Weed Control, Environmental Impact and Profitability of Weed Management Strategies in Glyphosate-Resistant Corn

With the number of glyphosate-resistant weed species increasing in North America and a lack of new herbicide chemistries being developed, growers are shifting toward using older herbicides that are more expensive and may be less environmentally friendly. Therefore, to determine which weed management strategies are most cost effective and have the lowest impact on the environment we evaluated the efficacy, environmental impact, and the profitability of several weed management strategies in glyphosate-resistant soybean over a 3-yr period (2007 to 2009) at three locations in southwestern Ontario, Canada. No visible injury to soybean was observed with the herbicide treatments evaluated. A sequential application of glyphosate consistently provided high levels of weed control (99 to 100%) at 56 d after treatment in comparison with one- or two-pass herbicide programs. Soybean yield did not differ between the two-pass herbicide programs and glyphosate applied early POST; however, a yield benefit was found with a sequential application of glyphosate or a PRE herbicide followed by glyphosate compared with glyphosate applied only at late POST. The two-pass herbicide programs had higher environmental impact (EI) (> 23) than the one-pass herbicide programs (< 15), except when imazethapyr was followed by or tank-mixed with glyphosate, which had an equivalent EI (∼ 14) to the one-pass herbicide programs. Not surprisingly because of the low purchase price of glyphosate, gross margins were highest for treatments that included glyphosate. However, to reduce the selection pressure on glyphosate-resistant weed biotypes, to reduce environmental impact, and to increase gross margins a combination of glyphosate with another mode of action would be most beneficial. In this study glyphosate + imazethapyr was the best alternative to a sequential two-pass glyphosate program.

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Weed Control, Environmental Impact and Profitability of Two-Pass Weed Management Strategies in Glyphosate-Resistant Corn

The Open Plant Science Journal ◽

10.2174/1874294701307010031 ◽

2013 ◽

Vol 7 (1) ◽

pp. 31-38

Author(s):

N. Soltani ◽

R.E. Nurse ◽

C. L. Gillard ◽

P.H. Sikkema

Keyword(s):

Environmental Impact ◽

Weed Control ◽

Weed Management ◽

Management Strategies ◽

Field Trials ◽

Corn Yield ◽

Weed Species ◽

Visible Injury ◽

Excellent Control ◽

Residual Herbicide

Twelve field trials were conducted over a three-year period (2010, 2011, 2012) at different locations in southwestern Ontario, Canada to compare various two-pass weed management strategies in glyphosate-resistant corn for crop injury, weed control, environmental impact, corn yield and profit margin. No visible injury resulted from the herbicide treatments evaluated. One early postemergence (EPOST) application of glyphosate provided good full season control of pigweed species and lady's thumb and fair control of velvetleaf, common ragweed, lamb's-quarters, barnyard grass and green foxtail. One late postemergence (LPOST) application of glyphosate provided excellent control of all weed species evaluated but corn yield was reduced due to early weed interference. The sequential application of glyphosate (EPOST fb LPOST) provided excellent control of all weed species evaluated with no adverse effect on corn yield. The sequential application of a preemergence residual herbicide followed by an application of glyphosate LPOST provided excellent full season control of all weed species evaluated and corn yield was equal to the weed free control. Among the sequential herbicide programs the lowest environmental impact was glyphosate EPOST fb LPOST and saflufenacil/dimethenamid-p, isoxaflutole + atrazine or rimsulfuron + s-metolachlor + dicamba applied PRE fb glyphosate LPOST. Based on this study, the most efficacious and profitable weed management programs in glyphosate-resistant corn are a sequential application of glyphosate or a two-pass program of a preemergence residual herbicide followed by glyphosate LPOST. The two-pass programs have glyphosate stewardship benefits.

