By Lane Tredway, Ph.D., technical services manager for Syngenta

Manuscript^® herbicide | Recognition^® herbicide | Monument^® 75 WG herbicide | Fusilade^® II herbicide

Dallisgrass is possibly the most difficult weed to control in the transition zone. This aggressively growing, perennial grass has an impressive ability to recover from herbicide applications thanks to its robust rhizomes. Dallisgrass is most sensitive to post-emergent herbicides in the spring to early summer and again in the late summer to early fall, so careful timing is essential to getting the best performance.

Growing Degree Days (GDDs) have proven to be a simple, effective tool to optimize the timing of spring applications. Based on research from the University of Tennessee, spring applications of Fusilade^® II herbicide were most effective beginning between 270 and 360 GDD₅₀ with accumulation beginning January 1. This GDD-based timing has also performed well for other chemistries targeting dallisgrass. Visit the GGD tool from Syngenta to see the current GDD accumulation in your area, or to sign up for email alerts when GDD thresholds are met.

Syngenta offers four solutions for dallisgrass management:

Monument^® 75WG herbicide 

• An effective option for dallisgrass control in bermudagrass and zoyisagrass turf
• Apply as a broadcast or spot treatment at 0.53 oz. or 15 g/A as directed by the label
  • A second application four to six weeks later is recommended in most cases 
• Provides broad-spectrum control of many broadleaves, grasses and sedges

Recognition^® herbicide

• Labeled for application to St. Augustinegrass and zoysiagrass turf
• Apply at 1.3 oz./A and tank mix with a non-ionic surfactant at 0.32 fl. oz./gallon of spray
• Repeat applications as needed on a 28-day interval
• In St. Augustinegrass and zoysiagrass turf, Recognition can be tank mixed with Fusilade II turf and ornamental herbicide at up to 24 fl. oz./A for control of dallisgrass, goosegrass and bermudagrass

Manuscript^® herbicide 

• Labeled for use in bermudagrass, zoysiagrass, centipedegrass and in St. Augustinegrass sod
• Apply as a spot treatment using 0.96 fl. oz. of Manuscript and 0.64 fl. oz. of Adigor™ surfactant in 1 gal. of water to treat 1,000 ft.²
  • Make a second application 14 to 21 days later and treat no more than 10,000 ft.²/A per year 
• Also provides effective control of crabgrasses and several other grassy weeds

Fusilade II herbicide 

• Labeled for use in tall fescue and zoysiagrass turf, including residential lawns
• Apply at 3-6 fl. oz./A as specified on the product label 
• Make a repeat application 30 days later 
  • Avoid spray overlaps or application to turfgrasses under stress, which may induce unacceptable turf injury
• Applications will also suppress or control bermudagrass contamination in tall fescue or zoysiagrass