Increased public health concerns over herbicide glyphosate

by Lucia Graves

The chemical at the heart of the planet’s most widely used herbicide -- Roundup weedkiller, used in farms and gardens across the U.S. -- is coming under more intense scrutiny following the release of a new report calling for a heightened regulatory response around its use.

Critics have argued for decades that glyphosate, the active ingredient in Roundup and other herbicides used around the globe, poses a serious threat to public health. Industry regulators, however, appear to have consistently overlooked their concerns.

A comprehensive review of existing data released this month by Earth Open Source, an organization that uses open-source collaboration to advance sustainable food production, suggests that industry regulators in Europe have known for years that glyphosate, originally introduced by American agricultural biotechnology giant Monsanto in 1976, causes birth defects in the embryos of laboratory animals.


Earth Open Source’s study is only the latest report to question the safety of glyphosate, which is the top-ranked herbicide used in the United States. The EPA estimates that the agricultural market used 180 to 185 million pounds of glyphosate between 2006 and 2007, while the non-agricultural market used 8 to 11 million pounds between 2005 and 2007...

full article...Huffington Post

Pastoralists in Ethiopia grapple with harmful weed

by Andualem Sisay

Pastoralists in Afar Region of Ethiopia engaged in a fierce battle with prosopis, a harmful weed to both pastoralists and their animals which rapidly is invading grazing and agricultural land of the region.

According to some of the pastoralists in the region who spoke to journalists who visited the area last week during a program organized by a civil society organization named Pastoralist Forum Ethiopia, rapid expansion of prosopis is threatening their livelihoods by grabbing grazing land of their animals.

“The number of our livestock animals is decreasing, as our land is being invaded rapidly by Dergi Hara (meaning Derg Tree, a name given to prosopis in Afar language),” says Abdule Hero, Chairman of Bedul Ali Kebele of Amibara Wereda (district) and beneficiary of a prosopis management project being implemented by a civil society organization in the area.

“Any other indigenous plants are disappearing from the areas where Dergi Hara is invading. In addition, those animals which feed the weed will be sick. It is a very serious problem that is forcing us to look for other means of survival,” he says.

According to a study conducted by Farm Africa, a civil society organization, which introduced a pilot program of managing prosopis three years ago in Afar Region, the pods of the weed eaten by the animals is one of the major reasons for fast invasion of prosopis, which is also called Weyane Zafe in Amharic, before it gets the Afar version.




The pods, which the animals eat but could not be digested, will turn to a seed dropping out as a waste. Currently over one million and one hundred thousand hectares of land in Afar Region is covered by Prosopis. In addition, it is also expanding to the northern and south west of Ethiopian regions covering million of hectares, according to Farm Africa’s research.


Introducing Pastoralists with Farming

“After Farm Africa, as a pioneer interventionist, has launched a three and half year prosopis management program in Afar Region, we are able to convince the pastoralists in the area and engage them in the effort of controlling the spread of this dangerous weed,” says Alawis Ahmed, manager of the project.








The project, which covered 9 weredas of the 18 highly affected parts of Afar Region, has been able to clear 250 hectares of land from the weed and introduced farming to the pastoralist people in the area.




“It was very difficult to engaged pastoralist communities to farming activity,” says, Hirut Kassa, senior project officer of the project. “In most cases pastoralists prefer to hire other highlanders to do the farming for them. But, here the situation was different all the pastoralist were ready to train themselves on how to do the farming,” she says.




Last year some 60 pastoralists of Bedul Ali Kebele of Amibara Wereda began their first farming business producing 100 quintals of sesame, which each quintal is worth 1,500 birr.




“We first started on 25 hectares of land and this year we are developing a total of 100 hectares of land for cotton production,” says Abdule.




According to Alawis, prosopis management project of Farm Africa is not limited to clearing the land and covering it with crops. It among others includes introducing the pastoralists on how they can make money by producing charcoal from prosopis and producing animal feed by crushing prosopis pods.




Is Pastoralism Dying?

Even though the land size they are farming is growing Abdule stressed that he or his friends have no intention of completely turning to farming by abandoning pastoralism once and for all.




“Well the money we get from farming will support us but it is not satisfactory like the money we make from livestock. If we take for instance one bucket of milk which was 25 cents is now three or four birr. Therefore, livestock production is not something we will abandon. Hence, we rather do both farming and the pastoralist activity simultaneously,” he said.




Executive Director of Pastoralist Form Ethiopia, Tezera Getahun, agrees with the idea of Abdule. “Many of us including policy makers and the media have misconception about pastoralism and underestimate its benefits.




“Many of us think that farming is better for pastoralists. But it is not true, the fact that some farmers in highland area such as Gojam still do not even have shoes and we can’t see any pastoralist in Somali Region without a shoes shows can be a simple example to compare the two,” he asserted.




Describing that most of the southern African country, Botswana’s, meat export is produced by pastoralists, Tezera argues that Ethiopia, which is the top in Africa in livestock population, can benefit better if it gives proper attention to pastoralists.

“Pastoralists do not move from one place to another only in search of pasture and water. There are about a dozen reasons for them to move such as avoiding diseases, difficult weather and the like,” he says.

In an attempt of reducing the level of their vulnerability to disasters and help them improve their livelihoods, Ethiopian government has been introducing farming to the pastoralists through settlement program.

Meanwhile many people argue that mobility, which is a unique characteristic of pastoralists, need to continue. “Ranching (settling people in one area) will not always work,” says Taffesse Mesfin (PhD), Animal Health expert who spent over 30 years working in pastoralist areas.

“By the principle of mobility the pastoralists preserve the ecosystem. Instead of making them farmers, government needs to involve them on issues that affect negatively their livelihoods and the environment,” he advices.

In Ethiopia about 75 percent of national parks are found in pastoralist areas, which covers 60 percent of the total land mass of the country with a total of ten million pastoralists in Somali, Oromia, Afar, Gambella and Benishangul Regions of Ethiopia.

Dr. Taffesse believes that consulting with pastoralists on management and benefit sharing from the income of these parks could lead to the reduction of conflicts and preservation of the natural resources.

