Effect of Pendimethalin Formulation and Application Rate on Cotton Fruit Partitioning

2010 ◽  
Vol 24 (2) ◽  
pp. 77-84 ◽  
Author(s):  
Darrin M. Dodds ◽  
Daniel B. Reynolds ◽  
Jonathan A. Huff ◽  
J. Trenton Irby

Because of the development of glyphosate-resistant weed species, the lack of new herbicide chemistry, and the late-season emergence of annual grass species, efforts are underway to expand the use of currently available herbicides for use in cotton. Field studies were conducted in 2005 and 2006 to evaluate the effect of POST-applied pendimethalin formulation and application rate on cotton fruit partitioning. Oil- and water-based pendimethalin formulations as well asS-metolachlor were applied to cotton that had four true leaves. All pendimethalin andS-metolachlor applications included glyphosate for broad-spectrum weed control. Pendimethalin formulation and application rate had no effect on seed-cotton partitioning to horizontal fruiting zones, on second- or third-position horizontal fruiting sites, or on monopodial branches. However, increased seed-cotton partitioned to plants that had lost apical dominance was observed when the water-based pendimethalin formulation was applied at rates of 1.7 kg ai/ha and higher as well as when the oil-based pendimethalin formulation was applied at 3.3 kg ai/ha. Application of water-based pendimethalin at rates of 1.7 and 3.4 kg ai/ha and oil-based pendimethalin at rates of 0.8, 1.7, and 3.3 kg ai/ha resulted in reduced seed-cotton located at position 1 fruiting sites compared with the untreated check. POST application ofS-metolachlor had no effect on fruit partitioning to horizontal fruiting positions or vertical fruiting zones. Minor differences in seed-cotton partitioning to cohorts and individual fruiting nodes were observed from application of glyphosate, pendimethalin, andS-metolachlor. However, no differences in seed-cotton yield were observed from application of glyphosate,S-metolachlor, or pendimethalin, regardless of formulation or application rate. POST pendimethalin application at rates less than 1.7 kg ai/ha is relatively safe and should provide cotton producers with an additional tool for herbicide-resistant weeds and late-season annual grasses.

1998 ◽  
Vol 23 (1) ◽  
pp. 245-246
Author(s):  
T. G. Teague ◽  
N. P. Tugwell

Abstract Field studies were conducted at the Cotton Branch Experiment Station in Marianna, AR to evaluate the late-season control of TPB. Cotton was planted 12 May in 8-row (38-inch centers) wide by 70-ft-long plots with 10-ft alleys and separated by a 6.5-ft non-planted buffer. The treatments were arranged in a RCBD with 4 replications. The insecticides were applied 14 Aug using a 8-row CO2-charged hi-boy sprayer calibrated to deliver 9.5 gpa at 30 psi with TJ-60 8002 VS nozzles on 19-inch spacing. The numbers of TPB nymphs and adults per plot were estimated 4 DAT using 24 sweeps with one 18-inch net. Numbers of TPB 4 DAT were significantly reduced in all plots sprayed with insecticides compared with the untreated check. Control with the CS formu-lation of Karate was reduced compared with the EC formulation.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
W. James Grichar ◽  
Jack J. Rose ◽  
Peter A. Dotray ◽  
Todd A. Baughman ◽  
D. Ray Langham ◽  
...  

