Critical Timing of Fall Panicum (Panicum dichotomiflorum) Removal in Sugarcane

Fall panicum is the most troublesome annual grass weed in sugarcane in Florida. The critical timing of fall panicum removal in sugarcane or the maximum amount of early season interference that sugarcane can tolerate before it suffers irrecoverable yield loss is not known. Field studies were conducted from 2012 to 2015 in Belle Glade, FL to determine the critical timing of fall panicum removal and season-long interference in sugarcane. The effect of season-long fall panicum interference and critical timing of removal based on 5 and 10% acceptable yield loss (AYL) levels were determined by fitting a log-logistic equation to percentage millable stalk, cane, and sugar yield loss data. Millable stalks, cane, and sucrose yield decreased as the duration of fall panicum interference increased. Season-long interference of fall panicum resulted in 34 to 60%, 34 to 62%, and 44 to 60% millable stalk, cane, and sucrose yield loss, respectively. The critical timing of fall panicum removal based on 5 and 10% AYL for millable stalks was 5 to 9 wk after sugarcane emergence (WAE). At 5 and 10% AYL, the critical timing of fall panicum removal ranged from 5 to 9 WAE and 6 to 8 WAE for cane and sucrose yield loss, respectively. These results show that fall panicum is competitive with sugarcane early in the season, demonstrating the need for timely early-season control to reduce negative effect on yield.

Download Full-text

Wild Buckwheat (Polygonum convolvulus) Interference in Sugarbeet

Weed Technology ◽

10.1614/wt-09-060.1 ◽

2010 ◽

Vol 24 (1) ◽

pp. 59-63 ◽

Cited By ~ 7

Author(s):

Dennis C. Odero ◽

Abdel O. Mesbah ◽

Stephen D. Miller ◽

Andrew R. Kniss

Keyword(s):

Yield Loss ◽

Field Studies ◽

Sucrose Content ◽

Root Yield ◽

Negative Effects ◽

Wild Buckwheat ◽

Weed Density ◽

Polygonum Convolvulus ◽

Negative Effect ◽

Critical Timing

Field studies were conducted in Powell, WY in 2006 and 2007 to determine the influence of season-long interference of various wild buckwheat densities and duration of interference on sugarbeet. Percent sucrose content was not affected by wild buckwheat interference. Root and sucrose yield loss per hectare increased as wild buckwheat density increased. The estimated percent yield loss as wild buckwheat density approaches infinity was 64 and 61% for root and sucrose yield loss, respectively. The estimated percent yield loss per unit weed density at low weed densities was 6% for both root and sucrose yield loss. Greater durations of wild buckwheat interference had a negative effect on sugarbeet root yield. The critical timing of weed removal (CTWR) to avoid 5 and 10% root yield loss was 32 and 48 d after sugarbeet emergence (DAE), respectively. These results show that wild buckwheat is competitive with sugarbeet and should be managed appropriately to forestall any negative effects on sugarbeet root and sucrose yield.

Download Full-text

Lanceleaf Sage (Salvia reflexa) Interference in Sugarbeet

Weed Technology ◽

10.1614/wt-d-10-00015.1 ◽

2010 ◽

Vol 24 (4) ◽

pp. 557-561 ◽

Cited By ~ 5

Author(s):

Dennis C. Odero ◽

Abdel O. Mesbah ◽

Stephen D. Miller ◽

Andrew R. Kniss

Keyword(s):

Yield Loss ◽

Maximum Yield ◽

Field Studies ◽

Control Measures ◽

Root Yield ◽

Rectangular Hyperbola ◽

Weed Density ◽

Negative Effect ◽

Critical Timing ◽

The Relationship

Field studies were conducted in Powell, WY, in 2006 and 2007 to determine the influence of season-long interference of various lanceleaf sage densities and durations of interference on sugarbeet. The rectangular hyperbola model with the asymptote (A) constrained to 100% maximum yield loss characterized the relationship between lanceleaf sage density and sugarbeet yield loss. The estimated parameterI(yield loss per unit weed density as density approaches zero) was 3% for both root and sucrose yield loss. Increasing duration of lanceleaf sage interference had a negative effect on sugarbeet root yield. The critical timing of weed removal to avoid 5 and 10% root yield loss was 37 and 52 d after sugarbeet emergence, respectively. Lanceleaf sage interference did not affect percentage of sucrose content. These results indicate that lanceleaf sage is not as competitive as other weeds but that appropriate control measures should be undertaken to minimize sugarbeet yield loss from interference.

