scholarly journals Mechanical weed control in organic winter wheat

2017 ◽  
Vol 11 ◽  
Author(s):  
Euro Pannacci ◽  
Francesco Tei ◽  
Marcello Guiducci
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Weed Control ◽  
Field Experiments ◽  
Central Italy ◽  
Ground Cover ◽  
Farming Systems ◽  
Row Spacing ◽  
Weed Species ◽  
Mechanical Weed Control

Three field experiments were carried out in organic winter wheat in three consecutive years (exp. 1, 2005-06; exp. 2, 2006-07; exp. 3, 2007-08) in central Italy (42°57' N - 12°22' E, 165 m a.s.l.) in order to evaluate the efficacy against weeds and the effects on winter wheat of two main mechanical weed control strategies: 1) spring tine harrowing used at three different application times (1 passage at T1; 2 passages at the time T1; 1 passage at T1 followed by 1 passage at T1 + 14 days) in the crop sowed at narrow (traditional) row spacing (0.15 m) and 2) split-hoeing and finger-weeder, alone and combined at T1, in the crop sowed at wider row spacing (0.30 m). At the time T1 winter wheat was at tillering and weeds were at the cotyledons-2 true leaves growth stage. The experimental design was a split-plot with four replicates. Six weeks after mechanical treatments, weed ground cover (%) was rated visually using the Braun–Blanquet cover-abundance scale; weeds on three squares (0.6 x 0.5 m each one) per plot were collected, counted, weighed, dried in oven at 105 °C to determine weed density and weed above-ground dry biomass. At harvest, wheat ears density, grain yield, weight of 1000 seeds and hectolitre weight were recorded. Total weed flora was quite different in the three experiments. The main weed species were: <em>Polygonum aviculare</em> L. (exp. 1 and 2), <em>Fallopia convolvulus</em> (L.) Á. Löve (exp. 1 and 3), <em>Stachys annua</em> (L.) L. (exp. 1), <em>Anagallis arvensis</em> L. (exp. 2), <em>Papaver rhoeas</em> L. (exp.3), <em>Veronica hederifolia</em> L. (exp. 3). In the winter wheat sowed at narrow rows, 2 passages with spring-tine harrowing at the same time seems to be the best option in order to reconcile a good efficacy with the feasibility of treatment. In wider rows spacing the best weed control was obtained by splithoeing alone or combined with finger-weeder. The grain yield, on average 10% higher in narrow rows, the lower costs and the good selectivity of spring-tine harrowing treatments seems to suggest the adoption of narrow rows spacing in wheat in organic and low-input farming systems.

Winter Annual Broadleaf Weeds and Winter Wheat Response to Postemergence Application of Two Saflufenacil Formulations

2010 ◽  
Vol 24 (4) ◽  
pp. 416-424 ◽  
Author(s):  
John C. Frihauf ◽  
Phillip W. Stahlman ◽  
Patrick W. Geier ◽  
Dallas E. Peterson
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Field Experiments ◽  
Weed Species ◽  
Herbicide Resistant ◽  
Water Dispersible ◽  
Leaf Necrosis ◽  
Winter Annual ◽  
Rate Formulation ◽  
Water Dispersible Granule

Field experiments in winter wheat were initiated at two locations in the fall of 2006 and 2007 to evaluate winter annual broadleaf weeds and winter wheat response to POST applications of two saflufenacil formulations applied alone and in combination with 2,4-D amine. Emulsifiable concentrate (EC) and water-dispersible granule (WG) formulations of saflufenacil at 13, 25, and 50 g ai ha−1were applied with 1.0% (v/v) crop oil concentrate (COC) and mixed with 2,4-D amine at 533 g ae ha−1without adjuvant. Regardless of rate or formulation, saflufenacil plus COC and saflufenacil plus 2,4-D amine controlled blue mustard ≥ 91% at 17 to 20 d after treatment (DAT) compared with ≤ 50% control with 2,4-D amine alone. At least 25 g ha−1of saflufenacil EC was necessary to control flixweed > 90%. Excluding COC from saflufenacil plus 2,4-D amine reduced flixweed control from the saflufenacil WG formulation more than the EC formulation. Most saflufenacil treatments did not control henbit satisfactorily (≤ 80%). Wheat foliar necrosis increased with increasing saflufenacil rate to as high as 30% at 3 to 6 DAT, but declined to < 15% at 10 to 20 DAT and was not evident at 30 DAT. Saflufenacil rate, formulation, and mixing with 2,4-D amine also influenced wheat stunting, but to a lesser extent than foliar necrosis. Saflufenacil EC consistently caused greater foliar necrosis and stunting on wheat than saflufenacil WG. Leaf necrosis and stunting were reduced by tank-mixing saflufenacil formulations with 2,4-D amine without COC. Grain yields of most saflufenacil treatments were similar to 2,4-D amine under weedy conditions and herbicide treatments had no effect on grain yield in weed-free experiments. Saflufenacil formulations at 25 to 50 g ha−1with 2,4-D amine and saflufenacil WG at 25 to 50 g ha−1with COC can control winter annual broadleaf weeds with minimal injury (< 15%) and no grain yield reductions. The addition of saflufenacil as a POST-applied herbicide would give wheat growers another useful tool to control annual broadleaf weeds, including herbicide-resistant weed species.

