Helping smallholder farmers reap the most from drought tolerant maize

Florence Sipalla, f.sipalla@cgiar.org

At the first sign of the short rain season, farmers know that it is time to till the land and plant. In these harsh times, when rain is scarce, some farmers opt to plant before the rain comes to take advantage of every drop. James Mativo from Makaveti Village in Kyanzasu sublocation in Machakos County is one such farmer. He proudly http://iupatdc5.org displays a healthy crop to visitors, with green maize ready for plucking. “I planted just before the season began, to ensure that the crop would sprout when the rain came,” he explains.

For many farmers in the semi-arid Eastern Province in Kenya, preparing fields ahead of the rain is not enough to guarantee a good harvest. Having the right seeds is vital too. Mativo buys certified seeds, suited to the area’s climate, from Dryland Seed Company in Machakos town. “For these dryland varieties, the first rains are very important,” explains Peter Mutua, a Dryland agronomist. “It allows the farmers to take full advantage of this scarce resource from germination. This is particularly important as most farmers in Kenya grow maize under rainfed conditions, even in the semi-arid areas.”

Just as a relay race is a team effort, so is the process of delivering quality seeds to farmers. It takes many people, working together, to ensure that farmers get the best seeds suited to the climatic conditions in their locales. Take the case of drought tolerant maize varieties: the process starts with breeders who develop the germplasm and share it with research partners. They pass the baton to the seed companies who produce large quantities of the seeds which smaller-scale farmers buy from them. The companies cross-pollinate sources of desirable traits to develop maize varieties relevant to the farmers. Often they start with sources from public research organizations such as IITA and the International Maize and Wheat Improvement Center, known by its Spanish acronym CIMMYT.

“We try to improve the existing varieties and come up with more that are better than those in the market,” says Peter Setimela, a CIMMYT maize breeder. “With climate change, varieties developed 20 years ago are no longer suitable for the changing environment.” Breeders working under the Drought Tolerant Maize for Africa Initiative led by CIMMYT have developed varieties known as the Kenya Dryland Varieties (KDV) series. KDV 1–6 varieties were released to farmers by the Kenya Agricultural Research Institute (KARI), as well as Freschco and Dryland Seed Companies. The fourth variety of the series is the one now growing on Mativo’s quarter-hectare farm.

It is not only climate change that concerns breeders; they also want to develop varieties that are disease resistant and relevant to the farmers’ other needs – proper milling and cooking quality or flavor, for example. “This is why we have farm trials,” explains Peter Setimela. These trials are done in collaboration with the national research organizations, such as KARI in Kenya. “We look for those traits that farmers prefer. In Kenya, they like white maize for making ugali. In Zimbabwe, some people prefer ZM309 because it is sweet when roasted.”

The seed companies and KARI multiply seeds to furnish supplies adequate to the farmers’ demands, but they also depend on farmers they hire to produce those seeds. “We work with groups of farmers who each have at least 5 acres (2.5 ha),” says Ngila Kimotho, Managing Director of Dryland Seed Company. The seed company clusters the farmers by sublocation and trains them. This, according to Musa Juma, a contract farmer for Dryland in Kibwezi, Eastern Province, is “risk-free planting. This is because you are planting for a known market; as you plant, you don’t have to start worrying about where to sell the produce. An additional perk is that the company provides the seeds.”

Seed companies also use local demonstration farms to show the performance of various maize varieties, winning over farmers to the new varieties that outperform traditional ones. Dryland Seed Company also uses vernacular radio programs to disseminate information on the most productive varieties. “These are interactive shows. We have farmers calling in to find out the best variety to grow, when and where to obtain the seeds,” explains Kimotho. He said that farmers prefer open-pollinated varieties that are early-maturing and drought tolerant and thus better suited to planting in the short rains in the region.

“The basic need in the dry areas is food security,” says Kimotho, adding that farmers sell the surplus grain only when they have a rare bumper harvest. To cater for the diversified market, Dryland markets seeds in packets from 100 g to 1 kg, so there is an affordable option for every farmer. The 100 g package is popular with those who are keen to try out new varieties. “Even students buy it for their parents to try,” says Kimotho. Smallholder farmers, most of whom are women, also choose this option to ensure a subsistence maize crop for their families.

By the same token, farmers are reluctant to place all their trust in a single variety. On Mativo’s farm, he spreads the risk by planting hybrids alongside beans and cowpea. “When the rains are good, the hybrids do well and have high yields, but if the rains are not so good, I still have food from the KDV,” says Mativo. “It would be very sad for a farmer to lack food. When I have food, then my neighbors are also food secure.” Mativo uses ox-drawn plows on his farm, but he also occasionally employs a few manual laborers, some of whom he pays in kind with maize grain, at their request.

In the rare years that farmers get a bumper harvest, they need to sell the surplus. But when there is a plentiful supply, the price of maize is low, and storage becomes an even more vital component of the value chain: the grain requires a pest-free mechanism that also saves the http://dailykhabarnama.com/buy/ maize from fungal infections, some of which can produce deadly toxins.

Ultimately, every participant in this value chain, the relay race, is focused on one thing–food security. “Working with partners in the national agricultural systems and seed companies, the DTMA program aims to produce 70,000 t of seeds by 2016 with drought tolerant maize varieties in 13 African countries,” said Tsedeke Abate, the Program Leader based in Nairobi. He added that this is enough to plant about 2.8 million ha, an area equivalent to the farms of about 7 million smallholder households.

New maize variety brings hope to Kenya’s drylands

Wandera Ojanji, w.ojanji@cgiar.org

Last harvest, many farmers in lower Eastern Kenya were left staring in dismay at their failed maize crops. Once again, droughts had left people in the area desperate; they must purchase maize themselves or rely on famine relief food operations.

However, a few farmers were expecting bumper maize harvests―neither via miracles nor witchcraft―thanks to a new maize variety which is both drought tolerant and resistant to stalk borers, two of the biggest production constraints in the region.

The variety, referred to as CKIR04003 (CIMMYT/Kenya Insect Resistant), represents joint breeding efforts between the Kenya Agricultural Research Institute (KARI) and CIMMYT, under the Developing Maize Resistant to Stem Borer and Storage Insect Pests for Eastern and Southern Africa – IRMA III Conventional Project (a predecessor to the Insect Resistant Maize for Africa Project). Released in 2006, CKIR04003 has the added advantage of being an open-pollinated, early maturing, and high yielding variety―31 to 45 bags/ha, according to Stephen Mugo, CIMMYT’s Maize Breeder.

