Interference and Critical Time of Removal of Hemp Sesbania (Sesbania exaltata) in Cotton (Gossypium hirsutum)

Hemp sesbania interference in cotton was investigated in the greenhouse and in a 2-yr field experiment at Stoneville, MS. In greenhouse experiments, cotton and hemp sesbania heights and plant dry weights (PDW) were not different in ratios of cotton to hemp sesbania of 4:0, 2:2, 1:3, and 0:4 at 3 and 5 wk after emergence (WAE). Hemp sesbania PDW were less for ratios of cotton to hemp sesbania of 3:1 when compared to hemp sesbania PDW of other ratios. Early season cotton seedling vigor and growth (0 to 28 DAP) were not affected by 32 000 hemp sesbania plants ha-1(3 plants m of row-1). Hemp sesbania plants were hand removed 28, 42, 56, 70, and 84 d after planting (DAP). White cotton blooms and yields were reduced when hemp sesbania plants were not removed by 70 DAP. Seed cotton yields were 2590, 2570, 2460, 2030, 1610, and 1070 kg ha-1for hemp sesbania removed at 28, 42, 46, 70 and 84 DAP or not removed, respectively. The critical period of weed control or removal of hemp sesbania in cotton is ≤62 DAP.

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Determination of the critical period of weed control in corn using a thermal basis

Pesquisa Agropecuária Brasileira ◽

10.1590/s0100-204x1999000200006 ◽

1999 ◽

Vol 34 (2) ◽

pp. 188-193 ◽

Cited By ~ 18

Author(s):

Francisco Bedmar ◽

Pablo Manetti ◽

Gloria Monterubbianesi

Keyword(s):

Weed Control ◽

Critical Period ◽

Zea Mays L ◽

Critical Time ◽

Field Studies ◽

Weed Biomass ◽

Logistic Equations ◽

Weed Interference ◽

Weed Removal

Field studies were conducted over 3 years in southeast Buenos Aires, Argentina, to determine the critical period of weed control in maize (Zea mays L.). The treatments consisted of two different periods of weed interference, a critical weed-free period, and a critical time of weed removal. The Gompertz and logistic equations were fitted to relative yields representing the critical weed-free and the critical time of weed removal, respectively. Accumulated thermal units were used to describe each period of weed-free or weed removal. The critical weed-free period and the critical time of weed removal ranged from 222 to 416 and 128 to 261 accumulated thermal units respectively, to prevent yield losses of 2.5%. Weed biomass proved to be inverse to the crop yield for all the years studied. When weeds competed with the crop from emergence, a large increase in weed biomass was achieved 10 days after crop emergence. However, few weed seedlings emerged and prospered after the 5-6 leaf maize stage (10-20 days after emergence).

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Hemp Sesbania (Sesbania exaltata) Competition in Soybeans (Glycine max)

Weed Science ◽

10.1017/s0043174500043496 ◽

1979 ◽

Vol 27 (1) ◽

pp. 58-64 ◽

Cited By ~ 39

Author(s):

C. G. McWhorter ◽

J. M. Anderson

Keyword(s):

Glycine Max ◽

Critical Period ◽

Soybean Seed ◽

Foreign Material ◽

Early Season ◽

Competitive Effects ◽

Sesbania Exaltata ◽

Sharkey Clay ◽

Hemp Sesbania

The competitive effects of hemp sesbania [Sesbania exaltata(Raf.) Cory] on soybeans [Glycine max(L.) Merr. ‘Forrest’] were studied on Sharkey clay for 2 yr. In full-season competition, hemp sesbania populations of 1,600, 3,200, 3,900, and 5,500 plants/ha did not reduce adjusted soybean yields, but populations of 8,100 to 129,200 plants/ha reduced yields 10 to 80%. Competition by hemp sesbania at 68,000 plants/ha for 1 to 4 weeks after soybean emergence reduced soybean yields 8% or less, whereas competition by the same population for 6, 8, and 10 weeks after soybean emergence reduced adjusted yields 18, 27, and 43%, respectively. Hemp sesbania populations of 3,200 plants/ha or more reduced the grade of harvested soybeans and populations of 5,500 plants/ha increased the level of foreign material found in seed samples taken at harvest. Hemp sesbania populations above 10,700 plants/ha increased the levels of damaged kernels and moisture in harvested soybean seed. Early-season control was required for highest soybean yields and total returns. The most critical period for control was 4 to 10 weeks after emergence of soybeans.

