Effects of Rimsulfuron Lateral Relocation on Creeping Bentgrass (Agrostis stolonifera)

Abstract

Concern has been raised that herbicides often used to control perennial ryegrass in warm-season turf could move laterally or “track” and injure neighboring cool-season grasses. Rimsulfuron was applied at 17.5 or 35 g ai/ha to perennial ryegrass in the afternoon. The following morning, while dew was still present, a greens mower was driven through the perennial ryegrass and across the adjacent creeping bentgrass. When evaluated 5, 10, and 25 d after treatment, visible track length and creeping bentgrass injury were greatly reduced by irrigating perennial ryegrass 2 h after treatment or by irrigating both perennial ryegrass and creeping bentgrass prior to simulated mowing. Visible injury of tracked turfgrass persisted for 36 d after treatment when irrigation was not applied and for as few as 5 d when both perennial ryegrass and creeping bentgrass were irrigated. Irrigation had no effect on perennial ryegrass control. Gibberellic acid at 0.12 kg ai/ha and foliar iron at 1.3 kg ai/ha, applied when tracks first appeared, did not improve the recovery of injured creeping bentgrass. Our results suggest that when applying rimsulfuron near susceptible bentgrass, the lowest effective rate should be applied and that the bentgrass should be irrigated at least 2 h after treatment to prevent nontarget injury.

Yellow Nutsedge (Cyperus esculentus) and Large Crabgrass (Digitaria sanguinalis) Response to Soil- and Foliar-Applied Mesotrione

“…Previous research demonstrates the potential for herbicide movement onto nontarget surfaces, both by mechanical and hydraulic movement (Barker et al 2005;Starrett et al 1996). Mesotrione injures creeping bentgrass, which is a desirable turfgrass species for golf course putting greens.…”

Persistence of Rimsulfuron on Perennial Ryegrass (Lolium perenne) and Annual Bluegrass (Poa annua) Foliage

“…Data from this study indicate that a substantial amount of rimsulfuron will persist on treated annual bluegrass and perennial ryegrass foliage in the herbicidally active form. Field studies have shown rimsulfuron can injure creeping bentgrass when mower tires traverse perennial ryegrass 1 DAT with rimsulfuron and deposit dislodged chemical onto creeping bentgrass (Barker et al 2005;Unruh 2003). Creeping bentgrass injury manifests as tire tracks that persist for up to 36 d and results in objectionable turf quality (Barker et al 2005).…”

“…Field studies have shown rimsulfuron can injure creeping bentgrass when mower tires traverse perennial ryegrass 1 DAT with rimsulfuron and deposit dislodged chemical onto creeping bentgrass (Barker et al 2005;Unruh 2003). Creeping bentgrass injury manifests as tire tracks that persist for up to 36 d and results in objectionable turf quality (Barker et al 2005). Because 43% of applied rimsulfuron was waterextractable after 3 d (Figure 4), simply waiting for the sprayed material to dry will not reduce the likelihood of causing nontarget injury via rimsulfuron tracking.…”

“…Current registration for rimsulfuron recommends a buffer area between a treated area and susceptible turf (Anonymous 2001). However, many turfgrass managers do not follow this recommendation and another solution is needed; the solution in field studies has been to wash persistent rimsulfuron from turf foliage with light irrigation prior to mowing or other traffic (Barker et al 2005).…”

“…Herbicide that persists on leaf surfaces may be dissolved in dew and tracked to neighboring susceptible cool-season turf, thus causing injury (Barker et al 2005;Unruh et al 2003). Turf injury in a golf course situation is unacceptable and herbicide injury resulting from lateral movement can last for varying time periods.…”