Influence of Rainfall on the Phytotoxicity of Foliarly Applied 2,4-D

Weed Science ◽  
1981 ◽  
Vol 29 (3) ◽  
pp. 349-355 ◽  
Author(s):  
Richard Behrens ◽  
M. A. Elakkad

To study rainfall effects, simulated rainfall was applied to velvetleaf (Abutilon theophrastiMedic.), common lambsquarters (Chenopodium albumL.), wild mustard [Brassica kaber(DC.) L. C. Wheeler var.pinnatifida(Stokes) L. C. Wheeler], soybean [Glycine max(L.) Merr. ‘Hodgson’], and redroot pigweed (Amaranthus retroflexusL.) in greenhouse and field studies following foliar applications of the alkanolamine (AKA) salt or the butoxyethanol (BE) ester of 2,4-D [(2,4-dichlorophenoxy)acetic acid] at rates that induced equivalent levels of phytotoxicity. Simulated rainfall less than 1 min after herbicide treatment reduced the phytotoxicity of the AKA salt of 2,4-D to a much greater extent than that of the BE ester with effects ranging from elimination of all injury from the AKA salt to soybeans to no reduction in phytotoxicity of the BE ester to common lambsquarters. The quantity of simulated rainfall required to induce maximum reductions in phytotoxicity of the BE ester ranged from 1 mm on common lambsquarters to 15 mm on velvetleaf. The time interval from 2,4-D treatment until rainfall required to achieve a phytotoxic response level of 80% of that attained without rainfall varied greatly among plant species and herbicide formulations; ranging from less than 1 min for the BE ester on common lambsquarters to more than 24 h for the AKA salt on velvetleaf. The addition of an alkylarylpolyoxyethylene glycol surfactant to 2,4-D spray solutions reduced herbicide rates required to induce equivalent levels of phytotoxicity, increased losses in phytotoxicity of the BE ester caused by rainfall, and reduced the time interval from treatment to rainfall required to attain an equivalent level of phytotoxicity with the AKA salt.

Weed Science ◽  
1974 ◽  
Vol 22 (2) ◽  
pp. 136-142 ◽  
Author(s):  
Robert N. Andersen ◽  
William E. Lueschen ◽  
Dennis D. Warnes ◽  
Wallace W. Nelson

In field studies, bentazon [3-isopropyl-1H-2,1,3-benzothiadiazin-(4)3H-one 2,2-dioxide] was applied as postemergence sprays over the top of weeds and soybeans[Glycine max(L.) Merr.]. Bentazon at 0.84 to 1.68 kg/ha applied as an early postemergence treatment controlled wild mustard[Brassica kaber(DC.) L.C. Wheeler var.pinnatifida(Stokes) L.C. Wheeler], common ragweed (Ambrosia artemisiifoliaL.), velvetleaf (Abutilon theophrastiMedic.), Pennsylvania smartweed, (Polygonum pensylvanicumL.), common cocklebur (Xanthium pensylvanicumWallr.), and wild common sunflower (Helianthus annuusL.). Pigweeds (Amaranthussp.) were controlled by applications in the three true-leaf stage but became more resistant at later stages. Control of common lambsquarters (Chenopodium albumL.) was erratic. The optimum time for controlling weeds with bentazon was around the first trifoliolate stage of soybeans. Rainfall within several hours after treatment reduced weed control. Eight yield studies, two of which included eight cultivars, were conducted on weed-free soybeans. In none were yields reduced significantly by bentazon at 3.36 kg/ha (the highest rate studied). Eight yield studies were conducted on soybeans infested with common cocklebur or velvetleaf. Weed control was generally excellent with 0.84 kg/ha of bentazon. Where infestations were sufficient to reduce yields, bentazon treatments increased the yields to levels generally comparable with those of the handweeded checks. One exception was an application of bentazon to soybeans growing in a low area that was periodically flooded by heavy rains. In that experiment the benefit of controlling common cocklebur was offset by bentazon injury to the soybeans, and yields from the treated plots were about the same as those of the weedy check.


