Agricultural Science Commons^™

Evaluating Integrated Weed Management: Russian Knapweed Control With Goat Grazing And Aminopyralid, Clarke G. Alder

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Invasion of natural communities by introduced plants is considered one of the biggest threats to biodiversity. Weeds in rangelands cause an estimated loss of $2 billion per year in the United States. These costs include losses in forage quality and yield, grazing interference, animal poisoning, lowering land values, depleting soil water and resources available to native plants, increasing costs of managing livestock, and impacts on wildlife habitat and forage. Integrated weed management (IWM) is a way for land managers such as farmers, ranchers, and government agencies to control invasive weeds. IWM uses several different control methods working in conjunction to …

Agricultural Development In The Northern Savannah Of Ghana, Tara N. Wood

Doctor of Plant Health Program: Dissertations and Student Research

Since declaring independence in 1957, the Republic of Ghana has become a stable constitutional democracy. Ghana’s economy has grown substantially over the past decade, yet remains primarily agrarian, accounting for 50% of the total employment and 25% of the country’s Gross Domestic Product. Smallholder rain-fed farming using rudimentary technologies dominates the agricultural sector accounting for 80% of total agricultural production. Approximately 90% of smallholder farms are less than two hectares in size, and produce a diversity of crops. The major crops cultivated in Ghana include numerous cereal, root and tuber, leguminous, fruit, vegetable and industrial crops. Maize is the most …

Genetic Diversity Of Seed Dormancy And Molecular Evolution Of Weedy Red Rice, Te Ming Tseng

Graduate Theses and Dissertations

Rice is the grain with the third-highest global production. In the US, Arkansas is the largest rice producing state; however, an estimated 62% of the rice fields in the state are infested with red rice, and can cause up to 80% yield reduction in rice. Among its weedy traits, seed dormancy plays an important role in its persistence, and helps red rice escape weed management techniques thereby increasing the red rice soil seedbank. Red rice also has the potential to hybridize among themselves and with cultivated rice, thus resulting in diverse phenotypes and genotypes. In this study we measured variation …

Dark Green Color Index As A Method Of Real-Time In-Season Corn Nitrogen Measurement And Fertilization, Upton Siddons

Graduate Theses and Dissertations

Corn (Zea mays L.) requires higher rates of nitrogen fertilizer than any other major U.S. crop partly because N fertilizers are subject to loss through various mechanisms. Because of this, corn may suffer from inadequate nitrogen fertilization or producers may over-apply nitrogen to compensate for early-season nitrogen losses. A timely, accurate, and precise method for measuring in-season corn N status is needed to allow producers to keep nitrogen use efficiency high within a growing season.

Using appropriate software, hue, saturation, and brightness values of digital images can be combined in a dark green color index (DGCI) which is closely associated …

Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri) In Arkansas: Resistance Mechanisms And Management Strategies, Griff Michael Griffith

Graduate Theses and Dissertations

Since 2000, there have been thirteen weed species confirmed resistant (R) to glyphosate in the United States, six of those resistant species are present in Arkansas. The goal of this research was to confirm and to determine the level of resistance in two R Palmer amaranth biotypes from Mississippi (MC-R) and Lincoln (LC-R) Counties, Arkansas, and one susceptible (S) biotype from Clarendon County, South Carolina, which had never been exposed to glyphosate. Shikimic acid concentration over time was significantly greater in the S biotype than both the MC-R and LC-R biotypes. The lethal dose required to kill 50% (LD_{50 …}

Local Food And Agriculture Awareness: The Literacy Of Local Produce And Agriculture In Northwest Arkansas, Kyle Colton Flynn

Graduate Theses and Dissertations

The Center for Disease Control and Prevention (CDC) suggests that adolescents and children, both male and female, are failing to meet the daily fruit and vegetable consumption requirements (Kim et al., 2011; Upton et al., 2012; Harris et al., 2012). Other studies have shown that with increased exposure and availability of produce, students (K-5) tend to consume more fruits and vegetables (Cullen et al., 2009; Evans et al., 2012). The purpose of this study is to identify whether Northwest Arkansas eleventh grade high school students possess experience and knowledge of local produce and agriculture. Out of 1054 students enrolled at …

Squash Variety Trials Summer 2012, Rebecca Brown

University of Rhode Island Vegetable Production Research Reports

Variety trials of summer squashes and zucchini conducted in Kingston, RI, USA.

Response Of Nebraska Horseweed (Conyza Canadensis) Populations To Dicamba, Roberto Crespo, Mark L. Bernards, Greg Kruger, Donald Lee, Robert Wilson Jr.

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

Dicamba-resistant soybeans are being developed to provide an additional herbicide mechanism-of-action for postemergence weed control in soybean. Numerous broadleaf species, including horseweed, have evolved resistance to glyphosate. It is anticipated that dicamba will be used by farmers as a primary tool to manage these weeds. Studying and understanding variability in horseweed response to dicamba will aid in developing appropriate risk management strategies to extend the utility of the dicamba-resistance technology. Horseweed plants from ten Nebraska populations were treated with one of nine doses of dicamba in greenhouse experiments. At 28 days after treatment (DAT) visual injury estimations were made and …

Squash Variety Trials Summer 2012, Rebecca Brown

University of Rhode Island Vegetable Production Research Reports

Variety trials of summer squashes conducted in Kingston, RI, USA.

