An Evaluation of Pre-emergence Metam-Potassium and S-metolachlor for Yellow Nutsedge (Cyperus esculentus) Management in Sweetpotato

2017 ◽  
Vol 31 (3) ◽  
pp. 436-440 ◽  
Author(s):  
Stephen L. Meyers ◽  
Mark W. Shankle

Field studies were conducted in 2014 and 2015 at Pontotoc, MS to evaluate combinations of metam-potassium and S-metolachlor for yellow nutsedge control and sweetpotato crop response. Treatments consisted of a factorial of five metam-potassium rates (0, 149, 261, 372, and 484 kgha−1) by three S-metolachlor rates (0, 0.80, and 1.34 kgha−1). Additionally, a hand-weeded check was included for comparison. Crop injury was limited to ≤4% at 4 weeks after transplanting (WAP) and was transient. At 2 WAP yellow nutsedge control was 58, 74, and 76% in plots treated with S-metolachlor at 0, 0.80, and 1.34 kgha−1, respectively. Nutsedge control in all treatments decreased from 2 to 15 WAP. At 15 WAP, S-metolachlor at 0, 0.80, and 1.34 kg ha−1 provided 35, 68, and 70% yellow nutsedge control, respectively. Metam-potassium rate did not influence yellow nutsedge control after transplanting. Sweetpotato yields in the hand-weeded check were 4,640; 22,180; 7,180; 34,000; and 1,360 kgha−1 for jumbo, no. 1, canner, marketable, and cull grades, respectively. S-metolachlor applied at either 0.80 or 1.34 kgha−1 provided jumbo, no. 1, and marketable sweetpotato yields equivalent to the hand-weeded check. Canner and cull yields were not influenced by S-metolachlor rate. Metam-potassium rates used in the present study resulted in yields equal to or greater than the hand-weeded check.

2016 ◽  
Vol 30 (1) ◽  
pp. 148-153 ◽  
Author(s):  
Stephen L. Meyers ◽  
Mark W. Shankle

Field studies were conducted in 2013 at Houlka, MS and in 2014 at Houston, MS to evaluate herbicide programs for yellow nutsedge control and sweetpotato crop response. Treatments consisted of halosulfuron-methyl at 13, 26, and 34 g ai ha−1 2 wk after transplanting (WAP) followed by (fb) S-metolachlor at 856 g ai ha−1 4 WAP; a sequential application of 13 g ha−1 halosulfuron-methyl at 2 and 4 WAP; and halosulfuron-methyl at 13 g ha−1 plus either S-metolachlor or 1,123 g ai ha−1 alachlor 2 WAP. Crop injury in treated plots ranged from 29 to 44% at 3 WAP. Injury from the sequential application increased slightly between 3 and 5 WAP (29 to 38%), but decreased between 5 WAP and harvest (19%). Injury with all other treatments was unchanged from 5 WAP through harvest. The sequential application of halosulfuron-methyl provided the greatest control of yellow nutsedge throughout the duration of the study with ≥ 83% control from 5 WAP through harvest. Control from all other treatments ranged from 38 to 78% from 5 WAP through harvest. No. 1, canner, and marketable sweetpotato yields of the hand-weeded check were 19,900; 7,140; and 27,590 kg ha−1, respectively. No. 1, canner, and marketable yields of the weedy check were only 15, 51, and 25% of the hand-weeded check, respectively. With the exception of halosulfuron-methyl at 13 g ha−1 fb S-metolachlor, which was similar to the weedy check, no. 1 and marketable yields with all treatments were greater than the weedy check, but less than the weed-free check. A sequential application of halosulfuron-methyl and a tank mix of halosulfuron-methyl plus S-metolachlor would fit well into an overall yellow nutsedge management program in sweetpotato. However, as halosulfuron-methyl is not registered for use in sweetpotato, growers must continue to manage yellow nutsedge primarily with crop rotation and sanitation.


