Peter M. Eure

Palmer Amaranth (Amaranthus palmeri) Management in Dicamba-Resistant Cotton

Cotton growers rely heavily upon glufosinate and various residual herbicides applied preplant, PRE, and POST to control Palmer amaranth resistant to glyphosate and acetolactate synthase-inhibiting herbicides. Recently deregulated in the United States, cotton resistant to dicamba, glufosinate, and glyphosate (B2XF cotton) offers a new platform for controlling herbicide-resistant Palmer amaranth. A field experiment was conducted in North Carolina and Georgia to determine B2XF cotton tolerance to dicamba, glufosinate, and glyphosate and to compare Palmer amaranth control by dicamba to a currently used, nondicamba program in both glufosinate- and glyphosate-based systems. Treatments consisted of glyphosate or glufosinate applied early POST (EPOST) and mid-POST (MPOST) in a factorial arrangement of treatments with seven dicamba options (no dicamba, PRE, EPOST, MPOST, PRE followed by [fb] EPOST, PRE fb MPOST, and EPOST fb MPOST) and a nondicamba standard. The nondicamba standard consisted of fomesafen PRE, pyrithiobac EPOST, and acetochlor MPOST. Dicamba caused no injury when applied PRE and only minor, transient injury when applied POST. At time of EPOST application, Palmer amaranth control by dicamba or fomesafen applied PRE, in combination with acetochlor, was similar and 13 to 17% greater than acetochlor alone. Dicamba was generally more effective on Palmer amaranth applied POST rather than PRE, and two applications were usually more effective than one. In glyphosate-based systems, greater Palmer amaranth control and cotton yield were obtained with dicamba applied EPOST, MPOST, or EPOST fb MPOST compared with the standard herbicides in North Carolina. In contrast, dicamba was no more effective than the standard herbicides in the glufosinate-based systems. In Georgia, dicamba was as effective as the standard herbicides in a glyphosate-based system only when dicamba was applied EPOST fb MPOST. In glufosinate-based systems in Georgia, dicamba was as effective as standard herbicides only when dicamba was applied twice. Nomenclature: Acetochlor; dicamba; diuron; fomesafen; glufosinate; glyphosate; MSMA; pyrithiobac; Palmer amaranth, Amaranthus palmeri S. Wats.; cotton, Gossypium hirsutum L. Los productores de algodón dependen mucho del uso de glufosinate y de varios herbicidas residuales aplicados pre-siembra, PRE, y POST, para el control de Amaranthus palmeri resistente a glyphosate y resistente a herbicidas inhibidores de acetolactate synthase. Recientemente desregulado en los Estados Unidos, el algodón resistente a dicamba, glufosinate, y glyphosate (algodón B2XF) ofrece una nueva plataforma para el control de A. palmeri resistente a herbicidas. En North Carolina y Georgia, se realizó un experimento de campo para determinar la tolerancia de B2XF a dicamba, glufosinate, y glyphosate y para comparar el control de A. palmeri con dicamba con un programa actualmente usado (sin dicamba) en sistemas basados en glufosinate y glyphosate. Los tratamientos de glyphosate y glufosinate aplicados POST temprano (EPOST) y POST medio (MPOST) en un arreglo factorial de tratamientos con siete opciones de dicamba (sin dicamba, PRE, EPOST, MPOST, PRE seguido de [fb] EPOST, PRE fb MPOST, y EPOST fb MPOST) y un estándar sin dicamba. El estándar sin dicamba consistió en fomesafen PRE, pyrithiobac EPOST, y acetochlor MPOST. Dicamba no causó ningún daño cuando se aplicó PRE y solamente un daño menor y temporal cuando se aplicó POST. Al momento de la aplicación EPOST, el control de A. palmeri con dicamba o fomesafen aplicados PRE, en combinación con acetochlor fue similar, y fue de 13 a 17% mayor al de acetochlor solo. Dicamba fue generalmente más efectivo sobre A. palmeri aplicado POST que PRE, y dos aplicaciones fueron usualmente más efectivas que una. En sistemas basados en glyphosate, un mayor control de A. palmeri y mayor rendimiento del algodón fueron obtenidos con dicamba aplicado EPOST, MPOST, o EPOST fb MPOST al compararse con los herbicidas estándar en North Carolina. En contraste, dicamba no fue más efectivo que los herbicidas estándar en sistemas basados en glufosinate. En Georgia, dicamba fue tan efectivo como los herbicidas estándar en un sistema basado en glyphosate solamente cuando dicamba fue aplicado EPOST fb MPOST. En sistemas basados en glufosinate, en Georgia, dicamba fue tan efectivo como los herbicidas estándar solamente cuando dicamba se aplicó dos veces.