One of the farmers benefiting from the new variety was Paul Ndambuki. He chose CKIR04003 because, as he said, he needed a variety that could withstand droughts as well as being resistant to stem borers. “From the information provided by KARI, I felt CKIR04003 was the variety I wanted. I did not need any further prodding before trying it out.”

It was a decision that paid off, despite less than perfect preparation. “I got the seeds towards the end of March. Because I was in a rush to plant before the onset of rains, I didn’t plant with fertilizer. I added compound fertilizer only after germination. I had hoped to top-dress with CAN fertilizer. But this did not happen as it rained for only two weeks in the entire growing season. I was a worried man,” states Ndambuki. “But my worries gradually turned into amazement. In complete contrast to my neighbors’ farms, under local varieties or other hybrids, my maize was so green and robust. It looked like a crop under irrigation.”

After six weeks, the maize remained free from stem borers. These borers normally cause huge losses in the region, and also make the attacked maize susceptible to fungal infestation and aflatoxin. Ndambuki got 35 bags of maize from his 0.8 ha of CKIR04003, compared with the 12 bags he had obtained from 1 ha the previous season.

Impressed by Ndambuki’s enthusiasm, KARI has named the variety Pamuka1, in honor of Paul, his wife Jane Mumbua, and the Kamba community.

Two extra-early maturing white maize hybrids released in Nigeria

B. Badu-Apraku, b.badu-apraku@cgiar.org, S.A. Olakojo, G. Olaoye, M. Oyekunle, M.A.B. Fakorede, B.A. Ogunbodede, and S.E. Aladele

Two extra-early maturing hybrids with combined resistance/tolerance to Striga, drought, and low soil nitrogen have been released in Nigeria by the Institute of Agricultural Research and Training (IAR &T) in Nigeria. The extra-early hybrids originally known as IITA Hybrid EEWH-21 and IITA Hybrid EEWH-26 and now designated as Ife Maizehyb-5 and Ife Maizehyb-6 were developed by IITA, and tested extensively in Nigeria in partnership with IAR & T, through the funding support of the Drought Tolerant Maize for Africa (DTMA) Project. The DTMA Project is executed by CIMMYT and IITA with funds provided by the Bill & Melinda Gates Foundation.

Early (90-95 days to maturity) and extra-early (80-85 days to maturity) maize varieties can contribute to food security especially in marginal rainfall areas of West and Central Africa. These varieties are ready for harvest early in the season when other traditional crops such as sorghum and millet are not ready, and are thus used to fill the hunger gap in July in the savanna zone when all food reserves are depleted after the long dry period. Furthermore, there is a high demand for the early and extra-early cultivars in the forest zone for peri-urban maize consumers.

These maize varieties provide farmers the opportunity to market the early crop as green maize at a premium price in addition to being compatible with cassava for intercropping (IITA 1992). However, despite the potential of early and extra-early maize to contribute to food security and increased incomes of farmers in the subregion, maize production and productivity in the savannas are severely constrained by drought, Striga parasitism and low soil-nitrogen.

During the last two decades, IITA in collaboration with national scientists in West and Central Africa, has developed a wide range of high-yielding drought-tolerant and/or escaping extra-early Striga resistant populations (white and yellow endosperm), inbred lines, and cultivars to combat these threats.

Extra-early inbreds and hybrids that are not only tolerant to low N and drought escaping (characteristics of extra earliness) but also possess genes for tolerance to drought during flowering and grain-filling periods are now available in Nigeria (Badu-Apraku and Oyekunle 2012).

Saving maize from parasitic Striga in Kenya and Nigeria

Thousands of farmers in Kenya and Nigeria are successfully battling the invasion in their farms by Striga, a deadly parasitic weed. They are now enjoying higher yields in maize, the number one staple in Kenya and an important cash crop in Nigeria.

The key to managing this weed is to combine sustainable multiple-pronged technology options being advocated by the Integrated Striga Management in Africa (ISMA) project to sustainably eliminate the weed from their fields, says Dr Mel Oluoch, ISMA project manager.

Striga attacks and greatly reduces the production of staple foods and commercial crops such as maize, sorghum, millet, rice, sugarcane, and cowpea. The weed attaches itself to the roots of plants and removes water and nutrients and can cause losses of up to 100% in farmers’ crops. Furthermore, a single flower of the weed can produce up to 50,000 seeds that can lie dormant in the soil for up to 20 years.

The weed is the number one maize production constraint in Western Kenya, and Nigeria, infesting most farmers’ fields.

The management technologies range from simple cultural practices such as intercropping maize with legumes such as groundnuts; crop rotation of maize with soybean which stimulates Striga to germinate but which later dies in the absence of the maize host to latch onto; deploying a “push-pull’ technology that involves intercropping cereals with specific Striga-suppressing desmodium forage legume; using Striga resistant maize varieties; and using CIMMYT-developed maize varieties resistant to Imazapyr—a BASF herbicide (StrigAway®), which kills the Striga seed as it germinates and before it can cause any damage; and adopting Striga biocontrol technologies which uses a naturally occurring host-specific fungal pathogen that kills the Striga at all stages without affecting other crops.

Imazapyr-resistant maize varieties with natural resistance to Striga hermonthica have been developed. The best hybrids produce 19% to 333% more grain yields under Striga infestation, sustain 17% to 57% less Striga damage, and support 63% to 98% less emerged Striga plants compared with the commercial hybrid check. In addition, new Striga resistant hybrids and open-pollinated synthetic varieties (OPVs) that combine Striga resistance with good standability have been developed. The hybrids and OPVs produce 47% to 126% more grain yields under Striga infestation, sustain 17% to 60% less Striga damage, and support 45% to 90% less emerged Striga plants compared with the common farmers’ varieties and commercial hybrids.

ISMA (http://www.iita.org/web/striga/) is funded by the Bill & Melinda Gates Foundation and is being implemented with the International Center of Insect Physiology and Ecology, CIMMYT, African Agricultural Technology Foundation, BASF Crop Protection, and other national agricultural research and extension services and private sector players in Kenya and Nigeria.

Promoting the use of drought tolerant maize in Nigeria

Tahirou Abdoulaye, t. Abdoulaye@cgiar.org and Onu Anyebe

The DTMA project of IITA-CIMMYT aims at developing and deploying drought tolerant varieties in 13 sub-Saharan African countries. In West Africa, the project, led by IITA and its national partners, is being implemented in Nigeria, Bénin, Mali, and Ghana. In Nigeria, the project covers all the maize-producing agroecologies.

As part of the promotion efforts, farmers’ groups were formed in Kano and Katsina States in northern Nigeria to demonstrate the performance of these improved varieties but also to organize the farmers so that they could have access to the critical inputs needed in maize production.

