Maize is the second most important cereal crop after rice in Asia. It is the substitute staple for people in the rural areas and mountainous regions, especially during periods of rice shortage. Maize is also the primary source of feed for the poultry and livestock industry as well as a source of raw material for the manufacturing sector, and is therefore an important source of income for many Asian farmers.

Asia contributes about one-third to the world's total maize production with China taking the lead both in terms of yield and harvested area (Table 1). In Southeast Asia, the total harvested area with maize is currently about 8.6 million ha (FAOSTAT 2007) with the largest areas in Indonesia (41%), the Philippines (29%), Thailand (13%), and Vietnam (12%).

The rapid adoption of high-yielding hybrid maize varieties in Asia has led to significant yield increases in the favorable rain-fed and irrigated maize growing areas. However, a systematic evaluation of current farmers' fertilizer practices and the development of more site-specific fertilizer recommendations are needed to assist farmers in their aim to increase yields and profitability in a sustainable fashion. The average national yield in Indonesia, Thailand, and Vietnam is only 3-4 mt/ha (2 mt/ha in the Philippines) and knowledge on yield potential, exploitable yield gaps, and constraints to improving productivity at the field level is still limited (Ekasingh et al., 2004; Gerparcio et al., 2004; Swastika et al., 2004; Thanh Ha et al., 2005). Current recorded average maize yields, in comparison to climatic-genetic yield potential, indicate that there is a large scope for further increasing maize production by closing this yield gap.

The average yield of maize in Asia is only 3.9 mt/ha but this includes a wide range of varieties (hybrids, open pollinated varieties, traditional) and growing conditions, including areas with water shortage or extensive farming. In recent years, the majority of farmers in favorable maize growing areas have switched to hybrid varieties for its superior yield and profit, despite the higher seed cost. The main limitation to achieving higher yields and associated higher profitability per unit of arable land is often the ineffective use of inputs (particularly nutrients, seed, and pesticide). Better crop, nutrient, pest, and water management practices, along with the use of germplasm with a higher yield potential, are required to ensure profitable maize production while meeting the growing demand.

The demand for maize in Asia is expected to grow in the years to come largely because of an increasing demand from the livestock and poultry feed industry as more animal protein is incorporated into the Asian diet. The rapid expansion of the biofuel industry in recent years driven by new policy developments and high fossil energy costs is also expected to have an impact on global maize demand and supply. The growing demand in the region cannot be met despite the increase in domestic production and yield of maize in the last 15 years. For example, Indonesia's maize production and yield continue to increase, and yet the country imported more than one million mt of maize annually in the last five years (Fig. 1). The United States has maintained its position as the world's most important maize trader, exporting an average of 47 million mt of maize annually (Fig. 2). After 2005, corn prices have sharply increased in the world market largely due to an increasing demand by ethanol producers, but US exports continue to be strong and may remain relatively stable in the years to come (FAPRI, 2007). Despite an annual maize production of 175 million mt, Asia continues to be the biggest importer of maize, with annual imports of 42 million mt of grain valued at US$ 5.7 billion.

References

• Ekasingh, B., Gypmantasiri, P., Thongngam, K., and P. Grudloyma. 2004. Maize in Thailand. Production systems, constraints and research priorities. Mexico: International Maize and Wheat Improvement Center (CIMMYT). p 1-35.
• FAO. 2007. FAOSTAT agriculture data [online]. In: www.fao.org. Available at http://faostat.fao.org (last update 2007; accessed 19 Nov. 2007). Rome, Italy: Food and Agriculture Organization (FAO).
• FAPRI. 2007. US and World Agricultural Outlook. January 2007. FAPRI Staff Report 07-FSR 1. Ames, Iowa, USA: Food and Agricultural Policy Research Institute, Iowa State University and University of Missouri-Columbia. p 1-395.
• Gerparcio, R.V., Labois, J.D., Labios, R.V., and E.I. Diangkinay. 2004. Maize in the Philippines. Production systems, constraints and research priorities. Mexico: International Maize and Wheat Improvement Center (CIMMYT). p 1-37.
• Swastika, D.K.S., Kasim, F., Sudana, W., Hendayana, R., Suhariyanto, K., Gerpacio, R.V., and P.L. Pingali. 2004. Maize in Indonesia. Production systems, constraints and priorities for research. Mexico: International Maize and Wheat Improvement Center (CIMMYT). p 1-40.
• Thanh, H.D., Dinh Thao, T., Tri Khiem, N., Xuan Trieu, M., Gerpacio, R.V., and P.L. Pingali. 2005. Maize in Vietnam. Production systems, constraints, and research priorities. Mexico: International Maize and Wheat Improvement Center (CIMMYT). p 1-42.