Wheat yield response to nitrogen from the perspective of intraspecific competition

Multivariate random-effects meta-analyses were conducted on 12 years of data from 14 U.S. states to determine the mean yield and test-weight responses of wheat to treatment with propiconazole, prothioconazole, tebuconazole, metconazole, and prothioconazole+tebuconazole. All fungicides led to a significant increase in mean yield and test weight relative to the check (D; P < 0.001). Metconazole resulted in the highest overall yield increase, with a D of 450 kg/ha, followed by prothioconazole+tebuconazole (444.5 kg/ha), prothioconazole (419.1 kg/ha), tebuconazole (272.6 kg/ha), and propiconazole (199.6 kg/ha). Metconazole, prothioconazole+tebuconazole, and prothioconazole also resulted in the highest increases in test weight, with D values of 17.4 to 19.4 kg/m3, respectively. On a relative scale, the best three fungicides resulted in an overall 13.8 to 15.0% increase in yield but only a 2.5 to 2.8% increase in test weight. Except for prothioconazole+tebuconazole, wheat type significantly affected the yield response to treatment; depending on the fungicide, D was 110.0 to 163.7 kg/ha higher in spring than in soft-red winter wheat. Fusarium head blight (FHB) disease index (field or plot-level severity) in the untreated check plots, a measure of the risk of disease development in a study, had a significant effect on the yield response to treatment, in that D increased with increasing FHB index. The probability was estimated that fungicide treatment in a randomly selected study will result in a positive yield increase (p+) and increases of at least 250 and 500 kg/ha (p250 and p500, respectively). For the three most effective fungicide treatments (metconazole, prothioconazole+tebuconazole, and prothioconazole) at the higher selected FHB index, p+ was very large (e.g., ≥0.99 for both wheat types) but p500 was considerably lower (e.g., 0.78 to 0.92 for spring and 0.54 to 0.68 for soft-red winter wheat); at the lower FHB index, p500 for the same three fungicides was 0.34 to 0.36 for spring and only 0.09 to 0.23 for soft-red winter wheat.

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Post-anthesis sink size in a high-yielding dwarf wheat: yield response to grain number

Australian Journal of Agricultural Research ◽

10.1071/ar9770165 ◽

1977 ◽

Vol 28 (2) ◽

pp. 165 ◽

Cited By ~ 36

Author(s):

RA Fischer ◽

I Aguilar ◽

DR Laing

Keyword(s):

Grain Yield ◽

Wheat Yield ◽

Kernel Weight ◽

Yield Response ◽

High Fertility ◽

Grain Number ◽

Wide Range ◽

Carbon Dioxide Fertilization ◽

Sink Size ◽

The One

Experiments to study the effect of grain number per sq metre on kernel weight and grain yield in a high-yielding dwarf spring wheat (Triticum aestivum cv. Yecora 70) were conducted in three seasons (1971–1973) under high-fertility irrigated conditions in north-western Mexico. Crop thinning, shading and carbon dioxide fertilization (reported elsewhere), and crowding treatments, all carried out at or before anthesis, led to a wide range in grain numbers (4000 to 34,000/m2). Results indicated the response of grain yield to changing sink size (grains per sq metre), with the post-anthesis environment identical for all crops each year, and with all but the thinner crops intercepting most of the post-anthesis solar radiation. Kernel weight fell linearly with increase in grain number over the whole range of grain numbers studied, but the rate of fall varied with the season. Grain yield, however, increased, reaching a maximum at grain numbers well above those of crops grown with optimal agronomic management but without manipulation. It was concluded that the grain yield in normal crops was limited by both sink and post-anthesis source. There was some doubt, however, as to the interpretation of results from crowded crops, because of likely artificial increases in crop respiration on the one hand, and on the other, in labile carbohydrate reserves in the crops at anthesis. Also deterioration in grain plumpness (hectolitre weight) complicates the simple inference that further gains in yield can come from increased grain numbers alone.

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The interaction between soil pH and phosphorus for wheat yield and the impact of lime-induced changes to soil aluminium and potassium

Soil Research ◽

10.1071/sr16274 ◽

2017 ◽

Vol 55 (4) ◽

pp. 341 ◽

Cited By ~ 7

Author(s):

Craig A. Scanlan ◽

Ross F. Brennan ◽

Mario F. D'Antuono ◽

Gavin A. Sarre

Keyword(s):

Grain Yield ◽

Soil Ph ◽

Field Experiments ◽

Wheat Yield ◽

Acid Soils ◽

Combined Effect ◽

Additive Effect ◽

Yield Response ◽

Response Curves ◽

The Impact

Interactions between soil pH and phosphorus (P) for plant growth have been widely reported; however, most studies have been based on pasture species, and the agronomic importance of this interaction for acid-tolerant wheat in soils with near-sufficient levels of fertility is unclear. We conducted field experiments with wheat at two sites with acid soils where lime treatments that had been applied in the 6 years preceding the experiments caused significant changes to soil pH, extractable aluminium (Al), soil nutrients and exchangeable cations. Soil pH(CaCl2) at 0–10cm was 4.7 without lime and 6.2 with lime at Merredin, and 4.7 without lime and 6.5 with lime at Wongan Hills. A significant lime×P interaction (P<0.05) for grain yield was observed at both sites. At Merredin, this interaction was negative, i.e. the combined effect of soil pH and P was less than their additive effect; the difference between the dose–response curves without lime and with lime was greatest at 0kgPha–1 and the curves converged at 32kgPha–1. At Wongan Hills, the interaction was positive (combined effect greater than the additive effect), and lime application reduced grain yield. The lime×P interactions observed are agronomically important because different fertiliser P levels were required to maximise grain yield. A lime-induced reduction in Al phytotoxicity was the dominant mechanism for this interaction at Merredin. The negative grain yield response to lime at Wongan Hills was attributed to a combination of marginal soil potassium (K) supply and lime-induced reduction in soil K availability.