Growth chamber experiments were conducted to evaluate the response of sesame to PRE and POST applications of soil residual herbicides. PRE applications of acetochlor andS-metolachlor at 1.26 and 1.43 kg ai·ha−1showed little or no sesame injury (0 to 1%) 4 wks after herbicide treatments (WAT). POST treatments of acetochlor and trifluralin made 3 wks after planting (WAP) resulted in greater sesame injury (40%) compared to applications at bloom (18%). Field studies were conducted in Texas and Oklahoma during the 2014 and 2015 growing seasons to determine sesame response to clethodim, diuron, fluometuron, ethalfluralin, quizalofop-P, pendimethalin, pyroxasulfone, trifluralin, and trifloxysulfuron-sodium applied 2, 3, or 4 weeks after planting (WAP). Late-season sesame injury with the dinitroaniline herbicides consisted of a proliferation of primary branching at the upper nodes of the sesame plant (in the shape/form of a broom). Ethalfluralin and trifluralin caused more “brooming” effect than pendimethalin. Some yield reductions were noted with the dinitroaniline herbicides. Trifloxysulfuron-sodium caused the greatest injury (up to 97%) and resulted in yield reductions from the untreated check. Early-season diuron injury (leaf chlorosis and necrosis) decreased as application timing was delayed, and late-season injury was virtually nonexistent with only slight chlorosis (<4%) still apparent on the lower leaves. Sesame yield was not consistently affected by the diuron treatments. Fluometuron caused early-season injury (stunting/chlorosis), and a reduction of yield was observed at one location. Pyroxasulfone applied 2 WAP caused up to 25% sesame injury (stunting) but did not result in a yield reduction. Quizalofop-P caused slight injury (<5%) and no reduction in yield.


2006 ◽  
Vol 20 (3) ◽  
pp. 633-639 ◽  
Author(s):  
W. James Grichar

Field studies were conducted at four locations over a 2-year period to evaluate the utility of soil-applied herbicides and glyphosate timing for weed control and soybean yield. Pendimethalin,S-metolachlor plus metribuzin, and flufenacet plus metribuzin were applied pre-emergence (PRE) alone or followed by glyphosate applied early postemergence (EPOST), late postemergence (LPOST), or EPOST plus LPOST. Soil-applied herbicides or glyphosate alone failed to control (<45%) broadleaf signalgrass in 2003 due to late-season rainfall, which accounted for a late flush of growth. In 2004, soil-applied herbicides alone controlled 79–100% broadleaf signalgrass, whereas glyphosate alone or in combination with soil-applied herbicides controlled at least 99%. Barnyardgrass and tall waterhemp were controlled at least 87% with soil-applied herbicides alone and at least 95% when glyphosate was used alone or in combination with a soil-applied herbicide. Soybean yield varied, but at only one location did herbicide treatments produce higher yields than the untreated check. Under low to moderate weed pressure, the use of a soil-applied herbicide followed by glyphosate failed to increase net returns over soil-applied herbicides alone.


Weed Science ◽  
2008 ◽  
Vol 56 (5) ◽  
pp. 714-721 ◽  
Author(s):  
Amy E. Sweeney ◽  
Karen A. Renner ◽  
Carrie Laboski ◽  
Adam Davis

The timing of nitrogen (N) fertilizer application may influence germination, emergence, and competitiveness of weeds. Research was conducted to determine the influence of total inorganic soil N (Nit) on the germination, emergence, and growth of five weed species. In a greenhouse experiment, seed of five weed species were exposed to four levels of N, and seed germination was measured. In the field, urea ammonium nitrate (UAN 28%) was applied at multiple rates at three spring timings, and Nit, weed emergence, and growth were measured for 21 to 35 d after application (DAA). Germination of the four dicotyledonous and single grass species was not stimulated by 450 ppmw of N compared with the untreated control. In the field, Nitof 112 or 168 kg N ha−1, measured at 7 and 21 DAA, was always greater than Nitin the untreated control. The duration of the available N pulse in the upper 8 cm of soil was dependent on N application rate and timing. At 8 to 16 cm of soil depth, Nitwas greater when 168 kg N ha−1was applied compared with no N at 21 and 35 DAA in 2004. Emergence of common lambsquarters increased as N application rate increased for each application date in 2003, but not in 2004. Emergence of ladysthumb increased with N application rate for the April 15, 2003, date; emergence of giant foxtail increased with N application rate for the April 6, 2004, date. Weed biomass was always greater when 168 kg N ha−1was applied compared with no N, and at four of six N application dates, when 112 kg N ha−1was applied. This research shows that spring N fertilizer applications increase Nitand weed growth, but the influence of N on weed emergence is dependent on the weed species, seed source, and environmental conditions.


