Early-Season Weed Control Using Herbicides with Adjuvants in Direct-Seeded Onion

2013 ◽  
Vol 27 (2) ◽  
pp. 369-372 ◽  
Author(s):  
James R. Loken ◽  
Harlene M. Hatterman-Valenti

Early-season weed competition may cause substantial yield losses in onion. Oxyfluorfen and bromoxynil are POST herbicide options for weed control once onion has developed two leaves, which often takes 4 to 6 wk. Multiple applications of oxyfluorfen at 35 and 18 g ai ha−1and bromoxynil at 35 and 18 g ae ha−1with adjuvants were evaluated for onion safety and weed control under controlled greenhouse conditions. Oxyfluorfen at 35 g ha−1plus organosilicone surfactant caused 42% onion injury at 12 d after three sequential applications. Onion treated with bromoxynil at 18 g ha−1plus high surfactant oil concentrate had lower fresh weight (0.7 g) compared to methylated seed oil (MSO) (1.2 g) or petroleum oil concentrate (POC) (1.3 g) at the same bromoxynil rate. The addition of nonionic surfactant to bromoxynil, averaged across bromoxynil rates, provided 17 and 39% control of redroot pigweed and common lambsquarters, respectively. Redroot pigweed control with oxyfluorfen at 35 or 18 g ha−1plus any tested adjuvant was excellent (≥ 93%). Results suggested the use of POC or MSO with either oxyfluorfen or bromoxynil for subsequent field trials because of similar common lambsquarters and redroot pigweed control and onion safety.

1998 ◽  
Vol 12 (2) ◽  
pp. 215-222
Author(s):  
Robin R. Bellinder ◽  
Marija Arsenovic ◽  
Jonathan J. Kirkwyland ◽  
Russell W. Wallace

Following suggested guidelines developed by the Environmental Protection Agency (EPA), comparative snap bean herbicide performance field trials were conducted from 1993 to 1995 in New York. Data were obtained on crop injury, weed control, and weed biomass, and crop yield, quality, and losses during harvest. Trifluralin, EPTC, and pendimethalin applied preplant incorporated (PPI) and applications of metolachlor applied preemergence (PRE) provided less than adequate control of redroot pigweed, common lambsquarters, and hairy galinsoga. Cultivation improved weed control with PPI and PRE applications. Metolachlor + fomesafen PRE provided good control of hairy galinsoga, adequate redroot pigweed control, and marginal control of common lambsquarters. Fomesafen applied postemergence (POST), combinations of metolachlor applied PRE with fomesafen or bentazon applied POST, and fomesafen + bentazon applied POST adequately controlled the three weed species without cultivation. Herbicide treatments had little measurable impact on snap bean quality or losses during harvest. Information from product comparison trials may be useful in developing recommendations for growers but may prove less than adequate in providing data necessary for a thorough evaluation of the relative benefits of individual herbicides as intended by EPA guidelines. Difficulties were encountered in following the guidelines, and costs of conducting the product comparison trials for a single crop in one growing region exceeded $90,000 over 3 yr.


2009 ◽  
Vol 23 (2) ◽  
pp. 264-269 ◽  
Author(s):  
Scott L. Bollman ◽  
Christy L. Sprague

Field trials were conducted to determine if tillage and soil-applied herbicides had an effect on weed control and sugarbeet growth with a micro-rate herbicide program. Sugarbeet emergence was earlier in the moldboard plowed system compared with the chisel plowed system at three of four sites. Conditions were dry and sugarbeets emerged 5 d later in the moldboard plowed system compared with the chisel plowed system at the fourth site. Even though the rate of sugarbeet emergence differed between tillage systems at all four sites, final sugarbeet populations did not differ at two of the four sites. Sugarbeet injury from PRE treatments ofS-metolachlor, ethofumesate, and ethofumesate plus pyrazon, followed by four POST micro-rate applications, ranged from 11 to 27% and 1 to 18% in the chisel and moldboard plowed systems, respectively, 6 wk after planting (WAP). Under wet conditions, sugarbeet stand was reduced and injury was greatest from PRE applications ofS-metolachlor. Common lambsquarters, pigweed (redroot pigweed and Powell amaranth), and giant foxtail control in mid-August was consistently higher when a PRE herbicide was applied prior to micro-rate herbicide treatments. Even though there were differences between PRE and no-PRE treatments with respect to sugarbeet injury and weed control, recoverable white sucrose yield did not differ between herbicide treatments. However, recoverable white sucrose yield was greater in the moldboard plowed treatments compared with the chisel plowed treatments at three out of the four sites.


HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 971D-972
Author(s):  
Harlene M. Hatterman-Valenti ◽  
Carrie E. Schumacher ◽  
Collin P. Auwarter ◽  
Paul E. Hendrickson

Field studies were conducted at Absaraka, Carrington, and Oakes, N.D., in 2005 to evaluate early season broadleaf weed control and onion (Allium cepa L.) injury with herbicides applied preemergence to the crop. DCPA is a common preemergence herbicide used in onion. However, DCPA can be uneconomical in most high-weed situations, or the usage may be restricted due to possible groundwater contamination. Potential substitutes evaluated were bromoxynil, dimethenamid-P, and pendimethalin. Main broadleaf weeds were redroot pigweed (Amaranthus retroflexus L.) and common lambsquarters (Chenopodium album L.). In general, all herbicides, except bromoxynil, provided acceptable broadleaf weed control 4 weeks after treatment. The highest herbicide rate provided greater weed control compared with the lowest rate for each herbicide. However, onion height was also reduced with the highest herbicide rate. In addition, the two highest rates of dimethenamid-P reduced the onion stand compared with the untreated. A postemergence application of bromoxynil + oxyfluorfen + pendimethalin to onion at the four- to five-leaf stage controlled the few broadleaf weeds that escaped the preemergence treatments and provided residual control of mid- and late-season germinating broadleaf weeds at two of the three locations. Intense germination of redroot pigweed during July at the Oakes location reduced onion yield with all treatments compared with the hand-weeded check. In contrast, total onion yields with all herbicide treatments except the high rate of dimethenamid-P were similar to the hand-weeded check at Absaraka and Carrington.


2006 ◽  
Vol 20 (4) ◽  
pp. 1023-1029 ◽  
Author(s):  
Pamela J.S. Hutchinson ◽  
Brent R. Beutler ◽  
Daniel M. Hancock

Sulfentrazone was applied POST at 13, 26, or 53 g ai/ha alone or in combination with metribuzin at 280 or 420 g ai/ha in field trials conducted with ‘Russet Burbank’ potatoes in 2002 to 2004. Sulfentrazone alone provided less than 84% redroot pigweed, common lambsquarters, and kochia control, although control usually improved to 90% or greater when metribuzin was included. Hairy nightshade control reached 90% only when the highest rates of both herbicides were applied in combination. Sulfentrazone alone did not provide any volunteer oat control, whereas control was 85% when the highest metribuzin rate was included. Potato crop injury, consisting of chlorosis, interveinal blackening of the leaves, eventual necrosis, leaf malformation, and plant stunting, increased as the sulfentrazone rate increased. In contrast, injury decreased as metribuzin rate increased from 0 to 420 g/ha, when averaged across sulfentrazone rates. Reduction in injury levels and increased weed control translated to improved tuber yields as metribuzin rate increased. However, when sulfentrazone was combined with the highest metribuzin rate, potato injury was still relatively high at 26 and 18% at 1 and 4 wk after treatment, and acceptance of sulfentrazone applied POST with metribuzin by potato growers is unlikely.


2012 ◽  
Vol 26 (4) ◽  
pp. 731-739 ◽  
Author(s):  
Rick A. Boydston ◽  
Joel Felix ◽  
Kassim Al-Khatib

Field trials were conducted in 2009 and 2010 near Paterson, WA and Ontario, OR to evaluate weed control and potato tolerance to PRE-applied pyroxasulfone, saflufenacil, and KSU12800 herbicides. Pyroxasulfone at 0.09 to 0.15 kg ai ha−1and saflufenacil at 0.05 to 0.07 kg ai ha−1applied PRE alone or in tank mixes with several currently labeled herbicides did not injure potatoes at either site in both years. KSU12800 at 0.15 kg ai ha−1injured potatoes from 18 to 26% for a period of about 4 wk after emergence at Ontario both years. In addition, KSU12800 at 0.29 and 0.45 kg ha−1injured potatoes from 17 to 38% at 17 d after treatment (DAT) at Paterson in 2009. Pyroxasulfone at 0.15 kg ha−1controlled barnyardgrass, hairy nightshade, and redroot pigweed 96% or greater, but control of common lambsquarters was variable. Saflufenacil at 0.07 kg ha−1provided greater than 93% control of common lambsquarters, hairy nightshade, and redroot pigweed at both sites in 2010. KSU12800 at 0.15 kg ha−1controlled common lambsquarters, hairy nightshade, and redroot pigweed 99% or more at Ontario, but only 87 to 93% at Paterson in 2010. These herbicides did not reduce yield of U.S. no. 1 tubers or total tuber yields compared to standard labeled herbicide treatments when weed control was adequate.


