Effect of Date of Treatment of Johnsongrass (Sorghum halepense) on Soybean (Glycine max) Yields

1991 ◽  
Vol 5 (2) ◽  
pp. 381-386 ◽  
Author(s):  
Chester G. McWhorter
Keyword(s):  
Glycine Max ◽  
Field Study ◽  
Growing Season ◽  
Sorghum Halepense

In a 6-yr field study, johnsongrass growing in ‘Forrest’ soybeans for the entire growing season reduced yields 45% in the year with most rainfall and 69% in the year with least rainfall. Yields of soybeans grown without johnsongrass competition were 56% higher in the year with the most rainfall than in the year with least rainfall. Yields of soybeans with full-season competition were reduced 75% from those in the year with most rainfall as compared with those in the year with least rainfall. The number of weeks of johnsongrass competition required to significantly reduce soybean yields varied from 3 wk, in the year with least rainfall, to 8 wk, in the year with most rainfall. Nine applications of sethoxydim at 0.84 kg ai ha-1or haloxyfop at 0.55 kg ai ha-1each year did not reduce soybean growth or yields.

Selective Postemergence Herbicidal Control of Johnsongrass (Sorghum halepense) in Soybeans (Glycine max)

Weed Science ◽  
1980 ◽  
Vol 28 (5) ◽  
pp. 529-534 ◽  
Author(s):  
B. A. Swisher ◽  
George Kapusta
Keyword(s):  
Glycine Max ◽  
Field Research ◽  
Growing Season ◽  
Sorghum Halepense ◽  
Single Application ◽  
Boot Stage ◽  
Drought Conditions ◽  
Excellent Control ◽  
Growing Conditions

Two yr of field research were conducted to evaluate the efficacy of BAS-9021 {2-[1-(N-allyloxyamino)butylidene]-5,5-dimethyl-4-methoxycarbonylcyclohexane-1,3-dione, Na salt}, HOE 29152 {methyl 2-[4-(4-trifluoromethylphenoxy)phenoxy]propanoate}, and mefluidideN-[2,4-dimethyl-5-[[(trifluoromethyl)sulfonyl] amino] phenyl] acetamide as selective herbicides applied postemergence to johnsongrass [Sorghum halepense(L.) Pers.]. All three herbicides afforded 85% or greater control of rhizome johnsongrass in one experiment in 1977, where repeat applications were made and ideal growing conditions prevailed. HOE 29152 also afforded excellent control with a single application made at the boot stage of johnsongrass. In a second experiment in 1977, when drought conditions prevailed, HOE 29152 was the only herbicide that afforded 70% or greater control of the johnsongrass. Both BAS-9021 and mefluidide afforded less than 60% control of johnsongrass in the single 1978 experiment, when evaluated at the end of the season. This study also was subject to drought conditions throughout the growing season.

Mutual Influences of Seedling Johnsongrass (Sorghum halepense), Sicklepod (Cassia obtusifolia), and Soybean (Glycine max)

Weed Science ◽  
1990 ◽  
Vol 38 (2) ◽  
pp. 139-147 ◽  
Author(s):  
Barry D. Sims ◽  
Lawrence R. Oliver
Keyword(s):  
Glycine Max ◽  
Seed Production ◽  
Seed Yield ◽  
Dry Matter ◽  
Field Experiments ◽  
Growing Season ◽  
Growth And Yield ◽  
Sorghum Halepense ◽  
Competitive Effects ◽  
Matter Production

Field experiments were conducted to evaluate competitive effects of johnsongrass and sicklepod on growth and yield of irrigated and nonirrigated soybeans. Johnsongrass reduced soybean growth early in the growing season. Sicklepod was competitive all season, but competitiveness was greatest during the soybean reproductive stage. Soybean yields were reduced 31% by sicklepod, 14% by johnsongrass, and 36% by both weeds growing together. Nonirrigated soybeans yielded less than irrigated, but percent yield reductions were similar. Johnsongrass dry matter production and seed yield were reduced more than sicklepod by soybean interference. Soybean and sicklepod interference reduced johnsongrass seed production 73 to 95%. Johnsongrass produced 245 to 1238 seeds per plant when interfering with soybeans and sicklepod. Sicklepod seeds per plant were reduced 6 to 31% by johnsongrass interference and 47 to 75% by soybeans and soybeans plus johnsongrass.