Weed Science ◽  
1995 ◽  
Vol 43 (2) ◽  
pp. 283-287
Author(s):  
Rafael Caballero ◽  
Carmen Barro ◽  
Carmen Alzueta ◽  
Mercedes Arauzo ◽  
Pedro J. Hernaiz

Field studies were conducted over 3 yr in central Spain to investigate the tolerance of common vetch and oat to some preemergence herbicides and their effects on weed control, forage yields, and botanical composition of the forage mixture. Pendimethalin was the only herbicide that injured common vetch. Pronamide and pronamide plus diuron injured oat by affecting plant emergence. Prevalent weed species were fumitory, henbit, and wild buckwheat. All herbicides provided more than 90% control of fumitory and most herbicides except pronamide provided more than 90% control of henbit relative to the untreated check. Wild buckwheat stands were reduced by isoxaben (68%), linuron (40%), prometryn (69%), pronamide (86%), and pronamide plus diuron (61%). More than 90% control of prostrate knotweed was achieved with isoxaben, pronamide, and terbutryn. Pronamide and pronamide plus diuron reduced forage yields and increased vetch in the forage. The untreated vetch and oat monocrop treatments showed the competitive advantage of oat over vetch and weedy species.


2004 ◽  
Vol 18 (4) ◽  
pp. 940-946 ◽  
Author(s):  
C. H. Tingle ◽  
J. M. Chandler

Field studies were conducted from 1998 through 2000 to determine the influence of crop rotation and level of herbicide system for johnsongrass, entireleaf morningglory, and smellmelon control in glyphosate-resistant cotton and corn. Three different crop rotation schedules were used including cotton–cotton–cotton, cotton–corn–cotton, and corn–cotton–corn. Herbicide systems involving various degrees of input levels (low, medium, and high) were compared with a conventional standard program. In 1998, weed control ranged from 80 to 95% for all herbicide systems when the rotation was corn–cotton–corn. In 1999 and 2000, the low-input herbicide system controlled entireleaf morningglory 76 to 78% late in the season. Decreased smellmelon control (78%) was also observed with the conventional standard during this same period. In the cotton–corn–cotton rotation, late-season entireleaf morningglory control decreased each year in the low-input system, regardless of crop. In 2000, late-season evaluations indicated lower weed control of all three species with the conventional standard program compared with the other input systems. Yield data from 2000 suggested that corn and seed cotton yields were influenced by crop rotation.


2007 ◽  
Vol 21 (1) ◽  
pp. 219-224 ◽  
Author(s):  
Shawn M. Hock ◽  
Stevan Z. Knezevic ◽  
William G. Johnson ◽  
Christy Sprague ◽  
Alex R. Martin

The ability to accurately estimate herbicide efficacy is critical for any decision-support system used in weed management. Recent efforts by weed scientists in the North Central United States to adopt WeedSOFT across a broad region have resulted in a number of regional research projects designed to assess and improve the predictive capability of WeedSOFT. Field studies were conducted from 2000 to 2002 in Nebraska, Missouri, and Illinois to evaluate herbicide-efficacy predictions made by WeedSOFT in two corn-row spacings. Following crop and weed emergence, input variables, such as weed densities and heights, were entered into WeedSOFT to generate a list of treatments ranked by predicted crop yields. The five treatments evaluated included those predicting highest crop-yield potential (recommended control treatment 1), a 10% yield reduction, a 20% yield reduction, a 10% yield reduction plus cultivation, and cultivation alone. These treatments were applied to corn grown in 38- and 76-cm rows. Generally, treatments applied in 38-cm rows had more accurate herbicide-efficacy predictions compared with 76-cm rows. WeedSOFT provided better control predictions for broadleaf than grass species. WeedSOFT provided excellent herbicide-efficacy predictions for the highest crop-yield potential, which indicates a good potential for practical use of this software for herbicide recommendations.


