scholarly journals Variability of optimum sowing time for wheat yield in Western Australia

2008 ◽  
Vol 59 (10) ◽  
pp. 958 ◽  
Author(s):  
D. L. Sharma ◽  
M. F. D'Antuono ◽  
W. K. Anderson ◽  
B. J. Shackley ◽  
C. M. Zaicou-Kunesch ◽  
...  
Keyword(s):  
Grain Yield ◽  
Western Australia ◽  
Wheat Yield ◽  
Regression Tree ◽  
Triticum Aestivum L ◽  
Yield Component ◽  
Yield Potential ◽  
Annual Rainfall ◽  
Optimum Time ◽  
Sowing Time

Sowing wheat (Triticum aestivum L.) at the right time is one of the most important means of maximising grain yield in dryland agriculture. Objectives of this study were to understand the variation in estimates of optimum sowing time as influenced by cultivar and environmental characteristics, and to assess the relative importance of location, season, sowing time, and cultivar factors in maximising grain yield in Western Australia. Twenty-seven cultivar × time of sowing experiments were conducted over three seasons (2003–05) at a range of locations (annual rainfall 300–450 mm, lat. 28–35°S). There were four types of cultivar × sowing time responses, namely, quadratic, linear declining, flat, and linear increasing, associated with opening rains before mid-May, opening rains after mid-May, low-yielding sites, and good spring rains, respectively. Regression-tree analysis revealed that differences among cultivars in Tmax (sowing time when maximum grain yield was achieved) were much less in the eastern sites (mostly drier seasons). A biplot differentiated cultivars for Tmax across the range of environments used, while the subset regression analysis specifically indicated an association of average temperature and growing-season rainfall with variation for Tmax of individual cultivars. The yield penalty for sowing before the optimum time in quadratic-type responses was clearly greater for shorter season cultivars but no clear relationship was apparent between maturity class of cultivars and the penalty for late sowing, possibly due to differential plasticity of cultivars for grain weight under harsh finishing conditions. The duration of the optimum sowing window at a given location was inversely proportional to the yield potential, implying that it is critical to sow at or close to the optimum time when the yield potential is high, most common when the season breaks early. Yield component analysis showed that the relative change in grain yield over sowing dates was significantly correlated with relative changes in grain numbers/m2 in the late May sowings but other yield components were also important in the early May experiments. Sowing time accounted for 10% of grain yield variation compared with cultivar (1%), while the rest was due to uncontrollable factors of location and season.

scholarly journals Yield component variation in winter wheat grown under drought stress

2000 ◽  
Vol 80 (4) ◽  
pp. 739-745 ◽  
Author(s):  
B. L. Duggan ◽  
D. R. Domitruk ◽  
D. B. Fowler
Keyword(s):  
Drought Stress ◽  
Winter Wheat ◽  
Grain Yield ◽  
Triticum Aestivum L ◽  
Yield Component ◽  
Yield Potential ◽  
High Yield ◽  
Crop Water ◽  
Kernel Number ◽  
High Yield Potential

Crops produced in the semiarid environment of western Canada are subjected to variable and unpredictable periods of drought stress. The objective of this study was to determine the inter-relationships among yield components and grain yield of winter wheat (Triticum aestivum L) so that guidelines could be established for the production of cultivars with high yield potential and stability. Five hard red winter wheat genotypes were grown in 15 field trials conducted throughout Saskatchewan from 1989–1991. Although this study included genotypes with widely different yield potential and yield component arrangements, only small differences in grain yield occurred within trials under dryland conditions. High kernel number, through greater tillering, was shown to be an adaptation to low-stress conditions. The ability of winter wheat to produce large numbers of tillers was evident in the spring in all trials; however, this early season potential was not maintained due to extensive tiller die-back. Tiller die-back often meant that high yield potential genotypes became sink limiting with reduced ability to respond to subsequent improvements in growing season weather conditions. As tiller number increased under more favourable crop water conditions genetic limits in kernels spike−1 became more identified with yield potential. It is likely then, that tillering capacity per se is less important in winter wheat than the development of vigorous tillers with numerous large kernels spike−1. For example, the highest yielding genotype under dryland conditions was a breeding line, S86-808, which was able to maintain a greater sink capacity as a result of a higher number of larger kernels spike−1. It appears that without yield component compensation, a cultivar can be unresponsive to improved crop water conditions (stable) or it can have a high mean yield, but it cannot possess both characteristics. Key words: Triticum aestivum L., wheat, drought stress, kernel weight, kernel number, spike density, grain yield

