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Potential for developing nitrogen use efficient maize for low input agricultural systems in the moist savannas of Africa

By: Kling, J.G | Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT), Mexico DF (Mexico).
Contributor(s): Akintoye, H.A [coaut.] | Edmeades, G.O.|Banziger, M.|Mickelson, H.R.|Pena-Valdivia, C.B [eds.] | Heuberger, H.T [coaut.] | Horst, W.J [coaut.] | Oikeh, S.O [coaut.].
Material type: materialTypeLabelBookAnalytics: Show analyticsPublisher: Mexico, DF (Mexico) CIMMYT : 1997ISBN: 968-6923-93-4.Subject(s): Africa | Nitrogen content | Plant production | Selection | CIMMYT | Zea mays AGROVOC | Soil fertility AGROVOC | Nitrogen fertilizers AGROVOC | Plant breeding AGROVOCDDC classification: 633.153 Summary: The moist savannas of Africa have considerable potential for maize production, but soils are generally low in available N. Improved N use efficiency is a key to economically and ecologically sustainable maize production. Studies have been conducted at IITA to determine the potential for breeding maize with greater N use efficiency (grain yield per unit available soil N) and to identify mechanisms of N stress tolerance. Elite populations and hybrids were found to differ in N uptake, utilization and grain yield, but genotype by N interactions (GxN) frequently were not significant. Phenological traits including grain- filling duration and anthesis-silking interval have shown GxN in some environments. GxN interactions for yield and ears plant-1 were detected among S2 families from the TZPB-SR population, indicating the potential for using population improvement methods to develop varieties with specific adaptation to N stress. Combining ability of elite inbred lines was evaluated under low and high N. Crosses involving Tzi lines 25, 34, and 35 performed well under low N. TZi 3 was the best parent under high N. Crosses with TZi 15 were susceptible to N stress. Precise selection criteria related to the mechanisms of N stress tolerance are needed to achieve more rapid progress through breeding. Studies were undertaken to investigate relationships between root morphology and N uptake efficiency and to develop screening techniques for root characteristics. The temporal movement of mineralized N through the soil profile was measured to see if rapid early root growth could increase N uptake. Results suggest that maximum rooting depth may be more critical in the savannas, because substantial quantities of N move out of the root zone around flowering time. Visual scores of root size at 5 weeks after sowing showed some correspondence with grain yield, but some stress tolerant inbreds had below average combining ability for root size. On- farm trials comparing an N-efficient hybrid (8644-27) and an N-inefficient open-pollinated variety (TZB- SR) demonstrated the need for an integrated approach that includes stress-tolerant cultivars and rotations with legumes to improve soil fertility and maize productivity in the African savannas.Collection: CIMMYT Publications Collection
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Conference proceedings CIMMYT Knowledge Center: John Woolston Library

Lic. Jose Juan Caballero Flores

 

CIMMYT Publications Collection 633.153 EDM (Browse shelf) 1 Available 3L624179
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The moist savannas of Africa have considerable potential for maize production, but soils are generally low in available N. Improved N use efficiency is a key to economically and ecologically sustainable maize production. Studies have been conducted at IITA to determine the potential for breeding maize with greater N use efficiency (grain yield per unit available soil N) and to identify mechanisms of N stress tolerance. Elite populations and hybrids were found to differ in N uptake, utilization and grain yield, but genotype by N interactions (GxN) frequently were not significant. Phenological traits including grain- filling duration and anthesis-silking interval have shown GxN in some environments. GxN interactions for yield and ears plant-1 were detected among S2 families from the TZPB-SR population, indicating the potential for using population improvement methods to develop varieties with specific adaptation to N stress. Combining ability of elite inbred lines was evaluated under low and high N. Crosses involving Tzi lines 25, 34, and 35 performed well under low N. TZi 3 was the best parent under high N. Crosses with TZi 15 were susceptible to N stress. Precise selection criteria related to the mechanisms of N stress tolerance are needed to achieve more rapid progress through breeding. Studies were undertaken to investigate relationships between root morphology and N uptake efficiency and to develop screening techniques for root characteristics. The temporal movement of mineralized N through the soil profile was measured to see if rapid early root growth could increase N uptake. Results suggest that maximum rooting depth may be more critical in the savannas, because substantial quantities of N move out of the root zone around flowering time. Visual scores of root size at 5 weeks after sowing showed some correspondence with grain yield, but some stress tolerant inbreds had below average combining ability for root size. On- farm trials comparing an N-efficient hybrid (8644-27) and an N-inefficient open-pollinated variety (TZB- SR) demonstrated the need for an integrated approach that includes stress-tolerant cultivars and rotations with legumes to improve soil fertility and maize productivity in the African savannas.

English

9802|AGRIS 9702

Jose Juan Caballero

CIMMYT Publications Collection

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