Response of Downy Brome (Bromus tectorum) and Rotational Crops to MON 37500

1998 ◽  
Vol 12 (4) ◽  
pp. 690-698 ◽  
Author(s):  
Sandra L. Shinn ◽  
Donald C. Thill ◽  
William J. Price ◽  
Daniel A. Ball

Field experiments were conducted to determine the effect of different rates and application times of MON 37500 on downy brome control in winter wheat and on rotational crop injury. In southeastern Washington, MON 37500 applied postemergence at 36 to 72 g ai/ha in the fall and spring controlled downy brome 90 to 97% and 45 to 71%, respectively. MON 37500 was applied postemergence to winter wheat at 18, 36, and 72 g/ha during fall 1995 and spring 1996 near Moscow, ID; Pendleton, OR; and Endicott, WA, to determine its effect on rotational crops planted during spring 1997. At Pendleton, OR, fall applications of MON 37500 at 18, 36, and 72 g/ha applied to actively growing wheat reduced seed yield of spring barley and pea 13 to 59% and 26 to 29%, respectively, when these crops followed winter wheat in the rotation. At this site, spring applications of 36 and 72 g/ha reduced seed yield of spring barley 17 to 34%; when applied in the fall or spring, MON 37500 reduced canola yield 31 to 73%. MON 37500 at 18 g/ha in the spring reduced pea biomass 32% at Endicott. Aboveground biomass and seed yield of barley, pea, lentil, and mustard at Moscow were not affected by MON 37500 carryover. However, using a grain sorghum bioassay, predicted final concentrations of MON 37500 in soil at all three locations 360 d after treatment (DAT) was similar, ranging from 0.5 to 2 ng ai/g. In growth chamber herbicide dose–response studies, grain sorghum shoot height was reduced more at lower doses (0.025 to 5 ng/g) of MON 37500 in Pendleton soil than in soils from the other field locations. Perhaps the greater rotational crop injury observed at the Pendleton location was partly related to greater soil activity of the herbicide.

2004 ◽  
Vol 18 (4) ◽  
pp. 1043-1048 ◽  
Author(s):  
Robert N. Stougaard ◽  
Carol A. Mallory-Smith ◽  
James A. Mickelson

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.


Weed Science ◽  
1993 ◽  
Vol 41 (4) ◽  
pp. 551-556 ◽  
Author(s):  
Robert E. Blackshaw

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.


2019 ◽  
Vol 9 (3) ◽  
pp. 198-207
Author(s):  
V. V. Bezpal'ko ◽  
L. V. Zhukova ◽  
S. V. Stankevich ◽  
Yu. H. Ogurtsov ◽  
I. I. Klymenko ◽  
...  

We analyzed various sources of scientific literature and our data at the experimental field of the National Academy of Agrarian Sciences Plant Growing Institute named after V.Ya. Yuryev within 2010-2013. The irradiation of winter wheat and spring barley seeds with the electromagnetic fields of the extremely high frequencies (MWF of EHF) was carried out with the help of the equipment of the Kharkiv Technical University of Radio Electronics. The treatment of seeds with the microwave oscillations of the extremely high frequency electromagnetic field (MWF of EHF) that is widely used for the operation of many radio and home microwave devices was done at the frequency range of 2.5-3.4 GHz, at the power of 0.9-1.8 kW for 5-95 seconds per 1 kg of seeds. The sowing quality of the seeds before and after treatment was determined in accordance with the current State Standard of Ukraine 4138-2002 in the laboratory of the seed production and seed science of the Plant Growing Institute named after V.Ya. Yuryev. The field experiments were performed in the crop rotation laboratory of the seed production and seed science. Pea for grain was sown before spring barley and the black fallow preceded winter wheat. During the experiments the area of the studied plot was 20 m2, the recurrence was four-times, and the placement of the plots were systemic.We suggested the optimum regimes of seeds irradiation with the microwave field of an extremely high frequency (MWF of EHF). They should be at range of 2.4-3.4 GHz with the power consumption of 0.9 kW per 1 kg of seed and at exposure of 45 seconds of 1.8 kW per 1 kg of seeds and exposure of 15-20 seconds. Such regimes cause the increased energy of germination, seeds sprouting, and crop capacity. We proposed to use this solution for improving and increasing the ecological features of winter wheat and spring barley by using the presowing microwave irradiation of seeds instead of chemical treatment. We considered the complex presowing treatment of seeds with MWF of EHF in combination with the plant growth regulators should be adopted and further enhanced.


