Competitive ability of hybrid and open-pollinated canola (Brassica napus) with wild oat (Avena fatua)

2002 ◽  
Vol 82 (2) ◽  
pp. 473-480 ◽  
Author(s):  
E. Zand ◽  
H. J. Beckie
Keyword(s):  
Brassica Napus ◽  
Weed Management ◽  
Plant Density ◽  
Management Program ◽  
Avena Fatua ◽  
Integrated Weed Management ◽  
Wild Oat ◽  
Replacement Series ◽  
Weed Interference ◽  
High Plant Density

The competitiveness of three hybrid and three open-pollinated canola cultivars against two wild oat populations was determined under controlled environment conditions at two plant densities and five canola:wild oat ratios (100:0, 75:25, 50:50, 25:75, 0:100). Analysis of replacement series and derivation of relative crowding coefficients (RCC), based on shoot dry weight or leaf area, indicated that hybrid canola cultivars were twice as competitive than open-pollinated cultivars when weed interference was relatively high (i.e., high plant density and vigorous wild oat growth). Little difference in competitiveness among cultivar types was apparent when weed interference was lower. The results of this study suggest that hybrid canola cultivars may be best suited for use in an integrated weed management program, particularly for farmers of organic or low input cropping systems. Key words: Hybrid canola, Brassica napus, Avena fatua, replacement series, competition

Chaff collection reduces seed dispersal of wild oat (Avena fatua) by a combine harvester

Weed Science ◽  
2005 ◽  
Vol 53 (4) ◽  
pp. 465-470 ◽  
Author(s):  
Steven J. Shirtliffe ◽  
Martin H. Entz
Keyword(s):  
Seed Dispersal ◽  
Weed Management ◽  
Management Program ◽  
Avena Fatua ◽  
Integrated Weed Management ◽  
Wild Oat ◽  
Collection System ◽  
Oat Seeds ◽  
Combine Harvester ◽  
Combine Harvesters

Combine harvesters have the potential to disperse weed seeds great distances. Reducing this dispersal may be important in an integrated weed management system. The objectives of this study were to determine the distance that wild oat seeds are dispersed by a combine harvester and the effect of chaff collection on combine harvester seed dispersal. This was measured by sampling wild oat seeds at varying distances behind a combine equipped with a removable chaff collection system after it passed through a wild oat patch. Chaff collection consistently reduced the amount and distance that wild oat seeds were dispersed. This occurred because more than 74% of the total wild oat seed that were ejected from the combine were in the chaff. Because most of the chaff falls in a row directly behind the combine, chaff collection only affected dispersal in this area. In 1996, chaff collection reduced wild oat seed dispersal past the wild oat patch to less than 10 seeds m−2at 45 m, whereas without chaff collection, there was greater than 10 seeds m−2up to 145 m. At distances beyond 145 m, chaff collection had no significant effect on seed dispersal. Chaff collection may be an important tool in an integrated weed management program because it may slow weed invasions and reduce the expansion of weed patches.

Growth, competitiveness, and seed germination of triallate/difenzoquat-susceptible and -resistant wild oat populations

1999 ◽  
Vol 79 (2) ◽  
pp. 303-312 ◽  
Author(s):  
J. T. O'Donovan ◽  
J. C. Newman ◽  
R. E. Blackshaw ◽  
K. N. Harker ◽  
D. A. Derksen ◽  
...  
Keyword(s):  
Seed Germination ◽  
Leaf Area ◽  
Weed Management ◽  
Field Experiments ◽  
Dry Weight ◽  
Avena Fatua ◽  
Integrated Weed Management ◽  
Wild Oat ◽  
Replacement Series ◽  
Shoot Dry Weight

