Agronomy and Crop Sciences Commons^™

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 …

Seed Storage In Relation To Germination, G R W Meadly

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

WE are often asked how long seed can be stored and remain suitable for sowing.

There is no single answer as the period depends on a number of factors, including the type of seed, its condition at the time of storing and the nature of the storage.

Turf Clippings Conference Proceedings, The Stockbridge School Turf Management Club

Turf Clippings

1. Recent Developments Affecting Golf Course Design (page 1)
2. From the Editor (3)
3. Five Year Results (3)
4. Turf Management Club News (4)
5. Quotes from 1960 Seniors (5)
6. Poa annua - - Friend or Foe (6)
7. The Horticulture Show (7)
8. Cartoons (8)
9. Message from the Winter School President of 1960 (10)
10. The Most Outstanding Turf Senior for 1959 (10)
11. The Value of the Proper Use of Lime (11)
12. Summer Placement (12)
13. A Greenhouse on the Golf Course (13)
14. More Opportunities in the Future for the Aggressive Superintendent at Country Clubs (14)
15. Soil, Sawdust and Turfgrass (15)
16. Picture - Senior Stockbridge Turf majors …

Commercial Vegetable Growing In The Perth Metropolitan Region, L T. Jones

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

MARKET gardening with sprinkler irrigation on deep sandy soils around Perth is really a commercial application of hydroponics or sand culture principles.

Provision of a continuous and adequate supply of nitrogen is the major problem. Peat swamps scattered among the sandy areas have higher natural fertility. However, their common problems are drainage, acidity ("sourness"), salt and various special soil deficiencies. Over-liming of acid swamps can cause new problems.

Field Bean Production Under Irrigation In Nebraska, F. V. Pumphrey

Nebraska Agricultural Experiment Station: Historical Circulars

The purpose of this bulletin is to bring together the latest information available on the production of dry edible beans under irrigation in Nebraska. Cultural practices and disease control are stressed, but included are items on marketing, cleaning, and the use of by-products - straw and cull beans.

Rate Of Potato Tuber Growth On Dryland At The Box Butte Experiment Farm, H. O. Werner

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

Relatively late planting of potatoes, i.e., between June 12 and 25, has become the prevailing practice in the dryland areas of western Nebraska. Late planting distinctly improves the color and type of tubers, and reduces losses due to insects and diseases (especially soil-borne diseases caused by Fusarium and Streptomyces). Growers must decide each year whether the increase in yield and tuber maturity gained by delaying harvest will be offset by the risk of impaired tuber quality due to scab or possible serious field frost damage. Information about the rate at which tubers are developing by various dates is essential …

Introduced Forage Grasses For Nebraska, F. D. Keim, L. C. Newell

Nebraska Agricultural Experiment Station: Historical Circulars

This circular presents illustrations, descriptions and recommended usage of fourteen introduced cultivated grasses that are worthy of practical consideration in Nebraska. Most of them can easily be identified by comparing plant specimens with the illustrations and descriptions. This circular has been prepared for use by farmers, county agricultural agents, teachers and others who are interested in our most important grasses. Station Circular 59 contains information and illustrations of the more common native perennial grasses of Nebraska.

Answers To Questions About Partridge Pea, T. H. Goodding, J. C. Russel

Nebraska Agricultural Experiment Station: Historical Circulars

The Nebraska Agricultural Experiment Station has been working with partridge pea since 1944. Seed has been distributed for tests, and several farmers are now growing it. It is primarily a plant for soil conservation and soil improvement. Its value in comparison with other legumes have not been fully established.

Fertilization And Improvement Of Native Subirrigated Meadows In Nebraska, P. Ehlers, G. Viehmeyer, R. Ramig, E. M. Brouse

Nebraska Agricultural Experiment Station: Historical Circulars

It is the purpose of this circular to summarize the 1948-51 results of fertilizer applications upon subirrigated native meadows. It is upon these lands that the cattleman depends to a large extent for winter feed.

Hairy Vetch For Nebraska, T. H. Goodding

Nebraska Agricultural Experiment Station: Historical Circulars

Hairy vetch is a winter annual legume. It may be planted either in the spring or fall. Hairy vetch often succeeds on soils where sweet clover and alfalfa fail. It is more tolerant to acid (lime-deficient) soils than most leguminous crops.

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 …

Safflower Production In The Western Part Of The Northern Great Plains, C. E. Classen

Nebraska Agricultural Experiment Station: Historical Circulars

Recent development of new varieties with seeds averaging more than 30 per cent oil give safflower a good chance of becoming an important oil seed crop in the United States. It is the purpose of this circular to acquaint farmers with the crop and to outline the most promising production practices for those who undertake its production in the western part of the northern Great Plains.