Influence of Water Quality and Coapplied Agrochemicals on Efficacy of Glyphosate

Abstract Experiments were conducted in 2008, 2009, and 2010 to determine the influence of water source as carrier and other agrochemicals on glyphosate efficacy and physicochemical compatibility. Glyphosate efficacy was not affected by most water sources, when compared with deionized water, although response was not consistent across all weed species, including cereal rye, common lambsquarters, common ragweed, goosegrass, Italian ryegrass, large crabgrass, Palmer amaranth, tall morningglory, and wheat. Control by glyphosate was not negatively affected when coapplied with cloransulam-methyl, dicamba, flumioxazin, pyrithiobac-sodium, thifensulfuron-methyl plus tribenuron-methyl, trifloxysulfuron-sodium, and 2,4-D but was affected by acifluorfen and glufosinate. Calcium, manganese, and zinc solutions consistently reduced weed control by glyphosate, whereas boron seldom affected efficacy. Compared with deionized water, Italian ryegrass control was affected by water sources when applied at seedling and jointing stages more so than at tillering and heading growth stages. Calcium, manganese, and zinc reduced control regardless of growth stage. Precipitates were not produced when glyphosate was applied with the water sources or fertilizer solutions. However, transient precipitates developed when glyphosate was coapplied with cloransulam-methyl, flumioxazin, thifensulfuron-methyl plus tribenuron-methyl, and trifloxysulfuron-sodium but not when coapplied with acifluorfen, dicamba, glufosinate, pyrithiobac-sodium, and 2,4-D. Solution pH ranged from 4.11 to 5.60 after glyphosate was added, regardless of solution pH before glyphosate addition. Nomenclature: 2,4-D; acifluorfen; boron; calcium; cloransulam-methyl; dicamba; flumioxazin; glufosinate; glyphosate; manganese; pyrithiobac-sodium; thifensulfuron-methyl plus tribenuron-methyl; trifloxysulfuron-sodium; zinc; cereal rye, Secale cereale L.; common lambsquarters, Chenopodium album L.; common ragweed, Ambrosia artemisiifolia L.; goosegrass, Eleusine indica (L.) Gaertn.; Italian ryegrass, Lolium perenne L. ssp. multiflorum (Lam.) Husnot.; large crabgrass, Digitaria sanguinalis (L.) Scop.; Palmer amaranth, Amaranthus palmeri (L.) S. Wats.; tall morningglory, Ipomoea purpurea (L.) Roth; wheat, Triticum aestivum L.

Controlling Glyphosate-Resistant Palmer Amaranth (Amaranthus palmeri) in Cotton with Resistance to Glyphosate, 2,4-D, and Glufosinate

