BEET Beta vulgaris

FAMILY CHARACTERISTICS
    Overview Beta vulgaris (Beet) develop a prominent root-like structure which is not a true root, but a hypocotyl. The top portion of the beet is consumed as a green leafy vegetable.  True roots develop from the tap root.
    Beets are grown as cool season vegetables.  Production of the enlarged hypocotyl occurs most significantly when cool nights slow plant respiration, allowing for an accumulation of carbohydrates.
    Other members of the beet family include:
        Atriplex hortensis L.; Orache
        Beta vulgaris L. (Cicla group); Chard
        Chenopodium bonus-henricus L.; Good King Henry, Mercury
        Spinacia oleracea L.; Spinach

CROP HISTORY AND DEVELOPMENT
    Beets originated in the Mediterranean regions of Europe and North Africa. The original use of the wild beets was for medicinal uses only.  It was first cultivated as a potherb.  In the 3rd and 4th centuries BC, beets were cultivated for human consumption and animal fodder.  Selection of beet types with enlarged hypocotyls were emphasized through selection and  cultivation. In the time of the Greeks and Romans, the beet was considered to be an “epicurean” fare.  By the 16th century, selection of beet varieties had changed this crop from a long, tapered hypocotyl into the modern rounded hypocotyl.  The fleshy ‘Roman beet’ (the Italian Bassano) was described during this era.  Two centuries later, the cultivars ‘Flat Egyptian’ (from Egypt and the Middle East) and ‘Long Red’ (common to the Britain) were added to the ranks.
    Modern cultivars are classified according to the shape, color and time of maturity of the hypocotyl, and to some extent, the intended use.  Canning beets have a globe shape, with the cultivar ‘Ruby Queen,’ being the most popular; it has excellent quality and is very sweet.  Table beets range from flat to elongated; from red to yellow to black.  The globe red cultivars, especially the ‘Detroit Dark Red,’ are the most popular in production.  Breeding programs have also emphasized disease and disorder resistance.  Hybrid beets, such as the Red Ace Hybrid, is heat resistant and is tolerant of Cercospora Leaf Spot.  The hybrid varieties often mature earlier and have excellent quality; however, vigor may deteriorate with successive generations.
    Beets are grown for both the fresh market and the processing industry.  The major beet producers are Russia, France, the US, Poland, and Italy.  In recent years, the US has grown beets on 14,000 acres.  Over 400,000 cwt. have been produced for the fresh market, with an additional volume of 200,000 tons for the processing industry.  Major production areas in the US are New York, Wisconsin, Oregon, and Texas.

PLANT CHARACTERISTICS
    Overview The beet (Beta vulgaris ssp rubra) is in the same genus as swiss chard, sugar beets, and mangelwurzels.  Commercially, the beet is grown as a biennial; however, it is highly variable, performing as an annual, biennial, and in instances, as a perennial crop.  Vegetative growth of a rosette of leaves and an enlarged hypocotyl form during the first year.  Bolting most often does not occur until the second year of growth, after a vernalization period.
    Cool weather promotes the production of high quality beets, developing high sugar content and deep coloration.

Root System  Beets develop a swollen hypocotyl consisting of alternating rings of conductive/xylem (broad and dark) and storage/phloem (narrow and light) tissues. The true tap root develops from the  hypocotyl and reaches a rooting depth of 36-48 inches. In a lose, friable soil, rooting depth may reach 10 feet.  Lateral roots develop from the base of the hypocotyl.  The root system is not nearly so dense as it is expansive. Optimum hypocotyl development occurs between 60 and 65°F.  Pigment synthesis is also best at this temperature.  A yellow pigment and a red pigment similar to anthocyanin, give beets their characteristic colors.      Cultivar differences in color range from deep red to bright yellow.     Temperatures higher than optimal tend to reduce photosynthate storage in the hypocotyl, impairing size and growth, textural quality and flavor.

    Temperatures lower than optimal, less than 50°F, favor reproductive growth, shrinking the hypocotyl.
    The root and hypocotyl over winters while the top dies back. Reproductive growth is promoted the following season.

