1 Department of Agronomy, College of Agricultural and Life Sciences and Cooperative Extension Service, University of Wisconsin-Madison, WI 53706.
2 Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN 55108.
3 Center for Alternative Plant and Animal Products, University of Minnesota, St. Paul, MN 55108. July 1991.
Mustard ( Brassica spp.), a native to temperate regions of Europe, was one of the first domesticated crops. This crop’s economic value resulted in its wide dispersal and it has been grown as a herb in Asia, North Africa, and Europe for thousands of years. Ancient Greeks and Romans enjoyed mustard (sinapis) seed as a paste and powder. In about 1300, the name “mustard” was given to the condiment made by mixing mustum, which is the Latin word for unfermented grape juice, with ground mustard seeds.
Mustard has been a major specialty crop in North America since supplies from western Europe were interrupted by World War II. California and Montana were the major production areas until the early 1950s. Production of mustard in the Upper Midwest began in the early 1960s. Mustard is currently grown on approximately 250,000 acres annually in the United States. North Dakota has the largest share of domestic production. Canadian mustard production increased for twenty years until it peaked in the mid-1980s. Alberta, Manitoba, and Saskatchewan currently grow a large share of the world’s mustard crop. The French people are the largest consumers of mustard (1.5 lbs/person/year), and buy approximately 70% of the annual Canadian production.
Three types of mustard, yellow, brown, and oriental, are grown in North America. Yellow mustard ( Brassica hirta ) comprises about 90% of the crop in the Upper Midwest. In Europe, yellow mustard is also known as white mustard ( Sinapis alba – an older botanical name).
Brown and oriental mustards ( Brassica juncea ) are grown on limited acres. This crop is commonly produced in a rotation with small grains.
More than 700 million lbs of mustard are consumed worldwide each year. Yellow mustard is usually used for prepared or table mustard, a condiment, and as dry mustard. Dry mustard is frequently used as a seasoning in mayonnaise, salad dressings, and sauces. Flour made from yellow mustard is an excellent emulsifying agent and stabilizer, and consequently, it is used in sausage preparation. Brown and oriental mustards are also used as oilseed crops. However, the strong flavor of this high-protein oilseed has made it unpopular in the livestock feed and vegetable oil markets of North America. As a result, mustard produced in North America is used primarily as a spice or condiment.
III. Growth Habit:
Mustard is an annual herb with seedlings that emerge rapidly, but then usually grow slowly. Plants cover the ground in 4 to 5 weeks with favorable moisture and temperature conditions. The tap roots will grow 5 ft into the soil under dry conditions, which allows for efficient use of stored soil moisture. Plant height at maturity varies from 30 to 45 in. depending on type, variety, and environmental conditions.
Flower buds are visible about five weeks after emergence. Yellow flowers begin to appear 7 to 10 days later and continue blooming for a longer period with an adequate water supply. A longer flowering period increases the yield potential. About half of the flowers produce dark, reddish-brown seeds that are retained in pods of 0.5 to 0.75 in. in length. Flowers pollinated during the first 15 days of the flowering period produce most of the seed.
IV. Environment Requirements:
Mustard is a cool season crop that can be grown in a short growing season. Varieties of yellow mustard usually mature in 80 to 85 days whereas brown and oriental types require 90 to 95 days. Seedlings are usually somewhat tolerant to mild frosts after emergence, but severe frosts can destroy the crop. Mustard, especially the brown and oriental types, has a partial drought tolerance between that of wheat and rapeseed. Moisture stress caused by hot, dry conditions during the flowering period frequently causes lower yields.
Mustard can be raised on variable soil types with good drainage, but is best adapted to fertile, well-drained, loamy soils. Soils prone to crusting prior to seedling emergence can cause problems. This crop will not tolerate waterlogged soils since growth will be stunted. Dry sand and dry, sandy loam soils should also be avoided.
C. Seed Germination:
Seed will germinate at a soil temperature as low as 40°F.
