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1
Stahlman, Phillip W. "Modeling Diclofop Activity on ThreeBromusSpecies." Weed Science 33, no. 2 (March 1985): 250–52. http://dx.doi.org/10.1017/s0043174500082199.
Full textAbstract:
The methyl ester of diclofop {2-[4-(2,4-dichlorophenoxy)phenoxy] propanoic acid} mixed with soil at 1, 2, and 3 ppmw reduced the growth ofBromusspecies in the greenhouse as follows: downy brome (Bromus tectorumL. ♯ BROTE) more than Japanese brome (Bromus japonicusThunb. ex Murr. ♯ BROJA) more than cheat (Bromus secalinusL. ♯ BROSE). The decrease in herbicide effect (decay) over time was described better using a second-order equation than a first-order equation. Plant response-herbicide dose relationships were described best with a cubic polynomial equation.
2
Metier, Emily P., Erik A. Lehnhoff, Jane Mangold, Matthew J. Rinella, and Lisa J. Rew. "Control of downy brome (Bromus tectorum) and Japanese brome (Bromus japonicus) using glyphosate and four graminicides: effects of herbicide rate, plant size, species, and accession." Weed Technology 34, no. 2 (November 5, 2019): 284–91. http://dx.doi.org/10.1017/wet.2019.112.
Full textAbstract:
AbstractNonnative annual brome invasion is a major problem in many ecosystems throughout the semiarid Intermountain West, decreasing production and biodiversity. Herbicides are the most widely used control technique but can have negative effects on co-occurring species. Graminicides, or grass-specific herbicides, may be able to control annual bromes without harming forbs and shrubs in restoration settings, but limited studies have addressed this potential. This study focused on evaluating the efficacy of glyphosate and four graminicides to control annual bromes, specifically downy brome and Japanese brome. In a greenhouse, glyphosate and four graminicides (clethodim, sethoxydim, fluazifop-P-butyl, and quizalofop-P-ethyl) were applied at two rates to downy brome plants of different heights (Experiment 1) and to three accessions of downy brome and Japanese brome of one height (Experiment 2). All herbicides reduced downy brome biomass, with most effective control on plants of less than 11 cm and with less than 12 leaves. Overall, quizalofop-P-ethyl and fluazifop-P-butyl treatments were most effective, and glyphosate and sethoxydim treatments least effective. Accessions demonstrated variable response to herbicides: the downy brome accession from the undisturbed site was more susceptible to herbicides than downy brome from the disturbed accession and Japanese brome accessions. These results demonstrate the potential for graminicides to target these annual bromes in ecosystems where they are growing intermixed with desired forbs and shrubs.
3
Challaiah, Orvin C. Burnside, Gail A. Wicks, and Virgil A. Johnson. "Competition Between Winter Wheat (Triticum aestivum) Cultivars and Downy Brome (Bromus tectorum)." Weed Science 34, no. 5 (September 1986): 689–93. http://dx.doi.org/10.1017/s0043174500067692.
Full textAbstract:
Field experiments were conducted to select winter wheat (Triticum aestivumL.) cultivar(s) that were competitive to downy brome (Bromus tectorumL. # BROTE). Downy brome significantly reduced winter wheat grain yields of all cultivars by 9 to 21% at Lincoln, while at North Platte yield reduction ranged from 20 to 41% depending upon cultivar. ‘Turkey’ was the most competitive cultivar to downy brome but it had the lowest grain yield. Compared to ‘Centurk 78’, ‘Centura’ at Lincoln and ‘SD 75284’ at North Platte proved to be significantly higher yielding and more competitive to downy brome. Winter wheat tiller number, canopy diameter, and plant height were negatively correlated with downy brome yield, but changes in these growth parameters did not always translate into grain yield advantage in downy brome-infested plots. Based on stepwise regression analysis, wheat height was better correlated with reduction in downy brome yield than were canopy diameter or number of tillers.
4
O'Connor, B. J., L. V. Gusta, and S. P. Paquette. "A comparison of the freezing tolerance of downy brome, Japanese brome and Norstar winter wheat." Canadian Journal of Plant Science 71, no. 2 (April 1, 1991): 565–69. http://dx.doi.org/10.4141/cjps91-084.
Full textAbstract:
The freezing tolerance of downy (Bromus tectorum L.) and Japanese (Bromus japonicus) brome were compared to Norstar winter wheat (Triticum aestivum L.) collected from similar sites. From December to April of 1987 downy brome was either equal to or superior in freezing tolerance to the winter wheat. Of the three species, Japanese brome was slightly less hardy in December but was of equal freezing tolerance in March and April. There was no correlation between freezing tolerance and tissue water content or tissue dry weight in the three species. These two bromes may become a serious weed in winter wheat because their cold hardiness is either equal or superior to our hardiest winter wheat cultivars. Key words: Downy brome, Japanese brome, winter wheat, freezing tolerance
5
Espeland, Erin K., and Robert Kilian. "Low-Dose Glyphosate Does Not Control Annual Bromes in the Northern Great Plains." Invasive Plant Science and Management 8, no. 3 (September 2015): 334–40. http://dx.doi.org/10.1614/ipsm-d-15-00004.1.
Full textAbstract:
AbstractAnnual bromes (downy brome and Japanese brome) have been shown to decrease perennial grass forage production and alter ecosystem functions in northern Great Plains rangelands. Large-scale chemical control might be a method for increasing rangeland forage production. Although fall application has been shown to be the most effective and least likely to impact co-occurring native species, spring germination of downy brome may reduce the efficacy of fall-only herbicide application. We assessed the impact of a low glyphosate dose rate (210 g ha−1) applied to rangelands in fall or in fall and spring on nontarget species and on annual brome abundance at two sites in eastern Montana over 2 yr. We tested the following hypotheses: (1) nontarget effects are greater with spring herbicide application, (2) fall and spring herbicide application are necessary for effective downy brome control, and (3) fall herbicide application is sufficient to control Japanese brome. Few nontarget effects occurred; two dicotyledonous species exhibited small increases in response to herbicide. We found that that a single fall application reduced downy brome cover and seed bank density, but after the second fall application in the following year, downy brome did not continue to show a response to herbicide. After 2 yr of fall herbicide application, Japanese brome had denser seed banks in plots where herbicide had been applied. Blanket glyphosate application on rangelands is an unreliable method for controlling annual brome invasions in the northern Great Plains.
6
Richardson, Jesse M., Larry A. Morrow, and David R. Gealy. "Floral Induction of Downy Brome (Bromus tectorum) as Influenced by Temperature and Photoperiod." Weed Science 34, no. 5 (September 1986): 698–703. http://dx.doi.org/10.1017/s0043174500067710.
Full textAbstract:
Seedling vernalization was more effective than seed vernalization in promoting flowering of downy brome (Bromus tectorumL. # BROTE). Vernalizing imbibed downy brome caryopses at 3 C for 0 to 30 days did not induce rapid flowering when the caryopses were planted. Downy brome seedlings were exposed for 30 days to six photoperiod/temperature treatments. After subsequent transfer to long days, plants from the short-day/3 C treatment flowered within 30 days. Flowering was delayed or was absent in treatments with higher temperatures or long days. The shoot apex increased in volume during the short-day/3 C vernalization period. Two days following vernalization, floral initiation had occurred. By day 5, lateral organs had proliferated. Rudimentary glumes and lemmas were visible by day 8.
7
Devlin, Daniel L., David R. Gealy, and Larry A. Morrow. "Differential Absorption and Translocation of Metribuzin by Downy Brome (Bromus tectorum) and Winter Wheat (Triticum aestivum)." Weed Science 35, no. 1 (January 1987): 1–5. http://dx.doi.org/10.1017/s0043174500026692.
Full textAbstract:
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.
8
Devlin, Daniel L., David R. Gealy, and Larry A. Morrow. "Differential Metabolism of Metribuzin by Downy Brome (Bromus tectorum) and Winter Wheat (Triticum aestivum)." Weed Science 35, no. 6 (November 1987): 741–45. http://dx.doi.org/10.1017/s004317450007925x.
Full textAbstract:
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.
9
Kon, KF, and WM Blacklow. "Identification, distribution and population variability of great brome (Bromus diandrus Roth) and rigid brome (Bromus rigidus Roth)." Australian Journal of Agricultural Research 39, no. 6 (1988): 1039. http://dx.doi.org/10.1071/ar9881039.
