The problem i have with this vineyard is complicated. 90% of it is going ok with the new grape vines. A friend let me down who was supposed to be getting my many mowers running. It wasnt his fault he wound up with a stent and had multiple other health issues. That left me in a difficult dilemma. The weeds grew like crazy because i have the soil right. Here comes the hard decisions and the ones that your paying for years from now. I know Glyphosate is the cheat I need to use but did so sparingly. It wipes out the soil microbes , good grasses and encourages broad leafs resistant to glyphosate to take over. I still had to use it to save the grapes in one of the rows. Even after the machete work today I’m likely looking at doing much more. These are the decisions most people won’t tell you they make but we need to. If I eliminate the moisture robbing weeds etc it will juice my grapes with a huge edge. This is thee part where everyone says you can’t do that grapes are not Glucophage resistant. Turn the pressure down on the sprayer on a still day and it can be done and I have done it. I’m not a fan of this approach. Most commercial orchards do this every year.
Why now is the best time you might wonder. I have a border with a neighbor where Poison Ivy is prevalent. They sprayed. Their part and I sprayed mine but I did notice there was some drift after they sprayed. Herbicide Drift Injury is on the Rise - American Vineyard Magazine
As neighbors we made mutual agreements that mean even it killed the vines they were authorized to do it. Any minimal damage is only brought up because it means it’s the best time to burn down the weeds. I will fight broad leafs like morning glory for years to come. I am mostly an organic orchardists but sometimes i make hard choices. These are the hardest choices and time is a factor.
I have been resorting to paper feed bags more lately. I have a tough time getting down low. But I can cut them easily to slip over the plant as a weed guard. There is a lot of round up piled up from estate sales; but I try to avoid it.
I credit the bags with really helping our grape vines this season. You have to weigh them down for a while. But they stay down after a month or so.
The truth is concentrated Roundup is useful. As much as I don’t like any chemicals we find we sometimes need them. Army worms for example need immediate attention. Until I find a better way to deal with some things chemicals are necessary at times. I do use small amounts in comparison with most people.
There’s a great method, put down cardboard, or lawn clipping bags, even newspaper is okay, but a lot more chemicals from the ink, probably, and mulch over them, it’s great, keeps the weeds down for a couple of years.
The short term trade off I made is paying off for now on the herbicide. I had to use it over a very small area. It absolutely will save those grapevines. This is why I say never take a hard and fast stance against anything or anyone until you realize the purpose. I’ve not ever been for Monsanto which has become Bayer. Glysophate is a safer form of a defoliant than its counter parts which are meant to kill trees. In the Vietnam War Agent Orange was a herbicide mixture used by the U.S. military during the war to defoliate forests and clear vegetation. It was primarily composed of two herbicides, 2,4-D and 2,4,5-T, and contained a toxic contaminant called dioxin. Glysophate is a safer version because it is not residual. None of these chemicals are good or safe. There is always a better long term solution but you may need a short term answer. Many of us use short term solutions that are effective while we come up with a better strategy. These are the trade offs we make. Honestly all people make trade offs as we drive we use fuel in a vehicle that is made by process of hundreds of chemicals. We live in houses constructed using similar methods. These are trade offs but there are better ways long term we discover to reduce our dependent living off these chemicals. In the future I hope to plant a better ground cover for the grapes. There are short times you cannot grow fruit free of chemicals in my area. It has been years since I had to use any and why this year is different is because of the heavy rains waking up dormant weed seed in the soil.
Fifty years ago I was like many of my uninformed youthful friends who thought any herbicide use was foolish, short-sighted, dangerous.
But if we had allowed the intelligent, careful use of things like tordon and roundup then, we would probably have much, much better control over the several invasives that are all over our mountains and trails: dyer’s woad, leafy spurge, spotted knapweed, and more.
