Nope, I’m not worried about “Superweeds”
May 3rd, 2010
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Rise of the Superweeds
DYERSBURG, Tenn. — For 15 years, Eddie Anderson, a farmer, has been a strict adherent of no-till agriculture, an environmentally friendly technique that all but eliminates plowing to curb erosion and the harmful runoff of fertilizers and pesticides.On a recent afternoon here, Mr. Anderson watched as tractors crisscrossed a rolling field — plowing and mixing herbicides into the soil to kill weeds where soybeans will soon be planted.
Just as the heavy use of antibiotics contributed to the rise of drug-resistant supergerms, American farmers’ near-ubiquitous use of the weedkiller Roundup has led to the rapid growth of tenacious new superweeds.
To fight them, Mr. Anderson and farmers throughout the East, Midwest and South are being forced to spray fields with more toxic herbicides, pull weeds by hand and return to more labor-intensive methods like regular plowing.
“We’re back to where we were 20 years ago,” said Mr. Anderson, who will plow about one-third of his 3,000 acres of soybean fields this spring, more than he has in years. “We’re trying to find out what works.”
Farm experts say that such efforts could lead to higher food prices, lower crop yields, rising farm costs and more pollution of land and water.
“It is the single largest threat to production agriculture that we have ever seen,” said Andrew Wargo III, the president of the Arkansas Association of Conservation Districts.
The first resistant species to pose a serious threat to agriculture was spotted in a Delaware soybean field in 2000. Since then, the problem has spread, with 10 resistant species in at least 22 states infesting millions of acres, predominantly soybeans, cotton and corn.
The superweeds could temper American agriculture’s enthusiasm for some genetically modified crops. Soybeans, corn and cotton that are engineered to survive spraying with Roundup have become standard in American fields. However, if Roundup doesn’t kill the weeds, farmers have little incentive to spend the extra money for the special seeds.
What we have here is yet another tired attack on genetically modified crops in general because just one of them has some minor secondary issues. Genetically modified crops come with numerous engineered traits. Some are modified to absorb nutrients more efficiently, others are modified to resist fungus or attacks by insects while others are modified to better withstand drought. The particular kind of genetically modified crop that this applies to are so-called “Roundup Ready” crops. These are crops which are resistant to the herbicide known as Roundup (Glyphosate).
While this is only one narrow example of genetic engineering, it has become one of the most popular. Although only around since 1996, most soybeans in the US are now planted with the genetically modified seed. Although they cost a little more, farmers love them, because they allow them to easily control weeds by using Roundup herbicide. The herbicide kills the weeds but leaves the genetically modified crops alone.
So apparently this has caused superweeds? No, not really. The increased use of the herbicide has lead to some weeds evolving a resistance to it. That’s their only “super” quality. They aren’t enormous in size, they don’t grow like crazy, they don’t grow legs and they won’t eat your children. They’re not really super in any way other than being resistant to this herbicide. This is not totally unexpected either. While Roundup is still fairly effective and probably will be for many m0re years, it’s quite normal for pests or invasive plants to evolve when pressured by human responses to mitigate them. It should not be a surprise that plants would evolve resistance to a popular herbicide.
The important thing to remember is that these weeds are only resistant to one herbicide, and while it’s an important one, it’s not the only one out there. Hell, there are at least thousands of chemicals that can kill plants. There are dozens that are commonly used as herbicides. There are also other methods of controlling weeds. They can be pulled, either by hand or mechanically. They can be burned, tilled or suppressed by placing fabric or mulch around crop plants.
If Roundup stops working well for weed control, farmers will stop using it and opt for other methods of controlling weeds. Not only that, but it’s likely the market will come up with other similar products to meet the need. Evolution will always work toward providing new traits to gain advantage, but so will the free market. Evolution, however, has some limits, such as having difficulty adapting to multiple stressors at the same time and being incapable of adapting to environmental stresses that kill all of an organism before it can produce offspring – at least some must survive so that progressive adaptations can occur.
Roundup Ready crops may be important and helpful in growing food crops, but their loss would not be catastrophic. We got by without it before 1996, after all. The reduction in effect may even be a good thing at least for those who argue that the success of Roundup Ready crops has made Monsanto too powerful when it comes to controlling food supply.
This is not a disaster and the weeds are not really “super.”