Download Full-text

Volunteer Barley (Hordeum vulgare) Interference in Canola (Brassica campestrisandB. napus)

Weed Science ◽

10.1017/s0043174500075743 ◽

1988 ◽

Vol 36 (6) ◽

pp. 734-739 ◽

Cited By ~ 11

Author(s):

John T. O'Donovan ◽

Arvind K. Sharma ◽

Ken J. Kirkland ◽

E. Ann De St. Remy

Keyword(s):

Hordeum Vulgare ◽

Yield Loss ◽

Field Studies ◽

Yield Potential ◽

Western Canada ◽

Effect On Yield ◽

Financial Losses ◽

Barley Crop

The yield potential and the effect on yield loss of canola of different densities of volunteer barley were investigated at three locations in western Canada. Field studies were conducted from 1982 to 1986. Rectangular hyperbolic models based on data pooled over years, locations, and canola cultivars, and incorporating different densities of volunteer barley and canola accurately portrayed field responses in most instances. Results indicated that volunteer barley severely reduced canola yield. However, financial losses due to reduced canola yield were partly offset by the volunteer barley crop.

Download Full-text

Critical timing of Palmer amaranth (Amaranthus palmeri) removal in sweetpotato

Weed Technology ◽

10.1017/wet.2020.1 ◽

2020 ◽

Vol 34 (4) ◽

pp. 547-551 ◽

Cited By ~ 1

Author(s):

Stephen C. Smith ◽

Katherine M. Jennings ◽

David W. Monks ◽

Sushila Chaudhari ◽

Jonathan R. Schultheis ◽

...

Keyword(s):

North Carolina ◽

Logistic Model ◽

Yield Loss ◽

Relative Yield ◽

Field Studies ◽

Palmer Amaranth ◽

Amaranthus Palmeri ◽

Marketable Yield ◽

Yield Data ◽

Critical Timing

AbstractPalmer amaranth is the most common and troublesome weed in North Carolina sweetpotato. Field studies were conducted in Clinton, NC, in 2016 and 2017 to determine the critical timing of Palmer amaranth removal in ‘Covington’ sweetpotato. Palmer amaranth was grown with sweetpotato from transplanting to 2, 3, 4, 5, 6, 7, 8, and 9 wk after transplanting (WAP) and maintained weed-free for the remainder of the season. Palmer amaranth height and shoot dry biomass increased as Palmer amaranth removal was delayed. Season-long competition by Palmer amaranth interference reduced marketable yields by 85% and 95% in 2016 and 2017, respectively. Sweetpotato yield loss displayed a strong inverse linear relationship with Palmer amaranth height. A 0.6% and 0.4% decrease in yield was observed for every centimeter of Palmer amaranth growth in 2016 and 2017, respectively. The critical timing for Palmer amaranth removal, based on 5% loss of marketable yield, was determined by fitting a log-logistic model to the relative yield data and was determined to be 2 WAP. These results show that Palmer amaranth is highly competitive with sweetpotato and should be managed as early as possible in the season. The requirement of an early critical timing of weed removal to prevent yield loss emphasizes the importance of early-season scouting and Palmer amaranth removal in sweetpotato fields. Any delay in removal can result in substantial yield reductions and fewer premium quality roots.

Download Full-text

Determining the critical period for grass control in high-yielding cotton using Japanese millet as a mimic weed

Weed Technology ◽

10.1017/wet.2019.113 ◽

2019 ◽

Vol 34 (2) ◽

pp. 292-300 ◽

Cited By ~ 1

Author(s):

Graham W. Charles ◽

Brian M. Sindel ◽

Annette L. Cowie ◽

Oliver G. G. Knox

Keyword(s):

Weed Control ◽

Critical Period ◽

Yield Loss ◽

Field Studies ◽

Cotton Yield ◽

Degree Days ◽

Cropping Season ◽

High Level ◽

The Cost ◽

Grass Weed

AbstractField studies were conducted over five seasons from 2004 to 2015 to determine the critical period for weed control (CPWC) in high-yielding, irrigated cotton using a competitive mimic grass weed, Japanese millet. Japanese millet was planted with or after cotton emergence at densities of 10, 20, 50, 100, and 200 plants m−2. Japanese millet was added and removed at approximately 0, 150, 300, 450, 600, 750, and 900 degree days of crop growth (GDD). Data were combined over years. Japanese millet competed strongly with cotton, with season-long interference resulting in an 84% reduction in cotton yield with 200 Japanese millet plants m−2. The data were fit to extended Gompertz and logistic curves including weed density as a covariate, allowing a dynamic CPWC to be estimated for densities of 10 to 200 Japanese millet plants m−2. Using a 1% yield-loss threshold, the CPWC commenced at 65 GDD, corresponding to 0 to 7 d after crop emergence (DAE), and ended at 803 GDD, 76 to 98 DAE with 10 Japanese millet plants m−2, and 975 GDD, 90 to 115 DAE with 200 Japanese millet plants m−2. These results highlight the high level of weed control required throughout the cropping season in high-yielding cotton to ensure crop losses do not exceed the cost of weed control.

