INFLUENCE OF STAGE OF APPLICATION OF GLYPHOSATE AND PARAQUAT WITH AND WITHOUT TWEEN 20 ON THE CONTROL OF ANNUAL GRASS SPECIES

1983 ◽  
Vol 63 (4) ◽  
pp. 1039-1046 ◽  
Author(s):  
P. A. O’SULLIVAN ◽  
J. T. O’DONOVAN ◽  
G. M. WEISS
Keyword(s):  
Triticum Aestivum L ◽  
Confidence Bands ◽  
Acceptable Level ◽  
Grass Species ◽  
Tween 20 ◽  
Annual Grass ◽  
Hordeum Vulgare L ◽  
Sorbitan Monolaurate ◽  
Leaf Stage ◽  
Wild Oats

Experiments were conducted in the field at Lacombe in 1980 and 1981 to determine the influence of leaf stage at application (one to six-leaf) on the effectiveness of glyphosate at 0.21 kg/ha and paraquat at 0.28 kg/ha with or without Tween 20 polyoxyethylene (20) sorbitan monolaurate (Tween is a trademark of ICI Amercas Inc.) for control of three annual grass species. Visual estimates of percent control were taken 3 wk after the last herbicide application. Curvilinear regression analysis of the data using linear plus quadratic effects produced a significant fit (P < 0.01) for determining percent control for a given leaf stage. Ninety percent control was selected as the minimum acceptable level, and the most restrictive leaf stage of application ranges to achieve this level of control over both years were determined. For glyphosate the ranges were 1 to >6-leaf for barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.) and 3 to >6-leaf for wild oats (Avena fatua L.). For glyphosate plus Tween 20, the ranges were 1 to >6-leaf for barley and wheat and 2 to >6-leaf for wild oats. For paraquat, the leaf stage ranges were 2 to 4.5-leaf for barley and wheat, and 2 to 5-leaf for oats (Avena sativa L.). For paraquat plus Tween 20, the ranges for barley, wheat and oats were 2- to 5-leaf, 2- to 4.5-leaf and 1.5- to 4.5-leaf, respectively. The data are presented so that any acceptable level of control may be selected, confidence bands [Formula: see text] may be included and the leaf stage range to obtain the selected level of control may be determined.Key words: Glyphosate, paraquat, surfactant, leaf stage, zero tillage

INFLUENCE OF VARIOUS HERBICIDES AND TWEEN 20 ON THE EFFECTIVENESS OF GLYPHOSATE

1980 ◽  
Vol 60 (3) ◽  
pp. 939-945 ◽  
Author(s):  
P. A. O’SULLIVAN ◽  
J. T. O’DONOVAN
Keyword(s):  
Brassica Campestris ◽  
Triticum Aestivum L ◽  
Grass Species ◽  
Tween 20 ◽  
Annual Grass ◽  
Hordeum Vulgare L ◽  
Initial Reduction ◽  
Annual Grasses ◽  
Excellent Control ◽  
High Degree

Glyphosate (N-phosphonomethyl glycine) at 0.21 kg/ha applied at the 4-leaf stage provided excellent control of wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), oats (Avena sativa L.), and rape (Brassica campestris L.). Tank mixtures of 0.21 kg/ha glyphosate with bromoxynil/MCPA, bromoxynil, MCPA, 2,4-D, or dicamba resulted in an initial reduction (antagonism) of glyphosate activity on the grass species at 5 days after treatment. At 34 days after treatment, the early differences had disappeared and grass kill was virtually complete with all treatments containing glyphosate. The early reduction in annual grass control with these mixtures was overcome in most cases by addition of Tween 20. Dicamba at 0.11 kg/ha, applied sequentially at various times in relation to glyphosate at 0.21 kg/ha, provided significantly increased early control of annual grasses over that obtained with glyphosate alone. Glyphosate combinations with bromoxynil/MCPA, bromoxynil, MCPA, 2,4-D, or dicamba were as effective or more effective for rape control than the various broad-leaved herbicides applied alone. Rape showed a high degree of tolerance to dicamba.