scholarly journals Three mechanical weed control techniques in spring cereals

2000 ◽  
Vol 9 (4) ◽  
pp. 269-278 ◽  
Author(s):  
T. LÖTJÖNEN ◽  
H. J. MIKKOLA
Keyword(s):  
Weed Control ◽  
Field Experiments ◽  
Yield Loss ◽  
Row Spacing ◽  
Silty Clay ◽  
Control Techniques ◽  
Mechanical Methods ◽  
Spring Cereals ◽  
Silty Clay Soil ◽  
Mechanical Weed Control

An inter-row hoe suitable for cereals was developed for the study, and field experiments were conducted to compare inter-row hoeing with weed harrowing, rotary hoeing and chemical control. The treatments were performed once during the growing season. Inter-row hoeing was studied at row spacings of 180 mm and 250 mm. The weeding effect of the different methods was measured by weighing the weeds remaining just before harvesting. Inter-row hoeing was the most effective of the mechanical methods. Weed harrowing was as good as hoeing in silty clay soil but less effective in mull soil. Rotary hoeing was the least effective. Herbicide spraying was more effective than the mechanical methods in both soils. Increasing the spacing between rows from the standard 125 mm to 250 mm decreased the yield of barley by 12-13%. Inter-row hoeing affected the yield very slightly. The yield decreasing was lower at a row spacing of 180 mm than at 250 mm. Weed harrowing and rotary hoeing decreased the yield 5-10%. Although inter-row hoeing seems to be a fairly effective method for weed control, it may be difficult to compensate for the yield loss due to the increase in row spacing.;

Horse purslane (Trianthema portulacastrum) control in pigeonpea with PRE and POST herbicides

2020 ◽  
Vol 34 (5) ◽  
pp. 764-769
Author(s):  
Gulshan Mahajan ◽  
R. C. N. Rachaputi ◽  
Bhagirath Singh Chauhan
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Field Experiments ◽  
Farming Systems ◽  
Treatment Control ◽  
Trianthema Portulacastrum ◽  
Rotational Crop ◽  
Biomass Reduction ◽  
Control Post ◽  
Subtropical Australia

AbstractPigeonpea has great potential as a profitable summer legume rotational crop in cereal farming systems of subtropical Australia. Pigeonpea requires season-long weed control, but options for controlling broadleaf weeds in pigeonpea with POST herbicides are limited. The objective of this study was to evaluate the performance of different herbicides (PRE: pendimethalin; POST: acifluorfen, bentazon, and imazapic) applied singly or in sequence for horse purslane control in pigeonpea and their impact on pigeonpea yield. Field experiments were conducted in 2017 and 2018 at Gatton, Australia. Pendimethalin applied PRE at 1.14 kg ai ha−1 reduced horse purslane biomass by 87% and 92% and produced 32% and 105% higher grain yield compared with the nontreated control in 2017 and 2018, respectively. Imazapic applied POST at 0.10 kg ai ha−1 reduced horse purslane biomass by 79% and 82% and increased grain yield by 60% and 88% compared with the nontreated control in 2017 and 2018, respectively. Acifluorfen applied POST (0.34 and 0.42 kg ai ha−1) caused 16% to 48% injury to pigeonpea at 45 d after treatment. Control of horse purslane ranged from 87% to 92% (biomass reduction) with pendimethalin applied PRE at 1.14 kg ai ha−1 and was comparable with pendimethalin applied PRE at 0.91 kg ai ha−1 in the sequential application, and imazapic at 0.08 kg ai ha−1 or bentazon at 0.96 kg ai ha−1. The study findings suggest if farmers miss the PRE application of pendimethalin or are unable to achieve season-long weed control, POST application of imazapic is an alternate. This research provided herbicide options for control of horse purslane in pigeonpea that could be used in rotations for reducing the selection pressure of weeds.

