Control Of Green Foxtail Research Articles

Influence of Growth Stage and Broadleaf Herbicides on Tralkoxydim Activity

Experiments were conducted at the Lacombe and Lethbridge Research Stations to determine tralkoxydim activity at two leaf stages of green foxtail and wild oat and to determine tralkoxydim activity in tank mixtures with bromoxynil and thifensulfuron. Green foxtail and wild oat control was usually better when tralkoxydim was applied at the 2- to 3-leaf stage. However, tralkoxydim applied at the 4- to 5-leaf stage of the weeds often led to less weed topgrowth at harvest because later flushes of green foxtail and wild oat often occurred after the early applications. Nevertheless, wheat and barley yields usually indicated the importance of early weed removal. In greenhouse and field tank mixture studies, thifensulfuron antagonized tralkoxydim activity on green foxtail more than wild oat. Bromoxynil was less antagonistic than thifensulfuron, but significant reductions in green foxtail and wild oat control were detected in tralkoxydim tank mixtures with bromoxynil. In field studies, control of false cleavers with thifensulfuron or bromoxynil was not reduced in tank mixtures with tralkoxydim.

Effect of Application Factors on Efficacy of Fluazifop-P-Butyl in Flax

Field experiments were conducted to determine the efficacy of fluazifop-P-butyl for the control of green foxtail, wild oat, barley, and wheat in flax as influenced by spray nozzle orientation, time of day, and growth stage. Under drought conditions in 1988, control of wild oat, wheat, and barley with fluazifop-P-butyl was enhanced 75%, 53% and 78%, respectively, when nozzles were oriented to spray forward 45°. Under adequate soil moisture conditions enhancement of control was minimal. Green foxtail control improved when fluazifop-P-butyl was applied from 1700 to 2100 h, but time of day had no effect on control of wild oat, barley, or wheat. Fluazifop-P-butyl effectiveness was reduced when applied 4 d after flax emergence due to late emerging grass seedlings. Green foxtail was the most tolerant to fluazifop-P-butyl, whereas wild oat, wheat, and barley were the most susceptible.

DPX-V9360 Efficacy with Adjuvants and Environment

Adjuvants enhanced DPX-V9360 control of green foxtail in the greenhouse and field as follows: methylated sunflower oil > petroleum oil > nonionic surfactant WK > nonionic surfactant X-77. DPX-V9360 applied at rates that controlled weeds did not injure corn. Green foxtail control with DPX-V9360 decreased as the amount of simulated rainfall after application increased from 0 to 4 mm and control increased as a 2 mm simulated rainfall was delayed up to 24 h. The influence of simulated rainfall differed with adjuvants, but adjuvants did not overcome the lower green foxtail control with simulated rainfall. DPX-V9360 was more phytotoxic to green foxtail and redroot pigweed at 95 to 100% than 45 to 50% relative humidity and at 20 or 30 C than 10 C after treatment.

Soil Water Content Affects the Activity of Four Herbicides on Green Foxtail (Setaria viridis)

Low soil water content for 10 to 14 days before and 7 days after herbicide application reduced control of green foxtail with fenoxaprop, fluazifop-P, haloxyfop, and sethoxydim. Withholding irrigation for 10 to 14 days before herbicide application did not reduce control of green foxtail with normal use rates of herbicides if plots were irrigated at the time of application. Low soil water content reduced the activity of sethoxydim less than the other herbicides.

