Research & Development Field Report – 7th Edition

NEW PBI-GORDON TECHNICAL SERVICE REPRESENTATIVE – Alan Estes, M.S., CCA

• Alan brings a wealth of knowledge and hands-on experience to the team from his extensive background in the turfgrass industry, particularly in his expertise with herbicides, having served as a research technician for Dr. Bert McCarty at Clemson University from 2000 to 2014.
• Alan is well versed in product development, having worked as a regional R&D scientist from 2014 to 2018, turf product distribution and sales from 2018-2022, and state pesticide regulatory services from 2022-2024.
• Alan will be stationed in Central, SC, and will focus on engaging with DSRs and end-users for product support, working with DSRs and end-users to research products currently pending registration, and to provide technical advice for pest control.

GENERAL OBSERVATIONS

• The Eastern U.S. has had above average rainfall in many locations from spring into early summer, and excessive heat has been widespread to close out the month of June.
• These conditions will aid in increased disease symptom development, especially with root diseases such as Pythium root rot and summer patch.
• Increases in breakthroughs of crabgrass, goosegrass, sedge and Kyllinga should be expected.
• As we approach mid-summer, ensure herbicide applications are not applied during droughty or adverse environmental conditions as these conditions may limit herbicidal activity.

WEEDS

• Post-emergent crabgrass control
  • Optimal crabgrass control in cool-season turf markets is achieved with applications in July before crabgrass plants have hit multi-tiller stages.
    • Apply Q4^® Plus Turf Herbicide for Grassy & Broadleaf Weeds at 8 PT/A with either a surfactant or with the addition of topramezone to enhance control.
    • The combination will reduce bleaching observed from topramezone only applications.
  • Addition of MSO and topramezone is especially important with low-volume sprayers.
  • If applying to warm-season turf, test to evaluate potential turfgrass injury.
• Post-emergent goosegrass control
  • Goosegrass germinates later than crabgrass, but targeting smaller plants is still preferred
  • SpeedZone^® EW Broadleaf Herbicide for Turf applied at 4 PT/A provides ~70% control
    with a single application.

     

    • Two applications of SpeedZone^® applied at 4 PT/A provides greater than 90% control.
    • Adding 0.25 fl. oz./A of Pylex^® with SpeedZone significantly improves goosegrass control and reduces bleaching.
    • If utilizing on warm-season species, test safety before making large scale applications as varieties and species differ in sensitivity.
• Doveweed control
  • Two applications of several PBI-Gordon branded herbicides provide industry leading control of doveweed: SpeedZone, Surge^® Broadleaf Herbicide for Turf and Avenue South™ Broadleaf Herbicide are all excellent options. Product should be elected based on turf species where control is desired.

DISEASES

• Summer patch
  • Symptoms may have already or will develop soon if preventive programs were not implemented.
  • “Curative” applications will not immediately fix symptoms, it takes time for fungicides to enter the plant, stop the infection process, and for plants to recover.
  • Premix products containing DMIs with QoIs or SDHIs are ideal for preventive/curative control.

• Mini-ring
  • Preventive applications should have already been initiated, or implemented now.
  • Prothioconazole tank-mixed with Pedigree Fungicide SC will provide excellent control.
  • Ideal rotational partners include penthiopyrad and pyraclostrobin.
• Gray leaf spot
  • Preventive applications are necessary when environmental conditions are conducive.
  • Tank-mixing chlorothalonil with thiophanate-methyl or prothioconazole are the best options.
  • Strobilurins are effective, but should be tank-mixed with one of the aforementioned active ingredients to aid in disease control, particularly on strobilurin resistant strains of the pathogen.

FORMULATION CHEMISTRY

• As the summer temperatures increase, so does the possibility of turf phytotoxicity on your various turf species. Emulsifiable concentrates (EC) contain solvents that can injure turf as temperatures increase. It is preferred to rely on Soluble Liquids (SL), Emulsions in Water (EW) and Suspension Concentrates (SC) during the summer months.
• Don’t underestimate the strength of sunlight to impact the efficacy of the active ingredients once applied. Consult the label and/or SDS for the impact of photodegradation on the active ingredient. Nontraditional pesticides (such as biological wettable powders) are dramatically impacted by UV exposure. Seek out adjuvants designed to reduce this loss of both traditional and nontraditional pesticides.
• Irrigation increases the possible hydrolysis of active ingredients, specifically sulfonylureas. The combination of increased water application combined with sunlight can result in hydrolytic photodegradation.

PLANNING AHEAD

• Now is the time to plan for purchases for problematic diseases and weeds for fall.
• Kabuto^® Fungicide SC is the premium fungicide for control of spring dead spot.
  • Single application at 3.2 fl. oz./1,000 sq. ft.; split applications from 1.0-1.6 fl. oz/.1,000 sq. ft.
• Early PRE/POST Poa control in warm-season turf (October to December depending on location):
• Katana^® Turf Herbicide+ Bensumec™ 4LF Pre-Emergent Grass & Weed Herbicide
  • Bensumec™ must be watered-in immediately; Katana^® should be left on foliage.
• Early POST Poa control in warm-season turf:
  • Katana + simazine + Preemergent of choice
  • Katana + pronamide (Kerb^® SC)
  • Katana + pronamide + Simazine

Avenue South™ and Bensumec™ are trademarks, and Q4^®, SpeedZone^®, and Surge^® are registered trademarks of PBI-Gordon Corp. Kabuto^® and Katana^® are registered trademarks of Ishihara Sangyo Kaisha, Ltd. Kerb^® is a registered trademark of Corteva Agroscience. Pylex^® is a registered trademark of BASF.