Glufosinate Efficacy as Influenced by Carrier Water pH, Hardness, Foliar Fertilizer, and Ammonium Sulfate

2016 ◽  
Vol 30 (4) ◽  
pp. 848-859 ◽  
Author(s):  
Pratap Devkota ◽  
William G. Johnson
Keyword(s):  
Ammonium Sulfate ◽  
Plant Density ◽  
Control Plant ◽  
Water Hardness ◽  
Palmer Amaranth ◽  
Foliar Fertilizer ◽  
Density Reduction ◽  
Giant Ragweed ◽  
Water Ph ◽  
Biomass Reduction

Carrier water quality is an important consideration for herbicide efficacy. Effect of carrier water pH (4, 6.5, or 9) and coapplied Zn or Mn foliar fertilizer was evaluated on glufosinate efficacy for horseweed and Palmer amaranth control in the field. Greenhouse studies were conducted to evaluate the effect of: (1) carrier water pH, foliar fertilizer (Zn, Mn, or without fertilizer), and ammonium sulfate (AMS) (at 0 or 2.5% v/v); and (2) carrier water hardness (0 to 1,000 mg L−1) and AMS (at 0 or 2.5% v/v) on glufosinate efficacy for giant ragweed, horseweed, and Palmer amaranth control. In a 2014 field study, control, plant density reduction, and biomass reduction were at least 8% greater for horseweed and at least 14% greater for Palmer amaranth when glufosinate was applied at carrier water pH 4 compared with pH 9. Glufosinate efficacy was at least 10 and 17% greater for giant ragweed and Palmer amaranth control, respectively, with carrier water pH 4 compared with pH 9 in the greenhouse. In the greenhouse studies, coapplied Zn or Mn fertilizer had no effect on glufosinate efficacy. Increased carrier water hardness from 0 to 1,000 mg L−1negatively influenced glufosinate efficacy and resulted in 20 and 17% lesser control and biomass reduction, respectively, on giant ragweed or Palmer amaranth. Use of AMS enhanced glufosinate efficacy on giant ragweed control in both greenhouse studies, whereas only the Palmer amaranth control was enhanced in the water hardness study. Horseweed control with glufosinate as affected by carrier water pH, hardness, or AMS remained unaffected in both greenhouse studies. Carrier water at alkaline pH or hardness > 200 mg L−1has potential to reduce glufosinate efficacy. Therefore, carrier water free of hardness cations and at acidic condition (pH = 4 to 6.5) should be considered for optimum glufosinate efficacy.

Influence of Carrier Water pH, Hardness, Foliar Fertilizer, and Ammonium Sulfate on Mesotrione Efficacy

2016 ◽  
Vol 30 (3) ◽  
pp. 617-628 ◽  
Author(s):  
Pratap Devkota ◽  
Douglas J. Spaunhorst ◽  
William G. Johnson
Keyword(s):  
Ammonium Sulfate ◽  
Plant Height ◽  
Water Hardness ◽  
Dry Weight ◽  
Field Studies ◽  
Palmer Amaranth ◽  
Foliar Fertilizer ◽  
Greenhouse Study ◽  
Giant Ragweed ◽  
Water Ph

Carrier water pH, hardness, coapplied foliar fertilizer, water conditioning agents, and plant height are critical considerations for optimum herbicide performance. Field studies were conducted to evaluate the effect of carrier water pH (4, 6.5, and 9) and zinc (Zn) or manganese (Mn) foliar fertilizer on mesotrione for horseweed and Palmer amaranth control. Additionally, effect of carrier water pH and foliar fertilizer was evaluated on 7.5-, 12.5-, and 17.5-cm tall horseweed. Greenhouse treatments consisted of carrier water pH and foliar fertilizer (Zn, Mn, or without fertilizer); or water hardness (0 to 1,000 mg L−1) in the presence or absence of ammonium sulfate (AMS) for mesotrione control of giant ragweed, horseweed, and Palmer amaranth. Mesotrione activity was greater on horseweed with carrier water pH 6.5 compared to pH 4 or 9. Coapplied Zn fertilizer reduced mesotrione activity on Palmer amaranth in the field study in 2014 and horseweed in the greenhouse study. Mesotrione efficacy was greatly influenced by horseweed height. Percent control ranged from 96 to 99%, 75 to 89%, or 61 to 64% with mesotrione applied on 7.5-, 12.5-, or 17.5-cm tall horseweed, respectively, and results were similar for plant height and dry weight reduction. Increasing carrier water hardness from 0 to 1,000 mg L−1reduced mesotrione efficacy 28, 18, and 18% (or greater) on giant ragweed, horseweed, and Palmer amaranth, respectively. The addition of AMS enhanced mesotrione efficacy 9, 6, or 9% (or greater) for giant ragweed, horseweed, and Palmer amaranth control, respectively. Mesotrione should be applied at near neutral carrier water pH, hardness < 200 mg L−1, and with AMS for achieving optimum weed control.

