The PBI-Gordon Research & Development Team is pleased to present the Sixth 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.
NEW PRODUCT CORNER – Aethon® Herbicide SL for Turfgrass
- A new, non-2,4-D product for broadleaf, sedge, and kyllinga control in warm-season turfgrass
- Contains the active ingredients pyrimisulfan and penoxsulam
- Perfect option for dollarweed, doveweed, and Virginia buttonweed control
- Learn more by visiting:
https://www.pbigordonturf.com/products/herbicides/selective-herbicides/aethon-herbicide-sl-for-turfgrass/
WEEDS
- Pyrimisulfan soil characteristics
- Questions on pyrimisulfan soil persistence and half-life have been raised. Other active ingredients do have a longer half-life, but half-life does not always equal herbicide activity.
- The soil half-life of pyrimisulfan is ~18 to 159 days; whereas sulfentrazone is ~121 to 302 days and halosulfuron ~4 to 34 days.
- Half-life is the amount of time to reduce any herbicide concentration by 50%. Many environmental factors influence this such as soil moisture, texture, temperature, organic matter, and pH.
- Active ingredient properties like soil sorption, mobility, and solubility also influence the half-life, moreover, they drive soil herbicide activity. Pyrimisulfan is mobile in soil and water soluble facilitating its soil herbicide activity.
- Pyrimisulfan soil characteristics also allow the active ingredient to be formulated as a granular product. Furthermore, field efficacy data indicate longer-term control than other active ingredients currently available in the turfgrass market.
- Set yourself up for success: NOW is the time to begin controlling summer weeds! Immature weeds are most susceptible to herbicides and environmental conditions facilitate herbicide activity.
- Crabgrass and goosegrass
- One of the primary goals for annual grassy weed control is to not let these weeds set seed.
- Q4® Plus Turf Herbicide for Grassy & Broadleaf Weeds will provide excellent POST crabgrass control at this timing and will also control broadleaf weeds.
- It’s never too early to think about goosegrass control. See link to goosegrass control article:
https://www.pbigordonturf.com/best-management-practice-goosegrass-control.
- Sedges and Kyllinga
- These weeds will begin to grow more underground tubers and/or rhizomes sooner rather than later, so early-POST applications are critical for long-term control.
- Arkon™ Herbicide Liquid will provide season-long control of nutsedge and kyllinga with well-timed spring applications.
- Two applications at 1.25 oz./1,000 ft2 (30-45 days apart) is most consistent herbicide program and safe on cool- and warm-season turfgrasses including putting greens.
- Broadleaf weeds
- Difficult-to-control weeds such as Virginia buttonweed, doveweed, Oxalis, wild violet, and ground ivy most always require two herbicide applications for complete control.
- The initial herbicide application at an early-POST timing doesn’t allow these weeds to fully mature to a point when herbicides are far less effective.
- Crabgrass and goosegrass
DISEASES
- Dollar Spot
- Documented resistance of the dollar spot pathogen(s) to the following fungicide groups exists: SDHI (i.e. boscalid), DMI (i.e. propiconazole), benzimidazole (i.e. thiophanate-methyl) and dicarboximide (i.e. iprodione).
- Consider adding fluazinam or chlorothalonil to the tank when applying these modes of action.
- For extended interval products (21-to-28-day intervals), monitor forecasted environmental conditions and reapply products if disease conditions are conducive to prevent dollar spot breakthrough.
- Documented resistance of the dollar spot pathogen(s) to the following fungicide groups exists: SDHI (i.e. boscalid), DMI (i.e. propiconazole), benzimidazole (i.e. thiophanate-methyl) and dicarboximide (i.e. iprodione).
- Summer patch
- Now is the time to initiate a preventive summer patch program (>65° F 2-inch soil depth). 3 applications of Tekken® Broad Spectrum Fungicide on a 28-day interval provides industry leading control of summer patch in research trials.
- Programs with 3 to 4 preventive applications at the high rate typically perform best.
- Combination products with DMI + strobilurin fungicides are ideal in a rotational program.
- Immediate post-application irrigation of at least 1/8” is required for any product choice.
- Pythium blight on perennial ryegrass and creeping bentgrass
- 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 develop.
- >85° F daytime, >65° F nighttime, 90% relative humidity for 14 hours or more.
- Propamocarb and mefenoxam are optimal rotation partners with Segway, phosphites offer additional control, but are best used when disease pressure is low.
- 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 develop.
- Pythium root rot of bentgrass or bent/Poa putting greens
- Now is the time to initiate a Pythium root rot program (>60° F 2-inch soil depth).
- Alternating 14-day program of Segway at 0.45 fl. oz./1,000 sq. ft. and picarbutrazox is the best program afforded to turfgrass managers.
- Immediate post-application irrigation of at least 1/8” is required.
INSECTS
- Preventive white grub control
- 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.
- Preventive white grub treatments are optimally applied at the first sign of adult activity.
FORMULATION CHEMISTRY
-
- Planning for the summer fungicide applications, fungicide formulations can differ even if they have the same active ingredient at the same percentage.
- The bulk of all fungicides are suspension concentrates (SC), which means the active ingredient has been milled to increase the performance of the fungicide. Preliminary lab analysis of non-exclusive fungicides reveal particle size of the active ingredient can be up to 3 times larger than an exclusive, name brand fungicide. This can decrease the efficacy of the product, impacting pathogen control.
- Co-formulants can likewise differ, impacting the wetting and penetration properties of the fungicide to control the specified pathogen. PBI-Gordon has optimized these properties to deliver the Pythium control needed with Segway.
- EWs (Stable Emulsion in Water) and SEs (SuspoEmulsions) remove solvents used in traditional ECs (emulsifiable concentrates), decreasing the VOC (volatile organic content) contribution to the atmosphere. SpeedZone® EW Broadleaf Herbicide for Turf, SpeedZone® Southern EW Broadleaf Herbicide for Turf, and TZone™ SE Broadleaf Herbicide for Tough Weeds offer reliable weed control, with increased environmental stewardship. Other attributes include:
- Lower odor profile – compared to traditional ECs (emulsifiable concentrates) that are solvent-based.
- Reduced drift potential- stop motion video scans reveal reduction of small droplets that can lead to off-target applications.
- Planning for the summer fungicide applications, fungicide formulations can differ even if they have the same active ingredient at the same percentage.
Aethon®, Arkon™, and TZone™ are trademarks, and Q4®, SpeedZone®, and Tekken® are registered trademarks of PBI-Gordon Corp.
Segway® is a registered trademark of Ishihara Sangyo Kaisha Ltd.