Peanut Response to Preemergence Applications of Metribuzin

Herbicide-resistant Palmer amaranth is one of the most problematic weeds in agronomic cropping systems in Georgia. The wide germination window of Palmer amaranth seed allows it to emerge after field corn harvest, and if left uncontrolled, can contribute significantly to the weed seed-bank causing problems in future rotational crops. One option for a lay-by (in-crop) or post-harvest burndown application in field corn for postemergence and residual control of Palmer amaranth is metribuzin. However, the current metribuzin label prohibits peanut planting for 18 months after application. Peanut tolerance to metribuzin has not been well documented. Therefore, the objective of this research was to evaluate the tolerance of peanut to metribuzin. Field studies were conducted in 2017-2019 in Ty Ty, GA to evaluate the tolerance of peanut to various rates of metribuzin. In a RCBD with four replications, metribuzin was applied preemergence (two days after planting) at 0, 70, 140, 280, 420, and 560 g ai/ha. Rainfall in the first month after planting was 13.1, 15.9, and 11.8 cm for 2017, 2018, and 2019, respectively. Data were subjected to nonlinear regression using log-logistic analysis to demonstrate a dose-response relationship. Year by treatment interactions were significant for late season injury, so data were separated by year. However, early season injury, stand loss, and yield loss data were pooled over years. There was a direct relationship between rate and the response variables. As metribuzin rate increased, injury, stand loss and yield loss increased. Generally, visual injury, stand loss, and yield loss were negligible at rates less than or equal to 140 g ai/ha. With a targeted application rate of 280 g ai/ha and an estimated half-life of 30 to 60 days, metribuzin residues should have minimal impact on peanut grown in rotation when used in lay-by or post-harvest treatments for the prevention of Palmer amaranth seed rain in field corn.

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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.

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Control of Volunteer Horseradish and Palmer Amaranth (Amaranthus palmeri) with Dicamba and Glyphosate

Weed Technology ◽

10.1017/wet.2017.77 ◽

2017 ◽

Vol 31 (6) ◽

pp. 852-862 ◽

Cited By ~ 2

Author(s):

Matthew E. Jenkins ◽

Ronald F. Krausz ◽

Joseph L. Matthews ◽

Karla L. Gage ◽

S. Alan Walters

Keyword(s):

Root Biomass ◽

Yield Loss ◽

Treatment Options ◽

Resistance Management ◽

Field Studies ◽

Palmer Amaranth ◽

High Rate ◽

Amaranthus Palmeri ◽

Soilborne Pathogens ◽

Biomass Reduction

Management of volunteer horseradish is a challenge when it is grown in rotation with other crops, such as corn and soybean. Although volunteer horseradish may not cause yield loss, these plants serve as hosts for various soilborne pathogens that damage subsequent horseradish crops. In addition to volunteer horseradish, glyphosate-resistant Palmer amaranth is becoming difficult to control in southwestern Illinois, as a consequence of the plant’s ability to withstand glyphosate and drought, produce many seeds, and grow rapidly. Field studies were conducted to evaluate the effect of glyphosate and dicamba on volunteer horseradish and Palmer amaranth control in 2014 and 2015. Glyphosate alone (1,265 and 1,893 g ae ha−1) and glyphosate plus dicamba at the high rate (1,680 g ae ha−1) provided the greatest volunteer horseradish control, ranging from 81% to 89% and 90% to 93%, respectively. Measures of root biomass reduction followed similar trends. Glyphosate alone provided the greatest reduction in volunteer horseradish root viability (79% to 100%) but was similar in efficacy to applications of glyphosate plus dicamba in most comparisons. Efficacy of PRE-only applications on Palmer amaranth control ranged from 92% to 99% control in 2014 and 68% to 99% in 2015. However, PRE-only applications were often similar in efficacy to PRE followed by (fb) glyphosate plus dicamba applied POST. Treatments containing flumioxazin did not control Palmer amaranth as well as other treatments. POST applications alone were not effective in managing Palmer amaranth. Many of the PRE fb POST treatment options tested will improve resistance management over PRE-only treatments, provide control of Palmer amaranth, and allow horseradish to be planted the following spring.

