Plant Pathology Commons^™

Thrips Damage Of Grapes, A N. Sproul

Journal of the Department of Agriculture, Western Australia, Series 4

IN mid-December, a few bunches of Semillon grapes were submitted for examination from a Caversham Vineyard.

Damage to grape berries by thrips has not been recorded before in Western Australia.

The 1965 Ord River Cotton Crop, G D. Oliver, A. W. Hogstrom

Journal of the Department of Agriculture, Western Australia, Series 4

THE financial results of 18 cotton growers in the Ord River Valley during the 1965 season were obtained during a survey conducted in August, 1965.

All farmers who have been allocated blocks and who grew cotton in 1965 were included in the survey.*

Black Spot And Powdery Mildew Of Grapes, H L. Harvey

Journal of the Department of Agriculture, Western Australia, Series 4

BLACK spot (or anthracnose) and powdery mildew (or oidium) are diseases that occur commonly on grape vines in W.A.

Take-All Of Wheat On The Esperance Downs : The Effect Of Multiple Cropping, S C. Chambers

Journal of the Department of Agriculture, Western Australia, Series 4

A considerable increase in take-all occurred in the second crop of wheat following linseed, oats or vetches at the Esperance Downs Research Station.

THE take-all disease of wheat, caused by the fungus Ophiobolus graminis, has been responsible for many crop failures in the Esperance district during the past 15 years.

In an endeavour to find a practical solution to this problem, a crop rotation experiment was started in 1961 at the Esperance Downs Research Station.

A Study Of Puccinia Graminis And Cronartium Ribicola, Duane W. Hughes

Graduate Student Research Papers

It was the purpose of this study (1) to review the literary history of rusts in the United States and in the Northwest in particular, ( 2) to learn where rusts generally are found geographically, (3) to gain further information regarding the etiology of wheat rust (Puccinia graminis tritici), of white pine blister rust (Cronartium ribicola) and to become enlightened on other rusts, (4) to learn ways of controlling the two rusts, black stem rust of wheat and white pine blister rust, and to gain an appreciation of the economic importance of rust prevention.

Root Diseases In Wheat On Clover Ley : Factors Under Investigation. 5. The Evaluation Of Fungicidal Treatments, S C. Chambers

Journal of the Department of Agriculture, Western Australia, Series 4

The use of fungicides, either as seed or soil dressings, for the control of root rotting diseases of wheat, was examined in a series of field experiments.

Results suggest that seed dressings have no effect on the incidence of root rotting fungi in the mature crop.

When fungicides were applied to the soil, a reduction in the incidence of take-all was noted in one experiment, but the same treatments had toxic effects on plants in a second similar experiment.

Powdery Mildew Or Oidium Of Grapes, H L. Harvey

Journal of the Department of Agriculture, Western Australia, Series 4

POWDERY mildew or oidium, is a disease which is always present to a greater or lesser extent in grapevines in Western Australia.

In seasons favourable for its development it stunts the growth of shoots and leaves and may seriously reduce fruit yields and quality.

Most of our commonly-grown varieties are quite susceptible to the disease, but for the reason that currants are the most extensively grown variety, the overall losses are greatest in this variety.

What's Wrong With That Plant?, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

EACH year several thousand inquiries are received from people who want to know "What's wrong with that plant?" The plants range from common fruit, vegeable and pasture plants to rare ornamentals.

In most cases, the inquiries can be answered satisfactorily by Departmental officers who specialise in the study of various plant troubles.

Ec59-1822 Plant Diseases: Peony Blight, John L. Weihing

University of Nebraska-Lincoln Extension: Historical Materials

EC 59-1822 is about plant diseases and especially peony blight (also called Botrytis blight) and how to control it.

False Smut Of Buffalograss, John L. Weihing

Nebraska Agricultural Experiment Station: Historical Research Bulletins

False smut of buffalograss, Buchloe dactyloides (Nutt.) Engelm., caused by Cercospora seminalis Ell. & Ev. is a disease that destroys the unfertilized ovary. The disease was first reported by J. B. Ellis and B. M. Everhart in 1888. They gave only a brief description of the disease and named the causal fungus Cercospora seminalis. There are no etiological studies of false smut recorded in the literature. The origin of the term "false smut" is unknown to the author, but it so descriptively fits the general appearances of the disease that one readily understands its usage. The following studies were …

Streak Mosaic Of Wheat In Nebraska And Its Control, R. Staples, W. B. Allington

Nebraska Agricultural Experiment Station: Historical Research Bulletins

This bulletin reports the results of studies on the epidemiology of wheat streak mosaic under Nebraska conditions. Particular attention is given to the occurrence and certain characteristics of the mite vector of the virus, the relation of weather and other factors to some of its activities, a correlation of certain mite situations with epidemics of the disease, and recommendations for disease control.

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.

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 …

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 …

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 …

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 …

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 …

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.

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 …

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 …

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 …