Full textAbstract:
Seventeen populations of Bromus spp. were sampled from across southern Australia and accessions in the state herbaria of Western and South Australia were examined. Rigid brome (B. rigudus) differed from great brome (B. diandrus) in having shorter, sparser hairs on leaf laminae, more compact and erect panicles with shorter spikelet branches. In rigid brome, the abscission scars on the rachillae were elliptical and the lemma calluses were elongated (> 1 mm), while in great brome, these characters were circular and short (5 1 mm). Rigid brome was further differentiated into a long and short-awned biotype. Rigid brome was hexaploid, 2n = 42, and great brome an octoploid, 2n = 56. Rigid brome is widely distributed across southern Australia, often growing unrecognized in association with great brome. Rigid brome matured earlier than great brome, and there was high genetic variation (26-34% of total variation) in the time of maturity of both species. Seed production in rigid brome and great brome ranged from 1156 to 2908 and 661 to 3380 seeds per plant respectively. A short-awned ecotype of rigid brome from Geraldton, W.A., had 30% residual innate dormancy. This, together with the earlier maturity of ecotypes of rigid brome, may make it more difficult to control than a great brome when both species coexist in the field. Leaves of great brome were susceptible to rust (Puccinia bromoides Guyot), but associated ecotypes of rigid brome were rust free.
10
Fleming, Gwen F., Frank L. Young, and Alex G. Ogg. "Competitive Relationships Among Winter Wheat (Triticum aestivum), Jointed Goatgrass (Aegilops cylindrica), and Downy Brome (Bromus tectorum)." Weed Science 36, no. 4 (July 1988): 479–86. http://dx.doi.org/10.1017/s0043174500075238.
Full textAbstract:
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.
11
Devlin, Daniel L., David R. Gealy, and Larry A. Morrow. "Retention, Absorption, and Loss of Foliage-Applied Metribuzin." Weed Science 35, no. 6 (November 1987): 775–79. http://dx.doi.org/10.1017/s0043174500079327.
Full textAbstract:
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.
12
Richardson, Jesse M., David R. Gealy, and Larry A. Morrow. "Preventing Downy Brome (Bromus tectorum) Seed Production with DPX-Y6202 and Fluazifop." Weed Science 35, no. 2 (March 1987): 277–81. http://dx.doi.org/10.1017/s0043174500079194.
Full textAbstract:
Ethyl ester of DPX-Y6202 {2-[4-[(6-chloro-2-quinoxalinyl)oxy] phenoxy] propanoic acid} and butyl ester of fluazifop {(±)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl] oxy] phenoxy] propanoic acid} applied during the reproductive phase of development at 0.07 and 0.28 kg ai/ha prevented seed formation in downy brome (Bromus tectorumL. # BROTE). Fluazifop prevented seed formation over a wider range of application rates and growth stages than did DPX-Y6202. Seed production was prevented most readily by herbicide applications made early in the reproductive phase. Environmental factors during reproduction affected herbicide performance. Foliar absorption and translocation of14C-fluazifop into the developing spikelets was greater than that of14C-DPX-Y6202 in downy brome.
13
Kelley, Windy K., Maria E. Fernandez-Gimenez, and Cynthia S. Brown. "Managing Downy Brome (Bromus tectorum) in the Central Rockies: Land Manager Perspectives." Invasive Plant Science and Management 6, no. 4 (December 2013): 521–35. http://dx.doi.org/10.1614/ipsm-d-12-00095.1.
Full textAbstract:
AbstractSuccessful management of downy brome (also known as cheatgrass) requires understanding land managers' perceptions and decisions about whether to invest in its control. We investigated ranchers' and natural resource professionals' (NRPs) perceptions and knowledge about downy brome ecology and its impacts, their current downy brome management practices and satisfaction with those practices, and their information and technical needs using focus groups and a mail survey of ranchers and NRPs in Colorado and Wyoming. Both groups thought downy brome was a problem, and perception of the severity of downy brome corresponded to the level of infestation in the respondent's region. NRPs identified downy brome as a bigger problem than did ranchers from the same area in all but one region. Ranchers were most likely to use early spring grazing to control downy brome, and NRPs were most likely to use seeding, imazapic herbicide, or a combination of methods. Both groups reported that the primary constraint to controlling downy brome was that other weeds were a higher priority. Ranchers and NRPs wanted more information about the control methods they were already likely to use as well as other downy brome control methods. Our findings suggest that (1) listing a species as a noxious weed may provide an important incentive to control it, but trade-offs among control efforts for different species must be carefully considered; (2) managers need to know more about low-cost, low-labor strategies for managing downy brome; and (3) some managers need to be informed about how to identify downy brome, its potential negative effects, and how to prevent its spread. Better quantification of the economic and ecological impacts of downy brome in the Central Rocky Mountains, continued development of effective and economically viable management methods, and improvement in the dissemination of that information to land managers are necessary for successful control of downy brome.
14
Blackshaw, Robert E. "Control of Downy Brome (Bromus tectorum) in Conservation Fallow Systems." Weed Technology 5, no. 3 (September 1991): 557–62. http://dx.doi.org/10.1017/s0890037x00027329.
Full textAbstract:
Field studies were conducted to determine the most effective rate of several herbicides applied at various growth stages to control downy brome in conservation fallow programs. Downy brome growth stage affected the efficacy of all herbicides. All herbicides were less effective when application was delayed until the boot stage of downy brome. Fluazifop-P and sethoxydim must be applied prior to tillering to effectively control downy brome. Glyphosate, the commercial mixture of glyphosate plus 2,4-D, paraquat, and HOE-39866 consistently controlled downy brome up to the 3- to 5-tiller stage. Glyphosate at 180 to 200 g ha-1, paraquat at 250 to 300 g ha-1, and the commercial mixture of glyphosate plus 2,4-D at 600 to 660 g ha-1controlled downy brome 80 to 90%. The effective rates were lower than rates currently registered for downy brome control in western Canada, and thus there is potential for making conservation fallow programs more economical when downy brome is the predominant weed.
15
Stahlman, Phillip W., and Stephen D. Miller. "Downy Brome (Bromus tectorum) Interference and Economic Thresholds in Winter Wheat (Triticum aestivum)." Weed Science 38, no. 3 (May 1990): 224–28. http://dx.doi.org/10.1017/s0043174500056447.
Full textAbstract:
Densities up to 100 downy brome m2were established in winter wheat in southeastern Wyoming and west-central Kansas to quantify wheat yield loss from downy brome interference and to approximate economic threshold levels. A quadratic equation best described wheat yield loss as a function of weed density when downy brome emerged within 14 days after wheat emergence. Densities of 24, 40, and 65 downy brome m2reduced wheat yield by 10, 15, and 20%, respectively. Wheat yield was not reduced when downy brome emerged 21 or more days later than wheat. Economic thresholds varied with changes in downy brome density, cost of control, wheat price, and potential wheat yield. In a greenhouse experiment, dry weight of 72-day-old wheat plants grown in association with downy brome was not affected by the distance between the weeds and wheat, whereas downy brome plant dry weight increased with increasing distance between the weeds and wheat.
16
Dao, Thanh H. "Crop Residues and Management of Annual Grass Weeds in Continuous No-Till Wheat (Triticum aestivum)." Weed Science 35, no. 3 (May 1987): 395–400. http://dx.doi.org/10.1017/s0043174500053881.
Full textAbstract:
Field and growth chamber experiments were conducted from 1983 to 1985 to determine the relationships between loss in plant productivity and plant residue-crop-weed density in no-till wheat (Triticum aestivumL.) and to document chemical management and cultivar options for such a cropping system. Untilled stubble left on the soil at rates of 0.5 and 3 t/ha reduced wheat density and grain yield in continuous winter wheat. Stem densities of cheat (Bromus secalinusL. # BROSE) and downy brome (B. tectorumL. # BROTE) in mulched treatments averaged about 682, 679, and 38 stems/m2in 1983, 1984, and 1985, respectively. In the nonmulched treatment, weed density and standing dry matter ranged from 5 to 30 stems/m2and 2 to 6 g/m2, respectively. Removal of residues eliminated key habitat characteristics required for the establishment ofBromusspp. Preemergence and early postemergence applications of BAY SMY 1500 [4-amino-6-(1,1-dimethylethyl)-3-(ethylthio)-1,2,4-triazin-5(4H)-one] at 2 kg/ha controlled both species ofBromusin no-till wheat. The herbicide treatment slightly delayed maturity of 10 wheat cultivars, but control of cheat and downy brome allowed nine cultivars to attain their yield potential, improving grain yield over that of untreated plots. ‘Vona’ wheat did not tolerate the herbicide and was susceptible after emergence. BAY SMY 1500 widens the spectrum of weed management and wheat cultivar options for an annual conservation production system of winter wheat.
