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

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.

1993 ◽  
Vol 7 (1) ◽  
pp. 159-162 ◽  
Author(s):  
David L. Jordan ◽  
Robert E. Frans ◽  
Marilyn R. McClelland

Field experiments were conducted from 1989 through 1991 to determine the effect of DPX-PE350 applied postemergence over-the-top on cotton yield and fiber quality. DPX-PE350, at rates ranging from 50 to 280 g ae ha−1applied to cotton in the VC to R6 growth stages, had no adverse effect on seed cotton yield, micronaire, fiber length, fiber length uniformity, or fiber strength. Cotton injury was 10% or less in all experiments.


2004 ◽  
Vol 18 (3) ◽  
pp. 527-531 ◽  
Author(s):  
Jason K. Norsworthy

Field studies were conducted to determine the sensitivity of conventional ‘Motte’ and ‘Pioneer 9831’ soybean to simulated glyphosate drift rates applied during vegetative and reproductive development and the effect of glyphosate on progeny. Glyphosate at 8, 84, and 420 g ae/ha was applied to soybean at the V3, V6, R2, and R5 growth stages. Glyphosate at 8 and 84 g/ha did not reduce soybean plant population, growth, or yield or cause deleterious effects on progeny, regardless of the growth stage at application. Soybean population, growth, and yield were reduced as much as 99 to 100% after application of 420 g/ha glyphosate at the V3 growth stage. Glyphosate at 420 g/ha applied at V6 was less detrimental to soybean compared with the V3 timing. Delaying the application of 420 g/ha glyphosate until R2 and R5 reduced soybean yields 22 to 49% and 43 to 44%, respectively. Soybean injury from 420 g/ha glyphosate was generally transient or less severe when applied at the V6 growth stage or later. However, 420 g/ha glyphosate at R5 (initial podfill) caused a 390 to 450 kg/ha yield reduction compared with the V6 application, which indicated greater soybean vulnerability to glyphosate drift during podfill than in the late-stage vegetative development. Although glyphosate at 420 g/ha was injurious to soybean, regardless of application timing, progeny was not affected.


Weed Science ◽  
1990 ◽  
Vol 38 (1) ◽  
pp. 45-49 ◽  
Author(s):  
Timothy T. Obrigawitch ◽  
William H. Kenyon ◽  
Henry Kuratle

Field, greenhouse, and laboratory studies were conducted to examine the effect of application timing on the activity of DPX-V9360 on rhizome johnsongrass. Field and greenhouse studies indicated that johnsongrass treated with postemergence applications of DPX-V9360 at late growth stages (>5 leaves) was controlled more effectively than when treated in early growth stages (<5 leaves). Johnsongrass control was optimized with split-postemergence applications (treatments applied at early and late growth stages) in field studies compared to a single postemergence application at either early or late growth stages. The pattern of translocation of 2-14C (pyrimidine)-labeled DPX-V9360 applied to a fully expanded johnsongrass leaf did not differ significantly between three different growth stages of 10-, 30-, and 60-cm height. Over 60% of the absorbed14C remained in the treated leaf. Most of the translocated14C moved out of the treated leaf within 3 days after application and distributed to the shoot in greater quantities than to the rhizomes. About 40% of14C-DPX-V9360 applied to the leaf surfaces of a tolerant species (corn) or susceptible species (johnsongrass) was absorbed into the leaf. Corn metabolized over 90% of absorbed DPX-V9360 within 20 h, while there was no perceptible metabolism of DPX-V9360 in johnsongrass leaves after 24 h. Late growth stage and split-postemergence applications appear to provide more effective control than early growth stage applications because of better control of regrowth (new shoot emergence from rhizomes after application) and because tillering and plant emergence are more nearly complete at application time.


Weed Science ◽  
1997 ◽  
Vol 45 (4) ◽  
pp. 497-501 ◽  
Author(s):  
Shane E. Taylor ◽  
Lawrence R. Oliver

Field studies were conducted at the Main Experiment Station, Fayetteville, AR, in 1994 and 1995 to evaluate the effect of postemergence herbicides applied at late-season timings on sicklepod seed production and viability. AC 263,222, dicamba, glyphosate, glufosinate, and paraquat were applied at five rates (zero; labeled rate; one-half, one-fourth, and one-eighth the labeled rate) to three sicklepod growth stages (bud formation, flowering to 9-cm pods, and 15- to 30-cm pods). The greatest reduction in seed production occurred when herbicides were applied at the flowering to 9-cm pod growth stage. All herbicides applied at one-half the labeled rate to sicklepod at bud formation and at the flowering to 9-cm pod growth stage reduced seed production greater than 80%, except glufosinate. Regardless of herbicide, rate, or application timing, viability of remaining seed was ≥ 90% with all treatments.


