ACIAR’s Dr. John Dixon and Dr. Daniel Rodriguez of the Queensland Alliance for Agriculture and Food Innovation, with farmers from Melkassa, Ethiopia

A maize – legume farm in Tanzania

Government extension officer Frank Swai, Tanzania

Farmer and single mother of four Felista Mateo, Tanzania

CIMMYT’s Dr. Fred Kanampiu, Tanzania

By Judie-Lynn Rabar and
Dr. Gio Braidotti

East African farmers are spearheading a research drive to intensify crop production of their most important staple foods. The farmers’ experiments with conservation agriculture and variety selection are part of a broader, 5-country push to stave off a looming food and soil-health crisis.

Kilima Tembo is a secondary school in the Karatu district in Tanzania’s rural highlands. Here, near the Ngorongoro Crater and Tarangira National Park, agriculture is king and food security rests squarely on grains grown in the region’s maize–legume intercropping system.

So important is farming to the community that the school has an agriculture teacher and the school head, Ms Odilia Basso, has allowed the Selian Agricultural Research Institute (SARI) to use school grounds to run field trials as part of a 5-country initiative to overhaul the maize and legumes supply chain—from farm to market.

That means breaking with a long-standing cycle of lifting production simply by bringing more land under the plough. The ecological consequences of that approach are catching up with farmers and their environment, but agricultural science is providing more sustainable alternatives to improve food security.

The research-based strategy is called SIMLESA—sustainable intensification of maize–legume cropping systems for food security in eastern and southern Africa. Launched in March 2010, the project is supported by the Australian Government through ACIAR.

Ambitious aims

A major objective is to introduce conservation agriculture techniques and more resilient varieties to increase the productivity and resilience of this vital cropping system. SIMLESA is aiming not only to increase yields by 30% from the 2009 average but also to reduce, by the same factor, risk from yield variability between seasons.

The Kilima Tembo Secondary School will help achieve these goals. The school is hosting the so-called ‘Mother Trial’—a long-term SARI field trial of conservation agriculture. This farming practice involves conserving ground cover between harvests to preserve soil moisture and, over a number of years, radically improve soil health and fertility.

Unlike 11 other farmer-led field sites established by SARI (the so-called ‘Baby Trials’), the Mother Trial is managed directly by the institute’s scientists, landing the school’s students with front-row seats on research and development activities designed to sustain a farming revolution.

Mr. Bashir Makoko, an agronomist working on the SIMLESA project, says students have the opportunity to learn about the project and its significance to the community at an open day with scientists and extension workers from SARI.

The socioeconomist running the trial, Mr. Frank Mbando, is encouraging student participation. He has arranged for data to be collected in ways that allow students to interact with technical staff. “Direct involvement in the project will equip the students with the information they need as potential farmers,” he says.

Household and regional impacts

Supporting these activities are partnerships that link farmers with a suite of national resources—extension officers, research centres and agricultural ministries—and international research centres.

Coordinating these linkages is Dr. Mulugetta Mekuria, from the South African regional office of the International Maize and Wheat Improvement Center (CIMMYT). Also involved is the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT).

Dr. Mekuria says SIMLESA was designed to have impacts at both the household and regional level.

“The aim is to ensure food security through agricultural research, stronger economic institutions, partnerships, and capacity building,” he says. “We want to increase food security and incomes while driving economic development through improved productivity from more resilient and sustainable maize-based farming systems.”

To implement the program, Dr. Mekuria is using the ‘3-I Approach’, a research for development (R4D) strategy designed to enhance smallholder prosperity based on the principles of integration, innovation, and impact. “SIMLESA activities will focus on integrated cropping systems, the use of innovation platforms to test and promote promising practices, and ensuring positive and measurable impacts on food security, sustainability and farm household incomes.”

ACIAR is funding SIMLESA with $20 million in financial support. The centre has enlisted Australian expertise through Dr. Daniel Rodriguez, of the Queensland Alliance for Agriculture and Food Innovation, and Professor John Howieson from the Institute for Crop and Plant Sciences at Murdoch University in Perth.

Positive experience

Ms. Felista Mateo, a 37-year-old farmer from Kilima Tembo village is already benefitting from participating in SIMLESA.

A single mother of four, Ms. Mateo supports her family with produce from her land, mainly maize and pigeon pea. Any surpluses, though small, are stored in granaries and either used domestically or sold to middlemen.

Following advice from government extension officer Mr. Frank Swai, she achieved yield gains that her neighbours are now attempting to duplicate. As her harvest increases, she plans to build a larger granary to store her surplus and sell more grain as a cash crop.

Traditionally, farmers have had no way of tracking the market and the middlemen who buy their produce have exercised control over prices. However, Ms. Mateo owns a mobile phone and since the inception of SIMLESA and its support network, she can now call an extension officer and check market prices. The result is greater bargaining power for the villagers when the middlemen come calling.

Averting food insecurity

More than 200 million people living in extreme poverty in the partner countries stand to benefit from SIMLESA.

Currently, the region is barely self-sufficient in grain, importing 10% of its needs—one quarter in the form of emergency food aid.
Maize is the main staple and legumes —primarily groundnut, pigeon pea and chickpea— are an important source of protein. Instead of a more prosperous future, however, the region is facing growth in demand for maize and legumes in the next 10 years. It is that trend towards food insecurity that SIMLESA is attempting to avert.

But it is not just on-farm practices that are targeted for innovation. Urban grain prices have remained stubbornly high following the global food crisis of 2007–08. But higher prices for consumers have not translated into higher prices for farmers. This has weakened incentives for farmers to increase food crop production, a state of affairs that SIMLESA is attempting to change.

CIMMYT’s Dr. Fred Kanampiu says that the SIMLESA project is aiming to achieve a ‘whole-chain’ impact. “Despite the multiple efforts underway with the researchers, the final focus should not be lost,” he says. “It is the farmer who is to be the end beneficiary of the research. The farmers’ lives should be improved, their pockets well-lined and their families well catered for.”

Of all the crops produced by farmers such as Ms. Mateo, it is pigeon pea that has an important role to play as a cash crop. Farmers are fond of this legume because it yields two harvests a year and there is a good export market to India. Pigeon pea retails up to TZS150,000 (about US$100) per 100 kilogram bag. On average, one acre (0.405 hectares) of land yields 300–400 kg of pigeon pea. Typically, 95% of the crop is sold.

In Karatu district some 15% of farmers live on less than a dollar a day. Mr. Makoko says the major obstacles to lifting their profitability are high inputs costs, low produce prices, lack of markets, and prolonged drought. By introducing pigeon pea or similar crops, and integrating the ‘whole-chain’ approach, these obstacles can be reduced or overcome.

Socioeconomist Frank Mbando, Tanzania.

Senior agronomist Tuaeli Mmbaga, Tanzania. The way forward will include training farmers to provide them with further education on how to manage their land.” –Tuaeli Mmbaga

Better varieties

While the main research thrust is on conservation agriculture, CIMMY T and ICRISAT are participating in accelerated breeding and performance trials that aim to introduce farmers to maize and legume varieties that yield well in good years and are resilient enough in the bad seasons to help reduce farmers’ risks.

Mr. Mbando is tracking impacts associated with the new varieties and says the farmers’ response to the studies has been positive.

“They suggested that breeders take into account farmers’ criteria when making selections, so a participatory approach will be used to evaluate varieties,” he says. “So far, farmers have indicated early maturity, pest and disease tolerance, high yields and marketability as the preferred traits. Variety registration and production will then also be stepped up to make the seed available in sufficient quantities.”

