scholarly journals Tolerance of Glyphosate-Resistant Maize to Glyphosate Plus MCPA Amine Is Influenced by Dose and Timing

2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
Nader Soltani ◽  
Kris McNaughton ◽  
Chris L. Gillard ◽  
Robert E. Nurse ◽  
Peter H. Sikkema
Keyword(s):  
Environmental Conditions ◽  
Yield Loss ◽  
Dry Weight ◽  
Field Trials ◽  
Recommended Dose ◽  
Yield Reduction ◽  
Leaf Stage ◽  
Shoot Dry Weight ◽  
Significant Injury

There is little information on tolerance of glyphosate-resistant maize to glyphosate plus MCPA amine as influenced by dose and timing under Ontario environmental conditions. A total of seven field trials were conducted at various locations in Ontario, Canada, in 2011–2013 to evaluate tolerance of field maize to tank mixes of glyphosate (900 g a.e./ha) plus MCPA amine (79, 158, 315, 630, 1260, 2520, or 5040 g a.e./ha) at either the 4- or 8-leaf stage. The predicted dose of MCPA amine that caused 5, 10, and 20% injury was 339, 751, and 1914 g a.e./ha when applied to 4-leaf maize but only 64, 140, and 344 g a.e./ha when applied to 8-leaf maize, respectively. The predicted dose of MCPA amine that caused 5, 10, and 20% reduction in shoot dry weight of maize was 488, 844, and 1971 g a.e./ha when applied to 4-leaf maize and only 14, 136, and 616 g a.e./ha when applied to 8-leaf maize, respectively. The predicted dose of MCPA amine that caused 5, 10, and 20% yield reduction was 2557, 4247, and >5040 g a.e./ha when applied to 4-leaf maize and 184, 441, and 1245 g a.e./ha when applied to 8-leaf maize, respectively. Based on these results, glyphosate plus MCPA amine applied at the manufacturer’s recommended dose of 630 g a.e./ha applied to 4-leaf maize has potential to cause injury but the injury is transient with no significant reduction in yield. However, when glyphosate plus MCPA amine is applied to 8-leaf maize it has the potential to cause significant injury and yield loss in maize.

Control of common cocklebur (Xanthium strumarium L.) in corn

2010 ◽  
Vol 90 (6) ◽  
pp. 933-938 ◽  
Author(s):  
N. Soltani ◽  
C. Shropshire ◽  
P.H. Sikkema
Keyword(s):  
Environmental Conditions ◽  
Dry Weight ◽  
Field Trials ◽  
Xanthium Strumarium ◽  
Corn Yield ◽  
Shoot Dry Weight ◽  
Herbicide Treatments ◽  
Excellent Control

Nine field trials (five with PRE and four with POST herbicides) were conducted in 2006 to 2009 on various Ontario farms with heavy common cocklebur infestations to determine the effectiveness of PRE and POST herbicides for the control of common cocklebur in corn. There was no commercially significant corn injury from the PRE herbicides evaluated. Saflufenacil, saflufenacil/dimethenamid-p, isoxaflutole + atrazine, mesotrione + atrazine and dicamba/atrazine, applied PRE provided 85, 85, 76, 73 and 67% control of common cocklebur in corn 8 wk after emergence (WAE), respectively. Common cocklebur shoot dry weight was reduced 84, 80, 79, 75 and 68% with saflufenacil/dimethenamid-p, isoxaflutole + atrazine, mesotrione + atrazine, saflufenacil and dicamba/atrazine, respectively. There was no effect on corn yield compared with the weedy control with the PRE herbicides evaluated. The application of 2,4-D/atrazine POST resulted in unacceptable injury (28%) in corn. Dicamba/atrazine, dicamba/diflufenzopyr, dicamba and mesotrione + atrazine provided up to 98, 95, 90 and 90% control of common cocklebur 8 wk after application (WAA), respectively. All POST herbicide treatments increased corn yield compared with the non-treated control. Saflufenacil and saflufenacil/dimethenamid-p applied PRE and dicamba, dicamba/diflufenzopyr, dicamba/atrazine or mesotrione + atrazine applied POST have potential to provide good to excellent control of common cocklebur in corn under Ontario environmental conditions.