Effects of density and spatial pattern of winter wheat on suppression of different weed species

Weed Science ◽  
2005 ◽  
Vol 53 (5) ◽  
pp. 690-694 ◽  
Author(s):  
Jannie Olsen ◽  
Lars Kristensen ◽  
Jacob Weiner
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Field Experiments ◽  
Uniform Grid ◽  
First Year ◽  
Weed Species ◽  
Weed Biomass ◽  
Uniform Pattern ◽  
Growing Seasons ◽  
Total Crop

Field experiments on suppression of three species (scentless chamomile, field poppy, and canola) by winter wheat sown in two different spatial patterns (normal 12.8-cm rows and a uniform, grid-like pattern) and three densities (204, 449, and 721 plants m−2) in two growing seasons were performed. The effects of crop-sowing density and pattern when weeds were controlled by herbicide were also investigated in one season. Weed and crop biomass were measured when weed biomass was at its maximum (late June/early July), and grain was harvested in August. Weed biomass comprised on average 30% of the total (crop + weed) biomass in the first year and only 5% in the second year. Weed biomass decreased and grain yield increased with increasing sowing density. Weed biomass was on average 23% lower and grain yield 14% higher in the uniform pattern than in rows. Weed biomass decreased 27% and 38% in the row pattern and 36% and 50% in the uniform pattern by increasing sowing density from low to medium and from low to high density, respectively. When weeds were controlled with herbicide, increasing sowing density had no influence on grain yield, but grain yield was 7% higher in the uniform pattern. Field poppy was the weed with the largest biomass and the largest impact on yield, whereas canola had the lowest biomass and the least impact on yield.

Efficacy of Interrow Weed Control Techniques in Wide Row Narrow-Leaf Lupin

2011 ◽  
Vol 25 (1) ◽  
pp. 135-140 ◽  
Author(s):  
Abul Hashem ◽  
R. Michael Collins ◽  
David G. Bowran
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Strong Relationship ◽  
Row Spacing ◽  
Weed Species ◽  
Herbicide Resistant ◽  
Control Techniques ◽  
Narrow Leaf ◽  
Wide Row Spacing ◽  
Rigid Ryegrass

The sharp decline in the area of lupin grown in Australia is partly attributed to the failure to control herbicide-resistant weeds in narrow-leaf lupin crops grown with the conventional 25-cm-wide row spacing. Growing lupin with wider row spacing allows for interrow weed control by nonselective herbicides using a sprayshield or physical methods. During 2003 to 2006, two experiments conducted at five sites evaluated the efficacy of interrow weed control techniques in narrow-leaf lupin crops grown in 55- to 65-cm-wide rows within the Western Australia wheatbelt. Interrow herbicides were applied POST using sprayshields, intrarow herbicides were banded on lupin rows at seeding, and interrow weeds were mowed using a garden mower. The main weed species at each site was rigid ryegrass, blue lupin, or wild radish. Paraquat plus diquat applied on the interrow of the lupin crop with sprayshields controlled up to 100% of weeds between rows, leading to increases in lupin grain yield in most of the sites. Glyphosate alone, a mixture of glyphosate plus metribuzin, and glyphosate followed by paraquat plus diquat also controlled interrow weeds, but did not increase lupin grain yield at any site. Thus, paraquat plus diquat is a better choice for interrow weed control in wide row lupin than glyphosate. Mowing did not improve weed control, but mowing followed by paraquat plus diquat increased lupin grain yield at one site. Regression models predicted that there was a strong relationship between weed biomass and lupin grain yield.

scholarly journals Improving Winter Wheat Yields In Organic Farming Systems Through Innovations In Green Manure Management

2015 ◽  
Vol 2 ◽  
pp. 268
Author(s):  
Danguolė Nemeikšienė ◽  
Aušra Arlauskienė ◽  
Alvyra Šlepetienė
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Nitrogen Content ◽  
Field Experiments ◽  
Trifolium Pratense ◽  
Inorganic Nitrogen ◽  
Farming Systems ◽  
Perennial Grasses ◽  
Research Station ◽  
Trifolium Pratense L

