General summary of results showing the influence of manure upon the quality of sugar beets

Attention is directed to the figures of the preceding tables, but more especially to the general summary in the table just given. The data here presented are strikingly opposed to what is regarded as the orthodox method of manuring sugar-beet land. It so happens that, with the exception of the crop of 1901, not only does the stable manure fail to depress the quality of the beets, but the crops grown where it was applied in the spring show a higher percentage of sugar than where commercial fertilizer was used or where no manure was applied. In 1901 the percentage of sugar was but little lower, but the coefficient of purity appeared to drop. But in this case the stable manure was used in an excessive quantity.

CONTRIBUTIONS FROM THE BUREAU OF PLANT INDUSTRY.

LETTER OF SUBMITTAL.

U. S. DEPARTMENT OF AGRICULTURE,

BUREAU OF PLANT INDUSTRY, Washington, D. C., February 14, 1905.

SIR: I submit herewith for publication as part of the report on Progress of the Beet-Sugar Industry in the United States for 1904 the following papers, prepared under my direction by experts of this Bureau who are conducting investigations with sugar beets: (1) Single-Germ Beet Seed, by C. O. Townsend; (2) Fertilizers and Sugar Beets, by C. O. Townsend; and (3) Commercial Sugar-Beet Seed, by J. E. W. Tracy. Respectfully, B. T. GALLOWAY, Chief.

Hon. JAMES WILSON,

Secretary of Agriculture.

SINGLE-GERM BEET SEED."

By C. O. TOWNSEND, Pathologist, Bureau of Plant Industry.

INTRODUCTION.

The great amount of hand labor involved in thinning sugar beets, together with the scarcity of laborers competent and willing to do such work, makes exceedingly desirable any change in the beet which will have a tendency to eliminate part or all of this tedious work. The principal reason why hand labor is necessary in thinning the beets is that each of the beet seeds or balls planted usually contains from 2 to 7 germs, each of which may germinate and produce a plant. The plants arising from the germs of a multiple-germ seed ball stand in a compact bunch. In thinning, all but one of these plants must be removed, an operation which can be done only by hand. If, however, each beet seed contained but a single germ and these seeds were planted at regular short distances, it is evident that all or a large part of the thinning might be done with a hoe or other suitable implement. The fact that a small percentage of the seeds does contain single germs has led to an effort to

a For a complete record of the work to date see Bul. No. 73, Bureau of Plant Indus. try, U. S. Department of Agriculture, entitled: The Development of Single-germ Beet Seed. By C. O. Townsend and E. C. Rittue.

develop by selection a race or strain of beets having only single-germ seeds.

The attempt to develop a single-germ beet seed was taken up by the Department of Agriculture in the fall of 1902. The importance of developing a seed of this kind was set forth at that time in a paper by Mr. Truman G. Palmer,' secretary of the Beet-Sugar Manufacturers' Association; and the various objections to a beet seed of this kind were also discussed. The real value of a single-germ beet seed as a factor in sugar-beet production can be determined only by actual test when a sufficient quantity of the seed has been produced to make it possible to grow trial plots of beets produced from single-germ and multiplegerm seed under precisely the same conditions and in sufficient quantity to secure definite results on a commercial scale.

The first step of the Department of Agriculture toward the produc tion of an increased percentage of single-germ beet seed consisted in

the selection of a large number of single-germ seeds from commercial seed. It is noticeable that single-germ seeds are present in practically all commercial seed, but the percentage-usually about 1 per cent-is much smaller than is generally supposed. About 4,000 single-germ seeds were selected from eight varieties of commercial seed and planted on the farm of the Department of Agriculture

parts.

the production of the

first crop of seed beets. From the beets produced from the seed about 1,000 seed beets were selected and siloed, and these in turn were planted last season for the production of the first crop of seed.

THE BEET FLOWER.