INFLUENCE OF SEVERAL HERBICIDES FOR BROAD-LEAVED WEED CONTROL AND TWEEN 20 ON THE PHYTOTOXICITY OF PARAQUAT

1982 ◽  
Vol 62 (2) ◽  
pp. 445-452 ◽  
Author(s):  
P. A. O’SULLIVAN ◽  
J. T. O’DONOVAN
Keyword(s):  
Weed Control ◽  
Avena Sativa ◽  
Brassica Campestris ◽  
Triticum Aestivum L ◽  
Grass Species ◽  
Tween 20 ◽  
Annual Grass ◽  
Hordeum Vulgare L ◽  
Excellent Control ◽  
Permanent Reduction

Paraquat at 0.28 kg/ha provided excellent control of barley (Hordeum vulgare L.), wheat (Triticum aestivum L.) and oats Avena sativa L.) when applied at the four-leaf stage of growth. Applications of paraquat in tank mixtures with ester formulations of 2,4-D, MCPA, bromoxynil or bromoxynil/MCPA did not affect paraquat activity on the grasses. Tank mixtures of paraquat with dimethylamine formulations of 2,4-D and MCPA resulted in a permanent reduction of paraquat activity on the annual grass species. Sequential applications of 2,4-D amine or MCPA amine in relation to paraquat did not reduce paraquat activity on the annual grass species. Control of rapeseed (Brassica campestris L.) with 0.28 kg/ha paraquat was not acceptable and was variable. However, excellent control of rapeseed was obtained when one of several herbicides for broad-leaved weed control were combined with paraquat.

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

1982 ◽  
Vol 62 (4) ◽  
pp. 995-1001
Author(s):  
P. A. O’SULLIVAN ◽  
P. N. P. CHOW ◽  
J. H. HUNTER ◽  
K. J. KIRKLAND
Keyword(s):  
Root Zone ◽  
Soil Surface ◽  
Triticum Aestivum L ◽  
Western Canada ◽  
Setaria Viridis ◽  
Hordeum Vulgare L ◽  
Leaf Stage ◽  
Wild Oats ◽  
Soil Zone ◽  
Green Foxtail

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.

RELATIONSHIP BETWEEN LEAF STAGES OF CEREAL CROPS OR GRASSY WEEDS AND DAYS FROM SEEDING

1980 ◽  
Vol 60 (4) ◽  
pp. 1263-1267
Author(s):  
D.A. DEW
Keyword(s):  
Flag Leaf ◽  
Triticum Aestivum L ◽  
Cereal Crops ◽  
Setaria Viridis ◽  
Hordeum Vulgare L ◽  
Leaf Stage ◽  
Wild Oats ◽  
Green Foxtail ◽  
Spring Cereals ◽  
Stage Development

Rate of leaf development was studied on three spring cereals and two grassy weeds for 4 yr. Plots were seeded on two dates in each of 3 yr and on only one in the fourth year. Leaf stage development was determined three times a week from emergence to flag leaf stage. The time to advance from one leaf stage to the next was found to be: 6.3, 5.1, 5.2, 5.8 and 5.7 days, respectively, for wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), oats (Avena sativa L.), wild oats (Avena fatua L.), and green foxtail (Setaria viridis (L.) Beauv.). Time from seeding to emergence was found to be reasonably consistent within species and an estimate is given for the number of days from seeding when the spring cereals can be expected to reach a given leaf stage.

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

1976 ◽  
Vol 56 (3) ◽  
pp. 567-578 ◽  
Author(s):  
H. A. FRIESEN ◽  
P. A. O’SULLIVAN ◽  
W. H. VANDEN BORN
Keyword(s):  
Foliar Application ◽  
Acid Methyl Ester ◽  
Growth Period ◽  
Triticum Aestivum L ◽  
Yield Reduction ◽  
Growth Stages ◽  
Weed Species ◽  
Hordeum Vulgare L ◽  
Wild Oats ◽  
Green Foxtail

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.

