Rainfall, sowing time, soil type, and cultivar influence optimum plant population for wheat in Western Australia

2004 ◽  
Vol 55 (9) ◽  
pp. 921 ◽  
Author(s):  
W. K. Anderson ◽  
D. L. Sharma ◽  
B. J. Shackley ◽  
M. F. D'Antuono
Keyword(s):  
Grain Yield ◽  
Soil Type ◽  
Yield Components ◽  
Regression Tree ◽  
Growing Season ◽  
Sowing Date ◽  
Plant Population ◽  
Plant Populations ◽  
Optimum Population ◽  
Growing Conditions

In this paper we analyse existing experimental data (grain yield and yield components) from seed rate experiments on wheat in Western Australia, with the aims of determining which factors most influence the optimum plant population, and advancing some practical guidelines for improving the choice of seed rate under rain-fed conditions. Experiments (32) were conducted in the rain-fed cropping zone of Western Australia between 1996 and 2001, using factorial combinations of wheat cultivars (3–25) and target plant populations (4 or 5). Some of them also contained treatments of nitrogen fertiliser (0 or 40 kg/ha of N) or sowing times (2). Each cultivar × plant population dataset (248) was considered to be a record for the sake of the subsequent analyses. Actual plant numbers were counted in each experiment and the optimum plant population was estimated when the slope of an inverse polynomial curve (choosing the most appropriate of the LDL and QDL models in GenStat) fitted to each record was 2.5 kg/ha of grain yield for each extra plant/m2. The optimum populations were initially grouped using a regression tree technique into groups with similar characteristics using pre-sowing rainfall, rainfall in the growing season, sowing date, and soil type. The variables cultivar and nitrogen fertiliser rate were later added to the regression tree analysis. Yield components available for most experiments were used as an aid to interpretation of the results. The optimum plant population varied from 35 to 175 plants/m2 and average grain yields varied from 0.42 to 3.91 t/ha. Rainfall in the growing season (sowing date to harvest date) provided the first split in the regression tree, but pre-sowing rainfall (January to sowing date), sowing date, and soil type further modified the optimum population. The addition of N fertiliser rate as a variable in the regression tree did not induce any different groupings of the optimum population sets, but cultivars were grouped into 4 response types according to pre- and post-sowing rainfall amounts. Where rainfall in the growing season was <205 mm, improved growing conditions due to more pre-sowing rainfall, earlier sowing, and more seasonal rainfall, were associated with higher optimum plant populations. Where rainfall in the growing season exceeded 205 mm, higher pre-sowing rainfall was associated with lower optimum populations. The optimum population was greater on sands than on clay loams. However, on sandy loam soils the optimum was less where rainfall in the growing season was <291 mm, or more for crops sown after 27 May at rainfall >291 mm. Increases in yield components in response to improved growing conditions above about 400 culms/m2, 300 ears/m2, 10 000 kernels/m2, and 600 g/m2 of dry matter at anthesis were not associated with higher optimum plant populations. In general, the optimum plant population increased at about 40 plants/m2 for each tonne of grain yield up to about 3.0 t/ha. The effect of cultivar on the optimum population appeared at yield levels above 2.5 t/ha, but was only detectable when the rainfall in the growing season exceeded 205 mm. Growing conditions and cultivars associated with lower weight per ear (due to fewer kernels and/or lower kernel weight) were associated with higher optimum plant population when the rainfall in the growing season exceeded 205 mm. It is suggested that farmers can make better estimates of the appropriate plant population (and hence can calculate seed rate) on the basis of pre-sowing rainfall (likely stored water), rainfall zone (probability of rainfall in the growing season), sowing date, soil type, and characteristics of individual cultivars where known.

