Posts Tagged ‘CIMMYT’





By Maurice Alal
Johnstone Onyango was used to buying maize from Uganda due to the low production in his three-acre piece of land.

The 35-year-old maize farmer in Lwanya location, Matayos sub county, Busia county, says he could only get 20 tins of maize after toiling hard only for his crops to be infested by the striga weed.

Onyango, a member of Imbako group, says the situation has however changed, thanks to the StrigaAway maize control technology.

“I never knew that my production would improve tremendously until I adopted Imazapyr Resistan (IR) maize seeds. I now harvest more than 18 bags of maize. I am now food secure since I don’t have to buy maize to feed my family anymore,” he said, adding that so far more than 300 farmers have embraced IR maize seed in the area.

The Africa Agricultural Technology Foundation (AATF) has introduced the StrigaAway IR maize technology to help farmers manage the striga weed, which attacks cereal crops, retarding plant growth, resulting in stunted and withered plants.

This comes at a time when scientists have warned of an imminent spread of the weed to other parts of the country where it never used to thrive due to climatic changes.

The researchers at AATF have warned that the weed, which has been causing havoc in Nyanza and Western regions, is likely to spread to other parts of the country like Rift Valley due to increasing temperatures.

According to AATF, striga weed constrains the productivity of staples such as maize, sorghum, millet and upland rice in Sub-Saharan Africa, affecting livelihoods of more than 100 million people.

Grace Wachoro, AATF communications officer, said the weed thrives on water and nutrients siphoned from the crops for its own growth. “It causes serious damage to its host crop before emerging from the soil by producing phytotoxins which are harmful the host crop. Striga infests as much as 40 million hectares of smallholder farms, causing yield losses ranging from 20 to 80 per cent and total crop failure in severe infestation,” Wachoro said.

She said they are partnering with four seeds companies in East Africa to commercially avail the technology to farmers to fight the striga and boost maize production.

Wachoro explained that the Imazapyr acts before or at the time of striga attachment to the maize root and prevents the phytotoxic effects of the weed on the maize plant, thus enabling the plant to grow to its full potential.

“Imazapyr that is not absorbed by the maize seedlings diffuses into the surrounding soil and kills ungerminated striga seeds in its vicinity. The low-dose herbicide seed dressing used in the StrigaAway technology controls the weed without impacting sensitive intercrops when planted at least 10cm away from maize hills. This allows smallholder farmers who practice intercropping to incorporate this technology in their farming systems,” she adds.

Through the Integrated Striga Management in Africa project, AAFT encourages farmers to incorporate soil fertility practices such as use of legume rotation and intercrops and fertiliser additions to replenish soil nutrients and optimise crop yields.

Since its inception three years ago, IR maize technology has enabled farmers increase harvests from a paltry average of 500kg per hectare to over 1,500kg.

The project is being implemented in partnership with the International Maize and Wheat Improvement Centre and the International Center for Insect Physiology and Ecology in Kisumu Siaya, Bondo, Rachuonyo, Homa Bay, Busia and Vihiga.

Striga at a glance

Striga, which is also known as Violet Vampire because of its beautiful violet flowers, is a parasitic weed and a big constrain to agriculture in Sub- Saharan Africa.

The weed produces hundreds of thousands of seeds per plant leading to a massive build-up in the soil that can remain viable for more than 20 years.

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Photo: Jaspreet Kindra/IRINWheat under threat

JOHANNESBURG, 2 April 2014 (IRIN) – Outbreaks of a deadly fungal disease in wheat crops in Germany and Ethiopia in 2013 have had the scientific community buzzing over the threat posed to global food security.

Wheat stem rust, also known as wheat black rust, is often referred to as the “polio of agriculture”: The rapidly mutating fungal disease can travel thousands of kilometres and wipe out crops.

Wheat farmers and scientists at a recent summit hosted by the Mexico-based International Maize and Wheat Improvement Center (CIMMYT ) have been examining outbreaks of different strains of wheat stem rust in the two countries to identify any similarities.

In Germany “the occurrence of stem rust was favoured by a period of unusually high temperatures… and an unusually late development of the wheat crop due to cold spring and early summer temperatures,” explained Kerstin Flath, senior scientist at Germany’s Federal Research Centre for Cultivated Plants at the Julius Kuehn-Institut. The outbreak occurred in June in central Germany, a mainly wheat producing area, and was the first in the country in several decades.

“A changing climate will ‘definitely’ favour this thermophilic fungus” Scientists noted that the rust came so late that even the fungicides sprayed earlier to prevent leaf rust epidemics proved ineffective.

Then in November 2013 the disease struck a popular variety of wheat in Ethiopia called digalu, used to make bread, said Bekele Abeyo, a senior scientist and wheat breeder at CIMMYT.

What was particularly disconcerting for the scientists was that digalu had been bred with inherent resistance to certain strains of stem rust and another wheat disease called “yellow rust” or “stripe”.

The fact that the fungus has been rapidly mutating has prompted scientists to study the two cases with a view to helping with the preparation of new wheat varieties.

David Hodson, a senior scientist with the Global Cereal Rust Monitoring Program at CIMMYT, says the analysis presented on the German outbreak showed “there were some clear specific differences between the races present in Germany compared to Ethiopia, although the races were similar and fitted into the same race group.”

In Ethiopia, he said, the season had also been favourable for rusts, with above-average and well distributed rainfall – conditions similar to those in 2010 when wheat crops there were affected by yellow rust.

However, said Hodson, “the key factor was the presence of a suitable host and the appearance of a race that was able to attack this host.”

Flath said the big question on the German outbreak was whether it “was a unique situation or if it will repeat this year” – particularly because they had had a rather mild winter, so the spores might have survived.

She reckons a changing climate will “definitely” favour this thermophilic fungus. In the last two years two new aggressive variants of the yellow rust-causing fungus have made huge inroads in central and northern Europe.


Fungicides are the first line of defence. A longer term solution is replacing the world’s entire wheat varieties with those that contain several minor rust-resistant genes, which are pooled together to counter the infection, giving them an edge over single rust-resistant genes in combating various mutated variants of the fungus. Digalu contains single rust-resistant genes.

There are 20 new stem-rust-resistant varieties of wheat available. But getting the new seeds to farmers has been a problem, mainly due to poor distribution networks and cost.

Industrialized countries have an edge in terms of resources, said Flath. But even developing countries, realizing that food security is at stake, are beginning to make massive investments, says Abeyo. For instance, after the outbreak in Ethiopia in 2010, the government invested US$3 in fungicides, which helped contain the fungus in 2013.

With global wheat supplies vulnerable to changing weather patterns, Abeyo says developing countries are realizing the need to become self-sufficient in grain.

“Countries are now making the investment in infrastructure and research to develop better varieties.” But they still have a long way to go. Better partnerships with the developed world in sharing information and skills to monitor and protect their crops are also proving to be effective, he added.


All wheat varieties will have to be replaced
Two new wheat varieties offer hope against stem rust
Mutant wheat killer on the prowl
Another strain of deadly wheat fungus in South Africa

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