The paper presents effect of perennial grasses (Trifolium pratense L., Medicago sativa L., xFestulolium) and their aboveground mass management methods (removed from the field, mixed, mulching) as preceding crops on Ninorg in the soil as well as on yield of winter wheat under conditions of ecological farming. Field experiments were carried out at the Joniškėlis Research Station of the Lithuanian Institute of Agriculture (LIA) on an Gleyic Cambisol. Experimental evidence indicated that content of symbiotically fixed nitrogen in the biomass of legumes accounted for the largest share (61–84 %) of the total nitrogen content (208.0–298.0 kg ha- 1), accumulated in the biomass. Winter wheat grain yield significantly (r = 0.783; P &lt; 0.05) correlated with soil inorganic nitrogen content in spring. Grain yield productivity increased by 0.01 t ha-1 after incorporation of 1 kg ha-1 nitrogen of legume crops biomass.

Bio-efficacy of post emergence herbicides in boro rice nursery as well as main field and their residual effects on non-target microorganisms

2020 ◽  
Vol 57 (3) ◽  
pp. 199-210
Author(s):  
Rajib Kundu ◽  
Mousumi Mondal ◽  
Sourav Garai ◽  
Ramyajit Mondal ◽  
Ratneswar Poddar
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Field Experiments ◽  
Block Design ◽  
Resistance Index ◽  
Residual Effects ◽  
Cost Ratio ◽  
Main Field ◽  
Weed Species ◽  
Similar Treatment

Field experiments were conducted at research farm of Bidhan Chandra Krishi Viswavidyalaya, Kalyani, West Bengal, India (22°97' N latitude and 88°44' E longitude, 9.75 m above mean sea level) under natural weed infestations in boro season rice (nursery bed as well as main field) during 2017-18 and 2018-19 to evaluate the herbicidal effects on weed floras, yield, non-target soil organisms to optimize the herbicide use for sustainable rice-production. Seven weed control treatments including three doses of bispyribac-sodium 10% SC (150,200, and 250 ml ha-1), two doses of fenoxaprop-p-ethyl 9.3% EC (500 and 625 ml ha-1), one weed free and weedy check were laid out in a randomized complete block design, replicated thrice. Among the tested herbicides, bispyribac-sodium with its highest dose (250 ml ha-1) resulted in maximum weed control efficiency, treatment efficiency index and crop resistance index irrespective of weed species and dates of observation in both nursery as well as main field. Similar treatment also revealed maximum grain yield (5.20 t ha-1), which was 38.38% higher than control, closely followed by Fenoxaprop-p-ethyl (625 ml ha-1) had high efficacy against grasses, sedge and broadleaf weed flora. Maximum net return (Rs. 48765 ha-1) and benefit cost ratio (1.72) were obtained from the treatment which received bispyribac-sodium @ 250 ml ha-1. Based on overall performance, the bispyribac-sodium (250 ml ha-1) may be considered as the best herbicide treatment for weed management in transplanted rice as well as nursery bed.

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.

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.

Effect of herbicides on the weed infestation and grain yield of soybean (Glycine max)

2004 ◽  
Vol 52 (2) ◽  
pp. 199-203 ◽  
Author(s):  
G. Singh ◽  
R. S. Jolly
Keyword(s):  
Glycine Max ◽  
Grain Yield ◽  
Weed Control ◽  
Negative Correlation ◽  
Rainy Season ◽  
Dry Matter ◽  
Field Experiments ◽  
Sand Soil ◽  
Loamy Sand Soil ◽  
Weed Infestation

Two field experiments were conducted during the kharif (rainy) season of 1999 and 2000 on a loamy sand soil to study the effect of various pre- and post-emergence herbicides on the weed infestation and grain yield of soybean. The presence of weeds in the weedy control plots resulted in 58.8 and 58.1% reduction in the grain yield in the two years compared to two hand weedings (HW) at 30 and 45 days after sowing (DAS), which gave grain yields of 1326 and 2029 kg ha-1. None of the herbicides was significantly superior to the two hand weedings treatment in influencing the grain yield. However, the pre-emergence application of 0.75 kg ha-1 S-metolachlor, and 0.5 kg ha-1 pendimethalin (pre-emergence) + HW 30 DAS were at par or numerically superior to this treatment. There was a good negative correlation between the weed dry matter at harvest and the grain yield of soybean, which showed that effective weed control is necessary for obtaining higher yields of soybean.

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