In addition experts in the area also suggest that preparing pastoralists’ focused extension program that will make easy the provision of basic service to the pastoralists and their animals as well as setting in place proper pastoralist land use policy, regulations and manuals could also improve the current poor livelihoods of Ethiopian pastoralists and the environment.

Even though Afar Region was the first to prepare land use policy, still some investors still complain that the policy is not implemented on the ground as it is mandatory for them to get green light from clan leaders to undertake commercial farming peacefully.

Globally it is estimated that there are over 200 million pastoralists. Now the question is, ‘Will Ethiopian pastoralists preserve their century old life style for the coming decades will their mobility stop and they become settled farmers?

New Business Ethiopia

New drive to save African crops from parasitic weeds

by Mazera Ndurya

Scientists in Nigeria and Kenya have started a major war against parasitic weeds that cost small scale farmers in Sub-Saharan Africa $1.2billion in harvests every year, aggravating food deficits.

An initiative coordinated by the Nigeria-based International Institute of Tropical Agriculture (IITA), will introduce new methods for fighting Striga, or witchweed, and Alectra. Known as the “violet vampire” because of its bright purple colour, Striga attaches itself to the roots of plants like maize and cow peas and sucks out nutrients, reducing yields and destroying entire harvests.

Witchweed primarily affects smallholder farmers who cannot afford herbicides for fighting the parasitic plant. The most widespread Striga species is estimated to have infested up to four million hectares of land under maize in sub-Saharan Africa, causing yield losses of up to 80 per cent. According to researchers at IITA, this represents up to $1.2 billion in losses for farmers and affects about 100 million people in the region.

The parasitic weeds have spread widely in Africa because of their seeds feed on substances released by the roots of crop plants to germinate faster. The weeds also produce seeds that can remain dormant in soils for decades.

The Bill and Melinda Gates Foundation has given IITA $6.75 million as part of a campaign to help 200,000 maize farmers and 50,000 cow pea farmers raise yields by 50 per cent and 100 per cent, respectively.

The  four-year project aim to improve and expand access to methods of Striga control including using a “push-pull” technology that involves intercropping with legumes that inhibit the germination of Striga, using herbicide-coated seeds and deploying bio-control of Striga.

Scientists expect that the integrated witchweed control interventions will generate an estimated $8.6 million worth of additional grain (maize and legumes) increasing incomes, improving nutrition and reducing poverty.

“The project aims to raise farmers’ awareness of the technologies, and supporting community-based organisations with technical assistance,” said Prasanna Boddupalli, director of the Global Maize Programme based in Nairobi. About 80 per cent of the population in sub-Saharan Africa depends on agriculture for food, income, and employment.

Business Daily Africa

Weed control: organic vs conventional methods compete

Weeds are hard to kill; they seem to come back no matter what steps people take to eradicate them. One reason is because of the persistence of weed seeds in the soil. Organic farming and conventional farming systems both have their methods of taking on weed seeds, but does one show better results than the other?

The authors of a study reported in the current issue of the journal Weed Science conducted tests that compared conventional farming with organic systems. This research determined weed seed viability under both systems over a two-year period in two separate locations.

To compare these systems, researchers buried seeds of two types of weeds, smooth pigweed and common lambsquarters, in mesh bags. Tests were conducted at agricultural research locations in Maryland and Pennsylvania. Seed viability was determined by retrieving seeds every six months over the two-year period.

Depth of seeds in the soil, environmental conditions, and soil management are among the factors that affect seed persistence. Under conventional soil management, tillage is an important practice that manipulates the depth of seeds and environmental conditions that can influence weed seed persistence. Organic soils have enhanced biological activity, with more carbon, moisture, and microbial activity that could lead to greater seed decomposition.

The organic soils in this study were higher in total soil microbial biomass than the soils of the conventional farming tests. This was measured by phospholipid fatty acid content. But the results of the tests did not lead researchers to conclude that this microbial biomass has a dominating role in seed mortality.

Pigweed seeds showed a shorter life span under the organic system in two of four experiments. Organic system lambsquarters seeds had a shorter life span in just one of the four experiments, while the conventional methods had the shorter life span in two of four experiments. These results leave an ambiguous answer to the question of which farming system can better eliminate seeds deep in the soil to control weeds from their source.

Science Daily

New way to control 'superweed' developed

They pop up in farm fields across 22 states, and they’ve been called the single largest threat to production agriculture that farmers have ever seen. They are “superweeds” – undesirable plants that can tolerate multiple herbicides, including the popular gylphosate, also known as RoundUp – and they cost time and money because the only real solution is for farmers to plow them out of the field before they suffocate corn, soybeans or cotton.

Now, thanks to the work of researchers at Dow AgroSciences, who have been collaborating with a University of Missouri researcher, a new weapon may be on the horizon to eliminate superweeds.

Zhanyuan Zhang, a research associate professor of plant sciences and director of the MU Plant Transformation Core facility, partnered with research scientists at Dow AgroSciences to engineer soybean plants that can tolerate an alternative herbicide that may help slow the spread of superweeds, such as tall waterhemp.

According to an article in the May 3 2010 edition of the New York Times, farmers considered RoundUp a “miracle chemical” when it was introduced because it killed a wide variety of weeds, is safe to work with, and broke down quickly, reducing environmental impact. However, weeds quickly evolved to survive gylphosate, and that threatened to reverse an agricultural advance known as minimum-till farming. As the superweeds survive in the fields, farmers must spend more time to get rid of them, even going so far as pulling the weeds by hand. The Times noted that there were 10 resistant species in at least 22 states infesting millions of acres of farmland.

Using a massive genetic database and a bioinformatic approach, Dow AgroSciences researchers identified two bacterial enzymes that, when transformed into plants, conferred resistance to an herbicide called “2,4-D,” commonly used in controlling dandelions. The enzymes were successfully put into corn and soybean plants, and those new plants showed excellent resistance to 2,4-D, including no negative effects on yield or other agronomic traits. Other advantages of 2,4-D include low cost, short environmental persistence, and low toxicity to humans and wildlife.

“Unlike glyphosate, which targets amino acid synthesis, 2,4-D is a hormone regulator. Because it has a different mode of action, 2,4-D is an ideal herbicide to deal with glyphosate-resistant weeds,” said Zhang, who managed the soybean transformation portion of the study and contributed to some data analysis.

