Seeding rate, herbicide timing and competitive hybrids contribute to integrated weed management in canola (Brassica napus)

2003 ◽  
Vol 83 (2) ◽  
pp. 433-440 ◽  
Author(s):  
K. N. Harker ◽  
G. W. Clayton ◽  
R. E. Blackshaw ◽  
J. T. O’Donovan ◽  
F. C. Stevenson
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Weed Suppression ◽  
Integrated Weed Management ◽  
Seeding Rate ◽  
Yield Increase ◽  
Net Returns ◽  
Herbicide Timing ◽  
Crop Health ◽  
Weed Removal

Implementing a favourable agronomic practice often enhances canola production. Combining several optimal practices may further increase production, and, given greater crop health and competitiveness, could also improve weed control. A field experiment was conducted at Lacombe and Lethbridge, Alberta, from 1998 to 2000, to determine the optimal combination of glufosinate-tolerant cultivar (hybrid InVigor 2153 or open-pollinated Exceed), crop seeding rate (100, 150, or 200 seeds m-2) and time of weed removal (two-, four-, or six-leaf stage of canola) for canola yield and weed suppression. At equal targeted seeding rates, the hybrid cultivar had greater seedling density (8 plants m-2 higher) and seed yield (22% higher) when compared with the open-pollinated cultivar. Combining the better cultivar with the highest seeding rate, and the earliest time of weed removal led to a 41% yield increase compared with the combination of the weaker cultivar, the lowest seeding rate and the latest time of weed removal. The same optimal factor levels also favoured higher levels of weed control and lower weed biomass variability. Managing these factors at optimal levels may help increase net returns, reduce herbicide dependence and favour the adoption of more integrated weed management systems. Key words: Crop health, direct seeding, glufosinate, integrated weed management, weed population variability

Impact of Spring Wheat Planting Density, Row Spacing, and Mechanical Weed Control on Yield, Grain Protein, and Economic Return in Maine

Weed Science ◽  
2012 ◽  
Vol 60 (2) ◽  
pp. 244-253 ◽  
Author(s):  
Lauren N. Kolb ◽  
Eric R. Gallandt ◽  
Ellen B. Mallory
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Weed Suppression ◽  
Planting Density ◽  
Grain Protein ◽  
Seeding Rate ◽  
Management Options ◽  
Weed Density ◽  
Net Returns ◽  
Farmer Practices

Effective in-season weed management options are limited for organic cereal farmers. Two alternatives to current farmer practices are improving efficacy of physical weed control through use of interrow cultivation or increasing the competitive ability of the crop through elevated seeding rates and more uniform spatial planting patterns. It is unknown how these two methods affect yield, quality, and economic returns. Field experiments were conducted in the northeast United States to determine whether the yield gain from increased weed control from these contrasting weed management strategies resulted in increased net returns and how these different systems affected grain quality. Wheat was planted at two seeding rates (400 and 600 plants m−2), in three row spacings (11, 18, and 23 cm). A fourth crop arrangement that approaches a more uniform spatial distribution through a combination of drilling and broadcasting seed was included. For weed control, treatments received tine harrowing. Wheat sown in wide rows also received interrow cultivation. Each system was sown in the presence and absence of condiment mustard, which was sown as a surrogate weed. Increased seeding rate reduced weed density 64% compared to a crop-free check and 30% compared to regional farmers' practices of 18-cm rows and 400 plants m−2. Increased seeding rates lowered grain protein 5% compared to standard seeding rates. Wide rows, in combination with interrow cultivation, reduced weed density 62%, increased yield 16%, and net returns 19% compared to regional organic practices. Significant increases in grain N were limited to weed-free plots. While increased seeding rates improved weed suppression, the high input cost of organic seed make this an unsatisfactory alternative to interrow cultivation and current farmer practices, as yield would need to be. 15 t ha−1higher at elevated density to offset the extra cost of seed.