This entry was posted on Monday, May 3rd, 2010 at 10:53 pm and is filed under Agriculture, Bad Science, Enviornment, Good Science, media. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
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May 4th, 2010 at 6:43 am
I eaglery await the day that plants sprout out of pipes and attempt to bite people and/or spit fireballs at them.
I note that “Mr Anderson” uses no-till farming, which is described as “environmentally friendly” but still continues to use GM crops and the associated weedkiller and fertilisers.
How “environmentally friendly” is this really? Whilst I clearly understand the advantages of avoiding run-off, does a no-till farmer need to use more fertiliser / weed-killer than a conventional farmer? Does no-till farming actually benefit the wider environment, or does it just lead to a more concentrated area (a field) of more elevated pollutant levels?
Surely it just delays the inevitable, as drainage and groundwater flow will surely end up spreading whatever chemicals are applied? Which would mean that persistant use of such methods really shouldn’t change an awful lot?
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May 4th, 2010 at 8:41 am
Another key issue here is that plant species that develop individuals with a resistance to a certain herbicide can rarely maintain that resistance for more than a few generations after exposure has stopped. This is because, far from being ’superplants’ the plant that express this resistance cannot compete with their normal cousins unless those plants are kept suppressed by the very herbicide in question. Without that help the resistant hybrids are quickly selected against.
It would seem that there is some costs in maintaining resistance which is generally paid for in slower growth, or later maturity, or reduced fecundity, that gets overwhelmed by unmodified stocks in a few seasons.
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May 4th, 2010 at 11:08 am
I’mnotreallyhere said:
Reduced tillage or no-till reduces erosion and also produces less nitrous oxide and methane from soil oxidation. In many ways it is more environmentally friendly. It uses less energy too.
Reduced tilling is usually dependent on using synthetic fertilizers because organic fertilizer is so bulky and need to be tilled into the soil.
Fertilizer is not environmentally unfriendly on its own. It sometimes causes runoff problems, but so does organic fertilizer. Weed killers could be either way. Roundup usually decomposes in the environment in a few days so its not so bad. It has its impacts though, especially if it is overused.
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May 4th, 2010 at 11:53 am
DV82XL said:
That answers the big question that came to my mind as I read the story. I wonder if the resistance faded after the stressor was removed. Or as you explain, the resistant variety loses dominance.
So if farmers switch to some herbicide other than Roundup for the next 5-10 years then the non-resistant weeds would return as the dominant form slowly to be replaced by a variant resistant to the new herbicide. But in 2020 or so farmers could go back to Roundup which will again be effective.
Sounds just like crop rotation cycles. Just rotate your herbicide and the ‘evolution’ of weeds can’t keep up.
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May 4th, 2010 at 12:53 pm
I have not seen any credible arguments against genetic engineering based on the scientific or environmental side of things. The only credible argument that I have heard for a bad side to gmo is that it can be so vastly supperior to conventional crops that it becomes a necessity in the marketplace and in so doing, it effectively grants monopoly-like control to the company that holds the rights to the gene that has become a necessity and therefore they can be pretty strong-handed in their contracts and force users of their product into binding agreements.
That is not an argument against GMO, however. You can’t argue to ban something because it’s too good and could make the inventor too powerful. That is an argument for contract law reform and intellectual property law reform. As I understand it, the rights to patent a gene and organism are a bit conflicting. Supposedly you can’t patent a gene, you can only patent the method of altering or inserting it. I have no idea what that even really means.
The legislatures can fix this because the laws in use are not intended to address these kind of properties, they’re just old hold-overs.
BTW: Monsanto’s patents on Roundup Ready crop strains begin to expire in just a couple of years, so hopefully that will mean more freedom for these products. That is the point of a patent, after all, to give someone enough time to benefit from their invention but prevent them from having a stranglehold on it forever.
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May 4th, 2010 at 2:52 pm
Just a couple of notes.
First of the concept of losing a resistance to a resistance to a chemical after it is stopped be applied is based upon the microbial/antibiotic relationship. The classic example is E. coli where the resistance is held on a plasmid. These plasmids are quickly discarded by the bacteria if there is no use for them. They take time to replicate and when your generation time is only 20 minutes a few seconds matters. This process is vastly different in eukaryotes where the resistance is generally held in the nuclear DNA. Once a mutation has occurred Hardy-Weinberg equilibrium population genetics states that unless there is a selection pressure against the resistance the ratio of the resistance gene will stay the same. This means that 10,000 years from there will very likely still be pigweed immune to RoundUp.
