Resistance of Enlist™ (AAD-12) Cotton to Glufosinate

2017 ◽  
Vol 31 (3) ◽  
pp. 380-386 ◽  
Author(s):  
L. Bo Braxton ◽  
John S. Richburg ◽  
Alan C. York ◽  
A. Stanley Culpepper ◽  
Robert A. Haygood ◽  
...  
Keyword(s):  
Growth Stage ◽  
Field Trials ◽  
Application Rate ◽  
Growth Stages ◽  
Cotton Yield ◽  
Single Application

Enlist™ cotton contains the aad-12 and pat genes that confer resistance to 2,4-D and glufosinate, respectively. Thirty-three field trials were conducted focused on Enlist cotton injury from glufosinate as affected by cotton growth stage, application rate, and single or sequential applications. Maximum injury from a single application of typical 1X (542 g ae ha-1) and 2X use rates was 3 and 13%, respectively, regardless of growth stage. Injury from sequential applications of 1X or 2X rates was equivalent to single applications. Similar injury was observed with four commercial formulations of glufosinate. Cotton yield was never affected by glufosinate. This research demonstrates Enlist™ cotton has robust resistance to glufosinate at rates at least twice the typical use rate when applied once or twice at growth stages ranging from 2 to 12 leaves.

Soybean Sensitivity to Drift Rates of Imazosulfuron

2014 ◽  
Vol 28 (3) ◽  
pp. 443-453 ◽  
Author(s):  
Sandeep S. Rana ◽  
Jason K. Norsworthy ◽  
Robert C. Scott
Keyword(s):  
Growth Stage ◽  
Yield Loss ◽  
Field Trials ◽  
Application Rate ◽  
Early Growth ◽  
Growth Stages ◽  
Sulfonylurea Herbicide ◽  
Full Bloom ◽  
Close Proximity ◽  
Different Growth Stages

Imazosulfuron is a sulfonylurea herbicide recently labeled in U.S. rice at a maximum rate of 336 g ai ha−1. Soybean is prone to drift of herbicides from rice fields in the southern United States because these crops are often grown in close proximity. Field trials were conducted to determine the effect of low rates of imazosulfuron applied to nonsulfonylurea-resistant soybean at different growth stages. Soybean was treated at the vegetative cotyledonary (VC); vegetative second trifoliate (V2); vegetative sixth trifoliate (V6); and reproductive full bloom (R2) growth stages with 1/256 (1.3 g ha−1) to 1/4 (84.1 g ha−1) times (X) the maximum labeled rate of imazosulfuron. Soybean was injured regardless of application rate or timing. At 2 wk after treatment (WAT), imazosulfuron injured soybean 23 to 79, 44 to 76, 32 to 68, and 14 to 50% when applied at the VC, V2, V6, and R2 growth stages, respectively, where the highest injury was caused by the highest imazosulfuron rate (1/4X). However, by 20 wk after planting (WAP), soybean treated with imazosulfuron at the VC and V2 growth stages had only 0 to 17% and 8 to 53% injury, respectively. At higher rates [1/8 (42 g ha−1) and 1/4X] of imazosulfuron, soybean treated at the VC growth stage recovered more from injury than did soybean treated at the V2 growth stage. Soybean treated with imazosulfuron at the V6 and R2 growth stages had better recovery from the injury at the lower two rates [1/256 and 1/128X (2.6 g ha−1)] than at the higher rates [1/64 (5.3 g ha−1) to 1/4X]. Imazosulfuron, at all rates tested, delayed soybean maturity by 1 to 4, 2 to 6, 1 to 12, and 3 to 16 d for the VC, V2, V6, and R2 growth stages, respectively. Yield loss was greater when imazosulfuron was applied at V6 and R2 compared to applications at VC and V2. Results from this research indicate that imazosulfuron can severely injure soybean regardless of the growth stage at which drift occurs; however, soybean injured by imazosulfuron at early growth stages (VC and V2) has a better chance of recovery over time compared to drift at later growth stages (V6 and R2).

