Selectivity and Site of Action in Relation to Field Performance of Diclofop

Weed Science ◽  
1978 ◽  
Vol 26 (4) ◽  
pp. 352-358 ◽  
Author(s):  
P. N. P. Chow

In the greenhouse, the methyl ester of diclofop {2-[4-(2,4-diclorophenoxy)phenoxy] propanoic acid} as a postemergence application at 1.1 kg/ha ai did not affect the growth of the seven dicotyledonous crops with the exception of slight injury to yellow [white] mustard(Brassica hirtaMoench). Of the 13 gramineous species, corn(Zea maysL.), green foxtail [Setaria viridis(L.) Beauv.], oats(Avena sativaL.) wild oats(Avena fatuaL.), sorghum [Sorghum bicolor(L.) Moench], and timothy(Phleum pratenseL.) were rated highly susceptible, while barley(Hordeum vulgareL.), bromegrass [smooth brome](Bromus inermisLeyss.), durum wheat(Triticum durumDesf.), intermediate wheatgrass [Agropyron intermedium(Host) Beauv.], Russian wild ryegrass(Elymus junceusFisch.), triticale(X TriticosecaleWittmack), and wheat(Triticum aestivumL.) were relatively tolerant. Residue of diclofop in the soil partially controlled green foxtail which was seeded 3 weeks after herbicide application. Whether applied to wild oat shoots or roots, diclofop affected the entire plant, but growth reduction was great when applied to the shoots. Field results confirmed that foliar application gave the best weed control resulting in larger wheat yield increases. Wild oat control was greatly enhanced when an adjuvant was added to diclofop. This enhanced herbicidal activity appeared to have no effect on tolerance of barley at 0.8 kg/ha nor wheat at 1.1 kg/ha. Increasing the temperature from 12 to 28 C decreased wild oat control from diclofop at 1.1 kg/ha. In the field, diclofop at rates ranging from 0.8 to 2.2 kg/ha gave good control of wild oats and green foxtail resulting in significantly increased wheat yield compared to the checks. However, barley yield increases were obtained only at the rates from 0.8 to 1.1 kg/ha, indicating that at the higher rates barley was less tolerant than wheat. The 0.6 kg/ha rate with an adjuvant gave adequate weed control and significant barley yield increases over the checks, when evaluated on five barley cultivars.

1976 ◽  
Vol 56 (3) ◽  
pp. 705-713 ◽  
Author(s):  
P. N. P. CHOW

Five substituted dinitroaniline herbicides applied as preplanting soil incorporation treatments were evaluated in six field experiments in 1971, 1973, and 1974 for controlling green foxtail (Setaria viridis (L.) Beauv.) and wild oats (Avena fatua L.), and for tolerance of rapeseed (Brassica campestris L. and B. napus L.). In these experiments, A-820 (N-sec-butyl-4-tert-butyl-2,6-dinitroapiline) had the least activity, while dinitramine (N4,N4-diethyl-α,α,α,-trifluoro-3,5-dinitrotoluene-2,4-diamine) had the greatest activity, and in some tests injured germinating rapeseed, resulting in thinned stands and reduced yield. The activity of fluchloralin [N-(2-chloroethyl)-2,6-dinitro-N-propyl-4-(trifluoro-methyl) aniline] and profluralin [N(cyclopropyl-methyl)-α,α,α-trifluro-2, 6-dinitro-N-propyl-p-toluidine] was slightly weaker than that of trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine). All these herbicides gave good control of green foxtail and wild oats. In 1971, due to low populations of green foxtail, good weed control did not give rapeseed yield increases. In 1973, under normal climatic conditions, rapeseed yields were increased significantly when the application of dinitramine, fluchloralin, profluralin, and trifluralin controlled green foxtail and wild oats successfully. In 1974, under drought conditions, good weed control from four dinitroanilines and triallate [S-(2,3,3-trichloroallyl) diisopropylthiocarbamate] was not reflected in significant yield increases although profluralin gave a significant yield increase in one test. Disc soil incorporation (7.5–10 cm deep) of dinitramine and trifluralin gave slightly better weed control and higher, though not significant, yield increases than harrow soil incorporation (2.5–5 cm deep).


