Central and South America [Wheat, Tropics]
1988
Wall, P. (CIMMYT, Quito (Ecuador). Wheat Program)
Most of the problems associated with wheat production in the warmer areas of South America and Central America are a function of three basic environmental factors: temperature, moisture, and soils. The definitions of Papadakis and soil maps have been used to delineate different environments on the basis of winter temperatures, moisture, and soil type. Wheat is produced, or is under experimentation, in a diverse set of environments in the region. High temperatures may limit yield potential, but the effects of temperature in general, appear less serious to the crop than the effects of moisture regimes or acid soils. There is some indication that very high temperatures may cause physiological disorders. Frosts can be a problem in limited areas of the region. Moisture regimes vary widely within the warmer areas, and in many of the environments lack of moisture is a severely limiting factor. In the wetter parts of the region, high humidity is conducive to disease development, and the combinations of temperature and moisture regimes necessary for the mayor diseases encountered are discussed. Acid soils cover most of the warmer areas of South and Central America. These impose severe limitations on crop growth. Wheat varieties with some resistance to aluminum toxicity have been developed. However, it is unlikely that varieties alone will be sufficient to overcome the problems of these soils, and crop and soil management techniques will need more emphasis in the future
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