scholarly journals Texas Panicum (Panicum texanum) Control in Strip-Tillage Peanut (Arachis hypogaea) Production

2002 ◽  
Vol 29 (2) ◽  
pp. 141-145 ◽  
Author(s):  
W. C. Johnson ◽  
E. P. Prostko ◽  
B. G. Mullinix

Abstract Studies were conducted from 1999 through 2001 in Georgia to develop Texas panicum management systems in strip-tillage peanut production into a killed rye cover crop. The experimental design was a split-plot with four replications. Main plots were preemergence (PRE) herbicides for annual grass control—ethalfluralin, pendimethalin, metolachlor, alachlor, dimethenamid, and a nontreated PRE control. All plots were irrigated immediately after PRE applications to activate herbicides. Subplots were postemergence (POST) graminicides applied 28 d after peanut emergence—sethoxydim, clethodim, and a nontreated POST control. POST graminicides were applied with a crop oil concentrate. None of the PRE herbicides alone adequately controlled Texas panicum in strip-till peanut production, even with optimum activation with irrigation. Sethoxydim and clethodim controlled Texas panicum at least 91%, regardless of PRE treatments. Peanut yields were greater where ethalfluralin or pendimethalin PRE were applied sequentially with a POST graminicides, compared to PRE herbicides or POST graminicides alone. This suggests that, while POST graminicides effectively control Texas panicum, the reduced efficacy of dinitroaniline herbicides is still beneficial. The additional cost of a POST graminicide needs to be factored into production budgets for strip-tillage peanut production.

Weed Science ◽  
1985 ◽  
Vol 33 (2) ◽  
pp. 233-237 ◽  
Author(s):  
Daniel L. Colvin ◽  
Glenn R. Wehtje ◽  
Mike Patterson ◽  
Robert H. Walker

Field experiments were conducted in 1982 and 1983 on a Dothan sandy loam (Plinthic Paleudult) at Headland, AL, to investigate minimum-tillage production of peanuts (Arachis hypogaeaL.). The experiments included two peanut varieties: a) ‘Pronto’ (an earlier maturing Spanish type), and b) ‘Florunner’ (a later maturing runner type). Two row-spacing patterns were used: a) conventional 91-cm rows, and b) a modified twin 18-cm row pattern. A constant seeding rate (140 kg/ha) was used regardless of row spacing. Six herbicide systems were evaluated within each combination of variety and row spacing. The Florunner variety outyielded the Pronto variety across both years and weed management systems. Modified twin 18-cm rows outyielded conventional 91-cm rows across years and peanut varieties. Two of the six weed management systems were successful: 1) paraquat (1,1’-dimethyl-4,4’-bipyridinium ion) + oryzalin (3,5-dinitro-N4,N4-dipropylsulfanilamide) (preemergence), paraquat (ground cracking), naptalam (N-1-naphthylphthalamic acid) + dinoseb (2-sec-butyl-4,6-dinitrophenol) (postemergence); and 2) paraquat + pendimethalin [N-(1-ethylpropyl-3,4-dimethyl-2,6-dinitrobenzenamine] (preemergence), acetochlor [2-chloro-N(ethoxymethyl)-6’-ethyl-o-acetotoluidide] + dinoseb (ground cracking), and cyanazine {2-[[4-chloro-6-(ethylamino)-s-triazine-2-yl]amino]-2-methylpropionitrile} (early postdirected spray). Both systems provided the best overall control of Texas panicum (Panicum texanumBuckl. ♯ PANTE), Florida beggarweed [Desmodium tortuosum(Sw.) DC. ♯ DEDTO], and sicklepod (Cassia obtusifoliaL. ♯ CASOB) and were acceptable for use in minimum-tillage peanut production.


2010 ◽  
Vol 24 (1) ◽  
pp. 1-5 ◽  
Author(s):  
W. Carroll Johnson ◽  
Eric P. Prostko ◽  
Benjamin G. Mullinix

In strip-tillage peanut production, situations occur when dinitroaniline herbicides are not applied in a timely manner. In these cases, dinitroaniline herbicides would be applied days or weeks after seeding. However, there is no information that documents the effects of delayed applications on weed control. Trials were conducted in 2004, 2005, and 2007 in Georgia to determine the weed control efficacy of delayed applications of pendimethalin in strip-tillage peanut production. Treatments included seven timings of pendimethalin application and three pendimethalin-containing herbicide combinations. Timings of application were immediately after seeding (PRE), vegetative emergence of peanut (VE), 1 wk after VE (VE+1wk), VE+2wk, VE+3wk, VE+4wk, and a nontreated control. Pendimethalin containing herbicide programs included pendimethalin plus paraquat, pendimethalin plus imazapic, and pendimethalin alone. Among the possible treatment combinations was a current producer standard timing for nonpendimethalin weed control programs in peanut, which was either imazapic or paraquat alone applied VE+3wk. Pendimethalin alone did not effectively control Texas millet regardless of time of application (69 to 77%), whereas southern crabgrass was controlled by pendimethalin alone PRE (87%). Delayed applications of pendimethalin controlled Texas millet and southern crabgrass when combined with either paraquat or imazapic, with imazapic being the preferred combination due to better efficacy on southern crabgrass than paraquat at most delayed applications. Peanut yield was improved when any of the herbicide combinations were applied PRE compared to later applications. Across all times of application, pendimethalin plus imazapic effectively maximized peanut yield with interference from annual grasses.


