scholarly journals Source capacity during flowering affects grain yield of amaranth (Amaranthus sp.)

2013 ◽  
Vol 59 (No. 10) ◽  
pp. 472-477 ◽  
Author(s):  
B. Roitner-Schobesberger ◽  
Kaul H-P
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Field Experiments ◽  
Growth Conditions ◽  
Yield Reduction ◽  
Sources And Sinks ◽  
Yield Level ◽  
Eastern Austria ◽  
Source Sink ◽  
Yield Formation

Amaranth is a promising C4-crop. However, for a wider spread of the crop a better understanding of factors that are influencing yield formation is crucial for optimizing the plant phenotype and enhancing yield. The present study wanted to clarify the effects of assimilate sources and sinks on yield formation by artificially altering source or sink size. Field experiments were conducted in Eastern Austria during three years with three genotypes, applying source-sink manipulation treatments at mid flowering (control, 50% of inflorescence removed, 50% or 100% of leaves removed). At maturity we measured shoot, inflorescence and grain dry matter, thousand kernel mass and number of seeds per plant. An average grain yield level of about 3.5 t/ha dry matter on control plots indicated favorable growth conditions for amaranth in general. The removal of all leaves had a strong detrimental effect on all parameters, but severity of yield reduction due to defoliation differed between genotypes, ranging from –49% to –73%. Contrastingly, 50% flower reduction did not have any significant effects. Also with 50% defoliation no significant yield reduction was observed. We conclude that source strength of amaranth during flowering is more yield limiting than its sink capacity.

Contribution of Stem Dry Matter to Grain Yield in Wheat Cultivars

1991 ◽  
Vol 18 (1) ◽  
pp. 53 ◽  
Author(s):  
PC Pheloung ◽  
KHM Siddique
Keyword(s):  
Water Stress ◽  
Grain Yield ◽  
Dry Matter ◽  
Field Experiments ◽  
Yield Potential ◽  
Percentage Reduction ◽  
Wheat Cultivars ◽  
Activity Increase ◽  
Structural Carbohydrate ◽  
Days After Anthesis

Field experiments were conducted in the eastern wheat belt of Western Australia in a dry year with and without irrigation (1987) and in a wet year (1988), comparing three cultivars of wheat differing in height and yield potential. The aim of the study was to determine the contribution of remobilisable stem dry matter to grain dry matter under different water regimes in old and modern wheats. Stem non-structural carbohydrate was labelled with 14C 1 day after anthesis and the activity and weight of this pool and the grain was measured at 2, 18 and 58 days after anthesis. Gutha and Kulin, modern tall and semi-dwarf cultivars respectively, yielded higher than Gamenya, a tall older cultivar in all conditions, but the percentage reduction in yield under water stress was greater for the modern cultivars (41, 34 and 23%). In the grain of Gamenya, the increase in 14C activity after the initial labelling was highest under water stress. Generally, loss of 14C activity from the non-structural stem dry matter was less than the increase in grain activity under water stress but similar to or greater than grain activity increase under well watered conditions. Averaged over environments and cultivars, non-structural dry matter stored in the stem contributed at least 20% of the grain dry matter.

Effect of herbicides on the weed infestation and grain yield of soybean (Glycine max)

2004 ◽  
Vol 52 (2) ◽  
pp. 199-203 ◽  
Author(s):  
G. Singh ◽  
R. S. Jolly
Keyword(s):  
Glycine Max ◽  
Grain Yield ◽  
Weed Control ◽  
Negative Correlation ◽  
Rainy Season ◽  
Dry Matter ◽  
Field Experiments ◽  
Sand Soil ◽  
Loamy Sand Soil ◽  
Weed Infestation

Two field experiments were conducted during the kharif (rainy) season of 1999 and 2000 on a loamy sand soil to study the effect of various pre- and post-emergence herbicides on the weed infestation and grain yield of soybean. The presence of weeds in the weedy control plots resulted in 58.8 and 58.1% reduction in the grain yield in the two years compared to two hand weedings (HW) at 30 and 45 days after sowing (DAS), which gave grain yields of 1326 and 2029 kg ha-1. None of the herbicides was significantly superior to the two hand weedings treatment in influencing the grain yield. However, the pre-emergence application of 0.75 kg ha-1 S-metolachlor, and 0.5 kg ha-1 pendimethalin (pre-emergence) + HW 30 DAS were at par or numerically superior to this treatment. There was a good negative correlation between the weed dry matter at harvest and the grain yield of soybean, which showed that effective weed control is necessary for obtaining higher yields of soybean.