Moderation in all things - except when you just have to go all out …
Well put and very true. I have seen many people lose control of a property over that principle that it has done in a certain way. There are times ways cannot be adhered to that sternly.
I don’t think that very many of my generation had any idea of how much institutional knowledge there is in a farming community. People whose families have worked the land for generations don’t always get it right, but they keep getting closer. I think know-it-all sixties and seventies kids like me read Rodale and Ruth Stout and just thought we had it all figured out.
And I doubt we understood the reverence and devotion farmers and ranchers have for the land they live in. Today some of the people working hardest to keep land out of development are those same farmers and ranchers - and sometimes their allies are the same kids who grew up, shut up and listened and learned, and some of them know their way around a courtroom or a mortgage contract and the legislative process.
My DH gifted me many sections of snap together metal ducting to place around my plants to spray/burn safely. Do not snap them together though, they are a bear to get apart, i use clothes pins. Makes my life so much easier, being old and sore and stiff i no longer have the luxury of hand weeding all day.
Glyphosate kills the roots by killing essential bacteria by blocking the processes of internal production of vitamins and proteins, shutting of the ability to survive, almost immediately. As bad as glyphosate is, there are hundreds of agro-toxins (as people properly call them in Europe) that are worse, like Atrazine which can actuallu be blamed for much of the US’s mental disorders now.
Yes the Swiss is where glysophate came from “Glyphosate works by inhibiting a specific enzyme called 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), which is essential for the synthesis of certain amino acids in plants. This disruption prevents the plants from producing proteins necessary for growth, ultimately leading to their death.”
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How Does Glyphosate Work: The Hidden Science Behind the World’s Most Used Herbicide
How Does Glyphosate Work: The Hidden Science Behind the World’s Most Used Herbicide
Glyphosate has emerged as the world’s most used weed killer since 1974, serving as the active ingredient in Roundup and more than 750 other herbicide products across the United States. Farmers, gardeners, and groundskeepers have sprayed roughly 6.1 billion kilograms of this powerful herbicide globally in the past decade alone. The chemical’s effectiveness as a nonselective, postemergent herbicide helps control more than 150 different weed species. The World Health Organization’s International Agency for Research on Cancer raises serious concerns by classifying glyphosate as “probably carcinogenic to humans”.
The chemical’s persistence and reach create additional worries. Scientists originally believed glyphosate would quickly become inactive after spraying, but it can persist in soil for up to 6 months, depending on climate and soil conditions. The chemical shows up in 36% of water samples from Midwestern U.S. states where corn farmers use it heavily. FDA testing found glyphosate residues in 59% of the corn and soy samples tested. A 2019 University of Washington study found that high exposure levels increased the risk of non-Hodgkin lymphoma by 41%. This piece explores glyphosate’s molecular mechanisms, its environmental effects, and the ongoing debate over its safety for humans and ecosystems.
What is Glyphosate and How Does It Work?
The chemical N-(phosphonomethyl)glycine, better known as glyphosate, disrupts plant biology through a complex process. Let’s take a closer look at glyphosate’s chemical properties and its interactions with plant systems.
Glyphosate as a Non-Selective Herbicide
This non-selective systemic herbicide kills almost any plant it touches instead of targeting specific weeds. Its broad-spectrum action controls more than 150 weed species, including annual broadleaf weeds and grasses. Plants absorb glyphosate through their leaves and stems, and it moves to growing points. The herbicide only affects growing plants, so it doesn’t work on dormant seeds or inactive growth.
Shikimic Acid Pathway Disruption
Glyphosate’s molecular action blocks the shikimic acid pathway – a metabolic sequence that exists in plants, fungi, and some microorganisms but not in mammals. The herbicide stops the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) from working. This enzyme helps produce three vital aromatic amino acids: tyrosine, tryptophan, and phenylalanine.
The herbicide binds to this enzyme and prevents shikimate-3-phosphate (S3P) from becoming 5-enolpyruvyl-shikimate-3-phosphate (EPSP). This causes shikimate to build up in plant tissues while amino acid production stops. Plants stop growing within hours because they lack these protein-building blocks.
