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VII. Control of Insect Pests of Wheat

VII. Control of Insect Pests of Wheat

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fly, jointworm, and sawfly attack wheat only or principally. Some are

native to the United States and have found in cultivated crops ideal

conditions for their development and spread. Others, including some

of our most destructive pests, have been introduced from foreign countries. Build-up of populations and damage by all of them are affected

greatly by weather and other environmental conditions. Often they are

quiescent for a number of years only to become agents of disaster when

conditions become favorable. In practically all cases, areas of infestation and losses have increased more or less continuously during the last

fifty years.

Control is often difficult or impractical even when effective methods

are known. For example, an insect that causes a consistent but small

percentage loss may account for a very material decrease in production

for the country BS a whole and yet mean very little to the individual

farmers. This is especially so if control measures involve inconvenient

or costly changes in management or cultural practices. Sometimes such

changes invite losses from other causes that are more important. It is

for these reasons that known control measures sometimes are used very

sparingly or not a t all. Another difficulty stems from the fact that in

many cases concerted community action is necessary in order to achieve

effective control. It is only when losses become heavy, as they often do

in particular localities, that serious attention is given to control measures. This means that research must and does aim to develop methods

of control that may be incorporated as a part of the general cultural

pattern insofar as is feasible, and to develop those that are simple and

inexpensive when special measures are necessary.

Such research has included especially investigations of insecticides,

cultural practices, life history studies including egg-laying and feeding

habits, and breeding resistant varieties. Methods of applying insecticides have had much attention. Correlating insect epidemics with

weather and other environmental conditions has provided information

that is very useful for predicting or forecasting outbreaks and thereby

preparing for them. Breeding resistant varieties has had a prominent

place in research to control insects only in relatively recent years.

1. Hessian F l y

The Hessian fly is without doubt the most destructive insect pest of

wheat. The estimated loss in a single year has amounted to as much as

$100,000,000. Haeussler (1952) estimated the annual loss in the United

States in 1945 at $37,000,000.

The Hessian fly occurs in California and in the Pacific Northwest and

generally from western Kansas and Nebraska the Atlantic seaboard



and from northern Oklahoma to Minnesota. It is most common in winter wheat but sporadically damages spring wheat. It was first discovered

on Long Island in 1779 in the vicinity of Lord Howe’s camp of three

years before. It is thought by many to have been brought in in bedding

used by the Hessian soldiers included in the British army; hence, the

name. It spread westward almost as rapidly as did wheat, reaching

Kansas in about 1871 (McColloch, 1923) and the West Coast by 1884.

Cultural practices, including destruction of volunteer wheat plants,

plowing under of stubble, and late seeding, which had developed largely

as a result of general observation were the commonly recommended control practices before the tu rn of the century. Late seeding, according to

Bidwell and Falconer (1941, p. 9 6 ) , was recommended as early as 1811.

These methods are still used. Other measures now known to be ineffective

or objectionable or both were also frequently recommended. These included pasturing, burning stubble, and the use of decoy o r trap crops.

Varieties of wheat believed to be less susceptible to the Hessian fly than

others were recommended in the nineteenth century but not until the

early 1940’s were varieties available in which fly resistance actually had

been bred as a n important character.

Date-of-seeding tests with wheat were conducted systematically and

for several years in Indiana and Ohio and perhaps other states beginning as early as 1887. Based on these tests and observations on time of

emergence of Hessicn fly in the fall, a map of Ohio showing approximate

dates for safe p1an;ing in various parts of the state was published by

Webster (1899) of the Ohio Station in 1899. I n the following year,

A. D. Hopkins (19Ci)), using these data and his own observations in

West Virginia as starting points and making use of the relation between

altitude and latitude on the one hand and certain phenological data on

the other, constructed a similar map for West Virginia. These probably were the first maps to be published showing “safe” or “fly-free”

dates of seeding. The West Virginia map was probably the first practical application of the principles that later became the well-known

Hopkins bioclimatic law.