Safflower Production In The Western Part Of The Northern Great Plains, C. E. Classen

Nebraska Agricultural Experiment Station: Historical Circulars

Recent development of new varieties with seeds averaging more than 30 per cent oil give safflower a good chance of becoming an important oil seed crop in the United States. It is the purpose of this circular to acquaint farmers with the crop and to outline the most promising production practices for those who undertake its production in the western part of the northern Great Plains.

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.”

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 Relative Frequency Of Crossing Over In Microspore And In Megaspore Development In Maize, R. A. Emerson, C. B. Hutchison

Department of Agronomy and Horticulture: Faculty Publications

One of the early developments in the study of linkage in Drosophila was the discovery that the phenomenon of crossing over is confined to the female sex (Morgan 1912). The fact that no crossing over occurs in the male Drosophila holds true not only for sex-linked genes but for factors in the autosomes as well and is so well established that it affords a most convenient method of determining to which of the different linkage groups a new factor belongs.

The same phenomenon, but with the sexes reversed, obtains in the silkworm moth. Tanaka (1914, 1915) has found from back-cross …

Heritable Characters Of Maize: Ix. Crinkly Leaf, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

In 1910 a strain of dent corn obtained at the National Corn Exposition held at Omaha was crossed with a strain of flint corn obtained from the Department of Agronomy of the University of Nebraska. The F₁ plants of this cross were normal and no abnormalities had been observed in the parent strains. But since the latter had not been subjected to self-pollination, there is no assurance that one or other of them did not have in it the character to be described here. In the F₂ generation of this cross there occurred a tpe of plant that …

Heritable Characters Of Maize Ii.-Pistillate Flowered Maize Plants, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

In the "freak"

class at the Annual

Corn Show held at Lincoln, Nebraska,

in the winter of 1913-14,

there was exhibited a corn tassel

with a heavy setting of seeds. A few

seeds are not infrequently found in the

staminate inflorescence of maize, particularly

in pod com, and tillers of various

corn varieties often end in ears instead

of in tassels or have tassels, the central

spikes of which are ear like. The freak

exhibited at the com show, however,

was a large. much branched affair.

wholly tassel-like in form except for the

fact that it bore a heavy crop …

Genetical Studies Of Variegated Pericarp In Maize, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

Two years ago there were presented some results of a study of the inheritance of self pattern in the pericarp of maize seeds, occurring as a sporophytic2 variation in variegated ears (EMERSON1 914). Further results, in entire accord with those previously reported, have now been obtained. In addition, data bearing upon new phases of the problem are also available.

The chief results reported in the earlier paper were the following: ( I ) The more nearly self-colored the pericarp of any seed of a variegated ear, the more likely is the progeny of that seed to produce a self-colored ear …

The Inheritance Of A Recurring Somatic Variation In Variegated Ears Of Maize, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

The inheritance of variegation has special interest and importance in genetics. It is with forms of variegation that the only two certainly known cases of non-Mendelian inheritance have had to do. I refer to Baur's experiments with Pelargonium, in which crosses of green-leaved and white-leaved forms exhibited somatic segregations in F₁ that bred true in later generations, and to Correns 's work with Mirabilis, which showed green and white leaf color, to be inherited through the mother only. De Vries's con- ception of "ever-sporting" varieties was apparently founded largely upon the behavior of variegated flowers in pedigree …

Multiple Factors Vs. "Golden Mean" In Size Inheritance, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

Groth's preliminary note on the "golden mean" in the inheritance of sizes in SCIENCE of April 17, 1914, pp. 581-584, deserves the attention of geneticists. Its publication is of such recent date that I need only call attention to one or two points that seem to me of particular moment.

In brief, Groth's hypothesis is that the mode

of inheritance in F_l not only of surfaces and

volumes, but also of linear dimensions is to be

expressed by √ab rather than by a + b /2

where a and b are parent sizes. The hypothesis

is based upon …

Shorter Articles And Reports: The Simultaneous Modification Of Distinct Mendelian Factors, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

In another paper on the inheritance of a recurring somatic variation in variegated ears of maize, it was shown that the amount of red color developed in the pericarp of variegated seeds bears a definite relation to the development of color in the progeny of such seeds. The relation is such that the more color there is in the pericarp of the seeds planted the more likely are they to produce plants with wholly self-red ears and correspondingly the less likely to produce plants with variegated ears. Self-red ears thus produced behave just as if they were hybrids between self-red …

The Possible Origin Of Mutations In Somatic Cells, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

That mutations are accompanied by some change in the germ-plasm is, I take it, indisputable. Have we, however, any reason to suppose that the change takes place within the germ cells? I am not sure, as a matter of fact, that genetists in general regard the gametes as the place of origin of mutations. It is true, however, that experiments in the artificial production of mutations in plants have been limited largely to treatments of the ovaries from about the time of the reduction division to about the time of fertilization. This suggests a belief on the part of investigators …