Glyphosate is a widely available, favored herbicide. It effectively kills when applied directly to the leaves of grass and broadleaf plants. It is non-selective so will kill almost all plant life. The herbicide works by halting the plant’s ability to use growth proteins. It stops the enzyme pathway (known as the shikimic acid pathway) so the plant quickly dies.
History of Glyphosate
Glyphosate was registered in 1974 for use in the United States. It quickly became the most widely used herbicide by gardeners to control weeds and, in some instances, aquatic plants. Nowadays, glyphosate is available in many forms such as salts and acids. They can be used as solids or liquid. In the U.S. there are over 750 products that contain glyphosate as the active ingredient.
Pros and Cons of Glyphosate
As with any herbicide, there are pros and cons involved in the use. You’ll need to carefully evaluate each to decide if glyphosate is right for your projected uses.
Pros of Glyphosate
- Low Persistence: The term ‘persistence’ refers to how long an herbicide will function after application. In some cases, herbicides can persist for years. They will continue to kill off plant life that grows in application. However, glyphosate will not last an exceedingly long time after application. The soil where you apply the glyphosate absorbs the particles and breaks them down into a nontoxic substance, so its rate of persistence is relatively low at only about 40 days.
- Low Toxicity: Glyphosate has a low toxicity which makes it safer than other chemicals. However, even though glyphosate has low toxicity when compared to other herbicides, it is still toxic. It can cause skin irritation, vomiting, diarrhea and make swallowing difficult if you accidentally ingest the substance. You should always wear protective gear such as a face mask, goggles, and rubber gloves when applying it.
- Good Weed Control: It takes from two to 10 days to effectively kill plants after application. Many plants, such as corn, have been modified to tolerate glyphosate which has made it a common herbicide for farm use. Glyphosate resistant plants will tolerate the herbicide which makes it highly beneficial for weed control.
Cons of Glyphosate
- Nonselective: If a plant hasn’t been bred to withstand glyphosate then it will kill it. The nonselective nature of glyphosate is a definite con. Any foliage that meets it will start to wither and die. You must be incredibly careful when applying the herbicide or you’ll end up killing other garden plants. Never use it on a windy day or it could easily blow somewhere you don’t want it to.
- Environmental Harm: The potential for runoff is extremely limited because glyphosate binds well with the soil. However, even low doses could stimulate the overgrowth of toxic algae which can quickly impact wildlife, aquatic life, and livestock.
Health Dangers of Glyphosate
Compared to other herbicides, glyphosate poses fewer health dangers. In a respected study, it was found that glyphosate was safe for use and posed no significant cancer risk. However, other studies have shown that there might be a link between the herbicide and kidney disease, reproductive problems, or certain cancers. In 2015, the World Health Organization (WHO) found that the herbicide is potentially carcinogenic in animals. At the same time, the International Agency for Research on Cancer (IARC) classified glyphosate as a carcinogen. Clearly, more studies are needed to make a concrete determination on the potential risks of exposure.
Currently, many regions in the U.S. are limiting the use of or banning glyphosate in public parks, schools, and playgrounds. The state of California has now issued a warning concerning the use of glyphosate. Also, it has been banned in seven of the state’s cities. Other areas in the nation might also take steps to limit or ban its use soon.
- Follow the following precautions when using glyphosate.
- Do not use it on a windy day.
- Wear protective clothing that completely covers arms and legs.
- Use goggles, gloves, and face masks.
- Never touch the plant’s foliage when wet with glyphosate.
- Wash using soap after using the herbicide.
- Do not mix glyphosate inside an unlined steel or galvanized steel container or spray tank because it can quickly create combustible hydrogen gas which causes metal corrosion.
- Do not irrigate after use.
- Avoid using if rain is projected in the forecast.
Considerations When Using Glyphosate
Glyphosate does not persist in the soil and is quickly inactivated so weed seeds will start to germinate after application. Most types of annual weeds are hard to control if they have grown large. Ideally, for control success, you should treat the weeds prior to reproductive organ development so before the plant develops flowers, cones, or seeds.
During times of drought, glyphosate is not as effective because the plant will enter a state of dormancy instead of active growth. This can also occur if the weeds have recently been cut which appears to halt their growth cycle rendering the herbicide less effective until the plant renews its growth cycle.
The herbicides effects can take days to show up, this is especially true if the weather is cold or the sky is overcast.
Whenever you apply glyphosate, make sure that you thoroughly coat the plant’s foliage but not to the degrees that it runs off. Depending on the brand, it might boast a dye additive that helps you see exactly how well you have covered the foliage in the chemical.
When applying the herbicide, try to only target the weeds. If the herbicide drifts onto desirable plants, then it will also quickly kill them.
Avoid using a spray nozzle that creates a fine spray. Mist drifts easier than a steady stream. You can also use sprayer shields or hoods to protect the surrounding plants.
Glyphosate remains a popular herbicide option. Currently, it is the favored active ingredient in a wide array of popular brands such as Roundup and others.