POMAIS
Quinclorac for torpedo grass: A Targeted Post-Emergent Herbicide
Why Torpedo Grass Is a Major Problem in Turf and Landscapes
Torpedo grass (Panicum repens), commonly known as couch panicum or creeping panic grass, is a perennial warm-season weed that spreads aggressively through both rhizomes and seeds. Native to Africa and Asia, torpedo grass is now a major invasive species in southern regions of the United States and tropical countries, posing serious challenges in:
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Turfgrass management (especially Bermuda and St. Augustine lawns)
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Golf courses, sports fields, and ornamental landscapes
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Pastures and ditches
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Wetland and shoreline restoration areas
Due to its extensive underground rhizome network, mechanical removal is rarely effective, and most non-selective herbicides (e.g., glyphosate) can cause collateral damage to desirable grass species. This is where Quinclorac provides a significant advantage.
What Is Quinclorac and Why Is It Used for Torpedo Grass Control?
Quinclorac is a selective post-emergent herbicide classified under Group 4 (synthetic auxins). It disrupts the plant's hormone balance, causing abnormal growth and eventual death, particularly in grassy weed species. Its unique feature is its selectivity—meaning it can kill certain weeds without damaging established turfgrass, depending on species and application timing.
Key Benefits of Quinclorac for Torpedo Grass:
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Effective post-emergent control of established torpedo grass
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Minimal injury to tolerant turf species (e.g., Bermuda, Zoysia, Buffalograss)
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Long residual control helps prevent regrowth
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Can be tank-mixed with other herbicides for broader-spectrum weed management
How Does Quinclorac Kill Torpedo Grass?
Quinclorac mimics natural plant hormones (auxins), disrupting cell elongation and photosynthesis. In torpedo grass, it causes:
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Twisting, leaf cupping, and stem swelling
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Disruption of shoot and root development
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Eventual dieback of rhizomes and stolons
While initial yellowing can be seen in 7–14 days, full control typically occurs within 3–6 weeks depending on environmental conditions.
Recommended Application Guidelines
| Application Type | Rate | Notes |
|---|---|---|
| Quinclorac 75% WDG | 0.367–0.73 lb/acre (16.6–32.6 g/1000 ft²) | Use with methylated seed oil (MSO) for enhanced uptake |
| Quinclorac 20% SC | 1–2 pints/acre | Best applied to actively growing torpedo grass |
| Carrier Volume | 20–40 GPA (ground) | Spray volume ensures good foliar contact |
| Rainfast Interval | 6–8 hours | Avoid irrigation or rainfall during this period |
| Frequency | Reapply after 21–28 days if regrowth occurs | A follow-up treatment is often needed for dense rhizome networks |
Tip: For maximum efficacy, mow the turfgrass 2–3 days before application and avoid mowing for 2–3 days after.
Turfgrass Tolerance to Quinclorac
| Grass Type | Tolerance Level |
|---|---|
| Bermuda grass | Excellent |
| Zoysia grass | Good |
| Tall fescue | Moderate |
| Centipede grass | Poor (injury risk) |
| St. Augustine grass | Do not use – severe damage likely |
| Buffalo grass | Good |
Warning: Do not apply Quinclorac to St. Augustine lawns or ornamental beds unless clearly labeled and tested.
Quinclorac vs Other Herbicides for Torpedo Grass
| Herbicide | Effectiveness on Torpedo Grass | Selectivity | Use Case |
|---|---|---|---|
| Quinclorac | High (multiple applications may be needed) | Selective (some turf-safe) | Lawns, athletic fields, golf roughs |
| Glyphosate | Very high (non-selective) | Non-selective | Spot treatment or renovation sites |
| Sethoxydim | Ineffective on torpedo grass | Grass-selective, but not for lawns | Not recommended |
| Fenoxaprop-P | Weak on torpedo grass | Turf-selective (limited spectrum) | Used mostly for crabgrass |
Best Practices for Long-Term Torpedo Grass Control
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Use Quinclorac as part of an integrated program: Repeated spot treatments may be required to deplete underground rhizomes.
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Combine with pre-emergent herbicides: Prevents new seed germination (e.g., prodiamine, dithiopyr).
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Control nearby infestations: Torpedo grass spreads aggressively, including from adjacent unmanaged areas.
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Improve turf vigor: Proper mowing height, irrigation, and fertilization help your turf outcompete residual torpedo grass.
FAQs
Can Quinclorac completely eliminate torpedo grass?
No herbicide guarantees 100% elimination of well-established torpedo grass, but Quinclorac provides effective suppression and long-term control when used correctly.
Can I use Quinclorac on St. Augustine grass to control torpedo grass?
No. St. Augustine grass is sensitive to Quinclorac and will likely be damaged. Consider non-selective spot treatments like glyphosate followed by replanting.
How many applications are needed?
Typically 2–3 applications, spaced 3–4 weeks apart, are required for dense torpedo grass infestations.
Does Quinclorac leave residue in the soil?
Yes, Quinclorac has moderate residual activity, which can prevent regrowth for several weeks, but may also impact certain sensitive plants in reseeding or transplanting situations.
Wholesale Supply
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Customized packaging with private label options
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Regulatory support: COA, MSDS, export documents
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Free samples for distributors and field testing
We are actively seeking partnerships with agrochemical importers, pest control product retailers, and turf management contractors. If you are a B2B customer looking for a reliable, high-quality supply of Quinclorac, contact our export team today.
Get in Touch for B2B Orders or Sample Requests
POMAIS Agriculture is a trusted China-based manufacturer of high-performance herbicides for turf, forestry, and specialty agriculture. We serve clients in over 30 countries and support custom product development, local registration, and logistics solutions.
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Global shipping with container & pallet options
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MOQ support for emerging distributors
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Formulation R&D support for product line expansion
Let’s work together to eliminate tough weeds like torpedo grass – with science-backed solutions.