Contribution of population improvement to the development of maize lines with commercial value

2003 ◽  
Vol 51 (1) ◽  
pp. 11-17 ◽  
Author(s):  
G Hadi
Keyword(s):  
Grain Yield ◽  
Recurrent Selection ◽  
Plant Density ◽  
High Plant Density ◽  
Grain Moisture ◽  
Population Improvement ◽  
Commercial Value ◽  
Correlated Characters ◽  
Stalk Lodging ◽  
Positive Effect

The grain yield was increased by 8.2% per cycle (32.8% overall) in a population of Mindszentpusztai Yellow Dent (MYD), by 8.9% per cycle (35.6% overall) in a population of Mv Syn. I and by 4.9% per cycle (19.7% overall) in a population of Westigua when tested on the closed pedigree line HMv 124-2. Averaged over the three populations the rise in grain yield was 7.5% per cycle, giving a total of around 30% after four cycles. The grain moisture at harvest showed a slight but significant decrease, while there was no change in the percentage stalk lodging. It seems probable that this increase in grain yield was achieved not at the expense of other correlated characters, but as the result of a greater frequency of gene combinations having a positive effect on grain yield, since recurrent selection was combined with selection for multiple ears at high plant density. The hybrid performance of the improved populations was extremely good, reaching 87.9% of that of commercial hybrids. Over the last 25 years around 11,500 S1 families have been tested from a total of 115 populations (including the three discussed above) and the inbreeding of the selected families was continued until the homozygous state was reached. Despite careful selection, it has not proved possible to breed inbred lines suitable for the development of hybrids with commercial value. Further research will be required to discover the reasons for this failure.

scholarly journals Optimizing Planting Density and Impact of Panicle Types on Grain Yield and Microclimatic Response Index of Hybrid Rice (Oryza sativa L.)

2021 ◽  
Author(s):  
Guotao Yang ◽  
Xuechun Wang ◽  
Farhan Nabi ◽  
Hongni Wang ◽  
Changkun Zhao ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Light Intensity ◽  
Grain Yield ◽  
Hybrid Rice ◽  
Plant Density ◽  
Oryza Sativa L ◽  
Planting Density ◽  
Response Index ◽  
Lower Position ◽  
High Plant Density

AbstractThe architecture of rice plant represents important and complex agronomic traits, such as panicles morphology, which directly influence the microclimate of rice population and consequently grain yield. To enhance yield, modification of plant architecture to create new hybrid cultivars is considered a sustainable approach. The current study includes an investigation of yield and microclimate response index under low to high plant density of two indica hybrid rice R498 (curved panicles) and R499 (erect panicles), from 2017 to 2018. The split-plot design included planting densities of 11.9–36.2 plant/m2. The results showed that compared with R498, R499 produced a higher grain yield of 8.02–8.83 t/ha at a higher planting density of 26.5–36.2 plant/m2. The response index of light intensity and relative humidity to the planting density of R499 was higher than that of R498 at the lower position of the rice population. However, the response index of temperature to the planting density of R499 was higher at the upper position (0.2–1.4%) than at the lower position. Compared with R498, R499 at a high planting density developed lower relative humidity (78–88%) and higher light intensity (9900–15,916 lx) at the lower position of the rice population. Our finding suggests that erect panicles are highly related to grain yield microclimatic contributors under a highly dense rice population, such as light intensity utilization, humidity, and temperature. The application of erect panicle rice type provides a potential strategy for yield improvement by increasing microclimatic conditions in rice.

scholarly journals Ethephon Reduces Maize Nitrogen Uptake but Improves Nitrogen Utilization in Zea mays L.

2022 ◽  
Vol 12 ◽  
Author(s):  
Yushi Zhang ◽  
Yubin Wang ◽  
Churong Liu ◽  
Delian Ye ◽  
Danyang Ren ◽  
...  
Keyword(s):  
Grain Yield ◽  
Plant Density ◽  
N Uptake ◽  
Utilization Efficiency ◽  
N Application ◽  
Total N ◽  
N Concentration ◽  
High Plant Density ◽  
Ethephon Treatment ◽  
N Use