1981 ◽  
Vol 61 (2) ◽  
pp. 383-390 ◽  
Author(s):  
P. A. O’SULLIVAN

The phytotoxicity of barban, diclofop, difenzoquat and flamprop to wild oats (Avena fatua L.) was reduced when these herbicides were tank-mixed with propanil or propanil/MCPA. Green foxtail (Setaria viridis L.) control with propanil and propanil/MCPA was poor. Propanil/MCPA in a tank mixture with diclofop reduced diclofop control of green foxtail. Barban in a tank mixture with propanil increased green foxtail and Tartary buckwheat (Fagopyrum tataricum L. Beauv.) control compared to propanil alone. All other tank mixtures of propanil or propanil/MCPA with the wild oat herbicides had no significant effects on green foxtail control compared with propanil or propanil/MCPA. Tartary buckwheat control with propanil was good and the wild oat herbicides (except barban) in tank mixtures with propanil did not influence Tartary buckwheat control. There was an early chlorosis of wheat following treatments containing propanil or propanil/MCPA but this disappeared later in the growing season. Because of the reduced wild oat control with tank mixtures of propanil or propanil/MCPA with barban, diclofop, difenzoquat or flamprop, use of these mixtures for broadspectrum weed control is not practical.


Weed Science ◽  
1990 ◽  
Vol 38 (3) ◽  
pp. 267-272 ◽  
Author(s):  
Steven G. Russell ◽  
Thomas J. Monaco ◽  
Jerome B. Weber

Field trials were conducted in 1986 and 1987 to determine the effects of moisture on herbicidal activity of cinmethylin applied preemergence at 0.0, 0.3, 0.6, and 0.9 kg ai ha to both dry and moist sandy loam soil. Herbicide application was followed by varying amounts of irrigation. Weed species included velvetleaf, prickly sida, green foxtail, and barnyardgrass. When cinmethylin was applied to a moist soil or when 2.5 cm of irrigation was applied 5 days after cinmethylin application to a dry soil, overall weed control was reduced. Optimum weed control resulted from cinmethylin application to dry soil followed either by a 2.5-cm irrigation within 8 h or a 7.6-cm irrigation within 36 h.


1994 ◽  
Vol 8 (4) ◽  
pp. 673-678 ◽  
Author(s):  
David A. Wall

Field studies were undertaken in 1992 and 1993 to investigate the control of wild oat and green foxtail in flax with reduced rates of fluazifop-P and clethodim applied as tank-mixtures. Fluazifop-P plus clethodim at 50 + 18 g ai/ha controlled wild oat and green foxtail and was as effective as full rates of either herbicide applied alone. These rates represent a 20% reduction in total amount of active ingredient required to control wild oat and green foxtail. Application of fluazifop-P, and/or clethodim prior to the 3- to 4-leaf stage failed to control late emerging grass weeds. Application of graminicide mixtures at or after the 3- to 4-leaf stage controlled late emerging grass weeds and did not affect flax yield. When applied late, fluazifop-P at 175 g/ha tended to reduce flax yield, although weed control was acceptable and no foliar injury was observed following treatment. The efficacy of graminicide mixtures was reduced by addition of bromoxynil plus MCPA to the spray mix.


1973 ◽  
Vol 13 (60) ◽  
pp. 102
Author(s):  
TG Reeves ◽  
IS Smith ◽  
CL Tuohey

Results are presented from experiments in which di-allate and barban were used for wild oat control in wheat at 21 sites in the Wimmera and Northern Districts of Victoria. Both chemicals significantly reduced the wild oat densities at most sites but where direct comparisons were made di-allate was more effective than barban. Wheat yield response to applied herbicide was obtained in 17 of the 21 experiments. However, the yield response to barban application showed greater variation than the yield response to di-allate application. Barban was more effective, at all tested rates, n the Wimmera than it was-in the Northern District.


1976 ◽  
Vol 56 (3) ◽  
pp. 567-578 ◽  
Author(s):  
H. A. FRIESEN ◽  
P. A. O’SULLIVAN ◽  
W. H. VANDEN BORN

A series of field, growth chamber, and laboratory experiments showed that HOE 23408 [4-(2,4-dichlorophenoxy)-phenoxy propionic acid methyl ester] as a post-emergence herbicide provided selective control of wild oats (Avena fatua L.) and green foxtail (Seteria viridis L. Beauv.) in wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) equal to or better than barban (4-chloro-2-butynyl m-chlorocarbanilate) over a growth period extending from the 2- to 5-leaf stages in both weed species. Wheat was highly tolerant to HOE 23408 at all growth stages, while with barley there was some leaf mottling and suppression of both shoot and root development. The 6-row cultivars Gait, Bonanza and Conquest largely recovered from the effects, but the 2-row cultivar Betzes suffered significant yield reduction. HOE 23408 moved mainly in an acropetal direction when applied to different parts of the wild oats plant. Application made on or below the meristematic area of the stem apex caused necrosis and eventual death of the entire plant. Phytotoxicity following soil application was markedly less than with foliar application. Indications were that it was also more phytotoxic to the emerging weeds via shoot than via root contact. Although HOE 23408 is relatively insoluble in water, it leached to a limited extent in soils.


