Agronomy and Crop Sciences Commons^™

Influence Of Transplanter Modification And Previous Crop On The Production Of No-Till Dark Tobacco, William Frazier Penick

Masters Theses & Specialist Projects

Dark tobacco (Nicotiana tabacum L.) has historically been produced using
conventional tillage practices. Soil is cultivated multiple times throughout a growing season leading to an increased incidence of soil erosion. No-till systems have been growing in popularity with the advent of new technology that has enabled the practice to be performed effectively and efficiently. With the recent expansion of no-till practices throughout the agricultural community, many crops have had success in producing comparable yields while reducing input costs and saving soil resources. For this experiment, a traditional tobacco transplanter was modified for use in a no-till environment. All modifications were ...

Application Carrier Volume: A Comprehensive Evaluation Of An Ultra-Low Volume Sprayer Compared To A Conventional Sprayer For Row-Crop And Turfgrass Production Systems, Jason Connor Ferguson

Theses, Dissertations, and Student Research in Agronomy and Horticulture

An Ultra-Low Volume (ULV) sprayer was developed to decrease carrier volume required for pesticide applications in row and turfgrass cropping systems. The ULV sprayer can make spray applications at or below 19 L ha^-1, which is far lower than a conventional sprayer in row crop or turfgrass production systems. Field studies were conducted at the University of Nebraska West Central Research and Extension Center Dryland Farm near North Platte, NE and the John Seaton Anderson Turfgrass Research Facility near Mead, NE to compare the ULV sprayer to a conventional sprayer. Studies were conducted to compare the two sprayers with ...

Evaluating The Sustainability Of Four Organic Vegetable Production Systems, Delia W. Scott

Theses and Dissertations--Plant and Soil Sciences

A field study evaluating the sustainability of four organic vegetable production systems was conducted in Lexington, Kentucky in 2006 and 2007. The four systems included no-till, raised beds covered with biodegradable black mulch, bare ground with shallow cultivation, and bare ground with shallow cultivation and wood chip mulch. The two-year study compared yield, weed control, labor, and costs associated with each system, as well as physical, chemical, and microbiological soil characteristics. In 2006, tomatoes (Lycopersicon esculentum Mill.) were grown in the four systems, with no significant difference in yield. Summer squash (Cucurbita pepo L.) was grown in the four systems ...

Twin And Narrow Row Width Effects On Corn (Zea Mays L.) Yield And Weed Management, Grant Mackey

Theses and Dissertations--Plant and Soil Sciences

Corn or maize (Zea mays L.) has been grown in North America for many centuries, and an increase in corn production will continue to be needed. Agriculture producers must meet the demands of feeding and providing for an increasing population of people. In order to meet those needs, different production practices are being investigated as a way to increase grain yield.

Field plots were conducted across the state of Kentucky in 2011 and 2012 to evaluate the interaction between hybrid, row width, and plant density on corn yield. The primary objectives were to test if 1) narrower rows increase grain ...

Hybrid, Row Width, And Plant Population Effect On Corn Yield In Kentucky, Chelsea Clay Mcfarland

Theses and Dissertations--Plant and Soil Sciences

Studies were conducted in 2011 and 2012 to determine if narrow row corn (Zea mays L.) and/or greater plant populations could affect yield, time to silking, and other physiological characteristics. Main plots of six hybrids were arranged as a randomized complete bock design with three replications. Split plots were row widths of 76-cm (wide rows) and 20-cm rows on 76-cm spacing (twin rows). Split-split plots were target plant populations of 75 000 and 111 000 plants ha^-1. Corn was no-till seeded into soybean stubble near Lexington, KY in 2011 and 2012. Year interacted with most factors analyzed in ...

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

Theses, Dissertations, and Student Research in Agronomy and Horticulture

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 ...

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

Doctoral Documents from Doctor of Plant Health Program

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 ...

Anaerobic Soil Disinfestation: Evaluation Of Anaerobic Soil Disinfestation (Asd) For Warm-Season Vegetable Production In Tennessee, David Grant Mccarty

Masters Theses

Anaerobic soil disinfestation (ASD) is a non-chemical, pre-plant soil treatment recently developed for control of pests such as soilborne plant pathogens, plant-parasitic nematodes, and weeds in specialty crop systems. Soil treatment by ASD includes incorporating a labile carbon (C) source, tarping with plastic, and irrigation of the topsoil to saturation to facilitate the development of strongly anaerobic soil conditions driven by soil microbes. Processes occurring during the anaerobic decomposition of the added C source have been reported control plant pests. The goal of this project was to evaluate and adapt the ASD procedure to environmental conditions and production systems in ...

Detection Of Soybean Amino Acid Qtls And Seed Yield Qtls Using Selective Genotyping, Benjamin David Fallen

Doctoral Dissertations

The U.S. Census Bureau projects the world’s population will top more than nine billion by 2050. Today, soybeans account for 56 % of the world oilseed production and 68 % of the world protein meal consumption, with U.S. soybean production accounting for 33 % of the world soybean production. So, to meet the demand of the world’s growing population and of the livestock industry improvements in both the composition and the yield of soybean is essential.

The primary objective of this project was to use molecular markers to identify genomic regions associated with amino acid composition and yield in ...