Yield improvement and associated characteristics of some Australian spring wheat cultivars introduced between 1860 and 1982

1989 ◽  
Vol 40 (3) ◽  
pp. 457 ◽  
Author(s):  
MW Perry ◽  
MF D'Antuono
Keyword(s):  
Grain Yield ◽  
Western Australia ◽  
Harvest Index ◽  
Triticum Aestivum L ◽  
Field Trials ◽  
Grain Weight ◽  
Yield Potential ◽  
Rate Of Increase ◽  
Australian Wheat ◽  
1000 Grain Weight

Twenty-eight Australian wheat (Triticum aestivum L. em. Thell.) cultivars representing a series from the 1860s to 1982, were grown in 20 field trials over four years in the wheatbelt of Western Australia. The cultivars included introductions and selections made before 1900, plus important cultivars bred or grown in Western Australia up to 1982. Five of the latter group were from crosses including semidwarf cultivars as parents. Grain yields were measured on all trials, and six trials were also sampled for biomass and yield components.Based on the regression of mean grain yield versus the number of years elapsed since 1884, yields have increased from 1022 kg ha-1 in 1884 to 1588 kg ha-1 in 1982. This represents a rate of increase of 5.8 kg ha-1 year-1 or 0.57% per year. Regression of cultivar yield on site mean yield gave values of b, the slope of the regression, from 0.66 to 1.24, and these were higher for modern than for old cultivars.In six trials sampled for yield components, above-ground biomass appeared to have increased slightly when comparing early selections and their derivatives with later cultivars, but over 80% of the overall increase in grain yield was due to increase in harvest index. Grains per car and grains m-2 were strongly and positively correlated with grain yield, but there were weak negative correlations between 1000-grain weight and yield, and between 1000 grain weight and years since 1884. Cultivars with a semi-dwarf background had equal biomass, but higher yield, harvest index, ear number m-2 and grains ear-2 than modern tall cultivars. The results show that genetic improvement has substantially increased yield potential in this environment and that this has been achieved through substantial increases in grain number m-2 associated with an improvement in harvest index.

PERFORMANCE OF CROSSES BETWEEN STANDARD-HEIGHT AND SEMIDWARF SPRING WHEATS

1976 ◽  
Vol 56 (3) ◽  
pp. 475-480 ◽  
Author(s):  
F. H. McNEAL ◽  
E. P. SMITH ◽  
M. A. BERG ◽  
D. E. BALDRIDGE
Keyword(s):  
Triticum Aestivum ◽  
Grain Yield ◽  
Correlation Coefficients ◽  
Triticum Aestivum L ◽  
Kernel Weight ◽  
Yield Component ◽  
Yield Potential ◽  
Yield Data ◽  
Average Performance

Three semidwarf wheat (Triticum aestivum L.) cultivars were each crossed to three standard-height cultivars, and bulk F2 and F3 generations of each cross were compared with parents in the field at two locations. Yield component and grain yield data of parents vs. bulks were evaluated to determine whether a relationship existed between bulk and parent populations. Yield component data did not consistently relate to grain yield in either bulks or parents. However, correlation coefficients of 0.89 and 0.81 suggested a strong yield relationship between standard-height parents vs. their bulks and semidwarf parents vs. their bulks, respectively. We conclude that the average performance of the parents generally predicted the average performance of the F2 and F3 bulks for culm number, kernel weight, and grain yield. Heterosis was indicated for spikelets per head in crosses with P.I. 295619. There were no differences between semidwarf and standard-height cultivars in ability to impart yield component and grain yield potential to their offspring.

