Field Dissipation of Atrazine and Metribuzin in Organic Soils in Florida

2014 ◽  
Vol 28 (4) ◽  
pp. 578-586 ◽  
Author(s):  
Dennis C. Odero ◽  
Dale L. Shaner
Keyword(s):  
Weed Control ◽  
Residual Activity ◽  
Field Studies ◽  
South Florida ◽  
Field Conditions ◽  
Agricultural Area ◽  
Organic Soils ◽  
Bioavailable Fraction ◽  
Rate Of Dissipation ◽  
Atrazine Degradation

Sugarcane growers have observed reduced residual activity of atrazine on organic soils in the Everglades Agricultural Area (EAA) of south Florida. Field studies were conducted between 2011 and 2012 to determine the rate of dissipation of atrazine at 2.24, 4.48, and 8.96 kg ha−1and metribuzin at 0.56, 1.12, and 2.24 kg ha−1in the top 10 cm of soil in sugarcane fields in the EAA. The bioavailable fraction of atrazine dissipated more rapidly than the total amount of atrazine in the soil. Half-lives of the total and bioavailable fraction of atrazine ranged between 3.9 to 12.1 d and 1.0 to 7.5 d, respectively. Metribuzin dissipated much more slowly than atrazine on organic soils. Similarly, dissipation of the bioavailable fraction of metribuzin was more rapid than was the dissipation of the total amount of metribuzin in the soil. Half-lives of the total and bioavailable fraction of metribuzin ranged between 16.2 and 24.8 d and 6.0 and 14.3 d, respectively. These results indicate that enhanced atrazine degradation occurs on organic soils under field conditions in the EAA, resulting in shorter residual atrazine activity. This implies that metribuzin is a better option for weed control in sugarcane grown on organic soils of the EAA exhibiting enhanced atrazine degradation.

Enhanced Atrazine Degradation: Evidence for Reduced Residual Weed Control and a Method for Identifying Adapted Soils and Predicting Herbicide Persistence

Weed Science ◽  
2009 ◽  
Vol 57 (4) ◽  
pp. 427-434 ◽  
Author(s):  
L. Jason Krutz ◽  
Ian C. Burke ◽  
Krishna N. Reddy ◽  
Robert M. Zablotowicz ◽  
Andrew J. Price
Keyword(s):  
Weed Control ◽  
Diagnostic Test ◽  
Residual Activity ◽  
Field Conditions ◽  
Published Data ◽  
Planting Dates ◽  
Prickly Sida ◽  
Persistence Model ◽  
Enhanced Degradation ◽  
Atrazine Degradation

Soilborne bacteria with novel metabolic abilities have been linked with enhanced atrazine degradation and complaints of reduced residual weed control in soils with ans-triazine use history. However, no field study has verified that enhanced degradation reduces atrazine's residual weed control. The objectives of this study were to (1) compare atrazine persistence and prickly sida density ins-triazine-adapted and nonadapted field sites at two planting dates; (2) utilize original and published data to construct a diagnostic test for identifyings-triazine-adapted soils; and (3) develop and validate ans-triazine persistence model based on data generated from the diagnostic test, i.e., mineralization of ring-labeled14C-s-triazine. Atrazine half-life values ins-triazine-adapted soil were at least 1.4-fold lower than nonadapted soil and 5-fold lower than historic estimates (60 d). At both planting dates atrazine reduced prickly sida density in the nonadapted soils (P ≤ 0.0091). Conversely, in thes-triazine-adapted soil, prickly sida density was not different between no atrazine PRE and atrazine PRE at the March 15 planting date (P = 0.1397). A lack of significance in this contrast signifies that enhanced degradation can reduce atrazine's residual control of sensitive weed species. Analyses of published data indicate that cumulative mineralization in excess of 50% of C0after 30 d of incubation is diagnostic for enhanceds-triazine degradation. Ans-triazine persistence model was developed and validated; model predictions for atrazine persistence under field conditions were within the 95% confidence intervals of observed values. Results indicate that enhanced atrazine degradation can decrease the herbicide's persistence and residual activity; however, coupling the diagnostic test with the persistence model could enable weed scientists to identifys-triazine-adapted soils, predict herbicide persistence under field conditions, and implement alternative weed control strategies in affected areas if warranted.