In recent years Monsanto has had a strangle hold on field crops with RoundUp Ready, and BT GMO’s. The major appeal was low cost and low labor crops. From a growers standpoint a weed free field with very low inputs is a dream come true. Surprise!!! the dreams was too good to last. There will be a re-balancing of the market very soon as the many field crop pests are now immune to BT and weeds are immune to Roundup.
GMO’s are not inherently bad, however the use of them has proven to be foolish. When a strong selection pressure is applied against an organism they have two choices – mutate or die. BT GMO’s and Roundup are both very strong selectors. Given the billions of weeds and insects exposed to the chemicals it was only a matter of time before they overcome them. Everyone farmer is told to rotate their pesticide program to slow down resistant organisms. This was completely forgotten with these GMO’s.
The early attempts at creating GMO’s were like taking a sledgehammer to a window and hoping some of the pieces fell together right. Crude with a lot of linkage drag associated with them now. Todays techniques are vastly ahead of those early attempts that so got the public up at arms (and rightly so in some cases “terminator gene”). There needs to be a re-evaluating of the technology as our understanding of genetics has increased in the last two decades.
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May 4th, 2010 at 3:10 pm
“The only credible argument that I have heard for a bad side to gmo is that it can be so vastly supperior to conventional crops that it becomes a necessity in the marketplace and in so doing, it effectively grants monopoly-like control to the company that holds the rights to the gene that has become a necessity and therefore they can be pretty strong-handed in their contracts and force users of their product into binding agreements.”
That’s an argument against patents, which ostensibly do not provide much additional incentive for innovation(first mover advantage is already huge; inventions that are difficult to make are difficult to copy), discourage further refinement(once a major patent is granted, the dozen other people working toward the same goal drop what they’re doing and go somewhere else).
Patents discourage start ups. The major players build up a portfolio of patents with varying degrees of vagueness as a detterent against patent suits. If they get sued they launch a counter-suit with a dozen alledged patent infringements and duke it out in court for years. Other firms know this and so avoid suing unless they have a really good case. But small start ups haven’t acquired this kind of protection and they can’t pursue it unless they spend a huge amount of money that is at best tangential to what they’re doing.
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May 4th, 2010 at 8:29 pm
Soylent said:
The flip side to that is the inventor or R&D department that does not have the resources or desire to commercialize an invention and relies on a patent to provide royalties when the technology is licensed out to a manufacturer who can more easily put it on the market. If you take away the patent, you force the inventor to go into the manufacturing business at great expense, and leave him exposed to being undercut by established players when they copy his product.
There is nothing inherently wrong with Monsanto holding a patent on a technique for lowering farming costs. The only power Monsanto has is the power the growers give them in exchange for using a superior product. The growers have the right to use traditional stocks.
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May 5th, 2010 at 12:23 am
I actually like patents. The thing about patents is that they have limitations on them. A patent only protects your rights to manufacture and sell a product. It does not stop others from making devices that make use of your product (as long as you produce the product) or from making devices which interface with or enhance your product. It does not stop anyone from modifying your product or creating after-market enhancements for it. It doesn’t stop anyone from reselling or reconditioning your product after it has been bought. Also patents have limited lifespans, they don’t last forever.
Now, what bothers the hell out of me is manufacturers and product rights owners who like to use copyright laws or the DMCA to try to place a stranglehold on their product even after someone has bought it outright.
As far as I’m concerned, if I buy your print cartridge, I own it. It’s my physical property, and granted I can’t manufacture copies of it, but if I want to sell it to someone else that’s my right to do with my property. If I want to drill a hole in it and put ink back into it, that’s also my right. And furthermore, if I want to make a body kit for the car you manufacture or make an aftermarket APU for the airplane you manufacture, that’s my goddamned business and you should not be able to stop me.
Patent law is designed for inventions and technology. Crap like the DMCA should never be applied to that stuff.
We likely need a new subset of laws to deal specifically with genetically modified organisms and the intellectual property aspects. It has to address the fact that these things reproduce and can do things like pollinate other crops. Our current set of laws does not do a very good job in addressing the unique aspects of gmo.