1992 ◽  
Vol 6 (1) ◽  
pp. 108-112 ◽  
Author(s):  
W. James Grichar

Field studies were conducted from 1986 through 1988 to evaluate various herbicides for yellow nutsedge control and peanut yields. Three applications of pyridate provided control comparable to two applications of bentazon with yellow nutsedge regrowth beginning 3 to 4 wk after application depending on moisture conditions. Crop oil concentrate did not improve the activity of pyridate. Flurtamone provided control comparable with that of metolachlor. Nutsedge control with fomesafen was erratic with peanut injury noted. Peanut yields did not reflect the competitive nature of nutsedge.


1996 ◽  
Vol 10 (2) ◽  
pp. 278-281 ◽  
Author(s):  
W. James Grichar ◽  
A. Edwin Colburn ◽  
Paul A. Baumann

Field studies conducted from 1989 through 1991 evaluated methods of metolachlor application including POST followed by irrigation for yellow nutsedge control and peanut response. Metolachlor PPI stunted peanut in two of three years while metolachlor applied at emergence, 10, 20, or 30 days after peanut emergence (DAE) caused no peanut injury. Metolachlor 20 DAE provided > 95% yellow nutsedge control. Metolachlor soil-applied and again POST controlled yellow nutsedge at least 70%; however, some peanut stunting was noted. Bentazon plus metolachlor at 2.24 kg ai/ha controlled yellow nutsedge at least 92% when applied 30 DAE. Peanut yields were consistently the highest with metolachlor PRE at 1.40 kg ai/ha followed by a POST application of 1.40 kg ai/ha at 45 DAE.


Weed Science ◽  
1996 ◽  
Vol 44 (3) ◽  
pp. 615-621 ◽  
Author(s):  
John W. Wilcut ◽  
John S. Richburg ◽  
Gerald L. Wiley ◽  
F. Robert Walls

Field studies in 1990 and 1991 at six locations in Georgia and one location in North Carolina evaluated AC 263,222 for weed control, peanut tolerance, and yield. AC 263,222 applied early postemergence at 71 g ai ha−1controlled bristly starbur, coffee senna, common lambsquarters,Ipomoeaspecies, prickly sida, sicklepod, smallflower morningglory, and yellow nutsedge at least 91%. AC 263,222 controlled common cocklebur 77% and Florida beggarweed from 47 to 100%. Crop injury was 4% for AC 263,222 applied once and 12% or less from two applications. Mixtures of bentazon with AC 263,222 did not improve control compared to AC 263,222 alone. Imazethapyr did not improve control of AC 263,222 systems. In several locations, bentazon reduced control of Florida beggarweed with AC 263,222 when applied in a mixture compared to AC 263,222 alone. Weed control from the standard of paraquat plus bentazon applied early postemergence followed by paraquat, bentazon plus 2,4-DB applied POST did not provide the level or spectrum of weed control as AC 263,222 systems.


1994 ◽  
Vol 21 (1) ◽  
pp. 23-28 ◽  
Author(s):  
John W. Wilcut ◽  
John S. Richburg ◽  
Gerald Wiley ◽  
F. Robert Walls ◽  
Stan R. Jones ◽  
...  