V. Cultural Practices:
A small grain crop following mustard in the rotation will usually yield more than when following continuous small grain. Mustard has several of the same diseases and insect pests as flax, oilseed rape (canola), sweet clover, soybeans, field peas, lentils, and sunflowers. Therefore, crops from this group should be avoided in the same rotation as mustard. Cereal grains are not very susceptible to the pest and disease problems of mustard.
A. Seedbed Preparation:
The seedbed should be firm, fairly level, and free of weeds and previous crop residue. Soil is firm enough for seeding when only a shallow depression of a heel is made when someone stands on the soil. Shallow tillage, just deep enough to kill weeds, should keep soil moisture
close to the surface and leave a firm seedbed. If necessary, the seedbed should be packed before planting to obtain a firm seedbed. Firm seedbeds with adequate moisture allow shallow planting and encourage rapid, uniform seed germination and emergence of seedlings. A number of growers in North Dakota have also successfully planted mustard in standing small-grain stubble and minimum-tilled stubble.
B. Seeding Date:
Planting should occur as early in the season as the environmental conditions allow. The soil temperature should be at least 40 to 45°F at a depth of 1 in. If seedlings are damaged by frost after emergence, 4 or 5 days may pass before the full extent of the damage is known. Plants should recover if the growing points are not destroyed. An earlier seeding date allows plants to benefit from the spring moisture in establishing a good canopy before weeds emerge, and to avoid heat stress during summer that causes flower or pod abortion. Early seeding also reduces the risk of damage from fall frosts that can reduce crop yields and quality. The recommended seeding date in northern Minnesota and Wisconsin is May 1 to 25. Seeding later than May 15 frequently results in lower yields.
C. Method and Rate of Seeding:
Yellow mustard, which has approximately 100,000 seeds/lb, is solid seeded with a grain drill at a rate of 8 to 14 lbs/acre. The higher rate should be used on heavy, fertile soils or on those where emergence is difficult. Brown and oriental mustards have 200,000 seeds/lb and should be solid seeded at a rate of 5 to 7 lbs/acre. Seed is small and must be planted shallow at a 1/2 to 1 in. depth. If very dry soil conditions exist seeding depth should be increased to 1 1/2 in. If mustard stands are poor, quick decisions for reworking and reseeding should be made.
D. Fertility Requirements:
Mustard generally responds to nutrient additions in a similar way as does rape or canola. Soil tests should be used to determine nutrient need. Optimal (medium) soil test levels are about 15 to 20 ppm Bray P, and 80 to 100 ppm K. At these levels fertilizer should be applied at a rate of about 45 lbs/acre P 2 O 5 and 80 lb/acre K 2 O. When fertilizer is banded, the bands should be placed below and to the side of the seed furrow. Mustard responds well to nitrogen additions with optimum yields occurring at about 100 to 120 lb/acre N. Where mustard follows legumes or manure additions, appropriate credits should be taken.
Work in the western U.S. shows that mustard responds well to sulfur(s) on low S-supplying soils. Sulfur fertil-sandy soils in northwestern Wisconsin and northern Minnesota which have not been manured in the past two years.
On soils deficient in boron (testing at less than 0.5 ppm B), apply 0.5 to 1 lb/acre in a uniform broadcast application. Never band B near the seed.
Soils with a pH near neutral (7.0) are desired for this crop. Nevertheless, an alkaline pH and slightly saline soils are tolerated. Mustard has a tolerance to soil salinity that is similar to barley.
E. Variety Selection:
Varieties of yellow mustard are usually earlier maturing, lower yielding, and shorter in height than brown or oriental varieties. Yield differences among the types of mustard are reflected usually in the prices offered by contracting firms. Contracting firms usually supply growers with the appropriate varieties. Some mustard varieties include:
Gisilba Yellow mustard. Similar to Ochre in field performance. Originated in Germany. Distributed by Northern Sales Co. Ltd., Winnipeg. Licensed in 1974.
