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The Metabolism Of Some Nitrogen-Fixing Clostridia, W. Hillman Willis 2017 Iowa State College

The Metabolism Of Some Nitrogen-Fixing Clostridia, W. Hillman Willis

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

Studies have been conducted upon certain nitrogen-fixing clostridia isolated from Tama silt loam and Grundy silt loam, two acid soils widely distributed in Iowa. Tests have been made of their reaction requirements, capacity to fix gaseous nitrogen and production of carbon dioxide under varying controlled conditions in the laboratory. The results appear to warrant the following conclusions.

1. Nitrogen-fixing anaerobes were present in rather large numbers in the acid soils studied.

2. Varying applications of lime had little or no effect upon the numbers of anaerobic nitrogen-fixers or upon their ability to fix nitrogen in soil-solution cultures in the presence ...


Factors Influencing A Malformation Of The Leg Bones Of Growing Chickens, Thomas Theodore Milby 2017 Iowa State College

Factors Influencing A Malformation Of The Leg Bones Of Growing Chickens, Thomas Theodore Milby

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

When varying amounts of phosphorus from inorganic sources were added to a basal ration of ground yellow corn, wheat middlings and dry skimmilk, in which the amount of calcium in the various rations was held practically constant, the incidence of slipped tendon increased as the phosphorus increased. Though the trend was very definite, the relation between the amount of phosphorus in the ration and the percentage of slipped tendon was not exactly linear, indicating that factors other than the amount of phosphorus in the ration may have been operating to influence the incidence of slipped tendon. Two groups of chicks ...


Competitive Position Of Lard In The Market Of Animal And Vegetable Fats And Oils, Rainer Schickele, Theodore W. Schultz 2017 Iowa State College

Competitive Position Of Lard In The Market Of Animal And Vegetable Fats And Oils, Rainer Schickele, Theodore W. Schultz

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

Lard ranks second among the domestically consumed fats and oils, exceeded only by butter. Lard constitutes about one-sixth of the total value of hog products. It is one of our most important export commodities; between 85 and 90 percent of the lard entering international commerce is of American origin. Yet in spite of its economic importance, especially to the hog producers of the Corn Belt, practically no work has been done to investigate the production and market characteristics of lard and its competitive position relative to other fats and oils. The literature dealing with the market situation of butter, margarine ...


Growth Responses Of The Gladiolus As Influenced By Storage Temperatures, David C. Fairburn 2017 Iowa State College

Growth Responses Of The Gladiolus As Influenced By Storage Temperatures, David C. Fairburn

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

The gladiolus, one of the most popular ornamental bulbous plants, is a tender perennial and will not survive if exposed to severe winter weather. The corms must be removed from the garden in the fall and stored until planting time in the spring. The conditions to which the corms are subjected during storage determine to a large extent the growth responses the following season. Consequently, this phase of gladiolus culture is of paramount importance. The present knowledge regarding proper storage temperatures is far from comprehensive. Further study is necessary, and the following investigation concerned with the physiology, morphology and growth ...


The Numbers Of Lipolytic Bacteria In Various Dairy Products, As Determined With Nile-Blue Sulfate, B. W. Hammer, M. A. Collins 2017 Iowa State College

The Numbers Of Lipolytic Bacteria In Various Dairy Products, As Determined With Nile-Blue Sulfate, B. W. Hammer, M. A. Collins

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

The lipolytic bacteria in milk, cream and butter are of interest from the standpoint of the development of defects in these products. Presumably, rancidity is the most important of such defects, although since many of the lipolytic bacteria also attack constituents of milk other than fat, additional defects may be involved. Comparatively little attention has been given to the numbers of lipolytic organisms in various dairy products, because methods of determining these organisms have not come into such common use as have the methods of determining proteolytic and acid-forming organisms.


Pathogenicity, Host Response And Control Of Cercospora Leaf-Spot Of Sugar Beets, Edgar F. Vestal 2017 Iowa State College

Pathogenicity, Host Response And Control Of Cercospora Leaf-Spot Of Sugar Beets, Edgar F. Vestal

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

On artificial media conidia of Cercospora beticola began to appear in 12 to 20 hours after inoculation, and the optimum production was from 48 to 96 hours after transfer.

Germination of the conidium may take place at any point, but more often near a septum and from the basal end of the cell first.

Germination of the conidia did not take place on the living leaf in an atmosphere containing less than 90 percent humidity.

The humidity of the leaf surface was found to be an average of 3.5 percent higher than the surrounding atmosphere.

An air humidity of ...


Resistance Of Dent Corn To Basisporium Gallarum Moll., C. S. Reddy 2017 Iowa State College

Resistance Of Dent Corn To Basisporium Gallarum Moll., C. S. Reddy

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

Injury by Basisporium gallarum is associated with cessation of translocation within the corn plant. It occurs at the time of germination, after normal maturity, and when plants die prematurely from cold or other causes.