IITA introduced the drought tolerant variety EVDT 99 to the community of Ruwan Kanya in Rano Local Government Area (LGA) of Kano State, in 2009. This was done as part of the efforts of the DTMA project to inform farmers about drought tolerant maize, both established and newly developed varieties.

A maize production innovation platform was organized around EVDT 99 in the village of Ruwan Kanya. Fourteen farmers initially participated in the production of seeds. For the first year, six farmers each planted 10 kg of the improved variety and eight farmers each planted 5 kg. Other farmers saw the maize fields during the growing season and requested seeds from the participating farmers; eventually the number of participants increased to 36 in 2010. They formed an association to enable them to obtain fertilizer from the State Government.

In the following season, more farmers planted the variety. Six were able to increase their farmland; others bought inputs that increased their production. For example, Alhaji Bako Monitor bought a pair of bullocks for his farm work and for the transportation of goods to the market.

Almost four years later, the DT variety EVDT 99 is now being called Ar Ashiru (named after the president of the farmers’ group). It is grown in the 10 communities in Rano LGA, one community in Sumaila LGA, one community in Tudun Wada LGA, all in Kano State and in Soba/Risipa in Kaduna State. Other communities in Kano State that got EVDT 99 from Ruwan Kanya LGA include Gidan Zangi, Garabi, Doka, Zazaye, Takalafia, Gana, Kajorawa, Yelwa ciki, Tadesha, and Kundu.

Some farmers also planted EVDT 99 in the dry season after harvesting tomatoes between February/March. The dry season maize is harvested fresh and consumed after being roasted or boiled.

The farmers’ association in Ruwan Kanya was linked to the Kano State Government in 2010. The members were able to purchase subsidized fertilizer at 1100 naira/bag (~US$7) including transportation to the village. The following year, in 2011, the government changed; the new government did not allocate fertilizer to the farmers’ group. The farmers put their money together and the project helped by linking them with a dealer who provided good quality input. They bought the fertilizer in bulk at 5000 naira (~$31) for NPK and 5200 naira for urea and continued seed production.

The farmers say that they appreciate the productivity and earliness of the variety. EVDT 99 responds well to fertilizer and those growing it have had no problem in getting the fertilizer they need to apply.

During the new phase of DTMA, the project team is focusing on getting these farmers linked to seed companies so they can renew their seed stock and continue to purchase quality certified seeds. The drought tolerant maize varieties and hybrids are now being produced and sold by some seed companies in Nigeria, thanks to the efforts of these farmers.

Farmers need to be made aware of the need to renew their seed stock regularly including seeds for open-pollinated varieties such as EVDT to maintain the purity and productivity level of their cultivars.

Increasing productivity the ISFM way

Farm productivity has been cited as a major entry point to achieving success in overcoming rural poverty. Photo by IITA
Farm productivity has been cited as a major entry point to achieving success in overcoming rural poverty. Photo by IITA

Bernard Vanlauwe, b.vanlauwe@cgiar.org

The need to grow more food without depleting important natural resources makes the intensification of African agriculture essential. The Green Revolution in South Asia and Latin America raised crop productivity through the deployment of improved varieties, water, and fertilizer. However, efforts to achieve similar results in sub-Saharan Africa (SSA) have largely failed. The sustainable intensification of agriculture in SSA has gained support in recent years, especially in densely populated areas where natural fallows are no longer an option.

There is growing recognition that farm productivity is a major entry point to achieving success in overcoming rural poverty. A recent landmark event was the launching of the Alliance for a Green Revolution in Africa (AGRA). AGRA has adopted integrated soil fertility management (ISFM) as a framework for raising crop productivity through a reliance on soil fertility management technologies, with an emphasis on the increased availability and use of mineral fertilizer (www.agra-alliance.org). Within the refreshed IITA Strategy 2012–2020, ISFM is one of the main pillars of the natural resource management (NRM) research area.

Figure 1. Conceptual relationship between agronomic efficiency of fertilizers and organic resource and implementation of various ISFM components.
Figure 1. Conceptual relationship between agronomic efficiency of fertilizers and organic resource and implementation of various ISFM components.

Whats is ISFM?
We defined ISFM as “A set of soil fertility management practices that necessarily include the use of fertilizer, organic inputs, and improved germplasm combined with the knowledge on how to adapt these practices to local conditions, aiming at maximizing agronomic use efficiency of the applied nutrients and improving crop productivity. All inputs need to be managed following sound agronomic principles” (Vanlauwe et al. 2011a). The definition focuses on maximizing the efficiency with which fertilizer and organic inputs are used since these are both scarce resources in the areas where agricultural intensification is needed. Agronomic efficiency (AE) is defined as the extra crop yield obtained per unit of nutrient applied and is expressed in kg crop produced per kg nutrient input.

Fertilizer and improved germplasm
In terms of response to management, two general classes of soils are distinguished: responsive soils, i.e., soils that show acceptable responses to fertilizer (Path A, Fig. 1), and poor, less-responsive soils that show little or no response to fertilizer due to constraints apart from the nutrients contained in the fertilizer (Path B, Fig. 1). Sometimes, where land is newly cleared or where fields are close to homesteads and receive large amounts of organic inputs each year, a third class exists where crops show little response to fertilizer since the soils are fertile.

The ISFM definition proposes that the application of fertilizer to improved germplasm on responsive soils will raise crop yield and improve AE relative to the current farmers’ practice. This is characterized by traditional varieties receiving poorly managed nutrient inputs and/or too little of them (Path A, Fig. 1). Major requirements for achieving production gains on responsive fields within Path A (Fig. 1) include the following: the use of disease- resistant and improved germplasm, crop and water management practices, and the application of the “4R” Nutrient Stewardship Framework—a science-based framework that focuses on applying the right fertilizer source at the right rate, at the right time during the growing season, and in the right place (Fig. 2). Poor, less-responsive soils should be avoided when deploying improved germplasm and fertilizer.

Figure 2. The 4R Nutrient Stewardship model, International Plant Nutrition Institute.
Figure 2. The 4R Nutrient Stewardship model, International Plant Nutrition Institute.

Combined application of fertilizer and organic inputs
Organic inputs contain nutrients that are released at a rate determined in part by their chemical characteristics or organic resource quality. However, organic inputs applied at realistic rates seldom release sufficient nutrients for optimum crop yield. Combining organic and mineral inputs has been advocated for smallholder farming in the tropics because neither input is usually available in sufficient quantities to maximize yields and because both are needed in the long term to sustain soil fertility and crop production. Substantial enhancements in fertilizer AE have been observed in an analysis related to N fertilizer applied to maize in Africa, but these were strongly influenced by the quality and application rate of the organic resources (Fig. 3).