Weed Science ◽  
1979 ◽  
Vol 27 (6) ◽  
pp. 608-611 ◽  
Author(s):  
A. G. Ogg ◽  
S. Drake

Alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide] at 3.4 kg/ha, EPTC (S-ethyl dipropylthiocarbamate) + R-25788 (N,N-diallyl-2,2-dichloroacetamide) at 4.5 + 0.4 and 9.0 + 0.8 kg/ha, vernolate (S-propyl dipropylthiocarbamate) + R-25788 at 4.5 + 0.4 and 9.0 + 0.8 kg/ha, metolachlor [2-chloro N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide] at 1.7 and 3.4 kg/ha, and metolachlor + procyazine {2-[[4-chloro-6-(cyclopropylamino)1,3,5-triazine-2-yl] amino]-2-methylpropanenitrile} at 1.3 + 1.3 kg/ha were preplant incorporated. These herbicides controlled 95% or more of the barnyardgrass [Echinochloa crus-galli (L.) Beauv.], common lambsquarters (Chenopodium album L.), redroot pigweed (Amaranthus retroflexus L.), Powell amaranth (A. powellii S. Wats.), and yellow foxtail [Setaria lutescens (Weigel) Hubb.] without injuring sweetcorn (Zea mays L. ‘Golden Jubilee’) or reducing corn yields or quality. Similar results were obtained with preplant incorporated applications of butylate (S-ethyldiisobutylthiocarbamate) + R-25788 at 4.5 + 0.2 kg/ha followed by a postemergence application of the amine salt of 2,4-D [(2,4-dichlorophenoxy)acetic acid] at 0.6 kg/ha. Metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one] at 0.3 and 0.6 kg/ha and metribuzin + alachlor at 0.6 + 2.2 kg/ha applied preplant and incorporated reduced corn stands, primary ear production, and corn yields significantly. None of the herbicides significantly affected total sugars, reducing sugars, soluble solids, moisture content, or succulence of the corn.


HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 971D-972
Author(s):  
Harlene M. Hatterman-Valenti ◽  
Carrie E. Schumacher ◽  
Collin P. Auwarter ◽  
Paul E. Hendrickson

Field studies were conducted at Absaraka, Carrington, and Oakes, N.D., in 2005 to evaluate early season broadleaf weed control and onion (Allium cepa L.) injury with herbicides applied preemergence to the crop. DCPA is a common preemergence herbicide used in onion. However, DCPA can be uneconomical in most high-weed situations, or the usage may be restricted due to possible groundwater contamination. Potential substitutes evaluated were bromoxynil, dimethenamid-P, and pendimethalin. Main broadleaf weeds were redroot pigweed (Amaranthus retroflexus L.) and common lambsquarters (Chenopodium album L.). In general, all herbicides, except bromoxynil, provided acceptable broadleaf weed control 4 weeks after treatment. The highest herbicide rate provided greater weed control compared with the lowest rate for each herbicide. However, onion height was also reduced with the highest herbicide rate. In addition, the two highest rates of dimethenamid-P reduced the onion stand compared with the untreated. A postemergence application of bromoxynil + oxyfluorfen + pendimethalin to onion at the four- to five-leaf stage controlled the few broadleaf weeds that escaped the preemergence treatments and provided residual control of mid- and late-season germinating broadleaf weeds at two of the three locations. Intense germination of redroot pigweed during July at the Oakes location reduced onion yield with all treatments compared with the hand-weeded check. In contrast, total onion yields with all herbicide treatments except the high rate of dimethenamid-P were similar to the hand-weeded check at Absaraka and Carrington.


