Agronomy and Crop Sciences Commons^™

Characterization Of Ground Nozzles For Pesticide Applications, Ryan Henry

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

Pesticide applications are a common component of crop production systems in the United States (US). For row crop systems (e.g. corn, soybean, or wheat), pesticides are applied by ground, aerial, or chemigation methods. The exact method of pesticide delivery is not universally regulated/ prescribed in the US, and the equipment and application technique are largely defined by the individual applicator. A wide variety of choices and decisions must be made by applicators to result in a successful pesticide application. Examples of these choices include proper active ingredient(s), carrier volume and equipment (e.g. nozzle type, spacing, and operating pressure) selection while …

Over-Summering Ecology Of The Wheat Curl Mite (Aceria Tosichella Keifer), Anthony J. Mcmechan

Department of Entomology: Dissertations, Theses, and Student Research

The wheat-mite-virus complex is a consistent and significant threat to winter wheat production in the western Great Plains. This complex consists of three viruses (Wheat streak mosaic virus, Triticum mosaic virus, and Wheat mosaic virus that are transmitted by the wheat curl mite (Aceria tosichella Keifer). Yield impacts from this complex are typically associated with the presence of volunteer wheat that emerges prior to harvest as a result of hail occurring during the heading stages of wheat in early summer. Historical literature on pre-harvest germination has been primarily focused on accelerating breeding programs; however, critical gaps in knowledge exist on …

Characterization Of Echinochloa Spp. In Arkansas, Hussain Tahir

Graduate Theses and Dissertations

Echinochloa species are the most problematic grass weeds in rice and soybean production throughout the southern United States. The species under this genus has high intra- and interspecific variability, with many ecotypes, observed within a species. This study was conducted to: i) characterize the morphology and phenology of Echinochloa accessions from Arkansas in a common garden; ii) verify the species identity of these accessions based on their morphological traits, and iii) evaluate the dormancy characteristics of Echinochloa accessions. Junglerice (E. colona) was identified as the most common species, comprising about 78% of the accessions collected, with barnyardgrass (E. crus-galli) and …

Cover Crop Mixture Diversity And Function, Angela Florence

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

The objective of this study was to evaluate the effect of cover crop mixture diversity on cover crop function. Specifically, this study evaluated the effect of cover crop species and functional richness on aboveground biomass productivity, weed suppression, soil nutrient retention, soil microbial community characteristics, and performance stability. Twenty to forty cover crop treatments were replicated three to four times at eleven sites across southeastern Nebraska using a pool of eighteen species representing three cover crop species each from six pre-defined functional groups: cool-season grasses, cool-season legumes, cool-season brassicas, warm-season grasses, warm-season legumes, and warm-season broadleaves. Each species was planted …

Biology, Gene Flow, And Management Of Glyphosate-Resistant Common Waterhemp (Amaranthus Rudis Sauer) In Nebraska, Debalin Sarangi

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

Common waterhemp is the most troublesome weed in the midwestern United States. Growers from Nebraska reported failure to control common waterhemp following sequential applications of glyphosate in glyphosate-tolerant corn and soybean, which led to moderate to severe yield loss; justifying the need to confirm resistance and study the biology and management of common waterhemp. The objectives of this research were: 1) to confirm the presence of glyphosate-resistant (GR) common waterhemp biotypes in Nebraska and to evaluate their sensitivity to herbicides belonging to alternative sites-of-action; 2) to evaluate the response of common waterhemp to water stress; 3) to quantify pollen-mediated gene …

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.

Plant Functional Trait And Hyperspectral Reflectance Responses To Comp B Exposure: Efficacy Of Plants As Landmine Detectors, Paul V. Manley Ii

Theses and Dissertations

At least 110 million landmines have been planted since the 1970s in about 70 nations, many of which remain in place today. Some risk of detection may be mitigated using currently available remote sensing techniques when vegetation is present. My study focused on using plants as phytosensors to detect buried explosives. I exposed three species representing different functional types (Cyperus esculentus (sedge), Ulmus alata (tree), Vitis labrusca (vine)) to 500 mg kg^-1 of Composition B (Comp B; 60/40 mixture of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and 2,4,6-trinitrotoluene (TNT)), a commonly used explosive mixture, and measured functional traits and reflectance over …

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.

Effects Of Growing-Season Prescribed Burning On Vigor Of The Noxious Weed Sericea Lespedeza (Lespedeza Cuneata) In The Kansas Flint Hills, J. A. Alexander, W. H. Fick, J. Lemmon, C. A. Gurule, G. W. Preedy, K C. Olson

Kansas Agricultural Experiment Station Research Reports

Sericea lespedeza (SL) was introduced into the United States from Asia in the late 19th century. Early land managers recognized that SL was adaptable; tolerant of shallow, acidic or low-fertility soils; and resistant to insects and disease. This combination of traits made SL a widely-used plant for reseeding strip-mined lands, highway right-ofways, dams, and waterways in the US for nearly a century.

Regrettably, SL is highly fecund. Individual plants are capable of producing up to 850 lb of seed per acre annually. Vigorous seed production allows SL to rapidly infiltrate native grasslands that are adjacent to reseeding projects; seed can …

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.

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.

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 …

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 …

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.

Efficacy Of Preemergence And Sequential Applications With Corvus, Atrazine, Starane, Balance, Anthem, Capreno, Diflexx And Halex Gt In Irrigated Corn, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

Control of kochia and quinoa was 98 to 100% regardless of herbicide treatment at 48 days after post applications (DAPT), and 95% or more with all herbicides for Russian thistle. Palmer amaranth control was slightly less with preemergent (PRE) treatments alone compared to sequential treatments. Corvus (isoxaflutole + thiencarbazone) plus atrazine, Starane Ultra (fluroxypyr), and nonionic surfactant preemergence controlled crabgrass by 88%; whereas all other treatments provided 91% or more crabgrass control. Corn with the best herbicide treatments yielded 33 to 66 bu/a more than untreated corn.

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.

Preemergence Weed Control With Fultime Nxt And Competitive Standards In Grain Sorghum, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

At 71 days after treatment, FulTime NXT (acetochlor + atrazine) at 2.5 or 3.0 qt/a and Lumax EZ (S-metolachlor + atrazine + mesotrione) at 2.0 qt/a were the only treatments to control Palmer amaranth at 90% or more. All treatments provided similar velvetleaf control. Green foxtail control was 75 to 83% with all rates of FulTime NXT or Lumax EZ. Sorghum receiving FulTime NXT at 2.5 or 3.0 qt/a or Lumax EZ yielded significantly more than the control treatments.

Fallow Weed Control With Postemergence Applications Of Agh15004, Ag14039, Roundup Powermax, And Atrazine, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

All treatments except AGH15004 at 1.5 pt/a plus Roundup PowerMax (glyphosate) and nonionic surfactant provided more than 95% kochia control at 14 days after treatment (DAT). By 28 DAT, only those treatments containing atrazine provided greater than 95% kochia control. However, kochia control at 42 DAT was greater than 90% with all treatments except Roundup PowerMax plus nonionic surfactant.