17
Wilson, Henry P., Martin P. Mascianica, Thomas E. Hines, and Ronald F. Walden. "Influence of Tillage and Herbicides on Weed Control in a Wheat (Triticum aestivum)–Soybean (Glycine max) Rotation." Weed Science 34, no. 4 (July 1986): 590–94. http://dx.doi.org/10.1017/s0043174500067497.
Full textAbstract:
Field studies were conducted for 4 yr to investigate the effects of tillage and herbicide programs on weed control and wheat (Triticum aestivumL. ‘Potomac’ in 1981 and ‘Wheeler’ from 1982 to 1984) grain yields in a wheat-soy bean [Glycine max(L.) Merr.] double-crop rotation. Predominant weed species were common chickweed [Stellaria media(L.) Vill. # STEME], corn chamomile (Anthemis arvensisL. # ANTAR), and annual bluegrass (Poa annuaL. # POAAN) at the onset of research and cheat (Bromus secalinusL. # BROSE) and soft brome (Bromus mollisL. # BROMO) at the conclusion of the study. Control of all species was excellent with conventional tillage and no-till plus nonselective herbicides but was significantly less with no-till without nonselective herbicides and with minimum tillage. After 4 yr, maximum wheat grain yields were significantly higher in conventional- than in minimum- or no-till systems.
18
Blackshaw, Robert E. "Downy Brome (Bromus tectorum) Density and Relative Time of Emergence Affects Interference in Winter Wheat (Triticum aestivum)." Weed Science 41, no. 4 (December 1993): 551–56. http://dx.doi.org/10.1017/s004317450007630x.
Full textAbstract:
Field experiments over 3 yr at Lethbridge, Alberta, determined the effect of various downy brome densities and times of its emergence on winter wheat biomass and seed yield. Downy brome reduced wheat biomass up to 59% and seed yield up to 68%. Time of downy brome emergence relative to wheat affected the magnitude of these yield reductions more than the density of downy brome. At comparable densities, downy brome caused 2- to 5-fold greater reductions in yield when it emerged within 3 wk after winter wheat than when it emerged 6 wk after wheat or in early spring. Late-emerging downy brome caused significant wheat yield or biomass losses only at densities of 200 to 400 plants m-2. Late-emerging downy brome plants were strongly shaded (70 to 90%) by winter wheat throughout much of the growing season.
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Otfinowski, R., N. C. Kenkel, and P. M. Catling. "The biology of Canadian weeds. 134. Bromus inermis Leyss." Canadian Journal of Plant Science 87, no. 1 (January 1, 2007): 183–98. http://dx.doi.org/10.4141/p06-071.
Full textAbstract:
Smooth brome (Bromus inermis Leyss.), a native of central Eurasia, was introduced to Canada as a forage and hay crop around 1888. Early reports of plants escaped from cultivation appear in 1903, however, based on the number of collections prior to 1920, smooth brome spread more rapidly in western Canada. Smooth brome is common along roadsides, forest margins, clearings, shorelines and disturbed areas, but its most detrimental impact is on the diversity of prairies and native grasslands. In Riding Mountain National Park, MB, plant diversity of fescue prairies recently invaded by smooth brome decreased by 70%. Vegetative proliferation through underground rhizomes is key to the invasiveness of smooth brome, but long-range dispersal of seeds is facilitated by animals, wind and the transport of hay. Smooth brome is effectively controlled using selective applications of glyphosate and well-timed clipping. However, restoration of infested areas depends on the composition of native seed banks. Smooth brome remains valuable as a forage and cover crop in every province and territory in Canada. Key words: Bromus inermis, weed biology, prairie, Canada distribution, alien, smooth brome, biological invasion
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Марковская, Галина, Galina Markovskaya, Светлана Гусева, and Svetlana Guseva. "INFLUENCE OF SINGLE AND MIXED CROPS OF PERMANENT GRASS ON SOIL ENZYMIC ACTIVITY IN THE CONDITIONS OF FOREST-STEPPE OF THE MIDDLE VOLGA REGION." Bulletin Samara State Agricultural Academy 4, no. 2 (May 20, 2019): 27–34. http://dx.doi.org/10.12737/article_5cdbc12353b663.24196889.
Full textAbstract:
The research is aimed at the development of effective methods to restore soil fertility under intensive agrogenic loads. The studies were conducted in the fields of the Department of Plant Cultivation and Agriculture from 2016 to 2018. The following variants of single-species and mixed crops of perennial grasses were studied: 1. awnless brome; 2. crested wheat grass; 3. awnless brome + smooth brome; 4. crested wheat grass + Agropyron; 5 awnless brome + smooth brome + Hungarian sainfoin; 6. crested wheat grass + Agropyron + Hungarian sainfoin. Medium soil samples were taken from the experimental field from all variants of single-species and mixed crops of perennial grasses in triplicate in three periods: beginning, middle, and end of the growing season. Samples were taken from depth of
0-20 cm and 20-40 cm. Bacteria number was assessed by sowing special soil mixture on the solid sterile MPA media according to the method of J. Sega. Enzyme activity was determined by the method of A. Sh. Galstyan. When studying the activity of PPO, a high activity of this enzyme was observed in the soil layer of 20-40 cm. The analysis of the activity of the enzyme peroxidase has various indicators both between the studied variants and in the soil section. The high activity of the enzymes was noted in the variants «awnless brome + smooth brome» and «crested wheat grass + Agropyron + Hungarian sainfoin». In the process of research, a correlation was found between peroxidase activity and the number of bacteria. The highest coefficient of humification was noted in the «awnless brome», the lowest – «crested wheat grass + Agropyron + Hungarian sainfoin». From 2016 to 2018, in the first variant, a decrease in the coefficient of humification is observed. Thus, of the above options, with the optimal species composition, the following options turned out to be: « awnless brome», «awnless brome +smooth brome», «awnless brome +smooth brome + Hungarian sainfoin». Research data were processed by the dispersion method.
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Dastgheib, F., M. P. Rolston, and W. J. Archie. "Chemical control of brome grasses (Bromus spp) in cereals." New Zealand Plant Protection 56 (August 1, 2003): 227–32. http://dx.doi.org/10.30843/nzpp.2003.56.6096.
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Ripgut brome (Bromus diandrus) prairie grass (B willdenowii) and soft brome (B hordeaceus) are becoming serious weed problems in arable farms of New Zealand This paper reports results from three years of field experiments evaluating chemical treatments for brome control in cereal crops Ripgut brome was shown to be very competitive with moderate infestations reducing grain yields by 2530 A strong relationship (R2096) was found between seedling numbers of ripgut brome and final grain yield The study found several promising chemical treatments that offer a good degree of control These include preemergence applications of cyanazine terbuthylazine chlorsulfuron terbuthylazine and metribuzin The same herbicides applied postemergence were not as effective for brome grass control
22
Gill, GS, ML Poole, and JE Holmes. "Competition between wheat and brome grass in Western Australia." Australian Journal of Experimental Agriculture 27, no. 2 (1987): 291. http://dx.doi.org/10.1071/ea9870291.
Full textAbstract:
Brome grass (Bromus diandrus Roth) has become a serious weed of wheat in Western Australia, particularly on light textured soils. Six field experiments were carried out to investigate competition between brome grass and wheat. Results showed that brome grass is an extremely aggressive weed in wheat. Although the experimental sites varied considerably in soil type, rainfall and other growing conditions the relationship between brome grass and reduction in wheat yield was remarkably consistent across the sites. An exponential model was found to adequately describe yield loss due to competition with brome grass and will be used for extension purposes in Western Australia. An examination of yield contributing characters of wheat suggested that yield loss due to brome grass had been determined before the crop reached the grainfilling stage and such a result diminishes the importance of competition for water in wheat-brome grass mixtures.
