CIMMYT E-News, vol 4 no. 9, September 2007

The larger grain borer is taking a beating from CIMMYT breeders in Kenya as new African maize withstands the onslaught of one of the most damaging pests.

Scientists from CIMMYT, working with the Kenya Agricultural Research Institute (KARI), have developed maize with significantly increased resistance to attack in storage bins from a pest called the larger grain borer. In just six months this small beetle can destroy more than a third of the maize farmers have stored. The new maize varieties, which dramatically decrease the damage and increase the storability of the grain, will be nominated by KARI maize breeders to the Kenya national maize performance trials run by the Kenya Plant Health Inspectorate Services (KEPHIS). The same varieties will also be distributed for evaluation by interested parties in other countries through the CIMMYT international maize testing program in 2008.

“This is a major achievement and will be of great help to farmers in Kenya and more than 20 African countries, who have had few options to control this pest for nearly 30 years” says Stephen Mugo, the CIMMYT maize breeder who headed the CIMMYT-KARI collaboration, which has been funded in part by the Syngenta Foundation for Sustainable Agriculture.

The larger grain borer, native to Central America, was first observed in Africa in Tanzania in the late 1970s and early 1980s. A particularly severe drought struck eastern Africa in 1979 and there was little local maize. The world responded with large shipments of maize as aid. The borer may well have been an uninvited guest in a food aid shipment.

Even in Latin America, where it has co-evolved with natural predators, losses are significant. In Africa, where there are no similar predators to control the insect, its spread has been most dramatic. Attempts to introduce some of those predators to Africa to control the borer (a technique called biological control) have met with limited success and regionally concerted action is essential if biological control is to be effective across borer-infested areas. Researchers also studied the habits of the borer, hoping to find ways to reduce the damage it does. They discovered that it needs a solid platform, such as that provided by maize kernels still on the cob, before it will bore into a kernel. Unfortunately African farmers often store maize on the cob, increasing the potential for borer damage. By shelling the maize and storing the kernels off the cob, the damage can be reduced by small amounts, but losses are still very high. This is what makes the development of new varieties, where the resistance lies in the seed, so exciting.

“Having the solution in the seed itself makes adoption much easier for farmers,” says Marianne Banziger, the director of CIMMYT’s Global Maize Program. “There is no added workload or expense to the farmer, no longstanding practices or habits to change.” But Banziger cautions that resistant maize is not a silver bullet solution to the grain borer problem. “We strongly encourage the use of the new varieties in combination with other measures,” she says. “The varieties are more resistant but as time progresses there will still be some damage, though much less than before.”

CIMMYT researchers found resistance to the borer in the Center’s germplasm bank, in maize seed originally from the Caribbean. The bank holds 25,000 unique collections of native maize races. By using conventional plant breeding techniques, crossing those plants with maize already adapted to the conditions found in eastern Africa, Mugo and the breeding team were able to combine the resistance of the Caribbean maize with the key traits valued by Kenyan maize farmers. The maize was tested for resistance at the KARI research station in Kiboko, Kenya. Larger grain borers were placed in glass jars with a known weight of maize. Weight changes to the maize and a visual assessment of damage were recorded, allowing researchers to select the best lines. The result is new maize varieties that will benefit farmers in Kenya and help reduce Kenya’s dependence on imported maize for national food security.

Testing by Kenya Plant Health Inspectorate Services and by national seed authorities in other countries is expected to take 1-3 years, after which seed of the new maize hybrids and open pollinated varieties will be available to seed companies for seed production and sale to farmers.

For more information: Stephen Mugo, Maize breeder (s.mugo@cgiar.org)

CIMMYT E-News, vol 4 no. 2, February 2007

At an agricultural research station in Kenya, ingenuity, improvised tools, and a small group of talented, dedicated researchers and technicians using good science, are on the front line of the battle to prevent a potential multi-billion dollar crop disaster for the world.

Peter Njau has a look of concern on his face and a sense of urgency in his voice. “Be very gentle,” he says. “You don’t have to separate each seedling from the others.” Njau, KARI-Njoro’s wheat breeder, is teaching technicians at the Njoro Agriculture Research Centre of the Kenya Agricultural Research Institute (KARI) to transplant thousands of extremely delicate winter wheat seedlings. The seedlings have been kept in a cool environment to simulate a temperate winter and now they are ready for what they will interpret as springtime.