Some relationships between plant population, yield components and grain yield of wheat in a Mediterranean environment

1986 ◽  
Vol 37 (3) ◽  
pp. 219 ◽  
Author(s):  
WK Anderson
Keyword(s):  
Grain Yield ◽  
Yield Components ◽  
Plant Density ◽  
Plant Population ◽  
Individual Plant ◽  
Spring Bread Wheat ◽  
Grain Yields ◽  
Optimum Population ◽  
Large Numbers ◽  
The Relationship

Eight spring bread wheat cultivars (Triticum aestivum L.), differing widely in their nominal yield component characteristics, were tested under rain-fed conditions for three years at sowing densities ranging from 50 to 800 seeds m-2. The objectives of the experiments were to estimate the relationship between grain yield and particular yield components, the expression of plant type (yield components) in relation to plant density, and the plant population x cultivar interaction for grain yield over a range of seasons in a given environment. The 'optimum' plant population (at maximum grain yield) varied over 30-220 plants m-2, depending on season and cultivar. In general, variation in the 'optimum' population was greater between seasons for a given cultivar than between cultivars within seasons. The relationship between grain yield and yield components was examined at the 'optimum' population rather than at an arbitrary population at which grain yield may have been suboptimal for some cultivars or seasons. Grain yields at the optimum populations for the various cultivar x season combinations were positively related to culms m-2, spikes m-2 and seeds m-2. They were not clearly related to culm mortality (%). When averaged across seasons, cultivar grain yields were positively related to harvest index, but the general relationship was not so clear when seasons and cultivars were examined individually. Spike size (seeds spike-I or spike weight) and seed size were also not clearly related to grain yield at the 'optimum' population, and it was thus postulated that the production and survival of large numbers of culms, which in turn led to large numbers of seeds per unit area, were the source of large grain yields. Some interactions were found between yield components and plant population for some cultivars that could have implications for plant breeders selecting at low plant densities. The implications for crop ideotypes of the individual plant characters at the 'optimum' population are also discussed. Interactions between cultivars and plant populations implied that some cultivars required different populations to achieve maximum yields in some seasons. There was a tendency for larger yields to be achieved from cultivar x season combinations where the optimum population was larger, which suggested that commercial seed rates should be re-examined when changes to plant types or yield levels are made.

scholarly journals Yield performance of oat cultivars in response to sowing dates and densities

2021 ◽  
Vol 42 (5) ◽  
pp. 2785-2800
Author(s):  
José Henrique Bizzarri Bazzo ◽  
◽  
Klever Márcio Antunes Arruda ◽  
Inês Cristina de Batista Fonseca ◽  
Claudemir Zucareli ◽  
...  
Keyword(s):  
Grain Yield ◽  
Yield Components ◽  
Block Design ◽  
Growing Season ◽  
Sowing Date ◽  
Yield Performance ◽  
Sowing Dates ◽  
Panicle Number ◽  
Oat Cultivars ◽  
Viable Seeds

Adjustment of seeding density oriented by genotype and conditions of the growing environment may favor growth, development and yield performance of the oat crop. This study aimed to evaluate the growth, lodging, yield components, and grain yield of oat cultivars grown at different sowing dates and densities. Two independent experiments were conducted at two sowing dates (May 5 and June 24) in Londrina-PR under a randomized block design in a 4 × 2 factorial scheme, with four replications. Treatments consisted of four sowing densities (180, 240, 300, and 360 viable seeds m−2) and two cultivars (IPR Afrodite and IPR Artemis). Plant height, number of panicles.m−2, number of spikelets per panicle, number of grains per spikelet, number of grains per panicle, thousand-grain weight, plant lodging, and grain yield were evaluated. The data were submitted to the analysis of joint variance for sowing dates, separately for the cultivars. The averages of sowing dates were compared by the F test and densities submitted to polynomial regression analysis up to 2nd degree, at 5% probability. The first sowing date favors most yield components and grain yield of the cultivars IPR Afrodite and IPR Artemis. In contrast, the number of panicles m−2 was reduced during this growing season for both cultivars. The late sowing date for the IPR Artemis cultivar resulted in a high percentage of lodging at all evaluated densities. However, this phenomenon is more intense at higher sowing densities during the first sowing date. Yield components and grain yield varied according to sowing dates and densities and the cultivar. The highest grain yield of the cultivar IPR Afrodite at the first sowing date was achieved with a lower sowing density than in the later date. However, the highest grain yield of the IPR Artemis cultivar was achieved at density of 280 viable seeds m−2, regardless of the growing season.

scholarly journals Rattail fescue (Vulpia myuros) interference and seed production as affected by sowing time and crop density in winter wheat

Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Seed Production ◽  
Yield Components ◽  
Field Experiments ◽  
Growing Season ◽  
Sowing Time ◽  
Growing Seasons ◽  
Crop Density ◽  
Wide Range

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.

