Life Sciences Commons^™

Future Carbon Dioxide Concentration Decreases Canopy Evapotranspiration And Soil Water Depletion By Field-Grown Maize, Andy Vanloocke, Mir Zaman Houssain, Matthew H. Siebers, Ursula M. Ruiz-Vera, R. J. Cody Markelz, Andrew D. B. Leakey, Donald R. Orr, Carl J. Bernacchi

Andy VanLoocke

Arbuscular Mycorrhizal Fungi Differ In Their Ability To Regulate The Expression Of Phosphate Transporters In Maize (Zea Mays L.), Hui Tian, Rhae A. Drijber, Xiaolin Li, Daniel N. Miller, Brian J. Wienhold

Department of Agronomy and Horticulture: Faculty Publications

Previous studies have found that some phosphate (Pi) starvation inducible transporter genes are downregulated and arbuscular mycorrhizal (AM) inducible Pi transporter genes are upregulated in maize roots associated with the fungus Glomus intraradices. However, little is known about the functional diversity of different AM fungal species in influencing the expression of Pi transporters in maize roots. Here, we studied the expression of two Pi transporter genes ZEAma:Pht1;3 (Pi starvation inducible) and ZEAma:Pht1;6 (AM inducible) in maize root colonized by different AM fungal inoculants. Non-mycorrhizal maize, maize colonized by Glomus deserticola (CA113), Glomus intraradices (IA506), Glomus mosseae (CA201), Gigaspora gigantea …

Estimating Crop Yield Potential At Regional To National Scales, Justin Van Wart, Kurt Christian Kersebaum, Shaobing Peng, Maribeth Milner, Kenneth Cassman

Department of Agronomy and Horticulture: Faculty Publications

World population will increase 35% by 2050, which may require doubling crop yields on existing farm land to minimize expansion of agriculture into remaining rainforests, wetlands, and grasslands. Whether this is possible depends on closing the gap between yield potential (Yp, yield without pest, disease, nutrient or water stresses, or Yw under water-limited rainfed conditions) and current average farm yields in both developed and developing countries. Quantifying the yield gap is therefore essential to inform policies and prioritize research to achieve food security without environmental degradation. Previous attempts to estimate Yp and Yw at a global level have been too …

A Regional Comparison Of Water Use Efficiency For Miscanthus, Switchgrass And Maize, Andy Vanloocke, Tracy E. Twine, Marcelo Zeri, Carl J. Bernacchi

Andy VanLoocke

Estimating Maize Grain Yield From Crop Biophysical Parameters Using Remote Sensing, Noemi Guindin-Garcia

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

The overall objective of this investigation was to develop a robust technique to predict maize (Zea mays L.) grain yield that could be applied at a regional level using remote sensing with or without a simple crop growth simulation model. This study evaluated capabilities and limitations of the Moderate Resolution Imaging Spectroradiometer (MODIS) Vegetation Index 250-m and MODIS surface reflectance 500-m products to track and retrieve information over maize fields. Results demonstrated the feasibility of using MODIS data to estimate maize green leaf area index (LAI_g). Estimates of maize LAI_g obtained from Wide Dynamic Range Vegetation …

Xenia Effects On Quality Of Maize Female Inbred In Production Of Hybrid Seeds, Leandro Castañeda

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

In Maize (Zea maize L.), cost of hybrid seed production is directly related to the yield and quality of seed obtained per hectare of female parent. It is also important to consider the effects that a male parent can exert on the development of hybrid seed in the female parent. This effect is known as xenia. The objectives of this study were to evaluate xenia effects on 1) yield as 80K units, 2) germination of the hybrid seed and 3) susceptibility of the hybrid seed to mechanical damage. One female inbred and four male inbred lines were selected from a …

Effect Of Spontaneous Fermentation And Amylase Rich Flour (Arf) On The Nutritive Value, Functional And Viscoelastic Properties Of Cowpea-Fortified Nixtamalized Maize, Dr. Emmanuel Ohene Afoakwa (Phd), Philip Roger Aidoo, Randy Adjonu

Professor Emmanuel Ohene Afoakwa

Studied were conducted to evaluate the combined effects of spontaneous fermentation and Amylase Rich Flours (ARF) on some nutritive value, functional and viscoelastic properties of cowpea-fortified nixtamalized maize. A 2x3x3 factorial design, with fermentation medium, fermentation time and ARF level was performed. The blends were fermented for the specific times and analysed for their titratable acidity, pH, water absorption capacity, viscoelastic properties, texture, protein and mineral content. Fermentation and ARF addition influenced titratable acidity, pH, water absorption, viscoelastic properties and texture of the cowpea-fortified nixtamalized maize. Addition of ARF decreased the viscoelastic properties, texture and pH of all the blends …

