Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons™

Open Access. Powered by Scholars. Published by Universities.®

Plant Pathology

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 11581 - 11610 of 11634

Full-Text Articles in Life Sciences

Studies Of The Dodder Transmission Of The Western-X Virus From Peach To Herbaceous Plants, Lewis G. Weathers May 1951

Studies Of The Dodder Transmission Of The Western-X Virus From Peach To Herbaceous Plants, Lewis G. Weathers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Western-X disease is considered to be the most serious and destructive virus disease affecting peaches in the northwestern United States. The virus causing this disease in peach also infects chokecherries and most varieties of sweet and sour cherries. There is also evidence (13) that certain varieties of plums and apricots are susceptible. No information now exists to indicate that the virus occurs in plants outside of the genus Prunus. It is found that woody plants such as stone fruit trees are not particularly favorable plants for studying the virus. All attempts to isolate the western-X virus from woody tissue …

Go to article

Effect Of Low Temperature On The Germination Of Artificially Dried Seed Corn, J. E. Livingston Jan 1951

Effect Of Low Temperature On The Germination Of Artificially Dried Seed Corn, J. E. Livingston

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Soil pathogens were primarily responsible for the reduction in emergence of corn seedlings following the cold treatment. The susceptibility of the seedlings to soil pathogens was much greater when the seedlings were exposed to a soil temperature of 5° C for 7 to 14 days than when they were held continuously at 20° C. Seedling emergence was in inverse relation to kernel moisture content at time of harvest. Artificial drying of the seed intensified this effect, particularly in nonsterile soil. Treatment of the seed with Arasan prior to planting completely eliminated the effect of soil pathogens on seedling emergence either …

Go to article

The Sedimentation Rate Of Potato Yellow-Dwarf Virus, M. K. Brakke, L. M. Black, Ralph W. G. Wyckoff Jan 1951

The Sedimentation Rate Of Potato Yellow-Dwarf Virus, M. K. Brakke, L. M. Black, Ralph W. G. Wyckoff

Department of Plant Pathology: Faculty Publications

BLACK et al. (1948) have published electron micrographs of bodies believed to represent the New York variety of potato yellow-dwarf virus (Aureogenus vastans (H) Black) (Holmes 1948). The photographs showed bodies in several different extracts of infected plants of Nicotiana rustica L., but not in corresponding preparations from healthy plants. Similar bodies were found in concentrates from plants infected with the New Jersey variety of the virus (var. agalliae Black). These bodies were larger than, and of a different character from, those of plant viruses hitherto examined in the electron microscope. The present study was undertaken to obtain evidence …

Go to article

An Etiological And Host Range Study Of Celery Mosaic In Utah, Dennis H. Hall May 1950

An Etiological And Host Range Study Of Celery Mosaic In Utah, Dennis H. Hall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Celery mosaic is a virus disease of major economic importance in Utah. In years of severe epiphytotics, it has been a limiting factor in celery production. In 1947 losses due to this disease were estimated to exceed 8 per cent of the total crop. This estimate does not include losses resulting from reduction in grade or from plants discarded in the packing sheds. The celery acreage in Utah dropped from a high of 950 acres in 1946 to 750 acres in 1947 and dropped again in 1948 to 420 acres. Leaders in the industry attributed this reduction in acreage, in …

Go to article

Pink Rot Of Potatoes Caused By Phytophthora Erythroseptica Pethyb., R. W. Goss Jun 1949

Pink Rot Of Potatoes Caused By Phytophthora Erythroseptica Pethyb., R. W. Goss

Nebraska Agricultural Experiment Station: Historical Research Bulletins

During the summer of 1943 reports were received of rotted tubers occurring in fields of early potatoes in central Nebraska. An estimated 10 per cent of the tubers were found rotted in some fields on August 5. In November and December of the same year the late-producing area of western Nebraska reported the occurrence, at harvest and in storage, of tuber rots differing from those previously recorded for that area. Specimens appeared similar to those observed during the summer in central Nebraska. Isolations were made and pathogenicity tests were conducted both on tubers and growing plants to study the influence …

Go to article

Mechanical Transmission Of A Plant Tumor Virus To An Insect Vector, Karl Maramorosch, Myron K. Brakke, L. M. Black Jan 1949

Mechanical Transmission Of A Plant Tumor Virus To An Insect Vector, Karl Maramorosch, Myron K. Brakke, L. M. Black

Department of Plant Pathology: Faculty Publications

Most plant viruses transmitted by leafhoppers have not been demonstrated to be infective in extracts. The virus dealt with in this paper causes tumors in certain susceptible plants, is carried by leafhoppers, and like others in that group has proven difficult to detect in extracts. It is our purpose to recount briefly the variety of methods that failed to transmit the virus and to report on the success of insect-to-insect transmission by injection.

