Control of common waterhemp (Amaranthus tuberculatus var. rudis) in corn and soybean with sequential herbicide applications

2009 ◽  
Vol 89 (1) ◽  
pp. 127-132 ◽  
Author(s):  
Nader Soltani ◽  
Joshua D Vyn ◽  
Peter H Sikkema

Common waterhemp (Amaranthus tuberculatus) is an aggressive annual broadleaf whose distribution is expected to increase rapidly in agricultural land in eastern Canada. Eight field experiments (four in corn and four in soybean) over a 2-yr period (2005 and 2006) were established on two Ontario farms (near Comber and Petrolia, Ontario) with waterhemp infestations to evaluate the efficacy of various PRE- and POST-emergence herbicides applied alone or in sequence for the control of waterhemp in corn and soybean. There was minimal injury (up to 3.8%) to corn and soybean from the herbicide treatments evaluated. In corn, sequential herbicide programs of isoxaflutole + atrazine PRE fb either dicamba POST, dicamba/diflufenzopyr POST, dicamba/atrazine POST or mesotrione + atrazine POST provided consistent full-season control of waterhemp. Corn yield was reduced 48% when waterhemp was not controlled. Corn yield was equivalent to the weed-free check with the herbicide treatments evaluated. In soybean, PRE or POST herbicides alone provided 41 to 94% control of waterhemp, however, waterhemp control was increased to 90 to 99% with the sequential herbicide programs. Dimethenamid (PRE; 1250 g ha-1) followed by glyphosate (POST1; 900 g ha-1) followed by glyphosate (POST2; 900 g ha-1) controlled waterhemp 99%. Results with waterhemp density and biomass were similar to visible control. Soybean yield was reduced 41% when waterhemp was not controlled. Soybean yield was equivalent to the weed-free check with all the herbicide treatment except dimethenamid PRE, acifluorfen POST1 and fomesafen POST1 where the yield was 30, 19, and 19% lower, respectively. Key words: Waterhemp, weed control, glyphosate, corn, soybean, pre-emergence herbicide, post-emergence herbicide

2020 ◽  
pp. 1-8
Author(s):  
Chandrima Shyam ◽  
Parminder S. Chahal ◽  
Amit J. Jhala ◽  
Mithila Jugulam

Abstract Glyphosate-resistant (GR) Palmer amaranth is a problematic, annual broadleaf weed in soybean production fields in Nebraska and many other states in the United States. Soybean resistant to 2,4-D, glyphosate, and glufosinate (Enlist E3TM) has been developed and was first grown commercially in 2019. The objectives of this research were to evaluate the effect of herbicide programs applied PRE, PRE followed by (fb) late-POST (LPOST), and early-POST (EPOST) fb LPOST on GR Palmer amaranth control, density, and biomass reduction, soybean injury, and yield. Field experiments were conducted near Carleton, NE, in 2018, and 2019 in a grower’s field infested with GR Palmer amaranth in 2,4-D–, glyphosate-, and glufosinate-resistant soybean. Sulfentrazone + cloransulam-methyl, imazethapyr + saflufenacil + pyroxasulfone, and chlorimuron ethyl + flumioxazin + metribuzin applied PRE provided 84% to 97% control of GR Palmer amaranth compared with the nontreated control 14 d after PRE. Averaged across herbicide programs, PRE fb 2,4-D and/or glufosinate, and sequential application of 2,4-D or glufosinate applied EPOST fb LPOST resulted in 92% and 88% control of GR Palmer amaranth, respectively, compared with 62% control with PRE-only programs 14 d after LPOST. Reductions in Palmer amaranth biomass followed the same trend; however, Palmer amaranth density was reduced 98% in EPOST fb LPOST programs compared with 91% reduction in PRE fb LPOST and 76% reduction in PRE-only programs. PRE fb LPOST and EPOST fb LPOST programs resulted in an average soybean yield of 4,478 and 4,706 kg ha−1, respectively, compared with 3,043 kg ha−1 in PRE-only programs. Herbicide programs evaluated in this study resulted in no soybean injury. The results of this research illustrate that herbicide programs are available for the management of GR Palmer amaranth in 2,4-D–, glyphosate-, and glufosinate-resistant soybean.