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Economic Evaluation of Common Sunflower (Helianthus annuus) Competition in Field Corn

Weed Technology ◽

10.1614/wt-d-10-00158.1 ◽

2012 ◽

Vol 26 (1) ◽

pp. 137-144 ◽

Cited By ~ 2

Author(s):

Nyland R. Falkenberg ◽

Todd J. Cogdill ◽

M. Edward Rister ◽

James M. Chandler

Keyword(s):

Economic Impact ◽

Yield Loss ◽

Field Studies ◽

Planting Density ◽

Corn Yield ◽

Net Returns ◽

Field Corn ◽

Corn Prices ◽

Extended Duration ◽

Crop Planting

Field studies were conducted near College Station, TX, in 2006 and 2007 to evaluate the economic impact of common sunflower interference in field corn. A density of one common sunflower per 6 m of crop row caused a yield loss of 293 kg ha−1. Estimated losses at a net corn price of $0.08 kg−1was $92 ha−1for infestation levels of four common sunflower plants per 6 m of row. Corn yield was increased by 32 kg ha−1by each 1,000 plant ha−1increase in corn planting density. Corn planting densities of 49,400 and 59,300 plants ha−1provided the greatest net returns with or without the presence of common sunflower competition. Corn yields were reduced by extended duration of sunflower competition, with losses exceeding 1,500 kg ha−1per week and increasing in magnitude at a decreasing rate throughout the growing season. Herbicide treatments provided net returns of $600 to $1,300 ha−1above no weed control in both 2006 and 2007. Net returns of $609 and $653 ha−1were obtained without the use of any herbicide for sunflower control. Determining the economic impact of common sunflower interference in field corn allows producers to estimate the overall net return on the basis of duration of common sunflower interference and density, while considering varying net corn prices, crop planting density, and herbicide application costs.

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EFFECTS OF INTERCROPPING SYSTEM AND NITROGEN FERTILIZATION ON LAND EQUIVALENT RATIO, YIELD AND MINERAL CONTENT OF BROCCOLI

Acta Scientiarum Polonorum Hortorum Cultus ◽

10.24326/asphc.2020.3.9 ◽

2020 ◽

Vol 19 (3) ◽

pp. 101-109

Author(s):

Ertan Yildirim ◽

Büsra Cil ◽

Melek Ekinci ◽

Metin Turan ◽

Atilla Dursun ◽

...

Keyword(s):

Nitrogen Fertilization ◽

Cropping Systems ◽

Growth Yield ◽

Field Studies ◽

Application Rate ◽

Nitrogen Application ◽

Plant Weight ◽

Nutrient Contents ◽

Nitrogen Concentrations ◽

Microelement Content

To determine effects of intercropping broccoli with onion and their correspondence to different nitrogen concentrations on growth, yield and nutrient contents, field studies were conducted for two years. In intercropping plots, onion sets were planted between broccoli rows. Broccoli and onion plants were also grown as monocrops. Nitrogen was applied at three different rates (160, 200 and 240 kg ha–1) in both mono and intercrop plots of broccoli. The overall efficiency of intercropping was evaluated by employing land equivalent ratios (LERs). Cropping systems significantly did not affect chlorophyll reading value, yield and other parameters observed. However, nitrogen application rate had significant effect on these parameters. The highest values of these parameters were generally observed in 240 kg ha–1 nitrogen application. Macro and microelement content of broccoli leaves was affected neither by cropping systems nor by nitrogen fertilization except for N, Mn, Zn and NO3. Intercropping increased plant height but decreased the plant diameter of onion. There wasn’t significant decrease in plant weight of intercropped onion at 240 kg ha–1 nitrogen treatment when compared to monocropping. Broccoli intercropped with onion at 240 kg ha–1 nitrogen had the highest LER values, showing that intercropping practice could be more productive than monocropping especially in case of 240 kg ha–1 nitrogen application.

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Interspecific and intraspecific interference of Palmer amaranth (Amaranthus palmeri) and large crabgrass (Digitaria sanguinalis) in sweetpotato

Weed Science ◽

10.1017/wsc.2019.16 ◽

2019 ◽

Vol 67 (4) ◽

pp. 426-432 ◽

Cited By ~ 4

Author(s):

Nicholas T. Basinger ◽

Katherine M. Jennings ◽

David W. Monks ◽

David L. Jordan ◽

Wesley J. Everman ◽

...