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Efficacy and Economics of Weed Control Methods in Cotton (Gossypium hirsutum)

Weed Science ◽

10.1017/s0043174500058574 ◽

1984 ◽

Vol 32 (1) ◽

pp. 95-100 ◽

Cited By ~ 28

Author(s):

Charles E. Snipes ◽

Robert H. Walker ◽

Ted Whitwell ◽

Gale A. Buchanan ◽

John A. McGuire ◽

...

Keyword(s):

Gossypium Hirsutum ◽

Effective Treatment ◽

Weed Control ◽

Control Treatment ◽

Control Methods ◽

Seed Cotton ◽

Weed Biomass ◽

Net Return

Four cultivations of cotton [Gossypium hirsutumL. ‘Stoneville 213′] alone failed to reduce green weed biomass or increase seed cotton yields above that of the no weed control treatment, and thus resulted in a negative net return (−200 to −450 $/ha) all 4 yr. Two cultivations plus two hand-hoeings reduced green weed biomass and increased seed cotton yields 3 out of 4 yr, thus a positive net return was produced for 3 yr ranging from 300 to 640 $/ha. Fluometuron [1,1-dimethyl-3-(α,α,α-trifluoro-m-tolyl)urea] alone was the most effective treatment in reducing green weed biomass and increasing seed cotton yields, and produced the highest net return, 280 to 420 $/ha for the 4-yr period. The addition of cultivation did not improve the fluometuron treatment. However, diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea)] required three supplementary cultivations to equal the single fluometuron treatment. Trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) plus three cultivations did not equal the single fluometuron treatment, although a positive net return was obtained every year. The addition of trifluralin to fluometuron also failed to improve weed control or net return over that of fluometuron alone.

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Control and Competitiveness of Johnsongrass (Sorghum halepense) in Cotton (Gossypium hirsutum)

Weed Science ◽

10.1017/s0043174500062123 ◽

1981 ◽

Vol 29 (3) ◽

pp. 356-359 ◽

Cited By ~ 14

Author(s):

P. E. Keeley ◽

R. J. Thullen

Keyword(s):

Gossypium Hirsutum ◽

Weed Control ◽

Field Experiments ◽

Yield Loss ◽

Sorghum Halepense ◽

Cotton Yield ◽

Yield Losses ◽

Seed Cotton ◽

Average Yield ◽

Labor Costs

Four field experiments conducted over 3 yr indicated that cultivation alone failed to prevent johnsongrass [Sorghum halepense(L.) Pers.] from reaching densities that severely reduced yields of cotton (Gossypium hirsutumL. ‘Acala SJ-2’). Density of johnsongrass in plots cultivated four times and hoed weekly for 8 weeks after emergence was reduced to 1 shoot/m2at harvest compared to 74 shoots/m2for plots that were only cultivated. In addition to a 60% average yield loss of seed cotton, yield losses ranging from 40 to 76%, ginning losses were also greater from cultivated than from hand-weeded plots. Compared to cultivated plots, supplementing cultivation with two postemergence applications of 3.0 kg/ha of DSMA (disodium methanearsonate) increased the average yield of cotton by 20% and reduced perennial johnsongrass densities by 64% at harvest. Although yields were improved by applying DSMA, they averaged 40% less than those of hand-weeded plots. The temporary weed control obtained with DSMA was profitable in terms of the additional lint and seed obtained, but insufficient cotton was produced to pay expenses for producing the crop by any of the methods of weed control. High labor costs for hoeing prevented this treatment from being profitable.