2008 ◽  
Vol 35 (1) ◽  
pp. 38-42 ◽  
Author(s):  
W. James Grichar

Abstract Field studies were conducted during the 2003 through 2005 growing seasons to evaluate soil-applied herbicides alone or in combination with postemergence (POST) herbicides for horse purslane, smellmelon, and Palmer amaranth control in peanut. Pendimethalin alone applied preplant incorporated (PPI) failed to control any of the three weeds (&lt; 70% control). Pendimethalin in combination with diclosulam, followed by imazethapyr applied preemergence (PRE), or followed by either acifluorfen or imazapic applied postemergence (POST) controlled all three weed species at least 80%. The soil-applied herbicides flumioxazin, imazethapyr, S-metolachlor, or dimethenamid applied alone failed to control horse purslane and smellmelon (&lt; 75%). Pendimethalin controlled Palmer amaranth less than 42% while flumioxazin at 0.07 kg/ha or dimethenamid at 1.12 kg/ha controlled Palmer amaranth less than 75%. Imazethapyr alone or pendimethalin applied PPI followed by imazethapyr applied PRE or imazapic applied POST controlled Palmer amaranth at least 99%. Pendimethalin applied PPI was present in all herbicide systems that yielded greater than the untreated check. In addition, 80% or greater control of at least 2 of 3 weed species resulted in the highest yields, with the exception of pendimethalin followed by acifluorfen.


2011 ◽  
Vol 25 (4) ◽  
pp. 526-534 ◽  
Author(s):  
Dilpreet S. Riar ◽  
Jason K. Norsworthy ◽  
Griff M. Griffith

Research was conducted at experimental research stations near Keiser and Marianna (Marianna-A), AR, in 2007, and in a grower's field near Marianna (Marianna-B), AR, in 2008, to compare herbicide programs, including POST application(s) of glyphosate/glufosinate alone or in combination with residual herbicides applied as PRE, mid-POST (MPOST), or layby POST-directed (PD) in enhanced glyphosate- and glufosinate-resistant cotton. Weed species evaluated included Palmer amaranth, pitted morningglory, hemp sesbania, barnyardgrass, and a mixture of large crabgrass and goosegrass. At Marianna-B, AR, the Palmer amaranth population was a mixture of glyphosate-resistant and -susceptible plants. For both cotton cultivars and at all locations, inclusion ofS-metolachlor plus fluometuron PRE increased weed control and/or decreased the number of glufosinate or glyphosate applications needed in-season. At Marianna-B, AR, PRE residual herbicides and/or glufosinate were required to control glyphosate-resistant Palmer amaranth. Addition of pyrithiobac to glufosinate or glyphosate did not increase weed control. A layby PD application of flumioxazin plus MSMA was required to increase late-season control of all weed species in POST glufosinate-only programs, but not in POST glyphosate-only programs. None of the programs caused > 5% injury to either cotton cultivar. Seed-cotton yield was similar in all herbicide programs at Keiser, AR, and Marianna-A, AR, except for the POST glyphosate-only program, which yielded less than the PRE followed by POST programs in glyphosate-resistant cotton at Keiser, AR. In general, PRE herbicides did not increase cotton yield but did improve early and late-season control of glyphosate-susceptible and -resistant weeds in both cotton cultivars.


2004 ◽  
Vol 18 (4) ◽  
pp. 887-892 ◽  
Author(s):  
Ryan F. Hasty ◽  
Christy L. Sprague ◽  
Aaron G. Hager

Field studies were conducted during 1999 and 2000 to compare weed control after fall and early-preplant (EPP) herbicide applications in no-till soybean. Three residual treatments (chlorimuron plus metribuzin, chlorimuron plus sulfentrazone, and metribuzin) were applied at two rates and timings (fall and 30 d EPP) either alone or in combination with glyphosate and 2,4-D. The addition of glyphosate and 2,4-D to fall-applied residual herbicides significantly increased control of common chickweed, annual bluegrass, cressleaf groundsel, and shepherd's-purse. The effect of application rate on weed control was species dependent. Fall-applied residual herbicides were comparable with EPP treatments with respect to winter annual weed control; however, at planting control of summer annual weed species with fall treatments was less consistent compared with EPP residual herbicides.


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