Herbicide Timing and Rate Effects on Weed Management in Three Herbicide-Resistant Canola Systems

2004 ◽  
Vol 18 (4) ◽  
pp. 1006-1012 ◽  
Author(s):  
K. Neil Harker ◽  
George W. Clayton ◽  
John T. O'Donovan ◽  
Robert E. Blackshaw ◽  
F. Craig Stevenson
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Management Practices ◽  
Integrated Weed Management ◽  
Weed Biomass ◽  
Herbicide Resistant ◽  
Leaf Stage ◽  
Rate Effects ◽  
Herbicide Timing ◽  
Weed Removal

Herbicide-resistant canola dominates the canola market in Canada. A multiyear field experiment was conducted at three locations to investigate the effect of time of weed removal (two-, four-, or six-leaf canola) and herbicide rate (50 or 100% recommended) in three herbicide-resistant canola systems. Weeds were controlled in glufosinate-resistant canola (GLU) with glufosinate, in glyphosate-resistant canola (GLY) with glyphosate, and in imidazolinone-resistant canola (IMI) with a 50:50 mixture of imazamox and imazethapyr. Canola yields were similar among the three canola cultivar–herbicide systems. Yields were not influenced by 50 vs. 100% herbicide rates. Timing of weed removal had the greatest effect on canola yield, with weed removal at the four-leaf stage giving the highest yields in most cases. Percent dockage was often greater for GLU and IMI than for GLY. In comparison with the other treatments, dockage levels doubled for GLU after application at 50% herbicide rates. The consistency of monocot weed control was usually greater for GLY than for GLU or IMI systems. However, weed biomass data revealed no differences in dicot weed control consistency between IMI and GLY systems. Greater dockage and weed biomass variability after weed removal at the six-leaf stage or after low herbicide rates suggests higher weed seed production, which could constrain the adoption of integrated weed management practices in subsequent years.

Economics of integrated weed management in herbicide-resistant canola

Weed Science ◽  
2006 ◽  
Vol 54 (1) ◽  
pp. 138-147 ◽  
Author(s):  
Bharat M. Upadhyay ◽  
Elwin G. Smith ◽  
G. W. Clayton ◽  
K. N. Harker ◽  
R. E. Blackshaw
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Field Experiments ◽  
Production Systems ◽  
Statistical Significance ◽  
Integrated Weed Management ◽  
Seeding Rate ◽  
Herbicide Resistant ◽  
Leaf Stage ◽  
Weed Removal

Integrated weed management (IWM) decision strategies in herbicide-resistant canola-production systems were assessed for net returns and relative risk. Data from two field experiments conducted during 1998 to 2000 at two locations in Alberta, Canada, were evaluated. A herbicide-based experiment included combinations of herbicide system (glufosinate-, glyphosate-, and imazethapyr-resistant canola varieties), herbicide rate (50 and 100% of recommended dose), and time of weed removal (two-, four-, and six-leaf stages of canola). A seed-based experiment included canola variety (hybrid and open-pollinated), seeding rate (100, 150, and 200 seeds m−2), and time of weed removal (two-, four-, and six-leaf stages of canola). For the herbicide-based experiment, strategies with glyphosate were profitable at Lacombe, but both imazethapyr and glyphosate strategies were profitable at Lethbridge. Weed control at the four-leaf stage was at least as profitable as the two-leaf stage at both sites. For the seed-based experiment, the hybrid was more profitable than the open-pollinated cultivar, seed rates of 100 and 150 seeds m−2were more profitable than 200 seeds m−2, and weed control at the two- and four-leaf stages was more profitable than at the six-leaf stage. When risk of returns and statistical significance was considered, several strategies were included in the risk-efficient set for risk-averse and risk-neutral attitudes at each location. However, the glyphosate-resistant cultivar, the 50% herbicide rate, and weed control at four-leaf stage were more frequent in the risk-efficient IWM strategy set. The open-pollinated cultivar, 200 seeds m−2rate, and weed control at the six-leaf stage were less frequent in the set. The risk-efficient sets of IWM strategies were consistent across a range of canola prices.

Integrated Weed Management Using Planting Pattern, Cultivar, and Herbicide in Dry-Seeded Rice in Northwest India

Weed Science ◽  
2014 ◽  
Vol 62 (2) ◽  
pp. 350-359 ◽  
Author(s):  
Gulshan Mahajan ◽  
Vikas Poonia ◽  
Bhagirath S. Chauhan
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Weed Management ◽  
Field Experiments ◽  
Weed Suppression ◽  
Integrated Weed Management ◽  
Rice Grain ◽  
Planting Pattern ◽  
Weed Biomass ◽  
Northwest India

