Farmers have always looked for solutions to control weeds and maximize yields. The discovery and use of Diquat Dibromide changed the game in the early 1960s, streamlining weed management in fields and along waterways. Syngenta, which succeeded ICI as the manufacturer, brought it to wide markets. Decades ago, chemical weed control was seen as a way to free up time and labor. Instead of hours with a hoe, people could spray a solution and watch the tough, perennial weeds turn yellow in days. Field demonstrations in the 1960s convinced growers and research stations alike of its potential. From those early trials, Diquat quickly earned a place as a key pre-harvest desiccant for potatoes and beans, especially in countries with wet harvests.
Diquat, commonly sold as “Reglone” among other names, stands out for its contact action: it burns green plant tissue on contact, leaving roots in perennial weeds to re-grow less vigorously season after season. Ag retailers present it as a knockdown herbicide, suited for non-selective weed control and aquatic management. People working with crops have trusted it because it skips the soil – once sprayed, it doesn’t move around like other chemicals, and it won’t hit crops that haven’t emerged yet. In the market, growers recognize it by names like Deiquat, Aquacide, and Crisquat.
As a dibromide salt, Diquat forms a yellow crystalline powder, soluble in water – making tank mixing straightforward. Chemical structure matters: the bipyridyl backbone drives its reactivity. Growers can recognize Diquat solutions by their slight yellow or orange tint, and a sharp, almost musty chemical smell. Diquat holds up in most storage conditions if kept sealed and away from direct sunlight. It breaks down slowly when left in the environment, much slower on dry soil than in pools of water. Laboratory tests clock its melting point around 280°C, with vapor pressure so low that field workers won’t be inhaling fumes under normal use.
Retailers offer Diquat Dibromide as a concentrate, usually in strengths between 150-200 grams of active ingredient per liter. Labels spell out PPE requirements, often gloves, eye protection, and long sleeves. You’ll find restrictions on use near wells and aquatic reserves. Farms buying Diquat must check tank sizes, compatible nozzles, and spray volumes to hit label rates for either desiccation or weed control. Technical bulletins warn about potential mixing problems with hard water or organosilicone surfactants; chemical reps at co-ops often troubleshoot on the spot.
Manufacturing Diquat Dibromide relies on synthetic organic chemistry. Production uses 2,2'-bipyridine with elemental bromine in controlled reactors. The process produces a quaternary ammonium salt, which then dissolves in water and gets formulated with stabilizers. Labs watch for purity, confirming minimal residue of unreacted starting materials since even trace impurities can skew results in bioassays or cause issues with regulatory compliance. I’ve seen production batches checked by HPLC and titrated for bromine content, keeping each batch close to the 98% purity standard most worldwide markets expect.
In application, Diquat generates reactive oxygen species when it contacts living plant cells. This rapid oxidation damages cell membranes, making leaves shrivel in hours after a good spray. Sometimes researchers tweak the bipyridyl ring or its substitution to aim for less persistence in water, or to create derivatives with altered activity. In industrial settings, attempts to modify Diquat’s chemical backbone always need to consider both efficacy and breakdown time. In field runoff, Diquat tends to bind tightly to sediments, but water treatment facilities monitor inflows to catch any residuals escaping fields.
Beyond “Diquat Dibromide,” people in agriculture hear it called names like “Reglone,” “Deiquat,” “Aquacide,” and technical shorthand “1,1'-ethylene-2,2'-bipyridylium dibromide.” Every regulatory agency registers these names, tying them back to one international chemical profile. Reading older agronomy journals, you’ll see references to “Gramoxone” (often a mixture with Paraquat, though Diquat is less toxic). Some aquatic labels market it under different names entirely, trading on localized branding rather than generic chemistry.
