In praise of loose cannon
We Need to Look Critically at GE CropsBy E. Ann Clark
The future of agricultural biotechnology is in serious jeopardy, as consumers, grain buyers, processors and supermarket chains around the world refuse to buy genetically engineered (GE) products. Barely a year ago it looked exceedingly bright for those who had glued their careers to the rapidly climbing fortunes of Monsanto and the other life-science companies. But that was a year ago.Under the pressure of independent scientific scrutiny the overblown bubble of biotechnological optimism has burst, and farmers are left holding the bag. All the transparent efforts of the ag biotech industry to contain and control public discussion in industry-friendly directions have been seen for what they are - and are failing. Consider the stern admonition of Gordon Conway, president of the Rockefeller Foundation, to the Monsanto board of directors: "Admit that you do not have all the answers . . . Commit yourselves to prompt, full and honest sharing of data. This is not the time for a new pr offensive but for a new relationship based on honesty, full disclosure and a very uncertain shared future." He warned that continued subterfuge on the part of Monsanto-- a major funding source for Canadian ag biotech research --risked bringing down the wrath of the scientific, political and global communities.
The Deutsche Bank, largest bank in Europe, has gone public with its concerns, advising thousands of institutional investors across the world to sell GE. And so they have, affecting not just stock prices but encouraging major life-science companies to consider spinning off their GE divisions. In a revealing report entitled Ag Biotech: Thanks, But No Thanks? (http://www.biotech-info.net/Deutsche.html) published in July, Deutsche Bank stated that "Today, the term GMO has become a liability." This highly influential report downgraded Pioneer Hi-Bred from HOLD to SELL, and gave the seed sector in general a broad negative recommendation.
Deutsche Bank highlighted the potential development of a two-tiered marketing system with the premium going to non-GE crops - just the opposite of industry projections. And now, just a few months later, premiums of $0.08-0.15/bu for non-GE corn and $0.20-0.30/bu for non-GE soybean were reported to be on offer in the United States. Much higher premia, it is reported, are being paid in Japan even now. Much energy has been devoted to ridiculing and trivializing the efforts of activist groups to influence public opinion. Proponents of GE crops (also known as GMOs or genetically modified organisms) have taken much comfort from the claim that activist positions are all just so much fluff. Through skillful re-education, they think, consumers will eventually see things their way.
However, the opposite appears to be happening. The more people learn about GE, and in particular about the absence of meaningful assessment of risks to human health1 and the environment2 before GE crops enter commerce, the more concerned they become. Case in point is the $1.5 million campaign waged by Monsanto in Great Britain to shift public opinion in their favour; it had precisely the opposite effect.
Independent (not industry-supported) scientists, also known as loose cannon, have begun to challenge many of the assumptions underlying the commercialization of field crop GE. Almost weekly, articles by respected scientists appear in mainstream journals such as Science, Nature, and Nature Biotechnology. Their findings are uncovering ever more problems caused by commercializing technology without first understanding either the basic science or the agronomic implications. Some examples will suffice to make the point that GE proponents have not done their homework.
If you grow corn, you know about the high dose/refugia model to control resistance in target organisms, such as the cornborer. Pretty well each year, the size of the recommended non-GE refuge gets larger. The theory - and that is all it is - is that if the population of potentially resistant cornborers is diluted with a continuing flux of unselected individuals from the refuge, the rate of evolution of resistance within the over-all population is retarded. There's just one problem. "None of the essential assumptions of the high dose/refugia strategy have been verified for BT corn", according to Andow and Hutchison (1998) in a chapter on Bt resistance in Now or Never, edited by Mellon and Rissler.
In cornborers on corn and in pink bollworms on cotton (Liu et al. 19099. Nature 400:519), controlled studies have shown that resistant individuals reach sexual maturity at a different time to unselected individuals. Thus, resistant and unselected individuals cannot mate. Such results, if confirmed in field-scale studies, would invalidate the one and only model currently on the table. You'd think they might have checked this first.