Field experiments were conducted in Punjab, India, in 2011 and 2012 to study the integrated effect of planting pattern [uniform rows (20-cm spacing) and paired rows (15-, 25-, and 15-cm spacing)], cultivars (PR-115 and IET-21214), and weed control treatments (nontreated control, pendimethalin 750 g ai ha−1, bispyribac-sodium 25 g ai ha−1, and pendimethalin 750 g ha−1 followed by bispyribac-sodium 25 g ha−1) on weed suppression and rice grain yield in dry-seeded rice. In the nontreated control, IET-21214 had higher grain yield than PR-115 in both planting patterns. However, such differences were not observed within the herbicide treatment. IET-21214 in paired rows, even in nontreated control, provided grain yield (4.7 t ha−1) similar to that in uniform rows coupled with the sole application of pendimethalin (4.3 t ha−1) and bispyribac-sodium (5.0 t ha−1). In uniform rows, sequential application of pendimethalin (PRE) and bispyribac-sodium (POST) provided the highest grain yield among all the weed control treatments and this treatment produced grain yield of 5.9 and 6.1 t ha−1 for PR-115 and IET-21214, respectively. Similarly, in paired rows, PR-115 in paired rows treated with sequential application of pendimethalin and bispyribac-sodium had highest grain yield (6.1 t ha−1) among all the weed control treatments. However, IET-21214 with the sole application of bispyribac-sodium produced grain yield similar to the sequential application of pendimethalin and bispyribac-sodium. At 30 days after sowing, PR-115 in paired rows coupled with pendimethalin application accrued weed biomass (10.7 g m−2) similar to the sequential application of pendimethalin and bispyribac-sodium coupled with uniform rows (8.1 g m−2). Similarly, IET-21214 with bispyribac-sodium application provided weed control similar to the sequential application of pendimethalin and bispyribac-sodium. Our study implied that grain yield of some cultivars could be improved by exploring their competitiveness through paired-row planting patterns with less use of herbicides.

Effect of Seeding Rate on Dose Response of Wild Mustard (Sinapis arvensis) to Fluthiacet-Methyl

Weed Science ◽  
2017 ◽  
Vol 65 (4) ◽  
pp. 525-533 ◽  
Author(s):  
Collen Redlick ◽  
Hema S. N. Duddu ◽  
Lena D. Syrovy ◽  
Christian J. Willenborg ◽  
Eric N. Johnson ◽  
...  
Keyword(s):  
Weed Control ◽  
Dose Response ◽  
Weed Management ◽  
Management Practices ◽  
Indian Mustard ◽  
Integrated Weed Management ◽  
Seeding Rate ◽  
Weed Biomass ◽  
Wild Mustard ◽  
Seed Yields

Concern over the development of herbicide-resistant weeds has led to interest in integrated weed management systems that reduce selection pressure by utilizing mechanical and cultural weed control practices in addition to herbicides. Increasing crop seeding rate increases crop competitive ability and thus can enhance herbicide efficacy. However, it is unknown how increasing the seeding rate affects an herbicide’s efficacy. The objective of this study was to examine the interaction between increasing seeding rate and herbicide dose to control weeds. To meet this objective, the herbicide fluthiacet-methyl was applied to field-grown lentil, with Indian mustard, a proxy for wild mustard, used as a model weed. The experiment was a factorial design with four lentil seeding rates and seven herbicide rates. Overall the herbicide dose response was altered by changing lentil seeding rate. Increasing lentil seeding rate decreased the weed biomass production when herbicides were not applied. In two of the four site-years, increasing lentil seeding rate lowered the herbicide ED50, the dose required to result in a 50% reduction in weed biomass. Increasing the crop seeding rate altered the dose response to provide greater weed control at lower herbicide rates compared with normal crop seeding rates. Increased seeding rates also resulted in higher and more stable crop seed yields across a wider range of herbicide dosages. These results suggest that dose–response models can be used to evaluate the efficacy of other weed management practices that can interact with herbicide performance.

scholarly journals Integrated weed management in transplanted rice: Options for addressing labor constraints and improving farmers’ income in Bangladesh

2021 ◽  
pp. 1-34
Author(s):  
Sharif Ahmed ◽  
Virender Kumar ◽  
Murshedul Alam ◽  
Mahbubur Rahman Dewan ◽  
Khairul Alam Bhuiyan ◽  
...  
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Weed Management ◽  
Cost Effective ◽  
Integrated Weed Management ◽  
Control Cost ◽  
Control Practice ◽  
Net Returns ◽  
Transplanted Rice ◽  
Hand Weeding