Partnership approach

Mbulu district, located about 50 kilometres from Karatu, is the next community targeted for SIMLESA activities in Tanzania, to start after the current crop has been harvested. At the SIMLESA inception meeting, farmers agreed to leave post-harvest residue on the ground in preparation for the trials. Field activities in the Eastern Zone districts of Gairo and Mvomero are expected to begin in the next growing season.

Ms. Tuaeli Mmbaga, the senior agronomist on this project, says that with support from extension officers, farmers will assess the technology both pre-harvest and post-harvest.

“The way forward will include training farmers to provide them with further education on how to manage their land,” she says. “This will include an Innovation Learning Platform in partnership with farm produce stockists, community leaders, and other stakeholders to ensure that more people become involved with the project.”

Crop modeling scientist Dr. Daniel Rodriguez, who leads the Queensland component of ACIAR’s SIMLESA program, is convinced that research to reduce food shortages in eastern and southern Africa could have many benefits for farmers, including in his native Queensland.

“Our scientists will be working to improve the resilience and profitability of African farms, providing access to better seeds and fertilisers to raise the productivity of local maize–legume farming systems,” Dr. Rodriguez says. “Together we may be able to help solve one of the greatest challenges for the developed world—eliminating hunger and poverty in Africa—while at the same time boosting legume production here in Australia.”

Building agricultural research capacity

ACIAR’s Dr. John Dixon says the emphasis of Australia’s direct involvement is on building capacity within the African agricultural research system.

“Conservation agriculture amounts to a substantial shift in farming practices for the region,” Dr. Dixon says. “But it stands to provide so many advantages—not just greater water-use efficiency and soil health but also opportunities to break disease cycles and improve livestock nutrition.”

These are long-term efforts that need to be adapted to many agro-climatically diverse locations, Dr. Dixon says. “So it is vital that the African agricultural research system is built up so that it can take lead responsibility for implementing innovation into the future.”

In Malawi, farmers who have in the past few years witnessed crop failure due to poor rains are switching to two new drought tolerant maize varieties, and seed companies are changing their business models to keep up.

“The climate is changing, rainfall is decreasing and the weather is now dictating which varieties farmers grow and in turn which varieties seed companies produce,” says Dellings Phiri, general manager of Seed Co. Malawi, a leading southern African seed company.

He refers to two new drought tolerant maize varieties–ZM 309 and ZM 523–developed specifically for Malawi’s drought-prone areas with infertile soils by CIMMYT, Malawi’s Ministry of Agriculture and Food Security, and the Chitedze Research Station, through the Drought Tolerant maize for Africa (DTMA) project. The research was supported by the Bill & Melinda Gates Foundation, and the Howard G. Buffett Foundation. The varieties were officially launched in March 2009.

“In Malawi, each adult eats 300 kilos of maize annually, and ZM 309 and ZM 523 will give farmers a boost in safeguarding their maize harvests from the increasing threat of drought,” says Wilfred Mwangi, associate director of CIMMYT’s Global Maize Program and leader of the DTMA project.

First introduced by local extension agents to farmers in the drought-prone Balaka area through farmer-managed demonstration plots, these varieties have rapidly become popular among farmers, who have been impressed by their superior performance and accepted them. Compared to other popular commercially marketed varieties, farmers have found ZM 309 and ZM 523 to have higher yields, mature earlier, offer better resistance to common maize leafy diseases, and be better for pounding into flour. Locally, ZM 309 is known as Msunga banja, Chichewa for “that which takes care of or feeds the family,” while ZM 523 is Mwayi, which means “fortunate.”

Malawi supports for food security
In March 2009, farmers recommended ZM 309 for inclusion in Malawi’s Agricultural Input Subsidy Program, introduced in 2004 and credited with improving the country’s agricultural productivity and food security. Targeting smallholder farmers with access to land and other production resources, the program involves distribution of coupons for subsidized improved maize seed and fertilizer–one for a 100-kilogram bag of fertilizer and another for either 3 kilograms of standard seed or 2 kilograms of hybrid seed. In September 2009, Malawi’s President Dr. Bingu wa Mutharika endorsed ZM 309 saying, “ZM 309 will give Malawi farmers an advantage because it is high-yielding and drought tolerant. We welcome this research because it will help Malawi cope with climate change and improve food security.” The inclusion of ZM 309 in the subsidy program has seen the variety grown in six of the most drought-prone districts in Malawi, contributing to improved food security of thousands of farm families.

No more hungry months
One such family is that of Bamusi Stambuli, 63. Together with his wife Sagulani, they have they have 7 children and 5 grandchildren. In April 2010, Stambuli harvested nearly 1.8 tons of ZM 309 from his 0.6-hectare plot. “I will now be able to feed my family for a whole year,” says Stambuli proudly.

This year Stambuli will save at least USD 330 that he would have spent to purchase maize for his family. Farmers who grew ZM 309 obtained yields of 3.0 to 3.5 tons per hectare–twice those for the popular local varieties, Kanjelenjele and Kagolo.

In an area where locals rely on farming, fishing, basket-making, sale of firewood, and general trading, Stambuli’s success with ZM 309 is drawing many peers to his farm to buy ZM 309 seed.

Business as (un)usual
ZM 309 and ZM 523 are open pollinated varieties (OPVs), meaning farmers can save seed from one season and plant it for up to three subsequent seasons without punitive losses in yields or other desirable traits. Ordinarily, OPVs are not as attractive to commercial seed companies as hybrids, because with hybrids farmers have to buy and sow fresh seed every season or risk decreased performance of their crops. With ZM 309 and ZM 523 this is not the case. Seed Co. is changing its business model and investing in producing adequate amounts of both varieties to meet increased demand from farmers.

“We hope that from seeing the performance of ZM 309, farmers will be encouraged to start buying certified maize seed to boost production,” says Phiri.

CIMMYT E-News, vol 5 no. 5, May 2008

CIMMYT is adapting an advanced technology—the doubled haploid approach—to develop inbred lines of tropical maize for sub-Saharan Africa. It promises to reduce costs and speed the arrival of better-adapted maize for resource-poor farmers in the world’s toughest environments.

CIMMYT scientists have begun developing drought tolerant varieties of tropical maize for places like sub-Saharan Africa using a high-tech approach—known as doubled haploids—previously applied principally by commercial seed companies working mostly on temperate maize.

“Haploid” refers to the number of chromosomes in a reproductive cell, like sperm or ovum. In grasses like maize, the reproductive cells—pollen and ovules—contain half the chromosomes of a full-grown individual. Fertilization joins the genetic information from the two parents, and offspring carry paired sets of chromosomes, reflecting the diversity of each parent.

“Maize breeders working on hybrids—the most productive type of maize variety and the one marketed by most seed companies—must at some point create genetically-stable and pure lines of desirable, individual plants, for use as parents of hybrids,” says CIMMYT maize physiologist Jose Luis Araus. Conventionally, breeders get the lines by repeatedly fertilizing selected, individual maize plants with the plant’s own pollen. The process requires expensive field space, labor, and time—normally, seven or more generations, which represents at least three years, even in settings where it’s possible to grow two crops per season.

