| dc.description.abstract | The conclusion from this study is that three criteria,
moisture percentage, GDD and black layer formation, are not
adequate to measure corn maturity, although they differ in
suitability. The close association of ELF with maximum dry
weight, and hence the physiological maturity and the ease
of detection, gives it an advantage over the other two.
However, cases of premature black layer formation are a
pitfall and care should be taken in using this criterion
of maturity. A combination of the determination of moisture
content after black layer detection would save unnecessary
sampling when nnisture content is high and filling
is not complete. Further, the growing degree days would
support the other two in guiding the planning of the crop
growing in a given environment, so that on the basis of expected
temperature (GDD), a rough estimate of a sampling
date could be made. The data indicate a relatively small
GDD variation within an inbred or hybrid in a specific environment.
Thus, this third criterion would support a
combination of the first two.
The negative association of GDD from planting to
pollination with GDD in the filling period suggests genes
causing an increased GDD for filling period also would
decrease GDD from planting to pollination. If indeed the
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extension of the filling period would increase the yield,
this would look like a favorable situation. However,
further studies are required to support this view. From
this study it is also clear that there is a positive
correlation between the grain filling period and yield in
hybrids, but a negative relationship in inbreds. It
appears that selection for longer grain filling period may
be beneficial, but there is need to study this relationship
in several environments and years as well as establish
its genetic basis.
Days to silk were also found highly indicative of
yield in the hybrids used in this study. | en |
