Maize is most important staple food crop in sub-Saharan Africa (SSA). Levels of infestation are often so high that maize can suffer total yield loss. There is urgent need for the identification of diverse parental combinations for commercial hybrid production.

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Grain yield performance and stability of early maturing maize hybrids
under Striga-infested and Striga-free environments
Samuel A. Adewale
Maize Improvement Program, IITA, Ibadan
Department of Crop Production and Protection, OAU, Ile Ife.

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Introduction
• Maize is most important staple food crop in
sub-Saharan Africa (SSA).
• Maize grain yield is greatly constrained by the
parasitic weed, Striga hermonthica.
• Levels of infestation are often so high that
maize can suffer total yield loss and farmers
usually abandon severely infested fields.
Plate 1: Striga occurrence under natural
infestation in sorghum field.

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• Therefore, there is urgent need for the
identification of diverse parental
combinations for commercial hybrid
production.
Objective
• This study examined the grain yield
performance and stability of hybrids derived
from early maturing inbreds under Striga
infestation and optimal environments.
Plate 2: Striga occurrence under artificial infestation
in maize field.

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Materials and Methods
• Genotype: 190 early hybrids (testcrosses) plus six hybrid checks
• Locations:
 Mokwa (Striga & optimal) (90
18’N, 50
4’E, 457 m altitude, 1100 mm annual rainfall),
 Abuja (Striga) (90
16’N, 70
20’E, 300 m altitude, and 1500 mm annual rainfall)
 Ikenne (Optimal) (60
87’N, 30
7’E, altitude of 60 m, 1500 m rainfall)
• Experimental design: 14 × 14 alpha lattice design, in two replicates.

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• Artificial Striga infestation (Kim 1991; Kim and Winslow 1991)
• Data collection:
Days to anthesis and silking
Plant and ear height
Plant aspect on a scale of 1 to 9
Ear aspect on a scale of 1 to 9
Host plant damage syndrome rating on a scale of 1 to 9
Number of emerged Striga plants
Grain yield
• Statistical analysis
 Analysis of variance (ANOVA) and AMMI biplot analyses

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Results and Discussion

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Table 1: Mean squares of grain yield and other traits of hybrids evaluated across Striga
infested and optimal environments in 2017 growing season.
Source of
variation
Df Yield (kg/ha) EPP ASI PLHT ERHT RATING1 COUNT1
Site 3 304577381** 5.26** 793.00** 45000** 8106.21** 168.07** 102537.19**
Blk(Site*Rep) 104 2617173** 0.06** 1.84* 329.91** 258.66** 1.08* 275.34**
Hybrid 195 5429378** 0.10** 4.45** 331.31** 166.38** 4.19** 250.05**
Hybrid*Site 585 2175969** 0.05** 2.98** 213.00** 127.05178** 1.35** 180.63**
Error 675 1248287 0.04 1.45 211.62 1074.02 0.76 112.73
EPP = Ears per plant, ASI = Anthesis-silking interval, PLHT = Plant height, ERHT = Ear height, RATING1 = Striga damage rating at 8wks after planting,
COUNT1 = Striga count at 8wks after planting;
*, **, significant at 0.05 and 0.01 probability levels respectively.

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Fig 1: Grain yield (kg/ha) of 5 best early maturing maize hybrids under Striga infested, optimal
and across environments.
Entry Pedigree
185 TZEI 1344 x TZdEI 352
190 TZEI 1348 x TZdEI 352
165 TZEI 1305 x TZdEI 352
124 TZEI 1203 x TZEI 31
4 TZEI 762 x TZEI 31
11 TZEI 771 x TZEI 7
12 TZEI 771 x TZEI 18
151 TZEI 1252 x TZEI 7
145 TZEI 1238 x TZdEI 352
121 TZEI 1203 x TZEI 7
15 TZEI 771 x TZdEI 352
Check 1 TZEI 86 x TZEI 60
Check 5 TZEI 32 x TZEI 18
Check 4 TZEI 32 x TZEI 56
Check 2 ENT 3 x TZEI 65
Check 3 TZE-W Pop DT STR C4 x TZEI 7
YIELD(Kg/ha)

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Fig 2: AMMI biplot of grain yield and IPCA 1 of 15 best and 5 worst hybrids evaluated across 4
environments in 2017, in Nigeria.
Entry Pedigree
151 TZEI 1252 x TZEI 7
145 TZEI 1238 x TZdEI 352
4 TZEI 762 x TZEI 31
121 TZEI 1203 x TZEI 7
15 TZEI 771 x TZdEI 352
173 TZEI 1323 x TZEI 19
152 TZEI 1252 x TZEI 18
165 TZEI 1305 x TZdEI 352
188 TZEI 1348 x TZEI 19
124 TZEI 1203 x TZEI 31
186 TZEI 1348 x TZEI 7
12 TZEI 771 x TZEI 18
141 TZEI 1238 x TZEI 7
155 TZEI 1252 x TZdEI 352
176 TZEI 1341 x TZEI 7
118 TZEI 1145 x TZEI 19
104 TZEI 1107 x TZEI 31
24 TZEI 806 x TZEI 31
113 TZEI 1137 x TZEI 19
105 TZEI 1107 x TZdEI 352

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Plate 3: Effects of Striga on maize hybrids at flowering and grain filling stages
Striga susceptible Striga resistant

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Plate 4: Effects of Striga on grain yield of maize hybrids.
Striga susceptibleStriga resistant

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• Significant genetic variability exists among the genotypes, hence good
progress could be made from selection.
• Hybrids TZEI 1344 × TZdEI 352 and TZEI 762 x TZEI 31 were the top
performing in grain yield, under Striga infestation and Striga-free
conditions, respectively.
• Hybrids TZEI 1252 X TZEI 7 and TZEI 771 x TZdEI 352 were high yielding and
most stable across all research environments.
• Top performing hybrids should be tested extensively for release and
commercialization in SSA.
Conclusions

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THANK YOU
MERCI

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