Diuron Sorption by Pine-Bark Substrate and Foliar vs. Root Absorption by Yellow Woodsorrel (Oxalis stricta)

2005 ◽  
Vol 19 (3) ◽  
pp. 532-538 ◽  
Author(s):  
Carey V. Simpson ◽  
Glenn Wehtje ◽  
Charles H. Gilliam ◽  
Jeff L. Sibley ◽  
James E. Altland
Keyword(s):  
Aqueous Solution ◽  
Aqueous Phase ◽  
Weight Reduction ◽  
Pine Bark ◽  
Fresh Weight ◽  
Shoot Fresh Weight ◽  
Root Absorption ◽  
Nursery Crops ◽  
Radiotracer Techniques

Postemergence-applied diuron effectively controls yellow woodsorrel in nursery crops grown in pine bark–based container substrate. Whether the phytotoxicity of diuron on yellow woodsorrel is exclusively the result of foliar activity or is partially the result of root-based activity has not been determined. Application in which diuron was allowed to contact both the foliage and the pine bark–based substrate provided 84% control as determined by shoot fresh-weight reduction relative to that of a nontreated control. Foliar-only and root-only applications provided 52 and 12% shoot fresh-weight reduction, respectively. Absorption and translocation of foliar-applied diuron by yellow woodsorrel was evaluated using radiotracer techniques. After 24 h, 86% of the applied diuron had been absorbed, and 76% of the amount applied remained in the treated leaflet, indicating minimal translocation. Diuron sorption by the pine bark–based substrate was evaluated using radiotracer techniques. After 3 h, less than 6% of applied diuron remained in the aqueous phase, indicating 94% sorption. Exposing yellow woodsorrel roots to diuron concentrations as low as 0.50 mg/L resulted in injury, and concentrations equal to or greater than 10 mg/L resulted in death. Calculations described herein indicate the concentration that probably would occur within the aqueous solution held within the substrate following a 1.12-kg ai/ha application is sufficient to be phytotoxic to yellow woodsorrel. Thus, root-based absorption is a contributing factor in the overall efficacy of postemergence-applied diuron in controlling yellow woodsorrel.

Bentazon Spray Retention, Activity, and Foliar Washoff in Weed Species

1995 ◽  
Vol 9 (4) ◽  
pp. 773-778 ◽  
Author(s):  
Krishna N. Reddy ◽  
Martin A. Locke ◽  
Kevin D. Howard
Keyword(s):  
Nonionic Surfactant ◽  
Weight Reduction ◽  
Simulated Rainfall ◽  
Fresh Weight ◽  
Weed Species ◽  
Leaf Stage ◽  
Shoot Fresh Weight ◽  
Hemp Sesbania ◽  
Smooth Pigweed

Greenhouse studies were conducted to investigate the effects of adjuvant and rainfall on bentazon spray retention, efficacy, and foliar washoff in hemp sesbania, sicklepod, smooth pigweed, and velvetleaf. Bentazon was applied at 0.28 to 2.24 kg ai/ha with Agri-Dex, a crop oil concentrate (COC) or Kinetic, an organiosilicone-nonionic surfactant blend (OSB) when weeds were at the three- to five-leaf stage. Plants were subjected to 2.5 cm simulated rainfall for 20 min at 1 and 24 h after application of bentazon. Shoot fresh weight reduction assessed 2 wk after treatment was similar with either adjuvant on velvetleaf and smooth pigweed. OSB enhanced bentazon efficacy in hemp sesbania and sicklepod as compared to COC. Rainfall at 1 h after application generally reduced bentazon activity in all weeds. OSB maintained bentazon activity in hemp sesbania when subjected to rainfall at 1 h after application as compared to COC. Overall, bentazon spray retention on plants was 9 to 550% higher with OSB as compared to COC among the species at 1 h after application. Amount of bentazon residue washed off from the foliage by rainfall within a weed species was relatively similar for both adjuvants except in smooth pigweed and ranged from 39 to 98% among the four weed species at 1 h after application. OSB exhibited specificity for certain weed species and the potential to minimize bentazon spray reaching the soil by increasing deposition.

