Effect of nitrogen fertilizer and herbicides on weed control and wheat grain yield under subtropical conditions

Field trials at Beverley (19911, Salmon Gums (1991; 2 sites) and Merredin (1992; 2 sites), each with 5 rates of nitrogen (N) and 3 levels of weed control, were used to investigate the effect of weeds and N on wheat grain yield and protein concentration during 1991 and 1992. Weeds in the study were grasses (G) and broadleaf (BL). Weeds reduced both vegetative dry matter yield and grain yield of wheat at all sites except for dry matter at Merredin (BL). Nitrogen fertiliser increased wheat dry matter yield at all sites. Nitrogen increased wheat grain yield at Beverley and Merredin (BL), but decreased yield at both Salmon Gums sites in 1991. Nitrogen fertiliser increased grain protein concentration at all 5 sites-at all rates for 3 sites [Salmon Gums (G) and (BL) and Merredin (G)] and at rates of 69 kg N/ha or more at the other 2 sites [Beverley and Merredin (BL)]. However, the effect of weeds on grain protein varied across sites. At Merredin (G) protein concentration was higher where there was no weed control, possibly due to competition for soil moisture by the greater weed burden. At Salmon Gums (G), grain protein concentration was greater when weeds were controlled than in the presence of weeds, probably due to competition for N between crop and weeds. In the other 3 trials, there was no effect of weeds on grain protein. The effect of weeds on grain protein appears complex and depends on competition between crop and weeds for N and for water at the end of the season, and the interaction between the two.

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Chondrilla juncea in Australia. 2. Preplanting weed control and wheat production

Australian Journal of Experimental Agriculture ◽

10.1071/ea9690027 ◽

1969 ◽

Vol 9 (36) ◽

pp. 27 ◽

Cited By ~ 1

Author(s):

EG Cuthbertson

Keyword(s):

Water Stress ◽

Grain Yield ◽

Weed Control ◽

Nitrogen Fertilizer ◽

Nitrogen Fertilization ◽

New South ◽

Spray Application ◽

South Wales ◽

Severe Water Stress ◽

Weed Cover

The response of wheat to nitrogen fertilization and to the time and mode of skeleton weed control was determined at three locations in southern New South Wales. Nitrogen fertilization was found to increase grain yield significantly in most situations. But nitrogen reduced total grain yield where adverse seasonal conditions caused severe water stress after flowering. Added nitrogen exaggerated the water stress and reduced grain weight. Temporary removal of skeleton weed, obtained by spraying the fallow with 2,4-D four to six weeks before seeding, increased grain yield by an average of nearly 5 bushels an acre. The magnitude of the response was modified by rainfall incidence, weed cover, and time of spray application relative to seeding. The effects of chemical weed control, followed by crop competition, were apparent in stubble sown crops 12 to 18 months later in the form of reduced weed populations and increased grain yield. Preplanting sprays reduced the response to nitrogen fertilizer but the interaction, generally, was not significant. Spraying the fallow with a contact herbicide, or substituting an additional cultivation for the 2,4-D fallow spray, also increased grain yield. These results emphasize the importance of suppressing skeleton weed, by the most appropriate means available, in the period before sowing.

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A nitrogen fertilizer strategy for simultaneously increasing wheat grain yield and protein content: Mixed application of controlled-release urea and normal urea

Field Crops Research ◽

10.1016/j.fcr.2021.108405 ◽

2022 ◽

Vol 277 ◽

pp. 108405

Author(s):

Guangxin Zhang ◽

Shiju Liu ◽

Yunjie Dong ◽

Yuncheng Liao ◽

Juan Han

Keyword(s):

Controlled Release ◽

Grain Yield ◽

Protein Content ◽

Nitrogen Fertilizer ◽

Wheat Grain ◽

Controlled Release Urea

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Pyroxsulam: Sulfonamide Herbicide for Weed Control in Wheat in Brazil

Planta Daninha ◽

10.1590/s0100-83582018360100064 ◽

2018 ◽

Vol 36 (0) ◽

Author(s):

L.H.S. ZOBIOLE ◽

R. GAST ◽

R.A. MASTERS ◽

G.R. PEREIRA ◽

R. RUBIN

Keyword(s):

Adverse Effect ◽

Grain Yield ◽

Weed Control ◽

Field Experiments ◽

Lolium Multiflorum ◽

Wheat Crop ◽

Wheat Grain ◽

Excellent Control

ABSTRACT: Few herbicides are currently registered in Brazil for weed control in wheat. The objective of this research was to determine the wheat crop selectivity and the response of Lolium multiflorum to pyroxsulam. Field experiments were conducted at two locations in Paraná, Brazil. At the proposed commercial rates of 15 and 18 g a.i. ha-1 pyroxsulam did not cause visual injury above 10% in wheat. Pyroxsulam caused >10% injury in wheat at one location (Cascavel) when applied at 21, 30, 36 and 42 g a.i. ha-1; however, the crop fully recovered from the injury by 28 days after application and did not have an adverse effect on wheat grain yield, regardless of the rate applied. Pyroxsulam applied at 15 or 18 g a.i. ha-1 provided excellent control (>85%) of Lolium multiflorum in both trials.

