Weed Control and Peanut (Arachis hypogaea L.) Response to Acetochlor Alone and in Combination with Various Herbicides

Abstract

Acetochlor, a chloroacetamide herbicide, is now registered for preplant (PPI), preemergence (PRE), and postemergence (POST) application in peanut. Field research was conducted during 2011 and 2012 in Georgia and North Carolina to determine peanut response and weed control by acetochlor compared with S-metolachlor alone and in programs with other herbicides. In weedfree experiments, peanut tolerance to acetochlor (1.26 and 2.52 kg ai/ha) and S-metolachlor (1.42 kg ai/ha) were evaluated when applied PPI, PRE, early postemergence (EPOST), or POST. Peanut tolerance to acetochlor was similar to S-metolachlor with no negative impact of either herbicide on peanut yield compared with non-treated peanut in absence of weed interference. When applied PRE, acetochlor controlled Palmer amaranth, pitted morningglory, sicklepod, and Texas millet similarly to S-metolachlor while control of broadleaf signalgrass was greater with S-metolachlor. Weed control programs containing EPOST and/or POST applications of herbicides following PRE herbicides provided the best overall weed control but did not affect yellow nutsedge control regardless of whether acetochlor or S-metolachlor were applied. Herbicide programs including PRE, EPOST, and POST herbicides most often resulted in the greatest yields. There was no difference in peanut yield regardless of the presence of acetochlor or S-metolachlor in a comprehensive herbicide program.

Irrigated and Non-Irrigated Peanut (Arachis hypogaea L.) Cultivar Response to Postemergence Paraquat Tank-Mixtures

“…By 14 DAT all herbicide treatments exhibited less than 3% injury. Overall, there were negligible differences in vegetative injury between acetochlor and S-metolachlor, similar to previous research (Chaudhari et al, 2018).…”

“…(1995). S-metolachlor and acetochlor showed analogous results across all ratings, similar to previous research (Chaudhari et al, 2018). MIXED model analysis in SAS 9.4 t were performed.…”

Competing with the competitors in an endless competition: a systematic review of nonchemical weed management research in peanut (Arachis hypogea) in the United States

“…Weeds are generally considered the most important biotic constraint to crop production (Chauhan 2020). Peanut is a poor early-season competitor due to a relatively short canopy, and it requires a long growing season (140 to 160 d), which results in ample opportunity for weeds to occupy space, compete for growth resources, and reduce productivity (Chaudhari et al 2018; Wilcut et al 1995). Season-long weed interference from combinations of broadleaf and grass weeds was reported to reduce harvest efficiency and peanut yield by 60% to 80% (Everman et al 2008b; Webster et al 2007).…”

“…From the 1970s to 2021, peanut yield in the United States increased from 2,760 to 4,640 kg ha– 1 (USDA-NASS 2021), due to advances in agronomic practices, the development of improved cultivars with greater yield potential and disease resistance, and improved weed control with more effective herbicides (Dotray et al 2012; Holbrook 2019). However, weeds continue to be a major problem in all the peanut-producing regions in the United States despite continuous research efforts made in weed science (Chaudhari et al 2018; Tubbs 2019).…”

“…Preemergence control in peanut is achieved mainly with very long-chain fatty acid inhibitors from the chloroacetamide chemical family (e.g., acetochlor, alachlor, dimethenamid- P , and S -metolachlor) and mitosis inhibitors from the dinitroaniline chemical family (e.g., pendimethalin and trifluralin) (Leon et al 2019). More recently, the use of the protoporphyrinogen oxidase (PPO) inhibitor flumioxazin for preemergence control and acetolactate synthase (ALS) inhibitors (diclosulam and imazapic) for residual weed control in peanut has increased considerably (Chaudhari et al 2018). Postemergence broadleaf weed control in peanut is achieved with bentazon and paraquat (photosynthetic inhibitors), acifluorfen and lactofen (PPO inhibitors), 2,4-DB (synthetic auxin), and chlorimuron, diclosulam, imazapic, and imazethapyr (ALS inhibitors), while graminicides such as clethodim and sethoxydim are the major postemergence grass weed herbicides in peanut (Burke et al 2004; Leon et al 2019).…”