2017 ◽  
Vol 31 (1) ◽  
pp. 32-45 ◽  
Author(s):  
Amit J. Jhala ◽  
Lowell D. Sandell ◽  
Debalin Sarangi ◽  
Greg R. Kruger ◽  
Steven Z. Knezevic

Glyphosate-resistant (GR) common waterhemp has become a significant problem weed in Nebraska and several Midwestern states. Several populations of GR common waterhemp are also resistant to acetolactate synthase (ALS)-inhibiting herbicides, making them difficult to control with POST herbicides in GR soybean. Glufosinate-resistant (GFR) soybean is an alternate system for controlling GR common waterhemp, justifying the need for evaluating glufosinate-based herbicide programs. The objectives of this study were to compare POST-only herbicide programs (including one-pass and two-pass POST programs) with PRE followed by (fb) POST herbicide programs for control of GR common waterhemp in GFR soybean and their effect on common waterhemp density, biomass, and soybean yield. Field experiments were conducted in 2013 and 2014 near Fremont, NE in a grower’s field infested with GR common waterhemp. Glufosinate applied early- and late-POST provided 76% control of GR common waterhemp at 14 d after late-POST (DALPOST) compared with 93% control with a PRE fb POST program when averaged across treatments. The PRE application of chlorimuron plus thifensulfuron plus flumioxazin,S-metolachlor plus fomesafen or metribuzin, saflufenacil plus dimethenamid-P fb glufosinate provided ≥95% control of common waterhemp throughout the growing season, reduced common waterhemp density to ≤2.0 plants m─2, caused ≥94% biomass reduction, and led to 1,984 to 2,210 kg ha─1soybean yield. Averaged across treatments, the PRE fb POST program provided 82% common waterhemp control at soybean harvest, reduced density to 23 plants m─2at 14 DALPOST, and caused 86% biomass reduction and 1,803 kg ha─1soybean yield compared with 77% control, 99 plants m─2, 53% biomass reduction, and 1,190 kg ha─1yield with POST-only program. It is concluded that PRE fb POST programs with multiple effective modes of action are available for control of GR common waterhemp in GFR soybean.


2020 ◽  
pp. 1-28
Author(s):  
Christian Willemse ◽  
Nader Soltani ◽  
Lauren Benoit ◽  
David C. Hooker ◽  
Amit J. Jhala ◽  
...  

Abstract Control of waterhemp is becoming more difficult in Ontario as biotypes have evolved resistance to four herbicide sites of action (SOA) including groups 2, 5, 9, and 14. The objective of this study was to compare PRE, POST, and PRE followed by (fb) POST herbicide programs and their effect on control, density, and biomass of multiple herbicide-resistant (MHR) waterhemp as well as corn injury and grain yield. Two separate field experiments, each consisting of five field trials, were conducted over a two-year period (2018 and 2019) in corn in Ontario, Canada. The first experiment evaluated MHR waterhemp control with 4-hydroxyphenyl-pyruvate dioxygenase (HPPD) inhibitor containing programs applied PRE, HPPD-inhibitor containing programs applied PRE fb glufosinate applied POST, and glufosinate applied POST. The second experiment evaluated MHR waterhemp control with non-HPPD inhibitor containing programs applied PRE, non-HPPD inhibitor containing programs applied PRE fb atrazine + mesotrione applied POST, and atrazine + mesotrione applied POST. Atrazine + isoxaflutole caused 3 to 5% corn injury at E1; no corn injury was observed with PRE and POST herbicide programs at other environments. In general, atrazine/bicyclopyrone/mesotrione/S-metolachlor and dimethenamid-P/saflufenacil, applied PRE, controlled MHR waterhemp ≥ 95% 12 weeks after POST application (WAA). A POST application of glufosinate following atrazine + tolpyralate PRE, and a POST application of atrazine + mesotrione following atrazine/dicamba or atrazine/S-metolachlor PRE, improved control at 4, 8, and 12 WAA in most environments. In general, PRE fb POST applications resulted in better control of MHR waterhemp throughout the growing season than PRE and POST applications (P<0.05). It is concluded that herbicide programs based on multiple effective SOA are available for effective control of MHR waterhemp in field corn and it is advisable that when choosing a herbicide program, excellent control of MHR waterhemp should be the goal given its high fecundity and competitive ability.


