scholarly journals Weed Control in Sweet Bell Pepper Using Sequential Postdirected Applications of Pelargonic Acid

2014 ◽  
Vol 24 (6) ◽  
pp. 663-667 ◽  
Author(s):  
Charles L. Webber ◽  
Merritt J. Taylor ◽  
James W. Shrefler
Keyword(s):  
Weed Control ◽  
Sweet Pepper ◽  
Application Rate ◽  
Bell Pepper ◽  
Pelargonic Acid ◽  
Yellow Nutsedge ◽  
Crop Injury ◽  
Application Rates ◽  
Control Research ◽  
The Impact

Pepper (Capsicum annuum) producers would benefit from additional herbicide options that are safe to the crop and provide effective weed control. Research was conducted in southeastern Oklahoma (Atoka County, Lane, OK) during 2010 and 2011 to determine the impact of pelargonic acid on weed control efficacy, crop injury, and pepper yields. The experiment included pelargonic acid applied unshielded postdirected at 5, 10, and 15 lb/acre, plus an untreated weedy control and an untreated weed-free control. ‘Jupiter’ sweet bell pepper, a tobacco mosaic virus-resistant sweet pepper with a 70-day maturity, was transplanted into single rows on 3-ft centered raised beds with 18 inches between plants (9680 plants/acre) on 28 May 2010 and 27 May 2011, respectively. Weeds included smooth crabgrass (Digitaria ischaemum), cutleaf groundcherry (Physalis angulata), spiny amaranth (Amaranthus spinosus), and yellow nutsedge (Cyperus esculentus). Pelargonic acid was applied postdirected each year in mid-June and then reapplied 8 days later. The 15-lb/acre pelargonic acid treatment resulted in the maximum smooth crabgrass control (56%) and broadleaf weed control (66%) at 1 day after the initial spray treatment (DAIT), and 33% yellow nutsedge control at 3 DAIT. Pelargonic acid at 15 lb/acre provided equal or slightly greater smooth crabgrass and broadleaf (cutleaf groundcherry and spiny amaranth) control compared with the 10-lb/acre application, and consistently greater control than the 5-lb/acre rate and the weedy control. Pelargonic acid was less effective at controlling yellow nutsedge than smooth crabgrass and broadleaf weeds. As the rate of pelargonic acid increased from 5 to 15 lb/acre, yellow nutsedge control also increased significantly for all observation dates. Increasing the pelargonic acid application rate increased the crop injury rating. The maximum crop injury occurred for each application rate at 1 DAIT with 7%, 8.0%, and 13.8% injury for pelargonic acid rates 5, 10, and 15 lb/acre, respectively. There was little or no new crop injury after the second postdirected application of pelargonic acid and crop injury following 3 DAIT for application rates was 2% or less. Only the 15-lb/acre pelargonic acid application produced greater fruit per hectare (4784 fruit/ha) and yields (58.65 kg·ha−1) than the weedy control (1196 fruit/ha and 19.59 kg·ha−1). The weed-free yields (7176 fruit/ha, 178.11 kg·ha−1, and 24.82 g/fruit) were significantly greater than all pelargonic acid treatments and the weedy control. Pelargonic acid provided unsatisfactory weed control for all rates and did not significantly benefit from the sequential applications. The authors suggest the pelargonic acid be applied to smaller weeds to increase the weed control to acceptable levels (>80%).

scholarly journals Weed Control in Yellow Squash Using Sequential Postdirected Applications of Pelargonic Acid

2014 ◽  
Vol 24 (1) ◽  
pp. 25-29 ◽  
Author(s):  
Charles L. Webber ◽  
Merritt J. Taylor ◽  
James W. Shrefler
Keyword(s):  
Weed Control ◽  
Application Rate ◽  
Pelargonic Acid ◽  
Fruit Number ◽  
Yellow Nutsedge ◽  
Crop Injury ◽  
Free Treatment ◽  
Control Research ◽  
Hand Weeding ◽  
The Impact