Preemergence and Postemergence Yellow Nutsedge (Cyperus esculentus) Control with MON 12000 in Nursery Crops

1996 ◽  
Vol 10 (1) ◽  
pp. 95-99 ◽  
Author(s):  
Jeffrey F. Derr ◽  
Rakesh S. Chandran ◽  
William D. Ward
Keyword(s):  
Cyperus Esculentus ◽  
Fresh Weight ◽  
Shoot Fresh Weight ◽  
Yellow Nutsedge ◽  
Nursery Crops ◽  
Better Than

Yellow nutsedge is a common and troublesome weed in the nursery industry. A selective postemergence herbicide is not available for yellow nutsedge control in most nursery crops. The effectiveness of MON 12000 for PRE and POST control of yellow nutsedge was evaluated in selected field-grown nursery crops. Preemergence control of yellow nutsedge 4 weeks after treatment (WAT) increased from 68% to 95% as MON 12000 rate increased from 0.03 to 0.28 kg ai/ha. At 9 WAT, control ranged from 16 to 73%. MON 12000 at 0.14 kg/ha provided similar PRE control of yellow nutsedge as metolachlor at 2.2 kg/ha. Four WAT, MON 12000 applied POST at 0.03 kg/ha controlled 73% and controlled 86% with the 0.28 kg/ha rate. MON 12000 at 0.14 and 0.28 kg/ha applied POST controlled yellow nutsedge better than bentazon at 1.12, chlorimuron at 0.01, imazaquin at 0.14, or glyphosate at 3.33 kg/ha. MON 12000 injured the foliage of azalea, crape myrtle, cotoneaster, and Japanese holly. Injury was most severe to cotoneaster. MON 12000 reduced azalea, cotoneaster, and crape myrtle shoot fresh weight compared to hand-weeded plots in at least one study. Metolachlor at 2.2 and 4.5 kg/ha caused little injury to the nursery species tested.

scholarly journals Physiological responses of Pea plants to treatment with synthetic auxins and auxin-type herbicide

Botanica ◽  
2021 ◽  
pp. 125-133
Author(s):  
Dessislava Todorova ◽  
Iskren Sergiev ◽  
Elena Shopova ◽  
Liliana Brankova ◽  
Jurga Jankauskienė ◽  
...  
Keyword(s):  
Weight Reduction ◽  
Enzyme Activities ◽  
Moderate Degree ◽  
Enzymatic Antioxidants ◽  
Free Proline ◽  
Fresh Weight ◽  
Antioxidant Defence ◽  
Shoot Fresh Weight ◽  
Synthetic Auxins ◽  
Antioxidant Defence System

The effect of exogenously applied 2,4-D (2,4-dichlorophenoxyacetic acid) on growth and antioxidant defence of pea plants, preliminary treated with two synthetic auxin compounds 1-[2-chloroethoxycarbonyl-methyl]-4-naphthalenesulfonic acid calcium salt (TA-12) and 1-[2-dimethylaminoethoxycarbonylmethyl]naphthalene chlormethylate (TA-14) was examined. All chemicals were applied by foliar spraying. Applied alone, TA-12 and TA-14 had no significant effects, but they modulated the 2,4-D induced changes on most investigated biochemical parameters. The shoot fresh weight reduction caused by 2,4-D was partially overcome by the use of TAs. The use of TAs partially overcame the shoot fresh weight reduction induced by 2,4-D. Apart from this, no significant changes were observed in the other biometric parameters. Treatment with 2,4-D did not enhance lipid peroxidation, and hydrogen peroxide content was slightly increased. These data indicate that treatment with 2,4-D did not cause severe oxidative stress, which is also confirmed by the results of the antioxidant defence system. The application of 2,4-D provoked mild accumulation of thiol-containing compounds, free proline and phenolic compounds and increased the antioxidant enzyme activities (GST, SOD, CAT, POD and GR) to a moderate degree. Pretreatment with TAs noticeably decreased the non-enzymatic antioxidants (free proline, total phenolics and total low-molecular thiols) compared to plants treated with 2,4-D only. Except for GR, TAs pretreatment returned the enzyme activities to levels close to the controls. Based on the results obtained, we suggest that the application of both synthetic auxins could modulate 2,4-D herbicide effects.

scholarly journals Diuron: Postemergence Oxalis Control in Container-grown Plants

2004 ◽  
Vol 22 (1) ◽  
pp. 45-49
Author(s):  
Carey V. Simpson ◽  
Charles H. Gilliam ◽  
James E. Altland ◽  
Glenn R. Wehtje ◽  
Jeff L. Sibley
Keyword(s):  
Dry Weight ◽  
Fresh Weight ◽  
Shoot Fresh Weight ◽  
Shoot Dry Weight ◽  
Nursery Crops ◽  
Size Interaction ◽  
Container Nursery

