Drought and low levels of available nitrogen (low N) are two of the major limiting factors in maize production in Asia. The regular occurrence of drought, particularly that related to the El Niño phenomenon, has brought severe yield losses to the affected countries in the region. Low N, on the other hand, has been exacerbated by inappropriate farming systems practiced by farmers. Continuous monocropping of maize on large tracts of land with little, if any, provision for soil fertility maintenance, has contributed to the rapid depletion of soil nitrogen. Soil erosion, largely caused by massive deforestation and cultivation of steep slopes, has also been a major factor in rapid loss of soil fertility. A survey was conducted during the Sixth Asian Regional Maize Workshop in India, November 1995, to determine the effect of drought and low N on Asian maize yields. It revealed that each stress affects about half of the total maize growing area in Asia. Yield losses due to drought and low N were estimated to range from 10-75% and 10-50%, respectively. Considering the importance of maize as a feed and staple food in the region, these staggering yield losses could threaten the food security of Asia. Development of stress tolerant maize germplasm should be vigorously pursued as part of a long-term solution. The status of maize breeding programs, including innovative screening techniques, new cultivars developed, and collaboration among public and private research institutions in selected Asian countries, are discussed.

English

9801|AGRIS 9702|anterior|R97-98PROCE|FINAL9798

Jose Juan Caballero

CIMMYT Publications Collection