Another nail in the coffin of high dose/refugia came from another untested assumption that resistance to Bt was conferred by a recessive (not dominant) allele. Indeed, the whole theory hinges on this assumption. However, a recent study (Huang et al. 1999. Science 284:965-967) reported that resistance in the European cornborer is in fact partially dominant.
Did you hear about the $147,000 order of Terra Prima organic tortilla chips that were rejected and had to be destroyed due to cross-pollination by Bt corn, or the non-GE PIONEER seed co that was found, after sale, to have inadvertently been polluted by GE pollen? Genetic pollution, where pollen from one crop strays into adjoining lands, was well documented long before GE. But who pays when it happens with GE pollen, affecting not just your own weed-control practices in the following years but loss of the premium for non-GE grain? With GE crops selling at a discount because major clients don't want to buy them, genetic pollution poses a clear risk to every farmer. And are GE crops actually safe to eat? The government says so, and so does industry. But how do they know? Are you prepared to accept the judgement of a risk assessment system based largely on unvalidated assumptions, like the high dose/refugia model? Why aren't ACTUAL food safety tests a requirement for all foodstuffs created when foreign genes are randomly inserted into crop chromosomes, with metabolic outcomes that cannot be anticipated without testing? Has the rush to expedite the movement of GE crops into commerce compromised the safety of the food when we, or our livestock, eat it?
Consumer Reports provided a sobering look at the prevalence and risks of GE food in its September 1999 issue, but says there is "no evidence" of harm from GE foods. Don't derive too much comfort from this homily. There is no evidence of risk because the proprietors of GE crops were not obliged to provide evidence of food safety as a condition of registration. If you don't look for something, you are unlikely to find it - and that is just about where GE food safety testing currently rests in Canada and the world.
According to Health Canada's new Guidelines for the Safety Assessment of Novel Foods, Vols. I and II (http://www.hc-sc.ge.ca), only those GE crops that are not "substantially equivalent" to conventional crops even require an official notification to Health Canada. Perhaps not surprisingly, all of the GE crops approved in Canada have been found to be "substantially equivalent". Even in the unlikely event a GE crop is found not to be "substantially equivalent", food safety tests are still not required. "Information demonstrating the safety of such products as food may be requested by the Director." Reinforcing this position, the guidelines say "It is expected that once substantial equivalence to an existing food product can be established, no additional safety testing would be required".
If a GE crop looks and behaves like a conventional crop on the basis of a few rudimentary measurements, it is deemed "substantially equivalent" to conventional crops and treated as such. This is an "assumptions-based" process, without validation. The principle of substantial equivalence means that GE crops containing novel genes from wholly unrelated organisms, genes that can interact unpredictably with crop host genes, move expeditiously into commerce because they require no more testing for food safety, or environmental risk, than any conventionally bred crop.
A scientifically rigorous examination of potential health risks of a GE crop is a difficult, expensive task, and one that can be hazardous to your own health. Just ask Dr. Arpad Pusztai, an eminent senior scientist who was sacked by the Rowett Research Institute in Scotland after going public - with permission - with preliminary evidence suggesting that GE potatoes could be harmful to rats. His goal in "going public" was to obtain more money to support more rigorous testing of his disquieting findings. The outcome was the opposite; he was unceremoniously fired and ordered not to speak to the press for seven months, or risk losing his pension; all of his research grants were frozen and his program was halted prematurely, his longstanding team, disbanded; and the awkward questions raised by his findings have been shelved. Even the editor of the celebrated journal Lancet, which just published his findings, was threatened with the loss of his own job if he published the work.
His colleagues and other industry advocates have made extraordinary efforts to discredit him and to justify his ouster. These include what industry advocates have called a "damning" audit by an internal committee headed by Dr. Andrew Chesson. You see, the real threat of Pusztai's work was to expose the fallacy of this concept of substantial equivalence.