Tolerance of identity preserved soybean cultivars to preemergence herbicides

2015 ◽  
Vol 95 (4) ◽  
pp. 719-726 ◽  
Author(s):  
Kimberly D. Belfry ◽  
Nader Soltani ◽  
Lynette R. Brown ◽  
Peter H. Sikkema
Keyword(s):  
Yield Loss ◽  
Field Trials ◽  
Climatic Conditions ◽  
Recommended Dose ◽  
Yield Reduction ◽  
Soybean Yield ◽  
Soybean Cultivars ◽  
Chlorimuron Ethyl ◽  
Preemergence Herbicides

Belfry, K. D., Soltani, N., Brown, L. R. and Sikkema, P. H. 2015. Tolerance of identity preserved soybean cultivars to preemergence herbicides. Can. J. Plant Sci. 95: 719–726. Six field trials were conducted over a 3-yr period (2011 to 2013) near Exeter and Ridgetown, Ontario, Canada, to assess the tolerance of seven identity-preserved (IP) soybean cultivars to preemergence (PRE) herbicides applied at 2×the recommended dose. All cultivars demonstrated excellent tolerance to dimethenamid-P, pyroxasulfone, S-metolachlor, chlorimuron-ethyl, clomazone, cloransulam-methyl, flumetsulam and imazethapyr, showing 5% or less injury. At Exeter, linuron caused as much as 13 and 18% injury at 2 and 4 wk after soybean emergence, while injury due to metribuzin was as high as 22 and 47% for the same dates, respectively. At Exeter, linuron, metribuzin and S-metolachlor plus metribuzin reduced soybean height up to 17, 41 and 24%, respectively; soybean height was generally not affected at the Ridgetown sites. At Exeter, metribuzin reduced soybean yield up to 38% for cultivars S03W4, Madison and OAC Lakeview, while S23T5 was not significantly reduced. On the contrary, metribuzin yield loss at Ridgetown was nonsignificant. Results from this study suggest that PRE application of metribuzin at 2× field dose has potential to cause unacceptable injury and yield reduction in IP soybeans under some soil and climatic conditions and may vary according to cultivar.

Sodium Safens Saflufenacil Applied Postemergence to Corn (Zea mays)

Weed Science ◽  
2011 ◽  
Vol 59 (1) ◽  
pp. 4-13 ◽  
Author(s):  
Meghan Moran ◽  
Peter H. Sikkema ◽  
J. Christopher Hall ◽  
Clarence J. Swanton
Keyword(s):  
Zea Mays ◽  
Yield Loss ◽  
Dry Weight ◽  
Recommended Dose ◽  
Foliar Uptake ◽  
Leaf Stage ◽  
Crop Injury ◽  
Growth Room ◽  
Field And Laboratory Conditions ◽  
Potential Use

Saflufenacil is a PRE herbicide for the control of broadleaf weeds. Field and growth room studies were conducted to explore the tolerance of corn to POST treatments of saflufenacil and BAS 781. Additionally, the potential use of sodium as a safener for saflufenacil was evaluated. Crop injury caused by saflufenacil or BAS 781 was 8 and 38%, respectively, when applied at twice the recommended dose at the spike to two-leaf stage of crop growth. This injury increased to 28 and 65%, respectively, when applied at the three- to four-leaf stage. This level of crop injury resulted in yield loss, particularly when applied at the three- to four-leaf stage. The addition of Na-bentazon to saflufenacil reduced this injury and increased crop dry weight under both field and laboratory conditions. In the field, Na-bentazon also increased corn collar height and yield compared with saflufenacil applied alone. Na-bentazon reduced injury through a reduction in foliar uptake of saflufenacil. Sodium derived from baking soda also provided a safening effect, but only at the lowest dose of saflufenacil tested.

scholarly journals Yield Loss Associated with Different Levels of Stem Rust Resistance in Bread Wheat

Plant Disease ◽  
2018 ◽  
Vol 102 (12) ◽  
pp. 2531-2538 ◽  
Author(s):  
Tegwe Soko ◽  
Cornelia M. Bender ◽  
Renée Prins ◽  
Zacharias A. Pretorius
Keyword(s):  
Stem Rust ◽  
Yield Loss ◽  
Field Trials ◽  
Susceptible Variety ◽  
Yield Reduction ◽  
Adult Plant ◽  
Different Types ◽  
The Mean ◽  
Disease Pressure ◽  
Different Levels

