National Academies Press: OpenBook

Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia (2009)

Chapter:2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia

« Previous: 1 Introduction
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page31
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page32
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page33
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page34
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page35
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page36
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page37
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page38
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page39
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page40
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page41
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page42
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page43
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page44
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page45
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page46
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page47
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page48
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page49
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page50
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page51
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page52
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page53
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page54
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page55
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page56
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page57
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page58
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page59
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page60
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page61
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page62
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page63
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page64
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page65
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page66
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page67
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page68
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page69
Suggested Citation:"2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia." National Research Council. 2009. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, DC: The National Academies Press. doi: 10.17226/12455.
×
Page70

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

2 Constraints on Crop and Animal Productivity in Sub-Saharan Africa and South Asia As the committee began its task—to identify technologies emerging in different fields of science and engineering that could be most helpful to poor farmers in sub-Saharan Africa (SSA) and South Asia (SA)—it quickly agreed that the first place to look for opportunities to transform agriculture was in the fields and pastures where conditions that constrain agricultural produc- tivity are manifested. Any technology that could help a farmer to overcome the worst conditions would have a substantial impact on crop yields, im- prove food security, and increase the farmer’s potential for income. This chapter provides a broad sketch of crop and animal production in SSA and SA and identifies general and specific constraints that limit the ability of farmers in these regions to sustain reliable food production. The constraints were identified on the basis of the committee’s own expertise and responses to the committee’s request for input from scientists in the two regions, and the constraints provide the context for the rest of the report. Overview of Crop Production in sub‑Saharan Africa AND South Asia High-Priority Crops As shown in Figure 2-1, there are substantial differences between the crops of SSA and the crops of SA. The major crops of the Green Revolu- tion—rice and wheat—still predominate in Asia. However, increases in   The Green Revolution of the 1960s and 1970s came as a result of scientific efforts to improve rice and wheat varieties—combined with the expanded use of fertilizers, other chemi- cal inputs, and irrigation—and ultimately led to dramatic yield increases in Asia and Latin America (IFPRI, 2002). 31

32 Emerging Technologies to Benefit Farmers FIGURE 2-1  Major food crops of Asia and sub-Saharan Africa. NOTE: Percentages refer to hectares harvested, averaged for 2000-2004. SOURCE: FAO, 2006a; de Janvry and2-1.eps2007. Byerlee, bitmap image productivity are tapering off in the classic rice-wheat cropping rotation that has been used for more than 1,000 years in Asia; it now encom- passes about 24 million hectares in Asia, of which 13.5 million are in SA (Rice-Wheat Consortium, 2007). Sorghum and pearl millet are also widely grown, although they are on the decline, being replaced by maize in many areas, which is important for the burgeoning livestock and poultry feed industries (Joshi et al., 2005). The legumes that are important for nutrition are chickpea, lentil, pigeon pea, and groundnuts; they are less abundant as crops. The Indian government claims to be promoting diversification of crops away from the intense reliance on cereal grains with recommenda- tions to increase growth of legumes, fruits, vegetables, and oilseeds and more emphasis on dairy, poultry, and fish and with concomitant strength- ening of markets and the government’s ability to meet health and safety standards. Cotton and tea remain important export crops, although the declining yields of tea plantations and competition from abroad still pose problems; unlike SSA, India has a strong textile industry that complements the widespread production of cotton. The major crops of SSA are somewhat more diverse, and this makes priority-setting for improvement more challenging. Most of the crops shown in Figure 2-1 are also listed by DeVries and Toenniessen (2002). Among cereals, maize continues to emerge as the dominant crop, particu- larly in eastern and southern Africa, and sorghum and millet are important in drier areas of SSA. Rice has always been grown in the wetter areas of

Constraints on Crop and Animal Productivity 33 west Africa and is increasingly popular for consumption especially in the growing urban populations throughout SSA. Among the legumes, cowpea, pigeon pea, common bean, and groundnuts are important in many parts of SSA. Because of its ability to yield well despite stress and low inputs (externally supplied nutrients, pesticides, etc.), cassava is an important crop to millions of poor farmers throughout SSA, and yams also are hugely popular in countries such as Nigeria. Sweet potato is a major source of calories in some countries of eastern and southern Africa. An orange-flesh sweet potato that is rich in beta-carotene, the precursor of vitamin A, is be- ing promoted to address the problem of nutritional deficiency (see Box 2-1) (Low et al., 2007). Banana has emerged as a major cash crop, and tissue- culture production of virus-free plantlets is becoming a viable business in eastern and southern Africa. The starchy east African highland banana is the major staple crop of countries such as Uganda, Rwanda, and Burundi. Forests are increasingly recognized as important in SSA, not so much as a crop (although they are now for biofuels) but rather for their benefits to the environment—in protecting watersheds and preventing land degrada- tion—and as a major source of fuel and building materials for small-holder farmers, and for their potential to offer income in schemes involving trad- ing of carbon credits. Crop Yields Data on yields in SSA and SA and in the developed world are rel- evant to food security and the relative health of the agricultural economy. Table 2-1 shows selected data on Kenya, Ethiopia, and India as representa- tive of the regions in question. Yields are particularly low for maize and legumes, but yields of all crops listed are substantially lower in the three countries than in the developed world. Yields of cereals like wheat and rice showed striking rises in India in past decades but are now leveling off, and as previously mentioned, per capita yields of cereals in SSA are actually declining. Most African crop and animal production is practiced under low- input agricultural systems, and the chances of substantial improvement under those conditions may be limited (IAC, 2004). Figure 2-2 (Henoa and Baanante, 2006) compares SSA and Asia with respect to agricultural productivity and land use. The data provide a striking contrast: almost all the yield gain in SSA has come from increased land use, whereas in Asia it has resulted largely from increasing the yield on the same land area. The increased yield in Asia on the same amount of land can be attrib- uted largely to three factors: the new Green Revolution varieties of wheat and rice, which continue to be adapted and improved; the widespread use of inorganic fertilizer and herbicides; and irrigation of large areas in India

34 Emerging Technologies to Benefit Farmers BOX 2-1 Agriculture and Malnutrition In the last decade, the number and proportion of malnourished children and mothers in sub-Saharan Africa has increased. Undernutrition—deficiencies in macronutrients, protein, and energy, as well as micronutrients, iron, vitamin A, zinc, and iodine—is the underlying cause of half of all child mortality (Chopra and Darnton-Hill, 2006). About 84 percent of children under 5 years old in Kenya have some level of vitamin A deficiency, 73.4 percent are iron-deficient (anemic), and 51 percent are zinc-deficient. Women, especially pregnant women, are among the most vulnerable, with a high risk of iron deficiency (60 percent of pregnant woman) and vitamin A deficiency (39 percent of women). An estimated 16 per- cent of men have iron deficiency. Approximately 4.5 billion people living in the developing world are chronically exposed to aflatoxin, a fungal toxin that is con- sidered an unavoidable contaminant of foods that is a major cause of malnutrition (Williams et al., 2004). At the same time as undernutrition persists in parts of the population, rates of obesity are skyrocketing in other parts, especially in urban areas, because of greater consumption of refined fats and carbohydrates and more sedentary lifestyles (Prentice, 2006). In South Africa, 56 percent of women are considered overweight, and 30 percent are obese. Interrelationships among micronutrients and age-sex biases dictate that solutions more complex than single-nutrient sup- plementation are required. Similarly, food-based solutions to malnutrition—such as the orange-flesh sweet potato (Low et al., 2007), biofortified rice (Haas et al., 2005), and meat and milk (Neumann et al., 2003)—although time-consuming to implement, can result in beneficial long-term dietary change. The HarvestPlus program (www.harvestplus.org) of the CGIAR aims to ad- dress biofortification primarily through conventional breeding. Other efforts, in- cluding the Grand Challenge 9 Program, support biotechnological approaches to raise the concentrations of vitamin A, iron, and zinc in banana, rice, cassava, and sorghum beyond those possible through conventional breeding. The goal to raise micronutrient levels in those crops is attainable with today’s technologies; the biggest challenges for the projects may well be in finding ways to deal with regulatory approvals for traits that have not yet been evaluated by any regulatory system. Folate (a form of vitamin B) deficiency is a global problem that leads to neural tube defects, and transgenic approaches have been successful in increas- ing folate levels in tomato and rice (Diaz de la Garza et al., 2007; Storozhenko et al., 2007). Because obesity is becoming more prevalent in the developing world, lowering the rate of starch digestion by altering the amylose-to-amylopectin ratio would be one way to address the issue.

Constraints on Crop and Animal Productivity 35 TABLE 2-1  Cereal and Legume Yields in 2005 Kenya Ethiopia India Developed World Crop (kg/ha) (kg/ha) (kg/ha) (kg/ha) Maize 1,640 2,006 1,907 8,340 Sorghum 1,230 1,455 797 3,910 Millet 580 1,186 1,000 2,010 Rice (paddy) 3,930 1,872 3,284 6,810 Wheat 2,310 1,469 2,601 3,110 Beans, cowpea 378 730 332 1,790 Chickpea 314 1,026 814 7,980 SOURCE: FAO, 2006a. and Pakistan, because water has not at least until recently been a major lim- iting factor as it has been in the largely rain-fed agriculture of SSA. Quality seed, adequate nutrients, and water synergize to enhance yield, and lack of a combination of these three goes a long way toward explaining why yields of all major crops in SSA are among the lowest in the world. General CONSTRAINTS on Crop Production Poor Soil and Poor Soil Fertility Not all soils are the same: soils arise from different geophysical pro- cesses that give them different characteristics. In Africa, soils are catego- rized in three groups. The first group includes highly erodible, weathered soils and low-activity clays with high acidity and aluminum phytotoxicity; these soils occur mostly in the subhumid tropical uplands and humid equa- torial and coastal lowland regions. The second group includes the more moderately weathered, fertile soils derived mainly from basic rocks and vol- canic materials in western Cameroon, Rwanda, Burundi, the Kivu region of Zaire, and parts of eastern Africa; this is where the most productive planta- tions of perennial crops—such as coffee, tea, and banana—are grown. The third group is the hydromorphic or ancient alluvial soils that predominate in the subhumid tropical uplands, where an underlying hardened plinthite (an iron-rich clay-quartz mixture) at shallow depths limits the downward growth of plant roots; these soils are easily compacted and eroded. Many of the soils of SSA are less than ideal for agriculture, and the situation is made worse by the extensive nutrient mining caused by poor agricultural practices in the region. In addition to natural wind and water erosion, much of the soil erosion is caused by overgrazing, deforestation, and intensive row cropping. Erosion rates of 10 to 40 t/ha per year are

36 Emerging Technologies to Benefit Farmers FIGURE 2-2  Changes in cereal production, 1961-2001, in sub-Saharan Africa and Asia. 2-2.eps NOTE: Increases in yields were bitmap images due primarily to increased land use in sub-Saharan Africa but to increased production per unit of land area in South Asia. SOURCE: Henoa and Baanante, 2006. Reprinted with permission. © 2006 by In- ternational Center for Soil Fertility and Agricultural Development.

