Developing drought-tolerant maize germplasm has a unique importance for the Southern African Development Community (SADC) as maize production strongly fluctuates with seasonal rainfall. This study compares 16 commercial hybrids grown in the SADC region with a random set of testcrosses that was based on 288 drought-tolerant lines introduced from Mexico. The germplasm was evaluated at two to three rain-fed sites and under managed drought stress conditions in Zimbabwe 1996/97. Commercial hybrids yielded on average 23% better than drought- tolerant testcrosses under near optimal conditions. The opposite was observed under severe drought stress conditions where yields of the commercial hybrids were on average 27% less than those of the testcrosses. Commercial hybrids had a longer anthesis-silking interval and more barren plants, indicating the reason for their inferior drought tolerance relative to the testcrosses. We conclude that even though the commercial hybrids have been developed regionally using multi-location testing that supposedly included results from randomly drought stressed sites, deliberate improvement for drought tolerance may lead to maize germplasm with higher drought tolerance. Employing such methods to adapted germplasm may lead to drought-tolerant, responsive maize cultivars that may contribute to stabilized maize production in the SADC region.

Research and Partnership Program

English

0103|R98-99CIMPU|AL Maize Program|AGRIS 0102|3

Jose Juan Caballero

INT1888

CIMMYT Staff Publications Collection