Keyword(s):

Ipomoea Batatas ◽

Yield Loss ◽

Field Studies ◽

Palmer Amaranth ◽

Amaranthus Palmeri ◽

Digitaria Sanguinalis ◽

Weed Density ◽

Dry Biomass ◽

Presence And Absence ◽

Large Crabgrass

AbstractField studies were conducted in 2016 and 2017 in Clinton, NC, to determine the interspecific and intraspecific interference of Palmer amaranth (Amaranthus palmeri S. Watson) or large crabgrass [Digitaria sanguinalis (L.) Scop.] in ‘Covington’ sweetpotato [Ipomoea batatas (L.) Lam.]. Amaranthus palmeri and D. sanguinalis were established 1 d after sweetpotato transplanting and maintained season-long at 0, 1, 2, 4, 8 and 0, 1, 2, 4, 16 plants m−1 of row in the presence and absence of sweetpotato, respectively. Predicted yield loss for sweetpotato was 35% to 76% for D. sanguinalis at 1 to 16 plants m−1 of row and 50% to 79% for A. palmeri at 1 to 8 plants m−1 of row. Weed dry biomass per meter of row increased linearly with increasing weed density. Individual dry biomass of A. palmeri and D. sanguinalis was not affected by weed density when grown in the presence of sweetpotato. When grown without sweetpotato, individual weed dry biomass decreased 71% and 62% from 1 to 4 plants m−1 row for A. palmeri and D. sanguinalis, respectively. Individual weed dry biomass was not affected above 4 plants m−1 row to the highest densities of 8 and 16 plants m−1 row for A. palmeri and D. sanguinalis, respectively.

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Effect of DPX-V9360 and Terbufos on Field and Sweet Corn (Zea mays) Under Three Environments

Weed Technology ◽

10.1017/s0890037x0003339x ◽

1991 ◽

Vol 5 (1) ◽

pp. 130-136 ◽

Cited By ~ 37

Author(s):

Cathy A. Morton ◽

R. Gordon Harvey ◽

James J. Kells ◽

William E. Lueschen ◽

Vincent A. Fritz

Keyword(s):

Zea Mays ◽

Nonionic Surfactant ◽

Sweet Corn ◽

Field Studies ◽

Application Rate ◽

Yield Reduction ◽

Crop Response ◽

Field Corn ◽

Significant Yield ◽

Fertilizer Solution

Field studies were conducted in Michigan, Minnesota, and Wisconsin to explore interactions among DPX-V9360 herbicide applied postemergence, terbufos insecticide applied as an in-furrow treatment, and the environment. Field corn (‘Pioneer 3751’) and sweet corn (‘Jubilee’) were planted with and without an in-furrow application of terbufos. DPX-V9360 was applied postemergence when the corn was in the 4- to 6-leaf stage at 0, 35, 70, 140, and 280 g ai ha-1with nonionic surfactant and 28% N fertilizer solution. Crop response to DPX-V9360 was similar at all three locations, varying only in magnitude of injury. Crop injury was greater with Jubilee sweet corn than with Pioneer 3751 field corn. Injury to both hybrids increased as DPX-V9360 application rate increased. Application of terbufos increased injury from DPX-V9360 to both hybrids. Significant yield reduction did not occur with either hybrid when DPX-V9360 was applied at rates of 140 g ha-1or less and no terbufos was applied.

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Application Rate and Timing of Acifluorfen, Bentazon, Chlorimuron, and Imazaquin

Weed Technology ◽

10.1017/s0890037x00035740 ◽

1992 ◽

Vol 6 (3) ◽

pp. 526-534 ◽

Cited By ~ 28

Author(s):

Charles A. King ◽

Lawrence R. Oliver

Keyword(s):