Constraints on Crop and Animal Productivity 37 common on crop lands, compared with annual soil losses of 5 to 10 t/ha per year in the U.S. corn belt (Lal, 1995, 1998). The soils of SSA have also been robbed of their nutrient content. The Tropical Soil Biology and Fertility Institute has published an excellent re- view of challenges to soil management in the tropics (TSBF-CIAT, 2005). Most cropland soils in SSA are affected by negative nutrient balance: nitrogen-phosphorus-potassium (NPK) depletion occurs at 20 to 40 kg/ha per year throughout the continent (Smaling, 1993; Smaling et al., 1993; Sanchez, 2002). African farmers traditionally left lands fallow to restore nutrients and regain fertility, but because of food demand crops now grow continuously with little or no nutrient input. The result is extensive and sometimes irreversible soil degradation, as illustrated in Figure 2-3. Fertilizer use in SSA is low (NPK at 8.8 kg/ha per year) (Henoa and Baanante, 2006). That situation is attributable to the inaccessibility and exorbitant cost of inorganic fertilizer—up to 4 times that paid by a farmer in the United States (Camara and Heinemann, 2006; Eilittä, 2006). Efforts to address the accessibility and cost of fertilizer were highlighted at a recent African Fertilizer Summit. In addition, the Alliance for a Green Revolution in Africa (AGRA)—established by the Bill & Melinda Gates Foundation and the Rockefeller Foundation—has launched a new program in soils that aims to increase sustainable use of fertilizers, organic matter, and soil management methods. In contrast with Africa, fertilizer use in SA is high (NPK at 100 kg/ha per year). Fertilizer consumption in SA increased by a factor of 42 from 1961 to 2003 and accounts for much of the yield gain in the region during the period (Lal, 2007). However, there seem to have been recent widespread decreases in the responses of crops to agricultural inputs. For example, cereal production in India declined from a peak of 235 kg/ha in 1995 to a low of 205 kg/ha in 2002. One possible reason for the decline, which also occurred in SSA, is the loss of soil organic matter as farmers strip off all plant matter. In SA, this includes weeds and roots, to use for animal feed or for cooking fuel (Eswaran et al., 1999). Lacking input of organic matter, degraded soils have low holding capacities, so they often do not respond to the addition of inorganic fertilizer. Numerous studies indicate that there can be strong synergism in the use of both organic and inorganic fertilizer. However, dif- ficult tradeoffs with respect to organic amendments remain. In SA, manure is used for cooking fuel; in many parts of SSA, the poorest farmers use some crop residues as building material and might not have animals as a source of manure, and they are reluctant to use their small plots to grow crops that yield only green manures. Low organic matter may lead to a decrease in the abundance of important soil organisms, such as bacteria, fungi, termites,

38 Emerging Technologies to Benefit Farmers FIGURE 2-3  Areas in red are where current population exceeds agricultural capac- ity because of severe soil degradation and nutrient mining. SOURCE: Henoa and Baanante, 2006. Reprinted with permission. © 2006 by In- ternational Center for Soil Fertility and Agricultural Development. 2-3.eps bitmap image

Constraints on Crop and Animal Productivity 39 earthworms, insects, and small animals that inhabit the rhizosphere, an area of biological diversity whose importance continues to be studied. Poor Water Use and Management Water constraints intersect with issues of soil fertility, water-use ef- ficiency, and climate change. As recently stated, “water may seem to be everywhere, but for a rising portion of the world’s population, there may soon be hardly a drop to drink—or to use for growing food, supporting in- dustries and cities, and preserving life-giving ecosystems” (Postel, 1997). The climate of Afghanistan, Pakistan, and one-fourth of northwestern India is predominantly arid, and that of Bangladesh, Bhutan, Nepal, eastern India, and Sri Lanka is humid. In SA, the proportion of cropland under irri- gation is among the highest in the world (Table 2-2), but the water resource is poorly managed. Overuse of water through inefficient canal irrigation systems led to increased salinization and serious rising of the water table. A transition to tube wells has lowered the water table, but poor water quality remains a serious issue. Estimates for Pakistan indicate that over 50 per- cent of the groundwater is saline and not fit for irrigation. Other problems include the discovery of arsenic in many groundwater sources, the gradual depletion of major aquifers in some regions, and pollution from runoff. Wastewater could be an important source of water for agriculture, but it also carries health hazards. In Pakistan, for instance, it was found that hookworm is a major problem for those exposed to wastewater, and fear of contamination of vegetables is a major health issue for consumers (IWMI, 2003b). As an alternative solution, wastewater could be suitable for growth of bioenergy crops, which would not be associated with health issues. In substantial areas of SA—areas where there is also widespread rural poverty—agriculture is carried out under rain-fed conditions. As pointed out to the committee by Bharat Sharma, of the International Water Man- agement Institute (IWMI), the northwestern region of India (Rajasthan and TABLE 2-2  Irrigated Areas in South Asia 1975 1985 1995 1998 2003 Per Capita in 2003 Country (Mha) (Mha) (Mha) (Mha) (Mha) (ha/person) Afghanistan 2.4 2.6 2.8 2.8 2.7 0.09 Bangladesh 1.4 2.1 3.2 4.2 4.7 0.03 India 33.7 41.8 50.1 54.8 55.8 0.05 Nepal 0.2 0.8 0.9 1.1 1.2 0.04 Pakistan 13.6 15.8 17.2 18.1 18.2 0.11 Sri Lanka 0.5 0.6 0.6 0.7 0.7 0.03 SOURCE: Kaosa-ard and Rerkasem, 2000; FAO, 2006a; Lal, 2007.

40 Emerging Technologies to Benefit Farmers Gujarat), the Sind and Baluchistan provinces of Pakistan, and Afghanistan constitute one of the largest blocks in SA confronted with frequent and devastating droughts. In contrast with drought-prone areas, flooding of the Indo-Gangetic plains is an all-too-common occurrence and of increasing concern in climate change scenarios. Only 5 percent of agricultural land in Africa is under irrigation, compared with more than 60 percent in many parts of Asia, and most small-scale poor farmers in SSA suffer the vagaries of fluctuating weather conditions that are inevitable in rain-fed agriculture. In both SSA and SA, there is increasing use of low-cost bucket and drip irrigation systems and treadle pumps, even by the very poor (IWMI, 2003a; www.acumen.org; www.kickstart.com), but the general lack of irrigation in SSA is an obvi- ous target for technological intervention. The recently published Water for Food. Water for Life. Comprehensive Assessment of Water Management for Agriculture (IMWI, 2007) regards the upgrading of rain-fed systems as one of the most important opportunities to both reduce poverty and increase productivity in the rain-fed regions of SSA and SA, as is indicated in Table 2-3. Several reports (Camara and Heinemann, 2006; Rockstrom et al., 2006, 2007) emphasize that yields can be increased by a factor of 2-4 in many parts of SSA through better water management practices, such as adding organic matter to soils, preventing soil erosion, using water harvest- ing technologies, and increasing water retention with tied ridges, bunds, and terraces. The InterAcademy Council (IAC) report (2004) indicates that there is also an opportunity to improve current irrigation practices and to increase the amount of land under irrigation, inasmuch as current TABLE 2-3  Regional Potential for Increasing Crop Water Productivity Comprehensive Assessment Scenario Characteristics Scope for Improved Scope for Improved Scope for Productivity in Productivity in Irrigated Area Region Rain-Fed Areas Irrigated Areas Expansion Sub-Saharan Africa High Some High Middle East and North Africa Some Some Very limited Central Asia and Eastern Some Good Some Europe South Asia Good High Some East Asia Good High Some Latin America Good Some Some OECD countries Some Some Some SOURCE: IWMI, 2007. Reprinted with permission. © International Water Management Institute (http://www.iwmi.org).

Constraints on Crop and Animal Productivity 41 estimates indicate that only 30 percent of what is potentially available has been reached in SSA, with the greatest opportunities lying in humid regions, such as the Congo Basin. Lack of Plant Breeding Resources The importance of plant breeding for the health of a modern agricul- tural system cannot be overstated. Even in the United States and Europe, where there is private-sector investment in crop-trait improvement, substan- tial public-sector and philanthropic resources are essential if for no other reason than that breeding is needed to cope with changing pathogens and pests that affect food production. Progress in crop improvement can be sustained over decades, but advances become more difficult when the envi- ronments are prone to change as a consequence of different temperatures, length of seasons, rainfall patterns, and pests and diseases. Thus, where climate change and associated factors pose additional threats to future crop production, more active breeding programs are needed so that crop selec- tions can be responsive to expected environmental change; for example, crops can be selected for tolerance to higher temperatures. National breeding programs in SA have been greatly enhanced since the onset of the Green Revolution, but progress in developing modern varieties of the major crops for SSA has been much slower. If they exist at all, national breeding programs for rice, wheat, tropical maize, sorghum, cassava, beans, banana, pearl millet, lentil, cowpea, pigeon pea, common beans, yam, groundnuts, banana, sweet potato, and various fruits and vegetables are generally small and modestly staffed. The poorest countries only have a few testing facilities to help local farmers to find better strains of the crops they grow. Some countries, such as Kenya and India, manage to adopt, and to a limited extent improve, germplasm developed elsewhere. In some cases, private breeding companies are paying more attention to crops in SSA and SA, but often the fruits of these endeavors are effective only for wealthy farmers. Advanced breeding programs of any important scale that focus on the needs of poor farmers are limited to the International Agricultural Research Centres (IARCs) of the World Bank’s Consulta- tive Group on International Agricultural Research (CGIAR). While these programs have been faulted by some for trying to “short-cut” germplasm improvement in SSA by transferring less than suitable varieties from Asia and Latin America (Evenson and Gollin, 2003), there are now positive signs with respect to yield increases for most major crops. The CGIAR system as a whole has made major contributions in terms of new varieties and crop improvement in a range of crops. CGIAR has been a pioneer of participa- tory breeding: germplasm developed by many of the centers found its way into national breeding programs and subsequently into the fields of small-

42 Emerging Technologies to Benefit Farmers scale farmers. In an ideal world, the IARCs would have strong capacity to serve national breeding programs by maintaining germplasm collections, developing knowledge about germplasm characteristics, and identifying superior traits and introducing them into relevant crops that the national programs could routinely introduce into locally adapted germplasm. The centers could also help to build technologies and systems that recognize the issues of intellectual property, ownership, and preferences of the recipient countries. Thus, it is unfortunate that funding for those centers, particularly for core activities as opposed to donor-driven research agendas, has not kept pace with the need. Government and donor support for public breeding in the national breeding programs of SSA has also been sparse until recently. The develop- ment of capacity for conventional breeding approaches should be acceler- ated by the new Program for Africa’s Seed System (PASS), which is part of the recently established AGRA. Lack of High-Quality Seed In India and South Africa, a number of private-sector seed companies are active in providing high-quality hybrid seed. India is unique in its use of hybrid cotton—partly because of the availability of cheap labor required for seed production. The seed is increasingly transgenic, incorporating genes for herbicide tolerance and insect resistance, and is widely used; in most cases, it provides increased yield and permits reduction in the use of pesticides, which benefits small-scale farmers (Delmer, 2007). Hybrid maize and vegetable seed are also widely marketed in SA, which, unlike SSA, has a wide variety of hybrids available for sorghum and pearl millet. In SA, very poor farmers still rely heavily on open- pollinated varieties of these crops that are bred and distributed through public-sector efforts involving universities and national laboratories. In the maize-growing regions of eastern and southern Africa, several large multinational seed companies are active and business is largely driven by the existence of large farms using high inputs, but there is also substantial growth in small and medium-size African-led companies, a few of which have their own maize breeding programs. Fewer than 30 percent of small- holder maize farmers in SSA are buying and growing hybrid maize, but the number is rising (IFPRI, 1996; Smale et al., 2006). However, African farmers—especially women, who bear the responsibility for feeding their families—are very risk-averse: if they have indications of a bad year for rain or inadequate access to fertilizer, they will usually choose not to buy seed of the fertilizer-responsive, high-yielding hybrids. They increasingly recognize that such seed represents a good investment if seed and fertilizer can be purchased together. While farmer-saved seed will continue to be important

Constraints on Crop and Animal Productivity 43 for the very poor, it is counterproductive to suggest that it is the only good policy; farmers who wish to enter into a dynamic agricultural sector will need high-quality seed that has a high germination rate, is pathogen-free, and is clear of weed seed. Land and Labor Availability Almost 40 percent of the total land area of SA is used to grow crops—a reflection of the high population density of the region. Huge numbers of small-scale farmers and a sizable rural population of landless poor subsist among the fields. At the extreme is Bangladesh, where the land area per person is already limited and projected to be a mere 0.03 ha by 2050. All food, feed, fiber, and fuel demands of the present and future population in Bangladesh will have to be met on a very small land area, which may be reduced by projected sea level rise. In SSA, about 6 percent (173 million hectares) of the total land area is used to grow crops, and another 24 percent (720 million hectares) is used for pasture (FAO, 2006b). However, there is a lack of agricultural labor in SSA, whereas in SA, there is a limitation of crop land but not a shortage of labor. Although Africa has the highest rate of population growth in the world (the projected population by 2025 is 1.5 billion), the population density in rural and urban areas of SSA is much lower than that of SA (FAO, 2005). That small-holder agriculture in SSA is constrained by labor shortages is counterintuitive, but cases of labor scarcity have been docu- mented in Malawi (Alwang and Siegel, 1999), Burkina Faso (Fafchamps, 1993), and Ethiopia (Barrett and Clay, 2003). Farm workers are primarily female, and the woman with the hoe is the woman who raises children and cares for the sick and elderly. That is often unrecognized by nongovern- ment organizations and governments when they promote labor-intensive crop management or cultivation of crops that require extensive hand labor. The labor shortage is compounded by the impact of HIV/AIDS on the rural population in SSA (Du Guerney, 2002 and references therein). Malnutrition (see Box 2-1) and disease (including HIV/AIDS) in the rural poor sap crucial energy needed for labor-intensive work. Lack of Fuel and Electricity The largest concentrations of the “energy-poor” in the world live in SSA and SA. In most of the poorer countries, fewer than 25 percent of rural households have access to electricity, and only 5 percent of the rural population is connected to the national electric power grid. The primary region where the expansion of services has not kept pace with population growth is SSA, where the total number of people without access to electric-