How Fast Does Glyphosate Work on Weeds?
Plants react to glyphosate right away, but you won’t see results immediately. Most plants show their first signs of damage through wilting and yellowing 2-6 hours after application. Annual weeds usually die completely in 7-14 days. Larger, 4-week-old weeds or perennials with big root systems might take up to 4 weeks to die.
Several factors influence glyphosate’s effectiveness:
Weather conditions: Weed control works better on warm, sunny days above 60°F
Application timing: Treatment works best between 9 a.m. and 6 p.m.
Rainfall: Plants need at least 30 minutes without rain; bigger weeds need several hours
Plants die because they spend their energy dealing with metabolic disruption instead of normal growth, which leads to complete system failure.
Routes of Exposure and Environmental Spread
Glyphosate moves through several environmental pathways after application. The herbicide often reaches beyond its intended targets, and its journey through ecosystems reveals broader environmental impacts.
Spray Drift and Foliar Wash-Off
Wind can carry glyphosate to unintended areas during aerial spraying. Swedish railway studies showed the herbicide’s concentration dropped faster with distance. The amount fell from 1800 g/ha at the spray point to just 5 g/ha at 1 m away. Even these small amounts can damage 5% of plant species. Weather plays a big role in drift patterns. Ground sprayers that work at low pressure create less drift than aerial spraying methods.
Rain or irrigation can wash glyphosate off plants right after spraying. Most products need at least 30 minutes without rain. Larger weeds might need several hours of dry conditions. This runoff can contaminate soil and pollute water sources.
Glyphosate in Soil, Water, and Food Crops
The herbicide usually stays in soil for about 30 days in temperate climates. Soil type and weather affect how long it lasts. It can move down to 40 cm in soil, which lets non-target plants absorb it through their roots.
Tests found glyphosate in 66 out of 70 U.S. waterways. Its breakdown product AMPA showed up even more – in 80% of samples across 84% of sites. FDA testing revealed glyphosate in 63% of corn and 67% of soybean samples.
Root Uptake and Translocation in Plants
Plants take in glyphosate through their roots and move it throughout their structure. Research shows that roots contain about 12% of the applied glyphosate after eight days. The chemical travels through the plant’s vascular system, mainly through phloem to sink organs. This movement leads to higher concentrations in reproductive parts like bolls and squares.
Health and Safety Concerns in Humans and Animals
Scientists and regulators across the globe remain divided about glyphosate’s safety profile. Their contradictory findings have sparked heated debates about its health effects.
Is Glyphosate Harmful to Humans?
The U.S. Environmental Protection Agency and other regulatory bodies disagree about glyphosate’s risks to human health. EPA’s stance shows “no risks of concern to human health from current uses of glyphosate”. The World Health Organization’s International Agency for Research on Cancer (IARC) took a different view in 2015 and labeled glyphosate as “probably carcinogenic to humans”. These opposing views stem from their different approaches. IARC looked at fewer but public studies, while EPA examined a broader dataset that included industry submissions.
Roundup Lawsuit and Carcinogenicity Debate
Bayer has faced heavy Roundup litigation since buying Monsanto in 2018. ConsumerShield notes that a California jury awarded $289 million to a school groundskeeper with non-Hodgkin lymphoma in 2018, and a separate California case awarded a couple $2.055 billion, though the award was later reduced. By 2020, Bayer was facing around 125,000 cases, which led to $10 billion in settlements
Glyphosate Side Effects from Short-Term Exposure
People exposed to glyphosate for short periods typically experience mild symptoms. The effects range from skin irritation and eye damage to breathing difficulties when they inhale spray mist. Those who accidentally swallow it might experience stomach problems, including nausea, vomiting, and diarrhea.