Safety is front and center with every jug. Diquat’s an irritant, with documented cases of skin, eye, and inhalation exposure in careless applications. PPE rules stem from real-world incidents – as a teenager, I helped mix and load tanks and learned the hard way how quickly hands dried out after accidental splashes. Drinking water supplies near fields and rivers always receive top attention, so re-entry intervals get enforced without shortcuts. Labels set exclusion zones, not only for fieldworkers but also for grazing livestock. On-farm safety training drills these numbers home every spring. Farmers constantly hear reminders that workers and nearby residents face the greatest risks when mixing or applying concentrates.
Fields, orchards, lakesides, even dense aquatic weed beds – Diquat’s reach isn’t limited to row crops. It’s crucial for potato vine kill, aiding in even tuber skin set before harvest. In wetter regions, growers use it before combine harvesting beans or oilseeds, trusting it to bring crops to uniform dryness. Aquatic application teams lean on it to clear invasive waterweeds, maintaining navigation and recreation access on reservoirs and canals. Municipal operators use it to keep ditches and rights-of-way clear. Regulatory controls vary greatly: the UK and many EU countries restrict its use, but other regions still consider it a backbone tool.
Researchers push boundaries on safer, more targeted application. Innovations in spray drift reduction and nozzle technology get tested each season. Agronomy labs report on tank-mix compatibility, trying to broaden Diquat’s role with nutrients or other pest controls. Scientists keep pushing for formulas with lower leaching risk, especially in waterlogged soils near conservation lands. Recent projects investigate enzyme systems in soil microbiota that could speed post-spray breakdown, reducing environmental impact. New trials look at precision mapping: drones imaging fields to map exactly where Diquat gets sprayed, minimizing the area and volume used.
Toxicology studies weigh Diquat’s acute toxicity against its rapid environmental binding. Oral ingestion causes gastric and renal effects, leading to clear protocols for emergency treatment. Unlike Paraquat, Diquat isn’t as likely to be fatal in dose-for-dose comparisons, but labeling and poison center records prove the risk is real. Agencies like the EPA, WHO, and European Food Safety Authority monitor residue in export crops. Researchers publish on chronic exposure risks for both farmworkers and local wildlife. Field experience reinforces that misuse or failure to follow label rates increases ecological risk, especially in watersheds draining into sensitive aquatic systems.
Diquat’s place has shifted as regulators scrutinize all older actives. In many markets, biological and mechanical weed control challenge its status. Newer contact herbicides receive more attention in R&D pipelines, but Diquat’s simplicity and cost lock it in some rotations. International NGOs and research institutes take up field trials using combinations of low-dose herbicides plus cover crops, aiming to reduce overall chemical use and bolster sustainability. Calls for zero-residue food export standards will likely trim Diquat’s use in high-value crops. My experience suggests that wherever crop desiccation speed and reliability matter, demand persists, at least until non-chemical options meet the same performance. Regenerative farming, robotics, and sensor-driven application will all shape the next chapter for how, and whether, Diquat keeps a foothold in agriculture worldwide.
Diquat dibromide shows up as a solution for killing tough weeds. Farmers reach for it when they need fields cleared fast. Rain or shine, the chemical zaps plant cells and leaves the land brown in a day or two. It won’t stick around in soil, so it helps manage late-season crops without waiting weeks for breakdown.
The chemical fits into all sorts of farming—from potatoes needing an even harvest, to rights-of-way where overgrown grass crowds roads. I spent time on farms where sprayers ran before the potato diggers came out. The potato vines fell back, and the farmers could harvest cleaner tubers with less disease. In the ditches and along fence lines, application crews used diquat to stop unwanted saplings and stubborn weeds from taking over. It also keeps canals clear for water to move where it should.
Crop harvests work on a tight schedule. Weather changes and a missed window can snap profits in half. With diquat, vine killing or desiccation becomes quick and reliable. Take potatoes—if those stems don’t die off, tubers might stay soft, rot, or take up dirt, all of which drop sale prices. This speed also matters for crops like peas, lentils, or canola. I’ve watched as quick drying brought fields down to moisture levels safe for storage, stopping spoilage before it starts.
In non-crop areas, fast control matters for fire breaks and safe sightlines. Cities and water districts don’t have weeks to wait. Diquat brings rapid plant death, helping keep systems running smooth.
