Comparison of Imazethapyr and Paraquat-Based Weed Control Systems in Peanut ( Arachis hypogaea )

Paraquat postemergence (POST) applied is often used to control broadleaf and grass weed species in peanut in the Southeast US. The objective of this study was to determine the effects of POST herbicide tank-mixtures including paraquat on vegetation, yield, and grade for runner-type peanut cultivars under irrigated and non-irrigated conditions. Two separate experiments (irrigated and non-irrigated) were conducted in 2016 and 2017 in Ty Ty and Plains Georgia. Georgia-06G, Georgia-14N, TUFRunnere '511', and FloRune '157' cultivars were evaluated. Herbicide tank-mixtures included paraquat, paraquat plus acifluorfen plus bentazon, paraquat plus acifluorfen plus bentazon plus S-metolachlor, and paraquat plus acifluorfen plus bentazon plus acetochlor. Leaf burn, stunting injury, yield, and grade were evaluated. There were no interactions between herbicide and cultivar for all variables. Paraquat alone resulted in significantly greater foliar injury (3 DAT) than the other herbicide treatments for the irrigated (34 to 16%) and non-irrigated (28 to 15%) studies. Stunting for paraquat alone was noted at 15 and 35% for irrigated and non-irrigated, respectively. Similarly, in both studies, Georgia-06G and TUFRunnere '511' yielded 10 to 12% greater than Georgia-14N and FloRune '157'. Overall, the herbicide tank-mixtures did not have a negative effect on yield. With no interactions observed, these herbicide treatments can be used in conjunction with the given runner-type peanut cultivars in either irrigated or non-irrigated conditions without concern for excessive injury or decline in yield or grade.

“…Including acifluorfen plus bentazon in the tankmixture resulted in a reduction in injury when compared to paraquat alone. Similar results were noted by Grey at al. (1995).…”

Section: Non-irrigated Studysupporting

confidence: 92%

“…containing paraquat reduced visible injury to the peanut crop similar to previous research (Grey et al, 1995;Wehtje et al, 1992). Grade variation was due to cultivar differences for both the irrigated and non-irrigated studies.…”

Section: Discussionsupporting

confidence: 78%

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

Eason

Tubbs

Grey³

et al. 2019

“…must occur with the addition of other herbicides such as imazethapyr and imazapic (Cole et al, 1989, Grey et al, 1995, Wilcut et al, 1991a, 1994c. Imazethapyr applied postemergence (POST) provided broad-spectrum and most consistent control when applied within 10 d of weed emergence (Cole et al, 1989;Grey et al, 1995;Grichar et al, 1992;Wilcut et al 1991a, b;1994b, c). Imazapic applied POST controls the same spectrum of weeds as imazethapyr (Nester and Grichar, 1993;Grichar et al, 1994;Wilcut et al, 1993Wilcut et al, , 1994cWilcut et al, , 1995 (Grey et al, 2001).…”

mentioning

confidence: 99%

Peanut (Arachis hypogaea L.) Response to Lactofen at Various Postemergence Timings1

Dotray

Grichar²,

Baughman³

et al. 2012

Field experiments were conducted at nine locations in Texas and Georgia in 2005 and 2006 to evaluate peanut tolerance to lactofen. Lactofen at 220 g ai/ha plus crop oil concentrate was applied to peanut at 6 leaf (lf), 6 lf followed by (fb) 15 days after the initial treatment (DAIT), 15 DAIT alone, 6 lf fb 30 DAIT, 30 DAIT alone, 6 lf fb 45 DAIT, 45 DAIT alone, 6 lf fb 60 DAIT, and 60 DAIT alone in weed-free plots. Lactofen caused visible leaf bronzing at all locations. Yield loss was observed when applications were made 45 DAIT, a timing that would correspond to plants in the R5 (beginning seed) to R6 (full seed) stage of growth. At all locations except the Texas High Plains, this application timing was within the 90 d preharvest interval. Growers who apply lactofen early in the peanut growing season to small weeds should have confidence that yields will not be negatively impacted despite dramatic aboveground injury symptoms; however, applications made later in the season, during seed fill, may adversely affect yield.

“…Imazethapyr can be applied either preplant incorporated, preemergence, or postemergence (Wilcutei al, 1991a,b;1994a,b). Grey et al (1995) reported that tank-mixed combinations of paraquat and imazethapyr applied early postemergence, followed by various other treatments, generally resulted in optimum net returns. Conversely, systems in which imazethapyr was applied alone generally had lower eco nomic returns.…”

mentioning

confidence: 99%

Imazapic-Based Herbicide Systems for Peanut and Factors Affecting Activity on Florida Beggarweed

Wehtje¹,

Padgett²,

Martin

2000

Field studies were conducted over 3 yr to evaluate imazapic, applied either alone or combined with other commonly used herbicides for peanut weed control. Imazapic applied early postemergence alone at 71 g/ha provided excellent weed control, maximum yields, and optimum economic returns. Variations of this treat ment-such as half rate of imazapic applied alone, tank mixed with other herbicides, or supplemented with other herbicides-frequently had equivalent weed con trol and yield. However, these variations did not im prove economic return. Greenhouse studies evaluated Florida beggarweed control as influenced by weed age, imazapic rate, and application type. The three applica tion types were foliage only, soil only, and soil plus foliage. Control was independent of application type when Florida beggarweed seedlings were less than 20 d old. The soil-only application did not adequately control older seedlings. Foliage-only and foliage plus soil appli cation were equally effective. Averaged across all other factors, imazapic was less effective controlling seedlings older than 20 d. At this age, seedlings produced trifoliate rather than unifoliate leaves. Absorption of 14 C-imazapic by unifoliate and trifoliate leaves was equivalent. How ever, translocation was greater in unifoliate leaves. Re duced translocation by trifoliate foliage contributes to imazapic tolerance of older Florida beggarweed seed lings.