Physiological basis for cotton tolerance to flumioxazin applied postemergence directed

Previous research has shown that flumioxazin, a herbicide being developed as a postemergence-directed spray (PDS) in cotton, has the potential to injure cotton less than 30 cm tall if the herbicide contacts green stem tissue by rain splash or misapplication. In response to this concern, five-leaf cotton plants with chlorophyllous stems and older cotton, 16-leaf cotton plants, with bark on the lower stem were treated with a PDS containing flumioxazin plus crop oil concentrate (COC) or nonionic surfactant (NIS). Stems of treated plants and untreated plants at the respective growth stage were cross-sectioned and then magnified and photographed using bright-field microscopy techniques. More visible injury consisting of necrosis and desiccation was evident in younger cotton. Also, there was a decrease in treated-stem diameter and an increase in visible injury with COC compared with NIS in younger cotton. The effects of plant growth stage and harvest time on absorption, translocation, and metabolism of14C-flumioxazin in cotton were also investigated. Total14C absorbed at 72 h after treatment (HAT) was 77, 76, and 94% of applied at 4-, 8-, and 12-leaf growth stages, respectively. Cotton at the 12-leaf stage absorbed more14C within 48 HAT than was absorbed by four- or eight-leaf cotton by 72 HAT. A majority (31 to 57%) of applied14C remained in the treated stem for all growth stages and harvest times. Treated cotton stems at all growth stages and harvest times contained higher concentrations (Bq g−1) of14C than any other tissues. Flumioxazin metabolites made up less than 5% of the radioactivity found in the treated stem. Because of the undetectable levels of metabolites in other tissues when flumioxazin was applied PDS, flumioxazin was foliar applied to determine whether flumioxazin transported to the leaves may have been metabolized. In foliar-treated cotton, flumioxazin metabolites in the treated leaf of four-leaf cotton totaled 4% of the recovered14C 72 HAT. Flumioxazin metabolites in the treated leaf of 12-leaf cotton totaled 35% of the recovered14C 48 HAT. These data suggest that differential absorption, translocation, and metabolism at various growth stages, as well as the development of a bark layer, are the bases for differential tolerances of cotton to flumioxazin applied PDS.

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Absorption, Translocation, and Activity of CGA-136872, DPX-V9360, and Glyphosate in Rhizome Johnsongrass (Sorghum halepense)

Weed Science ◽

10.1017/s0043174500073057 ◽

1991 ◽

Vol 39 (3) ◽

pp. 354-357 ◽

Cited By ~ 23

Author(s):

Rolando F. Camacho ◽

Loren J. Moshier

Keyword(s):

Growth Stage ◽

Leaf Growth ◽

Sorghum Halepense ◽

Growth Stages ◽

Foliar Absorption ◽

Treated Leaf

Rhizome johnsongrass grown in the greenhouse and treated with glyphosate at 1680 g ai ha−1at an early (3- to 4-leaf) or late (6- to 8-leaf) growth stage displayed injury within a week. Plants treated with CGA-136872 or DPX-V9360 at 40 g ai ha−1at both growth stages displayed injury 1 to 2 weeks later. CGA-136872 did not prevent regrowth at either growth stage. No regrowth occurred from DPX-V9360 or glyphosate-treated plants. Foliar absorption by greenhouse-grown plants within 24 h of application was greater with14C-glyphosate than with14C-DPX-V9360 or14C-CGA-136872. More14C-DPX-V9360 was absorbed than14C-CGA-136872. Growth stage influenced glyphosate absorption (more by younger plants) but not CGA-136872 or DPX-V9360 absorption. Translocation of the14C-CGA-136872 and14C-DPX-V9360 out of the treated leaf was less than 20% of the absorbed label and was less than glyphosate translocation. Growth stage of rhizome johnsongrass at the time of treatment had no effect on the distribution of radiolabeled herbicides within 24 h.