Squash (Cucurbita pepo) producers could benefit from additional herbicide options that are safe to the crop and provide effective weed control. Research was conducted in southeastern Oklahoma (Atoka County, Lane, OK) during 2010 and 2011 to determine the impact of pelargonic acid (PA) on weed control efficacy, crop injury, and squash yields. The experiment included PA applied unshielded postdirected at 5, 10, and 15 lb/acre, plus an untreated weedy control and an untreated weed-free control. ‘Enterprise’ yellow squash was direct-seeded in single rows into raised beds. Weeds included smooth crabgrass (Digitaria ischaemum), cutleaf groundcherry (Physalis angulata), spiny amaranth (Amaranthus spinosus), and yellow nutsedge (Cyperus esculentus). Pelargonic acid was applied each year in mid-July and then reapplied 8 days later. The maximum smooth crabgrass control (98%), broadleaf weed control (94%), and yellow nutsedge control (41%) was observed with the 15-lb/acre PA treatment at 9 days after initial spray treatment (DAIT), 1 day after sequential treatment (1 DAST). Pelargonic acid at 15 lb/acre provided equal or slightly greater smooth crabgrass and broadleaf (cutleaf groundcherry and spiny amaranth) control compared with the 10-lb/acre application, and consistently greater control than the 5-lb/acre rate and the weedy control. Pelargonic acid was less effective at controlling yellow nutsedge than smooth crabgrass and broadleaf weeds. Yellow nutsedge control peaked at 9 DAIT (1 DAST) with 10-lb/acre PA (41%). As the rate of PA increased from 5 to 15 lb/acre, yellow nutsedge control also increased significantly for all observation dates, except for 28 DAIT. Increasing the PA application rate increased the crop injury rating at 1 and 3 days after each application (1 and 3 DAIT, 1 and 3 DAST). Maximum squash injury occurred for each application rate at 9 DAIT (1 DAST) with 4.4%, 8.0%, and 12.5% injury for PA rates 5, 10, and 15 lb/acre, respectively. The 10-lb/acre PA treatment produced the highest squash yields (kilograms per hectare) and fruit number (fruit per hectare) compared with either the 5- or 15-lb/acre rates, and equivalent yields and fruit number as the hand-weeded weed-free treatment. The 10-lb/acre PA rate applied in a timely sequential application has the potential of providing good weed control with minimal crop injury resulting in yields equivalent to weed-free hand-weeding conditions.

scholarly journals Cover Crop and Herbicide Combinations for Weed Control in Polyethylene-mulched Bell Pepper

2009 ◽  
Vol 19 (2) ◽  
pp. 405-410 ◽  
Author(s):  
Sanjeev K. Bangarwa ◽  
Jason K. Norsworthy ◽  
Edward E. Gbur
Keyword(s):  
Weed Control ◽  
Cover Crop ◽  
Application Rate ◽  
Palmer Amaranth ◽  
Cyperus Rotundus ◽  
Bell Pepper ◽  
Purple Nutsedge ◽  
Yellow Nutsedge ◽  
Herbicide Treatments ◽  
Large Crabgrass

Field trials were conducted in 2006 and 2007 to evaluate the performance of ‘Caliente’ mustard cover crop and herbicide combinations for weed control in polyethylene-mulched bell pepper (Capsicum annuum). ‘Caliente’ mustard is a blend of brown mustard (Brassica juncea) and white mustard (Sinapis alba). Herbicide treatments included 1/2× and 1× rates of two pre-emergence (PRE) and two postdirected (PD) herbicides. PRE herbicides were applied 1 week before transplanting, whereas PD herbicides were applied at 4 to 5 weeks after transplanting. ‘Caliente’ mustard did not supplement weed control or improve bell pepper yield in herbicide-treated plots. There was a significant herbicide selection by application rate interaction for large crabgrass (Digitaria sanguinalis) control and bell pepper yield, but only the main effect of herbicide selection and application rate affected the control of purple nutsedge (Cyperus rotundus), yellow nutsedge (Cyperus esculentus), and palmer amaranth (Amaranthus palmeri). Bell pepper injury was not more than 9% from all herbicides and application rates. Except for large crabgrass, control of all weed species improved by increasing the application rate from 1/2× to 1×. S-metolachlor PRE provided more broad-spectrum weed control than other herbicides. Halosulfuron applied PRE or PD was selective to purple nutsedge and yellow nutsedge, whereas trifloxysulfuron performed better than halosulfuron on palmer amaranth and large crabgrass. Plots treated with the 1× rate of S-metolachlor or trifloxysulfuron produced the highest marketable bell pepper yield among the herbicide treatments, but no herbicide treatment allowed for marketable yield equivalent to the weed-free treatment.

