Efficacy and Tolerance of Flumioxazin on Sweetpotato (Ipomoea batatas)

2006 ◽  
Vol 20 (2) ◽  
pp. 334-339 ◽  
Author(s):  
Steven T. Kelly ◽  
Mark W. Shankle ◽  
Donnie K. Miller

Experiments were conducted at three locations in Louisiana in 2002 and 2003 to evaluate flumioxazin (36, 72, or 109 g ai/ha) applied pretransplant (PRE) or post-transplant (POST) to sweetpotato. All treatments were applied immediately before or after sweetpotato transplanting to weed-free beds. PRE applications caused 4% or less injury with any rate of flumioxazin at 9 or 18 d after transplanting (DATr) compared with 18 to 20% injury at 9 DATr and 6 to 14% at 18 DATr with 72 or 109 g/ha POST, respectively. Injury from PRE applications of flumioxazin were not different from injury with clomazone (840 g ai/ha) applied POST. Injury at Chase, LA, in 2002 was 8% and less with flumioxazin PRE, but 35 to 83% with flumioxazin POST and appeared to be due to the use of greenhouse-grown cuttings instead of field-grown cuttings, which were used in the other two experiments. There was no interaction between experiments for sweetpotato yield. Plots treated with flumioxazin PRE or 36 g/ha POST yielded greater than sweetpotato treated with clomazone for U.S. No. 1 and 2 grade yield as well as total marketable yield. No differences were observed in yellow nutsedge control with any rate of flumioxazin. At 34 or 50 DATr, flumioxazin controlled yellow nutsedge 73 to 85% with 72 or 109 g/ha applied PRE or POST. Flumioxazin, regardless of application timing or rate, controlled carpetweed and spiny amaranth at least 86%. A similar experiment in Mississippi evaluated tank-mixes of flumioxazin (36, 72, or 109 g/ha) and clomazone (840 g/ha) applied PRE or POST. No sweetpotato injury was observed with flumioxazin PRE. However, injury from flumioxazin POST increased with increased rates (18 to 50% at 18 DATr and 16 to 93% at 25 DATr). Weed control was greater than 80% with all treatments.

1997 ◽  
Vol 11 (3) ◽  
pp. 520-526 ◽  
Author(s):  
Theodore M. Webster ◽  
John W. Wilcut ◽  
Harold D. Coble

Experiments were conducted in 1991 and 1992 to evaluate the weed control effectiveness from several rates of AC 263,222 applied PPI and PRE (36 and 72 g ai/ha), early POST (EPOST) (18, 36, 54, or 72 g/ha), POST (18, 36, 54, or 72 g/ha), and EPOST followed by (fb) POST (27 fb 27 g/ha or 36 fb 36 g/ha). These treatments were compared to the commercial standard of bentazon at 0.28 kg ai/ha plus paraquat at 0.14 kg ai/ha EPOST fb bentazon at 0.56 kg/ha plus paraquat at 0.14 kg/ha plus 2,4-DB at 0.28 kg ae/ha. Application method had little effect on weed control with AC 263,222. In contrast, application rate affected control. Purple nutsedge, yellow nutsedge, prickly sida, smallflower morningglory, bristly starbur, common cocklebur, and coffee senna were controlled at least 82% with AC 263,222 at 36 g/ha (one-half the maximum registered use rate) regardless of application method. AC 263,222 at 72 g/ha (registered use rate) controlled sicklepod 84 to 93%, Florida beggarweed 65 to 100%, andIpomoeamorningglory species 89 to 99%. A single application of AC 263,222 at 36 g/ha or more controlled all weeds (with the exception of Florida beggarweed) as well or greater than sequential applications of bentazon plus paraquat fb bentazon, paraquat, and 2,4-DB. All rates of AC 263,222 applied POST and all application methods of AC 263,222 at 72 g/ha had better yields than the pendimethalin control.


2012 ◽  
Vol 26 (4) ◽  
pp. 699-707 ◽  
Author(s):  
Jared A. Hoyle ◽  
J. Scott McElroy ◽  
J. Jack Rose

Weed control by heat or flaming typically uses flames to burn small weeds, directed away from desired crops. This research studied an enclosed flaming system for weed control before turfgrass establishment. Field research trials were conducted to explore the efficacy of a PL-8750 flame sanitizer at two application timings. Treatments included various application methods of PL-8750 flame sanitizer and common thermal and chemical weed control methods. Data were weed control relative to the control treatment. Species evaluated included carpetweed, Virginia buttonweed, spotted spurge, large crabgrass, goosegrass, old world diamond-flower, cocks-comb kyllinga, and yellow nutsedge. Turfgrass establishment was not successful in summer but was successful in fall. Fall-application timing trials resulted in > 60% tall fescue establishment at 6 wk after seeding (WAS) for all treatments. Summer-application timing trials resulted in unacceptable turfgrass establishment (≤ 18%) for all evaluated turfgrass species at 6 WAS. Broadleaf and grassy weeds were better controlled compared with sedge weeds. Overall, solarization; covered, emerged-weed flaming; and double applications of covered, emerged-weed flaming were the most successful treatments. Solarization controlled carpetweed, Virginia buttonweed, spotted spurge, large crabgrass, and goosegrass > 80% at 6 WAS. Weed control across thermal treatments were equal to or greater than the comparison chemical treatment (dazomet at 389 kg ha−1). Results indicate thermal weed control has potential for reducing weed populations before turfgrass establishment.


