Life Sciences Commons^™

Spinach And Aphid Control By Ladybird Beetles, James E. Roberts

Journal of the Arkansas Academy of Science

No abstract provided.

Cowpea And Bean Weevils, W. D. Wylie

Journal of the Arkansas Academy of Science

No abstract provided.

Prussic Acid Poisoning In Common Vetch (Vicia Sativa) Seed, E. S. Ruby, J. Beasley, E. L. Stephenson

Journal of the Arkansas Academy of Science

No abstract provided.

Nebraska Plant Disease 4-H Club Manual : Extension Circular 19-01-2, John L. Weihing

Nebraska 4-H Clubs: Historical Materials and Publications

This 4-H extension circular, EC 19-01-2, EC 19012, is used for the Nebraska Plant Disease Club manual. Members of the 4-H plant disease club will learn to recognize the usual signs or symptoms of several types of disease, to collect, preserve and classify disease samples and specimens, to exhibit these specimens at public events such as fairs and to demonstrate methods for control of plant disease.

Secretion Of Amylase By Rumex Virus Tumors In Vitro, L. G. Nickell, M. K. Brakke

Department of Plant Pathology: Faculty Publications

The secretion of extracellular enzymes by intact cells of higher plants apparently is a rare occurrence. One example of it is the secretion of an extra, cellular amylase by the tissue of a virus-induced tumor from the root of Rumex wetosa L. An amylase is secreted in sufficient quantities by this tissue to enable it to grow as well in vitro on a starch-containing medium as on one containing sucrose.

Nitrogen-Fixing Bacteria For The Inoculation Of Leguminous Seeds

Journal of the Department of Agriculture, Western Australia, Series 3

The Plant Pathology Branch of the Department of Agriculture can supply the cultures listed below. Owing to the time taken to prepare the cultures, however, and owing also to the fact that in the busy time of the year there is frequently a tremendous accumulation of orders, farmers are requested to lodge their applications together with the requisite payment at least a fortnight before they wish the culture to be forwarded.

The Testing Of Bacterial Strains Used In The Inoculation Of Legumes, Olga M. Goss

Journal of the Department of Agriculture, Western Australia, Series 3

A part from their value as fodder plants, legumes such as peas, beans, clovers, vetches and lucerne play an important role in increasing soil fertility. Their value in the soil-enriching sphere has been recognised for centuries, but it is only comparatively recently that the reason for it has been fully understood.

Brown Rot And Collar Rot Of Citrus, W P. Cass Smith

Journal of the Department of Agriculture, Western Australia, Series 3

Plant disease

Brown rot is a serious disease of citrus, which fortunately has proved to be readily controllable. It attacks both leaves and fruits causing partial or complete defoliation, and a rather characteristic fruit rot. The disease may also affect the bark of citrus trees in the basal trunk region resulting in "collar rot," or as it is sometimes called, brown rot gummosis. This phase of the disease will be referred to later.

Breeding Cereal Crops For The Control Of Disease, H. R. Rosen

Journal of the Arkansas Academy of Science

No abstract provided.

Virus Diseases Of Cereal Crops In South Dakota, J.T. Slykhuis

Agricultural Experiment Station Technical Bulletins (1939-2011)

Virus diseases of wheat, oats and barley have been reported from various parts of the world during the last three decades. In some instances viruses have proven be the real causes diseases formerly attributed to other agents. The earliest reports of a virus disease of wheat concerned a mosaicrosette disease first observed in southeastern Illinois in 1919. The disease caused by a soil-borne virus was later found in a number of localities in the eastern half of the United States, but to date it has not been reported west of the Missouri River. However, other mosaic disease of wheat have …

Lack Of Effect Of Plant Growth-Regulators On The Action Of Alpha-Amylase Secreted By Virus Tumor Tissue, M. K. Brakke, L. G. Nickell

Department of Plant Pathology: Faculty Publications

This report deals with the effect of certain synthetic plant growth-regulators on the activity of alpha-amylase (1) secreted by virus tumor tissue grown in vitro. Previous studies have lacked adequately controlled conditions and have been carried out with enzyme preparations obtained through the usual methods of destruction of cells. In this particular study (a) the assay employed to measure enzyme activity includes control of pH and temperature and (b) this enzyme, being secreted, is not subject to the drastic preparative procedures involving destruction of cellular structure usually necessary to obtain enzymes.

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 …

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 …

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 …

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 …

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.

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.

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 …

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 …

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.

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 …

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 …

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 …

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 …

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 …

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.

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 …

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 …

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 …

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 …