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Weed control in soybean (Glycine max L.) through resource management strategies and its influence on yield and nutrient uptake

Journal of Applied and Natural Science ◽

10.31018/jans.v9i1.1226 ◽

2017 ◽

Vol 9 (1) ◽

pp. 539-543

Author(s):

Aradhana Bali ◽

B. R. Bazaya ◽

Sandeep Rawal

Keyword(s):

Resource Management ◽

Nutrient Uptake ◽

Weed Control ◽

Weed Management ◽

Management Strategies ◽

Climatic Conditions ◽

Glycine Max L ◽

Effect On Yield ◽

Hand Weeding ◽

Quizalofop Ethyl

A field experiment was conducted during kharif season of 2011 at Research Farm, Sher-e-Kashmir University of Agricultural Sciences and Technology, Chatha, Jammu to evaluate the effect of weed management prac-tices on yield and nutrient uptake of soybean utilizing different resource management strategies. The lowest weed density and dry matter of weeds was recorded with hand weeding at 15 and 35 days after sowing (DAS) which was equally effective as imazethapyr @ 75 g ha -1 (PoE) fb hoeing at 35 DAS and quizalofop-ethyl @ 40 g ha-1 (PoE) fb hoeing at 35 DAS. All weed control treatments had significant effect on yield and nutrient up-take of soybean. Among the different weed control treatments, lowest N, P and K uptake by weeds were recorded in hand-weeding (15 and 35 DAS) which was statistically at par with imazethapyr @ 75 g ha -1 fb hoeing at 35 DAS. The maximum uptake by seed and straw were recorded in weed free which was statistically at par with twice hand weeding at 15 and 35 DAS, imazethapyr @ 75 g ha-1 fb hoeing at 35 DAS and quizalofop-ethyl @ 40 g ha-1 fb hoeing at 35 DAS. The highest seed and straw yield of soybean was harvested with hand-weeding (15 and 35 DAS) followed by imazethapyr @ 75 g ha -1 fb hoeing at 35 DAS. For the first time, soybean crop has been introduced in Jammu region for research purpose. Weed management varies with agro-climatic conditions. The study would be helpful to understand weed menace in this particular climatic condition of Jammu and to manage them combinedly and efficiently.

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Weed management strategies in long-term organic blueberry production systems – impact of mulch type and weed control methods on economics

Acta Horticulturae ◽

10.17660/actahortic.2017.1180.47 ◽

2017 ◽

pp. 347-354

Author(s):

B.C. Strik ◽

A.J. Vance

Keyword(s):

Weed Control ◽

Weed Management ◽

Production Systems ◽

Management Strategies ◽

Control Methods

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The Effect of Different Weed Management Strategies on the Growth and Yield of Direct-Seeded Dry Rice (Oryza sativa)

Planta Daninha ◽

10.1590/s0100-83582016340100006 ◽

2016 ◽

Vol 34 (1) ◽

pp. 57-64 ◽

Cited By ~ 6

Author(s):

S. MUHAMMAD ◽

I. MUHAMMAD ◽

A. SAJID ◽

L. MUHAMMAD ◽

A. MAQSHOOF ◽

...

Keyword(s):

Weed Control ◽

Crop Yield ◽

Weed Management ◽

Management Strategies ◽

Control Measures ◽

Growth And Yield ◽

Primary Concern ◽

Herbicide Treatment ◽

Direct Seeded ◽

Hand Weeding

Weed management is a primary concern in direct seeded rice (DSR) cropping because weed growth becomes a major constraint on crop yield. A two year field study was set up to evaluate the effect of various weed control measures on crop growth, grain yield and grain quality of DSR. The experiment involved five different weed control measures: hand weeding, hoeing, inter-row tine cultivation, inter-row spike hoeing and herbicide treatment (Nominee 100 SC). The extent of weed control (compared to a non-weeded control) ranged from 50-95%. The highest crop yield was obtained using hand weeding. Hand weeding, tine cultivation and herbicide treatment raised the number of fertile rice tillers formed per unit area and the thousand grain weight. Tine cultivation provided an effective and economical level of weed control in the DSR crop.

