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

îhe lodgíng oecu¡red when the straw <strong>of</strong> the higher yieliling
lines was unable to support thelr larger heavier spikes late
in the seasonr lodging discussed in most other reports
occurred earlier in the season and eaused lower yield by
giving rLse to <strong>reduced</strong> kernel devel0pment (sisler and 01sen,
1951). In the present study, lodging was also strongly and
positively related to <strong>height</strong>, and the negative <strong>height</strong> to
yield associations nay have been reflected fn the yield to
lodging reìationships.
Although this type <strong>of</strong> todging did not tead to yield
reductions, it is tikely to result in harvest l0sses and
inconvenience at the farm level. Breeding for resistance
to lodging at the late stage, through <strong>height</strong> reduction,
would therefore be a worthwhile goal.
HÍgher yietds result fro¡n Íncreased carbohydrates in
the grain, with consequent lowering <strong>of</strong> the n5"trogen leve1
on a percentage basÍs. Hence, the negative associatíons
between yield and nitrogen and two nftrogen-related quality
parameters, soluble ar¿ino nitrogen and saccharifying activity
are readily explained.
Kerne]-g per spike. The negative conelatíons between
this trait and kernel weight, plumpness and test weight
probably resuLted fron competÍtion within the spike for
photosynthate during grain filling.
îhe significant positive correlations <strong>of</strong> kernels per
spike wlth days to maturity and days ín post-anthesis were
weak. In fact, that with rnâturity was not sÍgnificant in
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