scholarly journals Leaf Removal Affects Maize Morphology and Grain Yield

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 269 ◽  
Author(s):  
Guangzhou Liu ◽  
Yunshan Yang ◽  
Wanmao Liu ◽  
Xiaoxia Guo ◽  
Jun Xue ◽  
...  
Keyword(s):  
Grain Yield ◽  
Leaf Area ◽  
Field Experiments ◽  
Photosynthetic Capacity ◽  
Maize Yield ◽  
Light Distribution ◽  
Planting Density ◽  
Leaf Removal ◽  
Area Index ◽  
Source Sink

Increasing planting density is an important practice associated with increases in maize yield, but densely planted maize can suffer from poor light conditions. In our two-year field experiments, two morphologically different cultivars, ZD958 (less compact) and DH618 (more compact), were planted at 120,000 plants ha−1 and 135,000 plants ha−1, respectively. We established different leaf area index (LAI) treatments by removing leaves three days after silking: (1) control, no leaves removed (D0); (2) the two uppermost leaves removed (D1); (3) the four uppermost leaves removed (D2); (4) the leaves below the third leaf below the ear removed (D3); (5) the leaves of D1 and D3 removed (D4); (6) the leaves of D2 and D3 removed (D5). Optimal leaf removal improved light distribution, increased photosynthetic capacity and the post-silking source-sink ratio, and thus the grain yield, with an average LAI of 5.9 (5.6 and 6.2 for ZD958 and DH618, respectively) for the highest yields in each year. Therefore, less-compact cultivars should have smaller or fewer topmost leaves or leaves below the ear that quickly senesce post-silking, so as to decrease leaf area and thus improve light distribution and photosynthetic capacity in the canopy under dense planting conditions. However, for more compact cultivars, leaves below the ear should senesce quickly after silking to reduce leaf respiration and improve the photosynthetic capacity of the remaining top residual leaves. In future maize cultivation, compact cultivars with optimal post-silking LAI should be adopted when planting densely.

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 Simulated Assessment of Summer Maize Drought Loss Sensitivity in Huaibei Plain, China

Agronomy ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 78 ◽  
Author(s):  
Yanqi Wei ◽  
Juliang Jin ◽  
Shangming Jiang ◽  
Shaowei Ning ◽  
Yi Cui ◽  
...  
Keyword(s):  
Drought Stress ◽  
Grain Yield ◽  
Water Deficit ◽  
Dry Matter ◽  
Yield Loss ◽  
Agricultural Drought ◽  
Summer Maize ◽  
Jointing Stage ◽  
Two Stages ◽  
Yield Formation

In an agricultural drought risk system, crop drought loss sensitivity evaluation is a fundamental link for quantitative agricultural drought loss risk assessment. Summer maize growth processes under various drought patterns were simulated using the Cropping System Model (CSM)-CERES-maize, which was calibrated and validated based on pit experiments conducted in the Huaibei Plain during 2016 and 2017 seasons. Then S-shaped maize drought loss sensitivity curve was built for fitting the relationship between drought hazard index intensity at a given stage and the corresponding dry matter accumulation and grain yield loss rate, respectively. Drought stress reduced summer maize evapotranspiration, dry matter, and yield accumulation, and the reductions increased with the drought intensity at each stage. Moreover, the losses caused by drought at different stages were significantly different. When maize plants were exposed to a severe water deficit at the jointing stage, the dry matter and grain yield formation were greatly affected. Therefore, maize growth was more sensitive to drought stress at the jointing stage when the stress was serious. Furthermore, when plants encountered a relatively slight drought during the seedling or jointing stage, which represented as a lower soil water deficit intensity, the grain yield loss rates approached the maximum for the sensitivity curves of these two stages. Therefore, summer maize tolerance to water deficit at the seedling and jointing stages were weak, and yield formation was more sensitive to water deficit during these two stages when the deficit was relatively slight.

scholarly journals Tillering does not interfere on white oat grain yield response to plant density

2003 ◽  
Vol 60 (2) ◽  
pp. 253-258 ◽  
Author(s):  
Milton Luiz de Almeida ◽  
Luís Sangoi ◽  
Márcio Ender ◽  
Anderson Fernando Wamser
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Field Experiments ◽  
Plant Density ◽  
Dry Mass ◽  
Main Stem ◽  
Yield Response ◽  
Individual Plant ◽  
Growing Seasons ◽  
Plant Densities

Plant density is one of the cropping practices that has the largest impact on individual plant growth. This work was conducted to evaluate the response of white oat (Avena sativa) cultivars with contrasting tillering patterns to variations in plant density. Two field experiments were carried out in Lages, SC, Brazil, during the 1998 and 1999 growing seasons. A split plot experimental design was used. Four oat cultivars were tested in the main plots: UFRGS 14, UFRGS 18, UPF 16 and UPF 17 using five plant densities split plots: 50, 185, 320, 455 and 550 plants m-2. Five plant samples were taken 25, 34, 48, 58 and 70 days after plant emergence to assess the treatment effects on dry matter partition between main stem and tillers. UFRGS 18 promoted dry matter allocation to tillers whereas UPF 17 directed dry mass mostly to the main stem. Differences in dry mass allocation between the main stem and tillers had no impact on grain yield, UPF 16 presenting the highest values for both growing seasons. The lack of interaction between population density and cultivar and the small effect of plant population on grain yield indicates that the oat tillering ability is not fundamental to define its grain yield.