Puccinia graminis f. sp. tritici race Ug99 (syn. TTKSK) has been identified as a major threat to wheat production based on its broad virulence. Despite its importance, the effect of Ug99 on different types of resistance in wheat has not been thoroughly researched. In field trials conducted with P. graminis f. sp. tritici race PTKST (Ug99 race group) over 2 years, AUDPC differentiated the moderately susceptible variety SC Stallion (515) and susceptible entries SC Nduna (995) and Line 37-07 (1634) from those with adult plant resistance (APR). AUDPC of APR varieties W1406 (256), W6979 (399), and Kingbird (209) was higher than the mean of 25 recorded for the all stage resistant (ASR) variety SC Sky. In fungicide-protected and unprotected plots, race PTKST resulted in a mean yield loss of 21.3%, with susceptible Line 37-03 recording a 47.9% decrease in grain yield. Yield reduction in APR varieties reached 19.5% in W1406, whereas the ASR control SC Sky showed a mean loss of 6.4%. Although APR reduced the effects of stem rust on yield and yield components under conditions of high disease pressure, it did not provide the same protection as effective ASR.

Dry Bean Response to Preemergence-Applied KIH-485

2007 ◽  
Vol 21 (1) ◽  
pp. 230-234 ◽  
Author(s):  
Peter H. Sikkema ◽  
Christy Shropshire ◽  
Nader Soltani
Keyword(s):  
Dry Weight ◽  
Field Trials ◽  
Dry Beans ◽  
Seed Moisture Content ◽  
Dry Bean ◽  
Shoot Dry Weight ◽  
Seed Moisture ◽  
Reduced Height ◽  
White Bean ◽  
Pinto Beans

Three field trials were conducted over a 2-yr period (2004 and 2005) at Exeter and Ridgetown, Ontario to evaluate the tolerance of eight market classes of dry beans to KIH-485 applied PRE at 210 and 420 g ai/ha. KIH-485 PRE caused as much as 67% visual injury in small-seeded and 44% visual injury in large-seeded dry beans. KIH-485 applied PRE at 420 g/ha reduced plant height up to 47% at Ridgetown and 8% at Exeter in 2004, and reduced height of brown and white bean by 15 and 19%, respectively, but had no effect on the height of the other beans in 2005. Shoot dry weight was not affected at Exeter in 2004 but was reduced by 46% at Ridgetown in 2004 and 14% at Exeter in 2005. In 2004, seed moisture content increased by 5, 6, and 12% in black, otebo, and pinto beans, respectively. Seed yield was reduced up to 27% at Ridgetown and 11% at Exeter in 2004 but was not affected at Exeter in 2005. On the basis of this research, KIH-485 PRE causes unacceptable injury in some dry bean market classes.

Reduced Transpiration and Increased Water Efficiency by Diuron in Corn (Zea mays)

Weed Science ◽  
1980 ◽  
Vol 28 (2) ◽  
pp. 180-185 ◽  
Author(s):  
Shabir Ahmed ◽  
R. A. Fletcher
Keyword(s):  
Zea Mays ◽  
Active Component ◽  
Dry Weight ◽  
Water Efficiency ◽  
Commercial Formulation ◽  
Leaf Stage ◽  
Stages Of Growth ◽  
Shoot Dry Weight ◽  
Low Concentrations ◽  
Corn Plants

Of several herbicides tested on both monocotyledon and dicotyledon species, diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] was found to be the most effective in reducing transpiration in corn (Zea maysL.) plants; a reduction of 40% occurred. It was established that diuron was the active component in reducing transpiration, and not the additives in the commercial formulation (Karmex) used in this study. Foliar applications of low concentrations (0.035 to 0.56 kg/ha) of diuron effectively reduced transpiration in both cultivars (Pioneer 3780A and Pride 1108) of corn plants, at all stages of growth tested (from 3- to 10-leaf stage). This effect of diuron on reduced transpiration occurred when the supply of water or nutrients to the corn plants was either limiting or non-limiting. The reduction of transpiration of corn plants after treatment also prevented the leaves from wilting and becoming senescent. This effect was persistent over 16 days. Diuron treatment increased the water efficiency of the plants and this effect was more pronounced when water was limiting. Compared to the control, the treated plants used up to 68% less water for each gram of shoot dry weight produced. The increase in water efficiency indicates that transpiration was reduced more than photosynthesis.

