The Response of Different Weed Species to Glyphosate Using Ammonium Sulfate and Hard Water

ABSTRACT: Water hardness antagonism and the effect of ammonium sulphate (AMS) on efficacy of glyphosate have been well documented. However conflicting results between weed species were noted by the authors. Greenhouse experiments were conducted twice at the Ferdowsi University of Mashhad in a randomized complete block design with a factorial arrangement and three replications during 2014-2015. Four experiments were arranged separately on cypress (Kochia scoparia), redroot pigweed (Amaranthus retroflexus), little seed canary grass (Phalaris minor) and winter wild oat (Avena ludoviciana) using ammonium sulphate and deionizad water and in the presence of different salts, (i.e. NaHCO3, CaCO3, MgCl2 and CaCl2 at 500 ppm) against three doses of glyphosate (256.25, 512.5 and 1,025 g a.i. ha-1), with and without ammonium sulphate (AMS) as adjuvant (2% w/v). The results showed the application of AMS overcomes the inhibitory effects of salts in the spray solution in tested species. The degree of effectiveness in A. retroflexus was more than A. ludoviciana and P. minor. Glyphosate with AMS caused reduction in dry matter in grasses from 0.34 to 0.28 g, while glyphosate toxicity in A. retroflexus with AMS was 100 percent and all of the plants were destroyed (0.82 to 0 g). The application of AMS in overcoming the inhibitory effects of water hardness had no effect on K. scoparia control. However, Increasing AMS could overcome the inhibitory effects of hard water in the spray solution on glyphosate efficacy in A. retroflexus and K. scoparia, but it had no effect on tested grassy weeds. We may conclude that glyphosate work differently on weed species using AMS and hard water.

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Effect of Carrier Water Hardness and Ammonium Sulfate on Efficacy of 2,4-D Choline and Premixed 2,4-D Choline Plus Glyphosate

Weed Technology ◽

10.1614/wt-d-16-00040.1 ◽

2016 ◽

Vol 30 (4) ◽

pp. 878-887 ◽

Cited By ~ 3

Author(s):

Pratap Devkota ◽

William G. Johnson

Keyword(s):

Water Quality ◽

Ammonium Sulfate ◽

Linear Trend ◽

Water Hardness ◽

Hard Water ◽

Palmer Amaranth ◽

Weed Species ◽

Hardness Level ◽

Spray Solution ◽

Giant Ragweed

Spray water quality is an important consideration for optimizing herbicide efficacy. Hard water cations in the carrier water can reduce herbicide performance. Greenhouse studies were conducted to evaluate the influence of hard water cations and the use of ammonium sulfate (AMS) on the efficacy of 2,4-D choline and premixed 2,4-D choline plus glyphosate for giant ragweed, horseweed, and Palmer amaranth control. Carrier water hardness was established at 0, 200, 400, 600, 800, or 1,000 mg L−1using CaCl2and MgSO4, and each hardness level consisted of without or with AMS at 10.2 g L−1. One-third of the proposed use rates of 2,4-D choline at 280 g ae ha−1and 2,4-D choline plus glyphosate at 266 plus 283 g ae ha−1, respectively, were applied in the study. An increase in carrier water hardness showed a linear trend for reducing 2,4-D choline and 2,4-D choline plus glyphosate efficacy on all weed species evaluated in both studies. The increase in water hardness level reduced giant ragweed control with 2,4-D choline and the premix formulation of 2,4-D choline plus glyphosate to a greater extent without AMS than it did with AMS in the spray solution. Increases in water hardness from 0 to 1,000 mg L−1reduced weed control 20% or greater with 2,4-D choline. Likewise, the efficacy of the premixed 2,4-D choline plus glyphosate was reduced 21% or greater with increased water hardness from 0 to 1,000 mg L−1. The addition of AMS improved giant ragweed, horseweed, and Palmer amaranth control ≥ 17% and ≥ 10% for 2,4-D choline and 2,4-D choline plus glyphosate application, respectively. The biomass of all weed species was reduced by ≥ 8% and ≥ 5% with 2,4-D choline and 2,4-D choline plus glyphosate application, respectively, when AMS was added to hard water.