An important question arises within the context of ISFM: Can organic resources be used to rehabilitate less-responsive soils and make these responsive to fertilizer (Path C in Fig. 1)? In southwestern Nigeria, the integration of residues from Siamese senna (Senna siamea), a leguminous tree, reduced topsoil acidification resulting from repeated applications of urea fertilizer (Vanlauwe et al. 2005).

Figure 3. Agronomic efficiency of fertilizer N as affected by combination with different classes of organic inputs.
Figure 3. Agronomic efficiency of fertilizer N as affected by combination with different classes of organic inputs.

Adaptation to local conditions
As previously stated, soil fertility status can vary considerably between fields within a single farm and between farms with substantial impacts on fertilizer-use efficiency (see photo on next page). In addition to adjustments to fertilizer and organic input management, measures with adaptation to local conditions are needed, such as the application of lime on acid soils, water harvesting techniques on soils susceptible to crusting under semi-arid conditions, or soil erosion control on hillsides, to address other constraints. Lastly, adaptation also includes considering the farming resources available to a specific farming household, often referred to as the farmer’s resource endowment, the status of which is related to a specific set of farm typologies. ISFM options available to a specific household will depend on the resource endowment of that household.

Towards complete ISFM
Complete ISFM comprises the use of improved germplasm, fertilizer, appropriate organic resource management, and local adaptation. Several intermediate phases have been identified that assist farmers in moving towards complete ISFM, starting from the current average practice of applying 8 kg/ha of fertilizer nutrients to local varieties. Each step is expected to provide the management skills that result in improvements in yield and in AE, with technological complexity increasing towards the right (Fig. 1). Figure 1 is not intended to prioritize interventions but rather suggests a stepwise adoption of the elements of complete ISFM. It does, however, depict key components that lead to better soil fertility management. In areas, for instance, where farmyard manure is targeted towards specific fields within a farm, local adaptation is already taking place, even if no fertilizer is used. This is the situation in much of Central Africa.

A 3-week-old maize crop in two different plots within the same farm, Western Kenya
A 3-week-old maize crop in two different plots within the same farm, Western Kenya

Successful uptake of ISFM practices
Several examples can be identified where ISFM has made a difference to smallholder farmers, including (1) dual-purpose grain legume–maize rotations with targeted fertilizer applications pioneered by IITA for the moist savannas (Sanginga et al. 2003) and (2) micro-dose fertilizer applications in legume–sorghum or legume–millet rotations with the retention of crop residues and combined with water harvesting techniques in the semi-arid agroecozone (Tabo et al. 2007).

As for the grain legume–maize rotations, the application of appropriate amounts mainly of P to the legume phase ensures good grain and biomass production. The latter in turn benefits a subsequent maize crop and thus reduces the need for external N fertilizer. Choosing an appropriate legume germplasm with a low harvest index will favor the accumulation of organic matter and N in the plant parts not harvested and choosing adapted maize germplasm will favor a matching demand for nutrients by the maize. Selection of fertilizer application rates based on local knowledge of the initial soil fertility status within these systems would qualify the soil management practices as complete ISFM.

Outlook
In view of the many ongoing investments related to the dissemination of ISFM practices, it is expected that the examples of successful uptake will be amplified over large areas across various farming systems.

The principles underlying ISFM have also been observed to be applicable to cassava-based systems (see other articles in this publication). Notwithstanding the good prospects for impact generated through improved soil management, several technical issues remain to be resolved. These include (1) how farmers can diagnose the soil fertility status of their plots, including non-responsiveness, (2) how ISFM recommendations vary along such within-farm soil fertility gradients, (3) how non-responsive soils can be rehabilitated (or does this not make sense under certain circumstances?), (4) what minimal level of resource endowment is required to engage in ISFM, (5) how ISFM principles can be condensed to a set of easy-to-implement rules of thumb, adapted to a specific cropping environment, (6) whether efficient fertilizer use is a valid entry point towards sustainable intensification, (7) whether ISFM produces sufficient in-situ crop residues to ensure that soil carbon values remain about a minimal threshold, (8) what minimal conditions are needed (e.g., population density, policy) to allow large-scale uptake of ISFM, and (9) how ISFM relates to conservation agriculture.

References
Sanginga, N., K. Dashiell, J. Diels, B. Vanlauwe, O. Lyasse, R.J. Carsky, S. Tarawali, B. Asafo-Adjei, A. Menkir, S. Schulz, B.B. Singh, D. Chikoye, D. Keatinge, and R. Ortiz. 2003. Sustainable resource management coupled to resilient germplasm to provide new intensive cereal–grain legume–livestock systems in the dry savanna. Agriculture, Ecosystems and Environment, 100: 305–314.
Tabo, R., A. Bationo, B. Gerard, J. Ndjeunga, D. Marchal, B. Amadou, G. Annou, D. Sogodogo, J.B.S. Taonda, O. Hassane, Maimouna K. Diallo, and S. Koala. 2007. Improving cereal productivity and farmers’ income using a strategic application of fertilizers in West Africa. Pages 201–208 in: Advances in integrated soil fertility management in sub-Saharan Africa: Challenges and opportunities, edited by A. Bationo, B. Waswa, J. Kihara, and J. Kimetu, J. Kluwer Publishers, The Netherlands.
Vanlauwe, B, J. Diels, N. Sanginga, and R. Merckx. 2005. Long-term integrated soil fertility management in south-western Nigeria: crop performance and impact on the soil fertility status. Plant and Soil 273: 337–354.
Vanlauwe, B, A. Bationo,  J. Chianu, K.E. Giller, R. Merckx U. Mokwunye, O. Ohiokpehai, P. Pypers, R. Tabo, K. Shepherd, E. Smaling, P.L. Woomer, and N. Sanginga. 2011a. Integrated soil fertility management: operational definition and consequences for implementation and dissemination. Outlook on Agriculture 39: 17–24.
Vanlauwe, B, J. Kihara, P. Chivenge, P. Pypers, R. Coe, and J. Six. 2011b. Agronomic use efficiency of N fertilizer in maize-based systems in sub-Saharan Africa within the context of Integrated Soil Fertility Management. Plant and Soil 339: 35–50.
Zingore, S. and A. Johnston. 2013. The 4R Nutrient Stewardship in the context of smallholder Agriculture in Africa, in: Agroecological Intensification of Farming Systems in the East and Central African Highlands, edited by B. Vanlauwe, G. Blomme, and P. Van Asten. Earthscan, UK, in press.