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Whitson, Tom D., Mark E. Majerus, Reginald D. Hall, and Jay D. Jenkins. "Effects of Herbicides on Grass Seed Production and Downy Brome (Bromus tectorum)." Weed Technology 11, no. 4 (December 1997): 644–48. http://dx.doi.org/10.1017/s0890037x00043189.
Full textAbstract:
Control of downy brome in cool-season perennial grasses grown for seed production must be done prior to seed harvest, because downy brome seeds cannot be separated from cool-season grass seeds. Field experiments were conducted near Powell, WY, and Bridger, MT, to evaluate several herbicides for control of downy brome from 1992 through 1994 in western wheatgrass, slender wheatgrass, beardless wild rye, thickspike wheatgrass, and meadow bromegrass. When fall-applied, only metribuzin at 0.4 kg/ha and oxyfluorfen plus metribuzin at 1.1 plus 0.3 kg/ha controlled 98 and 95% of the downy brome, respectively, without affecting grass seed viability or seed yield. Early spring applications of paraquat at 0.8 kg/ha controlled 100% of the downy brome, but suppressed perennial grasses. Glyphosate applied in early spring at 0.3 kg/ha controlled 48% of the downy brome, but suppressed perennial grasses. Seed yield reductions occurred when thickspike wheatgrass and meadow brome were treated with glyphosate at 0.3 kg/ha.
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Burnett, Shayla A., and Brian A. Mealor. "Imazapic Effects on Competition Dynamics Between Native Perennial Grasses and Downy Brome (Bromus tectorum)." Invasive Plant Science and Management 8, no. 1 (March 2015): 72–80. http://dx.doi.org/10.1614/ipsm-d-14-00032.1.
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AbstractDowny brome inhibits revegetation efforts following ecosystem disturbance. Imazapic is a commonly used herbicide for downy brome management, but more information is needed regarding effective application timing for restoration efforts. We wished to determine (1) if native species establishment exhibited a tradeoff between downy brome competition and injury from herbicide and (2) if this differed between pre- and postemergent applications of imazapic. We used a standard replacement series design and overlaid herbicide treatments. Nine weeks after planting, aboveground biomass was harvested and relative yield (RY) indices calculated. Both imazapic applications reduced downy brome biomass by 91% or more (P < 0.05). Imazapic caused drastic reductions in native biomass but less than what was caused by downy brome competition (P < 0.05). Natives were less injured by a pre- than postemergent application (P < 0.05). In situations where downy brome may impact restoration efforts, pre-emergent applications of imazapic at 70 g ai ha−1 (0.06 lb ai ac−1) may reduce downy brome with less negative impacts on newly-seeded native grasses than post-emergent applications. Ensuring sufficient proportions of native species seeds on restoration sites may reduce downy brome.
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Abella, Scott R., Donovan J. Craig, Lindsay P. Chiquoine, Kathryn A. Prengaman, Sarah M. Schmid, and Teague M. Embrey. "Relationships of Native Desert Plants with Red Brome (Bromus rubens): Toward Identifying Invasion-Reducing Species." Invasive Plant Science and Management 4, no. 1 (March 2011): 115–24. http://dx.doi.org/10.1614/ipsm-d-10-00013.1.
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AbstractThe interactions between native and exotic species occur on a continuum from facilitative to competitive. A growing thrust in invasive species science is differentiating where particular native species occur along this continuum, with practical implications for identifying species that might reduce the invasibility of ecosystems. We used a greenhouse experiment to develop a competitive hierarchy of 27 native species with red brome, an invasive annual grass in the arid lands of the southwestern United States, and a field study to assess in situ responses of brome to native perennial species in the Mojave Desert. Native species most competitive with brome in the competition experiment included the annuals Esteve's pincushion and western fiddleneck and the perennials eastern Mojave buckwheat, sweetbush, and brittlebush, which reduced brome biomass to 49 to 70% of its grown-alone amount. There was no clear difference in competitive abilities with brome between annual and perennial natives, and competiveness was not strongly correlated (r = 0.15) with the biomass of the native species. In the field, sweetbush and brittlebush supported among the least cover of brome, suggesting congruence of the strong early competitive abilities of these species with in situ patterns of brome distribution. At the other extreme, brome attained its highest average cover (19%) below littleleaf ratany, significantly greater than all but 3 of the 16 species evaluated. Cover by brome was only weakly related (r = 0.19) to the area of the perennial canopy, suggesting that factors other than the sizes of perennial plants were linked to differences in brome cover among species. Results suggest that (1) interactions with brome differ substantially among native species, (2) these interactions are not as closely linked to biomass production as in more temperate regions, and (3) there is potential for identifying native species that can reduce invasion of desert ecosystems.
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Abella, Scott R., Teague M. Embrey, Sarah M. Schmid, and Kathryn A. Prengaman. "Biophysical Correlates with the Distribution of the Invasive Annual Red Brome (Bromus rubens) on a Mojave Desert Landscape." Invasive Plant Science and Management 5, no. 1 (March 2012): 47–56. http://dx.doi.org/10.1614/ipsm-d-11-00030.1.
Full textAbstract:
AbstractBecause of its ability to transform ecosystems by increasing the prevalence of fire, the invasive annual red brome is a priority exotic species for management in arid lands of the southwestern United States. By sampling red brome presence and 97 environmental (climatic, topographic, and soil) and native vegetation (e.g., perennial species richness) variables on 126 sites, we assessed biophysical correlates with red brome distribution on a 755,000-ha (1.9 million ac) Mojave Desert landscape. Brome occupied 55 of 126 (44%) 0.09-ha plots. The simplest models (i.e., those containing the fewest or most easily obtained variables) in multivariate (classification trees and nonparametric multiplicative regression) and univariate (χ2) models often portrayed red brome distribution as well, or nearly as well, as more complicated models containing more variables harder to obtain. The models varied, however, in their abilities for describing brome presence compared with absence. For example, a simple classification tree using only elevation, soil great group, parent material, and vegetation type improved estimates of brome presence for 55% of sites, absences for 87%, and overall for 73% of sites compared with a naïve model containing the observed frequency of brome in the data. Conversely, a more complicated model, including soil boron and sulfur, performed better for presences (96%) than for absences (73%; 83% overall). Results also showed variable support for two general postulates in invasive species science. Red brome distribution was not correlated with soil N, which is inconsistent with the supposition that nutrient-rich soils are more prone to invasion. Brome was correlated with native perennial species richness to support the postulate that exotic species abundance is correlated with species-rich habitats, but the correlation was weak (r = 0.38) and similar in strength to correlations with many other environmental variables. On this relatively low-elevation landscape, the areas currently most invaded by red brome include the higher elevations (> 777 m [2,549 ft]), limestone–sandstone soils, and burrobush and mixed perennial communities. Areas least inhabited by brome are the lowest elevations (< 491 m), gypsum soils, and creosotebush and saltbush communities.
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Blackshaw, Robert E. "Downy Brome (Bromus tectorum) Interference in Winter Rye (Secale cereale)." Weed Science 41, no. 4 (December 1993): 557–62. http://dx.doi.org/10.1017/s0043174500076311.
Full textAbstract:
Field experiments over 3 yr at Lethbridge, Alberta, determined the effect of various downy brome densities and times of its emergence on winter rye biomass and seed yield. Downy brome reduced yields most when it emerged within 3 wk of rye, but densities of more than 100 downy brome m-2were required to reduce yields by 20 to 30%. The greatest reductions in rye biomass (28%) and seed (33%) yields over the 3 yr occurred when 400 downy brome m-2emerged with the crop. Downy brome, at densities up to 400 plants m-2, emerging 6 wk after rye or in early spring, reduced rye biomass and seed yield less than 10% in all years. Winter rye effectively shaded downy brome (40 to 90%) for much of the growing season.
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Stougaard, Robert N., Carol A. Mallory-Smith, and James A. Mickelson. "Downy Brome (Bromus tectorum) Response to Imazamox Rate and Application Timing in Herbicide-Resistant Winter Wheat." Weed Technology 18, no. 4 (December 2004): 1043–48. http://dx.doi.org/10.1614/wt-03-216r1.