Abstract In Bangladesh, weeds in transplanted rice are largely controlled by labor-intensive and costly manual weeding, resulting in inadequate and untimely weed control. Labor scarcity coupled with intensive rice production has triggered increased use of herbicides. These factors warrant a cost-effective and strategic integrated weed management (IWM) approaches. On-farm trials with transplanted rice were conducted during monsoon (‘Aman’) season in 2016 and 2017 and winter (‘Boro’) season in 2016 to 2017 in agroecological zones 11 and 12 with ten treatments - seven herbicide-based IWM options, one mechanical weed control-based option, and two checks – farmers’ current weed control practice and weed-free, to assess effects on weed control, grain yield, labor use, and profitability. Compared to farmers’ practice, herbicide-based IWM options with mefenacet+bensulfuron-methyl as preemergence (PRE) followed by (fb) either bispyribac-sodium or penoxsulam as postemergence (POST) fb one hand-weeding (HW) were most profitable alternatives, with reductions in labor requirement by 11 to 25 persons-day ha−1 and total weed control cost by USD 44 to 94 ha−1, resulting in net returns increases by USD 54 to 77 ha−1 without compromising on grain yield. In contrast, IWM options with bispyrbac-sodium or penoxsulam as POST application fb one HW reduced yields by 12 to 13% and profits by USD 71 to 190 ha−1. Non-chemical option with mechanical weeding fb one HW performed similarly to farmers’ practice on yield and profitability. We suggest additional research to develop feasible herbicide-free approaches to weed management in transplanted rice that can offer competitive advantages to current practices.

scholarly journals Influence of Cereal Rye Management on Weed Control in Soybean

2020 ◽  
Vol 2 ◽  
Author(s):  
Kurt M. Vollmer ◽  
Mark J. VanGessel ◽  
Quintin R. Johnson ◽  
Barbara A. Scott
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Cover Crop ◽  
Management Program ◽  
Weed Suppression ◽  
Integrated Weed Management ◽  
Weed Species ◽  
Delayed Effect ◽  
Cereal Rye ◽  
Winter Annual

Cereal rye as a cover crop is often used to improve soil health and as part of integrated weed management programs. Despite this, cereal rye biomass is often not managed for optimal weed suppression. This study evaluated the effects of managing cereal rye as part of an integrated weed management strategy in soybean. Factors consisted of levels of cereal rye management (no cereal rye, no nitrogen, or 20 kg/ha of nitrogen); cereal rye termination timing (20 or 10 d before soybean planting); and residual herbicide treatment applied at cereal rye termination (with or without). Winter annual weed control with cereal rye was generally greater compared to no cereal rye. Winter annual weed control was consistently better when cereal rye was terminated at 20 d before soybean planting compared to 10 d; while summer annual weed control was improved if termination was delayed. Effect of cereal rye management on summer annual weed control varied by weed species. In the absence of residual herbicides, Palmer amaranth control responded to the different levels of cereal rye management. However, morningglory spp. only responded to rye with supplemental N applications. Large crabgrass control was similar for treatments containing cereal rye, regardless of nitrogen input. Our results demonstrate the importance of cover crop management when incorporating cereal rye into an integrated weed management program for soybean.

scholarly journals Integrated Management of Weeds in Direct-Seeded Rice in Cambodia

Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1557
Author(s):  
Robert Martin ◽  
Bunna Som ◽  
Joel Janiya ◽  
Ratha Rien ◽  
Sophea Yous ◽  
...  
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Rice Field ◽  
Field Experiments ◽  
Integrated Management ◽  
Weed Suppression ◽  
Crop Damage ◽  
Integrated Weed Management ◽  
Crop Tolerance ◽  
Direct Seeded

The objective of this work was to determine the value of improved establishment methods and herbicide applications as alternatives to high seeding rates to improve weed suppression in rice. Field experiments were carried out in 2010 and 2011 to determine optimal seeding rates and seeding methods with and without weed competition in wet-seeded rice. Under wet seeding conditions, drum seeding at 80 kg ha−1 was the most profitable treatment for both weed-free and unweeded rice. Although pre-emergence herbicides are beginning to be adopted in wet-seeded rice, they are seldom used in dry direct-seeded rice in Cambodia. Experiments were carried out in 2018 and 2019 to test crop tolerance and the efficacy of butachlor, oxadiazon, pendimethalin and pretilachlor applied post-sowing and pre-emergence to dry direct-seeded rice. Oxadiazon and butachlor, with the option for a post-emergence herbicide, provided effective weed control and a high grain yield in dry direct-seeded rice. Pretilachlor did not effectively control weeds under dry seeding conditions. Although pendimethalin exhibited good weed control, crop damage was a risk in poorly prepared seedbeds which typify Cambodian rice systems. With an effective integrated weed management strategy, it might be possible to safely reduce seeding rates below 80 kg ha−1 using drum or drill seeding machines.

