Flax Production in North Dakota, an article on
the history and use of flax in North Dakota
by Duane R. Berglund and Richard K. Zollinger.
Flax Production in North Dakota
A-1038 (Revised), April 2002
Duane R. Berglund , Extension Agronomist
Richard K. Zollinger , Extension Weeds Agronomist
History and Use
Flax (Linum usitatissimum) production goes back to ancient history. Flax remnants were found in Stone Age dwellings in Switzerland, and ancient Egyptians made fine linens from flax fiber. Flax production moved west across the northern United States and Canada during the 1800s. As settlers moved west, flax was one of the crops produced. North Dakota farmers have grown flax since the first sod was broken.
Two types of flax are grown, seed flax, for the oil in its seed, and fiber flax, for the fiber in its stem. Today producers in the Upper Midwest and the Prairie Provinces of Canada grow seed flax. Flax seed is crushed to produce linseed oil and linseed meal. Linseed oil has many industrial uses; linseed meal is used for livestock feed. The fiber in seed flax stems is used to make fine paper and as tow or padding in upholstered furniture. Cigarette paper is a major flax paper product.
Human consumption of flax seed is increasing rapidly for its high dietary fiber, omega 3 oils, and anticarcinogenic lignans. Flax seed oil is used as a vegetable oil by some consumers and processors say its use is doubling annually. Whole or (preferably) ground flax seed is consumed mostly in bakery products. "Omega eggs" from hens fed flax seed are produced and sold in the U.S. and Canada for their high omega 3 oil content. Much flax seed meal also is fed to pets and other animals. Research is being conducted to determine the health benefits of human consumption of flax seed products.
Fiber flax is grown in Europe and Asia. Its fiber is used to make fine linen cloth. Fiber flax varieties are very tall with few branches and low seed production. Seed flax is short, multiple branched and selected for high seed production. Straw from seed flax is harvested for fine paper products.
Growth and Development
Flax is an annual plant that has one main stem. At low plant populations, branching at the base similar to tillers in a cereal grain is seen. The stems terminate in a multi-branched inflorescence that bears blue to white flowers. Flax grows to a height of about 24-36 inches. The plant has a tap root, which may penetrate to 40 inches if growing conditions are good. It requires a 50-day vegetative period, 25-day flowering period, and about 35 days to mature. In years when moisture is available the maturation period may extend until a hard frost kills the crop. In a wet fall new flowers are often observed until frost.
Flax is a self pollinated crop. Seed is produced in a boll or capsule. A complete boll can have 10 seeds, but most bolls will have fewer, averaging around six seeds. Seed color can be brown, golden, or yellow. The seed is covered with a mucilaginous coating. This coating becomes sticky when wet. During a wet harvest, this coating may discolor, giving the seed a weathered appearance and a reduced test weight.
Growing the Crop
Flax is usually sown on the same type of land that grows wheat and barley. Poorly drained soils, soils subject to drought and erosion, and soils high in soluble salts should be avoided. Flax should fit into many small grain rotations. For optimum yields and disease control, do not plant flax closer than three years in any rotation. Also, try to avoid planting flax after potato, canola and sugarbeet.
Select a variety adapted to your area. Variety descriptions and recent yield performance can be obtained in NDSU Extension Circular A-1049, North Dakota Barley, Oat, Rye and Flax Variety Performance Descriptions, available at your county extension office. Consider planting certified seed. Certified seed is tested to ensure minimal weed content, high genetic purity and good seed viability. Certified seed consistently outyields bin run seed. All recent varieties have an adequate oil yield and oil quality (iodine number) to meet industry specifications.
Treating flax seed with a recommended fungicide is necessary. Seed treatment reduces seed decay and seedling blights and can significantly increase stand. A thicker and more uniform stand produces higher yields. Yellow-seeded varieties are more susceptible to seed decay than brown varieties. Treated seed stored for long periods needs to be retested for germination before use. Flax can be grown under fertility levels similar to small grains. Use soil testing as a guide for applying fertilizer whenever possible. Recommendations for fertilizer use in flax are presented in NDSU Extension Circular SF-717, Fertilizing Flax. Zinc deficiency has been reported on flax in North Dakota, so information on zinc levels should be requested when soil testing.
Flax should be sown into firm, moist soil. A well-prepared, firm seedbed will ensure sowing at the proper depth. This, in turn, will result in uniform germination and rapid, even emergence. A planting depth of ¾ to 1½ inches is recommended. Press drill packer wheels do a satisfactory job of firming the soil after planting. If other types of planters are used, special efforts are needed, such as a soil packer behind the drill or harrowing prior to planting to firm the seedbed. Avoid deep seeding as delayed emergence weakens seedlings, and weak seedlings are more likely to die. When pre-plant incorporated herbicides are used, shallow planting is a must to reduce stress on emerging flax seedlings. Flax seedlings are less able to force their way through a soil crust than wheat seedlings.