The technicians are using a new transplanting method for the very first time. It should be more efficient but the team only has one chance to get it right. All day they have been preparing the plot, wetting it down and cooling the soil using a new sprinkler irrigation system; making small furrows in the damp soil and putting in beads of fertilizer; carefully marking and labeling the location for each plant. The transplanting has to take place just before sunset so the seedlings will have cool soil and a cool night to start establishing their young root systems. Any mistake and they will die and the opportunity to test them for resistance to the new stem rust will be lost until the next season.

Speed and precision are vital since the airborne fungus that was discovered in Uganda in 1999 has now spread beyond the African continent. It is following a path that will take it to the great wheat growing areas of south Asia where farmers grow wheat eaten by a billion people. In the last great stem rust outbreak in North America in 1954, the fungus destroyed as much as 40% of the spring wheat crop.

The Njoro station is in the Great Rift Valley of Kenya, not far from the city of Nakuru and very close to the Equator. The new stem rust spores have been present in the air at the station for at least three years, making it the perfect location for testing wheat to see if it can resist the fungus. Called Ug99, the new stem rust is such a large threat to wheat around the world that scientists dare not transport the spores themselves to other test locations. Instead as part of the CIMMYT-ICARDA Global Rust Initiative, which also includes national partners like KARI and the Ethiopian Institute of Agriculture Research (EIAR), the world’s wheat comes to East Africa. Similar work is being conducted at several sites in Ethiopia by EIAR. “We are committed to work with international partners to fight the looming threat of stem rust,” says Dr. Bedada Girma, leader of EIAR’s Stem Rust Task Force.

Njau works for KARI and manages both his KARI assigned research as well as the GRI wheat nurseries (plots of different wheat plants) at the station. In one area the team grows three different kinds of wheat that are known to be easily infected with Ug99. The three wheats mature at different times so there is always a source of infection to challenge the wheat being tested. An adjacent field has over 3,000 samples of spring wheat in nurseries designed to confirm what appears to be resistances found in previous seasons. Those nurseries also include CIMMYT and KARI breeding populations from which breeders hope to extract high performance, Ug99 varieties for Kenya and the world.

Not far from the plots, inside a small building, sheets of polyethylene shroud a makeshift innoculum chamber. Plastic garbage bags act as blinds to keep the room dark. On the floor are two old plastic spray bottles for water to keep the leaves of the host wheat plants damp. It is here where the fungus is grown and multiplied for use later on test plants. “We improvise a lot here,” says Miriam Kinyua, the Director of the station and overall coordinator of Kenya wheat research, including GRI activities. “The world needs this work to be done.” She also expresses gratitude to the Canadian International Development Agency for providing funding that let the station put in a good irrigation system. “We can now grow wheat in the off season and ensure that if the rains fail, our testing won’t,” she says. She is also pleased that the research station is now connected to the rest of the world via a satellite dish and the internet, another result of the CIDA contribution. New contributions from USAID are adding to the support for GRI work in both Kenya and Ethiopia.

Back at the transplant plot each group of seedlings is hand watered. Early the next morning the team will put small tree branches in the ground around the plot as stakes to hold up some old canvas sheets. The canvas will shade the fragile seedlings from the hot equatorial sun for another three days. Perhaps under the flapping canvas is a seedling that holds the key to durable resistance to the Ug99 fungus.

For more information Rick Ward, Coordinator, Global Rust Initiative (r.w.ward@cgiar.org)

CIMMYT E-News, vol 3 no. 12, December 2006

Wheat lines that resisted virulent stem rust last season have now succumbed.

Observations from wheat rust screening trials in Kenya indicate even more of the world’s wheat is at risk from a stem rust attack than originally thought. Scientists from CIMMYT and its partners, studying wheat planted at the Njoro Agriculture Research Centre, report that more than 85% of sample wheats, including cultivars from the major wheat producing regions of the world, have succumbed to the stem rust known as Ug99. Most importantly some wheat lines which showed resistance to Ug99 stem rust a year ago now appear to be susceptible to the disease.

In August, 2005 an expert panel raised the first alarm about the new, virulent form of stem rust that could devastate world wheat crops. These new observations could mean the threat to the global wheat harvest is now significantly greater.

