BECAUSE of its restless, roving character, flax has been called one of the curiosities of agriculture. All through the nineteenth century it was a migratory crop in the United States, advancing from New York and Pennsylvania to Ohio, Indiana, Illinois, Iowa, Minnesota, the Dakotas, and Montana as new lands were opened to settlement.

It was a crop for the pioneer farmer, always moving a step ahead of the fatal wilt disease that developed in soils frequently cropped to flax.

H. L. Bolley, at the North Dakota Agricultural Experiment Station, found in 1900 that flax wilt was caused by a soil-borne fungus which he described and named Fusarium lini. Later, Bolley and others developed varieties that withstood the disease, and flax settled down as a permanent crop in the North Central States.

Flax was destined to make another move—the long hop from Mandan, N. Dak., to the Imperial Valley Experiment Station, near El Centro, Calif. Several stations in California had experimented with flax between 1915 and 1918, with little success. Nevertheless, we decided that flax was worth another trial out there.

Accordingly, on November 14, 1927, seed of 10 varieties were sown in single 3-row plots 50 feet long. These were harvested in April 1928. The average yield was the equivalent of 25 bushels an acre, but one variety made 31.2 bushels. It was Punjab, a kind that C. H. Clark had selected from a sample of flaxseed obtained from Punjab, India, in 1913. Clark had made several selections at Mandan in 1914 and 1915. He retained one of the taller selections, probably a natural hybrid, and grew it several years under the designation Punjab.

The first increase plot of Punjab, grown at the Imperial Valley station, produced 212 pounds. In 1931, 2 acres were harvested. The seed was distributed to a few farmers, who harvested 110 acres in 1932 and 350 acres in 1933. All the seed harvested in 1933 was used for planting 8,000 acres in the Imperial Valley. The crop, harvested in May 1934, produced nearly 242,000 bushels.

Now flax was on its way. The one ounce of flaxseed, planted in November 1927, had established a new industry that was to bring employment and a measure of wealth to thousands of people.

In the 1930’s, the Imperial Valley, in common with agriculture elsewhere, suffered from low prices and a surplus of its farm products, chiefly alfalfa, barley, wheat, melons, lettuce, and other vegetable crops. Vegetables are high-cost crops, and losses are great when there is an oversupply. That was the general situation from 1930 to 1934. Then, in 1934, flax came to the rescue. It was not a speculative crop. It found a ready-cash market and it made a modest but sure return to growers. As a result, accumulated taxes were paid up; abandoned farms were bought and paid for with one or two crops of flax; and, above all, with the acreage of grain and vegetable crops adjusted to the market, agriculture in general became more profitable.

War always increases the demand for fats and oils. After Pearl Harbor, imports of vegetable oils were greatly reduced. The United States had to depend on domestic production. The response of farmers to the need was notable, indeed. The production of fats and oils increased to the point where large quantities could be exported to our allies. In 1943 and 1944, total exports were approximately 1,600,000,000 pounds annually. Of this total, exports of linseed oil amounted to 224,466,000 pounds in 1943 and 313,244,000 pounds in 1944. In terms of flaxseed, this represents a total of 28 million bushels for the 2 years.

The increase of flaxseed production in California was remarkable. To the Imperial Valley, flax was as important as corn to Iowa. Forty percent of the farm land in the valley in 1943 was put into flax. The higher production of flaxseed in California and Arizona not only supplied the needs of the Pacific coast area for linseed oil and linseed meal, but saved the overtaxed railroads from shipping flaxseed into the area, as was the practice 10 years earlier.

The acreage harvested in California in 1939-44 averaged 183,000; the production of flaxseed averaged 3,136,000 bushels a year. Arizona farmers, chiefly those in the irrigated valley of the Colorado below Yuma, planted an average of 15,000 acres each of the 6 years, and harvested an average of nearly 340,000 bushels. Allowing for seed used on farms, the total commercial crop in California and Arizona for the 6 years was approximately 20 million bushels, or 20 thousand carloads of 1,000 bushels each. For it, the farmers received more than $50,000,000.

Weeds are a serious problem. Where flax is sown in the fall, as in California and Arizona, farmers have a long period before seeding time when weeds can be destroyed by cultivation. A common practice is to irrigate the land two or three times in early fall and cultivate after each irrigation. The land should be plowed or subsoiled (chiseled), disked, and leveled (floated) before the first irrigation. When weeds appear and the surface soil becomes dry, the field should be cultivated thoroughly, but only 3 or 4 inches deep. A spring-tooth harrow is satisfactory for the purpose. A second irrigation, followed by thorough cultivation and harrowing, will generally be enough to eliminate most weeds, and leave the soil in good condition for planting. Sometimes a third irrigation and cultivation are needed to destroy wild oats, canary grass, and other weeds that do not appear until cooler weather comes on.