A stand of 70 plants per square foot is desired. However, if uniform, stands of 30 to 40 plants per square foot may provide a satisfactory yield. As stands drop below 30 plants per square foot, weed infestation and delayed maturity are added problems. Seeding rates of 25 to 45 pounds per acre are common. In general, use lower rates in western North Dakota and higher rates in the east. Seed size varies among varieties and should also be considered. Yellow seeded varieties may require higher seeding rates because of lower seedling vigor. If untreated seed is used, then higher rates are necessary. Early seeded flax generally produces the highest yields. This would be late April for all of the state except the northeast, where early May seeding is possible. Frost seldom kills flax seedlings. Plants just emerging (breaking ground) are the most tender but can withstand temperatures down to 28 degrees Fahrenheit for a few hours. After the seedlings have a second leaf they can take temperatures into the low 20F range. Deferred sowing may aid in weed control and labor-equipment utilization but almost always results in lower yields. Non-uniform maturity and ripening is a problem in late seeded fields and additional management at harvest is often needed. Flax varieties vary in response to date of planting. Full season varieties should be planted early.
North Dakota Flax Variety Descriptions
Variety1 Origin Year Released Relative Maturity2 Seed Color3 Plant Height Wilt Relative Yield Ability NorLin Can. 1982 Early Br. Med. MS Good AC-Watson Can. 1996 Early Br. Short MR V. Good CDC-Valour Can. 1996 Early Br. Short MR V. Good Linton ND 1985 Early Br. Med. R V. Good Prompt SD 1988 Ealry Br. Med. MR Good AC-Emerson Can. 1994 Mid. Br. Med. VR V. Good CDC-Normandy Can. 1995 Mid. Br. Short MR V. Good Cathay ND 1998 Mid. Br. Med. MR V. Good Pembina ND 1998 Mid. Br. Med. MR V. Good Neche ND 1988 Mid. Br. Med. R Good Omega ND 1989 Mid. Yel. Med. MS V. Good NorMan Can. 1984 Mid. Br. Med. MR Good Rahab 94 SD 1994 Mid. Br. Med. MR Good CDC Arras Can. 1999 Mid. Br. Med. MR V. Good CDC Bethume Can. 1999 Mid./Late Br. Med. Tall MR V. Good AC Carnduff Can. 1998 Mid./Late Br. Med. Tall MR V. Good Flanders Can. 1989 Late Br. Med. MS Good Webster SD 1998 Late Br. Tall MR V. Good McDuff Can. 1993 Late Br. Med. Tall MR V. Good AC Linora Can. 1993 Late Br. Tall R V. Good McGregor Can. 1980 Late Br. Tall R V. Good Selby SD 2000 Late Br. Tall MR Good York ND 2002 Late Br. Med. R V. Good
1 All varieties have resistance to prevalent races of rust; all have good oil yield and oil quality.
2 Varieties listed order of mature..
3 br = brown, yel = yellow.
For variety performance information, see NDSU Extension Circular A-1049, North Dakota Barley, Oat, Rye and Flax Variety Selection Guide.
Seed Flax Straw
Combines should be equipped with straw-choppers and spreaders to redistribute the straw evenly. It was once a common practice to burn flax residue. This is no longer recommended. If industrial markets develop for seed flax straw, other methods of collecting straw and transporting it from the field will be identified. Green flax straw may have a prussic acid problem if used as livestock feed. Caution should especially be taken immediately after a frost.
Flax is less competitive with weeds than small grains and should be grown on relatively weed-free fields. Control weeds in and following harvest of the preceding crop. Post-harvest tillage of small grain stubble will prevent weed seed production, suppress perennial weeds and encourage annual weed seed germination prior to freeze-up. Flax should be seeded directly or with shallow spring tillage in fields. Deep tillage on such fields could bring dormant seeds to the surface and increase weed problems. For weedy fields, moldboard plow the soil to bury the weed seeds, reducing the weed infestation the following crop season. Moldboard plowing can reduce infestations of small-seeded weeds like foxtails and kochia, which have short seed survival.
Delayed seeding of flax with tillage prior to seeding will control wild oat and reduce infestations of other early germinating weeds. However, delayed seeding generally reduces flax yields. Early maturing flax varieties should be used with late seeding. Weed control is needed by flax emergence to reduce yield losses since flax is a poor competitor with weeds. Soil applied herbicides reduce weed emergence and minimize early weed competition to maximize flax yields. POST herbicides applied soon after weed emergence to small weeds and flax usually give better control and allow more time for flax recovery from possible herbicide injury than to larger weeds and flax.
Bromoxynil at 1 pt/A on 2- to 8-inch flax controls some broadleaf weeds. Some flax leaf burn may occur if applied during high temperatures. Bromoxynil plus MCPA may cause flax injury if applied during hot, humid conditions.