The Njoro Research Centre is in an area of Kenya where the virulent form of stem rust fungus is endemic. For the past three years scientists have used the station to expose wheat to the disease to see which is susceptible and most importantly, which is not. In March of 2006 more than 11000 different types of wheat and relatives of wheat from all over the world were planted and exposed to the fungus.

Studies are still underway to clarify the situation but it appears that at least one of the major stem rust resistance genes that has protected many of the world’s wheats for decades is no longer effective against the rust fungus at Njoro. This new development enhances the significance of what is already recognized as a dangerous threat to future global wheat harvests.

Wheat grows on more than 200 million hectares in both the developed and the developing world and the new data indicate that very little of that area is planted to varieties which resist the stem rust found at Njoro. Though stem rust may not be able to thrive in all parts of the world, scientists estimate that well over half of the total wheat area could suffer rust epidemics if susceptible varieties planted there are exposed to the pathogen.

“I was shocked at what I saw this season,” says Rick Ward, coordinator of the CIMMYT-ICARDA led Global Rust Initiative. “Essentially we have to find a way to replace all of the world’s wheat.”

Stem rust is one of the most dreaded of all plant diseases. In the mid-1950s it wiped out up to 40% of the North American spring wheat crop. Thanks in large part to the wheat breeding work of Nobel Peace Prize laureate, Dr. Norman Borlaug and those who followed him, the disease has not been a significant threat for almost half a century. Breeders combined several sources of resistance to the fungus into new varieties of wheat. Unfortunately, over time, the rust pathogen evolved and mutated and in 1999 scientists found a strain in Uganda (Ug99) that could bypass much of that resistance. The spores of the Ug99 fungus can travel great distances on the wind. The pathogen has already spread from Uganda into Kenya and Ethiopia. An outbreak of yellow rust originated in the same region of eastern Africa and eventually spread across the Arabian Peninsula and into the major wheat-growing areas of India and Pakistan. Studies of wind patterns in the region have led scientists to conclude that the new pathogen will eventually threaten wheat crops on a global scale.

CIMMYT and the International Center for Agricultural Research in the Dry Areas (ICARDA), together with partners such as the Kenya Agricultural Research Institute (KARI) are leading a global effort to characterize the rust pathogen; to track its spread and to find new sources of resistance to the disease and breed them into new wheats. This is especially important to farmers in the developing world who have little access to fungicides that could help reduce the damage.

“The good news is that some samples at Njoro did resist the fungus,” says CIMMYT wheat scientist, Ravi Singh. “That has given us a good place to start.” In fact Njoro is also the site where potential resistant breeding lines are now undergoing test.

For more information, Rick Ward (r.w.ward@cgiar.org)

June, 2005

A new study reports on the extensive use and benefits of CIMMYT wheat.

The advantage is clear: the use of CIMMYT wheat creates enormous benefits for those who grow them. Even by conservative estimates, every US $1 invested in wheat research by CIMMYT generates at least US $50 for those involved in growing CIMMYT-related wheats. According to the publication, Impacts of International Wheat Breeding Research in the Developing World, 1988-2002, farmers sowed CIMMYT-improved varieties on 62 million hectares in 2002.

“This report reaffirms the major contributions of CIMMYT wheat around the world, including areas of smallholder, resource-poor farmers,” says John Dixon, director of CIMMYT’s Impacts Targeting and Assessment Program. Farmers in developing countries yield 14 million more tons of wheat per year because of international wheat breeding research. In addition, 80% of wheat grown in developing countries has CIMMYT wheat in its family tree.

Because this report documents the successful adoption of modern wheat lines, policy-makers will be able to assess progress and set priorities for future research investment. Its conclusions support those found in two earlier studies, and the coverage extends to include many countries in Eastern Europe and the former Soviet Union.

In countries such as Argentina, Brazil, Chile, and Uruguay, more than 75% of wheat marketed by private companies has CIMMYT ancestry. Widespread adoption of CIMMYT lines reflects the extensive use of partnerships and networks with other breeding programs to reach farmers with relevant varieties. This adoption and the subsequent higher on-farm yields generate enormous benefits for farmers, enhancing their food security and livelihoods (see box)—a central part of CIMMYT’s mission.

