successfully. He might not at all be adapted to dairying or to the feeding of live stock. Some people can not handle live stock successfully, even though they have right ideas in regard to the handling of crops; likewise, the grain farmer may not be adapted to the growing of sugar beets. Frequently grain production is extensive rather than intensive, while sugar beets should be handled intensively rather than extensively. At any rate, intensive methods should be employed in growing this crop. Some growers of the extensively grown crops, like grains, forage, etc., sometimes become very successful growers of sugar beets, but generally they prefer the line of agriculture which they have followed and from which they do not wish to depart. The same is true of the live-stock man, although the man who handles live stock, especially dairy cows, is more inclined to take up the growing of such an intensive crop as sugar beets and is more apt to succeed in this line of agriculture than the grain or forage crop man. This does not apply, however, to the live-stock man who grows for the market, and especially the man who produces or handles large herds of cattle. The point to be made in regard to the grower is that he must have the natural qualifications for intensive agriculture and must be fitted by training and experience for the growing and handling of crops requiring intensive cultivation.

DISEASES.

Diseases are among the most apparent limiting factors in sugarbeet production. A crop of beets that might otherwise be very profitable is frequently turned to a loss by some disease. The sugar beet, like all other plants, is subject to disease from the time it begins its growth until it is harvested; and even after the plants are harvested, if stored under certain conditions, the beets may decay to a greater or less extent, impairing or destroying their value for sugar-making purposes. Some of the diseases are well known and easily controlled; others, while known, are handled with difficulty: and still others are obscure as to their causes. The losses produced by diseases may be brought about by a destruction of the plant itself or by some injury which reduces the size or quality of the beet root.

Damping off.-Among the diseases which attack the beet during the early stages of its growth is the so-called damping-off. There are several forms of this disease, due, apparently, to different organisms. Frequently the young beet plants turn black just at the surface of the ground, fall over, and die. Sometimes the entire root tur black and softens, and sometimes the blackening is confined to the outer layer or epidermis. In the latter case the beets frequent! recover. This disease is caused either by a fungus or a bacterium which is in the soil or on the seed when planted. If the disease s

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widespread, so that the stand is seriously injured, the field should be disked and replanted. Damping-off is more common in the early spring, when the ground is damp and not thoroughly warm, but the disease will not occur unless one of the damping-off organisms is present.

Nematodes.-The sugar-beet nematode is a minute wormlike organism, sometimes called an eelworm, which attaches itself to the root and when present in sufficiently large numbers retards the growth of the beet. There are several species of the nematode which attack the sugar beet, but only one is considered especially serious; hence, this species is known as the sugar-beet nematode (Heterodera schachtii). This pest has been known for many years in Europe and has, existed in isolated localities in this country for more than a decade. It is spreading, both by its own activity in certain stages of its existence and by being carried from the present infested areas by various agencies. The pest lives in the soil from year to year and travels slowly, so that the infested area is gradually increased, until frequently an entire field or even a group of fields may become useless from the standpoint of beet production. Unfortunately, this pest will attack many plants besides the sugar beet. This makes it extremely difficult to control by crop rotation, which is one of the best methods known for the control of many of our plant pests. However, there are a number of plants that the nematode attacks to a very slight extent or not at all. Again, the nematode passes through several stages of development; one of these is known as the brown-cyst stage. In this stage the nematode is very resistant to unfavorable conditions and will remain alive in the soil for a number of years; the exact length of time is not known. The Office of Sugar-Plant Investigations is making every effort to determine the crops that are resistant to the nematode under the local soil and climatic conditions where the nematode exists and also to determine the proper length of the rotation with these resistant crops, so that the nematode will be eradicated or at least reduced to such a small number that sugar beets may be grown with profit. Various soil treatments also are being tested on nematode-infested areas. Some of these tests are very promising but will need to be repeated before anything definite can be said regarding their beneficial effects. Careful surveys have been made in some of the infested areas, and all fields or spots in fields containing nematodes have been listed and marked, either for study or for the purpose of growing crops other than sugar beets on them. A similar campaign is planned in the other infested areas where the sugar-beet nematode has gained a foothold, while a careful watch is being kept over all sugar-beet areas in order to detect and combat the pest on its first appearance.

Curly-top.-This disease of the sugar beet is confined to the western part of the United States. So far as is known, it has not been.

seen in the eastern portion of the sugar-beet area or in any of the beet fields of foreign countries. It has appeared in practically all States west of Minnesota and Iowa where sugar beets are grown commercially, although it has not been seen in all of the sugar-beet areas of the West. It is not due to unfavorable climatic or soil conditions, nor is it due to the kind or quality of seed used. It is connected in some way with a so-called leafhopper, which appears to be only a carrier and not the real cause of the disease. A further study of curly-top is being undertaken by the Office of Sugar-Plant Investigations in cooperation with the Bureau of Entomology, in the hope of being able to determine the exact cause of the disease, and especially for the purpose of finding some practical means of control. Curly-top does not usually occur to any serious extent two years in succession in the same field, although there are some exceptions to this rule. Frequently it will occur over a given area, destroying or stunting to a worthless size practically all of the beets for a season and then almost entirely disappear, so that the next year beets of good tonnage and quality may be grown on the same fields. It is possible that there are other carriers besides the leafhopper and that certain soil and climatic conditions favor the development of this disease. The real cause, however, is undoubtedly organic in nature; it is probably either an organism or an organic compound; but until this cause is known little progress can be made in finding a reliable method of control. Curly-top has played an important part in closing at least two beet-sugar mills and has caused losses of hundreds of thousands of dollars in other localities.