Abstract Field experiments were conducted in Macon County, Georgia, during 2010 and 2011 to determine the impact of new herbicide-resistant cotton and respective herbicide systems on the control of glyphosate-resistant Palmer amaranth. Sequential POST applications of 2,4-D or glufosinate followed by diuron plus MSMA directed at layby (late POST-directed) controlled Palmer amaranth 62 to 79% and 46 to 49% at harvest when the initial application was made to 8- or 18–cm-tall Palmer amaranth, in separate trials, respectively. Mixtures of glufosinate plus 2,4-D applied sequentially followed by the layby controlled Palmer amaranth 95 to 97% regardless of Palmer amaranth height. Mixing glyphosate with 2,4-D improved control beyond that observed with 2,4-D alone, but control was still only 79 to 86% at harvest depending on 2,4-D rate. Sequential applications of glyphosate plus 2,4-D controlled Palmer amaranth 95 to 96% following the use of either pendimethalin or fomesafen. Seed cotton yield was at least 30% higher with 2,4-D plus glufosinate systems compared to systems with either herbicide alone. The addition of pendimethalin and/or fomesafen PRE did not improve Palmer amaranth control or yields when glufosinate plus 2,4-D were applied sequentially followed by the layby. The addition of these residual herbicides improved at harvest control (87 to 96%) when followed by sequential applications of 2,4-D or 2,4-D plus glyphosate; yields from these systems were similar to those with glufosinate plus 2,4-D. Comparison of 2,4-D and 2,4-DB treatments confirmed that 2,4-D is a more effective option for the control of Palmer amaranth. Results from these experiments suggest cotton with resistance to glufosinate, glyphosate, and 2,4-D will improve Palmer amaranth management. At-plant residual herbicides should be recommended for consistent performance of all 2,4-D systems across environments, although cotton with resistance to glyphosate, glufosinate, and 2,4-D will allow greater flexibility in selecting PRE herbicide(s), which should reduce input costs, carryover concerns, and crop injury when compared to current systems. Nomenclature: 2,4-D; 2,4-DB; diuron; glufosinate; glyphosate; MSMA; Palmer amaranth, Amaranthus palmeri (S.) Wats. AMAPA; cotton, Gossypium hirsutum L. Resumen Experimentos de campo fueron realizados en el condado Macon, Georgia, durante 2010 y 2011 para determinar el impacto de nuevos sistemas de algodón resistentes a herbicidas y sus respectivos herbicidas en el control de Amaranthus palmeri resistente a glyphosate. Aplicaciones secuenciales POST de 2,4-D o glufosinate seguidas de diuron más MSMA dirigidas a la base del cultivo (aplicaciones POST dirigidas tarde en el ciclo de crecimiento) controlaron A. palmeri 62 a 79% y 46 a 49% al momento de la cosecha cuando la aplicación inicial se hizo a A. palmeri de 8 a 18 cm de altura, en estudios independientes, respectivamente. Mezclas de glufosinate más 2,4-D aplicados secuencialmente seguidos por la aplicación dirigida controlaron A. palmeri 95 a 97% sin importar la altura de la maleza. El mezclar glyphosate con 2,4-D mejoró el control más allá del control observado con 2,4-D solo, pero aún así el control fue solamente 79 a 86% al momento de la cosecha, dependiendo de la dosis de 2,4-D. Aplicaciones secuenciales de glyphosate más 2,4-D controlaron A. palmeri 95 a 96% cuando se usaron después de aplicaciones de pendimethalin o fomesafen. El rendimiento de semilla del algodón fue al menos 30% mayor en sistemas con 2,4-D más glufosinate en comparación con los sistemas que tuvieron solamente aplicaciones de cualquiera de estos dos herbicidas solos. La adición de pendimethalin y/o fomesafen PRE no mejoró el control de A. palmeri ni los rendimientos cuando se realizaron aplicaciones secuenciales de glufosinate más 2,4-D seguidas por aplicaciones dirigidas. La adición de estos herbicidas residuales mejoró el control al momento de la cosecha (87 a 96%) cuando fueron seguidos de aplicaciones secuenciales de 2,4-D o 2,4-D más glyphosate. Los rendimientos de estos sistemas fueron similares a los de glufosinate más 2,4-D. Comparaciones entre tratamientos de 2,4-D y 2,4-DB confirmaron que 2,4-D es una opción más efectiva para el control de A. palmeri. Los resultados de estos experimentos sugieren que el algodón con resistencia a glufosinate, glyphosate, y 2,4-D mejorará el manejo de A. palmeri. El uso de herbicidas residuales debería ser recomendado para promover un desempeño consistente de todos los sistemas con 2,4-D en diferentes ambientes, aunque el algodón con resistencia a glyphosate, glufosinate, y 2,4-D permitirá una mayor flexibilidad en la selección de herbicidas PRE, lo cual podría reducir el costo en insumos, las preocupaciones por limitaciones en la rotación de cultivos debido a larga residualidad, y el riesgo de daño del cultivo, en comparación con los sistemas actuales.

Salvage Palmer Amaranth Programs Can Be Effective in Cotton Resistant to Glyphosate, 2,4-D, and Glufosinate