Tolerance of Otebo Bean (Phaseolus vulgaris) to New Herbicides in Ontario

2006 ◽  
Vol 20 (4) ◽  
pp. 862-866 ◽  
Author(s):  
Peter H. Sikkema ◽  
Darren E. Robinson ◽  
Christy Shropshire ◽  
Nader Soltani
Keyword(s):  
Moisture Content ◽  
Plant Height ◽  
Weed Management ◽  
Safety Margin ◽  
Dry Weight ◽  
Field Trials ◽  
High Rate ◽  
Seed Moisture Content ◽  
Shoot Dry Weight ◽  
Seed Moisture

Weed management is a major production issue facing otebo bean growers in Ontario. Field trials were conducted at six Ontario locations during a 2-yr period (2003 and 2004) to evaluate the tolerance of otebo bean to the preplant incorporated (PPI) application of EPTC at 4,400 and 8,800 g ai/ha, trifluralin at 1,155 and 2,310 g ai/ha, dimethenamid at 1,250 and 2,500 g ai/ha,S-metolachlor at 1,600 and 3,200 g ai/ha, and imazethapyr at 75 and 150 g ai/ha. EPTC, trifluralin, dimethenamid, andS-metolachlor applied PPI resulted in minimal (less than 5%) visual injury and with exception of the low rate of dimethenamid causing a 16% reduction in shoot dry weight and the high rate causing an 8% plant height reduction had no adverse effect on plant height, shoot dry weight, seed moisture content, and yield. Imazethapyr applied PPI caused up to 7% visual injury and reduced plant height, shoot dry weight, and yield 8, 18, and 12% at 75 g/ha and 19, 38, and 27% at 150 g/ ha, respectively. Seed moisture content was also reduced by 0.4% with both rates. Based on these results, otebo bean is not tolerant of imazethapyr applied PPI at rates as low as 75 g/ha, the proposed use rate. EPTC, trifluralin, dimethenamid, andS-metolachlor applied PPI have a 2× rate crop safety margin for use in otebo bean weed management.

Control of Large Crabgrass (Digitaria sanguinalis) and Fall Panicum (Panicum dichotomiflorum) in Corn (Zea mays) by Tridiphane and Atrazine Combinations

Weed Science ◽  
1988 ◽  
Vol 36 (3) ◽  
pp. 359-362 ◽  
Author(s):  
Prasanta C. Bhowmik ◽  
Ujjanagouda B. Nandihalli
Keyword(s):  
Zea Mays ◽  
Dry Weight ◽  
Grass Species ◽  
Single Application ◽  
Digitaria Sanguinalis ◽  
Leaf Stage ◽  
Shoot Dry Weight ◽  
The One ◽  
Panicum Dichotomiflorum ◽  
Large Crabgrass

A single application of 0.56 or 0.84 kg ai/ha tridiphane [2-(3,5-dichlorophenyl)-2-(2,2,2-trichloroethyl) oxirane] plus 2.3 kg ai/ha of atrazine [6-chloro-N-ethyl-N′-(1-niethylethyl)-1,3,5-triazine-2,4-diamine] at the one-to three-leaf stage controlled large crabgrass [Digitaria sanguinalis(L.) Scop. # DIGSA] and fall panicum (Panicum dichotomiflorumMichx. #PANDI) 96% or more. A sequential application of 1.1 kg/ha of atrazine, in addition to the above single application, was required for control of the two grass species at the four-to six-leaf stage. Application of tridiphane plus atrazine to large crabgrass and fall panicum beyond the six-leaf stage was ineffective. Tridiphane at 0.75 kg/ha, applied alone, reduced the shoot dry weight of large crabgrass by 71%. The response of tridiphane and atrazine combinations at the four- to five-leaf stage of large crabgrass was additive.