Extensive date-of-seeding tests since conducted by the Bureau of

Entomology and Plant Quarantine and by the state agricultural experiment stations have provided the information for similar maps for all

Hessian fly-infested areas of the United States. Although the general

principles have not been changed, the application has been improved

and refined. One improvement in particular stems from recognition of

the fact that the best dates for seeding fluctuate considerably from year

to year, depending on weather conditions and the prevalence of Hessian

fly. Timely information regarding these factors supplied by entomolo-



gists and county agents for each infested area has aided materially in

preventing serious losses.

Seeding on or after the fly-safe dates has been used extensively in

all Hessian fly-infested areas. It has not been fully effective, partly

because unexpected delays in seeding caused by unfavorable weather

invite losses from other causes and hence farmers tend to seed earlier

than the fly-safe dates, especially when infestation is light. Concerted

community action, sometimes difficult to achieve, is also necessary for

fully effective control. Other measures of control have therefore been


The most recent and theoretically, at least, the most satisfactory of

any control measure is the use of resistant varieties. Obviously, of

course, success here depends on the availability of varieties that not only

are resistant to Hessian fly but also satisfactory in other respects and

adapted to the areas where they are to be grown. Producing such varieties has, as would be expected, proved to be a difficult and time-consuming process.

The best examples of resistant varieties now in use by farmers are

the hard winter varieties PAWNEE and PONCA and the California varieties

BIG CLUB 43, POSO 44, and POSO 48, described in Section IV. 4b. The latter are credited with practically eliminating the Hessian fly in the

Montezuma Hills section of California, and PAWNEE is believed to be responsible for a very material reduction of Hessian fly in eastern Kansas

and contiguous areas. PONCA wheat, released by the Kansas and Oklahoma Agricultural Experiment Stations in 1951, is the most resistant

variety of hard red winter wheat available commercially.

Especially significant in relation to breeding other resistant varieties

is the discovery at the Indiana Station of an unusually high degree of

resistance in a durum wheat introduced from Portugal by the United

States Department of Agriculture. This resistance, unlike that found

in PAWNEE and other commercial varieties, appears t o be effective in all

areas of the United States and at high temperatures. Much progress

has been made in transferring this resistance t o commercial varieties of

common wheat, but the work is slow because of sterility and linkage such

as is invariably encountered in crosses of common and durum wheat.

2. Grasshoppers

Perhaps the most spectacular and useful research relating to the control of wheat insects is that concerned with the control of grasshoppers,

including Mormon crickets. These insects, of course, attack all crops,

including wheat, and are of particular concern here since they are most

destructive in areas where wheat is an important crop. According to




Hyslop (1938), severe outbreaks occur in the United States a t least once

in every ten years and each may last from one to six years. On the

basis of reports by entomologists from twenty-three of the most heavily

infested states, Hyslop has estimated the annual loss from all crops a t

about $25,000,000 per year for the ten-year period 1925-1934. Haeussler (1952) recorded the estimated loss in eighteen states in 1950 a t

nineteen million dollars. Infestation and damage are greatest in those

areas where the annual rainfall is about 25 inches or less, partly because

dry climates favor the build-up of large populations and partly because

there is less vegetation other than cultivated crops on which grasshoppers

may feed.

The most notorious outbreaks were those of the Rocky Mountain

grasshoppers, or locusts, as they were then called, during the developmental stages of agriculture in the Great Plains. This particular species disappeared about 1880 or were replaced by similar or identical

species with a different name. Three of the most important species in

the west today are the lesser migratory grasshopper, the differential

grasshopper, and the two-striped grasshopper. Depopulation of large

sections of the southern Plains in the 1880’s and 1890’s was in part due

to these and other species. Recurring ohtbreaks, aa indicated above,

continued to be a feature of Great Plains agriculture until new methods

of control were developed in recent years.

Various methods to control grasshoppers have been used. The first

ones were mechanical, such as hopperdozers, and for the nonflying Mormon crickets, trench, wood, or sheet iron barriers with pits at frequent

intervals in which the insects were collected and killed. Poison bait,

first used in the San Joaquin Valley of California in 1885, was a n important forward step. This device worked surprisingly well but was not

consistently effective because the grasshoppers would not always take

the bait. An important improvement was almost immediately made by

substituting wheat bran for middlings, and numerous subsequent attempts were made to make the bait more attractive by adding fruit

juices, molasses, banana oil, or flavoring of various kinds. In general,

however, according to Packard (1942) , the increase in effectiveness obtained with such attractants was not enough to offset the additional costs.