Zhang believes that 2,4-D could eventually be combined with other herbicides in the near future. In the meantime, Zhang says an integrated weed management plan can help farmers be productive and ultimately save money for the consumer.

“The less chemicals farmers use in the field, the less money they spend on production,” said Zhang. “That leads to less cost for the consumer, as well as improved food safety and environmental safety.”
Study results were published in the November 2010 issue of The Proceedings of the National Academies of Science.

University of Missouri

Striga weed needs more spirited efforts against it

by C. Bukenya

In 2008, a looming crisis was reported in Western Kenya and parts of eastern Uganda. This crisis was about the prevalence of striga weed, which was increasingly threatening the production of cereals, particularly maize. Since then, striga has continued to spread to new areas with devastating effects on crop yields and serious consequences for household food and income security.

Reports show that striga is infesting between 20 million to 40 million hectares of farm land in sub-Saharan Africa. It leads to drastic decline in the yield of crops like maize, millet, sorghum and rice. Believed to be a parasitic plant, striga competes for water and nutrients from the roots of the crop thereby reducing its growth. For example, the weed reduces the yield of maize by more than a half and leads to complete crop failure in severe cases.

In Uganda, striga infestation has been reported in the eastern districts of Busia, Budaka, Tororo, Namutamba and Iganga.

Because it has very small seeds and attractive flowers, striga can easily be spread by farm tools and equipment, wind, water plus animals and human beings.

There is ongoing research aimed at addressing the striga problem, both in Uganda and elsewhere. The research has focused on augmenting the conventional agronomic field management practices, such as crop rotation with the application of nitrogen fertilisers and herbicides in addition to the use of crop varieties that are resistant to the weed.

Unfortunately, these efforts have not yet yielded effective and practical solutions for controlling striga. As a recent visit to Bulamagi sub-county in Iganga district revealed, both traditional methods of weed management and individual farmer innovation do not seem to offer much success.

The striga weed problem has also not received much attention from government agencies like NAADS and the district production departments. I believe that the striga weed problem calls for urgent strategic intervention and concerted efforts involving sensitisation and mobilisation of communities in the same way the water hyacinth problem was addressed.

The writer is a lecturer at Makerere University

New Vision

Fears of pesticide-resistant weeds as GM crops escape into the wild

by Jessica Marshall

Genetically modified canola plants have been found growing wild in the U.S., in some cases far from fields of cultivated genetically modified canola.

Results reported today at a meeting of the Ecological Society of America in Pittsburgh, Penn., suggest that the plants are reproducing on their own, making this the first report of an established population of GM organisms in the wild in the U.S., according to the team.

Meredith Schafer of the University of Arkansas in Fayetteville had been scouring North Dakota without success for weedy relatives of the canola plant, to test whether they had acquired GM traits through cross-pollination with the GM canola plants widely cultivated throughout the state.

"We were in a local grocery store and saw some yellow flowers growing by the side of the road and we thought, 'There's some of the weeds we were looking for.' Lo and behold, it was canola," she said.

The team used test strips that work much like a pregnancy test to determine within 5 minutes whether a plant is carrying one of the two most commonly introduced genes in genetically modified canola.

The genes each produce a protein that lends resistance to two different common herbicides. One gives resistance to Roundup, or glyphosate, and the other gives resistance to Liberty, or glufosinate. These GM traits allow farmers to spray their fields with these herbicides, eliminating other weeds while allowing the herbicide-resistant crop to grow.

"We had genetically modified canola (by the road near) the grocery store and in a large density," Schafer said.

The finding encouraged the team to look further for escaped canola, instead of its weed relative. "We set out across the state in a car. We tested every five miles and where we found canola we did the test," Schafer said. They expanded their search the following season.

The team found canola at 46 percent of the more than 600 stops they made, and 80 percent of the canola plants tested were the genetically modified variety.

The researchers could not test for a third type of genetically modified canola, which represents about 10 percent of the canola planted in North Dakota, so there may be more GM canola present than they detected.

They found high densities of GM canola on major roads, which may result in part from GM seeds being spilled in transit. "We also found a lot in the middle of nowhere, not close to cultivated fields at all," said Cynthia Sagers, Schafer's advisor at the University of Arkansas.

The team's key finding was two plants that each carried both types of herbicide resistance -- a combination that is not commercially available. "The only way this can happen in the wild is if these are perpetuating in the wild, if they're reproducing out there," Sagers said.

There is some chance they did not detect reproducing plants, said Ignacio Chapela of the University of California, Berkeley. The combination could also have been found if a seed carrying both GM traits that was made for research had been released with the commercial product, he said. "We've seen so many cases where the stock gets contaminated with seeds. Research seeds get put into the seeds that are being marketed," he said.

That said, the findings are not surprising, he added. "This is something that was predicted that then has been observed by farmers for many years, especially in Canada where canola is planted so widely."

"We know that they are getting out there," Chapela continued, speaking of the GM plants. "Before it was a rhetorical question, now it is a reality."

The reality that plants can escape cultivation should become part of the discussion about how GM plants are used, Chapela and Sagers agreed.

"I don´t think the findings are necessarily a human health risk," Sagers told Discovery News. But they could be a problem for farmers. "I think the herbicide resistance is going to be a very serious problem for agronomists and farmers in the near future," she said. "I think it could be an environmental problem if we find we've created these herbicide-resistant weeds."

Other GM traits could raise different concerns, including human health risks, she added. "There have been 1100 plants approved for field trials and who knows what those are -- pharmaceutical proteins, drought-resistant crops? Herbicide-resistances are very simple traits. Products in development are more complicated."

Discovery

Striga-resistant varieties to boost sorghum yields

by Steven Tendo

In April, scientists in eastern and central Africa embarked on identifying sources of resistance to Striga, a parasitic weed. Supported by the Association for Strengthening Agricultural Research in Eastern and Central Africa (Asareca), the researchers from Sudan, Kenya, Eritrea and the International Crop Research Institute (ICRISAT) are using biotechnological tools in locating and identifying Quantitative Trait Loci (QTL) that gives resistance to Striga.

QTL is a statistical method that links two types of information phenotypic data (trait measurements) and genotypic data (usually molecular markers)—in an attempt to explain the genetic basis of variation in complex traits.