Nothing’s simple with farm chemistry. Diquat doesn’t drift far because it sinks into soil, locking to particles. The molecule breaks down in place, so you’re unlikely to find much in water or food after a short wait. Regulators in the U.S. and Europe put it through the wringer: research suggests most risks are tied to spray mishandling or ignoring label limits.
Still, worker safety looms large. I remember old-timers who mixed spray tank loads by hand, skipping gloves or goggles. Their skin took a beating and, in rare cases, accidents led to more severe health issues. Protective equipment and modern closed transfer systems cut down on these problems, but it only works if crews use them. Strong oversight and regular safety reminders make a world of difference.
Some folks want crops grown with less chemistry, worried about water runoff or impacts on insects in nearby ditches. The push for alternative weed strategies is loud: more mowing, burning, crop rotations, or green manures. On our family’s land, using cover crops keeps problem weeds down, though it takes effort and time to build those habits.
Farmers face a crossroads—stuck between rising weed challenges and the demand for safer, less synthetic solutions. As herbicide options like paraquat see tighter restrictions or bans, diquat faces more scrutiny. Public trust follows transparency, honest risk assessments, and a willingness to adapt—whether through safer applications or exploring seeds and rotations that fight weeds naturally.
Diquat dibromide won't carry the load alone forever. Real progress comes from field-tested advice, open research, and listening to farm crews who live with these chemicals. That’s where true expertise grows: not from a label alone, but from years spent tracking both yield and health on the same land.
A walk through any hardware store paints a seductive picture. Bottles of herbicides claim to save hours of backbreaking weeding. On those labels, “Diquat Dibromide” often shows up, promising fast results on stubborn weeds. But a closer look at what goes into a lawn goes well beyond claims of a perfect backyard. From personal experience caring for both gardens and pets, I’ve learned that the shortcut of chemical weedkillers usually comes with tradeoffs that stretch beyond the fence.
Doctors and scientists have a clear message: Diquat Dibromide’s chemical formula does more than just zap weeds. Exposure can trigger irritation in eyes, skin, and lungs. Even a light wind can blow sprayed particles where they’re not welcome. Swallowing or heavy contact brings a higher risk—nausea, vomiting, and worse. Hospital cases of accidental Diquat poisoning show real threats to kidneys and nervous systems. The U.S. Environmental Protection Agency lists it as moderately toxic, with warnings of eye and skin burns, breathing problems, and even possible death after large intake.
Most risks come from handling the concentrate. Pouring, mixing, or spraying sets up chances for splashes or drift clouds, especially without gloves, goggles, or masks. Outdoor chores can easily turn risky if the product isn’t handled with full caution. For me, garden work means kids and pets wander close. That’s never been a mix that feels safe if strong chemicals are involved.
Pets discover the world nose-first. Cats and dogs roll, sniff, and lick at patches of recently sprayed ground. Diquat Dibromide doesn’t vanish when the spray dries; residue lingers in soil, on grass, even on water surfaces after rain. There have been cases where pets suffered cramps, vomiting, and seizures after accidental contact. Birds and rabbits, even backyard chickens, find themselves especially vulnerable—sometimes after eating treated plants or slurping at puddles.
The labels do warn: keep animals away for at least a day after spraying. But a single missed detail—a stray paw, a leaf blown into a bowl—can cause serious harm. That’s a risk I’ve never felt comfortable taking.
Plenty of families juggle weed control and safety. Physical weeding remains time-consuming but safe. Mulching blocks many weeds naturally, no chemical residue left for paws or fingers. Boiling water and vinegar mix offer an old-school option, hitting weeds hard without lasting soil impact.
Some newer products labeled “pet safe” draw interest, though it pays to read past the bold claims and peek at actual ingredients. Public spaces and parks often lean more on integrated pest management, mixing mechanical removal and careful monitoring over blanket chemical fixes.
