Effect of Herbicides on Field Violet (Viola arvensis) in Direct-Seeded Spring Wheat

2005 ◽  
Vol 19 (2) ◽  
pp. 359-371 ◽  
Author(s):  
Rory F. Degenhardt ◽  
Dean Spaner ◽  
K. Neil Harker ◽  
William R. Mcgregor ◽  
Linda M. Hall
Keyword(s):  
Spring Wheat ◽  
Crop Production ◽  
Field Experiments ◽  
Plant Density ◽  
Dry Weight ◽  
Effective Control ◽  
Weed Species ◽  
Weed Growth ◽  
Direct Seeded ◽  
Cereal Fields

The agrestal field violet, a pervasive weed in Europe, has been identified in reduced-tillage cereal fields in Alberta. The efficacy of herbicides in direct-seeded spring wheat was assessed on natural field violet infestations in Alberta in 2002 and 2003. Only fluroxypyr + 2,4-D, applied postemergence, provided control of field violet in 2002 when rainfall was limiting. Over both years, this herbicide combination reduced biomass by 59 to 69% and plant density by 83 to 91%, relative to nontreated plots. The herbicides metsulfuron, sulfosulfuron, and thifensulfuron + tribenuron only suppressed weed growth under drought conditions in 2002 but controlled the weed in 2003 when rainfall was greater, reducing plant density by 82 to 92% and rendering remaining plants sterile. Suppression was also observed with MCPA + mecoprop + dicamba in 2002 and 2003 and with metribuzin only in 2003. Effective control of field violet was conferred by a pre–crop emergence application of glyphosate at 445 g ae/ha in 2003, the only year that this treatment was evaluated. Activity of herbicides on three- to four-leaf seedlings was also evaluated in a greenhouse dose– response assay. All herbicides had greater efficacy in the greenhouse, and those that provided control in situ reduced field violet dry weight by 85% at less than the recommended rate used in field experiments. Management of field violet is possible with herbicides registered for use on spring wheat in Alberta. However, the weed does not appear to cause significant crop production losses; hence, herbicide selection should be based on knowledge of all weed species present within the field.

Seed Production and Control of Sicklepod (Senna obtusifolia) and Pitted Morningglory (Ipomoea lacunosa) with 2,4-D, Dicamba, and Glyphosate Combinations

2016 ◽  
Vol 30 (1) ◽  
pp. 76-84 ◽  
Author(s):  
Ramon G. Leon ◽  
Jason A. Ferrell ◽  
Brent A. Sellers
Keyword(s):  
Seed Production ◽  
Crop Production ◽  
Field Experiments ◽  
Effective Control ◽  
Weed Species ◽  
Application Timing ◽  
Pitted Morningglory ◽  
Herbicide Treatments ◽  
Viable Seeds ◽  
And Control

Sicklepod and pitted morningglory are two of the most important weed species in row-crop production in the southeastern United States. The upcoming introduction of soybean and cotton varieties resistant to 2,4-D and dicamba will increase the reliance on these auxinic herbicides. However, it is not clear how these herbicides will affect sicklepod and pitted morningglory control. Field experiments were conducted in 2013 and 2014 in Jay, FL to determine whether 2,4-D (560 and 1,120 g ae ha−1), dicamba (420 and 840 g ae ha−1), and glyphosate (1,060 g ae ha−1) alone or in combination applied when weed shoots were 11 (early POST [EPOST]) and 22 (late POST [LPOST]) cm long effectively control and prevent seed production of sicklepod and pitted morningglory. LPOST provided more effective control of sicklepod than EPOST. This was attributed to emergence of sicklepod seedlings after the EPOST application. When glyphosate was tank mixed with 2,4-D or dicamba, sicklepod control was higher (78 to 89% and 87 to 98% in 2013 and 2014, respectively) than for single-herbicide treatments (45 to 77% and 38 to 80% in 2013 and 2014, respectively) 6 wk after treatment (WAT). Pitted morningglory control was not affected by application timing, and 2,4-D provided 91 to 100% 6 WAT, which was equivalent to treatments with tank mixtures containing glyphosate. Dicamba applied at 420 g ha−1had the lowest pitted morningglory control (44 to 70% and 82 to 86% in 2013 and 2014, respectively). Sicklepod and pitted morningglory plants that survived and recovered from herbicide treatments produced the same number of viable seeds as nontreated plants in most treatments. The results of the present study indicated that the use of 2,4-D and dicamba alone will not provide adequate extended control of sicklepod, and the use of tank mixtures that combine auxinic herbicides with glyphosate or other POST herbicides will be necessary to manage sicklepod adequately in 2,4-D- or dicamba-resistant soybean and cotton. Because sicklepod plants that survived a single herbicide application are capable of producing abundant viable seeds, integrated approaches that include PRE herbicides and sequential POST control options may be necessary to ensure weed seed bank reductions.

