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

freedom comparison indicated lqínn 6U-62 had significantly
more spikes per unit areâ than Bonanza at thís site as we1l,
Kernels pqr_Þpike. As was the caee in experiments reported
by Gardener and Rathjen (Lg?S) and Schreiber and Stanberry
QgAl) the results <strong>of</strong> this study (fãble lB) showed. inereased
kernels per spike with Ínereased fertilizer N. lhe increase
was signifícant at three <strong>of</strong> five locatíons and the means in
Table 19C indicate the major effect to be fron the fírst N
inerement. However, at Carman lplJ, tìne response continued
to the third N 1eveL. Again no F x G interaction was
indicated (Table 18).
Single degree <strong>of</strong> freedom cornparisons (ga¡fe fB)
revealed significant differenees between genotypes and
between <strong>height</strong> classes for kernels per spíke. The data <strong>of</strong>
table 198 showed this to be in favour <strong>of</strong> the ta1ls. In view
<strong>of</strong> the higher spíke nunber per unit area <strong>of</strong> the semi-dwarfs,
and the negative relationships between yield conponents
(Davis, Lg6?), this would be expected"
At aI1 sÍtes C703032 and Minn 64-62 had significantty
fewer kernels per spike than did the tall genotypes
(fanfe f9e.). 0n the other hand, the semi-dwarf C2030]1
had as many or rnore kernels per head than the tal1s. fn
fact, i.t had significantly more than Bonanza at portage in
1975. this genotype, in general, had the lowest nunber <strong>of</strong>
spikes per unit area among the lines in thÍs test (Table WA).
It is worth noting that, at Portage lg?6, Mirull 64-62
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