Herbicide-Grazing Interactions in Cheat (Bromus secalinus)–Infested Winter Wheat (Triticum aestivum)1

Weed Science ◽  
1990 ◽  
Vol 38 (6) ◽  
pp. 532-535 ◽  
Author(s):  
Jeffrey A. Koscelny ◽  
Thomas F. Peeper

Field experiments were conducted to determine the interaction of grazing and herbicide treatments on cheat control and biomass, wheat biomass, wheat grain yield, and wheat yield components. Ethyl-metribuzin at 1120 g ai ha−1and metribuzin at 420 g ai ha−1reduced cheat biomass 91 to 99 and 97 to 98%, respectively. Grazing had no effect on herbicide efficacy. Grazing increased cheat biomass in the check by 24% at only one location but did not affect total wheat plus cheat biomass. With one exception, controlled cheat was replaced by wheat on a 1:1 biomass basis when herbicides caused no crop injury. All herbicide treatments increased grain yield, but grazing did not alter yield. At two locations, increased heads m−2and spikelets/head accounted for most of the grain yield increases, but at one location seeds/spikelet and weight/seed were also increased. Harvest index was unaffected.

1997 ◽  
Vol 11 (1) ◽  
pp. 30-34
Author(s):  
Jeffrey A. Koscelny ◽  
Thomas F. Peeper

Seven field experiments were conducted in Oklahoma to compare efficacy and wheat response to currently registered cheat suppression or control herbicide treatments. Chlorsulfuron + metsulfuron premix (5:1 w/w) at 26 g ai/ha applied PRE controlled cheat 20 to 61%, increased wheat grain yields at two of seven locations, and decreased dockage due to cheat at five of seven locations. Chlorsulfuron + metsulfuron at 21 g/ha tank-mixed with metribuzin at 210 g/ha, applied early fall POST, controlled cheat 36 to 98% and increased wheat yield at four of seven locations. Metribuzin applied POST in the fall at 420 g/ha controlled cheat 56 to 98% and increased wheat yields at five of seven locations. Both POST treatments decreased dockage at all locations.


1990 ◽  
Vol 4 (3) ◽  
pp. 565-568 ◽  
Author(s):  
Jeffrey A. Koscelny ◽  
Thomas F. Peeper

Data from three field experiments were used to determine the effects of grazing cheat-infested winter wheat during tillering on cheat and wheat growth, mature biomass, and wheat grain yield components. When terminated, grazing had reduced wheat leaf area 52% and cheat leaf area by 28%. Pooled over experiments, grazing decreased mature wheat height 7 cm and wheat yield 17%. Grazing increased dockage due primarily to cheat 9%. Grazing effects on wheat yield components, biomass, and cheat panicle density varied. Grazing did not affect cheat tillering or wheat harvest index.


1996 ◽  
Vol 10 (3) ◽  
pp. 531-534 ◽  
Author(s):  
Jeffrey A. Koscelny ◽  
Thomas F. Peeper ◽  
Eugene G. Krenzer

Field experiments were conducted to determine whether residual sulfonylurea herbicides applied at cheat suppression rates affect hard red winter wheat forage production and grain yield. Triasulfuron at 30 g/ha or chlorsulfuron plus metsulfuron at 26 g/ha applied PRE and metribuzin applied early POST alone at 280 g/ha or tank-mixed with triasulfuron at 158 + 30 g/ha or chlorsulfuron plus metsulfuron at 210 + 21 g/ha, all decreased total forage production of weed-free wheat. Conversely, all herbicide treatments except triasulfuron applied PRE increased wheat grain yield.


1991 ◽  
Vol 5 (4) ◽  
pp. 707-712 ◽  
Author(s):  
Jeffrey A. Koscelny ◽  
Thomas F. Peeper ◽  
John B. Solie ◽  
Stanley G. Solomon

Field experiments were conducted in Oklahoma to determine the effects of winter wheat seeding date and cheat infestation level on cultural cheat control obtained by increasing winter wheat seeding rates and decreasing row spacing. Seeding rate and row spacing interactions influenced cheat density, biomass, or seed in harvested wheat (dockage) at two of three locations. Suppressive effects on cheat of increasing wheat seeding rates and reduced row spacings were greater in wheat seeded in September than later. At two other locations, increasing seeding rate from 67 to 101 kg ha–1or reducing row spacings from 22.5 to 15 cm increased winter wheat yield over a range of cheat infestation levels.