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May 5th, 2010 at 8:45 am
The iconic example of harm from patents is probably the steam engine. After the separate condensor principle had been invented by James Watt the efficiency of steam engines barely changed at all for the duration of the patent because nobody could combine their invention with the separate condensor principle; not for lack of trying, they were beat back in court. After the patent expired there was a huge flurry of activity, as a several decades long backlog of inventions were applied to steam engines. Efficiency improved by a factor of 5 in the 25 years after Watt’s patent expired.
Ironically Watt himself had to invent an expensive and less efficient mechanism of converting reciprocating motion to rotational motion, the “sun and planet gear”, in order to skirt the patent on the crank and flywheel.
I don’t know for sure that patents are on the whole damaging to the economy and technological development, but I strongly suspect so. I find patents morally repugnant and would need strong evidence of a net benefit to accept them in any form(If a CNC machine is truly mine I should be allowed to machine whatever shape I want out of a block of aluminium for any purpose except doing physical harm to others; if a computer is truly mine I should be allowed to freely make any programme short of malicious software).
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May 5th, 2010 at 8:55 am
Shafe said:
How so? Without patents there are still commercial secrets and you can approach potential manufacturers and reach a licensing contract under which you help them commerciallize some invention and promise to not tell any other company. You’re transfering the first mover advantage to the one who is commercializing the product and they’re paying you in return.
Late comers will have to reverse-engineer a finished product and re-invent production processes. This is not necessarily an unproductive use of labour; they may invent a much better production process.
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May 5th, 2010 at 2:00 pm
THE V said:
The Hardy-Weinberg law does not apply in all these these cases. Hardy-Weinberg may be violated if there is differential mortality and/or differential fecundity, and this is often the case, simply because the nature of the selection pressure is to remove competition from members of the same species. Hardy-Weinberg can also fail for the same reason if the resistant allele being expressed is recessive. So while resistance may not disappear, (after all it must have been expressed in at least some of the population to begin with) the frequency of expression will drift downward to the original rate over time.
Naturally this is not guaranteed, and may take some time to occur depending on the size of the local gene pool available, but resistance is not necessarily a permanent condition.
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May 5th, 2010 at 8:34 pm
soylent said:
That’s fine if you’ve invented a genetic engineering technique or a soda formula. But many inventions are much more trivial to reverse engineer. Had I invented in-line skates, I could have approached a manufacturer about producing it, but there’s no way I could secure a contract before completely revealing such a simple idea, and as soon as word gets out that a toy manufacturer is considering making roller skates with the wheels in one row, the playing field immediately levels and I’ve lost all advantage as an inventor.
Many inventions (more consequential than in-line skates) are the sort of “Aha!” simple genius epiphanies that can’t be protected as a trade secret, because they’re so obvious. Those inventions warrant a reward for the inventor, a reward that cannot be easily usurped by competitors in an unprotected market.
Soylent said:
Neither the rail industry nor humanity in general had a “right” to Watt’s invention. I suspect some people would argue that technologies will inevitably develop, and if Watt hadn’t come up with the separate condensor, someone else would have in short order, thus Watt has no special claim to it. But the fact is, Watt came up with it, and if he hadn’t, it might have been another 50 years before an equivalent efficiency improvement was made. A short-lived patent was a fair way to reward Watt for his work by providing him the opportunity to capitalize on his invention before giving everyone else a crack at it.
Unhappily, Watt squandered an opportunity to make a real, immediate contribution to the industry by not licensing his invention more freely. That’s a failing of Watt, not patent law.
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May 5th, 2010 at 9:05 pm
DV82XL said:
A little more clarification.
The resistance might or might not have been extant in the population before RoundUp began to be used. The speed of mutation is very constant. Since the time Roundup began to be used these annual weeds have gone through at least 20 generations. Some species can accomplish 4-5 generations in a single season. A single female pigweed can produce 40,000 seeds in a season most other weeds have a comparable reproductive ability. So once resistance is introduced into the population it quickly becomes present in very high numbers.
With the removal of Roundup UNLESS there is a selection pressure against the resistant alleles or a linked trait the frequency will not change. The allele frequency as described by Hardy-Weinberg is independent of the method of inheritance. Selection pressure generally is defined as anything that effects the probability of an organism to reproduce. Selection pressure is greatly affected by the method of inheritance.
The scenerio you described may happen or the frequency may increase or remain the same. It alll depends on what the environment is.
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May 5th, 2010 at 9:58 pm
THE V said:
Well that’s the whole point when you think about it, isn’t it.