Well, who comes out now with the very same conclusion but Chesson himself. According to an article in the London Daily Express of September 7th Chesson told the Royal Society of Chemistry that current tests "may be insufficient" to detect new chemicals inadvertently produced in GE crops. He acknowledged that inserting novel genes in a crop background could elicit unintended and unpredictable metabolic changes, leading to novel health risks. Chesson was said to have called for a more broad-ranging and incisive alternative to the "assumptions-based" principle of substantial equivalence.
It has been stated, with evident pride, that commercial GE crops are supported by 20 years of extensive research, as if that should suffice to deflect all challenges. A thousand years of research will not suffice to safeguard human health if the question asked is only "how do we make it work?" instead of "what happens when it does?" and "why we are doing this in the first place?". The loose cannon who are somehow finding funds to pursue and publish research into the "what happens" and "why" questions are deserving of our praise, and thanks.
E. Ann Clark is an associate professork, Plant Agriculture, University of Guelph
© copyright 1999 AgMedia Co-operative Inc..
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One-Pass Weed Control
Everyone wants it but nobody is getting itby Pat Lynch
If you check out the ads you see a lot of talk about one-pass weed control. One of the features of the Roundup Ready Crops is the one-pass feature. Growers want one-pass weed control to reduce application costs. Look at the new registrations; there are a lot of multiple herbicide combinations to try to achieve one-pass weed control.But if you have farmed very long, you know that every time you get something you give something up. A common attempt to get one-pass weed control is to add more products to the tank mix. Some of the cocktails I see remind me of a tillage slide that Dr. Charles Baldwin from RCAT used in a tillage/erosion talk. In this slide there was a big tractor pulling four pieces of tillage equipment. In jest Charlie would say, "It looks like this guy hooked on to every piece of tillage equipment he had and pulled it across the field." If Charlie were talking about weed control, he might say, "It looks like some growers are throwing all their favourite crop-specific registered herbicides into a tank and spraying the field."
One problem with many tank mixes is that one herbicide can dramatically interfere with another. When Basagran was first registered by BASF we had our first real post emergent broadleaf weed herbicide. When BASF registered Poast, we were excited about tank-mixing these two products to get one-pass weed control in soys. Think how disappointed we were when BASF informed us there was antagonism and lost weed control when they tank-mixed their two products. Other currently registered tank mixes have the same type of antagonism. With some of these mixes you can increase the rate of one or the other to overcome this antagonism. Generally, though, the cost of this extra product is more than the cost of spraying the field twice. And quite often, if the stage of the grassy weed herbicide is correct, the stage is not right for the broadleaf weed herbicide. And sometimes one of the products is very weather-specific, so this limits the time available for application.
Another way to get one-pass weed control is the use of additives. There are many out there. Most aggressive are the corn and soy oil products. These products increase the herbicide activity by getting more of the herbicide through the cuticle and into the plants. This is one way to decrease costs and trips across the field. Again this year we saw herbicides along with a crop oil give great one-pass weed control. Unfortunately, there were cases where a combination gave great crop control as well as great weed control. This is the problem with adding crop oils. The results are still unpredictable. They will increase weed control but can increase the chance of crop injury. Quite often this injury is small and undetectable. You can use an oil mixture and lose two to three bu/acre of beans or five to six bu/ac of corn and never know it. If the whole field is treated the same, how can you measure it?
If you have a crop insurance claim and you used one of the non-registered tank mixes, you are putting your insurance contract at risk.
The newest one-pass weed control is glyphosate in its many forms from different companies. In fact, there are so many companies selling glyphosate now that it is reminiscent of the time when atrazine came out. Atrazine was probably the best one-pass system. When it started to fail us, we increased the rate. Then, when even high rates failed us, we started using surfactants. When this started to fail us, we began adding tank-mix partners. If history repeats itself, the one-pass strategy of glyphosate will falter and then we will start adding additives, then increase the rate, and then start adding other products to it. The alternative is to use two or more passes to obtain good weed control. It is interesting to watch companies and farmers match their weed control program to their equipment or other personal factors, rather than matching it to the weeds in the fields.