A more important achievement was the reduction in costs by diluting

the bran with relatively inert materials such as sawdust and cotton seed


An interesting and significant discovery was the fact that Mormon

crickets, in contrast with other grasshoppers, would not eat bait containing axsenic compounds but readily took those containing the equally

poisonous sodium fluosilicates. Since grasshoppers readily took to either,



the cost of baiting was greatly reduced and the general effectiveness of

baits was greatly increased. The use of the motorized truck to transport

and spread poison bait, power mixing machines and spreaders, and the

adaptation of the airplane for distributing poison baits greatly extended

their use. The reduction in costs made control by poison baits practical

on a large scale, and they were used extensively for many years.

Without doubt, the most significant and far-reaching research achievements of all time relating to insect control methods were the discovery

and use of the new insecticides aldrin, chlordane, toxaphene, and others.

Incredible though it may seem, as little as 2 ounces of aldrin per acre,

applied as a spray or dust by airplane or ground equipment, will, under

favorable conditions, result in almost complete destruction of grasshoppers on the treated areas, and the residual effects are often sufficient to

protect the crop from later invasions. Sprays in general are less expensive and more effective than dusts, and they have many advantages

over baits. As a result of this development, sprays and dusts have practically replaced baits for the control of grasshoppers. Most useful also

in rela,tion to airplane spraying is the fact that good distribution may

be achieved with as little as a gallon or less of spray liquid per acre.

This means that a plane may spray a hundred acres or more with one

loading. It is not unusual to treat 1,000 acres per day per plane, and

large planes capable of treating 10,000 acres per day have been equipped

for the purpose. This, of course, is many times as rapid as treating with

ground equipment.

Airplane spraying with the new methods is sufficiently inexpensive

that range and wastelands on which the large migratory swarms of grasshoppers once originated may now be treated. Some 12,000,000 acres of

range and cultivated land have been so treated during the past few

years with the result that migrations have been all but stopped, and

control is now largely on a preventive basis. As an example of control

a t the source of infestation, the area infested with Mormon crickets was

reduced from some 19,000,000 acres in 1938 to about 116,000 acres in

1949. Incidentally, the new insecticides and methods are used also for

the control of other insects.

3. Wheat-Stern Sawfly

Research designed to develop methods of controlling wheat-stem sawBy is a n excellent illustration of the interdependence of different countries and of the value of co-operation in developing control methods.

The most promising method for controlling this insect is by the use of

resistant varieties. The only resistant variety so far grown by the farm-



ers in the United States is the spring variety RESCUE, produced by Canadian research workers and introduced into the United States in 1947.

The wheat-stem sawfly is indigenous to the Great Plains, where it

has lived for untold centuries on wild grasses. It was collected in wheat

in Canada as early as 1895, in Montana in 1900, and in North Dakota in

1906. Infestation in Montana and Saskatchewan in 1908 was sufficient

to cause some alarm and likewise in North Dakota i n 1916. It has been

and sporadic outbreaks

a serious pest in Canada since the early 1930’~~

have continued in Montana and North Dakota. The insect appears to

have become firmly established in both states in about 1941 or soon thereafter and the infested area has increased nearly every year. Platt and

Farstad (1946) regard the wheat-stem sawfly as a major limiting factor

in the production of wheat in many areas of the Prairie Provinces of

Canada and have estimated the annual losses a t 20,000,000 bushels. The

estimated loss in the United States in 1951 was almost 5,000,000 bushels.

I n the United States it has been most destructive in spring wheat but in

recent years has caused severe losses in winter wheat in central Montana.

It has not as yet been a serious pest in the main winter wheat belt of

the United States. The use of strip cropping in Montana and Canada,

in which a narrow strip of wheat alternates with a strip of fallow, provides ideal conditions for the sawfly to migrate from stubble to the growing crop and is believed to have been a factor in establishing this insect

as a major wheat pest in recent years.

