Diverse Rotations and Optimal Cultural Practices Control Wild Oat (Avena fatua)

Weed Science ◽  
2016 ◽  
Vol 64 (1) ◽  
pp. 170-180 ◽  
Author(s):  
K. Neil Harker ◽  
John T. O'Donovan ◽  
T. Kelly Turkington ◽  
Robert E. Blackshaw ◽  
Newton Z. Lupwayi ◽  
...  
Keyword(s):  
Cultural Practices ◽  
Wild Oat ◽  
Weed Species ◽  
Seeding Rate ◽  
Crop Species ◽  
Winter Cereals ◽  
Resistance To Herbicides ◽  
Oat Biomass ◽  
Herbicide Use ◽  
Barley Silage

In western Canada, more money is spent on wild oat herbicides than on any other weed species, and wild oat resistance to herbicides is the most widespread resistance issue. A direct-seeded field experiment was conducted from 2010 to 2014 at eight Canadian sites to determine crop life cycle, crop species, crop seeding rate, crop usage, and herbicide rate combination effects on wild oat management and canola yield. Combining 2× seeding rates of early-cut barley silage with 2× seeding rates of winter cereals and excluding wild oat herbicides for 3 of 5 yr (2011 to 2013) often led to similar wild oat density, aboveground wild oat biomass, wild oat seed density in the soil, and canola yield as a repeated canola–wheat rotation under a full wild oat herbicide rate regime. Wild oat was similarly well managed after 3 yr of perennial alfalfa without wild oat herbicides. Forgoing wild oat herbicides in only 2 of 5 yr from exclusively summer annual crop rotations resulted in higher wild oat density, biomass, and seed banks. Management systems that effectively combine diverse and optimal cultural practices against weeds, and limit herbicide use, reduce selection pressure for weed resistance to herbicides and prolong the utility of threatened herbicide tools.

Integrating Cropping Systems with Cultural Techniques Augments Wild Oat (Avena fatua) Management in Barley

Weed Science ◽  
2009 ◽  
Vol 57 (3) ◽  
pp. 326-337 ◽  
Author(s):  
K. Neil Harker ◽  
John T. O'Donovan ◽  
R. Byron Irvine ◽  
T. Kelly Turkington ◽  
George W. Clayton
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Management Practices ◽  
Cultural Practices ◽  
Field Pea ◽  
Wild Oat ◽  
Weed Species ◽  
Seeding Rate ◽  
Canadian Prairie ◽  
Barley Cultivars

Wild oat causes more crop yield losses and accounts for more herbicide expenditures than any other weed species on the Canadian Prairies. A study was conducted from 2001 to 2005 at four Canadian Prairie locations to determine the influence of repeated cultural and herbicidal management practices on wild oat population density, biomass, and seed production, and on barley biomass and seed yield. Short or tall cultivars of barley were combined with normal or double barley seeding rates in continuous barley or a barley–canola–barley–field-pea rotation under three herbicide rate regimes. The same herbicide rate regime was applied to the same plots in all crops each year. In barley, cultivar type and seeding rate were also repeated on the same plots year after year. Optimal cultural practices (tall cultivars, double seeding rates, and crop rotation) reduced wild oat emergence, biomass, and seed production, and increased barley biomass and seed yield, especially at low herbicide rates. Wild oat seed production at the quarter herbicide rate was reduced by 91, 95, and 97% in 2001, 2003, and 2005, respectively, when tall barley cultivars at double seeding rates were rotated with canola and field pea (high management) compared to short barley cultivars at normal seeding rates continuously planted to barley (low management). Combinations of favorable cultural practices interacted synergistically to reduce wild oat emergence, biomass and seed production, and to increase barley yield. For example, at the quarter herbicide rate, wild oat biomass was reduced 2- to 3-, 6- to 7-, or 19-fold when optimal single, double, or triple treatments were combined, respectively. Barley yield reductions in the low-management scenario were somewhat compensated for by full herbicide rates. However, high management at low herbicide rates often produced more barley than low management in higher herbicide rate regimes.