Increasing use of plant density or/and nitrogen (N) application has been introduced to maize production in the past few decades. However, excessive planting density or/and use of fertilizer may cause reduced N use efficiency (NUE) and increased lodging risks. Ethephon application improves maize lodging resistance and has been an essential measure in maize intensive production systems associated with high plant density and N input in China. Limited information is available about the effect of ethephon on maize N use and the response to plant density under different N rates in the field. A three-year field study was conducted with two ethephon applications (0 and 90 g ha−1), four N application rates (0, 75, 150, and 225 kg N ha−1), and two plant densities (6.75 plants m−2 and 7.5 plants m−2) to evaluate the effects of ethephon on maize NUE indices (N agronomic efficiency, NAE; N recovery efficiency, NRE; N uptake efficiency, NUpE; N utilization efficiency, NUtE; partial factor productivity of N, PFPN), biomass, N concentration, grain yield and N uptake, and translocation properties. The results suggest that the application of ethephon decreased the grain yield by 1.83–5.74% due to the decrease of grain numbers and grain weight during the three experimental seasons. Meanwhile, lower biomass, NO3- and NH4+ fluxes in xylem bleeding sap, and total N uptake were observed under ethephon treatments. These resulted in lower NAE and NUpE under the ethephon treatment at a corresponding N application rate and plant density. The ethephon treatment had no significant effects on the N concentration in grains, and it decreased the N concentration in stover at the harvesting stage, while increasing the plant N concentration at the silking stage. Consequently, post-silking N remobilization was significantly increased by 14.10–32.64% under the ethephon treatment during the experimental periods. Meanwhile, NUtE significantly increased by ethephon.

Grain Yield Gains and Associated Traits in Tropical X Temperate Maize Germplasm Under High and Low Plant Density

2021 ◽  
Author(s):  
Vince Ndou ◽  
Edmore Gasura ◽  
Pauline Chivenge ◽  
John Derera
Keyword(s):  
Population Density ◽  
Grain Yield ◽  
Plant Density ◽  
Plant Population ◽  
Population Densities ◽  
Genetic Gains ◽  
Maize Germplasm ◽  
High Plant Density ◽  
Number Of Leaves ◽  
Plant Population Density

Abstract Development of ideal breeding and crop management strategies that can improve maize grain yield under tropical environments is crucial. In the temperate regions, such yield improvements were achieved through use of genotypes that adapt high plant population density stress. However, tropical germplasm has poor tolerance to high plant population density stress, and thus it should be improved by temperate maize. The aim of this study was to estimate the genetic gains and identify traits associated with such gains in stable and high yielding temperate x tropical hybrids under low and high plant population densities. A total of 200 hybrids derived from a line x tester mating design of tropical x temperate germplasm were developed. These hybrids were evaluated for grain yield and allied traits under varied plant population densities. High yielding and stable hybrids, such as 15XH214, 15XH215 and 15XH121 were resistant to lodging and had higher number of leaves above the cob. The high genetic gains of 26% and desirable stress tolerance indices of these hybrids made them better performers over check hybrids under high plant population density. At high plant population density yield was correlated to stem lodging and number of leaves above the cob. Future gains in grain yield of these hybrids derived from temperate x tropical maize germplasm can be achieved by exploiting indirect selection for resistance to stem lodging and increased number of leaves above the cob under high plant density conditions.

scholarly journals Marginal superiority of maize: an indicator for density tolerance under high plant density

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Guangzhou Liu ◽  
Wanmao Liu ◽  
Yunshan Yang ◽  
Xiaoxia Guo ◽  
Guoqiang Zhang ◽  
...  
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Plant Density ◽  
Significant Negative Correlation ◽  
Growth Conditions ◽  
High Density ◽  
Leaf Angle ◽  
Individual Plant ◽  
High Plant Density ◽  
Tolerance Field

Abstract Marginal superiority is a common phenomenon in crops, and is caused by the competitiveness of individual plant for resources and crop adaptability to crowded growth conditions. In this study, in order to clarify the response of marginal superiority to maize morphology and plant-density tolerance, field experiments without water and nutrition stress were conducted at Qitai Farm in Xinjiang, China, in 2013–2014 and 2016–2019. The results showed that no more than three border rows of all the cultivars had marginal superiority under high density, about 90% of all the cultivars had no more than two border row that had marginal superiority and a significant negative correlation was observed between marginal superiority and population grain yield (first border row: y = − 2.193x + 213.9, p < 0.05; second border row: y = − 2.076x + 159.2, p < 0.01). Additionally, marginal superiority was found to have a significant positive relationship with plant density (first border row: y = 6.049x + 73.76, p < 0.01; second border row: y = 1.88x + 95.41, p < 0.05) and the average leaf angle above the ear (first border row: y = 2.306x + 103.1, p < 0.01). These results indicated that the smaller the leaf angle above the ear, the weaker the marginal superiority and the higher the grain yield. It suggests that the magnitude of marginal superiority in the border rows can be an indicator for plant-density tolerance under high density. What’s more, cultivars with small leaf angle above the ear can be selected to weaken the marginal superiority and improve grain yield under high plant density. Conversely, cultivars with a large leaf angle above the ear can be selected to achieve higher individual yield in intercropping systems with no more than four rows alternated with other crops.

scholarly journals EFFECT OF SPRAYING WITH DIFFERENT CONCENTRATION OF LICORICE EXTRACT AND PLANT DENSITIES IN GROWTH AND YIELD OF SORGHUM BICOLOR L.