scholarly journals The effectiveness of weed regulation methods in spring wheat cultivated in integrated, conventional and organic crop production systems

2012 ◽  
Vol 52 (4) ◽  
pp. 486-493 ◽  
Author(s):  
Beata Feledyn-Szewczyk
Keyword(s):  
Spring Wheat ◽  
Crop Production ◽  
Dry Matter ◽  
Production Systems ◽  
Integrated System ◽  
Integrated Systems ◽  
Conventional System ◽  
Weed Species ◽  
Organic System ◽  
Weed Communities

Abstract The research was conducted from 2008 to 2010, and compared the influence of different weed control methods used in spring wheat on the structure of the weed communities and the crop yield. The study was carried out at the Experimental Station of the Institute of Soil Science and Plant Cultivation - State Research Institute in Osiny as part of a long-term trial where these crop production systems had been compared since 1994. In the conventional and integrated systems, spring wheat was grown in a pure stand, whereas in the organic system, the wheat was grown with undersown clover and grasses. In the conventional system, herbicides were applied two times in a growing season, but in the integrated system - only once. The effectiveness of weed management was lower in the organic system than in other systems, but the dry matter of weeds did not exceed 60 g/m2. In the integrated system, the average dry matter of weeds in spring wheat was 4 times lower, and in the conventional system 10 times lower than in the organic system. Weed diversity was the largest in spring wheat cultivated in the organic system. In the conventional and integrated systems, compensation of some weed species was observed (Viola arvensis, Fallopia convolvulus, Equisetum arvense). The comparison of weed communities using Sorenson’s indices revealed more of a similarity between systems in terms of number of weed species than in the number of individuals. Such results imply that qualitative changes are slower than quantitative ones. The yield of grain was the biggest in the integrated system (5.5 t/ha of average). It was 35% higher than in the organic system, and 20% higher than in conventional ones.

scholarly journals Impact of Different Seed Rates and Knocking Down Days of Sesbania on Weed Density and Yield of Dry Direct Seeded Rice

2018 ◽  
Vol 6 (4) ◽  
pp. 359-365
Author(s):  
Sunil Kumar Chaudhary ◽  
Santosh Marahatta ◽  
Manisha Chaudhary
Keyword(s):  
Monsoon Season ◽  
Dry Weight ◽  
Effective Control ◽  
Seed Rate ◽  
Weed Density ◽  
Plot Size ◽  
Major Constraint ◽  
Direct Seeded ◽  
The Individual ◽  
Plot Design

The weed is a major constraint of dry-direct seeded rice (DDSR) due to change in establishment methods and shifting weed flora towards competitive grasses and sedges. To minimize the weed density, its species and dry weight with brown manuring and for optimizing the yield of DDSR, the experiment was conducted during monsoon season of 2014 at Chitwan, Nepal. The experiment was done using a strip plot design to find the optimum seed rate and killing date of Sesbania under rice-Sesbania co-culture. Among different seed rates (60, 80, 100 kg ha-1) and knocking down days (21, 28, 35 & 42 DAS) of Sesbania, the optimum seed rate of Sesbania was 102 kg ha-1 and killing date was 32 days. The individual plot size was 5 x 4 m2. The growing of Sesbania with 100 kg seeds ha-1 along with its knocked down at 28 DAS was seen best to minimize the weeds having better performance of rice. The experiment clearly demonstrated the importance of brown manuring on effective control of weeds and on grain yield of rice under dry direct seeded rice. Int. J. Appl. Sci. Biotechnol. Vol 6(4): 359-365