Purer, faster, cheaper

In the latter part of the 20th century, crop scientists developed a quicker, cheaper path to genetically-uniform parent lines—though a technically intricate method. The first step involves crossing normal maize with special maize types called “inducers,” whose pollen causes the normal maize to produce seed containing haploid embryos. The haploid embryo carries a single set of its own chromosomes, rather than the normal paired sets. The embryos are planted, and subsequent treatment of the seedlings with a particular chemical causes them to make “photocopies” of their haploid chromosomes, resulting in a fertile plant endowed with a doubled set of identical chromosomes and able to produce seed of 100% genetic purity. “The actual treatment, as well as getting from the embryo to a reasonable amount of seed of the pure line, is very complicated,” says Ciro Sánchez Rodríguez, CIMMYT technician in charge of doubled haploid field trials, “but when the process is perfected, it only takes two generations—about one year—and the logistical advantages are tremendous.”

First extensive use in the tropics

CIMMYT is implementing the doubled haploid technology on a research station in Mexico, using drought tolerant plants adapted to sub-Saharan Africa. “CIMMYT’s use of the practice is another example of how we put advanced technologies at the service of disadvantaged, small-scale farmers,” says Araus. “Among other things, this represents a significant opportunity to increase the availability of improved, drought tolerant maize varieties for sub-Saharan Africa,” he says.

Commercial seed companies in Europe and North America have been the main users of the doubled haploid technology, and the inducer genotypes available are of temperate adaptation. “The inducers perform very poorly in the tropical conditions of our Mexico stations,” says Vanessa Prigge, a PhD student from the University of Hohenheim working at CIMMYT to perfect the technique. To generate inducers that work better in tropical settings, Prigge and colleagues are crossing temperate inducers from Hohenheim with CIMMYT maize from Mexico, Kenya, and Zimbabwe. “We expect to have tropical versions of the inducers in a couple years,” she says.

Reaching farmers’ fields

Maize lines from this work will be used initially in the Drought Tolerant Maize for Africa (DTMA) and the Water Efficient Maize for Africa (WEMA) projects.

“This is a very exciting technology,” says Aida Kebede, an Ethiopian PhD student from Hohenheim helping to establish the doubled haploid technology at CIMMYT. “It holds the key to addressing more quickly the persistent problems of African maize growers: drought, disease pressure, and low productivity. I’m happy to contribute!”

CIMMYT E-News, vol 4 no. 5, May 2007

OPVs perform as well as hybrids or better under the low-input conditions of many smallholder farmers in Zimbabwe, but farmers need information and training about how properly to use them.

A new study to assess the effectiveness of a large-scale maize seed relief effort in Zimbabwe during 2003-07 shows that, even among vulnerable, small-scale farmers living on the edge of survival under the most difficult conditions, a livelihood-saving technology like quality seed of open-pollinated maize varieties (OPVs) is not enough, without knowledge about how best to use it.

Farmers can save grain of OPVs from their harvest and sow it the following year without the yield or other qualities of the variety diminishing substantially. Hybrids normally yield more than OPVs under favorable conditions, but “recycling” the seed in subsequent seasons will result in a significant loss of that yield and of other advantages; farmers must purchase fresh seed each season to retain them. “Zimbabwe farmers have historically favored hybrids, and they have limited knowledge about OPVs,” says Augustine Langyintuo, CIMMYT socioeconomist and lead author of the study. “Changing economic circumstances in the country have meant that many farmers can no longer purchase fertilizer to take best advantage of hybrid yield potential. We interviewed 597 households in 6 districts of Zimbabwe where a major seed-relief effort had, among other aims, promoted the broader diffusion of OPVs over hybrids, thereby giving smallholder farmers the possibility to save and re-use their own seed without sacrificing their meager yields.”

The seed aid effort, which was funded by British Department for International Development (DfID) and coordinated by the Food and Agricultural Organization (FAO) regional office in Harare, enlisted the assistance of 16 non-government organizations (NGOs) to distribute improved maize seed to more than 25,000 needy farmers. “The average household size in our survey group was 6.5 members, supported by a cultivated farm size of just 1.7 hectares, over 60% of which is planted to maize,” says Langyintuo. “Nearly a third of the households were headed by widowed females, a factor highly correlated with poverty.”

Under the relief program, the NGOs were expected to inform farmers of the types of seed being distributed and the need to select, store, and re-use the seed properly in subsequent seasons. Less than half the beneficiaries in the first year of the program were informed of the type of seeds to be provided, although the proportion increased to more than 60% over time. Information on OPVs was limited to the fact that they can be recycled. Less than half were ever taught how to select or store their seed.

According to Langyintuo, many farmers continue to recycle hybrids, or improperly select OPV grain for future use as seed, or—in the worst cases—eat all their grain and hope for another aid shipment to sow next year. “The relatively well-endowed farmers were more willing to recycle OPV seed. In future efforts, NGOs should perhaps target them to ensure larger-scale spillovers,” he says. “In general, whoever distributes seed of improved OPVs should provide information on proper seed selection and follow up with field-level training. Farmers should also be involved in the choice of the varieties.”

Another key issue to grapple with is the unavailability of OPV seed on the market. This stems from the unwillingness of seed companies to develop and promote OPVs, given the perception that farmers will simply recycle them and never buy fresh seed. “Zimbabwe farmers recycle both OPVs and hybrids, but if given a choice, they will purchase fresh seed whenever they can,” says Langyintuo. “OPVs perform as well as hybrids or better under the low-input conditions of many smallholder farmers in Zimbabwe, so they constitute a good option for such farmers.”

You can view or download the study “Assessment of the effectiveness of maize seed assistance to vulnerable farm households in Zimbabwe.”

For more information: Augustine Langyintuo, socioeconomist (a.langyintuo@cgiar.org)

CIMMYT E-News, vol 3 no. 2, February 2006

Norman E. Borlaug, former CIMMYT wheat breeder, 1970 Nobel Peace Laureate, and scientist whose work helped spark the Green Revolution, was awarded the National Medal of Science by US President George W. Bush at a ceremony in the White House on 13 February 2006. The award was established in 1959 to recognize special achievements and outstanding contributions in the sciences.

Borlaug has dedicated more than five decades to ending world hunger and to boosting agricultural productivity in the developing world. He has been awarded more than 50 honorary doctorates from institutions in 18 countries, and has talked to more peasant farmers and visited more wheat fields than any living person. At 91 he continues to travel worldwide to promote improved farming. He also supports CIMMYT as a senior consultant and serves as Distinguished Professor of International Agriculture at Texas A&M University.

Borlaug grew up on a small farm in Iowa, and attended a one-room schoolhouse for his first eight grades. He studied plant pathology at the University of Minnesota and was awarded his doctorate in 1941. Between 1944 and 1960, Borlaug served as the Rockefeller Foundation scientist in charge of wheat improvement under the Cooperative Mexican Agricultural Program. He later acted as a consultant to Mexico’s Ministry of Agriculture, and was assigned to the Inter-American Food Crop Program as an associate director of the Rockefeller Foundation.

With the establishment of CIMMYT in Mexico in 1963, Borlaug assumed leadership of the Wheat Program, a position he held until his official retirement in 1979. By the mid-1960s, he and partners took technical components of Mexican wheat technology to Asia, launching the so-called “Green Revolution.” Between 1964 and 1990, wheat production in India rose from 12 to 54 million tons, while wheat production in Pakistan increased from 4.5 to 14.5 million tons.

In 1988, Borlaug became President of the Sasakawa Africa Association and a Senior Consultant to Global 2000. During 1990-92, he was a member of the US President’s Council of Advisors for Science and Technology. He also serves on many advisory boards, including the international juries of the annual World Food Prize, sponsored by the John T. Ruan Foundation, and the annual Africa Prize for Leadership for the Sustainable End of Hunger, sponsored by the Hunger Project.

Other recent honors conferred to Borlaug include the Danforth Award for Plant Science and the Padma Vibhushan, India’s second highest national award.