According to Dr Charles Mugoya, the programme manager of the Agro biodiversity and biotechnology programme of Asareca, knowing the location and identification of QTLs for Striga resistance is a useful tool in aiding marker assisted breeding/selection (MAB or MAS) of Sorghum for Striga resistance.

MAS is an indirect selection process where a trait of interest is chosen not based on the trait itself but on a marker (morphological, biochemical or one based on DNA/RNA variation) linked to it. So far, QTLs underlying different resistance phenotypes have been identified and the scientists are now backcrossing populations to generate striga resistance QTLs into farmer preferred sorghum varieties.

Mugoya said Striga hermonthica, also locally known as the witchweed, is a major constraint to sorghum production in particular and cereal production in general, especially in more marginal areas like semi-arid regions, where continuous cropping as a result of population pressure, has led to widespread soil infertility.

The weed is genetically diverse and several factors contribute to its diversity. These include a high turnover of several generations of witch weed populations leading to high genetic diversity; hybridisation; broad geographic distributions; long distance dispersal and locally adapted host races.

“Owing to its great potential genetic diversity, efforts to control it, through conventional breeding to generate striga resistant varieties or agronomic practices to reduce the striga seed bank in the soil, have been ineffective and striga continues to be a menace, with reported cases of up to 100 per cent sorghum yield loss in the region,” he noted.

Sorghum is ranked second, after maize as the most important cereal crop in East Africa and in the Asareca region. According to statistics from the Food and Agricultural Organisation (FAO), sorghum is the fifth most important cereal crop worldwide and together with maize and pearl millet, it forms the most important dry land cereal crop for the semi-arid tropics particularly in Africa.

It is grown in at least 86 countries, on an area of 47 million hectares, with annual grain production of 69 million tonnes and average productivity of 1.45 tonnes per hectare. Sorghum yields in Africa however range between 500-800 kg per hectare compared with yield levels of up to 7,000kg (7 tonnes) per hectare in the developed world.

The bulk of African sorghum production is centred around the savannah areas of east, west and central Africa, where it forms a major component of the daily menu for millions of people, either as porridge or as traditional beer. Uganda is using sorghum for the beer industry. In addition, in many developing countries, sorghum stover is used to feed cattle.

Striga infested areas in Africa is estimated at 21 million ha. In many parts of East Africa, people lose half of their crop production to Striga and total yield losses occurs in infested farmer’s fields especially during drought periods. The change in farming systems from shifting cultivation to more permanent cropping, concomitant with loss in soil fertility, and frequent cultivation of susceptible host plants, are main factors responsible for increased Striga infestation.

The project promises to increase sorghum productivity in order to address food insecurity and poverty in East and Central African semi-arid zones and boost yields by at least by 20 per cent.

Widespread cultivation of striga resistant varieties is expected to reduce labour demand, since weeding to control striga seeds will not be necessary. In addition, control of striga by the application of herbicides will become unnecessary, thus saving the environment.

Daily Monitor

Farmers cope with Roundup-resistant weeds

by William Neuman and Andrew Pollack

For 15 years, Eddie Anderson, a farmer in Tennessee? USA, has been a strict adherent of no-till agriculture, an environmentally friendly technique that all but eliminates plowing to curb erosion and the harmful run-off of fertilizers and pesticides.

But not this year.

On a recent afternoon, 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 super-germs, American farmers’ near-ubiquitous use of the weedkiller Roundup has led to the rapid growth of tenacious new super-weeds.

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 super-weeds 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.

Roundup — originally made by Monsanto but now also sold by others under the generic name glyphosate — has been little short of a miracle chemical for farmers. It kills a broad spectrum of weeds, is easy and safe to work with, and breaks down quickly, reducing its environmental impact.

Sales took off in the late 1990s, after Monsanto created its brand of Roundup Ready crops that were genetically modified to tolerate the chemical, allowing farmers to spray their fields to kill the weeds while leaving the crop unharmed. Today, Roundup Ready crops account for about 90 percent of the soybeans and 70 percent of the corn and cotton grown in the United States.

But farmers sprayed so much Roundup that weeds quickly evolved to survive it. “What we’re talking about here is Darwinian evolution in fast-forward,” Mike Owen, a weed scientist at Iowa State University, said.

Now, Roundup-resistant weeds like horseweed and giant ragweed are forcing farmers to go back to more expensive techniques that they had long ago abandoned.

Mr. Anderson, the farmer, is wrestling with a particularly tenacious species of glyphosate-resistant pest called Palmer amaranth, or pigweed, whose resistant form began seriously infesting farms in western Tennessee only last year.

Pigweed can grow three inches a day and reach seven feet or more, choking out crops; it is so sturdy that it can damage harvesting equipment. In an attempt to kill the pest before it becomes that big, Mr. Anderson and his neighbors are plowing their fields and mixing herbicides into the soil.

That threatens to reverse one of the agricultural advances bolstered by the Roundup revolution: minimum-till farming. By combining Roundup and Roundup Ready crops, farmers did not have to plow under the weeds to control them. That reduced erosion, the runoff of chemicals into waterways and the use of fuel for tractors.

If frequent plowing becomes necessary again, “that is certainly a major concern for our environment,” Ken Smith, a weed scientist at the University of Arkansas, said. In addition, some critics of genetically engineered crops say that the use of extra herbicides, including some old ones that are less environmentally tolerable than Roundup, belies the claims made by the biotechnology industry that its crops would be better for the environment.

“The biotech industry is taking us into a more pesticide-dependent agriculture when they’ve always promised, and we need to be going in, the opposite direction,” said Bill Freese, a science policy analyst for the Center for Food Safety in Washington.

So far, weed scientists estimate that the total amount of United States farmland afflicted by Roundup-resistant weeds is relatively small — seven million to 10 million acres, according to Ian Heap, director of the International Survey of Herbicide Resistant Weeds, which is financed by the agricultural chemical industry. There are roughly 170 million acres planted with corn, soybeans and cotton, the crops most affected.

Roundup-resistant weeds are also found in several other countries, including Australia, China and Brazil, according to the survey.