Influence of carrier water pH, foliar fertilizer, and ammonium sulfate on 2,4-D and 2,4-D plus glyphosate efficacy

2019 ◽  
Vol 33 (04) ◽  
pp. 562-568 ◽  
Author(s):  
Pratap Devkota ◽  
William G. Johnson
Keyword(s):  
Field Study ◽  
Ammonium Sulfate ◽  
Weed Control ◽  
Palmer Amaranth ◽  
Weed Species ◽  
Foliar Fertilizer ◽  
Greenhouse Study ◽  
Giant Ragweed ◽  
Negative Effect ◽  
Water Ph

AbstractCarrier water pH is an important factor for enhancing herbicide efficacy. Coapplying agrochemical products with the herbicide might save time and resources; however, the negative effect of foliar fertilizers on herbicide efficacy should be thoroughly evaluated. In greenhouse studies, the effect of carrier water pH (4, 6.5, and 9), foliar fertilizer (zinc [Zn], manganese [Mn], or without fertilizer), and ammonium sulfate (AMS) at 0% or 2.5% vol/vol was evaluated on 2,4-D and premixed 2,4-D plus glyphosate efficacy for giant ragweed, horseweed, and Palmer amaranth control. In addition, a field study was conducted to evaluate the effect of carrier water pH (4, 6.5, and 9); and Zn or Mn foliar fertilizer on premixed 2,4-D plus glyphosate efficacy for horseweed and Palmer amaranth control. In the greenhouse study, 2,4-D and premixed 2,4-D plus glyphosate provided 5% greater weed control at acidic compared with alkaline carrier water pH. Coapplied Mn foliar fertilizer reduced 2,4-D and premixed 2,4-D plus glyphosate efficacy at least 5% for weed control. Addition of AMS enhanced 2,4-D and premixed 2,4-D plus glyphosate efficacy at least 6% for giant ragweed, horseweed, and Palmer amaranth control. In the field study, few significant differences occurred between coapplied Zn or Mn foliar fertilizer for any treatment variables. Therefore, carrier water pH, coapplied foliar fertilizer, and water-conditioning adjuvants have potential to influence herbicide performance. However, weed species could play a role in the differential response of these factors on herbicide efficacy.

Efficacy of dicamba and glyphosate as influenced by carrier water pH and hardness

2019 ◽  
Vol 34 (1) ◽  
pp. 101-106
Author(s):  
Pratap Devkota ◽  
William G. Johnson
Keyword(s):  
Field Study ◽  
Water Hardness ◽  
Palmer Amaranth ◽  
Common Ragweed ◽  
Common Lambsquarters ◽  
Greenhouse Study ◽  
Spray Solution ◽  
Giant Ragweed ◽  
Pitted Morningglory ◽  
Water Ph

AbstractHerbicide carrier water hardness and pH can be variable depending on the source and geographic location. Herbicide efficacy can be affected by the pH and hardness of water used for spray solution. Field and greenhouse studies were conducted to evaluate the effect of carrier water pH and hardness on premixed dicamba and glyphosate efficacy. Treatments were combinations of water pH at 4, 6.5, or 9; and water hardness at 0 (deionized water), 400, or 800 mg L−1 of CaCO3 equivalent. In the field study, dicamba and glyphosate were applied at 0.55 and 1.11 kg ae ha−1, respectively, and half of these rates were applied in the greenhouse study. There was no interaction between carrier water pH and hardness on dicamba and glyphosate efficacy; however, the main effects of carrier water pH and hardness were significant. Herbicide efficacy was reduced with carrier water at pH 9 compared with pH 4. In the field study, common lambsquarters, common ragweed, horseweed, or Palmer amaranth control was improved 6% or more at carrier water at pH 4 compared with pH 9. Similar results were observed with water pH for giant ragweed, Palmer amaranth, or pitted morningglory control in the greenhouse study. Carrier water hardness at 400 or 800 mg L−1 reduced common ragweed, giant ragweed, or horseweed control compared with 0 mg L−1. Similarly, common lambsquarters, Palmer amaranth, or pitted morningglory control was reduced at least 10% with carrier water hardness at 800 mg L−1 compared with 0 mg L−1. These results indicate carrier water at acidic pH and of no hardness is critical for dicamba and glyphosate application, and spray solution needs to be amended appropriately for an optimum efficacy.