Kirby Yellow mustard. Released by Colman Foods, Norwich, England in 1970. Distributed by Minn-Dak Growers Association, Grand Forks, ND.
Ochre Yellow mustard. Released by Agriculture Canada, Saskatoon. Licensed in 1981.
Tilney Yellow mustard. Similar to Kirby in field performance but has a high mucilage content desired by processors. Released by Colman Foods Norwich, England in 1978. Distributed by Minn-Dak Growers Association, Grand Forks, ND.
Carrow 85 Oriental mustard. Undesirable small seed. Released by Colman Foods, Norwich, England in 1980.
Domo Oriental mustard. Released by Agriculture Canada, Saskatoon. Licensed in 1977.
Lethbridge 22A Oriental mustard. Released by Agriculture Canada in 1967, Lethbridge. Licensed in 1974.
Blaze Brown mustard. Released by Agriculture Canada, Saskatoon. Licensed in 1976.
Varietal trials for mustard in your area should be consulted for yield and other agronomic characters as in Minnesota (Table 1).
F. Weed Control:
Weeds can greatly reduce mustard yields. Weed seeds, which are difficult to remove, can cause high losses during seed cleaning and lower market grades. Good weed control is based on preparation of a clean field and shallow seeding to encourage quick, uniform emergence. Young mustard seedlings do not compete well with weeds and the early establishment of a uniform, vigorous crop helps control annual weeds. The crop cannot be cultivated after emergence.
Mustard, especially the oriental and brown types, should be grown on land with as little wild mustard as possible to avoid costs of removal and loss of tame mustard seeds. Wild mustard seed can be mechanically separated from the larger-seeded yellow type, but separation is not possible with the smaller-seeded brown and oriental types. Wild mustard seed often reduces the crop quality to the sample grade. Production of rapeseed and mustard on the same fields is also not recommended since seed mixtures can occur easily and degrade both crops.
Control of perennial weeds such as Canada thistle, field bindweed, and quackgrass, should be started in the fall or prior to planting in the spring. Control Canada thistle by applying Roundup (glyphosate) before the last killing frost in the fall when it is still actively growing. Spring treatment of Canada thistle prior to planting is not usually adequate for complete control. Apply Roundup to quackgrass when it is at least 8 in. tall and growing actively. Allow 3 days between application and tillage. Control field bindweed with Roundup when it is actively growing on moist sod and is at or past full bloom, preferably in late summer or fall the year before planting mustard. Spring treatment to control perennial weeds before planting is usually not practical.
Trifluralin (Treflan EC) is labeled for use on mustard in Minnesota and North Dakota for control of a wide variety of grasses and broadleaf weeds; however, it will not control wild mustard. The rate of herbicide applied will vary with the soil type, organic matter content, and species of weeds that need to be controlled. Check the label for the correct rate to use on your fields. Trifluralin must be applied before seeding and incorporated thoroughly in the soil for maximum effectiveness. Mustard is sensitive to the broadleaf herbicides used on cereal crops, such as 2,4-D and MCPA, and spray drift from adjacent fields must be avoided. Crops that can be sprayed with 2 4-D or MCPA should follow mustard in the rotation so volunteer plants can be controlled.
G. Diseases and Control:
This crop is vulnerable to several diseases, among which the most serious are Sclerotinia stalk rot (white mold), downy mildew, white rust, leaf spots, and mosaic virus. Good cultural practices are the most effective control measures for diseases. These practices should include keeping records of disease occurrence, compliance with the proper crop rotation, control of host plants for diseases in fallow fields and non-crop areas, and use of seed treatments.