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Weed control by 2,4-D dimethylamine depends on mixture water hardness and adjuvant inclusion but not spray solution storage time

Weed Technology ◽

10.1017/wet.2019.117 ◽

2020 ◽

Vol 34 (1) ◽

pp. 107-116 ◽

Cited By ~ 1

Author(s):

Geoffrey P. Schortgen ◽

Aaron J. Patton

Keyword(s):

Weed Control ◽

Storage Time ◽

Water Hardness ◽

Hard Water ◽

Quality Parameters ◽

Weak Acid ◽

Hardness Level ◽

Spray Solution ◽

Water Conditioning ◽

Acid Herbicides

AbstractHerbicides are an important tool in managing weeds in turf and agricultural production. One of the earliest selective herbicides, 2,4-D, is a weak acid herbicide used to control broadleaf weeds. Water-quality parameters, such as pH and hardness, influence the efficacy of weak acid herbicides. Greenhouse experiments were conducted to evaluate how varying water hardness level, spray solution storage time, and adjuvant inclusion affected broadleaf weed control by 2,4-D dimethylamine. The first experiment evaluated a range of water-hardness levels (from 0 to 600 mg calcium carbonate [CaCO3] L−1) on efficacy of 2,4-D dimethylamine applied at 1.60 kg ae ha−1 for dandelion and horseweed control. A second experiment evaluated dandelion control from spray solutions prepared 0, 1, 4, 24, and 72 h before application. Dandelion and horseweed control by 2,4-D dimethylamine was reduced when the CaCO3 level in water was at least 422 or at least 390 mg L−1, respectively. Hard-water antagonism was overcome by the addition of 20 g L−1 ammonium sulfate (AMS) into the mixture. When AMS was included in spray mixtures, no differences were observed at 600 mg CaCO3 L−1, compared with distilled water. Spray solution storage time did not influence dandelion control, regardless of water-hardness level or adjuvant inclusion. To prevent antagonism, applicators should use a water-conditioning agent such as AMS when applying 2,4-D dimethylamine in hard water.

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Potential and Persistence of the Inhibitory Effect of Sorghum on Weeds

Planta Daninha ◽

10.1590/s0100-83582018360100100 ◽

2018 ◽

Vol 36 (0) ◽

Cited By ~ 1

Author(s):

E.M. BIESDORF ◽

L.D. PIMENTEL ◽

M.F.F. TEIXEIRA ◽

E. BIESDORF ◽

P.H.H. SALLA ◽

...

Keyword(s):

Weed Management ◽

Block Design ◽

Inhibitory Effect ◽

Integrated Weed Management ◽

Lower Amount ◽

Inhibitory Effects ◽

Weed Species ◽

Inhibitory Interaction ◽

Randomized Block Design ◽

Weed Infestation

ABSTRACT: The inhibitory interaction between plants may be an important strategy of integrated weed management (IWM). This study aimed to investigate the inhibitory effects of sorghum on phytosociology and infestation of weeds during cultivation and after harvest. An experiment was carried out in the field in a randomized block design in a split-plot arrangement. Plots consisted of sorghum and corn (control) and subplots were composed of different periods of weed community assessment after crop harvest (DAH) (0, 20, 40, 60, and 80 days). An increased number of species and botanical families was observed after harvest. Degradation of sorghum and corn straw reached the stabilization at 60 DAH. Although sorghum has presented a lower amount of straw and soil cover, weed infestation was, on average, 30% lower in relation to areas cultivated with corn. Sorghum showed an inhibitory effect on some weed species, influencing phytosociology, especially during the first 40 DAH, and can be used as part of IWM strategy.

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Germination of Exhumed Weed Seed in Nebraska

Weed Science ◽

10.1017/s0043174500063761 ◽

1981 ◽

Vol 29 (5) ◽

pp. 577-586 ◽

Cited By ~ 51

Author(s):

Orvin C. Burnside ◽

Charles R. Fenster ◽

Larry L. Evetts ◽

Robert F. Mumm

Keyword(s):

