Ethametsulfuron Interactions with Grass Herbicides on Canola (Brassica napus, B. rapa)

1995 ◽  
Vol 9 (1) ◽  
pp. 91-98 ◽  
Author(s):  
K. Neil Harker ◽  
Robert E. Blackshaw ◽  
Ken J. Kirkland

Field experiments were conducted from 1986 to 1988 at Lacombe and Lethbridge, Alberta and Scott, Saskatchewan to determine growth and yield response of canola to mixtures of ethametsulfuron with specific grass herbicides. Ethametsulfuron did not usually cause canola injury when mixed with sethoxydim. However, ethametsulfuron mixtures with the following grass herbicides listed in decreasing order of injury potential, often caused canola injury and yield loss: haloxyfop > fluazifop > fluazifop-P > quizalofop > quizalofop-P. Canola yield losses were severe in some experiments, ranging from 59% with quizalofop mixtures to 97% with haloxyfop mixtures; in other experiments, the same mixtures did not cause significant yield losses. ‘Tobin,’ aBrassica rapacultivar, tended to be more susceptible to injury than theB. napuscultivars ‘Pivot’ and ‘Westar.’ Canola injury symptoms were consistent with those expected from sulfonylurea herbicides. Therefore, we suggest that specific grass herbicides differentially impair the ability of canola to metabolize ethametsulfuron to inactive forms.

2009 ◽  
Vol 23 (4) ◽  
pp. 503-506 ◽  
Author(s):  
John D. Everitt ◽  
J. Wayne Keeling

Field experiments were conducted in Hale Co., TX, in 2005 and 2006 to determine the effects of 2,4-D amine and dicamba applied at varying rates and growth stages on cotton growth and yield, and to correlate cotton injury levels and lint yield reductions. Dicamba or 2,4-D amine was applied at four growth stages including cotyledon to two-leaf, four- to five-leaf, pinhead square, and early bloom. Dicamba and 2,4-D amine were applied at 1/2, 1/20, 1/200, and 1/2000 of the recommended use rate. Crop injury was recorded at 14 days after treatments and late-season, and cotton lint yields were determined. Across all growth stages, 2,4-D caused more crop injury and yield loss than dicamba. Cotton lint was reduced more by later applications (especially pinhead square) and injury underestimated yield loss with 2,4-D. Visual estimates of injury overestimated yield loss when 2,4-D or dicamba was applied early (cotyledon to two leaf) and was not a good predictor of yield loss.


2018 ◽  
Vol 32 (4) ◽  
pp. 431-438 ◽  
Author(s):  
Xiao Li ◽  
Timothy Grey ◽  
William Vencill ◽  
James Freeman ◽  
Katilyn Price ◽  
...  

AbstractFomesafen provides effective control of glyphosate-resistant Palmer amaranth in cotton. However, cotton seedlings can be injured when fomesafen is applied PRE. Therefore, greenhouse and field experiments were conducted at Athens, GA, and at six locations in Alabama and Georgia in 2013 and 2016 to evaluate cotton growth and yield response to fomesafen applied PRE at 70, 140, 280, 560, 1,120, or 2,240 g ai ha−1, and in combination with pendimethalin, diuron, acetochlor, and fluridone at 1×label rates. Greenhouse bioassays indicated that fomesafen reduced cotton height and dry weight with increasing rate in Cecil sandy loam and Tifton loamy sand but not in Greenville sandy clay loam––possibly as a result of this soil’s higher organic matter (OM) and clay content. Fomesafen applied at 2,240 g ai ha−1 reduced cotton stand by as much as 83% compared to the nontreated check (NTC) at all field locations except Alabama’s Macon and Baldwin counties, and 1,120 g ai ha−1 reduced cotton stand only at Pulaski County, GA, by 52%. Cotton height was reduced by the two highest rates of fomesafen at all locations except Clarke County, GA, and Baldwin County, AL. Injury data indicated more visual injury followed increasing fomesafen rates, and high-rate treatments produced more injury in sandier soils. Cotton yield was unaffected by herbicide treatments at any location, except for the 1,120 g ai ha−1 rate at Pulaski County (49% yield loss compared to NTC), 2,240 g ai ha−1 at Pulaski County (72% yield loss), and Tift County (29% yield loss). These data indicated cotton yield should not be negatively affected by fomesafen applied PRE alone within label rates or in combination with pendimethalin, diuron, acetochlor, and fluridone at 1×label rates, although some visual injury, or stand or height reduction may occur early in the growing season.