Nitrate Reduction Coupled To Iron(Ii) And Manganese(Ii) Oxidation In An Agricultural Soil, Stephanie Pyzola

Theses and Dissertations--Plant and Soil Sciences

New evidence shows iron(II) oxidation is strongly coupled to nitrate reduction under anaerobic conditions in freshwater sediments and agricultural soils. However, the contribution of iron(II) oxidation to nitrate reduction is unknown. Furthermore, oxidation of manganese(II) by nitrate has been largely overlooked. This study investigated nitrate-dependent iron(II) and manganese(II) oxidation in an agricultural soil (Sadler silt loam) using stirred-batch kinetic techniques with native soil organic carbon (SOC) as the electron donor and included addition of amendments (hydrogen gas and wheat residue). In the presence of native SOC, nitrate-dependent Fe(II) and Mn(II) oxidation occurred at ...

Impact Of Water And Nitrogen Management On Maize Actual Evapotranspiration, Soil Water Extraction And Crop Water Productivity In South Central Nebraska, Usa, Daran Rudnick

Biological Systems Engineering--Dissertations, Theses, and Student Research

Maize actual evapotranspiration (ETa), soil water extraction and crop water productivity was assessed for five nitrogen (N) levels 0, 84, 140, 196 and 252 kg ha^-1 under fully-irrigated (FIT), limited irrigation (75% FIT) and rainfed conditions. Field experiments were conducted at the University of Nebraska-Lincoln South Central Agricultural Laboratory near Clay Center, Nebraska, USA, in 2011 and 2012. The study site was irrigated using a GPS-guided seven-span variable rate linear-move irrigation system (Valmont Industries, Valley, NE).

Seasonal cumulative ETa ranged from 426 (rainfed-196 kg ha^-1) to 550 mm (FIT-196 kg ha^-1) in 2011 and from 401 (rainfed-0 ...

Every Other Row Furrow Irrigation Trial, Jason Mast

Agricultural Education and Communication

Abstract

Silage corn yields are limited by irrigation effectiveness in the Central Valley of California. This experiment was conducted to determine if silage yield would suffer after altering irrigation methods and timing. The effects of irrigation method and timing were tested on field corn [Zea mays (DKC 67-86)]. The study was carried out in Denair, California on a Whitney Rocklin sandy loam. Silage tonnage, grain yield, and plant height were compared across four treatments with three repetitions of each treatment. The treatments were every other row, the grower’s standard practice, deficit, and a control. The experiment showed that every ...

Sediment Removal By Prairie Filter Strips In Row-Cropped Ephemeral Watersheds, Matthew J. Helmers, Xiaobo Zhou, Heidi Asbjornsen, Randy Kolka, Mark D. Tomer, Richard M. Cruse

Agricultural and Biosystems Engineering Publications and Papers

Twelve small watersheds in central Iowa were used to evaluate the effectiveness of prairie filter strips (PFS) in trapping sediment from agricultural runoff. Four treatments with PFS of different size and location (100% rowcrop, 10% PFS of total watershed area at footslope, 10% PFS at footslope and in contour strips, 20% PFS at footslope and in contour strips) arranged in a balanced incomplete block design were seeded in July 2007. All watersheds were in bromegrass ( L.) for at least 10 yr before treatment establishment. Cropped areas were managed under a no-till, 2-yr corn ( L.)-soybean [ (L.) Merr.] rotation beginning in ...

Cucumber Variety Trials 2012, Rebecca Brown

Rhode Island Agricultural Experiment Station Bulletin

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

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

Rhode Island Agricultural Experiment Station Bulletin

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

Melon Variety Trials, 2012, Rebecca Brown

Rhode Island Agricultural Experiment Station Bulletin

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

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

Rhode Island Agricultural Experiment Station Bulletin

No abstract provided.

Brassica Variety Trials 2012, Rebecca Brown

Rhode Island Agricultural Experiment Station Bulletin

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

Variation In Seed Dormancy In Echinochloa And The Development Of A Standard Protocol For Germination Testing. Ii: Breaking Dormancy In Seeds Unresponsive To Light Or Dark Conditions Alone By Using Heat And Ethanol Pretreatment, David A. Kovach, Mark P. Widrlechner, David M. Brenner

NCRPIS Publications and Papers

A recently established method for the germination of Echinochloa seeds recognised and accounted for variation in responses to light and darkness. This method used parallel light and dark tests and was successful in promoting germination in most seed lots. However, some samples exhibited deeper dormancy and were not fully responsive to either test. In the present study, we employed warm pretreatments where seeds were exposed to dilute aqueous ethanol solutions to attempt to break their dormancy. Based on tests of five Echinochloa accessions, we propose a new, follow-up protocol that can be used on samples unresponsive to the established method ...

Ecology And Invasive Properties Of Musk Thistle (Carduus Nutans) In The Central Prairies Of Nebraska, Chengchou Han

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Musk thistle (Carduus nutans) is an herbaceous monocarpic herb introduced to the U. S. from Eurasia. The invasion of musk thistle can reduce forage area, soil stability, and reduce recreation and open areas for humans and wildlife.

Resistance of warm season and cool season perennial grass communities to musk thistle invasion is important for land managers to consider, especially where disturbance has made an area particularly susceptible. Our results show that disturbances, such as overgrazing can open up niches in canopies of warm season grass communities and facilitate invasion but not in cool season grass communities. The mechanism of invasion ...