Abstract Glyphosate-resistant Palmer amaranth escaping residual herbicides is difficult to manage in cotton because of its rapid growth and a limited number of effective herbicide options to control emerged plants. An experiment was conducted at two dryland and two irrigated sites in Georgia during 2011 and 2012 to determine if cotton resistant to glyphosate, 2,4-D, and glufosinate could be used to salvage a crop infested with large Palmer amaranth. Three POST herbicide systems, including sequential applications of 2,4-D, sequential applications of 2,4-D plus glufosinate, or 2,4-D followed by (fb) glufosinate, were applied with intervals of 5, 10, or 15 d between POST applications. All three systems were followed by diuron plus MSMA directed at layby. At the dryland sites with high temperatures and drought conditions, no program provided greater than 90% control. However, the 2,4-D plus glufosinate system was at least twice as effective in controlling 20-cm-tall Palmer amaranth and produced at least three times more cotton than the other two systems, when pooled over POST application intervals. Intervals of 10 or 15 d between POST applications were 23 to 27% more effective than a 5-d interval in controlling Palmer amaranth when pooled over POST herbicide systems; yields were nearly twice as much with the 10-d interval compared to 5 d. At the irrigated site, overall weed control was greater with less treatment differences noted. Palmer amaranth that was 20 cm tall at application was controlled 98 to 99%, 92 to 93%, and 81 to 94% by glufosinate plus 2,4-D, 2,4-D fb glufosinate, and 2,4-D fb 2,4-D systems at harvest, respectively. Intervals between POST applications only influenced control by the POST 2,4-D system, and the 10-d interval was more effective than the 5-d interval. Carpetweed, Florida beggarweed, and smallflower morningglory were controlled 99% at harvest by all systems; however, it was noted that control of carpetweed and Florida beggarweed prior to layby was less effective with 2,4-D than systems including glufosinate. In the event of an at-plant residual herbicide failure in fields infested with glyphosate-resistant Palmer amaranth, our research demonstrates that glufosinate plus 2,4-D sequentially applied 10 to 15 d apart followed by a timely layby application controlled the target weeds in cotton with resistance to 2,4-D, glyphosate, and glufosinate. Nomenclature: 2,4-D; diuron; glufosinate; glyphosate; MSMA; carpetweed, Mollugo verticillata L. MOLVE; Florida beggarweed, Desmodium tortuosum [Sw] DC. DEDTO; Palmer amaranth, Amaranthus palmeri (S.) Wats. AMAPA; smallflower morningglory, Jacquemontia tamnifolia [L.] Griseb. IAQTA; cotton, Gossypium hirsutum L. Resumen En algodón y cuando escapa a herbicidas residuales, Amaranthus palmeri resistente a glyphosate es difícil de manejar debido a su rápido crecimiento y al limitado número de opciones de herbicidas efectivos para el control de plantas emergidas. Se realizó un experimento en dos sitios sin riego y en dos sitios con riego en Georgia en 2011 y 2012 para determinar si el algodón resistente a glyphosate, 2,4-D, y glufosinate podría ser usado para salvar a un cultivo infestado con plantas grandes de A. palmeri. Tres sistemas de herbicidas POST, los cuales incluyeron aplicaciones secuenciales de 2,4-D, aplicaciones secuenciales de 2,4-D más glufosinate, o 2,4-D seguido de (fb) glufosinate, fueron aplicados a intervalos de 5, 10 ó 15 d entre aplicaciones POST. Los tres sistemas fueron seguidos por diuron más MSMA dirigido antes del cierre del dosel. En los sitios sin riego, con altas temperaturas y condiciones de sequía, ningún programa brindó control superior a 90%. Sin embargo, el sistema de 2,4-D más glufosinate fue al menos el doble de efectivo controlando A. palmeri de 20 cm de altura y produjo al menos tres veces más algodón que los otros dos sistemas, cuando se promediaron los intervalos de aplicación POST. Los intervalos de 10 ó 15 d entre aplicaciones POST fueron 23 a 27% más efectivos que el intervalo de 5 d para el control de A. palmeri cuando se promediaron los sistemas de herbicidas POST. El rendimiento con el intervalo de 10 d fue casi el doble al compararse con el intervalo de 5 d. En el sitio con riego, el control de malezas fue en general mayor y se notaron menos diferencias entre tratamientos. A. palmeri que tenía 20 cm de altura al momento de aplicación fue controlado 98 a 99%, 92 a 93%, y 81 a 94% con los sistemas glufosinate más 2,4-D, 2,4-D fb glufosinate, y 2,4-D fb 2,4-D, respectivamente al momento de la cosecha. Los intervalos entre aplicaciones POST solamente influenciaron el control de los sistemas POST con 2,4-D, y el intervalo de 10 d fue más efectivo que el de 5 d. Mollugo verticillata, Desmodium tortuosum, y Jacquemontia tamnifolia fueron controlados 99% al momento de la cosecha en todos los sistemas. Sin embargo, se notó que el control de M. verticillata y D. tortuosum antes del cierre del dosel fue menos efectivo con 2,4-D que los sistemas que incluyeron glufosinate. En la eventualidad de una falla en el control residual al momento de la siembra, en campos infestados con A. palmeri resistente a glyphosate, nuestra investigación demuestra que glufosinate más 2,4-D aplicados secuencialmente 10 a 15 d aparte seguidos por una aplicación antes del cierre del dosel controló las malezas deseadas en algodón con resistencia a 2,4-D, glyphosate, y glufosinate.

