Agronomy and Crop Sciences Commons^™

Cynodon Dactylon Control In Conservation Tillage Systems, A Rios, J M. Sanz

IGC Proceedings (1997-2023)

Bermudagrass (Cynodon dactylon L. PERS.) is the most important weed in Uruguay. With the development of conservation tillage systems, chemical control of bermudagrass becomes essential. The objective of this research was to evaluate, in a long term integrated program, bermudagrass chemical control during the first year of a pasture. Application of glyphosate and no-tillage seeding of the pasture took place during fall. A 70% reduction of underground part of the weed was detected. The chemical control, together with a conservation tillage system and an adequate pasture management allowed an important reduction in bermudagrass level for the first year pasture. …

A Solution To Weed Control In Grassland Containing White Clover, E. Bardsley, T. Schulz, R. Bentley, V. Van Damme, D. Gurney, N. Blanchier, B. B. Sleugh

IGC Proceedings (1997-2023)

Productive grass with white clover can lead to advantages both in forage quantity and quality, economics and in meeting wider expectations detailed in recent EU and UK policy. The ability to achieve this agronomic success is currently difficult due to a lack of options for broad spectrum weed control that also allow establishment or preservation of a white clover population. The aim of this paper is to demonstrate that 3730XL, developed by Corteva Agriscience, is a solution to this critical success factor. Data is presented from 16 efficacy trials (10 from established grassland and 5 from newly sown) where white …

Forage Response And Economic Benefits To Weed Management In Grasslands, E. S. Flynn, S. Ingram, B. B. Sleugh

IGC Proceedings (1997-2023)

A common question among managers of grazing operations is “At what level of weed pressure does it become economical to apply herbicides on pastures?” Unfortunately, there isn’t just one answer to this question as production goals and practices differ between operations and even within an operation over time. Regardless, the real question being ask is if weed control will increase profit per acre.

There are three basic avenues that may be taken to improve profit per acre through weed control. The first is to increase the carrying capacity of the grazing operation by controlling weeds and replacing them with desirable …

Impact Of Lime, Phosphorus, And Potassium On Yield And Forage Quality On Native Hay Meadows In Southeast Kansas, Junior I. Yasuoka, Wendie Powell, Walter H. Fick, Bruno C. Pedreira

Kansas Agricultural Experiment Station Research Reports

Native meadows are frequently harvested for hay in southeast Kansas to produce forage for winter use. However, the low soil fertility associated with nutrient removal has resulted in limited yield potential and broomsedge infestation. This study evaluated the effect of phosphorus, potassium, and lime on the forage yield and quality in a native meadow. Our results indicated that P and K fertilization contributes to improving yield and quality on native meadows in southeast Kansas. This study will be repeated in 2023, including broomsedge measurements.

Nutrient Management Strategies To Control Broomsedge Infestation And Improve Yield And Quality Of Tall Fescue Hayfields, Junior I. Yasuoka, Dale Helwig, Wendie Powell, Jaymelynn K. Farney, Gretchen F. Sassenrath, Bruno C. Pedreira

Kansas Agricultural Experiment Station Research Reports

A study in tall fescue hayfields infested with broomsedge and bluestem was conducted at four locations in southeast Kansas. The purpose of this study was to evaluate how phosphorus, nitrogen, and potassium fertilization affect yield, forage quality, and broomsedge/bluestem control in tall fescue hayfields. This trial will be repeated in 2023.

Effect Of Corn Row Spacing On Herbicide Effectiveness For Weed Control In 2022, S. H. Lancaster, E. Adee

Kansas Agricultural Experiment Station Research Reports

Cultural weed control practices such as narrow row spacing can be a key component of successful weed management. Experiments were conducted in the Kansas River Valley to evaluate interactions of herbicide programs and corn row spacings on weed control and grain yield. There were no differences in weed control at a site with low weed density. However, at a site with high Palmer amaranth density, Resicore applied to 15- and 30-inch rows and Bicep + Acuron applied to 15-inch rows resulted in the greatest weed control. Corn yield was similar across all treatments at both locations.