Yield performance of late-maturing winter canola (Brassica napus L.) types in the High Rainfall Zone of southern Australia

2012 ◽  
Vol 63 (1) ◽  
pp. 17 ◽  
Author(s):  
Penny Riffkin ◽  
Trent Potter ◽  
Gavin Kearney
Keyword(s):  
Brassica Napus ◽  
Grain Yield ◽  
Dry Matter ◽  
Management Practices ◽  
Field Experiments ◽  
Plant Size ◽  
Dry Matter Production ◽  
Brassica Napus L ◽  
High Rainfall ◽  
Matter Production

Area and production of canola (Brassica napus L.) in the High Rainfall Zone (HRZ) of southern Australia has increased significantly over the past decade. Varieties available to growers have not been bred specifically for the HRZ and are generally adapted to the drier regions of the cropping belt. Field experiments were conducted at Hamilton in south-west Victoria in 2005, 2006 and 2008 to identify canola traits and management suited to the HRZ of southern Australia. Nine varieties with different reported maturities (winter and spring types) were sown at either two times of sowing and/or under different nitrogen (N) fertiliser regimes. Dates of key phenological development were recorded, dry matter was determined at bud, flowering and maturity and grain yield and yield components were determined at harvest. Plant traits and climate data were assessed in relation to grain yield. Yields of the winter types were either significantly (P < 0.05) greater or not significantly less than the spring types in all 3 years and similar to those reported under experimental conditions in Europe. This was despite the winter types flowering up to 35 days later than the spring types and spring rainfall being approximately half that of the long-term average. In general, the winter types had greater early vigour, greater dry matter production at the bud, flowering and maturity stages and were taller than the spring types. Regression analysis showed positive relationships between grain yield and pod density and plant size (dry matter and plant height). Plant size was influenced by variety, time of sowing and N fertiliser application rates. Crops in the HRZ were able to sustain more seeds per pod at larger canopy sizes and pod densities than those achieved in the northern hemisphere. Despite the number of pods per g of dry matter at flowering being nearly double that reported in the UK, there was little apparent reduction in the number of seeds per pod. It is possible that higher solar radiation and warmer minimum temperatures in the HRZ of Australia provide conditions more favourable for growth before, and during grainfill. This indicates that different dry matter production and yield component targets may be appropriate for canola in this environment especially in more typical seasons. It is likely that growers will need to sow new, later maturing varieties earlier and with higher rates of N fertiliser than is current practice in Australia. This study indicates that winter types may have the potential to provide improvements to the yield of canola in the HRZ either through the direct importation of varieties from overseas or through the identification and incorporation of desired traits into existing material. It is recommended that a wider range of germplasm be assessed over a greater geographical area to identify traits and management practices to optimise phenology and canopy structure. This information can be used to help inform breeders on crop improvement priorities as well providing tailored management practices to maximise grain yields for this environment.

Agronomic Evaluation of Performance of Sesame Varieties in Maize-based Intercropping System in the Southern Guinean Savanna of Nigeria

2019 ◽  
pp. 1-10
Author(s):  
A. T. Ajibola ◽  
G. O. Kolawole
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Block Design ◽  
Yield Reduction ◽  
K Value ◽  
Land Equivalent Ratio ◽  
Sesame Seeds ◽  
Evaluation Of Performance ◽  
Percentage Yield ◽  
Cropping Seasons