Monsanto, which once argued that resistance would not become a major problem, now cautions against exaggerating its impact. “It’s a serious issue, but it’s manageable,” said Rick Cole, who manages weed resistance issues in the United States for the company.

Of course, Monsanto stands to lose a lot of business if farmers use less Roundup and Roundup Ready seeds.

“You’re having to add another product with the Roundup to kill your weeds,” said Steve Doster, a corn and soybean farmer in Barnum, Iowa. “So then why are we buying the Roundup Ready product?”

Monsanto argues that Roundup still controls hundreds of weeds. But the company is concerned enough about the problem that it is taking the extraordinary step of subsidizing cotton farmers’ purchases of competing herbicides to supplement Roundup.

Monsanto and other agricultural biotech companies are also developing genetically engineered crops resistant to other herbicides.

Bayer is already selling cotton and soybeans resistant to glufosinate, another weedkiller. Monsanto’s newest corn is tolerant of both glyphosate and glufosinate, and the company is developing crops resistant to dicamba, an older pesticide. Syngenta is developing soybeans tolerant of its Callisto product. And Dow Chemical is developing corn and soybeans resistant to 2,4-D, a component of Agent Orange, the defoliant used in the Vietnam War.

Still, scientists and farmers say that glyphosate is a once-in-a-century discovery, and steps need to be taken to preserve its effectiveness.

Glyphosate “is as important for reliable global food production as penicillin is for battling disease,” Stephen B. Powles, an Australian weed expert, wrote in a commentary in January in The Proceedings of the National Academy of Sciences.

The National Research Council, which advises the federal government on scientific matters, sounded its own warning recently, saying that the emergence of resistant weeds jeopardized the substantial benefits that genetically engineered crops were providing to farmers and the environment.

Weed scientists are urging farmers to alternate glyphosate with other herbicides. But the price of glyphosate has been falling as competition increases from generic versions, encouraging farmers to keep relying on it.

Something needs to be done, said Louie Perry Jr., a cotton grower whose great-great-grandfather started his farm in Moultrie, Ga., in 1830.

Georgia has been one of the states hit hardest by Roundup-resistant pigweed, and Mr. Perry said the pest could pose as big a threat to cotton farming in the South as the beetle that devastated the industry in the early 20th century.

“If we don’t whip this thing, it’s going to be like the boll weevil did to cotton,” said Mr. Perry, who is also chairman of the Georgia Cotton Commission. “It will take it away.”

New York Times

Developing weed resistance in maize hybrids

Millions of people in the savannas of west and central Africa rely on maize (corn) as a staple crop, and as an “insurance” food crop at the beginning of the rainy season. A destructive parasitic weed, Striga hermonthica, poses a threat to this valuable crop. Almost 64% of cropland in this area of Africa is affected by the parasite, which causes an average grain yield loss of 68%.

Farmers in Striga-infested areas have not yet adopted Striga-resistant hybrids.
Scientists at the International Institute of Tropical Agriculture (IITA) in partnership with scientists in the University of Ibadan in Nigeria and the National Institute of Agricultural Research in Benin Republic investigated the relationship between the genetic diversity of maize inbred lines having different levels of resistance to Striga and the performance of their hybrids under parasite infestation. The results are reported in the March-April 2010 edition of Crop Science, published by the Crop Science Society of America.

The study experimented on all combinations of ten lines of maize with varying levels of resistance to the parasitic weeds in different locations in Africa over three years. Hybrids from two resistant parental lines exhibited the highest level of field resistance, while hybrids from parents with low resistance fared the worst. Hybrids with only one parent with high Striga resistance showed moderate levels of field resistance.

Another important finding was that the genetic diversity of the parental lines did not affect grain yield or other traits among the hybrids. The researchers expect that genetically diverse, Striga-resistant maize crops will provide opportunities to further increase the levels of field resistance to S. hermonthica through breeding.

Such Striga resistant maize hybrids may encourage farmers that abandoned farms due to severe Striga infestation to go back into maize production. This would contribute to food security and provide income-generating opportunities to farmers that depend on maize as an important food crop in Striga infested areas.

www.crops.org

Scientists identify gene for resistance to Striga

The parasitic flowering plant Striga, or "witchweed," attacks the roots of host plants, draining needed water and nutrients and leaving them unable to grow and produce any grains. Witchweed is endemic throughout sub-Saharan Africa, causing crop losses that surpass hundreds of millions of dollars annually and exacerbating food shortages in the region.

Among the crops heavily parasitized by witchweed is black-eyed pea, known in Africa as "cowpea" or "niebe" in Francophone countries.

About 80 percent of the world's cowpea crop is grown in sub-Saharan Africa, mostly by subsistence farmers who lack the resources to purchase expensive herbicides and fertilizers. In this region, cowpea is the primary protein source for millions of people, who consume the entire plant – the pea for soups, stews and breads, the leaves as fresh greens, the stems as hay and fodder for cattle.

As the use of cowpea expanded over time, so did the prevalence of Striga gesnerioides, the type of witchweed adapted to parasitize it. Today, witchweed is so virulent that farmers in this semi-arid region must relocate their cowpea crop to new soil every few years.

Now, scientists at the University of Virginia have identified a gene in cowpea that confers resistance to witchweed attack. This discovery will help researchers better understand how some plants can resist Striga, while others, such as corn and sorghum, are susceptible.

The findings are presented in the Aug. 28 issue of the journal Science.

"Discovery of this resistance gene is not only important for improving cowpea, but may help us develop strategies for improving resistance to Striga in other affected crops," said Michael P.Timko, the U.Va. biology professor who led the study.

Currently there are no natural sources of Striga resistance in corn or sorghum, both of which are major cereal grains in the African diet.

"Making plants durably resistant to Striga could have a significant impact on food security for Africa," Timko said.

In recent years, he and other scientists have sequenced the cowpea genome and are using this information to develop cowpea plants with multiple improved agronomic traits.

"It is now possible for us to identify all possible genes for Striga resistance in cowpeas, as well as resistance to other cowpea pathogens," Timko said. "We may even eventually breed a more drought-resistant plant and varieties that have higher levels and a better balance of nutrients. We've reached a point where we can manipulate this plant for the good of millions of people."

Timko's approach is to improve the performance of plants by identifying genes that control key characteristics, and then using selective breeding to emphasize those traits.

