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.

Effects of Environment on the Toxicity of Glyphosate to Johnsongrass(Sorghum halepense)and Soybeans(Glycine max)

Weed Science ◽  
1978 ◽  
Vol 26 (6) ◽  
pp. 605-608 ◽  
Author(s):  
C. G. McWhorter ◽  
W. R. Azlin
Keyword(s):  
Soil Moisture ◽  
Glycine Max ◽  
Relative Humidity ◽  
Sorghum Halepense ◽  
Growth Chamber ◽  
Environmental Condition ◽  
Over The Top

Johnsongrass [Sorghum halepense(L.) Pers.] and soybeans [Glycine max(L.) Merr. ‘Lee 68’] were treated over-the-top with glyphosate [N-(phosphonomethyl)glycine] at 0.2 and 0.4 kg/ha with surfactant in spray solutions and 0.4 and 0.7 kg/ha without surfactant in spray solutions. Treated plants were maintained in the growth chamber for 2 weeks after treatment at 24, 29, and 35 C; 45 and 100% relative humidity (RH); and 12 and 20% soil moisture. Glyphosate at 0.4 kg/ha applied without surfactant controlled johnsongrass better at 100% than at 45% RH. Johnsongrass control was better with 20% than with 12% soil moisture. Averaged over all evironments, the order of glyphosate toxicity to johnsongrass at 0.4 and 0.7 kg/ha was 35 C > 29 C > 24 C. The environmental condition of 45% RH and 12% soil, moisture resulted in least johnsongrass control regardless of temperature. The order of glyphosate toxicity to soybeans when applied without surfactant was 24 C > 29 C > 35 C. Glyphosate applied without surfactant was more toxic to soybeans at 100% than at 45% RH and more toxic at 12% than at 20% soil moisture. Surfactant in spray solutions increased glyphosate toxicity to johnsongrass and soybeans.

Factors Affecting the Translocation of14C-Mefluidide in Soybeans(Glycine max), Common Cocklebur(Xanthium pensylvanicum), and Johnsongrass(Sorghum halepense)

Weed Science ◽  
1978 ◽  
Vol 26 (4) ◽  
pp. 382-388 ◽  
Author(s):  
C. G. McWhorter ◽  
G. D. Wills
Keyword(s):  
Glycine Max ◽  
Relative Humidity ◽  
Air Temperature ◽  
Environmental Conditions ◽  
Fold Increase ◽  
Constant Level ◽  
Sorghum Halepense ◽  
Factors Affecting ◽  
Treated Area ◽  
Lower Stem

Absorption and translocation of14C-mefluidide {N-[2,4-dimethyl-5-[[(trifluoromethyl)sulfonyl] amino] phenyl] acetamide} in soybeans [Glycine max(L.) Merr. ‘Lee 68’], common cocklebur(Xanthium pensylvanicumWallr.), and johnsongrass [Sorghum halepense(L.) Pers.] were evaluated under different environmental conditions with and without adjuvants. At a constant level of 40 or 100% relative humidity (RH), an increase in air temperature from 22 to 32 C resulted in a two- to three-fold increase in absorption and a four- to eight-fold increase in translocation of the14C in soybeans following application to the second trifoliolate. At constant 22 or 32 C an increase from 40 to 100% RH resulted in less than a two-fold increase in absorption or translocation of14C in soybeans. Autoradiograms indicated that movement of the14C was primarily into leaves above the treated area. Translocation of14C was significantly greater following application to the lower stem than to leaves. In common cocklebur,14C absorption increased about three-fold at both 22 and 32 C with an increase from 40 to 100% RH following application to the second alternate leaf. At both levels of RH, absorption and translocation increased as the temperature was increased from 22 to 32 C. The addition of an adjuvant increased absorption and translocation in common cocklebur under all environmental conditions. When14C-mefluidide was applied without an adjuvant to johnsongrass, absorption increased five- to six-fold at both 22 and 32 C as RH was increased from 40 to 100%. Translocation in johnsongrass was often affected less by variations in temperature than it was in soybeans or common cocklebur. The adjuvant increased absorption and translocation of the14C-label of mefluidide in johnsongrass. The14C-label accumulated primarily in the distal leaf of johnsongrass or in leaves above the treated area.