Influence of Temperature, Rainfall, Grass Species, and Growth Stage on Efficacy of Fluazifop

Field experiments were initiated to determine the efficacy of fluazifop as influenced by growth stage for green, yellow, and giant foxtail, large crabgrass, and Japanese millet. Additionally, the influence of air temperature and simulated rainfall on fluazifop efficacy for green foxtail and Japanese millet was determined by greenhouse and growth-room experiments. In both 1983 and 1984, fluazifop activity was reduced as the growth stage increased from 3- to 5- to 7-leaf for all species. Significant differences among species in susceptibility to fluazifop were evident with the descending order of tolerance: green foxtail > large crabgrass > yellow foxtail > giant foxtail > Japanese millet. Increasing the air temperature from 18 to 30 C reduced fluazifop control of green foxtail at herbicide rates less than 0.14 kg ai/ha but did not affect Japanese millet. A 1- to 2-h rain-free interval was required for optimum control of green foxtail and Japanese millet at 0.07 kg/ha fluazifop; the interval was reduced to 45 and 15 min, respectively, when fluazifop rates were 0.14 kg/ha. The longer rain-free interval required for optimum control of green foxtail compared to Japanese millet may reflect a slower rate of herbicide absorption in green foxtail.

Broadening weed control with imazamethabenz combinations

Broad-spectrum weed control by use of imazamethabenz (AC 222 293) in herbicide combinations was investigated in the greenhouse. Imazamethabenz at rates ranging from 0·1 to 0·4 kg a.i./ha effectively controlled wild oats ( Avena fatua L.). Additional control of redroot pigweed ( Amaranthus retroflexus L.) was achieved when imazamethabenz, plus octoxynol surfactant, was applied in combination with MCPA (amine or ester) or commercial MCPA mixtures (bromoxynil/MCPA and cyanazine/MCPA). Only inclusion of propanil/MCPA in the combination reduced wild-oat control by imazamethabenz at the lower rate (0·1 kg/ha). Control of green foxtail ( Setaria viridis (L.) Beauv.) was also obtained by use of fenoxaprop-ethyl in combination with imazamethabenz (plus octoxynol). Three-way mixtures of imazamethabenz (or plus octoxynol), MCPA alone or mixture, and fenoxaprop-ethyl may provide practical control of grass and broad-leaved weeds in the field.

Response of Monocot and Dicot Weed Species to Fresnel Lens Concentrated Solar Radiation

Fresnel lenses are used to concentrate solar radiation to a line or point. A linear Fresnel lens (0.91 by 1.52 m, 0.74-m focal length, 0.01- by 1.52-m line focus) was investigated as a method for weed control. Field experiments were conducted to assess the effect of Fresnel lens concentrated solar radiation at various exposure times, stages of plant growth, and soil surface moisture conditions. On a dry soil surface exposure times of 1 to 10 s at 290 C resulted in control of redroot pigweed from 100% for a 1-s exposure at the cotyledon stage to 89% for a 10-s exposure at the 10-leaf stage. Redroot pigweed and kochia control was similar at exposures of 3 to 10 s, but less for kochia at 1 and 2 s. Green foxtail control was less than that of kochia and redroot pigweed. Control was reduced on a moist compared to a dry soil surface. Concentrated solar radiation holds the greatest potential for control of small dicot weeds on a dry soil surface.

AMMONIUM SULPHATE ENHANCES CONTROL OF ANNUAL GRASS WEEDS IN CANOLA (Brassica campestris) WITH SETHOXYDIM

Field studies were conducted from 1984 to 1986 to determine the ability of ammonium sulphate to enhance the activity of sethoxydim on green foxtail (Setaria viridis (L.) Beauv.), wild oat (Avena fatua L.), volunteer wheat (Triticum aestivum L.) and volunteer barley (Hardeum vulgare L.) in canola (Brassica campestris L.). Considerable variation in control from year to year was observed. However, green foxtail control was 100% with 0.15 kg ha−1 of sethoxydim alone for the entire study. In 1984 and 1985, control of the other grass species was usually improved with the addition of 4.0 kg ha−1 of ammonium sulphate to 0.15 kg ha−1 of sethoxydim. In 1986, all grasses were completely killed. The high degree of weed control observed in 1986 was attributed to high temperatures at application time followed by more moderate temperatures, adequate relative humidity and rainfall which occurred the day of and the day after application. The lower level of control observed in 1985 was attributed to poor growing conditions including less rainfall and high temperatures in the days following application.Key words: Rapeseed, green foxtail, wild oat, volunteer cereals, adjuvants, environment