Full textAbstract:
Field experiments were conducted at Kalispell, MT, and Corvallis, OR, to determine the optimum rate and application timing of imazamox for downy brome control in winter wheat. Crop injury occurred as a reduction in plant height and was minimal at Kalispell, never exceeding 10%. Crop injury at Corvallis was more severe and was dependant on application timing. No injury was observed with spring applications, but fall applications resulted in as much as 33% injury at the highest rate of imazamox. Fall applications generally provided more consistent control of downy brome, as evidenced by the lower dosage required to reduce downy brome dry weight by 50% (lowerI50values). Nonetheless, spring applications generally provided control comparable with that of fall applications when imazamox was applied at the highest rate. The one exception was at Corvallis during 1997 to 1998, where spring applications failed to provide adequate control of downy brome even at the highest rate applied. Although imazamox generally provided excellent control of downy brome, wheat yield response to downy brome interference was negligible, declining by less than 10% in the absence of imazamox. The absence of a yield response to downy brome interference was attributed to the lack of competition for soil moisture from downy brome under the high-rainfall conditions of the experiment.
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Blackshaw, Robert E. "Rotation Affects Downy Brome (Bromus tectorum) in Winter Wheat (Triticum aestivum)." Weed Technology 8, no. 4 (December 1994): 728–32. http://dx.doi.org/10.1017/s0890037x00028591.
Full textAbstract:
Downy brome control in winter wheat is often inadequate. The effects of three crop rotations and two tillage intensities on downy brome populations and associated crop yields were determined in an experiment at Lethbridge, Alberta from 1987 to 1993. Downy brome densities in continuous winter wheat increased from 24 to 970 plants/m2between 1988 and 1993; and were often higher with zero tillage. Inclusion of fallow or spring canola in rotation with winter wheat suppressed downy brome densities to less than 55 and 100 plants/m2, respectively, over the six years. In continuous winter wheat, yields decreased as downy brome densities increased progressively over years, indicating that monoculture winter wheat production will not be viable in regions where downy brome is prevalent unless effective herbicides are developed. In the more arid areas of the Canadian prairies, a winter wheat-fallow rotation may be most suitable but in higher precipitation areas, a winter wheat-canola rotation is a viable alternative. Crop rotation is a key component of an improved management system for control of downy brome.
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Geier, Patrick W., and Phillip W. Stahlman. "Dose-Responses of Weeds and Winter Wheat (Triticum aestivum) to MON 37500." Weed Technology 10, no. 4 (December 1996): 870–75. http://dx.doi.org/10.1017/s0890037x0004094x.
Full textAbstract:
Greenhouse studies determined the dose-responses of cheat, downy brome, Japanese brome, jointed goatgrass, and winter wheat to preplant-incorporated MON 37500 and its residual effects on kochia. Concentrations of MON 37500 up to 60 ppbw did not affect winter wheat. MON 37500 did not prevent weed emergence, but increasingly inhibited weed growth as the dose was increased up to about 20 ppbw. GR50values were 16, 16, 11, and 31 ppbw for cheat, downy brome, Japanese brome, and jointed goatgrass, respectively. Japanese brome was more susceptible than cheat or downy brome, and jointed goatgrass tolerated two to three times more MON 37500 than theBromusspecies. Plant dry weights of kochia seeded after removal of the winter annual grasses decreased with increasing initial MON 37500 concentrations up to 20 ppbw. Kochia density was influenced by which winter annual grass was grown previously.
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Escorial, Concepción, Iñigo Loureiro, Enrique Rodríguez-García, and Cristina Chueca. "Population Variability in the Response of Ripgut Brome (Bromus diandrus) to Sulfosulfuron and Glyphosate Herbicides." Weed Science 59, no. 1 (March 2011): 107–12. http://dx.doi.org/10.1614/ws-d-10-00033.1.
Full textAbstract:
Ripgut brome has become a problematic weed in Spain both as a consequence of the continuous cropping of winter wheat through minimal tillage systems and its difficult control with selective herbicides. Ripgut brome populations collected in the regions of Castilla-León and Cataluña, two main cereal-growing areas in Spain, were screened in the greenhouse for response to sulfosulfuron, a selective herbicide for the control of brome grasses in wheat, and to glyphosate, often used as a pre-plant knockdown to control bromes in no-till systems. The fresh weight percentage relative to the untreated controls was calculated for each ripgut brome population and herbicide and was used as a measure of the herbicide response. Results showed variation in fresh weight response to both herbicides among populations. Fresh weight of the populations after sulfosulfuron was applied at the two-leaf stage at a rate of 20 g ai ha−1varied from 3% in the most susceptible population to 35% in the most resistant; the response was similar (6 to 38%) when the herbicide dose was reduced to half. For glyphosate at 800 g ae ha−1, fresh weight varied from 2 to 25% among populations, but the range of variation in fresh weight response increased as herbicide dose decreased to one half, with rates of from 4% to 90% among populations. The location of the collection site (inside the field or in-margin) showed no differences in response to both herbicides, but there was a statistically significant, geographically correlated differentiation for glyphosate response, with a greater resistance in the populations from Castilla-León. Undamaged plants were found after treatments with both herbicides, showing differences in resistance among plants. The study shows inter- and intrapopulation variability for the response of ripgut brome to sulfosulfuron and glyphosate. The implications for resistance development are discussed within the framework of relationships of the structure of the populations relative to their herbicide response.
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Anderson, Randy L. "Timing of Nitrogen Application Affects Downy Brome (Bromus tectorum) Growth in Winter Wheat." Weed Technology 5, no. 3 (September 1991): 582–85. http://dx.doi.org/10.1017/s0890037x00027378.
Full textAbstract:
Field studies were conducted to determine if varying the time N fertilizer was applied would affect downy brome interference in winter wheat. Five treatments were compared: four broadcast application times of NH4NO3at 56 kg N ha-1during the fallow-crop cycle: 1) during fallow; 2) at planting; 3) during crop dormancy; 4) before winter wheat jointing; and 5) a control where no N was applied. Downy brome was least responsive to N applied during fallow. All N applications during the growing season of winter wheat increased downy brome biomass and culms m-2. Downy brome interference prevented winter wheat from responding positively to N. For example, when crop season precipitation was only 70% of normal, applying N reduced grain yield of winter wheat infested with downy brome from 12 to 28%. This study indicates that N manipulation offers potential for reducing downy brome interference in winter wheat.
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Mangold, Jane, Hilary Parkinson, Celestine Duncan, Peter Rice, Ed Davis, and Fabian Menalled. "Downy Brome (Bromus tectorum) Control with Imazapic on Montana Grasslands." Invasive Plant Science and Management 6, no. 4 (December 2013): 554–58. http://dx.doi.org/10.1614/ipsm-d-13-00016.1.
Full textAbstract:
AbstractDowny brome is a problematic invasive annual grass throughout western rangeland and has been increasing its abundance, spread, and impacts across Montana during the past several years. In an effort to develop effective management recommendations for control of downy brome on Montana rangeland, we compiled data from 24 trials across the state that investigated efficacy of imazapic (Plateau®, BASF Corporation, Research Triangle Park, NC) applied at various rates and timings and with methylated seed oil (MSO) or a nonionic surfactant (NIS). We ran a mixed-model ANOVA to test for main effects and interactions across application rate (70, 105, 141, 176, and 211 g ai ha−1), application timing (preemergent [PRE], early postemergent [EPOST, one- to two-leaf growth stage], and postemergent [POST, three- to four-leaf growth stage]), and adjuvant (MSO, NIS). Application timing and rate interacted to affect downy brome control (P = 0.0033). PRE imazapic application resulted in the lowest downy brome control (5 to 19%), followed by POST application (25 to 77%) and EPOST application (70 to 95%). Downy brome control remained fairly consistent across rates within application timing. Adjuvant (MSO or NIS) did not affect downy brome control (P = 0.2789). Our data indicate that POST application at 105 to 141 g ai ha−1 provides the most-consistent, short-term control of downy brome. Furthermore, applying imazapic to downy brome seedlings shortly after emergence (one- to two-leaf growth stage) provided better control than applying it to older downy brome seedlings (three- to four-leaf growth stage).
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Mealor, Brian A., Samuel Cox, and D. Terrance Booth. "Postfire Downy Brome (Bromus tectorum) Invasion at High Elevations in Wyoming." Invasive Plant Science and Management 5, no. 4 (December 2012): 427–35. http://dx.doi.org/10.1614/ipsm-d-11-00096.1.