Johnsongrass (Sorghum halepense) Control in Reduced-Tillage Systems

Weed Science ◽  
1986 ◽  
Vol 34 (5) ◽  
pp. 751-755 ◽  
Author(s):  
Mark A. Langemeier ◽  
William W. Witt
Keyword(s):  
Glycine Max ◽  
Production Systems ◽  
Growing Season ◽  
Sorghum Halepense ◽  
Reduced Tillage ◽  
Propanoic Acid ◽  
Tillage Systems ◽  
Soybean Yield ◽  
Herbicide Treatments

Fluchloralin [N-(2-chloroethyl)-2,6-dinitro-N-propyl-4-(trifluoromethyl)benzenamine], pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine], and trifluralin [2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzenamine] either alone or in combination with fluazifop {(±)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy] propanoic acid}, haloxyfop {2-[4-[[3-chloro-5-(trifluoromethyl)-2-pyridinyl] oxy] phenoxy] propanoic acid}, or sethoxydim {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one} were evaluated for johnsongrass [Sorghum halepense(L.) Pers. # SORHA] control in reduced-tillage soybean [Glycine max(L.) Merr.] production systems. Data obtained in 1983 and 1984 near Lexington and Princeton, KY, indicated that johnsongrass could be effectively controlled. A single discing before application of the soil-active herbicides usually had no effect on johnsongrass control. Johnsongrass control was primarily dependent on foliarly applied herbicides. Preplant-incorporated treatments did not provide adequate johnsongrass control when used alone. Johnsongrass panicle numbers recorded in September corresponded to visual evaluations of control recorded earlier in the growing season. Soybean yield with all herbicide treatments was greater than with a nontreated control and was closely associated with the degree of johnsongrass control.

Johnsongrass (Sorghum halepense) Control and Soil Moisture Relationships in No-Tillage, Doublecropped Soybeans (Glycine max)

Weed Science ◽  
1987 ◽  
Vol 35 (1) ◽  
pp. 108-114 ◽  
Author(s):  
Michael S. Defelice ◽  
William W. Witt ◽  
James R. Martin
Keyword(s):  
Soil Moisture ◽  
Glycine Max ◽  
Field Experiments ◽  
Growing Season ◽  
Sorghum Halepense ◽  
Propanoic Acid ◽  
No Tillage ◽  
Control Programs

Field experiments were conducted in Princeton, KY, in 1982, 1983, and 1984 to evaluate johnsongrass [Sorghum halepense(L.) Pers. # SORHA] control programs in no-tillage, doublecropped soybeans [Glycine max(L.) Merr. ‘Essex′]. Sequential applications of sethoxydim {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one} or fluazifop {(±)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl] oxy] phenoxy] propanoic acid} at 0.2 kg ai/ha provided 36 to 94% johnsongrass control. The lower control values from these treatments were obtained in the droughty 1983 growing season while the higher and acceptable control ratings were obtained in 1982 and 1984 when rainfall was more plentiful. Preplant applications that contained glyphosate [N-(phosphonomethyl)glycine] provided johnsongrass control greater than those containing paraquat (1,1′-dimethyl-4,4′-bypyridinium ion). Soybean yields and soil moisture were greater with preplant applications of glyphosate than with preplant applications of paraquat or foliar applications of sethoxydim, fluazifop, or glyphosate. Greatest yields were obtained with a combination of a preplant application of glyphosate and a postemergence application of sethoxydim.

Efficacy of Bentazon and MSMA as Affected by a Humic Acid-Type Polymeric Polyhydroxy Acid Adjuvant

Weed Science ◽  
1987 ◽  
Vol 35 (2) ◽  
pp. 237-242 ◽  
Author(s):  
Chester G. McWhorter ◽  
Gene D. Wills ◽  
Robert D. Wauchope
Keyword(s):  
Glycine Max ◽  
Humic Acid ◽  
Sorghum Halepense ◽  
Xanthium Strumarium ◽  
Amaranthus Hybridus ◽  
Acid Type ◽  
Monosodium Salt ◽  
Treated Leaf ◽  
Methylarsonic Acid ◽  
Smooth Pigweed

Foliar applications of14C-bentazon [3-(1-methylethyl)-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide] with PPA (polymeric polyhydroxy acid) at 1 or 2% (v/v) or nonoxynol (9.5 POE) [α-(p-nonylpheny1)-ω-hydroxypoly(oxyethylene)] at 1% (v/v) or mixtures of PPA and nonoxynol did not increase absorption or translocation of14C-bentazon in soybeans [Glycine max(L.) Merr. ‘Lee 74′] or common cocklebur (Xanthium strumariumL. # XANST). PPA alone at 1 to 2% (v/v) did not significantly affect absorption or translocation of14C-bentazon in smooth pigweed (Amaranthus hybridusL. # AMACH), but PPA with nonoxynol significantly increased translocation out of the treated leaf. Both PPA and nonoxynol decreased absorption and movement of14C-MSMA [monosodium salt of methylarsonic acid] out of the treated leaf of johnsongrass [Sorghum halepense(L.) Pers. # SORHA]. In greenhouse research, PPA at 0.25 and 0.5% (v/v) did not increase the level of control of common cocklebur obtained following postemergence applications of bentazon at 0.24 and 0.48 kg ai/ha. Similarly, PPA at 0.25 and 0.50% (v/v) did not increase the toxicity of MSMA at 0.3 and 0.6 kg ai/ha to either johnsongrass or common cocklebur.