Peanut Response to Postemergence Application of Pyroxasulfone

ABSTRACT Field experiments were conducted from 2009 through 2011 to evaluate peanut tolerance to postemergence (POST) applications of pyroxasulfone applied alone or in combination with commonly used foliar herbicides. Hherbicide treatments were arranged in a factorial arrangement that included three pyroxasulfone rates (0, 240, and 480 g ai/ha) and four POST application timings [10, 30, 60, and 90 days after planting (DAP)]. Pyroxasulfone applied at 240 or 480 g ai/ha 10 DAP caused 24 and 33% stunting 2 weeks after treatment (WAT), respectively. Regardless of pyroxasulfone rate, peanut stunting following application 30, 60, or 90 DAP was less than 3%. Peanut yield was not influenced by POST applied pyroxasulfone applied alone. In a second experiment, herbicide treatments were applied in a factorial treatment arrangement that included two pyroxasulfone rates (0 and 240 g ai/ha) and six POST herbicide systems [none; paraquat (140 g ai/ha); paraquat (210 g ai/ha) plus bentazon (280 g ai/ha); paraquat (210 g ...

Efficacy of Herbicides When Spray Solution Application Is Delayed

Information is limited concerning the impact of delaying applications of pesticides after solution preparation on efficacy. Experiments were conducted to determine weed control when diclosulam, dimethenamid-P, flumioxazin, fomesafen, imazethapyr, pendimethalin, and S-metolachlor were applied preemergence the day of solution preparation or 3, 6, and 9 days after solution preparation. Herbicide solutions were applied on the same day regardless of when prepared. Control of broadleaf signalgrass, common lambsquarters, entireleaf morningglory, and Palmer amaranth by these herbicides was not reduced regardless of when herbicide solutions were prepared. Surprisingly entireleaf morningglory control by all herbicides increased when herbicide application was delayed by 9 days. In separate experiments, control of broadleaf signalgrass by clethodim, common ragweed by glyphosate and lactofen, entireleaf morningglory by lactofen, Italian rye grass by glyphosate and paraquat, and Palmer amaranth by atrazine, dicamba, glufosinate, glyphosate, imazethapyr, lactofen, and 2,4-D was affected more by increase in weed size due to delayed application than the time between solution preparation and application.

Time of Application Influences Translocation of Auxinic Herbicides in Palmer Amaranth (Amaranthus palmeri)

The efficacy of WSSA Group 4 herbicides has been reported to vary with dependence on the time of day the application is made, which may affect the value of this mechanism of action as a control option and resistance management tool for Palmer amaranth. The objectives of this research were to evaluate the effect of time of day for application on 2,4-D and dicamba translocation and whether or not altering translocation affected any existing variation in phytotoxicity seen across application time of day. Maximum translocation (Tmax) of [14C]2,4-D and [14C]dicamba out of the treated leaf was significantly increased 52% and 29% to 34% in one of two repeated experiments for each herbicide, respectively, with application at 7:00 AM compared with applications at 2:00 PM and/or 12:00 AM. Applications at 7:00 AM increased [14C]2,4-D distribution to roots and increased [14C]dicamba distribution above the treated leaf compared with other application timings. In phytotoxicity experiments, dicamba application at 8 h after exposure to darkness (HAED) resulted in significantly lower dry root biomass than dicamba application at 8 h after exposure to light (HAEL). Contrasts indicated that injury resulting from dicamba application at 8 HAEL, corresponding to midday, was significantly reduced with a root treatment of 5-[N-(3,4-dimethoxyphenylethyl)methylamino]-2-(3,4-dimethoxyphenyl)-2-isopropylvaleronitrile hydrochloride (verapamil) compared with injury observed with dicamba application and a root treatment of verapamil at 8 HAED, which corresponded to dawn. Overall, time of application appears to potentially influence translocation of 2,4-D and dicamba. Furthermore, inhibition of translocation appears to somewhat influence variation in phytotoxicity across times of application. Therefore, translocation may be involved in the varying efficacy of WSSA Group 4 herbicides due to application time of day, which has implications for the use of this mechanism of action for effective control and resistance management of Palmer amaranth. Nomenclature: 2,4-D; 5-[N-(3,4-dimethoxyphenylethyl)methylamino]-2-(3,4-dimethoxyphenyl)- 2-isopropylvaleronitrile hydrochloride; dicamba; Palmer amaranth, Amaranthus palmeri S. Wats.