Johnsongrass (Sorghum halepense) Control in Soybeans (Glycine max) with Metriflufen

Weed Science ◽  
1981 ◽  
Vol 29 (3) ◽  
pp. 291-296 ◽  
Author(s):  
N. K. Rogers ◽  
R. E. Talbert ◽  
L. R. Oliver
Keyword(s):  
Glycine Max ◽  
Polyethylene Glycol ◽  
Methyl Ester ◽  
Field Experiments ◽  
Acid Methyl Ester ◽  
Sorghum Halepense ◽  
Propanoic Acid ◽  
Growth Stages ◽  
Stages Of Growth ◽  
Acid Methyl

Field experiments were conducted in 1977 and 1978 to determine susceptibility of rhizome johnsongrass [Sorghum halepense(L.) Pers.] to metriflufen3{2-[4-(4-trifluoromethylphenoxy) phenoxy] propanoic acid, methyl ester} applied as preplant-incorporated, preemergence, or postemergence treatments. Rates of metriflufen applied preplant incorporated and preemergence were 1.12, 2.24, and 3.36 kg/ha. Postemergence treatments consisted of 0.56, 1.12, and 1.68 kg/ha of metriflufen plus a non-ionic polyethylene glycol alkyl ester, each applied to johnsongrass at growth stages of 30 to 38 cm, 60 to 75 cm, and heading. Johnsongrass control increased with each increase in rate of soil-applied metriflufen with no differences in control between preplant incorporated and preemergence treatments. Johnsongrass density was reduced by increased rates of metriflufen, and 1978 soil-applied treatments reduced densities by 62%. Preplant-incorporated and preemergence applications of 3.36 kg/ha of metriflufen resulted in higher soybean yields than did the two lower rates. Results from treatments with trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) were similar to those with metriflufen at the same rate. Metriflufen applied to 30-to 38-cm johnsongrass reduced stands by 60% in 1978, but stands increased by 51 and 71% in plots treated at the 60- to 75-cm or heading stages of growth. Soybean tolerance to postemergence applications of metriflufen was excellent for all stages of growth and rates of metriflufen.

Effect of Temperature and Relative Humidity on Translocation of14C-Metriflufen in Johnsongrass (Sorghum halepense) and Soybean (Glycine max)

Weed Science ◽  
1981 ◽  
Vol 29 (1) ◽  
pp. 87-93 ◽  
Author(s):  
C. G. McWhorter
Keyword(s):  
Glycine Max ◽  
Relative Humidity ◽  
Air Temperature ◽  
Sorghum Halepense ◽  
Effect Of Temperature ◽  
The Third ◽  
Proximal Half ◽  
Treated Leaf ◽  
Soybean Plants ◽  
Soybean Leaves

Absorption and translocation of14C-metriflufen {2-[4-(4-trifluoromethylphenoxy)phenoxy] propanoic acid} in johnsongrass [Sorghum halepense(L.) Pers.] and soybean [Glycine max(L.) Merr. ‘Lee 68’] were evaluated under different environmental conditions. At 40% relative humidity (RH), an increase in air temperature from 18 to 35 C increased translocation of the14C in johnsongrass more than four-fold following application of14C-metriflufen to an area on the third leaf. At 100% RH, translocation of the14C was twice as great at 27 C as at 18 C, but translocation at 35 C was intermediate. In the combined analysis, translocation in johnsongrass was no better at 100% RH than at 40% RH. Regardless of level of RH, most translocation in johnsongrass at 18 and 27 C was toward the distal half of the treated leaf, but at 35 C most translocation was toward the proximal half of the treated leaf. Translocation of14C in soybeans increased more than four-fold as air temperature was increased from 18 C to 35 C, and more translocation occurred at 100% RH than at 40% RH at 18, 27, and 35 C. More than 80% of the14C-metriflufen remained in the treated leaf or on the surface of treated soybean leaves 48 h after application. More of the applied radioactivity was recovered from soybean plants than from johnsongrass plants.