scholarly journals Optimisation of Weed Control in Organic Processing Spinach (Spinacia oleracea L.): Impacts of Cultivar, Seeding Rate, Plant Spacing and Integrated Weed Management Strategy

Agronomy ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 53
Author(s):  
Benny De Cauwer ◽  
Lieven Delanote ◽  
Michaël Devos ◽  
Sander De Ryck ◽  
Dirk Reheul
Keyword(s):  
Growth Rate ◽  
Weed Control ◽  
Weed Management ◽  
Management Strategy ◽  
Growth Habit ◽  
Integrated Weed Management ◽  
Plant Spacing ◽  
Seeding Rate ◽  
Weed Biomass ◽  
The Impact

Weed control in organic spinach for the processing market is challenging because of the low tolerance of weed contamination in the harvested produce and the limited physical weeding options. Optimisation of weed control systems is therefore urgently needed. Three field experiments with autumn spinach were carried out in organic fields to evaluate the impact of cultivar choice, seeding rate (300 and 400 seeds m−2), plant spacing management (10.5-cm-wide single rows and 21-cm-wide single or twin rows) and integrated weed management strategy (combinations of pre-sowing, pre-emergence and post-emergence tactics) on weed biomass and spinach yield and quality. Spinach cultivars with a planophile growth habit and a high growth rate were more weed suppressive than the cultivar with an erectophile growth habit and a slower growth rate. Spinach density was significantly negatively correlated with weed biomass and weed biomass fraction in the harvested produce, but significantly positively correlated with (marketable) spinach biomass and petiole fraction in the harvested produce. Narrow row spacing systems with post-emergence broadcast harrowing had the lowest weed biomass and weed biomass fraction but also the lowest (marketable) spinach biomass as a result of the thinning action of harrowing. Post-emergence harrowing is of key importance for reducing weed biomass in any integrated weed control strategy. Weediness was lowest in systems comprising flaming on false seedbed or in pre-emergence followed by post-emergence harrowing. To mitigate the risk of crop failure, the field should preferably be cropped with quickly growing spinach plants arranged in narrow spaced rows at high plant density and weeded by pre-sowing or pre-emergence flaming followed by post-emergence harrowing.

Intrarow Weed Removal in Broccoli and Transplanted Lettuce with an Intelligent Cultivator

2016 ◽  
Vol 30 (3) ◽  
pp. 655-663 ◽  
Author(s):  
Ran N. Lati ◽  
Mark C. Siemens ◽  
John S. Rachuy ◽  
Steven A. Fennimore
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Integrated Weed Management ◽  
Marketable Yield ◽  
Control Efficacy ◽  
Direct Seeded ◽  
Hand Weeding ◽  
Crop Stand ◽  
Weed Removal

The performance of the Robovator (F. Poulsen Engineering ApS, Hvals⊘, Denmark), a commercial robotic intrarow cultivator, was evaluated in direct-seeded broccoli and transplanted lettuce during 2014 and 2015 in Salinas, CA, and Yuma, AZ. The main objective was to evaluate the crop stand after cultivation, crop yield, and weed control efficacy of the Robovator compared with a standard cultivator. A second objective was to compare hand weeding time after cultivation within a complete integrated weed management (IWM) system. Herbicides were included as a component of the IWM system. The Robovator did not reduce crop stand or marketable yield compared with the standard cultivator. The Robovator removed 18 to 41% more weeds at moderate to high weed densities and reduced hand-weeding times by 20 to 45% compared with the standard cultivator. At low weed densities there was little difference between the cultivators in terms of weed control and hand-weeding times. The lower-hand weeding time with the Robovator treatments suggest that robotic intrarow cultivators can reduce dependency on hand weeding compared with standard cultivators. Technological advancements and price reductions of these types of machines will likely improve their weed removal efficacy and the long-term viability of IWM programs that will use them.

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