Research & Development Field Report – 5th Edition

The PBI-Gordon Research & Development Team is pleased to present the 5th Edition of the R&D Field Report. This report contains scientific information to support the important work underway by our agronomic partners, distribution representatives, and end-users. Our intent is to provide useful, research-based information prior to the seasonal emergence of pests. You can look for updated R&D Field Reports on a quarterly basis throughout 2024.

WEEDS

• Early post-emergent applications with Arkon™ Herbicide
  • Arkon Liquid Herbicide applications have demonstrated near season-long control of yellow nutsedge, false-green Kyllinga, and green Kyllinga when (2) applications are initiated when new shoots start to grow (2 apps of Arkon at 3.4 PT/A). 4-week interval is ideal for Kyllinga species. Light post application irrigation aids efficacy.
  • Arkon Liquid Herbicide may be applied to putting greens.
• Pre-emergent crabgrass applications
  • Make applications when soil temperatures consistently reach 50-55°F for 4-5 consecutive days, or by using growing degree day (GDD) models to optimize timing.
  • Bensumec™ Pre-emergent Grass and Weed Control is an excellent tool for golf course greens.
    • Apply 2 applications at 6 fl. oz./1,000 sq. ft. spaced 30 days apart; immediate post application irrigation is required.
• Pre-emergent goosegrass applications
  • Apply pre-goosegrass applications 4-6 weeks after pre-emergent crabgrass applications.
  • Oxadiazon and indaziflam (warm-season turf only) are highly effective; granular versions of oxadiazon must be used in cool-season turfgrass to avoid injury.
• Winter annual weed control in cool-season turfgrass
  • SpeedZone® EW Broadleaf Herbicide for Turf is ideal for spring weed control.
  • TZone™ SE Broadleaf Herbicide for Tough Weeds is also excellent for controlling a variety of winter annuals and perennial weeds.
    • Use caution when significant temperature swings occur in spring (>25°F in a 24-hour period), as tip-bronzing may occur; bronzing will go away after 1-2 mowings.
      • Using quick release nitrogen may enhance injury under these conditions.

  • Ester formulations of 2,4-D are more efficacious under cooler temperatures than amine formulations.

• Spring broadleaf weed control in warm-season turfgrass
  • Spring transition for warm-season turfgrasses can be a susceptible time for herbicide injury especially for St. Augustinegrass and centipedegrass. Bermudagrass and zoysiagrass are also susceptible, but their recovery potential is typically greater.
  • Avoid high rates of 2,4-D for broadleaf weed control during spring transition. Products such as Avenue™ South Broadleaf herbicide and SpeedZone® Southern EW Broadleaf herbicide for turf have less 2,4-D and can be less injurious.

DISEASES

• Fairy Ring control
  • Two applications, 30-days apart of Pedigree Fungicide SC (a.i. flutalonil) @ 3.25 fl. oz./1,000 sq. ft. provides industry leading preventive fairy ring control.
    • Applications should be initiated when 2-inch soil temperatures reach 55°F for 4-5 consecutive days.
    • Immediate post-application irrigation for any fairy ring treatment (~1/4”) is essential.
    • Incorporation of a wetting agent as part of an application is optimal.
    • Applications using this strategy will also control Waitea patch and Yellow patch.
  • PBI-Gordon Corporation now has a fairy ring guarantee program! Ask your PBI-Gordon sales representative for detailed information.

