Seasonal Application Timings Affect Dallisgrass (Paspalum dilatatum) Control in Tall Fescue

Abstract

Field research was conducted in 2010 and 2011 to investigate the efficacy of herbicides for dallisgrass control when applied at various growing (GDD) or cooling degree day (CDD) –based application timings. Herbicide treatments included fluazifop-p-butyl (fluazifop; 105 g ai ha−1), mesotrione (280 g ai ha−1), tembotrione (92 g ai ha−1), topramezone (37 g ai ha−1), and tank mixtures of fluazifop plus mesotrione, tembotrione, or topramezone. Herbicide treatments were applied at either 75, 175, 375, 775 GDD, or 5 CDD. Treated plots were subjected to three tall fescue interseeding regimes: no seeding, seeding in spring, or seeding in fall (0, 353, and 353 kg pure live seed ha−1, respectively). In 2010, dallisgrass control from fluazifop applied at 75, 375, and 775 GDD was poor (< 50%) by 52 wk after treatment (WAT); in 2011, control from fluazifop application at these timings was higher (62 to 72%). When applied at 175 GDD or 5 CDD in 2010 and 2011, dallisgrass control from fluazifop ranged from 79 to 93% at 52 WAT. The addition of mesotrione, tembotrione, or topramezone to fluazifop did not affect dallisgrass control at any application timing, and control provided by these herbicides alone was low (< 65%). Interseeding tall fescue in the fall improved dallisgrass control from herbicides applied at 75 GDD in 2010 and 175, 375, and 775 GDD at 52 WAT in both years. Results suggest that timing of fluazifop applications at 175 GDD and 5 CDD enhances dallisgrass control.

Growing Degree Day Models for Plant Growth Regulator Applications on Ultradwarf Hybrid Bermudagrass Putting Greens

“…Peak suppression of ultradwarf hybrid bermudagrass clipping yield after TE application was similar to that of PH on Tif Eagle in Mississippi and Champion in North previous GDD studies with C 4 plants (Cross and Zuber, 1972;Elmore et al, 2013). Research predicting the base temperatures of warm-season turfgrasses has been limited to that of Unruh et al (1996), who reported that base temperatures ranged from −0.1 to 12.3°C across warm-season turfgrass species.…”

“…Consecutive daily GDD values were then added to calculate cumulative GDD. The base temperature of 10°C was selected as that is the temperature where photosynthesis becomes minimal for C 4 plants (Berry and Björkman, 1980; McMaster and Wilhelm, 1997) and has been used as the base temperature in previous GDD studies with C 4 plants (Cross and Zuber, 1972; Elmore et al, 2013). Research predicting the base temperatures of warm‐season turfgrasses has been limited to that of Unruh et al (1996), who reported that base temperatures ranged from −0.1 to 12.3°C across warm‐season turfgrass species.…”

Dallisgrass (Paspalum dilatatum) Control with Thiencarbazone-methyl, Foramsulfuron, and Halosulfuron-methyl in Bermudagrass Turf

“…Effective fall herbicide timings for dallisgrass control may be environmentally dependent; changing both spatially and temporally. Future research with TFH applications for dallisgrass control should incorporate the accumulation of cooling degree days similar to Elmore et al (2013) to further increase herbicide efficiency and long-term control.…”

“…Dallisgrass is often considered a desirable grass species in pastures and roadsides; however, its wide adaptability to different environmental conditions has likely contributed to it becoming a weed in turfgrass settings. The presence of dallisgrass reduces turfgrass aesthetics and functionality of recreational, commercial, and residential turfgrass stands (Elmore et al, 2013;Henry et al, 2007a). Tolerance of dallisgrass to low mowing heights (1.3 cm) has been reported, suggesting that it can be problematic in both golf course fairways and roughs (Henry et al, 2007a).…”

False-green kyllinga (Kyllinga gracillima) control in cool-season turfgrass

“…Previous research investigating the control of warm-season perennials bermudagrass and dallisgrass (Paspalum dilatatum Poir.) demonstrated that late-summer herbicide applications are the most effective seasonal application timing (Brosnan et al 2011;Elmore et al 2013).…”