Effects of Plant Population on Sole-crop Cassava in Sierra Leone

1978 ◽  
Vol 14 (3) ◽  
pp. 239-244 ◽  
Author(s):  
W. Godfrey-Sam-Aggrey
Keyword(s):  
Sierra Leone ◽  
Yield Components ◽  
Dry Matter ◽  
Weight Ratio ◽  
Land Plant ◽  
Plant Population ◽  
Root Weight ◽  
Plant Populations ◽  
Sole Crop ◽  
Yield And Yield Components

SUMMARYEffects of plant population on mean yield and yield components of 2-year sole cassava crops were studied on Njala upland soils of Sierra Leone in two experiments. Increasing plant population of multi-shoot Cocoa cassava over 7000/ha decreased all the parameters studied except top/root weight ratio, which increased. The observed effects were attributed to competition for environmental resources, since area of land/plant unit decreased as plant population increased. The relations between plant populations and yields of fresh root and cortex dry matter were asymptotic, indicating that the respective yields were products of the vegetative phase of cropping.

scholarly journals Increasing population density reduces soybean yield components and productivity

2021 ◽  
Vol 37 ◽  
pp. e37042
Author(s):  
Marcelo De Almeida Silva ◽  
Ana Carolina De Santana Soares ◽  
Melina Rodrigues Alves Carnietto ◽  
Alexandrius De Moraes Barbosa
Keyword(s):  
Grain Yield ◽  
Yield Components ◽  
Spatial Arrangement ◽  
Plant Population ◽  
Row Spacing ◽  
Individual Plant ◽  
Growth Type ◽  
Soybean Yield ◽  
Plant Densities ◽  
Plant Yields

Studies addressing the interaction of different spatial arrangement in soybean are needed in order to achieve management that leads to higher grain yield associated with rational seed use. The objective of this work was to evaluate the yield components and productivity of an undetermined growth type soybean as a function of different row spacing and plant densities. The treatments consisted of three row spaces (0.25, 0.35 and 0.45 m) and three plant population densities (30, 40 and 50 plants/m²). There was no interaction of row spaces and plant population on soybean yield. Regarding the overall spacing average, the grain yield of the population of 30/m² plants was higher than the productivity of the populations of 40 and 50/m² plants. The largest populations reduce plant sizes due to greater competition between plants. In addition, smaller populations promote higher individual plant yields due to the increase components of the production. This characteristic is defined as the ability of the plant to change its morphology and yield components in order to adapt to the conditions imposed by the spatial arrangement.

scholarly journals Grain Yield and Yield Components of Quality Protein Maize Genotypes as Influenced by Irrigation and Plant Population in the Nigerian Savannah

2014 ◽  
Vol 6 (4) ◽  
pp. 166 ◽  
Author(s):  
B. M. Sani ◽  
I. U. Abubakar ◽  
A. M. Falaki ◽  
H. Mani ◽  
M. M. Jaliya
Keyword(s):  
Grain Yield ◽  
Yield Components ◽  
Agricultural Research ◽  
Field Trials ◽  
Irrigation Scheduling ◽  
Plant Population ◽  
Growth And Yield ◽  
Quality Protein Maize ◽  
Research Station ◽  
Yield And Yield Components

An experiment was conducted to assess the yield and yield components of QPM genotypes to plant population under irrigated conditions in a semi arid ecology of Northern Nigeria. Field trials were conducted at the Irrigation Research Station, Institute for Agricultural Research, Kadawa (11° 39'N, 08° 20'E) and 500 m above sea level) during dry seasons 2007, 2008 and 2009 to study the effect of (Zea mays L.) genotypes (TZE-W Pop X 1368, EV-DT W99 STR and DMR-ESRW), four plant population (33333, 44444, 55555 and 66666 plants ha-1) and three irrigation scheduling (40, 60 and 80 centibars soil moisture tension) on the growth and yield of quality protein maize. A split plot design was used with combinations of genotypes and irrigation regimes assigned to the main plot and plant population assigned to the sub-plot. The treatments were replicated three times. The study revealed that genotype EV-DT W99 STR had significantly higher weight of ears per plant, cob length, cob diameter, number of rows per cob, 100 grain weight, grain yield, shelling percentage and harvest index than the other two genotypes used in the trial. Irrigating at 40 and 60 centibars significantly increased weight of ears per plant, while delayed irrigation significantly depressed total dry matter production. Based on the results obtained in this study, it can be concluded that the use of genotype EV-DT W99 STR, at 60 centibars irrigation scheduling and population of 55,555 plants ha-1 had resulted in good agro-physiological characters of QPM at Kadawa.

