Influence of preseason weed management and in-crop treatments in two successive wheat crops 1. Weed seedling numbers and wheat grain yield

1993 ◽  
Vol 33 (2) ◽  
pp. 167 ◽  
Author(s):  
PM Dowling ◽  
PTW Wong
Keyword(s):  
Grain Yield ◽  
Weed Management ◽  
Seed Set ◽  
Seedling Emergence ◽  
Grass Species ◽  
Wheat Crop ◽  
Annual Grass ◽  
Wheat Grain ◽  
Heavy Grazing ◽  
Annual Grasses

The effect of 5 preseason management treatments on seed set reduction of annual weed grasses and their regeneration in the following autumn was evaluated in a 2-year field experiment commencing at Orange in spring 1986. Preseason (spring) treatments were paraquat, glyphosate (2 rates), unsprayed heavy grazing, and unsprayed control. In the first of 2 successive wheat crops (planted 1987), 3 in-crop weed control treatments [control, chlorsulfuron (both sod-seeded), and trifluralin plus cultivation] were imposed. In 1988, the second wheat crop was sown into a cultivated seedbed or direct-drilled. The preseason treatments reduced potential annual grass regeneration by 91-99% compared with the control, with heavy grazing being the best treatment. For each preseason treatment compared with the control, the pattern of actual seedling emergence within the crop during 1987 was similar to that of potential emergence for each grass species (except Lolium rigidum), but numbers were lower and more variable (7-86% of potential numbers). The proportion of Bromus spp. and Vulpia spp. emerging within the crop declined from the first to the second crop, while L. rigidum increased to an average of 93% of the annual grass population in 1988. Trifluralin plus cultivation increased the control of annual grasses in 1987. In 1988, the 1987 in-crop treatments had little carryover effect on annual grass control; however, wheat grain yield was increased by both chlorsulfuron and trifluralin. Preseason management reduced seed set of annual grass weeds, and this control was maintained under cropping for at least 2 years (except for L. rigidum). Wheat grain yield responded to this control. Long-term control of L. rigidum where soil is disturbed appears difficult because of apparent long-lived seed in the soil.

Increasing production of an annual medic - wheat rotation by grazing and grass removal with herbicides in the Victorian Mallee

1998 ◽  
Vol 38 (3) ◽  
pp. 211 ◽  
Author(s):  
R. A. Latta ◽  
E. D. Carter
Keyword(s):  
Grain Yield ◽  
Wheat Yield ◽  
Wheat Crop ◽  
Stocking Rate ◽  
Annual Grass ◽  
Wheat Grain ◽  
Cereal Production ◽  
Herbicide Treatments ◽  
Seed Yields

Summary. The productivity of an annual medic-based pasture–pasture–wheat rotation in response to chemical grass control and stocking rate treatments was evaluated over 3 years. Fluazifop applied in 1991 reduced the annual grass component during the pasture years (to <2% in 1991 and <5% in 1992) and grass densities in the 1993 wheat phase. This improved winter herbage production in 1992 (>50%) and the 1993 wheat yield (>40%). Glyphosate applied during the winter of 1991 reduced the grass component and the winter and total herbage production in that year, and grass populations in 1992. Glyphosate applied during the spring of 1991 reduced the medic seed yields and the grass and medic densities in 1992. There were no pasture or cereal production benefits measured from the 1991 glyphosate applications. All the above comparisons were made with no herbicide in 1991 followed by glyphosate applied during the winter of 1992, a common district practice. Stocking at twice the district average, over all herbicide treatments, reduced the 1991 winter herbage production but maintained or improved the 1992 winter and total herbage production, compared with the district average stocking rate. The high stocking rate resulted in lower grass densities in the 1993 wheat crop and increased the wheat grain yield by 0.5 t/ha.

Control of annual grasses by spraytopping and the effect on triticale grain yield

1993 ◽  
Vol 44 (8) ◽  
pp. 1959 ◽  
Author(s):  
PM Dowling ◽  
HI Nicol
Keyword(s):  
Grain Yield ◽  
Seed Set ◽  
Application Rate ◽  
Wetting Agent ◽  
Annual Grass ◽  
Annual Grasses ◽  
Total Seed ◽  
Main Component ◽  
Grass Sward ◽  
Grass Weed

