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

with the overall results <strong>of</strong> this experinent, Iead to the
concl-usion that semi_dwarf r¡arieties should be eìraluated
under more optimum conditions¡ (i.e" high fertility), in
order to identify the superior genotypes.
îestíng under stressful conditions, like those at
Carman in 19?5, makes meaningful deeisíons coneerning genotypie
superíority difficult, However, since such conditions
may be encountered at the farm level, thê author feel"s that
new selections should be ehecked out under these situations
prior to being released. Sinee the genotypes are tailored
for areas with relatively optimum conditÍons, failure to
perform under less than ideal conditions should not necessarily
stop the release <strong>of</strong> such a cultir¡ar " ¡iowever,
prospeetive growers should. be made aware <strong>of</strong> their intorerance
<strong>of</strong> such stress conditions. llhus, initiaL sereening under
optirnurn conditions would identify the inherently superior
genotypes most useful under intensive nanagement, with
further testing identifying stress reaetions.
As regards the <strong>plant</strong> type and growth habÍt <strong>of</strong> the serni-
dwarfs, the results <strong>of</strong> this experiment again indicated the
need for a more optimum baLance among the yield components"
0f the genotypes studied thê better performer, Mínn64-62,
achíeved its performance prinarily through a large number
<strong>of</strong> spikes per unit area. In so doing its kernel size was
less than ideal. This imbalance must be Ímproved in a
phenotype <strong>of</strong> this nature. Ihe lateness <strong>of</strong> Minn64-62 also
contributed to -its performanee leveln lhÍs faetor is not
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