2010 ◽  
Vol 24 (2) ◽  
pp. 153-159 ◽  
Author(s):  
James R. Loken ◽  
Harlene M. Hatterman-Valenti

Field experiments were conducted at Oakes, Absaraka, and Tappen, ND, in 2006 and repeated at Oakes and Absaraka, ND, in 2007 to evaluate early season weed control of common lambsquarters and redroot pigweed in onion with POST herbicides applied at multiple reduced rates (microrates) and to determine whether microrate herbicide treatments effectively reduced early season broadleaf weed competition, caused crop injury, or affected yield. Application rates of bromoxynil, oxyfluorfen, metribuzin, and acifluorfen were reduced to 0.25, 0.13, and 0.06× of their lowest labeled rate and applied in sequential applications (every 7 d) either two or three times. The 0.25× rate of bromoxynil (70.1 g ae/ha) provided the greatest control of common lambsquarters (95%). The 0.25× rates of bromoxynil and oxyfluorfen (70.1 g ai/ha) provided the greatest control of redroot pigweed (93 and 85%, respectively). Microrate applications of metribuzin or acifluorfen did not effectively control common lambsquarters or redroot pigweed. In 2006, no onion injury was observed. However, in 2007, applications of oxyfluorfen resulted in approximately 15% injury, regardless of the herbicide rate or the number of applications. Plants outgrew symptoms by 4 wk after treatment and were similar to the untreated plants. Onion treated with oxyfluorfen had the greatest total yield, followed by onion treated with bromoxynil. Onion treated with acifluorfen had a greater total marketable bulb yield than onion treated with metribuzin, but yield was considered poor compared to the other herbicide treatments. Three microrate applications provided greater weed control and increased yield compared with two applications across herbicides and rates. Results suggest that microrate applications of bromoxynil and oxyfluorfen will provide early season broadleaf weed control in onion.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Nader Soltani ◽  
Robert E. Nurse ◽  
Christy Shropshire ◽  
Peter H. Sikkema

Four field trials were conducted over a three-year period (2011–2013) in southwestern Ontario to evaluate the level of weed control provided by various halosulfuron tankmixes applied preplant incorporated (PPI) in white bean. Trifluralin, s-metolachlor, halosulfuron, and imazethapyr applied alone or in combination caused 4% or less visible injury 1 and 4 weeks after emergence (WAE) in white bean. Trifluralin, s-metolachlor, halosulfuron, and imazethapyr applied PPI provided 80–96%, 84–95%, 83–100%, and 75–92% control of redroot pigweed; 19–28%, 30–40%, 97–99%, and 73–84% control of common ragweed; 94–96%, 63–82%, 96–100%, and 96–100% control of common lambsquarters; 14-15%, 12–35%, 100%, and 96–97% control of wild mustard; and 96–97%, 95–97%, 53–56%, and 80–82% control of green foxtail, respectively. The two- and three-way tankmixes of halosulfuron with trifluralin, s-metolachlor, or imazethapyr provided 85–100% control of redroot pigweed, 90–98% control of common ragweed, 97–100% control of common lambsquarters, 100% control of wild mustard, and 93–98% control of green foxtail. Weed density, weed biomass and white bean seed yields reflected the level of visible weed control.


2004 ◽  
Vol 18 (3) ◽  
pp. 801-809 ◽  
Author(s):  
Peter H. Sikkema ◽  
Allan S. Hamill ◽  
Mirwais M. Qaderi ◽  
Colleen Doucet

Field experiments were conducted in 1998, 1999, and 2000 at two locations (Harrow and Ridgetown) in southwestern Ontario to determine the biologically effective rates (I90) of a commercial formulation of flufenacet plus metribuzin for weed control and processing tomato tolerance. At the proposed label use rate, flufenacet plus metribuzin provided excellent (≥90%) early-season (22 to 29 d after planting) control of velvetleaf, good (80 to 89%) control of barnyardgrass and redroot pigweed, and fair (60 to 79%) control of common lambsquarters. Flufenacet plus metribuzin provided fair late-season (59 to 97 d after planting) control of redroot pigweed and common lambsquarters and poor (≤59%) control of barnyardgrass and velvetleaf. At Harrow and Ridgetown, I90values for early-season weed control ranged from 70 to 1,300 g ai/ha and 50 to 1,900 g ai/ha, respectively. Flufenacet plus metribuzin provided poor weed control at Ridgetown. This result was not attributable to higher weed density or particular weed species but may have been caused by lack of rainfall and too low application rates for the medium-textured soil type. It is estimated that flufenacet plus metribuzin at 1,400 g/ha can control green foxtail season-long, whereas barnyardgrass and common lambsquarters would require 1,900 g/ha. Season-long control of velvetleaf and redroot pigweed would require application rates of 3,200 and 7,100 g/ha, respectively. Only slight early-season crop injury was observed, which was not reflected in yields. Optimum yields of tomatoes were obtained at Harrow at rates lower or slightly higher than the registered rates for corn and soybean. Tomato yields were higher at Harrow than at Ridgetown, which may have been due to differences in soil texture. Tomatoes grown in a medium-textured (Ridgetown) soil appeared to be less competitive against weeds than those grown in a coarse-textured soil (Harrow).


