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III. The Sugar Beet in the United States
SUGAR BEET IMPROVEMENT
where they could operate successfully, the sugar beet was grown from
seed obtained from European breeding establishments. I n spite of early
recommendations of the Department of Agriculture and a clear showing, by experiments over a score of years from 1890 on, of the advantage
of home-grown varieties and home-grown seed, the industry, dominated
by European technologists brought over to run the sugar-making equipment, insisted on imported brands. There is no question that the European seed was capable of giving good crops under conditions comparable
to those of Europe, but far too often it was not adapted to conditions
encountered in one area or another in the United States. As we shall
see, the long-continued use of imported seed was at the bottom of much
of the trouble of American factories.
Four major areas are engaged in growing sugar beets, and each of
these has its own special conditions of soil and climate. In the humid
area, sugar beets are grown in Michigan, Ohio, Wisconsin, Illinois,
eastern North Dakota, Minnesota, Iowa, and eastern Nebraska. The
soils used are clays or heavy loams; the crop depends on natural rainfall
which is frequently heavy in the spring months and adequate in most
years in the growing season for good crop production. In the Midwest,
particularly in Colorado, western Nebraska, Kansas, western North
Dakota, South Dakota, Wyoming, and eastern Montana, sugar beets are
grown on heavy soils that are alkaline in reaction; rainfall in spring is
fairly frequent but scanty; and there are occasional summer rains.
This rainfall needs to be supplemented by irrigation and frequently the
crops are irrigated up, since the spring rains do not wet the soils deeply
enough. In the intermountain area-Utah, Idaho, Montana, eastern
Oregon, and Washington-agriculture is confined to sedimentary, valley soils that can be reached by irrigation water, since rainfall is inadequate to produce the crop. On the Pacific coast, in California, the sugar
beet crop is grown on a wide range of soils and under irrigation, the
water coming either from streams or wells. The climate allows the crop
to be grown either as a summer or a winter crop.
3 . The Sugar Beet Threatened by Disease and Insect Attack
Sugar beet culture is limited to acreages within economical transportation distance of a beet sugar factory equipped to carry on the highly
technical process of sugar manufacture. This and other factors have
tended towards intensification of sugar beet culture; accordingly, problems associated with intensified agriculture, especially serious diseases,
have been encountered. In each of the major districts, plant diseases
have been responsible for serious crop failures and, as the industry was
becoming established, were the chief causes of the lack of success of one
G . H. COONS, F. V. OWEN, A N D DEWEY STEWART
factory after another, bringing about the frequent moves from one place
to another as stable crop production was sought. Thus, the humid area
had a long period of persistently low yields because of black root
(Aphanomyces cochlioides Drechs. and other fungi) (Fig. 1) and leaf
spot (Cercospora beticola Sacc.) . Abundant rainfall, which should have
FIG. 1. Black root of sugar beet. The taproot of the sugar beet plant at the right
is blackened and its lateral roots are killed by the water mold, Aphanomyces
cochlioides. Some measure of the stunting of growth is afforded by comparison with
the healthy plant of the same age on the left. Frequently, affected plants die. (Photograph by J. E. Kotila.)
meant bumper crops, brought about poor stands, low tonnages, and low
sugars (Coons, 1953b). As a consequence, factories were unable to contract adequate acreages in their vicinities.
The Midwest has had serious losses from leaf spot, and, even now,
certain states are experiencing outbreaks of curly top. In the period
1920 to 1940, serious leaf spot epidemics occurred frequently in many
districts, particularly in Iowa, Nebraska, Kansas, and eastern Colorado.
SUGAR BEET IMPROVEMENT
Often the disease so reduced yield and quality as to make the sugar
beet crop unprofitable to the farmer as well as the factory, and the industry was brought to a low ebb.
I n the intermountain area and in California, curly top, a virus disease that was studied so intensively by Carsner (Carsner and Stahl,
1924), was, over the years, the most serious menace to the sugar beet
industry, almost bringing about the abandonment of the sugar beet
culture west of the Rocky Mountains. In its capacity for producing
injury, curly top ranks with the most destructive plant disease (Fig. 2).
FIG. 2. Sugar beet curly top. Affected plants are stunted, their leaves upcurled,
and the veinlets i n the leaves are enlarged and distorted. A diseased plant, such as
shown, will make little or no growth throughout the entire season.