Abstract Field studies conducted in 1990 and 1991 at five locations in Georgia and one location in Virginia in 1991 evaluated imazethapyr [2-[4,5-dihydro-4-methyl-4-(l-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-ethyl-3-pyridinecarboxylic acid] and AC 263,222 [(±)-2[4,5-dihydro-4-methyl-4-(l-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-methyl-3-pyridinecarboxylic acid] for weed control, peanut tolerance, and yield. Imazethapyr and AC 263,222 applied early postemergence (EPOST) controlled smallflower morningglory [Jacquemontia tamnifolia (L.) Griseb], Ipomoea morningglory species, prickly sida (Sida spinosa L.), and coffee senna (Cassia occidentalis L.) greater than 90%. Imazethapyr did not control Florida beggarweed [Desmodium tortuosum (SW.) DC.] or sicklepod (Cassia obtusifolia L.) adequately, with control generally less than 40%. AC 263,222 controlled Florida beggarweed greater than 92% when applied EPOST and from 54 to 100% when applied postemergence (POST). Imazethapyr applied preplant incorporated (PPI) controlled bristly starbur (Acanthospermum hispidium DC.) 89% and imazethapyr and AC 263,222 applied EPOST controlled at least 96%. Imazethapyr controlled yellow nutsedge (Cyperus esculentus L.) 83% when applied PPI and 93% as an EPOST application. AC 263,222 controlled yellow nutsedge at least 90%. Peanut yields were higher with AC 263,222 than with imazethapyr. Imazethapyr systems that included alachlor (2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide), lactofen ([(±)2-ethoxy-l-methyl-2-oxoethyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoate] + 2,4-DB [4-(2,4-dichlorophenoxy)butanoic acid], paraquat [1,1′-dimethyl-4,4′-bipyridinium ion] + 2,4-DB, pyridate [O-(6-chloro-3-phenyl-4-pyridazinyl)-S-octyl carbonothioate] + 2,4-DB, metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-l-methylethyl)acetamide], or 2,4-DB provided yields equivalent to AC 263,222.


2010 ◽  
Vol 24 (4) ◽  
pp. 478-482 ◽  
Author(s):  
Oleg Daugovish ◽  
Maren J. Mochizuki

Yellow nutsedge is a problematic weed in plasticulture strawberry because herbicides and fumigants currently used in California provide little to no control and because nutsedge shoots easily penetrate standard low-density polyethylene (LDPE) mulch to rapidly establish and compete with the crop. Field studies were conducted at two California locations near Oxnard and Camarillo from 2007 to 2009 to evaluate yellow nutsedge control with physical barriers. Nutsedge germinated in both autumn and spring through LDPE mulch alone, but paper placed between two layers of standard 0.15-mm black LDPE mulch, weed barrier fabric commonly used in landscapes placed under LDPE mulch, and Tyvek Home Wrap placed under LDPE mulch suppressed nutsedge emergence. In 1 yr, the size of strawberry plants grown with weed barrier fabric was reduced 23% compared with the other treatments and the number of marketable fruit in the third month of harvest was reduced 20% compared with LDPE mulch alone, likely because inadequately cut planting holes in this barrier restricted plant growth. Estimated costs for barrier treatments ranged from $5,000 to $12,000 ha−1compared with estimated hand-weeding costs of up to $24,000 ha−1. In 2007 to 2008 barrier treatments reduced the number of wind-dispersed weeds that commonly land and germinate in strawberry planting holes 67% compared with LDPE mulch alone. Removing the barriers at the end of the two seasons revealed that nutsedge plants sprouted but failed to grow and produce new tubers under the barriers. This observation suggests that nutsedge-impermeable barriers may aid in depletion of the soil tuber bank and therefore can be an effective tool in managing nutsedge for the length of the growing season.


1994 ◽  
Vol 21 (1) ◽  
pp. 65-68 ◽  
Author(s):  
W. Carroll Johnson ◽  
Benjamin G. Mullinix

Abstract Field studies in 1991 and 1992 at Tifton and Attapulgus, GA evaluated the weed control efficacy and crop safety of F6285 on peanut. Treated peanut were stunted by F6285 and had chlorotic leaflet margins. The degree and persistence of injury varied according to rate of F6285. The lowest rate of F6285 (0.14 kg ai ha-1) produced the aforementioned symptoms early in the season, but peanut recovered by late season with no yield effects (P≤0.05). F6285 at 0.28 and 0.42 kg ha-1 severely injured peanut and reduced yields. Preemergence and vegetative emergence applications of F6285 were equally injurious. F6285 effectively controlled yellow nutsedge at rates as low as 0.14 kg ha-1, but sicklepod was not controlled at rates up to 0.42 kg ha-1. F6285 controlled yellow nutsedge more effectively that standard treatments of metolachlor or imazethapyr, but crop injury from F6285 was greater (P≤0.05) than from other herbicides.


