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

Although no significant genotype by seed rate inter_
action waË detected, Minn64-62 tended to show more response
than Bonanza, especially under the near ideal Winnipeg
eonditions, where Bonanza showed a negative yield response
to increased seed rates. tombining all three sites
t[inn64-62 showed a 4"0 and. 8"0 pereent yield response to
each respectrve seeding rate increase, whire Bonanza showed
onJ-y a 1.0 and 4.O percent response to each increase.
Cornbiníng the two genotJrpes, no significant d.ifferences
were detected between yields at the IJ.o crn. and 10.0 cm.
spacíngs at any site. However, at carrna¡, there was a nonsignifÍcant
(6.8%) yield increase at the narrower row
spacing. In âl1 the trial_s, even nnder near j_deal condítions
at ltlinnipeg, there was a drastic yield reduction at the
widest row spacing.
Although no signfficant genotln)e by rov, spacÍng inter_
action was shown, ULru:r6b-62 díd show a posltive (tS,o/")
response to narrower rows under the stress conditions at
Carman, whÍle the tal1 genotype showed 1Ítt1e response.
This was ltkely due to the semi-dwarf beíng nore able to
compete with the weeds when <strong>plant</strong>ed at namower row spacings
at that site.
îhe results suggest then, that there should be some
examination <strong>of</strong> the row widths and seeding rates used. in
testing procedures in relation to the evaruation <strong>of</strong> material
with a wÍ.de range <strong>of</strong> <strong>height</strong> variation. Furthermore, the
resuLts suggest that semi-dwarfs <strong>of</strong> the Minn64_ 62 type
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