HETEROSIS OF  SOME TROPICAL MAIZE GENOTYPES DERIVED FROM TWO DIFFERENT MAIZE  BREEDING ERAS

Heterosis for maize grain yield was studied to identify cross combinations that may be useful sources for inbred line extraction, recurrent selection and, to estimate changes in the maize grain yield heterosis across two breeding eras in the tropics. Field studies were conducted at the International Institute of Tropical Agriculture (IITA), Ibadan during the cropping seasons of 2010, 2011 and 2012, with 10 open pollinated maize varieties (OPVs) derived two breeding eras (1 and 2). The ten OPVs and the crosses generated from them were evaluated under stem borer infested and non-infested, high-N versus low-N and natural conditions. Mid and High-heterosis (MPH & HPH) were estimated from grain yield data from the tested environments. MPH & HPH under natural, optimum N-Fertilizer application, and borer infested environments were 37.20 and 25.38%, 19.85 and 12.3%, 30.98 and 18.94% respectively. Cross combination DMR-LSR-W (Era 1) x TZSR-Y-I (Era 1) expressed the highest magnitude of (MPH & HPH) (97.70 and 87.15%) for grain yield across the tested environments except low-N. It suggest the suitability of the hybrid for cultivation only in environments with high productivity index. Hybrid ACR99TZLCOMP4-DMRSR (Era 1) x BR9928DMRSR (Era 2) had highest HPH under low-N environments. Suggesting this combination as a good source of genes for the development of low nitrogen tolerance maize varieties in the tropics. Cross combinations that expressed better (HPH) under borer infestation are good gene pools for the development of stem borer tolerance maize varieties in stem borer endemic zone. These crosses hold promise as future candidates for commercial exploitation of heterosis or for the extraction of inbred lines in the tropics. Better (HPH) were derived from the crosses between Era 1 and & 2, indicates the older and newer maize varieties complement each other for (HPH) across environments.

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Comparative Efficiency of Tillage Practices in Maize

Current Agriculture Research Journal ◽

10.12944/carj.2.2.04 ◽

2014 ◽

Vol 2 (2) ◽

pp. 89-93 ◽

Cited By ~ 1

Author(s):

B Ita ◽

E Ariga ◽

R Michieka ◽

W Muiru

Keyword(s):

Grain Yield ◽

Weed Management ◽

Management Practices ◽

Block Design ◽

Small Scale ◽

Tillage Practices ◽

Maize Grain Yield ◽

Maize Varieties ◽

Maize Grain ◽

Hand Weeding

Weed management practices used by small scale farmers determine maize productivity. The trials were executed in Kigumo district during the long and short rains in 2010 to compare effectiveness of glyphosate and hand weeding on weed management in maize (Zea mays L.). Treatments were arranged in a Completely Randomized Complete Block Design replicated three times in a split plot arrangement. The main plots were two maize varieties DUMA SC 41 and DK 8031 and the subplots three weed management practices,(glyphosate, hand weeding and no tillage). Data collected included weed count by species,fresh and dry weed biomass and maize grain yield. Data was subjected to ANOVA using Genstat computer software package at P<0.05. Treatments means were separated by Student-Newman Keuls Test. Results revealed that there were significant differences in weed count among weed management practices (P < 0.05). Weeds, significantly established faster under hand weeding than other weed management practices. There were no significant differences among weed management practices in biomass and maize grain yield (P < 0.05). The two maize varieties significantly differed in grain yield under different weed management practices, DK 8031 under glyphosate had the highest yield among the tillage practices involved.

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Correlation and Path Coefficient Analysis Studies on Grain Yield and Its Contributing Characters in Maize (Zea mays L.)

