Agronomy and Crop Sciences Commons^™

How Does Agroforestry Help Crop Pollination?

Working Trees (USDA-NAC)

Agroforestry helps crop pollination via enhanced pollination efficiency, pollinator habitat, and pollinator protection.

Crop Selection, Cost Analysis, And Irrigation System Design For The Replanting Of A Nut Orchard, Maximilian Bricker

BioResource and Agricultural Engineering

This report was made to help the landowner of Bricker Farms make decisions regarding the replanting of his orchard. The decisions that need to be made in this process include: which crop to plant, how to plant it, and how to improve the distribution uniformity of irrigation water on the orchard. The report does not give definitive final decisions, but presents viable options that the landowner can utilize when deciding. In addition to the options that are presented, the report offers suggestions to the landowner so that the replanting process is done properly in a timely and economically-friendly manner.

Genetic Engineering And Sustainable Crop Disease Management: Opportunities For Case-By-Case Decision-Making, Paul Vincelli

Plant Pathology Faculty Publications

Genetic engineering (GE) offers an expanding array of strategies for enhancing disease resistance of crop plants in sustainable ways, including the potential for reduced pesticide usage. Certain GE applications involve transgenesis, in some cases creating a metabolic pathway novel to the GE crop. In other cases, only cisgenessis is employed. In yet other cases, engineered genetic changes can be so minimal as to be indistinguishable from natural mutations. Thus, GE crops vary substantially and should be evaluated for risks, benefits, and social considerations on a case-by-case basis. Deployment of GE traits should be with an eye towards long-term sustainability; several …

Compost Land Management And Soil Carbon Sequestration, Kylene A. Hohman

Senior Honors Projects, 2010-2019

Extensive fossil fuel burning has released carbon dioxide into the atmosphere. Under proper ecological conditions plants convert atmospheric carbon dioxide into stable soil organic matter, a natural and efficient means of mitigating climate change. In the symbiotic relationship between mycorrhizae and plants, mycorrhizae provide plants with essential nutrients in exchange for carbon sugars leaked from the plants. Mycorrhizae convert carbon sugars to an exudate called glomalin, a protein that assists in developing soil aggregates composed of sand, silt, and clay. These aggregates, called humus, store carbon for hundreds of years under healthy ecological conditions. Compost prompts soil microbes to aerobically …

A Brief History Of Corn: Looking Back To Move Forward, Jon Derek Pruitt

Doctor of Plant Health Program: Dissertations and Student Research

Maize was domesticated from teosinte in Mexico some 7,000 to 10,000 years ago and quickly spread through the Americas. It has become one of the most important crops at a local and global level. Two types, Northern Flint corn and Southern Dent corns provided the basis of the genetic background of modern maize hybrids. The development of hybrids, first double-cross and later single-cross hybrids, along with a transition to high input farming provided huge yield increases, which have continued to improve with improving technology.

Increase in maize production also caused a rise in Western corn Rootworm (Diabrotica virgifera virgifera …

Arkansas Soybean Research Studies 2014, Jeremy Ross

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

Assessment Of An Industrial Type Radiant Heating System For Drying Rough Rice, Anne Adhiambo Okeyo

Graduate Theses and Dissertations

Rough rice is normally harvested at moisture contents (MCs) higher than that for safe storage. The objective for this study was to investigate the effectiveness of scaled-up infrared (IR) heating followed by tempering steps to dry freshly-harvested rough rice. An industrial type, pilot scale, IR drying equipment, designed to convey rough rice on a vibrating conveyor belt was used in this study. The heating zone of the equipment had catalytic IR emitters powered by natural gas. Freshly-harvested rough rice of long-grain pureline (cv. Cheniere), long-grain hybrid (cv. 6XP 756) and medium-grain (cv. CL 271) cultivars at initial moisture contents (IMCs) …

Heat Stress Effects On Cotton During Reproductive Development And Subsequent Acclimation Responses, Toby Ryan Fitzsimons

