Environment Influences Green Foxtail (Setaria viridis) Competition with Wheat (Triticum aestivum)

1992 ◽  
Vol 6 (3) ◽  
pp. 607-610 ◽  
Author(s):  
Dallas E. Peterson ◽  
John D. Nalewaja

Temperature, soil moisture, green foxtail density, relative emergence dates, and soil fertility effects on green foxtail and spring wheat competition were evaluated in controlled environments. Green foxtail competition was highest at 30 C and without moisture stress. Early green foxtail emergence increased competition with wheat more than changes in temperature, soil moisture, or green foxtail density. At 30 C, wheat fresh weight was reduced 50% by green foxtail seeded 4 d before wheat, but only 13% by foxtail seeded 4 d after wheat. Doubling the nitrogen and total nutrient concentration did not increase wheat growth, but increased foxtail weight 41 and 75%, respectively.

Weed Science ◽  
1981 ◽  
Vol 29 (2) ◽  
pp. 212-217 ◽  
Author(s):  
R. E. Blackshaw ◽  
E. H. Stobbe ◽  
A. R. W. Sturko

Competition of green foxtail [Setaria viridis(L.) Beauv.] was studied in a semi-dwarf wheat (Triticum aestivumL. ‘Norquay’) and in two normal-height wheats (‘Napayo’ and ‘Sinton’) from 1975 through 1978. Green foxtail suppressed wheat growth as well as grain yield. Tiller number, leaf area, and dry weight of wheat were reduced. Green foxtail was more competitive in the semi-dwarf variety than in either normal height variety. The intensity of green foxtail competition could not be determined by density alone. In 1975, as few as 100 green foxtail plants/m2significantly reduced yield of Napayo and Norquay wheat by 21 and 44%, respectively. In 1977, however, 1600 green foxtail plants/m2did not reduce the yield of Sinton wheat significantly. The intensity of green foxtail competition was highly variable from one date of seeding to the next, but there was no correlation between the level of green foxtail competition and the date of seeding. Soil temperature and moisture at the time of seeding and early growth are thought to affect green foxtail competition in wheat critically.


1992 ◽  
Vol 6 (2) ◽  
pp. 291-296 ◽  
Author(s):  
Dallas E. Peterson ◽  
John D. Nalewaja

Yield reductions due to green foxtail competition with hard red spring wheat varied with environment in field experiments conducted in 1984, 1985, and 1986 at Oakes, Langdon, Prosper, and Fargo, North Dakota. Wheat yield reductions ranged from 0 to 47% from 720 green foxtail plants per m2. Inclusion of early season temperature and precipitation, soil texture, and foxtail density into multiple regression analysis of wheat yield reductions significantly increased the coefficient of determination to 0.62 compared with 0.12 for regression based on green foxtail density alone. Wheat yield reduction decreased as green foxtail seeding was delayed after wheat seeding in 1986. Wheat yield generally decreased as time of diclofop application was delayed from 2 to 6 wk after wheat emergence in 1986.


Weed Science ◽  
1984 ◽  
Vol 32 (1) ◽  
pp. 13-16 ◽  
Author(s):  
Charlotte V. Eberlein ◽  
Richard Behrens

Retention, absorption, translocation, and metabolism of propanil (3′,4′-dichloropropionanilide) in tolerant wheat (Triticum aestivumL. ‘Era’) and susceptible green foxtail [Setaria viridis(L.) Beauv. ♯3SETVI] were studied to determine the basis of selectivity. Green foxtail retained 7.7 times more spray on a mg/g fresh weight basis than did wheat. Absorption of14C-propanil by green foxtail was greater than by wheat during most of the 48-h uptake period, but differences in absorption were not large enough for absorption to be a major selectivity factor. Translocation of foliar-applied14C-propanil was limited in both species; after 48 h, 96.7% of absorbed14C remained in the treated wheat leaf and 99.7% remained in the treated green foxtail leaf. Limited metabolism of14C-propanil occurred in green foxtail, with only 6.4% of extractable14C-propanil metabolized to dichlorolactanilide and unknown14C-compounds during a 72-h period. Wheat metabolized 65.8% of the extractable14C-propanil to dichloroaniline and unknown14C compounds by 72 h after treatment. The results of this research indicate that spray retention and propanil metabolism are the major factors involved in wheat tolerance and green foxtail susceptibility to propanil.


Weed Science ◽  
1981 ◽  
Vol 29 (2) ◽  
pp. 179-184 ◽  
Author(s):  
R. E. Blackshaw ◽  
E. H. Stobbe ◽  
C. F. Shaykewich ◽  
W. Woodbury