Go to article

Seed And Soil Treatments For Vegetable Crops Grown In Nebraska, M. W. Felton, J. E. Livingston Nov 1948

Seed And Soil Treatments For Vegetable Crops Grown In Nebraska, M. W. Felton, J. E. Livingston

Nebraska Agricultural Experiment Station: Historical Circulars

Tests conducted during the past four years at the Nebraska Agricultural Experiment Station have shown that when seeds are planted in cold, wet soils, better stands of vigorous seedlings are generally obtained when the seeds are treated before they are planted.

Go to article

Charcoal Rot Of Corn And Sorghum, J. E. Livingston Apr 1945

Charcoal Rot Of Corn And Sorghum, J. E. Livingston

Nebraska Agricultural Experiment Station: Historical Research Bulletins

In Nebraska, the charcoal rot caused considerable damage to the 1940 grain sorghum crop in the south central counties, and the following year it caused serious lodging and reduction of yield in both corn and sorghum in all sections of the state. Field observations indicated that some varieties of sorghum were damaged less than others; thus it appeared desirable to test thoroughly all varieties to determine whether any were sufficiently resistant to be recommended for field planting or to be used in a breeding program. It seemed desirable to study the influence of soil environment on infection and the development …

Go to article

Controlling The Ph Of Cultures Of Penicillium Notatum Through Its Carbon And Nitrogen Nutrition, Albert E. Dimond, George L. Peltier Jan 1945

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 …

Go to article

A Study Of The Physiology Of Grape Roots And Stocks In Relation To A Lime-Induced Chlorosis, Eldrow Reeve May 1941

A Study Of The Physiology Of Grape Roots And Stocks In Relation To A Lime-Induced Chlorosis, Eldrow Reeve

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The word chlorosis comes from the Greek "chloros" meaning light green and is used by plant science workers to designate a disease of plants, the characteristic symptom of which is the yellowing of the leaves.

Go to article

Spraying Tree Fruits, C. C. Wiggans, E. H. Hoppert Mar 1940

Spraying Tree Fruits, C. C. Wiggans, E. H. Hoppert

Nebraska Agricultural Experiment Station: Historical Circulars

The production of sound, clean fruit is unquestionably one of the major problems facing the modern fruit grower. Culture may be neglected and pruning delayed for a time but the omission of sprays for even a single season demonstrates their absolute necessity. This applies equally to the commercial grower and to the farmer or gardener who has only a few trees.

Go to article

The Effects Of Stinking Smut (Bunt) And Seed Treatment Upon The Yield Of Winter Wheat, T. A. Kiesselbach, W. E. Lyness Apr 1939

The Effects Of Stinking Smut (Bunt) And Seed Treatment Upon The Yield Of Winter Wheat, T. A. Kiesselbach, W. E. Lyness

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The depreciating effects of bunt or stinking smut (Tilletia levis Kuhn and tritici [Bjerk.] Wint.) upon the yield and quality of winter wheat in Nebraska and many other states are well known. The practical control of this disease through seed treatment has also been established and is being extensively practiced by growers. At the time these experiments were initiated in 1923, formaldehyde was the most commonly used disinfectant, while copper carbonate was just gaining recognition following its introduction by Darnell-Smith in 1915. It has been the chief purpose of the investigations herein reported to study the relative merits of …

Go to article

Comparative Physiology Of Actinomyces In Relation To Potato Scab, Mitrofan M. Afanasiev Aug 1937

Comparative Physiology Of Actinomyces In Relation To Potato Scab, Mitrofan M. Afanasiev

