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

and the treatments which increased the number <strong>of</strong> <strong>plant</strong>s per
unit <strong>of</strong> row length showed j_ncreased <strong>height</strong>, with Bonanza the
more responsive" rrt carrnan, the combined effeets <strong>of</strong> rate
seeding, drought and early weed infe station gave the opposite
effect, wíth both genotypes responding and the widest row
spacing having the shortest prants. The eãrly weed infestation
whlch rimited growth and utilized rnuch <strong>of</strong> the available
moisture appeared to be the rnain cause <strong>of</strong> this reaction.
The lack <strong>of</strong> sigrrificant seeding rate effects demonstra_
ted the ability <strong>of</strong> the rnaterial to compensate for those
differences. However, under stress conditíons at Carman
the semL-dwarf showêd a trend towards taller <strong>plant</strong>s at the
highest seeding rate, while Bonanza had the g:.eatest <strong>height</strong>
at the intermediate seed rate. Thís suggested that the
semi-dwarf may require higher seeding rates when grown under
stress. At Winnipeg, under very ideal conditions, Bonanza
was tallest at the lowest seeding rate, whi.Ie Mírn64_62
showed no <strong>height</strong> differenee across seeding rates.
The very short stature <strong>of</strong> Minn64-62 under the stress
condÍtions at Carman raises the question <strong>of</strong> whether such a
heíght may be too short for. practical purposes. Such a
very short genotype might, under adverse conditions, be less
desirable than one <strong>of</strong> an intermedj.ate <strong>height</strong> Ín terrns <strong>of</strong>
suitability for modern harvesting procêdures.
Yield
It is considered important to deternÍne whether such a
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