Atrazine Dissipation as Affected by Surface pH and Tillage

Weed Science ◽  
1980 ◽  
Vol 28 (1) ◽  
pp. 101-104 ◽  
Author(s):  
J. J. Kells ◽  
C. E. Rieck ◽  
R. L. Blevins ◽  
W. M. Muir
Keyword(s):  
Weed Control ◽  
Soil Ph ◽  
Field Studies ◽  
Conventional Tillage ◽  
Field Conditions ◽  
No Tillage ◽  
Tillage Systems ◽  
Surface Ph ◽  
Factors Affecting ◽  
Decreasing Ph

Field studies and laboratory analyses were conducted to examine factors affecting degradation of14C-atrazine [2-chloro-4-(ethylamine)-6-(isopropylamino)-s-triazine] under field conditions. The effects of these factors on weed control under no-tillage and conventional tillage systems were also examined. The amount of radioactivity which was unextractable in 90% methanol increased with time following treatment with14C-atrazine. The rate of formation of unextractable14C compounds was greater under no-tillage and increased with decreasing pH. After 14 to 18 days, a greater amount of extractable atrazine was present in areas receiving lime. The degradation of atrazine occurred more rapidly when surface pH was less than 5.0 compared with a pH greater than 6.5. The effect of lime on the amount of parent atrazine present in the soil was directly correlated to its effect on soil pH. Extractable atrazine in the soil 45 days after treatment was significantly correlated with weed control with the greatest effect under no-tillage.

Weed Control and Yield with Flumioxazin, Fomesafen, andS-Metolachlor Systems for Glufosinate-Resistant Cotton Residual Weed Management

2009 ◽  
Vol 23 (3) ◽  
pp. 391-397 ◽  
Author(s):  
Wesley J. Everman ◽  
Scott B. Clewis ◽  
Alan C. York ◽  
John W. Wilcut
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Residual Activity ◽  
Field Studies ◽  
Lint Yield ◽  
Cotton Lint ◽  
Common Lambsquarters ◽  
Control Programs ◽  
Pitted Morningglory ◽  
Cotton Lint Yield

Field studies were conducted near Clayton, Lewiston, and Rocky Mount, NC in 2005 to evaluate weed control and cotton response to preemergence treatments of pendimethalin alone or in a tank mixture with fomesafen, postemergence treatments of glufosinate applied alone or in a tank mixture withS-metolachlor, and POST-directed treatments of glufosinate in a tank mixture with flumioxazin or prometryn. Excellent weed control (> 91%) was observed where at least two applications were made in addition to glufosinate early postemergence (EPOST). A reduction in control of common lambsquarters (8%), goosegrass (20%), large crabgrass (18%), Palmer amaranth (13%), and pitted morningglory (9%) was observed when residual herbicides were not included in PRE or mid-POST programs. No differences in weed control or cotton lint yield were observed between POST-directed applications of glufosinate with flumioxazin compared to prometryn. Weed control programs containing three or more herbicide applications resulted in similar cotton lint yields at Clayton and Lewiston, and Rocky Mount showed the greatest variability with up to 590 kg/ha greater lint yield where fomesafen was included PRE compared to pendimethalin applied alone. Similarly, an increase in cotton lint yields of up to 200 kg/ha was observed whereS-metolachlor was included mid-POST when compared to glufosinate applied alone, showing the importance of residual herbicides to help maintain optimal yields. Including additional modes of action with residual activity preemergence and postemergence provides a longer period of weed control, which helps maintain cotton lint yields.

scholarly journals Critical Period of Weed Control in Snap Bean on Organic Soils in South Florida

HortScience ◽  
2018 ◽  
Vol 53 (8) ◽  
pp. 1129-1132
Author(s):  
Dennis C. Odero ◽  
Alan L. Wright
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Yield Loss ◽  
South Florida ◽  
Maximum Length ◽  
Organic Soils ◽  
Open Flower ◽  
Trifoliate Leaf ◽  
Snap Bean ◽  
Weed Interference

Field studies were conducted in 2011 and 2012 in Belle Glade, FL, to evaluate the critical period of weed control (CPWC) in snap bean grown on organic soils in the Everglades Agricultural Area (EAA) of South Florida. Treatments consisting of increasing duration of weed interference and weed-free period were imposed at weekly intervals from 0 to 7 weeks after emergence (WAE) of snap bean. The beginning and end of the CPWC based on 2.5%, 5%, and 10% snap bean acceptable yield loss (AYL) levels were determined by fitting log-logistic and Gompertz models to represent increasing duration of weed interference and weed-free period, respectively. Based on 2.5% yield loss, the CPWC was 7.2 weeks long, beginning 1.2 (cotyledon and unifoliate leaf) and ending 8.4 WAE (mid-pod set, 50% of pods reached maximum length). At 5% yield loss, the CPWC was 5.0 weeks, beginning 1.7 (first to second trifoliate leaf) and ending 6.7 WAE (mid-flower to early pod set, 50% of flowers open and one pod reached maximum length). At 10% yield loss, the CPWC was 3.0 weeks, beginning 2.2 (second trifoliate leaf) and ending 5.2 WAE (early flowering, one open flower). Based on these results, the beginning of CPWC was hastened, whereas the end was delayed at different yield loss levels showing that acceptable weed control in snap bean on organic soils in the EAA is required throughout much of the growing season to minimize yield loss.