One-pass weed control has a place in some fields, some times, with some weeds. But you cannot expect it to work all the time. The solution to weed control is to make the herbicide program fit the weeds. This generally will be more economical with more than one trip. Seldom will one-pass weed control be the more economical.
Pat Lynch is Head Agronomist for Cargill in Ontario.
© copyright 1999 AgMedia Co-operative Inc..
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Adverse Affects of High and Low pH's-Normally high pH's above 8.0 will NOT have adverse affects on crops. However, some herbicides, e.g., Broadstrike, ATZ are more available to plants at higher pH's. Some nutrients, such as phosphorous, zinc and manganese, are less available at higher pH's. Low pH's can also have adverse effects. At low pH's, some nutrients become so available they can become toxic to plants. Low pH's are associated with toxic levels of aluminum, manganese and iron. Low pH's can also mean either Ca or Mg are so low they limit crop growth.
Liming To Change pHAll farming operations lower pH with the exception of ploughing up sub soil, which tends to raise pH. Nitrogen materials, especially anhydrous lower pH. When you add lime, it is to raise pH, plus adding calcium and/or magnesium. The cost of liming includes a proportionately high cost for application. Historically, we have tended to apply high rates and count on that rate lasting for five to ten years. With the advent of variable lime applicators and grid soil sampling, we probably can be more efficient in terms of lime use. We probably need to be sampling more often but only applying lime where needed. This may mean liming every three to four years.
Liming In No-Till SystemsPennsylvania researchers began a nine-year study in 1985, making surface applications of 1 1/2, 3, 4 1/2 ton/ac CaC03 equivalent lime at intervals of one to five years. Initial pH at 0-6" was 5.1, and initial pH at 0-2" was 4.5, with a target pH of 6.5. In the box are representative results from three ton/ac added every three years. The pH at 0-2" went to 6.5 within two months, mainly in the top half inch. Note: After nine years, pH at 2-6" was only 6.0. Results suggest it is better to bring the entire plough layer to the target pH before starting no-till Other studies have shown that once target pH is attained, it can be maintained by surface application in no-till. Some agronomists recommend yearly liming in no-till. The Pennsylvania group found no advantage to this. A triazine weed control study was run in the above plots. Although pH was only raised at the surface, it did improve the efficacy of triazines.
Calcium Ammonium Nitrate (CAN)This is a formulation of ammonium nitrate with dolomitic limestone. Original purpose of CAN was its ability to be transported in bulk by water under T.D.G. regulations. Since the explosion in Oklahoma City where ammonium nitrate was used to blow up a building, there has been more emphasis on ammonium nitrate. CAN reduces some of the fear of ammonium nitrate without reducing any of its agronomic benefits. Once CAN is in the soil it reacts the same way as ammonium nitrate. You should expect the same benefits to CAN over other sources as you would with ammonium nitrate over other nitrogen materials. An added benefit to CAN is that it can be used in the same fertilizer plant as urea without incurring the soupy mess that occurs with urea, and ammonium is a minor source of calcium and magnesium. In a typical starter blend, applied @ 200 lbs/ac., you would be applying about 1-2 lbs of Cclcium and half that amount of magnesium.
Giant Foxtail- A native weed of China, it has recently spread into Ontario from the U.S. where it has been troublesome for a long time.
Giant foxtail is an annual weed, similar to its cousin, green foxtail. It grows larger and taller than green foxtail with a large, greenish yellow seed head that looks like a bottle brush. It tends to nod over with the weight of developing seeds. The leaves are broader than those of green foxtail and the upper leaf surface is covered with fine hairs. Herbicides that control green foxtail usually control giant foxtail also. Giant foxtail is more robust, so dosages required for control tend to be a little higher.
Use the mid to high end of the rate range labelled for soil-applied herbicides. With post-emergence products that have a labelled rate range, select a slightly higher rate than is recommended for green foxtail. Time the application to coincide with giant foxtail seedlings in the 2-3 leaf stage rather then later stages for best results.
Bill Stevens is Cargill AgHorizons Agronomist
© copyright 1999 AgMedia Co-operative Inc..
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