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The present work was undertaken with the purpose of investigating the physiology of different strains of A. scabies as compared with saprophytic Actinomyces. By a comparative study of these groups, it was thought that differences in the physiology of the two might be found which would give a better understanding of the nature of this parasitism and also of the metabolism of Actinomyces in general. In addition, it was hoped that the determination of the factors influencing the parasitism of Actinomyces might establish a basis for the development of more efficient methods of controlling scab diseases. The present investigation …

Go to article

The Influence Of Various Soil Factors Upon Potato Scab Caused By Actinomyces Scabies, R. W. Goss Aug 1937

The Influence Of Various Soil Factors Upon Potato Scab Caused By Actinomyces Scabies, R. W. Goss

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Scab, caused by Actinomyces scabies (Thaxt.) Giiss., is a potato disease of major importance in western Nebraska. Seed treatments are effective in controlling seed-borne scab, but it has been shown that even when healthy or treated seed potatoes are used the disease may be very severe because of infection from the soil. Crop rotation will reduce the incidence of the disease, but the fact that potato scab may cause serious loss in soils never before planted to potatoes indicates that there are numerous factors other than the time interval between potato crops which affect the occurrence of the disease. A …

Go to article

The Tympanis Canker Of Red Pine, John Raymond Hansbrough Jan 1936

The Tympanis Canker Of Red Pine, John Raymond Hansbrough

Yale School of the Environment Bulletin Series

A new disease of red pine has recently been found in southern Connecticut, Rhode Island, eastern Massachusetts, western and central New York, northern New Jersey, eastern Pennsylvania, central Ohio, and southern Michigan. It is of serious consequence only on plantation-grown red pine, but it also occurs occasionally on eastern white pine. On the former host it is characterized by axially elongated, annual main-stem cankers which are always centered at the nodes. Infection takes place through adhering lateral dead branches and the growth of the fungus after it gains entrance to the stem.is usually very rapid-Le., cankers up to three feet …

Go to article

Wilt And Cold Resistance Of Self-Fertilized Lines Of Alfalfas, George L. Peltier, H. M. Tysdal Sep 1934

Wilt And Cold Resistance Of Self-Fertilized Lines Of Alfalfas, George L. Peltier, H. M. Tysdal

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The relative reactions to cold and wilt of self-fertilized lines of alfalfa through to the fifth generation are reported. Some of the reasons for undertaking a breeding program are given as well as methods used in the controlled cold and wilt determinations. Preliminary studies showed that reinoculating healthy individuals which had already resisted one wilt infection test served to eliminate additional plants, but the percentage healthy was much higher after the reinoculation than after the first inoculation. The foundation materials from which selections were made consisted of selected plants from a number of old Nebraska fields and a large collection …

Go to article

Cephalosporium Wilt And Die-Back Of The White Elm, R. W. Goss, Paul Raymond Frink Jan 1934

Cephalosporium Wilt And Die-Back Of The White Elm, R. W. Goss, Paul Raymond Frink

Nebraska Agricultural Experiment Station: Historical Research Bulletins

A new disease of the white elm has been found to be common in eastern Nebraska. The causal organism has been isolated and its pathogenicity proved by inoculation. The fungus belongs to the genus Cephalosporium and is considered to be the same as that described by Curtis May of Ohio and found by him in specimens obtained in Iowa, Missouri, New York, and Washington, D.C. The morphology and cultural characters of the organism are described.

Go to article

The Relative Susceptibility Of Alfalfas To Wilt, George L. Peltier Apr 1933

The Relative Susceptibility Of Alfalfas To Wilt, George L. Peltier

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Except for alfalfa seed originating from a few old fields of Turkestan and Ladak, all varieties and strains now grown for commercial seed production in the United States, so far tested, have proved susceptible to wilt. All seed lots tested from South America (Chile, Argentina, and Uruguay), Europe (France, Spain, Portugal, Germany, Hungary, Italy, Roumania, and Ukranian S.S.R.), Africa (Morocco, Algeria, and Abyssinia), and Asia (Palestine, Manchuria, China, Korea, and Chinese Turkestan) were found to be susceptible to wilt. All seed lots of Turkestan origin so far tested are as resistant as Hardistan, or more so. Seed samples from the …

Go to article

The Nature Of Resistance In Alfalfa To Wilt (Aplanobacter Insidiosum L. Mc.), George L. Peltier, F. R. Schroeder Oct 1932

The Nature Of Resistance In Alfalfa To Wilt (Aplanobacter Insidiosum L. Mc.), George L. Peltier, F. R. Schroeder