Download Full-text

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

Peanut Science ◽

10.3146/ps18-15.1 ◽

2019 ◽

Vol 46 (1) ◽

pp. 50-55

Author(s):

K.M. Eason ◽

R.S. Tubbs ◽

T.L. Grey ◽

X.S. Li

Keyword(s):

Foliar Injury ◽

Weed Species ◽

Arachis Hypogaea L ◽

Herbicide Treatments ◽

Negative Effect ◽

Peanut Cultivars ◽

Southeast Us ◽

Effect On Yield ◽

The Given ◽

Grass Weed

ABSTRACT 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, TUFRunner™ ‘511’, and FloRun™ ‘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 TUFRunner™ ‘511’ yielded 10 to 12% greater than Georgia-14N and FloRun™ ‘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.

Download Full-text

Response of Teff, Barnyardgrass, and Broadleaf Weeds to Postemergence Herbicides

Weed Technology ◽

10.1614/wt-d-13-00153.1 ◽

2014 ◽

Vol 28 (2) ◽

pp. 371-376

Author(s):

O. Steven Norberg ◽

Joel Felix

Keyword(s):

Weed Control ◽

Warm Season ◽

Field Studies ◽

The United States ◽

Production Costs ◽

Grain Production ◽

Annual Grass ◽

Food Grain ◽

Postemergence Herbicides ◽

Grass Weed

Teff is a warm-season C4 annual grass crop grown for forage and food grain that has recently increased in production in parts of the United States. Hay from teff is well suited for livestock, especially horses. The objective of this study was to evaluate teff and weed response to selected herbicides in field studies conducted at the Malheur Experiment Station, Ontario, OR in 2009 and 2010. Herbicides were applied POST when teff was at the four-leaf stage. Broadleaf weed control at 21 d after treatment was greater than 91% across herbicide treatments. Only the premix of 2.5 g ai ha−1florasulam + 99 g ae ha−1fluroxypyr + 15 g ai ha−1pyroxsulam provided acceptable control of barnyardgrass. Due primarily to barnyardgrass competition, teff treated with a premix of 2.5 g ha−1florasulam + 99 g ha−1fluroxypyr + 15 g ha−1pyroxsulam produced 7,200 kg ha−1of teff hay compared with 4,800 kg ha−1of teff hay for 2,4-D and dicamba and 4,200 kg ha−1teff hay when no herbicides were used. Teff grain production was greater with 2.5 g ha−1florasulam + 99 g ha−1fluroxypyr + 15 g ha−1pyroxsulam compared with any of the other treatments. The use of a premix of florasulam + fluroxypyr + pyroxsulam would improve broadleaf and grass weed control in ‘Tiffany' and ‘Dessie' teff varieties, improve hay and grain yield, and reduce production costs.

Download Full-text

Phytotoxicity of Delayed Applications of Flumioxazin on Peanut (Arachis hypogaea)

Weed Technology ◽

10.1614/wt-04-328r.1 ◽

2006 ◽

Vol 20 (1) ◽

pp. 157-163 ◽

Cited By ~ 7

Author(s):

W. Carroll Johnson ◽

Eric P. Prostko ◽

Benjamin G. Mullinix

Keyword(s):