Full textAbstract:
AbstractThe invasive annual grass downy brome is the most ubiquitous weed in sagebrush systems of western North America. The center of invasion has largely been the Great Basin region, but there is an increasing abundance and distribution in the Rocky Mountain States. We evaluated postfire vegetation change using very large–scale aerial (VLSA) and near-earth imagery in an area where six different fires occurred over a 4-yr period at elevations ranging from 1,900 to over 2,700 m. The frequency of downy brome increased from 8% in 2003 to 44% in 2008 and downy brome canopy cover increased from < 1% in 2003 to 6% in 2008 across the entire study area. Principal component analyses of vegetation cover indicate a shift from plant communities characterized by high bare soil and forbs immediately postfire to communities with increasing downy brome cover with time after fire. The highest-elevation sampling area exhibited the least downy brome cover, but cover at some midelevation locations approached 100%. We postulate that the loss of ground-level shade beneath shrubs and conifers, accompanied by diminished perennial vegetative cover, created conditions suitable for downy brome establishment and dominance. Without a cost-effective means of landscape-scale downy brome control, and with infestation levels and climate warming increasing, we predict there will be continued encroachment of downy brome at higher elevations and latitudes where disturbance creates suitable conditions.
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Wicks, Gail A. "Survival of downy brome (Bromus tectorum) seed in four environments." Weed Science 45, no. 2 (April 1997): 225–28. http://dx.doi.org/10.1017/s0043174500092754.
Full textAbstract:
Downy brome is one of the most troublesome winter annual weeds in winter wheat-fallow rotations in the central Great Plains. A 3-yr seed burial study was initiated to determine how long downy brome seed remained germinable when placed on the soil surface or 2.5 cm deep at four different times in four environments. Only 1 to 7% of the downy brome seed survived after 1 yr on the soil surface in chemical fallow and stubble mulch when deposited in August, but survival varied in September, October, and November. In 1970, a year with low fall and winter precipitation, 36 to 46% of the seed placed on the soil surface of chemical fallow in September, October, and November survived, compared with 1 to 8% for stubble mulch tillage. Early spring tillage covered more seed with soil, and downy brome seed survival decreased. When fall and winter precipitation was normal, stubble mulch and chemical fallow had 1 to 20% germinable seed remaining. Induced dormancy existed in some years. More downy brome seed survived when placed on the soil surface of crested wheatgrass sod (14 to 50%) than on smooth brome sod (0 to 36%). No differences existed among environments when downy brome seed was buried 2.5 cm deep. Only 0.4% of downy brome seed buried 2.5 cm survived after 1 yr when averaged across all environments.
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Slopek, Jessica I., and Eric G. Lamb. "Long-Term Efficacy of Glyphosate for Smooth Brome Control in Native Prairie." Invasive Plant Science and Management 10, no. 4 (November 21, 2017): 350–55. http://dx.doi.org/10.1017/inp.2017.33.
Full textAbstract:
Effective control measures are required for the invasive forage grass smooth brome in native prairie to maintain native prairie diversity and function. The objective of this study was to assess the long-term effectiveness of glyphosate as a control method for smooth brome and to evaluate the subsequent recovery of native prairie species at Kernen Prairie near Saskatoon, SK, Canada. In 1999 and 2000, a total of forty 6- to 8-m-diameter patches of smooth brome were spot sprayed with glyphosate; community composition in each patch was monitored for 17 yr. Following glyphosate application, the abundance of smooth brome decreased, and recovery of native species richness and the abundance of important native species, including plains rough fescue, was observed. In the long term however, the elimination of smooth brome created empty niche space ultimately occupied by other invasive species, particularly Kentucky bluegrass. The spot application of glyphosate is thus an effective control method for reducing smooth brome in native prairie; however, maintaining desirable native species composition in this system posttreatment depends on other factors, including the presence of additional invasive species that may move in after the elimination of smooth brome.
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Gealy, David R., S. Gurusiddaiah, Alex G. Ogg, and Ann C. Kennedy. "Metabolites fromPseudomonas fluorescensStrain D7 Inhibit Downy Brome (Bromus tectorum) Seedling Growth." Weed Technology 10, no. 2 (June 1996): 282–87. http://dx.doi.org/10.1017/s0890037x00039968.
Full textAbstract:
Phytotoxins produced by the naturally-occurring rhizobacterium,Pseudomonas fluorescensstrain D7 (strain D7), in shake cultures from several media sources adversely affected downy brome at several growth stages and affected seeds, whole plants, and isolated cells. These uncharacterized phytotoxins inhibited root and shoot growth of downy brome by 80% in a seed germination agar assay at 2 and 400 ng total solids/ml, respectively. In a hydroponics assay, downy brome and winter wheat dry weights were reduced 50% by cell-free broth concentrations of 15 and 26% of the initial broth concentration, respectively, indicating an almost 2x selectivity between winter wheat and downy brome. Plant water use was reduced similarly. Plasma membranes of isolated protoplasts of downy brome were damaged within 2 h by diluted cell-free broth. Cold-precipitated phytotoxins of strain D7 produced in semi-synthetic and synthetic media reduced dry weight of downy brome seedlings by 100 and 89%, respectively, and killed plants rapidly.
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Whitson, Tom D., and David W. Koch. "Control of Downy Brome (Bromus tectorum) with Herbicides and Perennial Grass Competition." Weed Technology 12, no. 2 (June 1998): 391–96. http://dx.doi.org/10.1017/s0890037x00043980.
Full textAbstract:
Long-term control of downy brome with an integrated approach is needed in order to sustain range productivity. Studies were conducted to study the effectiveness of a combination of downy brome control practices. In two studies, glyphosate and paraquat were evaluated at various rates for up to three successive years for control of downy brome in rangeland. A third study evaluated the competitiveness of perennial cool-season grasses against downy brome in the absence of herbicides. Glyphosate, at 0.55 kg/ha, and 0.6 kg/ha paraquat provided selective downy brome control on rangeland when applications were combined with intensive grazing. Downy brome control was greater than 90% following two sequential years of 0.6 kg/ha paraquat at either the two- to eight-leaf stage or bloom stage at both study locations. At one study location, 0.55 kg/ha glyphosate provided 97% control after the first application at both growth stages. In the second study, control averaged greater than 92% following three sequential applications of glyphosate. When perennial cool-season grasses were seeded in the spring following fall tillage (no herbicides) and allowed to establish for three growing seasons, three of the five species were effective in reducing the reestablishment of downy brome. ‘Luna’ pubescent wheatgrass, ‘Hycrest’ crested wheatgrass, ‘Sodar’ streambank wheatgrass, ‘Bozoisky’ Russian wildrye, and ‘Critana’ thickspike wheatgrass controlled 100, 91, 85, 45, and 32% of the downy brome, respectively. Yields of perennial grass dry matter were 1,714, 1,596, 1,135, 900, and 792 kg/ha. Replacing noncompetitive annual grasses with competitive cool-season perennials will provide a longer term solution to a downy brome problem than the use of herbicides alone or with intensive grazing.
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DOUGLAS, B. J., A. G. THOMAS, and D. A. DERKSEN. "DOWNY BROME (Bromus tectorum) INVASION INTO SOUTHWESTERN SASKATCHEWAN." Canadian Journal of Plant Science 70, no. 4 (October 1, 1990): 1143–51. http://dx.doi.org/10.4141/cjps90-136.
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Downy brome (Bromus tectorum L.) has rapidly invaded crop and pasture land in southwestern Saskatchewan since 1960. By 1989, 116 townships in 31 rural municipalities were infested. The spread of downy brome is associated with the increased area of winter wheat and fall rye grown using minimum and zero tillage practices, a lack of effective herbicides for selective in crop control and weather conditions which favor autumn germination and early spring competition. Although downy brome has been found on seven soil associations in the Brown soil zone and one association in the Dark Brown soil zone, the occurrence of the weed is related to cropping practices rather than soil texture or association.Key words: Downy brome distribution, downy brome invasion, Bromus tectorum, winter wheat
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Johnston, Danielle Bilyeu, and Phillip L. Chapman. "Rough Surface and High-Forb Seed Mix Promote Ecological Restoration of Simulated Well Pads." Invasive Plant Science and Management 7, no. 3 (September 2014): 408–24. http://dx.doi.org/10.1614/ipsm-d-13-00087.1.