COMPARISON OF THE EFFICACY AND SOIL CONCENTRATIONS OF FALL- AND SPRING-APPLIED TRIFLURALIN IN FLAX

The efficacy of fall and spring treatments of trifluralin (α,α-trifluoro-2,6- dinitro-N, N-diproply-p-toluidine) applied to a sandy loam soil seeded to flax and the residual soil concentrations of trifluralin during the growing season were compared over 2 yr. Fall application of trifluralin at 1.12 kg/ha caused less crop injury and resulted in better green foxtail (Setaria viridis (L.) Beauv.) control than a spring application at 0.84 kg/ha. Initial soil concentrations were higher in plots treated in the fall at 1.12 kg/ha than in plots treated in the spring at 0.84 kg/ha. Six weeks after the experiments were seeded to flax and after harvest, more trifluralin persisted in the fall-treated plots. Calculated on the basis of the amount detected at the time of seeding, an average of 31 and 30% of the trifluralin persisted until after harvest in 1978 and 1979, respectively. In controlled environment studies in which yellow foxtail (Setaria glauca L. Beauv.) was seeded into soil collected six weeks after seeding, growth of the weed was reduced more in soil that was treated in the fall compared to the spring. In soil samples taken after harvest, growth of yellow foxtail was significantly reduced only in soil that had been treated the previous fall, with about a 50% reduction resulting from the 1.12-kg/ha rate and a 90% reduction occurring from the 2.24-kg/ha rate.Key words: Setaria viridis, flax tolerance, green foxtail control, trifluralin residues

CONTROL OF GREEN FOXTAIL IN CEREALS WITH AC 206,784, ALONE AND IN MIXTURES WITH TRIALLATE FOR WILD OATS

Control of green foxtail (Setaria viridis (L.) Beauv.) with AC 206,784 (2-chloro-N-isopropyl-2′,3′-acetoxylidide) was evaluated at four locations in western Canada. With soil applications, control was good at Lacombe in 1978 but poor at Lacombe and Regina during 1979. Control was good at Brandon and Scott in 1979. At two locations in 1979, soil surface (PE) applications were less effective for control of green foxtail than preplant-incorporated (PPI) treatments. PPI treatments to a depth of 5 cm were more effective than PPI to 10 cm. Soil applications of AC 206,784 did not control wild oats (Avena fatua L.) or injure wheat (Triticum aestivum L.) under field conditions but did provide suppression of these species under greenhouse conditions. Barley (Hordeum vulgare L.) tolerance to AC 206,784 was good. Treating the soil zone containing the emerging coleoptiles of green foxtail and wheat caused more injury that treating the root zone. Application of AC 206,784 as a tank-mixture with triallate did not affect its activity on green foxtail or influence triallate activity on wild oats. In field and greenhouse experiments, control of green foxtail with AC 206,784 applied at the two-leaf stage was variable; at the four-leaf stage it was poor.

