Efficacy and Dissipation of Pyroxasulfone and Three Chloroacetamides in a Tennessee Field Soil

Weed Science ◽  
2011 ◽  
Vol 59 (4) ◽  
pp. 574-579 ◽  
Author(s):  
Thomas C. Mueller ◽  
Lawrence E. Steckel
Keyword(s):  
Weed Control ◽  
Half Life ◽  
Dissipation Rate ◽  
Resistance Management ◽  
Growing Season ◽  
Field Studies ◽  
Poor Correlation ◽  
Field Soil ◽  
Rainfall Patterns ◽  
Residual Control

Field studies were conducted in Knoxville, TN, over a 2-yr period (2007 and 2008) to determine the field dissipation rate and efficacy of pyroxasulfone, acetochlor, dimethenamid, ands-metolachlor to broadleaf signalgrass. Depending on rainfall patterns, pyroxasulfone at 209 g ai ha−1provided broadleaf signalgrass control of > 75%, which was equal to or superior to acetochlor at 1,740 g ai ha−1, dimethenamid at 1,500 g ai ha−1ands-metolachlor at 1,420 g ai ha−1. Pyroxasulfone provided residual control into the growing season and provides a tool for resistance management of later-emerging weeds. Herbicide dissipation was rapid in all soils (half-life usually < 20 d), although it was slower in a dry year. The order of herbicide dissipation and half-life in days in the 2 yr was acetochlor (3.5, 5 d) > dimethenamid (5, 9 d) >s-metolachlor (8.8, 27 d) > pyroxasulfone (8.2, > 71 d). There was poor correlation between observed weed control at 45 d after treatment and chemically determined herbicide concentrations at that same time, with ∼ 40% difference in 2007 and ∼ 50% difference in 2008.

Relative Dissipation of Acetochlor, Alachlor, Metolachlor, and SAN 582 from Three Surface Soils

1999 ◽  
Vol 13 (2) ◽  
pp. 341-346 ◽  
Author(s):  
Thomas C. Mueller ◽  
David R. Shaw ◽  
William W. Witt
Keyword(s):  
Soil Moisture ◽  
Weed Control ◽  
Half Life ◽  
Soil Surface ◽  
Growing Season ◽  
Sampling Interval ◽  
Relative Order ◽  
Sampling Depth ◽  
Herbicide Degradation ◽  
Southern States

The dissipation of four commonly used soil-applied herbicides was examined in a standardized field experiment in three southern states (Kentucky, Mississippi, and Tennessee). Averaged over the three soils and 2 yr, the relative order of increasing half-life defined as time for 50% disappearance in days (DT50) was acetochlor (6.3 d) = alachlor (6.3 d) = SAN 582 (7.3 d) < metolachlor (13.7 d). Metolachlor was the most persistent in the soil surface, and this could potentially translate into greater duration of weed control into the growing season. All examined herbicides had a DT50that averaged less than 14 d in all states in both years, so full-season weed control of susceptible species would not be expected. Rapid herbicide degradation was encouraged in these field sites by adequate to excessive soil moisture and warm temperatures throughout the sampling interval. The soils also were light textured, and the lower adsorption of the herbicide allowed for degradation ease and perhaps leaching below the sampling depth.

Cotton Planting Date Affects The Critical Period of Benghal Dayflower (Commelina benghalensis) Control

Weed Science ◽  
2009 ◽  
Vol 57 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Theodore M. Webster ◽  
Timothy L. Grey ◽  
J. Timothy Flanders ◽  
A. Stanley Culpepper
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Yield Loss ◽  
Maximum Yield ◽  
Growing Season ◽  
Field Studies ◽  
Cotton Field ◽  
Commelina Benghalensis ◽  
Critical Range ◽  
Benghal Dayflower

Benghal dayflower (formerly known as tropical spiderwort) is one of the most troublesome weeds in Georgia cotton. Field studies were conducted from 2003 to 2005 to evaluate the relationship between the duration of Benghal dayflower interference and cotton yield to establish optimum weed-control timing. To determine the critical period of weed control (CPWC), Benghal dayflower interference with cotton was allowed or prohibited in 2-wk intervals between 0 to 12 wk after crop planting. Maximum yield loss from Benghal dayflower in May-planted cotton was 21 to 30% in 2004 and 2005, whereas cotton planting delayed until June resulted in maximum yield losses of 40 to 60%. June-planted cotton had a CPWC of 190 to 800 growing degree days (GDD) in 2004 (52-d interval beginning at 16 d after planting [DAP]) and 190 to 910 GDD in 2005 (59-d interval beginning at 18 DAP). In contrast, May-planted cotton in 2005 had a narrower CPWC interval of 396 to 587 GDD (18 d) that occurred 3 wk later in the growing season (initiated at 39 DAP). May-planted cotton in 2004 did not have a critical range of weed-free conditions. Instead, a single weed removal at 490 GDD (44 DAP) averted a yield loss greater than 5%. It is recommended that fields infested with Benghal dayflower be planted with cotton early in the growing season to minimize weed interference with the crop.