Full textAbstract:
AbstractBecause of disturbance and exotic plant invasions, ecological restoration is necessary for maintaining functional big sagebrush ecosystems in western North America. Downy brome control is often necessary in restoring this ecosystem type; however, many brome control measures hinder ecological restoration by limiting the types of plants which can be established. Microtopography manipulation may aid weed control by entrapping undesirable seeds. We undertook a field experiment at four sites in the Piceance Basin of western Colorado, USA to test the effects of microtopography (rough with brush mulch or flat with straw mulch), seed mix (high-forb or balanced), and herbicide (140 g ai ha−1 imazapic ammonium salt or none) on downy brome control and perennial plant establishment following disturbance. Three years post-treatment, downy brome had become established at two of the four sites, one each with high (GVM) and low (MTN) downy brome seed rain. At GVM, the rough/brush treatment augmented the effectiveness of imazapic, reducing downy brome biomass six-fold. At MTN, the rough/brush surface reduced downy brome biomass 10-fold in the absence of imazapic. Across all four sites, forb and shrub biomass were higher with the high-forb mix, and there was no effect of seed mix on downy brome or annual forb biomass. Restoring a full complement of plant functional groups in big sagebrush ecosystems may be aided by increasing forbs in seed mixes, and manipulating soil microtopography.
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Vashurin, Artur, Vladimir Maizlish, Ilya Kuzmin, Serafima Znoyko, Anastasiya Morozova, Mikhail Razumov, and Oscar Koifman. "Symmetrical and difunctional substituted cobalt phthalocyanines with benzoic acids fragments: Synthesis and catalytic activity." Journal of Porphyrins and Phthalocyanines 21, no. 01 (January 2017): 37–47. http://dx.doi.org/10.1142/s108842461750002x.
Full textAbstract:
Difunctional and symmetric phthalonitriles were synthesized by nucleophilic substitution of brome and nitro-group in 4-bromo-5-nitro-phthalonitrile for residues 4-amino-, 4-hydroxyl- and 4-sulfanyl benzoic acid. Symmetrical and difunctional substituted cobalt phthalocyanines were obtained by template synthesis based on mentioned phthalonitriles. Their spectral properties and catalytic activity in aerobic oxidation of sodium [Formula: see text],[Formula: see text]-carbomoditiolate were investigated.
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Hendrickson, Paul E., and Carol A. Mallory-Smith. "Response of Downy Brome (Bromus tectorum) and Kentucky Bluegrass (Poa pratensis) to Applications of Primisulfuron." Weed Technology 13, no. 3 (September 1999): 461–65. http://dx.doi.org/10.1017/s0890037x00046030.
Full textAbstract:
Greenhouse and growth chamber experiments were conducted to evaluate primisulfuron phytotoxicity to downy brome (Bromus tectorum) and Kentucky bluegrass (Poa pratensis) as a function of herbicide placement, adjuvants, and environmental conditions. Primisulfuron rates needed to produce GR50(50% growth reduction) values were 0.97 ± 0.57 and 8.07 ± 1.85 g/ha for downy brome and Kentucky bluegrass, respectively. Primisulfuron was applied to downy brome and Kentucky bluegrass at three placement sites: foliar, soil, and foliar plus soil. Foliar or foliar plus soil applications were more effective at reducing downy brome dry weights than the soil application of primisulfuron, whereas Kentucky bluegrass was injured more from the soil or foliar plus soil applications than from the foliar application of primisulfuron. Primisulfuron at 5 g/ha applied alone reduced downy brome dry weights by 5%, whereas when an adjuvant was added, dry weights were reduced by 52 to 83%. Primisulfuron was more phytotoxic to downy brome at alternating temperatures of 8 to 16 C and 16 to 24 C than at 0 to 8 C. Phytotoxicity of primisulfuron was less when downy brome plants were stressed for soil moisture after herbicide treatments than when the plants were not stressed or only stressed before treatment.
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Bromberg, James E., Sunil Kumar, Cynthia S. Brown, and Thomas J. Stohlgren. "Distributional Changes and Range Predictions of Downy Brome (Bromus tectorum) in Rocky Mountain National Park." Invasive Plant Science and Management 4, no. 2 (April 2011): 173–82. http://dx.doi.org/10.1614/ipsm-d-10-00022.1.
Full textAbstract:
AbstractDowny brome (Bromus tectorumL.), an invasive winter annual grass, may be increasing in extent and abundance at high elevations in the western United States. This would pose a great threat to high-elevation plant communities and resources. However, data to track this species in high-elevation environments are limited. To address changes in the distribution and abundance of downy brome and the factors most associated with its occurrence, we used field sampling and statistical methods, and niche modeling. In 2007, we resampled plots from two vegetation surveys in Rocky Mountain National Park for presence and cover of downy brome. One survey was established in 1993 and had been resampled in 1999. The other survey was established in 1996 and had not been resampled until our study. Although not all comparisons between years demonstrated significant changes in downy brome abundance, its mean cover increased nearly fivefold from 1993 (0.7%) to 2007 (3.6%) in one of the two vegetation surveys (P = 0.06). Although the average cover of downy brome within the second survey appeared to be increasing from 1996 to 2007, this slight change from 0.5% to 1.2% was not statistically significant (P = 0.24). Downy brome was present in 50% more plots in 1999 than in 1993 (P = 0.02) in the first survey. In the second survey, downy brome was present in 30% more plots in 2007 than in 1996 (P = 0.08). Maxent, a species–environmental matching model, was generally able to predict occurrences of downy brome, as new locations were in the ranges predicted by earlier generated models. The model found that distance to roads, elevation, and vegetation community influenced the predictions most. The strong response of downy brome to interannual environmental variability makes detecting change challenging, especially with small sample sizes. However, our results suggest that the area in which downy brome occurs is likely increasing in Rocky Mountain National Park through increased frequency and cover. Field surveys along with predictive modeling will be vital in directing efforts to manage this highly invasive species.
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Morris, Christo, Thomas A. Monaco, and Craig W. Rigby. "Variable Impacts of Imazapic Rate on Downy Brome (Bromus tectorum) and Seeded Species in Two Rangeland Communities." Invasive Plant Science and Management 2, no. 2 (April 2009): 110–19. http://dx.doi.org/10.1614/ipsm-08-104.1.
Full textAbstract:
AbstractThe herbicide imazapic is registered for use on rangelands and provides effective short-term control of certain invasive annual grasses. However, details about optimal application rates for downy brome and susceptibility of simultaneously seeded species are lacking. Thus, we investigated downy brome and seeded species responses to variable rates of imazapic (0, 35, 70, 105, and 140 g ai/ha) in two plant communities (salt desert shrub and Wyoming big sagebrush). In autumn 2003, plots were treated with imazapic and seeded with one of five perennial plant materials (Siberian wheatgrass [‘Vavilov’ and the experimental source Kazak]; prostrate kochia [‘Immigrant’ and the experimental source 6X], and Russian wildrye [‘Bozoisky II’]). Downy brome cover and seeded species establishment were evaluated in spring 2004 and 2006. Downy brome cover in 2004 decreased with increasing imazapic rate at both sites, although more so at the Wyoming big sagebrush site. In 2006, no difference in downy brome cover existed among herbicide rates at the Wyoming big sagebrush site. At the salt desert shrub site, the high rate of imazapic reduced downy brome cover by about 25% compared to untreated plots. ‘Vavilov’ Siberian wheatgrass was the only seeded species with lower downy brome cover in 2006 than 2004. Seeded species establishment increased with imazapic rate in the salt desert shrub community, but in the Wyoming big sagebrush community it peaked at intermediate rates and declined at higher rates. Variation in downy brome control and seeded species establishment might have been associated with differences in precipitation, soil organic matter, and disturbance history between sites. Overall, imazapic was useful for helping establish desirable perennial species, but unless downy brome is reduced below a critical threshold, favorable precipitation can return sites to pretreatment levels within two years.
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Ball, Daniel A. "Effects of Aminocyclopyrachlor Herbicide on Downy Brome (Bromus tectorum) Seed Production under Field Conditions." Invasive Plant Science and Management 7, no. 4 (December 2014): 561–64. http://dx.doi.org/10.1614/ipsm-d-13-00097.1.
