Grain production of tropical maize is generally limited by the number
of kernels, and my experience is that proper calibration of the
relation between growth/photosynthesis rate and the final kernel
number is crucial for acceptable model performance. However,
calibration is complicated by the fact that there exists a fair amount
of genetic variation, which at the field level translates into
tolerance/susceptibility to e.g. drought or low nitrogen. A second
complication that probably should be addressed is the variation
in prolificacy: the amount of available energy at which a specific
genotype puts on a second ear, is genetically variable. A second ear
initially brings along great overhead costs (cob, husks), but at high
growth rates, the extra kernels will absorb the excess of carbohydrates
supplied by the source.
 
Regards,
 
Anne Elings
 
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CENTRO INTERNACIONAL DE MEJORAMIENTO DE MAIZ Y TRIGO (CIMMYT,INT)
        International Maize and Wheat Improvement Center
 
      - Sustainable Maize and Wheat Systems for the Poor -
 
   Lisboa 27  Apdo. Postal 6-641  CP 06600  Mexico, D.F. MEXICO
Telephone: +52(5)726-9091                     FAX: +52(5)726-7559
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