Allelopathic Potential Of Winter Wheat Varieties For Weed Suppression, C. Bott, A. Dille, A. Mohammad, L. Simão, L. O. Pradella, R. P. Lollato

Kansas Agricultural Experiment Station Research Reports

Summer weeds are an expensive economic and environmental problem during the fallow period following the harvest of a wheat crop. Anecdotal evidence suggests that different wheat varieties impact the need for weed control in the subsequent fallow period differently, with reasons ranging from residue amount and quality to the allelopathic potential of such residue. Thus, our objectives were to compare the allelopathic effects of different winter wheat varieties on weed and crop germination suppression. We collected the residue left after harvest of 25 varieties grown in a randomized complete block design in two Kansas locations (Hays and Great Bend) during …

Evaluation Of Fenclorim Safener For Use In Rice With Group 15 Herbicides, Tristen Heath Avent

Graduate Theses and Dissertations

The development of herbicide resistance and the lack of effective herbicides to control problematic weeds has caused Arkansas rice (Oryza sativa L.) production to pursue alternative sites of action. Currently, very long-chain fatty acid elongase inhibitors are not labeled for U.S. rice production but have been widely used for Asian rice production systems. Previous research has demonstrated the utility of acetochlor and pyroxasulfone to provide in-season weed control for Arkansas rice production, but variable crop tolerance has been observed. Additionally, acetochlor at 1,260 g ai ha-1 elicited less rice injury when seeds were treated with a herbicide safener seed treatment …

Using Cover Crops To Control Weeds And Improve Soil Health, J. Dille, A. Hewitt, G. Sassenrath

Kansas Agricultural Experiment Station Research Reports

Herbicide-resistant weeds are challenging for producers to control in crop fields. This study explores the potential of cover crops to reduce weed pressure and improve soil health. Cover crops that had good canopy development, including grasses such as ryegrass and wheat, had the best weed control. Soybean yields were similar for all cover crops, though there was a trend towards lower yields for the brassica cover crops, Graza radish and forage collards. Soybeans grown after ryegrass had the highest yields.

Mitigating Herbicide Impacts To Soybean, Grant Lawson Priess

Graduate Theses and Dissertations

The rapidity in evolution of herbicide-resistant weeds and the resulting cost to U.S. farmers demonstrate the need to responsibly steward the limited number of herbicides available in agricultural systems. To reduce weed emergence and likewise added selection pressures placed on herbicides, early-season crop canopy formation has been promoted. However, impacts to soybean following a potentially injurious herbicide application have not been thoroughly evaluated. Therefore, field experiments were conducted to determine whether: 1) soybean injury from metribuzin or flumioxazin delayed canopy formation or changed the incidence of pathogen colonization; 2) residual herbicides applied preplant reduced the potential for soybean injury and …

Challenges And Opportunities For Weed Control In Nebraska Popcorn, Ethann R. Barnes

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Weed control in popcorn is challenging with limited herbicide options and popcorn’s perceived sensitivity to herbicides. Understanding the impact of weeds maximizes yield and profit. New herbicide-resistant crops increase chances of drift or misapplication into popcorn, which doesn’t have herbicide-resistant traits. Herbicides that are labeled in popcorn are often only conditionally labeled with reduce rates, warnings, or limited popcorn types. Dent-sterility in popcorn is contingent on the Ga1 gene (Ga1-s), but this system is at risk from Ga1-m field corn introduced from Mexico because it overcomes dent-sterility. This risk is under-assessed as Ga1-m carriers are undocumented and Mexican germplasm usage …

Evaluation Of Crop Tolerance And Weed Control In Corn And Grain Sorghum With Atrazine Replacements, Jacob Thomas Richburg

Graduate Theses and Dissertations

Atrazine is a foundational herbicide for weed control in both corn (Zea mays L.) and grain sorghum [Sorghum bicolor (L.) Moench] production. However, studies have shown that while atrazine may be an effective herbicide for preemergence and postemergence control of weeds, it also has risks. The low Koc of atrazine as well as its extensive use over the past 50 years have led it to become the most common groundwater contaminant near agricultural soils. Given these findings, atrazine has faced severe scrutiny while under consideration for reregistration. In the event that atrazine is not reregistered, corn and grain sorghum producers …

Mulch Treatment Effect On Weed Biomass And Yields Of Organic Sweetpotato Cultivars, Sochinwechi I Nwosisi, Dilip Nandwani, Dafeng Hui