Curtail M may be labeled in flax through Section 18 emergency exemption registration. Apply Curtail M at 1.33 to 1.75 pt/A for Canada thistle control and 1.75 pt/A for perennial sowthistle control. Apply when flax is 2 to 6 inches tall. Extreme growing conditions prior to, at, and following application may reduce weed control and increase risk of flax injury. *Check for Section 18 status before using.
MCPA at 0.5 pt/A on 2- to 6-inch flax controls broadleaf weeds. MCPA ester or high MCPA amine rates should be used in flax for improved kochia and Russian thistle control.
Spartan (sulfentrazone) may be registered in flax through Section 18 emergency registration. Spartan applied PRE at 2.67 to 5.33 oz WDG/A controls most annual small-seeded broadleaf weeds. *Check for Section 18 status before using.
Trifluralin at 1 to 2 pt/A or 10 to 12 lb 10G/A may be fall applied for foxtail and broadleaf weed control on fields to be planted to flax. Granular formulations may be applied to standing stubble. Use liquid or granular formulations when residue will not interfere with incorporation. Seed flax less than 1.5 inches deep into a moist seedbed. Incorporate shallow and seed deep or seed shallow with deep incorporation to maximize crop safety.
FLAX -- Herbicides for Weed Control
Weeds When to Apply Remarks and Paragraphs Trifluralin 1 to 2 pt
5 to 10 lbs 10 G.
(0.5 to 1)
Grass and some broadleaf weeds Fall: PPI Use higher rates on fine textured soils. Incorporate once in the fall within 24 hours after application. Keep spring tillage depth shallower than fall.
2.67 to 5.33 oz
(0.125 to 0.25)
Annual small-seeded broadleaf weeds including, kochia, pigweed, lambsquarters, nightshade, and biennial wormwood. EPP, PPI, or PRE Make EPP application up to 30 days prior to planting. Adjust rate to soil type. Requires precipitation for activation. Close furrow at planting. Temporary flax injury may occur in coarse, low organic matter soils with pH greater than 8.0. May give 6 to 8 weeks residual weed control. Check for Sec. 18 status prior to use. Bromoxynil
Broadleaf weeds including wild buckwheat Flax: 2-8 inches tall Use for wild buckwheat control. Weak on wild mustard. Flax injury is possible. MCPA 0.5 pt of a 4 lb/gal conc. (0.25) Broadleaf weeds Use MCPA ester on hard-to-kill weeds. Early application is less injurious to flax. Bromoxynil + MCPA 0.9 pt
Apply to small weeds prior to bud stage of flax. Risk of crop injury. Commercial mixtures available: Bison, Bromac, Bronate, Bronate Advanced. Curtail M (clopyralid + MCPA) Section 18 Registration Pending 1.33 to 1.75 pt (2 to 3 oz) Broadleaf weeds including Canada thistle and perrennial sowthistle Post.
Flax: 2-6 inches tall
Canada thistle: 4-6 inches tall
Apply after most thistle shoots have emerged. Allow a 72 day PHI. Follow rotational crop interval and other precautions on product label. Check for Sec. 18 status prior to use. Poast (sethoxydim) 0.5 to 1.5 pt (0.1 to 0.3) Annual Grasses Post.
Flax: prior to bloom
Apply with 1 qt/A oil additive to actively growing grasses. See narrative for rates to control different weed species. May be tank-mixed with bromoxynil or MCPA ester for broad spectrum weed control. Allow a 75 day PHI. Select Prism (clethodim) 4 to 5 fl oz 8.5 to 11 fl oz (1 to 1.25 oz) Grass weeds: 2 to 6 inches tall. Preharvest Application Glyphosate (Only certain brands are registered i.e. Roundup Ultra Max, Glyphomax Plus, Gly Star, Touchdown) 2 pt of a 3 lb ae/gal conc. or 1.6 pt of a 3.7 lb ae/gal conc or 1.5 pt of a 4 lb ae/gal conc or 18.5 oz of a 65% SG (0.75) Emerged grass and broadleaf weeds includeing Canada thistle and perrennial sowthistle Preharvast. Falx: Physiolog- ically mature. Seed contains 30% or less moisture. Greater perennial weed control will result if at least 10 to 14 days are allowed between application and harvest. Allow a minimum 7 day PHI. Apply with AMS fertilizer. Refer to label for adjuvant use. Do not apply to flax grown for seed because reduced germination/vigor may occur. Drexel Defol (sodium chlorate) 1 gal of a 6 lb/gal conc. (6) Desiccant 7 to 10 days prior to harvest 70 to 80% of the bolls should be brown. Thorough spray coverage of vegetation is essential. Do not graze or feed treated straw. Apply in 5 to 10 gpa by air or 20 to 30 gpa by ground.