The high-priced labor of this country is nearly a complete barrier to the production of flax for fiber chiefly. For this reason it is imperative, in the Middle Northwest at least, that a fair crop of both seed and fiber be produced. Varieties of superior seed- and fiber-yielding properties have been se cured, but until labor is cheaper and more reliable, or until a higher price is paid for fiber, the grow ing of flax fiber will have to be coupled with seed production. It must not be inferred from this that flax is grown for fiber alone in the flax-producing countries of Europe, excepting perhaps in parts of Ireland ; the seed is saved and is regarded to be a secondary product of considerable value.
Breeding.
The systematic American breeding of flax has been limited to the Minnesota and North Dakota Experiment Stations. But limited as it is, some lessons have been learned and results have been secured that are of vast economic importance. The Minnesota Station has bred two high-yielding varie ties, one for seed and one for fiber. North Dakota Station has bred one that has proved to be notice ably wilt-resistant.
Minnesota experiments.—The general plan for breeding flax at Minnesota has been as follows : (1) To secure, through systematic methods of testing, a few of the most promising varieties.
(2) To save the seed of these and to grade it carefully, eliminating all but the very best seeds.
(3) To plant two to five thousand bills of each, with two or three seeds per hill. (Fig. 408.) (4) When the plants are a few inches high, to thin to one plant per hill.
(5) At maturity the best ten to twenty-five plants are secured by a gradual elimination of the poorest plants. These are selected on the basis of the economic character that is desired : If seed is the object, the plants selected are those that have a number of top branches and bear a large number of seed-bolls. If fiber is desired, the tallest, stiffest and least branched are saved. The plants thus selected are termed mother-plants and are given a register number (nursery-stock number). Certain notes are taken on them, as height, number of branches, quantity of seed, and the like, and the best 250 seeds are saved to plant a centgener the succeeding year.' (6) At harvest the next year, the best ten plants are again selected from which the seeds are saved as one lot. The total number of plants is recorded. All plants are carefully tied in a bundle and threshed in an especially devised centgener thresher. The total weight of the seed from all the plants is divided by the number of plants, thus giving the average weight per plant. This weight,
together with centgener notes, is a measure of the inherited ability of the mother-plant. Such a cent gener test goes on for three years.
(7) At the end of three years an average is made of each mother-plant's progeny for the three years. The best one or two nursery-stock numbers having highest yields, other things being equal, are saved for future trial. All others are discarded.
(8) The best of all the bulk seed, saved from all plants harvested the last year of the three years' test, is planted in a "nursery increase plot," and given a Minnesota number.' From the field plot results another three years' test, and the average is made. Each year such notes as height, days to mature, per cent lodged, evenness in height and ripening, type, yield per acre, and the like, are taken.
(9) If in this test a certain stock shows by its record, as did Minnesota No. 25, that it is superior to all others, the bulk seed is again saved. This seed is planted in "field increase plots" until sev eral hundred bushels of well- graded seed are secured.
(10) This "field increased " seed is then sold to farmers of the state in lots of four bushels or less, at a price slightly above the ordinary market price of flax.
(11) These farmers, by signing a contract, be come cooperators of the Experiment Station. At harvest time a blank form of inquiry is sent to each cooperating farmer to fill out and return to the Experiment Station. From the replies, a com parison of the new variety with the common variety under farm conditions is made.
(12) Inquiries coming in from other farmers in following years for the improved variety are re ferred to the cooperators.
To illustrate the results that have been secured, the following table giving the results of compara tive tests made by forty-eight farmers in various parts of Minnesota is introduced: In addition to the improvement shown in these tables, No. 25 is a week earlier than common vari eties, and is more even in growth and in maturity.
North Dakota experiments.—At the North Dakota Experiment Station, Bolley has been breeding flax with a view to getting a variety that is immune to the wilt disease. In this work, he has followed closely the Darwinian hypothesis that success attends the survival of the fittest. One of the common varieties was selected and planted on a Minnesota number is given to any new accession introduced into the field test in comparison with all other promising stocks and varieties from various sources.