Biology Faculty Research

Weeds are a challenge, particularly in organic agriculture, due to restrictions on the application of synthetic herbicides and chemicals. A preliminary cultivar evaluation trial of organic sweetpotato was conducted in 2015 at Tennessee State University certified organic farm. Three mulches: wheat straw, pine needle, and black plastic mulch, along with a control (no mulch), were evaluated for their weed management abilities in a sweetpotato field. Four cultivars of sweetpotato were planted in 0.91 m wide mulch beds with 0.3 m row spacing anddrip irrigated with four replications. Data was collected during the growing season on the dry weight of weeds …

Optimizing Cover Crop Rotations For Water, Nitrogen And Weed Management, Cintia Soledad Sciarresi

Theses and Dissertations--Plant and Soil Sciences

Winter cover crops grown in rotation with grain crops can be an efficient integrated pest management tool (IPM). However, cover crop biomass production and thus successful provisioning of ecosystem services depend on a timely planting and cover crop establishment after harvest of a cash crop in the fall. One potential management adaptation is the use of short-season soybeans to advance cover crop planting date in the fall. Cover crops planted earlier in the fall may provide a greater percentage of ground cover early in the season because of higher biomass accumulation that may improve weed suppression. However, adapting to short-season …

Using Cover Crops As An Effective Weed Control Method In Southeast Kansas, L. I. Chism, J. A. Dille, G. F. Sassenrath

Kansas Agricultural Experiment Station Research Reports

Weed control is important to optimize crop production. This study was conducted to compare the effectiveness of different methods of fall-implemented weed control strategies. These strategies included different cover crop mixes, chemical control, and mechanical control. The cover crop mixes included four different commonly-planted winter cover crops. The chemical control was a fall-applied burndown, and the me­chanical control was vertical tillage. We found cover crop mixes that contained cereal rye provided the most weed control, with the chemical control being a close second. Spring oats die during the winter because of the low temperatures. The three cover crop mixes containing …

Mulch And Groundcover Effects On Soil Temperature And Moisture, Surface Reflectance, Grapevine Water Potential, And Vineyard Weed Management, Christina M. Bavougian, Paul E. Read

Department of Agronomy and Horticulture: Faculty Publications

The objectives of this research were to identify alternatives to glyphosate for intra- row (under-trellis) vineyard floor management and to evaluate the potential for intra- row and inter-row (alleyway) groundcovers to reduce vegetative vigor of `Marquette' grapevines (Vitis spp.) in a southeast Nebraska vineyard. The experiment was a randomized factorial design with five intra-row treatments (crushed glass mulch [CG], distillers' grain mulch [DG], creeping red fescue [CRF], non-sprayed control [NSC], and glyphosate [GLY]) and three inter-row treatments (creeping red fescue [CRF], Kentucky bluegrass [KB], and resident vegetation [RV]). Treatments were established in 2010-2011 and measurements were conducted during 2012 …

Glyphosate-Resistant Weed Control And Soybean Injury In Response To Different Ppo-Inhibiting Herbicides, Jatinder S. Aulakh, P. S. Chahal, Amit J. Jhala

Department of Agronomy and Horticulture: Faculty Publications

In Nebraska, 5-enolpyruvyl shikimate-3-phosphate synthase (EPSPS) as well as acetolactate synthase (ALS)-inhibitor-resistant weeds occur in many soybean fields where herbicides from these modes-of-action have been frequently used in the past. Currently, the protoporphyrinogen oxidase (PPO)-inhibitors are the only effective herbicides for POST control of both glyphosate- and ALS-inhibitor-resistant weeds in soybean. Greenhouse experiments were conducted in 2014 to evaluate the efficacy of PPO-inhibitors applied POST for the control of three glyphosate-resistant (GR) weeds and potential for soybean injury, when applied at two growth stages. All herbicide treatments controlled 10- and 20-cm tall GR common waterhemp ≥ 95% at 21 DAT. …

Weed Control With Postemergence Applications Of Status, Armezon, Atrazine, Corvus, Verdict, And Roundup Powermax In Irrigated Corn, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

All postemergence herbicides provided greater than 98% control of quinoa, common sunflower, Palmer amaranth, and green foxtail. Crabgrass and Russian thistle were more difficult to control. All postemergence herbicides except Roundup PowerMax (glypho­sate) alone controlled Russian thistle and crabgrass greater than 89%. Diflexx (dicamba) plus Roundup PowerMax was slightly more efficacious on kochia than Status (diflufen­zopyr + dicamba) plus Armezon (topramezone) with atrazine and Roundup Power­Max, and all other herbicides were intermediate for kochia control. Corn yields did not differ between herbicide treatments. However, all herbicides increased grain yields.