2015 ◽  
Vol 42 (2) ◽  
pp. 109-120 ◽  
Author(s):  
B.H. Blanchett ◽  
T.L. Grey ◽  
E.P. Prostko ◽  
T.M. Webster

ABSTRACT The development of dicamba-resistant cotton and soybean cultivars has created great concern about the potential off-target movement of dicamba onto sensitive species, including broadleaf crops. Peanut is often grown in close proximity to cotton and soybean. Therefore, field studies were conducted during 2012 and 2013 at Plains, Ty Ty, and Attapulgus, GA to evaluate peanut response to rates of dicamba (35, 70, 140, 280, and 560 g ae ha−1) applied at preemergence (PRE), 10, 20, or 30 d after planting (DAP) corresponding to PRE, V2, V3, and V5 peanut growth stages, respectively. Nontreated controls were included for comparison. As dicamba rate increased, both peanut injury and peanut yield loss increased. Peanut response to dicamba was fit to log-logistic regression models for injury and linear regression models for yield loss. Peanut injury increased with rate of dicamba, but was variable among the locations. A general trend was that peanut plants became more sensitive to dicamba injury as plants approached reproductive stage, as evidenced through a declining linear relationship between I50 values (i.e. rate of dicamba that elicits a 50% crop response) and timing of application. PRE applications of dicamba had I50 values that ranged from 125 to 323 g ha−1 of dicamba, while I50 values were 44 to 48 g ha−1 of dicamba at the V5 peanut growth stage. There was a linear relationship between peanut yield and dicamba rate, with 560 g ha−1 causing maximum yield losses ranging from 0 to 86% when applied PRE, 24 to 82% when applied at V2 growth stage, 30 to 95% when applied at V3 growth stage, and 45 to 88% when applied at V5 growth stage. Across all treatments and locations, there was also a negative linear relationship between peanut yield and peanut crop injury, with a decline of 8.5% yield for every 10% increase in crop injury. Growers and their consultants/extension agents can use this peanut injury data to predict potential peanut yield loss from sprayer contamination or off-target movement of dicamba.


2011 ◽  
Vol 25 (2) ◽  
pp. 192-197 ◽  
Author(s):  
Jason A. Bond ◽  
Timothy W. Walker

Field studies were conducted to compare the response of one inbred (‘CL161’) and two hybrid (‘CLXL729’ and ‘CLXL745’) Clearfield (CL) rice cultivars to imazamox. Imazamox was applied at 44 and 88 g ai ha−1to rice in the panicle initiation (PI) and PI plus 14 d (PI + 14) growth stages and at 44 g ha−1to rice in the midboot growth stage. Maturity of hybrid CL cultivars was delayed following imazamox at 44 g ha−1applied at PI + 14 and midboot. Furthermore, imazamox at 44 g ha−1, applied at midboot, delayed maturity of CLXL745 more than CLXL729. Expressed as a percentage of the weed-free control plots, rough rice yields for CLXL729 were 91% following imazamox at 44 g ha−1applied at PI + 14, 78% following imazamox at 44 g ha−1applied at midboot, and 77% for imazamox at 88 g ha−1applied at PI + 14. Rough rice yield for CLXL745 was 77 to 92% of the control following all imazamox treatments. All imazamox treatments reduced CLXL745 rough rice yield compared with CL161. Rough rice yield, pooled across CL cultivar, varied with imazamox treatment between years, and these differences may have been a consequence of lower temperatures and solar radiation in the first year. Hybrid CL cultivars CLXL729 and CLXL745 were less tolerant than was CL161 when imazamox was applied at nonlabeled rates (88 g ha−1) and/or timings (PI + 14 or midboot). Because of variability in rice growth stages and irregularities in imazamox application in commercial fields, inbred CL cultivars should be planted where an imazamox application will likely be required.


