk when CGA 163935 was applied at 0.2 kg ha–1 followed by 0.1 kg ha–1 2 wk later and mowed Tifway bermudagrass was suppressed for 4 wk after application of 0.2 kg ha–1. CGA 163935 suppressed vegetative growth of non-mowed common bermudagrass for 9 wk and non-mowed Tifway bermudagrass for 2 to 8 wk at the same rates. Common bermudagrass tolerated CGA 163935 when applied initially at 0.2 kg ha–1 and followed by 0.1 kg ha–1 at a 2-wk interval for a total 0.3 kg ha–1 rate. However, common bermudagrass was severely injured (> 30%) when CGA 163935 was applied at 0.2 kg ha–1 in each of two applications for a total rate of 0.4 kg ha–1. Tifway bermudagrass tolerated CGA 163935 when applied at 0.2 kg ha–1 as a single application or when the 0.2 kg ha–1 was followed by 0.1 kg ha–1 at a 4-wk interval. Tifway bermudagrass was severely injured (> 30%) when CGA 163935 was applied at 0.4 kg ha–1 as a single application or when 0.2 kg ha–1 was followed by 0.1 kg ha–1 at 2- or 3-wk interval. Seedheads were suppressed in common bermudagrass for 1 to 2 wk with CGA 163935 at 0.4 kg ha–1.

Imazethapyr, glyphosate-isopropylamine salt, and glyphosate-sodium sesqui salt plus 2,4-D injured bahiagrass severely for 4 to 6 wk after treatment (WAT) but effectively controlled seedheads for 10 WAT without permanently reducing turf density. Imazethapyr applied twice at 0.08 kg ha-1 suppressed vegetative growth of mowed bahiagrass by 5 WAT while unmowed turf was suppressed 62% by 6 WAT. Glyphosate-isopropylamine salt suppressed vegetative growth by 3 WAT, but did not consistently suppress unmowed bahiagrass. Bahiagrass treated with glyphosate-sodium sesqui salt injured bahiagrass more than glyphosate-isopropylamine salt when each was applied at the same rate. CGA 163935 suppressed bahiagrass seedheads for 8 WAT and vegetative growth from 2 to 4 WAT. The activity of mefluidide, MON 4620 plus paclobutrazol, paclobutrazol plus mefluidide, and flurprimidol plus mefluidide was minimal on bahiagrass.

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.