Effect of barley plant density on wild oat interference, shoot biomass and seed yield under zero tillage

1999 ◽  
Vol 79 (4) ◽  
pp. 655-662 ◽  
Author(s):  
J. T. O'Donovan ◽  
J. C. Newman ◽  
K. N. Harker ◽  
R. E. Blackshaw ◽  
D. W. McAndrew
Keyword(s):  
Seed Yield ◽  
Yield Loss ◽  
Plant Density ◽  
Interactive Effect ◽  
Dry Weight ◽  
Barley Plant ◽  
Wild Oat ◽  
Zero Tillage ◽  
Shoot Dry Weight ◽  
Plant Densities

There has been little research aimed at developing regression models to describe the effects of barley and wild oat plant density on barley yield loss, or wild oat biomass and seed yield. Such models are an important component of integrated weed management systems, and can help determine when weed control with herbicides is economical. Field experiments were conducted over 4 yr at Vegreville, Alberta, to determine the interactive effects of wild oat and barley plant density on barley and wild oat variables in a zero tillage system. A nonlinear regression model in most cases provided good descriptions of barley yield loss, wild oat shoot dry weight, and wild oat seed yield as functions of wild oat and barley plant densities. The interactive effect of wild oat and barley plant density on percentage barley yield loss did not differ significantly (P = 0.05) among years. A pooled regression model describing barley yield loss accounted for 57% of the variation, and provides a means of estimating yield loss due to wild oat in barley grown under zero tillage. Barley yield loss increased as wild oat density increased but the magnitude of the yield loss diminished with increasing barley plant density. Wild oat economic threshold densities varied among years, and were strongly influenced by barley price and expected wild oat-free yield. Economic thresholds were greater at higher barley plant densities. Barley seed weight decreased with increasing barley plant density, and to a lesser extent with increasing wild oat density. The interactive effect of wild oat and barley plant density on wild oat seed yield varied significantly with year, and appeared to be influenced by climatic conditions. The cooler, wetter spring of 1996 favored wild oat seed production (by several orders of magnitude) compared with the relatively warmer and drier spring of 1995. Each year wild oat seed yield and shoot dry weight decreased as barley plant density increased. The results suggest that seeding barley at relatively high rates may reduce the need for wild oat control with herbicides in zero tillage systems. Key words: Zero tillage, wild oat interference, barley seeding rate, nonlinear regression

Response of Four Market Classes of Dry Bean (Phaseolus vulgaris) to Foramsulfuron, Isoxaflutole, and Isoxaflutole plus Atrazine Applied in Previous Years

2006 ◽  
Vol 20 (3) ◽  
pp. 558-563 ◽  
Author(s):  
Darren E. Robinson ◽  
Nader Soltani ◽  
Peter H. Sikkema
Keyword(s):  
Phaseolus Vulgaris ◽  
Dry Weight ◽  
Field Trials ◽  
Navy Bean ◽  
Visible Injury ◽  
Dry Bean ◽  
Shoot Dry Weight ◽  
Field Corn ◽  
White Bean

Three field trials were established from 2001 to 2003 in Ontario to determine the effect of foramsulfuron POST (35 and 70 g ai/ha), isoxaflutole PRE (105 and 210 g ai/ha), and isoxaflutole plus atrazine PRE (105 + 1063 and 210 + 2126 g ai/ha) applied in the previous years to field corn on cranberry, black, kidney, and white (navy) bean. Foramsulfuron residues did not cause visible injury, or reductions in shoot dry weight or yield of dry bean 1 yr after application in corn. In contrast, visual injury across the four market classes varied from 4 to 37% 1 yr after application of isoxaflutole, and from 30 to 54% 1 yr after application of isoxaflutole plus atrazine. Isoxaflutole residues reduced shoot dry weight and yield as much as 81 and 44% in cranberry, 52 and 39% in black, 53 and 19% in kidney, and 42 and 19% in white bean, respectively. Isoxaflutole plus atrazine residues reduced shoot dry weight and yield as much as 87 and 64% in cranberry, 75 and 61% in black, 71 and 46% in kidney, and 65 and 33% in white navy bean, respectively. Injury was not detected regardless of market classes 2 yr after application of isoxaflutole alone or in tank mix with atrazine. Based on these results, it is recommended that none of the market classes of dry bean tested in this study should be grown 1 year after an application of isoxaflutole or isoxaflutole plus atrazine. A recropping interval of 2 years is currently recommended following applications of isoxaflutole or isoxaflutole plus atrazine for these market classes of dry bean.

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