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Weed Management Strategies in Chickpea (Cicer arietinum): A Review

Agricultural Reviews ◽

10.18805/ag.r-1996 ◽

2020 ◽

Author(s):

Akashdeep Singh ◽

S. S. Rana ◽

Anju Bala

Keyword(s):

Weed Control ◽

Cicer Arietinum ◽

Weed Management ◽

Management Practices ◽

Management Strategies ◽

Detailed Knowledge ◽

Basic Requirement ◽

Weed Species ◽

The World ◽

Hand Weeding

Chickpea (Cicer arietinum) is one of the most important pulse crops but it’s productivity in India is quite low. There are various reasons for low productivity. Weed control is the basic requirement and the major component of crop management. Weeds on an average reduce the crop yield by 40-87 per cent. Deciding time to control weeds requires detailed knowledge of the weed populations in the field. Different management practices like altering spacing, competitive cultivars, etc. can help in enhancing the productivity. With the world entering the precision-farming era, more emphasis is being put on the use of post-emergence herbicides. Application of two or more herbicide at the same time or as a double knockdown and integrating with hand-weeding provides desirable control of different weed species besides reducing the hazard of chemical weed control.

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(416) Weed Management in Organic Sweet Corn

HortScience ◽

10.21273/hortsci.40.4.1071e ◽

2005 ◽

Vol 40 (4) ◽

pp. 1071E-1072

Author(s):

Anthony Silvernail

Keyword(s):

Weed Control ◽

Weed Management ◽

Sweet Corn ◽

Management Strategies ◽

Organic Production ◽

Control Methods ◽

Weed Biomass ◽

Corn Gluten ◽

And Control ◽

Smooth Pigweed

Organic weed control in direct seeded vegetables depends on management strategies that control weed germination or growth which depletes the weed seedbank. In 2004, a randomized complete-block experiment conducted on land transitioning to organic production examined the effects of tillage and control treatments on weed pressure in sweet corn [Zeamays (L.) cv. Silver Queen]. The two tillage treatments consisted of conventional (moldboard and rototill) and spader tillage. Weed control treatments included a weed free control, a spring-tine weeder, rolling cultivator, row flamer, stale seedbed, and corn gluten meal. In August, the weed infestation was primarily goose grass [Eleusineindica (L.) Gaertn.], crab grass [Digitariasanguinalis (L.) Scop.], giant foxtail (Setariafaberi Herrm.), and smooth pigweed [Amaranthushybridus (L.)] species. Dried weed weights indicated that smooth pigweed constituted about 80% of the total weed biomass in all but the control and flamer treatments. Plots managed with the spring-tine weeder or corn gluten had twice the weed biomass of those managed with the rolling cultivator and flamer. The rolling cultivator and control treatments produced equivalent husked corn yields (6.9 t·ha-1); yields were reduced by the other weed control methods. At 5.4 t·ha-1, yields in the flamer treatment were the lowest among all weed control methods. The flamer suppressed both weeds and the crop, which may preclude its utility for sweet corn production. Results demonstrated that the rolling cultivator provided the best weed control without negatively affecting potential yields.

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Initial Weed Densities Affect No-Tillage Weed Management with a Rye (Secale cereale) Cover Crop

Weed Technology ◽

10.1017/s0890037x00045279 ◽

1997 ◽

Vol 11 (3) ◽

pp. 473-477 ◽

Cited By ~ 22

Author(s):

Inga A. Zasada ◽

H. Michael Linker ◽

Harold D. Coble

Keyword(s):

North Carolina ◽

Weed Control ◽

Weed Management ◽

Cover Crop ◽

Management Strategies ◽

No Tillage ◽

Density Estimates ◽

Common Lambsquarters ◽

Weed Density ◽

Control Effectiveness

The objective of this research was to evaluate the influence of different initial weed densities on weed control effectiveness in no-tillage corn at two locations in North Carolina during 1994 and 1995. Different weed densities were established over a 4-year period (1989–1992) by using various weed management strategies. Resultant density levels were estimated and used to establish high and low weed density plots. Treatments applied were PRE, POST, at-planting, and an untreated control. Weed density estimates were made 37 and 57 DAP. Common lambsquarters at low densities (20 to 40 weeds/m2) was controlled with the cover crop alone, but common lambsquarters at high densities (150 to 170 weeds/m2) and redroot pigweed at any density were not controlled. POST herbicides reduced weed densities as well as the PRE herbicides, regardless of initial weed densities.

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