While he is finding success breeding parasite-resistant hybrids, there are at least seven different races of Striga, each capable of adapting to changing varieties of cowpeas.

"We are trying to create a plant that is resistant across the board," he said. "Striga is hyper-virulent. This is warfare between the cowpea plant and its parasite, and we keep trying to stay ahead of the enemy."

Science Daily

Will 'energy crops' become the new invasive species?

by Jessica Leber

U.S. policies are subsidizing new energy crops that are likely to spread off the farm and wreak economic and ecological havoc, a federal advisory board cautioned yesterday.

For years, researchers have worked to develop "advanced" biofuel feeds from unconventional crops such as grasses and algae.

The goal is to enable a switch away from corn- and soy-based biofuel to cellulosic energy crops that don't compete on the food or feed market and have a smaller carbon footprint. A 2007 energy law, in fact, requires a total of 160 billion gallons of the plant-based cellulosic fuels by 2022 that these crops would produce.

As a result, researchers are now selecting, breeding and engineering species that demand less water, fertilizer and agricultural land and grow year-round at high yields.

But it is often exactly these traits, such as drought tolerance or pathogen resistance, that make the fuels of the future ripe to become invasive species and cause widespread damage. The issue highlights another potential complication in what has been a bumpy road in the development of the biofuels industry.

"Absent strategic mitigation efforts, there is substantial risk that some biofuel crops will escape cultivation and cause socio-economic and/or ecological harm," the white paper, adopted by the Invasive Species Advisory Committee, warns.

The group of outside experts advises a federal council tasked with coordinating invasive species policies among 13 departments and agencies. It called on the U.S. government to take major steps to combat the substantial risks from biofuels as it promotes and funds biofuels development.

Invasive species are already costly

Every year, invasive plants cost the United States a minimum of $34 billion in losses and control costs, according to one study the group's paper cites. The potential scale of biofuel cultivation, at more than 150 million acres, provides ample opportunity to add to those costs, the committee says.

Some proposed biofuel crops already are invasive species.

One of the most alarming examples is giant reed, or Arundo donax, according to Joseph DiTomaso, the University of California, Davis, weed specialist who drafted the paper.

The grass grows in dense clumps up to 20 feet tall and is classified a noxious weed in California and in Texas, as well as other areas of the South. But in Florida, researchers are looking to plant even more of it as a biofuel crop, he said.

Proposed energy crops like miscanthus and reed canary grass also are already invasive species in some areas of the world, he said. And jatropha and algae, crops that could one day supplant jet fuels used in aviation, also pose high invasion risk, according to the Global Invasive Species Programme.

Other heavily publicized biofuel crops, such as switchgrass, look to be safer bets in the United States, DiTomaso said.

The laws of unintended consequences are well-known to anyone familiar with the history of invasive species.

A field plowed with good intentions

One of the 10 worst weeds in the world, known as Johnson grass, was originally brought from the Mediterranean to the United States in 1830 as forage material for livestock. Today it's invasive in 23 states, according to the U.S. Department of Agriculture, and spreads aggressively in the South.

And kudzu -- the colorful "mile a minute" vine that has engulfed the southern United States -- was first imported from Japan to ornament gardens in the late 19th century.

The committee has made nine recommendations to avoid a more modern disaster.

It calls, for example, for long-term flexible funding for an early detection and rapid response system to monitor and respond to potential biofuel crop invasions.

But it also says that agencies need to craft proactive policies that minimize these risks in advance. It recommends evaluating each candidate biofuel crop in the region where it is proposed for cultivation and encouraging the use of low-risk species or cultivars.

Examples might be plants that are sterile or can't survive outside of the cultivated environment. Planting, harvesting, field abandonment, transport and storage practices should also be tailored to combat the threat, they said.

Selecting the right region is important, too. The committee recommended that federally supported research and demonstration projects select sites that minimize escape potential.

The issue goes beyond U.S. borders. The International Union for Conservation of Nature is also drafting guidelines on biofuels and invasive species. In Africa, it says, many governments are rushing to encourage biofuels development. But there, especially in countries lacking the resources to manage the risk of invasion, the threat has received scant attention, the group says.

New York Times

Weeds are farmers' natural enemy number one, says FAO expert

Weeds should be regarded as a top natural killer for farmers around the world, especially in Africa, according to an expert from the Food and Agriculture Organization (FAO) of the United Nations.

More than 1 billion people nowadays in the world are hungry, the result of flawed policies, wars, natural hazards like floods, droughts, pests, diseases and climate change. But one huge hunger-maker lurks largely unnoticed, FAO's weed expert Ricardo Labrada-Romero said in the report.

"Maybe it's because weeds are not very spectacular," he said. "Droughts, insects and diseases like swine flu are attention-grabbers because their effects are dramatic. Weeds are different. They play havoc out quietly all year round, year after year."

Considering the damage caused by one weed alone, Broomrape (Orobanche spp), an aggressive root weed which attacks legumes and vegetables, it can not only lead to complete crop failure but also make fields infertile for many years, the expert pointed out. Figures clearly show that weeds should be regarded as farmers' natural enemy No. 1, Labrada-Romero said.

According to a leading environmental research organization, Land Care of New Zealand, they cause some 95 billion U.S. dollars a year in lost food production at global level, compared with 85 billion dollars for pathogens, 46 billion dollars for insects and 2.4 billion dollars for vertebrates, he said.

Economic losses may be even greater considering that more than half of the time farmers spend in the fields goes to weed control, Labrada-Romero said. If farms are to increase their productivity one of the first things they must do is to improve weed management, he added. Nowhere is this more important than in Africa, where weeds are a major cause of stagnating yields and production, Labrada-Romero stressed.

"With only manual labor available, African smallholders need to weed every day and that means a family physically can't handle more than 1-1.5 hectares," he said. "But proper management would allow them to farm more land and grow more food."

Modern integrated weed management involves much more than spraying herbicides. Crop rotation is one effective technique because weeds are often biologically adapted to a given food crop so that changing the crop can reduce weeds too.

Also important, said Labrada-Romero, is the use of certified, quality seeds. Many of the seeds produced and used by farmers are contaminated by weed seeds. If smallholders produce their own seeds, they should be taught to clean them so as to avoid planting weeds in their fields at sowing time.