RESPONSE OF VARIOUS BROAD-LEAVED WEEDS, AND TOLERANCE OF CEREALS, TO SOIL AND FOLIAR APPLICATIONS OF DPX-4189

DPX-4189 (2-chloro-N-[4-methoxy-6-methyl-1,3,5-triazin-2-yl) amino-carbonyl]-benzenesulfonamide), applied at relatively low rates to the soil (40–200 g/ha) or foliage (1–100 g/ha), generally provided excellent control of a variety of broad-leaved weeds, but poor control of green foxtail (Setaria viridis (L.) Beauv.). Wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) showed excellent tolerence. At equivalent dosages, foliar applications were more effective than soil applications in the year of application. With foliar applications, herbicidal activity on a variety of annual broad-leaved weed species was reduced with application at later (four to eight) versus earlier (two to four) leaf stages. Preplant incorporated (PPI) treatments were more effective for control of Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn.) than soil surface (PE) or preemergence incorporated (PEI) treatments. DPX-4189 provided weed control 8 mo after application at 20 g/ha in the greenhouse and 12 mo after application at 40 g/ha in the field. Canada thistle (Cirsium arvense (L.) Scop.) topgrowth control during the year of application, and control of regrowth 1 yr after application of DPX-4189 at 50 g/ha under field conditions was excellent. DPX-4189 may be transported from the leaves to the roots of Canada thistle, but soil residue carryover is probably more important for control during the second year. DPX-4189 was readily leached in a silt-loam soil.

INTERACTION BETWEEN DIFENZOQUAT AND PROPANIL OR PROPANIL/MCPA COMBINATIONS FOR WILD OAT AND GREEN FOXTAIL CONTROL IN BARLEY

Tank mixtures of difenzoquat and propanil or propanil/MCPA were evaluated for the control of wild oats (Avena factua L.) and green foxtail (Setaria viridis (L.) Beauv.) in a single spray operation. Both propanil and propanil/MCPA reduced the efficacy of difenzoquat on wild oats, but the efficacy of propanil or propanil/MCPA on green foxtail was not adversely affected. Barley (Hordeum vulgare L.) tolerance to the tank mixture was lower than to either of the components of the mixture. Uptake of 14C-difenzoquat by wild oats was reduced markedly in the presense of propanil and propanil/MCPA. If the herbicides were applied separately, the reduction in uptake depended on the extent of overlap of droplets of the two spray preparations on the leaf surface. There was no evidence of a chemical change in difenzoquat in the tank mixes, but the observed separation of components of the mixture soon after mixing may be partly responsible for the reduced uptake. We conclude that the marked inhibition of difenzoquat uptake in the presence of propanil or propanil/MCPA plays an important role in bringing about the antagonism between these herbicides.

CONTROL OF WILD OATS, GREEN FOXTAIL AND TARTARY BUCKWHEAT WITH MIXTURES OF PROPANIL OR PROPANIL/MCPA AND POSTEMERGENCE WILD OAT HERBICIDES

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.

PROPANIL FOR CONTROL OF GREEN FOXTAIL IN WHEAT AND BARLEY

In a series of field and greenhouse experiments, propanil (3′, 4′-dichloropropionalide) as a postemergent herbicide provided excellent control of green foxtail (Setaria viridis (L.) Beauv.) in wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.). Although some initial chlorosis occurred, wheat and barley recovered quickly and were considered tolerant to propanil at up to 1 kg/ha applied over a growth period extending from the 2- to 8-leaf stages of the green foxtail. Propanil at rates greater than 1 kg/ha resulted in considerable chlorosis and leaf tip burn, and although grain yields were not reduced, crop tolerance was visually assessed as unsatisfactory. Control of green foxtail was satisfactory with 1 kg/ha at the 2- to 4-leaf stages but not at later stages. Control was significantly better when the spray pressure at application was 310 kPa compared to 207 kPa. Analysis indicated that at the 2 and 4 kg/ha rate of propanil the residues in wheat and barley disappeared very quickly. At harvest, wheat grain contained 0.09 ppm of propanil.

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

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.