January, 2005

New Publication Presents Outcomes of Eighth Asian Regional Maize Workshop

A copy of the Proceedings of the Eighth Asian Maize Workshop is now available in PDF form. The workshop, which took place during 5 – 8 August 2002 in Bangkok, Thailand, was titled “New Technologies and Technology Delivery Systems for the New Millennium.” Jointly organized by CIMMYT, Kasetsart University, and Thailand’s Department of Agriculture, the event drew more than 150 participants from Asia and invited speakers from Latin America and Africa. The 61 papers included in the proceedings cover molecular tools for maize improvement, genetics and breeding, crop management, biotic and abiotic stresses affecting maize, technology adoption and dissemination, and country reports. Published by CIMMYT, it was edited by G. Grinivasan, P.H. Zaidi, B.M. Prasanna, F. Gonzalez, and K. Lesnick. In addition to the PDF, seven hundred paper copies are available.

Slated for September 2005, the Ninth Asian Regional Maize Workshop will convene in Beijing, China. For further information, please contact Dr. Zhang Shihuang, CAAS, Beijing, China. Executive Secretary, Organizing Committee, 9th ARMW. Email: cshzhang@public.bta.net.cn

The PDF can be found here: http://staging.cimmyt.org/english/docs/proceedings/armw/contents.htm

CIMMYT E-News, vol 2 no. 7, July 2005

In a country where each person consumes at least 100 kilograms of maize a year, a new, easy-to-use, affordable practice that could raise the crop’s production by 200,000 tons is, naturally, greeted with much celebration in Kenya.

Such was the mood at Kisumu, Kenya, during the 5 July launch of the Clearfield® technology for Striga weed control. “This is good news for farmers, and good news for the government,” stated the chief guest, Romano Kiome, director of the Kenya Agricultural Research Institute (KARI). If widely adopted, according to Kiome, the technology could “…lift poor farmers from subsistence to income generation, poverty to wealth, and food insecurity to security.”

A highly invasive parasite, Striga infests 400,000 hectares of Kenya’s farmland. Striga sprouts fasten directly to roots of maize seedlings, sucking away nutrients and 50 to 100% of yields by harvest time. The weed overruns 40% of the arable land in Africa’s savannahs, threatening the livelihoods of more than 100 million people who depend on cereal crops for food and income. Kenyan maize farmers lose at least US$ 50 million annually in grain to Striga.

Taking advantage of a natural variation in maize, for nine years CIMMYT and partners have conventionally bred varieties that yield well under tropical conditions and withstand imidazolinone, an active ingredient in several herbicides and the BASF product, Strigaway®. This imidazolinone-resistant (IR) maize is the starting point for an elegant control method, as CIMMYT agronomist Fred Kanampiu explains: “The IR maize seed is coated with a low dose of the herbicide, which kills Striga as it germinates, allowing the maize to grow clear of the weed.” Besides producing healthy maize plants, over several years the practice helps clear fields of residual Striga seed—a boon to farmers, given that a single Striga plant produces up to 50,000 tiny seeds that can remain viable for 20 years or more.

Four new maize hybrids have been released for marketing in Kenya under the common name Ua Kayongo (literally “kill Striga”) H1–4, and farmers are enthusiastic, as their statements in the Nairobi Daily Nation show: “I have already seen major changes in my farm compared to my neighbors’, whose parcels remain covered with the purple flowers of the parasitic weed,” says Zedekiah Onyango of Baridi farm in Nyahera. “My maize yield is many times higher since I started using IR maize, and I look forward to even higher yields.” Farmers are also urging the government to promote the technology to arrest the perennial food shortages caused by Striga. “I believe it would be much cheaper for the government to invest money in the technology, so that this menace is cleared once and for all, and the production of various cereals is restored,” says Beatrice Ayoo, another small-scale farmer who is interested in the new Clearfield® practice.

The technology was developed through global cooperation involving CIMMYT; KARI; the Weizmann Institute of Science, Israel; BASF; private seed companies; and the Rockefeller Foundation; among others. Peter Matlon, director for the Africa Regional Program, the Rockefeller Foundation, was at the launch, and called the cross-sectoral collaboration “a classic example of partnership.” The Clearfield® control package will be released soon in Tanzania, Uganda and, eventually, 16 other countries of sub-Saharan Africa, in a process spearheaded by the African Agricultural Technology Foundation (AATF) with DFID support.

For more information, contact Fred Kanampiu (f.kanampiu@cgiar.org).

CIMMYT E-News, vol 2 no. 11, November 2005

Kazakhstan and Siberia connect with CIMMYT to improve their wheat.

Grigoriy Sereda, Head of the Breeding Department at the Central Kazakhstan Agricultural Research Center, is nothing if not direct. “The future of our breeding program relies on KASIB. Without it, germplasm exchange would be nonexistent. And without germplasm exchange, crop breeding cannot move forward.”

KASIB, the Kazakhstan-Siberia Network for Spring Wheat Improvement, was established in 2000 as the brainchild of CIMMYT regional representative Alexei Morgounov. In the former Soviet Union, there was considerable seed exchange among the republics and interactions among breeders and crop research institutes. But after the break-up of the U.S.S.R., many scientists found themselves isolated professionally and with little access to breeding lines from outside sources. Through KASIB, CIMMYT, with modest funding from GTZ, a German development agency, and the International Cooperation for Agricultural Research in Central Asia and the Caucasus, endeavored to rectify the situation

The principles of the network are simple: participants share breeding lines and data and abide by a Wheat Workers Code of Ethics (a declaration by the U.S. National Wheat Improvement Committee). Aside from active exchange and evaluation of experimental lines, the network publishes trial results and proceedings from an annual meeting where scientists from participating institutions present and discuss their work.

Each of the 17 participating institutions submits 2-4 recent varieties or breeding lines to CIMMYT’s Kazakhstan office, where seed for the trials and the field books are prepared and distributed to cooperators in April, prior to planting. The trials are grown at the diverse sites with three replications. Data from trials are submitted to CIMMYT, where they are summarized, published in Russian and English, and distributed to cooperators and others. The trials are a key source of lines and varieties carrying important traits such as drought tolerance, disease resistance (primarily to leaf rust and septoria leaf blotch), and improved grain quality.

Illustrating the point, in 2000 northern Kazakhstan and Siberia suffered a leaf rust outbreak, Morgounov recounts. None of the 80 modern varieties and lines being tested showed resistance to the pathogen. This clearly indicated a pressing need for the breeders to address, and one for which CIMMYT was well equipped to assist.

Another facet of KASIB is an innovative shuttle breeding program between the network and CIMMYT-Mexico. Following several years of trials, says CIMMYT wheat breeder Richard Trethowan, scientists in the network select elite local lines and varieties with promising agronomic or quality traits and send seed to Mexico to be crossed with CIMMYT materials that possess leaf rust resistance and other locally-desirable traits, such as a tall profile and photoperiod sensitivity. The lines are crossed with a Kazakh parent or to another Kazakh or Canadian line and returned to Kazakhstan and Siberia for additional breeding to ensure adaptation to local environments.

Once adapted, Trethowen continues, the line can then be sent back to Mexico for further crossing and improvement, hence the term shuttle. The system not only allows incorporation of traits not found in the region’s wheat, but accelerates breeding by allowing multiple cycles per year. The first full cycle of the shuttle was completed in 2004, with the first advanced lines reaching Mexico. Trethowen credits KASIB for enabling the approach to be applied in Central Asia and for benefits that accrue to CIMMYT wheat research through the added genetic diversity introduced from Kazakh and Siberian lines—diversity that may well serve farmers elsewhere in the developing world.