scholarly journals Early Season Broadleaf Weed Control in Onion

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 971D-972
Author(s):  
Harlene M. Hatterman-Valenti ◽  
Carrie E. Schumacher ◽  
Collin P. Auwarter ◽  
Paul E. Hendrickson
Keyword(s):  
Weed Control ◽  
Chenopodium Album ◽  
Field Studies ◽  
Amaranthus Retroflexus ◽  
High Rate ◽  
Early Season ◽  
Common Lambsquarters ◽  
Redroot Pigweed ◽  
Herbicide Treatments ◽  
Residual Control

Field studies were conducted at Absaraka, Carrington, and Oakes, N.D., in 2005 to evaluate early season broadleaf weed control and onion (Allium cepa L.) injury with herbicides applied preemergence to the crop. DCPA is a common preemergence herbicide used in onion. However, DCPA can be uneconomical in most high-weed situations, or the usage may be restricted due to possible groundwater contamination. Potential substitutes evaluated were bromoxynil, dimethenamid-P, and pendimethalin. Main broadleaf weeds were redroot pigweed (Amaranthus retroflexus L.) and common lambsquarters (Chenopodium album L.). In general, all herbicides, except bromoxynil, provided acceptable broadleaf weed control 4 weeks after treatment. The highest herbicide rate provided greater weed control compared with the lowest rate for each herbicide. However, onion height was also reduced with the highest herbicide rate. In addition, the two highest rates of dimethenamid-P reduced the onion stand compared with the untreated. A postemergence application of bromoxynil + oxyfluorfen + pendimethalin to onion at the four- to five-leaf stage controlled the few broadleaf weeds that escaped the preemergence treatments and provided residual control of mid- and late-season germinating broadleaf weeds at two of the three locations. Intense germination of redroot pigweed during July at the Oakes location reduced onion yield with all treatments compared with the hand-weeded check. In contrast, total onion yields with all herbicide treatments except the high rate of dimethenamid-P were similar to the hand-weeded check at Absaraka and Carrington.

Evaluating Soil Solarization for Weed Control and Strawberry (Fragariaxananassa) Yield in Annual Plasticulture Production

2017 ◽  
Vol 31 (3) ◽  
pp. 455-463 ◽  
Author(s):  
Jayesh B. Samtani ◽  
Jeffrey Derr ◽  
Mikel A. Conway ◽  
Roy D. Flanagan
Keyword(s):  
Data Collection ◽  
Weed Control ◽  
Crop Yield ◽  
Crop Yields ◽  
Growing Season ◽  
Field Studies ◽  
Soil Solarization ◽  
Row Spacing ◽  
Weed Density ◽  
Growing Seasons

Field studies were initiated in the 2013-14 and 2014-15 growing seasons to evaluate the potential of soil solarization (SS) treatments for their efficacy on weed control and crop yields and to compare SS to 1,3-dichloropropene (1,3-D)+chloropicrin (Pic) fumigation. Each replicate was a bed with dimension 10.6 m long by 0.8 m wide on top. The center 4.6 m length of each bed, referred to as plots, was used for strawberry plug transplanting and data collection. Treatments included: i) 1,3-D+Pic (39% 1,3-dichloropropene+59.6% chloropicrin) that was shank-fumigated in beds at 157 kg ha−1and covered with VIF on August 30 in both seasons; ii) SS for a 6 wk duration initiated on August 15, 2013 and August 21, 2014 by covering the bed with 1 mil clear polyethylene tarp; iii) SS for a 4wk duration initiated on September 6, 2013 and September 3, 2014; iv) SS 4 wk treatment initiated September 6, 2013 and September 3, 2014 and replaced with black VIF on October 4, 2013 and October 1, 2014 and v) a nontreated control covered with black VIF on October 4, 2013 and October 1, 2014. In both seasons, following completion of the preplant treatments, ‘Chandler’ strawberry was planted in two rows at a 36 cm in-row spacing in plots during the first wk of October. Over both seasons, the 6 wk SS treatment consistently lowered the weed density compared to the nontreated control. Weed density in the 6wk SS treatment was not statistically different from the 4wk SS treatments in the 2013-14 growing season. In both seasons, crop yield in the 4 wk SS was significantly lower than other treatments.