Fungicide efficacy on tar spot and yield of corn in the Midwestern United States

2022 ◽  
Author(s):  
Darcy E. P. Telenko ◽  
Martin I. Chilvers ◽  
Adam Byrne ◽  
Jill Check ◽  
Camila Rocco Da Silva ◽  
...  
Keyword(s):  
United States ◽  
Growth Stage ◽  
Field Trials ◽  
Corn Belt ◽  
Yield Losses ◽  
Single Application ◽  
Midwestern United States ◽  
Tar Spot ◽  
Significant Yield ◽  
Foliar Fungicide

Tar spot of corn caused by Phyllachora maydis has recently led to significant yield losses in the eastern corn belt of the Midwestern United States. Foliar fungicides containing quinone outside inhibitors(QoI), demethylation inhibitors(DMI), and succinate dehydrogenase inhibitors(SDHI) are commonly used to manage foliar diseases in corn. To mitigate the losses from tar spot thirteen foliar fungicides containing single or multiple modes of action (MOA/FRAC groups) were applied at their recommended rates in a single application at the standard tassel/silk growth stage timing to evaluate their efficacy against tar spot in a total of eight field trials in Illinois, Indiana, Michigan, and Wisconsin during 2019 and 2020. The single MOA fungicides included either a QoI or DMI. The dual MOA fungicides included a DMI with either a QoI or SDHI, and fungicides containing three MOAs included a QoI, DMI, and SDHI. Tar spot severity estimated as the percentage of leaf area covered by P. maydis stroma of the non-treated control at dent growth stage ranged from 1.6 to 23.3% on the ear leaf. Averaged across eight field trials all foliar fungicide treatments reduced tar spot severity, but only prothioconazole+trifloxystrobin, mefentrifluconazole+pyraclostrobin+fluxapyroxad, and mefentrifluconazole+pyraclostrobin significantly increased yield over the non-treated control. When comparing fungicide treatments by the number of MOAs foliar fungicide products that had two or three MOAs decreased tar spot severity over not treating and products with one MOA. The fungicide group that contained all three MOAs significantly increased yield over not treating with a fungicide or using a single MOA.

Control of Early Watergrass (Echinochloa Oryzoides) and Late Watergrass (Echinochloa Phyllopogon) with Cyhalofop, Clefoxydim, and Penoxsulam Applied Alone and in Mixture with Broadleaf Herbicides

2006 ◽  
Vol 20 (4) ◽  
pp. 992-998 ◽  
Author(s):  
Christos A. Damalas ◽  
Kico V. Dhima ◽  
Ilias G. Eleftherohorinos
Keyword(s):  
Growth Stage ◽  
Leaf Growth ◽  
Application Rate ◽  
Early Growth ◽  
Rice Fields ◽  
Growth Stages ◽  
Early Growth Stage ◽  
Late Growth ◽  
Echinochloa Phyllopogon

Experiments were conducted to study the effect of application rate, growth stage, and tank-mixing azimsulfuron or bentazon on the activity of cyhalofop, clefoxydim, and penoxsulam against two morphologically distinctEchinochloaspecies from rice fields in Greece. Mixtures of penoxsulam with MCPA were also evaluated. Cyhalofop (300 to 600 g ai/ha) applied at the three- to four-leaf growth stage provided 62 to 85% control of early watergrass but 41 to 83% control of late watergrass averaged over mixture treatments. Control ranged from 37 to 80% for early watergrass and from 35 to 78% for late watergrass when cyhalofop was applied at the five- to six-leaf growth stage averaged over mixture treatments. Mixtures of cyhalofop with azimsulfuron or bentazon reduced efficacy on both species irrespective of growth stage or cyhalofop application rate compared with cyhalofop alone. Clefoxydim (100 to 250 g ai/ha) applied alone at the three- to four-leaf growth stage provided 98 to 100% control of early watergrass and 91 to 100% control of late watergrass; when clefoxydim was applied alone at the five- to six-leaf growth stage the control obtained was 91 to 100% for early watergrass and 79 to 100% for late watergrass. Mixtures of clefoxydim with azimsulfuron or bentazon reduced efficacy on late watergrass at the early growth stage and on both species at the late growth stage. Penoxsulam (20 to 40 g ai/ha) applied alone provided 94 to 100% control of both species at both growth stages. Mixtures of MCPA with penoxsulam reduced efficacy on late watergrass at the early growth stage and on both species at the late growth stage. Mixtures of penoxsulam with azimsulfuron or bentazon reduced efficacy only on late watergrass at the late growth stage.