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The effect of cotton growth stage on response to a sublethal concentration of 2,4-D

Weed Technology ◽

10.1017/wet.2019.9 ◽

2019 ◽

Vol 33 (2) ◽

pp. 321-328 ◽

Cited By ~ 1

Author(s):

John T. Buol ◽

Daniel B. Reynolds ◽

Darrin M. Dodds ◽

J. Anthony Mills ◽

Robert L. Nichols ◽

...

Keyword(s):

Fiber Length ◽

Growth Stage ◽

Field Experiments ◽

Fruit Set ◽

Sublethal Concentration ◽

Growth Stages ◽

Visible Injury ◽

Fiber Properties ◽

Low Concentrations ◽

Auxin Herbicides

AbstractRecent commercialization of auxin herbicide–based weed control systems has led to increased off-target exposure of susceptible cotton cultivars to auxin herbicides. Off-target deposition of dilute concentrations of auxin herbicides can occur on cotton at any stage of growth. Field experiments were conducted at two locations in Mississippi from 2014 to 2016 to assess the response of cotton at various growth stages after exposure to a sublethal 2,4-D concentration of 8.3 g ae ha−1. Herbicide applications occurred weekly from 0 to 14 weeks after emergence (WAE). Cotton exposure to 2,4-D at 2 to 9 WAE resulted in up to 64% visible injury, whereas 2,4-D exposure 5 to 6 WAE resulted in machine-harvested yield reductions of 18% to 21%. Cotton maturity was delayed after exposure 2 to 10 WAE, and height was increased from exposure 6 to 9 WAE due to decreased fruit set after exposure. Total hand-harvested yield was reduced from 2,4-D exposure 3, 5 to 8, and 13 WAE. Growth stage at time of exposure influenced the distribution of yield by node and position. Yield on lower and inner fruiting sites generally decreased from exposure, and yield partitioned to vegetative or aborted positions and upper fruiting sites increased. Reductions in gin turnout, micronaire, fiber length, fiber-length uniformity, and fiber elongation were observed after exposure at certain growth stages, but the overall effects on fiber properties were small. These results indicate that cotton is most sensitive to low concentrations of 2,4-D during late vegetative and squaring growth stages.

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Safening Influence of LAB 145 138 on Nicosulfuron, Terbufos and Bentazon Interactions in Sweet Corn (Zea mays)

Weed Science ◽

10.1017/s0043174500093978 ◽

1996 ◽

Vol 44 (2) ◽

pp. 339-344 ◽

Cited By ~ 2

Author(s):

Darren K. Robinson ◽

David W. Monks ◽

James D. Burton

Keyword(s):

Zea Mays ◽

Seed Treatment ◽

Growth Stage ◽

Yield Loss ◽

Sweet Corn ◽

Leaf Growth ◽

Growth Stages ◽

Height Reduction ◽

Reduced Height ◽

Previously Treated

LAB 145 138 (LAB) was evaluated as a safener to improve sweet corn tolerance to nicosulfuron applied POST alone or with terbufos applied in the planting furrow or bentazon applied POST. To ensure enhanced injury for experimental purposes, nicosulfuron was applied at twice the registered rate alone or mixed with bentazon at the six- to seven-leaf growth stage of corn previously treated with the highest labeled rate of terbufos 15 G formulation. LAB applied as a seed treatment (ST) or POST at the two- to three-, four- to five-, or six- to seven-leaf growth stages reduced height reduction and yield loss from nicosulfuron applied POST in combination with terbufos applied in-furrow. LAB applied POST at the four- to five-leaf growth stage was most effective in preventing injury from this treatment, with yield reduced only 8% compared with 54% from the nicosulfuron and terbufos treatment. LAB applied POST at the eight- to nine-leaf growth stage did not alleviate injury. With the nicosulfuron, terbufos, and bentazon combination, LAB applied POST at the three- to four- or six- to seven-leaf growth stages decreased height reduction and yield loss caused by this combination, with LAB at the three- to four-leaf growth stage being most effective.