Leaves  Each leaf arises from the crown of the hypocotyl.  New leaves arise to the interior of older leaves.  Leaves are typically triangular in shape, having a long petiole which broadens at the base of the blade.  Leaf color ranges from deep greenish-red to light green.     Flower  Floral initiation occurs after a prolonged temperature below 50°F for periods of 30 to 60 days. Long days accelerate floral induction.  After stem elongation of up to 4 feet in height, a terminal flower spike is formed.  Individual flowers are arranged singly or in clusters.     Flowers are small, perfect, and may be greenish or reddish in color.  They consist of an ovary embedded in the receptacle surrounded by five anthers fused at the base to a calyx of five petals.     Pollen granules are wind borne.  For production of true seed type it is important to plant different varieties at distances greater than one mile.

Seed The corky seed ball or fruit consists of several true seeds, brown to black in color.  Individual seeds are difficult to harvest.  For propagation purposes, the seed ball is crushed into uniform pieces to facilitate mechanical planting.     There are 1,500 seeds per ounce.  Seeds maintain their viability for five years.

PROPAGATION METHODS
    Direct Seeding  Beet seeds are produced in cold climates where vernalization is possible and disease pressures are minimal.
    Seed scarification or decorking is used by the grower to overcome problem of seedling vigor, enhance final stand and reduce the necessity of thinning.  Soaking seeds in water for about 12 hours before sowing improves seed germination.
    Seeds are generally sown in early spring, often several weeks before the last frost, when soil temperature is between 45 to 80°F.  A germination time of 5 to 10 days can be expected under ideal conditions.
    Six to 10 pounds of seeds per acre are planted at a depth of ¾ to 1 inch.  Seeds are sown by broadcast, drilling, or dibbling in rows spaced 18 to 24 inches apart.  Thinning of seedlings to 5 or 6 plants per foot occurs while seedlings are less than 2 inches in height.  Thinning procedures may be avoided by planting seed balls at a spacing to avoid excessive competition.  Seed may be sown in bands using a scattering deflector on the seeder for industries preferring smaller beets (pickling or canning).

CULTURAL PRACTICES
    Overview Beets are a cool season biennial vegetable that can be grown on a wide range of soils. Ideal soil types are deep, light, fertile soils.  Soil pH most suitable is from 6.0 to 7.0.  Potassium and phosphorous fertility are needed in excess portions to ensure hypocotyl growth and development.
     Seeds are planted in rows of raised beds.  Irrigation is useful from planting to harvest to sustain proper hypocotyl growth and development.  Cultivation or chemical applications are made (primarily early in growing season) to diminish weed competition.
     Beets can tolerate frosts but cannot withstand hot, dry conditions.  Optimal temperatures are between 60 and 65°F
     Soil Type Deep, well drained, sandy loams with high organic matter are best.   Heavy clays hinder root and hypocotyl development.  Rows of raised beds enhance drainage.
    Alkaline soils (8.0 to 9.0) are better tolerated than acidic soils. Acidic soils should be limed to pH 6.0 to 7.0.
    Crop rotation with legumes in a three to four year rotation is recommended to promote improved soil growing conditions.
    Temperature Optimal growth of beet hypocotyls occurs between 60 and 65°F.  Temperatures below 50°F for 2 weeks causes a physiological shift from vegetative (rosette) to reproductive (flower bolting) growth.  Cooler weather will promote the development of deep red pigmentation.
    Fertility Beets do not require high amounts of nitrogen if the soil is rich in organic matter.  High levels of potassium and phosphorous are required and should be supplied at planting (applied in bands 2 inches to the side and beneath seed) and be present throughout development.  Soil testing will show the current soil level and provide information for fertility scheduling.
    Boron levels should be closely monitored as B deficiencies are common for this crop.
    Foliar analysis will provide current nutrient levels and provide needed information for fertilization scheduling.  The following tables show the nutrient sufficiency levels from samples of 20 new mature leaves taken in summer.