Weed Control With Single Or Sequential Herbicide Applications In Acetolactase Synthase-Tolerant Grain Sorghum, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

Palmer amaranth control was best when Resolve (rimsulfuron) plus Harmony GT (thifensulfuron) and Abundit Extra (glyphosate) were applied 15 days preplant fol­lowed by Zest (nicosulfuron) and atrazine postemergence, or by Zest plus atrazine alone postemergence. Palmer amaranth control was less than 80% with all other herbicide treatments. Preemergence herbicides alone provided less than 60% green foxtail control at 53 days after postemergence applications, and Zest plus atrazine alone postemergence controlled green foxtail 70%. Sequential applications of preemergence and postemer­gence herbicides were needed to provide the best green foxtail control. The relatively low weed control provided by these treatments may be …

Fallow Weed Control With Preemergence Applications Of Balance Pro, Corvus, Banvel, Atrazine, And Authority Mtz, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

Atrazine alone applied in the fall was less effective for kochia and Russian thistle control than other fall- or spring-applied herbicides in early summer. In mid season, control of kochia and Russian thistle was 85% or less with all fall-applied herbicides. Banvel (dicamba) increased kochia control when added to Balance Pro (isoxaflutole), plus Autumn Super (iodosulfuron + thiencarbazone), plus atrazine applied in the spring at mid season. All other spring herbicides were similar for kochia control. Russian thistle control was similar among all spring-applied herbicides except atrazine plus Banvel.

Efficacy Of Anthem Maxx, Solstice, Cadet, Roundup Powermax, And Competitive Standards In Irrigated Corn, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

Control of Palmer amaranth and green foxtail was generally best when herbicides were applied as sequential treatments of preemergence (PRE) followed by late postemergence (LPOST) or as postemergence (POST) alone. Velvetleaf and puncturevine control was 95 and 93% or more, respectively, regardless of herbicide or application timing. Corn receiving herbicide treatments yielded 42 to 72 bu/a more grain than non-treated corn.

Alion, Sencor, And Sharpen For Preemergence Kochia Control In An Abandoned Alfalfa Field, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

Alion (indaziflam) combined with Sencor (metribuzin) were the most effective herbi­cides for kochia control. Sharpen (saflufenacil) alone or with Prowl H2O (pendimeth­alin), Sencor, or Alion was less effective at controlling kochia compared to Alion plus Sencor. By 91 days after treatment (DAT), Alion at rates above 3 oz/a plus Sencor were more effective than lower rates for kochia control. However, all Alion plus Sencor treat­ments were better than Sharpen-containing tank mixes 91 DAT.

Weed Control With Accent, Callisto, Isoxadifen, Impact, Cinch, Dicamba, And Atrazine In Irrigated Corn, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

Some timings and combinations of the herbicides tested in this study controlled Palmer amaranth, kochia, quinoa, Russian thistle, and green foxtail from 95 to 100% 51 days after postemergence application (DA-B). Accent (nicosulfuron) plus Callisto (mesotri­one) and isoxadifen alone postemergence provided 88% Palmer amaranth control at 51 DA-B. Kochia control was 92 and 90% when Accent plus Callisto and isoxadifen alone or with atrazine and Dicamba XP (dicamba) was applied postemergence following Cinch (S-metolachlor) preemergence application. Crabgrass control with preemergence followed by postemergence treatments exceeded 89%. Crabgrass control was 83 and 88% when no preemergence herbicide was applied …

Fallow Weed Control With Preemergence Applications Of Clarity, Atrazine, Spartan Guard, Sharpen, Zidua, And Corvus, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

Kochia control at 8 weeks after spring application (WAST) was greatest when Clar­ity (dicamba) was included in the spring applications or when Corvus (isoxaflutole + thiencarbazone) was applied with atrazine and Clarity in the fall. The best kochia con­trol at 13 WAST occurred with spring applications containing Clarity. Only Clarity plus Atrazine, Sharpen, Zidua, Spartan Guard, or Corvus applied in the spring provided as much as 90% kochia control at 20 WAST. Only the spring application of Spartan Guard and Clarity controlled Russian thistle 90% at 20 WAST.