Graduate Theses and Dissertations

High temperature stress is among the most difficult to control abiotic factors affecting crop yields in the Southern United States due to its wide regional influence. Cotton (Gossypium hirsutum L.) though a tropical plant in origin, it is sensitive to the effects of high temperature. This is of particular concern when the warmest temperatures coincide with the most sensitive developmental stage of flowering. Thus, the capacity to improve cotton’s ability to tolerate heat stress has been a significant focus for many decades. Therefore, this research was composed of several different components all designed to investigate heat stress effects. Using a …

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 …

Effect Of Potassium Deficiency On Uptake And Partitioning In The Cotton (Gossypium Hirsutum L.) Plant And Detection By A Crop Reflectance Sensor, Taylor Dayne Coomer

Graduate Theses and Dissertations

For cotton (Gossypium hirsutum L.) to grow and develop normally, plants need to uptake the necessary amount of nutrients and use those nutrients in a beneficial fashion. It is recognized that cotton needs a certain tissue concentration of ions to achieve and maintain growth rates (Siddiqi et al., 1987). One of the most essential and abundant nutrients in cotton is potassium (K), second only by mass to nitrogen (N) (Marschner, 1995; Oosterhuis et al., 2013). Potassium exists in the soil in four separate pools and moves through soil to roots mainly through diffusion (Rengel & Damon, 2008; Samal et al., …

Gene Expression And Physiological Analysis To Study Differences Between Oryza Sativa Cultivars Susceptible And Resistant To Chalky Grain Formation Subjected To High Nighttime Temperatures., Nicholas Lawson

Graduate Theses and Dissertations

Starch composition and grain quality of rice is greatly influenced by genotype and environmental factors. The detrimental effects of high nighttime temperatures on rice yield and quality has recently become apparent, with some of the warmest average nighttime temperatures being recorded in the past few years. One of the most notable effects of this stress, an increase in grain chalk formation, correlates with a decrease in quality. This effect varies greatly between cultivars as some show less temperature-sensitive quality reduction than others. The goal of this research is to elucidate fundamental changes that occur in developing plants and grains as …

Grazing Method Effects On Forage Production, Utilization, Animal Performance And Animal Activity On Nebraska Sandhills Meadow, Torie Lindsey

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

A study was conducted on a subirrigated meadow in the Nebraska Sandhills to determine differences in aboveground plant production, utilization, trampling, harvest efficiency, ground cover, plant functional group composition and animal performance among four grazing treatments. Grazing treatments included ultrahigh stocking density, four-pasture rotation with one occupation (4-PR-1), and four-pasture rotation with two occupations (4-PR-2). Pastures were grazed from May to August in 2014 and 2015 at equal stocking rates within years but varied among years. Stocking densities were 225,000 kg ha^-1 for ultrahigh stocking density, 7,000 kg ha^-1 for 4-PR-1, and 5,000 kg ha^-1 for 4-PR-2. …

Influence Of Fatty Acids And Their Derivatives On Aphid Resistance In Arabidopsis And Tomato, Jiamei Li

Graduate Theses and Dissertations

Fatty acid desaturases (FADs) are enzymes that act in the chloroplast or the endoplasmic reticulum (ER) to incorporate double bonds into the acyl chains of fatty acids, and recent evidence indicates that at least one of these enzymes, FAD7, also influences plant resistance to aphids. FAD7 is an enzyme in the chloroplast that is found throughout the plant kingdom and that desaturates 16- and 18-carbon fatty acids (FAs) with two double bonds (dienoic acids) to generate FAs with three double bonds (trienoic acids). In tomato (Solanum lycopersicum) and the model plant Arabidopsis thaliana, mutants with impaired FAD7 function are more …

Effects Of Delayed Drying And Storage Conditions On Milling, Color, And Viscosity Properties Of Rice, Kathryn Nicole Haydon

Graduate Theses and Dissertations

Head rice yields (HRYs), kernel discoloration, and functional properties are three hallmarks of rice quality, and can be impacted after harvest by storage conditions. This study evaluated impacts on rice quality due to controlled storage at moisture contents (MCs), temperatures, and storage durations that may be incurred during Mid-South rice farming practices. Three hybrid, long-grain cultivars, harvested in Arkansas in 2014 and 2015, were stored in rough rice form at 4 MCs (12.5%, 16%, 19%, and 21%), and 5 temperatures (10°C, 15°C, 20°C, 27°C, and 40°C), for 16 weeks, with samples taken every 2 weeks. After drying and milling, HRYs, …