Coupling Of Carbon Dioxide And Water Vapor Exchanges Of Irrigated And Rainfed Maize–Soybean Cropping Systems And Water Productivity, Andrew E. Suyker, Shashi B. Verma

School of Natural Resources: Faculty Publications

Continuous measurements of CO₂ and water vapor exchanges made in three cropping systems (irrigated continuous maize, irrigated maize–soybean rotation, and rainfed maize–soybean rotation) in eastern Nebraska, USA during 6 years are discussed. Close coupling between seasonal distributions of gross primary production (GPP) and evapotranspiration (ET) were observed in each growing season. Mean growing season totals of GPP in irrigated maize and soybean were 1738 ± 114 and 996 ± 69 g C m⁻², respectively (±standard deviation). Corresponding mean values of growing season ET totals were 545 ± 27 and 454 ± 23 mm, respectively. Irrigation affected GPP …

Inoculation With Arbuscular Mycorrhizal Fungi Or Crop Rotation With Mycorrhizal Plants Improves The Growth Of Maize In Limed Acid Sulfate Soil, Hasao Higo, Katsunori Isobe, Dong-Jin Kang, Kazuhiro Ujie, Rhae A. Drijber, Ryuichi Ishii

Department of Agronomy and Horticulture: Faculty Publications

Arbuscular mycorrhizal fungi (AMF) improve the uptake of immobile mineral nutrients such as phosphate, thereby improving plant growth. In acid sulfate soil (ASS), AMF spore density is generally low which impacts root colonization and phosphate uptake. Thus, inoculation may help increase AMF colonization of crops grown in ASS. AMF spore density decreases after cultivation of a non-host crop or bare fallow. In addition, preceding crops affect the growth and yield of subsequent crops. The production of AMF inocula requires AMF-compatible plants. The objective of the present study is to elucidate the effect of preceding crops on the persistence of inoculated …

Yield Potential And Resource-Use Efficiency Of Maize Systems In The Western U.S. Corn Belt, Patricio Grassini

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

Maize demand for food, livestock feed, and biofuel is expected to increase substantially. The Western U.S. Corn Belt accounts for 23% of U.S. maize production, and irrigated maize accounts for 43 and 58% of maize land area and total production, respectively, in this region. The most sensitive parameters (yield potential [YP], water-limited yield potential [YP-W], yield gap between actual yield and YP, and resource-use efficiency) governing performance of maize systems in the region are lacking. A simulation model was used to quantify YP under irrigated and rainfed conditions based on weather data, soil properties, and crop management at 18 locations. …

Viscoelastic Properties And Pasting Characteristics Of Fermented Maize: Influence Of The Addition Of Malted Cereals, Dr. Emmanuel Ohene Afoakwa (Phd), Randy Adjonu, Justice Asomaning

Professor Emmanuel Ohene Afoakwa

Investigations were conducted on the viscoelastic properties and pasting characteristics of fermented maize with malted cereals and their suitability for infant feeding. A 3x3x2 factorial experimental design with malting time, cereal malt concentration and cereal type was used. Maize, millet, and sorghum malts were added to fermented maize to reducing its bulk density. Samples were analysed for their viscoelastic properties and pasting characteristics using Brabender Viscoamylograph. Sorghum malt in comparison to millet and maize malts was not effective in terms of lowering the hot and cold paste viscosities of the fermented maize. Maize and millet malts liquefied the dough considerably …

Acidification And Starch Behaviour During Co-Fermentation Of Cassava And Soybean Into Gari., Dr. Emmanuel Ohene Afoakwa (Phd), Edem John Kongor, George Annor, Randy Adjonu

Professor Emmanuel Ohene Afoakwa

Changes in acidification and starch behaviour were investigated during co-fermentation of cassava and soybean into gari, an African fermented product. Non-volatile acidity, pH and starch content were evaluated using standard analytical methods. Starch breakdown and pasting characteristics were also analysed using Brabender Viscoamylograph. Fermentation caused significant variations in the pH, non-volatile acidity and starch concentration. The pH decreased with concomitant increases in non-volatile acidity during co-fermentation of the cassava dough. Soy-fortification upto 20% caused only minimal effects on the pH, titratable acidity and starch content during the fermentation period. Starch content decreased from 69.8%-60.4% within the 48 h fermentation time …

Limits To Maize Productivity In The Western Corn-Belt: A Simulation Analysis For Fully Irrigated And Rainfed Conditions, Patricio Grassini, Haishun Yang, Kenneth G. Cassman