Management of wild oat (Avena fatua L.) in tame oat (Avena sativa L.) with early seeding dates and high seeding rates

2009 ◽  
Vol 89 (4) ◽  
pp. 763-773 ◽  
Author(s):  
W E May ◽  
S J Shirtliffe ◽  
D W McAndrew ◽  
C B Holzapfel ◽  
G P Lafond
Keyword(s):  
Grain Yield ◽  
Avena Sativa ◽  
Test Weight ◽  
Wild Oat ◽  
Seeding Rate ◽  
Yield And Quality ◽  
Seeding Date ◽  
Grain Yield And Quality ◽  
Oat Biomass ◽  
Density Treatment

Traditionally, farmers have delayed seeding to manage wild oat (Avena fatua L.) in tame oat (Avena sativa L.) crops, but this practice can adversely affect grain yield and quality. The objectives of this study were: (1) to evaluate the effectiveness of using high seeding rates with early-seeded oat to maintain grain yield and quality, and (2) to determine an optimum seeding rate to manage wild oat and maximize grain yield and quality. The factors of interest were wild oat density (low and high density), seeding date (early May, mid May, early June and mid June), and tame oat seeding rate (150, 250, 350 and 450 viable seeds m-2). The study was conducted at Indian Head and Saskatoon, SK, in 2002, 2003 and 2004, at Winnipeg, MB, in 2002, and at Morden, MB, in 2003 and 2004. Wild oat biomass, wild oat panicle density and wild oat seed in the harvested sample decreased as seeding rate increased, while tame oat biomass and grain yield increased. Wild oat density ranged between 0 and 100 plants m-2 with averages of 10 plants m-2 in the low density treatment and 27 plants m-2 in the high density treatment. At low seeding rates, grain yield decreased with increasing wild oat density. The difference in grain yield between the two wild oat densities decreased as the seeding rate increased. There was a curvilinear decrease in grain yield as seeding was delayed. A seeding date × seeding rate interaction was noted for test weight, plump seed, thin seed and groat yield. Seed quality improved as seeding rate increased for only the mid-June seeding date. Even though the mid-June test weight increased as the seeding rate increased it was always lower than the early May test weight at any seeding rate. The results from this study established that in the presence of wild oats, early seeding of tame oat is possible providing high seeding rates, 350 plants m-2 are used.Key words: Wild oat competition, wild oat density, wild oat biomass, grain yield, grain quality

A Review of Herbicide Resistance in Iran

Weed Science ◽  
2016 ◽  
Vol 64 (4) ◽  
pp. 551-561 ◽  
Author(s):  
Javid Gherekhloo ◽  
Mostafa Oveisi ◽  
Eskandar Zand ◽  
Rafael De Prado
Keyword(s):  
Herbicide Resistance ◽  
Crop Production ◽  
Arable Land ◽  
Wheat Crop ◽  
Wild Oat ◽  
Weed Species ◽  
Wild Mustard ◽  
Development Of Resistance ◽  
Resistance To Herbicides ◽  
Continuous Use

Continuous use of herbicides has triggered a phenomenon called herbicide resistance. Nowadays, herbicide resistance is a worldwide problem that threatens sustainable agriculture. A study of over a decade on herbicides in Iran has revealed that herbicide resistance has been occurring since 2004 in some weed species. Almost all the results of these studies have been published in national scientific journals and in conference proceedings on the subject. In the current review, studies on herbicide resistance in Iran were included to provide a perspective of developing weed resistance to herbicides for international scientists. More than 70% of arable land in Iran is given over to cultivation of wheat, barley, and rice; wheat alone covers nearly 52%. Within the past 40 years, 108 herbicides from different groups of modes of action have been registered in Iran, of which 28 are for the selective control of weeds in wheat and barley. Major resistance to ACCase-inhibiting herbicides has been shown in some weed species, such as winter wild oat, wild oat, littleseed canarygrass, hood canarygrass, and rigid ryegrass. With respect to the broad area of wheat crop production and continuous use of herbicides with the sole mechanism of action of ACCase inhibition, the provinces of West Azerbaijan, Tehran, Khorasan, Isfahan, Markazi, and Semnan are at risk of resistance development. In addition, because of continuous long-term use of tribenuron-methyl, resistance in broadleaf species is also being developed. Evidence has recently shown resistance of turnipweed and wild mustard populations to this herbicide. Stable monitoring of fields in doubtful areas and providing good education and training for technicians and farmers to practice integrated methods would help to prevent or delay the development of resistance to herbicides.