Weed Science ◽  
2006 ◽  
Vol 54 (1) ◽  
pp. 156-165 ◽  
Author(s):  
Konanani B. Liphadzi ◽  
J. Anita Dille

Competitiveness of weeds that survive a PRE herbicide application (escaped weeds) might be altered because of herbicide injury. As a result, potential crop yield loss may be reduced. Field experiments were conducted at Ashland Bottoms, KS, in 2001 and 2002 and at Rossville, KS, in 2002. The objectives were to quantify corn growth and yield response to Palmer amaranth or velvetleaf competition, with or without isoxaflutole (0.03 kg ha−1) or flumetsulam (0.04 kg ha−1) application, and to determine seed production of Palmer amaranth or velvetleaf as affected by PRE herbicide. Palmer amaranth and velvetleaf densities ranged from 0 to 6 and 0 to 32 plants m−1of corn row, respectively. At Ashland Bottoms in 2002, corn height at tasseling decreased with increasing Palmer amaranth (1.58 cm weed−1m−1) and velvetleaf (1.32 cm weed−1m−1) density when no herbicide was applied. With flumetsulam application, each increase in velvetleaf density reduced corn height by 0.4 cm. Escaped Palmer amaranth and velvetleaf were shorter than untreated plants at corn tasseling. At Rossville in 2002, Palmer amaranth that escaped isoxaflutole or flumetsulam application caused 13% corn yield loss (YL) at a density of 3 plants m−1. In contrast, corn YL from untreated Palmer amaranth at the same density was 30%. At Ashland Bottoms in 2002, velvetleaf that escaped flumetsulam caused 3% corn YL at a density of 3 plants m−1compared with 38% YL caused by untreated velvetleaf at the same density. Seed production of Palmer amaranth was independent of density or herbicide treatment, whereas production of velvetleaf seed increased with density, with or without flumetsulam. The study showed that corn YL from both Palmer amaranth and velvetleaf that escaped a PRE herbicide was less than from untreated weeds, but seed production by escaped weeds was similar to that of untreated weeds.


2016 ◽  
Vol 34 (1) ◽  
pp. 35-46 ◽  
Author(s):  
M.M. JAVAID ◽  
A. TANVEER ◽  
H.H. ALI ◽  
M.A. SHAHID ◽  
R.M. BALAL ◽  
...  

Emex australis and E. spinosa are significant weed species in wheat and other crops. Information on the extent of competition of the Emex species will be helpful to access yield losses in wheat. Field experiments were conducted to quantify the interference of tested weed densities each as single or mixture of both at 1:1 on their growth and yield, wheat yield components and wheat grain yield losses in two consecutive years. Dry weight of both weed species increased from 3-6 g m-2 with every additional plant of weed, whereas seed number and weight per plant decreased with increasing density of either weed. Both weed species caused considerable decrease in yield components like spike bearing tillers, number of grains per spike, 1000-grain weight of wheat with increasing density population of the weeds. Based on non-linear hyperbolic regression model equation, maximum yield loss at asymptotic weed density was estimated to be 44 and 62% with E. australis, 56 and 70% with E. spinosa and 63 and 72% with mixture of both species at 1:1 during both year of study, respectively. It was concluded that E. spinosa has more competition effects on wheat crop as compared to E. australis.


1988 ◽  
Vol 28 (2) ◽  
pp. 263 ◽  
Author(s):  
TN Khan

The effect of a range of sowing rates on scald infection and yield in barley cv. Stirling was studied to investigate if increased plant density will lead to more ears/m2 and therefore compensate for yield losses due to scald. Increased sowing rate (50 v. 100 kg/ha) did not compensate for yield loss due to scald. However, significant yield increases (3.0 v. 4.0 t/ha) with increased sowing rates (25 v. 125 kg/ha) occurred when scald was controlled. Such yield in creases were accompanied by increases in the number of ears/m2 and number of grains/ha, but decreases in number of grains/ear and 100-grain weight. The severity of scald infection was not affected by sowing rates.