COMPARISON OF PRESEEDING TILLAGE WITH TOTAL AND MINIMAL TILLAGE BY VARIOUS SEEDING MACHINES ON SPRING WHEAT PRODUCTION IN SOUTHERN SASKATCHEWAN

1975 ◽  
Vol 55 (1) ◽  
pp. 59-67 ◽  
Author(s):  
C. H. ANDERSON
Keyword(s):  
Protein Content ◽  
Spring Wheat ◽  
Plant Density ◽  
Triticum Aestivum L ◽  
Western Canada ◽  
Volume Weight ◽  
Soil Zone ◽  
Weight Yield ◽  
Seed Placement ◽  
Direct Seeded

In a 6-yr study at Swift Current, Saskatchewan in the Brown soil zone of Western Canada, preseeding tillage did not significantly influence the volume weight or yield of spring wheat (Triticum aestivum L.). There were some indications that protein content of wheat was enhanced by preseeding tillage but the results were not consistent. A 2-yr supplementary study, on the other hand, did not show any benefits from preseeding tillage. Plant density was lower on plots seeded with the discer, whether direct-seeded or following preseeding tillage. The seed was also placed deeper in the soil compared to seeding with the hoe press or double-disc seeders, as indicated by the length of the plants’ subcoronal internodes. However, the differences in plant density and depth of seed placement were not reflected in the final wheat yields; this emphasized the ability of the wheat plants to compensate for establishment differences within the moisture limits encountered. There were no significant differences in volume weight, yield, or protein content of wheat for those seeders that provided total tillage during the seeding operation (discer or cultivator-rod weeder drills) as compared to seeders that provided only minimal tillage in the seed row (hoe, single-disc or triple-disc drills) when preseeding tillage was not practiced.

Winter Annual Weed Suppression in Rye–Vetch Cover Crop Mixtures

2012 ◽  
Vol 26 (4) ◽  
pp. 818-825 ◽  
Author(s):  
Zachary D. Hayden ◽  
Daniel C. Brainard ◽  
Ben Henshaw ◽  
Mathieu Ngouajio
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Field Experiments ◽  
Dry Weight ◽  
Weed Suppression ◽  
Weed Species ◽  
Cereal Rye ◽  
Winter Annual ◽  
Winter Annual Weeds ◽  
Annual Weeds

Winter annual weeds can interfere directly with crops and serve as alternative hosts for important pests, particularly in reduced tillage systems. Field experiments were conducted on loamy sand soils at two sites in Holt, MI, between 2008 and 2011 to evaluate the relative effects of cereal rye, hairy vetch, and rye–vetch mixture cover crops on the biomass and density of winter annual weed communities. All cover crop treatments significantly reduced total weed biomass compared with a no-cover-crop control, with suppression ranging from 71 to 91% for vetch to 95 to 98% for rye. In all trials, the density of nonmustard family broadleaf weeds was either not suppressed or suppressed equally by all cover crop treatments. In contrast, the density of mustard family weed species was suppressed more by rye and rye–vetch mixtures than by vetch. Cover crops were more consistently suppressive of weed dry weight per plant than of weed density, with rye-containing cover crops generally more suppressive than vetch. Overall, rye was most effective at suppressing winter annual weeds; however, rye–vetch mixtures can match the level of control achieved by rye, in addition to providing a potential source of fixed nitrogen for subsequent cash crops.

Wild Oat (Avena fatua) Competition with Spring Wheat: Effects of Nitrogen Fertilization

Weed Science ◽  
1986 ◽  
Vol 34 (1) ◽  
pp. 29-33 ◽  
Author(s):  
Harry L. Carlson ◽  
James E. Hill
Keyword(s):  
Spring Wheat ◽  
Nitrogen Fertilization ◽  
Field Experiments ◽  
Plant Density ◽  
Crop Yields ◽  
Wheat Yield ◽  
Avena Fatua ◽  
Yield Response ◽  
Wild Oat ◽  
Total Plant