IA range of pre-season management treatments was imposed on a mixed annual grass sward in October 1987, prior to planting triticale into a cultivated and a direct-drilled seedbed in June 1988. The management treatments included three rates of glyphosate: Roundup� (110, 180, 360 g a.i./ha); two rates of paraquat: Gramoxone� (100, 200 g a.i. ha); and one rate of fluazifop-butyl: Fusilade� (53 g a.i./ha � Pulse� wetting agent). All treatments decreased potential grass regeneration, with V. bromozdes being the least affected. Improved control was achieved by increasing application rate, and by adding a wetting agent to fluazifop. Actual grass seedlings emerging within the crop followed a similar pattern to potential grass regeneration. Grass emergence, particularly of V. bromoides and L. rigidum, was always greater on the direct-drilled seedbed. Grain yield was greater on the prepared seedbed. On both seedbeds, yield was inversely related to grass DM 97 days after sowing (DAS) and grass weed seedling numbers 50 DAS. The effectiveness of the herbicides appeared to be related to maturity dates of the target species. The high potential seed-set of the annual grasses present (> 500 000/m2), of which V. bromozdes was the main component, highlights the difficulty of controlling such species. It is suggested that the large apparent decline from total seed-set to potential seedling numbers (14000/m2) resulted from the high stocking pressure by sheep over summer. For a number of annual grasses, a more rapid method for determining seed number based on seed weight and seedhead number is proposed, providing a more informed basis for decision making. We conclude that spraytopping to maximize yield of later sown direct-drilled crops (e.g. triticale) is essential, despite the difficulty in optimizing timing of spraytopping in mixed pasture swards.

Interference of Three Annual Grasses with Grain Sorghum (Sorghum bicolor)

1990 ◽  
Vol 4 (2) ◽  
pp. 245-249 ◽  
Author(s):  
Brenda S. Smith ◽  
Don S. Murray ◽  
J. D. Green ◽  
Wan M. Wanyahaya ◽  
David L. Weeks
Keyword(s):  
Linear Regression ◽  
Grain Yield ◽  
Field Experiments ◽  
Grain Sorghum ◽  
Grass Species ◽  
Row Spacing ◽  
Yield Data ◽  
Weed Density ◽  
Annual Grasses ◽  
Wide Row Spacing

Barnyardgrass, large crabgrass, and Texas panicum were evaluated in field experiments over 3 yr to measure their duration of interference and density on grain sorghum yield. When grain yield data were converted to a percentage of the weed-free control, linear regression predicted a 3.6% yield loss for each week of weed interference regardless of year or grass species. Grain sorghum grown in a narrow (61-cm) row spacing was affected little by full-season interference; however, in wide (91-cm) rows, interference increased as grass density increased. Data from the wide-row spacing were described by linear regression following conversion of grain yield to percentages and weed density to log10. A separate nonlinear model also was derived which could predict the effect of weed density on grain sorghum yield.

Annual weed management in isoxaflutole-resistant soybean using a two-pass weed control strategy

2019 ◽  
Vol 33 (03) ◽  
pp. 411-425
Author(s):  
Andrea Smith ◽  
Nader Soltani ◽  
Allan J. Kaastra ◽  
David C. Hooker ◽  
Darren E. Robinson ◽  
...  
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Field Experiments ◽  
High Rate ◽  
Grass Species ◽  
Annual Grass ◽  
Common Lambsquarters ◽  
Control Programs ◽  
The One ◽  
Herbicide Programs

AbstractTransgenic crops are being developed with herbicide resistance traits to expand innovative weed management solutions for crop producers. Soybean with traits that confer resistance to the hydroxyphenylpyruvate dioxygenase herbicide isoxaflutole is under development and will provide a novel herbicide mode of action for weed management in soybean. Ten field experiments were conducted over 2 years (2017 and 2018) on five soil textures with isoxaflutole-resistant soybean to evaluate annual weed control using one- and two-pass herbicide programs. The one-pass weed control programs included isoxaflutole plus metribuzin, applied PRE, at a low rate (52.5 + 210 g ai ha−1), medium rate (79 + 316 g ai ha−1), and high rate (105 + 420 g ai ha−1); and glyphosate applied early postemergence (EPOST) or late postemergence (LPOST). The two-pass weed control programs included isoxaflutole plus metribuzin, applied PRE, followed by glyphosate applied LPOST, and glyphosate applied EPOST followed by LPOST. At 4 weeks after the LPOST application, control of common lambsquarters, pigweed species, common ragweed, and velvetleaf was variable at 25% to 69%, 49% to 86%, and 71% to 95% at the low, medium, and high rates of isoxaflutole plus metribuzin, respectively. Isoxaflutole plus metribuzin at the low, medium, and high rates controlled grass species evaluated (i.e., barnyardgrass, foxtail, crabgrass, and witchgrass) 85% to 97%, 75% to 99%, and 86% to 100%, respectively. All two-pass weed management programs provided 98% to 100% control of all species. Weed control improved as the rate of isoxaflutole plus metribuzin increased. Two-pass programs provided excellent, full-season annual grass and broadleaf weed control in isoxaflutole-resistant soybean.