The RESCUE variety was produced from a cross of the Canadian variety APEX with another known as s-615, which was originally from Portugal but was secured by Canadian workers from New Zealand. I n the

United States RESCUE has yielded somewhat less than other varieties in

the absence of sawfly and f o r other reasons is not regarded as completely

satisfactory. It has reduced losses in the sawfly-infested areas, however,

and is grown extensively by Montana farmers for that reason. Additional sources of resistance have been discovered in recent years, and

breeding is under way to incorporate these into commercial varieties.

4 . Other Insect Pests of Wheat

Control of some insect pests of wheat has not been conspicuously successful. In some cases, losses suffered by individual farmers have been

small or they have been infrequent, which means that it has been difficult or quite impossible to get the continuing support that is often necessary for successful research, Nevertheless, much has been learned in

the past fifty years that will be most useful if serious outbreaks do occur

and for most insect pests methods of control now recommended and



sometimes used are, without doubt, f a r superior to those used in the

nineteenth century.

As a result of recent research, for example, about 1,000,000 acres of

wheat was sprayed, mostly with parathion, to control greenbugs in Oklahoma in 1950 and 1,800,000 acres in the state were treated in 1951. This

is the first successful method developed for the control of this pest, credited with the destruction of 50,000,000 bushels of grain or more in the

southern Great Plains in 1907 and again in 1942, and with that of 25,000,000 bushels in Oklahoma in 1950 (Haeussler, 1952), with several

serious outbreaks in other years.

New insecticides have also been found useful in the control of the

armyworm, fall armyworm, wireworm, stored-grain insects, and others.

Chemical dust barriers of which the active ingredients are DDT or dinitro compounds have been found useful supplements to other methods in

preventing the migration of chinch bugs from small grains to corn and


Studies of the taxonomy, life histories, and egg-laying and feeding

habits, have been most useful in suggesting control methods. Knowledge

of these for many insects was completely lacking or was very incomplete

fifty years ago. Wade and St. George (1923), for example, state that

false wireworms have often been confused with other species, and hence

not recognized ag the destructive pests they really are. The reliability

of forecasts and warnings of destructive epidemics so necessary for organized large-scale control campaigns has been greatly improved in recent

years as a result of more complete information regarding the relation of

insect populations to weather and other environmental factors.

Among the more significant discoveries of recent years in relation to

future control is the resistance or tolerance of varieties of wheat to most

insects that attack it. Jones (1943), for example, points out that varieties of wheat have been reported as resistant or tolerant to a t least fifteen

insects besides Hessian fly. Painter (1951) has published an excellent

review of the attempts to breed varieties of wheat resistant to various

insects. Briefly, the principal achievements are the varieties mentioned

above that are resistant to Hessian fly and to the wheat-stem sawfly, and

the discovery more or less incidentally of several sources of resistance,

as mentioned by Jones. Efforts to transfer newly discovered genes for

resistance to commercial varieties will be made a t the first opportunity.




The experimental data on which most of this paper is based were obtained by

various agencies, principally the various state agricultural experiment stations in

those states in which wheat is an important crop; by the Bureau of Plant Industry,

Soils, and Agricultural Engineering, usually i n cooperation with the state agricultural

experiment stations; by the Bureau of Entomology and Plant Quarantine; and by the

Grain Branch, Production and Marketing Administration, of the United State8 Department of Agriculture. Much of these data have been published and are referred

to in the text. The use of unpublished data is, in general, referred to i n footnotes to

tables or in text. Permission for the use of these data is gratefully acknowledged.

The authors are indebted to various individuals for providing data, and for assistance

in assembling data and in reviewing the manuscript. Among these are E. R. Ausemus, B. B. Bayles, C. C. Fifield, K. F. Finney, J. H. Martin, L. P. Reitz, C. A.

