Plant Biology Commons^™

Lysimetric Calibration Of The Bowen Ratio-Energy Balance Method For Evapotranspiration Estimation In The Central Great Plains, Blaine L. Blad, Norman J. Rosenberg

Department of Agronomy and Horticulture: Faculty Publications

Most reports show good agreement between evapotranspiration (ET) rates estimated by Bowen Ratio-Energy Balance (BREB) method and rates measured with lysimeters, although underestimation by the BREB model has occasionally been reported. This study was conducted to evaluate the performance of the BREB technique in the climatic conditions characteristic of the central Great Plains, a region where a significant proportion of the energy consumed by evapotranspiration is supplied from advected sensible heat.

Agreement between the BREB method and lysimetric measurements of ET is good during non-advective periods but during advective periods the BREB model underestimates ET by about 20%. Data collected …

A Mode Of Action Of Herbicides: Inhibition Of The Normal Process Of Nitrite Reduction, Lowell Klepper

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Herbicides were shown to interfere in the normal process of enzymatic nitrite reduction by the plant in photosynthetic and nonphotosynthetic plant tissues with little effect on nitrate reduction. This preferential inhibition caused nitrite to accumulate. The occurrence of free nitrite within the plant can help to explain the toxicity symptoms, nastic growth reactions, abnormal metabolism and rapid death due to herbicide action. This blockage of nitrite reduction was shown with all photosynthetic inhibitor herbicides tested and with numerous other herbicides. The effect was demonstrated using an in vivo assay, intact green plants and germinating seedlings. A basic in vivo method …

Survival Mechanisms Of Phytopathogenic Bacteria, M. L. Schuster, D. P. Coyne

Department of Plant Pathology: Faculty Publications

Natural habitats usually do not provide bacteria the continuity of agricultural crops. With continuous culture. perpetuation of pathogen is no problem. Although agricul­ tural practices provide some discontinuity between crops. it is less than that in nature. Uniformity of crop germ plasm also favors inoculum buildup and perhaps perpetuation of the pathogens.

Penstemon In Your Garden [Revised], Roger D. Uhlinger, Glenn Viehmeyer

Department of Agronomy and Horticulture: Faculty Publications

The Genus Penstemon

Penstemon Breeding: Emasculation • Pollen Collection • Pollination • Keeping Records

Selection of ParentaI MateriaIs

Species Crosses

Breeding Behavior

Sources of Breeding Material

Penstemon Propagation: Propagation by Seed • Propagation by Division and Layering • Propagation by Cuttings • Tip Cuttings • Single Node and Single Eye Cuttings • Striking the Cuttings • Rooting Mediums • Setting the Cuttings

Penstemon Diseases : Leaf Diseases • Soil Borne Diseases • Virus Diseases

Insects that Affect Penstemon: Aphids • Cutworms • False Plant Bug • Flea Beetle • Grasshoppers • Leaf hoppers • Slugs • Red Spider Mites • …

Rollins Adams Emerson (1873-1947) Horticulturist Pioneer Plant Geneticist Administrator Inspiring Student Adviser, Rosalind Morris

Department of Agronomy and Horticulture: Faculty Publications

The vigorous and highly productive life of Professor R. A. Emerson spanned 74 years and 7 months. His birth and death took place In New York State, but Nebraska nurtured his early development and schooling. He spent 15 years of his professional career at the University of Nebraska, followed by 33 years at Cornell University.

Rollins Adams Emerson, son of Charles David and Mary C. Adams Emerson (a direct descendant of Henry Adams), was born May 5, 1873 at Pillar Point, New York State on the eastern shore of Lake Ontario. In 1880 his family moved to Nebraska and settled …

Floral Morphology And Phylogeny In The Hydrocharitaceae, Robert B. Kaul

School of Biological Sciences: Faculty Publications

The vascular anatomy of 13 of the 15 genera of the Hydrocharitaceae has been studied, and certain aspects of floral morphology are considered. The flowers of the family show a broad range of specialized structures combined with primitive characteristics. The origin of paired and single stamens is interpreted as probable modifications of fascicled stamens. Extreme reduction in the androecium is shown for several genera. Tendencies toward reduction and fusion within the gynoecium are pronounced. Most genera are at least slightly syncarpous, but a few are apocarpous. The inferior ovary is appendicular in nature, with some genera exhibiting more complete fusion …