2015 ◽  
Vol 95 (2) ◽  
pp. 339-344 ◽  
Author(s):  
Kimberly D. Walsh ◽  
Nader Soltani ◽  
David C. Hooker ◽  
Robert E. Nurse ◽  
Peter H. Sikkema

Walsh, K. D., Soltani, N., Hooker, D. C., Nurse, R. E. and Sikkema, P. H. 2015. Biologically effective rate of sulfentrazone applied pre-emergence in soybean. Can. J. Plant Sci. 95: 339–344. Sulfentrazone is a protoporphyrinogen (PPO)-inhibiting herbicide under evaluation for use in soybean in Ontario, Canada. The primary objective of this study was to determine the dose of sulfentrazone applied pre-emergence (PRE) needed to provide 50 and 90% control of redroot pigweed, common ragweed, common lambsquarters and green foxtail. Seven field trials were conducted over a 3-yr period (2007, 2008 and 2009) in southwestern Ontario to evaluate the efficacy of sulfentrazone applied PRE at doses ranging from 26 to 1120 g a.i. ha−1. The doses of sulfentrazone applied PRE to reduce redroot pigweed, common ragweed, common lambsquarters and green foxtail dry weight by 50% were 104, 139, 15 and 65 g a.i. ha−1; doses of 241, 514, 133 and 721 g a.i. ha−1 of sulfentrazone were required for 90% reduction in above-ground biomass of those weed species, respectively. Sulfentrazone applied PRE caused soybean injury only at 560 and 1120 g a.i. ha−1, with 6 and 13% soybean injury at 4 wk after herbicide application (WAT), respectively. Weed control provided by sulfentrazone applied PRE at a dose of 600 g a.i. ha−1 was sufficient to maintain 90% of the soybean yield compared with the weed-free control. Therefore, PRE application of sulfentrazone has the potential to provide excellent (>90%) control of selected weeds with minimal to no crop injury; however, weed control varied by species, and thus broad spectrum weed control is not feasible using sulfentrazone alone.


Weed Science ◽  
1998 ◽  
Vol 46 (5) ◽  
pp. 587-594 ◽  
Author(s):  
Kelly A. Nelson ◽  
Karen A. Renner ◽  
Donald Penner

Field and greenhouse experiments were conducted in 1995 and 1996 to determine soybean injury and weed control differences from imazamox and imazethapyr applied postemergence with a nonionic surfactant or methylated seed oil and with selected tank mixtures. Soybean injury from imazamox at 35 g ai ha−1plus either a methylated seed oil or nonionic surfactant was equal to injury from imazethapyr at 70 g ai ha−1in the greenhouse and field. Imazamox provided greater common lambsquarters control than imazethapyr in the field in 1995 and in the greenhouse. Thifensulfuron tank mixed with imazethapyr increased common lambsquarters control, while soybean response increased when thifensulfuron was tank mixed with imazamox. Common ragweed dry weight was reduced 61 to 64% from 35 g ha−1imazamox and 70 g ha−1imazethapyr in the field; however, imazamox provided greater common ragweed control than imazethapyr in the greenhouse. Tank mixtures of lactofen with imazamox or imazethapyr increased common ragweed control and resulted in greater soybean seed yield in 1996 than when imazamox and imazethapyr were applied alone; however, lactofen antagonized giant foxtail control with imazamox and imazethapyr, and antagonized common lambsquarters control with imazamox. Giant foxtail control in the greenhouse was antagonized more when acifluorfen, fomesafen, and lactofen were tank mixed with 35 g ha−1imazethapyr than with 35 g ha−1imazamox. Giant foxtail control with imazamox or imazethapyr applied alone or with diphenyl ether herbicides increased when 28% urea ammonium nitrate was added with nonionic surfactant compared with nonionic surfactant only. Imazethapyr antagonized giant foxtail control by clethodim in the field and was more antagonistic than imazamox in the greenhouse. A methylated seed oil improved common ragweed control by imazethapyr at 70 g ha−1and imazamox at 18 and 35 g ha−1, while common lambsquarters and velvetleaf control increased when a methylated seed oil was included with 18 g ha−1imazethapyr compared to nonionic surfactant in the greenhouse.


Sign in / Sign up

Export Citation Format

Share Document