Economic Comparison of Herbicides for Johnsongrass (Sorghum halepense) Control in Glyphosate-Tolerant Soybean (Glycine max)

1999 ◽  
Vol 13 (1) ◽  
pp. 30-36 ◽  
Author(s):  
Tammy L. Mckinley ◽  
Roland K. Roberts ◽  
Robert M. Hayes ◽  
Burton C. English
Keyword(s):  
Glycine Max ◽  
Land Management ◽  
Soybean Cultivar ◽  
Sorghum Halepense ◽  
Standard Cultivar ◽  
Economic Comparison

Returns to land, management, and risk were compared where glyphosate and four graminicides (quizalofop-P, fluazifop-P, sethoxydim, and clethodim) were used for johnsongrass control in glyphosate-tolerant soybean. In 1994 and 1995, returns to land, management, and risk for glyphosate-tolerant soybean were highest using glyphosate and lowest using sethoxydim. Break-even analysis showed that yields needed for equivalent returns with any nontransgenic soybean cultivar treated with any of the graminicides could range from 67 kg/ha less to 202 kg/ha more than the yields achieved with glyphosate. Based on this methodology, farmers would increase their return to land, management, and risk by planting glyphosate-tolerant soybean if expected yield from a standard cultivar treated with a standard herbicide program were less than the break-even yield.

Factors Affecting the Toxicity of Glyphosate Applied in the Recirculating Sprayer to Johnsongrass (Sorghum halepense)and Soybeans (Glycine max)

Weed Science ◽  
1980 ◽  
Vol 28 (1) ◽  
pp. 59-63 ◽  
Author(s):  
C. G. McWhorter ◽  
J. R. Williford
Keyword(s):  
Glycine Max ◽  
Field Experiments ◽  
Sorghum Halepense ◽  
Soybean Yield ◽  
Factors Affecting ◽  
Over The Top ◽  
Uniform Droplet ◽  
Better Than

Field experiments were conducted to determine optimum nozzle settings for applying glyphosate [N-(phosphonomethyl)glycine] in the recirculating sprayer for postemergence control of johnsongrass [Sorghum halepense(L.) Pers.] in soybeans [Glycine max(L.) Merr.]. Herbicide sprays were directed across the row to johnsongrass growing taller than soybeans in July and August. Herbicide not sprayed on johnsongrass was trapped and reused. Glyphosate at 0.56, 1.12, and 2.24 kg/ha applied with commercially available 25° spray nozzles provided johnsongrass control and soybean yields equal to those following applications with specialized uniform droplet nozzles. Glyphosate at 1.7 kg/ha applied in the recirculating sprayer using only one nozzle per row provided control of johnsongrass equal to or better than that from applications made with two, three, or four nozzles per row. Soybean yield following application of glyphosate at 1.7 kg/ha with one nozzle per row was equal to yields obtained following its application with two, three, or four nozzles per row, with or without surfactant at 0.1% in spray solutions. Soybean yield was higher with four nozzles per row than with one nozzle per row when 0.5% surfactant was included in spray solutions. Soybean injury was lower and yield was higher when glyphosate was applied in the recirculating sprayer rather than over-the-top with a conventional sprayer. Glyphosate at 1.12 kg/ha applied in the recirculating sprayer caused more injury to ‘Hill’ and ‘Bragg’ than to ‘Forrest’ or ‘Tracy’ soybeans.