Northern Corn Leaf Blight (Helminthosporium Turcicum Pass.) On Susceptible And Resistant Corn, Saffet Baydar

Open Access Master's Theses (through 2010)

The objectives of the research reported herein were to (1) become familiar with the technique of inoculating corn with Helminthosporium turcicum, (2) become familiar with a technique of evaluating the susceptibility of corn lines to H. turcicum, (3) become familiar with plant reaction and organism development in the various types of corn and (4) evaluate Turkish corn susceptibility in relation to various types of germ plasm in American corn lines in order to assist in combating the serious disease of Northern corn left blight in Turkey.

Comparative reactions of 10 Turkish, 5 multigenic resistant, 2 heterozygous monogenic …

A Soil And Vegetation Inventory And Analysis Of Three Nebraska Sandhills Range Sites, Donald F. Burzlaff

Nebraska Agricultural Experiment Station: Historical Research Bulletins

This study was undertaken to inventory the soils and vegetation of certain areas of the Sandhills and to seek edaphic characteristics that may be the limiting factor in the distribution of various plant species. Information of this nature will permit formulation of more accurate management practices because of a refinement in delineation of range sites.

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

Nebraska Agricultural Experiment Station: Historical Research Bulletins

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.

Microorganisms And Soil Structure, T. M. Mccalla, F. A. Haskins

Department of Agronomy and Horticulture: Faculty Publications

SUMMARY

Good stable soil structure is valuable for promoting the growth of plants and micro-organisms by permitting enhanced aeration and water penetration and by decreasing erosion under some conditions.

Micro-organisms influence water percolation through the soil. They may plug up soil pores with byproducts of growth and reduce water percolation. On the other hand, if a soil containing a large amount of microbial products is stirred and allowed to dry, then the percolation may be high.

Micro-organisms are involved in stabilizing soil structure by their products of decomposition and their cellular binding material, such as mycelia. Microorganisms differ greatly in …

Pensternon In Your Garden, Glenn Viehmeyer

Department of Agronomy and Horticulture: Faculty Publications

A new race of hardy perennials is beginning to appear in American gardens. These are the penstemons, a genus of plants closely related to the familiar snapdragon, which may become important ornamentals as they become better known to gardeners. The purpose of this bulletin is to show the possibility of the genus as an ornamental and to suggest species and species hybrids of possible value to Great Plains gardeners; to provide information about propagation and culture; and to encourage gardeners to engage in penstemon breeding as an avocation.

The Significance Of Xenia Effects On The Kernel Weight Of Corn, T. A. Kiesselbach

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The purpose of this paper is to appraise the xenia effects of the pollen parent on the kernel weight of corn (Zea mays L.), and to interpret so far as possible their genetic, physiologic and applied significance. The conclusions will be based on local experiments and a review of the literature.

Influence Of Atmospheric And Soil Moisture Conditions On Diurnal Variations In Relative Turgidity Of Potato Leaves, H. O. Werner

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The experimental work reported herein was planned to determine: 1. The extent and nature of the changes of the relative turgidity (R.T.) of leaves of the potato plant during the diurnal cycle. 2. The extent to which R.T. of potato leaves is influenced by atmospheric conditions, soil moisture, variety and age of plants. 3. The extent to which visible evidence of water shortage in leaves is indicative of water loss from them as revealed by R.T. and the extent to which this relationship varies with different varieties. 4. The nature of the relationships between morphological characteristics of leaves and stems …

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

Nebraska Agricultural Experiment Station: Historical Research Bulletins

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.

Progressive Development And Seasonal Variations Of The Corn Crop, T. A. Kiesselbach

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The chief purpose of these studies has been to determine the normal growth changes that occur in the corn plant at successive intervals when growing in the field, and to observe annual yield variations in relation to prevailing weather conditions. Aside from supplying information regarding the physiology of this crop, the data are of interest to the corn grower because they indicate comparative yields, shelling percentages, moisture contents, and feed constituents at various stages of development. Some data also are presented concerning the effects of frost, drouth, day length, and the economic value of tillers and seminal roots.

Microorganisms And Soil Structure, T. M. Mccalla

Department of Agronomy and Horticulture: Faculty Publications

SUMMARY

Laboratory tests were made to determine the effectiveness of different compounds and microbial groups in increasing the stability of Peorian loess lumps against the action of falling water drops. The influence of these on percolation tests in the laboratory was also determined.