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Yield response of restricted-tillering wheat to transient waterlogging on duplex soils

Australian Journal of Agricultural Research ◽

10.1071/ar03089 ◽

2003 ◽

Vol 54 (10) ◽

pp. 957 ◽

Cited By ~ 13

Author(s):

A. G. Condon ◽

F. Giunta

Keyword(s):

Grain Size ◽

Biomass Production ◽

Wheat Yield ◽

Relative Yield ◽

Field Trials ◽

Growth And Yield ◽

Yield Response ◽

South West ◽

Relative Extent ◽

Before And After

Transient waterlogging during winter and spring reduces wheat yield in many parts of southern Australia. Yield reductions from waterlogging are associated with reduced production and survival of tillers, fewer and smaller fertile tillers, and smaller grain size. Under favourable conditions, wheats that have the tiller-inhibition ('tin') gene produce a lower total number of tillers but a higher proportion of large, productive tillers and larger grains than wheats without this gene. These characteristics of restricted-tillering wheat may contribute to improved yield under transient waterlogging. We compared the growth and yield of the commercial variety Bodallin and 2 Bodallin backcross derivatives containing the 'tin' gene in 8 field trials grown on shallow, duplex soils in 1995 and 1996 at 3 locations in the south-west of Western Australia. Trials were sown at standard (1995) and standard and high (1996) seeding rates. Trial-mean yield ranged from 0.5 to 4.7 t/ha, depending on the occurrence and severity of waterlogging before anthesis and of soil water deficit before and after anthesis. Grain yield of the restricted-tillering (RT) lines averaged only c. 80% of Bodallin. At all sites and seeding rates the RT lines had fewer spikes per m2 (45% fewer, on average) but averaged 44% more grains per spike. In 1996 only, grain weight of the RT lines was 6% greater than of Bodallin. There was no evidence that the relative yield of the RT lines was greater at waterlogged sites than at other sites. Waterlogging reduced the number of fertile spikes of RT lines and of Bodallin to the same relative extent and differences in grains per spike and grain size had little effect on relative yields. Even though harvest index of the RT lines was slightly elevated in some environments, biomass production of the RT lines was low in all environments. We conclude that wheats with the 'tin' gene are unlikely to have a yield advantage under transient waterlogging unless their biomass production can match that of more freely tillering wheats.

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Wheat yield response to fertilisation: An investigation of a functional form

Developments in Plant Breeding - Wheat: Prospects for Global Improvement ◽

10.1007/978-94-011-4896-2_63 ◽

1997 ◽

pp. 485-490

Author(s):

A. Bayaner ◽

A. Erkus ◽

V. Uzunlu

Keyword(s):

Functional Form ◽

Wheat Yield ◽

Yield Response

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Wheat yield response to input and socioeconomic factors under changing climate: Evidence from rainfed environments of Pakistan

The Science of The Total Environment ◽

10.1016/j.scitotenv.2019.06.266 ◽

2019 ◽

Vol 688 ◽

pp. 1275-1285 ◽

Cited By ~ 15

Author(s):

Nasir Mahmood ◽

Muhammad Arshad ◽

Harald Kächele ◽

Hua Ma ◽

Ayat Ullah ◽

...

Keyword(s):

Socioeconomic Factors ◽

Wheat Yield ◽

Yield Response ◽

Changing Climate

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Wheat Yield Response to Limited Irrigation and Fungicides

10.13031/aim.20152190459 ◽

2015 ◽

Keyword(s):

Wheat Yield ◽

Yield Response

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Soil measurements and wheat yield response to superphosphate in Victoria

Australian Journal of Experimental Agriculture ◽

10.1071/ea9750093 ◽

1975 ◽

Vol 15 (72) ◽

pp. 93

Author(s):

B Palmer ◽

VF McClelland ◽

R Jardine

Keyword(s):

Wheat Yield ◽

Geographic Location ◽

Yield Response ◽

Soil Test ◽

Soil Tests ◽

Yield Data ◽

Chemical Measurements ◽

Soil Measurements ◽

Yield Responses ◽

Available Phosphate

The relationships between soil tests for 'plant available' phosphate and wheat yield response to applied superphosphate were examined and the extent to which these relationships were modified by other soil measurements was determined. Soil samples and wheat yield data were obtained from experiments conducted in the Victorian wheat belt. The sites were grouped into four relatively uniform classes using soil pH measurement and geographic location. The soil test values differed widely and were accountable for by the soil characteristics measured. However, the overall and within group yield responses to applied superphosphate could not be accounted for in terms of either the soil test value or the associated chemical measurements. By inference, yield response was clearly dependent on factors other than those determining the results of soil tests.

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Chemical control of wild oats in wheat with di-allate and barban

Australian Journal of Experimental Agriculture ◽

10.1071/ea9730102 ◽

1973 ◽

Vol 13 (60) ◽

pp. 102

Author(s):

TG Reeves ◽

IS Smith ◽

CL Tuohey

Keyword(s):

Chemical Control ◽

Wheat Yield ◽

Yield Response ◽

Wild Oat ◽

Wild Oats ◽

Northern District

Results are presented from experiments in which di-allate and barban were used for wild oat control in wheat at 21 sites in the Wimmera and Northern Districts of Victoria. Both chemicals significantly reduced the wild oat densities at most sites but where direct comparisons were made di-allate was more effective than barban. Wheat yield response to applied herbicide was obtained in 17 of the 21 experiments. However, the yield response to barban application showed greater variation than the yield response to di-allate application. Barban was more effective, at all tested rates, n the Wimmera than it was-in the Northern District.

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