Growth Stage Affects Cotton Response to Trifloxysulfuron

2007 ◽  
Vol 21 (1) ◽  
pp. 37-40 ◽  
Author(s):  
Robert J. Richardson ◽  
Henry P. Wilson ◽  
Gregory R. Armel ◽  
Thomas E. Hines
Keyword(s):  
Nonionic Surfactant ◽  
Growth Stage ◽  
Fiber Quality ◽  
Field Studies ◽  
Growth Stages ◽  
Cotton Yield ◽  
Cotton Crop ◽  
Application Timing ◽  
Crop Injury ◽  
Over The Top

Field studies were conducted in 1999, 2000, and 2001 to evaluate cotton response to trifloxysulfuron applied postemergence over the top (POT) or postemergence-directed (PDIR) at various growth stages. Treatments included trifloxysulfuron at 3.8 or 7.5 g ai/ha plus nonionic surfactant (NIS) applied POT to one-, three-, and five-leaf cotton or applied PDIR to 30- and 45-cm tall cotton. Crop injury 7 d after treatment (DAT) varied by year and ranged from 17 to 50%, 19 to 46%, and 5 to 23% with trifloxysulfuron applied POT to one-, three-, and five-leaf cotton, respectively. Injury 21DAT averaged 22, 16, and 6% with one-, three-, and five-leaf applications respectively. Trifloxysulfuron applied PDIR injured cotton 2 to 9% 7 DAT and 0 to 12% 21 DAT. At 30 DAT, cotton height was reduced with one-leaf trifloxysulfuron application, whereas differences were not present across other treatments. Heights at 90 days after planting (DAP) did not differ between treatments. Neither trifloxysulfuron rate or application timing negatively affected cotton yield or fiber quality.

scholarly journals Effect of Different Durations of Water-Logging at Different Growth Stages on Seed Yield of Sesame

2018 ◽  
Vol 1 (2) ◽  
pp. p68
Author(s):  
M. H. Ali
Keyword(s):  
Seed Yield ◽  
Growth Stage ◽  
Field Trials ◽  
Growth Stages ◽  
Differential Effects ◽  
Growing Period ◽  
Water Logging ◽  
Different Growth Stages

In Bangladesh, sesame suffers from water-logging during its growing period. Multi-year and multi-location field trials were carried out to study the effect of different durations of water-logging at different growth stages on seed yield of sesame. From two years results, it is revealed that the effects of water-logging during a particular growth stage or particular duration of water-logging on seed yield depends on pre- and/or post water-logging from the rainfall. Differential effects of the cultivars were also observed. The cultivar Binatil-2 and Binatil-3 showed reasonable seed yield under water-logging at flowering and mid pod-formation stages for 24 to36 hours.

scholarly journals The influence of fertilization and tillage method on the formation root system capacity and grain production of spring barley

2011 ◽  
pp. 89-93
Author(s):  
Andrej Kupecsek ◽  
Juliana Monárová
Keyword(s):  
Grain Yield ◽  
Root System ◽  
Growth Stage ◽  
Spring Barley ◽  
Field Trials ◽  
Conventional Tillage ◽  
System Capacity ◽  
Growth Stages ◽  
Lcr Meter ◽  
Tillage Method

To evaluate the interaction of year x variety, year x tillage method and year x fertilization on the grain yield and root system capacity (RSC) of spring barley, we ran polyfactorial field trials in agroecological conditions of a warm corn production area in Slovakia, at  Malanta, in 2009 and 2010. The RSC measurements were done using LCR - meter at a frequency of 1 kHz and they took place in four growth stages: at leaf development in the stage of four leaves (RSC1), in full tillering (RSC2), in the stage heading (RSC 3) and at the stage of ripening (RSC4). The values of grain yield, RSC1, RSC2, RSC3, RSC4 reached in 2009 comparison to 2010 were significantly lower. The highest yield in 2009 was reached by variety Marthe (4.49 t.ha-1) and by variety Bojos (7.19 t ha-1) in 2010. The highest values of RSC in observed growth stages were achieved by variety Bojos in 2009, and in 2010 also besides RSC1. Within both years, difference in yields between tillage methods was not observed. The values of RSC in growth stage of 4 leaves and tillering was higher at conventional tillage, butthe values of RSC3 and RSC4 were higher with minimized tillage. The highest grain yield and values of RSC in every growth stage were achieved on the fertilization variant “c“ in 2009 and on the fertilization variant “b“ in 2010. The correlation relationships between grain yield and RSC were significant and positive in every growth stage. The strongest relationship was found among grain yield and RSC (r=0.6047).

scholarly journals Glyphosate Tolerance of Two Perennial Ryegrass Cultivars from Fall Applications and at Seedling Growth Stages

HortScience ◽  
2015 ◽  
Vol 50 (2) ◽  
pp. 304-309
Author(s):  
Christian M. Baldwin ◽  
Eugene K. Blythe ◽  
A. Douglas Brede ◽  
Jami J. Mayer ◽  
R. Golembiewski
Keyword(s):  
Perennial Ryegrass ◽  
Temperature Response ◽  
Field Trials ◽  
Application Rate ◽  
Growth Stages ◽  
Annual Bluegrass ◽  
Air Temperatures ◽  
The One ◽  
Fall Application ◽  
Response Trial