Imazethapyr plus Residual Herbicide Programs for Imidazolinone-Resistant Rice

2012 ◽  
Vol 26 (3) ◽  
pp. 410-416 ◽  
Author(s):  
Eric P. Webster ◽  
Tyler P. Carlson ◽  
Michael E. Salassi ◽  
Justin B. Hensley ◽  
David C. Blouin
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Residual Activity ◽  
Field Studies ◽  
Management Program ◽  
Red Rice ◽  
Initial Application ◽  
Residual Herbicide ◽  
Herbicide Programs

Field studies were conducted in 2008 and 2009 near Crowley, LA to evaluate the addition of a herbicide with soil-residual activity in mixture with imazethapyr applied very early POST followed by an application of imazethapyr or imazamox 2 wk after the initial application. Weeds evaluated included red rice, barnyardgrass, and alligatorweed. Weed control with treatments including a herbicide with soil-residual activity was equivalent to or higher than imazethapyr applied alone followed by imazethapyr or imazamox. Yield and economical returns were maximized with quinclorac or penoxsulam mixed with imazethapyr followed by imazethapyr or imazamox. The addition of quinclorac or penoxsulam proved to be beneficial in a total weed management program.

Confirmation, Characterization, and Management of Glyphosate-Resistant Ragweed Parthenium (Parthenium hysterophorus L.) in the Everglades Agricultural Area of South Florida

2015 ◽  
Vol 29 (2) ◽  
pp. 233-242 ◽  
Author(s):  
Jose V. Fernandez ◽  
Dennis C. Odero ◽  
Gregory E. MacDonald ◽  
Jason Ferrell ◽  
Lyn A. Gettys
Keyword(s):  
Weed Control ◽  
Dose Response ◽  
Glyphosate Resistance ◽  
South Florida ◽  
Agricultural Area ◽  
Complete Control ◽  
Everglades Agricultural Area ◽  
Significant Difference ◽  
Lack Of Control ◽  
Treated Leaf

Growers have observed lack of control of ragweed parthenium with glyphosate at 0.84 kg ae ha−1 used for weed control in noncrop areas and fallow fields in the Everglades Agricultural Area (EAA) of South Florida. Therefore, studies were conducted to (1) confirm and characterize the level of glyphosate resistance in ragweed parthenium from the EAA, (2) determine if reduced absorption or translocation is the mechanism of resistance of ragweed parthenium to glyphosate, and (3) evaluate the efficacy of POST herbicides commonly used in cultivated and noncrop areas for broadleaf weed control on flowering ragweed parthenium at the full and half labeled rate. A dose-response bioassay was used to determine the response of the rosette ragweed parthenium biotype from the EAA (resistant) and a susceptible biotype from Stoneville, MS, to glyphosate. The bioassay showed that the resistant biotype was 40- to 43-fold less sensitive to glyphosate when compared to the susceptible biotype. There was no significant difference in glyphosate absorption or translocation from the treated leaf to the rest of the plant 168 h after treatment between resistant and susceptible biotypes. This shows that absorption or translocation is not a mechanism of glyphosate resistance by ragweed parthenium. Saflufenacil + dimethenamid-P and hexazinone provided rapid and complete control of flowering ragweed parthenium 3 wk after treatment (WAT). Aminocyclopyrachlor + chlorsulfuron and aminopyralid at the full and the half label rates provided 100% control of ragweed parthenium by 9 WAT. Clopyralid, 2,4-D amine, and glufosinate at the full label rate provided 89 to 98% control of ragweed parthenium 9 WAT. Control of ragweed parthenium 9 WAT was < 75% with flumioxazin, fomesafen, glyphosate, imazapic, imazethapyr, mesotrione, oxyfluorfen, and paraquat, irrespective of use rate.

Sweet Corn Response and Weed Control to Saflufenacil plus Dimethenamid-P in Organic Soils

2014 ◽  
Vol 28 (1) ◽  
pp. 281-285 ◽  
Author(s):  
Dennis C. Odero ◽  
Alan L. Wright ◽  
Jose V. Fernandez
Keyword(s):  
Weed Control ◽  
Sweet Corn ◽  
Field Studies ◽  
Organic Soils ◽  
Corn Yield ◽  
Common Lambsquarters ◽  
Field Corn ◽  
Phytotoxic Effect ◽  
Mineral Soils ◽  
Common Purslane