Field Studies ◽

Application Rate ◽

Palmer Amaranth ◽

Red Rice ◽

Pitted Morningglory ◽

Hemp Sesbania ◽

Prickly Sida ◽

Smooth Pigweed ◽

Large Crabgrass

Data from field studies at Fayetteville, AR, were used to predict the herbicide rate needed to provide 70, 80, or 90% control of a weed based upon weed age. Reduced herbicide rates generally needed to be applied within 6 to 12 d after emergence to control weeds 90%. Reduced rates (280 g ai ha–1or less) of acifluorfen controlled hemp sesbania, smooth pigweed, Palmer amaranth, and pitted and entireleaf morningglory 90%. Bentazon at 350 to 650 g ai ha–1controlled common cocklebur and prickly sida 90%. Common cocklebur, smooth pigweed, and pitted morningglory were controlled 90% with chlorimuron at 2 to 5 g ai ha–1and imazaquin at 20 to 80 g ai ha–1. Prickly sida and hemp sesbania were controlled 90% with imazaquin at 70 g ha–1and chlorimuron at 6 g ha–1, respectively. Barnyardgrass, large crabgrass, red rice, and sicklepod were not controlled with reduced herbicide rates.

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Large crabgrass (Digitaria sanguinalis) and Palmer amaranth (Amaranthus palmeri) intraspecific and interspecific interference in soybean

Weed Science ◽

10.1017/wsc.2019.43 ◽

2019 ◽

Vol 67 (6) ◽

pp. 649-656 ◽

Cited By ~ 3

Author(s):

Nicholas T. Basinger ◽

Katherine M. Jennings ◽

David W. Monks ◽

David L. Jordan ◽

Wesley J. Everman ◽

...

Keyword(s):

Yield Loss ◽

Maximum Yield ◽

Field Studies ◽

Palmer Amaranth ◽

Amaranthus Palmeri ◽

Weed Species ◽

Digitaria Sanguinalis ◽

Weed Density ◽

Loss Estimate ◽

Large Crabgrass

AbstractField studies were conducted in 2016 and 2017 at Clinton, NC, to quantify the effects of season-long interference of large crabgrass [Digitaria sanguinalis (L.) Scop.] and Palmer amaranth (Amaranthus palmeri S. Watson) on ‘AG6536’ soybean [Glycine max (L.) Merr.]. Weed density treatments consisted of 0, 1, 2, 4, and 8 plants m−2 for A. palmeri and 0, 1, 2, 4, and 16 plants m−2 for D. sanguinalis with (interspecific interference) and without (intraspecific interference) soybean to determine the impacts on weed biomass, soybean biomass, and seed yield. Biomass per square meter increased with increasing weed density for both weed species with and without soybean present. Biomass per square meter of D. sanguinalis was 617% and 37% greater when grown without soybean than with soybean, for 1 and 16 plants m−2 respectively. Biomass per square meter of A. palmeri was 272% and 115% greater when grown without soybean than with soybean for 1 and 8 plants m−2, respectively. Biomass per plant for D. sanguinalis and A. palmeri grown without soybean was greatest at the 1 plant m−2 density. Biomass per plant of D. sanguinalis plants across measured densities was 33% to 83% greater when grown without soybean compared with biomass per plant when soybean was present for 1 and 16 plants m−2, respectively. Similarly, biomass per plant for A. palmeri was 56% to 74% greater when grown without soybean for 1 and 8 plants m−2, respectively. Biomass per plant of either weed species was not affected by weed density when grown with soybean due to interspecific competition with soybean. Yield loss for soybean grown with A. palmeri ranged from 14% to 37% for densities of 1 to 8 plants m−2, respectively, with a maximum yield loss estimate of 49%. Similarly, predicted loss for soybean grown with D. sanguinalis was 0 % to 37% for densities of 1 to 16 m−2 with a maximum yield loss estimate of 50%. Soybean biomass was not affected by weed species or density. Results from these studies indicate that A. palmeri is more competitive than D. sanguinalis at lower densities, but that similar yield loss can occur when densities greater than 4 plants m−2 of either weed are present.

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Evaluating shade cloth to simulate Palmer amaranth (Amaranthus palmeri) competition in sweetpotato

Weed Science ◽

10.1017/wsc.2021.21 ◽

2021 ◽

pp. 1-7

Author(s):

Levi D. Moore ◽

Katherine M. Jennings ◽

David W. Monks ◽

David L. Jordan ◽

Ramon G. Leon ◽

...