Climate-smart perennial systems

Banana-coffee systems in East Africa. Photo by P. van Asten
Banana-coffee systems in East Africa. Photo by P. van Asten

Laurence Jassogne, l.jassogne@gmail.com, Piet van Asten, Peter Laderach, Alessandro Craparo, Ibrahim Wanyama, Anaclet Nibasumba, and Charles Bielders

Coffee is a major cash crop in the East African highland farming systems. It represents a high proportion of export values at the national level (for example >20% for Uganda). It is also crucial for the sustainability of the livelihoods of smallholder farmers.

During a survey in Uganda, smallholder farmers explained that the income generated by coffee had sent their children to school and helped to build permanent houses. Prices of coffee have also been increasing in the past decennia, motivating them to continue growing the crop.

Although coffee is a promising cash crop, smallholder farmers that grow coffee are still vulnerable. Soil fertility is declining, pest and disease pressure is increasing, populations are rising, and land is continuously fragmented. Above all, climate change is starting to take its toll and puts further pressure on the coffee-based farming systems—directly, because temperature and rainfall have an impact on the physiology of Arabica coffee, and indirectly because the incidence and severity of certain pests and diseases such as the coffee berry borer and coffee leaf rust will increase.

Figure 1. Change of suitability for Arabica-growing areas in Uganda using MAXENT approach and based on a ‘business as usual’ climate change scenario.
Figure 1. Change of suitability for Arabica-growing areas in Uganda using MAXENT approach and based on a ‘business as usual’ climate change scenario.

Current and future suitability of coffee growing areas
In collaboration with Dr Peter Laderach (CIAT), the direct effect of climate change on the suitability of coffee-growing areas in Uganda was mapped (Fig. 1).

If the current coffee crop systems do not change (i.e., same coffee varieties and management practices), these areas will move up the slope and the suitable surface area will decrease. In this light, climate-smart coffee- based systems need to be developed to sustain the existing coffee- based systems.

Adaptation strategies in coffee systems
IITA-led field surveys in the region, combined with a literature review, revealed that there is a multitude of coffee systems that exist. This diversity reflects the variability among farmers in terms of their resource availability, objectives, political history, and opportunities (Fig. 2).

Highest yields can be obtained in systems without shade or with low shade levels (Fig. 2). However, these same systems represent higher production risks and a higher use of external inputs. In polyculture systems and forest systems, on the other hand, highest yield quality can be obtained with the minimum use of external inputs. Furthermore, they allow, among others, a better adaptation to climate change, higher carbon stocks, and more ecological services. Quantifying these trade-offs and raising awareness among farmers and other stakeholders along the coffee value chain will help informed and sustainable decisions to be made about the coffee systems.

Figure 2. Trade-offs at a farmer-plot level in coffee systems.
Figure 2. Trade-offs at a farmer-plot level in coffee systems.

The more coffee is shaded, the more it is protected from rising temperatures and extreme weather events. Shade in coffee systems can reduce the average temperature in the lower coffee canopy by a few degrees. Although shade is an interesting technology to make coffee systems “climate smart” and hence, adapted to climate change, it is not the primary reason why farmers add shade to their coffee. Shade plants often produce fruit and/or timber. This diversifies the income of the farmer.

The same happens when farmers intercrop coffee with banana. Adding banana to the system increases food security, diversifies income, and adds shading to coffee. A country-wide survey in Uganda showed that coffee/banana intercropping was a common cropping system except in North and North-West Uganda. The incidence of coffee leaf rust was 50% when coffee was intercropped with banana.

Most farmers have some shade trees in their coffee; many practice intercropping with common beans. The combination of short- and long-term benefits of such shade systems makes them ideal climate-smart candidates. Shade trees also sequester carbon, contributing to the mitigation of the effects of climate change. In the end, few farmers (<5%) have pure full-sun monocropped coffee.

Figure 3. Pie charts depict major nutrient deficiencies based on soil and foliar samples of 10 coffee farms per site (black dots).
Figure 3. Pie charts depict major nutrient deficiencies based on soil and foliar samples of 10 coffee farms per site (black dots).

Constraints in diversified systems
However, shade trees also compete with coffee for light, nutrients, and water. If this competition is not managed well, then the shaded coffee system risks collapse, especially in conditions of poor soil fertility. Due to increasing population pressure and land fragmentation, integrated soil fertility management (ISFM) will help to manage nutrient competition. In a shaded system, the turn-over of biomass contributes to nutrient recycling. Organic matter from shade trees or banana will act as in-situ mulch. However, soils in Uganda are poor and have some major nutrient deficiencies (Fig. 3).

Replenishing soil fertility by adding external inputs is necessary if farming systems need to be sustained. Adding small amounts of fertilizers adapted to site-specific deficiencies increases fertilizer use efficiency and forms part of the ISFM approach. Coffee can be a major driver for the adoption of fertilizers by smallholders since farmers are generally organized for access to output markets. The same organizational lines can then be used to provide access to input markets.

Outlook
Understanding the farmers’ objectives, perceptions, and constraints is critical in identifying the adoption pathways of production-increasing technologies. To continue this research, IITA will start a case study in Rakai (Uganda) at a site of the CGIAR Research Program on Climate Change, Agriculture, and Food Security (CCAFS). Here, climate-smart coffee scenarios will be developed in a participatory manner with smallholder farmers, based on data from previous projects, interviews with individual farmers and groups, and farm measurements. Greenhouse gas emissions will be quantified to measure the mitigation potential of the existing coffee systems. Furthermore, fertilizer trials throughout Uganda will be set up to test the site-specific recommendations. IITA also plans to further advance its collaborative research efforts on modeling trade-offs and synergies in coffee smallholder systems in East Africa.

Soil: nature’s Pandora’s box

Danny Coyne, d.coyne@cgiar.org

Slash-and-burn forest clearance for crop cultivation in West Africa. Photo by Danny Coyne
Slash-and-burn forest clearance for crop cultivation in West Africa. Photo by Danny Coyne

Soil, a natural resource of overwhelming magnitude, is too often taken for granted, even if its importance is recognized at the highest levels. Franklin Delano Roosevelt, for example, lamented that “The nation that destroys its soil, destroys itself” when reflecting on the USA’s dustbowl era.

The “anchor” for the great majority of crops and plants, the soil is a physical support system for crop production and survival. However, it is also a paradoxical Pandora’s box of contrasts and opposing forces. As a refuge for pests and diseases capable of broad-scale crop devastation, it acts to harbor the death knell of the very life it supports. The soil-borne bacterium that causes bacterial wilt, Ralstonia solanacearum, for instance, can inflict 100% mortality to a field of tomatoes; cysts of some nematode species or spores of certain bacteria can lie dormant in the soil for decades, and then wreak havoc on susceptible crops when stimulated.