Toxicity of Co-formulants like POEA
Scientists have found that polyethoxylated tallow amine (POEA), a surfactant used in many glyphosate products, raises serious toxicity concerns. Lab tests show that POEA and commercial products like RangerPro are more toxic to cells than pure glyphosate alone. Studies on amphibian tadpoles further prove that POEA, not glyphosate, causes most of the harmful effects.
Ecological and Agricultural Impacts
Glyphosate does more than just kill weeds. It creates lasting ripple effects throughout soil ecosystems and agricultural systems that continue long after farmers spray it.
Soil Microbial Disruption and AMPA Accumulation
Microbes in the soil break down glyphosate into aminomethylphosphonic acid (AMPA), its main metabolite. When glyphosate binds to clay and organic matter particles, both compounds last longer than scientists first thought. The time for 90% dissipation can stretch beyond 1,000 days based on soil type. AMPA’s breakdown varies dramatically – some soils break it down in weeks, while others see it build up over time. The soil microbiome shows mixed reactions. Some studies show glyphosate boosts microbial activity, but others reveal it harms beneficial microflora. The herbicide changes nitrogen cycling by reducing nitrification and denitrification genes.
Impact on Earthworms and Soil Fauna
Earthworms play a vital role in soil health, with populations reaching up to 1000 individuals and 300g biomass per square meter. These creatures take a big hit from glyphosate exposure. Research shows their reproduction rates drop sharply – hatching rates fall from 43% to 17% for L. terrestris and from 71% to 32% for A. caliginosa after herbicide treatment. Pure glyphosate causes earthworms to lose 14.8-25.9% of their body mass. They also survive stress tests for 22.2-33.3% less time. Pesticides cut soil fauna species richness by 21%, with specific group declines ranging from 17% to 55%. Native species struggle more than introduced ones to survive.
Crop Disease Susceptibility and Yield Loss
Plants become more vulnerable to diseases when exposed to glyphosate. The herbicide disrupts the shikimate pathway, which stops plants from making defense compounds. This makes them easy targets for pathogens like Fusarium and Rhizoctonia. Non-glyphosate-resistant corn yields drop by 49-54% when sprayed. Studies in Martinique revealed that even glyphosate-resistant crops get hit harder by diseases. Root biomass shrinks regardless of cutting intensity, limiting carbon storage and weakening plant resilience. When glyphosate drifts onto nearby crops, it reduces leaf nitrogen by 7-16% and seed oil by 18-23%.
Conclusion
Glyphosate remains one of the most debated agricultural chemicals in modern farming. This piece dives into the complex science behind this accessible herbicide. The chemical disrupts the shikimic acid pathway in plants. While this kills plants effectively, it raises serious questions about collateral damage.
The biggest problem with glyphosate is its persistence in the environment. The chemical remains active in soils for weeks to months, which contradicts earlier safety claims. On top of that, it shows up in water systems, food crops, and human testing studies. This proves it spreads well beyond where it’s sprayed.
Major regulatory bodies can’t agree on health risks. The EPA considers the risk to human health minimal. The World Health Organization labels it as “probably carcinogenic.” This stark divide has triggered thousands of lawsuits that link Roundup exposure to non-Hodgkin lymphoma.
The ecological effects go way beyond just killing weeds. The chemical disrupts soil microbiomes. Beneficial creatures like earthworms see their numbers drop. Even crops we want to protect become more vulnerable to diseases. These chain reactions could hurt the very farm productivity glyphosate wants to boost.
The evidence keeps growing that products with glyphosate – not just the pure chemical – might be riskier because of added substances like POEA. This difference helps explain why research findings often clash and explains why we need to test complete formulations.
The science of glyphosate tells a complex story of effectiveness mixed with substantial risks. Farmers, gardeners, and policymakers now face tough choices. They must balance farming needs against mounting evidence of environmental and health risks. Without doubt, farming methods must change as we learn more about this common herbicide.”