The effects of soil type and seasonal rainfall on the optimum seed rate for wheat in Western Australia

2004 ◽  
Vol 44 (6) ◽  
pp. 585 ◽  
Author(s):  
R. Del Cima ◽  
M. F. D'Antuono ◽  
W. K. Anderson
Keyword(s):  
Grain Yield ◽  
Western Australia ◽  
Soil Type ◽  
Regression Tree ◽  
Seasonal Rainfall ◽  
Response Patterns ◽  
Seeding Rate ◽  
Sowing Time ◽  
Seed Rate ◽  
Major Factors

Seventeen experiments were conducted in 1996, 1997 and 1998 in the central and northern wheatbelt of Western Australia, covering a range of soil types, seasonal rainfall, cultivars and sowing times. The objective of the experiments was to investigate how these factors affect the range of optimum seed rates derived from seeding rate experiments and, thus, to improve advice to farmers. Our results suggest that soil type and seasonal rainfall were the major factors influencing the differences in optimum seed rate. Regression tree methods were used to show that experiments in clay loam soils had higher optimum seed rates (52–76 kg/ha, depending on the cultivars used). In sandier soils, the optimum seed rate was lower (35–60 kg/ha, depending on cultivar and sowing time) but higher (67�kg/ha) at higher seasonal rainfall (>450 mm). We found some cultivars were grouped into consistent response patterns. Sowing time also influenced optimum seed rate; later sowing required higher seed rates, to maximise grain yield. A positive correlation was not observed between grain yield and optimum seed rate, possibly due to the narrow range of yields recorded in the experiments. Our data showed that the percentage of establishment fell off rapidly at higher seed rates. This implies that lower establishment percentages should be used when calculating the seed rates required to produce high plant populations in the field.

scholarly journals Seeding Rate Effects on Hybrid Spring Wheat Yield, Yield Components and Quality

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1240
Author(s):  
Peder K. Schmitz ◽  
Joel K. Ransom
Keyword(s):  
Spring Wheat ◽  
Yield Components ◽  
Wheat Yield ◽  
Triticum Aestivum L ◽  
Yield Component ◽  
Economic Feasibility ◽  
Protein Yield ◽  
Seeding Rate ◽  
Hard Red Spring Wheat ◽  
End Use

Agronomic practices, such as planting date, seeding rate, and genotype, commonly influence hard red spring wheat (HRSW, Triticum aestivum L. emend. Thell.) production. Determining the agronomic optimum seeding rate (AOSR) of newly developed hybrids is needed as they respond to seeding rates differently from inbred cultivars. The objectives of this research were to determine the AOSR of new HRSW hybrids, how seeding rate alters their various yield components, and whether hybrids offer increased end-use quality, compared to conventional cultivars. The performance of two cultivars (inbreds) and five hybrids was evaluated in nine North Dakota environments at five seeding rates in 2019−2020. Responses to seeding rate for yield and protein yield differed among the genotypes. The AOSR ranged from 3.60 to 5.19 million seeds ha−1 and 2.22 to 3.89 million seeds ha−1 for yield and protein yield, respectively. The average AOSR for yield for the hybrids was similar to that of conventional cultivars. However, the maximum protein yield of the hybrids was achieved at 0.50 million seeds ha−1 less than that of the cultivars tested. The yield component that explained the greatest proportion of differences in yield as seeding rates varied was kernels spike−1 (r = 0.17 to 0.43). The end-use quality of the hybrids tested was not superior to that of the conventional cultivars, indicating that yield will likely be the determinant of the economic feasibility of any future released hybrids.