Actively suppressing the resistant population with another herbicide is one of those environmental changes, and can be very helpful in pushing the allele frequency down, particularly as the resistant strain is likely to be found among cultivars anyway. The wild population may contain resistant members, but unless that resistance confers other advantageous adaptations, these individuals will not dominate.
The fact is that Hardy-Weinberg is not carved in stone, and the best examples are in cases where the property it is measuring matters little, like the colour of eyes or hair.
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May 6th, 2010 at 2:23 pm
IF a resistance to glyphosate (the active ingredient in Roundup) were to become common in weeds, it is not as though it somehow makes weeds an impossible problem to deal with. There are plenty of chemicals that kill plants. I highly doubt we’re going to run out of them.
There are about two dozen generally used broad spectrum herbacides in use today. If it absolutely came down to it and they all stopped working, it’s not like weeds are likely to ever be immune to something like hydrofluoric acid, or for that matter, fire.
My original point is that these really are not “superweeds” The word implies weeds that are somehow “super” like enormous, extremely difficult to kill, spread like crazy, grow faster than normal etc etc. These are not super in any way other than a resistance to one herbicide.
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May 10th, 2010 at 11:40 pm
Biotech never leads to anything good.
God made plants as is for good reason. Biotech is only good to make killer things or make them worse and harm people. Toxins of all kinds, global warming, invasions and mutations, cancer and disease. Bye bye to nature and good health. Genes will cross over that’s for sure. Superweeds are just the beginning.
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May 10th, 2010 at 11:52 pm
JASPP said:
Fascinating thesis. Could you just repeat your credentials in making this statement? I seem to have missed them.
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May 11th, 2010 at 11:33 am
JASPP said:
Yeah, we should have remained hunter-gatherers.
JASPP said:
That’s a curious inversion; in the reality that I inhabit humans made gods, repeatedly.
If you don’t like the plants humans made, which is most of them, go back to hunter-gathering and leave the farming to sane people.
JASPP said:
What does it matter to you if a weed is resistant to herbicide when you’re against using herbicides in the first place?
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May 11th, 2010 at 11:45 am
drbuzz0 said:
It’s also interesting to contemplate what makes weeds in general hardier than food crops. When we stopped hunter-gathering and started farming, the first crops were miserable, weed-like things. These original crops did quite well in competition against things we didn’t like to eat; weeds still mattered, but much less than today.
The artificial selection pressures that humans exerted eventually gave rise to enormously more productive crops that spend a much larger fraction of their energy and nutrients on producing that which humans like to eat and sometimes are not even capable of spreading without direct help from humans. It is precisely because a plant is a good food-crop that it is so vulnerable to weeds. This enormous bounty of food that JASPP attributes to the work of god, and sane people attribute to last 10 000 years of primitive biotech, continues only as long as we obsessively beat back weeds with mechanical and chemical methods.
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May 20th, 2010 at 5:09 pm
Soylent said:
This is pretty good question. The effect on weeds has more to do with the environment portion of the genotype x environment = phenotype relationship.
Generally the genotype of the individual codes for a given amount of nutrients the plant will produce a proportional gain in yield up to its genetic/physical limit.
The effect of weeds by decreasing the amount of available nutrients for the plant. The most important of these nutrients in the weed/crop interaction is light. Generally the weeds that cause the most damage shade out the crop at critical stages of growth. It’s not that the weeds are hardier or stronger than the vegetable crop. The competition for the same nutrients greatly effects the phenotype of both species.
I’ve seen several good examples of the amount of effect weeds can have on a crop over the years. The best one I can think of was last fall. I was out in a hybrid cantaloupe field in San Joaquin Valley in California. They had a major issue with purslane (Portulaca oleracea). Where the weeds were dense the melons were about the size of a golf ball. If you cut the little golf balls in half they had almost no flesh and a ton of seeds. In other areas where the weeds were less the melons were in the 4-6lb range but had the same number of seeds. The grower reported harvesting around 300 boxes/acre of marketable fruit. On a field nearby with better weed control the grower reported around 850 boxes/acre of the same variety. I believe the market right then was around $12 per box and the fields were in the 200 acre range. A little math and you can see how much money the weeds cost the grower.
BTW Cherry/grape tomatoes are really great examples of a weedy domesticated crop. They are very close to the wild type.
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