Both too much and too little water are major causes of crop yield losses around the world, and in the major food systems of the tropics. Significant yield losses due to drought and/or excess-moisture (waterlogging) conditions occur one out of every three to four years, and climate change caused by global warming is expected to add to the uncertainty of weather patterns and contribute to an increase in the occurrence of such stresses. Genetic studies showed that yield components and morpho-physicological traits involved in water-stress tolerance in maize are regulated by several genes. Therefore, development of germplasm with stress-adaptive genes needs to be conducted in a systematic manner. At the International Center for Maize and Wheat Improvement (CIMMYT), various approaches to improving drought tolerance in maize have been explored. About three decades of work on drought tolerance in maize has resulted in improved source populations and useful open-pollinated and hybrid products that perform well under drought stress. Results from recent studies show the usefulness of this germplasm under severe drought-stress conditions. Furthermore, improvement in mid-season drought tolerance appears to impart tolerance to various other stresses, such as low-nitrogen soil fertility. Under the Indian Council of Agriculture Research-CIMMYT collaborative program, a large number of materials, including inbred lines from CIMMYT and the Indian national program, were screened for excess-moisture (waterlogging) tolerance in maize at sites managed by the Directorate for Maiz Research, India. Promising tolerant lines were identified and further improves toward developing waterlogging-tolerant cultivars for waterlogging-prone areas in India. Secondary traits, such as anthesis-silking interval, early and increased brace-root development, and high root porosity were found to be associated with excess-moisture tolerance.

Global Maize Program

Tex in English

0505|AL-Maize Program

INT2823

CIMMYT Staff Publications Collection