2011 ◽  
Vol 38 (1) ◽  
pp. 57-60
Author(s):  
W. Carroll Johnson ◽  
E. P. Prostko ◽  
Jerry Davis

Abstract Dinitroaniline herbicides are typically applied preplant incorporated or preemergence (PRE) immediately after seeding peanut. Situations frequently arise where dinitroaniline herbicides are not applied in a timely manner in strip-tillage peanut production. In these cases, dinitroaniline herbicides are be applied several days or weeks after seeding peanut. Weed-free, irrigated field trials were conducted in Tifton, GA in 2004 and 2005 to evaluate the phytotoxic effects of delayed applications of ethalfluralin and pendimethalin on peanut. Both herbicides were applied PRE, at vegetative emergence (VE), 1wk after vegetative emergence (VE+1wk), VE+2wk, VE+3wk, VE+4wk, and included a nontreated control. Dinitroaniline herbicides neither visually injured peanut nor affected foliage biomass collected at mid- and late-season. Timing of herbicide application did not consistently affect peanut vegetative growth. Pod biomass was reduced by dinitroaniline herbicides applied VE+3wk when measured mid-season, but recovered late-season. Across all application timings, ethalfluralin reduced peanut yield compared to pendimethalin. Across both dinitroaniline herbicides, peanut yields were reduced when herbicides were applied at VE. These data show that visual estimates of peanut response to dinitroaniline herbicides may not detect subtle phytotoxic effects. The data also suggests that pod biomass and yield responses may be difficult to predict. However, there is potential for significant injury if peanut are treated with delayed applications of dinitroaniline herbicides in strip-tillage peanut production. In contrast, PRE applications are not injurious to strip-tillage peanut and must be a priority to ensure crop safety.


1997 ◽  
Vol 11 (3) ◽  
pp. 573-579 ◽  
Author(s):  
Anthony D. White ◽  
Harold D. Coble

Researchers are currently developing predictive weed management models to aid producers in maintaining or improving economic profitability of peanut production while minimizing herbicide inputs and reducing environmental impact. HERB (Version 2.1.P), a computer decision model, has recently been developed for peanut and is now awaiting validation of weed control decisions before being released to the public. Field validation trials in 1994 and 1995 indicate that the current competitive index parameters in the HERB model are invalid, and statistically estimated competitive indices were generated. Estimating new parameters improvedR2values from 0.37 to 0.61. New competitive index parameters allow the HERB model to more accurately predict the level of yield loss at a given weed density.


1990 ◽  
Vol 4 (2) ◽  
pp. 239-244 ◽  
Author(s):  
John W. Wilcut ◽  
Glenn R. Wehtje ◽  
T. Vint Hicks ◽  
Tracy A. Cole

Field studies were conducted from 1985 to 1987 to evaluate postemergence herbicide systems with preemergence systems to control Texas panicum, Florida beggarweed, sicklepod, and pitted morningglory in peanuts. Adding paraquat at 0.14 kg ai/ha to postemergence herbicide systems reduced fresh weight of Florida beggarweed 92% (18% increase over the same systems without paraquat), sicklepod 95% (21% increase), and pitted morningglory 95% (11% increase). Herbicide systems containing paraquat improved peanut yields by 230 kg/ha and net returns by $52/ha over herbicide systems not containing paraquat. Fluazifop-P and sethoxydim systems reduced Texas panicum fresh weight (at least 96%) more than a preemergence system (92% reduction) that used benefin applied preplant incorporated and alachlor plus naptalam and dinoseb applied at cracking (GC) or a postemergence system that used alachlor and naptalam plus dinoseb GC and paraquat applied early postemergence (86% reduction). Systems containing fluazifop-P provided greater yields (4190 kg/ha) and net returns ($383/ha) than systems containing sethoxydim (4010 kg/ha, $305/ha) when averaged across all rates of application.