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Effect of waterlogging on the growth, grain and straw yield of wheat, barley and oats

Australian Journal of Experimental Agriculture ◽

10.1071/ea9760114 ◽

1976 ◽

Vol 16 (78) ◽

pp. 114 ◽

Cited By ~ 49

Author(s):

ER Watson ◽

P Lapins ◽

RJW Barron

Keyword(s):

Grain Yield ◽

Nitrogen Fertilizer ◽

Growth Stage ◽

Growth Yield ◽

Yield Reduction ◽

Soil Composition ◽

Wheat Grain ◽

The Mean ◽

Water Holding ◽

Practical Implications

Wheat, barley and oats were grown in undrained plastic buckets containing soil collected from upper, mid and lower slopes of a valley that was subject to winter waterlogging. Two weeks after planting, the water content for each soil was either maintained at 80 per cent of full water holding capacity or subjected to intermittent or continuous waterlogging for six weeks. In a second experiment, using lowerslope soil only, the same three cereals were subjected to similar waterlogging treatments commencing at two or six weeks after planting or at ear emergence. In this experiment the plants received either no nitrogen fertilizer or 100 kg nitrogen ha-1. Both soil composition and waterlogging had a significant effect on plant yield but the effect of waterlogging was much greater. Waterlogging reduced root growth and penetration, the production of tillers and fertile heads, and delayed ear emergence and plant maturation. Reduction in plant growth rate was measurable within three days from the onset of waterlogging. In the first experiment intermittent and continuous waterlogging reduced vegetative growth yield (mean of three cereals in three soils) by 37 per cent and 55 per cent respectively; and wheat grain yields by 40 per cent and 53 per cent respectively. However, there was no differential effect of the two waterlogging treatments on the grain yield of barley and oats, the mean reduction being 39 per cent for barley and 48 per cent for oats. In the second experiment waterlogging at the earliest growth stage resulted in the greatest reduction in root, herbage and grain yield. Waterlogging at ear emergence killed some tillers and roots and reduced the plants stability at maturity. Grain size was reduced in some treatments. Application of nitrogen fertilizer compensated, either partially or fully, for reduction in grain yield due to waterlogging treatments on all three cereals. Some reasons for yield reduction in the three species and the practical implications of the results are discussed.

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Nitrogen content of wheat grain as as indication of potential yield response to nitrogen fertilizer

Australian Journal of Experimental Agriculture ◽

10.1071/ea9630319 ◽

1963 ◽

Vol 3 (11) ◽

pp. 319 ◽

Cited By ~ 8

Author(s):

JS Russell

Keyword(s):

Grain Yield ◽

Nitrogen Content ◽

Nitrogen Fertilizer ◽

Cultural Practices ◽

South Australia ◽

Yield Response ◽

Regression Equations ◽

Wheat Grain ◽

Potential Yield ◽

Grain Nitrogen

Examination of results from a large number of experiments in the wheat growing areas of South Australia has shown a relation between grain yield response to nitrogen fertilizer and both grain nitrogen percentage and the ratio. (Yield of grain)/(Amount of nitrogen in grain and straw) of corresponding unfertilized wheat plants. With Gabo, large yield responses to nitrogen fertilizer were associated with grain nitrogen percentages of less than 2.0 per cent N (9.9 per cent protein). Above 2.3 per cent N (11.3 per cent protein) positive responses to nitrogen were small and some negative responses were found. Similar overall trend were shorn by Insignia 49, Sabre and Quadrat. Exponential regression equations were calculated for Gabo allowing prediction of grain yield response at rates up to 46 lb fertilizer N an acre under conditions which result in grain protein contents of 7.5 to 16 per cent. Most profitable rates of nitrogen fertilizer application were also calculated for several different fertilizer-grain price levels. Possible value of the nitrogen content of wheat grain in the selection of regions, soil types, and cultural practices where nitrogen fertilizer may be used is discussed.

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Growth stage of Phalaris minor Retz. and wheat determines weed control and crop tolerance of four post-emergence herbicides

Spanish Journal of Agricultural Research ◽

10.5424/sjar/2017151-9728 ◽

2017 ◽

Vol 15 (1) ◽

pp. e1001

Author(s):

Rubia Rasool ◽

Makhan S. Bhullar ◽

Gurjeet S. Gill

Keyword(s):

Grain Yield ◽

Weed Control ◽

Growth Stage ◽

Herbicide Tolerance ◽

Field Studies ◽

Growth Stages ◽

Wheat Grain ◽

Current Recommendation ◽

Phalaris Minor ◽

Crop Tolerance

Phalaris minor Retz. has evolved multiple herbicide resistance in wheat growing areas in northwestern India. An understanding of the effect of growth stage on herbicide tolerance of wheat and control of P. minor will help in selecting the most appropriate herbicide for different situations. The weed control and crop safety of four commonly used wheat herbicides (sulfosulfuron, pinoxaden, fenoxaprop plus metribuzin and mesosulfuron plus iodosulfuron), each applied at four different wheat growth stages was investigated in field studies for two years. P. minor plants were at 1, 2-3, 3-4 and 7-8 leaf stages when the herbicides were applied at Zadok 12-Z12, Z13, Z21 and Z23 stages of wheat, respectively. Sulfosulfuron application at Z12 and Z13 wheat stages (before first irrigation), provided >80% control of P. minor and produced wheat grain yield (4.5-4.7 t/ha) similar to the weed-free check (4.9 t/ha) in both years. Pinoxaden, fenoxaprop plus metribuzin and mesosulfuron plus iodosulfuron application at Z12 and Z13 wheat stages recorded significantly lower wheat grain yield (3.62-3.95 t/ha) due to poor weed control, crop toxicity or both. All the four herbicides were equally effective on P. minor when applied at Z21 wheat stage. At Z23 wheat stage, pinoxaden gave >90% control of P. minor and the highest wheat grain yield (4.82 t/ha). The results are expected to allow changes in the current recommendation of the timing of post-emergence herbicides for the management of P. minor in wheat.

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