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

2016 ◽  
Vol 30 (4) ◽  
pp. 878-887 ◽  
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.

The Influence of Carrier Water pH and Hardness on Saflufenacil Efficacy and Solubility

2013 ◽  
Vol 27 (3) ◽  
pp. 527-533 ◽  
Author(s):  
Jared M. Roskamp ◽  
Ronald F. Turco ◽  
Marianne Bischoff ◽  
William G. Johnson
Keyword(s):  
Field Experiment ◽  
Field Experiments ◽  
Water Hardness ◽  
Common Lambsquarters ◽  
Greenhouse Experiments ◽  
Field Corn ◽  
Spray Solution ◽  
Giant Ragweed ◽  
Water Ph

The pH and hardness of water used as agrochemical carrier can influence herbicide efficacy. The objective of this research was to determine the role of carrier water pH and hardness on saflufenacil efficacy and solubility. Saflufenacil was mixed in eight different carrier waters with one of five pH levels (4.0, 5.2, 6.5, 7.7, 9.0) or one of three hardness levels (0, 310, 620 mg L−1) and applied POST to common lambsquarters and giant ragweed in a field experiment and to field corn in a greenhouse experiment. Solubility testing was also completed on saflufenacil mixed in the five pH levels used in the field and greenhouse experiments. Water hardness did not influence the efficacy of saflufenacil on common lambsquarters, giant ragweed, or field corn. Control of giant ragweed or common lambsquarters in field experiments was reduced by up to 56% when saflufenacil was applied in water with a pH of 4.0 compared with water with a pH of 7.7. When nonsoluble saflufenacil was removed from the spray solution, saflufenacil efficacy on field corn in the greenhouse was reduced by 61% or more when applied in water with a pH of 4.0 than when applied with water with a pH of 5.2 or higher. When nonsoluble saflufenacil was applied with the soluble saflufenacil in the spray solution, at least a 7% reduction in control of field corn was observed when applied in water with pH of 4.0 as compared with saflufenacil applied in water with pH of 5.2 or higher. Solubility of saflufenacil was (1) 10.1 mg L−1in water with a pH of 4.0, (2) 3,461.4 mg L−1in water with a pH of 7.7, and (3) > 5,000 mg L−1at a pH of 9. Some degradation of parent saflufenacil was detected in the pH at 9.0 treatment, with only 90% of added product being recovered after 3 d of storage. This research provides information on how saflufenacil efficacy and solubility is influenced by carrier water pH and potentially explains some differences noticed between field applications of saflufenacil.

Evaluation of Florpyrauxifen-benzyl on Herbicide-Resistant and Herbicide-Susceptible Barnyardgrass Accessions

2017 ◽  
Vol 32 (2) ◽  
pp. 126-134 ◽  
Author(s):  
M. Ryan Miller ◽  
Jason K. Norsworthy ◽  
Robert C. Scott
Keyword(s):  
Plant Height ◽  
Mechanism Of Action ◽  
Control Plant ◽  
Resistance Management ◽  
Acetolactate Synthase ◽  
Management Tool ◽  
Alternative Mechanism ◽  
Alternative Mode ◽  
Herbicide Resistant ◽  
Biomass Reduction

AbstractFlorpyrauxifen-benzyl is a new herbicide under development in rice that will provide an alternative mode of action to control barnyardgrass. Multiple greenhouse experiments evaluated florpyrauxifen-benzyl efficacy on barnyardgrass accessions collected in rice fields across Arkansas, and to evaluate its efficacy on herbicide-resistant biotypes. In one experiment, florpyrauxifen-benzyl was applied at the labeled rate of 30 g ai ha−1to 152 barnyardgrass accessions collected from 21 Arkansas counties. Florpyrauxifen-benzyl at 30 g ai ha−1effectively controlled barnyardgrass and subsequently reduced plant height and aboveground biomass. In a dose-response experiment, susceptible-, acetolactate synthase (ALS)-, propanil-, and quinclorac-resistant barnyardgrass biotypes were subjected to nine rates of florpyrauxifen-benzyl ranging from 0 to 120 g ai ha−1. The effective dose required to provide 90% control, plant height reduction, and biomass reduction of the susceptible and resistant biotypes fell below the anticipated labeled rate of 30 g ai ha−1. Based on these results, quinclorac-resistant barnyardgrass as well as other resistant biotypes can be controlled with florpyrauxifen-benzyl at 30 g ai ha−1. Overall, results from these studies indicate that florpyrauxifen-benzyl can be an effective tool for controlling susceptible and currently existing herbicide-resistant barnyardgrass biotypes in rice. Additionally, the unique auxin chemistry of florpyrauxifen-benzyl will introduce an alternative mechanism of action in rice weed control thus acting as an herbicide-resistance management tool.