Arachis Hypogaea ◽

Yield Loss ◽

Sand Soil ◽

Optimum Time ◽

Early Season ◽

Application Timing ◽

Time Of Application ◽

Loamy Sand Soil ◽

Effect On Yield ◽

The Times

Trials were conducted under weed-free conditions in 2001, 2002, and 2003 on a loamy sand soil in Georgia to investigate the phytotoxicity of flumioxazin on peanut, and in separate trials, the effects on peanut maturity. The first study evaluated time of flumioxazin application (0, 2, 4, 6, 8, and 10 d after planting [DAP]) and flumioxazin rate (nontreated, 71, and 105 g ai/ha). Peanut (variety ‘C99R’) were seeded 3.2 cm deep and irrigated immediately after seeding. Flumioxazin applied to peanut 6, 8, and 10 DAP significantly injured peanut (20 to 59%) early season, with more phytotoxicity from flumioxazin at 105 g/ha than 71 g/ha. However, peanut stand was not reduced by any of the times of application or rates. Peanut recovered by midseason, except in cases of severe (up to 49%) visual phytotoxic injury. Peanut yields were not affected by either flumioxazin application timing or rate. The second study (variety ‘Georgia Green’) evaluated flumioxazin applied at 105 g/ha at varying intervals after planting to determine the phytotoxic effects on peanut maturity using the hull-scrape method. Peanut maturity was delayed by flumioxazin when applied 1 d after planting and later. These results show that the optimum time of application is from immediately after planting to 2 d after planting, but ideally, the application should be made immediately after planting. The highest recommended flumioxazin rate, 105 g/ha, is not significantly phytotoxic when applied within the recommended range of timings and has no effect on yield. However, there is potential for yield loss as peanut maturity is delayed in cases of severe injury.

Download Full-text

Response of Soybean to Halosulfuron Herbicide

International Journal of Agronomy ◽

10.1155/2009/754510 ◽

2009 ◽

Vol 2009 ◽

pp. 1-7 ◽

Cited By ~ 7

Author(s):

V. K. Nandula ◽

D. H. Poston ◽

K. N. Reddy ◽

K. Whiting

Keyword(s):

Growth Stage ◽

Yield Loss ◽

Field Studies ◽

Glyphosate Resistance ◽

Growth And Yield ◽

Full Bloom ◽

Target Movement ◽

Resistance Trait ◽

Soybean Plants ◽

Effect On Yield

Recently, halosulfuron injury in soybean through off-target movement of halosulfuron when applied to rice fields has been reported. Sulfonylurea-tolerant (ST) soybean varieties have enhanced tolerance for sulfonylurea herbicides and might provide an option for mitigating injury to soybean from halosulfuron drift. Experiments were conducted to evaluate the effect of halosulfuron on growth and yield of selected soybean varieties with ST trait alone and stacked with glyphosate resistance trait. Soybean plants were treated with halosulfuron at 0, 0.0043, 0.0087, 0.017, 0.034, and 0.069 kg ai/ha rate at the V3 growth stage in the greenhouse and at 0.034 kg/ha rate (labeled use rate in rice) in the field studies. All soybean varieties containing the ST trait exhibited some halosulfuron injury, but survived the halosulfuron application in the greenhouse. In field studies, a single POST application of halosulfuron at 0.034 kg/ha to soybean at three-trifoliolate leaf stage or at full bloom stage resulted in halosulfuron injury to a certain extent regardless of ST trait. Halosulfuron did not have a significant effect on yield of ST varieties compared to their respective nontreated controls. Severe halosulfuron injury in two non-ST varieties resulted in yield loss.

Download Full-text

Green Peanut Tolerance to Preemergence and Postemergence Herbicides

Weed Technology ◽

10.1614/wt-03-165r ◽

2004 ◽

Vol 18 (3) ◽

pp. 719-722 ◽

Cited By ~ 6

Author(s):

Travis C. Teuton ◽

Christopher L. Main ◽

Gregory E. MacDonald ◽

Joyce Tredaway Ducar ◽

Barry J. Brecke

Keyword(s):

Untreated Control ◽

Field Studies ◽

Yield Reduction ◽

Early Season ◽

Peanut Production ◽

Effect On Yield ◽

Postemergence Herbicides

Field studies were conducted near Sparr, FL, in 2001 and 2002 to evaluate the response of ‘Valencia 102’ grown for the green peanut market (or boiling peanut) to preemergence (PRE) and postemergence (POST) applications of herbicides registered for dry peanut production (roasted market). Green peanut exhibited excellent tolerance to most PRE and POST treatments. There was minimal injury (8%) from flumioxazin applications when evaluated early season in both years, and peanut quickly recovered. Norflurazon caused chlorosis to peanut foliage (23%) in both years. Yield reduction was observed in 2001 for flumioxazin (15%), metolachlor (20%), and norflurazon (41%) compared with the untreated control. However, there were no yield reductions for any of the PRE treatments in 2002. Bentazon + paraquat early postemergence (EPOST) followed by (fb) 2,4-DB POST, bentazon + paraquat EPOST fb clethodim POST, and imazapic EPOST caused ≤5% injury and had no effect on yield in either year.

Download Full-text