Department of Agronomy and Horticulture: Faculty Publications

Unlike the Central and Eastern U.S. Corn-Belt where maize is grown almost entirely under rainfed conditions, maize in the Western Corn-Belt is produced under both irrigated (3.2 million ha) and rainfed (4.1 million ha) conditions. Simulation modeling, regression, and boundary-function analysis were used to assess constraints to maize productivity in the Western Corn-Belt. Aboveground biomass, grain yield, and water balance were simulated for fully irrigated and rainfed crops, using 20-year weather records from 18 locations in combination with actual soil, planting date, plant population, and hybrid-maturity data. Mean values of meteorological variables were estimated for three growth periods (pre- and …

Corn Stover Availability And Collection Efficiency Using Typical Hay Equipment, Robert M. Prewitt, Michael D. Montross, Scott A. Shearer, Timothy S. Stombaugh, Stephen F. Higgins, Samuel G. Mcneill, Shahab Sokhansanj

Biosystems and Agricultural Engineering Faculty Publications

Corn stover has been identified as a potential feedstock for the production of fermentable sugars and thermochemical processes. The availability and efficiency of typical hay equipment for collecting corn stover has not been well quantified. Corn stover was collected for two years on a central Kentucky farm near Louisville. Six different harvesting treatments, using traditional hay equipment, were used to harvest corn stover. A rotary mower, rotary scythe (flail-type mower with windrow-forming shields), parallel bar rake, and a round baler were utilized. The average stover moisture content prior to grain harvest was above 40%, and field drying was required before …

Why Is Maize A Sacred Plant? Social History And Agrarian Change On Sumba, Cynthia Twyford Fowler

Faculty Scholarship

Why has maize, a plant with origins in the New World, become ritually important in an indigenous Southeast Asian religion? While environmental conditions and agricultural economics are key determinants of everyday resource management practices in insular Southeast Asia, it is necessary to consider ethnic identity, political economy, and social structure in order to understand the religious significance of natural resources in contemporary society. Linguistic, cosmological, and horticultural data are combined with an analysis of local perceptions of culture and environment. This information is used to explain the transformation of an introduced plant into an indigenous sacrament. Ethnographic data, including a …

Effects Of Cowpea Fortification, Dehydration Method And Storage Time On Some Quality Characteristics Of Maize-Based Traditional Weaning Foods., Emmanuel Ohene Afoakwa, Samuel Sefa-Dedeh, Esther Sakyi-Dawson

Professor Emmanuel Ohene Afoakwa

Fortification of cereal-based traditional foods with legume protein can improve their nutritional value. It is, however, important to find out the extent to which the addition of cowpea affects the desirable quality characteristics of traditional weaning foods prepared from fermented maize and also to assess the effect of dehydration method and storage time on the chemical, physico-chemical and functional properties of the products. A 3 x 2 x 4 factorial experiment with cowpea level, drying method and storage time as the respective variables was done. The traditional weaning food was prepared by steeping maize in water for 24 hours, mixed …

Sterol Composition Of The Corn Root Lesion Nematode, Pratylenchus Agilis, And Corn Root Cultures, David J. Chitwood, William R. Lusby

Harold W. Manter Laboratory of Parasitology: Faculty and Staff Publications

Sterols from mixed stages of the com root lesion nematode, Pratylenchus agilis, and uninfected corn root cultures were analyzed by gas chromatography-mass spectrometry. Twenty-eight sterols were identified in P. agilis, including nine not previously detected in nematodes. The major sterols were 24-ethylcholest-22-enol, 24-ethylcholesta-5,22-dienol, 24-methy1cholestanol, 24-ethylcholestanol, isofucostanol, and 24-ethylcholesterol. The principal corn root sterols were 24-ethylcholesta-5,22-dienol, 24-methylcholesterol, 24-ethylcholesterol, isofucosterol, and cycloartenol. Therefore, the major metabolic transformation of sterols by P. agilis was saturation of the sterol nucleus. In addition, very small amounts of 4α-methylsterols were biosynthesized by P. agilis. The 4-methylation pathway is unique to nematodes and was …

Molecular-Marker-Facilitated Investigations Of Quantitative-Trait Loci In Maize. I. Numbers, Genomic Distribution And Types Of Gene Action, Jonathan F. Wendel, M. D. Edwards, Charles W. Stuber

Jonathan F. Wendel

Individual genetic factors which underlie variation in quantitative traits of maize were investigated in each of two F 2 populations by examining the mean trait expressions of genotypic classes at each of 17-20 segregating marker loci. It was demonstrated that the trait expression of marker locus classes could be interpreted in terms of genetic behavior at linked quantitative trait loci (QTLs). For each of 82 traits evaluated, QTLs were detected and located to genomic sites. The numbers of detected factors varied according to trait, with the average trait significantly influenced by almost two-thirds of the marked genomic sites. Most of …