Suneson, and 0. A. Vogel, of the Bureau of Plant Industry, Soils, and Agricultural

Engineering; and numerous staff members of the various state agricultural experiment stations. The authors are also indebted to the Division of Cereal and Forage

Insect Investigations of the Bureau of Entomology and Plant Quarantine for suggestions and criticisms of the section on the Control of Insects of Wheat. Limitations

of space and time have prevented the use of many suggested additions to this paper,

including important contributions relating to soil chemistry and soil physics, genetics

and cytology, plant pathology, plant physiology, and cereal chemistry.


Aasheim, T. S. 1949. Montana Agr. Expt. Sta. Bull. 468, 38 pp.

Adams, J. F. 1921. Phytopathology 11, 115-124.

Albrecht, W. A. 1926. J. Am. SOC.&on. 18(10), 841-853.

Alexander, G. L. 1933. Cereal Chem. 10(6), 623-626.

Anonymous. 1932. Wheat yield summary. Intermountain and Pacific Coast States.

U.S.D.A., B.P.I.S. & A.E., Div. Cereal Crops and Diseases, 33 pp. (Processed.)

Atkinson, A., and Donaldson, N. C. 1916. M o n t a w A g r . E x p t . Bta. Bull. 110,


Ausemus, E. R. 1943. B o t m . Rev. 9(4), 207-260.

Ausemus, E. R., Markley, M. C., Bailey, C. H., a n b Hayes, H. K. 1938. J . A g r .

Research 66(6), 453-464.

Bailey, D. L., and Greaney, F. J. 1926. Phytopathology 16, 64.

Bailey, D. L., and Greaney, F. J. 1928. Phytopathology 18, 480.

Baker, G. O., and Klages, K. H. W. 1938. Idaho Agr. E x p t . Sta. Bull. 227, 34 pp.

Baker, 0. E. 1931. 17.5. Dept. Agr. Miso. Publ. 105, 224 pp.

Baker, 0. E. 1937. U.S. Dept. Agr. M k c . Publ. 260, 56 pp.

Baker, W. A., and Mathews, 0. R. 1952. U,S. Dept. Agr. Yearbook, pp. 437-440.

Ball, C. R. 1930. Agr. Hist. 4(2), 48-71.

Ball, C. R., and Clark, J. A. 1916. U.S. Dept. Agr. Bull. 400, 40 pp.

Ball, C. R., and Clark, J. A. 1918. U.5. Dept. AgT. Bull. 618, 64 pp.

Ball, C. R., Leighty, C. E., Stine, 0. C., and Baker, 0. E. 1921. U.S. Dept. Agr.

Yearbook, pp. 77-160.

Bamberg, R. H. 1947. Results from Cooperative Wheat Varietal Experiments in

the Western Region. U.S.D.A., B.P.I.B. & A.E., Div. Cereal Crops and Diaeases. (Processed.)





Barbee, 0. E. 1933. Washington Agr. Expt. Sta. Bull. 289, 44 pp.

Barmore, M. A. et al. 1937-1942, inclusive. Quality Characteristics of Hard Red

Winter Wheat Varieties Grown in Cooperative Plot and Nursery Experiments.



Div. Cereal Crops and Diseases. (Processed.)

U.S.D.A., B.P.I.S. &

Barmore, M. A. et al. 1947-1951. Quality Characteristics of Varieties of Wheat

Grown in the Western United States. U.S.D.A., B.P.I.S. & A.E., Div. Cereal

Crops and Diseases. (Processed.)

Bartel, A. T. 1947. J . Agr. Research 74(3), 97-112.

Bayfield, E. G. et al. 1937, 1938. Annual Reports of the Federal Soft Wheat

Laboratory. U.S.D.A., B.P.I.S. & A.E., Div. Cereal Crops and Diseases. (Processed.)

Bayles, B. B. 1931-1936, inclusive. Results from Cooperative Wheat Varietal Experiments in the Western Region. U.S.D.A., B.P.I.S. & A.E., Div. Cereal Crops

and Diseases. (Processed.)

Bayles, B. B., and Taylor, J. W. 1938-1950, inclusive. Report of the Uniform

Eastern Soft Winter Wheat Nurseries. U.S.D.A., B.P.I.S. & A.E., Div. Cereal

Crops and Diseases. (Processed.)

Bayles, B. B., and Taylor, J. W. 1951. U.8. Dept. Agr. Parmers Bull. 2006, 50 pp.