Another way is to grow a green-manure crop in summer. Sesbania, commonly used as a summer crop, thrives in hot weather. The frequent and heavy irrigation required for a summer crop kills most weed seeds in the surface soil. The green-manure crop is plowed shallow or, better, disked into the surface when the soil is still moist. With heat and moisture, the green crop rots rapidly.

A third method, growing the flax in cultivated rows, has been used successfully but not widely in the Imperial Valley. For row planting, the ground should be well prepared by irrigation and tillage, as for ordinary seeding. The seed is sown in drill rows 18, 21, or 24 inches apart, the spacing determined by the tread of the tractor and the type of cultivator used. The seed should be sown 24 to 30 pounds an acre so as to obtain a thick stand that will check weeds in the rows.

Shallow cultivation should be given as soon as possible after the first and second irrigations. Two cultivations are usually sufficient to eliminate most weeds until the flax is bolled. Timely harvest will then prevent any late weeds from going to seed. Where flax is grown for sale as certified seed, the few weeds that escape in the rows can be pulled by hand.

The broadleafed annual weeds can be checked or killed by spraying with Sinox or other selective spray material that adheres to the rough hairy surface of many weeds but does not wet the smoother leaves and stems of flax or grasses. Sinox is of no value in the control of wild oats, cheat, darnell, or other grass weeds. For best results, spraying should be done when the weeds are very small and the flax is 4 to 6 inches high. In no case should the spray be applied after the flax plants reach the flower-bud stage; at that stage, serious injury may occur. Sinox is most effective on clear warm days when the temperature is above 65° F.

Fifteen years of experiments at the Imperial Valley station indicate that early November is the best time for seeding. The highest yields and quality have been obtained from seedings made from November 1 to 20. In general, there is a reduction in yield when seeding is delayed until mid- December or early January, apparently because of the shorter growing season of the later planting.

Flax sown at different dates, October to December, ripens at about the same time; that is, in late April or early May, when high temperatures force maturity of the crop. Flax sown early in November has a long blossoming period (30 to 50 days), and a growing season of 150 to 180 days. These conditions permit the maximum setting of seed bolls and full maturity of the crop. In the date-of-seeding tests at El Centro, November plantings have shown, on the average, taller plants, a longer blossoming season, larger seeds, a higher oil content, and a higher iodine number of the oil than obtained from December plantings.

In the Imperial Valley it is a common practice to seed flax following alfalfa, sugar beets, carrots, lettuce, or another vegetable crop. Perhaps the best soil preparation for flax is a green-manure crop of sesbania, guar, cowpeas, or clover. These improve the soil, help maintain the nitrogen, control weeds, and reduce the hazard of diseases that may be carried over in the soil. Two or more crops of flax are often grown in succession. Generally, however, this is not a good practice, because both weeds and flax diseases are apt to increase under continuous cropping.

The use of fertilizers depends to some extent on the previous crop or the rotation system followed. Both phosphorus and nitrogen are usually needed for maximum yields. A safe rule is to apply about 65 units of available phosphate before planting, and 32 units of nitrogen in the first irrigation after the flax is up, or any time before the flower buds appear.

The success of flax in California and Arizona has been due to several factors: The excellent adaptation of the Punjab variety as a winter crop under irrigation in the area; the skill, resourcefulness, and cooperation of the pioneer growers of the crop; and a ready market for the high-quality seed. Perhaps the world record for yield of flaxseed was made by Harrison Emrick, of Yuma County, Ariz., in 1939. His field of 24.7 acres of Punjab flax made the remarkable yield of 61.6 bushels an acre.

THE AUTHORS
Arthur C. Dillman, formerly an associate agronomist, Division of Cereal Crops and Diseases, in the Bureau of Plant Industry, Soils, and Agricultural Engineering, is now an agronomist with the Flax Development Committee, of the Flax-Institute of the United States, in Minneapolis.
L. G. Goar is an associate in the Experiment Station (Agronomy), California College of Agriculture, and is Superintendent of the Imperial Valley Experiment Station, El Centro, Calif. He has worked with flax and other oil-bearing crops continuously since 1926.

ALSO, IN THIS BOOK
Genetics and Farming, by E. R. Sears, page 245.
Paper From Flax, by Arthur C. Dillman, page 750.

For more than half a century flax research has been under way at the North Dakota Experiment Station (above). Development of varieties resistant to a fatal wilt disease, Fusarium lini, has been one of many accomplishments. Below, left, Richard Heising at the North Dakota station carefully harvests a new disease-resistant hybrid. In 1927 flax was first tried in California; the variety was Punjab (lower, right). Under irrigation yields run up to 35 bushels an acre. From 1939 to 1944 California and Arizona produced nearly 21 million bushels of flaxseed. An article entitled Flax Moves West, by A.C. Dillman and L. G. Goar, begins on page 385.