For Sereda, KASIB has breathed fresh life into his work: for example, he has received more than 200 entries to plant through the network and has selected about 60 for crosses. He is particularly enthused about the experimental wheats from CIMMYT’s wide-cross research—derived from crosses with wild relatives of wheat—received through the KASIB-CIMMYT shuttle. After 35 years of plant breeding, the wide-cross collection brings an entirely new tool on which to focus his vast experience. And he thanks KASIB meetings and publications for providing a forum to share his knowledge and more quickly move improved wheats to the farmers of Kazakhstan.

For further information, contact Alex Morgounov (a.morgounov@cgiar.org).

June, 2005

What role do farmers play in the evolution of maize diversity? How extensive are the farming networks and other social systems that influence gene flow? These and other questions are helping researchers to combine knowledge of the genetic behavior of plants with information on human behavior to understand the many factors that affect maize diversity.

Outside a straw and mud-walled house in rural Hidalgo, Mexico, with chickens walking around and the smell of the cooking fire wafting through the air, CIMMYT researcher Dagoberto Flores drew lines with a stick in the red earth as he explained to a farmer’s wife how maize seed should be planted for an experiment. Along with CIMMYT researcher Alejandro Ramírez, Flores was distributing improved seed in communities where they had conducted surveys for a study on gene flow.

The movement of genes between populations, or gene flow, happens when individuals from different populations cross with each other. CIMMYT social scientist Mauricio Bellon is leading a study that aims to find out the impact of farmers’ practices on gene flow and on the genetic structure of landraces. It will document how practices differ across farming systems, analyze their determinants, figure out how much farmers control gene flow, and explore gene flow’s impacts on maize fitness and diversity and on farmers’ livelihoods.

The farmers visited by Flores and Ramírez in early June near Huatzalingo and Tlaxcoapan, Hidalgo are from just 2 of 20 study communities spanning ecologies from Mexico’s highlands down to the lowlands. Six months earlier, when farmers in these communities responded to researchers’ survey question, they asked some questions of their own: What does CIMMYT do? How can we get seed?

The team made it a priority to give the farmers what they requested for free. They drove around in a pick-up truck with seed they had acquired from CIMMYT scientists. They brought black, white, and yellow varieties that were native to the area and had been improved with weevil and drought resistance, and they also brought three CIMMYT varieties that were well adapted to a similar environment in Morelos, Mexico. They explained to the farmers how each variety should be planted in separate squares to facilitate pure seed selection.

“It’s a way to thank them, to bring something back to the communities,” says Bellon. Bringing improved germplasm for experimentation to interested small-scale farmers also allows researchers to get feedback in a more systematic way. The farmers will produce the maize independently, and they can save or discard seed from whichever varieties they choose. The team also distributed seed to farmers in Veracruz, and they plan to return after flowering and at harvest time to see how the improved seed fares compared with native varieties. That component of the project could be the beginning of further research in collaboration with farmers.

Farmers in the survey area of rural Hidalgo grow maize on the poorest, most steeply sloping land and struggle with soil diseases, low soil fertility, leaf diseases, low grain prices, and limited information about the use of chemical herbicides. Strong wind, rain, and hurricanes damage crops. Landslides cause erosion. Some farmers have access to roads and can transport their harvest by vehicle, but some farms located far from the communities have no highway access. The paths to farmers’ fields can be so narrow that not even cargo animals can maneuver on them with loads, so farmers must carry the harvest on their backs. Some walk 10 kilometers up and down slopes with heavy bags on their backs.

Many people grew coffee around Huatzalingo until about 10 years ago when the price plummeted. A kilogram of coffee used to fetch a price of about 20 pesos, or US$ 2. Now it fetches about five pesos, or 50 cents, per kilo, and even less during harvest time when the crop is abundant. Coffee producers in the area receive average government subsidies of between 125 and 300 pesos, or between US$ 10-30. One effect of the price drop has been increased immigration to Mexico City, to the city of Reynosa near the US border, and to lowland areas where orange cultivation is booming.

Partly in response to the crisis, farmers have started diversifying into alternative crops such as vanilla, citrus fruits, bananas, sugar cane, sesame, beans, chayote, chili peppers, and lentils, but the poor soils do not favor more lucrative crops. Maize is still the most important agricultural product in people’s diets in this area, and farmers grow it primarily for family consumption. They exchange seed with friends, neighbors, and producers in nearby communities, and they have conserved diverse native varieties.

In Mexico, maize has such great genetic diversity because farmers’ practices encourage the further evolution of maize landraces. Maize was domesticated about 6,000 years ago within the current borders of Mexico. Farmers created a variety of races to fit different needs by mixing different maize types, and they still experiment like that to this day. They save seed between seasons and trade seed with each other, and the wind carries pollen between different cultivars to create new mixtures.

“They are not artifacts in a museum,” Bellon says about landraces. “They are changing, they are moving.” Seed selection has a great impact on gene flow. Poor farmers typically exchange seed with each other, but little has been documented about the social relations that drive seed systems. With growing concerns about a loss of crop genetic diversity and a need to conserve genetic resources in recent years, it is important to understand the social principles of seed flow (and ultimately gene flow) in Mexico. The study findings will assist in exploration of the potential impact of transgenes. The researchers will develop models to try to predict how a transgene would diffuse and behave after it has been in a population for 10 or 20 years.

By learning about the relationships between farmers’ practices and gene flow, researchers hope to promote more effective policies regarding the conservation of diversity in farmers’ fields, the distribution of improved germplasm, and transgene management. Funded by the Rockefeller Foundation, the study combines social science with genetics to connect social and biological factors in maize varieties. Molecular markers will help show how much gene flow has occurred over time between the Mexican highlands and lowlands.

Researchers used geographic information systems to choose varied environments for the survey. Starting in October 2003, they sampled maize populations and interviewed the male and female heads of 20 households in each community for a total of 800 intensive interviews in 400 households. They asked about topics such as principal crops, planting cycles and methods, maize varieties, machinery and tools, infrastructure, language, seed selection, fertilizer, pest and weed control, plant height, harvest, transportation, production problems, maize uses, the sale and demand of different varieties, knowledge about maize reproduction, husk commercialization, and level of migration.

Preliminary findings have already surprised Bellon. A growing market for maize husks, which are used to wrap traditional foods such as tamales, is changing the economics of maize production. Owing to increasing demand from the US, husks have become more commercially important and profitable than grain in some communities. Facing abysmally low grain prices, the success of husk production has caused some producers to seek maize varieties with high quality husks, almost regardless of grain quality.

Bellon was also surprised at the lack of improved varieties in the areas they studied. Farmers tended to seek out and plant native varieties instead of hybrids. Some farmers thought hybrids were expensive, produced poor quality husks, and required good land, chemicals, and fertilizer, but they thought native varieties adapted easily to marginal local conditions.

The study grew out of a six-year project in Oaxaca that examined the relationship between farmers’ practices and the genetic structure of maize landraces and seed flow among farmers. It also explored the implications of transgenic technologies. However, while the Oaxaca project examined a few communities located in one environment, the idea with this follow-up study was to examine many locations in the same and different environments. In that way researchers can find out if gene flow is localized or if it crosses between regional environments. “It’s the same research model on a broader scale,” says Bellon.

For information: Mauricio Bellon

December, 2004

On December 1, CIMMYT handed over a greenhouse to the Plant Pathology Division of the Nepal Agricultural Research Council (NARC). Built with the support of CIMMYT’s project on foliar pathogens and funded by Belgian Development Cooperation (DGCD), this greenhouse will help sustain research on wheat diseases, despite Nepal’s current social conflict.

