Flax-wilt is different from many fungous dis eases, in that it lives a long time in the soil and that it is carried with the seed. Thus, a wilt-free soil may produce a flax-wilt crop if the seed-flax was grown on flax-wilt ground ; or a flax-wilt soil will produce a flax-wilt crop even though the seed had no flax-wilt to carry with it. In either case, however, the first crop under these conditions may not give much evidence of the disease. Succeeding crops would be badly infested.
A careful and exact study of the life-history of the cause of flax-wilt has made it possible suc cessfully to combat it. The fungus is an imper fect one and lives normally as a saprophyte, but occasionally becomes a parasite. Its chief means of distribution is by the spores which are carried on the seed of the flax. Obviously, then, by treat ing the seed, the disease can be very largely obviated.
Until recently, no treatment for the dreaded flax wilt disease had been discovered, but the working out of the life-history of the fungus by Bolley, brought out the fact that treatment of the seed with certain fungicides will eliminate the disease from seeds known to be from an infected crop. A farmer with soil free from flax-wilt germs can safely sow seed from a flax-wilt crop if the seed has been thoroughly treated. At the North Dakota Experiment Station, a series of tests were made to prove the value of seed treatment for flax-wilt, and in every instance when the seed was treated and sown on soil free from wilt, there were no signs of the disease. But the same lot, untreated, sown on wilt-free soil, showed the presence of the disease.
There were several fungicides which might be used, but it was necessary to find one that was strong enough to kill the spores of the wilt and yet not injure the vitality of the seed. Formalin is recommended as the cheapest and quickest effectual solution. The treatment as recommended by Bolley is as follows : Mix thoroughly one pint or one pound of the formalin with forty gallons of water. This quantity of solution is sufficient to treat about one hundred bushels of seed. Before applying the solu tion, the seed must be carefully cleaned and graded with a fanning-mill. If this is not done, pieces of broken stems and shriveled seeds carrying the disease will not be completely disinfected. Thus
the wilt will be carried to the soil.
In treating the seed, it is advised that about five bushels be spread thinly on a floor or canvas. The solution is then sprayed on the seed with a fine nozzle (a common sprinkling-pot or a patent sprayer may be used). At the same time the flax is stirred rapidly with a rake or shovel in order to get every seed in contact with the fungicide. After spraying, the stirring should continue a short time to aid the drying.
Care in the application of the solution is impor tant. An excess of water will cause the flax seed to stick together and will interfere with seeding. Ordinarily, with careful treatment, the grain can be seeded in a few hours after treatment. [See also page 50.] Flax rust (.1Ielampsora lint) is another menace to the flax crop, but happily it is not causing much damage. It was first reported in the Northwest in 1905—a very wet season. It completely destroyed some fields in the Red river valley. It is not prob able that great damage will come from this dis ease, since flax for the most part is grown in small, disconnected areas and is changed from field to field.
Manufacture.
Flax has long been known as a valuable plant for the production of wearing apparel and matting fiber. It has also been the source of a valuable oil, useful for many purposes, especially in the making of paints. Until recently, flax has been grown almost exclusively for its oil in this country. There were no means to make use of the fiber and com pete with the fiber productions of Europe.
At present there are four distinct manufactur ing interests which employ the flax crop. One of these uses only the seed. The other three are dis tinctly fiber industries, and manufacture cloth, thread and yarn, insulating material and binding twine. For these interests, the crop is generally taken from the farmer just as he is pleased to har vest it. In a few instances, as at Yale, Michigan, the crop is sometimes pulled by hand. For the oil mills, the flax seed is commonly delivered direct to the local elevator from the threshing machine. From here, in due time, it finds its way to the mill, where it is separated from weed seeds and other foreign material before being ground.