Aims: Field experiments were conducted to determine compatibility of sesame varieties for intercropping with maize. Study Design: The experiment was a randomized complete block design with three replications. Place and Duration of Study: Teaching and Research Farm, LAUTECH, Ogbomoso, southern guinea savanna area of Nigeria during the 2010 and 2011 cropping seasons. Methodology: The treatments included Sole maize (Oba Super 1 variety), five sole sesame varieties (E-8, O3l, O1m, O2 m, Exotic-Sudan) and their intercrops, making a total of eleven treatments.  Sole maize was planted at a spacing of 75 cm x 25 cm. For intercrops, maize was planted at a spacing of 100 cm x 25  cm and sesame seeds were planted at a spacing of 100 cm x 10 cm such that sesame row alternated maize row. Maize was planted first and sesame was introduced two weeks after. Results: Intercropping maize with sesame varieties significantly (P = 0.05) reduced number of pods and grain yield of sesame varieties in both years. However, variety O2m produced grain yield in the intercrop similar to the mono crop. Generally, Intercropping sesame with maize significantly reduced the grain yield of maize by 36% compared to the sole crop. Exotic-Sudan varieties caused the highest percentage yield reduction (52%). Sesame varieties O2m and O3l were the only varieties whose yield advantage in intercropping with maize had land equivalent ratio (LER) of 1.28 and 1.18 while other varieties had values less than 1 indicating yield advantage of O2m and O3l with maize. The relative crowding coefficient (K) value of maize (4.98) was higher than sesame (0.44) thus indicating its dominance in the mixture. Conclusion: It is concluded that the prospective sesame farmers could grow varieties O2m and O3l in place of the popular E-8 because intercropping with maize did not affect their performances in both years.

scholarly journals Effect of Magnesium Fertilization Systems on Grain Yield Formation by Winter Wheat (Triticum aestivum L.) during the Grain-Filling Period

Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 12
Author(s):  
Witold Grzebisz ◽  
Jarosław Potarzycki
Keyword(s):  
Grain Yield ◽  
Plant Material ◽  
Dry Matter ◽  
Wheat Yield ◽  
Grain Filling ◽  
Triticum Aestivum L ◽  
Dry Matter Partitioning ◽  
Wheat Growth ◽  
Grain Filling Period ◽  
Yield Formation

The application of magnesium significantly affects the components of the wheat yield and the dry matter partitioning in the grain-filling period (GFP). This hypothesis was tested in 2013, 2014, and 2015. A two-factorial experiment with three rates of magnesium (0, 25, 50 kg ha−1) and four stages of Mg foliar fertilization (without, BBCH 30, 49/50, two-stage) was carried out. Plant material collected at BBCH: 58, 79, 89 was divided into leaves, stems, ears, chaff, and grain. The wheat yield increased by 0.5 and 0.7 t ha−1 in response to the soil and foliar Mg application. The interaction of both systems gave + 0.9 t ha−1. The Mg application affected the grain yield by increasing grain density (GD), wheat biomass at the onset of wheat flowering, durability of leaves in GFP, and share of remobilized dry matter (REQ) in the grain yield. The current photosynthesis accounted for 66% and the REQ for 34%. The soil-applied Mg increased the REQ share in the grain yield to over 50% in 2014 and 2015. The highest yield is possible, but provided a sufficiently high GD, and a balanced share of both assimilate sources in the grain yield during the maturation phase of wheat growth.

scholarly journals Timing applications of growth regulators to alter spring cereal development at high latitudes

2002 ◽  
Vol 11 (3) ◽  
pp. 233-244 ◽  
Author(s):  
A. RAJALA ◽  
P. PELTONEN-SAINIO
Keyword(s):  
Grain Yield ◽  
Growth Regulators ◽  
Stand Structure ◽  
Stem Length ◽  
Yield Reduction ◽  
Gibberellin Biosynthesis ◽  
Chlormequat Chloride ◽  
Plant Stand ◽  
Growing Conditions ◽  
Yield Formation

Plant growth regulators (PGRs) are commonly used in commercial farming to control lodging in cereals. PGRs have been shown to alter yield formation and plant stand structure, other than the straw length. To study their potential in Northern growing conditions PGRs and their application time impacts on plant stand structure and yield formation in tall and short statured cultivars of barley, oat, and wheat were studied in the field. Crop stands were sprayed with the gibberellin biosynthesis inhibitors CCC [chlormequat chloride CCC], Moddus [Trinexapac-ethyl TE], or with ethylene-releasing Cerone [ethephon ETH] at the recommended times or at an earlier growth stage. CCC applied at Zadoks growth scale (ZGS) 13-14 increased and ETH applied at ZGS 39-40 reduced grain yield of oat by 370 kg ha-1 and 270 kg ha-1, respectively. In wheat, CCC applied at ZGS 31-32 reduced grain yield by 480 kg ha-1. This yield reduction was associated with lower grain yield production by the main head and particularly lower single grain weight. In barley cv. Kymppi, ETH and TE treatments promoted yield formation, whereas in cv. Saana they tended to reduce yield. Early applied PGRs reduced stem height at 14 days after treatment irrespective of species or stem stature, but at maturity no constant PGR effect was noted. Excluding the stem length, PGRs did not modify plant stand structure or yield formation markedly.

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