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

Weed Technology ◽

10.1614/wt-05-140.1 ◽

2006 ◽

Vol 20 (4) ◽

pp. 992-998 ◽

Cited By ~ 9

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.

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Relative effectiveness of various sources, methods, times and rates of copper fertilizers in improving grain yield of wheat on a Cu-deficient soil

Canadian Journal of Plant Science ◽

10.4141/p04-089 ◽

2005 ◽

Vol 85 (1) ◽

pp. 59-65 ◽

Cited By ~ 12

Author(s):

S. S. Malhi ◽

L. Cowell ◽

H. R. Kutcher

Keyword(s):

Grain Yield ◽

Protein Concentration ◽

Growth Stage ◽

Foliar Application ◽

Leaf Growth ◽

Flag Leaf ◽

Relative Effectiveness ◽

Growing Season ◽

Growth Stages ◽

Cu Deficiency

A field experiment was conducted to determine the relative effectiveness of various sources, methods, times and rates of Cu fertilizers on grain yield, protein concentration in grain, concentration of Cu in grain and uptake of Cu in grain of wheat (Triticum aestivum L.), and residual concentration of DTPA-extractable Cu in soil on a Cu-deficient soil near Porcupine Plain in northeastern Saskatchewan. The experiment was conducted from 1999 to 2002 on the same site, but the results for 2002 were not presented because of very low grain yield due to drought in the growing season. The 25 treatments included soil application of four granular Cu fertilizers (Cu lignosulphonate, Cu sulphate, Cu oxysulphate I and Cu oxysulphate II) as soil-incorporated (at 0.5 and 2.0 kg Cu ha-1), seedrow-placed (at 0.25 and 1.0 kg Cu ha-1) and foliar application of four solution Cu fertilizers (Cu chelate-EDTA, Cu sequestered I, Cu sulphate/chelate and Cu sequestered II at 0.25 kg Cu ha-1) at the four-leaf and flag-leaf growth stages, plus a zero-Cu check. Soil was tilled only once to incorporate all designated Cu and blanket fertilizers into the soil a few days prior to seeding. Wheat plants in the zero-Cu treatment exhibited Cu deficiency in all years. For foliar application at the flag-leaf stage, grain yield increased with all four of the Cu fertilizers in 2000 and 2001, and in all but Cu sequestered II in 1999. Foliar application at the four-leaf growth stage of three Cu fertilizers (Cu chelate-EDTA, Cu sequestered I and Cu sulphate/chelate), soil incorporation of all Cu fertilizers at 2 kg Cu ha-1 and two Cu fertilizers (Cu lignosulphonate and Cu sulphate) at 0.5 kg Cu ha-1 rate, and seedrow placement of two Cu fertilizers (Cu lignosulphonate and Cu sulphate) at 1 kg Cu ha-1 increased grain yield of wheat only in 2001. There was no effect of Cu fertilization on protein concentration in grain. The increase in concentration and uptake of Cu in grain from Cu fertilization usually showed a trend similar to grain yield. There was some increase in residual DTPA-extractable Cu in the 0–60 cm soil in Cu lignosulphonate, Cu sulphate and Cu oxysulphate II soil incorporation treatments, particularly at the 2 kg Cu ha-1 rate. In summary, the results indicate that foliar application of Cu fertilizers at the flag-leaf growth stage can be used for immediate correction of Cu deficiency in wheat. Because Cu deficiency in crops often occurs in irregular patches within fields, foliar application may be the most practical and economical way to correct Cu deficiency during the growing season, as lower Cu rates can correct Cu deficiency. Key words: Application time, Cu source, foliar application, granular Cu, growth stage, placement method, rate of Cu, seedrow-placed Cu, soil incorporation

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Effect of timing of propiconazole application on foliar disease and yield of irrigated spring wheat in Saskatchewan from 1990 to 1992

Canadian Journal of Plant Science ◽

10.4141/cjps94-041 ◽

1994 ◽

Vol 74 (1) ◽

pp. 205-207 ◽

Cited By ~ 9

Author(s):