Plant Disease ◽  
2007 ◽  
Vol 91 (7) ◽  
pp. 822-827 ◽  
Author(s):  
E. G. Cantonwine ◽  
A. K. Culbreath ◽  
K. L. Stevenson

Epidemics of early leaf spot, caused by Cercospora arachidicola, of peanut (Arachis hypogaea) are delayed in strip-tilled compared to conventionally tilled fields. This effect may be due to applications of glyphosate used to kill the winter cover crop in strip-tilled fields and/or the presence of cover crop residue at the soil surface of strip-tilled fields. Preplant herbicide (no herbicide, glyphosate, and paraquat), reciprocal residue (plus residue in conventionally tilled plots and minus residue in strip-tilled plots), and added straw mulch were evaluated to determine their effects on early leaf spot epidemics (AUDPC based on incidence and severity, and final percent defoliation) in conventionally tilled and strip-tilled plots. Additional experiments were conducted to characterize the effects of mulch (straw, fumigated straw, and plastic straw [Textraw]) treatments on disease, and to study tillage effects on disease in nonrotated peanut fields. Glyphosate and paraquat had no effect on AUDPC values or defoliation. The addition of straw to conventionally tilled plots significantly reduced disease levels. Cover crop and straw treatments had no significant effect on disease in the strip-tilled plots. AUDPC values were highest in the bare soil plots, lowest in the straw and fumigated straw plots, and intermediate in the plots with Textraw. Fewer initial infections were detected in the Textraw plots compared to the bare soil plots based on results of a trap leaf experiment. Strip-tillage did not consistently suppress early leaf spot epidemics in nonrotated fields. These results show that the presence of cover crop residue is partly responsible for the early leaf spot suppression observed in strip-tilled fields. Cover crop residue may interfere with the dispersal of primary inoculum from overwintering stroma in the soil to the plant tissues.


2001 ◽  
Vol 28 (2) ◽  
pp. 64-73 ◽  
Author(s):  
J. W. Chapin ◽  
J. S. Thomas ◽  
P. H. Joost

Abstract A 2-yr study was conducted on the effects of tillage and soil insecticide (chlorpyrifos) treatment on peanut arthropod pests. A 3 by 2 split-plot experiment with five replications was subjected to factorial ANOVA. Main plot treatments consisted of three tillage systems: conventional moldboard plow, strip tillage into a killed wheat cover crop, and strip tillage into corn stubble residue. Subplot insecticide treatments were granular chlorpyrifos applied at early pegging (growth stage R2) and untreated. Populations of corn earworn, Helicoverpa zea (Boddie), and velevetbean caterpillar, Anticarsia gemmatalis Hübner, were lower in strip tillage systems. Chlorpyrifos applications caused corn earworm outbreaks in all tillage systems, but these applications were more disruptive in strip tillage. Chlorpyrifos treatment also increased populations of fall armyworm, Spodoptera frugiperda (J.E. Smith), but had no measurable effect on velvetbean caterpillar populations. Pod damage from lesser cornstalk borer, Elasmopalpus lignosellus (Zeller), and wire-worms, Conoderus spp., was lower in strip tillage systems, and chlorpyrifos suppressed pod damage in all systems. Threecornered alfalfa hopper, Spissistilus festinus (Say), damage to peanut was greater in the wheat residue strip tillage system. Chlorpyrifos treatment reduced threecornered alfalfa hopper damage in all systems. Spider mite injury was not affected by tillage, but chlorpyrifos treatments resulted in mite outbreaks in all tillage systems. Burrower bug, Pangaeus bilineatus Say, injury to peanut kernels was greater in the strip tillage systems in 1999; and burrower bug injury was suppressed in the strip tillage systems by chlorpyrifos treatment. There was a significant interaction effect for burrower bug injury between tillage and insecticide treatment. Incidence of tomato spotted wilt virus also was reduced by strip tillage. Use of an effective fungicide program and a 3-yr crop rotation out of peanut production probably obscured any potential tillage effects on fungal diseases (southern stem rot, Rhizoctonia limb rot, and leaf spot). However, chlorpyrifos treatment increased Rhizoctonia limb rot incidence. Weed populations were generally greater in strip tillage systems, but postemergence herbicides effectively eliminated any potential confounding effect on yield and grade. Yield was not affected by tillage in either year, and chlorpyrifos had no effect on yield in 1998. In 1999, however, chlorpyrifos increased yield in both strip tillage systems. Neither tillage nor insecticide treatment affected grade (percentage total mature kernels) in 1998, but in 1999 grade was highest in conventional tillage and grade was improved by chlorpyrifos treatment in strip tillage systems. Crop value losses of $249 and $388/ha were attributed to burrower bug injury in untreated corn and wheat residue strip tillage systems, respectively. This injury may have been an anomaly of drought conditions but, given the potential economic impact, burrower bug merits further study in conservation tillage peanut production.


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