Abstract Three experiments were conducted to evaluate the effectiveness of postemergence applied diuron (Direx 4L) for oxalis control and crop safety in container nursery crops. The first experiment, treated on March 15, 2001, evaluated diuron at 0.14, 0.28, 0.56, and 1.12 kg ai/ha (0.125, 0.25, 0.5, and 1.0 lb ai/A) rates without a surfactant and provided a maximum of 74% oxalis control in liriope and 57% in camellia. Diuron caused slight to no injury on ‘Pink Icicle’ camellia, ‘Anthony Waterer’ spirea and ‘Big Blue’ liriope which dissipated completely by 60 DAT. Experiment two, treated on April 6, 2001, used higher rates and included a surfactant. Diuron provided excellent oxalis control at rates ≥ 0.56 kg ai/ha (0.5 lb ai/A) by 21 days after treatment (DAT) and reduced oxalis shoot fresh weight (SFW) and shoot dry weight (SDW) by ≥ 95%. Unlike the first experiment, no injury was observed on either liriope or camellia. Experiment three, treated on April 15, 2001, evaluated diuron rate and oxalis size on oxalis control. At 9 DAT a significant diuron rate × oxalis size interaction occurred, but at 15 and 21 DAT only diuron rate affected oxalis control for the sizes of oxalis tested. At 21 DAT, rates of 0.56 kg ai/ha (0.5 lb ai/A) and higher provided excellent oxalis control. These data indicate that diuron provides excellent oxalis control when applied postemergence in tolerant nursery crops.

Interactions of Foliarly Applied Herbicides on Three Weed Species in Peanut (Arachis hypogaea)

Weed Science ◽  
1991 ◽  
Vol 39 (4) ◽  
pp. 614-621 ◽  
Author(s):  
J. David Moore ◽  
Philip A. Banks
Keyword(s):  
Arachis Hypogaea ◽  
Weight Reduction ◽  
Fresh Weight ◽  
Weed Species ◽  
Antagonistic Effects ◽  
Shoot Fresh Weight

In the greenhouse, naptalam at 1.1 to 4.5 kg ai ha−1antagonized activity of paraquat at 0.04 to 0.14 kg ai ha−1in 14 of 16 rate combinations when applied to sicklepod. Sicklepod shoot fresh weight reduction was less compared to that obtained with paraquat alone when paraquat at 0.04 kg ha−1was mixed with bentazon at 0.42 to 0.84 kg ai ha−1or monocarbamide dihydrogensulfate at 14 to 58 kg ai ha−1. Paraquat activity on Florida beggarweed was antagonized by mixtures of paraquat at 0.04 or 0.07 kg ha−1with bentazon at 0.63 or 0.84 kg ha−1or paraquat at 0.04 to 0.14 kg ha−1with naptalam at 3.4 or 4.5 kg ha−1. Mixtures of lactofen at 0.06 to 0.22 kg ai ha−1with monocarbamide dihydrogensulfate at 14 kg ha−1or lactofen at 0.06 or 0.16 kg ha−1with alachlor at 1.4 to 2.8 kg ai ha−1synergistically increased tall morningglory shoot fresh weight reduction. In the field, excellent sicklepod shoot fresh weight reduction by paraquat applied alone masked most antagonistic effects of paraquat mixtures. Addition of alachlor to monocarbamide dihydrogensulfate at 29 kg ha−1improved activity on sicklepod compared to monocarbamide dihydrogensulfate applied alone.

scholarly journals Herbicide Efficacy in Alternative Substrates for Container-grown Nursery Crops

2010 ◽  
Vol 28 (1) ◽  
pp. 19-26
Author(s):  
Diana R. Cochran ◽  
Charles H. Gilliam ◽  
Glenn Wehtje ◽  
Glenn B. Fain ◽  
Robert D. Wright ◽  
...  
Keyword(s):  
Poultry Litter ◽  
Wood Chips ◽  
Pine Bark ◽  
Control Treatment ◽  
Fresh Weight ◽  
Alternative Substrates ◽  
Pine Trees ◽  
Excellent Control ◽  
Nursery Crops ◽  
Pine Wood Chips