2015 ◽  
Vol 29 (3) ◽  
pp. 431-443 ◽  
Author(s):  
Parminder S. Chahal ◽  
Amit J. Jhala

Glyphosate-resistant (GR) volunteer corn is a significant problem weed in soybean grown in rotation with corn in the midwestern United States and eastern Canada. The objective of this study was to evaluate the efficacy of glufosinate applied in single or sequential applications compared with acetyl-coenzyme A carboxylase (ACCase) inhibitors applied alone or tank mixed with glufosinate for controlling GR volunteer corn in glufosinate-resistant soybean. At 15 d after early-POST (DAEP), ACCase inhibitors applied alone controlled volunteer corn 76 to 93% compared to 71 to 82% control when tank mixed with glufosinate. The expected volunteer corn control achieved by tank mixing ACCase inhibitors and glufosinate was greater than the glufosinate alone, indicating that glufosinate antagonized ACCase inhibitors at 15 DAEP, but not at later rating dates. ACCase inhibitors applied alone or tank mixed with glufosinate followed by late-POST glufosinate application controlled volunteer corn and green foxtail ≥ 97% at 30 DAEP. Single early-POST application of glufosinate controlled common waterhemp and volunteer corn 53 to 78%, and green foxtail 72 to 93% at 15 DAEP. Single as well as sequential glufosinate applications controlled green foxtail and volunteer corn greater than or equal to 90%, and common waterhemp greater than 85% at 75 d after late-POST (DALP). Contrast analysis suggested that glufosinate applied sequentially provided greater control of volunteer corn at 15 and 75 DALP compared to a single application. Similar results were reflected in volunteer corn density and biomass at 75 DALP. Volunteer corn interference did not affect soybean yield, partly because of extreme weather conditions (hail and high winds) in both years of this study.


2020 ◽  
Vol 100 (6) ◽  
pp. 629-641
Author(s):  
Zahoor A. Ganie ◽  
Amit J. Jhala

A soybean trait resistant to sulfonylurea herbicides along with glyphosate (Bolt™ soybean) has been developed. Information is needed to determine herbicide programs for weed control and crop safety in this new multiple herbicide–resistant soybean trait. The objectives of this study were to evaluate weed control and crop safety in sulfonylurea/glyphosate-resistant soybean with herbicide programs, including but not limited to acetolactate synthase (ALS) inhibitors. Field experiments were conducted near Clay Center, NE, USA, in 2016 and 2017. Herbicide programs with multiple sites-of-action including rimsulfuron/thifensulfuron in mixture with flumioxazin, flumioxazin/chlorimuron, pyroxasulfone, chlorimuron/metribuzin, or saflufenacil/imazethapyr plus dimethenamid-P provided 91%–97% control of common waterhemp, velvetleaf, and common lambsquarters. Rimsulfuron and (or) thifensulfuron resulted in 92%–97% control of velvetleaf and common lambsquarters and 81%–87% common waterhemp control at 21 d after pre-emergence (PRE) (DAPRE) herbicide application. Soybean injury was transient and varied from 3% to 11% at 21 DAPRE and 14 d after post-emergence (POST) (DAPOST) herbicide application without causing yield loss. At 30 and 60 DAPOST, 87%–97% velvetleaf control and 92%–98% common lambsquarters control was achieved with herbicide programs tested (PRE, POST, or PRE followed by POST). Common waterhemp control at 30 and 60 DAPOST was not consistent between years. Weed density and biomass reduction were mostly similar to weed control achieved. Untreated control resulted in the lowest soybean yield (1811 kg ha−1) in 2016 compared with 3406–4611 kg ha−1 in herbicide programs.