2008 ◽  
Vol 88 (1) ◽  
pp. 267-270 ◽  
Author(s):  
Y. Gan ◽  
S. S. Malhi ◽  
S. A. Brandt ◽  
C. L. McDonald

Use of appropriate harvest management can minimize the yield loss of crucifer crops due to seed and pod shattering. This study determined the difference among five canola/mustard species in the degree of resistance to seed shattering and yield losses. Sinapis alba yellow mustard AC Base, Brassica juncea canola Amulet, Brassica juncea mustard Cutlass, Brassica rapa canola Hysyn, and Brassica napus canola InVigor 2663 were grown at Star City, Scott and Swift Current, SK, from 2004 to 2006. Seed yield was highest for napus canola (2146 kg ha-1), followed by juncea mustard (1971 kg ha-1) and juncea and rapa canola, while alba mustard (1547 kg ha-1) was the lowest. Straight combining compared with swathing resulted in 13% greater seed yield for juncea canola and juncea mustard, and 7% greater for rapa canola, while napus canola did not show yield difference between the two operation regimes. Under high shattering conditions, juncea mustard shed about 400 pods m-2, significantly greater than the four other species. Rapa canola had the lowest number of shed pods. Juncea mustard and napus canola had largest yield loss (about 7% of the total seed yield) during straight combining, followed by alba mustard (5%), and rapa and juncea canola (< 4%). Selection of shattering resistant species and use of straight combining can minimize seed yield losses in the production of crucifer oilseed crops. Key words: Brassica napus, Brassica rapa, Brassica juncea, Sinapis alba, swathing, straight–combine


2010 ◽  
Vol 46 (No. 1) ◽  
pp. 21-26 ◽  
Author(s):  
V. Šíp ◽  
J. Chrpová ◽  
O. Veškrna ◽  
L. Bobková

Reactions to artificial infection with Fusarium graminearum isolates and a new fungicide Swing Top were studied in nine winter wheat cultivars evaluated in field experiments at two sites for three years for expression of symptoms, deoxynivalenol (DON) content in grain and grain yield. The results demonstrate a pronounced and relatively stable effect of cultivar resistance on reducing head blight, grain yield losses and contamination of grain by the mycotoxin DON. It is advantageous that the moderate level of resistance to Fusarium head blight (FHB) was detected also in two commonly grown Czech cultivars Sakura and Simila. Average fungicide efficacy for DON was 49.5% and 63.9% for a reduction in yield loss, however, it was found highly variable in different years and sites. The joint effect of cultivar resistance and fungicide treatment was 86.5% for DON and even 95.4% for reducing the yield loss. A very high risk was documented for susceptible cultivars and also the effects of medium responsive cultivars were found to be highly variable in different environments and therefore not guaranteeing sufficient protection against FHB under different conditions.


2018 ◽  
Vol 36 (0) ◽  
Author(s):  
R.M. IKRAM ◽  
A. TANVEER ◽  
R. MAQBOOL ◽  
M.A. NADEEN

ABSTRACT: Brown chickpea (Cicer arietinum L.) is one of the two chickpea types grown in Pakistan and other countries. The critical period for weed removal in a rainfed chickpea system is an important consideration in devising weed management strategies. Field experiments were conducted in the winter season of 2011 and 2012 to determine the extent of yield loss with different periods of weed crop competition. Seven weed crop competition periods (0, 45, 60, 75, 90, 105 and 160 days after sowing - DAS) were used to identify the critical period for weed removal in rainfed chickpea. Experimental plots were naturally infested with Euphorbia dracunculoides and Astragalus sp. in both years. Individual, composite density and dry weights of E. dracunculoides and Astragalussp. increased significantly with an increase in the competition period. However, yield and yield-contributing traits of chickpea significantly decreased with an increase in the competition period. Chickpea seed yield loss was 11-53% in different weed crop competition periods. Euphorbia dracunculoides and Astragalus sp. removed 39.9 and 36.9 kg ha-1 of N, 9.61 and 7.27 kg ha-1 of P and 38.3 and 36.9 kg ha-1 of K, respectively. Season long weed competition (160 days after sowing) resulted in 19.5% seed protein content compared with 24.5% seed protein content in weed-free chickpea. A Logistic equation was fitted to yield data in response to increasing periods of weed crop competition. The critical timing of weed removal at 5 and 10% acceptable yield losses were 26 and 39 DAS, respectively. The observed critical period suggests that in rainfed chickpea, a carefully timed weed removal could prevent grain yield losses.


