FIELD MEASUREMENT OF DROPLET DRIFT FROM GROUND SPRAYERS. I. SAMPLING, ANALYTICAL, AND DATA INTEGRATION TECHNIQUES

A procedure for the evaluation of ground deposits and droplet drift characteristics from a typical farm sprayer under actual field conditions is described. It involves sampling both the ground deposits on the swath and the air-borne cloud mass, the latter at various heights and distances downwind from the target area. The system was evaluated with the commonly used 65° flat-fan nozzles operated at 280 kPa which provided an application rate of 0.56 kg/ha of 2,4-D amine (2,4-dichlorophenoxyacetic acid) in 56 ℓ water/ha. The spray solution also contained a fluorescent dye as a tracer. A portable meteorological station, where a number of meteorological parameters can be measured or recorded during the course of a field trial, is also described. Results of four field trials are presented with discussion regarding on-swath deposit density and its distribution over the swath, off-swath drifting cloud mass and its deposition and decay as a function of distance, and mass balance.

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Effect of protective shields on drift and deposition characteristics of field sprayers

Canadian Journal of Plant Science ◽

10.4141/cjps93-165 ◽

1993 ◽

Vol 73 (4) ◽

pp. 1261-1273 ◽

Cited By ~ 27

Author(s):

Thomas M. Wolf ◽

Raj Grover ◽

Keith Wallace ◽

Stan R. Shewchuk ◽

John Maybank

Keyword(s):

Wind Speed ◽

Droplet Size ◽

Field Trials ◽

Application Rate ◽

Target Area ◽

High Wind ◽

Ground Speed ◽

Wind Speeds ◽

Spray Solution ◽

Deposition Uniformity

Field trials were conducted to determine the effectiveness of shields in reducing off-target droplet drift from ground-rig sprayers. Sprayer booms ranging in width from 10 to 13.5 m and equipped with commercially available shields were operated along a 150-m swath in a field of approximately 20-cm-tall spring wheat in wind speeds ranging from 10 to 35 km h−1. Airborne drift was measured using aspirated air samplers. The use of an 80 flat fan tip (8001) at a pressure of 275 kPa and a ground speed of 8 km h−1 resulted in 7.5% of the 50 L ha−1 spray solution drifting off the target area. The use of protective cones with 8001 tips without lowering the boom reduced airborne drift by 33% at a 20 km h−1 wind speed, while a 65–85% drift reduction was accomplished with the combination of solid or perforated shielding and lowering the sprayer boom. Increasing the application rate to 100 L ha−1 by using 8002 tips reduced drift of the unshielded sprayer by 65%. Decreasing application rate to 15 L ha−1 by using 800017 tips increased drift by 29% despite the use of a shield. Off-target drift increased with increasing wind speeds for all sprayers, but the increase was less for shielded sprayers and coarser sprays. The decreased droplet size of spray from 110 tips increased drift when the boom height was the same as for 80 tips. High wind speeds, lower carrier volumes and finer sprays, 110 tips, and solid shields tended to decrease on-swath deposit uniformity, whereas a perforated shield or cones did not affect deposit uniformity. Key words: 2,4-D amine, droplet drift, aspirated air samplers, flat fan tips, deposition uniformity, droplet size

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Hygroscopic Additives to Phenoxy Herbicides for Control of Saltcedar

Weed Science ◽

10.1017/s0043174500047822 ◽

1968 ◽

Vol 16 (4) ◽

pp. 486-488 ◽

Cited By ~ 2

Author(s):

Eugene E. Hughes

Keyword(s):

Acetic Acid ◽

Propionic Acid ◽

Dichlorophenoxyacetic Acid ◽

Water Solutions ◽

Molecular Weights ◽

Spray Solution ◽

Phenoxy Herbicides ◽

2,4 Dichlorophenoxyacetic Acid ◽

Increased Activity

Greenhouse studies on control of saltcedar (Tamarix pentandra Pall.), a problem phreatophyte, showed that when one of three hygroscopic compounds, polypropylenediol (a mixture of polypropylenediols with molecular weights ranging from 375 to 425) was added to water solutions of phenoxy herbicides, it significantly increased injury from most treatments. Injury to foliage from all herbicides tested, except the oil-soluble amine formulations (a mixture containing 80% tertiary dodecyl and 20% tertiary tetradecyl amine) of 2,4-dichlorophenoxyacetic acid (2,4-D), 2-(2,4,5-trichlorophenoxy) propionic acid (silvex), and 2,4-D plus 2,4,5-trichlorophenoxy acetic acid (2,4,5-T) (1:1), increased when polypropylenediol was added to the spray solution at 5% by volume. The increased activity was affected by the rate of the additive, temperature, humidity, and herbicide formulation.