2009 ◽  
Vol 23 (2) ◽  
pp. 280-286 ◽  
Author(s):  
Sanjeev K. Bangarwa ◽  
Jason K. Norsworthy ◽  
Edward E. Gbur

Weeds are a major constraint in tomato production, especially in the absence of methyl bromide. Field trials were conducted in 2006 and 2007 to evaluate the integrated use of a mustard ‘Caliente’ (a blend of brown and white mustard) cover crop with one-half and full rate PRE/POST herbicides for weed control and crop response in polyethylene-mulched tomato. Caliente was flail mowed and incorporated into the soil prior to forming beds. PRE herbicides were applied under polyethylene mulch, and POST herbicides were sprayed over the top of tomato. Full rates for S-metolachlor, halosulfuron, and trifloxysulfuron were 1,600, 27, and 7.9 g ai/ha, respectively. Caliente had no effect on weed control or tomato injury and yield. Except for large crabgrass control and tomato injury and yield, only the main effect of herbicide selection and application rate affected these parameters. Tomato injury was minimal (< 6%) from PRE- and POST-applied herbicides. S-metolachlor applied PRE provided 66% purple nutsedge, 67% yellow nutsedge, and 77% Palmer amaranth control at 4 wk after transplanting (WATP). S-metolachlor–treated plots at the full rate produced the highest marketable fruit yield among herbicide treatments, with jumbo fruit yield equivalent to the hand-weeded treatment. Trifloxysulfuron was the best POST-applied herbicide based on marketable yield and weed control. POST-applied trifloxysulfuron provided 41% purple nutsedge, 58% yellow nutsedge, and 55% Palmer amaranth control at 8 to 9 WATP. Halosulfuron applied PRE controlled purple and yellow nutsedge 70 and 78%, respectively, at 4 WATP, and POST-applied halosulfuron controlled purple nutsedge 74% and yellow nutsedge 78% at 8 to 9 WATP. Halosulfuron applied either PRE or POST failed to control Palmer amaranth and large crabgrass. Greater weed control and marketable tomato yield were achieved with full rates of herbicides. This research demonstrates no additional advantage of Caliente mustard when used with herbicides in tomato. None of the PRE or POST herbicides applied alone were sufficient to maintain season-long, broad-spectrum weed control and optimum marketable yield in tomato. Therefore, integration of PRE and POST herbicides at full rates is suggested.


1990 ◽  
Vol 4 (3) ◽  
pp. 518-523 ◽  
Author(s):  
Norman C. Glaze ◽  
Melvin R. Hall

Alachlor, chloramben, cinmethylin, diphenamid, fluazifop, fluazifop-P, metolachlor, metribuzin, napropamide, oryzalin, and sethoxydim were applied on transplanted sweet potato at Tifton, GA, during 1982 to 1985. The weeds most prevalent were large crabgrass, Florida pusley, smallflower morningglory, and yellow nutsedge. No significant phytotoxicity was observed from any herbicide treatment over the 4 yr. Cultivation at 4 wk is advantageous to eliminate early flushes of weeds which escape control and reform the beds. Alachlor or metolachlor at 4.5 and 3.4 kg ha-1, respectively, and metribuzin controlled weeds best. Although no serious phytotoxicity was evident, these treatments tended to cause lowered yields of marketable roots while marginally affecting total yields in most cases. Metribuzin was the only compound which controlled late-season broadleaf weeds such as smallflower morningglory effectively.


