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

Sanford, where under better growing conditions, it had a
nurnber <strong>of</strong> spikes per unit area greater than the talls and
the sâme aÊ C?O3O3Z, With this advantage, C?O3OLI was the
hÍghest yieläing seni-dwarf at that location.
Minn6&-62rs large number <strong>of</strong> spikes per unit area was
probabry related to itrs sl0wer early devel0pment and overall
lateness relative to Bonanza and the other genotypes. These
characteristics may in fact be the very reason why Minn6ll-62
had the advantage in terns <strong>of</strong> spikes per unit area. From an
agronomic viewpoint, this association <strong>of</strong> good performance
wíth poor early competitive ability and late maturity would
be undeslrable, Ín Western tanada, With this in rnind the
<strong>plant</strong> breeder atternpting to develop the best genotJæe wouLd
have to select for what he considered to be an optimum
number <strong>of</strong> spikes per unit area, rather than a maxirnum number.
Kernels Þer SDike
There was evídence <strong>of</strong> yield component conpensation in
this study. fhose genotypes whieh had large numbers <strong>of</strong>
spikes per unit area tended to have significantly fewer
kernels per spike.
Àdding N tended to increase spike size, and again the
initial N increment was the most effective. All genotypes
responded to added N in essentialJ.y the same manner. The
Carman site was again influenced the most, probably d.ue to
the poor gnowing conditions.
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