After two decades fighting weeds, Labrada-Romero, a 62-year-old Cuban, recently went into well-deserved retirement, according to FAO. "But the fight against weeds must go on," the FAO expert said, "otherwise more people will starve."

Xinhua

ICRISAT makes gains against Striga with new genetic technique

Agricultural researchers have successfully identified and transferred genes that confer resistance to Africa’s most deadly weed (Striga) using the novel marker assisted selection technique successfully for the first time in the history of crop breeding in Africa.

Researchers have managed to confer resistance to Striga in sorghum, overcoming a barrier that has for decades held back scientists’efforts to protect key food crops - sorghum, millet, maize and rice, from this destructive weed. These crops are primary food sources for 300 million people across sub-Saharan Africa.

Striga (Striga hermonthica), also known as witchweed, destroys between 40 to 100 percent of a complete season’s crop, its annual crop damage across Africa estimated at seven billion dollars (US$7 billion). Currently, the weed threatens to wipe out cereal crops in most of Western Kenya and Eastern Uganda, national agricultural research institutes in the two countries have warned.

“Scientists have searched for the solution to Striga damage using a variety of methods, but without much success,” says Dr Dionysious Kiambi, a molecular geneticist with the International Crops Research Institute for Semi-Arid Tropics (ICRISAT). “Through marker assisted selection, we have determined the precise segments of the sorghum genome known to confer Striga-resistance and have transferred them to farmer-preferred varieties through conventional breeding with very promising results.”

Marker assisted selection is a new technique which entails use of genetic landmarks (markers) to tag and transfer specific genes or group of genes that control characteristics of interest such as improved crop productivity, resistance to diseases or pests, or tolerance to stresses like floods and drought. This is the first time the technology has been used successfully for crop improvement in Africa.



ICRISAT scientists has been working with national and international collaborators for several years experimenting with marker assisted selection in search for Striga resistance genes from other sorghum varieties conserved in gene-banks across the world. They found one sorghum variety (N13), that is neither high-yielding nor drought-tolerant, to possess the highly sought after Striga-resistance genes.

Segments of the N13 sorghum DNA containing genes for Striga-resistance were tagged with markers and crossed with farmer varieties using conventional breeding. The use of markers enabled scientists to precisely transfer only the Striga- resistance genes to farmer-preferred sorghum varieties without jeopardising farmer-desired characteristics such as drought-tolerance and higher yields.

“We had to make sure that other genetic information from N13 was not transferred to farmer varieties alongside the qualitative trait loci with Striga-resistance. We were not replacing any genetic components of farmer varieties, we are just adding to it,” says Dr Kiambi. “The resulting variety is almost identical to the original farmer variety plus the component that confers Striga resistance.”

ICRISAT has been collaborating with scientists from the University of Hohenheim in Germany and national agricultural research institutes of Eritrea, Kenya, Mali and Sudan. The team has to date created five Striga-resistant sorghum varieties whose initial trials on-station have been able to ward off Striga attacks, some as effectively as the donor parent, sorghum N13. In Kenya, Mali and Sudan, scientists are currently testing the new witchweed-resistant varieties in farmer fields.

Researchers in Africa have for decades experimented with a number of “potentially successful” techniques for managing this deathly weed including breeding for Striga tolerance in various crops, promotion of rotational cropping of cereals with legumes such as groundnuts, cowpeas and soybean in order to break the weed’s breeding circle, as well as the use of biological and herbicidal control methods.

Africa’s resource-poor farmers manage Striga primarily by weeding, a pointless, back-breaking activity which comes too late. By the time the crop sprouts, the weed, whose seeds reside in the soil, has long-since attached to plant roots and begun sapping off plant nutrients in earnest. Striga is a prolific seed producer, whose seeds lie dormant in the soil for up to two decades.

Crop breeders are enthusiastic about marker assisted breeding because it significantly reduces the duration required to produce improved crop. While conventional breeding is a hit-or-miss technique that requires scientists to wait for the crops to grow to maturity in order to observe expression of desired traits like Striga-resistance, marker assisted breeding enables scientists to check for the transfer of the trait as early as when the plant is only two weeks old, and focus on plants with the desired trait. This has more than halved the amount of time crop breeders need to develop improved varieties.

If the on-station results are successfully replicated on-farm, Africa’s biggest cereal crop menace – Striga - may well be reigned in, boosting agricultural production, food security and farmer incomes across the continent.

www.icrisat.org

Striga weed attacks cereal crops in western Kenya, eastern Uganda

Many small-scale cereal farmers in Busia,Uganda may lose all their crops after the Striga weed attacked their gardens. Striga weed, which is a parasite on cereals such as maize, millet, rice and sorghum, has pink flowers.

It is very difficult to get rid of the weeds because their roots grow into the maize roots and sap out all the plants' nutrients. The weeds can lead to loss of the entire crop in the fields.

Food and Agriculture Organisation officials recently established that the most hit area is Lumino sub-county where all the maize and rice gardens have been attacked.

The head of the cereals programme at National Crop Resources Research Institute, Dr. Godfrey Asea, said they were training farmers on using desmodium, a new weed that is inter-cropped with maize to keep off stem borers, which are believed to be the lead cause of the striga.

Desmodium has a pungent smell which repels the borers away from the maize. Asea advised farmers to plant elephant grass near the maize rows so that when the desmodium plant emits its offensive smell, the maize borer is pushed away from the maize plant to the elephant grass.

"When the borers get to the elephant grass, they die because of lack of enough food. When they lay eggs in the grass, the eggs do not hatch," said Asea.

Desmodium also prevents striga from growing in between the maize plants in addition to adding fertility to the soil because it is a leguminous plant.

Asea advises farmers to trim the weed to reduce competition for light.

He said they were trying out a new variety of maize that is believed to be resistant to the weed. They started the trials in the most infested districts of Busia, Budaka, Tororo and Namutumba in Eastern Uganda.

New Vision

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A crop production crisis is looming large in parts of Western Kenya following rapid spread of the deadly striga weed.

A Kenya Agricultural Research Institute (Kari) report says the weed threatens crops in at least eight districts. The report further says high population growth in some of these districts has interfered with crop rotation, which in turn has promoted the spread of the weed.