Root-rot. There are several destructive diseases of the sugar beet known as root-rot. One of these is due to a fungus called Phoma and another is due to a fungus known as Rhizoctonia. Other rootrots less extensive or little known are due to other fungi or to bacteria. The Phoma rot seems to be more prevalent and more destructive than the Rhizoctonia. These fungi attack the beets in the field, usually in midsummer. Sometimes they destroy the plants before they are harvested, causing a serious loss to the grower. In other cases they make only a slight attack on the beet in the field, but develop more or less rapidly when the beet has been placed in storage, either for sugar-making purposes or for seed production. The Phoma fungus causes more loss to stored roots than any other agency. especially if the temperature favors the development of the fungus. These diseases are found in all parts of the sugar-beet area in this country and in Europe. The most successful means of combating the root-rot of beets in the field is crop rotation, and if it does not get started in the field there is little danger of its developing in storage. Leaf-spot.-There are two fungi that produce spots on the leaves of beets which are more or less general throughout the United States

and Europe. One of these is known as Cercospora and the other as Phoma; the latter is the same fungus that produces the root-rot. When the spores of either of these fungi fall upon the beet leaves and the conditions are favorable the fungus growth attacks the tissue of the leaf, producing distinct and characteristic spots. The Cercospora fungus does not generally attack any part of the beet plant except the leaf blade and the petiole, while the Phoma may attack leaf and root. If these fungi are present in large numbers they may do considerable damage to the beet crop. If the attacks are severe early in the season, the growth of the beets is retarded and consequently the yield is reduced. If the attacks do not occur until late in the season, after the beets have practically reached their normal growth, the diseases will reduce the sugar without appreciably affecting the tonnage. If these fungi attack the beets in midsummer, both the yield and the quality will be generally reduced. These diseases may best be controlled by deep fall plowing and by crop rotation. Crop rotation is especially recommended where it can be practiced, but in cases where it is necessary to follow beets with beets after these diseases have appeared, the ground should be plowed in the fall to a good depth, not less than 12 to 14 inches. In fact, all plant-pathological problems, from a practical standpoint, are closely connected with the cultural phases of crop production. Production. can not be successfully studied without a knowledge of the diseases affecting that particular crop, nor can the disease of a crop be intelligently considered with reference to control measures except in conjunction with the cultural practices and with a knowledge of the conditions under which that crop is grown.

INSECTS.

The principal insects affecting sugar beets have been treated in various publications of the Bureau of Entomology. A list of these publications is given at the end of this bulletin. Among the important forms which affect the leaves are the webworms and the beet army worm. In some localities blister beetles, flea beetles, and local pests do considerable damage, mainly by destroying the foliage. They also have a retarding effect on the growth of the beet, but the principal injury is due to the destruction of the foliage and the consequent expenditure of energy and food required by the plant to produce a new set of leaves. Usually these insects start in small areas on one side or a corner of a field and spread rapidly. Of some species there are several generations in a season, and if weather conditions favor their development much damage is frequently done. In the case of insects working early in the season the tonnage of the beets may be greatly reduced, and if the insects continue until late.

in the season the sugar content also will be lowered considerably. Sugar-beet insects as a general rule are more or less local and are seldom very destructive for more than one or two years in succession.

All biting or chewing forms of insects are susceptible to poisons and may be controlled by the use of arsenate of lead, Paris green, or other arsenicals.

The leafhopper previously mentioned as a carrier of curly-top is frequently very destructive indirectly. It punctures the leaves or leaf blades of the beets with its slender beak and injects into the plant some substance or organism which exerts a decidedly unfavorable effect upon its growth.

Among insects working in or near the roots are cutworms, wireworms, and white grubs, all of which are very destructive. White grubs are abundant in sod land; therefore such lands should not be selected for growing sugar beets. Wireworms and cutworms as a rule are more destructive early in the season while the beets are small. They frequently destroy the stand to such an extent that replanting is necessary. Cutworms come from the surface of the ground and cut off the plants during the night. They may be destroyed by the use of poisoned baits, according to directions which will be furnished by the Bureau of Entomology. Wireworms usually follow the row of young beets when they have begun their work of destruction, and since they usually remain in a row a second planting should be made in the same direction, so that the rows are parallel and several inches from the original planting, i. e., without harrowing or disking. By pursuing this method the second planting will often become so large that little wireworm damage will be done. Other remedies, however, are necessary.1

The false chinch bug is a serious enemy to seed beets, frequently appearing in immense numbers and working on the growing tender seed stalks and leaves. When present in large numbers it frequently absorbs by suction so much of the vital juices of the plant that either the seed stalks are destroyed or the seed fails to mature. This insect may be controlled by the use of contact sprays, among which nicotine sulphate, 40 per cent, is most valuable. Experiments in cooperation with the Bureau of Entomology are now in progress to determine whether or not spraying seed-beet fields is a practical method of controlling this pest.2

BY-PRODUCTS.

The principal by-products connected with sugar-beet growing and beet-sugar production are the beet tops, pulp, and lime. The first

1 See Bulletin 123, Bureau of Entomology, U. S. Dept. Agr., "A preliminary report en the sugar-beet wireworm," 68 p., 23 pls., 9 figs. 1914.

2 See Farmers' Bulletin 762, "The false chinch bug and measures for controlling It," 4 p., 2 fig. 1916.