Macronutrients	N	P	K	Ca	Mg
	---------	---------	---%---	---------	---------
Low	3.5	0.25	3.0	2.5	0.3
Sufficient	5.5	0.5	4.5	3.5	1.0

 

Micronutrients	Fe	Mn	B	Cu	Zn
	---------	---------	---ppm---	---------	---------
Low	50	50	30	5	15
Sufficient	200	250	85	15	200

    Weed Control Weed competition is most intense early in seedling growth.  Early cultivation of crop diminishes weed pressure.  Excessive cultivation destroys feeder roots if carried into production season.  Herbicides provide control of various weeds.  Planting beets year after year may promote better weed control.
    Irrigation Early in the season, moisture is important; however, over watering during this time is detrimental.  Water logging can cause leaves to turn red and reduce plant growth.  Light and frequent irrigation is essential for seedling emergence, with the primary time for irrigation during hypocotyl development.  Beets develop most of their size in the last half of their growth, therefore, it is critical to supply adequate moisture during this period. During the last phase of growth, limit irrigation to morning hours to allow the foliage to dry and thus reducing fungal pathogens.
    Both a lack of water and poor soil drainage result in lower quality beets.

INSECTS
    Beet Armyworm (Spodoptera exigua)  Larvae are 1 inch when full grown.  They are greenish with a broad, dark, lateral band, edged with a narrow white line.  Larvae tend to defoliate crops after migrating from Pigweed.
    Cutworms (Peridroma saucia)  Cutworms are moth larvae living in the top three inches of soil.  They are brownish in color with distinctive markings.  Damage to the hypocotyl generally occurs after some defoliation.
    Flea Beetles Flea Beetles are small, brown to dark blue jumping beetles.  They create a “shot hole” appearance on leaves, causing serious damage to seedlings.
    Aphids  Aphids tend to colonize on shoots and leaves.  They are primarily a pest on beets grown for seed.
    Beet Leafminer (Pegomya sp) White maggots of a fly, they inhabit and feed on the epidermal cells of leaves, killing large areas of leaf tissue.

DISEASES
    Damping-off and Seed Rot  (Pythium sp and Phytophtora sp) Early spring planting tends to  present a greater occurrence of these diseases.  Proper soil preparation of the seed beds can be helpful in avoidance.
    Cercospora Leaf Spots This is the most common disease occurring on beets.  It appears as circular spots with reddish or purplish margins.
    Downy Mildew (Peronospora schachtii)  Cool, moist weather favors downy mildew infestation.  The Pacific Coast is the primary area where downy mildew occurs.  It appears on all aboveground parts.  The affected tissue discolors to a light green.  White conidia form on the lower leaf surfaces, spores may spread infection to crown and into the hypocotyl.  Flowers and seed balls are often infected.  Sustained freezing temperatures kill spores; however, mycelia can over winter in roots or seed balls.  Therefore, rouging of infected plant material is useful in reducing inoculum.
    Black Spot Boron deficiencies cause the disorder of black spotting on the hypocotyl structure.   Avoid by analyzing soil and leaves throughout growing season for boron and applying as needed.

HARVESTING
    Fresh market beets are harvested 50 to 65 days after planting when they are 1 ¾ to 4 inches in diameter, depending on the desired grade.  Usually, they are harvested when hypocotyl size distribution approaches 25% in grade 1 (1-1 5/8 inches), 60% grade 2 (2 – 2 5/8 inches), and 15% grade 3 (3 – 3.5 or 4 inches).  Maturity of beets may also be indicated when the leaves fall away from the upright position.  Fall crops may be left in the field during light frosts.  These low temperatures may enhance beet sweetness.
    Harvest continues over a several week period.  Beets for the fresh market are primarily hand harvested and collected in bunches of 3 to 6 depending on their size.  The dead leaves are removed and the beets are washed to remove the soil.
    Mechanical harvesting is used for the processing industry and for some fresh market:  mowers top leaves in two waves, the first cuts off the bulk of the leaves, the second crops the tops to within an inch or two of the beet crown; a harvester then comes through and lifts the beets into bulk trailers.  The beets destined for the fresh market are washed and packaged or boxed.
    Fresh market beets yield 140 to 200 cwt. per acre; processing beets yield 18 to 25 tons per acre.

POST HARVEST

Beets intended for fresh market may either be topped or have leaves intact.  Those with intact leaves are washed thoroughly, trimmed of dead or damaged leaves, then  packed in crates and marketed immediately.  Topped beets for fresh market are graded, washed and packaged in polyethylene bags.  They can be stored for up to five months at 32°F and 90-95% relative humidity.  Beets can be piled in bags or palletized if good air circulation is permitted.     Beets for the processing market may be stock-piled for several days without serious deterioration, and are then sent to the processor to be cleaned and processed - sliced, diced, or pickled.