Weed Management in Southeastern Peanut (Arachis hypogaea) with AC 263,222

1996 ◽  
Vol 10 (1) ◽  
pp. 145-152 ◽  
Author(s):  
John S. Richburg ◽  
John W. Wilcut ◽  
Daniel L. Colvin ◽  
Gerald R. Wiley
Keyword(s):  
Weed Control ◽  
Arachis Hypogaea ◽  
Weed Management ◽  
Field Experiments ◽  
Common Ragweed ◽  
Yellow Nutsedge ◽  
Application Rates ◽  
Ac 263,222

Field experiments conducted at four locations in Georgia and two locations in Florida during 1992 and 1993 evaluated AC 263,222 application rates and timings, systems, and mixtures for weed control, peanut injury, and yield. All rates of AC 263,222 applied early POST (EPOST) or POST controlledIpomoeamorningglories and smallflower morningglory at least 90%, and purple and yellow nutsedge at least 81%. Florida beggarweed and sicklepod control generally was highest when metolachlor was applied PPI followed by AC 263,222 applied EPOST at 71 g/ha, AC 263,222 at 27 or 36 g/ha plus bentazon plus paraquat applied POST, or with bentazon plus paraquat applied EPOST followed by AC 263,222 applied POST at 36 or 53 g/ha. Acifluorfen and acifluorfen plus bentazon reduced Florida beggarweed and sicklepod control at several locations when applied in mixture with AC 263,222. Common ragweed and hairy indigo control were 85 to 95% with bentazon plus paraquat applied EPOST followed by AC 263,222 applied POST at 36 or 53 g/ha. Highest peanut yields were obtained with treatments providing high levels of weed control.

Postemergence AC 263,222 Systems for Weed Control in Peanut (Arachis hypogaea)

Weed Science ◽  
1996 ◽  
Vol 44 (3) ◽  
pp. 615-621 ◽  
Author(s):  
John W. Wilcut ◽  
John S. Richburg ◽  
Gerald L. Wiley ◽  
F. Robert Walls
Keyword(s):  
North Carolina ◽  
Weed Control ◽  
Arachis Hypogaea ◽  
Field Studies ◽  
Common Lambsquarters ◽  
Yellow Nutsedge ◽  
Crop Injury ◽  
Ac 263,222 ◽  
Prickly Sida

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.

Influence of AC 263,222 Rate and Application Method on Weed Management in Peanut (Arachis hypogaea)

1997 ◽  
Vol 11 (3) ◽  
pp. 520-526 ◽  
Author(s):  
Theodore M. Webster ◽  
John W. Wilcut ◽  
Harold D. Coble
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Application Rate ◽  
Purple Nutsedge ◽  
Yellow Nutsedge ◽  
Control Effectiveness ◽  
Application Method ◽  
Rate Controlled ◽  
Ac 263,222 ◽  
Prickly Sida

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.

scholarly journals Quantifying N2O emissions from intensive grassland production: the role of synthetic fertilizer type, application rate, timing and nitrification inhibitors

2016 ◽  
Vol 154 (5) ◽  
pp. 812-827 ◽  
Author(s):  
M. J. BELL ◽  
J. M. CLOY ◽  
C. F. E. TOPP ◽  
B. C. BALL ◽  
A. BAGNALL ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Fertilizer Application ◽  
Application Rate ◽  
Nitrous Oxide Emissions ◽  
Mineral Fertilizers ◽  
Urea Fertilizer ◽  
Mitigation Options ◽  
Application Rates ◽  
The Impact ◽  
Ipcc Default