Consumer Willingness To Pay For Genetically Engineered Edamame, Elijah John Wolfe

Graduate Theses and Dissertations

This study examined the effect of GM labeling on consumer willingness to pay (WTP) for edamame. It also investigated how people reacted to different messages and whether the order of receiving positive or negative information about GM technology impacted their willingness to pay (WTP). The study had three components: (1) a sensory test of GM and non-GM labeled products; (2) a non-hypothetical experimental auction to assess WTP for GM, non-GM and unlabeled products; and (3) a questionnaire to collect demographics and other information from the participants. Results of the sensory evaluation revealed no statistically significant difference between GM and non-GM …

Geospatial Analysis Of Droughts, Rice And Wheat Production, And Agrarian Vulnerability: A District-Level Study Of The Self-Calibrated Palmer Drought Severity Index In India, Aaron Michael Shew

Graduate Theses and Dissertations

Droughts have affected more people than any other natural disaster in the last century, causing billions in economic damages and millions of deaths. As the Sea Surface Temperatures (SST) have heated in the Indian Ocean, drought patterns across South Asia have changed; the Indian monsoon has become more volatile and less predictable. In this study, monthly self-calibrated Palmer Drought Severity Index (sc-PDSI) data for the time period between 1950 and 2009 were interpolated to India’s districts; then the data were analyzed for changes in frequency and severity. The data were further evaluated using Anselin’s Local Moran’s I Statistic to elicit …

Preserving Rice Quality: Fine-Mapping And Introgressing A Fissure Resistance Locus, Haley Marie Sater

Graduate Theses and Dissertations

Rice (Oryza sativa L.) kernel fissuring is a major concern of both rice producers and millers. Fissures are small cracks in rice kernels that increase breakage of kernels when milled, and decrease the value of processed rice. This study employed molecular gene tagging methods to fine-map a fissure resistance (FR) locus found in ‘Cybonnet’, a semidwarf tropical japonica cultivar, as well as transfer this trait to rice genotypes of taller, non-semidwarf plant height that are better adapted to some rice production systems. Three QTLs for FR were previously reported; the FR locus with strongest effect resides near the semidwarf sd-1 …

Growth And Productivity Of Irrigated Rice (Oryza Sativa L.) For A Tropical High Altitude Environment In Rwanda, Elie Rene Gasore

Graduate Theses and Dissertations

Yield components, grain yield, biomass and plant N accumulation, and N fertilizer responses of irrigated rice (Oryza sativa, L.) were evaluated for a tropical inland valley environment in the high altitudes in Rwanda. Effects were measured for nitrogen (N) fertilizer rate (0, 60, 90,120,150,180 kg N ha-1), season, growth stage and cultivar of different subspecies and plant types during 2012 dry season (DS) and 2013 wet season (WS) at Cyili Rice Research Farm (1380 m above sea level). Variations in irradiance (17.2± 0.32 MJ m-2 day-1 in DS and 9.4 ± 0.66 MJ m-2 day-1in WS) were linked to seasonal …

Aphid Performance Changes With Plant Defense Mediated By Cucumber Mosaic Virus Titer, Xiaobin Shi, Yang Gao, Shuo Yan, Xin Tang, Xuguo Zhou, Deyong Zhang, Yong Liu

Entomology Faculty Publications

Background: Cucumber mosaic virus (CMV) causes appreciable losses in vegetables, ornamentals and agricultural crops. The green peach aphid, Myzus persicae Sulzer (Aphididae) is one of the most efficient vectors for CMV. The transmission ecology of aphid-vectored CMV has been well investigated. However, the detailed description of the dynamic change in the plant-CMV-aphid interaction associated with plant defense and virus epidemics is not well known.

