Effects of moisture stress at flowering on phenotypic characters of selected maize local landraces in Kenya. 

Munyiri S. W

2010

SUMMARY

Arid and semi arid areas constitute about 82% of the total land area and supports about 20% of Kenya’s human population. Local maize landraces are an important livelihood resource in these areas. The objective of the study was to characterize selected Kenyan maize landraces for drought tolerance. Secondary traits exhibiting high heritability for drought tolerance such as grain yield, anthesis-silking interval (ASI), tassel size, ears per plant and leaf rolling were evaluated. In season I, the 25 genotypes were grown under optimal conditions (under normal rainfall supplemented with irrigation) for the determination of the anthesis-silking interval (ASI), ears/plant, tassel size and grain yield. In season II, based on the ASI the genotypes were planted in an Alpha lattice design in two separate experiments; optimum and water stressed conditions each replicated 3 times. In the water stressed plots, irrigation was withheld one week to tassel anthesis and resumed after male flowering had been achieved. Among the characters evaluated, a low ASI (1-6 days) was associated with a high level of drought tolerance and low yield losses. Drought stress resulted in 17 to 81% relative grain yield loss. Landraces GBK-032419 and GBK-034659 exhibited lowest grain yield losses of 28 and 17%, respectively, while two dry-land Composites, Katumani Composite B (KCB) and Makueni Dryland Composite (DLC) used as controls exhibited higher grain yield losses of 62 and 68%, respectively. In general, an increase in the number of ears per plant, 100-seed weight, increased plant height, reduced leaf rolling and low ASI were associated with yield increases under moisture stress. Local landraces that exhibit drought tolerance were identified. Drought tolerant landraces included GBK-034659, GBK-032419, GBK-044593, GBK-032423 and GBK-027054. These could be recommended for production in marginal areas of Kenya. Research to further stabilize yields in these landraces could play a key role in mitigating hunger in Kenya. Drought tolerance traits identified could be introgressed into recommended Composites for the marginal areas.

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