Check out our website to order this publication and click here to view a research summary of this report. (PDF)

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

CIMMYT E-News, vol 6 no. 2, February 2009

Demand for maize has popped up across Asia, but much of the grain is enjoyed by poultry, not people. In Bangladesh, maize is a fairly new crop, yet demand in this country already mirrors that of neighboring nations like China and India. A recent CIMMYT report explores these emerging trends and the efforts to incorporate sustainable and economically viable maize cropping systems into a traditionally rice-based country.

“Simply put, people have more money,” says Olaf Erenstein, a CIMMYT agricultural economist. “Asia’s population growth has slowed and incomes have increased. This means dietary demands and expectations are changing as well.”

With extra money in their pockets, many people across Asia are starting to desire something with a bit more bite. In the past 40 years, increased prosperity and a related meat demand have sent two-thirds of global maize production toward animal feed instead of direct consumption. Currently, 62% of maize in Asia is used to feed livestock while only 22% goes straight to the dinner plate. This is not surprising, as total meat consumption in the seven major Asian maize-producing countries1 rose 280% between 1980 and 2000. Poultry, particularly, plays a large role. During the same time period, poultry production rose 7% each year in Asia, compared to a 5% global average.

The bare-bones reason for this shift is that it takes more grain to produce meat than would be used if people ate the product directly. Grain-to-meat conversion ratios for pork are on the order of 4:1. Chicken is more efficient, requiring only 2 kilograms of grain feed for a kilogram of growth. Either way, when people substitute meat for grain, grain production must increase to meet the demand.

From a farmer’s perspective, this is not a bad thing, and what is occurring now in Bangladesh illustrates how farmers can benefit, according to a recently published CIMMYT study. With a 15%-per-year increase in Bangladesh’s poultry sector since 1991, the feed demand has opened a new market for maize. And since the country’s current average per person poultry consumption is at less than 2 kg a year—compared to almost 4 kg in Pakistan, 14 kg in Thailand, and 33 kg in Malaysia—the maize and poultry industries have plenty of room to spread their wings.

What came first: The chicken or the seed?

The poultry industry in Bangladesh employs five million people, with millions of additional households relying on poultry production for income generation and nutrition. “Only in the past 10 to 15 years, as many people got a bit richer, especially in urban centers, did the market for poultry products, and therefore the profitability of maize, take off in Bangladesh,” says Stephen Waddington, who worked as regional agronomist in the center’s Bangladesh office during 2005-07 and is a co-author of the CIMMYT study.

“Many maize growers keep chickens, feed grain to them, and sell the poultry and eggs; more value is added than by just selling maize grain,” he says. “Most Bangladeshis have no history of using maize as human food, although roasting cobs, popcorn, and mixing maize flour with wheat in chapattis are all increasing.” Waddington adds that maize could grow in dinnertime popularity, as the price of wheat flour has increased and the price of maize grain remains almost 40% lower than that for wheat.

Worldwide, more maize is produced than any other cereal. In Asia, it is third, after rice and wheat. But due to the increasing demand for feed, maize production in Asia has almost quadrupled since 1960, primarily through improved yields, rather than area expansion. Future rapid population growth and maize demand will lead to maize being grown in place of other crops, the intensification of existing maize lands, the commercialization of maize-based production systems, and the expansion of maize cultivation into lands not currently farmed. The International Food Policy Research Institute estimates that Asia will account for 60% of global maize demand by 2020.

Maize in Bangladesh is mainly a high-input crop, grown with hybrid seed, large amounts of fertilizer, and irrigation. While a successful maize crop requires high inputs, it also provides several advantages. “Maize is more than two times as economical in terms of yield per unit of land as wheat or Boro rice,” says Yusuf Ali.”Maize also requires less water than Boro rice and has fewer pest and disease problems than Boro rice or wheat.” The maize area in Bangladesh is increasing around 20% per year.

Maize-rice cropping challenges

“The high potential productivity of maize in Bangladesh has yet to be fully realized,” says Yusuf Ali, a principal scientific officer with the On-Farm Research Division (OFRD) of the Bangladesh Agricultural Research Institute (BARI) and first author of the CIMMYT study. Bangladesh has a subtropical climate and fertile alluvial soils, both ideal for maize. From only a few thousand hectares in the 1980s, by 2007-08 its maize area had expanded to at least 221,000 hectares, he said.