Results: In this report, we investigated the relationship of virus titer with plant defense of salicylic acid (SA) and jasmonic acid (JA) during the different infection time and their interaction with aphids in CMV-infected tobacco plants. …

Managing Drought Stress In California Agricultural Systems, Gregory D. Brittain Jr.

Doctor of Plant Health Program: Dissertations and Student Research

California is currently facing a historic drought, and this has led many farmers in the state to severely cut back on irrigation. Optimal use of water for irrigation requires a comprehensive understanding of how plants respond physiologically to water stress (Chapter 1). By monitoring water requirements in crops and managing irrigation to meet those requirements, growers can significantly reduce water use (Chapter 2). This can be done through improving application efficiency of irrigation technology as well as increasing the water use efficiency of the crops themselves. Deficit irrigation practices can be used to manipulate the physiology of water use in …

A Vision For Extension: Case Studies On Managing Extreme Weather Challenges In Corn, Anthony J. Mcmechan

Doctor of Plant Health Program: Dissertations and Student Research

Global demand for corn is projected to rise in the coming decades to meet the food and fuel requirements of an increasing human population. Technological innovations have significantly improved corn yields over the past few decades; however, corn production is continually limited by unfavorable weather conditions. Extreme weather events put pressure on producers, adjustors, and consultants to make quick management decisions to maintain the highest return on their investment. Proper management decisions require an understanding of plant response and practical ways of applying this knowledge under real world conditions.

The following document was written after completing a six-month internship at …

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 …

On-Farm Demonstration Of Computerized Hole Selection Programs In Arkansas Commercial Soybean And Cotton Fields And Evaluation Of Polyacrylamide In Plot-Scale Furrow Irrigated Cotton, Austin Lorenzo Lewis

Student Theses and Dissertations

Groundwater depletion is a rising concern in the Midsouth region of the U.S. Many crops depend on the use of groundwater in order to meet water demands and potentially reach higher yields. Products and practices have been developed to conserve both groundwater and surface water by using easily collected field data to improve irrigation advance uniformity, infiltration, irrigation runoff water quality, and reduce irrigation runoff. A field demonstration was initiated to determine the value of incorporating the computerized hole selection program, Pipe Planner, into two commercial cotton fields and two commercial soybean fields. The cotton fields were located in Judd …

Regeneration And Transformation Of Common Bean (Phaseolus Vulgaris L.), Iqbal Singh

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

Common bean is the most important grain legume for direct human consumption and serves as main source of dietary protein for millions of people in developing world. Genetic transformation methods can serve as an important tool to complement traditional plant breeding methods for common bean improvement. Low transformation frequencies and unstable genetic integration associated with biolistic methods limits its use for routine transformation of common bean. In an attempt to develop Agrobacterium tumefaciens mediated transformation protocol for common bean, potential of primary leaves as an explant was analyzed following unsuccessful results with other tissues. Primary leaf explants were prepared from …

Micronutrient Foliar Analysis And Supplementation In Nutrient Management For High Yield Maize (Zea Mays L.), Zachary P. Stewart

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

Micronutrient supplementation in maize production is of growing interest to producers and agronomists as means to further increase yield as other crop needs are increasingly met. Plant tissue and soil sampling for micronutrient concentrations have been used to determine likely responses to micronutrient supplementation. Nebraska soils are generally micronutrient sufficient and usually do not have soil or plant tissue micronutrient concentrations below critical levels, however, during precise periods where specific micronutrients are in greatest need due to physiological demands, there may be opportunity for micronutrient supplementation to increase grain yield. The compiled chapters indicate that in most scenarios in Nebraska, …

Analisis Penurunan Produksi Tanaman Padi Akibat Perubahan Iklim Di Kabupaten Bandung Jawa Barat, Ruminta