Bayles, B. B., Taylor, J. W., and Bartel, A. T. 1937. J . Am. SOC.Agron. 29(1),


Bell, M. A. 1937. Montana Agr. Expt. Sta. Bull. 336, 118 pp.

Bever, W. M. 1938. U.S. Dept. Agr. Ciro. 601, 15 pp.

Bever, W. M. 1947. Phytopathology 37, 889-895.

Bidwell, P. W., and Falconer, J. I. 1941. History of Agriculture in the Northern

United States, 1620-1860. 512 pp. Carnegie Institution of Washington Pub.

No. 358. Reprinted by Peter Smith, New Pork.

Blanchard, H. F. 1910. 27.5. Dept. Agr., Bur. P h n t Inamtry Bull. 178, 37 pp.

Bledsoe, R. P. 1932. Georgia Agr. Expt. Sta. Bull. 171, 16 pp.

Bode, C. E. et al. 1948 to 1950, inclusive. Quality Characteristics of Soft Winter

Varieties Grown in the Eastern United States. U.S.D.A., B.P.I.S. & A.E., Div.

Cereal Crops and Diseases. (Processed.)

Bolley, H. L. 1897. North Dakota Agr. Expt. Sta. Bull. 27, 109-164.

Bolley, H.L. 1905. Proc. Am. Breeders’ Assoc. 1, 131-135.

Bonnett, 0.T., Woodworth, C. M., Dungan, G. H., Koehler, B. 1945. Illinois Agr.

Expt. Sta. BuW. 613, pp. 595-600.

Brandon, J. F., and Mathews, 0. R. 1944. U.8. Dept. Agr. Circ. 700, 53 pp.

Briggs, F. N. 1938. Am. Naturalist 72, 285-292.

Brodell, A. P., Strickler, P. E., and Pittman, D. D. 1952. U.S.D.A., Bur. Agr.

Econ., Farm Management, p. 91.

Brown, H. M., and Down, E. E. 1937. Michigan Exten. Bull. 187, 16 pp.

Burr, W. W. 1914. Nebraska Agr. Expt. Sto. Research. Bull. 6, 88 pp.

Caldwell, R. M., and Compton, L. E. 1947. Purdue Univ. Agr. Expt. Sta. Bull.

621, 11 pp.

Call, L. E. 1913. Kansas Agr. EBpt. 8ta. Bull. 186, 16 pp.

Call, L. E., Salmon, 8. C., and Cunningham, C. C. 1916. Kansas Agr. Expt. Sta.

Bull. 213, 16 pp.

Call, L. E., and Sewell, M. C. 1917. J . Am. SOC.Agron. 9(2), 49-61.

Carleton, M. A. 1896. U.S. Dept. Agr. Yearbook, pp. 489-498.

Carleton, M. A. 1900. U.S. Dept. Agr., Div. Vegetable Physiology and Pathology

Bull. 24, 87 pp.



Carleton, M. A. 1901. U.S. Dept. Agr., Bur. Plant Indus. Bull. 3, 62 pp.

Carter, J., J r . 1939. N e w Mexico Agr. E x p t . Sta. Bull. 265, 15 pp.

Carter, J., Jr. 1944. N e w Mexico Agr. Expt. Sta. Bull. 312, 20 pp.

Cartwright, W. B., and LaHue, D. W. 1944. J. Econ. Entomol. 37(3), 385-387.

Cauthen, E. F. 1918. Akzbama Agr. Ezpcpt. Sta. Butt. 205, pp. 135-142.

Champlin, M. 1914. 17.5. Dept. Agr. Bull. 39, 37 pp.

Chandler, W. H. 1942. Science 95(2475), 563-567.

Cherewick, W. J. 1946. Sci. Agr. 26(11), 548-551.

Chester, TI. S. 1939. Phytopathology 29, 4.

Chester, K. S., and Jamison, C. 1939. Phytopathabgg 29, 962 967.

Chilcott, E. C., and Cole, J. S. 1918. J. A g r . Research 14(11), 481-521.