Maize in Bangladesh is cropped during the dry winter season, which lasts from November to April. The other two crops commonly grown during winter are high-yielding irrigated rice (known in Asia as “Boro,” differentiating it from the flooded paddy rice common throughout the region) and wheat. Adding another crop into the mix and thereby increasing cropping diversity is beneficial for farmers, offering them more options.

Rice, the traditional staple cereal crop in Bangladesh, is grown throughout the country year round, often with two to three crops per year on the same land. So as the new crop on the block, maize must be merged with existing cropping patterns, the most common of which is winter maize sown after the harvest of paddy rice. And since rice is the key to food security in Bangladesh, farmers prefer to grow longer-season T. aman rice that provides higher yields than earlier-maturing varieties. This delays the sowing of maize until the second or third week of December. Low temperatures at that time slow maize germination and growth, and can decrease yields more than 20%. In addition, the later-resulting harvest can be hindered by early monsoon rains, which increase ear rot and the threat of waterlogging.

Another problem with maize-rice cropping systems is that the two crops require distinct soil environments. Maize needs loamy soils of good tilth and aeration, whereas rice needs puddled wet clay soils with high water-holding capacity. Puddling for rice obliterates the soil structure, and heavy tillage is required to rebuild the soil for maize. This is often difficult due to a lack of proper equipment, time, or irrigation. Moreover, excessive tillage for maize can deplete soils of nutrients and organic matter. Thus, as maize moves into rice-based cropping systems, agronomists need to develop sustainable cropping patterns, tillage management options, and integrated plant nutrient systems.

Support and supplies vital for success

“For a new crop like hybrid maize to flourish, there needs to be a flow of information and technology to and among farmers,” Waddington says.

In collaboration with the Bangladesh Agricultural Research Institute (BARI), the Department of Agricultural Extension (DAE), and various non-governmental organizations, CIMMYT provided hands-on training for maize production and distributed hybrid seed (which tends to be higher-yielding and more uniform, but must be purchased and planted each year to experience full benefits) to over 11,000 farm families across 35 districts in Bangladesh from 2000-06. A CIMMYT report showed that farmers who received the training were more likely to plant their maize at the best times and also irrigated more frequently and adopted optimal cropping patterns and fertilizer use, resulting in higher yields and better livelihoods.

“This training is vital, since the country is full of tiny, intensively-managed farms. Maize tends to be grown by the somewhat better resourced farmers, but these are still small-scale, even by regional standards,” says Waddingon, adding that farm families were eager to improve their maize-cropping knowledge and their fields.

Other efforts include BARI’s development and release of seven maize hybrids largely based on germplasm from CIMMYT. Two of the hybrids consistently produce comparable grain yields to those of commercial hybrids. The Institute is also working on short duration T. aman rice varieties that have yields and quality comparable to traditional varieties and could thus allow timelier planting of maize.

Power tillers seed the future

Another important advancement is the power-tiller-operated seeder (PTOS) created by the Wheat Research Center (WRC) of BARI. Originally for wheat, the machine has been modified and used to plant maize. Additional PTOSs need to be built, tested, and marketed. Another promising piece of equipment in the works is a power-tiller-operated bed former. Because making and destroying soil beds between every rice/maize rotation is not practical or efficient, the WRC-BARI/CIMMYT farm machinery program is working on a tiller that simultaneously creates a raised bed, sows seed, and fertilizes. This is vital since the turnaround time between rice and maize crops is limited. Like the PTOS, further testing and promotion are needed.

Though much work is still required to incorporate maize fully and sustainably into Bangladesh’s cropping systems, it has already spread across the country quicker than anticipated. Even so, scientists believe future production will fall short of demand. This gap provides farmers an additional crop option, and plants maize in a good position for future growth in Bangladesh.

For more information: Enamul Haque, program manager, CIMMYT-Bangladesh office (e.haque@cgiar.org).

1 China, India, Indonesia, Nepal, the Philippines, Thailand, and Vietnam were identified in a CIMMYT study as Asian countries with more than 100 K hectares sown with maize. At the time of the study, Bangladesh did not meet this maize area requirement and therefore is not included in this statistic.