Growth and yield studies of Lupinus angustifolius and L. albus in Victoria

1982 ◽  
Vol 22 (115) ◽  
pp. 76 ◽  
Author(s):  
KA Boundy ◽  
TG Reeves ◽  
HD Brooke
Keyword(s):  
Grain Yield ◽  
Leaf Area ◽  
Dry Matter ◽  
Yield Component ◽  
Early Flowering ◽  
Growth And Yield ◽  
Dry Matter Production ◽  
Sowing Time ◽  
Dry Matter Partitioning ◽  
Matter Production

The effect of serial planting on dry matter production, leaf area, grain yield and yield components cf Lupinus angustifoiius (cvv. Uniwhite, Uniharvest and Unicrop) and L. albus (cv. Ultra) was investigated in field plots at Rutherglen in 1973 and 1974. Delayed planting reduced dry matter production of all cultivars, and leaf area for Ultra. Differences in dry matter partitioning were observed between the late flowering Uniharvest, and the early flowering Unicrop and Ultra. In Uniharvest, delayed plantings resulted in a greater proportion of total dry matter being produced during the flowering phase, whereas the reverse was true for Unicrop and Ultra. The later flowering cultivars showed marked grain yield and yield component reduction with later sowing. Yields were reduced by 160.6 kg/ha and 222.5 kg/ha for each week's delay in sowing Uniharvest and Uniwhite, respectively. This effect was offset in the early flowering cultivars by greater development of lateral branches. In addition, when Unicrop and Ultra were planted in April, pod and flower abortion on the main stem resulted from low temperatures at flowering time. Optimum sowing time was early April for Uniwhite and Uniharvest, and early May for Unicrop and Ultra. Excellent vegetative growth under ideal moisture conditions highlighted the poor harvest indices of lupins and the scope for genetic improvement in the genus.

Wheat for fodder and grain on the Northern Tablelands of New South Wales

1995 ◽  
Vol 35 (1) ◽  
pp. 93 ◽  
Author(s):  
RD FitzGerald ◽  
ML Curll ◽  
EW Heap
Keyword(s):  
Grain Yield ◽  
New South ◽  
New South Wales ◽  
Annual Rainfall ◽  
Sowing Time ◽  
Wheat Varieties ◽  
Dual Purpose ◽  
Grain Yields ◽  
High Rainfall ◽  
South Wales

Thirty varieties of wheat originating from Australia, UK, USA, Ukraine, and France were evaluated over 3 years as dual-purpose wheats for the high rainfall environment of the Northern Tablelands of New South Wales (mean annual rainfall 851 mm). Mean grain yields (1.9-4.3 t/ha) compared favourably with record yields in the traditional Australian wheatbelt, but were much poorer than average yields of 6.5 t/ha reported for UK crops. A 6-week delay in sowing time halved grain yield in 1983; cutting in spring reduced yield by 40% in 1986. Grazing during winter did not significantly reduce yields. Results indicate that the development of wheat varieties adapted to the higher rainfall tablelands and suited to Australian marketing requirements might help to provide a useful alternative enterprise for tableland livestock producers.

Influence of planting date and environment on Oklahoma wheat grain yield trend from 1963 to 1995

1998 ◽  
Vol 78 (1) ◽  
pp. 71-77 ◽  
Author(s):  
F. M. Epplin ◽  
T. F. Peeper
Keyword(s):  
Grain Yield ◽  
Linear Trend ◽  
Moving Average ◽  
Wheat Yield ◽  
Triticum Aestivum L ◽  
Planting Date ◽  
Wheat Grain ◽  
Explanatory Variables ◽  
The Past ◽  
Key Words Wheat

The five-year moving average (5YRMA) wheat (Triticum aestivum L.) grain yield per harvested hectare has declined by more than 18% over the past decade in Oklahoma. By contrast, world wheat yields have increased steadily over the same period. The Oklahoma wheat yield trend during the past decade is inconsistent with expectations. The objective of the research was to determine why the 5YRMA wheat grain yield per harvested hectare did not increase in Oklahoma during the past decade. Five types of potential explanatory variables were investigated: structural change (including government programs), fertilizer use, proportion grazed, planting date and environment. Regression analysis was used to determine that the consequences of improvements in technology, research and education programs, as measured by a linear trend variable, were positive. However, during the past decade, these advancements were overwhelmed by changes in planting date and environmental factors. Key words: Wheat, yield, trend, planting date, environment