2019 ◽  
Vol 50 (6) ◽  
Author(s):  
Al-Mohmadi & Al-Ani
Keyword(s):  
Grain Yield ◽  
Plant Density ◽  
Foliar Application ◽  
Growth And Yield ◽  
Control Treatment ◽  
Spring Season ◽  
Area Index ◽  
Fall Season ◽  
High Plant Density ◽  
Plant Densities

A field experiment was condueted at the experimental Farm, College of Agriculture University of AL-Anbar in replace location (Abu-Gheaib) in spring season of 2017. While in Fall season it was applied at AL-saqluwiya-Anbar Province 10 km west north of Falluga city to study the effect of four levels of licorice extractor (Glycyrrhiza glabra L.) (0,2,4 and 6) g.L-1 water and three (53,333, 66,666 and 88,888 plant) plant.ha-1. On growth and grain yield of Sorghum cv. Rabih. The experiment was applied using R.C.B.D. arranged in split plots with three replications. levels of plant densities were used as main-plot, while licorice extractor were used as sub-plot. Foliar application of licorice extractor was applied during vegetative growth. The results showed that, high plant density (88888) plant.h-1 significantly increase plant height and leaf area index, while most of traits were not significantly influenced by plant density including grain yield. Results revealed that foliar application of licorice extractor with 2,4,6 g.L-1 of water significantly influenced grain yield in spring season compane with control treatment and it is amounted to (9.62, 9.55 and 9.78) t.h-1 respectively. There were significant interaction between Licorice extractor and plant density in spring and fall season in grain yield. The higher grain yield of 10.31 and 10.33 t.h-1 were obtained when sorghum plants were sowing at hight density and sprayed with Licorice extractor at level          4 g.L-1 respectively

scholarly journals Sowing Systems as a Factor of Grain Yield in Sunflower Production

Poljoprivreda ◽  
2021 ◽  
Vol 27 (2) ◽  
pp. 84-90
Author(s):  
Anamarija Banaj ◽  
Đuro Banaj ◽  
Davor Petrović ◽  
Bojan Stipešević ◽  
Vjekoslav Tadić
Keyword(s):  
Grain Yield ◽  
Plant Density ◽  
Statistical Significance ◽  
Weak Acid ◽  
Row Spacing ◽  
Iso Standard ◽  
Grain Moisture ◽  
Silty Loam ◽  
Acid Reaction ◽  
Sowing Machine

The paper presents the results of a triennial study of the sowing system influence on the yied, grain weight per head, plant set per ha and of the grain moisture of a medium-early sunflower hybrid . Standard sowing was performed with the PSK OLT sowing machine at a row spacing amounting to 70 cm, while a twin row sowing was performed with the MaterMacc Twin Row-2 sowing machine at a row spacing of 22*48 cm. Both sowing machines were adjusted according to the ISO standard 7256/1 and 7256/2, with a high QFI index (PSK OLT: 96.32 %; MaterMacc Twin Row-2: 93.93 %). The research was conducted at the Gorjani Experimental Field on psudogley bearing the textured markings of a silty loam, with a weak acid reaction and a small amount of humus. An analysis of variance determined a statistical significance of the sowing system on the grain yield and the grain mass per sunflower head. Sowing in twin rows achieved the higher yields for all three research years : 19.59% in 2017, 19.11% in 2018, and 18.45% in 2019. Plant density was not statistically significantly affected by the sowing systems and vegetation year, but the grain moisture was statistically significantly different between the analyzed research years .

scholarly journals Effect of sowing technology on the yield and harvest grain moisture content of maize (Zea mays L.) hybrids with different genotypes

2016 ◽  
pp. 17-22
Author(s):  
Eszter Murányi
Keyword(s):  
Moisture Content ◽  
Grain Yield ◽  
Plant Density ◽  
Research Work ◽  
Field Research ◽  
Weather Conditions ◽  
Research Centre ◽  
Row Spacing ◽  
Grain Moisture ◽  
Significant Difference

