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Identification of maize
streak virus–resistant hybrids for commercialization in Kenya
Jane
Ininda, L.Gichuru, J.G.M. Njuguna, P. Lorroki
This study evaluated the agronomic performance of maize streak virus (MSV)
resistance in three-way cross hybrids developed in Kenya and assessed the
effect of MSV on grain yield. Eight hybrids and four checks were planted
in a randomized, complete block design in two replications at Embu (1460
m) and Muguga (2093 m). In a parallel trial in both sites, hybrids were
also evaluated in two replications under artificial
inoculation with MSV. Data were collected on reactions to MSV (on a scale
of 1 to 5), grain yield, days to
flowering
and other agronomic traits. Yield for hybrids were measured relative to
grain yields of the susceptible check hybrids, H614 and H513. The analyses
of variance, combined across environments, showed significant
differences (P
< 0.05) among genotypes for resistance to MSV, grain yield, days to 50%
pollen shed and days to mid-silk. Genotype x environment interaction was
significant
(P
< 0.01) for grain yield and days to mid-silk, indicating some hybrids were
more adapted in some environments. The best-performing hybrids for both
disease resistance and grain yields were MU03-012, MU03-014, MU03-022 and
MU03-036. The mean maize streak disease scores were < 2.0 for the hybrids
MU03-012 and MU03-014 and 2.5 for the hybrids MU03-022 and MU03-036. The
check hybrids H614 and H513 had a mean score of 4.5. The grain yield of
MU03-012 in the disease-inoculated trial was 7 t ha–1,
more than that of H614, at
P
< 0.05. Hybrid MU03-022 had grain yield of H614 + 6 t ha–1,
MU03-036 had H614 + 5.5 t ha–1
and MU03-014 had H614 + 3.5 5.5 t ha–1.
Results on the non-inoculated trial showed the yields of these hybrids
were significantly
higher than H513 and equal to those of H614. The results of days to
maturity show that the hybrid MU03-014 is early and suited to the
mid-altitude transitional dry areas. MU03-022 and MU03-012 are suited for
medium altitudes, while the hybrid MU03-036 has later maturity and is
suited for medium-moist transitional areas. The results support the
performance and pre-release of hybrids MU03-022, and MU03-036 for
commercialization in mid-altitude Kenya in 2007. The expected
final
impact is a reduction in disease on farmers’
fields
and stability in maize yields. The indicators will be the number of
farmers adopting the streak resistant hybrids to lead to food security.
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