Full textAbstract:
AbstractPrevious research has shown that pyridine growth regulator herbicides can affect seed production in annual grasses including downy brome, Japanese brome, wheat, and other cereal grain crops. Aminocyclopyrachlor is a pyridine carboxylic acid growth regulator herbicide that has recently been registered for broadleaf weed and brush control in nonagricultural areas, which may help facilitate release of native perennial grasses in native plant restoration sites. The influence of aminocyclopyrachlor on downy brome seed production was evaluated at multiple application rates and timings under controlled field conditions. The effect of aminocyclopyrachlor on seed production was compared with aminopyralid, another pyridine growth regulator herbicide. When applied to downy brome plants in the early vegetative stage (EPOST) at approximately 580 growing degree days (GDD), aminocyclopyrachlor at 320 g ae ha−1 reduced seed germination by 50 to 88% in the first and second study years, respectively. Aminopyralid reduced seed germination by 94% in the first study year, but only 20% in the second year. When applied to downy brome plants in the early heading stage at approximately 1,235 GDD (LPOST), aminocyclopyrachlor at 320 g ae ha−1 reduced seed germination by 100% both years. Aminopyralid reduced seed germination by 95% in the first year, and 81% in the second year. Other than the observed reduction in seed germination, herbicides did not produce any visible changes in downy brome aboveground plant growth or development. Because downy brome seeds are relatively short-lived in soil, aminocyclopyrachlor and aminopyralid applications to downy brome–infested rangelands and other natural areas could result in reductions in downy brome population densities over time. No published data exist on the effect of aminocyclopyrachlor on seed production of desirable perennial grasses in natural ecosystems, thereby suggesting the need for further research.
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Rinella, Matthew J., Robert A. Masters, and Susan E. Bellows. "Effects of Growth Regulator Herbicide on Downy Brome (Bromus tectorum) Seed Production." Invasive Plant Science and Management 6, no. 1 (March 2013): 60–64. http://dx.doi.org/10.1614/ipsm-d-12-00033.1.
Full textAbstract:
AbstractPrevious research showed growth regulator herbicides, such as picloram and aminopyralid, have a sterilizing effect on Japanese brome (Bromus japonicus Thunb.) that can reduce this invasive annual grass's seed production nearly 100%. This suggests growth regulators might be used to control invasive annual grasses by depleting their short-lived seed banks. The goal of this study was to extend the previous Japanese brome research to downy brome (Bromus tectorum L.), the most damaging invasive annual grass of U.S. grasslands. In a greenhouse, we found picloram did not greatly influence downy brome seed production, while point estimates suggest aminopyralid reduced seed production 55 to 80%. If not for a highly abnormal retillering response that we somewhat doubt would occur in the field, point estimates suggest aminopyralid would have reduced downy brome seed production approximately 90% when applied at the heading stage and approximately 98% when applied at three earlier growth stages. Our greenhouse study should encourage field studies designed to further explore the potential for using growth regulators to control downy brome and other invasive annual grasses.
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Orloff, L. Noelle, Jane M. Mangold, and Fabian D. Menalled. "Role of Size and Nitrogen in Competition between Annual and Perennial Grasses." Invasive Plant Science and Management 6, no. 1 (March 2013): 87–98. http://dx.doi.org/10.1614/ipsm-d-12-00035.1.
Full textAbstract:
AbstractDiffering life histories contribute to difficulties establishing perennial grasses on lands dominated by exotic annual grasses. In a greenhouse study, we investigated to what extent allowing the perennial grass bluebunch wheatgrass to emerge before the exotic annual grass downy brome would increase its competitive ability and whether modifying nitrogen (N) would affect competition. We conducted an addition-series factorial experiment. In three cohort treatments, the two species were seeded concurrently or bluebunch wheatgrass was at the two- or four-leaf stage when downy brome was planted. N treatments were low (ambient) or high (N added to maintain 10 mg kg−1 [0.1286 oz lb−1]). Larger bluebunch wheatgrass avoided suppression by downy brome regardless of N. Under concurrent sowing, doubling downy brome density decreased bluebunch wheatgrass biomass by 22.6% ± 2.38 SE. In contrast, when bluebunch wheatgrass had a four-leaf size advantage, the same increase in downy brome density decreased bluebunch wheatgrass biomass by 4.14% ± 2.31. Larger bluebunch wheatgrass also suppressed downy brome more effectively, but N enrichment decreased the suppressive ability of bluebunch wheatgrass.
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Buman, Robert A., David R. Gealy, and Alex G. Ogg. "Inhibition of Photosynthesis in Downy Brome (Bromus tectorum) and Jointed Goatgrass (Aegilops cylindrica) Protoplasts by Metribuzin and its Ethylthio Analog." Weed Science 39, no. 1 (March 1991): 13–17. http://dx.doi.org/10.1017/s0043174500057799.
Full textAbstract:
Inhibition of net photosynthesis of jointed goatgrass and downy brome protoplasts by metribuzin and its ethylthio analog (ethyl-metribuzin) was greater at 25 than at 10 C. As temperature increased from 10 to 25 C, the concentration of ethyl-metribuzin required to inhibit net photosynthesis 50% (I50) decreased by a factor of 3.5 and 4.3, respectively, in jointed goatgrass and downy brome. I50values for metribuzin decreased by a factor of 1.5 and 2.5 in jointed goatgrass and downy brome, respectively, for the same 15 C increase in temperature. Based on I50values at 10 C, metribuzin was nine times more inhibitory than ethyl-metribuzin in jointed goatgrass and eight times more inhibitory in downy brome. At 25 C, metribuzin was only 4.7 and 3.9 times more inhibitory than ethyl-metribuzin in jointed goatgrass and downy brome, respectively. Thus, cold temperatures reduced the activity of ethyl-metribuzin more than metribuzin. The activity of both herbicides was reduced less in protoplasts of jointed goatgrass than in protoplasts of downy brome over the 15 C range.
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Johnston, Danielle B. "Downy Brome (Bromus tectorum) Control for Pipeline Restoration." Invasive Plant Science and Management 8, no. 2 (June 2015): 181–92. http://dx.doi.org/10.1614/ipsm-d-14-00001.1.
Full textAbstract:
Energy-extraction disturbances entail soil handling and often have large edge-to-area ratios. These characteristics should be considered when designing weed-control strategies. In western North America, many energy developments coincide with infestations of downy brome, an annual grass that severely curtails productivity, diversity, and habitat value of invaded areas. Downy brome is sensitive to soil compaction and seed burial, both of which may occur when soil is handled. In this study, I examined the effect of soil-density manipulations and herbicide application (105 g ai ha−1 imazapic with 280 g ai ha−1 glyphosate) on six simulated pipeline disturbances in a Wyoming big sagebrush ecosystem invaded by downy brome. Disturbances occurred at the end of the growing season, after ambient downy brome seed rain in the study areas had abated. Treatments and seeding occurred shortly after disturbances. The following spring, downy brome seedling density was 10-fold lower within disturbances than in control areas, but seedling density quickly rebounded in disturbed areas where no herbicide had been applied. In herbicide plots, downy brome seedling density remained low during the first growing season, and shrub cover after 3 yr was eight times higher than in no-herbicide plots. Soil density manipulations via disking and rolling treatments had little effect on downy brome. Prior research has shown that imazapic is more effective when combined with disturbances, such as fire. This study demonstrates that imazapic may also be effective in combination with a disturbance that is timed to bury downy brome seeds.
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Swan, Dean G., and Ralph E. Whitesides. "Downy Brome (Bromus tectorum) Control in Winter Wheat." Weed Technology 2, no. 4 (October 1988): 481–85. http://dx.doi.org/10.1017/s0890037x00032309.
Full textAbstract:
Metribuzin at 0.42 kg ai/ha and metribuzin plus terbutryn at 0.28 plus 0.67 kg/ha were applied in the fall and spring to control downy brome in winter wheat from 1981 through 1985. Downy brome control averaged 88% from the fall-applied treatments and 63% from the spring-applied treatments. Yields from the fall- and spring-applied treatments averaged 136% and 132% of the check, respectively. Metribuzin plus terbutryn fall-applied controlled downy brome best (93%), and wheat yields were significantly higher than the checks in all experiments. Moreover, as downy brome density among locations increased, wheat yields decreased.