Johnsongrass (Sorghum halepense) Control in Soybeans (Glycine max) with Metriflufen Applied Postemergence

Weed Science ◽  
1981 ◽  
Vol 29 (1) ◽  
pp. 139-143 ◽  
Author(s):  
W. R. Azlin ◽  
C. G. McWhorter
Keyword(s):  
Glycine Max ◽  
Sorghum Halepense ◽  
Propanoic Acid ◽  
Morphological Development ◽  
Over The Top

Over-the-top applications of metriflufen {2-[4-(4-trifluoromethylphenoxy)phenoxy] propanoic acid} at 0.6 to 2.2 kg/ha were highly toxic to johnsongrass [Sorghum halepense(L.) Pers.], but caused little visual injury to soybeans [Glycine max(L.) Merr. ‘Hill’]. Directed applications of metriflufen at 0.8 to 3.4 kg/ha provided equal and, in a few comparisons, better control of johnsongrass than did some rates of the herbicide applied over-the-top. Application of metriflufen at 0.8 and 1.7 kg/ha in directed sprays resulted in higher soybean yields than did comparable treatments applied over-the-top; yields of directed vs. over-the-top applications of metriflufen at 3.4 kg/ha resulted in statistically equal soybean yields. The research suggested that metriflufen entered johnsongrass plants through shoots and leaves and also through roots. Johnsongrass control was excellent following applications of metriflufen at 1.7 and 2.2 kg/ha without soybean injury and with greatly increased soybean yields. Results following over-the-top applications of metriflufen at 1.1 kg/ha to ‘Hill’, ‘Tracy’, ‘Lee 68’, ‘Bragg’, and ‘Forrest’ soybeans at three different stages of morphological development did not demonstrate any appreciable differences in the response of the cultivars to the herbicide.

Translocation of14C-Glyphosate in Soybeans (Glycine max) and Johnsongrass (Sorghum halepense)

Weed Science ◽  
1980 ◽  
Vol 28 (1) ◽  
pp. 113-118 ◽  
Author(s):  
C. G. McWhorter ◽  
T. N. Jordan ◽  
G. D. Wills
Keyword(s):  
Soil Moisture ◽  
Glycine Max ◽  
Relative Humidity ◽  
Air Temperature ◽  
Environmental Conditions ◽  
Moisture Absorption ◽  
Field Capacity ◽  
Sorghum Halepense ◽  
Total Absorption ◽  
Wilting Point

Absorption and translocation of14C-glyphosate [N-(phosphonomethyl)glycine] in johnsongrass [Sorghum halepense(L.) Pers.] and soybeans [Glycine max(L.) Merr. ‘Lee 68’] were evaluated under various environmental conditions. The toxicity of unlabeled glyphosate applied similarly was determined in soybeans under similar conditions. In johnsongrass, absorption of14C-glyphosate nearly doubled and translocation increased as air temperature increased from 24 to 35 C. Translocation in johnsongrass and soybeans was often greater at a relative humidity (RH) of 100% than at 45% and at a soil moisture level of 20% (field capacity) than at 12% (near the wilting point). In soybeans, absorption of14C-glyphosate increased about 100%, translocation increased between 100 and 1200%, and glyphosate toxicity increased more than 200% as temperature decreased from 35 to 24 C. At 35 C, translocation in soybeans was often greater at 20% than 12% soil moisture. Absorption of14C-glyphosate in soybeans was greater when the herbicide was applied to mature rather than immature leaves and stems, but the age of the treated tissue had less effect on14C translocation. The addition of surfactant plus KH2PO4to the treatment solution increased glyphosate absorption and translocation in soybeans, but addition of surfactant alone reduced translocation and addition of KH2PO4alone increased translocation. Injury to six soybean cultivars from application of unlabeled glyphosate at 0.4 kg/ha ranged from 37% to 95% while total absorption of14C-glyphosate into treated leaves of the same six cultivars ranged from 23% to 74% of the amount applied.

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.

Absorption, Translocation, and Metabolism of Diclofop by Sunflower (Helianthus annuus)

Weed Science ◽  
1983 ◽  
Vol 31 (5) ◽  
pp. 658-663 ◽  
Author(s):  
Greg R. Gillespie ◽  
Stephen D. Miller
Keyword(s):  
Methyl Ester ◽  
Relative Humidity ◽  
Helianthus Annuus ◽  
Propanoic Acid ◽  
Susceptible Line ◽  
Treated Leaf

The absorption, translocation, and metabolism of the methyl ester of diclofop {2-[4-(2,4-dichlorophenoxy)phenoxy] propanoic acid} by three sunflower (Helianthus annuusL.) lines was determined at 10 and 30C. Sunflower absorbed up to 27% more14C-diclofop while growing at 30C and 90 ± 5% relative humidity (RH) than at 10C and 40 ± 10% RH. Absorption of diclofop by susceptible (170415) and tolerant (296292 and Hybrid 894) sunflower lines was similar. Translocation of14C out of the treated sunflower leaf was greater at 30 (1.3%) than 10C (0.5%) 192 h after treatment when averaged across sunflower lines. The diclofop-susceptible line exported more of the applied diclofop from the treated leaf to the shoot portion below the treated leaf than the tolerant lines. Metabolism of diclofop was more rapid at 30 than 10C; however, the three sunflower lines metabolized diclofop similarly.