1981 ◽  
Vol 8 (1) ◽  
pp. 66-73 ◽  
Author(s):  
G. A. Buchanan ◽  
E. W. Hauser ◽  
R. M. Patterson

Abstract Experiments were conducted from 1975 to 1977 to determine the efficacy of herbicides for control of bur gherkin (Cucumis anguria L.) in peanuts (Arachis hypogaea L.). Most bur gherkins seed planted in the field germinated in the upper 2.5 cm of soil, although some seed germinated from 7 cm. In greenhouse and field experiments, preplant-incorporated applications of vernolate (S-propyl dipropylthiocarbamate) substantially reduced the green weight of bur gherkin plants and also improved the efficacy of several cracking and postemergence herbicidal treatments. Postemergence treatment sequences were much more effective when they were begun while bur gherkins were in the cotyledonary stage of development rather than the 3- to 5-leaf stage. Preplanting application and incorporation of vernolate + benefin (N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine), followed by a cracking application of alachlor [2-chloro-2',6'-diethyl-N-(methoxymethyl)acetanilide] + naptalam (N-1-naphthylphthalamic acid) + dinoseb (2-sec-butyl-4,6-dinitrophenol), followed by dinoseb controlled bur gherkins. Some of the most intensive herbicide programs reduced the yield of peanuts in some experiments. Bur gherkin plants that survived the herbicide treatments produced substantial quantities of fruit and seed.


2015 ◽  
Vol 95 (5) ◽  
pp. 973-981 ◽  
Author(s):  
Amit J. Jhala ◽  
Mayank S. Malik ◽  
John B. Willis

Jhala, A. J., Malik, M. S. and Willis, J. B. 2015. Weed control and crop tolerance of micro-encapsulated acetochlor applied sequentially in glyphosate-resistant soybean. Can. J. Plant Sci. 95: 973–981. Acetochlor, an acetamide herbicide, has been used for many years for weed control in several crops, including soybean. Micro-encapsulated acetochlor has been recently registered for preplant (PP), pre-emergence (PRE), and post-emergence (POST) application in soybean in the United States. Information is not available regarding the sequential application of acetochlor for weed control and soybean tolerance. The objectives of this research were to determine the effect of application timing of micro-encapsulated acetochlor applied in tank-mixture with glyphosate in single or sequential applications for weed control in glyphosate-resistant soybean, and to determine its impact on soybean injury and yields. Field experiments were conducted at Clay Center, Nebraska, in 2012 and 2013, and at Waverly, Nebraska, in 2013. Acetochlor tank-mixed with glyphosate applied alone PP, PRE, or tank-mixed with flumioxazin, fomesafen, or sulfentrazone plus chlorimuron provided 99% control of common waterhemp, green foxtail, and velvetleaf at 15 d after planting (DAP); however, control declined to ≤40% at 100 DAP. Acetochlor tank-mixed with glyphosate applied PRE followed by early POST (V2 to V3 stage of soybean) or late POST (V4 to V5 stage) resulted in ≥90% control of common waterhemp and green foxtail, reduced weed density to ≤2 plants m−2 and biomass to ≤12 g m−2, and resulted in soybean yields >3775 kg ha−1. The sequential applications of glyphosate plus acetochlor applied PP followed by early POST or late POST resulted in equivalent weed control to the best herbicide combinations included in this study and soybean yield equivalent to the weed free control. Injury to soybean was <10% in each of the treatments evaluated. Micro-encapsulated acetochlor can be a good option for soybean growers for controlling grasses and small-seeded broadleaf weeds if applied in a PRE followed by POST herbicide program in tank-mixture with herbicides of other modes of action.


2004 ◽  
Vol 18 (2) ◽  
pp. 388-396 ◽  
Author(s):  
Andrew R. Kniss ◽  
Robert G. Wilson ◽  
Alex R. Martin ◽  
Paul A. Burgener ◽  
Dillon M. Feuz