1995 ◽  
Vol 9 (1) ◽  
pp. 131-140 ◽  
Author(s):  
Lora M. Franetovich ◽  
Thomas F. Peeper

Thirteen field experiments were conducted to evaluate quinclorac for cheat control in hard red winter wheat. Cheat control with quinclorac was variable. Quinclorac at 560 and 1120 g a.i./ha applied to tillered wheat controlled cheat 93 to 100% at four sites. In contrast, pooled over four other experiments and four application times, quinclorac at 420 g/ha and 560 g/ha controlled cheat only 20 and 31%, respectively. Quinclorac at 420 g/ha plus chlorsulfuron:metsulfuron (5:1) at 35 g a.i./ha applied PRE increased wheat yield 28% at one of three sites. At two of these sites, averaged over chlorsulfuron:metsulfuron rates of 0, 18, and 35 g a.i./ha, quinclorac at 280 and 420 g/ha applied POST, increased wheat yield 32 to 112%. In two cultivar tolerance experiments, quinclorac treatments did not damage any cultivar. Pooled over cultivars, yields were increased 7 and 10% when quinclorac at 280 and 560 kg/ha was applied, respectively. In a greenhouse experiment, quinclorac plus dicamba or esfenvalerate consistently reduced the leaf area of cheat in a manner suggesting synergistic effects. Of eight adjuvants evaluated in a laboratory experiment, only quinclorac plus the adjuvant BCH 864 01S reduced cheat leaf area more than quinclorac alone.


1993 ◽  
Vol 7 (4) ◽  
pp. 851-854 ◽  
Author(s):  
Jacquelyn E. Driver ◽  
Thomas F. Peeper ◽  
Jeffrey A. Koscelny

Ten field experiments were conducted in Oklahoma from 1988 to 1992 to evaluate chlorsulfuron plus metsulfuron (5:1 w/w) and triasulfuron for cheat control in winter wheat. Cheat control by chlorsulfuron plus metsulfuron at 18 and 26 g ai/ha varied from 0 to 81% and by triasulfuron at 18 and 30 g ai/ha from 0 to 60%. Grain yield was increased in four experiments and dockage was reduced in five experiments by both rates of chlorsulfuron plus metsulfuron.


1993 ◽  
Vol 7 (2) ◽  
pp. 459-464 ◽  
Author(s):  
Greg G. Justice ◽  
Thomas F. Peeper ◽  
John B. Solie ◽  
Francis M. Epplin

In field experiments, wheat row spacing, seeding rate, and herbicide treatment affected cheat seed content of harvested wheat, wheat yield, and net returns. No individual practice or combination of practices consistently increased net returns from cheat-infested wheat. Net returns frequently were increased and never decreased by applying metribuzin at 420 g ha−1 or chlorsulfuron + metsulfuron at 21.9 + 4.4 g ha−1 or by increasing the seeding rate compared to baseline inputs. The data indicate that herbicide rates should not be reduced when row spacing is decreased and/or seeding rates increased.


Weed Science ◽  
1986 ◽  
Vol 34 (5) ◽  
pp. 689-693 ◽  
Author(s):  
Challaiah ◽  
Orvin C. Burnside ◽  
Gail A. Wicks ◽  
Virgil A. Johnson

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.


Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.


2020 ◽  
Vol 1 (1) ◽  
pp. 45-49
Author(s):  
Tsotne Samadashvili ◽  
Gulnari Chkhutiashvili ◽  
Mirian Chokheli ◽  
Zoia Sikharulidze ◽  
Qetevan Nacarishvili

Wheat is a vital crop in Georgia and in the world. Because of the increase in the rate of population growth, improving the grain yield is the way to meet food demand. Proper crop nutrition plays a vital role in maintaining the world’s food supply. Fertilizer is essential for accomplishing this.One of the most important means for increasing the wheat yield is fertilizer, especially, organic fertilizer. The present research was carried out to study the effects of different doses (150ml, 200ml and 300 ml on ha) of humic organic fertilizer “Ecorost” on yield of winter wheat cultivar “Tbilisuri 15”. The humic liquid fertilizer "Ecorost" is a peat-based organic-mineral fertilizer. The product is active and saturated due to the use of the latest technology and living bacteria found in peat. The field trials were conducted in 2017-2019 at the Experimental Site of Scientific Research Center of Agriculture in Dedopliskharo- arid region (Eastern Georgia).Liquid fertilizer was applied two times: in tillering stage in early spring and two weeks after - in stem elongation stage. Results indicated that the highest wheat grain yield (4t/ha) was achieved when the plants were fertilized with 300 ml on 1 ha ofEcorost. Applications of liquid fertilizer “Ecorost” increased grain yield of winter wheat by 16.2% in comparison with standard nitrogen fertilization. Thus, liquid fertilizer “Ecorost” had a significant effect on wheat grain yield compared to control standard nitrogen fertilizer.


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