Many organic substances-dextrose, sucrose, starch, peptone, cullulose, and gum arabic-did not themselves contribute directly to soil-structure stability, though these substances do furnish energy material for soil microorganisms, which can convert them readily into either microbial tissue or decomposition products that increase soil-structure stability. Lignin, proteins, oils, fats, waxes, resin, and paraffin increased the stability of lumps of …

Effect Of Storage Temperatures On Triumph Seed Potatoes Used For The Early Crop In The South And In Central Nebraska, H. O. Werner

Nebraska Agricultural Experiment Station: Historical Research Bulletins

During the decade 1931-1940 it became increasingly apparent that some factor (or factors) besides disease was responsible for much of the variation in yields produced by lots of certified seed potatoes planted in commercial fields and comparative trial plots in the South during midwinter. This bulletin reports investigations into the method of storing western Nebraska seed potatoes as a means of improving the production of the early crop of Triumphs in the Gulf Coast States.

Pollination Cycles And Pollen Dispersal In Relation To Grass Improvement, Melvin D. Jones, L. C. Newell

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The plant breeder is initially concerned with gaining a knowledge of the breeding behavior of his plant materials in order that improvement may be undertaken effectively. It is important to know the different characteristic pollination habits of these plants. To develop and apply techniques applicable to the improvement of a given grass crop, it is desirable to know the time of day and the number of days that the grass sheds pollen. The effects of temperature, humidity, light, and wind on pollination must be considered. Once superiority of germplasm is obtained, the most important consideration is the maintenance of this …

Controlling The Ph Of Cultures Of Penicillium Notatum Through Its Carbon And Nitrogen Nutrition, Albert E. Dimond, George L. Peltier

Department of Plant Pathology: Faculty Publications

A survey of published material reveals relatively little information concerning the nutritional physiology of Penicillium notatum Westl. on synthetic media. Metabolism studies of P. notatum on various media have appeared to be incidental to the more pressing problem of producing penicillin quickly and in quantity. Fleming (1929) originally used a nutrient broth non-synthetic in nature. The Oxford group (Abraham et al., 1941) then adopted a modification of the so-called Czapek-Dox synthetic medium which supplies nitrogen as sodium nitrate and glucose as carbohydrate. Hobby, Meyer, and Chaffee (1942) suggested that brown sugar be substituted for glucose in this nutrient, with …

The Genetics Congress, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

Mice and men reported from

Edinburgh after the Congress

(JOURNAL OF HEREDITY for

September 1939) but since then there

has been silence, as far as getting into the

record any details of the Congress. On

account of the disruption to trans-Atlantic

travel caused by the declaration of

war between England and Germany,

September 3, the American delegation to

the Congress was considerably delayed

in getting back. Only two failed ultimately

to return, Dr. and Mrs. F. W.

Tinney of the Division of Farm Crops

of the University of Wisconsin. They

were among about a dozen members of

the Congress who …

A Zygotic Lethal In Chromosome 1 Of Maize And Its Linkage With Neighboring Genes, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

A Bolivian maize

maize with mosaic red pericarp and cob, here designated by the symbol M-M, crossed with a local inbred strain of maize having white pericarp and cob, W-W, produced in F₁ 21 M-M and 28

W-W plants, not far from the I : I relation expected on the assumption that

the M-M parent was heterozygous for pericarp and cob color, M-M/W-W.

In F₂ and segregating F₃ cultures, however, there were 130 M-M and 64

W-W plants obviously a 2 : I instead of the 3 : I relation expected. Later cultures

increased these records to …

Relation Of The Differential Fertilization Genes, Ga Ga, To Certain Other Genes Of The Su-Tu Linkage Group Of Maize, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

The Ga, or “gamete” gene of maize can be studied only or principally by its disturbance of normal Mendelian ratios of contrasted characters differentiated by genes linked with it. The amount of this disturbance can be used as a measure of the intensity of linkage between Ga and other genes of the su-Tu group.