2011 ◽  
Vol 25 (4) ◽  
pp. 548-555 ◽  
Author(s):  
Dilpreet S. Riar ◽  
Jason K. Norsworthy

Research was conducted in 2009 and 2010 to evaluate influence of imazosulfuron rate and application timing on weed control in drill-seeded rice at Stuttgart, AR, and to evaluate imazosulfuron-containing herbicide programs in drill-seeded rice at Keiser and Stuttgart, AR. Weed species evaluated included barnyardgrass, broadleaf signalgrass, hemp sesbania, and yellow nutsedge. Imazosulfuron applied at 224 and 336 g ai ha−1during PRE, early POST (EPOST), or preflood (PREFLD) growth periods provided similar control of all weeds. Imazosulfuron applied EPOST or PREFLD controlled hemp sesbania and yellow nutsedge ≥ 93% both years at 5 and 7 wk after planting (WAP), except in 2009 when hemp sesbania control was ≤ 79% at 7 WAP. In 2010, because of inadequate rainfall, hemp sesbania and yellow nutsedge control with PRE-applied imazosulfuron was ≤29% at 5 and 7 WAP. Imazosulfuron plus clomazone PRE followed by (fb) quinclorac plus propanil EPOST and imazosulfuron plus quinclorac EPOST fb thiobencarb plus propanil PREFLD programs controlled hemp sesbania and barnyardgrass (in at least two site-years), and yellow nutsedge and broadleaf signalgrass (in at least one site-year) greater than or equal to clomazone plus quinclorac PRE fb propanil plus halosulfuron PRELD (standard program). No rice injury was observed with any herbicide program. Rice yield with all imazosulfuron-containing herbicide programs (6,630 to 8,130 kg ha−1) was similar to the standard herbicide program (7,240 kg ha−1). Imazosulfuron in mixture with clomazone, propanil, or quinclorac can be incorporated into herbicide programs of mid-South rice production for the control of broadleaf weeds and sedges.


2012 ◽  
Vol 26 (4) ◽  
pp. 763-768 ◽  
Author(s):  
Sanjeev K. Bangarwa ◽  
Jason K. Norsworthy ◽  
Edward E. Gbur

Methyl bromide is a common fumigant for effective weed control in polyethylene-mulched vegetable crops. However, the ban on methyl bromide in the United States has created a need to find a suitable alternative. This study investigated the herbicidal efficacy of phenyl isothiocyanate (ITC) as a methyl bromide alternative for weed control in polyethylene-mulched bell pepper during 2006 and 2007. Six rates of phenyl ITC (0, 15, 75, 150, 750, 1,500 kg ha−1) under low-density polyethylene (LDPE) or virtually impermeable film (VIF) mulch were tested against yellow nutsedge, Palmer amaranth, and large crabgrass. Additionally, a standard treatment of methyl bromide/chloropicrin (67 : 33%) at 390 kg ha−1under LDPE mulch was included for comparison. VIF mulch provided no advantage over LDPE mulch in either improving weed control or marketable yield in bell pepper. Unacceptable pepper injury (≥ 60%) occurred at the highest phenyl ITC rate of 1,500 kg ha−1at 2 WATP in both years, regardless of mulch type. Higher bell pepper injury was observed in 2006 (≥ 36%) than in 2007 (≤ 11%) at 750 kg ha−1of phenyl ITC. The lower injury in 2007 could be attributed to aeration of beds 48 h prior to transplanting. Regardless of mulch type, phenyl ITC at 2,071 (± 197) and 1,655 (± 309) kg ha−1was required to control yellow nutsedge, Palmer amaranth, and large crabgrass equivalent to methyl bromide in 2006 and 2007, respectively. Bell pepper marketable yield at all rates of phenyl ITC was lower than methyl bromide in 2006. In contrast, marketable yield in phenyl ITC at 750–kg ha−1was equivalent to methyl bromide in 2007. It is concluded that phenyl ITC should be applied at least 4.2 times higher rate than methyl bromide for effective weed control, and bed aeration is required to minimize crop injury and yield loss. Additional research is needed to test phenyl ITC in combination with other weed control strategies to obtain effective weed control with acceptable crop safety.


2010 ◽  
Vol 24 (1) ◽  
pp. 28-32 ◽  
Author(s):  
Barry J. Brecke ◽  
Daniel O. Stephenson ◽  
J. Bryan Unruh

Tolerance of sprigged ‘Tifsport’ and ‘Tifdwarf’ bermudagrass, ‘Meyer’ zoysiagrass, and ‘Salam’ seashore paspalum to oxadiazon (2,240 g/ha) or quinclorac (840 g/ha) applied 1 wk before sprigging (WBS), at sprigging (AS), 2 wk after sprigging (WAS), and 4 WAS was investigated in the field. Weed control was also evaluated. For both herbicides only the AS application timing injured the turfgrass greater than 22%, and injury for the other application timings ranged from 9 to 19% 5 WAS. When evaluated 8 WAS turfgrass injury following the AS application timing remained at 19%, and injury for all other timings was 8% or less. Eight WAS the 1 WBS, AS, 2 WAS, and 4 WAS application timings achieved 89, 79, 94, and 99% plot coverage, respectively, when averaged over all turfgrass species/cultivars and herbicides. By 13 WAS, all species/cultivars achieved at least 90% plot coverage. Presprigging applications of oxadiazon provided 98 to 100% goosegrass and old world diamond-flower control. Quinclorac applied AS provided greater than 70% control of these weeds. Results indicate that oxadiazon and quinclorac applied AS will cause unacceptable turfgrass injury. If goosegrass and/or old world diamond-flower are problematic, oxadiazon is a feasible choice for control of these weeds, but quinclorac is not.