Herbicide Phytotoxicity, Movement, and Persistence in Asphalt

Emulsifiable cationic (CM-4,CRS-1H,CSS-1,CSS-1H) and anionic (SS-1H) asphalts mixed with bromacil (5-bromo-3sec-butyl-6-methyluracil) varied in their toxicity to green foxtail [Setaria viridis(L.) Beauv.] and velvetleaf (Abutilon theophrastiMedic). Bromacil, picloram (4-amino-3,5,6-trichloropicolinic acid), prometone [2,4-bis(isopropylamino)-6-methoxy-s-triazine], and tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N-dimethylurea} mixed with CRS-1H or CSS-1H gave excellent control of green foxtail and velvetleaf. In greenhouse experiments prometone leached readily from SS-1H while bromacil, picloram, and tebuthiuron leached the least. Leachate from picloram and tebuthiuron at 10,000 ppmw gave excellent control of green foxtail and velvetleaf. After leaching combinations of bromacil or tebuthiuron in SS-1H asphalt with 554 cm of water, enough herbicide still remained in the asphalt to control green foxtail and velvetleaf. Results indicate control would persist for 7 yr if annual rainfall was 76 cm or less and the herbicides were applied at 10,000 ppmw. Bromacil, picloram, prometone, and tebuthiuron moved laterally and resulted in more vegetation kill along a highway shoulder than on a level smooth brome (Bromus inermisLeyss.) area. Herbicide rates of 1,000 and 10,000 ppmw often resulted in excessive lateral movement and vegetation kill 2 yr after treatment. Combining herbicides with asphalt appears to be a feasible method of controlling weed growth, reducing lateral herbicide movement, and lengthening herbicide persistence.

EFFECTS OF COMBINED APPLICATIONS OF TRIALLATE OR TRIFLURALIN WITH SOLUTION NITROGEN ON WHEAT, WILD OATS AND GREEN FOXTAIL

Tank mixtures of solution nitrogen, triallate [S-(2,3,3-trichloroallyl)diisopropyl-thiocarbamate] and/or trifluralin [α,α,α,-trifluro-2, 6-dinitro-N, N-dipropyl-p-toluidine] were evaluated for the control of wild oats (Avena fatua L.) and/or green foxtail (Setaria viridis (L.) Beauv.). The response of wheat (Triticum aestivum L.) cv. Neepawa to solution nitrogen applied alone or in combination with triallate and/or trifluralin were evaluated. Good control of wild oats and green foxtail was obtained with a tank mixture of solution nitrogen, trifluralin at 1.38 kg/ha, and triallate at 1.65 kg/ha. Tank mixtures of triallate at 1.65 kg/ha with solution nitrogen controlled wild oats. Trifluralin at 1.38 kg/ha with solution nitrogen controlled wild oats and green foxtail. Control of green foxtail and wild oats resulted in increased wheat yields, higher nitrogen content in wheat grain, and a more efficient use of applied nitrogen fertilizer. The response of wheat to nitrogen was similar when nitrogen was applied in tank mixes with herbicides or with water to hand-weeded plots.

Asulam mixtures for weed control in flax

Summary:Five field experiments were conducted from 1972 to 1975 to evaluate weed control in flax (Linum usitatissimum L.) using post‐emergence treatments of asulam [methyl (4‐aminobenzenesulphonyl) carbamatel alone and in combination with other herbicides. The 14C‐asulam absorption by leaf segments and roots of glasshouse grown wild oats (Avena fatua L.) was also investigated. Asulam at 1.12 kg/ha gave good wild oat control and acceptable control of green foxtail (Setaria viridis (L.) Beauv.). However, wild oat control was poorer when asulam was combined with other herbicides: on a 3‐year average, as compared with asulam alone at equal rates, the asulam+MCPA mixture resulted in a greater antagonism and a significant 6% reduction in flax seed yield, whereas the asulam+bromoxynil/MCPA mixture gave the least antagonistic effect, improved broadleaf weed control and increased yield by 13%. In mixtures, the potassium salt of MCPA was more compatible with asulam for weed control than the amine form. Both leaf segments and roots of wild oats absorbed and distributed less 14C‐asulam from solutions containing MCPA than from those containing bromoxynil or bromoxynil/MCPA.

HOE 23408, A NEW SELECTIVE HERBICIDE FOR WILD OATS AND GREEN FOXTAIL IN WHEAT AND BARLEY

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.

DINITROANILINE HERBICIDES FOR GRASSY WEED CONTROL IN RAPESEED

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).