At a ceremony in Khumaltar, CIMMYT regional pathologist Etienne Duveiller delivered the greenhouse keys to T.K. Lama, Chief of the Plant Pathology Division. The new facility will help NARC scientists screen for resistance in wheat against yellow rust, a potentially devastating disease in the hill areas of Nepal. Grain losses can soar to 30% when early outbreaks occur, as demonstrated by last year’s severe epidemic in parts of the Kathmandu Valley.

Replacing Outmoded Resistance

Due to the breakdown of resistance in popular varieties like Sonalika, which date back to the Green Revolution, yellow rust epidemics have occurred in Nepal since the mid-1980s. In 1997, a new strain of the rust pathogen became prevalent in the Nepal hills—a strain that is virulent against Yr9, a gene from rye that has conferred resistance to yellow rust in many improved wheats.

To develop disease resistant plants, breeders artificially inoculate fields of experimental varieties and select the individuals or families that survive and produce grain. With help from CIMMYT, advanced lines from Nepal are tested annually in Pakistan to ensure that promising genotypes are exposed to new pathotypes of yellow rust from western Asia. But research of this type in Nepal has suffered in recent years, mainly from a lack of inoculum to apply to experimental plants. First, insecurity in Nepal has caused severe financial constraints and reduced operations for national agricultural research scientists. Second, there is a lack of proper facilities to produce rust inoculum for the timely inoculation of breeders’ fields. An alternate approach used—collecting natural inoculum that survives in off-season wheat crops—became nearly impossible after a series of dry years eliminated this source of the pathogen and security restrictions made travel impossible in remote hilly regions. Finally, less than optimal moisture in the screening fields of Khumaltar, where the Plant Pathology Division is located, has necessitated repeated applications of fresh inoculum.

The timely production of inoculum in the new greenhouse will improve this situation. This greenhouse has a robust and simple cooling system to control temperature, as well as a misting system that guarantees proper humidity. It will allow both screening against yellow rust under optimal conditions and the multiplication of inoculum. Since the wheat season is just starting, researchers working on other diseases and crops will benefit from having inoculum ready for breeders’ plots in January.

Preserving Spores and Global Partnerships

In an important recent accomplishment, according to Duveiller, Senior Wheat Pathologist Sarala Sharma was able to produce fresh inoculum directly from leaf samples collected last season, using local methods and dried leaves. “This is the first time that she was able to preserve inoculum from last March,” says Duveiller. “Yellow rust must be kept alive for multiplication in the greenhouse and cannot be grown on artificial media. The main problem is that it is very sensitive to high temperatures. In Nepal, power failures, poor refrigeration, and no possibilities of vacuum preservation make it hard to keep spores.”

During the greenhouse opening ceremony, Sharma underlined the importance of the long-standing collaboration between NARC and CIMMYT. She acknowledged CIMMYT’s continuous support, initiated by former CIMMYT wheat pathologists Jesse Dubin and the late Eugene Saari, who encouraged scientists to collect inoculum from rust-prone areas as a way to record the disease’s incidence and spread. These surveys had continued with support from Duveiller until recently, when traveling by road became difficult. Also recognized at the ceremony were the benefits of training on yellow rust pathotyping that Nepali scientists had received at IPO-Wageningen, the Netherlands, and Shimla, India.

Similar work may become possible now in Nepal, according to Duveiller. “This greenhouse, built with Indian technology and including inexpensive but sturdy polyethylene sheets for siding, is another example of the importance CIMMYT ascribes to rust diseases on wheat in Nepal and south Asia,” says Duveiller. The center recently funded the installation of a sprinkler system for use in disease resistance experiments at Bhairhawa farm in the Tarai Plains, where the Nepal Wheat Research Program is based.

The greenhouse handover ceremony was combined with the farewell party for two NARC pathologists who retired recently, K. Shrestha and C.B. Karki. A recognized rust pathologist and longtime CIMMYT friend, Karki received his Ph.D. from Montana State University and attended the second Regional Yellow Rust Conference in Islamabad, Pakistan, in March 2004. Dr. K. Shrestha attended CIMMYT’s conference on helminthosporium blight in Mexico.

For more information: e.duveiller@cgiar.org

In order to contribute to world food security, the International Research Initiative for Wheat Improvement (IRIWI), supported by research organisations and funding agencies from about ten countries, has been adopted by the Ministers of Agriculture of the G20. INRA, with the Biotechnology and Biological Sciences Research Council (UK) and the International Maize and Wheat Improvement Center (CIMMYT, Mexico), will contribute to the coordination activities of the IRIWI during the first four years of the project.

The historic agreement between the Ministers of Agriculture of the G20 on 23 June 2011 in Paris underlines the importance of increasing world agricultural production, in particular that of wheat, to resolve the urgent challenges of hunger and food price volatility. Already very active on this issue, INRA, together with other national and international research and funding organisations from about ten countries, will launch the International Research Initiative for Wheat Improvement (IRIWI) in 2011. This initiative aims at reinforcing synergies between bread and durum wheat national and international research programmes to increase food security, nutritional value and safety while taking into account societal demands for sustainable and resilient agricultural production systems.

Wheat is one of the main staple crops in the world but the present production levels do not satisfy demand. With a world population of 9 billion in 2050, wheat demand is expected to increase by 70%. Annual wheat yield increases must jump from the current level of below 1% to at least 1.7%.

Repeated weather hazards in a context of global change, the constant rise in oil prices, speculation on agricultural markets are some of the factors reinforcing volatility of wheat prices and aggravating food insecurity in numerous countries.

Strengthening coordination of world wheat research

IRIWI will coordinate worldwide research efforts in the fields of wheat genetics, genomics and agronomy. Both Northern and Southern countries share the need to improve wheat yield, tolerance to stress, pathogens and pests, as well as wheat resource use efficiency. Improved agronomic practices and development of innovative cropping systems are also a priority. Several large national research programmes on wheat have been launched recently in Northern countries. CIMMYT and ICARDA have presented a new CGIAR research programme called WHEAT for the developing world.

As part of its activities, IRIWI will provide a forum to facilitate communication between research groups, identify potential synergies and encourage collaborations among major existing or emerging nationally, regionally and internationally (public and private) funded wheat research programmes. It will also support the development of publicly available integrated databases and platforms and establish and periodically update priorities for wheat research of global relevance.

Sharing resources, methods and expertise to improve and stabilise yields

The on-going efforts to decipher the wheat genome sequence, as well as the development of high throughput genotyping and phenotyping tools, will provide new ways to exploit more efficiently the available genetic diversity and create new wheat varieties by public and private breeders. Development and adoption of precise and site-specific management techniques will lead to the improvement of production systems. The IRIWI will facilitate and ensure the rapid exchange of information and know-how between researchers, and will organize knowledge transfer to breeders and farmers.

These actions will allow the creation of improved wheat varieties and the dissemination of better agronomic practices worldwide in the next 15 years. These new wheat varieties and agronomic practises will allow farmers to stably produce more and better wheat in different environments.

Presentation of the International Research Initiative for Wheat Improvement (pdf)

IRIWI reinforces INRA’s long-term involvement in research in wheat improvement. Recently, the BREEDWHEAT project was selected by the French Stimulus Initative. BREEDWHEAT is carried out in coordination with or contributes to other international initiatives, such as the WHEAT-Global Alliance project for food security in Southern countries, conducted by the CIMMYT and the International Wheat Sequencing Programme coordinated by the IWGSC.