scholarly journals Nitrogen application rate and timing management for improved grain quality parameters of wheat crop

2021 ◽  
Vol 58 (04) ◽  
pp. 1141-1153
Author(s):  
Gul Roz Khan
Keyword(s):  
Grain Yield ◽  
Grain Quality ◽  
Irrigation System ◽  
Quality Parameters ◽  
Wheat Crop ◽  
Change Scenario ◽  
Wheat Grain ◽  
Flood Irrigation ◽  
Recent Climate ◽  
Use Efficiency

Nitrogen use efficiency under flood irrigation system is generally low (30%) in field crops, which is one of the fundamental factors of high production cost in the developing countries. Optimum rate and timing of N-application is otherwise important to harvest good quality grain for backing in the recent climate change scenario. Optimum N-rate (NAR) corresponds with the application timing (NAT) has resulted in good quality grains. Aim of the study was to focus on spring wheat grain quality and N use efficiency (NUE) with NAR {i.e., 0, 100, 120, 140 and 160 kg ha-1) and NAT (i.e., 100% at sowing (NAR1), 50% at sowing and 50% at tillering (NAT2), 25% at sowing, 50% at tillering and 25% at booting (NAT3) and 25% at sowing, 25% at tillering and 50% at booting (NAT4)}. Treatment impacts were investigated focusing grain yield, grain-N, and quality parameters (i.e., crude protein, gluten, amylose and amylopectin). Experiment was a randomized complete block, in three replications, conducted at Agronomy Res. Farm of the University of Agric. Peshawar in 2016-17 and repeated in 2017-18. Results showed the highest NUE in100 kg N ha-1, followed by a decreasing rate (p<0.05) for every next N-increment. While averaged on N-rates, the highest NUE observed in NAT3 which did not differ fromNAT4 but decreased (p<0.05) for treatment NAT2 with lowest for theNAT1. Pakhtunkhuwa-2015 showed higher NUE among the varieties. Grain-N, grain yield, gluten and amylose did not differ with NAR 140 and 160 kg ha-1 as well as for the NAT3 and NAT4 but decreased for NAT2 and the lowest was noted for NAT1. The N-content of wheat grain was highest in Pakhtunkhuwa-2015, followed by Pirsabak-2015 and the lowest in DN-84. Nonetheless, grain amylopectin showed a reduction with increasing NAR and/or split N-applications from one to two and/or three doses. Cultivars did not show any changes in the amylopectin. It is concluded that in recent climate changes where flood irrigation system is practiced, three N-splits (NAT3 or NAT4) resulted higher quality grains with140 kg N ha-1 to wheat crop

scholarly journals Herbicide Use Strategy and Its Economy as a Weed Management Option in Wheat Varieties

2021 ◽  
Vol 23 (2) ◽  
pp. 119-125
Author(s):  
MG Mostafa ◽  
MF Karim ◽  
HMMT Hossain
Keyword(s):  
Grain Yield ◽  
Weed Management ◽  
Chenopodium Album ◽  
Cyperus Rotundus ◽  
Alternanthera Philoxeroides ◽  
Wheat Crop ◽  
Net Income ◽  
Wheat Varieties ◽  
Yield Attributes ◽  
Hand Weeding