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Determination of the Critical Period for Weed Control in Corn

Weed Technology ◽

10.1614/wt-d-12-00059.1 ◽

2013 ◽

Vol 27 (1) ◽

pp. 63-71 ◽

Cited By ~ 11

Author(s):

Geoffroy Gantoli ◽

Victor Rueda Ayala ◽

Roland Gerhards

Keyword(s):

Weed Control ◽

Critical Period ◽

Field Experiments ◽

Critical Time ◽

Weed Competition ◽

Growth Stages ◽

Leaf Stage ◽

Time Period ◽

Weed Infestation ◽

Hand Weeding

Field experiments were conducted in western Atakora, Benin, to determine the critical time period of weed competition in hand-weeded corn. Weeds were removed until different crop growth stages and then allowed to reemerge. Other treatments began weed control at different growth stages (four-, eight-, and ten-leaf stages and flowering) and were maintained until harvest. One treatment was permanently kept weed-free and one treatment was uncontrolled until harvest. Yields without weed competition ranged from 2.8 to 3.4 t ha−1. As expected, yield loss increased with duration of weed infestation and ranged from 38 to 65% compared to permanent weed-free plots. In three out of four site-years, the critical period for weed control started at the four- to six-leaf stage and continued until ten-leaf stage or flowering of corn. Approximately four hand-weeding applications were required in this critical period of weed control.

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Determining the critical period for broadleaf weed control in high-yielding cotton using mungbean as a mimic weed

Weed Technology ◽

10.1017/wet.2020.38 ◽

2020 ◽

Vol 34 (5) ◽

pp. 689-698

Author(s):

Graham W. Charles ◽

Brian M. Sindel ◽

Annette L. Cowie ◽

Oliver G. G. Knox

Keyword(s):

Weed Control ◽

Critical Period ◽

Yield Loss ◽

Critical Time ◽

Field Studies ◽

Cotton Field ◽

Control Input ◽

Degree Days ◽

Weed Density ◽

The Relationship

AbstractResearch using the critical period for weed control (CPWC) has shown that high-yielding cotton crops are very sensitive to competition from grasses and large broadleaf weeds, but the CPWC has not been defined for smaller broadleaf weeds in Australian cotton. Field studies were conducted over five seasons from 2003 to 2015 to determine the CPWC for smaller broadleaf weeds, using mungbean as a mimic weed. Mungbean was planted at densities of 1, 3, 6, 15, 30, and 60 plants m−2 with or after cotton emergence and added and removed at approximately 0, 150, 300, 450, 600, 750, and 900 degree days of crop growth (GDD). Mungbean competed strongly with cotton, with season-long interference; 60 mungbean plants m−2 resulted in an 84% reduction in cotton yield. A dynamic CPWC function was developed for densities of 1 to 60 mungbean plants m−2 using extended Gompertz and exponential curves including weed density as a covariate. Using a 1% yield-loss threshold, the CPWC defined by these curves extended for the full growing season of the crop at all weed densities. The minimum yield loss from a single weed control input was 35% at the highest weed density of 60 mungbean plants m−2. The relationship for the critical time of weed removal was further improved by substituting weed biomass for weed density in the relationship.

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Weed Control in Soybeans (Glycine max) with Mefluidide Applied Postemergence

Weed Science ◽

10.1017/s0043174500043459 ◽

1979 ◽

Vol 27 (1) ◽

pp. 42-47 ◽

Cited By ~ 7

Author(s):

C. G. McWhorter ◽

W. L. Barrentine

Keyword(s):

Glycine Max ◽

Weed Control ◽

Sorghum Halepense ◽

Sesbania Exaltata ◽

Naphthylphthalamic Acid ◽

Hemp Sesbania ◽

Over The Top

Mefluidide {N-[2,4-dimethyl-5-[[(trifluoromethyl)sulfonyl]-amino] phenyl] acetamide} was applied postemergence in soybean [Glycine max (L.) Merr.] fields and its effectiveness in controlling johnsongrass [Sorghum halepense (L.) Pers.], hemp sesbania [Sesbania exaltata (Raf.) Cory], and common cocklebur (Xanthium pensylvanicum Wallr.) was evaluated. In plots treated preplanting with trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), mefluidide gave 95% johnsongrass control when it was applied postemergence (over-the-top without surfactant) once at 0.90 kg/ha or twice at 0.44 kg/ha. Directed sprays of mefluidide at 0.22 to 0.67 kg/ha without surfactant were more effective on johnsongrass than similar treatments applied over-the-top. When 0.5% (v/v) nonoxynol [α-(p-nonyl-phenyl)-ω-hydroxypoly (oxyethylene)] surfactant was added, mefluidide at 0.44 or 0.67 kg/ha applied as directed or over-the-top sprays provided 76 to 90% johnsongrass control. Mefluidide at 1.12 kg/ha plus nonoxynol surfactant, applied as a directed spray, was required to provide 81% control of hemp sesbania. Directed sprays containing mixtures of mefluidide at 0.28 kg/ha plus dinoseb (2-sec-butyl-4,6-dinitrophenol) at 2.2 kg/ha, or mefluidide at 0.28 kg/ha plus a 2:1 mixture of naptalam (N-1-naphthylphthalamic acid)/dinoseb at 4.7 L/ha, effectively controlled 40- to 60-cm-tall hemp sesbania. A single, directed spray of mefluidide at 0.56 kg/ha plus nonoxynol provided 92% common cocklebur control, and mixtures of mefluidide at 0.28 kg/ha plus dinoseb at 2.2 kg/ha or naptalam/dinoseb (a 2:1 mixture) at 4.7 L/ha increased control above that provided by either of the herbicides alone.