Efficacy Of Preemergence Or Early Postemergence Weed Control With Keystone Nxt, Hornet Wdg, Atrazine, Surestart Ii, Lumax Ez, And Resicore, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

Control of buffalobur was complete regardless of herbicide used. Velvetleaf and punc­turevine control, although not perfect, was excellent by all herbicides. The premix of SureStart II (acetochlor + flumetsulam + clopyralid) with atrazine and Durango DMA (glyphosate) applied early postemergence and the preemergence herbicides Resicore (acetochlor + mesotrione + clopyralid) with atrazine and Lumax EZ (S-metolachlor + atrazine + mesotrione) provided excellent Palmer amaranth control. The early pos­temergence treatment of SureStart II plus atrazine and Durango DMA was the only treatment to provide excellent control of green foxtail.

Weed Control And Crop Injury With Single Or Sequential Herbicide Applications In Grain Sorghum, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

The preemergence application of Dual II Magnum (S-metolachlor) improved the over­all weed control compared to single postemergence treatments. Excessive rainfall after preemergence application compromised all treatments, producing abnormally low weed control.

Utilization Of Weed Ecology, Tank Mixtures, And Application Technology To Improve Efficacy Of Herbicide Applications In Soybean, Christopher John Meyer

Graduate Theses and Dissertations

New herbicide-resistant soybean traits will increase the number of herbicides that can be applied in soybean and change the technology currently used to make herbicide applications in soybean. Palmer amaranth (Amaranthus palmeri) remains one of the most difficult weeds to manage in soybean and thus is the primary focus of this research. Therefore, experiments were conducted to investigate Palmer amaranth temporal emergence, control of common Arkansas weeds with new soybean herbicide programs, and the effect of application technology on dicamba-containing tank mixtures. Palmer amaranth emergence exceeded 400 plants m-2 for tillage treatments in 2013 and 2014, and tillage events typically …

Use Of Fluridone For Control Of Palmer Amaranth (Amaranthus Palmeri) In Cotton (Gossypium Hirsutum) And On Ditchbanks, Zachary Thornton Hill

Graduate Theses and Dissertations

Since 2006, glyphosate-resistant Palmer amaranth has been considered the most problematic weed in agronomic crops across the Midsouth. As a result of glyphosate resistance, producers began to again utilize a diverse herbicide program for management of this weed, which consists of several soil-residual herbicides most notably diuron, fluometuron, fomesafen, and metolachlor. Fluridone inhibits phytoene desaturase in plants, and is unique in that its mechanism of action (MOA) is not currently registered for use in cotton. Studies were conducted to determine the length of residual that fluridone provides in controlling Palmer amaranth in Arkansas glyphosate- and glufosinate-resistant cotton programs and along …

Biology And Control Of Glyphosate-Resistant Giant Ragweed., Simranpreet Kaur

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Giant ragweed is a troublesome, early emerging, summer annual weed found throughout the eastern and midwestern corn and soybean growing regions of the United States. Since the emergence of giant ragweed varies at different locations, our first objective was to determine the emergence pattern of giant ragweed in Nebraska and how spring tillage influences emergence. Results of a two-year study suggested that giant ragweed emerged from late March until mid-June, with the majority of emergence ceasing by early May. Spring tillage could be used as an alternative method for managing glyphosate resistant giant ragweed.

Water stress can affect the growth …

Fallow Weed Control With Preemergence Tank Mixes Of Sharpen, Zidua, Sencor, Banvel, Atrazine, Balance Pro, And Corvus, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

With the exception of the tank mix of Sharpen and Sencor, all other tank mixes that provided 100% kochia control 53 days after treatment (DAT) were three-way tank mixes of atrazine herbicide plus, Banvel, and Balance Pro or Zidua. Only two tank mixes provided 98% kochia control 143 DAT. These were also three-way tank mixes of these chemistries. Combinations of Balance Pro and Sencor were needed to provide greater than 93% control of Russian thistle 143 DAT. No tank mix provided good control of Palmer amaranth 143 DAT. However, tank mixes of Sharpen, Sencor, and Zidua provided 84% control 143 …