The use of glyphosate-tolerant perennial ryegrass (Lolium perenne L.) (PRG) cultivars JS501 and Replay provides turfgrass managers a unique option for annual bluegrass (Poa annua L.) (ABG) control. Both cultivars can tolerate a maximum glyphosate rate of 0.81 kg·ha−1 acid equivalent (a.e.) after establishment under optimal growing temperatures (16 to 24 °C). However, tolerance to applications made immediately after germination and during low air temperatures has received limited investigation. Therefore, objectives of this research were to determine the seedling tolerance and low-temperature response after a fall season glyphosate application to both cultivars. Field trials were conducted in Idaho and Oregon. For the fall application response trial in Idaho, glyphosate was applied at 0, 0.15, 0.29, 0.58, 1.16, 1.74, 2.32, and 3.48 kg·ha−1 a.e. In Oregon, glyphosate was applied at 0, 0.15, 0.29, 0.44, 0.58, 1.16, and 3.48 kg·ha−1 a.e. At both sites, applications were made between late September and early October. To determine seedling tolerance, both cultivars were sprayed with glyphosate at the one-leaf stage (LS), two LS, three LS, or four LS at rates of 0, 0.15, 0.29, and 0.58 kg·ha−1 a.e. Across all trials, ratings included PRG color, cover, and injury. At both trial locations, regression analysis revealed a rate of ≈0.27 kg·ha−1 a.e. was required to cause 20% leaf firing in the fall application response trial. In the seedling tolerance trial, glyphosate applied at 0.58 kg·ha−1 a.e. at the one LS, two LS, and three LS had color ratings 8.0 or greater; however, color ratings dropped to 4.6 when an application was made at the four LS. Based on the environmental conditions of each trial, results suggest glyphosate applications greater than 0.27 kg·ha−1 a.e. as minimum air temperatures approach 0 °C should be avoided. Also, applications should be avoided at the three to four LS if the application rate is greater than 0.29 kg·ha−1 a.e.

Evaluating the double knockdown technique: sequence, application interval, and annual ryegrass growth stage

2007 ◽  
Vol 58 (3) ◽  
pp. 265 ◽  
Author(s):  
Catherine P. Borger ◽  
Abul Hashem
Keyword(s):  
Growth Stage ◽  
Field Experiments ◽  
Growth Stages ◽  
Annual Ryegrass ◽  
Application Time ◽  
Lolium Rigidum ◽  
Single Application ◽  
Herbicide Application ◽  
Leaf Stage ◽  
The Difference

Applying glyphosate followed by a mixture of paraquat + diquat in the same season for pre-planting weed control may reduce the risk of developing resistance to either herbicide. Glasshouse and field experiments at Merredin and Beverly, Western Australia, were conducted over 2 seasons to determine the best herbicide application sequence, growth stage of annual ryegrass at which to apply the 2 herbicides, and application time and interval to be allowed between applications for optimum control of annual ryegrass (Lolium rigidum Gaud.). Annual ryegrass plants were treated at 3 growth stages with either glyphosate 540 g a.i./ha alone, paraquat + diquat 250 g a.i./ha alone, glyphosate followed by paraquat + diquat 250 g a.i./ha, or paraquat + diquat 250 g a.i./ha followed by glyphosate 540 g a.i./ha (the double knockdown treatment). The herbicides were applied at different times of the day, with varied intervals between herbicides when applied in sequence. The glasshouse experiment showed that herbicides in sequence more effectively killed annual ryegrass plants at the 3–6-leaf stage than a single application of either herbicide. Field experiments showed that applying glyphosate followed by paraquat + diquat provided 98–100% control of annual ryegrass plants when applied at the 3- or 6-leaf stage in 2002 and at all 3 growth stages in 2003. Generally, the sequence of paraquat + diquat followed by glyphosate was less effective than the reverse sequence, although the difference was not large. Averaged over 2 seasons, herbicides in sequence were most effective when the first herbicide was applied at the 3- or 6-leaf stage of annual ryegrass. An interval of 2–10 days between applications of herbicides was more effective than 1 day or less. The application time did not significantly affect the efficacy of double knockdown herbicides on annual ryegrass plants under field conditions.