2020 ◽  
Vol 145 (6) ◽  
pp. 331-339
Author(s):  
Kirsten L. Lloyd ◽  
Donald D. Davis ◽  
Richard P. Marini ◽  
Dennis R. Decoteau

Effects of nighttime (2000 to 0700 hr) O3 on the pod mass of sensitive (S156) and resistant (R123) snap bean (Phaseolus vulgaris) genotypes were assessed using continuous stirred tank reactors located within a greenhouse. Two concentration-response relationship trials were designed to evaluate yield response to nighttime O3 exposure (10 to 265 ppb) in combination with daytime exposure at background levels (44 and 62 ppb). Three replicated trials tested the impact of nighttime O3 treatment at means of 145, 144, and 145 ppb on yields. In addition, stomatal conductance (gS) measurements documented diurnal variations and assessed the effects of genotype and leaf age. During the concentration-response experiments, pod mass had a significant linear relationship with the nighttime O3 concentration across genotypes. Yield losses of 15% and 50% occurred at nighttime exposure levels of ≈45 and 145 ppb, respectively, for S156, whereas R123 yields decreased by 15% at ≈150 ppb. At low nighttime O3 levels of ≈100 ppb, R123 yields initially increased up to 116% of the treatment that received no added nighttime O3, suggesting a potential hormesis effect for R123, but not for S156. Results from replicated trials revealed significant yield losses in both genotypes following combined day and night exposure, whereas night-only exposure caused significant decreases only for S156. The gS rates ranged from less than 100 mmol·m−2·s−1 in the evening to midday levels more than 1000 mmol·m−2·s−1. At sunrise and sunset, S156 had significantly higher gS rates than R123, suggesting a greater potential O3 flux into leaves. Across genotypes, younger rapidly growing leaves had higher gS rates than mature fully expanded leaves when evaluated at four different times during the day. Although these were long-term trials, gS measurements and observations of foliar injury development suggest that acute injury, occurring at approximately the time of sunrise, also may have contributed to yield losses. To our knowledge, these are the first results to confirm that the relative O3 sensitivity of the S156/R123 genotypes is valid for nighttime exposure.


Weed Science ◽  
1987 ◽  
Vol 35 (1) ◽  
pp. 63-67 ◽  
Author(s):  
David C. Bridges ◽  
James M. Chandler

Research was conducted from 1982 through 1984 on a Shipps clay soil (Udic chromustert) in east-central Texas to determine the density-dependent effects and critical periods of johnsongrass [Sorghum halepense(L.) Pers. # SORHA] competition with cotton (Gossypium hirsutumL.). Two experiments were conducted each year, one to assess cotton yield response to increasing johnsongrass density and the second to establish the johnsongrass-free requirement of cotton and the johnsongrass competition period. A critical minimum density of 2 plants/9.8 m of row was observed. Full-season johnsongrass competition densities exceeding 2 plants/9.8 m of row resulted in seed cotton yield reductions each year. Yield decline was most rapid as density increased from 2 to 8 plants/9.8 m of row. Yield loss averaged 1, 4, 14, 40, 65, and 70% for johnsongrass densities of 1, 2, 4, 8, 16, and 32 plants/9.8 m of row, respectively. Percent yield loss was proportional to yield potential at johnsongrass densities of 4 and 8 plants/9.8 m of row. Three to four weeks of rhizome johnsongrass competition or 6 weeks of seedling johnsongrass competition resulted in significant yield reductions. Maintaining cotton johnsongrass free for 4 weeks did not prevent significant yield reductions.


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