44 Emerging Technologies to Benefit Farmers ity has increased steadily and is projected to continue to do so for the next several decades (IEA, 2002). Energy to support all aspects of agriculture is severely limiting; in particular, power-driven agricultural tools and the cold storage and transport to market of fruits, vegetables, fish, dairy, and meat are not available. Poor farmers are seriously affected by rising prices of oil and gas, es- pecially farmers who depend on diesel-driven pumps in the Indo-Gangetic basin, where 70 percent of irrigation depends on such pumps. As a result of the cost and lack of availability of power sources and equipment, only 1 percent of the land in Africa is cultivated mechanically (IAC, 2004). Use of animal traction and small diesel-powered devices is much lower in SSA than in SA, where small rototillers are widely used by small-holder farmers. For example, the availability of energy and power tools would transform agriculture in SSA. A woman can farm twice the area and farm with far less drudgery with a lightweight herbidicide sprayer than with hand tillage to control weeds, and the yields are greater (Carl Pray, Rutgers University, personal communication, 2007). The rural poor rely on biomass or manure for cooking fuel and heat; on kerosene wick lamps, batteries, or candles for lighting; and on human-based or animal-based mechanical power for tilling and weeding the land, grind- ing or crushing grain, agroprocessing, and transport. The lack of access to improved cooking fuels is greatest in SSA, followed by SA, as measured by the direct use of solid biomass (charcoal, fuelwood, stalks and other farm waste, or manure). Some 575 million people in SSA (89 percent of the population) rely on traditional biomass for cooking and heating, compared with 713 million in SA (about 50 percent of the population) (IEA, 2002; Gordon et al., 2004). As a rule of thumb, biomass is the most important source of energy (largely for heating and cooking) for people who live on less than US$2 per day (this is an equity issue in that poor people pay proportionally more for basic services). As discussed previously, the cut- ting of forests for wood and charcoal and the burning of crop and animal residues for energy are necessities of life when other sources of energy are either scarce or too expensive. Those practices contribute to a loss of soil quality and to environmental degradation, and they create health hazards, so a critical challenge is to find alternative sources of energy that are afford- able and healthier for humans and the environment. For all those reasons, new designs of cooking stoves and fuels for the poor are gaining attention (Kammen, 1995; Goldemberg et al., 2004; Utria, 2004). Biotic Constraints ON Crop Productivity Diseases and insect pests rob humanity of over 40 percent of the at- tainable yield of eight of the most important food crops worldwide (Oerke

Constraints on Crop and Animal Productivity 45 et al., 1994), and invasive species threaten both crops and native biodiver- sity (McNeeley, 2001). Some of the major pests and diseases are described below. Insects and Other Pests There is no centralized source of data on crop losses due exclusively to pests, but all major crops of SSA and SA are attacked by numerous in- sects, and even birds pose a major problem. The red-billed quelea (Quelea quelea), with an estimated world population of 1.5 billion (Cheke et al., 2007), is a major pest in Africa, especially of the open-panicle cereals, such as sorghum, millet, and rice (Ruelle and Bruggers, 1982). Children in par- ticular are given the job of protecting crops from those birds. One hectare of acacia scrub can have 50,000 nests, which produce 100,000 young, hungry birds that migrate with their parents; the birds each eat 20-50 g of grain per day (Doggett, 1988). In Somalia, grain losses of 80 percent have been reported. Crops within 30 km of a roosting area are in danger of be- ing virtually destroyed by the birds, and much larger areas are subject to damage when the flocks migrate (Cheke and Walsh, 2000). Lepidopteran insects, such as the stem borer and bollworm, attack maize, cotton, rice, eggplant, and other crops. Mealybugs are a major pest of cassava, and pod borers attack legumes, such as chickpea, pigeon pea, and cowpea. Nematodes are a scourge in banana, and weevils in both banana and sweet potato. Storage pests, such as the grain weevils and bor- ers, are responsible for huge losses in SSA (Gressel et al., 2004). Vegetable producers in India suffer a US$2.5 billion annual loss to insect damage even while spending US$100-200 per hectare on insecticides (Padmanabhan, 2000). Insecticides can control some pests, and biological agents have been used with mixed success, as in the control of cassava mealybug with para- sitic wasps and of locusts with the fungus Metarhizium anisopliae sf. acri- dum (Calatayud and Le Rü, 2006). There has been little success in breeding plants that are resistant to the wide array of insects that affect crops in SSA and SA, because the germplasm available to breeders has limited genetic resistance. In contrast, there are many trials with transgenic crops (maize, cotton, banana, and eggplant) that have been engineered to express the Bacillus thuringiensis (Bt) toxin, and the crops have proved to be very suc- cessful where they have been adopted, primarily in maize and cotton (Ferry et al., 2006; James, 2006a; Delmer, 2007). Provided that intellectual prop- erty, regulatory, and other barriers are successfully addressed (Box 2-2), these technologies are predicted to be valuable new approaches for plant improvement in SSA and SA.

46 Emerging Technologies to Benefit Farmers BOX 2-2 Overcoming Barriers to the Use of Genetically Engineered Crops It is clear that modern agriculture has been transformed by the advent of genetically modified crops (James, 2006a,b), but in SSA and SA only South Africa and India are even beginning to benefit from them. Insect-resistant (Bt) and herbicide-tolerant cotton is being widely adopted in these two countries, yet South Africa is the only country in SSA where transgenic crops are grown by farmers, and it is one of many countries where Bt cotton and maize led the way (Eicher et al., 2006; Delmer, 2007). Other Bt crops—such as rice, cowpea, and eggplant—are under development in many countries. Transgenic maize that is resistant to the herbicide glyphosate has been released in South Africa and is increasingly popular among small-scale farmers because it has eliminated drudgery associated with hand weeding, allowed cultivation of larger areas, and substantially increased yields. It is obvious that many of the approaches to crop improvement for the poor discussed in this report could be transgenic approaches. An important point to emphasize is that transgenic techniques are important not only for the development of new crops but for the critical first steps of research because they can allow rapid testing of new genes for their potential role in altering crop productivity. To benefit the poor, there needs to be a dramatic alteration of the barriers that have prevented the development and release of such crops in the develop- ing world (Juma and Serageldin, 2007). Kent (2004) and Delmer (2005) ana- lyzed some of the barriers in detail and suggested a few solutions. The major needs include improved transformation efficiency in several crops, new ways to control gene flow that are acceptable to small-scale farmers, robust ways to insert (“stack”) multiple genes and a path to getting stacked transgenics through regulatory systems, predictable methods for targeted gene insertion, and widely acceptable confined and contained research trials in SSA and SA so that local sci- entists can participate in the development of transgenic crops important to their own countries. Unfortunately, the high costs and long time frames associated with regulatory approval are a major constraint globally (Bradford et al., 2005; Kalaitzandonakes et al., 2007). Weed Problems Parasitic Weeds of Sub-Saharan Africa: Orobanche, Striga, and Others Parasitic weeds present the most intractable weed problems throughout Africa. In northern Africa, Orobanche (broomrape) species attach to roots

Constraints on Crop and Animal Productivity 47 and devastate most vegetable crops, where they do the most economic dam- age. They also attack all the grain legumes and have thus become a food security problem; countries that were once self-sufficient in grain legumes are now net importers (Gressel et al., 2004). In SSA, Striga spp. (witchweed) are the major problem (Ejeta and Gressel, 2007). Border countries, such as Ethiopia and Sudan, have both Orobanche and Striga problems. Striga hermonthica and S. asiatica attack and devastate maize, sorghum, millet, and upland rice throughout SSA. S. gesnerioides attacks grain legumes in western Africa but for unclear reasons has not spread to eastern Africa. Rhamphicarpa fistulosa is a related species that is becoming a problem in paddy rice (Ouedraogo et al., 1999). Major Weed of Wheat in India: Phalaris minor Wheat (Triticum) cultivation throughout the world relies on the use of herbicides, such as 2,4-D, which has been able to control broadleaf weeds without the evolution of resistance. But the absence of broadleaf weeds in the field left an ecological niche that was filled by grass weeds, and control- ling them has posed a larger problem. In wheat, all selective graminicides (grass weed herbicides) except one can be detoxified by grass weeds. One in particular, Phalaris minor, has become the major weed in Green Revo- lution wheat in India, having evolved resistance to isoproturon, the sole graminicide used there. This herbicide-resistant weed now covers millions of hectares (Malik and Singh, 1995; Singh, 2007). Although isoproturon was replaced with other graminicides, the problem is worsening, and there is less control by these herbicides (Yadav and Malik, 2005; Singh, 2007). Major Weeds of Maize and Rice: Feral Rice and Echinochloa Feral, weedy rice (sometimes called red rice), a rice that was once culti- vated but has become dedomesticated, is becoming the major weed problem in rice production in SA (Vaughan et al., 2005). Two changes in farming practices are exacerbating the problem: The use of cheaper bulk rice seed that contains feral rice is replacing the planting of seed from hand-picked, elite germplasm from weed-free fields (the equivalent of certified seed); and rice production is moving away from the back-breaking, labor-intensive method of hand-transplanting rice seedlings into paddies to the direct seed- ing of paddies. The change in practices has encouraged the evolution and   In addition to the widespread problems in Haryana and Punjab, the development of new herbicides by major chemical companies is waning while there is a fairly rapid rise in emer- gence of weeds resistant to the most widely used and environmentally friendly herbicide, glyphosate (Powles, 2008).

48 Emerging Technologies to Benefit Farmers establishment of feral rice. With the older production method, the hand- transplanted seedlings had a head start over the development of the weedy rice seeds. Echinochloa species are major weeds of all grass crops. The Interna- tional Maize and Wheat Improvement Center lists the weeds Cynodon and Echinochloa as the most serious pests of maize (Joshi et al., 2005). In southern China, nearly 2 million hectares of rice is infested with Echino- chloa species that are resistant to two of the three most common inexpen- sive herbicides used to control the weeds (Huang and Gressel, 1997). In some parts of the world, Echinochloa has evolved resistance to the third herbicide, propanil, but compounds that suppress the propanil-degrading properties of the weed have been identified (Valverde and Itoh, 2001). No such solution has yet been reported to overcome resistance to thiobencarb or butachlor, the other two herbicides most commonly used in Asia. Viruses Geminiviruses Two important crops—cassava in SSA and cotton in SA—are expe- riencing catastrophic losses because of viral epidemics. Both epidemics involve single-stranded DNA (ssDNA) geminiviruses in combination with satellites. In SSA, there is a clear pandemic of African cassava mosaic disease (ACMD), which is spread by the whitefly Bemisia tabaci (Mansoor et al., 2003, 2006; Legg and Fauquet, 2004). This problem is compounded by increases in whitefly vector populations that may be due to evolved resis- tance to pesticides and to global warming (Seal et al., 2006). The outbreak began in Uganda in the 1990s and over the last 2 decades has spread to cover more than 3 million square kilometers in nine countries in eastern and central Africa. The consequence has been devastating to the largely subsistence agri- cultural communities affected. It is now known that the ACMD is caused by a number of variant viral strains that are highly mutable and can recom- bine and that are influenced by the presence of additional satellites (Legg et al., 2006). To make the situation worse, the RNA virus called Cassava brown streak virus, once confined to the coastal areas of Kenya, Mozam- bique, and Tanzania and now spreading further into eastern Africa, almost certainly synergizes to reduce yields further, to near zero in many areas.   Satellitesare short nucleotide sequences that are distinct from the virus but part of the viral system. Satellites are dependent on a helper virus for replication. Their function is often unclear; they have been shown in some cases to exacerbate symptoms and in others to ame- liorate them.