Field experiments were conducted near Scottsbluff, NE, in 2001 and 2002 to compare economic aspects of glyphosate applied to different glyphosate-resistant sugar beet cultivars with that of conventional herbicide programs applied to near-equivalent, non–glyphosate-resistant conventional cultivars. Glyphosate applied two or three times at 2-wk intervals, beginning when weeds were 10 cm tall, provided excellent weed control, yield, and net economic return regardless of the glyphosate-resistant sugar beet cultivar. All conventional herbicide treatments resulted in similar net economic returns. Although the conventional sugar beet cultivars ‘HM 1640’ and ‘Beta 4546’ responded similarly to herbicide treatments with respect to sucrose content, ‘Beta 4546RR’ produced roots with 1% more sucrose than ‘HM 1640RR’. When averaged over herbicide treatments, a producer planting Beta 4546RR could afford to pay US $185/ha more for glyphosate-resistant technology as could a producer planting HM 1640RR. When averaged over cultivars and herbicide treatments, it is estimated that a producer could afford to pay an additional US $385/ha for glyphosate-resistant technology without decreasing net return.


2020 ◽  
Vol 100 (6) ◽  
pp. 692-696
Author(s):  
Nader Soltani ◽  
Lynette R. Brown ◽  
Peter H. Sikkema

Herbicide-resistant (HR) crops, specifically glyphosate-, glufosinate-, and dicamba-resistant (HT3) soybean, will offer producers a new weed management option for the control of some HR weeds in soybean. Four field experiments were conducted near Cottam and on Walpole Island, ON, Canada, during 2017 and 2018 to assess the control of multiple-resistant (MR) waterhemp (herbicide groups 2, 5, and 9) in HT3 soybean treated with various herbicide programs. Pyroxasulfone/flumioxazin, flumioxazin plus metribuzin, or S-metolachlor/metribuzin applied preemergence (PRE) and followed by (fb) glyphosate postemergence (POST) controlled MR waterhemp at 94%, 66%, and 78%, respectively, in early September. Pyroxasulfone/flumioxazin, flumioxazin plus metribuzin, or S-metolachlor/metribuzin applied PRE controlled MR waterhemp 86%–97% when fb glufosinate POST; 100% when fb glyphosate plus dicamba POST; 99%–100% when fb glufosinate plus dicamba POST; and 100% when fb glyphosate plus dicamba POST and fb glufosinate POST2 (before the R2 soybean growth stage) in early September. Reduced MR waterhemp interference with all herbicide programs resulted in an increase in HT3 soybean yield (up to 59%) relative to the weedy control. Results indicate that pyroxasulfone/flumioxazin, flumioxazin plus metribuzin, or S-metolachlor/metribuzin applied PRE fb glufosinate POST, glyphosate plus dicamba POST, glufosinate plus dicamba POST, or glyphosate plus dicamba POST fb glufosinate POST2 provides similar and excellent season-long control of MR waterhemp in HT3 soybean.


1992 ◽  
Vol 6 (1) ◽  
pp. 36-44 ◽  
Author(s):  
Stacey A. Bruff ◽  
David R. Shaw

Field experiments were conducted in 1989 and 1990 on silty clay and sandy loam soils to evaluate weed control and soybean yield with early-April preplant incorporation of selective herbicides in stale seedbed soybean followed by non-selective weed control measures at planting. Metribuzin applied PPI early followed by chlorimuron POST coupled with either glyphosate or paraquat PRE controlled sicklepod, pitted morningglory, and hemp sesbania to the same extent of that treatment applied PPI at planting. All stale seedbed treatments with POST applications and glyphosate, paraquat, or tillage at planting controlled pitted morningglory over 70%. However, imazaquin or metribuzin applied PPI early without a POST treatment controlled sicklepod and pitted morningglory poorly. Frequently, applying PPI herbicides at planting increased control compared with early PPI applications, but this was overcome by POST treatments. Early stale seedbed applications of metribuzin did not result in more than 60% control of hemp sesbania, whereas metribuzin applied PPI at planting controlled over 85%. However, metribuzin plus chlorimuron controlled hemp sesbania at least 74%, regardless of application timing or tillage method, whereas no imazaquin treatment achieved over 65% control. All stale seedbed herbicide treatments increased soybean yield compared with the untreated stale seedbed check. Selective herbicide treatments with either non-selective herbicide in a stale seedbed program resulted in equivalent yield to PPI at planting treatments most often, except with metribuzin.


Sign in / Sign up

Export Citation Format

Share Document