EFFECTS OF POST-EMERGENCE WILD OAT HERBICIDES ON THE TRANSPIRATION OF WILD OATS

1977 ◽  
Vol 57 (1) ◽  
pp. 127-132 ◽  
Author(s):  
M. P. SHARMA ◽  
W. H. VANDEN BORN ◽  
D. K. McBEATH
Keyword(s):  
Triticum Aestivum ◽  
Acid Methyl Ester ◽  
Dry Weight ◽  
Triticum Aestivum L ◽  
Avena Fatua ◽  
Wild Oat ◽  
Hordeum Vulgare L ◽  
Wild Oats ◽  
Acid Methyl ◽  
Foliar Treatment

Transpiration of wild oat (Avena fatua L.) plants was markedly reduced after foliar treatment with barban (4-chloro-2-butynyl-m-chlorocarbanilate), asulam (methyl sulfanylcarbamate), dichlorfop methyl (4-(2′,4′-dichlorophenoxy)-phenoxypropionic acid methyl ester), difenzoquat (1,2-dimethyl-3,5-diphenyl-1 H-pyrazolium) or benzoylprop ethyl (ethyl-N-benzoyl-N(3,4-dichlorophenyl)-2-aminopropionate). Suppression of transpiration increased with increasing herbicide rates. Difenzoquat and dichlorfop methyl at 1.12 kg/ha reduced transpiration by more than 50% within 2 days after spraying. Barban, asulam and benzoylprop ethyl did not reduce transpiration to this level until about 12 days after spraying. When wild oats and barley (Hordeum vulgare L.) or wheat (Triticum aestivum L.) were grown together, removal of the weed with these herbicides resulted in significantly heavier barley and wheat plants with more tillers per plant than in the untreated control. The earlier removal of wild oat competition with dichlorfop methyl and difenzoquat treatments resulted in the production of more dry weight and culms per plant of barley and wheat than with the slower-acting barban and benzoylprop ethyl.

The tolerance of spring wheat and barley to post-emergence harrowing

1992 ◽  
Vol 72 (4) ◽  
pp. 1331-1336 ◽  
Author(s):  
Guy P. Lafond ◽  
Kevin H. Kattler
Keyword(s):  
Spring Wheat ◽  
Ammonium Phosphate ◽  
Phosphate Fertilizer ◽  
Triticum Aestivum L ◽  
Organic Production ◽  
Cultural Control ◽  
Hordeum Vulgare L ◽  
Leaf Stage ◽  
Alternative Weed Control ◽  
Surface Crust

Use of herbicides in certain situations may not always be appropriate for controlling weeds because of cost or improper crop stage. Crops produced without the use of herbicides require alternative weed-control methods. A 12-yr study was conducted at Indian Head, Saskatchewan, under weed-free conditions to determine the tolerance of spring wheat and barley, with or without ammonium phosphate fertilizer placed with the seed, to post-emergence harrowing. Barley and spring wheat harrowed with diamond-toothed harrows as it was emerging, at the 1.5-leaf stage, or at the 2.5-leaf stage in the absence of weeds produced yields similar to those from a non-harrowed check when averaged across years and fertilizer treatments. Ammonium phosphate fertilizer placed with the seed significantly increased yields of both barley and spring wheat (averaged across years and harrowing treatments) but did not alter the tolerance of barley and spring wheat to post-emergent harrowing. This implies that a delay between seeding and harrowing due to rain or using a harrowing operation to break a surface crust should not result in yield losses for barley and spring wheat.Key words: Triticum aestivum L., Hordeum vulgare L., cultural control, organic production phosphorus

EFFECTS OF A BRIEF MAGNETIC EXPOSURE ON CEREAL GERMINATION AND SEEDLING GROWTH

1978 ◽  
Vol 58 (1) ◽  
pp. 79-86 ◽  
Author(s):  
L. V. GUSTA ◽  
K. J. KIRKLAND ◽  
H. M. AUSTENSON
Keyword(s):  
Seedling Growth ◽  
Triticum Aestivum L ◽  
Magnetic Treatment ◽  
Controlled Environment ◽  
Hordeum Vulgare L ◽  
Wild Oats ◽  
Water Imbibition ◽  
Magnetic Exposure ◽  
Seedling Growth Rate ◽  
Triticum Durum Desf

The effects of magnetic treatment (0–4,000 gauss) on dry seeds of wheat (Triticum aestivum L. and Triticum durum Desf.), barley (Hordeum vulgare L.) and wild oats (Avena fatua L.) were investigated under controlled environment conditions. Exposure of dry seeds of wheat, barley and wild oats to a magnetic field had no effect on germination and seedling growth. The emergence rate of Neepawa wheat and Hercules durum was unaffected by exposure of seed to a field strength of 0,375 and 4,000 gauss. However, exposure of barley seeds imbibed for 10 h prior to treatment reduced seedling growth rate. Exposure of dry seeds of barley and wheat to 0 and 375 gauss had no effect on water imbibition or leakage of cellular electrolytes.