Weed pressure is an additional threat to high temperature stressed wheat crop for its optimum production. A field experiment was conducted at Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during Rabi 2017-2018 to assess the response of wheat varieties to different weed managements and its economical viability. As such three varieties i.e. BARI Gom-28, BARI Gom-29, and BARI Gom-30 along with five weed managements viz. control (no weeding), two hand weeding at 20 and 40 DAS, Panida 33EC (Pendimethalin) @ 2000 ml ha-1 spray at 5 DAS as pre-emergence, Affinity 50.75 WP (Isoproturon) @ 1500 g ha-1 spray at 25 DAS as post-emergence and Panida 33EC (Pendimethalin) @ 2000 ml ha-1 at 5 DAS + Affinity 50.75 WP (Isoproturon) @ 1500 g ha-1 at 5 & 25 DAS were treatment variables tested under split plot design.Cynodon dactylon, Cyperus rotundus, Echinochloa colona, Eleusine indica, Chenopodium album, Alternanthera philoxeroides, Brassica kaber, Leliotropium indicum, Vicia sativa,etc.werethe major weeds as determined based on their field intensity.Results revealed that BARI Gom-30 out-yielded other varieties with the highest grain yield (3.01 t ha-1). Pre-emergence application of Panida 33EC at 5 DAS proved as suitable weed management compared to other methods. BARI Gom-30 in combination with Panida 33EC @ 2000 ml ha-1 spray at 5 DAS as pre-emergence gave higher yield and yield attributes while BARI Gom-28 under no weeding check showed lower grain yield (2.09 t ha-1). Economically maximum gross return (Tk.75761.52ha-1),net income (Tk.21775.92ha-1), and BCR (1.41) were associated with Panida 33EC treatment when minimum values were obtained in the control plot (no weeding). So, the application of pre-emergence herbicide, Panida 33EC might be economically viable weed management ensuring a higher yield in wheat cultivation. Bangladesh Agron. J. 2020, 23(2): 119-125

scholarly journals Physiological quality, initial establishment and yield of wheat according to the seed treatment method1

2017 ◽  
Vol 47 (4) ◽  
pp. 448-455 ◽  
Author(s):  
Joice Aline Freiberg ◽  
Marcos Paulo Ludwig ◽  
Leticia Decarli ◽  
Eduardo Girotto ◽  
Lucas Navarini
Keyword(s):  
Grain Yield ◽  
Seed Treatment ◽  
New Technologies ◽  
Seed Quality ◽  
Block Design ◽  
Seedling Emergence ◽  
Treatment Method ◽  
Wheat Crop ◽  
Lambda Cyhalothrin ◽  
Physiological Quality

ABSTRACT New technologies are being incorporated to the seed treatment process, such as the use of products on industrial scale. This study aimed at evaluating the seed quality of wheat cultivars, as well as the influence of the seed treatment method on the establishment and yield of this crop. Seeds of the cultivars Jadeite 11, Quartzo and Tec Frontale were treated with the Spectro® fungicide (difenoconazole - 200 mL 100 kg-1 of seeds), Cruiser Opti® insecticide (thiamethoxam + lambda-cyhalothrin - 200 mL 100 kg-1 of seeds) and Polifix G4 polymer (100 mL 100 kg-1 of seeds). A completely randomized design, with four replicates, was used. The treatments consisted of industrial treatment, on farm treatment with the same products and control. Germination, first germination count and moisture content tests were carried out immediately after the seed treatment and at 30, 90 and 150 days of storage. Seedling emergence in beds was evaluated at 30, 60 and 120 days of storage. Under a randomized block design, seedling emergence and grain yield were evaluated in the field in two sowing seasons. The conventional or industrial seed treatment methods do not reduce the physiological quality and emergence of high-vigor seeds stored for 150 days, under controlled conditions of temperature and humidity. The conventional or industrial seed treatment with diphenoconazole + thiamethoxam + lambda-cyhalothrin + polymer does not increase the wheat crop plant stand and grain yield.

INFLUENCE OF VARIOUS HERBICIDES AND TWEEN 20 ON THE EFFECTIVENESS OF GLYPHOSATE

1980 ◽  
Vol 60 (3) ◽  
pp. 939-945 ◽  
Author(s):  
P. A. O’SULLIVAN ◽  
J. T. O’DONOVAN
Keyword(s):  
Brassica Campestris ◽  
Triticum Aestivum L ◽  
Grass Species ◽  
Tween 20 ◽  
Annual Grass ◽  
Hordeum Vulgare L ◽  
Initial Reduction ◽  
Annual Grasses ◽  
Excellent Control ◽  
High Degree

Glyphosate (N-phosphonomethyl glycine) at 0.21 kg/ha applied at the 4-leaf stage provided excellent control of wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), oats (Avena sativa L.), and rape (Brassica campestris L.). Tank mixtures of 0.21 kg/ha glyphosate with bromoxynil/MCPA, bromoxynil, MCPA, 2,4-D, or dicamba resulted in an initial reduction (antagonism) of glyphosate activity on the grass species at 5 days after treatment. At 34 days after treatment, the early differences had disappeared and grass kill was virtually complete with all treatments containing glyphosate. The early reduction in annual grass control with these mixtures was overcome in most cases by addition of Tween 20. Dicamba at 0.11 kg/ha, applied sequentially at various times in relation to glyphosate at 0.21 kg/ha, provided significantly increased early control of annual grasses over that obtained with glyphosate alone. Glyphosate combinations with bromoxynil/MCPA, bromoxynil, MCPA, 2,4-D, or dicamba were as effective or more effective for rape control than the various broad-leaved herbicides applied alone. Rape showed a high degree of tolerance to dicamba.