1964 ◽  
Vol 44 (4) ◽  
pp. 351-358 ◽  
Author(s):  
E. S. Molberg ◽  
H. A. Friesen ◽  
E. V. McCurdy ◽  
R. D. Dryden

Two years of field trials at a number of sites in Western Canada showed that selective control of wild oats in wheat with di-allate or tri-allate was feasible if the seed was planted 3 in. deep and the chemicals incorporated shallowly after seeding. The most reliable and practical means of achieving this placement of the chemical was by harrowing immediately after application. Harrowing twice resulted in slightly better wild oat control than harrowing once, but this did not increase crop yields. At one site, in 1962, under conditions of excessive moisture and late seeding, there was severe injury to wheat. However, even here the injury was less with the post-seeding than with the pre-seeding method. There was some evidence that wheat was more tolerant to tri-allate than di-allate. Pre-seeding incorporation with the disk gave slightly better weed control than post-seeding incorporation with a double harrow, but again differences were not great enough to affect yield.


1979 ◽  
Vol 59 (1) ◽  
pp. 275-277 ◽  
Author(s):  
JACINTA CROWLEY ◽  
G. N. PRENDEVILLE

Leakage of electrolytes from leaf discs of treated wild oats, barley and wheat plants was the criterion used to compare the effect of dichlofop methyl 2-{4-(2, 4-dichlorophenoxy) phenoxy} propionate on leaf-cell membrane permeability in these species. Leakage of electrolytes from wild oats and barley occurred within 12 h and increased up to 96 h following foliar application of the chemical at the rate of 0.112 kg/ha and 0.56 kg/ha, while in wheat it occurred only at the highest rate and after an interval of 48 h. Increases in leaf-cell membrane permeability occurred in each of the three species before the appearance of visible injury such as discoloration or necrotic areas in leaf tips.


1990 ◽  
Vol 4 (1) ◽  
pp. 97-104 ◽  
Author(s):  
Robert E. Blackshaw ◽  
Douglas A. Derksen ◽  
H.-Henning Muendel

Greenhouse and field studies were conducted to examine the interaction of sethoxydim or fluazifop-P tank mixed with chlorsulfuron or thiameturon for selective weed control in safflower. Under greenhouse conditions, the addition of chlorsulfuron to sethoxydim or fluazifop-P slightly improved the control of green foxtail above that achieved with either herbicide alone. Control of wild oat and wild mustard was similar with the tank mixes and each herbicide alone. In the field, control of wild oat with sethoxydim or fluazifop-P was not altered by adding chlorsulfuron or thiameturon in tank mixes. Similarly, control of common lambsquarters and wild mustard with chlorsulfuron or thiameturon was not affected by adding either sethoxydim or fluazifop-P in tank mixes. Plant height, date of flowering, seed yield, and quality data indicated that safflower tolerated these herbicides applied alone or in combination. Sethoxydim or fluazifop-P tank mixed with chlorsulfuron or thiameturon provide a postemergent alternative for selective control of grass and broadleaf weeds in safflower.


1989 ◽  
Vol 3 (2) ◽  
pp. 420-428 ◽  
Author(s):  
Robert E. Blackshaw

Studies were conducted to determine the usefulness of HOE-39866 (HOE-00661) in chemical fallow systems on the Canadian prairies. HOE-39866 at 0.5 to 1.0 kg ai/ha controlled Russian thistle, kochia, green foxtail, wild oats, and wheat comparable to paraquat, glyphosate, and glyphosate plus the isopropylamine salt of 2,4-D. However, control of barley with HOE-39866 was unacceptable. HOE-39866 was compatible in tank mixtures with ammonium sulfate, paraquat, chlorsulfuron, and metsulfuron. Ammonium sulfate improved weed control when HOE-39866 was applied at 0.25 kg/ha but not at 0.75 kg/ha. Adding paraquat at 0.07 to 0.21 kg ai/ha to HOE-39866 improved control of grass species over HOE-39866 alone. Adding chlorsulfuron and metsulfuron to HOE-39866 provided greater initial control of certain species as well as residual control of many weeds. HOE-39866 alone or in conjunction with other herbicides is an alternative to the herbicides used in chemical fallow systems.


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