Conversations about garden safety spread beyond one backyard. Neighbors share the same soil, water, and breeze. Towns have started putting up signs after spraying for transparency and public health. Communities are pushing for more education about pesticide risks, greater access to safe disposal, and local ordinances controlling the use of strong herbicides.
Staying informed and careful remains the best defense for human and pet health. I trust a hand-pulled weed over a quick spray, knowing everyone’s backyard adventures are a lot safer that way.
Diquat Dibromide keeps weeds and unwanted aquatic plants from getting the best of farmland, reservoirs, and even lawns. Farmers and groundskeepers pick it to clear land fast. You can see the results in just a couple of days. It doesn’t hang around for long—making it popular for crops like potatoes right before harvest. Plants dry up, dying right to the root, so you don’t have green stems jamming equipment or robbing moisture from the crop.
I first saw Diquat used on a stubborn patch of pondweed at a community park. Clear water, tighter budgets, and fewer chemical leftovers made the grounds team happy. It’s one of the few herbicides that works just as well above ground as it does in shallow water.
Diquat’s best work comes from a direct spray. Forget blanket applications. Spot-treating saves money, cuts down on run-off, and limits exposure for people and animals. A worker with a backpack sprayer, hitting only the problem plants, can stretch a jug much farther than a boom sprayer ever will. Overapplication, especially in high-traffic public spaces, risks people running through wet areas and pets tracking residue indoors.
Weather makes a real difference. It works fastest on sunny, dry, windless days. Even a hint of rain washes it away, wasting time and product. Strong wind blows sprays off target, pounding neighboring crops or natural areas. Teams out in the field check the forecast before every round. One thunderstorm can undo a whole day’s effort and cause overspray to reach the wrong plants.
It feels tempting to mix a strong batch and finish quickly. That’s a rookie mistake. Plant leaves burn fast, but deeper roots might hang on if you mix too much. Diquat works by breaking down cell walls, so coverage matters more than concentration. Labels give rates in ounces per gallon—stick with those. The EPA tested each ratio, and studies at land grant universities show why getting this wrong backs up resistance and pushes regulators to consider tougher rules.
Throwing in a surfactant helps, especially on tough, waxy weeds. It breaks the sheen on the leaf and pulls the chemical in deeper. Some states require using a marker dye to catch drips and make sure an operator doesn’t double-spray. Dyes also alert passers-by to stay off recently treated grass, reducing risk for pets and kids.
Most complaints arise from missed steps on personal safety. Long sleeves, gloves, and goggles aren’t extra—they’re basic gear. A local farmer ignored that last summer, splashing some on bare hands, and ended up with itchy skin and a whole week of concern. Local poison control lines see accidental exposures every summer when someone ignores a label. Labels exist for a reason; EPA’s incident records tell the real stories behind why.
Better training helps. Extension programs in my area now offer short courses and test on proper Diquat application. If you apply it in a commercial setting, you will need to hold a license—one slip can mean a fine or loss of the ability to buy restricted-use chemicals.
Employing buffer strips around water keeps Diquat away from fish and frogs. Tech for drift-control now comes standard on new boom sprayers—off-target damage declines, and water stays cleaner for longer. At home, keep a written record of application dates and weather conditions. Professionals photograph treated areas before and after, and log wind and temperature. That habit helps if neighbors complain or if something grows back stubbornly.
The takeaway stands clear: care in mixing, a sharp eye for weather, respect for personal safety, and a little precision make Diquat Dibromide useful without the risks spiraling out of control.
Diquat Dibromide gets used in fields, ponds, and irrigation canals because it wipes out tough weeds fast. Each time someone sprays it on land or into water, they expect weeds to wilt within hours or days. Many people working in farming and aquatics have come to rely on it. The story doesn’t stop when the sprayer turns off, though. What sticks with me is the question that pops up every time: How long does it linger where we don’t see it?