Cover-Crop Species as Distinct Biotic Filters in Weed Community Assembly

Weed Science ◽  
2015 ◽  
Vol 63 (1) ◽  
pp. 282-295 ◽  
Author(s):  
Richard G. Smith ◽  
Lesley W. Atwood ◽  
Fredric W. Pollnac ◽  
Nicholas D. Warren
Keyword(s):  
Cover Crops ◽  
Community Assembly ◽  
Cover Crop ◽  
Weed Species ◽  
Seeding Rate ◽  
Crop Species ◽  
Cover Cropping ◽  
Directional Filtering ◽  
Weed Communities ◽  
Sorghum Sudangrass

Cover crops represent a potentially important biological filter during weed community assembly in agroecosystems. This filtering could be considered directional if different cover-crop species result in weed communities with predictably different species composition. We examined the following four questions related to the potential filtering effects of cover crops in a field experiment involving five cover crops grown in monoculture and mixture: (1) Do cover crops differ in their effect on weed community composition? (2) Is competition more intense between cover crops and weeds that are in the same family or functional group? (3) Is competition more intense across weed functional types in a cover-crop mixture compared with cover crops grown in monocultures? (4) Within a cover-crop mixture, is a higher seeding rate associated with more effective biotic filtering of the weed community? We found some evidence that cover crops differentially filtered weed communities and that at least some of these filtering effects were due to differential biomass production across cover-crop species. Monocultures of buckwheat and sorghum–sudangrass reduced the number of weed species relative to the no-cover-crop control by an average of 36 and 59% (buckwheat) and 25 and 40% (sorghum–sudangrass) in 2011 and 2012, respectively. We found little evidence that competition intensity was dependent upon the family or functional classification of the cover crop or weeds, or that cover-crop mixtures were stronger assembly filters than the most effective monocultures. Although our results do not suggest that annual cover crops exert strong directional filtering during weed community assembly, our methodological framework for detecting such effects could be applied to similar future studies that incorporate a greater number of cover-crop species and are conducted under a greater range of cover-cropping conditions.

Annual broadleaf crop frequency and residual weed populations in Saskatchewan Parkland

Weed Science ◽  
1999 ◽  
Vol 47 (2) ◽  
pp. 208-214 ◽  
Author(s):  
F. Craig Stevenson ◽  
Adrian M. Johnston
Keyword(s):  
Reproductive Strategies ◽  
Cereal Crops ◽  
Wild Oat ◽  
Weed Species ◽  
Weed Density ◽  
Future Problem ◽  
Weed Infestation ◽  
The Difference ◽  
A Site ◽  
Herbicide Use

The development of problematic weed populations is a concern in western Canadian fields where canola and pea are grown in a 4-yr sequence with spring cereal grains. Weed densities were examined at a site near Melfort, Saskatchewan, Canada, from 1994 to 1997 in seven zero-till managed crop rotations. Four rotations that included canola, pea, or flax in at least 3 of 4 yr (HBF: high broadleaf–crop frequency) were compared with three rotations that included broadleaf crops grown in 2 of 4 yr (LBF: low broadleaf–crop frequency). Spring wheat and barley were the cereal crops in rotation. Residual (postherbicide application) weed density for each weed species in a given year was summed across all phases for each rotation to reflect the overall weed infestation. Four annual broadleaf weed species were most abundant in 1996 and a second group of three species, having a variety of reproductive strategies, became progressively less abundant as the study progressed. The difference between the HBF and LBF rotations for the density of these species varied and was most prominent in years when environmental conditions were conducive for their growth. More frequent applications of ethafluralin, with its residual weed control, best explained why wild oat and catchweed bedstraw generally were less abundant in the HBF rotations. Of particular interest was the 8 plants m−-2greater density of dandelion and perennial sowthistle in the HBF vs. LBF rotations in the last year of the study. It is thought that the limited herbicide options for the control of these species could present a future problem if they continued to develop in the HBF rotations. Differences in herbicide use between the HBF and LBF rotations were considered the primary factor controlling the rotation effects on weed density.

Altering the competitiveness of tame oat (Avena sativa L.) versus wild oat (Avena fatua L.) with phosphorus and seeding rate

2018 ◽  
Vol 98 (3) ◽  
pp. 582-590
Author(s):  
W.E. May
Keyword(s):  
Grain Yield ◽  
Avena Sativa ◽  
Avena Fatua ◽  
Wild Oat ◽  
Seeding Rate ◽  
Agronomic Practices ◽  
Yield And Quality ◽  
P Rate ◽  
Oat Biomass ◽  
Plot Design