Understanding the relative competitiveness and seed germination patterns of herbicide-resistant weeds has implications for integrated weed management. Replacement series experiments were conducted in the greenhouse to compare interspecific competition among two triallate/difenzoquat susceptible (S) and 10 resistant (R) wild oat (Avena fatua L.) populations. Each series included monocultures of each of the populations and three mixtures at relative S:R proportions of 3:1, 1:1 and 1:3. Shoot dry weight tended to be greater in the R than S populations, but results were not always statistically significant at the 5% level. Leaf area was more variable, but in most cases did not differ between R and S populations. With a few exceptions, relative crowding coefficients for shoot dry weight and leaf area were similar for S and R populations indicating little or no differences in competitiveness. In field experiments where two S and five R populations were grown in competition with wheat (Triticum aestivum L.), two of the R populations produced significantly (P < 0.05) greater shoot dry weight and seed yield than the S populations. Otherwise populations did not differ significantly. In seed germination studies, the S populations consistently displayed lower cumulative germination than the R populations. The higher seed germination associated with the R populations suggests that producers should be able to manage these populations effectively with a combination of alternative herbicides and cultural practices. Key words: Avena fatua, herbicide resistance, triallate, difenzoquat, relative competitiveness, seed germination

Response of Triallate-Resistant Wild Oat (Avena fatua) to Alternative Herbicides

1996 ◽  
Vol 10 (2) ◽  
pp. 258-262 ◽  
Author(s):  
Robert E. Blackshaw ◽  
John T. O'Donovan ◽  
M. Paul Sharma ◽  
K. Neil Harker ◽  
Denise Maurice
Keyword(s):  
Dose Response ◽  
Weed Management ◽  
Management Practices ◽  
Avena Fatua ◽  
Integrated Weed Management ◽  
Wild Oat ◽  
Wild Oats ◽  
Field Crops

Wild oat populations resistant to triallate have been identified in Alberta. Dose response experiments were conducted in the greenhouse to determine if triallate-resistant wild oat was controlled by other selective wild oat herbicides. Triallate-resistant wild oat populations were effectively controlled by atrazine, ethalfluralin, fenoxaprop-P, flamprop, imazamethabenz, and tralkoxydim. EPTC and cycloate, which are chemically related to triallate, differed in their efficacy on triallate-resistant wild oats. EPTC at the 0.25x field use rate was more efficacious on triallate-resistant than triallate-susceptible wild oat. In contrast, cycloate at the 0.25 to 0.5x field use rate was less efficacious on triallate-resistant than susceptible wild oats. At higher rates, both EPTC and cycloate killed triallate-resistant wild oat populations. Growers have several herbicide choices to selectively control triallate-resistant wild oat in prairie field crops but should plan to rotate herbicides among different chemical families and adopt integrated weed management practices to reduce the risk of these wild oat populations developing resistance to other wild oat herbicides.

scholarly journals Influence of Nitrogen Rate, Seeding Rate, and Weed Removal Timing on Weed Interference in Barley and Effect of Nitrogen on Weed Response to Herbicides

Weed Science ◽  
2016 ◽  
Vol 65 (1) ◽  
pp. 189-201 ◽  
Author(s):  
Vipan Kumar ◽  
Prashant Jha
Keyword(s):  
Field Experiments ◽  
Plant Density ◽  
Agricultural Research ◽  
Integrated Weed Management ◽  
Barley Plant ◽  
Wild Oat ◽  
Seeding Rate ◽  
Weed Interference ◽  
Green Foxtail ◽  
Weed Removal