Christensen, J. J., and Stakinan, E. C. 1927. Phytopathology 17, 40-41.

Clark, J. A. 1931 to 1950, inclusive. Results on Spring Wheat Varieties Grown in

Cooperative Plot and Nursery Experiments in the Spring Wheat Region.

U.S.D.A., B.P.I.S. & A.E., Div. Cereal Crops and Diseases. (Processed.)

Clark, J. A. 1936. U.S.Dept. Agr. Yearbook, pp. 207-346.

Clark, J. A., and Bayles, B. B. 1942. U.S. Dept. A g r . Tech. Bull. 795, 146 pp.

Clark, J. A., and Bayles, B. B. 1951. U.S. Dept. Agr. Circ. 861, 71 pp.


Clark, J. A., and Martin, J. H. 1925. U.S. Dept. Agr. Dept. Bull. 1276, 48 pp.

Clark, J. A,, Martin, J. H., and Ball, C. R. 1922. U.S. Dept. Agr. Dept. BUZZ.

1074, 238 pp.

Clark, J. A., Martin, J. H., Hooker, J. R., Quisenberry, K. S., Leighty, C . E., and

Dubois, C. N. 1929. U.S. Dept. Agr. Bull. 1498, 68 pp.

Clark, J. A., Martin, J. H., and Smith, R. W. 1920. U.S. Dept. Agr. Bull. 878,

48 PPClark, J . A., and Quisenberry, K. S. 1933. 77.5. Dept. Agr. Circ. 283, 76 pp.

Clark, J. A., and Quisenberry, K. S. 1937. U.S. Dept. Agr. Circ. 424, 68 pp.

Clark, J. A., and Quisenberry, K. S. 1942. U.S. Dept. Agr. Circ. 634, 75 pp.

Clark, J. A., and Quisenberry, K. 8. 1948. 27.9. Dept. Agr. Circ. 761, 80 pp.

Coffman, F. A. 1925. U S . Dept. Agr. Bull. 1287, 63 pp.

Coleman, D. A. 1935. Influence of Test Weight per Bushel on Milling and Baking

Quality of Hard Red Spring Wheat, Crop of 1935. U.S. Dept. Agr., Bur. Agr.

Eoon,, Grain Div. (Processed.)

Coleman, D. A., Dixon, H. B., and Fellows, H. C. 1927. J. Agr. Research 34(3),


Conner, C. M. 1893. Missouri Agr. E x p t . Sta. Bull. 21, 16 pp.

Cooper, M. R., Barton, G. T., and Brodell, A. P. 1947. U.S. Dept. A g r . ?disc.

Pub.!. 630, 101 pp.

Craigie, J. H. 1927. Nature 120, 765-767.

Craigie, J. H. 1928. Phytopathology 18, 479.

Craigie, J. H. 1944. Sci. Agr. 25(2), 51-64.

Crookes, Sir William. 1899. The Wheat Problem. J. Murray, London.

Cutler, G. H. 1942. Purdue Univ. Agr. E x p t . Sta. Circ. 276, 8 pp.

Daniel, H. A,, Elwell, H. M., and Cox, M. B. 1951. Oklahoma Agr. E x p t . Slu.

Circ. M-223, 9 pp. (Processed.)

Darnell-Smith, G. P. 1915. Agr. Gaz. N . S. Wales 26, 242-243.

Dickson, A. D., Link, K. P., Roche, B. H., and Dickson, J. G. 1930. Phytopathology

20, 132.

Dickson, J. G. 1921. Phytopathology 11, 35-36.

Dickson, J. G. 1923. J. Agr. Research 11, 837-870.



Dickson, J. G. 1947. Diseases of Field Crops. McGraw-Hill Book Company Inc.

New Pork.

Dimond, A. E., Davis, D., Chapman, R. A., and Stoddard, E. M. 1952. Comectimt

Agr. Expt. Eta. Bull. 667, 82 pp.

Down, E. E., and Brown, H. M. 1932. Yhhigan Agr. Expt. Xta. Spec. Bull. 223,

19 PP.

Down, E . E., Brown, H. M., Patten, A. J., Winter, 0. B., and Coons, G. H. 1928.