2020 ◽  
Vol 34 (5) ◽  
pp. 699-703
Author(s):  
Jason K. Norsworthy ◽  
Jacob Richburg ◽  
Tom Barber ◽  
Trenton L. Roberts ◽  
Edward Gbur

AbstractAtrazine offers growers a reliable option to control a broad spectrum of weeds in grain sorghum production systems when applied PRE or POST. However, because of the extensive use of atrazine in grain sorghum and corn, it has been found in groundwater in the United States. Given this issue, field experiments were conducted in 2017 and 2018 in Fayetteville and Marianna, Arkansas, to explore the tolerance of grain sorghum to applications of assorted photosystem II (PSII)-inhibiting herbicides in combination with S-metolachlor (PRE and POST) or mesotrione (POST only) as atrazine replacements. All experiments were designed as a factorial, randomized complete block; the two factors were (1) PSII herbicide and (2) the herbicide added to create the mixture. The PSII herbicides were prometryn, ametryn, simazine, fluometuron, metribuzin, linuron, diuron, atrazine, and propazine. The second factor consisted of either no additional herbicide, S-metolachlor, or mesotrione; however, mesotrione was excluded in the PRE experiments. Crop injury estimates, height, and yield data were collected or calculated in both studies. In the PRE study, injury was less than 10% for all treatments except those containing simazine, which caused 11% injury 28 d after application (DAA). Averaged over PSII herbicide, S-metolachlor–containing treatments caused 7% injury at 14 and 28 DAA. Grain sorghum in atrazine-containing treatments yielded 97% of the nontreated. Grain sorghum receiving other herbicide treatments had significant yield loss due to crop injury, compared with atrazine-containing treatments. In the POST study, ametryn- and prometryn-containing treatments were more injurious than all other treatments 14 DAA. Grain sorghum yield in all POST treatments was comparable to atrazine, except prometryn plus mesotrione, which was 65% of the nontreated. More herbicides should be evaluated to find a comparable fit to atrazine when applied PRE in grain sorghum. However, when applied POST, diuron, fluometuron, linuron, metribuzin, propazine, and simazine have some potential to replace atrazine in terms of crop tolerance and should be further tested as part of a weed control program across a greater range of environments.


2012 ◽  
Vol 26 (1) ◽  
pp. 14-18 ◽  
Author(s):  
M. Joy M. Abit ◽  
Kassim Al-Khatib ◽  
Phillip W. Stahlman ◽  
Patrick W. Geier

Conventional grain sorghum is highly susceptible to POST grass control herbicides. Development of aryloxyphenoxypropionate-resistant grain sorghum could provide additional opportunities for POST herbicide grass control in grain sorghum. Field experiments were conducted at Hays and Manhattan, KS, to determine the effect of quizalofop rate and crop growth stage on injury and yield of aryloxyphenoxypropionate-resistant grain sorghum. Quizalofop was applied at 62, 124, 186, and 248 g ai ha−1at sorghum heights of 8 to 10, 15 to 25, and 30 to 38 cm, which corresponded to early POST (EPOST), mid-POST (MPOST), and late POST (LPOST) application timings, respectively. Grain sorghum injury ranged from 0 to 68% at 1 wk after treatment (WAT); by 4 WAT, plants generally recovered from injury. The EPOST and MPOST applications caused 9 to 68% and 2 to 48% injury, respectively, whereas injury from LPOST was 0 to 16%, depending on rate. Crop injury from quizalofop was more prominent at rates higher than the proposed use rate in grain sorghum of 62 g ha−1. Grain yields were similar in treated and nontreated plots; applications of quizalofop at different timings did not reduce yield except when applied MPOST at the Manhattan site.


