Annual Report
1987-88 CIMMYT world wheat facts and trends: the wheat revolution revisited: recent trends and future challenges
Autor
Centro Internacional de Mejoramiento de Maíz y Trigo (CIMMYT)
Resumen
This issue of World Wheat Facts and Trends is divided into three parts: a discussion of recent changes in Third World wheat production and their implications for the future; an overview of the current world wheat situation; and selected statistics on world wheat production. Part 1 begins with a summary of major trends in cereal production in the postwar period, a time that saw a dramatic switch from increases in area to increases in yield as the primary source of growth in wheat production. We focus particularly on recent changes in Third World wheat production during the past decade, when yields and production in developing countries rose almost as rapidly as during the early years of the Green Revolution. Part 1 gives special attention to trends in regions that are irrigated or where rainfall is good, for they characterize the major wheat-producing regions in the developing world. However, some reference is made to the drier areas in which wheat is grown, where the pace of change has been slowest. To study the relation of moisture regime to adoption of new varieties and the use of fertilizer, CIMMYT, in collaboration with national programs and other sources, assembled data covering almost all developing as well as many industrialized countries to obtain rough estimates of area, production, and yields of wheat grown under four moisture regimes: 1) irrigated; 2) rainfed with more than 500 mm annual rainfall; 3) rainfed with 300-500 mm annual rainfall; and 4) rainfed with less than 300 mm annual rainfallt These data are used throughout the discussion in Part 1. The analysis by moisture regime is followed by information on the sources of the impressive yield increases in wheat in developing countries over the past decade: the spread of semidwarf wheats and greater use of fertilizer on wheat (expansion in irrigated area has been a less significant factor in recent yield increases). We also discuss assessments of how breeding, compared to other factors, has helped raise the productivity of wheat. Two cases of recent changes in wheat production in the Punjab of Pakistan and in China follow to illustrate some of the trends presented in this report. Part 1 concludes with an assessment of future increases in production and consumption. The evidence suggests that the major sources of growth in wheat production over the past two decades-improved varieties, fertilizer use, and irrigation-have now been largely exploited, and that to the year 2000 the rate of increase in wheat production will be considerably slower than in the past. Although wheat consumption will also increase more slowly, it is not certain whether current levels of self-sufficiency in Third World wheat production can be maintained. Future gains in productivity therefore depend on adopting a strategy somewhat different from that followed in the past, which relied chiefly on the interaction of improved germplasm, fertilizer, and irrigation to raise the productivity of wheat. A new strategy, suited to both favored and marginal areas, would be to further exploit available technology by increasing the efficiency with which it is used. This approach suggests that improved crop and resource management will play a greater role relative to improved varieties in raising productivity in the future. Implementing this new strategy will require effective crop management research systems, strong extension systems, and well-developed input support systems. Part 2 of this report is an overview of the current world wheat situation, covering production in developing and developed countries, wheat utilization, global trade and stocks of wheat (with a review of principal importers and exporters), and trends in wheat prices, freight rates, and fertilizer prices. The effect of the North American drought of 1988 on the world wheat economy is also discussed. Finally, Part 3 of this report assembles statistics on the production, consumption, trade, and prices of wheat. Statistics related to themes developed in Part 1 are also provided, including information on moisture availability, variety, and fertilizer use in wheat production. This information is organized by region and covers the major wheat-producing and wheat-consuming nations of the developing world as well as most developed countries. v, 57 pages