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

not significani at Carman "
At all sites decreased row spacing gave rise to
significantly nore spikes per unit area. Finlay e! A].
{79?L) reported a si¡nilar resu,lt.
i{o significant genotype by treatrnent interactions
occurred (qla¡te 58), but the first incremen-b in seeding
rate showed a greater response than the second for both
genotypes at all sites, particularly at V{ínnipeg (Table 5g).
The resulte also inclicated â greater nega_tive response to
incr.easeci row width at the second increraent âs cor,lpared to
the first. fhese t:'ends indicated no,¡ernents tovrard and
away from the optima respectiveiy.
At both Sanford. and Carrnan the combination <strong>of</strong> highest
seeding rate ând narrowest row width gave the greatest
nunber <strong>of</strong> spikes per u.rit area. I{owever, a significant
seeding rate X row spacing interaction occurred at Winnipeg
(fable 58)" The interaction resul-ted from seeding rate
having a negative effect at the nanowest spacing but a
positive effect at wider spacingsa lhis resulted. frorn the
ideal conditíons elir¡inating much <strong>of</strong> the differenee due to
the seeding rates at this site. tillering was suffici.ent
to compensate for fev/er <strong>plant</strong>sn particularly at the narrowest
row spacing in whieh there would also be less intra_row
crorvding <strong>of</strong> <strong>plant</strong>s "
Kernels Þer SÐike
Table 60 contains i;he .q"NOvA for kernels per spike "
L42