By contrast, the soil also acts as a treasure trove of beneficial microorganisms. Some are obligate parasites of crop pests and diseases, others facilitate plant access to nutrients, or enable plants to tolerate unfavorable conditions and toxic contaminants. The breadth of microbial biodiversity can also, in effect, be indicative of soil health. The rich tapestry of soil biodiversity involves a highly complex series of interactions, which facilitates biological equilibrium, including the suppression of pests and diseases. Determining how to measure this and relate it to soil health is currently a research topic at IITA. For instance, can a minimum number of non-parasitic nematode genera signify a healthy soil, as suggested by Ferris et al. (2001), and can we rapidly determine this using molecular barcoding? (e.g., Yu et al. 2012).
In Africa, our knowledge of the microbial diversity is particularly sparse and underexplored, and the biological rewards to be reaped vastly underrecognized. At IITA we intend to change this.

Intensifying agriculture in Africa
For Africa to reverse its current trend of declining crop productivity and raise it to a more globally reflective level (Hazel and Wood 2008) intensification of cropping systems is essential (see Vanlauwe this edition). The Asian Green Revolution was successful due to, among other things, the broad-scale use of pesticides to combat pests and diseases. However, their excessive use was a hard lesson learned, and numerous such pesticides are now no longer available.

More ecologically sensitive alternatives are now sought, increasingly so, with soil microbial biodiversity a clear target for exploration. Cropping intensification, however, needs to be carefully managed. The more intensified the system, the greater the selection pressure for pests and disease, and the more severe the problem. The appearance of nematode problems, regularly overlooked and famously misdiagnosed, is an initial indicator of the breakdown of a sustainable system.

Figure 1. AMF species abundance and diversity in relation to agroecological zones and relative water availability in Togo and Benin West Africa, under varying levels of cropping intensification.
Figure 1. AMF species abundance and diversity in relation to agroecological zones and relative water availability in Togo and Benin West Africa, under varying levels of cropping intensification.

At IITA, root-knot nematodes (Meloidogyne spp.) are a key focus of attention. With a short life cycle, rapid multiplication rates, broad host range, and scarcity of suitable management options, they pose a particular nuisance and are probably the most important biotic constraint across Africa (Coyne et al. 2009).

Intensification also results in reduced biodiversity, with many microorganisms unable to survive the heightened soil disturbance or a more uniform cropping pattern. At IITA, in collaboration with Basel University (Switzerland), we investigated the effect of cropping intensification on the diversity and occurrence of arbuscular mycorrhizal fungi (AMF) associated with yam (Dioscorea spp.) (Tchabi et al. 2008).

Yam is viewed as a nutrient-hungry crop, and thus often planted in more fertile soils following the removal (slash and burn) of forest or long-term fallow, an unsustainable and environmentally detrimental practice. It is also particularly afflicted by parasitic nematodes. AMF needs to attach to and grow on plant roots, forming a special relation which is mostly mutually beneficial, creating enhanced nutrient flow to plants. This relatively small and rather unique study showed that yam is associated with a wide array of AMF species and is highly mycorrhizal. The high diversity and incidence of AMF communities, however, decreased dramatically following the removal of forest and cropping intensification (Fig. 1).

Is there a link therefore between yam nutrient access and AMF? And can we exploit this AMF-yam relation to help preserve West African forests? Furthermore, yam tubers were less affected by yam nematodes in the presence of AMF! The limited knowledge of soil microbial diversity in Africa is acutely highlighted with this study, which alone led to four species being newly described and contributed to the revision of the Phylum Glomeromycetes (Oehl et al. 2011).

Balancing ecological equilibrium
At IITA we recognize the potential of healthy soils for crop productivity, in addition to the resource potential of beneficial soil microorganisms for use in pest and disease management. While specialists work on diagnostics, establishing economic importance and developing management solutions for soil-borne pests and disease, similar efforts are focused on the beneficial aspects of soil biodiversity and soil health.

We recently discovered, for example, that fungal antagonists isolated directly from Meloidogyne spp. eggs were far more effective against these pests than those isolated from the soil (see photo), as is the usual practice (Affokpon et al. 2011).

Outlook
Our plan is to work towards the identification of biological elements, which enhance crop productivity, as well as specific organisms, such as AMF, nitrogen-fixing bacteria and Trichoderma spp., for development as potential products.

As with the pain and suffering that Pandora’s box in the Greek mythology inflicted upon the world, so can the destructive potential to crops that the soil environment harbors be moderated, providing hope by balancing the ecological equilibrium. IITA strives to harness this equilibrium by understanding the mechanisms of the dynamics of healthy soils and determining the key factors that will help curtail pest and disease development.

References
Affokpon, A., D.L. Coyne, C.C. Htay, L. Lawouin, and J. Coosemans. 2011. Biocontrol potential of native Trichoderma isolates against root-knot nematodes in West African vegetable production systems. Soil Biology and Biochemistry 43: 600‒608.
Coyne, D.L., D. Fourie, and M. Moens. 2009. Current and future management strategies in resource-poor regions. In: Root-knot Nematodes. CAB International, UK. pp. 444‒475
Ferris, H., T. Bongers, and R.G.M. de Goede. 2001. A framework for soil food web diagnostics: extension of the nematode faunal analysis concept. Applied Soil Ecology 18: 13‒29.
Hazell, P. and S. Wood. 2008. Drivers of Change in Global Agriculture. Philosophical Transactions of the Royal Society B-Biological Science 363: 495‒515.
Oehl, F., G. Alves da Silva, I. Sánchez-Castro, B.T. Goto, L.C. Maia, H.E.V. Vieira, J-M. Barea, E. Sieverding, and J. Palenzuela. 2011. Revision of Glomeromycetes with entrophosporoid and glomoid spore formation with three new genera. Mycotaxon 117: 297–316.
Tchabi, A., D. Coyne, F. Hountondji, L. Lawouin,  Wiemken, A. and F. Oehl. 2008. Arbuscular mycorrhizal fungal communities in sub-Saharan Savannahs of Benin, West Africa, as affected by agricultural land use intensity and ecological zone. Mycorrhiza 18: 181‒195.
Yu, L., M. Nicolaisen, J. Larsen, and S. Ravnskov. 2012. Molecular characterization of root-associated fungal communities in relation to health status of Pisum sativum using barcoded pyrosequencing. Plant and Soil 357: 395‒405.

Bridging the grain legume yield gap through agronomy

Robert Abaidoo, r.abaidoo@cgiar.org, Steve Boahen, Anne Turner, and Mahamadi Dianda

Researcher inspecting cowpea pods. Photo by IITA

Researcher inspecting cowpea pods. Photo by IITA

IITA and its partners have made significant progress in breeding grain legumes that are high yielding and drought tolerant, and have better disease and pest resistance as well as consumer-preferred traits, such as seed size, texture, and color. The use of these new improved varieties has contributed to increases in productivity on farmers’ fields across sub-Saharan Africa.