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Alfalfa wilt was first discovered in 1924 in southern Wisconsin and northern Illinois. The causal organism, Aplanobacter insidiosum, was later described by McCulloch. Since that time wilt has been reported from most of the alfalfa-growing sections of the United States and in some states it has been responsible for a rapid decrease in the acreage of alfalfa. During the past three years a number of investigators have found that certain alfalfas are somewhat resistant to wilt, whereas others are very susceptible. At the Nebraska station the results to date indicate that all common and most variegated alfalfas are very …

Go to article

Tuber Development In Triumph Potatoes As Influenced By Time Of Planting On Dry Land In Northwestern Nebraska, H. O. Werner May 1932

Tuber Development In Triumph Potatoes As Influenced By Time Of Planting On Dry Land In Northwestern Nebraska, H. O. Werner

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Triumph potatoes were planted on four different dates during six years in order to determine the best planting date on dry land in northwestern Nebraska, where this variety is grown primarily for seed. Features considered in comparing the merits of these planting dates were: stand of plants; vine growth; disease prevalence; time of plant maturity; number, size, and shape of tubers; cracking at harvest time; prevalence and severity of common scab; total yields and yields of various grades of potatoes from various harvesting dates; weight loss in storage; and duration of the dormant period. The experimental aspects dealing with the …

Go to article

Infection Experiments With Spindle Tuber And Unmottled Curly Dwarf Of The Potato, R. W. Goss Feb 1931

Infection Experiments With Spindle Tuber And Unmottled Curly Dwarf Of The Potato, R. W. Goss

Nebraska Agricultural Experiment Station: Historical Research Bulletins

It is probable that more than one insect species are capable of spreading some of the potato virus diseases. This conclusion was also indicated by repeated observations in the dry-land section of western Nebraska. While aphids are abundant and are probably the chief vectors of potato virus diseases in the more humid sections of the country, they are usually scarce in the western upland plains area and are not present in large enough numbers to account for the rapid spread of spindle tuber and unmottled curly dwarf which sometimes occurs. It was therefore considered advisable to determine the common potato …

Go to article

The Relative Susceptibility Of Alfalfas To Wilt And Cold, George L. Peltier, H. M. Tysdal Dec 1930

The Relative Susceptibility Of Alfalfas To Wilt And Cold, George L. Peltier, H. M. Tysdal

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The final solution of the alfalfa-wilt problem in Nebraska probably lies in the development of resistant sorts that are winterhardy as well as productive. The relative susceptibility to wilt of 40 lots from Turkestan, 10 from France, 6 of Grimm from as many states, and 16 domestic alfalfas are reported on at this time, together with hardiness tests of a few well-known varieties and strains and the more recent introductions from Turkestan and France.

Go to article

Breeding Winter Wheat For Resistance To Stinking Smut (Tilletia Levis And Tilletia Tritici), T. A. Kiesselbach, Arthur Anderson Dec 1930

Breeding Winter Wheat For Resistance To Stinking Smut (Tilletia Levis And Tilletia Tritici), T. A. Kiesselbach, Arthur Anderson

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Several productive lines of hard red winter wheat which are highly resistant to both species of stinking smut (Tilletia levis and T. tritici) have been isolated from the Turkey variety. Artificial-smut and stem-rust epidemics and controlled freezing have been found useful supplements to field-performance tests. Differential reactions of the new Turkey selections and a number of hybrid selections and established resistant varieties to collections of bunt from a number of states give definite evidence of the occurrence of mild and virulent physiologic forms of both species. Certain selections have proved very resistant to some of the smut collections and …

Go to article

The Symptoms Of Spindle Tuber And Unmottled Curly Dwarf Of The Potato, R. W. Goss May 1930

The Symptoms Of Spindle Tuber And Unmottled Curly Dwarf Of The Potato, R. W. Goss

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The differentiation of the virus diseases of the potato on the basis of symptoms is an important but difficult phase of the virus problem. A knowledge of the variation in symptoms due to environmental factors is necessary both in investigational work and in the practical application of our knowledge to the control of these diseases in the field. A fairly comprehensive knowledge of the masking effect of certain environmental factors upon the symptoms of the mosaic group has been obtained through the work of various investigators. Considerably less information is available concerning the effect of environment upon the symptoms of …

