Controlling Weeds Found in Peanut with Lactofen

Abstract

Field studies were conducted from 2006 to 2008 in south Texas on peanut and in the Texas High Plains under fallow conditions to determine weed control using lactofen applied POST. At the High Plains location, under low humidity conditions, Palmer amaranth control decreased as weed size increased. Smellmelon control with lactofen in south Texas was influenced by weed length and surfactant. Adding a crop oil concentrate (Agridex) to lactofen resulted in at least 95% smellmelon control when applied to plants from 2 to 30 cm in length. Adding a non‐ionic surfactant (Induce) to lactofen resulted in 99% smellmelon control when applied to 2 to 5 cm long smellmelon and 82 to 87% control when applied to 15 to 30 cm long smellmelon. At the south Texas location, under high humidity conditions, Palmer amaranth control with lactofen was influenced by plant height but not as great as under the low humidity conditions of the High Plains. Peanut yield following lactofen application was greater than the untreated check regardless of application timing. Applying lactofen sequentially to 2,4‐DB improved buffalobur, Palmer amaranth, devil's‐claw, and puncturevine control over 2,4‐DB or lactofen alone at the High Plains location; however, Palmer amaranth, horse purslane, and smellmelon control in south Texas was not influenced as great by sequential lactofen applications.

Effect of Sequential Applications of Protoporphyrinogen Oxidase-Inhibiting Herbicides on Palmer Amaranth (Amaranthus palmeri) Control and Peanut Response

“…For mid-season application, the only other effective herbicides are the PPO-inhibitors. Palmer amaranth is adequately controlled by PPO-inhibiting herbicides when plants are less than 10 cm tall, but control declines quickly as plants surpass 10 cm in height (Gaeddert et al 1997;Grichar 2007Grichar , 2008Grichar and Dotray 2011;Mayo et al 1995;Morichetti et al 2012). If applied when plants are taller than 10 cm, most PPO-inhibiting herbicides control Palmer amaranth for 1 to 2 wk after treatment, but plants do not completely die and regrowth occurs (Morichetti et al 2012).…”

Weed Control and Peanut (Arachis hypogaea L.) Cultivar Response to Encapsulated Acetochlor

“…In 2012 Smetolachlor alone provided 95% control and the addition of lactofen to the PRE herbicides provided at least 94% smellmelon control. In previous work, Grichar (2008) and Grichar and Dotray (2011) reported that smellmelon control with lactofen varied from 66 to 88% regardless of application timing. Also, Grichar and Dotray (2011) reported that lactofen controlled smellmelon 2 to 5 cm long at least 97% with either Agridex or Induce; however, smellmelon 15 to 20 cm long was controlled 96% with lactofen plus Agridex but only 82% with lactofen plus Induce.…”

“…Subsequent new growth did not show the effects of the lactofen applications and was 2% or less four wks after application (data not shown). Other studies have reported that lactofen injury is transient and subsequent growth does not show any effects of the herbicide (Grichar, 2007;2008;Grichar and Dotray, 2011). Weed Control.…”

“…Combinations that included lactofen controlled this weed no better than 63%. Grichar and Dotray (2011) reported that lactofen alone failed to control devil's-claw but a sequential application of lactofen followed by 2,4-DB controlled at least 88%.…”

Peanut Response to Postemergence Application of Pyroxasulfone

“…Paraquat reduced yield of the runner type peanut cultivar`York following application 21 days after cracking while application 7, 14, or 28 days after cracking did not reduce yield . Lactofen may also cause leaf necrosis and bronzing in peanut; however, this injury does not result in yield loss Ferrell et al 2013;Grichar and Dotray 2011;.…”