While crop genetics is very important, the key to bridging the yield gap is to capitalize on the yield potential of a particular genotype and know how to manage it to maximize productivity in challenging environments. This is where the role of an agronomist becomes apparent: to design an integrated management system that reduces the effect of the biotic and abiotic stress factors limiting the productivity of a selected genotype in a given agroecology.Streaming and download Doctor Strange (2016)

Approach
Several collaborative projects, including N2Africa funded by the Bill & Melinda Gates Foundation through Wageningen University, are developing improved management options to enhance system productivity. The N2Africa project is being implemented in eight countries: DR Congo, Ghana, Kenya, Malawi, Mozambique, Nigeria, Rwanda, and Zimbabwe. It is a research-and-development partnership program that aims to develop, disseminate, and promote appropriate N2-fixation technologies for smallholder farmers, focusing on the major grain legumes. Although atmospheric air contains 78% N2, nitrogen (N) remains the most limiting nutrient for plant growth and also the most limited nutrient in degraded soils.

The good news is that legumes have the unique ability to fix atmospheric N through symbiotic association with root nodule bacteria. The opportunity exists through biological nitrogen fixation (BNF) to improve the yields of legumes in sub-Saharan Africa since current yields are only a small fraction of their potential. The integration of legumes in cropping systems can benefit associated cereal crops through N-sparing effects, N transfer, and non-N rotation effects. However, the process of BNF can be limited by several biotic and abiotic factors.

Enhancing biological N through bradyrhizobium inoculation and phosphorus application. Ino = inoculum, TSP = total super phosphate

Enhancing biological N through bradyrhizobium inoculation and phosphorus application. Ino = inoculum, TSP = total super phosphate

Evidence abounds that successful BNF depends on the interaction of environment (climate, rainfall day length, etc.), soil factors (acidity, aluminum toxicity, limiting nutrients), management (use of mineral fertilizers, planting dates and density, weed competition), legume species and variety, and rhizobium species and effectiveness. The current low crop productivity reported in legume-based systems can be attributed in part to the prevalence of these factors that limit BNF. In applying the study to legume-based systems, the N2Africa project expects that the identification of a combination of factors (see photos below), when appropriately managed, will optimize BNF and nutrient cycling in maize-based systems. This ability makes legumes a vital component of smallholder farming systems where the input of N fertilizer is almost negligible. Successful increases in legume productivity will lead to (1) increased availability of major sources of protein for direct consumption by rural households; (2) improved soil health through BNF and a reduced need for inorganic N fertilizers; (3) the breaking of pest and disease cycles of other crops when in rotation with legumes; and (4) improved income and health for the rural poor.

Preliminary results
In collaboration with the national agricultural research and extension systems (NARES) in the eight countries, the project has isolated several indigenous rhizobia strains, notably in Kenya, Nigeria, Rwanda, and DR Congo, from local farmlands to identify and characterize superior strains for enhanced BNF. The goal is to develop inoculum production capacity using superior native rhizobial strains through collaboration with private sector partners. In addition, several commercial inoculant strains are being evaluated to identify improved varieties with enhanced BNF for integration into specific farming systems. Results of the project have shown that the inoculation of improved soybean varieties resulted in higher yields in several project sites.

However, grain yields may be constrained in P-deficient soils, hence the combined use of P fertilizers and inoculum consistently produced higher yields (Fig. 1). Note from the same figure that responses to inoculants and P fertilizer are highly variable with yield in amended plots ranging from 0 to over 3 t/ha under on-farm conditions. This further stresses the need for local adaptation (see Vanlauwe6) and the need to observe the main factors determining such variability.

Figure 1. Range of responses to bradyrhizobium inoculation and phosphorus application.

Figure 1. Range of responses to bradyrhizobium inoculation and phosphorus application.

Within the N2Africa project, having detailed monitoring and evaluation (M&E) tools within large-scale adaptation and dissemination field campaigns is an important component of the ‘Research in Development’ concept, at the core of its learning objectives. Where soil pH and levels of P are not too low, an application of 20 kg P/ha is adequate for the proper growth of soybean, cowpea, and groundnut but in soils deficient in P or with low pH,40 kg/ha is optimum.

Related interventions
The project is also identifying high-yielding legume varieties with varying maturity durations for specific environments to provide farmers with options that will enable them to match varieties to the length of the growing season. For example, when the rain is delayed in a particular year or for some reason farmers delay planting, they can select short-maturing varieties that can fit into the remaining growing period.
A major emphasis is being placed on determining the best time to plant various legumes in several agroecologies in combination with appropriate row spacing and plant population. Planting at the right time enhances yield in many ways: (1) the growing period coincides with good rainfall despite its variability in some years; (2) the crop is exposed to optimum temperature regimes; (3) growth coincides with the optimum solar radiation and daylength that regulate vegetative and reproductive growth phases in legumes due to their photosensitivity; and (4) plants escape the major pests and diseases that limit yield.

Partnership
With project partners which include the national agricultural research and extension systems, nongovernmental organizations, community-based organizations, and farmers’ associations, these technologies have been developed into recommended packages and are being demonstrated on-farm. The demonstration plots are established with the direct participation of farmers who are responsible for the day-to-day maintenance to encourage hands-on learning. Field days are also organized during the growing season for individuals and farmers’ groups to create awareness about the technologies. The project encourages women’s participation as well. Other dissemination activities involve the distribution of inputs to project participants including improved seeds, inoculants, and P fertilizer and lime at agreed prices. The project has developed training programs to improve the skills of extension agents, farmers, and other stakeholders to ensure sustainability of the results after the project ends.

Outlook
It is expected that these agronomic interventions should lead to increased diversification of N2-fixing legume species in smallholder farming systems in sub-Saharan Africa, expansion in the cultivation of grain, greater productivity in legume-based farming systems, and enhanced family incomes and nutrition. In collaboration with microbiologists, plant breeders, and the private sector, the selection and dissemination of efficient rhizobial inoculant strains and improved varieties of grain legumes with enhanced BNF capacities adapted to various environmental stresses will improve the prospects of increasing legume components in cropping systems as well as enhancing the production of expanded ecosystem services.