2008 ◽  
Vol 22 (3) ◽  
pp. 442-447 ◽  
Author(s):  
W. James Grichar ◽  
Peter A. Dotray ◽  
Todd A. Baughman

Field studies were conducted in different peanut-growing areas of Texas during the 1999 through 2001 growing seasons to evaluate yellow nutsedge control and peanut tolerance to diclosulam alone applied PRE,S-metolachlor alone applied POST, or diclosulam applied PRE followed by (fb)S-metolachlor applied POST. Yellow nutsedge control was > 80% at five of six locations when diclosulam at 0.018 or 0.026 kg/ha applied PRE was fbS-metolachlor applied POST at 0.56, 1.12, or 1.46 kg ai/ha. Peanut stunting was noted with diclosulam at the High Plains locations but not at the Rolling Plains or south Texas locations. This stunting with diclosulam was due to a combination of peanut variety and high soil pH. Peanut yield was not always increased where yellow nutsedge was controlled.


Weed Science ◽  
1978 ◽  
Vol 26 (1) ◽  
pp. 10-16 ◽  
Author(s):  
P. E. Keeley ◽  
R. J. Thullen

The influence of artificial shading (0, 30, 47, 70, 80, and 94% shade) on growth of yellow nutsedge(Cyperus esculentusL.) and the time required for developing canopies of several crops to intercept a given amount of light were investigated in field studies to estimate the potential of crops to compete with yellow nutsedge for light. Average number of shoots and tubers and total dry matter production of yellow nutsedge increased in direct proportion to increased amounts of light (correlation coefficient (r ≥.98). Compared to no shade, flower production was substantially reduced by 30 and 47% shade and was essentially absent under more dense treatments. Photosynthetically active radiation (PAR) measured at weekly intervals indicated that light interception occurred first within the drill row of crops, then on shoulders of planting beds, and finally in furrows. The most rapidly developing canopies studied [corn(Zea maysL.), potatoes(Solanum tuberosumL.), and safflower(Carthamus tinctoriusL.)] intercepted 90% or greater PAR, including illumination in furrows, within 8 to 9 weeks after planting. About 12, 12, and 16 weeks were required for 80% interception for cowpeas [Vigna unguiculata(L.) Walp.], milo [Sorghum bicolor(L.) Moench.], and cotton(Gossypium hirsutumL.), respectively. Fall-planted barley(Hordeum vulgareL.) intercepted about 90% PAR by March 12. Alfalfa(Medicago sativaL.) intercepted about 90% PAR within 2 to 3 weeks after individual cuttings. Although onions(Allium cepaL.) planted in December intercepted 95% of the PAR in each of the two drill rows per bed about 26 weeks after planting, only 20 to 30% interception occurred in furrows and row middles.


Weed Science ◽  
1978 ◽  
Vol 26 (3) ◽  
pp. 280-283 ◽  
Author(s):  
A. D. Kern ◽  
W. F. Meggitt ◽  
Donald Penner

Bentazon [3-isopropyl-1H-2,1,3-benzothiadiazin-(4) 3H-one 2,2-dioxide], cyperquat (1-methyl-4-phenylpyridinium), and perfluidone {1,1,1-trifluoro-N-[2-methyl-4-(phenylsulfonyl)phenyl] methanesulfonamide} were evaluated for their potential use as postemergence herbicides for selective yellow nutsedge(Cyperus esculentusL.) control in Kentucky bluegrass(Poa pratensisL.) in field studies. High rates of these herbicides as single or split applications were effective and only slightly reduced verdure of Kentucky bluegrass, indicating excellent selectivity. In greenhouse studies perfluidone exhibited growth retardant properties. Shoot dry weight production was inhibited and root dry weight of treated plants was markedly reduced. These two factors are undesirable features for commercial sod production.


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