1989 ◽  
Vol 69 (3) ◽  
pp. 939-943 ◽  
Author(s):  
D. J. THOMPSON ◽  
K. W. CLARK

Three field experiments were performed to determine the effects of fall nitrogen fertilization and post-harvest mechanical stubble removal (to 2.5 cm) on seed yield in Kentucky bluegrass (Poa pratensis L. ’Nugget’). In all experiments, N fertilization and stubble removal increased seed yield. Increases were greater in a 3-yr-old than in a 5-yr-old stand. Nitrogen fertilization increased panicle density, panicle weight, shoot height and straw yield. Stubble removal increased panicle density, reduced panicle weight, shoot height, and straw yield and increased harvest index.Key words: Nitrogen, stubble removal, seed, Kentucky bluegrass


1988 ◽  
Vol 36 (4) ◽  
pp. 315-325 ◽  
Author(s):  
W.J.M. Meijer ◽  
S. Vreeke

In field experiments in 1981-86, Poa pratensis cv. Kimono and Baron and Festuca rubra cv. Agram and Koket were undersown in companion crops of winter wheat cv. Arminda. Cuts were made immediately after wheat harvest or 4-6 weeks later. N application as autumn and spring dressings did not alter the effects of cutting. In most experiments, cutting treatments increased production of inflorescence and seed yield, mainly due to better illumination, and increased survival of the late elongating reproductive tillers. (Abstract retrieved from CAB Abstracts by CABI’s permission)


Weed Science ◽  
1993 ◽  
Vol 41 (4) ◽  
pp. 557-562 ◽  
Author(s):  
Robert E. Blackshaw

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.


2016 ◽  
Vol 47 (1) ◽  
pp. 40-46 ◽  
Author(s):  
M. Vach ◽  
Z. Strašil ◽  
M. Javůrek

Abstract The objective of this study was the model comparison and economic evaluation of different methods of soil tillage and crop stand establishments used. Based on yield results (winter wheat, spring barley, and white mustard cultivated in three-crop rotation) from field experiments with conventional, conservation with minimum tillage, and no-tillage methods conducted at the site Prague-Ruzyně, model economic balances were evaluated. Prices of the main products were determined based on the yield results from the period 2010-2013 and the current market prices. In the individual tillage systems, the total costs of production of evaluated crops were counted up and profitability was calculated as a ratio of profit to total costs. The highest total costs of crop cultivation were identified in cereals under conventional soil tillage, on the contrary, the lowest in cereals cultivated under conservation tillage technology. As for the growing technologies, the highest profitability was found in winter wheat, as for the tillage methods, it was in the conservation variant with minimum tillage. The economic evaluation for individual crops was based on standards of growing technologies and particular work operations.


PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247809
Author(s):  
Hollman Motta-Romero ◽  
Ferdinand Niyongira ◽  
Jeffrey D. Boehm ◽  
Devin J. Rose

Plant breeding and disease management practices have increased the grain yield of hard winter wheat (Triticum aestivum L.) adapted to the Great Plains of the United States during the last century. However, the effect of genetic gains for seed yield and the application of fungicide on the micronutrient and cadmium (Cd) concentration in wheat grains is still unclear. The objectives of this study were to evaluate the effects of fungicide application on the productivity and nutritional quality of wheat cultivars representing 80 years of plant breeding efforts. Field experiments were conducted over two crop years (2017 and 2018) with eighteen hard winter wheat genotypes released between 1933 and 2013 in the presence or absence of fungicide application. For each growing season, the treatments were arranged in a split-plot design with the fungicide levels (treated and untreated) as the whole plot treatments and the genotypes as split-plot treatments in triplicate. The effects on seed yield, grain protein concentration (GPC), micronutrients, phytic acid, and Cd in grains were measured. While the yield of wheat was found to increase at annualized rates of 26.5 and 13.0 kg ha-1 yr-1 in the presence and absence of fungicide (P < 0.001), respectively, GPC (-190 and -180 mg kg-1 yr-1, P < 0.001), Fe (-35.0 and -44.0 μg kg-1 yr-1, P < 0.05), and Zn (-68.0 and -57.0 μg kg-1 yr-1, P < 0.01) significantly decreased during the period studied. In contrast to the other mineral elements, grain Cd significantly increased over time (0.4 μg kg-1 yr-1, P < 0.01) in the absence of fungicide. The results from this study are of great concern, as many mineral elements essential for human nutrition have decreased over time while the toxic heavy metal, Cd, has increased, indicating modern wheats are becoming a better vector of dietary Cd.


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