SUMMARYIncreasing recognition of the extent to which nitrous oxide (N2O) contributes to climate change has resulted in greater demand to improve quantification of N2O emissions, identify emission sources and suggest mitigation options. Agriculture is by far the largest source and grasslands, occupying c. 0·22 of European agricultural land, are a major land-use within this sector. The application of mineral fertilizers to optimize pasture yields is a major source of N2O and with increasing pressure to increase agricultural productivity, options to quantify and reduce emissions whilst maintaining sufficient grassland for a given intensity of production are required. Identification of the source and extent of emissions will help to improve reporting in national inventories, with the most common approach using the IPCC emission factor (EF) default, where 0·01 of added nitrogen fertilizer is assumed to be emitted directly as N2O. The current experiment aimed to establish the suitability of applying this EF to fertilized Scottish grasslands and to identify variation in the EF depending on the application rate of ammonium nitrate (AN). Mitigation options to reduce N2O emissions were also investigated, including the use of urea fertilizer in place of AN, addition of a nitrification inhibitor dicyandiamide (DCD) and application of AN in smaller, more frequent doses. Nitrous oxide emissions were measured from a cut grassland in south-west Scotland from March 2011 to March 2012. Grass yield was also measured to establish the impact of mitigation options on grass production, along with soil and environmental variables to improve understanding of the controls on N2O emissions. A monotonic increase in annual cumulative N2O emissions was observed with increasing AN application rate. Emission factors ranging from 1·06–1·34% were measured for AN application rates between 80 and 320 kg N/ha, with a mean of 1·19%. A lack of any significant difference between these EFs indicates that use of a uniform EF is suitable over these application rates. The mean EF of 1·19% exceeds the IPCC default 1%, suggesting that use of the default value may underestimate emissions of AN-fertilizer-induced N2O loss from Scottish grasslands. The increase in emissions beyond an application rate of 320 kg N/ha produced an EF of 1·74%, significantly different to that from lower application rates and much greater than the 1% default. An EF of 0·89% for urea fertilizer and 0·59% for urea with DCD suggests that N2O quantification using the IPCC default EF will overestimate emissions for grasslands where these fertilizers are applied. Large rainfall shortly after fertilizer application appears to be the main trigger for N2O emissions, thus applicability of the 1% EF could vary and depend on the weather conditions at the time of fertilizer application.

The influence of potassium and defoliation of ryegrass on the formation of acidic subsurface layers in stock urine patches

Soil Research ◽  
2005 ◽  
Vol 43 (2) ◽  
pp. 213 ◽  
Author(s):  
J. R. Condon ◽  
A. S. Black ◽  
M. K. Conyers
Keyword(s):  
N Uptake ◽  
Application Rate ◽  
Soil Columns ◽  
Surface Layers ◽  
Downward Movement ◽  
Application Rates ◽  
Subsurface Layers ◽  
N Rates ◽  
Main Effects ◽  
The Impact

This study examined the influence of simulated urine solutions containing various KCl and urea-N rates on the formation of acidic subsurface layers in soil columns. A factorial design was implemented with application rates equivalent to 0, 21, 42, 63, and 84 g urea-N/m2 and 0, 12.5, 25, and 37.5 g KCl-K/m2. The addition of N caused the formation of acidic subsurface layers at depths between 0.02 and 0.10 m. The magnitude of the resultant net acidification and the depth of the most acidic layer increased with N rate. More acidification occurred at depth at the higher N rates due to the downward movement of NH4+-N. The inclusion of K in the simulated urine produced less acidity in the surface layers and more acidity at depth as the K application rate increased owing to competition between K+ and NH4+-N for exchange sites, allowing more NH4+-N to move to depth. The residual acidity in the soil at the completion of the experiment was found to be greater than the alkalinity of plant material. Therefore, acidic subsurface layers are likely to persist after plant death and decomposition. We also examined the impact of defoliation on the resultant pH profiles formed following simulated urine addition. Defoliation accentuated the magnitude of acidic subsurface layers, possibly due to changes in the rate of N uptake. The influence of defoliation was minor compared with the main effects of N addition.

scholarly journals Nitrogen and Rainfall Effects on Crop Growth—Experimental Results and Scenario Analyses

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2219
Author(s):  
Saadi Sattar Shahadha ◽  
Ole Wendroth ◽  
Dianyuan Ding
Keyword(s):  
Soil Water ◽  
Application Rate ◽  
Crop Growth ◽  
Water Dynamics ◽  
Nitrogen Application ◽  
Soil Water Dynamics ◽  
Application Rates ◽  
Use Efficiency ◽  
The Impact ◽  
Nitrogen Application Rate