Field experiments were conducted to determine the effect of nitrogen fertilization on competition between wild oat (Avena fatuaL. # AVEFA) and spring wheat (Triticum aestivum‘Anza’). Nitrogen fertilizer treatments were applied over several wild oat-wheat density combinations. Wheat grain yield in wild oat-infested plots generally declined with fertilization while the density of wild oat panicles increased. Apparently, in competition with wheat, wild oat was better able to utilize the added nitrogen and thus gained a competitive advantage over the wheat. The increased competitiveness of wild oat resulted in reduced crop yields. Under the conditions of these experiments, nitrogen fertilization resulted in positive wheat yield response only when the wild oat plant density was below 1.6 percent of the total plant density.

scholarly journals Mechanisms Regulating Grain Contamination with Trichothecenes Translocated from the Stem Base of Wheat (Triticum aestivum) Infected with Fusarium culmorum

2013 ◽  
Vol 103 (7) ◽  
pp. 682-689 ◽  
Author(s):  
Mark Winter ◽  
Birger Koopmann ◽  
Katharina Döll ◽  
Petr Karlovsky ◽  
Ute Kropf ◽  
...  
Keyword(s):  
Crop Production ◽  
Fusarium Culmorum ◽  
Dry Weight ◽  
Effective Control ◽  
Uridine Diphosphate ◽  
Head Blight ◽  
Wheat Grains ◽  
Stem Base ◽  
Plant Parts ◽  
Major Interest

Factors limiting trichothecene contamination of mature wheat grains after Fusarium infection are of major interest in crop production. In addition to ear infection, systemic translocation of deoxynivalenol (DON) may contribute to mycotoxin levels in grains after stem base infection with toxigenic Fusarium spp. However, the exact and potential mechanisms regulating DON translocation into wheat grains from the plant base are still unknown. We analyzed two wheat cultivars differing in susceptibility to Fusarium head blight (FHB), which were infected at the stem base with Fusarium culmorum in climate chamber experiments. Fungal DNA was found only in the infected stem base tissue, whereas DON and its derivative, DON-3-glucoside (D3G), were detected in upper plant parts. Although infected stem bases contained more than 10,000 μg kg–1 dry weight (DW) of DON and mean levels of DON after translocation in the ear and husks reached 1,900 μg kg–1 DW, no DON or D3G was detectable in mature grains. D3G quantification revealed that DON detoxification took mainly place in the stem basis, where ≤50% of DON was metabolized into D3G. Enhanced expression of a gene putatively encoding a uridine diphosphate-glycosyltransferase (GenBank accession number FG985273) was observed in the stem base after infection with F. culmorum. Resistance to F. culmorum stem base infection, DON glycosylation in the stem base, and mycotoxin translocation were unrelated to cultivar resistance to FHB. Histological studies demonstrated that the vascular transport of DON labeled with fluorescein as a tracer from the peduncle to the grain was interrupted by a barrier zone at the interface between grain and rachilla, formerly described as “xylem discontinuity”. This is the first study to demonstrate the effective control of influx of systemically translocated fungal mycotoxins into grains at the rachilla–seed interface by the xylem discontinuity tissue in wheat ears.

Agronomic Aspects of Broad Beans (Vicia Faba L.) Grown in the Sudan

1968 ◽  
Vol 4 (2) ◽  
pp. 151-159 ◽  
Author(s):  
E. A. K. El Saeed
Keyword(s):  
Field Experiments ◽  
Plant Density ◽  
Dry Weight ◽  
Factors Affecting ◽  
Growing Seasons ◽  
Broad Beans ◽  
Final Yield ◽  
Total Seed ◽  
Leaf Dry Weight ◽  
Pod Growth

SummaryField experiments in three successive growing seasons (1963–66) studied effects of variety and plant density on yield components of broad beans. In 1963/64 total seed yield of a local variety (Beladi), increased with increasing seed rates from 70 to 280 lb per feddan, but yield increment diminished beyond 140 lb. The same results were obtained with Beladi and Rebaya 34 in 1964/65 and 1965/66, but Rebaya 34, yielded less than Beladi at all seed rates. Growth analysis revealed that Rebaya 34 had greater growth rate at the beginning of the season, due to its relatively large seed size, but eventually Beladi overtook it. Maximum pod growth in both varieties occurred when leaf dry weight was declining. The proportion of dry matter was greater in pods of Beladi than Rebaya 34 because of more sinks in the former variety. The present seed rate of 70 lb per feddan seems to be suboptimal and factors affecting establishment and/or effective leaf area at the time of pod growth are detrimental to the final yield.