scholarly journals Evaluation of Microbial and Conventional Insecticides for Control of Larval European Corn Borer on Whorl Stage Corn, Clay Center, Ne, 1995

1996 ◽  
Vol 21 (1) ◽  
pp. 218-218
Author(s):  
Terry A. DeVries ◽  
Robert J. Wright
Keyword(s):  
Relative Humidity ◽  
Air Temperature ◽  
Environmental Conditions ◽  
Wind Direction ◽  
Growth Stage ◽  
Crop Growth ◽  
Larval Feeding ◽  
Egg Masses ◽  
Crop Growth Stage ◽  
Over The Top

Abstract Bacillus thuringiensis formulations and conventional insecticides were evaluated for efficacy against larval ECB in whorl stage field corn. All plots were planted without soil insecticide on 16 May. The experimental design was a RCB with 4 replicates. Each plot consisted of a single row, 40 ft long with a 30-inch row spacing. Plots were artificially infested with black-head stage ECB egg masses. The egg masses were deposited on wax paper discs, precounted in the laboratory and placed in the whorl of the infested plants on 30 Jun and 9 Jul. Crop growth stage was 37 and 57 inches extended leaf height, respectively. The same 5 plants in each treatment replicate were infested with 10 egg masses per infestation date. All granular insecticides were applied on 13 Jul. Environmental conditions were: air temperature, 81°F; wind direction and speed, west (250°) at 7 mph; relative humidity, 53%; and crop growth stage, 63 inches extended leaf height. A 10-inch Almaco smooth belt cone rear mounted on a Hahn Hi-Boy was used to apply preweighed amounts of the granular insecticides over the top of the plant whorls (G). Liquid insecticides were applied on 15 Jul. Environmental conditions were: air temperature, 74°F; wind direction and speed, east (80°) at 5 mph; relative humidity, 76%; and crop growth stage, 67 inches extended leaf height. A CO2 pressurized backpack sprayer at 30 psi was used to apply a band application over the top of the whorl (total spray volume = 1050 ml/plot) of premeasured amounts of the liquid insecticides (L). All infested plants were evaluated for ECB larval feeding damage on 14-15 Aug. The stalks of the infested plants were split lengthwise and the accumulated length and number of cavities in the 5 plants per treatment replicate were used to evaluate ECB larval damage. The percent infestation at evaluation was determined by the plants with a minimum of 1 cavity per treatment replicate. Data were analyzed by ANOVA for RCB with mean separation using DMRT.

The Effects of Fall Application of Glyphosate on Corn (Zea mays), Soybeans (Glycine max), and Johnsongrass (Sorghum halepense)

Weed Science ◽  
1981 ◽  
Vol 29 (2) ◽  
pp. 190-195 ◽  
Author(s):  
L. S. Jeffery ◽  
J. R. English ◽  
John Connell
Keyword(s):  
Zea Mays ◽  
Glycine Max ◽  
Seed Weight ◽  
Seedling Emergence ◽  
Moisture Level ◽  
Sorghum Halepense ◽  
Grain Moisture ◽  
Black Layer ◽  
Over The Top ◽  
Fall Application

Glyphosate [N-(phosphonomethyl)glycine] was applied at various stages of maturity to corn (Zea mays L. ‘Pioneer brand 3147’ and ‘Dekalb XL 394’), soybeans [Glycine max (L.) Merr. ‘Forrest’ and ‘Essex’], and johnsongrass [Sorghum halepense (L.) Pers.]. Glyphosate applied over-the-top of corn before the grain moisture level decreased to 30% (black layer will have been formed) caused various seed and subsequent progeny abnormalities. Depending on grain moisture level at the time of glyphosate application, seed weight was sometimes reduced and progeny seedling emergence, vigor, and weight were reduced. Also, abnormal seedlings, albino or straited, occurred. Glyphosate applied 2½ weeks or more before soybean maturity reduced seed weight, caused seed discoloration, and drastically reduced progeny seedling emergence, vigor, and weight. Glyphosate applied in September or early October controlled semimature johnsongrass. Later applications were less effective because of advanced senescence.

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