EFFECT OF BARBAN AND FLAMPROP METHYL WITH SOLUTION NITROGEN ON WHEAT, WILD OATS AND GREEN FOXTAIL

1979 ◽  
Vol 59 (2) ◽  
pp. 351-356 ◽  
Author(s):  
J. R. MOYER ◽  
R. D. DRYDEN ◽  
P. N. P. CHOW
Keyword(s):  
Crop Yields ◽  
Plant Competition ◽  
Good Control ◽  
Triticum Aestivum L ◽  
Wheat Grain ◽  
Leaf Stage ◽  
Wild Oats ◽  
Green Foxtail ◽  
Initial Injury ◽  
Hand Weeding

Postemergent sprays of barban (4-chloro-2-butynyl m chlorocarbanilate) at the 2-leaf stage of wild oats (Avena fatua L.) and flamprop methyl [methyl N-benzoyl-N-(3-chloro-4-fluorophenyl)-2-aminopropionate] at the 3-leaf stage in water or solution nitrogen fertilizer gave moderate to good control of wild oats and significant increases of 21 and 30%, respectively, in yields of wheat (Triticum aestivum L. ’Neepawa’). Barban and flamprop methyl had no apparent effect on nitrogen content of wheat grain. When wild oats were controlled with herbicides the decrease in plant competition permitted increased growth of green foxtail (Setaria viridis L. Beauv.). Solution nitrogen and hand-weeding treatments increased nitrogen in the wheat grain significantly. Large increases in numbers and dry matter yields of wild oats resulted in relatively low crop yields from solution nitrogen, e.g. non-significant with barban and a 9% increase in the flamprop methyl experiment. Either herbicide applied with solution nitrogen produced an initial injury to plant leaves. However, wheat recovered rapidly and there was no indication of reduced growth at harvest. No effect was observed when herbicides were applied separately from solution nitrogen.

SELECTIVE CONTROL OF WILD OATS IN BARLEY WITH AC 84777

1975 ◽  
Vol 55 (4) ◽  
pp. 927-934 ◽  
Author(s):  
H. A. FRIESEN ◽  
O. B. LITWIN
Keyword(s):  
Leaf Area ◽  
Growth Period ◽  
Effective Control ◽  
Upward Movement ◽  
Hordeum Vulgare L ◽  
Stem Apex ◽  
Leaf Stage ◽  
Wild Oats ◽  
Selective Control ◽  
Eventual Death

A series of field plot experiments showed that AC 84777 (1,2 dimethyl-3, 5-diphenylpyrazolium methyl sulfate) as a postemergence herbicide provided selective control of wild oats (Avena fatua L.) in barley (Hordeum vulgare L.) equal to or better than barban over a growth period of the weed extending from the 3-leaf to the 5-leaf stage. Barban (4-chloro-2-butynyl m-chlorocarbanilate) must be applied at the 2-leaf stage of the wild oats to achieve effective control of the weed. AC 84777 increased in efficacy as the wild oats advanced from the 3- to the 5-leaf stage. Spot applications of AC 84777-C14 showed that the C14 label entered the leaf of wild oats or barley and moved quickly in an acropetal direction. It had concentrated in the leaf area above the point of application in a space of 30 min. Spot applications of AC 84777 made at the mid-point of the first through to the fourth leaf of wild oats resulted in necrosis of the leaf area above the point of application. Application at or below the meristematic area of the stem apex also resulted in rapid upward movement of the herbicide in both wild oats and barley but caused necrosis and death of the stem apex and eventual death of only the wild oats. Histological studies of the shoot apices of these wild oats plants showed extensive chromosome clumping, shrinking and necrosis of the cells. A wild oats plant that only had the mid-point of one of its leaves treated had a histologically normal shoot apex.

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