Production and survival of tillers of wheat and their contribution to yield

1974 ◽  
Vol 83 (1) ◽  
pp. 117-124 ◽  
Author(s):  
H. M. Ishag ◽  
M. B. Taha
Keyword(s):  
Grain Yield ◽  
Air Temperature ◽  
High Mortality ◽  
Growth Period ◽  
Dry Weight ◽  
Growing Season ◽  
Sowing Date ◽  
Wheat Cultivars ◽  
Nitrogen Application ◽  
True Leaf

SUMMARYThe effect of sowing date and nitrogen on tillering patterns, survival and contribution of reproductive tillers to grain yield of standard and Mexican wheat cultivars were studied for two seasons.Maximum number of tillers/plant, 3·2–4·5, was observed after 40 and 27 days from sowing for 1970–1 and 1971–2 respectively. The number of ears/plant was 1·4 at the end of the growing season. Varieties differed in tillering, and LRN10 and Giza 155 produced more reproductive tillers than Falchetto and Mexipak. Nitrogen application increased tillering efficiency, i.e. ratio of fertile to total tillers produced. Only 26% of tillers appearing in the axil of the first true leaf (T1) and 10% of tillers in the axil of the second true leaf (T2) survived to produce ears. The high mortality of tillers was attributed to high air temperature prevailing during the growth period (33 °C by day; 18 °C by night). Eared tillers did not die and were self supporting because of the photosynthesis by the ear.Grain weight/tiller was positively correlated with tiller dry weight at heading, r= 0·76–0·96. Main shoots contributed about 81% of the total grain yield and 19% came from T1 and T2 tillers.

scholarly journals Maize Yield Components as Affected by Plant Population, Planting Date and Soil Coverings in Brazil

Agriculture ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 579
Author(s):  
Gustavo Castilho Beruski ◽  
Luis Miguel Schiebelbein ◽  
André Belmont Pereira
Keyword(s):  
Yield Components ◽  
Management Practices ◽  
Field Experiments ◽  
Plant Density ◽  
Bare Soil ◽  
Plant Population ◽  
Positive Trend ◽  
Plant Populations ◽  
Potential Yield ◽  
Final Yield

The potential yield of annual crops is affected by management practices and water and energy availabilities throughout the crop season. The current work aimed to assess the effects of plant population, planting dates and soil covering on yield components of maize. Field experiments were carried out during the 2014–2015 and 2015–2016 growing seasons at areas grown with oat straw, voluntary plants and bare soil, considering five plant populations (40,000, 60,000, 80,000, 100,000 and 120,000 plants ha−1) and three sowing dates (15 September, 30 October and 15 December) for the hybrid P30F53YH in Ponta Grossa, State of Paraná, Brazil. Non-impacts of soil covering or plant population on plant height at the flowering phenological stage were observed. Significant effects of soil covering on yield components and final yield responses throughout the 2014–2015 season were detected. An influence of plant populations on yield components was evidenced, suggesting that, from 80,000 plants ha−1, the P30F53YH hybrid performs a compensatory effect among assessed yield components in such a way as to not compromise productivity insofar as the plant population increases up to 120,000 plants ha−1. It was noticed, a positive trend of yield components and crop final yield as a function of plant density increments.

scholarly journals Adaptability Of Wheat Varieties In Strongly Acidic Soils Of Sylhet