CIMMYT E-News, vol 4 no. 8, August 2007

Faster, cheaper, more efficient: gift from DuPont helps CIMMYT scientists look for genes in wheat and maize—and gives breeders an affordable tool to help select the best.

A quiet revolution is taking place in CIMMYT’s biotechnology labs. The team has just received a new generation of genotyping machines. These semi-automated work-horses will make it much easier to determine whether breeding lines contain specific useful genes. It is hoped that this will help maize and wheat breeders—through a process known as marker-assisted selection (MAS)—to make breeding more effective and get crop varieties with valuable traits to poor farmers more quickly.

Traditionally, the only way to find out whether the offspring from a particular cross have inherited useful characteristics, such as drought tolerance, disease resistance, or grain quality, has been to grow them in the field and evaluate the adult plants. MAS can speed up the breeding process, since it makes it possible to track the presence of desired genes in every generation. This does not bypass the need for field evaluation, but can greatly improve the efficiency of the process. “Field screening takes time, space, and resources, and our capacity is limited,” explains CIMMYT maize breeder Gary Atlin, “but with MAS we could use resources more effectively, zeroing in on the best lines to test in the field and filtering out those that haven’t inherited the characteristics we need.”

When researchers want to find out whether a particular line of wheat or maize has the useful version of a gene (for example, disease resistance rather than disease susceptibility), they use nearby, identifiable sections of DNA known as markers, labeled with a fluorescent dye. Different versions of markers and genes are called alleles. DNA that is close together on the chromosome tends to stay together over generations, so a specific allele of a marker will be routinely inherited alongside the desired allele of a nearby gene. Using the new capillary electrophoresis genotyping machines, the sample is forced along a narrow capillary tube under the influence of an electric current. A laser at the end of the tube detects the different alleles of the fluorescent markers, indicating to the scientist whether the sample contains the allele they want.

The two ABI 3700 machines have been generously donated to CIMMYT by DuPont through its Pioneer Hi-Bred seed business, reflecting a fruitful collaborative relationship of more than a decade’s standing. Until now, CIMMYT has run most of its marker-assisted selection work on manual, gel-based electrophoresis apparatuses. In addition, analyses of genetic relationships between different wheat or maize lines have been run on older ABI genotyping machines, including two based on the previous, much slower generation of gel-based machines. The new machines can handle many more samples—96 each at a time—but it’s the savings in hands-on time that makes the real difference. “There’s no comparison,” says Marilyn Warburton, Head of CIMMYT’s Applied Biotechnology Center. “It will take us ten minutes to load one of these new machines, whereas it takes about four hours to make and load a manual electrophoresis gel.”

As well as being much quicker and less labor-intensive, capillary electrophoresis makes it possible to test for more than one marker and run more than one sample at once in each tube. By using different colors of fluorescent dye for each sample, markers for each can be distinguished, like teams of runners wearing different-colored jerseys. For maximum efficiency, scientists can also set up groups of samples to run at slightly different times, like runners set off in a staggered start. CIMMYT will even be able to develop a new type of marker, known as SNPs, which allow numerous traits to be tested simultaneously, providing more information per sample.

All of this means that the new machines have a much higher throughput capacity, and can process many more samples for the same labor input, drastically reducing the per-sample cost—currently the major constraint on use of MAS. “If MAS were significantly cheaper, I would certainly use it in maize breeding,” says Atlin. “Effectively, it lets you quickly transfer the genes you want into improved varieties. If you’re doing a backcross between a donor with a desired trait and an improved parent with good agronomic performance, you’re trying to select for one characteristic from the donor, but against all its other genes. With a number of markers, MAS makes it possible to determine exactly which progeny combine the desired gene from the donor with the good genes from the other parent. You can get results in two generations, compared to four or five normally.”

The challenge for MAS is finding genes with substantial effects, especially for complex traits such as drought tolerance in maize. Atlin believes such genes are still to be found. “In the past, donors with a single useful gene or trait but otherwise poor agronomic qualities were very difficult to use in breeding, as they introduced so much bad material. We can get rid of that useless material through MAS. That opens up the field to look for useful genes in a wider range of parents. And genotyping technology is getting cheaper and better at finding genes all the time.”