Diquat doesn’t hang around in soil like a stubborn stain, at least not everywhere. In soil, it tends to stick tightly to clay and organic matter. Studies from the US Geological Survey show that after application, most of the chemical grabs hold of soil particles almost right away. When locked to soil, it doesn’t move with water easily. Independent research from agriculture extension offices shows that Diquat can lose its weed-killing punch within days because sunlight and microbes help break it down. Under strong sunlight, it starts losing power in less than three days. Some lab tests found traces lingering for up to three weeks in heavier soils, but the bulk of it drops off fast if conditions are right.
Diquat’s story shifts in water. As someone who grew up fishing in farm ponds, I used to worry about what these chemicals did to frogs and fish. Water doesn’t give Diquat many hiding spots. The chemical breaks apart under sunlight—a process called photolysis. In open water, the half-life can be as short as one or two days if the sun stays strong. In murky or shaded water, though, it stays active longer. It can persist for up to a week or two, soaking into bits of organic stuff floating around. Still, experts at the EPA say most Diquat leaves the water column within days, binding to sediments at the bottom where it stops being a threat to aquatic plants.
What weighs on my mind most is how this ties into what gets onto food and into the water I drink. Because Diquat latches onto soils, most crops don’t pick up much of it through their roots. This has been backed up by food safety tests showing only tiny traces in produce, far below federal limits. The story gets trickier in places with loose sandy soils or lots of rain; washing and leaching can sometimes move Diquat further than you’d expect. Some communities near heavily used cropland watch their water supplies closely for any sign of it, knowing that old routines can’t always predict what happens in a rainy season.
Rotating herbicides, reducing how often and how much gets sprayed, and planting cover crops all help cut down on leftover Diquat in fields. Some farms now choose to switch up weed-fighting tactics to break the cycle of chemical buildup. Monitoring runoff, using buffer strips near water, and running soil and water tests after spraying all work together to limit harmful drift. In my own experience with community gardens, careful timing and not overdoing it proved better than any label recommendation. Knowing your patch of ground and watching weather changes can keep both plants and water cleaner.
Diquat Dibromide doesn’t last forever, but its story doesn’t end with the first rainfall either. The time it stays active depends on sunlight, soil, water, and how much gets put down. People with hands in the dirt or water, who live near spray zones, already know the value of protecting their surroundings. Keeping a close eye on chemical use and searching for new methods grows more important as we push for healthier food and water. Staying informed and asking questions keeps everyone a little safer.
Diquat Dibromide works fast to burn down weeds and deal with dense aquatic plants. That quick action comes from how the chemical shuts down cells. Exposure can hurt skin, eyes, or lungs. Blood tests might show kidney and liver problems after accidents. It isn’t just irritating — in bad cases, it can poison people. Years ago, I saw a farmhand in my county end up in the ER with burns on his arms because of a spill. Most folks used to act casual around stuff like this, but hospitals remember those cases a lot longer than we do.
Farm crews don’t always have top-notch gear — half the time it’s just old gloves and a mask crumpled in a truck. Spills usually happen when people pour out concentrates or try to clear a clog in a spray nozzle. Wind gusts on a hot day can blow mist right back into your face. Cooling off with water from a tank rinsed with chemical just multiplies problems. Diquat doesn’t care if someone means well or hurries to beat rain; rules get skipped, folks get sick. That’s how lessons stick.
Pulling on chemical-resistant gloves and boots isn’t optional; bare hands burn fast, and shoes made with fabric soak up splashes. Good face shields beat goggles for splashy jobs. Always tie back sleeves and tuck pants into boots because stray drops find their way everywhere. Cotton shirts get drenched if a hose slips — a waterproof apron saves the day. Mixing tanks need to sit away from streams and wells. Years of careless pouring add up, and runoff isn’t invisible. It shows up downstream, sometimes far from where people notice.
Reading the label can sound like a joke, but skipping steps there is asking for trouble. Companies must put warnings on every jug, and those aren’t just lawyer-speak. Keep extra gloves, eye wash bottles, and fresh water by the mix station. Imagine dropping an open bottle on your lap—no one wants to drive to the ER with burning legs. Sprayers that leak around seals should get fixed before another shift starts. Tossing empty bottles in ordinary trash just spreads the risk. Safe disposal sites keep that stuff from leaching near drinking water.