scholarly journals Pollen-mediated gene flow and transfer of resistance alleles from herbicide-resistant broadleaf weeds

2020 ◽  
pp. 1-15
Author(s):  
Amit J. Jhala ◽  
Jason K. Norsworthy ◽  
Zahoor A. Ganie ◽  
Lynn M. Sosnoskie ◽  
Hugh J. Beckie ◽  
...  
Keyword(s):  
Gene Flow ◽  
Reproductive Biology ◽  
Interspecific Hybridization ◽  
Herbicide Resistance ◽  
Palmer Amaranth ◽  
High Genetic Diversity ◽  
Widespread Occurrence ◽  
Common Lambsquarters ◽  
Herbicide Resistant ◽  
Giant Ragweed

Abstract Pollen-mediated gene flow (PMGF) refers to the transfer of genetic information (alleles) from one plant to another compatible plant. With the evolution of herbicide-resistant (HR) weeds, PMGF plays an important role in the transfer of resistance alleles from HR to susceptible weeds; however, little attention is given to this topic. The objective of this work was to review reproductive biology, PMGF studies, and interspecific hybridization, as well as potential for herbicide resistance alleles to transfer in the economically important broadleaf weeds including common lambsquarters, giant ragweed, horseweed, kochia, Palmer amaranth, and waterhemp. The PMGF studies involving these species reveal that transfer of herbicide resistance alleles routinely occurs under field conditions and is influenced by several factors, such as reproductive biology, environment, and production practices. Interspecific hybridization studies within Amaranthus and Ambrosia spp. show that herbicide resistance allele transfer is possible between species of the same genus but at relatively low levels. The widespread occurrence of HR weed populations and high genetic diversity is at least partly due to PMGF, particularly in dioecious species such as Palmer amaranth and waterhemp compared with monoecious species such as common lambsquarters and horseweed. Prolific pollen production in giant ragweed contributes to PMGF. Kochia, a wind-pollinated species can efficiently disseminate herbicide resistance alleles via both PMGF and tumbleweed seed dispersal, resulting in widespread occurrence of multiple HR kochia populations. The findings from this review verify that intra- and interspecific gene flow can occur and, even at a low rate, could contribute to the rapid spread of herbicide resistance alleles. More research is needed to determine the role of PMGF in transferring multiple herbicide resistance alleles at the landscape level.

Droplet size impact on lactofen and acifluorfen efficacy for Palmer amaranth (Amaranthus palmeri) control

2019 ◽  
Vol 34 (3) ◽  
pp. 416-423
Author(s):  
Lucas X. Franca ◽  
Darrin M. Dodds ◽  
Thomas R. Butts ◽  
Greg R. Kruger ◽  
Daniel B. Reynolds ◽  
...  
Keyword(s):  
Droplet Size ◽  
Pulse Width Modulation ◽  
Effective Means ◽  
Cost Effective ◽  
Palmer Amaranth ◽  
Target Movement ◽  
Spray Droplet ◽  
Spray Droplets ◽  
Droplet Sizes ◽  
Biomass Reduction

AbstractHerbicide applications performed with pulse width modulation (PWM) sprayers to deliver specific spray droplet sizes could maintain product efficacy, minimize potential off-target movement, and increase flexibility in field operations. Given the continuous expansion of herbicide-resistant Palmer amaranth populations across the southern and midwestern United States, efficacious and cost-effective means of application are needed to maximize Palmer amaranth control. Experiments were conducted in two locations in Mississippi (2016, 2017, and 2018) and one location in Nebraska (2016 and 2017) for a total of 7 site-years. The objective of this study was to evaluate the influence of a range of spray droplet sizes [150 (Fine) to 900 μm (Ultra Coarse)] on lactofen and acifluorfen efficacy for Palmer amaranth control. The results of this research indicated that spray droplet size did not influence lactofen efficacy on Palmer amaranth. Palmer amaranth control and percent dry-biomass reduction remained consistent with lactofen applied within the aforementioned droplet size range. Therefore, larger spray droplets should be used as part of a drift mitigation approach. In contrast, acifluorfen application with 300-μm (Medium) spray droplets provided the greatest Palmer amaranth control. Although percent biomass reduction was numerically greater with 300-μm (Medium) droplets, results did not differ with respect to spray droplet size, possibly as a result of initial plant injury, causing weight loss, followed by regrowth. Overall, 900-μm (Ultra Coarse) droplets could be used effectively without compromising lactofen efficacy on Palmer amaranth, and 300-μm (Medium) droplets should be used to achieve maximum Palmer amaranth control with acifluorfen.