In Sub- Saharan Africa, it infests approximately twenty to 40 million hectares of farmland cultivated by peasant farmers causing huge yield losses.

Some of the districts affected include: Kisii, Nyamira, Gucha, Kuria, Bomet, Trans Mara, Suba and Homa Bay.

“Though the South Nyanza districts are worst hit by the striga weeds for decades now, the weed is now spreading to areas previously not infested and increasing in severity,” the Kari report says in part.

Continuous growing of maize, sorghum and minimal effort to control striga has increased the weed’s seed population in the soil.

“This has led to reduced crop yield or total crop failure and is some striga infested areas farmers have abandoned cereal production altogether,” the report by centre director and Dr Florence Makini and M Makelo says.

In the affected districts, the reports points out contributing factors may be inherent in the low soil fertility and decrease in use of fallow due to increase in population growth.

In some cereal producing divisions, the report estimates losses ranging from to 70 per cent to total crop failure, depending on the severity of the infestation.

The witch weed infestation and subsequent cereal losses threaten to worsen due to the fact that some of the herbicides used or other control methods have not been effectively integrated.

Some of the herbicides that have been tested before in infested areas like oxyflourfen, pendimethalin and Atrazine have little effect once not integrated with other control methods.

In one pilot project in Kisii, for example, the use of nitrogenous fertilizer proved that nitrogen could stifle the witch weed while increasing maize yields.

The Standard

Invasive weed grass reduces farmland in northern Nigeria

A species of cattail grass known locally as 'kachalla' is taking over river banks and farmlands around the Hadejia-Komadugu-Yobe wetlands in northern Nigeria’s Jigawa state, disrupting farming and fishing activities on which inhabitants rely.

“Fishermen cannot fish in the river because it has been taken over by the grass,” Jigawa state environment commissioner Yusuf Mato said.

“Kachalla has crippled economic activities, destroying not just fishing but farming as wel,l” he said. “They are the only two sources of wealth and employment in the area.”

Typha australis has an entangled roots system that spreads rapidly, blocking river canals and taking over farmland. The areas worst affected are in the eastern part of this rural, agrarian state, including the districts of Birniwa, Guri, Kirikasamma, Auyo and Hadejia.

“It is quite a disaster,” Jigawa State governor Sule Lamido said.

The grass only began to be noticed in the state after the construction of dams and barrages in 1972, according to agricultural researcher Umar Hassan Birniwa.

“Its spread has been rapid,” he said. In the last 20 years the land area infested has doubled to almost 10 percent of Jigawa State’s total landmass of 22,410 sq km. And typha is currently spreading annually at a rate of 10 percent, he added.

The problem for farmers is that when they try to pull the weed out of the ground, the top comes off but the root survives and the grass spreads further, the experts say.

“Farmers just dump the weeds they remove on the edge of their farms… which enhances the growth cycle,” Fouad Abba Jibrin a botanist at Bayero University Kano, told IRIN. “Typha grass has a high “water retention capacity” [and] can survive even when burnt.”

The Hadejia River is particularly rich in fish that sell in Kano, the commercial capital in the north, as well as in Nigeria’s capital Abuja, but the grass makes fish much harder to catch, Muazu Salmanu, a 56 years old fisherman who has been fishing along the Hadejia for 32 years.

“I used to catch at least 30 kilos of fish but now I hardly make a catch worth six kilos,” he said. “This has made life difficult for me and my wife and seven children - I don’t have any other way of making a living.”

The grass blocks some waterways so completely that during the rainy season it causes flooding of surrounding villages and crop fields. This then allows the grass to spread inland.

Farmers say that nowadays they need twice the amount of land they did 20 years ago to cultivate the same amount of produce. “Some 15 years ago the yield from three hectares was enough to feed me and my family for the whole year but now I need six hectares to get the same yield because a substantial part of the land has been taken over by Kachalla,” said Wakili Haladu, a local farmer in Hadejia who grows rice, sorghum, cowpea and sesame.

The grass also provides a breeding ground for birds, especially the miniature red-beaked quelea which invades farmlands and has destroyed many fields of crops before they could be harvested, Mato said.

Farmers and their children spend the best part of the growing season shooing the birds with drums and bonfires, often disrupting the children’s education.

“When my father’s crops begin to mature I had to stop my studies to help him guard against the quelea birds,” 14 years old Salele Nuhu, from a secondary school student in Hadejia, told IRIN.

According to Mato, the state environment commissioner, Jigawa State conducted a feasibility study which found that controlling the weed would cost US$6 million, money it is now seeking to borrow from the Islamic Development Bank (IDB).

But Jibrin, the botanist at Bayero University, said $6 million may not be enough to tackle the problem. “Just the research and analysis needed to [determine] the best control strategy… will take at least four months,” he said.

He also said the state government needs to look at the problem in relation to other environmental factors. “The easiest way to contain it is with chemical applications but this has the disadvantage of killing fauna.”

Another possible method is biological, involving the introduction of a plant parasite to compete with the grass. He said this could be combined with a programme to cut the buds off typha grass to inhibit cross pollination of seeds.

But he added that even if Jigawa state succeeded in getting rid of the grass, the weed would likely regenerate because the government does not control water pollution. “The presence of heavy metals in water provides fertile ground for the growth of typha grass,” he said.

IRIN

Livestock farmers warned against Lantana shrub

Livestock farmers in Uganda's Kaberamaido and Soroti districts have been cautioned against Lantana camara, a shrub that grows wild in the region and is believed to be a breeding place for tsetse flies.

The head of the vector control programme at the ministry of health, Dr. Abbas Kakembo, warned that unless farmers destroyed the shrub by cutting down or burning it, their agricultural production efforts were at stake. This is because the deadly vector which transmits germs that cause nagana in livestock and sleeping sickness in humans hides in the shrub.

The shrub grows best during the rainy season and this is the same time when the tsetse flies are rampant. It has for a long time been considered an ornamental shrub used by rural peasants as a toothbrush, until recently when the scarcity of trees in Kumi and Tororo hit hard, causing people to resort to using it as a major source of firewood for preparing light foodstuffs.

New Vision