The rate and final germination percentage and emergence of green foxtail [Setaria viridis(L.) Beauv.] was found to be very dependent on the soil temperature and moisture conditions at the time of seeding. In contrast, the germination and emergence of wheat (Triticum aestivumL. ‘Sinton’) was only slightly affected over the temperature and moisture range of the study. In laboratory studies, a temperature decrease from 20 to 15 C caused a 53- and 12-h delay in the time to reach 50% germination of green foxtail and wheat, respectively. Soil moisture was found to have a greater effect than soil temperature on green foxtail germination. At −5.3 bars water potential, the final germination percentage of green foxtail was less than at the higher water potentials. A further decrease in the water potential to −6.5 bars effectively reduced green foxtail germination to zero. Wheat germination was delayed only slightly, and the final germination percentage remained unchanged over the range of 0 to −15.3 bars water potential. In field studies, a soil temperature decrease from 22 to 14 C caused a 6-day delay in the time of 50% emergence of green foxtail, and the emergence of wheat was delayed only 1 day by a similar decrease in temperature. Field studies showed that when the soil was moist (0 to −4 bars) and soil temperatures were warm (20 to 25 C), green foxtail emerged within a few days of wheat. However, when the soil was dry (-4.0 to −6.5 bars) and soil temperatures were low (15 to 20 C), green foxtail emerged 7 to 14 days after wheat. The intensity of green foxtail competition was greater when green foxtail emerged within a few days of wheat than when green foxtail emerged 2 weeks after wheat.


1988 ◽  
Vol 2 (4) ◽  
pp. 445-455 ◽  
Author(s):  
Steven J. Carlson ◽  
William W. Donald

Effects of repeated late-fall applications of the isopropylamine salt of glyphosate at 1.7 kg ae/ha plus 0.5% (v/v) surfactant on adventitious root buds, thickened propagative roots (> 1.3 mm diam), and shoot density of Canada thistle were studied in continuous hard red spring wheat over a 4-yr period. Glyphosate suppressed Canada thistle shoot density more quickly and to a greater extent than thickened root fresh weight or root bud number. A single fall application of glyphosate drastically decreased Canada thistle shoot density for 1 yr after treatment. However, shoot density was the same as the untreated control by 2 yr after a single fall treatment. Two consecutive late-fall applications of glyphosate in 2 yr decreased Canada thistle shoot density 94% in the fall 1 yr after the last treatment. Glyphosate reduced Canada thistle thickened root fresh weight 70% in the first fall 1 yr after a single fall treatment. However, 2 yr after a single fall application of glyphosate, root fresh weight equalled the controls. Two consecutive fall applications of glyphosate reduced thickened root fresh weight 77% 1 yr after the second treatment.


1996 ◽  
Vol 10 (4) ◽  
pp. 907-913 ◽  
Author(s):  
Kenneth J. Kirkland

The comparison of incorporation vs no incorporation on a mid-October application of the granular formulation of trifluralin to control infestations of wild oat and green foxtail was evaluated in spring barley, wheat, and canola in west central Saskatchewan over a 3 yr period. Incorporation treatments consisted of: no incorporation, one incorporation in fall, one incorporation in fall and a second in spring, one incorporation in fall and two additional incorporations in spring. All treatments eliminated green foxtail. In all three crops wild oat panicle counts were equivalent from incorporated and non-incorporated trifluralin. Wild oat fresh weights in crops grown on stubble were similar for incorporated and non-incorporated trifluralin. In fallow crops, wild oat fresh weight reductions were greater in three of nine site years with incorporation. There was little difference in crop yields from incorporated and non-incorporated trifluralin.


Weed Science ◽  
1975 ◽  
Vol 23 (5) ◽  
pp. 364-368 ◽  
Author(s):  
P. L. Orwick ◽  
M. M. Schreiber

We studied the early root growth of fourSetariataxa: giant foxtail (Setaria faberiHerrm.), giant green foxtail [Setaria viridisvar.major(Gaud.) Posp.], robust white foxtail (Setaria viridisvar.robusta-albaSchreiber), robust purple foxtail (Setaria viridisvar.robusta-purpureaSchreiber). Growth studies in controlled environments showed significant differences in root elongation among the taxa at three photoperiods. Seminal root lengths after 4 days followed the order presented for selectivity and metabolism of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] and propazine [2-chloro-4,6-bis(isopropylamino)-s-triazine] (robust white foxtail > giant green foxtail = robust purple foxtail > giant foxtail). Giant foxtail had the greatest root diameter, resulting in the greatest surface area and volume when lengths were equated. The order of seminal root lengths or diameters changed little after 7 days. Robust white foxtail had the most and longest first order lateral roots. Diameter of first order laterals showed giant foxtail > giant green foxtail = robust purple foxtail > robust white foxtail.


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.


1994 ◽  
Vol 8 (3) ◽  
pp. 607-611 ◽  
Author(s):  
Kenneth J. Kirkland

The influence of incorporation vs no incorporation on the efficacy of granular triallate applied in mid-October at 1400 and 1700 g ai/ha to control wild oat was evaluated in spring wheat in west central Saskatchewan over a 7-yr period. All fall-applied triallate reduced wild oat panicles and fresh weight, and increased yield compared to untreated checks. With applications in standing wheat stubble there was no difference in wild oat control from incorporation versus no incorporation. All triallate treatments reduced wild oat panicles and fresh weight by over 95%, and resulted in wheat yield increases ranging from 29 to 67%. In tilled fallow, incorporated granules provided better wild oat control than when there was no incorporation. Wheat yield increases ranged from 50 to 85% for triallate treatments with yield for incorporated triallate approximately 15% greater than non-incorporated. The rate of triallate did not affect the level of wild oat control achieved with either incorporation method. In separate tolerance studies triallate incorporation method did not affect spring wheat emergence or subsequent development.


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