Constraints on Crop and Animal Productivity 49 Some progress in breeding for tolerance (but not true resistance) to Cas- sava brown streak has been recently reported. The CGIAR centers of the International Institute of Tropical Agriculture and the International Center for Tropical Agriculture have also worked to deploy varieties of cassava that are resistant to ACMD, and it is encouraging that molecular markers that segregate with resistance to ACMD have been developed and widely distributed in western Kenya and Uganda and have already contributed to averting a major food insecurity disaster (Okogbenin et al., 2007). How- ever, resistance has been observed to break down in the presence of some newly discovered satellites (Akano et al., 2002; Ndunguru, 2005). On the Indian subcontinent, a serious threat has emerged in the form of another geminivirus complex—the cotton leaf curl virus, which has re- emerged as a complex with two DNA satellite viruses (Amin et al., 2006; Briddon and Stanley, 2006; Mansoor, 2006) and has caused disastrous losses of the cotton yield. The threat is true especially in Pakistan, but a similar (although distinct) complex is now found to be emerging in SSA. Indeed, the emergence of satellites that form complexes that lead traditional forms of resistance to break down is one of the most serious issues of these DNA viruses. Another ssDNA virus, banana bunchy top, is problematic throughout Asia, causing more than a 50 percent decrease in production in Pakistan. It has now also been identified in SSA, where it is creating worries that it could constitute yet another constraint on banana production in the region. Another geminivirus, tomato yellow leaf curl, whose vector is the whitefly B. tabaci, affects the tomato crop worldwide, including in Africa. ssDNA viruses present a major constraint on production of maize in SSA, and their effects on many common vegetables continue to worsen globally (Rybicki and Pietersen, 1999; Mansoor et al., 2006; Vanderschuren et al., 2007). Maize streak virus (MSV), another geminivirus, is spread by leafhoppers and can cause widespread yield losses in maize; MSV is found only in Africa, so MSV resistance has not been a target for most of the major international seed companies. A few genes that confer some resis- tance are available and have been used in breeding programs in eastern and southern Africa, and large growers are able to afford insecticides to control the leafhoppers. Although breeders commonly say that MSV is under con- trol, the recent reported loss of up to 80 percent of the maize crop in one region of Tanzania (Joseph Ndunguru, Mikocheni Agricultural Research In- stitute, Tanzania, personal communication, 2007) is characteristic of many reports from farmers throughout eastern and central Africa. MSV shows much less variability than African cassava mosaic viruses, but recent work indicates that recombination between viral strains does occur (Owor et al., 2007), and little is known about how current resistance loci respond.

50 Emerging Technologies to Benefit Farmers RNA Viruses and Retroviruses In addition to Cassava brown streak virus, a single-stranded RNA virus of importance is rice yellow mottle virus (RYMV); there are at least five re- gional RYMV variants in eastern and western Africa. The virus limits yields particularly in western Africa, where rice is grown more intensively. Few sources of resistance exist, but some mutations of a rice gene—eukaryotic translation initiation factor 4G (eIF(iso)4G)—confer high resistance to the virus (Albar et al., 2006). Knowledge of that resistance allows both con- ventional breeding and the possibility of genetically engineering susceptible varieties with the mutant rice gene. Banana streak virus is a retrovirus that can integrate into the banana genome. It is now being spread and activated by some tissue-culture operations in SSA that lack proper viral-indexing capacities (James Dale, Queensland University of Technology, Australia, personal communication, 2007). The latter problem illustrates another serious constraint on disease control: the almost total lack of capacity, in- frastructure, and coordination needed to create a comprehensive diagnostic network in SSA. Such a network is critical for monitoring viral, fungal, and bacterial diseases and insects that vector disease, and for identifying and monitoring animal diseases. Fungal and Bacterial Pathogens Fungal diseases cause serious yield losses in SSA and SA. The fungal stem rust (Puccinia graminis) of wheat was effectively controlled decades ago through introgression of the Sr31 resistance gene by Norman Borlaug and colleagues in one of the key achievements of the Green Revolution. However, a resistant strain of the rust has recently emerged in Uganda and spread to Yemen, and in this age of globalization it poses a potential worldwide threat (Kolmer, 2005; Wanyera et al., 2006). Although it will take time, breeders are identifying sources of genetic resistance in wheat germplasm with help from DNA molecular markers. Soybeans in Africa, Asia, and Latin America are severely affected by rust (Phakospora). According to the International Potato Center, the late blight of potato (Phytophthora) is the most costly biotic constraint on global food production. Powdery mildews affect a wide array of crops, including such major cereals as wheat, sorghum, and millet; fungal an- thracnose affects crops such as sorghum, beans, and cassava; angular leaf spot and root rots plague beans and other important crops; turcicum and gray leaf spot diseases are serious pests of maize in SSA; and black sigatoka limits banana production worldwide. Similarly, bacterial diseases cause large crop losses. Particularly deadly are diseases caused by the genus Xanthomonas, which include blights of

Constraints on Crop and Animal Productivity 51 rice and cotton and, more recently, banana wilt blight, a serious disease of the east African highland banana, the major staple crop of Uganda. Small farm environments are susceptible to the development of fungi that lead to mycotoxin (aflatoxin or fumonisin) accumulation. Mycotoxins are highly toxic metabolites produced by a number of fungi, especially in drought-prone or unseasonably rainy environments or as a consequence of high moisture before harvesting, during harvesting, and in storage (Wid- strom, 1996). Many toxin-producing fungi have been found in stored food products, but two in particular have major impacts on tropical economies: aflatoxins produced by Aspergillus flavus and fumonisins A and B produced by Fusarium. Research in Asia and SSA has shown that mycotoxin con- tamination is widespread on staple crops. Aflatoxins are routinely found in maize, groundnut, sorghum, cashew, cassava, yam chips, pistachio, almond, and chili pepper; Fusarium toxins occur in maize, wheat, and sorghum; and ochratoxin (produced by some Aspergillus and Penicillium species) occurs in cocoa and cashew (Ortiz et al., 2008). Mycotoxins are also present in some processed food and feed and even in milk and meat products when animals are given contaminated feed. The presence of mycotoxins in agri- cultural products renders them unexportable (see Box 2-3). An estimated 4.5 billion people are chronically exposed to mycotoxins in the developing world (Williams et al., 2004). Mycotoxins get some public attention when people die after acute exposure to them, as in the aflatoxin poisoning in Kenya where 125 deaths were recorded in 2004 (Probst et al., 2007). But effects of chronic exposure are also widespread and often more insidious and therefore do not cause the alarm expected. Overview of Animal Production in Sub‑Saharan Africa and South Asia Livestock Globally, livestock production is in a period of rapid transition. Since 1995, more meat has been produced in developing countries than in devel- oped countries. Most livestock is owned by farmers who work on mixed crop-livestock farms. In Asia, more than 95 percent of the ruminants and many swine and poultry are raised on such farms. Worldwide, 57 percent of the 687 million poor who own livestock work in mixed crop-livestock systems (Devendra et al., 2005). The animals in these systems have mul- tiple purposes: they provide milk, meat, fiber, hides, manure (soil amend- ments), traction, and a means to accumulate assets. In Africa, 70 percent of the poor farmers own animals, and the animals represent about half their assets. Most African livestock are raised in the subhumid and semi-arid re-

52 Emerging Technologies to Benefit Farmers BOX 2-3 Meeting International Food Safety Standards The entrance of small-scale farmers into global food markets is prevented by their inability to meet the high standards of food safety set by the developed world. A classic example is the stringent standard for mycotoxins in imported foodstuffs imposed by the European Union. With the rise of supermarkets in SSA and SA, such standards are increasingly being set even locally and can lead to lost opportunities for such farmers to find markets in the growing urban populations of their own regions (see Weatherspoon and Reardon, 2003; Brown, 2005; and the many references in both). Poor farmers lack the tools to prevent mycotoxin problems—clean water; rapid and cheap diagnostic kits; an array of improved postharvest technologies, including local access to cold storage, solar drying, and improved packaging; and rapid and efficient transport systems. The good news is that when projects are in place to upgrade small-scale farmers’ ability to meet all those challenges, the large supermarket chains appear eager, at least sometimes, to have them participate. Some examples of success stories have been outlined by Page and Slater (2003) and Weatherspoon and Reardon (2003). In Zambia, the Luangeni project is using various actors (donors, the government, nongovernment organizations, and retailers) to help small-holders to meet quality, safety, and cost standards in conjunction with the South African retailer Shoprite. Dave Weatherspoon, of Michigan State University’s Partnership for Food Industry Development Project, funded by the U.S. Agency for International Development, is helping to connect small producers in South Africa’s Eastern Cape Province with Pick ’N Pay, the country’s second-largest supermarket chain. The farmers have agreed to a 3-year growing project in which they supply squash products and sweet corn to the chain. Pick ’N Pay specifies what varieties the farmers must plant, the farming practices and processing methods they must use, and when they must deliver the produce. In return for participating in this rigorous program, the farmers gain access to a profitable and reliable market. gions that extend in an inverted “L” from South Africa north to the Sudan and west across the Sahel (Figure 2-4) (Thornton et al., 2002). Of poor farmers who own animals, 20 percent operate in extensive systems (Devendra et al., 2005). They include livestock owners in eastern Africa (Ethiopia, Somalia, Eritrea, Kenya, and Sudan), in western Africa across the Sahel region, and in India (the Rajasthan). In those areas, which represent about one-fourth of the world’s land mass, millions of nomadic herders and pastoralist herders and their families tend livestock on lands that otherwise would probably be agriculturally unproductive because of

Constraints on Crop and Animal Productivity 53 Number km2 0– 5 5 – 10 10 – 20 20 – 40 > 40 FIGURE 2-4  Tropical livestock unit density in sub-Saharan Africa and South Asia. 2-4.eps SOURCE: Excerpted from Thornton et al., 2002. Reprinted with permission. © 2002 bitmap image by International Livestock Research Institute. low rainfall. About 10 percent of the global meat supply is produced in those areas, and livestock production is the primary food- and income- generating activity for the people living there. Up to 88 percent of agricul- tural income of farmers in the regions is derived from livestock (Winrock, 1992). Enormous social, economic, and environmental pressures threaten those pastoral systems. Dairy In 1998, India became the world’s largest milk producer, outstrip- ping the United States (FAO, 2006b). Small-holder farmers predominantly

54 Emerging Technologies to Benefit Farmers operate forage-based dairy production systems. The continued success of small-holder dairying in India is due, in part, to Operation Flood, a long- term (1970-1996) national program to promote dairying and to support more than 72,000 village milk cooperatives that purchase milk from small- holders. Lagging behind efforts in SA, the lack of ability to market dairy products represents an even more serious constraint in SSA. In China, India, Brazil, and other parts of Latin America and southeastern Asia, changes in the supply chains for milk and meat have led to more reliance on centralized processing and supermarkets (Reardon et al., 2003). Processing and mar- keting advances have provided outlets for livestock products and improved food safety, but these technology-linked benefits often are inaccessible to the poorest farmers. Aquaculture The Asia-Pacific region is the world’s largest producer of fish (over 80 percent of total world production) by both aquaculture and capture fisheries. Each sector is approaching 50 million tons per year. As might be expected, artisanal fishing is a major driver of the economy of island states, such as the Maldives, and is important in all the coastal regions of SA. Fishing is especially important in Bangladesh, a country of rivers and coastal flood plains where inland capture fisheries provide both income and important sources of protein for the poor. However, small pond sizes and their seasonal drying remain large constraints on this industry. Fishing is also important in SSA (although on a smaller scale than in SA), with a total production of about 7 million tons per year divided equally between marine and inland fisheries. The Food and Agriculture Organization of the United Nations (FAO, 2003) estimated that 20 percent of dietary protein in SSA comes from fish. Capture fishing predominates in many coastal communities of Africa, although the IAC report (2004) indicates that the per capita supply of such fish is declining, and capture fishing in some areas, such as Lake Victoria, is judged to be near its maximum. Assuming an average annual population growth of 1.9 percent, just maintaining the current production level in SSA up to 2015 will require that fish production increase by 27.7 percent over this period (World Bank, 2004; WorldFish Center, 2005). Globally, most forecasts are for a decreasing supply from capture fisheries and an increasing proportion from aquaculture, with an annual increase of 8.9 percent making it the fastest-growing food production sector (Hill, 2005). Thanks to visionaries like Mondadugu V. Gupta, winner of the 2005 World Food Prize, aquaculture, including co-cultivation of fish in rice paddies, has increased throughout SA and is judged still to have strong growth potential. FAO projections show that by developing only 5 percent