Disturbance of the 3:1 ratio of starchy, Su, to sugary, su, endosperm has been most studied. In one of the early papers on Mendelian inheritance, Correns (1902) reported that, although crosses between most starchy and sugary varieties gave an F₂ ratio of …

The A Series Of Allelomorphs In Relation To Pigmentation In Maize, R. A. Emerson, E. G. Anderson

Department of Agronomy and Horticulture: Faculty Publications

Introduction ... 503

The allelomorph A^b ... 504

The allelomorph a^p ... 505

Dominance ... 508

Summary ... 508

Literature Cited ... 509

The Frequency Of Somatic Mutation In Variegated Pericarp Of Maize, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

Some years ago (Emerson 1922) the writer announced that in F₂ of

certain crosses of variegated with colorless pericarp in maize the heterozygous

individuals changed to self color more frequently than did the homozygous

individuals of the same cultures. No “explanation” of this phenomenon

was then apparent, but later results, though still far from affording

an adequate solution of the problem, have furnished at least a working

hypothesis. The original unpublished paper, with minor modifications,

is given below, under the heading. “Somatic mutations in heterozygous

and in homozygous variegated pericarp.”

A Research Delusion, George L. Peltier

Department of Plant Pathology: Faculty Publications

With the administrative heads of many of our educational institutions demanding a doctorate of every member of the permanent staff, as it is supposed to be a prerogative for research, and the issuing of a list of titles published each year by their staff, the urge for so-called research, namely, a list of titles, goes madly on. In fact publication sometimes becomes a sort of self-defense, for the absence of any titles over a brief period of years stamps one either as lacking the ability of doing research or inefficient. Likewise, such a policy has permeated the staff, so that …

Control Of Flowering In Teosinte: Short-Day Treatment Brings Early Flowers, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

Attempts to force teosinte into flower in mid-summer, in order to facilitate hybridizing it with maize, have afforded considerable information concerning the flowering time of teosinte under diverse conditions. The possibility that some of this information may be of use to others suggests its publication. The paper is, therefore, to be considered as a help in the technique of teosinte and maize hybridization rather than a contribution ~to the solution of the physiological problems involved.

A Genetic View Of Sex Expression In The Flowering Plants, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

It seems a conservative statement to say that studies

of the past twenty years among animal forms have

tended increasingly to link the phenomena of sex inheritance

with the behavior of chromosomes. To this

result, cytology and genetics have contributed perhaps

almost equally. The number of forms in which

one sex is known to have a morphologically different

chromosome complex from the other sex are many.

That, with respect to the chromosomes, the female of

certain forms produces gametes of a single kind,

whereas the male produces two kinds, and that in

turn an egg fertilized by one kind of …

Pericarp Studies In Maize. I. The Inheritance Of Pericarp Colors, E. G. Anderson, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

Introduction ... 466

Nomenclature ... 467

Pigments present in colored pericarp ... 467

Factor relations of pericarp colors ... 468

Factor relations of red pericarp, P ... 468

Factor relations of cherry pericarp ... 471

Discussion and Summary ... 474

Literature Cited ... 475

Genetic Interrelations Of Two Andromonoecious Types Of Maize, Dwarf And Anther Ear, R. A. Emerson, Sterling H. Emerson

Department of Agronomy and Horticulture: Faculty Publications

Attention was called by Montgomery (1906)to the occasional appearance

of perfect flowers in the staminate inflorescence of maize and similar

cases were reported by Kempton (1913). Montgomery (1911) described

with illustrations a true-breeding type of semi-dwarf dent maize, the ears

of which were perfect-flowered. Perfect-flowered maize was described

and illustrated also by Blaringhem (1908, pp. 180-183). East and

Hayes (1911, pp. 13, 14) noted and illustrated a perfect-flowered sweet

corn. Weatherwax (1916, 1917) showed that typically pistillate

flowers of maize exhibit in microscopic sections the rudiments of stamens

and that staminate flowers show rudiments of pistils.

The Regional Adaptation Of Corn In Nebraska, T. A. Kiesselbach, F. D. Keim

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The purpose of this investigation was to determine some of the factors involved in the regional adaptation of corn. The procedure has been to make a comparative study of native corn types, known to be locally adapted to various regional areas in Nebraska through long growth there. The work has been confined to the single species group - Zea mays indentata. No one variety of a common source is grown throughout the state, and therefore it has been impossible to keep within a single variety. It would appear that the data should indicate morphological and histological plant characteristics involved …