Response of Asiatic Dayflower (Commelina communis) to Glyphosate and Alternatives in Soybean

Weed Science ◽  
2009 ◽  
Vol 57 (1) ◽  
pp. 74-80 ◽  
Author(s):  
Santiago M. Ulloa ◽  
Micheal D. K. Owen
Keyword(s):  
Growth Stage ◽  
Field Research ◽  
Early Growth ◽  
Growth Stages ◽  
Anecdotal Evidence ◽  
Single Application ◽  
Emergence Period ◽  
Early Growth Stage ◽  
Greenhouse Experiments ◽  
Corn Plants

Asiatic dayflower has recently become a troublesome weed in eastern Iowa. This weed demonstrates an extended emergence period and there is anecdotal evidence of glyphosate tolerance. Thus, Asiatic dayflower is difficult to manage in glyphosate-resistant (GR) corn and soybean. Greenhouse experiments were conducted to evaluate the response of Asiatic dayflower to glyphosate applied at different rates and growth stages. Field research was conducted in 2005 and 2006 to evaluate different herbicides for Asiatic dayflower control in soybean. PRE herbicides were applied at planting and POST herbicides were applied 21 and 42 d after planting (DAP). In addition, shikimate accumulation in response to glyphosate was compared among Asiatic dayflower and GR and non-GR corn and soybean. Under greenhouse conditions, a single application of glyphosate (0.84 kg ae ha−1) did not control Asiatic dayflower. Only the highest rate evaluated, 13.44 kg ae ha−1 (16X), was lethal to Asiatic dayflower. Even when applied at an early growth stage (two leaves) and using high rates (3.36 kg ae ha−1), glyphosate controlled Asiatic dayflower just 28%. In the field, metribuzin and KIH-485 controlled Asiatic dayflower 80 and 73%, respectively. Early POST applications (21 DAP) of cloransulam or lactofen controlled Asiatic dayflower 80 and 67%, respectively. A single glyphosate application of 0.86 kg ae ha−1 controlled Asiatic dayflower approximately 50%. Glyphosate-treated Asiatic dayflower and non-GR corn and soybeans accumulated shikimate after application. GR corn and soybeans did not accumulate shikimate in response to glyphosate. Twenty-one days after treatment, all the non-GR soybean and corn plants died; however, Asiatic dayflower plants survived.

scholarly journals Effect of Low Doses of Dicamba Alone and in Combination with Glyphosate on Parent Soybean and Offspring

2018 ◽  
Vol 33 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Gordon T. Jones ◽  
Jason K. Norsworthy ◽  
Tom Barber ◽  
Edward Gbur ◽  
Greg R. Kruger
Keyword(s):  
Growth Stage ◽  
Field Trials ◽  
Growth Stages ◽  
Low Doses ◽  
Limited Information ◽  
Negative Effects ◽  
Target Exposure ◽  
Highly Sensitive ◽  
Sublethal Doses

AbstractIt is well established that soybean that does not contain the dicamba-resistant (DR) trait is highly sensitive to off-target exposure to dicamba. However, there is limited information on the effect of low doses of dicamba plus glyphosate mixtures on dicamba-sensitive soybean—a mixture likely to be used on a vast acreage of dicamba/glyphosate-resistant soybean. The objective of this research was to examine leaf and pod malformation, along with height and yield effects, when dicamba, glyphosate, or a mixture of the two was applied to soybean sensitive to both dicamba and glyphosate at sublethal doses. Field applications were made at three growth stages (R1, R3, and R5) at multiple locations. Two glyphosate rates (1/64 and 1/256 of the labeled rate of 870 g ae ha−1) and two dicamba rates (1/64 and 1/256 of the labeled rate of 560 g ae ha−1) were used. Adding glyphosate to dicamba increased leaf malformation by 6% more than dicamba alone when applied at the R1 soybean growth stage. After R3 applications, pod malformation was 10% greater in treatments containing dicamba and glyphosate than dicamba alone. Applications at R5 showed minimal leaf and pod malformation. Seed from field trials was planted in the greenhouse to evaluate the offspring. The number of offspring plants showing dicamba-like symptomology was not increased with the addition of glyphosate to dicamba. Overall, injury to offspring was similar in dicamba alone and dicamba plus glyphosate treatments; however, the number of plants injured increased when parent plants were exposed to sublethal doses of dicamba at R3 and R5 compared with R1 growth-stage exposure. Vigor was reduced in dicamba-containing treatments, but not glyphosate-alone treatments. Glyphosate addition to dicamba had no effect on vigor of soybean offspring. Although there is increased injury to parent plants when glyphosate is added to dicamba, this research demonstrates that glyphosate does not contribute to the negative effects of dicamba on soybean offspring.

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