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Yield Stability in Relation to Striga Resistance in Cowpea Production in West and Central Africa
Muleba, N.; Ouedraogo, J.T. & Drabo, I.
Abstract
Striga gesnerioides causes severe cowpea ( Vigna
unguiculata ) yield losses in West and Central Africa.
Fields have been abandoned by farmers due to crop failures
attributed to Striga-infestations. Studies comprising
three sowing dates and two regional cultivar adaptation trials
were conducted in fields naturally infested by Striga.
The sowing date experiments were established in the Sudan
savanna zone in Burkina Faso from 1984 to 1987. Three dates,
namely, early (late-June to early-July), intermediate (mid- to
late-July), and late (early- to mid-August) were used. The
first regional adaptation trial included some countries in
West Africa in 1989 and 1990. The second trial was extended to
Central Africa in 1991 and 1992. The objectives were to study
Striga- resistance of genotypes, its stability (or
durability) both in time and space and to devise production
technologies for minimising yield losses under Striga -
infestations. Cultivar Suvita-2 had high and stable
resistance to Striga-infestation and a high yield that
was least stable across years. Regionally, no single cultivar
was immune from Striga-infestations across locations.
Only B301, in contrast to two other resistant controls
IT82D-849 and Suvita-2, combined high stable resistance to
Striga-infestation and high stable yield under
Striga-infestations across locations in West and
Central Africa. Other cultivars that combined high or moderate
resistance to Striga infestation and high yield, and
moderate to high stability across locations included TN93-80
and TNI21-80, in West Africa, and KVx402-19-1 in West and
Central Africa. Although no genotype was invulnerable to
Striga-infestation in all locations of the sub-region,
it appears that Striga damage could be controlled
through proper choice of sowing dates and better adapted, high
yielding and Striga resistant cultivars.
Keywords
Striga gesnerioides, tolerance, Vigna unguiculata
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