Evaluation of Cotton Responses to Fomesafen-Based Treatments Applied Preemergence

2018 ◽  
Vol 32 (4) ◽  
pp. 431-438 ◽  
Author(s):  
Xiao Li ◽  
Timothy Grey ◽  
William Vencill ◽  
James Freeman ◽  
Katilyn Price ◽  
...  
Keyword(s):  
Field Experiments ◽  
Yield Loss ◽  
Sandy Loam ◽  
Clay Content ◽  
Dry Weight ◽  
High Rate ◽  
Growth And Yield ◽  
Effective Control ◽  
Yield Response ◽  
Cotton Yield

AbstractFomesafen provides effective control of glyphosate-resistant Palmer amaranth in cotton. However, cotton seedlings can be injured when fomesafen is applied PRE. Therefore, greenhouse and field experiments were conducted at Athens, GA, and at six locations in Alabama and Georgia in 2013 and 2016 to evaluate cotton growth and yield response to fomesafen applied PRE at 70, 140, 280, 560, 1,120, or 2,240 g ai ha−1, and in combination with pendimethalin, diuron, acetochlor, and fluridone at 1×label rates. Greenhouse bioassays indicated that fomesafen reduced cotton height and dry weight with increasing rate in Cecil sandy loam and Tifton loamy sand but not in Greenville sandy clay loam––possibly as a result of this soil’s higher organic matter (OM) and clay content. Fomesafen applied at 2,240 g ai ha−1 reduced cotton stand by as much as 83% compared to the nontreated check (NTC) at all field locations except Alabama’s Macon and Baldwin counties, and 1,120 g ai ha−1 reduced cotton stand only at Pulaski County, GA, by 52%. Cotton height was reduced by the two highest rates of fomesafen at all locations except Clarke County, GA, and Baldwin County, AL. Injury data indicated more visual injury followed increasing fomesafen rates, and high-rate treatments produced more injury in sandier soils. Cotton yield was unaffected by herbicide treatments at any location, except for the 1,120 g ai ha−1 rate at Pulaski County (49% yield loss compared to NTC), 2,240 g ai ha−1 at Pulaski County (72% yield loss), and Tift County (29% yield loss). These data indicated cotton yield should not be negatively affected by fomesafen applied PRE alone within label rates or in combination with pendimethalin, diuron, acetochlor, and fluridone at 1×label rates, although some visual injury, or stand or height reduction may occur early in the growing season.

scholarly journals Effects of competition with weeds on growth, development and yield of groundnuts.

1992 ◽  
Vol 40 (1) ◽  
pp. 73-90
Author(s):  
A.P. Everaarts
Keyword(s):  
Weed Control ◽  
Field Experiments ◽  
Plant Density ◽  
Plant Competition ◽  
Ground Cover ◽  
Stem Length ◽  
Yield Losses ◽  
Weed Growth ◽  
Competition For Light ◽  
Number Of Leaves

Competition between weeds and groundnuts was studied in two field experiments in the inland Zanderij area of Suriname. The crop was kept weed-free or without weed control for increasing periods of time after planting. Observations made at the end of each period with or without weed control provided an analysis of the growth of a crop with weed control and of a crop without weed control. Uncontrolled weed growth was concentrated between the rows. Competition with weeds reduced ground cover and LAI of the crop. DM accumulation was affected, resulting in lower yields. Plant density and number of branches per plant were not influenced. Weed competition increased stem length and reduced the number of leaves and pods per plant. Timing of flowering was not influenced. Competition for nutrients was absent, but there was competition for light and water. About 15 weed-free days after planting were sufficient to prevent yield losses. Yield losses were due to a reduction in number of pods per plant. Competition should especially be prevented in the period when the number of pods per plant is established, i.e. around 35-60 days after planting. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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