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CTA. 1994. Drought-resistant maize. Spore 54. CTA, Wageningen, The Netherlands.
Permanent link to this item: http://hdl.handle.net/10568/49519
Hardy new breeds of maize that can increase yields by 40% in tough environments are now a reality. These new varieties can tolerate periodic droughts. Researchers in Mexico have found why periodic droughts effect yields so dramatically. In optimum...
Hardy new breeds of maize that can increase yields by 40% in tough environments are now a reality. These new varieties can tolerate periodic droughts. Researchers in Mexico have found why periodic droughts effect yields so dramatically. In optimum weather conditions, the emergence of the male flower (tassel) at the top of the plant coincides with the appearance of the female flowers (silks) borne near the middle of the plant, and good yields follow. If, however, there is a shortage of water in the two weeks before and after flowering, there is poor pollination which results in low yields, even if subsequently there are good rains. Researchers at the International Maize and Wheat Improvement Center (CIMMYT) have found that when water is short, the male tassels compete against the female silks for the available carbohydrates. This means that by the time the silks are ready for pollination the pollen from the tassels has come and gone. The researchers then found that there are some maize strains which do not work in this way: some are better at synchronizing the development of tassels and silks in times of drought. The CIMMYT team have been screening their maize strains to find those plants where the silks appear soon after the tassels. These varieties were bred further to improve drought tolerance and improve yields. These new varieties will, in times of severe mid-season droughts, produce 2.8 tons per hectare, a 40% increase over regular maize yields under similar drought conditions. Although these new varieties are under test in eastern and southern Africa, the CIMMYT researchers are keen that plan breeders in those region. should start screening their own maize germplasm to see i there are strains that show similar characteristics. Those varieties could then be multi plied up in the same way a' those already bred in Mexico. CIMMYT Apartado Postal 6-641 06600 Mexico, DF MEXICO