Tolerance of Seashore Paspalum Cultivars to Preemergence Herbicides
Abstract The efficacy of preemergence herbicides among seashore paspalum (Paspalum vaginatum Swartz) cultivars used for summer annual weed control is limited. No differences were found in turfgrass tolerance among four paspalum cultivars from preemergence herbicides during 1996 and 1997 at Griffin, GA. The tolerance of paspalum turfgrass was good when treated with Ronstar (oxadiazon) at rates ≤ 10.1 kg/ha (9.0 lb/A), pendimethalin (various trade names, water-dispersible granules) or Barricade (prodiamine) at recommended rates [3.4 kg/ha (3.0 lb/A) and 0.8 kg/ha (0.7 lb/A), respectively]. When rates of these herbicides were increased to three times recommended, 15% injury was noted. During May 1996, Dimension (dithiopyr) injured the turf 12% when applied at the normal rate [0.6 kg/ha (0.5 lb/A)], but the injury was 35% in plots treated with three times recommended. Dimension did not cause any injury in 1997. Surflan (oryzalin) at 3.4 kg/ha (3.0 lb/A) and XL (benefin + oryzalin) at 3.4 kg/ha (3.0 lb/A) caused a maximum of 26% and 20% injury, respectively, when applied at the recommended rates. Maximum injury ranged from 48% for Surflan and 38% for XL when applied to plots at the three times recommended. The quality of PI 509018-1, SIPV-2, and AP-10 was generally higher than Adalayd from early spring until late August both years.