CIMMYT E-News, vol 5 no. 3, March 2008

CIMMYT fosters regional partnerships and provides seed to help researchers in Thailand get drought resistant maize to farmers.

“We are very, very dry,” says farmer Yupin Ruanpeth. “Last year we had a drought at flowering time and we lost a lot of yield.” In fact, she explains, during the last five years, her family’s farm has suffered from severe drought three times in a row. The soil is good and in a year with no drought they can harvest five tons of maize per hectare, but last year they could only harvest three tons per hectare.

Geographically, the Thai province of Nakhon Sawan lies only a short drive from lush lowland paddy fields, but it seems a world away. In this region the rainy season (between May and September) brings enough water for a single crop, usually of maize or cassava, and in the dry season the fields lie fallow. Almost all maize in Thailand is rainfed, grown under similar conditions

At the Thai Department of Agriculture’s Nakhon Sawan Field Crops Research Center, Pichet Grudloyma, senior maize breeder, shows off the drought screening facilities. Screening is carried out in the dry season, so that water availability can be carefully controlled in two comparison plots: one well-watered and one “drought” plot, where watering is stopped for two weeks before and two weeks after flowering. Many of the experimental lines and varieties being tested this year are here as the result of the Asian Maize Network (AMNET). Funded by the Asian Development Bank, this CIMMYT-led project has brought together scientists from the national maize programs of five South East Asian countries to develop drought tolerant maize varieties and deliver them to farmers.

AMNET achievements

“We already have two releases under AMNET,” explains Grudloyma. These are varieties produced by the national maize program, focusing prior to AMNET on resistance to the disease downy mildew, which have also proved themselves under drought screening. The first, Nakhon Sawan 2, was released in 2006. The second, experimental hybrid NSX 042029, has been popular in farmer participatory trials and with local seed companies, and is slated for release in 2008. “This is the best hybrid we have,” says Grudloyma with pride. “It’s drought tolerant, disease resistant, and easy to harvest by hand.” The two hybrids incorporate both CIMMYT and Thai breeding materials, a legacy of Thailand’s long relationship with the Center.

In current work under AMNET, the Thai breeders are crossing lines from the national breeding program with new drought tolerant materials provided each year by CIMMYT. “We screen for drought tolerance in the dry season and downy mildew resistance in the rainy season, and take the best materials forward each year,” explains Grudloyma. “We now have many promising hybrids coming though.”

Funding from the project has also had a big impact on the team’s capacity to screen those hybrids. “We had a small one to two hectare facility before; now we have four hectares with a perfect controlled-irrigation system. Because we’ve been in AMNET, we have good varieties and good fieldwork and screening capacity. This is leading to other projects, for example we’re currently working with GCP [the Generation Challenge Program].” Thailand has also taken on a role in seed distribution, receiving and sharing seed from the AMNET member countries, and testing the varieties on the drought screening plots at the Research Center.

Sharing knowledge across borders

For Grudloyma, this collaborative approach is a big change. “We’ve learned a lot and gained a lot from our friends in different countries. We each have different experiences, and when we share problems we can adapt knowledge from others to our own situations.”

The Thai researchers can come up with many examples of things they have learned from their AMNET partners. “We saw the very friendly relationships between a number of seed companies and the Vietnam team, and we tried to modify the way we worked in Thailand,” says Grudloyma. “This year we shared promising hybrids with seed companies before release. Before that we just worked with farmers and small seed producers, and the seed companies could buy seed after varieties were released.” The result has been wider distribution of new drought tolerant varieties: this year the group received orders for enough parental materials for NSX 042029 to produce 300 tons of seed.

“We learned how to evaluate farmer preferences better from the Philippines team,” adds Amara Traisiri, an entomologist working on responding to these preferences. “We now use their method in all our field trials with farmers and we’re getting a more accurate picture of what farmers want.” This information caused the group to include ease of hand harvest as another trait to consider in their breeding program, after realizing how important it is to farmers. And the learning continued at this month’s annual regional training meeting. “Today, we learned a system for farmer participatory trials,” says Grudloyma, referring to a session on planning and analyzing trial data from CIMMYT maize breeder Gary Atlin. “With these new ideas to direct us we’ll be able to get better results.”

Almost all Thai maize farmers grow improved hybrid varieties, and for Ruanpeth, her priorities are clear. “Drought tolerance is very important”, she says, and dismisses other traits, such as yellow color. “No, I want varieties that are drought tolerant.” She likes to try the latest hybrids and has grown more than 10 commercial varieties. She eagerly accepts the suggestion from Grudloyma’s team to try their new hybrids on a small area this year.

The project has built capacity and relationships that will endure, according to Grudloyma. “Our station is now very good at working with drought,” he says, “and we’ll continue cooperation and providing germplasm. We already have plans for collaboration with China and Vietnam.” CIMMYT’s role in providing germplasm and access to new knowledge and technologies has been vital, as has its leadership. “It’s very hard to get hold of germplasm from anywhere except CIMMYT,” says Grudloyma. “It’s also difficult to come together: we needed an international organization to coordinate and facilitate regional interaction. With CIMMYT everything is easier.”

For more information: Kevin Pixley (k.pixley@cgiar.org)

CIMMYT E-News, vol 4 no. 5, May 2007

No need to dig for ancient seeds to discover how and when maize moved from its ancestral home in Mesoamerica to become one of the world’s most widely-sown and popular food crops. New work by gene sleuths from CIMMYT and numerous maize growing countries solves the puzzle using DNA of present-day maize.

How did a crop domesticated some 7,000 years ago from a humble Mexican grass called teosinte become the number-one food crop in Africa and Latin America, and a major food, feed, and industrial crop just about everywhere else?

The incredible story of maize has been told in books, but there have always been lingering doubts, unanswered questions. If, for example, as records show, in 1493 Columbus brought maize to Spain from his visit to the warm climes and long days of the Caribbean, how is it that reliable accounts have the crop being grown in 1539 in the cold, short daylengths of Germany? That’s only 46 years later, and far too soon for such a radical adaptation in tropical maize. In another case, maize was supposedly brought to African countries like Nigeria by Portuguese colonists, but the local names for maize in that country are of Arabic derivation, suggesting that the crop likely arrived via Arabic-speaking traders.

Deciphering the history in genes

Recent work by CIMMYT and partners sheds new light on maize’s global migration. With support from Generation, a Challenge Program of the Consultative Group on International Agricultural Research, and in collaboration with nine research institutes on four continents, scientists have used DNA markers—molecular signposts for genes of interest—and new approaches to analyze nearly 900 populations of maize and teosinte from around the world. “What is emerging is a far clearer picture of the crop’s global diversity and the pathways that led to it,” says CIMMYT molecular geneticist and leader of the effort, Marilyn Warburton.

Phase I of the work was funded by PROMAIS, a European maize consortium, and focused on North America and Europe. The Generation Challenge Program commissioned Phase II, which featured global coverage and brought the number of maize populations studied to 580. In Phase III, partners are adding another 300 populations of maize and teosinte, to fill any geographical gaps. A primary objective is to gather samples of landraces—local varieties developed through centuries of farmer selection—and ensure their conservation in germplasm banks. The diversity studies apply a method developed by Warburton for using DNA markers on bulk samples of individuals from large, heterogeneous populations like those typical for maize.