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Interference of Hemp Sesbania (Sesbania exaltata) with Cotton (Gossypium hirsutum)

Weed Science ◽

10.1017/s0043174500053741 ◽

1987 ◽

Vol 35 (3) ◽

pp. 314-318 ◽

Cited By ~ 17

Author(s):

Charles T. Bryson

Keyword(s):

Gossypium Hirsutum ◽

Plant Density ◽

Sandy Loam ◽

Soil Surface ◽

Light Penetration ◽

Interference Effects ◽

Cotton Boll ◽

Sesbania Exaltata ◽

Loam Soil ◽

Hemp Sesbania

Full-season interference effects of hemp sesbania [Sesbania exaltata(Raf.) Cory. # SEBEX] on cotton (Gossypium hirsutumL. 'Stoneville 213′) were investigated on a fine sandy loam soil for 3 yr at Stoneville, MS. Experimentally induced hemp sesbania populations of ≥ 3223 plants/ha significantly reduced cotton yields. Interference of hemp sesbania at 3223, 6456, 16 114, and 32 228 plants/ha, equivalent to 1, 2, 5, and 10 plants/3.3 m, reduced seed cotton yields by 19, 25, 45, and 53%, respectively. Cotton boll weights were reduced by 9% when hemp sesbania infestations were ≥ 16 114 plants/ha. Cotton plant density, seedling vigor, and initial cotton white blooms/ha at ≤75 days after planting (DAP) did not differ with varying densities of hemp sesbania. Cotton white blooms/ha were reduced by 32 228 hemp sesbania plants/ha by 77 DAP and by all weed densities by 98 DAP. Hemp sesbania height was equal to or greater than cotton height by 55 to 65 DAP. Light penetration at 1 m above the top of the cotton canopy was 36% less than in weed-free plots when hemp sesbania densities were ≤6446 plants/ha. Likewise, light penetration was reduced at the cotton canopy top and at midcanopy but was not less at the soil surface unless hemp sesbania densities were ≤ 32 223 plants/ha.

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Biological Control of Hemp Sesbania (Sesbania exaltata) Under Field Conditions withColletotrichum truncatumFormulated in an Invert Emulsion

Weed Science ◽

10.1017/s0043174500052243 ◽

1993 ◽

Vol 41 (3) ◽

pp. 497-500 ◽

Cited By ~ 45

Author(s):

C. Douglas Boyette ◽

Paul C. Quimby ◽

Charles T. Bryson ◽

Grant H. Egley ◽

Floyd E. Fulgham

Keyword(s):

Biological Control ◽

Weed Control ◽

Field Experiments ◽

Field Conditions ◽

Colletotrichum Truncatum ◽

Greenhouse Experiments ◽

Sesbania Exaltata ◽

Invert Emulsion ◽

Emulsion Formulation ◽

Hemp Sesbania

In greenhouse experiments, conidia ofColletotrichum truncatumapplied in an invert emulsion formulation controlled hemp sesbania 100% in the absence of a dew treatment. In field experiments, hemp sesbania control averaged 95 and 97% in 1989 and 1990, respectively, when this formulation was applied to hemp sesbania seedlings using tractor-mounted, air-assist nozzles. This level of weed control was comparable to that achieved from the herbicide acifluorfen. These results indicate thatC. truncatumhas excellent potential as a mycoherbicide for controlling hemp sesbania and that this potential can be augmented by formulating the pathogen as an invert emulsion.

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