Old habits anchor people to risky shortcuts. Training doesn’t have to come in a classroom — farm shops running quick demos or showing coworkers the bruises left by a splash can make the message stick. Workers look out for each other, so it pays to point out risk instead of letting pride get folks hurt. Managers who supply basic gear and enforce cleanup rules lose less time to sick days and don’t see as many hospital bills. Families watch out for trace chemicals on work clothes too; separate the laundry so kids stay safe.
The EPA, CDC, and state ag offices post short guides and lessons learned after bigger spills. Looking up these tips might save a life or just a weekend’s pay. Sharing stories about near-misses spreads faster than official warnings. Good safety isn’t just a poster on the wall — it grows day by day in real work, with tools that fit, warnings we remember, and lessons handed down from the ones who came before.
| Names | |
| Preferred IUPAC name | 7,7'-Ethane-1,2-diylbis(quinolin-1-ium) dibromide |
| Other names |
Reglone Dextrone Cecropat Deiquat Herbazone Aquacide Weedtrine-D Ortho Diquat Reward |
| Pronunciation | /ˈdaɪ.kwæt daɪˈbroʊ.maɪd/ |
| Identifiers | |
| CAS Number | 6385-62-2 |
| Beilstein Reference | 3858730 |
| ChEBI | CHEBI:34914 |
| ChEMBL | CHEMBL4899 |
| ChemSpider | 6988 |
| DrugBank | DB04723 |
| ECHA InfoCard | 100.028.267 |
| EC Number | 205-539-4 |
| Gmelin Reference | 87195 |
| KEGG | C18514 |
| MeSH | Diquats |
| PubChem CID | 3034614 |
| RTECS number | NL5600000 |
| UNII | 4XV943HM5O |
| UN number | UN1169 |
| CompTox Dashboard (EPA) | DTXSID5020282 |
| Properties | |
| Chemical formula | C12H12Br2N2 |
| Molar mass | 452.0 g/mol |
| Appearance | Yellow to dark brown liquid |
| Odor | Odorless |
| Density | 1.22 g/cm³ |
| Solubility in water | 700 g/L (20 °C) |
| log P | -4.60 |
| Vapor pressure | 1.87 x 10^-6 mm Hg at 25°C |
| Acidity (pKa) | 1.9 |
| Basicity (pKb) | 8.0 |
| Magnetic susceptibility (χ) | -56.0×10⁻⁶ cm³/mol |
| Refractive index (nD) | 1.564 |
| Viscosity | Viscous liquid |
| Dipole moment | 4.97 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 151.6 J·mol⁻¹·K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | –132.7 kJ/mol |
| Pharmacology | |
| ATC code | N06AX18 |
| Hazards | |
| Main hazards | Toxic if swallowed. Causes severe skin burns and eye damage. May cause respiratory irritation. Toxic to aquatic life with long lasting effects. |
| GHS labelling | GHS06, GHS09 |
| Pictograms | GHS06,GHS09 |
| Signal word | Warning |
| Hazard statements | H302, H315, H318, H373, H400, H410 |
| Precautionary statements | P264, P270, P273, P280, P301+P312, P330, P391, P501 |
| NFPA 704 (fire diamond) | Diquat Dibromide NFPA 704: 2-3-1 |
| Explosive limits | Not explosive |
| Lethal dose or concentration | LD₅₀ (rat, oral): 400 mg/kg |
| LD50 (median dose) | LD50 (oral, rat): 120 mg/kg |
| NIOSH | WQ3675000 |
| PEL (Permissible) | PEL (Permissible Exposure Limit) for Diquat Dibromide: 0.5 mg/m³ (as Diquat, respirable fraction) |
| REL (Recommended) | 2.0-4.0 |
| IDLH (Immediate danger) | 200 mg/m3 |
| Related compounds | |
| Related compounds |
Paraquat Bipyridine Diquat Methyl viologen Ethylene dibromide |