Weed Science ◽  
1985 ◽  
Vol 33 (3) ◽  
pp. 391-394 ◽  
Author(s):  
Monte D. Anderson ◽  
W. Eugene Arnold

The effect of rainfall on the performance of a tank mixture of desmedipham [ethylm-hydroxycarbanilate carbanilate(ester)] and phenmedipham (methylm-hydroxycarbanilatem-methylcarbanilate) applied postemergence to redroot pigweed (Amaranthus retroflexusL. ♯ AMARE), wild mustard (Sinapsis arvensisL. ♯ SINAR) and sunflower (Helianthus annuusL.) was evaluated in field studies. The occurrence of 1 mm of rain immediately after herbicide application significantly decreased the control of redroot pigweed and wild mustard. A rainfall quantity of 1 mm also reduced injury symptoms on sunflower. Simulating a 12.7-mm rain less than 18 h after desmedipham and phenmedipham application effectively reduced toxicity to redroot pigweed and sunflower. Toxicity to these two species increased at a lesser rate than for wild mustard as the time interval prior to rain was increased. A rain-free period of 6 h was predicted for near-maximum control of wild mustard with these herbicides.


2001 ◽  
Vol 81 (4) ◽  
pp. 881-884 ◽  
Author(s):  
P. D. Ominski ◽  
M. H. Entz

The influence of method (tillage vs. no-till) and time of year of alfalfa (Medicago sativa L.) termination on the population of naturally occurring weeds was assessed over three site-years in southern Manitoba. Termination method was found to be more important than timing. Populations of weeds such as green foxtail [Setaria viridis (L.) Beauv.], redroot pigweed (Amaranthus retroflexus L.), wild mustard [Brassica kaber (DC) L.C. Wheeler] and lamb’s quarters (Chenopodium album L.) were usually lower (P < 0.05) in the undisturbed (i.e., no-till) system, compared to where tillage was used. It was concluded that the combination of alfalfa in rotation and no-till management can provide significant weed control benefits to cropping systems. Key words: Weed ecology, no-till cropping, forages


Weed Science ◽  
1986 ◽  
Vol 34 (3) ◽  
pp. 440-443 ◽  
Author(s):  
E. Patrick Fuerst ◽  
Michael Barrett ◽  
Donald Penner

Various chemical treatments were evaluated over two growing seasons for control of triazine-resistant common lambsquarters (Chenopodium albumL. # CHEAL) and for control of a triazine-resistant infestation containing both redroot pigweed (Amaranthus retroflexusL. # AMARE) and Powell amaranth (A. powelliiS. Wats. # AMAPO). Atrazine [6-chloro-N-ethyl-N′-(1-methylethyl)-1,3,5-triazine-2,4-diamine], cyanazine {2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl] amino]-2-methylpropanenitrile}, and metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one] provided unsatisfactory control of these biotypes. Satisfactory control of common lambsquarters was obtained with preemergence applications of pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine] or dicamba (3,6-dichloro-2-methoxybenzoic acid), or postemergence applications of dicamba, bromoxynil (3,5-dibromo-4-hydroxybenzonitrile), or bentazon [3-(1-methylethyl)-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide]. Satisfactory control of pigweed was obtained with preemergence applications of alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide] or postemergence treatments of dicamba, bromoxynil, or 2,4-D [(2,4-dichlorophenoxy) acetic acid].


Weed Science ◽  
1973 ◽  
Vol 21 (1) ◽  
pp. 67-70 ◽  
Author(s):  
Stephen D. Miller ◽  
John D. Nalewaja

Weed control and sugarbeet (Beta vulgarisL.) injury from applications of methylm-hydroxycarbanilatem-methyl-carbanilate (phenmedipham) were influenced by additives, volume of additive, and species in both field and greenhouse experiments. Oils were more effective than the surfactant as additives to phenmedipham on green foxtail (Setaria virdis(L.) Beauv.), yellow foxtail (Setaria glauca(L.) Beauv.), redroot pigweed (Amaranthus retroflexusL.), or common lambsquarters (Chenopodium albumL.). Herbicidal activity of phenmedipham on kochia (Kochia scoparia(L.) Schrad.) or wild mustard (Brassica kaber(D.C.) L.C. Wheeler var.pinnatifida(Stokes) L.C. Wheeler) was not enhanced by any additive. Linseed oil (2.34 L/ha) enhanced the herbicidal activity of phenmedipham on green foxtail, yellow foxtail, and redroot pigweed more than petroleum (2.34 L/ha) or sunflower (Helianthus annusL.) oil (2.34 or 9.35 L/ha). However, linseed oil reduced the herbicidal activity of phenmedipham on kochia.