Amaranthus Retroflexus ◽

Setaria Viridis ◽

Weed Species ◽

Kochia Scoparia ◽

Asclepias Syriaca ◽

Rapid Loss ◽

Digitaria Sanguinalis ◽

Redroot Pigweed ◽

Green Foxtail ◽

Panicum Dichotomiflorum

An experiment was initiated in 1970 and continued through 1979 by exhuming and germinating seed of 12 economic weed species buried beneath 23 cm of soil in eastern and western Nebraska. Loss in germination of exhumed seeds over years is mathematically characterized by the formula for the rectangular hyperbola, which represents many shapes of curves that have zero as their lower limit. Of the 12 weed species, only fall panicum (Panicum dichotomiflorumMichx.) and redroot pigweed (Amaranthus retroflexusL.) seed germination did not drop significantly over the 10-yr burial period. Germination of redroot pigweed seed was higher when buried in eastern Nebraska, but was higher for smooth groundcherry (Physalis subglabrataMack&Bush.) and velvetleaf (Abutilon theophrastiMedic.) when buried in western Nebraska. Germination of the other nine species were not affected by burial location. The 12 weed species can be ranked as those showing most to least rapid loss of germination during burial for 10 yr as follows: honeyvine milkweed [Ampelamus albidus(Nutt.) Britt.], hemp dogbane (Apocynum cannabinumL.), kochia [Kochia scoparia(L.) Schrad.], sunflower (Helianthus annumL.), large crabgrass [Digitaria sanguinalis(L.) Scop.], common milkweed (Asclepias syriacaL.), musk thistle (Carduus nutansL.), velvetleaf, fall panicum, redroot pigweed, green foxtail [Setaria viridis(L.) Beauv.], and smooth groundcherry.

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Control of Three Weed Species in Sugarbeets (Beta vulgaris) with an Electrical Discharge System

Weed Science ◽

10.1017/s004317450002590x ◽

1981 ◽

Vol 29 (1) ◽

pp. 93-98 ◽

Cited By ~ 5

Author(s):

R. G. Wilson ◽

F. N. Anderson

Keyword(s):

Beta Vulgaris ◽

Electrical Discharge ◽

Chenopodium Album ◽

Field Studies ◽

Amaranthus Retroflexus ◽

Weed Species ◽

Kochia Scoparia ◽

Discharge System ◽

Common Lambsquarters ◽

Redroot Pigweed

An electrical discharge system (EDS) was evaluated in field studies conducted in 1977 through 1979 in western Nebraska for its ability to control weed escapes in sugarbeets (Beta vulgarisL. ‘Mono Hy D2′). Nine weeks after sugarbeets were planted, kochia [Kochia scoparia(L.) Schrad.] had attained a height above sugarbeets sufficient for EDS treatment. Redroot pigweed (Amaranthus retroflexusL.) and common lambsquarters (Chenopodium albumL.) generally attained sufficient height above sugarbeets 11 and 13 weeks after sugarbeet planting. Sugarbeet root yields were reduced 40, 20, and 10% from competition by kochia, common lambsquarters, and redroot pigweed, respectively. Treatment of kochia, redroot pigweed, and common lambsquarters with EDS in some cases resulted in a reduction in weed height. The EDS treatments reduced the stand of all weeds 32, 39, and 47% for 1977, 1978, and 1979, respectively. Although the EDS treatments failed to kill many weeds, it did suppress the competitive ability of the three weeds to the extent that sugarbeet yields were higher in areas receiving EDS treatments than areas receiving no EDS treatment.

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Divalent Cations in Spray Water Influence 2,4-D Efficacy on Dandelion (Taraxacum officinale) and Broadleaf Plantain (Plantago major)

Weed Technology ◽

10.1614/wt-d-15-00120.1 ◽

2016 ◽

Vol 30 (2) ◽

pp. 431-440 ◽

Cited By ~ 3

Author(s):

Aaron J. Patton ◽

Daniel V. Weisenberger ◽

William G. Johnson

Keyword(s):

Divalent Cations ◽

Hard Water ◽

Plant Size ◽

Weak Acid ◽

Dichlorophenoxyacetic Acid ◽

Plantago Major ◽

Weed Species ◽

Spray Solution ◽

2,4 Dichlorophenoxyacetic Acid ◽

Fertilizer Solutions

2,4-dichlorophenoxyacetic acid (2,4-D) is a common ingredient in POST broadleaf herbicides labeled for use in turf, pastures, rangeland, and grain crops. The herbicide 2,4-D is a weak acid, and when dissociated can bind to cations present in hard-water spray solutions and/or fertilizer solutions. Experiments were conducted with 2,4-D dimethylamine to evaluate the effect of cation solutions on herbicide efficacy on the perennial broadleaf weeds dandelion and broadleaf plantain. The objectives of this research were to (1) determine if 2,4-D efficacy is influenced by the divalent cations, calcium (Ca), magnesium (Mg), manganese (Mn), and zinc (Zn) in spray solution; and (2) determine if adding the adjuvant ammonium sulfate (AMS) to the spray solution can overcome antagonism. Broadleaf plantain and dandelion control was reduced and plant size and mass increased when 2,4-D was applied in a Ca solution in comparison to deionized water. However, 2,4-D antagonism was overcome when AMS was added as an adjuvant to the spray solution. Magnesium caused 2,4-D antagonism on both weed species in one run of the experiment similar to Ca solution and AMS was successful at overcoming antagonism when added to the tank mixture. Some 2,4-D antagonism from Mn was noticed even when AMS was in the tank mix, but Zn fertilizer solutions did not antagonize 2,4-D activity on either weed species. Although divalent cations can antagonize 2,4-D dimethylamine and reduce perennial broadleaf weed control, adding AMS can overcome this antagonism when Ca and Mg are the primary cations in spray solution. Applicators should avoid using Mn fertilizers when applying 2,4-D dimethylamine because AMS did not successfully overcome antagonism.