From the aspect of the efficiency of maize production harvest grain moisture content shall be considered beside the amount of harvested grain yield. Hybrids with different genotypes and vegetation period length lose their moisture content different that is affected by row spacing and plant density – among agrotechnical production factors – depending on the given crop year. In the present research work three crop years with different weather conditions were studied (2013, 2014, and 2015). The small-plot field experiment was set up at the Látókép Field Research Centre of the University of Debrecen, Centre for Agricultural Sciences with four replications on a chernozem soil type. The effect of three factors was analysed in the experiment on yield amount and its moisture content. Factors were row spacing (45 and 76 cm), plant density (50, 70 and 90 thousand plants ha-1), while hybrids were of very early (Sarolta: FAO 290), early (DKC 4014: FAO 320, P 9175: FAO 330, P 9494: FAO 390) and medium (SY Afinity: FAO 470) ripening. In the crop year of 2013 the highest yield was produced – regarding the average of the hybrids – by the application of a row spacing of 45 cm (4.5%, 673 kg ha-1), however there was no significant difference between the yield of the populations of different row spacings. Significant difference (14.9%, 1751 kg ha-1; 6.3%, 583 kg ha-1) could be found in case of yield between different row spacing applications in 2014 and 2015. The effect of insufficiently distributed low amount of precipitation and lasting heat days in 2015 could be revealed in yield amounts and harvest grain yield moisture content results that were lower than in the previous years. In 2015 grain yield moisture content varied between 10.3 and 13.9% in case of a row spacing of 45 cm, while by 76 cm between 11.0 and 13.9%.

Effect of Low Nitrogen Rate Combined with High Plant Density on Grain Yield and Nitrogen Use Efficiency in Super Rice

2015 ◽  
Vol 41 (10) ◽  
pp. 1591 ◽  
Author(s):  
Xiao-Bing XIE ◽  
Xue-Feng ZHOU ◽  
Peng JIANG ◽  
Jia-Na CHEN ◽  
Rui-Chun ZHANG ◽  
...  
Keyword(s):  
Grain Yield ◽  
Nitrogen Use Efficiency ◽  
Plant Density ◽  
Nitrogen Rate ◽  
Nitrogen Use ◽  
High Plant Density ◽  
Use Efficiency ◽  
Low Nitrogen

scholarly journals Genetic Diversity and Combining Ability of White Maize Inbred Lines under Different Plant Densities

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1140 ◽  
Author(s):  
Mohamed M. Kamara ◽  
Medhat Rehan ◽  
Khaled M. Ibrahim ◽  
Abdullah S. Alsohim ◽  
Mohsen M. Elsharkawy ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Grain Yield ◽  
Genetic Distance ◽  
Combining Ability ◽  
Plant Density ◽  
Inbred Lines ◽  
Hybrid Performance ◽  
High Plant Density ◽  
Plant Densities ◽  
Additive Gene

Knowledge of combining ability and genetic diversity are important prerequisites for the development of outstanding hybrids that are tolerant to high plant density. This work was carried out to assess general combining ability (GCA) and specific combining ability (SCA), identify promising hybrids, estimate genetic diversity among the inbred lines and correlate genetic distance to hybrid performance and SCA across different plant densities. A total of 28 F1 hybrids obtained by crossing eight adverse inbred lines (four local and four exotic) were evaluated under three plant densities 59,500 (D1), 71,400 (D2) and 83,300 (D3) plants ha−1 using spilt plot design with three replications at two locations during 2018 season. Increasing plant density from D1 to D3 significantly decreased leaf angle (LANG), chlorophyll content (CHLC), all ear characteristics and grain yield per plant (GYPP). Contrarily, days to silking (DTS), anthesis–silking interval (ASI), plant height (PLHT), ear height (EHT), and grain yield per hectare (GYPH) were significantly increased. Both additive and non-additive gene actions were involved in the inheritance of all the evaluated traits, but additive gene action was predominant for most traits. Inbred lines L1, L2, and L5 were the best general combiners for increasing grain yield and other desirable traits across research environments. Two hybrids L2 × L5 and L2 × L8 were found to be good specific combiners for ASI, LANG, GYPP and GYPH. Furthermore, these hybrids are ideal for further testing and promotion for commercialization under high plant density. Genetic distance (GD) among pairs of inbred lines ranged from 0.31 to 0.78, with an average of 0.61. Clustering based on molecular GD has effectively grouped the inbred lines according to their origin. No significant correlation was found between GD and both hybrid performance and SCA for grain yield and other traits and proved to be of no predictive value. Nevertheless, SCA could be used to predict the hybrid performance across all plant densities. Overall, this work presents useful information regarding the inheritance of maize grain yield and other important traits under high plant density.

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