Weed Science ◽  
1981 ◽  
Vol 29 (1) ◽  
pp. 93-98 ◽  
Author(s):  
R. G. Wilson ◽  
F. N. Anderson

An electrical discharge system (EDS) was evaluated in field studies conducted in 1977 through 1979 in western Nebraska for its ability to control weed escapes in sugarbeets (Beta vulgarisL. ‘Mono Hy D2′). Nine weeks after sugarbeets were planted, kochia [Kochia scoparia(L.) Schrad.] had attained a height above sugarbeets sufficient for EDS treatment. Redroot pigweed (Amaranthus retroflexusL.) and common lambsquarters (Chenopodium albumL.) generally attained sufficient height above sugarbeets 11 and 13 weeks after sugarbeet planting. Sugarbeet root yields were reduced 40, 20, and 10% from competition by kochia, common lambsquarters, and redroot pigweed, respectively. Treatment of kochia, redroot pigweed, and common lambsquarters with EDS in some cases resulted in a reduction in weed height. The EDS treatments reduced the stand of all weeds 32, 39, and 47% for 1977, 1978, and 1979, respectively. Although the EDS treatments failed to kill many weeds, it did suppress the competitive ability of the three weeds to the extent that sugarbeet yields were higher in areas receiving EDS treatments than areas receiving no EDS treatment.


Weed Science ◽  
1979 ◽  
Vol 27 (5) ◽  
pp. 516-519 ◽  
Author(s):  
E. E. Schweizer

Response of weeds and sugarbeets (Beta vulgaris L. ‘Mono Hy D2′) to preplanting treatments of mixtures of cycloate (S-ethyl N-ethylthiocyclohexanecarbamate) and ethofumesate [(±)-2-ethoxy-2,3-dihydro-3,3-dimethyl-5-benzofuranyl methanesulfonate] was evaluated in five field studies. A mixture containing 1.7 kg/ha of each herbicide reduced the stand of common lambsquarters (Chenopodium album L.) 90%, green foxtail [Setaria viridis (L.) Beauv.] and yellow foxtail [Setaria lutescens (Weigel) Hubb.] 97 to 99%, kochia [Kochia scoparia (L.) Schrad.] 64 to 77%, and redroot pigweed (Amaranthus retroflexus L.) 82 to 99%. The response of weeds to preplanting applications of mixtures of cycloate and ethofumesate was independent of soil texture, whereas response of sugarbeets was dependent on soil texture. The herbicide mixtures significantly reduced the pre-thinning stand of sugarbeets and root and sucrose yields on two sandy loams, but not on a clay loam.


1995 ◽  
Vol 9 (3) ◽  
pp. 610-616 ◽  
Author(s):  
David A. Wall

Field studies were conducted from 1991 to 1994 to investigate the effectiveness of reduced rates of bentazon in tank-mixtures with imazethapyr, thifensulfuron, or HOE 075032 for improved control of redroot pigweed and common lambsquarters in navy bean. Tank-mixtures of bentazon at 600 g ai/ha plus imazethapyr at 25 g/ha or HOE 075032 at 5 to 15 g/ha controlled both redroot pigweed and common lambsquarters. These rates represent an approximate 45% reduction in total amount of active ingredient needed to control these weeds compared with full label rates. Bentazon tank-mixtures with 2 or 4 g/ha of thifensulfuron controlled these weeds but caused severe injury and delayed crop maturity. In greenhouse studies, the GR25for HOE 075032 in navy bean was > 90 g/ha, while in soybean it was 16 to 24 g/ha.


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