Tillage and rotation influences on weed community composition in wheat (Triticum aestivum L.) in southwestern Saskatchewan

1991 ◽  
Vol 71 (3) ◽  
pp. 783-789 ◽  
Author(s):  
L. Hume ◽  
S. Tessier ◽  
F. B. Dyck

The effects on weed community composition of zero-, minimum-, and conventional tillage practices were examined on three soil types under both continuous wheat (Triticum aestivum L.) and wheat-fallow rotations between 1982 and 1989. Green foxtail [Setaria viridis (L.) Beauv.] became a problem on continuously cropped plots, especially on the sandy loam soil where densities reached a maximum of 2354 plants m−2 with conventional tillage. Without tillage, high densities of foxtail barley (Hordeum jubatum L.) developed since this species was not adequately controlled by herbicides. Even in a year when precipitation was only 63% of normal, perennial shoots of this species achieved a maximum density of 1222 plants m−2. A hoe seeder tended to improve foxtail barley control relative to the disc seeder used, likely due to greater soil disturbance. Wheat losses were significantly correlated to weed density, and it was concluded that, in terms of weed control in wheat, some degree of tillage may be required in southwestern Saskatchewan. Key words: Tillage, Setaria viridis, green foxtail, Hordeum jubatum, foxtail barley, wheat

1980 ◽  
Vol 60 (1) ◽  
pp. 177-184 ◽  
Author(s):  
JAMES H. HUNTER

In a series of field and greenhouse experiments, propanil (3′, 4′-dichloropropionalide) as a postemergent herbicide provided excellent control of green foxtail (Setaria viridis (L.) Beauv.) in wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.). Although some initial chlorosis occurred, wheat and barley recovered quickly and were considered tolerant to propanil at up to 1 kg/ha applied over a growth period extending from the 2- to 8-leaf stages of the green foxtail. Propanil at rates greater than 1 kg/ha resulted in considerable chlorosis and leaf tip burn, and although grain yields were not reduced, crop tolerance was visually assessed as unsatisfactory. Control of green foxtail was satisfactory with 1 kg/ha at the 2- to 4-leaf stages but not at later stages. Control was significantly better when the spray pressure at application was 310 kPa compared to 207 kPa. Analysis indicated that at the 2 and 4 kg/ha rate of propanil the residues in wheat and barley disappeared very quickly. At harvest, wheat grain contained 0.09 ppm of propanil.


1973 ◽  
Vol 53 (2) ◽  
pp. 369-376 ◽  
Author(s):  
J. D. BANTING ◽  
E. S. MOLBERG ◽  
J. P. GEBHARDT

Green foxtail, Setaria viridis (L.) Beauv., emerged at the same time in the spring as the wheat Triticum aestivum L. This was attributed to faster growth of green foxtail when the soil warmed up and its emergence from shallower depths than the wheat. There was a flush of emergence in the spring. Subsequent emergence appeared to depend on rainfall but some seedlings emerged in every 2-wk period throughout the season and in some years as late as October. A buildup of seeds occurred with the 3-yr rotation, i.e., when wheat was sown as a second crop. Germination was primarily controlled by temperature. No germination occurred in 10 days at 4.4 C and only a limited amount at 10 C. Eleven to 26% of the seeds in the soil and 7% of those on the surface were viable after 4 yr. Persistence increased markedly with depth, which emphasizes the need for shallow tillage. Primary dormancy disappeared rapidly. Secondary dormancy was detected thereafter in as many as 24% of the seeds.


1977 ◽  
Vol 57 (2) ◽  
pp. 479-484 ◽  
Author(s):  
J. R. MOYER ◽  
R. D. DRYDEN

Tank mixtures of solution nitrogen, triallate [S-(2,3,3-trichloroallyl)diisopropyl-thiocarbamate] and/or trifluralin [α,α,α,-trifluro-2, 6-dinitro-N, N-dipropyl-p-toluidine] were evaluated for the control of wild oats (Avena fatua L.) and/or green foxtail (Setaria viridis (L.) Beauv.). The response of wheat (Triticum aestivum L.) cv. Neepawa to solution nitrogen applied alone or in combination with triallate and/or trifluralin were evaluated. Good control of wild oats and green foxtail was obtained with a tank mixture of solution nitrogen, trifluralin at 1.38 kg/ha, and triallate at 1.65 kg/ha. Tank mixtures of triallate at 1.65 kg/ha with solution nitrogen controlled wild oats. Trifluralin at 1.38 kg/ha with solution nitrogen controlled wild oats and green foxtail. Control of green foxtail and wild oats resulted in increased wheat yields, higher nitrogen content in wheat grain, and a more efficient use of applied nitrogen fertilizer. The response of wheat to nitrogen was similar when nitrogen was applied in tank mixes with herbicides or with water to hand-weeded plots.


Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 291
Author(s):  
Ramón Bienes ◽  
Maria Jose Marques ◽  
Blanca Sastre ◽  
Andrés García-Díaz ◽  
Iris Esparza ◽  
...  

Long-term field trials are essential for monitoring the effects of sustainable land management strategies for adaptation and mitigation to climate change. The influence of more than thirty years of different management is analyzed on extensive crops under three tillage systems, conventional tillage (CT), minimum tillage (MT), and no-tillage (NT), and with two crop rotations, monoculture winter-wheat (Triticum aestivum L.) and wheat-vetch (Triticum aestivum L.-Vicia sativa L.), widely present in the center of Spain. The soil under NT experienced the largest change in organic carbon (SOC) sequestration, macroaggregate stability, and bulk density. In the MT and NT treatments, SOC content was still increasing after 32 years, being 26.5 and 32.2 Mg ha−1, respectively, compared to 20.8 Mg ha−1 in CT. The SOC stratification (ratio of SOC at the topsoil/SOC at the layer underneath), an indicator of soil conservation, increased with decreasing tillage intensity (2.32, 1.36, and 1.01 for NT, MT, and CT respectively). Tillage intensity affected the majority of soil parameters, except the water stable aggregates, infiltration, and porosity. The NT treatment increased available water, but only in monocropping. More water was retained at the permanent wilting point in NT treatments, which can be a disadvantage in dry periods of these edaphoclimatic conditions.


Weed Science ◽  
1977 ◽  
Vol 25 (5) ◽  
pp. 382-385 ◽  
Author(s):  
B.G. Todd ◽  
E.H. Stobbe

The selectivity of {2-[4-(2′,4′-dichlorophenoxy) phenoxy] methyl propionate}, (hereinafter referred to as dichlofop methyl), among wheat (Triticum aestivumL. ‘Neepawa’), barley (Hordeum vulgareL. ‘Bonanza’), wild oat (Avena fatuaL.), and green foxtail (Setaria viridis(L.) Beauv.) was investigated. On an ED50basis, barley, wild oat, and green foxtail were 2, 190, and 1,090 times more sensitive, respectively, to foliar-applied dichlofop methyl at the two-leaf stage than was wheat. Selectivity decreased with increasing maturity of the plant material with the ratio of selectivity between barley and wild oat decreasing from 55 at the two-leaf stage to three at the four-leaf-plus-one-tiller stage. Greater spray retention and more rapid penetration of dichlofop methyl partially explained the susceptibility of green foxtail, but did not explain selectivity between wheat, wild oat, and barley. Root uptake of14C-dichlofop methyl by the four species was proportional to the amount of solution absorbed during the treatment period and to the concentration of dichlofop methyl in the treatment solution but was not related to species sensitivity to this herbicide.


1998 ◽  
Vol 78 (1) ◽  
pp. 181-186 ◽  
Author(s):  
C. Shang ◽  
M. A. Arshad

Sorption is one of the key processes controlling the fate of agrochemicals in soil systems. The sorption of agrochemicals on a soil matrix can be affected by changes in chemical and physical properties caused by different tillage practices. Clopyralid (3,6-dichloro-2-pyridinecarboxylic acid), dicamba (3,6-dichloro-2-methoxybenzoic acid), and MCPA ((4-chloro-2-methylphenoxy)acetic acid), weakly acidic herbicides, are commonly used to control broadleaf weeds in crop production. The sorption of the three herbicides by surface soils (0–5 cm) from different tillage systems was studied by batch equilibrium. Of the herbicides used, MCPA was sorbed on soil in the greatest quantity, dicamba was the least sorbed, and the sorption was dependent on the pKa values of herbicides. In a sandy loam soil, more herbicide was sorbed under no-tillage (NT) than conventional tillage (CT). However, in a clay soil the difference in herbicide sorption between the two tillage systems was not consistent. The results can be explained in terms of changes in soil pH and organic matter content. The presence of clopyralid and MCPA lowered the sorption of dicamba, and MCPA was more effective than clopyralid in competing for sorption sites with dicamba. Key words: Herbicide sorption, clopyralid, dicamba, MCPA, tillage


1988 ◽  
Vol 15 (2) ◽  
pp. 94-97 ◽  
Author(s):  
D. L. Colvin ◽  
B. J. Brecke ◽  
E. B. Whitty