In wheat, the hunt for useful markers at CIMMYT is more advanced. “We’re working with new markers to select for nematode resistance, leaf and stem rust resistance, boron tolerance, Fusarium resistance, and grain quality,” says Susanne Dreisigacker, CIMMYT wheat molecular biologist. “Our current work is all gel-based, which means running tests sample by sample and marker by marker. Being able to run many samples at the same time will make a huge difference.”

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

CIMMYT E-News, vol 4 no. 1, January 2007

Farmers and community leaders in Kenya’s most densely-populated region have organized to produce and sell seed of a maize variety so well-suited for smallholders that distant peers in highland Nepal have also selected it.

According to Paul Okong’o, retired school teacher and leader of Technology Adoption through Research Organizations (TATRO), Ochur Village, Western Kenya, farmers first disliked the maize whose seed he and group members are producing. “It has small grains, and they thought this would reduce its market value,” he explains. “But when you sowed the seed, which looked small, what came out of it was not small!”

Small-scale maize farmers of the Regional Agricultural Association Group (RAAG), another community-based organization in Western Kenya, have quintupled their yields in only one year—now obtaining more than 2 tons of maize grain per hectare—using seed, fertilizer, and training from TATRO, according to RAAG coordinator, David Mukungu. “This has meant that, besides having enough to eat, farmers were able to sell something to cover children’s school fees or other expenses,” says Mukungu. “We started with six farmers the first year, but after other farmers saw the harvest, the number using the improved seed and practices increased to thirty, and we expect it will continue increasing.”

The variety whose seed TATRO grows is called Kakamega Synthetic-I. It is an open-pollinated variety—a type often preferred over hybrids by cash-strapped smallholders, because they can save grain from the harvest and sow it as seed the following year, without losing its high yield or other desirable traits. The variety is also drought tolerant, matures earlier than other local varieties, and is better for making Kenyan’s favorite starchy staple, ugali. “Women say it ‘pulls’ the water, which means you don’t need much maize flour to make a good, heavy ugali,” Okong’o explains. “These things seem small, but when taken together they weigh a lot for farmers who eat ugali as a daily staple.”

A maize that crosses many borders

Kakamega Synthetic-I was released by the KARI research station in Kakamega, Kenya. Its pedigree traces back to the work of CIMMYT and many partners in southern and eastern Africa—national maize research programs, private companies, and non-government organizations—to develop stress tolerant maize for the region’s smallholders. “Kakamega Synthetic I was selected from ZM621, a long-season, drought tolerant, open-pollinated variety now released in several African countries,” says Marianne Bänziger, CIMMYT maize physiologist who took part in the creation of ZM621 and now serves as director of the center’s Global Maize Program. “The variety has also been released in Nepal, after small-scale farmers from the mid-hills chose it as one of their favorites in participatory varietal trials.” Bänziger says. This highlights the role of a global organization like CIMMYT, which can draw upon and distribute public goods and expertise transcending national borders: “The center was predicated upon and has practiced collaborative science ‘globalization’ for agricultural development since its inception four decades ago—long before that term became fashionable in policy circles.”

Finding and filling entrepreneurial niches

By reducing risk for small-scale farmers, varieties like Kakamega Synthetic-I encourage investment in other amendments, like fertilizer, that can start smallholders on an upward spiral out of low-input, subsistence agriculture. Good varieties also entice enterprising farmers and community-based organizations like TATRO into potentially profitable businesses like seed production, for niches inadequately served by existing companies. “We observe the seed production regulations of the KEPHIS, the Kenyan plant health inspectorate, and would like to work toward certification of our organization, to be able to sell certified seed in labeled packages and fetch better prices,” says Okong’o. TATRO is currently producing and marketing just under 2 tons of Kakamega Synthetic-I—enough to sow more than 70 hectares—each year. The lack of effective informal seed production and distribution systems limits the spread of improved open pollinated maize varieties and farming practices in eastern Africa, according to Stephen Mugo. CIMMYT maize breeder in the region, Mugo also coordinated the former, Rockefeller Foundation-funded project “Strengthening maize seed supply systems for small-scale farmers in Western Kenya and Uganda” that involved TATRO and similar farmer organizations. “Improved varieties raised yields in the past and could do so again,” he says, “but only about one-fifth of the region’s farmers grow improved varieties.”

For more information, Stephen Mugo, maize breeder (s.mugo@cgiar.org)