International Journal of Plant & Soil Science ◽

10.9734/ijpss/2020/v32i730300 ◽

2020 ◽

pp. 7-13

Author(s):

O. P. Taiwo ◽

A. I. Nwonuala ◽

B. F. Isaiah ◽

D. O. Olawamide ◽

I. K. Agbugba

Keyword(s):

Grain Yield ◽

Block Design ◽

Path Coefficient ◽

Path Coefficient Analysis ◽

Maize Grain Yield ◽

Maize Varieties ◽

Ear Height ◽

Maize Grain ◽

Selection For ◽

Positive Direct

In crop breeding, the selection for yield is made complex because of the quantitative and polygenic nature of the character. This study was undertaken to assess character association and show the contribution of various yield contributing characters in some maize varieties through the help of correlation and path coefficient analyses in order to identify appropriate plant characters for selection to improve maize grain yield. Seventeen maize varieties were sown in a randomized complete block design with three replications in a humid environment of Port Harcourt, Nigeria in 2018 under rainfed condition. Data were recorded for days to 50% anthesis, days to 50% silking, anthesis-silking interval, plant height (cm) and ear height (cm), number of plants per plot, number of plants harvested, number of ears harvested, moisture content (%), field weight (kg), and grain yield (t ha-1). Results showed number of plants per plot, number of plants harvested, number of ears harvested and field weight correlated positively and significantly both phenotypically and genotypically with grain yield. Path coefficient analysis at the genotypic level also revealed field weight and days to 50% anthesis as the characters exerting the highest positive direct effect on grain yield. Therefore, maize grain yield could be improved through indirect selection for these characters.

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Improving Maize Grain Yield under Drought Stress and Non-stress Environments in Sub-Saharan Africa using Marker-Assisted Recurrent Selection

Crop Science ◽

10.2135/cropsci2015.02.0135 ◽

2016 ◽

Vol 56 (1) ◽

pp. 344-353 ◽

Cited By ~ 30

Author(s):

Yoseph Beyene ◽

Kassa Semagn ◽

Jose Crossa ◽

Stephen Mugo ◽

Gary N. Atlin ◽

...

Keyword(s):

Drought Stress ◽

Grain Yield ◽

Recurrent Selection ◽

Sub Saharan Africa ◽

Maize Grain Yield ◽

Stress Environments ◽

Maize Grain ◽

Sub Saharan

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Recurrent Selection for Maize Grain Yield: Dry Matter and Nitrogen Accumulation and Partitioning Changes

Crop Science ◽

10.2135/cropsci1994.0011183x003400040009x ◽

1994 ◽

Vol 34 (4) ◽

pp. 874-881 ◽

Cited By ~ 40

Author(s):

R. H. Moll ◽

W. A. Jackson ◽

R. L. Mikkelsen

Keyword(s):

Grain Yield ◽

Dry Matter ◽

Recurrent Selection ◽

Nitrogen Accumulation ◽

Maize Grain Yield ◽

Maize Grain ◽

Selection For

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Gene action in low nitrogen tolerance and implication on maize grain yield and associated traits of some tropical maize populations

Open Agriculture ◽

10.1515/opag-2020-0076 ◽

2020 ◽

Vol 5 (1) ◽

pp. 801-805

Author(s):

Ige Sunday ◽

Ajiboye Babatunde ◽

Abolusoro Stephen ◽

Aremu Charity ◽

Obaniyi Kayode

Keyword(s):