Constraints on Crop and Animal Productivity 55 of the suitable areas available for aquaculture use, Africa could meet its fish production target (FAO, 2003). That points clearly to the benefits that might accrue if aquaculture were more extensively developed in SSA using sustainable practices. Poultry Another fast-growing segment of the agricultural sector in SA is the poultry industry, with an average growth rate of 8 to 10 percent and pro- duction of 44 billion eggs and 1.6 billion broilers per year in India alone. At the National Seminar on Poultry Research Priorities to 2020, held in 2006 at the Central Avian Research Institute (http://www.icar.org.in/cari/index. html), a number of priorities for research were outlined. It provided a rich source of information on new directions for the poultry industry on issues such as the use of molecular tools for poultry breeding; disease manage- ment, including biosecurity and control of emerging zoonoses; and process- ing (Kannaki and Verma, 2006). The poultry industry in SSA is still lagging compared with that in other parts of the developing world. General Constraints on Animal Production Poor nutrition, diseases, and poor genetic potential are the three ma- jor constraints on animal production in SSA and SA (CAADP, 2003; IAC, 2004), but there are several ancillary constraints, such as the lack of animal identification and tracking measures for disease status, competition from imports, the need for mobile milking machines and chilling tanks, the need for reliable animal and meat transportation and storage, and alternatives to fish meal for aquaculture. The interactions between wildlife and domestic animals also contribute to important factors affecting the ability of poor farmers in SSA and SA to increase the productivity of their animals. One is the effect of wildlife on competition for land resources and land use, and another effect is the transmission of diseases between wildlife, domestic animals, and humans. The legal and illegal trade of bushmeat also has a tremendous impact on the sustainability of livestock and ecosystems in both SSA and SA (Loibooki et al., 2002; Rowcliffe et al., 2005). Water is another constraint. Production of meat from animals requires about 8 times the amount of water needed to produce the same amount of vegetable protein. Lack of water for grazing animals severely limits animal production in pastoral areas. On the basis of the goal of having 20 percent of all food come from animal sources, about 1,300 m3 of water per person will be required each year to produce animal protein for a balanced diet of 3,000 kcal/person per day (FAO, 2003).

56 Emerging Technologies to Benefit Farmers Lack of Nutrition and Reliable Feed Supply Livestock nutritional inadequacy is a severe seasonal constraint in dry areas, but improvement of extensive pasture systems is extremely dif- ficult. Farmers lack the equipment and improved forage varieties needed for pasture establishment, and free-ranging animals often consume newly planted pasture. To minimize losses to pests and diseases, pastoralists tend to overstock their herds, and this can lead to overgrazing and loss of for- age diversity. Forage in the tropics is often deficient in protein, energy, and micronu- trients, and these deficiencies sharply reduce animal productivity. Although considerable effort has gone into improving the quality of Brachiaria spp. in the humid and subhumid tropics, relatively little attention has been given to other grasses and legumes. Pennisetum purpureum (Napier grass), which is widely used in the eastern African highlands and elsewhere and is suscep- tible to Ustilago kamerunensis smut, deserves particular attention, as do the herbaceous legumes that can simultaneously improve soil fertility and the nitrogen status of animals. A forage-breeding program that could improve the nutritive value and disease resistance of grasses and legumes is needed. Molecular breeding approaches could be used in combination with regional trials to assess the adaptability of germplasm for different ecozones. Many forage-fed animals in the tropics grow slowly and produce small amounts of milk because their diets are inadequate in protein, energy, and micronutrients. In regions where mixed animal-crop systems prevail, there seems to be a great opportunity to address poor nutrition by strengthen- ing fledgling animal feed industries. Not only would that promote a more stable source of food for animals, but it would also present an opportunity to stabilize output markets and add value to crops such as maize, sorghum, cassava, and legumes. Protein is often scarce in many regions: many rumi- nant animals have nothing but wheat straw to eat in the dry season. Animal Diseases Animal diseases have an extraordinary impact on livestock productiv- ity and livestock production, especially in SSA and SA where the control of animal diseases has been more challenging with limited resources. The consequences of animal diseases range from direct economic costs, such as the loss of animal production and products, to indirect costs related to a disease outbreak, such as the loss of trade markets and job losses (OIE, 1999; Le Gall, 2006). In the 1980s, a foot-and-mouth outbreak caused the Kenyan dairy farming sector to suffer a 30 percent loss of milk production (Le Gall, 2006). In 1997-1998, abortions caused by Rift Valley fever virus impacted birth rates and milk production, and East Africa experienced a 75 percent decline in exports (Le Gall, 2006). The 2003-2004 outbreak of

Constraints on Crop and Animal Productivity 57 highly pathogenic avian influenza in Southeast Asia resulted in more than 140 million dead or destroyed birds and losses exceeding US$10 billion (World Bank, 2008). Even though poor countries in SSA and SA may not be ready to export some of their agricultural commodities, many countries are finding a market niche for some of their animal products and are facing significant obstacles in reaching international markets because of animal diseases in their countries. Some major animal diseases in SSA and SA include African swine fever, peste des petits ruminants, sheep and goat pox, hemorrhagic septicemia, foot-and-mouth disease, contagious bovine pleuropneumonia, blue tongue disease, clostridial diseases, and vector-borne diseases, such as heartwater, East Coast fever, Rift Valley fever, trypanosomiasis (animal and human), parasitic diseases, classical swine fever, highly pathogenic avian influenza, and Newcastle disease. Zoonotic diseases pose a continuing threat (see Box 2-4). The types of disease vary considerably among western Africa and eastern, central, and southern Africa, but ticks, worms, and the tsetse fly are common everywhere (Perry et al., 2002). Most of potentially produc- tive SSA is infested by the tsetse fly and affected by human and animal trypanosomes. According to the International Livestock Research Institute, the 300,000 cases of animal trypanosomiasis in Africa (40,000 new cases each year) result in annual losses of over US$4.5 billion. East Coast fever and Rift Valley fever take a heavy toll on cattle, and Newcastle disease severely limits poultry production by poor farmers (Gueye, 2000). Internal parasites of livestock, notably haemonchosis and fascioliasis, are also major constraints, as internal and external parasites have a severe impact on animal health and productivity at the level of poor farmers in SSA and SA. Many of these parasitic infections are easily controlled with low-cost medications and can be used with existing tech- nologies—such as ear tags with insecticides and slow release anti-parasitic boluses that can be given to ruminants—to control parasitic burdens. There have been considerable advances in the development of vaccines for im- portant parasitic diseases but little commercial interest in developing and marketing them. Endemic viral diseases often occur as focal or widespread outbreaks that cause immediate and short-term economic effects because of morbidity and mortality and restrictions on international trade and movement. Viral diseases constitute a particular problem in aquaculture (Hill, 2005). Constraints that Cannot Be Solved by Science and Technology Alone One of the striking features of the list of constraints identified by scientists in SSA and SA (see Box 1-1 in Chapter 1) is the number of non-

58 Emerging Technologies to Benefit Farmers BOX 2-4 Zoonotic Diseases The World Health Organization defines zoonoses as diseases caused by in- fectious agents that are naturally transmitted between animals and humans. Some well-known zoonoses are salmonellosis, swineherd’s disease (caused by Leptospira spp.), brucellosis, hepatitis E, HIV, bovine spongiform encephalopathy (BSE) and its zoonotic form the variant Creutzfeldt-Jakob disease (vCJD), Rift Valley fever (RVF), anthrax, adult meningitis (caused by Streptococcus suis), and influenza. Of most interest today are the so-called emerging zoonoses, which include SARS, West Nile virus, and highly pathogenic avian influenza. Increasing popula- tion, globalization, trade in exotic pets, and the close intermingling of animals and humans in urban settings have all contributed to outbreaks of emerging zoonoses. The diseases are especially threatening to the fragile economies of SSA, where livestock, dairy, and poultry industries are just emerging and could be seriously affected. In Africa, movements of domestic and wild animal populations are important in the spread of the diseases. A very serious emerging zoonotic disease in SA is Nipah Virus Disease, which is transmitted by Pteropus bats and the disease results in high levels of fatality in humans and in pigs. There are many opportunities for modern science and technology to contribute—through development of better and cheaper diagnostics, better sur- veillance, and rapid-response systems, including vastly enhanced capacities to rapidly create and deliver new vaccines. There is also much to learn about the mechanisms by which viruses recombine and create new and more deadly strains. Although the conventional wisdom is that mutations and recombinations are random and not predictable, novel approaches by, for example, Henry Niman and his company, Recombinomics (www.recombinomics.com), suggest that greater understanding will make these events more predictable. If so, there will be possibilities to create vaccines in advance of the recombination events. agricultural issues, such as insufficient markets, weak governments, and lack of infrastructure. Some of those issues have long been blamed for holding back social progress and blunting the impact of technical solutions to agricultural problems. It now seems remarkable that few anticipated the “perfect storm” of rising food prices worldwide due to a convergence of events only partly related to agricultural productivity: a rising middle class in the developing world demanding more grain for direct consumption and for feed to satisfy a growing desire for animal products, the high cost of energy for agriculture, diversion of food crops to biofuels, and long-term droughts in major cereal producing regions such as Australia.

Constraints on Crop and Animal Productivity 59 Weak Government and Policy Environment Many of the challenges are of a political, social, or economic nature: poor governance, corruption, tribal rivalries, and intense civil strife con- tinue to hinder development in many countries of Africa. Tribal customs can play a role in SSA, and remnants of the caste system in India still strongly reduce opportunities for the poor. Poor governance can create ex- cessive roadblocks to the development of business enterprises and decrease the pace of rural economic development. Particularly in SSA, the lack of good policies to support agricultural trade and lack of credit for the poor at fair interest rates are common problems. Weak legal structures related to women’s rights and land tenure provide little incentive for long-term farm improvement and, when coupled with the high death rate from HIV/AIDS, create instability in the rural sector. Outdated treaties on water rights that date from colonial times also impede development of sound water policies in some SSA countries, and inattention of SA governments to control the worsening depletion of major aquifers and the pollution of rivers is pre- dicted to have disastrous consequences for agriculture. In SSA, imposition of protective tariffs on needed inputs such as high- quality seed, fertilizers, and pesticides—coupled with the lack of specific government support systems for help with such issues as targeted subsidies for agricultural inputs—are also major constraints. The policies of interna- tional donors that prefer to donate surplus food from abroad as opposed to purchase food grown in African countries with surpluses and transfer of such to countries with shortfalls increase price volatility, distort markets, and discourage farmers from trying to be productive. Not all government policies have adverse effects. A recent Malawi gov- ernment investment in seed and fertilizer for poor farmers (and favorable weather) doubled maize yields, bringing some food security where famine had been rampant. Such approaches are clearly needed but with some cave- ats. One danger is that government “giveaways” of seed and fertilizer can compete unfairly with the fragile emerging private-sector seed companies and agrodealers—a danger that in the Malawi case was mitigated by the use of vouchers. Insufficient Investment in Agricultural Research and Development Most governments in SSA have not invested even a small percentage of gross domestic product in agricultural R&D, and even the recently set goals for boosting agricultural productivity by 6 percent per year in Africa (CAADP, 2002) appear to be quite inadequate in light of the rate of popu- lation growth and the dramatic rise in food prices worldwide. World grain prices, which by 2008 were roughly 75 percent higher than in 2005, are

