Competitive Relationships Among Winter Wheat (Triticum aestivum), Jointed Goatgrass (Aegilops cylindrica), and Downy Brome (Bromus tectorum)

Weed Science ◽  
1988 ◽  
Vol 36 (4) ◽  
pp. 479-486 ◽  
Author(s):  
Gwen F. Fleming ◽  
Frank L. Young ◽  
Alex G. Ogg
Keyword(s):  
Triticum Aestivum ◽  
Soil Moisture ◽  
Winter Wheat ◽  
Bromus Tectorum ◽  
Relative Yield ◽  
Growth Chamber ◽  
Downy Brome ◽  
Replacement Series ◽  
Aegilops Cylindrica ◽  
Jointed Goatgrass

In three replacement series experiments, winter wheat (Triticum aestivumL.), jointed goatgrass (Aegilops cylindricaHost. #3AEGCY), and downy brome (Bromus tectorumL. # BROTE) were paired in all possible combinations to determine competitive relationships during vegetative growth. Under growth chamber conditions of ample fertility and soil moisture and day/night temperatures of 18/10 C, relative yield totals for the three species were similar, indicating that they compete for the same resources. Both winter wheat and jointed goatgrass had greater plant growth and higher relative crowding coefficients than downy brome, which indicated a hierarchy of relative competitiveness of winter wheat > jointed goatgrass >> downy brome. In other growth chamber studies, winter wheat was slightly more competitive than jointed goatgrass regardless of fertility levels. Winter wheat was the superior competitor at 18/10 C and −33 kPa (soil moisture), whereas jointed goatgrass was superior at 27/10 C and −300 kPa, conditions that are frequently encountered in the Pacific Northwest.

Effect of Temperature on Root Absorption of Metribuzin and its Ethylthio Analog by Winter Wheat (Triticum aestivum), Jointed Goatgrass (Aegilops cylindrica), and Downy Brome (Bromus tectorum)

Weed Science ◽  
1992 ◽  
Vol 40 (4) ◽  
pp. 517-521 ◽  
Author(s):  
Robert A. Buman ◽  
David R. Gealy ◽  
Alex G. Ogg
Keyword(s):  
Winter Wheat ◽  
Water Absorption ◽  
Bromus Tectorum ◽  
Dry Weight ◽  
The Other ◽  
Effect Of Temperature ◽  
Downy Brome ◽  
Aegilops Cylindrica ◽  
Jointed Goatgrass ◽  
Root Absorption

Root absorption of subtoxic levels of metribuzin and its ethylthio analog (ethyl-metribuzin) by downy brome, jointed goatgrass, and winter wheat increased by a factor of three to five times as temperature increased from 10 to 20 C. Absorption of ethyl-metribuzin per gram dry weight was similar for all three species. Absorption and distribution of ethyl-metribuzin, but not metribuzin, were similar per gram dry weight in downy brome and jointed goatgrass. Absorption of metribuzin per gram dry weight was lower for winter wheat than for the other two species at 20 C. In general, the ratio of absorbed ethyl-metribuzin detected in shoots to that in roots was less in winter wheat and jointed goatgrass than in downy brome. The absorption by roots of14C-herbicides relative to water was similar for winter wheat and jointed goatgrass. Absorption of both14C-herbicides by winter wheat and jointed goatgrass was nonpreferential with respect to water absorption at 10 and 15 C. However, at 20 C14C-herbicide absorption was reduced 5 to 30% with respect to water absorption. Downy brome absorption of14C-herbicides with respect to water was 30 to 50% less than that of the other two species.

Effect of Herbicides on Germination and Growth of Four Grass Weeds

Weed Science ◽  
1984 ◽  
Vol 32 (4) ◽  
pp. 489-493 ◽  
Author(s):  
Frank L. Young ◽  
David R. Gealy ◽  
Larry A. Morrow
Keyword(s):  
Bromus Tectorum ◽  
Soil Surface ◽  
Dry Weight ◽  
Shoot Elongation ◽  
Downy Brome ◽  
Aegilops Cylindrica ◽  
Shoot Height ◽  
Shoot Dry Weight ◽  
Jointed Goatgrass ◽  
Germination And Growth

In the greenhouse, glyphosate [N-(phosphonomethyl)glycine] at 0.6 kg ae/ha applied directly to seeds alone or seeds on the soil surface reduced germination and shoot dry weight of common rye (Secale cerealeL. ♯3SECCE). Paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) applied similarly at 0.6 kg ai/ha reduced germination and shoot dry weight of downy brome (Bromus tectorumL. ♯ BROTE) and wheat (Triticum aestivumL. ‘Daws' ♯ TRZAX). Metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5 (4H)-one] at 0.6 kg ai/ha applied to seeds, soil, or seeds and soil had very little effect on germination, but significantly reduced shoot dry weight of common rye, downy brome, wheat, and jointed goatgrass (Aegilops cylindricaHost. ♯ AEGCY). Pronamide [3,5-dichloro(N-1,1-dimethyl-2-propynyl)benzamide] at 0.6 kg ai/ha, and propham (isopropyl carbanilate) at 3.4 kg ai/ha plus extender (p-chlorophenyl-N-methylcarbamate) at 0.4 kg ai/ha substantially reduced shoot height and dry weight of all species, regardless of application method, with pronamide completely inhibiting shoot elongation and dry-weight production in three of the four species.