Basisporium-infected seed dies within a few days after it is planted in soils slightly below the temperature range for germination. The organism kills the germ before active translocation sets in. Active translocation, in this case, means germination and germination marks a change in the embryo from neutral to acid reaction. Acid reaction in the cob was shown to be correlated with resistance to Basisporium infection. Therefore ...


The Pathogenicity And Seasonal Development Of Gymnosporangium In Iowa, Donald E. Bliss 2017 Iowa State College

The Pathogenicity And Seasonal Development Of Gymnosporangium In Iowa, Donald E. Bliss

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

Seven species of the genus Gymnosporangium occur in Iowa, but only G. juniperi-virginianae, causing cedar-apple rust, and G. globosum, causing hawthorn rust, are common. The latter is of little economic importance.

The epidemic of cedar-apple rust in 1928 caused an estimated loss of $200,000 in Iowa.

Six to seven hours were required to produce abundant sporulation from air dry galls of G. juniperi-virginianae regardless of whether the period of soaking was 30 or 180 minutes.

Newly-matured aecidiospores of G. juniperi-virginianae germinated to the extent of 54 percent in July. A lot was divided and the percentage of germination in ...


The Relation Of Moisture To Respiration And Heating In Stored Oats, A. L. Bakke, N. L. Noecker 2017 Iowa State College

The Relation Of Moisture To Respiration And Heating In Stored Oats, A. L. Bakke, N. L. Noecker

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

1. Considerable variation in oxygen consumption is found even with oats of low moisture content.

2. Heating of oats in well insulated flasks is negligible when the moisture is below 15.00 percent.

3. Oats with the moisture content above 15.00 percent, heated as the moisture content was increased up to 24.00 percent, at which point the maximum heating was reached. When the moisture content was increased beyond 24.00 percent a gradual but irregular falling off in heating was noted.

4. Oats with a moisture content of 40.01 percent consumed the greatest quantity of oxygen, whereas ...


Annual Fluctuations In The Price Of Corn, Geoffrey Shepherd 2017 Iowa State College

Annual Fluctuations In The Price Of Corn, Geoffrey Shepherd

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

The United States average farm value of corn per bushel Dec. 1 before the World War was determined almost entirely by the size of the United States corn crop. The closeness of the relation is indicated by the simple correlation coefficient - .9738. The regression of corn value on corn production was - 1.62. Since the war, this regression has decreased to - 1.54.

Since the war, the farm value of corn has become sensitive to other influences besides the size of the corn crop. Three other factors now seem to influence the value of corn - the numbers of livestock on ...


Factors Affecting Experimental Error In Field Plot Tests With Corn, Arthur A. Bryan 2017 Iowa State College

Factors Affecting Experimental Error In Field Plot Tests With Corn, Arthur A. Bryan

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

1. Data are presented showing the variability among the yields of 2,304 hills of each of three commonly-grown strains of yellow dent corn. The variability among the mean yields of different numbers of randomly drawn perfect-stand hills decreased in close agreement with theoretical expectancy, as the number of hills increased to a total of 192. The reduction was rather small, however, after 48 hills were drawn so that this number may be considered about sufficient to represent a variety.

2. In a comparison of open-pollinated varieties and crosses of inbred lines equal degrees of precision were attained with about ...


Effect Of Time, Depth And Method Of Plowing Upon Yield And Eradication Of Biennial Sweet Clovers, F. S. Wilkins, E. V. Collins 2017 Iowa State College

Effect Of Time, Depth And Method Of Plowing Upon Yield And Eradication Of Biennial Sweet Clovers, F. S. Wilkins, E. V. Collins

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

From the standpoint of amount of dry matter and nitrogen added to the soil and the eradication of the plants, sweet clover may best be plowed for corn about April 25 to May 5. The five dates of harvest used rank as follows in yield of dry matter for tops and roots: May 3-18, Nov. 1-13, Oct. 1, April 9-13 and Sept. 1. Nitrogen yields rank in much the same order.

Of the total for tops and roots, the tops contained 68 percent of the dry matter and 73 percent of the nitrogen in September, 51 and 48 percent, respectively ...


Variations In Swine Prices Within Iowa Including A Study In Statistical Procedure, Theodore W. Schultz, A. G. Black 2017 Iowa State College

Variations In Swine Prices Within Iowa Including A Study In Statistical Procedure, Theodore W. Schultz, A. G. Black

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

Iowa's agriculture is chiefly corn-hog farming. Corn, which is produced in abundance, provides the raw material upon which the gigantic livestock industry depends. The sale of swine is the most important source of income of the state.

Profound changes have taken place in the economics of hog marketing during the last decade. Three-fifths of Iowa hogs are today sold direct to packers; receipts at public stockyards have declined accordingly. Concentration points have been established throughout the hog producing area. Order buying has become well developed. Add to these the improvements in rural transportation, better market news facilities, standardization of ...


The Uses Of Efficiency Factors In Analysis Of Farm Records, John A. Hopkins Jr. 2017 Iowa State College

The Uses Of Efficiency Factors In Analysis Of Farm Records, John A. Hopkins Jr.