Sunflower, rapeseed, canola, safflower, soybeans, crambe, and drybeans should not be grown in rotation with mustard since they have similar disease problems. If these crops are produced in rotation with mustard, damage from these diseases can increase to economic levels. Numerous broadleaf weeds can also serve as hosts or sources of infection for these diseases. Wild mustard, pigweed, field pennycress, and shepherd’s purse are examples of predominant hosts. One of the best methods to avoid serious disease problems in mustard (and leaf diseases of small grains) is to produce this crop in a small grain rotation. Mustard should be spaced four or more years apart in the crop rotation to avoid problems with soil-borne diseases. After potato or flax crops, one year should pass before mustard is raised on the same field due to the presence of root rot or damping-off pathogens.
H. Insects and Other Pests:
Growers should monitor fields closely to detect insect problems that can result in significant yield losses. Flea beetles and caterpillars of the diamondback moth have been the most serious pests. Young seedlings can be seriously damaged by flea beetles soon after emergence. Feeding activity of adult beetles causes a shot-holed appearance to cotyledons and the first true leaves. Damaged plants may die or suffer a reduction in vigor. Hot, sunny weather encourages feeding while cool, damp conditions slows insect feeding and promotes crop growth. Injured plants may wilt and die during hot, dry weather, which results in mild to severe yield losses. Serious crop damage does not usually occur once the crop develops beyond the seedling stage since vigorous plants can outgrow beetle defoliation.
Losses caused by flea beetles can be minimized by practicing the proper cultural methods. A well-tilled, firm seedbed with adequate fertility should permit young seedlings to outgrow beetle damage during the vulnerable stages early in the season. The presence of a few flea beetles or scattered shot-holing is not cause for serious concern. However, if beetles are numerous and feeding damage is present on most cotyledons, prompt control may be necessary. Malathion EC at 1 1/4 lbs/acre, Carbaryl (Sevin) at 1 lb/acre, Ethyl parathion 8E at 1/2 lb/acre, and Thiodan EC at 3/4 lb/acre can be used for control of flea beetles. Read labels for waiting period and correct timing.
Larvae of diamondback moths eat leaves, flowers, and green seed pods. Malathion used at 2 1/2 lbs/acre will control these caterpillars. Damage from sugar beet nematodes can be avoided when sugar beets are not grown on the same field two years before or after mustard, since mustard is a host plant for this nematode. Consult local Extension bulletins for further information on the control of insects and other pests.
The normal maturation of the crop, wind, and rain do not cause shattering before cutting. However, the actual harvesting operations can cause great shattering losses when the plants are overripe. Yellow mustard does not shatter readily and can be straight combined if the crop has matured uniformly (10% moisture) and is free of green weeds. If the crop is weedy or uneven in maturity it should be swathed. Swathing, if deemed necessary or preferred, should be done when 60 to 70% of the seed has turned yellow-green. Plants should be cut just beneath the height of the lowest seed pods. The swath will then settle into the stubble and reduce the chance of being blown by high winds. Yellow mustard does not cure quickly. Straight combining is therefore recommended at 12 to 13% moisture, followed by artificial drying, to obtain uniform quality and highest yield.
Brown and oriental varieties will shatter more readily when ripe and should be swathed. The swathing should begin after the general leaf drop and when the overall field color has changed from green to yellow or brown. Pods sampled from the middle of racemes from several plants, in arm representing the average maturity, should be examined for physiological maturity. About 75% of the seeds may have reached the mature color of yellow or brown. The remaining green seeds will mature in the swath before combining.
Swathing should be done under conditions of high humidity or when morning dew is on ripe pods to decrease shattering losses. Windrows tend to be bulky and subject to scattering by the wind. A roller or steel drum should be used to press the swath into the stubble. The combine should be adjusted so seeds are threshed completely by using the lowest cylinder speed, which is set at approximately 600 RPM, and the appropriate cylinder opening. The reel may cause shattering when straight combining, but it can be removed or lifted above the plants it the stand is good. If the reel is needed, remove half of the bats and reduce its speed. Cylinder speed may need to be adjusted during the day as crop moisture content may vary.
