Effects of reduced plant height on breeding requirements and ...

kez'ne 1 weight associations, as werf as the association <strong>of</strong>
post-anthesis period with both yield and kernel weight, the
laek <strong>of</strong> signifícant correlatíon between yielcl and kernel
weight was surprising. fhis indicated that this yield
eornponent was not <strong>of</strong> prirnary inportance in determining yietd
in these populations. fhe lâck <strong>of</strong> precision in measuring
yield may also, in part, account for the rack <strong>of</strong> significant
aseoc iation.
Although significant when pooled, and honogeneously
positíve over all populations, the correlation between yield
and test weight was signifÍcant on an individual population
basis only in c-zo-l. such assocíation may be the resur-t <strong>of</strong>
heavåer test weight lines having plrrmper and hence larger
kernels, whích would add to total yield"
The negative assocíation <strong>of</strong> yield with days to heading
indlcated early heading was advantageous and suggests that
the post-anthesis períod nay have been the critícal yield
determining period. fhis is further supported by the posi_
tíve yíe1d to days in post-anthesis correLations. However,
sinee both kernel weight and plumpness were positlvely
associated with days in post-anthesis, the lack <strong>of</strong> associa_
tÍon lretween these parameters and yíe1d casts doubt upon
this explanation. The negative yield to heading relationship
nay in fact be a reflection <strong>of</strong> the positive yield to <strong>height</strong>
and negative <strong>height</strong> to heading associations.
Furthermore, the relationship in question may have been
lnfluenced by the growing conditions encountered during the
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