Differences In Essential Oil Content Of Berries And Leaves Of Solanum Sarrachoides (Solanaceae) And The Effects On Oviposition Of The Tomato Spider Mite (Tetranychus Evansi), Lucy K. Murungi, Hillary Kirwa, Baldwyn Torto

All Peer-Reviewed Publications

Essential oils from leaves and berries of Solanum sarrachoides were obtained by hydro-distillation, analyzed by GC-MS and tested for oviposition deterrence against Tetranychus evansi. Plant oils comprised mainly of monoterpenes and fatty acids, but differed in terms of their relative abundance. The leaf oil contained mainly camphor (34.1%), limonene (8%), decanoic acid (9.3%) and hexadecanoic acid (7.3%). The berry oil contained mainly fatty acids (>20%) including hexadecanoic acid (9.8%) and dodecanoic acid (5.9%), hydrocarbons (>10%) and (E)-β-linalool (3.1%). In oviposition deterrence assays, the leaf essential oil and individual major monoterpenes compared favorably with the two positive controls, neem …

Leek Variety Trials, 2012, Rebecca Brown, Noah Leclaire-Conway

University of Rhode Island Vegetable Production Research Reports

Variety trial of leek varieties conducted at Kingston, RI, in 2012.

Melon Variety Trials, 2012, Rebecca Brown

University of Rhode Island Vegetable Production Research Reports

Melon variety trial conducted at Kingston, RI, in summer of 2012.

Onion Variety Trials, 2012, Rebecca Brown, Noah Leclaire-Conway

University of Rhode Island Vegetable Production Research Reports

No abstract provided.

Cucumber Variety Trials 2012, Rebecca Brown

University of Rhode Island Vegetable Production Research Reports

Slicing and pickling cucumber variety trials conducted at Kingston, RI, during the summer of 2012.

Brassica Variety Trials 2012, Rebecca Brown

University of Rhode Island Vegetable Production Research Reports

Variety trials of broccoli, cauliflower and Brussels sprouts conducted in Kingston, RI, USA.

Proceedings Of The 40th Annual Meeting, Southern Soybean Disease Workers (March 13-14, 2013, Pensacola Beach, Florida), Clayton A. Hollier, Tom Allen, Edward J. Sikora, Myra Purvis, Danise Beadle, Stephen R. Koenning

Southern Soybean Disease Workers: Conference Proceedings

Contents

Southern United States Soybean Disease Loss Estimates for 2012. Compiled by SR Koenning

Update on Detection and Management of QoI Fungicide Resistant Cercospora sojina, the Causal Agent of Frogeye Leaf Spot in Soybean. C Bradley, G Zhang, V Chapara, R Ming, F Zeng, H Young Kelly, and M Newman

Identification of Soybean Genotypes to Cercopsora sojina by Field Screening and Molecular Markers. A Mengistu and R Mian

Soybean Vein Necrosis Virus. D Hershman

Single Applications of Triazole Fungicides at R1 for Management of Cercospora Leaf Blight and Rust in Soybean. RW Schneider, CL Robertson, BM Ward, and EC …

Arkansas Cotton Variety Test 2012, Fred M. Bourland, A. B. Beach, D. P. Roberts Jr., C. Kennedy

Arkansas Agricultural Experiment Station Research Series

The primary goal of the Arkansas Cotton Variety Test is to provide unbiased data regarding the agronomic performance of cotton varieties and advanced breeding lines in the major cotton-growing areas of Arkansas. This information helps seed companies establish marketing strategies and assists producers in choosing varieties to plant.

Wayne E. Sabbe Arkansas Soil Fertility Studies 2012, Nathan A. Slaton

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that the research efforts be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies described within will allow producers to compare their practices with theuniversity's research efforts. Additionally, soil-test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.

Two Sugar Isomers Influence Host Plant Acceptance By A Cereal Caterpillar Pest, G. Juma, M. Thiongo, L. Dutaur, K. Rharrabe, F. Marion-Poll, B. Le Ru, G. Magoma, J. F. Silvain, P. A. Calatayud

All Peer-Reviewed Publications

Abstract Plant sugars are often considered as primary feeding stimuli, conditioning host plant acceptance by herbivorous insects. Of the nine sugars identified from methanolic extracts of seven grass species, only turanose, a sucrose isomer, was negatively correlated with the survival and growth of the noctuid larva of cereal stemborer, Busseola fusca. Sucrose was the most abundant sugar, although it did not vary significantly in concentration among the plant species studied. Using Styrofoam™ cylinders impregnated with increasing concentrations of turanose or sucrose, the two sugars had opposing effects: turanose appeared phagodeterrent while sucrose was phagostimulatory. Electrophysiological studies indicated that B. fusca …

Effects Of Mulching, N-Fertilization And Intercropping With Desmodium Uncinatum On Striga Hermonthica Infestation In Maize, Charles A.O. Midega, Jimmy Pittchar, Daisy Salifu, John A. Pickett, Zeyaur R. Khan

All Peer-Reviewed Publications

The parasitic weed Striga hermonthica is a major constraint to maize production in sub-Saharan Africa and causes serious food insecurity. We discovered serendipitously an effective control method for the weed that involves intercropping cereals with the fodder legume, silverleaf desmodium, Desmodium uncinatum (Jacq.) DC., through mechanisms that involve soil shading and nitrogen fixation. In the current study we investigated long-term effects of inorganic nitrogen (N), mulching and D. uncinatum, singly and in combinations, on S. hermonthica infestation, maize plant growth and grain yields. Treatments comprised sole maize with and without 120 kg N/ha; sole maize plots covered with maize straw …