Nitrogen (N) fertilization is critical for crop growth; however, its effect on crop growth and evapotranspiration (ETc) behaviors under different amounts of rainfall is not well understood. As such, there is a need for studying the impact of nitrogen application rates and rainfall amounts on crop growth and ETc components. Agricultural system models help to fill this knowledge gap, e.g., the Root Zone Water Quality Model (RZWQM2), which integrates crop growth-related processes. The objective of this study is to investigate the effect of the nitrogen application rate on crop growth, soil water dynamics, and ETc behavior under different rainfall amounts by using experimental data and the RZWQM2. A field study was conducted from 2016 to 2019 with three nitrogen application rates (0, 70 and 130 kg N ha−1) for unirrigated winter wheat (Triticum aestivum L.), and two nitrogen application rates (0 and 205 kg N ha−1) for unirrigated corn (Zea mays L.). For the period of 1986–2019, the amounts of actual rainfall during each crop growth period are categorized into four groups. Each rainfall group is used as a rainfall scenario in the RZWQM2 to explore the interactions between the rainfall amounts and N levels on the resulting crop growth and water status. The results show that the model satisfactorily captures the interaction effects of nitrogen application rates and rainfall amounts on the daily ETc and soil water dynamics. The nitrogen application rate showed a noticeable impact on the behavior of soil water dynamics and ETc components. The 75% rainfall scenario yielded the highest nitrogen uptake for both crops. This scenario revealed the highest water consumption for wheat, while corn showed the highest water uptake for the 100% rainfall scenario. The interaction between a high nitrogen level and 50% rainfall yielded the highest water use efficiency, while low nitrogen and 125% rainfall yielded the highest nitrogen use efficiency. A zero nitrogen rate yielded the highest ETc and lowest soil water content among all treatments. Moreover, the impacts of the nitrogen application rate on ETc behavior, crop growth, and soil water dynamics differed depending on the received rainfall amount.

scholarly journals Changing Fertilizer Management Practices in Sugarcane Production: Cane Grower Survey Insights

2020 ◽  
Author(s):  
Syezlin Hasan ◽  
James C. R. Smart ◽  
Rachel Hay ◽  
Sharyn Rundle-Thiele
Keyword(s):  
Management Practices ◽  
Negative Binomial ◽  
Fertilizer Application ◽  
Application Rate ◽  
Practice Change ◽  
Farm Income ◽  
Fertilizer Management ◽  
Application Rates ◽  
Fertilizer Application Rate ◽  
The Impact

Research focused on understanding wider systemic factors driving behavioral change is limited with a dominant focus on the role of individual farmer and psychosocial factors for farming practice change, including reducing fertilizer application in agriculture. Adopting a wider systems perspective, the current study examines change and the role that supporting services have on fertilizer application rate change. A total of 238 sugarcane growers completed surveys reporting on changes in fertilizer application along with factors that may explain behavior change. Logistic regressions and negative binomial count-data regressions were used to examine whether farmers had changed fertilizer application rates and if they had, how long ago they made the change, and to explore the impact of individual and system factors in influencing change. Approximately one in three sugarcane growers surveyed (37%) had changed the method they used to calculate fertilizer application rates for the cane land they owned/managed at some point. Logistic regression results indicated growers were less likely to change the basis for their fertilizer calculation if they regarded maintaining good relationships with other local growers as being extremely important, they had another source of off-farm income, and if they had not attended a government-funded fertilizer management workshop in the five years preceding the survey. Similar drivers promoted early adoption of fertilizer practice change; namely, regarding family traditions and heritage as being unimportant, having sole decision-making authority on farming activities and having attended up to 5 workshops in the five years prior to completing the survey. Results demonstrated the influence of government-funded services to support practice change.

Paraquat for Weed Control Prior to Establishing Legumes

Weed Science ◽  
1969 ◽  
Vol 17 (4) ◽  
pp. 428-431 ◽  
Author(s):  
D. L. Linscott ◽  
A. A. Akhavein ◽  
R. D. Hagin
Keyword(s):  
Medicago Sativa ◽  
Weed Control ◽  
Application Rate ◽  
Early Spring ◽  
Growth Time ◽  
Birdsfoot Trefoil ◽  
Cyperus Esculentus ◽  
Herbicide Application ◽  
Yellow Nutsedge ◽  
Weed Growth

Land was prepared conventionally in early spring for the planting of small seeded legumes. Planting was delayed to allow emergence of weeds. We applied 1,1'-dimethyl-4,4'-bipyridinium salts (paraquat) and planted legumes immediately afterwards. Stage of weed growth, time of herbicide application, rate of chemical applied, and the methods of seeding were variables imposed. Paraquat (plus surfactant) applied at 1.1 and 2.2 kg/ha to emerged weeds prior to the seeding of legumes controlled quackgrass [Agropyron repens(L.) Beauv.] sufficiently to allow excellent establishment of alfalfa (Medicago sativaL.) and birdsfoot trefoil (Lotus corniculatusL.). A paraquat application delayed until yellow nutsedge (Cyperus esculentusL.) was at least 10 cm in height, followed by a disking, controlled the sedge sufficiently to allow legume establishment. For annual weed control, 0.3% kg/ha of paraquat was sufficient. Drilling as a method of seeding gave better legume stands than did surface-seeding techniques.

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