Influence of Soil Type and Depth of Planting on Downy Brome Seed

Weed Science ◽  
1971 ◽  
Vol 19 (1) ◽  
pp. 82-86 ◽  
Author(s):  
G. A. Wicks ◽  
O. C. Burnside ◽  
C. R. Fenster
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Soil Type ◽  
Bromus Tectorum ◽  
Seedling Emergence ◽  
Cropping System ◽  
Soil Surface ◽  
Downy Brome ◽  
Moldboard Plow

Downy brome (Bromus tectorumL.) seedling emergence was greatest from soil depths of 1 inch or less, but occasionally seedlings emerged from depths of 4 inches. Downy brome seed covered by soil germinated more rapidly than those seed on the soil surface. More downy brome seedlings emerged, and from greater depths, from coarse-textured soils than fine-textured soils when moisture was not limiting. Soil type did not influence longevity of downy brome seed buried in the soil. Most (98%) 8-month-old downy brome seed buried 8 inches in the soil germinated but did not emerge in 1 year; and none remained viable in the soil after 5 years. The moldboard plow was more effective in reducing downy brome populations than a sweep plow or one-way disk in a continuous winter wheat (Triticum aestivumL.) cropping system.

Inactivation of Metribuzin in Winter Wheat by Activated Carbon

Weed Science ◽  
1985 ◽  
Vol 33 (2) ◽  
pp. 229-232 ◽  
Author(s):  
D. J. Rydrych
Keyword(s):  
Triticum Aestivum ◽  
Activated Carbon ◽  
Winter Wheat ◽  
Bromus Tectorum ◽  
Sandy Loam ◽  
Sandy Loam Soil ◽  
Silt Loam ◽  
Downy Brome ◽  
Chemical Injury ◽  
Loam Soil

Preemergence and postemergence application of metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazine-5(4H)-one] at 0.6 and 1.1 kg ai/ha controlled downy brome (Bromus tectorumL. ♯ BROTE) in winter wheat (Triticum aestivumL. ‘McDermid’) but caused considerable injury without the use of activated carbon over the seeded row. Activated carbon applied in 5-cm bands over the seeded row at 84, 167, and 336 kg/ha protected winter wheat at Pendleton on a silt loam soil. On a sandy loam soil, only a 336 kg/ha rate provided protection from metribuzin. Metribuzin toxicity to winter wheat was more difficult to neutralize when applied preemergence. Downy brome control was not reduced by carbon applied over the wheat row. The best treatment in this study was carbon at 336 kg/ha applied preemergence over the row followed by metribuzin at 0.6 or 1.1 kg/ha postemergence. A 10-week delay between preemergence carbon banding and postemergence metribuzin protected winter wheat from chemical injury.

Differential Absorption and Translocation of Metribuzin by Downy Brome (Bromus tectorum) and Winter Wheat (Triticum aestivum)

Weed Science ◽  
1987 ◽  
Vol 35 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Daniel L. Devlin ◽  
David R. Gealy ◽  
Larry A. Morrow
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Bromus Tectorum ◽  
Wheat Root ◽  
Downy Brome ◽  
Fresh Weight Basis ◽  
Plant Parts ◽  
Root Absorption ◽  
Treated Leaf ◽  
Total Plant

Foliar and root absorption and translocation of metribuzin (4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one) by downy brome (Bromus tectorumL. # BROTE) and winter wheat (Triticum aestivumL.) was determined. After a 48-h absorption period, roots of three-week-old downy brome plants had absorbed two times more metribuzin on a total plant fresh weight basis than had roots of winter wheat. Root-absorbed metribuzin was translocated similarly regardless of species with 80% of absorbed14C accumulating in leaf blades, 10% in the leaf sheaths, and 10% in the roots. After 24 h, leaves of downy brome and winter wheat had absorbed, respectively, 26 and 36% of foliar-applied metribuzin, and absorption increased threefold with the addition of a nonionic surfactant. Translocation of foliar-absorbed metribuzin was primarily towards the apex of the treated leaf. No translocation from the treated leaf to other plant parts occurred with either species. The greater tolerance of winter wheat to metribuzin is due in part to less root absorption of metribuzin by winter wheat than by downy brome.