• Microdochium patch
  • Microdochium patch may occur well into the spring, especially when cool and rainy conditions persist.
  • Preventive applications with fludioxonil at 2.0 fl. oz./1,000 sq. ft. is the standard treatment.
  • Incorporating fluazinam, chlorothalonil, or iprodione with fludioxonil will enhance control.
• Pythium blight & Bipolaris leaf spot on bermudagrass
  • Applications of Segway® Fungicide SC 0.5 fl. oz./1,000 sq. ft. on 14-day interval are highly recommended when environmental conditions are conducive for disease to occur.
  • Union® Fungicide SC will control both Pythium blight and Bipolaris leaf spot.
  • Additional active ingredients to tank-mix* with Segway® are fluazinam, chlorothalonil, azoxystrobin, and iprodione.
• Pythium root rot
  • Initiating applications in late spring are optimal for a preventive Pythium root rot program.
  • The best rotation program available to turfgrass managers is applications of Segway® Fungicide SC at 0.45 fl. oz./1,000 sq. ft. alternated every 14-days with picarbutrazox.
    • This program allows for a total of 10 applications and has been the best performing treatment in all trials where it has been evaluated.
  • Immediate post-application irrigation of at least 1/8” is necessary.
  • Chlorothalonil Proposed Interim Registration Review.
  • The EPA is currently reviewing the registration of chlorothalonil and proposing a reduction in use rates along with additional restrictions on certain use sites.
  • NC State University has an excellent summary which can be found on their website:
    https://turfpathology.ces.ncsu.edu/2023/12/proposed-interim-decision-for-chlorothalonil-and-implications-in-turfgrass-systems/

INSECTS

• Neonicotinoid ban updates from New York and New Jersey
  • Gov. Hochul of New York signed the “Birds and Bees Protection Act” in December 2023, which prohibits the application of dinotefuran and clothianidin to turf and ornamentals (except for agricultural commodities) effective immediately; applications of imidacloprid, thiamethoxam, and acetamiprid are banned after July 1st, 2025.
  • Currently, no exemptions for turfgrass for applications in New Jersey of any neonicotinoid.
• White Grubs
  • Most white grub species overwinter as larvae in the soil below the soil/thatch interface.
  • When spring soil temperatures exceed 50°F, grubs resume feeding of roots and organic matter, and may cause turfgrass injury and attract vertebrate pests such as skunks and racoons, resulting in even greater turf damage.
    • Spring rescue treatment applications of an insecticide are seldom effective.
  • Preventive white grub treatments are optimally applied at the first sign of adult activity.
    • Immediately irrigate following the application to ensure maximum efficacy.
    • Optimal preventive control is achieved with active ingredients including chlorantraniliprole, clothianidin and imidacloprid.
    • If applied early enough, the aforementioned preventive white grub treatments will also provide control of billbugs.
• Annual Bluegrass Weevil (ABW)
  • ABW damage was noticeably less severe in 2023 than in years prior according to some golf course superintendents and practitioners.
  • Adult ABWs migrate from tree lines, high grass, and leaf debris to lower cut turf in the spring and begin laying eggs in leaf sheaths when Forsythia plants are in full-bloom.
  • Preventive adulticide applications include: deltamethrin, bifenthrin and chlorpyrifos.
    • Review all federal, state, and local restrictions for chlorpyrifos applications.
  • Preventive larvicides such as novaluron or chlorantraniliprole should be applied in the spring when Dogwood plants are in full bloom.

INTEGRATED PEST MANAGEMENT (IPM)

• • Spring is an excellent time to implement your integrated pest management program. Scouting for weeds, diseases, and insects, when conditions are conducive for pests, will ensure timely control measures are implemented and not misused. Proper identification is vital for successful pest control.

FORMULATION CHEMISTRY

• • Late winter and early spring are ideal to fully clean spray equipment, including internal screens.
  • Recalibrate sprayers and spreaders so they are ready for season, and replace used, worn, or damaged spray nozzles.
  • Water quality should be evaluated twice per season (i.e. spring and fall).
  • Water quality tests for pH, dissolved solids, carbonates, bicarbonates, EC, and hardness are critical aspects for achieving optimal product performance.
    • High total dissolvable solid (TDS) concentrations may reduce product efficacy (i.e. Al+3, Fe+2, Mg+2) and result in precipitation/clogging in the spray tank.
    • Ensure product pH is +/- 2.0 from carrier water, particularly if mixture sits overnight.

Arkon™, Bensumec™ and TZone™ are trademarks and Segway®, SpeedZone®, and Union® are registered trademarks of PBI-Gordon Corporation 3/24 644362