Performance of Elite Drought Tolerant Maize Varieties Tested On-Farm in Eastern and Southern Africa.

Significant yield losses in maize (Zea mays L.) due to drought are expected to increase with global climate change as temperatures rise and rainfall distribution become less predictable.  In 2006 CIMMYT initiated the Drought Tolerant Maize for Africa (DTMA) project targeted at improving maize for the drought prone mid-altitude regions of ESA. Twenty two CIMMYT hybrids and open pollinated varieties (OPVs) were selected under optimal conditions, random and managed drought stress conditions and low soil nitrogen. The selected hybrids and OPVs were compared with the best commercial checks in 94 sites across, two seasons under small farmers’ conditions using genotype (G) plus genotype x environment (GE) interaction (GGE) biplot based on the site regression (SREG) model. Gender disaggregated trait preference data were generated on a sub-sample of the trials and varieties were compared based on composite preference index. The GGE biplot based on of the SREG model showed large environmental variations from year to year relative to genotypic performances under farmers’ conditions. In spite of the large environmental variations from year to year CZH 0616, CZH0837 and Pan53 the new drought tolerant hybrids were very stable and high yielding across years and environments.  The best new DTMA hybrids out-yielded the farmers’ own varieties by 35% and 25% under low- and high-yield conditions, respectively, while the best DT OPVs performed as well as the commercial hybrid SC513, which is one of the most popular varieties in southern Africa. The entries were found to be significantly different in terms of computed preference index and the traits considered by male and female farmers were also found to be overlapping.