Abstract Effects of minimum tillage (MT) production techniques on peanut (Arachis hypogaea L.) root growth and yield were unknown. Field experiments were therefore conducted during 1984 near Williston and Marianna, FL and during 1985 near Williston and Jay, FL to evaluate effects of surface and subsurface tillage on peanut production. Soil types were a Zuber loamy sand (fine, mixed hyperthermic Ultic Hapludalf) at Williston, a Chipola sandy loam (loamy, siliceous, thermic Arenic Hapludult) at Marianna, and a Red Bay sandy loam (fine, loamy, siliceous, thermic Rhodic Paleudult) at Jay. The Sunrunner peanut cultivar was planted using a modified twin 23 cm row spacing and seeded at a rate of 140 kg/ha. Eight tillage systems that included combinations of conventional tillage, strip-tillage, and no-tillage with and without subsoiling or subsurface slitting were evaluated. Peanuts germinated and grew well except in no-tillage plots that received no subsurface tillage. Without surface or subsurface tillage there was not sufficient soil disturbance to insure proper seed-soil contact or seed cover. Generally, plots that received some degree of conventional tillage yielded better than plots with no surface preparation (4090 vs. 3760 kg/ha avg.). Minimum tillage plots yielded numerically less than conventional plots but in only a few cases were significant differences in yield noted. At most locations, minimum tillage plots that received no subsurface tillage developed a “lazy root syndrome” in which the few roots produced were quite shallow and grew near the soil surface. These treatments yielded less (3680 vs. 4010 kg/ha avg.) than those with conventional seedbed preparation or the minimum tillage treatments receiving subsurface tillage. Root strength and penetration measurements roughly reflect the same trends as peanut yields. The slit-tillage system resulted in peanut yields equal to or better than those obtained with chisel point subsoiling. Slitter wear and breakage problems were encountered but overall, the subsurface slit system appears to be a functional alternative to chisel point subsoiling.


1983 ◽  
Vol 63 (4) ◽  
pp. 1031-1038 ◽  
Author(s):  
D. A. PCHAJEK ◽  
I. N. MORRISON ◽  
G. R. B. WEBSTER

The efficacy of fall and spring treatments of trifluralin (α,α-trifluoro-2,6- dinitro-N, N-diproply-p-toluidine) applied to a sandy loam soil seeded to flax and the residual soil concentrations of trifluralin during the growing season were compared over 2 yr. Fall application of trifluralin at 1.12 kg/ha caused less crop injury and resulted in better green foxtail (Setaria viridis (L.) Beauv.) control than a spring application at 0.84 kg/ha. Initial soil concentrations were higher in plots treated in the fall at 1.12 kg/ha than in plots treated in the spring at 0.84 kg/ha. Six weeks after the experiments were seeded to flax and after harvest, more trifluralin persisted in the fall-treated plots. Calculated on the basis of the amount detected at the time of seeding, an average of 31 and 30% of the trifluralin persisted until after harvest in 1978 and 1979, respectively. In controlled environment studies in which yellow foxtail (Setaria glauca L. Beauv.) was seeded into soil collected six weeks after seeding, growth of the weed was reduced more in soil that was treated in the fall compared to the spring. In soil samples taken after harvest, growth of yellow foxtail was significantly reduced only in soil that had been treated the previous fall, with about a 50% reduction resulting from the 1.12-kg/ha rate and a 90% reduction occurring from the 2.24-kg/ha rate.Key words: Setaria viridis, flax tolerance, green foxtail control, trifluralin residues


2019 ◽  
pp. 62-69
Author(s):  
Nabayi A. ◽  
Girei A.H. ◽  
Usman S. ◽  
Abubakar M.S. ◽  
Haruna F.D. ◽  
...  

Different tillage practices are being employed by the farmers of Jigawa state, and as such, there is a need to determine its influence on some physical and chemical properties, so that farmers will base their choices on scientific facts rather than assumptions. An experiment was conducted to investigate the effects of three tillage practices (TP) on soil properties in Federal University Dutse, Teachings and Research farm, Jigawa State. The TP adopted are conventional tillage (CT), reduced tillage (RT) and zero-tillage (ZT). Samples were collected at a depth of 0 -20 cm for the chemical and other physical properties determination, while core samplers were used for bulk density (Bd) determination. All data collected were analyzed using Statistical Analysis Software (SAS and analysis of variance (ANOVA) was used to determine the significant tillage effect on the parameters measured at 5% level of significance and the means were separated using Least Significance Difference (LSD). The results showed that the soil texture of the study area was sandy loam. ZT differed significantly from other TP with higher Bd value of 1.51 Mg m-3, lower porosity (42.7%), and lower moisture content (10.3). ZT also had higher organic carbon (OC), total nitrogen (TN), available phosphorus (AP), exchangeable acidity (0.48 cmol+ kg-1) and bases and most importantly higher CEC (7.5 cmol (+) kg-1) which differed significantly from other tillage practices and the lowest of the most parameters were found in RT. Conclusively, ZT is the best TP to be used by the farmers because of the im- proved physical and chemical parameters and been not only economically sus- tainable but also socially and environmentally friendly.


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