Additional Mapping Of Isozyme Loci: Localization Of Acp4, Dia2, Adkl, Tpi3, And Sadl, Jonathan F. Wendel, Major M. Goodman, Charles W. Stuber

Jonathan F. Wendel

We recently listed the isozyme loci being studied by starch gel electrophoresis in our laboratory and summarized the available mapping data in a series of reports (Wendel et al., MGCNL 59:87-90). Subsequent work has resulted in further clarification of the chromosomal locations of markers on chromosomes 1 (Acp4, Dia2), 6 (Adkl), 8 (Tpi3), and 10 (Sadl). Previously unreported information on these loci and their chromosomal locations follows.

Tpi4 Is Located Near The Centromere On The Long Arm Of Chromosome 3, Jonathan F. Wendel, J. B. Beckett

Jonathan F. Wendel

Tpi4, one of the three genes encoding cytosolic triose phosphate isomerase isozymes, was earlier shown to be on 3L between Pgd2 (phosphogluconate dehydrogenase) and the centromere (Wendel et al., MNL 59:88). In an effort to better localize Tpi4, a series of crosses was made between Tpi4 testers and stocks carrying three B-A translocations believed to be near the centromere on 3L.

Localization Of Two New Isozyme Loci, Hexl And Tpi4, To Chromosome 3, Jonathan F. Wendel, Charles W. Stuber, Major M. Goodman

Jonathan F. Wendel

Recent work with starch gel electrophoresis of coleoptile extracts has indicated that Hexl, the structural locus for the most anodal set of hexokinase isozymes, and Tpi4, which encodes the slowest migrating set of triose phosphate isomerase bands, are located on chromosome 3.

Mapping Data For 34 Isozyme Loci Currently Being Studied, Jonathan F. Wendel, Charles W. Stuber, Major M. Goodman

Jonathan F. Wendel

With the recent localization of several new loci, a composite listing of these loci and chromosomal locations has been compiled and is shown in Table 1. Although locations of some of the loci are tentative, many are very precisely located from studies involving 1600 to more than 1900 F2 plants.

Linkage Relationships Between A New Locus, Hex2, And Previously Assigned Loci On Chromosome 6, Jonathan F. Wendel, Charles W. Stuber, Major M. Goodman

Jonathan F. Wendel

Starch gel electrophoresis of maize coleoptile extracts in our laboratory has shown two zones of staining for isozymes of hexokinase. Genetic analyses 9 indicate that the slower migrating set of bands is encoded by the structural gene Hex2 and that the enzyme is monomeric. Recent linkage analyses and work with B-A translocation stocks (generously supplied by Jack Beckett) have allowed for the placement ofHex2 on the long arm of chromosome 6. Its location relative to other markers on 6L was determined from the analysis of two very large F2 populations generated for other reasons.

The Effects Of Irradiating Dormant Maize Seeds With Xrays And Thermal Neutrons, Rosalind Morris, E. F. Frolik

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

In 1951 a research program was started at the University of Nebraska to compare the developmental effects of thermal neutrons and X rays on different crop seeds. Three crops, barley, tomato and maize, were chosen for additional information involving induced chromosomal aberrations and seedling mutations. The maize investigations are presented in this bulletin, along with a comparison among the three crops with respect to irradiation effects.

Progress From Recurrent Selection Procedures For The Improvement Of Corn Populations, John H. Lonnquist

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

The possibilities of developing synthetic varieties suitable for the fringe areas of the corn belt, where cost of hybrid seed is high relative to the value of the expected crop, and in areas where hybrid corn might not be a feasible approach for other reasons, made it seem a worthwhile objective for study. Effort has been made in recent years to increase the productivity of hybrid combinations through selection of new superior lines using standard breeding procedures. The limited progress realized has resulted in an increased interest in the possible use of alternate methods for the development of superior germplasm …

The Effects Of Thermal-Neutron Irradiation Of Maize And Barley Kernels, John W. Schmidt, E. F. Frolik

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

It is the purpose of this paper to report the effects of thermal-neutron irradiation of maize and barley kernels on subsequent germination, plant establishment, and early plant development. Comparisons are made with equivalent neutron treatments of maize pollen, results of which have been reported in part in previous publications.

The Inheritance Of A Recurring Somatic Variation In Variegated Ears Of Maize, R. A. Emerson

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

The inheritance of variegation has special interest and importance in genetics. In this paper I shall present data from maize and attempt to show how they can be interpreted in strictly Mendelian terms.