L. J. Duczek ◽

L. L. Jones-Flory

Keyword(s):

Spring Wheat ◽

Growth Stage ◽

Leaf Growth ◽

Stem Elongation ◽

Maximum Yield ◽

Tan Spot ◽

Optimal Time ◽

Growth Stages ◽

Foliar Disease ◽

Yield Increase

Applications of propiconazole on spring wheat at various growth stages at Outlook, Saskatchewan showed that the optimal time to spray was between the extension of the flag leaf growth stage to the medium milk growth stage (G.S. 41–75). The maximum yield increase was about 10% on the soft white spring wheat, Fielder, compared to a 3% yield increase on the hard red spring wheat, Katepwa. The disease levels on penultimate leaves was reduced by spray applications between stem elongation and medium milk growth stages (G.S. 31–75). Most of the foliar disease was caused by Septoria spp. with S. nodorum being the most prevalent pathogen; Pyrenophora tritici-repentis was also present. Key words: Propiconazole, septoria leaf blotch, tan spot

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Response of Four Rice (Oryza sativa) Cultivars to Triclopyr

Weed Technology ◽

10.1017/s0890037x00043773 ◽

1998 ◽

Vol 12 (2) ◽

pp. 254-257 ◽

Cited By ~ 5

Author(s):

David L. Jordan ◽

Dearl E. Sanders ◽

Steven D. Linscombe ◽

Bill J. Williams

Keyword(s):

Growth Stage ◽

Leaf Growth ◽

Close Association ◽

Seedling Emergence ◽

Rice Grain ◽

Visible Injury ◽

Leaf Stage ◽

Stages Of Growth ◽

Standard Rate ◽

Made In

Experiments were conducted from 1994 through 1996 to determine the response of the rice cultivars ‘Bengal,’ ‘Cypress,’ ‘Jodon,’ and ‘Kaybonnet’ to triclopyr at 0.42 (standard rate) and 0.84 kg ai/ha applied postemergence at the four-leaf and panicle initiation stages of growth. Applications at the four-leaf stage were made in close association with fertilization and flood establishment, which often increases the potential for triclopyr to injure rice. Visible injury from triclopyr was slightly higher for the cultivar Jodon than for the cultivars Bengal, Cypress, or Kaybonnet. Injury was 3% or less when triclopyr at 0.42 kg/ha was applied at panicle initiation regardless of the cultivar. Triclopyr at 0.42 and 0.84 kg/ha applied at the four-leaf growth stage injured rice 7% and 22%, respectively. Triclopyr at 0.84 kg/ha applied at the four-leaf stage of growth delayed days from seedling emergence to seed head emergence and rice grain yield, irrespective of cultivar.

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Glyphosate-Resistant Horseweed (Conyza canadensis) in Mississippi

Weed Technology ◽

10.1614/wt-03-218r ◽

2004 ◽

Vol 18 (3) ◽

pp. 820-825 ◽

Cited By ~ 70

Author(s):

Clifford H. Koger ◽

Daniel H. Poston ◽

Robert M. Hayes ◽

Robert F. Montgomery

Keyword(s):