Differential Metabolism of Metribuzin by Downy Brome (Bromus tectorum) and Winter Wheat (Triticum aestivum)

Weed Science ◽  
1987 ◽  
Vol 35 (6) ◽  
pp. 741-745 ◽  
Author(s):  
Daniel L. Devlin ◽  
David R. Gealy ◽  
Larry A. Morrow
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Bromus Tectorum ◽  
Water Soluble ◽  
Chloroform Fraction ◽  
Downy Brome ◽  
Fresh Weight ◽  
Aqueous Fraction ◽  
Root Absorption

At both 15 and 25 C, following a 24-h root absorption period, absorbed14C-metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one] was metabolized approximately 30% more rapidly to water-soluble and terminal fiber metabolites by winter wheat (Triticum aestivumL.) than by downy brome (Bromus tectorumL. # BROTE). Both species metabolized a greater proportion of metribuzin in leaf sheaths and roots than in the leaf blades. This was attributed to the increased incorporation of metribuzin into fiber. After an initial leaf extraction, metribuzin and the metabolites deaminated metribuzin (DA), deaminated diketo metribuzin (DADK), and diketo metribuzin (DK) partitioned into a chloroform fraction and five unidentified water-soluble metabolites into an aqueous fraction. At both 15 and 25 C, downy brome absorbed approximately three times more metribuzin per fresh weight than did winter wheat. The mechanism of differential tolerance of downy brome and winter wheat to metribuzin was attributed to the ability of winter wheat to metabolize metribuzin more rapidly and absorb less metribuzin than downy brome.

BromusControl in Winter Wheat (Triticum aestivum) with the Ethylthio Analog of Metribuzin

1987 ◽  
Vol 1 (3) ◽  
pp. 235-241 ◽  
Author(s):  
Randall L. Ratliff ◽  
Thomas F. Peeper
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Field Experiments ◽  
Bromus Tectorum ◽  
Downy Brome ◽  
Selective Control ◽  
Bromus Secalinus ◽  
Wide Range

Twenty field experiments were conducted in Oklahoma from 1983 through 1986 to evaluate the ethylthio analog of metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(ethylthio)-1,2,4-triazin-5(4H)-one] for selective control of cheat (Bromus secalinusL. #3BROSE), downy brome (Bromus tectorumL. # BROTE), and rescuegrass (Bromus catharticusVahl. # BROCA) in winter wheat (Triticum aestivumL.). The ethylthio analog of metribuzin applied postemergence at 1.1 kg ai/ha before the weeds tillered controlled 91 to 100% of theseBromusspp. in winter wheat. Control of tilleredBromusspp. was less consistent. AsBromusspp. control increased, wheat yields increased, and dockage decreased. The herbicide was selective on wheat over a wide range of soils, including sands. Adding surfactant to very early postemergence applications of 0.6 kg ai/ha increased cheat control but injured wheat slightly. Surfactant use had little or no effect on dockage reduction and yields.

Retention, Absorption, and Loss of Foliage-Applied Metribuzin

Weed Science ◽  
1987 ◽  
Vol 35 (6) ◽  
pp. 775-779 ◽  
Author(s):  
Daniel L. Devlin ◽  
David R. Gealy ◽  
Larry A. Morrow
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Bromus Tectorum ◽  
Petri Dish ◽  
Downy Brome ◽  
Leaf Surfaces

Immediately following postemergence application, similar quantities of metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one] were retained on the foliage of downy brome (Bromus tectorumL. # BROTE) and winter wheat (Triticum aestivumL.). Three days following treatment, more metribuzin was present on the surface of the foliage of downy brome than of winter wheat and similar quantities of metribuzin had been absorbed into the interior of the foliage of both species. Fourteen days after treatment, metribuzin had disappeared from the surfaces of the foliage of both species but more metribuzin was present in the interior of the foliage of downy brome than of winter wheat. Results from petri dish studies in the field suggested that the amount of unaltered metribuzin available for absorption by leaves was influenced primarily by volatilization and secondarily by photodecomposition. In addition, small quantities of rainfall may have washed metribuzin from leaf surfaces. In 1984, yield of winter wheat was greater in metribuzin-treated plots than in nontreated check plots.

Fertilizer and Downy Brome (Bromus tectorum) Effect on Russian Wheat Aphid (Diuraphis noxis) in Winter Wheat (Triticum aestivum)

1993 ◽  
Vol 7 (3) ◽  
pp. 670-673
Author(s):  
James M. Krall ◽  
Stephen D. Miller ◽  
Larry E. Bennett ◽  
David E. Legg
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Bromus Tectorum ◽  
Field Studies ◽  
Russian Wheat Aphid ◽  
Alternative Host ◽  
Downy Brome ◽  
Insecticide Efficacy

Downy brome serves as an alternative host for Russian wheat aphid (RWA) in winter wheat. In field studies, downy brome infestations of 5 and 39 plants per m2increased RWA-infested winter wheat tillers 1.4 to 2.8 times that seen in non-infested plots, respectively. RWA-infested winter wheat tillers were not reduced consistently by fertilization. Chlorpyrifos reduced the number of RWA-infested winter wheat tillers to 15 to 43% of untreated wheat. Insecticide efficacy was not influenced by downy brome infestation or by fertilizer either band- or broadcast-applied.

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