2000 ◽  
Vol 53 ◽  
pp. 262-268
Author(s):  
S.L. Lewthwaite ◽  
C.M. Triggs

The sweetpotato (Ipomoea batatas (L) Lam) crop once established requires little field management apart from weed control Currently weeds are minimised by a combination of handweeding interrow cultivation and the application of paraquat (100 g ai/ha) over the crop In this study alternative herbicide treatments were examined in a field trial Handweeding produced the highest marketable yield (267 t/ha) significantly more than all other treatments apart from acetochlor (24 kg ai/ha) which produced 218 t/ha (P


2013 ◽  
Vol 27 (3) ◽  
pp. 580-589 ◽  
Author(s):  
Pratap Devkota ◽  
Jason K. Norsworthy ◽  
Ronald Rainey

Methyl bromide (MeBr), a widely used soil fumigant in tomato production, has been banned for ordinary agricultural uses. In the absence of MeBr, a viable alternative is imperative for weed control and prevention of economic loss in tomato production. A field study was conducted in the summers of 2010 and 2011 at Fayetteville, AR, to compare the efficacy and economics of herbicide programs consisting of pre-transplant followed by (fb) post-transplant herbicides in low-density polyethylene (LDPE) mulched tomato. Pre-transplant imazosulfuron at 0.112, 0.224, and 0.336 kg ai ha−1andS-metolachlor at 1.6 kg ai ha−1were fb a post-transplant mixture of trifloxysulfuron plus halosulfuron at 0.008 and 0.027 kg ai ha−1at 4 wk after transplant (WATP). The standard MeBr treatment (2:1 mixture of MeBr plus chloropicrin at 390 kg ai ha−1), weed-free (hand weeding) control, and nontreated weedy check were used for comparison. Pre-transplantS-metolachlor fb post-transplant herbicides controlled Palmer amaranth ≥ 89%, large crabgrass ≥ 88%, and yellow nutsedge ≥ 90%, which was comparable to the control with MeBr. Tomato recovered the injury (≤ 19% at 6 WATP) from post-transplant herbicides in the later weeks.S-metolachlor–containing herbicide programs yielded marketable tomato fruit comparable to the yield with MeBr. Economic evaluation of the herbicide programs demonstrated a net return of $3,758.50 ha−1from theS-metolachlor–containing herbicide program in LDPE-mulched tomato. Likewise, this herbicide program showed minimum loss of ≤ $671.61 ha−1in net return relative to MeBr. In conclusion, a herbicide program consisting of pre-transplantS-metolachlor fb post-transplant trifloxysulfuron plus halosulfuron is a viable alternative to MeBr for weed control and marketable yield in LDPE-mulched tomato production.


2012 ◽  
Vol 26 (4) ◽  
pp. 666-672 ◽  
Author(s):  
Sanjeev K. Bangarwa ◽  
Jason K. Norsworthy ◽  
Edward E. Gbur

Field experiments were conducted in 2006 and 2007 to evaluate the herbicidal activity of phenyl isothiocyanate (ITC) on yellow nutsedge, Palmer amaranth, and large crabgrass in tomato grown on two polyethylene-mulched types. Treatments included two mulch types (low density polyethylene [LDPE] mulch and virtually impermeable film [VIF] mulch) and phenyl ITC at 0, 15, 75, 150, 750, and 1,500 kg ha−1. A standard rate of methyl bromide/chloropicrin (67 : 33%) at 390 kg ha−1under LDPE mulch was included for comparison. Regardless of mulch type, phenyl ITC at 1,452 (±133) and 1,719 (±426) kg ha−1was required for broad-spectrum weed control equivalent to methyl bromide in 2006 and 2007, respectively. Tomato injury was ≥ 44% at the highest phenyl ITC rate of 1,500 kg ha−1at 2 wk after transplanting (WATP) both years, irrespective of mulch type. Greater crop injury was observed from 750 kg ha−1of phenyl ITC in 2006 (≥ 27%) than in 2007 (≤ 10%). The greater injury in 2006 was attributed to a higher phenyl ITC concentration because holes in the plastic mulch for transplanting were punched at the time of transplanting in 2006; whereas, in 2007 holes were punched 2 d before transplanting, allowing 2 d of aeration before transplanting. Tomato marketable yield at all rates of phenyl ITC was lower than with methyl bromide in 2006. However, in 2007, marketable yield in plots treated with phenyl ITC at 750 kg ha−1was equivalent to methyl bromide. Overall, VIF mulch was no more effective than LDPE mulch at increasing weed control or improving the marketable yield of tomato either year.


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