Abstract Three experiments were conducted to evaluate the influence of alternative substrates on herbicide efficacy in container grown nursery crops. In Experiment 1, alternative substrates evaluated were either pine wood chips hammer-milled, to pass between 0.48 cm (0.19 in) screen (PWCH1) or 0.64 cm (0.25 in) screen (PWCH2), whole pine trees chipped or hammer-milled (WTCH), to pass between a 0.48 cm (0.19 in) screen, or the previously mentioned combined with pinebark. A commercial pine bark substrate (PB) with a 6: 1 (by vol) ratio of pine bark to sand was maintained as a control treatment. Rout® at 3 lbs aia (oxyfluorfen + oryzalin at 2.24 + 1.12 kg·ha−1) and Ronstar at 4.0 lb aia (oxadiazon at 4.48 kg·ha−1) were applied at recommended label rates. Herbicides were applied and irrigated, and each container was overseeded with 25 spotted spurge (Euphorbia maculata) seed per container. In general, the greatest spurge numbers occurred in PB substrates. Rout provided superior spurge control compared to Ronstar. In Experiment 2, substrates evaluated were PWCH2, WTCH and PBS with 7.0 kgm−3 (12 lbsyd−3) of Polyon 17-6-12 or with an additional 8 lbs·yd−3 of Polyon 17-6-12, or PWCH2 and WTCH combined with composted poultry litter (CPL). PWCH2 tended to have the fewest spurge numbers throughout the experiment, while WTCH and PBS tended to have similar spurge numbers and spurge fresh weight. Addition of CPL and additional fertilizer tended to increase spurge numbers and spurge fresh weight in all substrates. Rout and Ronstar provided similar spurge control in this study. In Experiment 3, substrates evaluated were PB (100%), WTCH (100%), CCR (100%), and PB: S (6: 1 vol), WTCH: S (6: 1 vol), and CCR: S (6: 1 vol). Rout and Ronstar were each applied at 0.25×, 0.50×, 075×, and 1.0× label rate. There was a significant substrate affect on all dates except 14 DAT. Spurge numbers and spurge fresh weight were greatest in PB or PB: S substrates. Spurge numbers and spurge fresh weight in general decreased with increasing herbicide rates. At 45 DAT and 60 DAT, Rout had superior spurge control compared to Ronstar. With WT and CCR substrates, Rout provided excellent control (less than 1.0 gram fresh weight) at the 0.50× and 1.0× rates. In general, weed control in alternative substrates was superior to that obtained in commercially used pinebark.

Mesosilica materials and organic pollutant adsorption: part B removal from aqueous solution

2014 ◽  
Vol 43 (15) ◽  
pp. 5173-5182 ◽  
Author(s):  
L. T. Gibson
Keyword(s):  
Aqueous Solution ◽  
Mesoporous Silica ◽  
Aqueous Phase ◽  
Organic Pollutants ◽  
Organic Pollutant

This tutorial review will focus on the removal of organic pollutants from the aqueous phase by mesoporous silica.

scholarly journals Reverse Micelle Liquid-Liquid Extraction of a Pharmaceutical Product

2012 ◽  
Vol 545 ◽  
pp. 240-244 ◽  
Author(s):  
Siti Hamidah Mohd-Setapar ◽  
Siti Norazimah Mohamad-Aziz ◽  
N.H. Harun ◽  
S.H. Hussin
Keyword(s):  
Aqueous Solution ◽  
Aqueous Phase ◽  
Reverse Micelle ◽  
Surfactant Concentration ◽  
Protein Extraction ◽  
Biological Activities ◽  
Extraction Process ◽  
Pharmaceutical Product ◽  
Penicillin G ◽  
Reverse Micelle Extraction

Reverse micelle extraction has received considerable attention in recent years due to its ability to selectively solubilise solutes from an aqueous phase, and in the case of biomolecules to maintain their biological activities. The apparent success of research on protein extraction from the aqueous phase using reverse micelle provides motivation to study the solubilisation of antibiotic. The objective of this study is to investigate the extraction of antibiotic (penicillin G is chosen as model antibiotic) from aqueous solution (forward extraction) and from the reverse micelle to a new aqueous solution (backward extraction). Sodium di(2-ethylhexyl)sulfosuccinate (AOT) is chosen as the surfactant and isooctane as the organic solvent. The UV-Vis spectrophotometer is used to determine the mass of penicillin G in solution after the extraction process. The extraction is expected to be influenced by the initial penicillin G concentration, the salt type and concentration in the aqueous phase, pH, and surfactant concentration. It is expected that as penicillin is an interfacially active compound that will interacts with AOT surfactant, the interfacial association will be dependent on both pH and surfactant concentration.

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