60 Emerging Technologies to Benefit Farmers expected to remain high at high levels through 2017 (USDA, 2008), offer- ing a unique window of opportunity to assist poor farmers in transferring from subsistence to production agriculture if productivity in SSA and SA can be increased. Lack of Extension Services A major constraint to agriculture is the woefully inadequate extension services in both SSA and SA that are so critical for transferring new knowl- edge and technologies to farmers. Many countries in SSA and SA maintain a large number of agricultural extension agents on government payrolls, but they do not have sufficient resources to get into the field or to develop and provide the information needed to support farmers. In addition to lo- cal radio, the growing access to the Internet, particularly in SA, might be used to great advantage to transform those services. SA is in a much better position than SSA with respect to infrastructure for information technology; however, with the completion of fiber-optic cables that can surround SSA and efforts to connect the interior regions to them, one can expect rapid adoption of this powerful means of communication just as cellular phones have been adopted. Lack of Cash and Financing It is often not recognized that farmers live in a cash economy with little means to generate cash. Purchase of day-to-day necessities—such as clothes and food not grown at home, school fees, and costs of health services, wed- dings, and funerals—limit a farmer’s ability to purchase high-quality inputs, including seed, fertilizer, and irrigation and other farm equipment. For those and other complex reasons, the creation of dynamic rural enterprises depends on the availability of credit at manageable interest rates to small- scale farmers. The need for such credit impinges upon all efforts to increase agricultural productivity. Through the ability to purchase critical inputs that can increase primary productivity, excess yields of staple crops (beyond household needs) could be processed into higher-value commodities and sold in local and regional markets. Alternatively, with higher productivity, the land devoted to staple crops could be decreased to allow production of higher-value cash crops, such as fruits and vegetables, which contribute to both better nutrition and income. Need for Basic Infrastructure The lack of adequate roads in SSA severely limits the development of strong output markets; even in India, the Finance Minister in 2005

Constraints on Crop and Animal Productivity 61 stressed in a speech the importance of further development of rural roads, electrification, and increased access to markets that would be critical for rural development. Particularly in SSA, poor roads and lack of transport mean that farmers are also isolated from key inputs, such as improved seed, fertilizer, irrigation and other farm equipment, and information services. A recent push to promote farmer collectives (www.sacredafrica.org) and to create a much larger number of small local agro-dealers to provide the inputs and services has helped in some small way to mitigate the problem in a few countries in eastern Africa (Eilittä, 2006). On the output side, both in SSA and SA, poor storage conditions for grain, fruits and vegetables, fish, milk, and meat and lack of transport and roads limit a farmer’s ability to sell excess produce in years of abundance. The lack of roads coincides with the critical lack of energy, both on the farm and in the transportation sector. Together, the lack of these two critical aspects of infrastructure essentially ensures that efforts to modernize agriculture cannot succeed unless these two major limitations are addressed in a serious way. A Future Uncertainty: Climate Change A 2007 report by the Intergovernmental Panel on Climate Change leaves little room for doubt that the world is getting warmer. By the end of the century, average temperatures could increase by up to 6°C. Higher latitudes will experience greater temperature increases than coastal and lowland regions. The effects of climate change can also impact plant and animal disease patterns and prevalence. Increased carbon dioxide concen- trations decrease stomatal conductance and reduce water loss from plants under both irrigated and rain-fed conditions and can result in higher yields, although the results can vary seasonally in ways that are not completely understood (Bernacchi et al., 2007). On a larger scale, the decreases in plant evapotranspiration have been shown to increase continental water runoff to the seas and thus affect global hydrology (Gedney et al., 2006). The magnitude of any feedback loops in those systems locally, regionally, and globally is complex and deserves further study; genomic approaches that facilitate adaptation of important crop species is part of this research (White et al., 2004; Li et al., 2007). It is quite clear that, in terms of overall effects on world agriculture, there will be winners and losers as the climate changes. For example, it is predicted that southern and northern Africa will become drier and the trop- ics wetter (with regional variations), and there remains much controversy over how the Sahel will be affected. It is more certain that Africa and parts of Asia (Naylor et al., 2007) will be greatly affected by El Niño and that in general Africans, like most of the rest of the world, should expect more violent extremes of weather (DFID, 2004; IPCC, 2007). A recent study

62 Emerging Technologies to Benefit Farmers based on statistical crop models and climate projections for 2030 indicates that wheat in SA and maize in southern Africa are the most likely to suffer adverse effects of climate change (Lobell et al., 2008). Farmers in SSA have millennia of experience in dealing with the vaga- ries of weather (Giles, 2007), and it has often been pointed out that annual variations in weather can be more extreme than the changes predicted for the long term. As noted previously, poor farmers in SSA are conservative when faced with uncertain conditions. Therefore, enhancing the accuracy of seasonal weather predictions could have a profound effect on agriculture in SSA. If a cropping season for bumper crops could be reliably foretold, farmers would be much more willing to risk the purchase of high-quality seed and fertilizer or to make reasoned decisions about what percentage of maize vs. the more drought-tolerant sorghum to grow. It seems apparent that changing weather patterns will also affect the distribution and movements of pathogens and their vectors. Changes in the patterns, prevalence, and competency of arthropod vectors of infec- tious and parasitic disease agents are already having a serious impact on the emergence of vector-borne human and animal pathogens. Studies so far indicate that, in general, plants will be more predisposed to diseases as global warming proceeds (Chakaborty, 2005), but there are many complex feedback loops in the interactions (Harvell et al., 2002; White et al., 2004; Burdon et al., 2006; Garrett et al., 2006; Yamamura et al., 2006; Ziska and Goins, 2006; Zvereva and Kozlov, 2006). The roles of crop plants (such as rice) and animals in greenhouse gas emissions are coming into focus, but how the emissions might be mitigated, including soil carbon sequestration, is still an open question (Lal, 2004; Wassmann et al., 2004; Kerdchoechuen, 2005). Finally, how will rising sea levels affect the livelihoods of those engaged in agriculture and fishing in coastal areas? The situation could be so severe in some island countries, such as the Maldives and the coastal regions of Bangladesh, that relocation of people might be the only worthwhile op- tion. Rising sea levels and as well as more violent storms will certainly affect coastal ecosystems, including the mangroves that harbor rich fish- ing grounds, and lead to salinization of coastal aquifers (IPCC, 2001). Changes in sea level, temperature, and concentrations of CO2 and O2 can also lead to changes in population dynamics for all species. IWMI (2006) has provided an excellent summary of the challenges that global warming will probably create for both artisanal fishing and aquaculture. Efforts are needed to anticipate the changes and take adaptive actions before the ad- verse effects on agriculture occur.

Constraints on Crop and Animal Productivity 63 lack of Quick Fixes The Comprehensive Africa Agriculture Development Programme em- phasized that “there should be no illusion of quick fixes, or miracle paths, towards African self-reliance in food and agriculture. Achievement of a productive and profitable agricultural/agro-industrial sector will require Africa to address a complex set of challenges” (CAADP, 2002). Because agriculture in SSA and SA is so relatively unproductive, al- most any well-chosen effort to address some of the constraints in these regions might bring about substantial improvement in a short period of time, although one has to understand that such improvement is relative. For example, the yield increases experienced in Malawi after government financing of fertilizer and seed purchase were still only about two-thirds the world average. Therefore, more progress is needed. In the industrialized world, the implementation of a novel technology provides a marginal ben- efit to the production system, but no coherent production “system” exists in most places in the developing world. A whole suite of approaches, some technological and some not, must come together for farmers to realize the benefit of any innovation. For example, addressing the nutritive component of a crop will be of little use if the numerous other constraints that limit the crop’s productivity are not tackled. The opportunities suggested in the succeeding chapters must be viewed in that light—that at best they offer new approaches that can synergize with each other and with the many other activities supported by governments and donors worldwide to transform subsistence agriculture to productive agriculture in SSA and SA. REFERENCES Akano O., O. Dixon, C. Mba, E. Barerra, and M. Fregene. 2002. Genetic mapping of a dominant gene conferring resistance to cassava mosaic disease. Theoret. Appl. Genet. 106:58-66. Albar, L., M. Bangratz-Reyser, E. Hébrard, M. N. Ndjiondjop, M. Jones, and A. Ghesquière. 2006. Mutations in the eIF(iso)4G translation initiation factor confer high resistance of rice to Rice yellow mottle virus. Plant J. 47:417-426. Alwang, J., and P. B. Siegel. 1999. Labor shortages on small landholdings in Malawi: Implica- tions for policy reforms. World Develop. 27:1461-1475. Amin, I., S. Mansoor, L. Amrao, M. Hussain, S. Irum, Y. Zafar, S. E. Bull, and R. W. Briddon. 2006. Mobilisation into cotton and spread of a recombinant cotton leaf curl disease satellite. Arch. Virol. 151:2055-2065. Barrett, C. B., and D. C. Clay. 2003. How accurate is food-for-work self-targeting in the pres- ence of imperfect factor markets? Evidence from Ethiopia. J. Dev. Stud. 39:152-180. Bernacchi, C. J., B. A. Kimball, D. R. Quarles, S. P. Long, and D. R. Ort. 2007. Decreases in stomatal conductance of soybean under open-air elevation of CO2 are closely coupled to decreases in open air evaporation. Plant Physiol. 143:134-144.

64 Emerging Technologies to Benefit Farmers Bradford, K. J., A. Van Deynze, N. Gutterson, W. Parrott, and S. H. Strauss. 2005. Regulation of transgenic crops sensibly: lessons from plant breeding, biotechnology and genomics. Nat. Biotechnol. 23:439-444. Briddon, R. W., and J. Stanley. 2006. Subviral agents associated with single-stranded DNA viruses. Virology 344:198-210. Brown, O. 2005. Supermarket buying power, global market chains and smallholder farmers in the developing world. UNDP-Human Development Report 2005. Occasional Paper. Burdon, J. J., P. H. Thrall, and L. Ericson. 2006. The current and future dynamics of disease in plant communities. Annu. Rev. Phytopathol. 44:19-39. CAADP (Comprehensive Africa Agriculture Development Programme). 2002. Comprehensive Africa Agriculture Development Programme prepared by the New Partnerhsip for Afri- ca’s Development (NEPAD). Available online at http://www.fao.org/docrep/005/y6831e/ y6831e-02.htm [accessed February 20, 2008]. CAADP. 2003. Comprehensive Africa Agriculture Development Programme prepared by the New Partnerhsip for Africa’s Development (NEPAD). Supplement on Livestock, Fisher- ies, and Forestry. Calatayud, P. A., and B. Le Rü, eds. 2006. Cassava-Mealybug Interactions. Ird Collection. France: Institut de Recherche pour le Développement. Camara, O., and E. Heinemann. 2006. Overview of the fertilizer situation in Africa (back- ground paper prepared for the African Fertilizer Summit; www.africafertilizersummit. org). Chakaborty, S. 2005. Potential impact of climate change on plant-pathogen interactions. Australas. Plant Pathol. 34:443-448. Cheke, R. A., and J. F. Walsh. 2000. Behaviour of standard-wing nightjars in Togo. Ostrich 71:349-350. Cheke, R. A., J. F. Venn, and P. J. Jones. 2007. Forecasting suitable breeding conditions for the red-billed quelea Quelea quelea in southern Africa. J. Appl. Ecol. 44:523-533. Chopra, M., and I. Darnton-Hill. 2006. Responding to the crisis in sub-Saharan Africa: The role of nutrition. Public Health Nutr. 9:544-550. de Janvry, A., and D. Byerlee. 2007. Agriculture for development: World Development Report 2008. Washington, DC: The World Bank. Delmer, D. P. 2005. Agriculture in the developing world: Connecting innovations in plant research to downstream applications. Proc. Natl. Acad. Sci. U. S. A. 102:15739-15746. Delmer, D. 2007. Transferring biotechnology over the world. In: Plenary presentations and papers. Proceedings of World Cotton Research Conference—4, Lubbock, TX. D. Ethridge, ed. Devendra, C., J. Morton, B. Rischkowsky, and D. Thomas. 2005. Livestock systems. Pp. 29-52 in Livestock and Wealth Creation, E. Owen, A. Kitalyi, N. Jayasuriya and T. Smith, eds. Nottingham, UK: Nottingham University Press. DeVries, J., and G. Toenniessen. 2002. Securing the harvest: Biotechnology, breeding and seed systems for African crops. New York: The Rockefeller Foundation. DFID (Department for International Development). 2004. Key sheet 10: Climate change in Africa. Available online at http://www.dfid.gov.uk/pubs/files/climatechange/10africa.pdf [accessed February 20, 2008]. Diaz de la Garza, R. I., J. F. Gregory, and A. D. Hanson. 2007. Folate biofortification of tomato fruit. Proc. Natl. Acad. Sci. U. S. A. 104:4218-4222. Doggett, H. 1988. Sorghum. Harlow, UK: Longman. Du Guerney, J. 2002. Agriculture and HIV/AIDS. United Nations Development Program. Available online at http://www.undp.org/hiv/docs/alldocs/Asia%20-%20Agriculture%2 0and%20HIV-AIDS%20(2002).pdf [accessed December 14, 2007].