Grain Yield ◽

Breeding Method ◽

Gene Effects ◽

Yield Improvement ◽

Maize Grain Yield ◽

Maize Varieties ◽

Additive Gene ◽

Maize Grain ◽

Low Nitrogen ◽

Selection Of

AbstractUnderstanding the mode of inheritance of traits is vital in the selection of breeding methods for the grain yield and improvement of associated traits in a target environment. Combining ability is one of the powerful indices for the selection of the best cross combinations, parental lines that combine with other lines and the best breeding method for high grain yield improvement programmes. A total of 45 crosses were generated from ten maize varieties developed in low nitrogen environment in a diallel mating fashion without reciprocal. The resultant progenies were investigated in low- and highnitrogen soil to identify the mode of grain yield inheritance and those of related traits in the tested environments. Mean square analysis revealed the preponderance of additive and non-additive gene actions in the expression of maize grain yield and related characters tested under stress and optimal conditions. In this study, it is proved that both standard selection and hybridization breeding strategies are effective for the improvement of most traits involved. This experiment also confirmed the adequacy of sufficient variation in the gene pool present in the maize population that could be exploited in maize grain yield improvement programmes in the tropics. The ratio of SCA to GCA however emphasized the superiority of additive gene effects in the expression of most traits in the tested environments. The results, therefore, suggest that additive gene actions primarily condition the expression of maize grain yield and associated characters in the tested environments. Therefore, suggesting that the standard selection method would be effective for the improvement of most traits tested under the two environments.

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Combining Ability and Heterosis of Tolerance to Low Soil Nitrogen in Tropical Maize Cultivars Derived from Two Breeding Eras

Open Agriculture ◽

10.1515/opag-2018-0037 ◽

2018 ◽

Vol 3 (1) ◽

pp. 339-347 ◽

Cited By ~ 1

Author(s):

S.A. Ige ◽

O.B. Bello ◽

O. Alake

Keyword(s):

Grain Yield ◽

Soil Nitrogen ◽

Combining Ability ◽

Field Studies ◽

Sub Saharan Africa ◽

Productivity Index ◽

International Institute ◽

Mean Values ◽

Maize Productivity ◽

Maize Varieties

Abstract Low soil nitrogen is one of the principal abiotic stresses affecting maize productivity in Sub-saharan Africa. Field studies were conducted at the International Institute of Tropical Agriculture (IITA), Ibadan during the cropping seasons for three years, from 2010 to 2012, with ten open pollinated maize varieties (OPVs) derived from two breeding eras (1 and 2). The ten OPVs and their crosses were evaluated under high-N and low-N conditions. The aim was to identify superior populations that may be useful sources genes for inbred line extraction and hybrid development for grain yield. Under low-N condition, mid and high parent heterosis for grain yield were low indicating the suitability of the hybrids for cultivation only in environments with high productivity index. Hybrid DMR-LSR-W (Era 1) × TZSR-Y-I (Era 2) had greatest mid and high-parent heterosis for grain yield under high-N and across the other four test environments. Parent AMATZBR-WC2B with higher general combining ability effects and mean values for grain yield, and cross combinations DMR-LSR-W (Era 1) x BR9928DMRSR (Era 2) and BR9922DMRSR (Era 2) x TZBRELD-4C0W (Era 2) with higher specific combining ability for grain yield under low-N environment are promising candidates for the development of nitrogen use efficient varieties for cultivation in low-N environments.

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Analysis of the moisture content of maize kernels in over-ripe plants

Acta Agronomica Hungarica ◽

10.1556/aagr.54.2006.4.5 ◽

2006 ◽

Vol 54 (4) ◽

pp. 425-430

Author(s):

T. Árendás ◽

L. C. Marton ◽

P. Bónis ◽

Z. Berzsenyi

Keyword(s):

Linear Regression ◽

Moisture Content ◽

Grain Yield ◽

Equilibrium Moisture Content ◽

Weather Conditions ◽

Positive Correlation ◽

Maize Grain Yield ◽

Maize Grain ◽

Maize Kernels

The effect of varying weather conditions on the moisture content of the maize grain yield was investigated in Martonvásár, Hungary from late August to late September, and from the 3rd third of September to the 1st third of Novemberbetween 1999 and 2002. In every year a close positive correlation (P=0.1%) could be observed between the moisture content in late September and the rate of drying down in October. Linear regression was used each year to determine the equilibrium moisture content, to which the moisture content of kernels returned if they contained less than this quantity of water in late September and harvesting was delayed. In the experimental years this value ranged from 15.24-19.01%.

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