Miohigan Agr. Expt. Sta. Tech. Bull. 88, 35 pp.

Duley, F. L., and Russel, J. C. 1939. J . Am. Boo. Agrm. 31(8), 703-709.

Dungan, 0. If., Burlison, W. L., Koehler, B., and Bonnett, 0. T. 1939. I l l h i s

Agr. Expt. Xta. Bull. 460, pp. 87-104.

Englehorn, C. L. 1946. North Dakota Agr. Expt. Sta. Bull. 341, 35 pp.

Etheridge, W. C., and Helm, C. A. 1938. M k w o d Agr. Expt. Eta. Bull. 398, 41 pp.

Evans, A. T., and Janssen, G. 1922. South Dakota Agr. Expt. Sta. Bull. 200, pp.


Faris, J. A. 1927. Mycotogia 16, 259-282.

F'ifield, C. C. et 01. 1936 to 1950, inclusive. Quality Tests with Hard Red Spring

Wheat. U.S.D.A., B.P.I.S. L A.E., Div. Cereal Crops and Diseases. (Processed.)

Fifield, C. C., Bode, C. E., Fellows, H. C., Weaver, R., Hayes, J. F., Christie, A.,

Rothgeb, B. E., and Hoffecker, E. 1945. U.X. Dept. Agr. Tech. Bull. 887,

35 PP.

Fifield, C. C., Bode, C. E., Fellows, H. C., Weaver, R., Hayes, J. F., Christie, A.,

Hartsing, T. F., and Hoffecker, E. * 1950. 27.B. Dept. Agr.

Rothgeb, B. E,.,

Tech. Bull. 1014, 35 pp.

Fifield, C. C., Clark, J. A., Hoffecker, E., Weaver, R., Hartsing, T. F., and Hayes,

J. F. 1936 t o 1950, inclusive. Milling, Baking, and Chemical Experiments

with Hard Red Spring Wheat. U.S.D.A., B.P.I.S. & A.E., Div. Cereal Crops

and Diseases. (Processed.)

Fifield, C. C., Hoffecker, E., Hartsing, T. F., and Weaver, R. 1936 to 1948, inclusive. Quality Studies of Wheat Grown in the Western Region. U.S.D.A.,

B.P.I.S. & A. E., Div. Cereal Crops and Diseases. (Processed.)

Fifield, C. C., Smith, G. S., and Hayes, J. F. 1937. Cereal Chem. 14(5), 661-673.

Finney, K. F. et al. 1948 t o 1950, inclusive. Quality Characteristics of Hard Winter Varieties of Wheat Grown in Cooperative Experiments. U.B.D.A., B.P.I.S.

& A.E., Div. Cereal Crops and Diseases. (Processed.)

l?inney, K. F., and Barmore, M. A. 1944. Cerea2 Chem. 21(1), 65-74.

Finney, K. F., and Barmore, M. A. 1945, Cereul Chem. 22(3), 244-254.

Finney, K. F., and Barmore, M. A. 1948. Cereal Chem. 26(5), 291-312.

Finney, K. F., Morris, V. H., and Yamazaki, W. T. 1950. Cereal Chem. 27(1),


Finney, K. F., and Yamazaki, W. T. 1946. Cereal Chem. 23(4), 416-427.

Finney, K. F., and Yamazaki, W. T. 1953. Cereal Chem. (In press.)

Gaines, E. F. 1919. Washington Agr. Expt. Sta. Pop. Bull. 116, 7 pp.

Gaines, E. F. 1922. Washington Agr. Expt. Xta. Bull. 90, 5 pp.

Gaines, E. F. 1933. Northwest Xci. 7(1), 8-12.

Gaines, E. F. 1941. News Letter. Am. Assoc. Cereal Chemists Bull. 6, 1-2.

Gaines, E. F., and Schafer, E. 0. 1932. Northwest SOL 6(3), 98-107.

Garman, H. 1898. I n Kentucky Agr. Expt. Bta. Bull. 77, 116-122.

Garren, G. M. 1915. North Carolina Agr. Expt. Bta. Bull. 232, 28 pp.

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