The Influence of Adjusting Spray Solution pH on the Efficacy of Saflufenacil

2013 ◽  
Vol 27 (3) ◽  
pp. 445-447 ◽  
Author(s):  
Jared M. Roskamp ◽  
William G. Johnson
Keyword(s):  
Ammonium Sulfate ◽  
Weight Reduction ◽  
Seed Oil ◽  
Dry Weight ◽  
Final Solution ◽  
Solution Ph ◽  
Field Corn ◽  
Spray Solution ◽  
Initial Ph ◽  
Water Ph

Saflufenacil solubility and efficacy has been shown to be influenced by carrier water pH. This research was conducted to determine if altering the pH of a solution already containing saflufenacil would influence the efficacy of the herbicide. Saflufenacil at 25 g ai ha−1was applied to field corn in carrier water with one of five initial pH levels (4.0, 5.2, 6.5, 7.7, or 9.0) and then buffered to one of four final solution pH levels (4.0, 6.5, 9.0, or none) for a total of twenty treatments. All treatments included ammonium sulfate at 20.37 g L−1and methylated seed oil at 1% v/v. Generally, saflufenacil with a final solution pH of 6.5 or higher provided more dry weight reduction of corn than saflufenacil applied in a final pH of 5.2 or lower. When applying saflufenacil in water with an initial pH of 4.0 or 5.2, efficacy was increased by raising the final solution pH to either 6.5 or 9.0. Conversely, reduction in corn dry weight was less when solution pH of saflufenacil mixed in carrier water with an initial pH of 6.5 or 7.7 was lowered to a final pH of 4.0. When co-applying saflufenacil with herbicides that are very acidic, such as glyphosate, efficacy of saflufenacil may be reduced if solution pH is 5.2 or lower.

scholarly journals Application of Inorganic Fertilizers and Organic Manures on the Production of Autotrophic Plankton in Madhupur Tract Soil Contained Miniature Tank

2017 ◽  
Vol 10 (1) ◽  
pp. 9-14
Author(s):  
ME Huda ◽  
MR Nabi
Keyword(s):  
Drinking Water ◽  
Physicochemical Parameters ◽  
Water Hardness ◽  
Chemical Parameters ◽  
Average Water Temperature ◽  
Organic Manures ◽  
Physico Chemical ◽  
Water Ph ◽  
Average Water ◽  
Domestic Use

Appropriate fertilizer and their impact on physico-chemical parameters of water and productivity is very important for aquaculture and ecology. Optimum fertilizer dose can help in fish farmer as well as aquaculture sector. From the study it was found that the total physicochemical parameters of water were suitable for aquaculture, drinking water, irrigation and domestic use. The average water temperature was 26.45±2.75oC; 26.50±3.24oC; 25.83±4.08oC; 26.57±3.02oC and 26.53±2.93oC for MCRT-1 to 5 gradually. Water pH in an average was 7.37±0.61; 7.44±0.55; 7.25±0.58; 7.33±0.54 and 7.47±0.49 for Minature Circular Research Tank (MCRT)-1 to 5 respectively. Average water DO were 6.98±1.05 mgl-1; 6.75±1.53 mgl-1; 6.90±1.64 mgl-1; 6.59±1.19mgl-1 and 6.77±1.60mgl-1 for MCRT-1 to 5 respectively. Average water hardness were 71.88 ± 20.47 mgl-1; 60.5 ±2 1.25 mgl-1; 83.38 ± 23.39 mgl-1; 59.13 ± 25.57 mgl-1 and 52.63 ± 7.92 mgl-1 for MCRT-1 to 5 gradually. Average water total phosphorus were 0.77 ± 0.18 mgl-1; 0.83 ± 0.19 mgl-1; 0.78 ± 0.21 mgl-1; 0.84 ± 0.17 mgl-1 and 0.84 ± 0.16 mgl-1 for MCRT-1 to 5 gradually. From planktonic study it was found that the highest phytoplankton and Zooplankton were in MCRT-3. Phytoplanktons were under 27 no. of genera. Their groups were Cyanophyceae, Chlorophyceae, Bacillariophyceae, Euglenophyceae and Hepatecae.Zooplankton were five major taxa and they were Protozoa, Rotifera, Cladocera, Copepod and Ostracoda respectively.J. Environ. Sci. & Natural Resources, 10(1): 9-14 2017

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