| Sumario: | Striga and drought are major constraints to
maize (Zea mays L.) production in the savannas
of west and central Africa (WCA). A study
was conducted in 2005 and 2006 in Nigeria to
determine the level of resistance to Striga hermonthica
for two early-maturing maize populations,
one white and one yellow, and to assess
the progress made in improving each for grain
yield and level of resistance after four cycles of
S1 recurrent selection. Percentage yield gain
per cycle of the yellow population when Striga
infested was 13% with r2 = 82% and 5% with
r2 = 97% in a Striga-free environment. Corresponding
values for the white population were
15% with r2 = 40% and 1% with r2 = 9% for the
two Striga environments. For the two populations,
therefore, realized gain in grain yield was
higher under Striga-infested than Striga-free
conditions. Yield gains in the advanced cycles
of selection were accompanied by increased
number of ears per plant in both populations.
Striga damage at 10 wk after planting (WAP) and
Striga emergence at 8 WAP decreased by about
5 and 4% cycle–1, respectively in the yellow population.
For the white population, Striga damage
decreased also by about 5 and 4% per cycle–1 at
8 and 10 WAP, respectively, while Striga emergence
decreased by about 5% cycle–1 at 8 WAP.
In conclusion, S1 recurrent selection was effective
in improving grain yield and Striga resistance
in the two early maize populations.
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