Field experiments were conducted at the Montana State University Southern Agricultural Research Center, Huntley, MT, in 2011 through 2013 to determine the effect of nitrogen (N) rate, seeding rate, and weed removal timing on weed interference in barley. A delay in weed removal timing from the 3- to 4-leaf (LF) stage to the 8- to 10-LF stage of barley resulted in up to 3.5-fold increase in total weed biomass and 10% reduction in barley biomass, and this was unaffected by a N rate that ranged from 56 (low) to 168 (high) kg ha−1. The effect of N rate on barley biomass was more pronounced when weed removal was delayed from the 3- to 4-LF stage to the 8- to 10-LF stage of barley and in nontreated plots. Increasing the barley seeding rate from 38 to 152 kg ha−1increased the barley plant density by 50%, biomass by 13%, and grain yield by 29%, averaged over N rates and weed removal timing. On the basis of 5 and 10% levels of acceptable yield loss, the addition of ≥112 kg N ha−1delayed the critical timing of weed removal by at least 1.3 wk in barley, compared with the 56 kg N ha−1rate. A medium or high N rate prevented reduction in barley grain quality (plumpness and test weight) observed when the seeding rate was increased from 38 to 76 or 152 kg ha−1at the low N rate. In a separate greenhouse study, the effect of N rate on the effectiveness of various herbicides for controlling wild oat, green foxtail, kochia, or Russian thistle was investigated. Results highlighted that wild oat or green foxtail grown under 56 kg N ha−1(low N) soil required 1.4 to 2.6 times higher doses of clodinafop, fenoxaprop, flucarbazone, glyphosate, glufosinate, pinoxaden, or tralkoxydim for 50% reduction in shoot dry weights (GR50) compared with plants grown under 168 kg N ha−1(high N). Similarly, a reduced efficacy of thifensulfuron methyl + tribenuron methyl, metsulfuron methyl, or bromoxynil+pyrasulfotole was observed (evident from the GR50values) for kochia or Russian thistle grown under low- vs. high-N soil. Information gained from this research will aid in developing cost-effective, integrated weed management (IWM) strategies in cereals and in educating growers on the importance of fertilizer N management as a component of IWM programs.

scholarly journals The profitability of diverse crop rotations and other cultural methods that reduce wild oat (Avena fatua)

2018 ◽  
Vol 98 (5) ◽  
pp. 1094-1101
Author(s):  
Elwin G. Smith ◽  
K. Neil Harker ◽  
John T. O’Donovan ◽  
T. Kelly Turkington ◽  
Robert E. Blackshaw ◽  
...  
Keyword(s):  
Weed Management ◽  
Cultural Practices ◽  
Cropping Systems ◽  
Cropping System ◽  
Avena Fatua ◽  
Integrated Weed Management ◽  
Wild Oat ◽  
Hordeum Vulgare L ◽  
Brassica Napus L ◽  
Winter Crops

With the increasing resistance of wild oat (Avena fatua L.) to herbicides, there is a need to evaluate the potential of alternative cropping systems based on integrated weed management principles. A 5-yr field study at eight sites across Canada was used to evaluate the profitability of alternative cropping systems that have the potential to control wild oat using cultural practices in conjunction with herbicides. Cultural practices included twice the recommended seeding rates, fall-seeded winter crops, barley (Hordeum vulgare L.) silage, fallow, and alfalfa (Medicago sativa L.). Seven of the 14 cropping systems in this study did not include wild oat herbicide for three consecutive years, controlling wild oat entirely by cultural practices. Cropping system profitability varied by location. For many locations, combinations of barley silage and fall-seeded winter crops without wild oat herbicide application were as profitable as a system of canola (Brassica napus L.) and wheat (Triticum aestivum L.) with wild oat herbicide applied every year. Unprofitable systems generally included those with fallow, alfalfa, and fall-seeded winter crops in regions with rates of high winter kill. Wild oat control can be achieved with diverse cropping systems that are as profitable as conventional annual cropping that relies on herbicide control of wild oat.

Seeding rate and row spacing affect flax yields and weed interference

1996 ◽  
Vol 76 (3) ◽  
pp. 537-544 ◽  
Author(s):  
F. C. Stevenson ◽  
A. T. Wright
Keyword(s):  
Seed Yield ◽  
Weed Management ◽  
Management Practices ◽  
The Other ◽  
Integrated Weed Management ◽  
Row Spacing ◽  
Flax Seed ◽  
Seeding Rate ◽  
Weed Interference ◽  
Interference Study