Constraints on Crop and Animal Productivity 65 Eicher, C. K., K. Maredia, and I. Sithole-Niang. 2006. Crop biotechnology and the African farmer. Food Policy 31:504-527. Eilittä, M. 2006. Achieving an African Green Revolution: A vision for sustainable agricultural growth in Africa. Africa Fertilizer Summit. Available online at www.africanfertilizer summit.org/Background_Papers/ [accessed December 14, 2007]. Ejeta, G., and J. Gressel, eds. 2007. Integrating New Technologies for Striga Control: Ending the Witch-hunt. Singapore: World Scientific. Eswaran, H., F. Beinroth, and P. Reich. 1999. Global land resources and population-supporting capacity. Am. J. Altern. Agric. 14:129-136. Evenson, R. E., and D. Gollin. 2003. Assessing the impact of the green revolution, 1960 to 2000. Science 300:758-762. Fafchamps, M. 1993. Sequential labor decisions under uncertainty: An estimable household model of West-African farmers. Econometrica 61:1173-1197. FAO (Food and Agriculture Organization of the United Nations). 2003. World Agriculture: Towards 2015/2030. An FAO Perspective, J. Bruinsma, ed. London: Earthscan. FAO. 2005. Mapping global urban and rural population distributions. Rome, Italy: Food and Agriculture Organization of the United Nations. FAO. 2006a. Statistical yearbook 2005-2006. Rome, Italy: Food and Agriculture Organization of the United Nations. FAO. 2006b. The state of food security in the world, 2006. Rome, Italy: Food and Agriculture Organization of the United Nations. Ferry, N., M. Edwards, J. Gatehouse, T. Capell, P. Christou, and A. Gatehouse. 2006. Prey- mediated effects of transgenic canola on a beneficial, non-target carabid beetle. Trans- genic Res. 15:501-514. Garrett, K. A., S. P. Dendy, E. E. Frank, M. N. Rouse, and S. E. Travers. 2006. Climate change effects on plant disease: genomes to ecosystems. Annu. Rev Phytopathol. 44:201-221. Gedney, N., P. M. Cox, R. A. Betts, O. Boucher, C. Huntingford, and P. A. Stott. 2006. Detection of a direct carbon dioxide effect in continental river runoff records. Nature 439:835-838. Giles, G. 2007. Climate change 2007: How to survive a warming world. Nature 446: 716-717. Goldemberg, J., T. B. Johansson, A. K. N. Reddy, and R. H. Williams. 2004. A global clean cooking fuel initiative. Energy Sustain. Dev. 8(3):5-12. Gordon, B., R. Mackay, and E. Rehfuess. 2004. Inheriting the world: The atlas of chil- dren’s environmental health and the environment. Geneva, Switzerland: World Health Organization. Gressel, J., A. Hanafi, G. Head, W. Marasa, A. B. Obilana, J. Ochanda, T. Souissi, and G. Tzotzos. 2004. Major heretofore intractable biotic constraints to African food security that may be amenable to novel biotechnological solutions. Crop Prot. 23:661-689. Gueye, E. F. 2000. The role of family poultry in poverty alleviation, food security and the promotion of gender equality in rural Africa. Outlook Agric. 29:129-136. Haas, J. D., J. L. Beard, L. E. Murray-Kolb, A. M. Del Mundo, A. Felix, and G. B. Gregorio. 2005. Iron-biofortified rice improves the iron stores of nonanemic Filipino women. J. Nutr. 135:2923-2930. Harvell, C. D., C. E. Mitchell, J. R. Ward, S. Altizer, A. P. Dobson, R. S. Ostfeld, and M. D. Samuel. 2002. Climate warming and disease risks for terrestrial and marine biota. Sci- ence 296:2158-2162. Henoa, J., and C. Baanante. 2006. Agricultural production and soil nutrient mining in Africa. Implications for resource conservation and policy development. Muscle Shoals, AL: International Center for Soil Fertility and Agricultural Development. Available online at www.ifdc.org [accessed December 14, 2007].

66 Emerging Technologies to Benefit Farmers Hill, B. J. 2005. The need for effective disease control in international aquaculture. Dev. Biologicals (Basel) 121:3-12. Huang, B., and J. Gressel. 1997. Barnyardgrass (Echinochloa crus-galli) resistance to both butachlor and thiobencarb in China. Resistant Pest Manag. 9:5-7. IAC (InterAcademy Council). 2004. Realizing the promise and potential of African agriculture. Amsterdam, The Netherlands: InterAcademy Council. IEA (International Energy Agency). 2002. World energy outlook 2002. Chapter 13: Energy and poverty. Paris: International Energy Agency. Available online at http://www.iea.org/ textbase/nppdf/free/2002/energy_poverty.pdf [accessed April 3, 2008]. IFPRI (International Food Policy Research Institute). 1996. IFPRI Newsletter “2020 Vision. News and Views,” October 1996. Washington, DC: International Food Policy Research Institute. IFPRI. 2002. Green Revolution: Curse or blessing? Available online at http://ifpri.org/pubs/ib/ ib11.pdf [accessed April 3, 2008]. IPCC (Intergovernmental Panel on Climate Change). 2001. Climate Change 2001: Working Group II: Impacts, Adaptation, and Vulnerability. Chapter 17. Small Island States. Avail- able online at http://www.ipcc.ch/ipccreports/tar/wg2/621.htm [accessed July 9, 2008]. IPCC. 2007. Working Group II Contribution to the Intergovernmental Panel on Climate Change Fourth Assessment Report Climate Change 2007: Climate Change Impacts, Ad- aptation and Vulnerability. New York, NY: United Nations Intergovernmental Panel on Climate Change. February 2, 2007. Available online at http://www.ipcc.ch/SPM6avr07. pdf [accessed October 17, 2007]. IWMI (International Water Management Institute). 2003a. How do we improve water pro- ductivity: How do we get more crop per drop. Water Policy Briefing Issue 8. London: Earthscan, and Colombo: International Water Management Institute. IWMI. 2003b. Confronting the realities of waste water use in agriculture. Water Policy briefing. Issue 9. Water for Food. Water for Life. Comprehensive Assessment of Water Management in Agriculture. IWMI. 2006. The threat to fisheries and aquaculture from climate change. Policy Brief. Lon- don: Earthscan, and Colombo: International Water Management Institute. IWMI. 2007. Comprehensive Assessment of Water Management in Agriculture. Water for Food. Water for Life. London: Earthscan, and Colombo: International Water Manage- ment Institute. James, C. 2006a. GM Crops: The first ten years: Global socio-economic and environmental impacts. ISAAA Brief 36. Available online at www.isaaa.org/Resources/Publications/ briefs [accessed February 20, 2008]. James, C. 2006b. Global status of commercialized biotech/GM crops: 2006. ISAAA brief No. 35 Ithaca, NY: ISAAA. Available online at http://www.isaaa.org/Resources/Publications/ briefs [accessed February 20, 2008]. Joshi, P. K., N. P. Singh, N. N. Singh, R. V. Gerpacio, and P. L. Pingali. 2005. Maize in India: productions systems, constraints and research priorities. ICRISAT. Available online at http://www.cimmyt.org/english/docs/maize_producsys/india.pdf [accessed February 20, 2008]. Juma, C., and I. Serageldin. 2007. Freedom to innovate. Biotechnology in Africa’s De- velopment. Report of the High-Level Africa Panel on Modern Biotechnology. Addis Ababa, Ethiopia: African Union and Pretoria, South Africa: New Partnership for Africa’s Development. Kalaitzandonakes, N., J. M. Alston, and K. J. Bradford. 2007. Compliance costs for regulatory approval of new biotech crops. Nat. Biotechnol. 25:509-511. Kammen, D. M. 1995. Cookstoves for the developing world. Sci. Am. 273:72-75.

Constraints on Crop and Animal Productivity 67 Kannaki, T. R., and P. C. Verma. 2006. The challenges of 2020 and the role of nanotechnol- ogy in poultry research. Pp. 273-277 in Proc. Nat. Sem. Poult. Res. Prior. 2020, P. V. K. Sasidhar, ed. India: Central Avian Research Institute. Available online at http://www.icar. org.in/cari/lead%20papers.pdf [accessed December 26, 2007]. Kaosa-ard, M. S., and B. Rerkasem. 2000. The growth and sustainability of agriculture in Asia. Hong Kong: Oxford University Press. Kent, L. 2004. What’s the holdup? Addressing constraints to the use of plant biotechnology in developing countries. AgBioForum 7:1-7. Available online at www.agbioforum.org [accessed December 26, 2007]. Kerdchoechuen, O. 2005. Methane emissions in four rice varieties as related to sugars and organic acids or roots and root exudates and biomass yield. Agric. Ecosyst. Environ. 108:155-163. Kolmer, J. A. 2005. Tracking wheat rust on a continental scale. Curr. Opin. Plant Biol. 8:441-449. Lal, R. 1995. Erosion crop productivity relationship for soils of Africa. Soil Sci. Soc. Am. J. 59:661-667. Lal, R. 1998. Soil erosion impact on agronomic productivity and environment quality. Crit. Rev. Plant Sci. 17:319-464. Lal, R. 2004. Soil carbon sequestration impacts on global climate change and food security. Science 304:1623-1627. Lal, R. 2007. Soil degradation and environment quality in South Asia. International Journal of Ecology and Environmental Sciences 33(2-3):91-103. Le Gall, F. 2006. Economic and social consequences of animal diseases. Washington, DC: The World Bank. Available online at http://go.worldbank.org/PMRI0CP0R0 [accessed June 22, 2008]. Legg, J. P. and C. M. Fauquet. 2004. Cassava mosaic geminiviruses in Africa. Plant Mol. Biol. 56:585-599. Legg, J. P., B. Owor, G. Sseruwagi, and J. Ndunguru. 2006. Cassava mosaic virus disease in East and Central Africa: Epidemiology and management of a regional pandemic. Adv. Virus Res. 67:355-418. Li, P., H. J. Bohnert, and R. Grene. 2007. All about FACE: Plants in a high CO2 world. Trends Plant Sci. 12:87-89. Lobell, D. B., M. B. Burke, C. Tibaldi, M. D. Mastreandrea, W. P. Falcon, and R. Naylor. 2008. Prioritizing climate change adaptation needs for food security in 2030. Science 319:607-610. Loibooki, M., H. Hofer, K. L. I. Campbell, and M. L. East. 2002. Bushmeat hunting by com- munities adjacent to the Serengeti National Park, Tanzania: The importance of livestock ownership and alternative sources of protein and income. Environmental Conservation 29:391-398. Low, J. W., M. Arimond, N. Osman, B. Cunguara, F. Zano, and D. Tschirley. 2007. A food- based approach introducing orange-fleshed sweet potatoes increased Vitamin A intake and serum retinol concentrations in young children in rural Mozambique. J. Nutr. 137:1320-1327. Malik, R. K., and S. Singh. 1995. Littleseed canarygrass (Phalaris minor) resistance to isopro- turon in India. Weed Technol. 9:419-425. Mansoor, S., R. W. Briddon, Y. Zafar, and J. Stanley. 2003. Geminivirus disease complexes: An emerging threat. Trends Plant Sci. 8:128-134. Mansoor, S., Y. Zafar, and R. W. Briddon. 2006. Geminivirus disease complexes: The threat is spreading. Trends Plant Sci. 11:209-212. McNeeley, J. 2001. Invasive species, a costly catastrophe for native biodiversity. Land Use Water Resour. Res. 2:1-10.