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Effects of spray carrier quality on biological activity of terbuthylazine + mesotrione herbicide combination

Acta Agraria Debreceniensis ◽

10.34101/actaagrar/39/2748 ◽

2010 ◽

pp. 110-115

Author(s):

István Dávid ◽

Endre Máté

Keyword(s):

Biological Activity ◽

Ammonium Nitrate ◽

Field Experiments ◽

Water Hardness ◽

Hard Water ◽

Significant Loss ◽

Weed Species ◽

Control Efficacy ◽

Effects Of Ph ◽

Water Ph

Field experiments were conducted to study affects of pH and hardness of spray water on efficacy of a herbicide combination (terbuthylazine + mesotrione) influenced by several pH adjusters and adjuvants in Debrecen, Hungary in 2008, 2009 and 2010. Favourable or unfavourable effects of pH and hardness of spray water could be observed under field conditions. Evaluation of weed control efficacy is suitable for examination of affects of spray water pH and hardness on herbicides. The terbuthylazine and mesotrione herbicide combination is suitable to control monocotyledonous and dicotyledonous weed species, however, significant effects of hardness and pH of spray carrier was observed only in control of monocotyledonous weeds. Certain pH adjusters (e.g. ammonium nitrate) can lessen harmful affects of water hardness effectively. Significant loss of efficacy of sensitive herbicide was found in hard water (by about 50-60%), and surfactants was not able to eliminate that harmful affect. However, biological activity was the same as in soft water with ammonium nitrate which can overcome the antagonism of salts. That pH adjuster had a more significant affect on the efficacy of the herbicide than the surfactant had in that experiment.

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Phytotoxic effects of essential oils from Nepeta glocephalata Rech.f. and N. ispahanica Boiss. on se-lected weed species

Acta agriculturae Slovenica ◽

10.14720/aas.2021.117.4.1520 ◽

2021 ◽

Vol 117 (4) ◽

pp. 1

Author(s):

Marjan DYANAT ◽

Farzad ASGARI

Keyword(s):

Essential Oils ◽

Foliar Application ◽

Chenopodium Album ◽

Dry Mass ◽

Amaranthus Retroflexus ◽

Weed Species ◽

Visible Injury ◽

Phytotoxic Effects ◽

Root And Shoot Length ◽

Canary Grass

In the present study the bioherbicidal activity of essential oils hydrodistilled from Nepeta glocephalata Rech.f and N. ispahanica Boiss were investigated on four weed species (barnyard grass (Echinochloa crus-galli (L.) Beauv), redroot pigweed (Amaranthus retroflexus L.), lambsquarters (Chenopodium album L.) and canary grass (Phalaris canariensis L.)). A total of 37 components were identified from the essential oils of N. glocephalata and N. ispahanica constituting approximately 98.61 % and 96.1 % of the oils, respectively. In laboratory bioassay different concentrations (0, 1, 2, 4 and 8 μl ml-1) of two Nepeta essential oils on germination, root and shoot length were studied. Results showed by increasing the concentration of oils, all studied traits of the weeds were decreased compared with control. In a glass house bioassay post-emergence application of Nepeta essential oils (1.25 %, 2.5 %, 5 % and 10 %, v/v) on 3-week-old weed plants caused visible injury (7-days after spray) ranging from chlorosis to necrosis of plant weeds. In foliar application under glasshouse conditions, both Nepeta essential oils reduced the seedling dry mass and concentrations of chlorophyll a chlorophyll b. The study concludes that Nepeta essential oils have phytotoxic effects and could be used as bioherbicides but the selectivity of these compounds should be considered also.