Seeding rate and row spacing are management practices that affect flax seed yield. Two experiments were conducted from 1988 to 1990 to determine the influence of flax seeding rates (300, 600, and 900 seeds m−2) and row spacings (9, 18, and 27 cm). One was a flax-weed interference study (three sites) and the other was a weed-free study (13 sites). In the presence of weeds, increasing seeding rate from 300 to 900 seeds m−2 improved flax seed yield by 180 kg ha−1, and reduced broadleaf weed yields by 300 kg ha−1 and grassy weed yields by 180 kg ha−1. In weed-free conditions, seed yield was not affected by seeding rate. Row spacing did not affect flax yield and had minor effects on weed yields when weeds were not controlled. When weeds were controlled, seed yield in the 9-cm row spacing was 9% (15% in the flax-weed interference study) greater than in the two wider row spacings. Seeding rate and row spacing independently influenced flax yield, and their effect was consistent among sites with weeds present, but was not consistent when weeds were controlled. Our results showed that flax seeding rate was an important component of integrated weed management. Key words: Flax, seeding rate, row spacing, weed interference

scholarly journals Response of Barley Genotypes to Weed Interference in Australia

Agronomy ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 99 ◽  
Author(s):  
Gulshan Mahajan ◽  
Lee Hickey ◽  
Bhagirath Singh Chauhan
Keyword(s):  
Negative Correlation ◽  
Weed Management ◽  
Field Experiments ◽  
Yield Loss ◽  
Production Systems ◽  
Relative Yield ◽  
Organic Production ◽  
Integrated Weed Management ◽  
Weed Interference ◽  
Barley Genotypes

Weed-competitive genotypes could be an important tool in integrated weed management (IWM) practices. However, weed competitiveness is often not considered a priority for breeding high-yielding cultivars. Weed-competitive ability is often evaluated based on weed-suppressive ability (WSA) and weed-tolerance ability (WTA) parameters; however, there is little information on these aspects for barley genotypes in Australia. In this study, the effects of weed interference on eight barley genotypes were assessed. Two years of field experiments were performed in a split-plot design with three replications. Yield loss due to weed interference ranged from 43% to 78%. The weed yield amongst genotypes varied from 0.5 to 1.7 Mg ha−1. Relative yield loss due to weed interference was negatively correlated with WTA and WSA. A negative correlation was also found between WSA and weed seed production (r = −0.72). Similarly, a negative correlation was found between WTA and barley yield in the weedy environment (r = −0.91). The results suggest that a high tillering ability and plant height are desirable attributes for weed competitiveness in the barley genotypes. These results also demonstrated that among the eight barley genotypes, Commander exhibited superior WSA and WTA parameters and therefore, could be used in both low- and high-production systems for weed management. Westminster had a superior WSA parameter. Therefore, it could be used for weed management in organic production systems. These results also implied that genotypic ranking on the basis of WSA and WTA could be used as an important tool in strengthening IWM programs for barley.

Effects of Repeat Annual Applications of Dichlobenil on Weed Populations and Yield Components of Cranberry

2004 ◽  
Vol 18 (3) ◽  
pp. 648-657 ◽  
Author(s):  
Hilary A. Sandler ◽  
Joanne Mason ◽  
Wesley R. Autio ◽  
Thomas A. Bewick
Keyword(s):  
Weed Management ◽  
Fruit Set ◽  
Negative Impact ◽  
Field Studies ◽  
Management Program ◽  
Integrated Weed Management ◽  
Leaf Biomass ◽  
Herbicide Application ◽  
Weed Density ◽  
Marketable Fruit

To address grower concerns that repeated use of dichlobenil could negatively affect cranberry productivity, field studies were conducted at two commercial farms in either high weed density (HW) or low weed density (LW) areas. Data from 4 yr of repeat annual applications of 0, 1.8, and 4.5 kg ai/ha dichlobenil indicated minimal negative impact on cranberry vines. Herbicide application did not affect upright productivity, leaf biomass production, percent fruit set, or other yield parameters adversely; in addition, no improvement in these parameters was noted. Although the interaction of herbicide application with weed density on cranberry root length varied with sampling date, no consistent trend (adverse or positive) was seen. The presence of weeds, rather than herbicide application, was the important determinant of yield. Vines in LW areas produced more marketable fruit and had higher percentage of fruit set than vines growing in HW areas. Repeat annual applications of dichlobenil on commercial cranberry beds may be considered as part of a viable integrated weed management program with no adverse effect on crop growth or yield.

Sign in / Sign up

Export Citation Format

Share Document