68 Emerging Technologies to Benefit Farmers Naylor, R. L., D. S. Battisti, D. J. Vimont, W. P. Falcon, and M. B. Burke. 2007. Assessing risks of climate variability and climate change for Indonesian rice agriculture. Proc. Natl. Acad. Sci. U. S. A. 104:7752-7757. Ndunguru, J. 2005. Molecular characterization and dynamics of cassava mosaic geminiviruses in Tanzania. Ph. D. dissertation. University of Pretoria, South Africa. Neumann, C. G., N. O. Bwibo, S. P. Murphy, M. Sigman, S. Whaley, L. H. Allen, D. Guthrie, R. E. Weiss, and M. W. Demment. 2003. Animal source foods improve dietary quality, micronutrient status, growth and cognitive function in Kenyan school children: Back- ground, study design and baseline findings. J. Nutr. 131:3941S-3949S. Oerke, E. C., H. W. Dehne, F. Schonbeck, and A. Weber. 1994. Crop production and crop protections. Estimated losses in major food and cash crops. Amsterdam: Elsevier. OIE (Office International des Epizooties). 1999. The economics of animal disease control: Scientific and technical review. B.D. Perry, ed. Vol. 18(2). Paris: OIE. Available online at http://www.oie.int/eng/publicat/rt/a_rt18_2.htm [accessed July 25, 2008]. Okogbenin, E., M. C. M. Porto, C. Egesi, C. Mba, E. Ospinosa, L. G. Santos, C. Ospina, J. Marin, E. Barrera, J. Gutierrez, I. Ekanayake, C. Iglesias, and M. Fregene. 2007. Marker aided introgression of CMD resistance in Latin American germplasm for genetic improve- ment of cassava in Africa. Crop Sci. 47:1895-1904. Ortiz, R., T. Ban, R. Bandyopadhyay, M. Banziger, D. Bergvinson, K. Hell, B. James, D. Jeffers, P. L. Kumar, A. Menkir, J. Murakami, S. N. Nigam, H. D. Upadhyaya, and F. Waliyar. 2008. CGIAR research-for-development program on mycotoxins. P. 44 in Mycotoxins: Detection Methods, Management, Public Health and Agricultural Trade, J. F. Leslie, R. Bandyopadhyay, and A. Visconti, eds. UK: CABI Publishing. Ouedraogo, O., U. Neumann, A. Raynal-Roques, G. Salle, C. Tuquet, and B. Dembele. 1999. New insights concerning the ecology and the biology of Rhamphicarpa fistulosa (Scrophulariaceae). Weed Res. 39:159-169. Owor, B. E., B. P. Martin, D. N. Shepherd, R. Edema, A. L. Onjane, E. P. Rybicki, J. A. Thomson, and A. Varsani. 2007. Genetic analysis of maize streak virus isolates from Uganda reveals widespread distribution of a recombinant variant. J. Gen. Virol. 88: 3154-3165. Padmanabhan, A. 2000. Transgenic Seeds: Key to Green Revolution, Version 2.0. India Abroad August 4. Page, S., and R. Slater. 2003. Small producer participation in the global food system: Policy opportunities and constraints. Dev. Policy Rev. 21:641-654. Perry, B. D., T. F. Randolph, J. J. McDermott, K. R. Sones, and P. K. Thornton. 2002. Investing in animal health research to alleviate poverty. Nairobi, Kenya: International Livestock Research Institute (ILRI). Postel, S. 1997. Dividing the water. Technol. Rev. 100:54-62. Powles, S. 2008. Evolved glyphosate-resistant weeds around the world: Lessons to be learnt. Pest Management Science 64:360-365. Prentice, A. 2006. The emerging epidemic of obesity in developing countries. Int. J. Epidemiol. 35:93-99. Probst, C., H. Njapau, and P. J. Cotty. 2007. Outbreak of an acute aflatoxicosis in Kenya in 2004: Identification of the causal agent. Appl Environ Microbiol. 73(8):2762-2764. Reardon, T., C. P. Timmer, C. B. Barrett, and J. Berdegué. 2003.The rise of supermarkets in Africa, Asia, and Latin America. Am. J. Agr. Econ. 85:1140-1146. Rice-Wheat Consortium. 2007. Rice-wheat cropping systems. Rice-Wheat Consortium. Avail- able online at http://www.rwc.cgiar.org/Rwc_Crop.asp [accessed May 19, 2008]. Rockstrom, J., N. Hatibu, T. Oweis, S. Wan, J. Barron, C. Ruben, A. Bruggeman, Z. Qiang, and J. Farahani. 2006. Comprehensive assessment of water use in agriculture. London: Earthscan, and Colombo: International Water Management Institute.

Constraints on Crop and Animal Productivity 69 Rockstrom, J., M. Lannerstad, and M. Falkenmark. 2007. Assessing the water challenge of a new green revolution in developing countries. Proc. Natl. Acad. Sci. U. S. A. 104: 6253-6260. Rowcliffe, J. M, E. J. Milner-Gulland, and G. Cowlishaw. 2005. Do bushmeat consumers have other fish to fry? Trends in Ecology & Evolution 20 (6):274-276. Ruelle, P., and R. L. Bruggers. 1982. Traditional approaches for protection of cereal crops from birds in Africa. Pp. 80-86 in Proc. 10th Vertebrate Pest Convention, U. Nebraska, Lincoln. Rybicki, E. P., and G. Pietersen. 1999. Plant virus disease problems in the developing world. Adv. Vir. Res. 53:127-175. Sanchez, P. A. 2002. Soil fertility and hunger in Africa. Science 295:2019-2020. Seal, S. E., F. van den Bosch, and M. J. Jeger. 2006. Factors affecting begomovirus evolution and their increasing global significance: Implications for sustainable control. Crit. Rev. Plant Sci. 25:23-46. Singh, S. 2007. Role of management practices on control of isoproturon-resistant littleseed canarygrass (Phalaris minor) in India. Weed Technol. 21:339-346. Smale, M., H. De Groote, and G. Owuor. 2006. Predicting farmer demand for Bt maize in Kenya. In Promising Crop Biotechnologies for Smallholder Farmers in East Africa: Ba- nanas and Maize. Available online at http://www.ifpri.org/pubs/rag/br1004/br1004.pdf [accessed June 21, 2008]. Smaling, E. M. A. 1993. Soil nutrient depletion in sub-Saharan Africa. Pp. 53-67 in The Role of Plant Nutrients for Sustainable Food Crop Production in sub-Saharan Africa, H. van Reuler and W. H. Prins, eds. Leidschendam, The Netherlands: Vereniging van Kunstmest-producenten. Smaling, E. M. A., J. J. Stoorvogel, and P. N. Windmeijer. 1993. Calculating soil nutrient bal- ances in Africa at different scales. II. District scale. Fert. Res. 35:237-250. Storozhenko, S., V. DeDe Brower, M. VolckaertVolokaert, O. Navarreto, D. Blancquaert, G.-F. Zhang, W. Lambert and D. Van Der Straeten. 2007. Folate fortification of rice by metabolic engineering. Nat. Biotechnol. 1277-1279. Thornton, P. K., R. L. Kruska, N. Henninger, P. M. Kristjanson, R. S. Reid, F. Atieno, A. Odero, and T. Ndegwa. 2002. Mapping Poverty and Livestock in the Developing World. Nairobi, Kenya: International Livestock Research Institute. TSBF-CIAT (Tropical Soil Biology and Fertility Institute-Centro Internacional de Agricultura Tropical). 2005. Integrated soil fertility management in the tropics. TSBF-CIATS reflec- tions on achievements 2002-2005. Columbia: CIAT Publications. Available online at http://www.ciat.cgiar.org/tsbf_institute/pdf/tsbf_ciat_achievements_2002_2005.pdf [ac- cessed February 20, 2008]. USDA (U.S. Department of Agriculture). 2008. Interagency agricultural projections committee, 2008. USDA agricultural projections through 2017, OCE-2008-1, February 2008. Avail- able online at http://www.ers.usda.gov/Briefing/Baseline [accessed July 1, 2008]. Utria, B. E. 2004. Ethanol and gelfuel: Clean renewable cooking fuels for poverty alleviation in Africa. Energy Sustain. Dev. VIII:107-114. Valverde, B., and K. Itoh. 2001. World rice and herbicide resistance. Pp. 195-250 in Herbicide Resistance in World Grains, S. B. Powles, and D. Shaner, eds. Boca Raton, FL: CRC Press. Vanderschuren, V., M. Stupak, J. Futterer, W. Gruissem, and P. Zhang. 2007. Engineering resistance to geminiviruses—review and perspectives. Plant Biotechnol. J. 5:207-220. Vaughan, D. A., P. L. Sanchez, J. Ushiki, A. Kaga, and N. Tomooka. 2005. Asian rice and weedy rice—Evolutionary perspectives. Pp. 257-277 in Crop Ferality and Volunteerism, J. Gressel, ed. Boca Raton, FL: CRC Press.

70 Emerging Technologies to Benefit Farmers Wanyera, R., M. G. Kinyua, Y. Jin, and R. P. Singh. 2006. The spread of stem rust caused by Puccinia graminis f. sp. tritici, with virulence on Sr31 in wheat in Eastern Africa. Plant Dis. 90:113. Wassmann, R., H. U. Neue, J. K. Ladha, and M. S. Aulakh. 2004. Mitigating greenhouse gas emissions from rice-wheat cropping systems in Asia. Environ. Dev. Sustain. 6:65-90. Weatherspoon, D. D., and T. Reardon. 2003. The rise of supermarkets in Africa: Implications for agrifood systems and the rural poor. Development Policy Rev. 21:333-355. White, J. W., G. S. McMaster, and G. O. Edmeades. 2004. Genomics and crop response to global change: what have we learned? Field Crops Res. 90:165-169. Widstrom, N. W. 1996. The aflatoxin problem with corn grain. Adv. Agron. 56:219-280. Williams, J. H., T. D. Phillips, P. E. Jolly, J. K. Stiles, C. M. Jolly, and D. Aggarwal. 2004. Human aflatoxicosis in developing countries: A review of toxicology, exposure, potential health consequences and interventions. Am. J. Clin. Nutr 80:1106-1122. Winrock, I. 1992. Assessment of Animal Agriculture in Sub-Saharan Africa. Morrilton, AK: Winrock International Institute for Agricultural Development. World Bank. 2004. World Development Indicators 2004. Washington, DC: The World Bank. World Bank. 2008. Economic impact of avian influenza. Washington, DC: The World Bank. Available online at http://go.worldbank.org/DTHZZF6XS0 [accessed June 22, 2008]. WorldFish Center. 2005. Fish and food security in Africa. Penang, Malaysia: WorldFish Center. Available online at http://www.fishforall.org/ffa-summit/English/Fish&FoodSecurity_22_ 8_lowres.pdf [accessed July 25, 2008]. Yadav, A., and R. K. Malik. 2005. Herbicide resistant Phalaris minor—A sustainability issue. Haryana Agricultural Univ., Hisar, Haryana, India. [Resource Book. Hisar, India: Depart- ment of Agronomy and Directorate of Extension Education. CCS Haryana Agricultural University.] Yamamura, K., M. Yokozawa, M. Nishimori, Y. Ueda, and T. Yokosuka. 2006. How to ana- lyze long-term insect population dynamics under climate change: 50-year data of three insect pests in paddy fields. Popul. Ecol. 48:31-48. Ziska, L. H., and E. W. Goins. 2006. Elevated atmospheric carbon dioxide and weed popula- tions in glyphosate-treated soybean. Crop Sci. 46:1354-1359. Zvereva, E. L., and M. V. Kozlov. 2006. Consequences of simultaneous elevation of carbon dioxide and temperature for plant-herbivore interactions: A metaanalysis. Glob. Change Biol. 12:27-41.

Next: 3 Plant Improvement and Protection »
Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia Get This Book
×
Buy Paperback | $65.00 Buy Ebook | $54.99
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

Increased agricultural productivity is a major stepping stone on the path out of poverty in sub-Saharan Africa and South Asia, but farmers there face tremendous challenges improving production. Poor soil, inefficient water use, and a lack of access to plant breeding resources, nutritious animal feed, high quality seed, and fuel and electricity-combined with some of the most extreme environmental conditions on Earth-have made yields in crop and animal production far lower in these regions than world averages.

Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia identifies sixty emerging technologies with the potential to significantly improve agricultural productivity in sub-Saharan Africa and South Asia. Eighteen technologies are recommended for immediate development or further exploration. Scientists from all backgrounds have an opportunity to become involved in bringing these and other technologies to fruition. The opportunities suggested in this book offer new approaches that can synergize with each other and with many other activities to transform agriculture in sub-Saharan Africa and South Asia.

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  6. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  7. ×

    View our suggested citation for this chapter.

    « Back Next »
  8. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!