Wheat crop surveys in southern New South Wales. 4. The response by grain yield and other wheat attributes to weeds

1986 ◽  
Vol 26 (6) ◽  
pp. 709 ◽  
Author(s):  
AC Taylor ◽  
WJ Lill
Keyword(s):  
Grain Yield ◽  
Nitrogen Uptake ◽  
New South ◽  
New South Wales ◽  
Phosphorus Uptake ◽  
Wheat Crop ◽  
Mixed Stands ◽  
Nitrogen Yield ◽  
South Wales ◽  
Annual Grasses

Regular hand-weeding was undertaken in experiments located in 167 wheat crops in southern New South Wales from 1967 to 1970 to quantify the effect of weeds on 10 wheat attributes at flowering or maturity. Short annual grasses, skeleton weed, wild oats and annual legumes were the most widespread weeds, all of which tended to occur in mixed stands. At wheat flowering, over all sites, wheat DM, nitrogen concentration, nitrogen uptake, phosphorus uptake and number of ears were increased (P< 0.05) by 11.2, 3.3, 14.4, 13.6 and 7.8%, respectively by weeding; wheat phosphorus concentrations did not respond to weeding. At maturity, grain yield and nitrogen yield increased after weeding (P< 0.05) by 17.3 and 1 7.0%, respectively, but grain protein and kernel weight did not respond to weeding. Regression procedures were used to relate wheat responses to total weed DM and the DM of 8 weed classes. At flowering, for every 100 g of DM removed, wheat DM, nitrogen uptake, phosphorus uptake and ear number increased by 52.3 g m-2, 958 mg m-2, 92.6 mg m-2and 18.7 m-2, respectively. At maturity, grain yield and grain nitrogen yield increased by 31.9 g m-2 and 665 mg m-2, respectively, for every 100g m-2 of weed DM present at flowering. The regressions also showed that, at both flowering and maturity, fumitory, annual grasses and sundry weeds (a group made up of weeds not sufficiently widespread to consider separately) appeared to be the most aggressive weeds. Consideration of standardised responses of the wheat attributes increased by weeding showed that they all responded similarly when corrected for scale of measurement.

scholarly journals Invasive Grasses Increase Nitrogen Availability in California Grassland Soils

2010 ◽  
Vol 3 (1) ◽  
pp. 40-47 ◽  
Author(s):  
Sophie S. Parker ◽  
Joshua P. Schimel
Keyword(s):  
Nitrogen Availability ◽  
Perennial Grass ◽  
N Cycling ◽  
Rooting Depth ◽  
Grass Species ◽  
Annual Grass ◽  
Annual Grasses ◽  
California Grassland ◽  
Pool Sizes ◽  
Native Perennial Grass

AbstractAs Europeans colonized California, they introduced annual grasses from the Mediterranean Basin. These exotic annual grasses eventually invaded grasslands throughout the state, some of which were once dominated by native perennial grass species. Annual grasses differ from perennials in their phenology, longevity, rooting depth, litter chemistry, and interaction with the microbial community. As these traits may influence plant nitrogen (N) use, it is likely that the invasion by annual species resulted in changes in the availability and cycling of N in California grassland systems. We addressed the question of how invasive annual grasses influence rates of N cycling by measuring N pool sizes and rates of net and gross mineralization and nitrification, gross immobilization, and the denitrification potential of soils from experimentally planted annual and perennial-dominated grasslands. With an increase in annual grass cover, we saw increases in ammonium (NH4+) pool sizes and rates of N mineralization, nitrification, and denitrification in soils. These differences in N status suggest that N cycling in California grasslands was altered at sites where native perennial bunchgrasses were invaded by nonnative annual grasses. One consequence of annual grass invasion may be a legacy of NH4+-enriched soils that hinder the reestablishment of native perennial grass species.

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