Evaluation of Cycloate Followed by Evening Two-Leaf–Stage Phenmedipham Application in Fresh Market Spinach

2016 ◽  
Vol 30 (2) ◽  
pp. 464-471 ◽  
Author(s):  
Ran N. Lati ◽  
Beiquan Mou ◽  
John S. Rachuy ◽  
Steven A. Fennimore
Keyword(s):  
Light Intensity ◽  
Weed Control ◽  
Growing Season ◽  
Field Studies ◽  
High Light Intensity ◽  
Time Of Day ◽  
Light Conditions ◽  
Fresh Market ◽  
Reference Treatment ◽  
Leaf Stage

Fresh market spinach has one primary herbicide, cycloate, which does not control all weeds. Previous studies demonstrated that cycloate PRE followed by (fb) phenmedipham at the four-leaf spinach stage is a safe and effective treatment. However, this treatment is not useful for the main growing season of fresh spinach due to its short crop cycle and the 21-d preharvest interval requirement of phenmedipham. This study evaluates the potential to use the combination of cycloate PRE fb phenmedipham on two-leaf spinach. Greenhouse and field studies were conducted in 2014 using three spinach varieties with low (‘Nordic' and ‘Sardinia') and high (‘Regal') tolerance to phenmedipham. Greenhouse studies revealed that phenmedipham at 90 g ai ha−1was safe to Regal when applied at the two-leaf stage. Sardinia was more susceptible to phenmedipham injury under high (310 W m−2) light conditions than low (258 W m−2) light conditions. Impact of time of day on phenmedipham safety was evaluated in the field: day-long exposure to high light intensity following morning applications vs. evening applications fb exposure to low light intensity. Injury estimations taken 3 d after treatment (DAT) were lower for evening than for morning applications. Nonetheless, injury 11 DAT and spinach yield evaluations found no differences between morning and evening applications. Subsequently, cycloate (1,700 g ha−1) PRE fb phenmedipham (90 and 180 g ha−1) applied in the evening at the two-leaf stage was evaluated. A reference treatment was cycloate PRE fb phenmedipham (270 g ha−1) at the four-leaf stage. Treatments with cycloate fb two-leaf phenmedipham at 90 and 180 g ha−1were safe to spinach and improved weed control compared to cycloate alone. Cycloate fb 180 g ha−1phenmedipham at the two-leaf stage reduced weed biomass by 88% compared to cycloate alone. This level of weed control was similar to the reference treatment. Results here show that phenmedipham applied at the two-leaf stage is safe to fresh market spinach and it has the potential to be used during most of the fresh spinach growing season.

Comparison of Trifloxysulfuron and Pyrithiobac in Glyphosate-Resistant and Bromoxynil-Resistant Cotton

2005 ◽  
Vol 19 (2) ◽  
pp. 404-410 ◽  
Author(s):  
Jeffrey W. Branson ◽  
Kenneth L. Smith ◽  
James L. Barrentine
Keyword(s):  
Weed Control ◽  
Rate Control ◽  
Field Studies ◽  
Palmer Amaranth ◽  
Growth Stages ◽  
Control Programs ◽  
Pitted Morningglory ◽  
Hemp Sesbania ◽  
Prickly Sida ◽  
Residual Control

Field studies were conducted in 2000 and 2001 at Rohwer, AR. Trifloxysulfuron (5.3 and 8 g ai/ha) and pyrithiobac (70 g ai/ha) were applied preemergence (PRE) and postemergence (POST) broadcast at the two- to three-leaf (EP) and three- to four-leaf (MP) cotton growth stages. Both materials were also applied POST in combination with glyphosate at 560 g ae/ha or bromoxynil at 560 g ai/ha at both growth stages. Trifloxysulfuron applied EP or MP at 8 g/ha provided greater control of sicklepod and pitted morningglory 28 d after application (DAA) than trifloxysulfuron at 5.3 g/ha or pyrithiobac at 70 g/ha; however, control of prickly sida was greater with pyrithiobac than with trifloxysulfuron at either rate. Glyphosate alone controlled sicklepod, prickly sida, and pitted morningglory greater than 80%. The addition of trifloxysulfuron at 8 g/ha and pyrithiobac at 70 g/ ha increased control of all species over glyphosate alone 28 DAA. Bromoxynil at 560 g/ha controlled pitted morningglory and hemp sesbania at all application timings; however, sicklepod and Palmer amaranth control was less than 50% with bromoxynil applied alone. When bromoxynil was applied in combination with trifloxysulfuron at either rate, control of sicklepod and Palmer amaranth increased to 80% or greater at all application timings. Trifloxysulfuron has the potential to complement both the glyphosate-resistant and bromoxynil-resistant weed control programs by providing control of less susceptible weeds and by providing residual control to both programs.