Growth Stage ◽

Leaf Growth ◽

Glyphosate Resistance ◽

Plant Size ◽

Growth Stages ◽

Conyza Canadensis ◽

Fold Level

Survival of horseweed in several glyphosate-tolerant cotton and soybean fields treated with glyphosate at recommended rates preplant and postemergence was observed in Mississippi and Tennessee in 2001 and 2002. Plants originating from seed collected from fields where horseweed escapes occurred in 2002 were grown in the greenhouse to the 5-leaf, 13- to 15-leaf, and 25- to 30-leaf growth stages and treated with the isopropylamine salt of glyphosate at 0, 0.025, 0.05, 0.1, 0.21, 0.42, 0.84, 1.68, 3.36, 6.72, and 13.44 kg ae/ha to determine if resistance to glyphosate existed in any biotype. All biotypes exhibited an 8- to 12-fold level of resistance to glyphosate when compared with a susceptible biotype. One resistant biotype from Mississippi was two- to fourfold more resistant than other resistant biotypes. Growth stage had little effect on level of glyphosate resistance. The glyphosate rate required to reduce biomass of glyphosate-resistant horseweed by 50% (GR50) increased from 0.14 to 2.2 kg/ha as plant size increased from the 5-leaf to 25- to 30-leaf growth stage. The GR50rate for the susceptible biotype increased from 0.02 to 0.2 kg/ha glyphosate. These results demonstrate that the difficult-to-control biotypes were resistant to glyphosate, that resistant biotypes could survive glyphosate rates of up to 6.72 kg/ha, and that plant size affected both resistant and susceptible biotypes in a similar manner.

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Response of grain sorghum to low rates of glufosinate and nicosulfuron

Weed Technology ◽

10.1017/wet.2020.125 ◽

2020 ◽

pp. 1-5

Author(s):

Hunter D. Bowman ◽

Tom Barber ◽

Jason K. Norsworthy ◽

Trenton L. Roberts ◽

Jason Kelley ◽

...

Keyword(s):

Growth Stage ◽

Yield Loss ◽

Field Tests ◽

Grain Sorghum ◽

Yield Reduction ◽

Growth Stages ◽

Yield Losses ◽

Visible Injury ◽

Proportional Rate ◽

Factor C

Abstract Previous research has shown that glufosinate and nicosulfuron at low rates can cause yield loss to grain sorghum. However, research has not been conducted to pinpoint the growth stage at which these herbicides are most injurious to grain sorghum. Therefore, field tests were conducted in 2016 and 2017 to determine the most sensitive growth stage for grain sorghum exposure to both glufosinate and nicosulfuron. Field test were designed with factor A being the herbicide applied (glufosinate or nicosulfuron). Factor B consisted of timing of herbicide application including V3, V8, flagleaf, heading, and soft dough stages. Factor C was glufosinate or nicosulfuron rate where a proportional rate of 656 g ai ha−1 of glufosinate and 35 g ai ha−1 of nicosulfuron was applied at 1/10×, 1/50×, and 1/250×. Visible injury, crop canopy heights (cm), and yield were reported as a percent of the nontreated. At the V3 growth stage visible injury of 32% from the 1/10× rate of glufosinate and 51% from the 1/10× rate of nicosulfuron was observed. This injury was reduced by 4 wk after application (WAA) and no yield loss occurred. Nicosulfuron was more injurious than glufosinate at a 1/10× and 1/50× rate when applied at the V8 and flagleaf growth stages resulting in death of the shoot, reduced heading, and yield. Yield losses from the 1/10× rate of nicosulfuron were observed from V8 through early heading and ranged from 41% to 96%. Yield losses from the 1/50× rate of nicosulfuron were 14% to 16% at the flagleaf and V8 growth stages respectively. The 1/10× rate of glufosinate caused 36% visible injury 2 WAA when applied at the flagleaf stage, which resulted in a 16% yield reduction. By 4 WAA visible injury from either herbicide at less than the 1/10× rate was not greater than 4%. Results indicate that injury can occur, but yield losses are more probable from low rates of nicosulfuron at V8 and flagleaf growth stages.

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Effect of Application Timing on Rhizome Johnsongrass (Sorghum halepense) Control with DPX-V9360

Weed Science ◽

10.1017/s0043174500056095 ◽

1990 ◽

Vol 38 (1) ◽

pp. 45-49 ◽

Cited By ~ 50

Author(s):

Timothy T. Obrigawitch ◽

William H. Kenyon ◽

Henry Kuratle

Keyword(s):

Growth Stage ◽

Field Studies ◽

Early Growth ◽

Effective Control ◽

Growth Stages ◽

Application Timing ◽

Leaf Surfaces ◽

Treated Leaf ◽

Plant Emergence ◽

Late Growth

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.

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