Keyword(s):

Ipomoea Batatas ◽

Yield Loss ◽

Total Yield ◽

Field Studies ◽

Light Interception ◽

Palmer Amaranth ◽

Growing Degree Days ◽

Amaranthus Palmeri ◽

Degree Days ◽

Shade Cloth

Abstract Field studies were conducted in 2019 and 2020 to compare the effects of shade cloth light interception and Palmer amaranth (Amaranthus palmeri S. Watson) competition on ‘Covington’ sweetpotato [Ipomoea batatas (L.) Lam.]. Treatments consisted of a seven by two factorial arrangement, in which the first factor included shade cloth with an average measured light interception of 41%, 59%, 76%, and 94% and A. palmeri thinned to 0.6 or 3.1 plants m−2 or a nontreated weed-free check; and the second factor included shade cloth or A. palmeri removal timing at 6 or 10 wk after planting (WAP). Amaranthus palmeri light interception peaked around 710 to 840 growing degree days (base 10 C) (6 to 7 WAP) with a maximum light interception of 67% and 84% for the 0.6 and 3.1 plants m−2 densities, respectively. Increasing shade cloth light interception by 1% linearly increased yield loss by 1% for No. 1, jumbo, and total yield. Yield loss increased by 36%, 23%, and 35% as shade cloth removal was delayed from 6 to 10 WAP for No. 1, jumbo, and total yield, respectively. F-tests comparing reduced versus full models of yield loss provided no evidence that the presence of yield loss from A. palmeri light interception caused yield loss different than that explained by the shade cloth at similar light-interception levels. Results indicate that shade cloth structures could be used to simulate Covington sweetpotato yield loss from A. palmeri competition, and light interception could be used as a predictor for expected yield loss from A. palmeri competition.

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Weed Management and Peanut Response from Applications of Saflufenacil

Weed Technology ◽

10.1614/wt-d-11-00095.1 ◽

2012 ◽

Vol 26 (2) ◽

pp. 261-266 ◽

Cited By ~ 5

Author(s):

Sergio Morichetti ◽

Jason Ferrell ◽

Greg MacDonald ◽

Brent Sellers ◽

Diane Rowland

Keyword(s):

Weed Control ◽

Weed Management ◽

Application Rate ◽

Palmer Amaranth ◽

Yield Reduction ◽

Foliar Injury ◽

Application Timing ◽

Field Corn ◽

Free Environment ◽

Benghal Dayflower

Saflufenacil is a new protoporphyrinogen oxidase–inhibiting herbicide registered for use before establishment of field corn and soybean. Generally, peanut plants are tolerant to other herbicides in this class, and no reports document the utility of saflufenacil for in-season weed control. Experiments were conducted to determine whether saflufenacil applied at 12, 25, and 50 g ha−1could effectively control Benghal dayflower and Palmer amaranth. It was observed that saflufenacil, applied either PRE or POST, was ineffective for Benghal dayflower. The maximum control at 28 d after treatment (DAT) was 79% when 50 g ha−1was applied to 5- to 10-cm plants. Control of Palmer amaranth from PRE applications was less effective than flumioxazin at 28 DAT. However, POST applications provided > 87% control at 28 DAT when applied to plants 5 to 10 cm in height. For plants 10 to 15 cm in height, > 90% Palmer amaranth control was only achieved by the 50 g ha−1application rate. For plants 15 to 20 cm in height, no POST application provided > 70% control. Peanut response, in a weed-free environment, to saflufenacil rate and application timing were also evaluated. Peanut stunting ranged from 0 to 36%, relative to application timing. Applications made at 0 d after emergence (DAE) were least injurious, whereas those made at 15 DAE were most injurious. Application of 50 g ha−1provided the greatest amount of stunting and foliar injury. However, stunting and saflufenacil application rate did not correspond to yield reduction. Saflufenacil application timing did influence peanut yield. Applications made between 0 and 30 DAE did not result in yield loss, whereas applications made at 45 and 60 DAE resulted in a 5 and 19% reduction, respectively. Though saflufenacil has many positive characteristics, higher application rates are required for optimum weed control. However, these higher use rates also resulted in unacceptable levels of injury.

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