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

should not be recomnended for produetion in areas with
severe moisture stress, and that adequate weed eontrol ls
an absolute necessity when growíng such a cultivar.
Yield .Conponents
The number <strong>of</strong> spikes per unit area and the number <strong>of</strong>
kernels per spike were most affected by changes ín seedlng
rates and row spas i¡gs. Tn general, as one inereased, the
other decreased "
Kernel weight was relatively unaffected except at
carnan. There, due to rate seedÍng and environmentar stress,
kernel weight was <strong>reduced</strong>. at higher seedlng rates, and. was
partÍcularly low for ¡Uinn64-62. Tr¡ith the exception <strong>of</strong>
Winnipeg, where the better conditions aÌlowed MÍnn6h-62 to
complete its longer life cycle, ¡utínn6l+_62 had lighter ker_
neLs than Bonanza. In general, as the nurnbers <strong>of</strong> spíkes
per unit area and,/or kernels per spike increased, the kerneL
weight decreased.
fhe number <strong>of</strong> spikes per unit area was the rnost important
component influencing yÍeLd, as shown by the 6.0 percent
superior yield <strong>of</strong> Míru,'ú4-62 over Bonanza at Sanford. At
that site the two varietÍes were equal in the number <strong>of</strong>
kernels per splke and Bonanza had higher kernel weight than
Minn64'62, making spikes per unit area the sole reason for
the yield advantage <strong>of</strong> tvtínn64-62. Furthermore, at Winnj.peg,
where both its kernel number per head and its kernel weight
were equal to those <strong>of</strong> Bonanza, Miwß4-62 outyíelded Bonanza
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