The virus occurring in range plants is brought to sugar beet fields by
the beet leafhopper, Circulifer tenellus (Bak.). Douglass and Cook
(1954) have published a rksumd of the life history of the beet leafhopper. This leafhopper prefers dry climatic conditions. It breeds on
mustards (Tumblemustard, Sisymbrium altissimum L. and Flixweed
tansymustard, Descurainia Sophia (L.) Webb) , Russian thistle (Salsola
pestifer A. Nels.), filaree or alfilaria (Erodium spp.), and other weeds
that have invaded western range lands deteriorated as a consequence
of overgrazing. These weeds are hosts of the curly top virus.
The vicious cycle of range deterioration, weed invasion, beet leafhopper increase, and curly top epidemics has been outlined by Piemeisal
et a2. (1951). When the vegetation of the range lands becomes dry in
G. H. COONS, F. V. OWEN, A N D DEWEY STEWART
early spring, swarms of beet leafhoppers, some of them viruliferous,
move into the irrigated valleys. Here the insects feed on the young sugar
beet plants, infecting some of them with curly top virus picked up from
the weed host plants. Each infected sugar beet in the field becomes a
disease center where the insects breed and where nonviruliferous beet
leafhoppers become infectious, and thus they spread the virus. I n years
of high beet leafhopper populations, not a plant in a sugar beet field
escapes infection. Before the development of varieties resistant to curly
top, early-infested fields were, in a few weeks, almost a total loss. Thousands of acres around a factory would be abandoned, and the factory
would have either no run at all or a very short, unprofitable one.
The European varieties grown had no resistance to the diseases that
wrought havoc to American beet crops. Leaf spot and black root occur in
central Europe only sporadically and in mild form. Curly top does not
occur. Obviously, varieties as bred in Europe could not be expected to
exhibit resistance to these diseases.
Such was the situation in the United States at the close of World
War I. The industry had had a precarious existence during the war and
was hampered by shortages of sugar beet seed. All through the formative years, the industry had elected to depend upon imported seed. The
attempts to produce seed in the United States in 1917, 1918, and 1919
were notably too little and too late. They were dropped at the close of
World War I. Then, in the next decade, leaf spot, black root, and curly
top brought disaster to many companies.
In 1925, direct attack on curly top and leaf spot by disease-resistance
breeding was started in the Bureau of Plant Industry of the United
States Department of Agriculture. The wild relatives of the sugar beet
were collected in Europe; selection work was started with commercial
sugar beet varieties and with breeders' strains at field stations where
severe exposures to these diseases could be expected each year.
1. Resistance to Curly Top'
The first result of this breeding program was the production of a
variety of sugar beets having some resistance to curly top. Carsner and
Pack (Carsner ef al., 1933) selected vigorous roots from a number of
The breeding of curly-top-resistant varieties was conducted by Eubanks Carsner,
D. A. Pack, F. V. Owen, F. A. Abegg, and A. M. Murphy, assisted in the agronomic
testing by A. W. Skuderna, C. E. Cormany, Bion Tolman, J. 0. Culbertson, H. A.
Elcock, and Charles Price. The investigations were cooperative with the California,
Colorado, Idaho, New Mexico, Utah, and Oregon Agricultural Experiment Stations
and the western beet sugar companies.
SUGAR BEET IMPROVEMENT
Utah fields in which curly top was causing a decimating loss. Roots that
appeared to be definitely better than the general run of the field were
stored over winter and planted in a seed plot with other roots grown
from similar selections that had been made earlier by commercial companies. A total of 70 to 100 pounds of seed was produced in 1929. The
first test of this seed-later to be designated US l-was made in 1930
FIG.3. The initial test of US 1 sugar beet variety at Castleford, Idaho, in 1930.
Curly top exposure was severe, almost eliminating susceptible sorts. Plot 1703, left
foreground (to the right in front of the man), consists of four rows of US 1. Plot
1704, the four rows to the right, is a nonresistant European brand. In the background, other plots of US 1 and other curly-top-resistant varieties appear as green
“islands.” (Agronomic test by C. E. Corrnany; photographed September 19, 1930
by E. Carsner.)
under conditions of heavy curly top exposure (Fig. 3 ) . AS the photograph indicates, and in comparison with later achievements, the showing made by the variety was not impressive. But the situation of the
beet sugar factories, brought about by curly top, was so desperate that,
with this evidence of some superiority in US 1 over the European types,
steps were immediately taken to make a seed increase from the unused
seed stock as a source of a curly-top-resistant .variety. Details of the
increase and the subsequent multiplications have been given by Coons