There are limited PRE herbicide options available to provide residual weed control in sweet corn grown on organic soils in the Everglades Agricultural Area (EAA). Field studies were established to determine the efficacy of PRE applied saflufenacil + dimethenamid-P at six rates ranging from 10 + 88 to 319 + 2802 g ai ha−1 on weed control and sweet corn tolerance on organic soils in the EAA in 2011 and 2012. Saflufenacil + dimethenamid-P is a premix recently labeled for PRE weed control in field corn at 50 + 438 to 90 + 788 g ha−1 depending on soil texture. There was no phytotoxic effect of PRE applied saflufenacil + dimethenamid-P on sweet corn. At 42 d after treatment, common lambsquarters, common purslane, and spiny amaranth were controlled 90% with saflufenacil + dimethenamid-P at 58 + 508, 71 + 622, and 58 + 512 g ha−1, respectively. Sweet corn yield at 95% of the weed-free yield was estimated to be obtained at 69 + 606 g ha−1 of saflufenacil + dimethenamid-P. Our results show that saflufenacil + dimethenamid-P at 69 + 606 to 71 + 622 g ha−1 controlled three common weeds and maintained acceptable sweet corn yield. Labeled rates of saflufenacil + dimethenamid-P for field corn on mineral soils were adequate for weed control in sweet corn on organic soils.

Effect of Pyroxasulfone Formulation on Dissipation from a Winter Wheat Field in Tennessee

2017 ◽  
Vol 31 (6) ◽  
pp. 822-827
Author(s):  
Thomas C. Mueller
Keyword(s):  
Winter Wheat ◽  
Weed Control ◽  
Active Ingredient ◽  
Field Studies ◽  
Single Component ◽  
Field Conditions ◽  
Liquid Formulation ◽  
Wheat Production ◽  
Wheat Field

Field studies were conducted in 2014 and 2015 in Tennessee to examine pyroxasulfone dissipation under field conditions of winter wheat production. Three formulations were examined: (1) a single component active ingredient in an 85% dry flowable, (2) dry flowable formulation in combination of pyroxasulfone+flumioxazin, and (3) a liquid SC formulation of pyroxasulfone+carfentrazone. The liquid formulation is a suspo-emulsion. When averaged across the three studies, the DT 50 were 34.4, 30.2 and 29.9 d for pyroxasulfone plus carfentrazone, pyroxasulfone, and pyroxasulfone plus flumioxazin, respectively. These trends would indicate that formulation had little or no effect on pyroxasulfone dissipation in this experiment. Pyroxasulfone DT 50 in all studies ranged from a low of 15.4 d to a high of 53.3 d, and loss was more rapid under warm, moist conditions. These results indicate that pyroxasulfone would last long enough to provide residual weed control, but would not persist excessively to injure rotational crops.

Evaluation of Lettuce Cultivars for Production on Muck Soils in Southern Florida

EDIS ◽  
2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
German Sandoya ◽  
Huangjun Lu
Keyword(s):  
South Florida ◽  
Agricultural Area ◽  
Organic Soils ◽  
Everglades Agricultural Area ◽  
Commercial Crop ◽  
Southern Florida

Lettuce as a commercial crop is planted mainly in organic soils ("muck") in the Everglades Agricultural Area (EAA) in south Florida. This updated publication of the UF/IFAS Horticultural Sciences Department presents a summary of previous cultivar releases by UF/IFAS as well as a description of cultivars currently planted in the EAA. Written by German Sandoya and Huangjun Lu.https://edis.ifas.ufl.edu/hs1225

Effect of Soil pH and Previous Atrazine Use History on Atrazine Degradation in a Tennessee Field Soil

Weed Science ◽  
2010 ◽  
Vol 58 (4) ◽  
pp. 478-483 ◽  
Author(s):  
Thomas C. Mueller ◽  
Lawrence E. Steckel ◽  
Mark Radosevich
Keyword(s):  
Surface Water ◽  
Weed Control ◽  
Soil Ph ◽  
Marked Effect ◽  
Field Studies ◽  
Field Soil ◽  
Effect Of Ph ◽  
Plot Area ◽  
Previously Treated ◽  
Atrazine Degradation

Field studies examined the interaction of soil pH with differing levels of atrazine exposure over 4 yr. Soil pH was 5.2 to 7.1 with atrazine exposures ranging from none (0) to eight applications over a 4-yr period (for each year, one application at planting and one early postemergence). The entire plot area was uniformly managed to reduce potential confounding effects due to cropping history, tillage, and other factors. Soil from all plots previously treated with atrazine displayed rapid atrazine dissipation, with half-lives under laboratory conditions being less than 4 d in plots of pH 5.5 or greater and less than 8 d in the field. Soil pH had a marked effect, with slower atrazine dissipation in those plots that had a pH 5.5 or less. This effect of pH and previous atrazine history was consistent in laboratory and field environments. Implications of these findings include probable reduction in weed control due to more rapid atrazine dissipation and potentially reduced loadings into surface water due to this phenomenon.

Sign in / Sign up

Export Citation Format

Share Document