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

In interpreting data obtained from farm accounts, frequent use is made of financial ratios, and of rates of input per unit of labor, land, or capital employed in the farm business. These so-called farm efficiency factors are designed to give the farm operator an approximate measurement of his success in organizing and managing those elements of the farm business which are, to some degree, under his control.

Efficiency factors or operating ratios are also useful to the extension worker in farm management. This specialist, as he discusses applications of farm organization and management principles, often feels a need for some ...


Bacteriology Of Butter V. Studies On The Microorganisms In Churns, H. C. Olson, B. W. Hammer 2017 Iowa State College

Bacteriology Of Butter V. Studies On The Microorganisms In Churns, H. C. Olson, B. W. Hammer

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

The utensils and equipment with which dairy products come in contact on farms and in dairy plants constitute a very important source of the microorganisms in these materials. Because their construction makes them especially difficult to clean, certain pieces of equipment are of much greater significance in this connection than others. In butter plants the churns are a particularly important source of organisms and, moreover, this contamination occurs subsequent to the pasteurization of the cream so that none of the organisms added by it are destroyed.


The Production Of Gum By Certain Species Of Rhizobium, Dean A. Anderson 2017 Iowa State College

The Production Of Gum By Certain Species Of Rhizobium, Dean A. Anderson

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

It has long been known that the legume root-nodule bacteria produce a bacterial gum, but knowledge of the exact role of gum production in the metabolism of the organism is still rather incomplete. The results secured by a number of investigators indicate that gum production may be intimately connected in some way with the mechanism of symbiotic nitrogen fixation. In addition, some studies have shown that considerable differences exist in the quantity and chemical nature of the gum produced by different species of Rhizobium.


The Winogradsky Spontaneous Culture Method For Determining Certain Soil Deficiencies, Arthur W. Young 2017 Iowa State College

The Winogradsky Spontaneous Culture Method For Determining Certain Soil Deficiencies, Arthur W. Young

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

Various chemical and biological methods have been suggested for the determination of the fertilizer needs of soils but all have been found to be of limited practical value. The search for a suitable method continues, however, and recently Winogradsky3 suggested a biological method which, by more nearly duplicating the conditions existing in the field, would give more accurate results. He devised what has been called the spontaneous culture test. This depends upon the growth of Azotobacter and possibly other aerobic, non-symbiotic, nitrogen-fixing microorganisms on the surface of the soil, treated with a a carbohydrate, calcium carbonate, a phosphate and ...


The Donation-Based Approach To Solving Critical Social Issues: An Examination Of The Food Waste Recovery Approach To Solving Hunger In The United States, Desa Radic 2017 SIT Graduate Institute/SIT Study Abroad

The Donation-Based Approach To Solving Critical Social Issues: An Examination Of The Food Waste Recovery Approach To Solving Hunger In The United States, Desa Radic

Capstone Collection

As the issue of hunger continues to plague the lives of nearly 1 billion people around the world, we need to find real, lasting and empowering solutions. This is an interdisciplinary research study into the donation-based approach to solving critical social issues in the United States by examining the food waste recovery and hunger debate. Social, public and private sectors advocate that hunger can be solved through food waste recovery and redistribution methods. From a systems perspective, such thinking is not only problematic for the people facing hunger, but raises concern of achieving overall social justice and change. Using qualitative ...


An Economic Analysis Of Farm Mortgages In Story County, Iowa, 1854-1931, William G. Murray 2017 Iowa State College

An Economic Analysis Of Farm Mortgages In Story County, Iowa, 1854-1931, William G. Murray

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

1. A total of 25,993 farm mortgages were analyzed and tabulated in this study. This total represents all mortgages placed on Story County farm land from 1854 through 1931.

2. The farm mortgage debt in Story County increased in every year except 15 out of the total of 78 years of mortgage history.

3. A study of the debt changes revealed four well-defined periods characterized, from 1854 to 1879, by land settlement; from 1880 to 1910 by rising land values; from 1911 to 1920 by price inflation ; and from 1921 to 1931 by price deflation.

4. Cyclical fluctuations in ...


The Relationship Of Acetylmethylcarbinol And Diacetyl To Butter Cultures, M. B. Michaelian, R. S. Farmer, B. W. Hammer 2017 Iowa State College

The Relationship Of Acetylmethylcarbinol And Diacetyl To Butter Cultures, M. B. Michaelian, R. S. Farmer, B. W. Hammer

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

The value of selected cultures of bacteria for the development of a desirable flavor and aroma in butter has been thoroughly established through comparisons of butter made with and without culture and also through the extensive commercial use of cultures. There are two distinct types of organisms present in the butter cultures commonly used, one of which (Streptococcus lactis or, according to certain investigators, Streptococcus cremoris) attacks primarily the lactose with the formation of large amounts of lactic acid while the other type (Streptococcus citrovorus and Streptococcus paracitrovorus Hammer (4), or Betacoccus Cremoris Knudsen and Sorensen (11), or Leuconostoc dextranicus ...


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