Control of Triazine-Resistant Common Lambsquarters (Chenopodium album) and Two Pigweed Species (Amaranthusspp.) in Corn (Zea mays)

Abstract

Various chemical treatments were evaluated over two growing seasons for control of triazine-resistant common lambsquarters (Chenopodium albumL. # CHEAL) and for control of a triazine-resistant infestation containing both redroot pigweed (Amaranthus retroflexusL. # AMARE) and Powell amaranth (A. powelliiS. Wats. # AMAPO). Atrazine [6-chloro-N-ethyl-N′-(1-methylethyl)-1,3,5-triazine-2,4-diamine], cyanazine {2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl] amino]-2-methylpropanenitrile}, and metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one] provided unsatisfactory control of these biotypes. Satisfactory control of common lambsquarters was obtained with preemergence applications of pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine] or dicamba (3,6-dichloro-2-methoxybenzoic acid), or postemergence applications of dicamba, bromoxynil (3,5-dibromo-4-hydroxybenzonitrile), or bentazon [3-(1-methylethyl)-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide]. Satisfactory control of pigweed was obtained with preemergence applications of alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide] or postemergence treatments of dicamba, bromoxynil, or 2,4-D [(2,4-dichlorophenoxy) acetic acid].

Triazine-Resistant Common Lambsquarters (Chenopodium album) Control in Corn with Preemergence Herbicides

“…Pendimethalin provided greater (98%) and more consistent control of TR-CHEAL than metolachlor or acetochlor. Other researchers have reported similar results with pendimethalin applied PRE (Fuerst et al 1986;Myers and Harvey 1993).…”

“…Triazine-resistant common lambsquarters (TR-CHEAL) is widespread throughout Michigan and the north-central United States. Numerous studies have reported satisfactory control of TR-CHEAL with various preemergence (PRE) herbicides (Darmency and Gasquez 1990;Fuerst et al 1986;Hagood 1989;Myers and Harvey 1993;Parks et al 1996). However, an increased understanding of PRE herbicides that consistently control TR-CHEAL in corn is needed.…”

Preemergence and Postemergence Control of Triazine-Resistant Common Lambsquarters (Chenopodium album) in No-Till Corn (Zea mays)1

“…Control of TR-CHEAL with preemergence (PRE) ap-plications of pendimethalin has varied. Fuerst et al (1986) and Myers and Harvey (1993) obtained satisfactory control of TR-CHEAL with PRE applications of pendimethalin, whereas Hagood (1989) did not. In the Virginia study, a PRE application of pendimethalin followed by a POST application of pendimethalin was required to obtain 87% control or better by the final evaluation (Hagood 1989).…”

“…Myers and Harvey (1993) found that POST applications of dicamba, thifensulfuron, pendimethalin, pyridate, and 2,4-D amine were most effective in the control of TR-CHEAL. Fuerst et al (1986) and Parks et al (1995) found that POST applications of dicamba or bromoxynil provided good control of TR-CHEAL. Glenn et al (1997) reported that POST applications of nicosulfuron or primisulfuron tank-mixed with 2,4-D or dicamba provided excellent late-season control of TR-CHEAL.…”

Confirmation of a Three-Way (Glyphosate, ALS, and Atrazine) Herbicide-Resistant Population of Palmer Amaranth (Amaranthus palmeri) in Michigan

“…PRE applications of atrazine have also failed to control several other weed species, such as common groundsel ( Senecio vulgaris L.), common lambsquarters ( Chenopodium album L.), hood canarygrass ( Phalaris paradoxa L.), rigid ryegrass ( Lolium rigidum Gaudin), and blackgrass ( Alopecurus myosuroides Huds.) that have evolved resistance to atrazine applied POST (Fuerst et al 1986; Ryan 1970; Yaacoby et al 1986). The GR 50 values for atrazine applied PRE for the S and MR Palmer amaranth populations were 0.035 and 3.93 kg ha −1 , respectively (Table 2).…”