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The Effect of Picloram Plus 2,4-Dichlorphenoxyacetic Acid on Peanut Growth and Yield

Peanut Science ◽

10.3146/ps19-14.1 ◽

2020 ◽

Vol 47 (2) ◽

pp. 111-114

Author(s):

O.W. Carter ◽

E.P. Prostko

Keyword(s):

Plant Density ◽

Leaf Roll ◽

Field Trials ◽

Growth And Yield ◽

Dichlorophenoxyacetic Acid ◽

Livestock Waste ◽

Significant Yield ◽

Contaminated Irrigation Water ◽

Effect On Yield ◽

2,4 Dichlorophenoxyacetic Acid

ABSTRACT Picloram (4-amino-3,5,6-trichloropicolinic acid) injury, in the form of leaf roll, is often observed in peanut fields due to short crop rotations, contaminated irrigation water, treated hay, and contaminated livestock waste. Limited data on peanut response to picloram is available. Field trials were conducted near Tifton, GA from 2015-2017 to determine the effects of picloram plus 2,4-D (2,4-dichlorophenoxyacetic acid) on peanut growth and yield. Picloram plus 2,4-D was applied to ‘GA-06G' peanut at four different timings: preemergence (PRE), 30 d after planting (DAP), 60 DAP, and 90 DAP. At each timing, three rates of picloram plus 2,4-D were applied including the following: 1/10thX (0.18 + 0.67 kg ai/ha); 1/100thX (0.018 + 0.067 kg ai/ha); and 1/300thX (0.006 + 0.023 kg ai/ha). A non-treated control (NTC) or 0 rate was included for comparison. Peanut plant density was not influenced by any rate or timing of picloram plus 2,4-D. For peanut injury (leaf roll), a significant rate x timing interaction was observed (P=0.047). At 120 DAP, leaf roll was significant for the 1/10thX rate applied at 30, 60, and 90 DAP, the 1/100thX rate applied at 60 and 90 DAP, and for the 1/300thX rate applied at 90 DAP. When averaged over timing, peanut height at 120 DAP was significantly reduced by the 1/10thX and 1/100thX rates. When averaged over rate, peanut height reductions were greatest when picloram plus 2,4-D was applied at 60 DAP. When averaged over timing, only the 1/10thX rate caused significant yield reductions (11%). When averaged over rate, timing had no effect on yield (P=0.5403). Peanut fields unintentionally exposed to picloram plus 2,4-D rates ≤ 1/100thX can exhibit typical injury symptoms but most likely will not experience yield losses.

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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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Foliar Treatments of 2,4-Dichlorophenoxyacetic Acid for Control of Common Scab in Potato Have Beneficial Effects on Powdery Scab Control

The Scientific World JOURNAL ◽

10.1155/2014/947167 ◽

2014 ◽

Vol 2014 ◽

pp. 1-5 ◽

Cited By ~ 4

Author(s):

Hannah Katherine Thompson ◽

Robert Stephen Tegg ◽

Ross Corkrey ◽

Calum Rae Wilson

Keyword(s):

Common Scab ◽

Field Trials ◽

Powdery Scab ◽

Dichlorophenoxyacetic Acid ◽

Beneficial Effects ◽

Pathogen Invasion ◽

Potato Plants ◽

Scab Control ◽

Tuber Disease ◽

2,4 Dichlorophenoxyacetic Acid

Prior studies have shown that applications of the synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D) to the foliage of potato plants can reduce common scab. Here field and glasshouse trials suggest that 2,4-D foliar treatments may also reduce the biologically distinct tuber disease, powdery scab. Significant correlations between suppression of common and powdery scab from the field trials suggested an interaction between the two diseases or possible additional broad spectrum mechanisms of enhanced defence against pathogen invasion provided by 2,4-D treatment.

