Despite the 'fact' that it is constantly asserted that GE crops are good news for farmers, not to mention society at large, in terms of production, thousands of controlled varietal trials have shown exactly the opposite - significantly decreased yields with GE crops.
For example, University of Wisconsin research showed GE soya yields from the 1998 harvest as lower than non-modified varieties in over 80% of cases in trials right across nine US states - the states concerned accounting for 68% of that year's US soya production - for more on the Wisconsin study:
In May 2000 it was announced that a two-year study by University of Nebraska researchers had similarly shown that GE soy produced lower yields than conventional soybeans. The Nebraska University Institute of Agriculture and Natural Resources study showed Roundup Ready soybeans yield 6 percent less than their closest relatives and 11 percent less than high-yielding soybean varieties - for more on the Nebraska study:
University of Minnesota economist, Vernon W.Ruttan, sums up the broader picture: "Thus far, biotechnology has not raised the yield potential of crops" - 'Economist: Biotech Has Not Made Impact Yet', 11-21-2000, Farm Progress
The Nebraska and Wisconsin data are especially important as they comprise 'side-by-side' trials under controlled conditions. By contrast the USDA aggregated annual data on GM crops, for example, does not involve controls for variations in site conditions and husbandry methods, and therefore does not represent 'scientific' findings on the agronomic performance of such crops.
Still less reliable are the type of producer estimates circulated by the industry-funded ISAAA in their much hyped annual reports.
Such estimates are particularly unreliable because hype and fashion are such powerful shapers of opinion. For instance, Donald White, a University of Illinois plant pathologist, says US farmers have gone for GM corn because, "...what happens is there is a herd mentality. Everyone has to have a biotech program."
'Corn leaving bad taste in world markets as GMO worries build' - Reuters, Wednesday November 22, 2000
Clear evidence of how fashion distorts perceptions was shown in a 1998 opinion poll of approximately 800 farmers in Iowa, carried out by the Leopold Centre at Iowa State University, which revealed that most (53%) chose [GE] RR beans because they thought they produced higher yields than non-GM varieties. But when actual data from their farms was analysed exactly the opposite was found.
"It is interesting to note....that increasing crop yields was cited by over half the farmers as the reason for planting GMO soybeans, yet yields were actually lower", reported researchers at the Leopold Centre.
The other big claim is for reductions in pesticide use.
With GE (Bt) corn, despite industry claims, there has been no independent evidence of a reduction in overall pesticide applications - in fact, more acres of conventional corn are being treated with insecticides now than before the introduction of GE corn! And nor have agronomists considered the economics favourable to Bt corn usage except in areas with very high pest pressure.
This is an extraordinary situation when one takes into account that GE crops are predicted to increase resistance of pests to both pesticides and the GE crop itself, quite apart from all the marketing problems with GE crops. According to USDA's Foreign Ag Service Weekly Export Sales report, U.S. corn exports as of the week ending Nov. 15, 2001, compared to one year ago, are 10 percent less to Japan, 13 percent less to Taiwan and 18 percent less to the category 'other Asia and Oceania'.
Also in terms of economics, the greater expense of GE seeds and the increased herbicide costs can hit farmers pockets. One analysis showed a 50 per cent increase in farmers' weed management costs, for example.
The most hyped of all the GE crops has been Bt cotton. Yet even here an updated summary of the WWF International report, in Fall 2000 was titled "No Reduction of Pesticide Use with Genetically Engineered Cotton".
According to the data analysed in the updated report, although to date one fourth of American cotton is produced with genetically engineered Bt varieties, no significant reductions in the overall use of insecticides could be achieved. In fact, those insecticides which could be replaced by the genetically modified Bt cotton, only make up a minor proportion of the insecticides used. And herbicide use with herbicide-resistant GE cotton shows a similar picture.
The article below provides yet more evidence of the need to separate fact from fantasy in the promotion of these crops to farmers. It rightly points to the popularity of GE crops with many North American farmers because of their 'convenience', but that is a very different matter from greater productivity, reduced chemical use, better economics or improved environmental impact - the very things that are most frequently claimed for these crops.
Indeed, convenience (just as with a diet composed of 'convenience' food) brings its own set of problems. The Nebraska report, for instance, shows that US farmers are using the technology to needlessly destroy weeds to get a 'weed-free' field. The study shows that not only do the economics not justify this but that on-farm biodiversity is being needlessly destroyed as a result.
For more information on the frequently poor physical and economic performance of GE crops see also:
Conventional Vs. Transgenic Cotton
Edited by AgWeb.com Editors
While transgenic cotton varieties, including Bollgard and Roundup Ready technology, may make pest control easier, they are not always worth the added expense when it comes to yield and fiber quality, notes a cotton specialist.
"In the University's Official Variety Tests conducted by (cotton researcher) Fred Bourland, many of the highest yielding varieties were conventionals," noted Bill Robertson, cotton specialist with University of Arkansas Cooperative Extension. "Last year in Dr. Bourland's tests in the northern part of the state, eight of the top 10 producing varieties were conventionals. In the southern half of the state, seven of the top 10 were conventional varieties."
Robertson said more farmers are turning to Roundup Ready cotton for "their harder-to-control weeds such as pigweed. The Roundup Ready technology offers convenience. When cotton is small, it's easier and faster when you can spray over-the-top instead of having to post-direct. Timing isn't always as critical with the Roundup Ready program. It's a little more forgiving."
But despite the benefits, transgenic varieties aren't always the best choice, Robertson said.
"Last year, on one farm where Extension entomologist Gus Lorenz and I conducted a field study, we asked the grower to compare a Bollgard/Roundup Ready variety with a conventional variety," he said. "The farmer chose varieties, stacked and conventional, that he thought would be best for his farm. Then we compared the economics of the two systems."
"In a year when insect pressure was low in central Arkansas, the farmer spent about $10 an acre less for insect control with the conventional variety than he did with the more expensive stacked gene variety," Robertson said, noting that during years when insect pressure is high, especially worms, the Bt technology will "really pay, especially as we go farther north in the state."
The bottom line, he said, is that while yield is important, farmers need to pay more attention to fiber quality characteristics, including micronaire, fiber length or staple, fiber strength and uniformity.