Control of Annual Broadleaf Weeds in Pinto Beans (Phaseolus vulgaris)

1991 ◽  
Vol 5 (3) ◽  
pp. 532-538 ◽  
Author(s):  
Robert E. Blackshaw ◽  
Rudy Esau
Keyword(s):  
Phaseolus Vulgaris ◽  
Weed Control ◽  
Growing Season ◽  
Field Studies ◽  
Western Canada ◽  
Common Lambsquarters ◽  
Hairy Nightshade ◽  
Redroot Pigweed ◽  
Initial Control ◽  
Pinto Beans

Field studies were conducted to identify herbicides suitable for improved control of hairy nightshade, redroot pigweed, and common lambsquarters in pinto beans. Fomesafen at 0.25 kg ai ha-1did not adequately control these weeds. Clomazone at 0.5 kg ai ha-1controlled common lambsquarters but only suppressed the growth of redroot pigweed and hairy nightshade. Ethalfluralin at 0.84 to 1.1 kg ai ha-1gave excellent initial control of these weeds but did not control later flushes of hairy nightshade. Imazethapyr applied PPI or POST at 50 to 75 g ai ha-1controlled hairy nightshade, redroot pigweed, and common lambsquarters throughout the growing season. Imazethapyr combined with ethalfluralin gave superior weed control and resulted in greater yields than the most commonly used herbicides in pinto beans in western Canada.

scholarly journals Weed Control and Grain Sorghum (Sorghum bicolor) Tolerance to Pyrasulfotole plus Bromoxynil

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Dan D. Fromme ◽  
Peter A. Dotray ◽  
W. James Grichar ◽  
Carlos J. Fernandez
Keyword(s):  
Weed Control ◽  
Cucumis Melo ◽  
Growing Season ◽  
Field Studies ◽  
Grain Sorghum ◽  
Amaranthus Palmeri ◽  
Early Season ◽  
Growing Seasons ◽  
Untreated Check ◽  
Better Than

Field studies were conducted during the 2008 and 2009 growing seasons at five locations in the Texas grain sorghum producing regions to evaluate pyrasulfotole plus bromoxynil combinations for weed control and grain sorghum response. All pyrasulfotole plus bromoxynil combinations controlledAmaranthus palmeri,Cucumis melo, andProboscidea louisianicaat least 94% while control ofUrochloa texanawas never better than 69%. Pyrasulfotole plus bromoxynil combinations did result in early season chlorosis and stunting; however, by the end of the growing season no visual injury or stunting differences were noted when compared to the untreated check. Early season grain sorghum chlorosis and stunting with pyrasulfotole plus bromoxynil combinations did not affect grain sorghum yields with the exception of pyrasulfotole at 0.03 kg ai/ha plus bromoxynil at 0.26 kg ai/ha plus atrazine at 0.58 kg ai/ha applied early postemergence followed by pyrasulfotole plus bromoxynil applied mid-postemergence which reduced yield at one of two locations in 2008. Grain sorghum yield increased following all pyrasulfotole plus bromoxynil treatments compared to the untreated check in 2009.

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.

CONVISO® SMART – an innovative approach of weed control in sugar beet

2016 ◽  
pp. 517-524 ◽  
Author(s):  
Martin Wegener ◽  
Natalie Balgheim ◽  
Maik Klie ◽  
Carsten Stibbe ◽  
Bernd Holtschulte
Keyword(s):  
Sugar Beet ◽  
Weed Control ◽  
Field Studies ◽  
Essential Amino Acids ◽  
Global Market ◽  
Sugar Beets ◽  
Dose Rates ◽  
Innovative System ◽  
Bayer Cropscience ◽  
Als Inhibitor

KWS SAAT SE and Bayer CropScience AG are jointly developing and commercializing an innovative system of weed control in sugar beet for the global market under the name of CONVISO SMART. The technology is based on the breeding of sugar beet cultivars that are tolerant to herbicides of the ALS-inhibitor-class with a broad-spectrum weed control. This will give farmers a new opportunity to make sugar beet cultivation easier, more flexible in its timing and more efficient. The use of CONVISO, as new herbicide in sugar beet, will make it possible to control major weeds with low dose rates of product and reduced number of applications in the future. The tolerance is based on a change in the enzyme acetholactate synthase, which is involved in the biosynthesis of essential amino acids. This variation can occur spontaneously during cell division. During the development, sugar beets with this spontaneously changed enzyme were specifically selected and used for further breeding of CONVISO SMART cultivars. As such, these varieties are not a product of genetic modification. Field studies with CONVISO SMART hybrids showed complete crop selectivity and a broad and reliable efficacy against a large range of major weeds. The bio-dossier for an EU-wide registration of CONVISO was submitted in April in 2015. The variety inscription process is in preparation in different countries. The system CONVISO SMART is scheduled to be available to farmers in 2018 at the earliest.

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