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Efficacy of 2,4-D Choline as Influenced by Weed Size in the Texas High Plains

Journal of Experimental Agriculture International ◽

10.9734/jeai/2019/v35i230199 ◽

2019 ◽

pp. 1-8

Author(s):

Misha R. Manuchehri ◽

Peter A. Dotray ◽

J. Wayne Keeling

Keyword(s):

Field Experiments ◽

Block Design ◽

Palmer Amaranth ◽

High Plains ◽

Growth Stages ◽

Weed Species ◽

Kochia Scoparia ◽

Texas High Plains ◽

Randomized Complete Block Design ◽

Extension Center

Aim: Postemergence timing trials based on weed size were conducted near Lubbock, TX to assess the effectiveness of 2,4-D choline + glyphosate on control of Palmer amaranth (Amaranthus palmeri S. Wats.), Russian-thistle (Salsola tragus L.), and kochia (Kochia scoparia L.) at three growth stages (3 to 5 cm, 10 to 15 cm, and 20 to 30 cm). Study Design: All trials were arranged in a randomized complete block design with four replications. Place and Duration of Study: Field experiments were conducted in 2013, 2014, and 2015 in Lubbock, TX at the Texas A&M AgriLife Research and Extension Center near Lubbock, TX. Methodology: Herbicide treatments consisted of a single postemergence application of 2,4-D choline + glyphosate at two rates, 2,4-D choline + glyphosate at two rates + glufosinate, 2,4-D choline + glyphosate + S-metolachlor, 2,4-D choline + glyphosate + acetochlor, 2,4-D choline + glufosinate, glyphosate, or glufosinate. Results: The greatest level of weed control for all three weed species was achieved at the 3 to 5 cm timing; however, weed size was most critical for Palmer amaranth and Russian-thistle compared to kochia. Averaged over all three years, Palmer amaranth control decreased from 93 to 74% when evaluated 21 days after treatment following applications that included 2,4-D choline when applied to plants 3 to 5 and 10 to 30 cm, respectively. For Russian-thistle, control decreased from 98 to 78% when evaluated 21 days after treatment following treatments that included 2,4-D choline when applied to plants 3 to 5 and 10 to 30 cm, respectively. For kochia, control decreased from 98 to 84% when evaluated 21 days after treatment following treatments that included 2,4-D choline when applied to plant 3 to 5 and 10 to 30 cm, respectively.

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The effect of hard water, spray solution storage time, and ammonium sulfate on glyphosate efficacy and yield of glyphosate-resistant corn

Canadian Journal of Plant Science ◽

10.4141/cjps-2014-131 ◽

2014 ◽

Vol 94 (8) ◽

pp. 1401-1405 ◽

Cited By ~ 1

Author(s):

K. J. Mahoney ◽

R. E. Nurse ◽

P. H. Sikkema

Keyword(s):

Ammonium Sulfate ◽

Storage Time ◽

Water Hardness ◽

Hard Water ◽

Corn Yield ◽

Distilled Water ◽

Water Spray ◽

Above Ground Biomass ◽

Common Lambsquarters ◽

Spray Solution

Mahoney, K. J., Nurse, R. E. and Sikkema, P. H. 2014. The effect of hard water, spray solution storage time, and ammonium sulfate on glyphosate efficacy and yield of glyphosate-resistant corn. Can. J. Plant Sci. 94: 1401–1405. Effects of ammonium sulfate (AMS) on reduced glyphosate rates are well documented; however, these rates are not used by farmers. Studies in 2011 and 2012 determined the effects of AMS and hard water on glyphosate applied at a field rate. AMS (0 or 2.5 L ha−1) and glyphosate (900 g a.e. ha−1) were added to distilled or hard water carriers. Glyphosate plus AMS, in either distilled or hard water, did not usually affect velvetleaf, pigweed species, common ragweed, common lambsquarters and large crabgrass above-ground biomass and density 8 wk after treatment (WAT); however, velvetleaf biomass was reduced with the addition of AMS to glyphosate. Compared with the weedy control 8 WAT, glyphosate plus AMS reduced velvetleaf biomass by 93%, while treatments with no AMS reduced biomass by 77%. In distilled water, 4.8 common lambsquarters plants m−2 remained compared with 7.8 plants m−2 with glyphosate in hard water. For corn yield, an AMS×water hardness interaction was detected; however, no differences were observed among the treatment combinations and the addition of AMS to glyphosate did not affect yield. Therefore, advocating adding AMS to spray solutions containing glyphosate, especially when a labeled rate is used, should be called into question.

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