Currently, no in-crop herbicide is registered to control wild oat (Avena fatua L.) in tame oat (Avena sativa L.). Wild oat must be controlled in tame oat using other agronomic practices. The objective of this research was to determine if side-banded phosphorus (P) in combination with seeding rate would increase the competitiveness of tame oat with wild oat, increasing yield and quality. An experiment was conducted from 2003–2005 at Indian Head, SK. The experimental design was a strip-plot design with four replications. The strips were low and high wild oat density. A two-way factorial, seeding rate (150, 250, 350, and 450 plants m−2), and P rate (0, 15, and 30 kg P2O5 ha−1) were seeded across the strips. Phosphorus affected seed density, grain yield, oat biomass, and wild oat fecundity. Seeding rate affected most of the measured variables and interacted with wild oat and year. The application of P increased the competiveness of oat by increasing crop biomass by 7.6% and grain yield by 3.4% and decreasing wild oat seed from 1.26% to 0.76% in the harvested grain. Wild oat decreased grain yield by 23% in 2003, 4.4% in 2004, and 11% in 2005. Increasing the seeding rate increased grain yield by 5% when wild oat was present. Wild oat did not interfere with the uptake of side-banded P. Producers need to use both P fertilization and higher seeding rates to improve the competitiveness of tame oat and the management of wild oat in tame oat.

Alopecurus myosuroides (black-grass).

2021 ◽  
Author(s):  
Charlie Riches
Keyword(s):  
Western Europe ◽  
Large Degree ◽  
Agricultural Practice ◽  
Weed Species ◽  
Alopecurus Myosuroides ◽  
Winter Cereals ◽  
Resistance To Herbicides ◽  
Noxious Weed ◽  
Warm Temperate ◽  
Temperate Cereal

Abstract A. myosuroides is an annual grass which is native to Eurasia and grows in moist meadows, deciduous forests, and cultivated or disturbed ground. A significant weed species in temperate cereal crops, it has become one of the most damaging weeds of winter cereals in Western Europe with the changes in agricultural practice over the past 30 years from regular ploughing to reduced tillage systems, suppression of broadleaf weeds in continuous cereals, and the move away from burning of stubbles. These changes have allowed the weed to invade well-drained lighter soils in addition to the heavier clay soils on which it is dominant. It has been introduced repeatedly as a weed of cultivation into many temperate and warm temperate regions but has not spread to a large degree out of cultivation. A. myosuroides has been listed as a noxious weed in the state of Washington, one of the states where winter wheat is a major crop. Due to its propensity to evolve resistance to herbicides it is a threat to the productivity of continuous cereal growing in high-input systems of temperate areas.

Growth and development of spring crops in competition with oat in the dryland Mediterranean climate of eastern Washington

Weed Science ◽  
2020 ◽  
Vol 68 (6) ◽  
pp. 646-653
Author(s):  
Misha R. Manuchehri ◽  
E. Pat Fuerst ◽  
Stephen O. Guy ◽  
Bahman Shafii ◽  
Dennis L. Pittmann ◽  
...  
Keyword(s):  
Weed Management ◽  
Crop Production ◽  
Lens Culinaris ◽  
Mediterranean Climate ◽  
Seeding Rate ◽  
Crop Species ◽  
Spring Crop ◽  
Oat Biomass ◽  
Eastern Washington ◽  
Plot Design

AbstractWeed management during spring crop production in eastern Washington presents many challenges. Many spring crops are weak competitors with weeds. In May of 2010 and 2011, two spring crop trials were initiated near Pullman, WA, to compare the relative competitiveness of barley (Hordeum vulgare L.), wheat (Triticum aestivum L.), lentil (Lens culinaris Medik.), and pea (Pisum sativum L.) using cultivated oat (Avena sativa L.) as a surrogate for wild oat (Avena fatua L.) competition. The experiment was arranged as a split-block split-plot design with four replications. One set of main plots included three oat density treatments (0, 63, and 127 plants m−2), while a second set included each crop species. Crop species main plots were then split into subplots of two different seeding rates (recommended and doubled). Crop populations decreased as oat density increased and increased as crop seeding rate increased. As oat density increased, preharvest crop biomass decreased for all crops, while oat biomass and yield increased. Oat biomass and yield were greater in legume plots compared with cereal plots. Increasing oat density decreased yields for all crops, whereas doubling crop seeding rate increased yields for barley and wheat in 2010 and barley in 2011. Compared with legumes, cereals were taller, produced more biomass, and were more competitive with oat.