J. Drying and Storage:
When the mustard seed reaches a moisture content of 10% or less it can be stored safely. The harvested seed should be handled carefully since it will crack easily when moved in and out of storage. The damaged seed becomes dockage and is a loss to the grower. Air temperatures for seed drying should not exceed 150°F and seed temperature should stay below 120°F. Use of drying equipment designed for corn or wheat may require some modification when drying mustard. A fine screen will be needed to prevent loss of the smaller seed. Storage bins must be free of cracks or holes.
VI. Yield Potential and Performance Results:
Mustard yields in the Upper Midwest have been variable due to differences among varieties, cultural practices, and environmental conditions. Yields for research trials in Minnesota have ranged from 868 to 1,861 lbs/acre (Table 1.). The MINN-DAK Growers Association reported that yields in the past few years were low due to weather conditions. Growers were producing 800 to 900 lbs/acre of yellow mustard, while brown and oriental mustards were yielding 1,000 to 1,100 lbs/acre. A fair estimate for the yield potential of production fields in the Upper Midwest would be 800 to 1,000 lbs/acre. However, yields of 1,400 lbs or more per acre are possible in areas with favorable growing conditions.
Table 1. Average yield and other agronomic characteristics of yellow, brown, and oriental varieties of mustard in Minnesota field trials*.
Mustards, (Brassica spp.) are herbaceous annual plants in the family Brassicaceae grown for their seeds which are used as a spice. Mustard plants are thin herbaceous herbs with yellow flowers. The leaves of the plant are toothed, lobed, and occasionally have the larger terminal lobes. Plants can reach 16 cm (6.3 in) in length. The yellow flowers grow in spike like clusters of 2–12 flowers and individual flowers are 8 mm (0.3 in) in diameter. The seeds are red to brown in color and produced from each flower. Mustard can grow 1.2-2 m (4–6.6 ft) in height and as an annual plant, survives only one growing season. Mustard may also be referred to as mustard, brown mustard, red mustard, yellow mustard or wedlock and is believed to have originated in the temperate regions of Europe.
The leaves and shoots of the mustard plant are consumed as a vegetable in some countries. Mustard seed is incorporated into seasonings and dressings. Mustard may be grown as a cover crop in rotation with other vegetables.
Basic requirements Mustard grows very well in cool climates with short growing seasons, at temperatures as low as 4.4°C (40°F). Seedlings can tolerate some light frost but severe frost will kill the plants. The mustard plant can be grown in sandy, loamy or clay soils with a pH between 4.9 and 8.2 and prefers moist soil. The plant will tolerate partial shade. Propagation Mustards is propagated from seed and due to the small size of the seeds, should be planted in a well prepared seed bed which is firm and flat. Mustard seeds should be sown in Spring once soils have warmed to 4.4–7.2°C (40–45°F) and should be planted at a depth of 1.25–2.5 cm (0.5–1.0 in) at a density of 8–14 lbs of seeds per acre. The seed can be spread by broadcasting in the home garden or, in the case of commercial production, using a seed drill. Mustard generally matures in 80–85 days. General care and maintenance Weeds can cause huge losses in mustard cultivation as they quickly out compete seedlings and are difficult to eradicate once established. The best method of preventing weed growth in a mustard field is to plant seeds at the appropriate depth. Shallow planted seeds germinate rapidly, allowing the development of a uniform plant stand. Established plants are less susceptible to competition from weeds. soil should be tested to determine nutrient requirements prior to planting. Mustard will benefit from the addition of supplemental nitrogen and this is generally applied at a rate of 100–120 lb per acre. Harvesting Mustard is generally ready to harvest 80 to 85 days after planting. The crop should be harvested promptly to reduce losses to shattering. In commercially grown fields the recommended method of harvest is swathing. The plants should be cut just below the height of the lowest seed pods. In the home garden, mustard can be harvested by hand by cutting the plants. The seeds can then be recovered from the pods and dried for storage.