The great divide: Temperate vs tropical maize

Among other things, the studies corroborate the notion that northern European maize originates from North American varieties brought to the continent several decades after Columbus’ returned, and definitely not from tropical genotypes. “The two main modern divisions of maize arose about 3,000 years ago,” says Warburton, “as maize arrived in what is now the southwestern US and, at about the same time, on the islands of the Caribbean. Temperate maize spread further north and east across North America, while tropical maize spread south. The temperate-tropical division remains today. What maintains it are differences in disease susceptibility and photosensitivity—essentially, how daylength affects flowering time. The two maize types are now so different from each other that they do not cross well, and their hybrids are not well adapted anywhere.”

The work continues and, in addition to elucidating the epic journey of maize, will help breeders to home in on and more effectively use traits like drought tolerance from the vast gene pool of maize.

The above report is largely based on a longer description of this work, “Tracing history’s maize,” that appears in Generation’s “Partner and Product Highlights 2006.”

For more information: Marilyn Warburton, molecular geneticist (m.warburton@cgiar.org)

January, 2005

Thanks to pioneering research in Turkey, the links between zinc-deficient soils, plants, people, and continued malnutrition and poverty have been clearly articulated. Few other countries in the world are as well placed to show how plant breeding research can limit the impact of zinc deficiency on crop and human health. So what’s the next step?

In her work as a medical doctor and nutritionist, Prof. Ayhan Çavdar saw many women who could not give birth to healthy children. They had repeated miscarriages and stillbirths. Their babies had agonizing defects of the central nervous system, such as spina bifida, in which the spine fails to close properly, and anencephaly, characterized by an undeveloped brain and incomplete skull. One 18-year-old woman had already miscarried two anencephalitic fetuses. This devastating condition had a surprisingly simple treatment. Çavdar measured the levels of zinc in the young woman’s blood serum, plasma, and hair. They were extremely low. She prescribed zinc supplements for five months. The young woman conceived and gave birth to a healthy child after an uneventful pregnancy.

Zinc deficiency is implicated in health problems throughout the world (see box). The causes and consequences of the problem have been particularly well studied in Turkey, where Çavdar says “a nutrition-related, zinc-deficient milieu exists.”

Wheat is part of that milieu. Most people in Turkey and neighboring countries rely heavily on wheat as a staple. In rural areas, people can consume more than 500 grams of bread every day. Throughout West Asia and North Africa, wheat can constitute from 40 to 60% of daily caloric intake, compared with 21% in Europe or 20% worldwide. People risk zinc deficiency when they subsist on white bread, white rice, or other cereals and consume few vegetables, red meat, or other animal protein.

The Missing Zinc

The widespread zinc deficiency in Turkey’s soils and crops, including wheat, is considered a major
reason for the relatively high incidence of zinc deficiency in its people. In the early 1990s, researchers started a NATOsponsored project in Central Anatolia, Turkey’s major wheat growing area, to investigate the extent and significance of zinc deficiency in soils, plants, foods, and people. Partners included Çukorova University in Adana, the Transitional Zone Agricultural Research Institute in Eskisehir, the Bahri Dagdas International Agricultural Research Center in Konya, the Research Institute of Rural Affairs in Sanliurfa, CIMMYT and Advanced Research Institutes in Australia, Germany, and the USA.

The project, led by Prof. Ismail Çakmak (then with Çukurova University, now with Sabanci University), built on the work of Dr. Robin Graham from Adelaide University in Australia and Mufit Kalayci from the Transitional Zone Agricultural Research Institute in Eskisehir, who had shown the effects of zinc on plant growth and yield. Some wheat varieties, especially those developed from local landraces, used zinc much more effectively than others. Zinc application increased wheat yields by 5-500%, depending on location and soil zinc levels. Also seed that had higher zinc content yielded better than seed with low content.

Çakmak recalls that “when farmers saw the results with zinc fertilizer, they said, ‘Something good like aspirin has come!’ ”Because of the impressive project’s findings, fertilizer companies started producing zinc fertilizer. “Today, ten years after the problem was solidly diagnosed, Turkey uses 300,000 tons of zinc fertilizer. This is a success story,” emphasizes Çakmak. The Ministry of Agriculture estimates that the economic benefit from zinc fertilization in Turkey is about USD 150 million per year.

No Happy Ending—Yet

Plants that get a high dose of zinc fertilizer do not necessarily accumulate enough zinc in the grain to improve human nutrition. Some varieties cannot draw much zinc from the soil. Others easily extract zinc from the soil but cannot make good use of it. Finally, not every farmer can afford zinc fertilizer, and not every country provides it.

“Wheat varieties and landraces, and wheat’s wild relatives, have the genes to solve the zinc problem,” says Hans-Joachim Braun, director of CIMMYT’s Rainfed Wheat Systems Program and participant in the NATO project.

Getting Good Genes

Turkish wheat landraces and cultivars that use zinc efficiently are being combined with wheat varieties developed in the Turkey- CIMMYT-ICARDA International Wheat Improvement Program (IWWIP) that have resistance to yellow rust and root diseases. “We’re evaluating about 180 wheat lines with these traits right now,” says Çakmak. “They’re showing very high levels of zinc efficiency when grown in zinc-deficient soils.” Çakmak and colleagues also found that wild relatives of wheat (Triticum monococcum, T. diccocoides, and Aegilops tauschii) tolerate zinc-deficient soils well compared to bread wheat. “Many of the wild wheats and Aegilops species that exhibit very high tolerance to zinc-deficient soils originated in Turkey,” says Çakmak, “very probably because Turkey has such zincdeficient soils.” They feel this valuable trait can easily be passed to improved bread wheats. Researchers also have high hopes that rye can contribute a similar genetic advantage to wheat.

With funding from DANIDA, CIMMYT evaluated accessions from its wheat genebank for cultivars that produced zinc-rich grain, and considerable variation was found. Çakmak and his team, together with collaborators from Çukurova University (Hakan Ozkan),Tel Aviv University (Eitan Millet), and Haifa University (Eviatar Nevo), have identified wild and primitive wheats from the Fertile Crescent that have grain with seven times as much zinc as modern wheat varieties. Preliminary results also suggest that the grain of wild species has higher levels of proteins and amino acids that make it easier for people to absorb micronutrients such as zinc.

“We have access to nearly 10,000 unique accessions of wild relatives from the Fertile Crescent,” observes Çakmak. “Other research groups are not working with these materials. Because Turkey has zinc deficiency not only in soils and plants but also in people, we’re ideally suited to screen a range of crops for the HarvestPlus program.” (See box below)

HarvestPlus for a More Nutritious Harvest Zinc deficiencies have serious consequences for health. Because there is no widely accepted method for measuring zinc deficiency, no firm estimates are available on the number of people who are zinc deficient. But billions are at risk for zinc deficiency, with the prevalence highest for South and Southeast Asia and Africa. Zinc supplementation has been shown to reduce by a third the effects of common childhood infections, especially diarrhea, pneumonia, and possibly malaria. In addition, zinc deficiency is an important cause of stunting. As part of its contribution to HarvestPlus, the CGIAR’s global alliance to breed and disseminate crops for better nutrition, CIMMYT is developing nutritionally enhanced wheat varieties that will automatically increase people’s intake of essential dietary elements like zinc. Given that CIMMYTderived spring bread wheat varieties are planted on 80% of the global spring wheat area, the impacts could be wide-ranging. The white bars in the figure above show the zinc content of wheat lines that are far along in the breeding process, of excellent agronomic type, and into which CIMMYT breeders have incorporated high levels of zinc (172% of check, in the best line). The best will be used to transfer this trait to other wheat varieties and for studies in which DNA markers will help researchers identify genes associated with high zinc content.

For more information: h.j.braun@cgiar.org