Combining Cultural Practices with Herbicides Reduces Wild Oat (Avena fatua) Seed in the Soil Seed Bank and Improves Barley Yield

Weed Science ◽  
2013 ◽  
Vol 61 (2) ◽  
pp. 328-333 ◽  
Author(s):  
John T. O'Donovan ◽  
K. Neil Harker ◽  
T. Kelly Turkington ◽  
George W. Clayton
Keyword(s):  
Seed Bank ◽  
Cultural Practices ◽  
Soil Seed Bank ◽  
Integrated Approach ◽  
Cultural Practice ◽  
Second Phase ◽  
Wild Oat ◽  
Seeding Rate ◽  
Barley Cultivars ◽  
Long Term Impact

A study was initiated in 2001at four locations in western Canada to investigate an integrated approach to managing wild oat, the region's worst weed. The study examined the effects of combining semidwarf or tall barley cultivars with normal or twice-normal barley seeding rates in either continuous barley or a barley–canola–barley–field pea–barley rotation. Herbicides were applied at 25, 50, and 100% of recommended rates. The first phase of the study was completed in 2005. This paper reports on the second phase, which was continued for four more years at two of the locations, Beaverlodge and Fort Vermilion, AB, Canada. The objective was to determine the long-term impact of the treatments on wild oat seed in the soil seed bank. In 2009 (final year), the diverse rotation combined with the higher barley seeding rate (optimal cultural practice) resulted in higher barley yields and reduced wild oat biomass compared to continuous barley and lower barley seeding rate (suboptimal cultural practice). In contrast to the first phase, barley yield was higher with the semidwarf cultivar, and cultivar had no effect on wild oat management. Wild oat seed in the soil seed bank decreased with increasing herbicide rate, but amounts were often lower with the optimal cultural practice. For example, at the recommended herbicide rate at Beaverlodge, an approximate 40-fold reduction in wild oat seed occurred with the optimal compared to the suboptimal cultural practice. The results indicate that combining optimal cultural practices with herbicides will reduce the amount of wild oat seed in the soil seed bank, and result in higher barley yields. Optimal cultural practices may also compensate for reduced herbicidal effects in terms of reducing wild oat seed accumulation in the soil seed bank and increasing barley yield. The results have implications for mitigating the evolution of herbicide resistance in wild oat.

Influence of chaff and chaff lines on weed seed survival and seedling emergence in Australian cropping systems

2020 ◽  
pp. 1-22
Author(s):  
Michael J. Walsh ◽  
Annie E. Rayner ◽  
Annie Rutledge ◽  
John C. Broster
Keyword(s):  
Cropping Systems ◽  
Seedling Emergence ◽  
Field Studies ◽  
Wild Oat ◽  
Weed Seed ◽  
Weed Species ◽  
Environment Effect ◽  
Seed Survival ◽  
Cropping Seasons ◽  
Rigid Ryegrass

Abstract Chaff lining and chaff tramlining are harvest weed seed control (HWSC) systems that involve the concentration of weed seed containing chaff material into narrow (20 to 30 cm) rows between or on the harvester wheel tracks during harvest. These lines of chaff are left intact in the fields through subsequent cropping seasons in the assumption that the chaff environment is unfavourable for weed seed survival. The chaff row environment effect on weed seed survival was examined in field studies, while chaff response studies determined the influence of increasing amounts of chaff on weed seedling emergence. The objectives of these studies were to determine 1) the influence of chaff lines on the summer-autumn seed survival of selected weed species; and 2) the influence of chaff type and amount on rigid ryegrass seedling emergence. There was frequently no difference (P>0.05) in survival of seed of four weed species (rigid ryegrass, wild oat, annual sowthistle and turnip weed) when these seed were placed beneath or beside chaff lines. There was one instance where wild oat seed survival was increased (P<0.05) when seed were placed beneath compared to beside a chaff line. The pot studies determined that increasing amounts of chaff consistently resulted in decreasing numbers of rigid ryegrass seedlings emerging through chaff material. The suppression of emergence broadly followed a linear relationship where there was approximately a 2.0% reduction in emergence with every 1.0 t ha-1 increase in chaff material. This relationship was consistent across wheat, barley, canola and lupin chaff types, indicating that the physical presence of the chaff was more important than chaff type. These studies indicated that chaff lines may not affect the over summer-autumn survival of the contained weed seeds but the subsequent emergence of weed seedlings will be restricted by high amounts of chaff (>40 t ha-1).

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