Go to article

Seed Potato Treatment Tests For Control Of Scab And Rhizoctonia, R. W. Goss, H. O. Werner Dec 1929

Seed Potato Treatment Tests For Control Of Scab And Rhizoctonia, R. W. Goss, H. O. Werner

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Potato scab annually takes a very large toll from the potato growers of Nebraska. Rhizoctonia causes considerable loss each year, particularly in the early-potato sections, where it decreases stand and yield. These losses are caused by infection from both the soil and the seed. The investigations reported in this paper deal only with the control of the infection arising from the seed. Even though potato seed treatments have been recommended for many years, the diversity of recommendations being made at present by various agencies is very confusing to the grower and research worker alike. Many of the reports from different …

Go to article

Effect Of Cultural Methods And Maturity Upon The Seed Value Of Eastern Nebraska Potatoes, H. O. Werner Dec 1929

Effect Of Cultural Methods And Maturity Upon The Seed Value Of Eastern Nebraska Potatoes, H. O. Werner

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Seed potatoes as good as northern stocks have been produced under a straw mulch in eastern Nebraska by experimenters and growers. Occasionally reports are heard that a lot of seed potatoes has been grown in eastern Nebraska by ordinary cultural methods for many years, apparently without loss of vigor or yielding capacity. In view of this situation it seemed advisable to investigate this problem to determine whether, and to what extent, environment and maturity as such influence the productivity of seed potatoes and also whether it is feasible to produce satisfactory seed potatoes in the southern and eastern portions of …

Go to article

A Research Delusion, George L. Peltier Jan 1928

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 …

Go to article

Stem Rust In Nebraska. Part I. General Survey Of Sources. Part Ii. Identification Of The Physiologic Forms Of Puccinia Graminis From Various Sources, George L. Peltier, A. F. Thiel Jul 1927

Stem Rust In Nebraska. Part I. General Survey Of Sources. Part Ii. Identification Of The Physiologic Forms Of Puccinia Graminis From Various Sources, George L. Peltier, A. F. Thiel

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Part I: Since the inception of the barberry eradication campaign in 1918 in Nebraska, the question has continually been asked, "Will the eradication of the barberry in the state eliminate or materially reduce stem rust?" In order that an answer might be obtained, an investigation to determine the sources of primary infection of stem rust on cereals was inaugurated in the spring of 1921. Although these studies have been carried on for 6 years, no definite statement regarding the relative importance of the primary sources and the amount of stem rust prevalent in the state from season to season originating …

Go to article

The Effect Of Treatment With Ethylene Chlorhydrin Gas Upon The Respiration Of Dormant Potato Tubers, Leon M. Pultz Jan 1927

The Effect Of Treatment With Ethylene Chlorhydrin Gas Upon The Respiration Of Dormant Potato Tubers, Leon M. Pultz

Electronic Theses and Dissertations

Chemicals have long been in use as mean of eliminating or abbreviating the rest period of various plant organs. Usually, however, they have been in the hands of workers who were interested only in forcing the resting parts into growth and not in determining the physiological effect of the chemicals upon them. Since Appleman (1) presents a very comprehensive review of the earlier literature pertaining to the subject, it will not be again presented here. More recently Denny (4, 5) has given now impetus to this work by demonstrating that ethylene chlorhydrin and various other chemicals will greatly shorten the …

Go to article

The Differential Reaction Of Strains Within A Variety Of Wheat To Physiologic Forms Of Puccinia Graminis Tritici, T. A. Kiesselbach, George L. Peltier Dec 1926

The Differential Reaction Of Strains Within A Variety Of Wheat To Physiologic Forms Of Puccinia Graminis Tritici, T. A. Kiesselbach, George L. Peltier

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Black stem rust of wheat (Puccinia graminis tritici (Pers.) Erikss. & Henn.), which occurs in Nebraska and thruout most of the wheat producing regions of the world, is of a composite nature, in that it consists of a number of physiologic forms which can be determined by their action on different varieties of Triticum species, as shown by Stakman and Levine. The ordinary commercial variety of wheat may likewise be regarded as a mixture, in that it consists of numerous strains, which differ in some more or less important characteristics, as has been frequently indicated in the literature concerning …

Go to article

First Prev Next Last