2013 ◽  
Vol 38 (1) ◽  
pp. 97-104 ◽  
Author(s):  
M Ataur Rahman ◽  
NCD Barma ◽  
MH Sarker ◽  
MMR Sarker ◽  
MMI Nazrul
Keyword(s):  
Grain Yield ◽  
Yield Components ◽  
Wheat Variety ◽  
Growing Season ◽  
Low Ph ◽  
Soil Conditions ◽  
Acidic Soils ◽  
Wheat Varieties ◽  
Experimental Soil ◽  
Plot Design

A field trail was carried out at South-Surma, Sylhet, in 2009-10 and at FSRD site Jalalpur, Sylhet in 2010-11 in collaboration with WRC and OFRD, BARI to examine the response of 7 wheat varieties at two levels of lime in split-plot design where lime was applied in main plots and different wheat varieties were grown in sub-plots. The seeds were sown on 05 December 2009 and 30 November 2010 for the growing season of 2009-10 and 2010-11, respectively. The wheat varieties used in this study were Shatabdi, Sufi, Sourav, Bijoy, Prodip, BARI Gom-25 and BARI Gom-26. The index of relative performance of each variety in comparison to mean yield of all varieties under the contrast conditions of liming and non-liming was estimated to determine relative adaptability of wheat variety under experimental soil conditions. The result indicated that most of the yield components viz., spikes/m2, 100-grain weight, and grain yield of wheat were significantly improved by liming for both the years and locations. There were variations in lime response among the wheat varieties. The index of relative adaptability (IRA %) for yield of BARI Gom-26 and Bijoy was more than 100% for both the years. The results indicated that these two wheat varieties are relatively tolerant to low pH and could be adapted in acidic soil of Sylhet. Bangladesh J. Agril. Res. 38(1): 97-104, March 2013 DOI: http://dx.doi.org/10.3329/bjar.v38i1.15194

Companion crop performance in the absence and presence of agronomic manipulation

2007 ◽  
Vol 58 (7) ◽  
pp. 690 ◽  
Author(s):  
R. H. Harris ◽  
J. R. Hirth ◽  
M. C. Crawford ◽  
W. D. Bellotti ◽  
M. B. Peoples ◽  
...  
Keyword(s):  
Grain Yield ◽  
New South ◽  
Growing Season ◽  
Plant Populations ◽  
Grain Yields ◽  
South Wales ◽  
Cereal Grain ◽  
Crop Type ◽  
Biomass N ◽  
Crop Types

A field experiment located in southern New South Wales compared the component yields of cereal–lucerne companion crops (cereals sown into established lucerne) with the yields of cereal and lucerne monocultures. In-crop lucerne herbicide suppression, cereal crop types (wheat and barley), and top-dressed nitrogen (N) were evaluated for the potential to improve cereal production in the presence of lucerne. Plant populations and biomass, cereal grain yields, and grain quality (protein, screenings, and contamination) were measured. Over the 3-year study, cereals sown into established lucerne (4 years of age at the commencement of the experiment) yielded 17% less (P < 0.05) grain than the cereal monoculture. Companion cropping also resulted in a 71% reduction (P < 0.05) in lucerne biomass over the growing season compared with the lucerne monoculture, but a 3-fold (P < 0.05) increase in total (cereal and lucerne) biomass production. There were no differences between wheat and barley crops in the presence of lucerne, although extensive lodging in the 2003-barley monoculture did result in a significant main treatment (+/0 lucerne and +/0 in-crop lucerne suppression) × crop type (wheat and barley) interaction in grain yield, but not cereal biomass. N top-dressed after tillering onto cereal–lucerne companion crops did not increase grain yield, although it did increase cereal biomass in 2003. Whilst in-crop lucerne suppression did not increase cereal grain yields, it did increase (P < 0.05) cereal biomass and reduced lucerne biomass at cereal maturity and contamination (lucerne pods and flowers) of the cereal grain. However, this practice reduced (P < 0.05) lucerne populations, and therefore potentially threatens the longer term viability of lucerne stands so more research is recommended to develop less detrimental strategies for achieving effective in-crop lucerne suppression. This study combined with results from others, suggests that rainfall was a major factor determining cereal responses in the presence of lucerne, and although there were responses in cereal biomass to additional N and herbicide suppression, these strategies appear to only have potential under favourable growing-season conditions.

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