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In Vitro Shoot Regeneration from Callus Derived from Marubakaido Apple Rootstock under Different Aluminium Concentrations

HortScience ◽

10.21273/hortsci.33.3.460e ◽

1998 ◽

Vol 33 (3) ◽

pp. 460e-460 ◽

Cited By ~ 1

Author(s):

Marisa F. de Oliveira ◽

Gerson R. de L. Fortes ◽

João B. da Silva

Keyword(s):

Shoot Regeneration ◽

Dichlorophenoxyacetic Acid ◽

Apple Rootstock ◽

Under Five ◽

Significant Difference ◽

Previously Treated ◽

2,4 Dichlorophenoxyacetic Acid ◽

In Vitro Shoot Regeneration

The aim of this work was to evaluate the organogenesis of Marubakaido apple rootstock under different aluminium concentratons. The explants were calli derived from apple internodes treated with either 2,4-dichlorophenoxyacetic acid or pichloram at 0.5 and 1.0 μM and under five different aluminium concentrations (0, 5, 10, 15, 20 mg/L). These calli were then treated with aluminium at 0, 5, 10, 15, and 20 mg/L. It was observed shoot regeneration only for those calli previously treated with pichloram. There were no significant difference among the aluminium concentrations.

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Characterization of the Reproductive Mode in Guayule In Vitro

HortScience ◽

10.21273/hortsci.33.3.483a ◽

1998 ◽

Vol 33 (3) ◽

pp. 483a-483

Author(s):

Roy N. Keys ◽

Dennis T. Ray ◽

David A. Dierig

Keyword(s):

Field Experiments ◽

Reproductive Mode ◽

Dichlorophenoxyacetic Acid ◽

Initial Field ◽

Breeding Lines ◽

Reproductive Modes ◽

Desert Southwest ◽

2,4 Dichlorophenoxyacetic Acid

Guayule (Parthenium argentatum Gray, Asteraceae) is a latex-producing perennial desert shrub that is potentially of economic importance as an industrial crop for the desert Southwest. It is known to possess complex reproductive modes. Diploids are predominantly sexual and self-incompatible, while polyploids show a range of apomictic potential and self-compatibility. This paper describes the development of a relatively rapid and simple technique for characterizing reproductive modes of breeding lines of P. argentatum. Initial field experiments were based on an auxin test used successfully to characterize reproductive mode in the Poaceae. The application of 2,4-dichlorophenoxyacetic acid inhibited embryo formation in P. argentatum, but this was not the case with other auxins tested. Results of field experiments were ambiguous because: 1) the floral structure of P. argentatum is such that auxins might not have penetrated to the ovules, and 2) there was potential self-fertilization by pollen released within isolation bags. Therefore, in vitro culture of flower heads was tested because it provided much better control of environmental conditions, growth regulator application, and pollen release. Auxin alone, or in combination with gibberellic acid or kinetin, inhibited parthenogenesis in vitro. Embryo production did not vary using two substantially different nutrient media. In vitro flower head culture using a (Nitsch and Nitsch) liquid nutrient medium without growth regulators, enabled characterization of the reproductive mode of seven breeding lines, ranging from predominantly sexual to predominantly apomictic. The results of this technique were substantiated using RAPD analyzes of progeny arrays from controlled crosses.

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The role of a metabolic intermediate in the biodegradation of inhibitory substrates

Water Science & Technology ◽

10.2166/wst.1997.0352 ◽

1997 ◽

Vol 36 (10) ◽

pp. 27-36 ◽

Cited By ~ 1

Author(s):

P. Mungkarndee ◽

S. M. Rao Bhamidimarri ◽

A. J. Mawson ◽

R. Chong

Keyword(s):

The Other ◽

Metabolic Product ◽

Dichlorophenoxyacetic Acid ◽

Mutual Inhibition ◽

Metabolic Intermediate ◽

Batch Cultures ◽

Ortho Cresol ◽

2,4 Dichlorophenoxyacetic Acid

Biodegradation of the mixed inhibitory substrates, 2,4-dichlorophenoxyacetic acid (2,4-D) and para-chloro-ortho-cresol (PCOC) was studied in aerobic batch cultures. Each substrate added beyond certain concentrations inhibited the degradation of the other. This mutual inhibition was found to be enhanced by 2,4-dichlorophenol (2,4-DCP) which is an intermediate metabolic product of 2,4-D. When 2,4-DCP accumulated to approximatelY 40 mg/l degradation of all compounds in the mixed 2,4-D and PCOC substrate system was completely inhibited. The degradation of 2,4-D and PCOC individually was also found to be inhibited by elevated concentrations of 2,4-DCP added externally, while PCOC inhibited the utilization of the intermediate.

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