The beet flower consists of three sets of organs or parts arranged in three whorls, as shown in fig. 1. The outer whorl (A) consists of five green parts which are so arranged that they inclose and protect the other two sets of organs while the flower is in the bud stage. In

¿See Report on Progress of the Beet-Sugar Industry in the United States for 1902.

the second whorl or circle of parts (B) there are five small double sacs supported on the ends of five filaments. These sacs, called anthers, contain the fine yellow dust called pollen. The central part of the flower (C) is called the pistil. When the pollen becomes ripe the anthers burst and the pollen is carried about by the wind or other agency, such as insects, etc. Some of the grains lodge upon the upper part of the pistil, which at the time becomes sticky and causes. the pollen grains to adhere. Under proper conditions of warmth and moisture the pollen grains send out slender tubes which contain living matter, and which grow down into the lower part of the pistil where the living contents of the pollen tube unite with other living matter to form the germ of a new plant. The transfer of the pollen to the pistil is called pollination, and the union

of the living contents of the pollen tube with the living matter in the lower part of the pistil is called fertilization. It appears that certain characters of the plant may be transferred by the pollen, and united with other characters contained in the pistil, so that the new plant produced by the union of these parts may possess characters of both parents; hence, it is important that plants selected for the development of single-germ seed shall possess the character of single-germ seed production in as high a degree as possible. With this point in view, those plants possessing the highest percentage of single flowers were selected for the production of the new generation of single-germ seeds.

The arrangement of the flowers on the seed stalks determines whether the seeds produced from the flowers are to bear single or multiple germs. If the flowers stand by themselves, as in fig. 2 (at the right), the seeds produced will be single-germ seeds, while if the flowers are borne in clusters, as in fig. 2 (at the left), the seeds will have mul tiple germs.

SINGLE AND MULTIPLE-GERM SEEDS.

A single-germ beet seed may be recognized by its more or less flattened and star-shaped appearance. The five green parts which make up the outer whorl of the flower spread out as the seed develops and form a part of the seed coat or hull, the tips of these parts forming the points of the star. These points often become broken off in

handling the seed, in which case a little closer examination is required to determine whether the seed has a single or multiple germ. In addition to the few single-germ seeds present in commercial seed, there are large numbers of seed balls containing from 2 to 7 germs each. These balls are readily recognized by their more or less rounded appearance, as the term "ball" indicates, and a close examination of these balls shows that they are made up of two or more seeds firmly welded together by their coats or hulls. It is possible for two single flowers to grow side by side on the flower stem without the seeds resulting from these flowers becoming united. As already indicated, it is only when the flowers grow in clusters that multiple-germ seed balls are formed. Each flower gives rise to but a single seed, so that even before the flowers are open one can tell whether the seeds that may be produced from the buds are to have single or multiple germs. For example, if the cluster is composed of three flowers and these flowers are properly pollinated and fertilized, a seed ball containing three germs will be produced.

Repeated efforts have been made to separate these multiple-germ balls into the several parts of which they are composed, but thus far this object has not been accomplished without destroying a large number of the germs or seeds. Even if this could be done, it is doubtful whether the whole object of single-germ seed production would be accomplished, since the single-germ seeds produced from single flowers show by several tests already made that the germination is quicker and the resulting seedlings are stronger then when multiple-germ balls are used. It is possible also that other good results may follow the use of single-germ seeds. This can be determined only by repeated comparison of the plants produced from single and multiplegerm seeds grown under the same conditions.

THE METHODS EMPLOYED.

In an effort to produce only single-germ seeds it is important that single flowers only be used in the production of seed, and that pollen from single flowers only be used to pollinate and fertilize the single flowers selected for seed production. With this end in view, 50 of the most favorable plants produced from single-germ seeds were selected and all flowers produced in clusters were removed. The single flowers left on the flower stalks were covered with paper bags to prevent pollen from the flower clusters of other plants from reaching the pistils of these single flowers, and then the whole plant was covered with a cloth bag to keep the paper bags from being blown off and to prevent the flower stalks from becoming whipped and injured by the wind. The work of isolating the single flowers was begun as soon as the buds were sufficiently formed to be easily handled, but before they were open. This was about June 15 and the work was continued until