Maize genetic improvement for enhanced productivity gains

Abebe Menkir (a.menkir@cgiar.org), Baffour Badu-Apraku, and Sam Ajala
Maize Breeders, IITA, Ibadan, Nigeria

Maize streak virus disease causes severe stunting and extreme yield reduction in maize. Creating Maize streak virus-resistant varieties is one of the major successes of IITA's maize breeding program. Source: L. Kumar.
Maize streak virus disease causes severe stunting and extreme yield reduction in maize. Creating Maize streak virus-resistant varieties is one of the major successes of IITA's maize breeding program. Source: L. Kumar.
Maize is an important food security and income-generating crop for millions of people in West and Central Africa (WCA). Maize breeding at IITA was initiated around 1970. Using as base materials two composites created from diverse sources in Nigeria under a West African project supported by the Scientific and Technical Research Committee of the Organization for African Unity, breeders at IITA formed several broad-based populations and improved them through recurrent selection. The main research focus at that time was the development of open-pollinated maize varieties (OPVs) with resistance to diseases, and adapted to the humid forest and moist savannas of WCA. The products generated from this research were channelled to research and development partners for further testing, multiplication, and dissemination in various countries in the subregion.

The widespread outbreak of the maize streak virus (MSV) disease in the late 1970s prompted IITA to develop two resistant populations. These were crossed to high-yielding and broad-based germplasm from the International Maize and Wheat Improvement Center, eastern and southern Africa, the temperate zone, central and south America, Thailand, DECALB, and other sources to create populations and varieties resistant to MSV. IITA has supplied MSV-resistant inbred lines, OPVs, hybrids, and populations to partners within and outside WCA through diverse delivery pathways for more than 25 years. Direct use of MSV-resistant maize germplasm that also had resistance to southern leaf rust, southern leaf blight, downy mildew, and leaf spot has been recorded in several countries in Africa.

The significant breakthrough in the development and release of high-yielding extra-early, early, intermediate, and late-maturing varieties with resistance to leaf rust, leaf blight, and leaf spot has caused a phenomenal increase in maize production in WCA, notably in Bénin, Burkina Faso, Cameroon, Chad, The Gambia, Guinea, Ghana, Mali, Nigeria, Senegal, and Togo. Further expansion in production has also occurred in many countries in this subregion because of the adoption of extra-early maturing improved varieties identified from regional trials coordinated by the Semi-Arid Food Grain Research and Development (SAFGRAD) and the West and Central frica Collaborative Maize Research Network (WECAMAN).

IITA maize breeders in action, maize breeding program. Source: L. Kumar.
IITA maize breeders in action, maize breeding program. Source: L. Kumar.
The development of extra-early maturing varieties enabled production to expand into new areas, especially to the Sudan savannas where the short rainy season hitherto had precluded maize cultivation. The highest growth in maize area, yield, and production in sub-Saharan Africa since 1961 occurred in WCA. These productivity gains, achieved through farmers’ adoption of improved varieties in the 1980s, were driven by the suitability of the cultivars to the major production environments, the availability of inexpensive fertilizer and extension services, as well as favorable government policies that encouraged the use of these technologies.

In a recent impact assessment study conducted in nine countries, the number of varieties annually released in WCA had increased from fewer than one in 1970s to 12 in the late 1990s. The availability of such high-yielding and adapted varieties resulted in a 2% annual increase in land area planted to maize and a 3.5% annual increase in grain yield from 1971 to 2005. Among the varieties released from 1998 to 2005 in the nine countries, 67% were derived from IITA’s maize germplasm. Of the 4 million ha planted to improved maize in these countries, about 43% of the area was planted to varieties derived from IITA’s germplasm. The joint IITA-NARS investment in maize research in the nine countries had lifted an average of 1.6 million people out of poverty annually from 1980 to 2004.

While working with diverse partners to promote the dissemination of maize varieties in the various countries, IITA realized that the major constraint to the adoption of improved varieties in WCA was the absence of an effective seed production and delivery system. To promote the establishment of indigenous private seed companies, IITA embarked on the development of hybrids in 1979 with financial support from the Federal Government of Nigeria and the active participation of Nigerian scientists. This led to the release of the first generation of hybrids in 1983, with a spill-over effect of the establishment of seed companies in Nigeria for marketing hybrid maize seeds. The official announcement of IITA’s maize OPVs and hybrids in the catalogs of indigenous seed companies in Nigeria provide further evidence of the adoption, deployment, and commercialization of IITA-bred varieties and hybrids.

In recent years, IITA has also made significant progress in the development of a large number of maize inbred lines, OPVs and hybrids with resistance to Striga hermonthica, stem borers, and aflatoxin contamination, with tolerance to drought, efficient nitrogen use, and enhanced contents of lysine, tryptophan, and pro-vitamin A. We have the first generation of extra-early, early, intermediate, and late-maturing OPVs and hybrids that combine drought tolerance with resistance to S. hermonthica developed under the Drought Tolerant Maize for Africa Project and supplied to partners for testing through regional trials. The number of drought-tolerant OPVs identified from these trials and released for production since 2007 were 7 in Bénin Republic, 5 in Ghana, 3 in Mali, and 13 in Nigeria.

On the other hand, only one drought-tolerant hybrid selected in Mali and six drought-tolerant hybrids selected in Nigeria were released for production. Furthermore, three varieties with high lysine and tryptophan content, two varieties resistant to S. hermonthica, two varieties that are nitrogen use efficient, a stem borer-resistant variety, two yellow and two white hybrids were released from 2008 to 2011 in Nigeria.

Maize production in Saminaka area in Kaduna State, Nigeria. Photo. by A. Menkir.
Maize production in Saminaka area in Kaduna State, Nigeria. Photo. by A. Menkir.
To accelerate the release and commercialization of hybrids with different maturity classes, high yield potential, combining resistance to Striga and drought tolerance, and other desirable traits in different countries in WCA, IITA has supplied parental lines of promising hybrids to private seed companies for further testing, production, and commercialization. The institute has also trained technical and management staff of seed companies to strengthen their human capacity to produce and market hybrid maize.

In addition, IITA has promoted community-based seed production schemes through its work with WECAMAN and more recently with diverse partners to make improved seeds available to farmers in countries where the private sector is less developed and in areas with limited access to markets.
Despite the impressive strides that have been made so far, continued investment in maize productivity research still remains critical to sustain agricultural growth, food security, improved nutritional quality, and safe harvests. Considering the predominance of the crop in diverse farming systems, heterogeneous landscapes, and the diets of millions of people in WCA, enhanced yield gains have the potential to further expand production in WCA, thus contributing to bridging the gap between food supply and demand in the region, because research has led to and will continue to deliver excellent results.

Increased investment not only in research but also in strengthening the private seed sector will still be needed to promote the rapid turnover of maize hybrids on farmers’ fields that help to achieve higher yield gains to support improved farming in WCA.