Bell Pepper and Weed Response to Dimethyl Disulfide Plus Chloropicrin and Herbicide Systems

Bell pepper producers are faced with the challenge of controlling weeds following the phase-out of methyl bromide (MBr). Numerous attempts have been made to find a single fumigant or herbicide to control a broad spectrum of weeds. Adequate weed control in bell pepper will likely require weed management systems utilizing both fumigant and herbicide options. A weed management system including the fumigant dimethyl disulfide (DMDS) plus chloropicrin (Pic) plus the herbicide napropamide prior to transplant followed by S-metolachlor POST may be necessary to replace MBr. Field experiments were conducted during 2010 and 2011 near Ty Ty, Georgia to determine bell pepper and weed response to DMDS plus Pic or in systems with napropamide and/or S-metolachlor. Bell pepper were not significantly injured by DMDS plus Pic or napropamide. Injury caused by S-metolachlor was transient and plants fully recovered by 4 weeks after treatment (WAT). Yellow nutsedge control 6 WAT using DMDS plus Pic applied at 468 or 560 L ha-1 controlled yellow nutsedge 91 to 95%. Large crabgrass control 6 WAT was 92 to 100% when DMDS plus Pic was applied at 468 or 560 L ha-1 with or without a(n) herbicide (S-metolachlor or napropamide). Palmer Amaranth control prior to harvest was 21, 64, and 85% using DMDS plus Pic at 374, 468, or 560 L ha-1, respectively. DMDS plus Pic applied at 468 or 560 L ha-1 with napropamide followed by S-metolachlor POST gave 95 to 99% control of Palmer amaranth 6 WAT. Consistent weed control and optimum yields were obtained when DMDS plus Pic was used at 468 L ha-1 plus napropamide beneath plastic mulch followed by S-metolachlor POST. Nomenclature: Dimethyl disulfide (DMDS); napropamide; S-metolachlor; bell pepper, Capsicum annuum L. CPSAN.

Peanut Cultivar Response to Preemergence Applications of Pyroxasulfone

ABSTRACT Pyroxasulfone is a residual herbicide developed for use in several agronomic crops such as corn (Zea mays L.), soybean (Glycine max L.), wheat (Triticum aestivum L.), and sunflower (Helianthus annuus L.). Pyroxasulfone provides effective preemergence (PRE) control of annual grasses and broadleaf weeds, but little is known about peanut cultivar tolerance. Therefore, field trials were conducted in Georgia during 2012 and 2013 to evaluate peanut cultivars ‘Georgia-06G’, ‘Georgia Greener’, and ‘Tifguard’ response to pyroxasulfone applied PRE at 0, 120, or 240 g ai/ha. Greater stunting occurred during 2012 than 2013. Peanut stunting 10 days after planting (DAP) during 2012 and 2013 ranged from 38 to 55% and 3 to 11%, respectively. At 10 DAP, greater injury was observed in ‘Tifguard’ as compared to ‘Georgia-06G’ with pyroxasulfone at 120 g ai/ha. ‘Georgia Greener’ was injured more than ‘Tifguard’ following the 240 g ai/ha rate of pyroxasulfone. By 120 DAP, peanut had recovered substantially from stunti...

Compatibility of acephate with herbicides applied postemergence in peanut.

ABSTRACT Numerous agrochemicals can be applied in peanut to control pests. Field and laboratory experiments were conducted in North Carolina during 2009 and 2010 to determine peanut response to paraquat and tobacco thrips (Frankliniella fusca Hinds.) when acephate was applied in combination with chloroacetamide and contact herbicides. Experiments were also conducted during 2011 to determine peanut response to acephate applied alone or with paraquat when peanut was planted either without aldicarb or when aldicarb was applied in the seed furrow at planting. Visible peanut damage caused by tobacco thrips feeding was greater when chloroacetamide herbicides were applied without acephate compared with application with acephate regardless of paraquat treatment. Visible injury caused by paraquat was higher when chloroacetamide herbicides were included compared with paraquat alone in one of two years. Visible injury by paraquat was lower when applied with acephate compared to paraquat alone in one of two years. Ac...