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Full-Text Articles in Life Sciences
The Biological Control Of Spotted Knapweed In The Southeastern United States, Carey R. Minteer
The Biological Control Of Spotted Knapweed In The Southeastern United States, Carey R. Minteer
Graduate Theses and Dissertations
Spotted knapweed is an invasive, short-term-perennial plant that is native to Eurasia. It was accidentally introduced into North America in the early 1890's and has since spread across The United States and Canada. Spotted knapweed degrades rangelands and pastures by negatively impacting native plants, increasing soil surface runoff and stream sediment yields, and reducing soil infiltration. A biological control program for spotted knapweed using Larinus minutus (Coleoptera: Curculionidae), was initiated in Arkansas in 2008. In this dissertation I described the releases of L. minutus and investigated the adult activity in the southeastern United States (Chapter 1), investigated the effects of …
Alternative Herbicide Control Options For Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri), George Macmillan Botha
Alternative Herbicide Control Options For Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri), George Macmillan Botha
Graduate Theses and Dissertations
The occurrence of glyphosate-resistant (GR) Palmer amaranth has prompted a shift in weed management strategies worldwide. Studies were conducted with the aim to (1) establish and compare the degree of tolerance of GR Palmer amaranth populations; (2) assess the efficacy of glufosinate, tembotrione, 2,4-D or dicamba, applied alone or tank-mixed, on Palmer amaranth with higher tolerance to glufosinate in the greenhouse and corn field, and (3) establish the mechanism involved in the tolerance of Palmer amaranth to glufosinate. Tembotrione, 2,4-D, dicamba, and glufosinate applied at 1x controlled 80 to 100%, 98 to 100%, 84 to 100%, and 94 to 100% …
Soybean Maturity Group Tradeoffs: Irrigation, Weed Control, And Nitrogen Fixation, Ryan Wegerer
Soybean Maturity Group Tradeoffs: Irrigation, Weed Control, And Nitrogen Fixation, Ryan Wegerer
Graduate Theses and Dissertations
This thesis is divided into four chapters. Chapter I introduces the rationale behind the study and gives a brief overview of the overall study covering weed control, irrigation needs and nitrogen fixation amounts across soybean maturity group. Chapter II will go into further detail outlining the first applied experiment dealing with weed control and irrigation issues. Alternative weed control methods are analyzed in conjunction with irrigation risk analysis across soybean maturity group in response to agricultural issues of glyphosate resistance and declining ground water supply in the Arkansas delta region. Chapter III will jointly examine irrigation application amounts and nitrogen …
Evaluation Of Isothiocyanates And Herbicide Programs As Methyl Bromide Alternatives For Weed Control In Polyethylene-Mulched Tomato And Bell Pepper, Pratap Devkota
Graduate Theses and Dissertations
Methyl bromide (MeBr), a Class I ozone –depleting substance, has been banned for ordinary agricultural uses. In the absence of an effective MeBr alternative, weed control is a major challenge for commercial tomato and bell pepper production. Field trials were conducted at Fayetteville, AR, to compare allyl isothiocyanate (ITC), metam sodium, and herbicide programs with the standard MeBr application (mixture of MeBr plus chloropicrin at 67% plus 33%, respectively, hereafter referred to as MeBr) for crop injury, weed control, viable yellow nutsedge tubers, and marketable yield in low–density polyethylene (LDPE) mulched tomato and bell pepper production. In addition, herbicide programs …
Herbicide Resistance Mechanism(S) In Italian Ryegrass (Lolium Perenne Ssp. Multiflorum) Populations In The Southern United States, Reiofeli Algodon Salas
Herbicide Resistance Mechanism(S) In Italian Ryegrass (Lolium Perenne Ssp. Multiflorum) Populations In The Southern United States, Reiofeli Algodon Salas
Graduate Theses and Dissertations
Italian ryegrass is a principal weed problem in wheat production fields in the Southern US. Resistance to herbicides diclofop, mesosulfuron, and pinoxaden among ryegrass populations has been reported. Glyphosate-resistant Italian ryegrass populations were identified in Desha County, Arkansas. This research aimed to 1) determine resistance patterns to ACCase (diclofop and pinoxaden) and ALS (imazamox, mesosulfuron, and pyroxsulam) herbicides among Italian ryegrass populations from the southern US; 2) determine if cytochrome P450-mediated enhanced herbicide metabolism contributed to resistance; and 3) elucidate the resistance mechanism to glyphosate in four Arkansas populations (Des03, Des05, Des14, and D8). For objective 1, 30 accessions from …
Distribution And Control Of Herbicide-Resistant Italian Ryegrass (Lolium Perenne L. Ssp. Multiflorum Lam. Husnot) In Arkansas, James Walker Dickson
Distribution And Control Of Herbicide-Resistant Italian Ryegrass (Lolium Perenne L. Ssp. Multiflorum Lam. Husnot) In Arkansas, James Walker Dickson
Graduate Theses and Dissertations
Italian ryegrass populations have evolved resistance to herbicides that producers rely on for weed control both in wheat and burn-down. The objectives of this research were to: test populations of Italian ryegrass from across Arkansas for resistance to glyphosate, diclofop, pinoxaden, and pyroxsulam; determine if there were any differences in control of 12 glyphosate-resistant populations in relation to glyphosate rate or application timing; determine the level of glyphosate resistance in one selected population versus a susceptible standard and a previously discovered glyphosate-resistant population; and determine the best options for controlling Italian ryegrass prior to planting crops. A total of 215 …