Jurnal Kultivasi

Perubahan iklim mempunyai pengaruh signifikan pada budidaya tanaman padi, karena budidaya tanaman padi mempunyai ketergan-tungan yang kuat terhadap unsur iklim terutama curah hujan dan temperatur. Terkait dengan hal itu telah dilakukan kajian dampak perubahan iklim terhadap penurunan produksi tanaman padi di wilayah kabupaten Bandung Jawa Barat. Penelitian bertujuan untuk mengetahui dampak perubahan unsur iklim (curah hujan dan temperature) terhadap produksi tanaman padi dan mengidentifikasi usaha adaptasi yang harus dilakukan oleh para petani. Hasil penelitian menunjukkan bahwa dampak perubahan iklim di wilayah kabupaten Bandung sudah dirasakan oleh petani yang diindikasikan oleh bergesernya musim tanam dan waktu panen, penurunan luas tanam dan …

Pengaruh Pemberian Gibberellin Dan Sitokinin Pada Konsentrasi Yang Berbeda Terhadap Pertumbuhan Dan Hasil Gandum (Triticum Aestivum L.) Di Dataran Medium Jatinangor, Fiky Yulianto Wicaksono, Tati Nurmala, Aep Wawan Irwan, Annisa Sarah Utami Putri

Jurnal Kultivasi

Penelitian ini bertujuan untuk mengetahui pertumbuhan dan hasil tanaman gandum yang maksimum di dataran medium melalui pemberian giberelin dan sitokinin dengan konsentrasi yang berbeda. Percobaan dilakukan sejak Maret hingga Agustus 2015 di Kebun Percobaan Fakultas Pertanian Universitas Padja-djaran, Jatinangor, dengan ketinggian tempat yaitu ± 750 m di atas permukaan laut.Rancangan percobaan adalah Rancangan Acak Kelompok dengan rancangan perlakuan faktorial. Perla-kuan terdiri dari dua faktor, masing-masing terdiri dari tiga taraf,yang diulang tiga kali. Faktor pertama adalah konsentrasi giberelin, terdiri dari taraf 150 ppm, 250 ppm, dan 350 ppm. Faktor kedua adalah konsentrasi sitokinin, terdiri dari taraf 20, 40, dan 60 ppm. …

Respons Tanaman Jagung (Zea Mays L.) Toleran Herbisida Akibat Pemberian Berbagai Dosis Herbisida Ipa Glifosat 486 G/L, Agus Wahyudin, Fiky Yulianto Wicaksono, D. F. Sari

Jurnal Kultivasi

Jagung merupakan salah satu serealia yang strategis di Indonesia. Jagung mempunyai peluang untuk dikembangkan karena fungsinya sebagai bahan pangan utama dan sebagai sumber bahan pakan ternak. Penggunaan tanaman jagung PRG toleran herbisida glifosat diharapkan dapat mengurangi penurunan hasil tanaman jagung. Penelitian ini bertujuan untuk mengetahui pengaruh pemberian berbagai dosis herbisida glifosat terhadap pertumbuhan dan hasil tanaman jagung (Zea mays L.) PRG toleran herbisida glifosat. Penelitian dilaksanakan di Kebun Percobaan Ciparanje Fakultas Pertanian Universitas Padjadjaran, kecamatan Jatinangor, kabupaten Sumedang, Jawa Barat pada bulan Desember 2014 hingga April 2015. Rancangan percobaan yang digunakan adalah Rancangan Acak Kelompok (RAK) dengan 8 perlakuan dan …

Information Thermodynamics Of Cytosine Dna Methylation, Robersy Sanchez Rodriguez, Sally Ann Mackenzie

Department of Agronomy and Horticulture: Faculty Publications

Cytosine DNA methylation (CDM) is a stable epigenetic modification to the genome and a widespread regulatory process in living organisms that involves multicomponent molecular machines. Genome-wide cytosine methylation patterning participates in the epigenetic reprogramming of a cell, suggesting that the biological information contained within methylation positions may be amenable to decoding. Adaptation to a new cellular or organismal environment also implies the potential for genome-wide redistribution of CDM changes that will ensure the stability of DNA molecules. This raises the question of whether or not we would be able to sort out the regulatory methylation signals from the CDM background …

How Can Agroforestry Help Landowners Adapt To Increased Rain Intensity?

Working Trees (USDA-NAC)

Agroforestry practices can help landowners adapt to increased rain intensity.