2015 ◽  
Vol 29 (2) ◽  
pp. 207-216 ◽  
Author(s):  
Eric P. Webster ◽  
Justin B. Hensley ◽  
David C. Blouin ◽  
Dustin L. Harrell ◽  
Jason A. Bond

Field studies were conducted near Crowley, LA to evaluate the effects of simulated herbicide drift on ‘Cocodrie' rice. Each treatment was made with the spray volume varying proportionally to herbicide dosage based on a spray volume of 234 L ha−1and a glufosinate rate of 493 g ai ha−1. The 6.3%, 31 g ha−1, herbicide rate was applied at a spray volume of 15 L ha−1and the 12.5%, 62 g ha−1, herbicide rate was applied at a spray volume of 29 L ha−1. Glufosinate applied at one-tiller, panicle differentiation (PD) growth stage, and boot resulted in crop injury at 7 and 14 d after treatment. At 21 and 28 d after treatment, crop injury was still evident but was less than 10%. Glufosinate applied at one-tiller resulted in plant height reductions of 4 to 6%; however, at harvest, height reductions were 1% or less. Glufosinate applied to rice in the boot stage had lower rice yield in the primary crop, but no difference was observed in the ratoon crop. Harvested seed from the primary crop germinated 7 to 11% less than the nontreated when rice was treated with 31 and 62 g ha−1of glufosinate. Seedling vigor was reduced when treated with 31 and 62 g ha−1of glufosinate.


1991 ◽  
Vol 5 (3) ◽  
pp. 493-498 ◽  
Author(s):  
Charles E. Snipes ◽  
Joe E. Street ◽  
Thomas C. Mueller

Cotton response to triclopyr was evaluated when it was applied over-the-top at simulated drift rates to pin-head square and early bloom cotton growth stages in 1987 and 1988. The herbicidal effects of triclopyr were most evident after a lag period of 10 to 15 d. Triclopyr at 60 g ai ha-1applied at pin-head square reduced cotton height in 1987, but not in 1988. Triclopyr applied at pin-head square and early bloom reduced cotton flowering initially, as measured by white bloom counts, in both years. Total blooms were reduced in 1987, but not in 1988. Cotton maturity was delayed by triclopyr application during early bloom, as shown by a decrease in percent open bolls, and a decrease in first pick cotton yields. Cotton yield was lower in plots receiving triclopyr, with the greatest yield reduction caused by a 60 g ha-1triclopyr application at early bloom.


2020 ◽  
pp. 1-8
Author(s):  
Ayse Nur Ulusoy ◽  
O. Adewale Osipitan ◽  
Jon Scott ◽  
Amit J. Jhala ◽  
Nevin C. Lawrence ◽  
...  

Abstract Residual herbicides applied PRE provide early season weed control, potentially avoid the need for multiple POST herbicides, and can provide additional control of herbicide-resistant weeds. Thus, field studies were conducted in 2017 and 2018 at Concord, NE, to evaluate the influence of PRE herbicides on critical time for postemergence weed removal (CTWR) in corn. The studies were arranged in a split-plot design that consisted of three herbicide regimes as main plot treatments and seven weed removal timings as subplot treatments in four replications. The herbicide regimes included no PRE herbicide, atrazine, and a premix of saflufenacil/dimethenamid-P mixed with pyroxasulfone. The weed removal timings were at V3, V6, V9, V12, and V15 corn growth stages and then plots were kept weed-free until harvest. A weed-free and nontreated control were included for comparison. The relationship between corn growth or yield, and weed removal timings in growing degree days (GDD) was described by a four-parameter log-logistic model. This model was used to estimate the critical time for weed removal based on 5% crop yield loss threshold. A delay in weed removal until the V2 to V3 corn growth stage (91 to 126 GDD) reduced corn biomass by 5% without PRE herbicide application. The CTWR started at V3 without PRE herbicide in both years. Atrazine delayed the CTWR up to V5 in both years, whereas saflufenacil/dimethenamid-P plus pyroxasulfone further delayed the CTWR up to the V10 and V8 corn growth stages in 2017 and 2018, respectively. Herbicide applied PRE particularly with multiple sites of action can delay the CTWR in corn up to a maximum growth stage of V10, and delay or reduce the need for POST weed management.


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