Reactions of Several Crops to Dichlobenil

Weed Science ◽  
1971 ◽  
Vol 19 (6) ◽  
pp. 655-658 ◽  
Author(s):  
W. S. Hardcastle ◽  
R. E. Wilkinson
Keyword(s):  
Zea Mays ◽  
Glycine Max ◽  
Brassica Rapa ◽  
Clay Content ◽  
Cyperus Rotundus ◽  
Sorghum Halepense ◽  
Clay Loam ◽  
Purple Nutsedge ◽  
Crop Tolerance ◽  
Yellow Nutsedge

Tolerance of corn (Zea maysL. ‘B’), cotton (Gossypium hirsutumL. ‘coker 413’), soybean (Glycine maxMerr. ‘Hardee’), turnip (Brassica rapaL. ‘Tendergreen’), sorghum (Sorghum bicolor(L.) Moench. ‘Georgia 615’), purple nutsedge (Cyperus rotundusL.), yellow nutsedge (C. esculentusL.), and johnsongrass (Sorghum halepense(L.) Pers.) to 2,6-dichlorobenzonitrile (dichlobenil) at 0, 0.14, 0.28, 0.56, 1.12, and 2.24 kg/ha in four Georgia soils was determined. Equivalent rates of dichlobenil generally were more toxic in Davidson clay loam which had the highest clay content. Crop tolerance was corn > sorghum > cotton > turnip. Purple and yellow nutsedge tolerance to dichlobenil was intermediate to that of the crops tested. Johnsongrass response was equivalent to that shown by sorghum.

The Effect of Surfactant and Environment on the Toxicity of Metriflufen to Soybeans (Glycine max) and Johnsongrass (Sorghum halepense)

Weed Science ◽  
1979 ◽  
Vol 27 (6) ◽  
pp. 675-679 ◽  
Author(s):  
C. G. McWhorter
Keyword(s):  
Glycine Max ◽  
Methyl Ester ◽  
Relative Humidity ◽  
Air Temperature ◽  
Sorghum Halepense ◽  
Growth Chamber ◽  
Propanoic Acid ◽  
Herbicide Treatment ◽  
Over The Top

Metriflufen {2-[4-(4-trifluoromethylphenoxy)phenoxy] propanoic acid} was applied as the methyl ester at 0.28 and 0.56 kg/ha over-the-top to johnsongrass [Sorghum halepense(L.) Pers.] growing from rhizomes and to soybeans [Glycine max(L.) Merr. ‘Lee 68′]. After herbicide treatment, plants were grown in the growth chamber for 14 days at 16, 24, or 32 C with relative humidity (RH) at 40 or 100% at each air temperature. Johnsongrass was not controlled at 16 C regardless of metriflufen rate, RH, or the addition of nonoxynol [α-(p-nonylphenyl)-ω-hydroxypoly (oxyethylene)] (with 9.5 moles of polyoxyethylene) surfactant at 0.25 (g/100 ml) to spray solutions. Johnsongrass control at 24 C varied from 5 to 98%, with significantly better control at 100% than at 40% RH. The presence of surfactant increased johnsongrass control at 24 C and 40% RH but not at 24 C and 100% RH. Johnsongrass control at 32 C varied from 48 to 98%, and it was not increased by the presence of the surfactant, regardless of metriflufen rate or RH level. At 16 C metriflufen was more injurious to soybeans than to johnsongrass, but at 24 and 32 C johnsongrass control was significantly greater than soybean injury. The presence of surfactant in spray solutions generally did not increase soybean injury, regardless of temperature or RH level. These results suggest that metriflufen is most selective in controlling johnsongrass in soybeans at 24 C, especially under high RH.

Weed Control from Imazaquin and Metolachlor in No-till Soybeans (Glycine max)

Weed Science ◽  
1989 ◽  
Vol 37 (3) ◽  
pp. 392-399 ◽  
Author(s):  
Douglas D. Buhler ◽  
Virginia L. Werling
Keyword(s):  
Glycine Max ◽  
Weed Control ◽  
Untreated Control ◽  
Growing Season ◽  
Common Lambsquarters ◽  
No Till ◽  
Herbicide Treatments

In 1985, when weed densities were low (169 plants/m2in untreated control), imazaquin applied at 0.07 kg ai/ha early preplant controlled over 90% of all weeds before no-till planting of soybeans. In 1986 and 1987 when weed densities were higher (589 plants/m2in untreated control), addition of 1.1 kg ai/ha or more of metolachlor to imazaquin (0.07 kg/ha) before soybean planting controlled 95% or more of the grass weeds and 83% or more of the broadleaf weeds. Imazaquin plus metolachlor applied less than 1 day after soybean planting controlled less than 70% of the emerged weeds in 1986 and 1987; common lambsquarters was most tolerant. Early preplant treatments controlled more weeds throughout the growing season than treatments applied after planting. Splitting herbicide treatments among application times generally did not increase weed control compared to single applications. Early preplant applications resulted in higher soybean densities and taller soybeans 30 days after planting in 1986 and 1987 than treatments applied after planting. Soybean yields increased as weed control increased. Weed control and soybean yields were greater with early preplant treatments than paraquat plus alachlor plus metribuzin applied preemergence in 1986 and 1987. No carryover of imazaquin residue was detected through corn bioassay in the field.

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