Influence of genotype, sowing date, and seeding rate on wheat development and yield

1993 ◽  
Vol 33 (6) ◽  
pp. 751 ◽  
Author(s):  
DR Coventry ◽  
TG Reeves ◽  
HD Brooke ◽  
DK Cann
Keyword(s):  
Grain Yield ◽  
Sowing Date ◽  
Triticum Aestivum L ◽  
Climatic Conditions ◽  
Wheat Cultivars ◽  
Seeding Rate ◽  
Sowing Time ◽  
Spike Density ◽  
Early Maturity ◽  
North Eastern

A 3-year study was conducted to measure the effect of sowing time and seeding rate on the development and yield of wheat (Triticum aestivum L.) grown under high-yielding conditions in north-eastern Victoria. A range of wheat cultivars with different development responses, including 'winter' types, was used in 2 experiments in each season. High grain yields for dryland wheat were measured in the first 2 seasons (1985-86), and in 1985, near-optimal water use efficiencies (>18 kg/ha. mm effective rainfall) were obtained. In the third season (1987) grain yield was limited by adverse climatic conditions-in the me- and post-anthesis period. In each season, grain yield declined with delay in sowing time. In 1985 there was a loss of 200-250 kg grain/ha for each week's delay in sowing time. In 1987, yield loss with delayed sowing was 50-110 kg grain/ha. In each season, cultivars with late or midseason maturity development gave the highest mean yields, and the use of these maturity types allowed earlier sowing, in mid April. However, with late sowing of wheat there was a trend for early maturity types to give higher yields, and so the use of 2 wheat cultivars with distinct maturity development responses to climate is recommended. If only 1 wheat cultivar is to be used, then a late maturity type is recommended. Higher wheat yields were also obtained as spike density increased, as a result of higher seeding rates. Our data suggest that in the higher rainfall region of north-eastern Victoria, a spike density of about 500 spikes/m2 is required to optimise wheat yields.

Estimates of relative yield potential and genetic improvement of wheat cultivars in the Mediterranean region

2009 ◽  
Vol 147 (3) ◽  
pp. 323-332 ◽  
Author(s):  
O. SENER ◽  
M. ARSLAN ◽  
Y. SOYSAL ◽  
M. ERAYMAN
Keyword(s):  
Grain Yield ◽  
Bread Wheat ◽  
Genetic Improvement ◽  
Mediterranean Region ◽  
Block Design ◽  
Wheat Yield ◽  
Relative Yield ◽  
Yield Potential ◽  
Wheat Cultivars ◽  
The Mediterranean

SUMMARYInformation about changes associated with advances in crop productivity is essential for understanding yield-limiting factors and developing new strategies for future breeding programmes. National bread wheat (Triticum aestivum L.) yields in Turkey have risen by an average of 20·8 kg/ha/year from 1925 to 2006. Annual gain in yield attributable to agronomic and genetic improvement averaged c. 11·6 kg/ha/year prior to 1975, but is now averaging c. 15·1 kg/ha/year. In the Mediterranean region, however, the wheat yield trend line (10·9 kg/ha/year) is c. 0·38 lower than that of Turkey. In order to understand whether such a trend was due to the cultivars released over the years, 16 bread wheat cultivars, commonly grown in the region and representing 23 years of breeding, introduction and selection (from 1976 to 1999), were grown in a randomized complete block design with three replicates across 2 years. Data were collected on maturation time, plant height, spike length, spikelet number/spike, grain number/spike, grain weight/spike, 1000 seed weight, harvest index and grain yield. None of the measured plant traits showed any historical cultivar patterns; therefore, the increase in grain yield could not be attributed to a single yield component. Several physiological traits changed during two decades of cultivar releases in the Mediterranean region that led to a genetic gain in grain yield of about 0·5% per year. Years of data and the present field study in the Mediterranean region suggested that the genetic improvement in wheat seemed inadequate and should be reinforced with modern agricultural management practices as well as technological innovations.

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