Beet

Description

Beets, Beta vulgaris, are herbacious biennial root vegetables in the family Chenopodiaceae grown for their edible root. The plant is usually erect with a long main root and a rosette of leaves growing on stems. The leaves are oval in shape, arranged alternately on the stem and grow 20–40 cm (7.9–15.7 in) in length. The roots are usually red in color. The plant produces sessile green flowers and can reach 1–2 m (3.3–6.6 ft) in height. Beets are usually grown as annual plants, harvested after one growing season. Beets may also be referred to as beetroot, garden beet or spinach beet and originated from the Mediterranean.


Uses

The roots are consumed after boiling and may be pickled in vinegar. The leaves of the spinach beet plant are consumed as a herb in Indonesia and Japan. Chemicals in the roots can be extracted and used as food coloring.


Propagation


Basic requirements
Beets are cool season vegetables with a long growing season. They grow best in cool climates but can tolerate some heat as well as some freezing. The optimum temperature for their growth is between 15.5 and 18.3°C (60–65°F). Beets grow best in a loose, well draining soil with a pH between 6.2 and 6.8 and should be planted in full sun for optimum development.

Sowing seeds
Beets are direct seeded and can be planted as soon as the soil is workable in Spring. The soil should be prepared for planting by first removing any large rocks and stones and then working in 2–3 inches of compost or well-rotted manure. Plant one seed every 2.5 cm (1 in) at a depth of 13 mm (0.5 in) in rows spaced 30–40 cm (12–16 in) apart. Keep the seedbed well watered. Seedlings should emerge in 5 to 17 days at temperatures between 10 and 24°C (50–75°F). When seedlings have reached between 7 and 10 cm (3–4 in) in height, thin to a final spacing of 7–10 cm (3–4 in) between plants. For a continuous harvest, plant seeds every 2–3 weeks as long as the daytime temperature stays below 26.6°C (80°F). Most beet varieties mature in 55 to 70 days.

General care and maintenance
Beets require plenty of moisture to develop optimally. Even watering will promote the development of good quality roots and prevent the formation of rings in the root. Soil moisture can be conserved by applying a layer of mulch around the plants. In addition to moisture, beets also require an adequate supply of nutrients, particularly phosphorus. Apply a complete fertilizer at planting to ensure optimum development. Remove any weeds around plants by cultivating shallowly to avoid damaging the developing roots.

Harvesting
Young beet greens can be harvested for salads when they are 2.5–5.0 cm (1–2 in) high and older greens before they reach 15 cm (6 in) in length. The roots are ready for harvest when they have reached 2.5 cm (1 in) in diameter and are most tender before the exceed 7.5–10 cm (3–4 in). Watering the soil the day before harvest or the day after rainfall makes pulling the beets easier. Pull beets out of the soil by firmly grasping the top and pulling the root out of the soil vertically. Alternatively, use a garden fork to dig the beets out of the soil. Cut the tops of the beets to 1.25–2.5 cm (0.5–1.0 in) above the root before storing the root. This helps keep the beets fresh.


References

CABI Crop Protection Compendium. (2010). Beta vulgaris datasheet. Available at: http://www.cabi.org/cpc/datasheet/8778. [Accessed 06 November 14]. Paid subscription required.

Harveson, R. M., Hanson, L. E. & Hein, G. L. (2009). Compendium of Beet Diseases and Pests. Available at: http://www.apsnet.org/apsstore/shopap.... Available for purchase from APS Press.

Schrader, W. L. & Mayberry, K. S. (2003). Beet and Swiss Chard Production in California. University of California Division of Agriculture and Natural Resources. Available at: http://anrcatalog.ucdavis.edu/pdf/809.... [Accessed 06 November 14]. Free to access




Common Pests and Diseases

Scab
Streptomyces scabies

Symptoms
Small round spots on roots that enlarge, turn brown and rupture the epidermis; raised corky spots on root surface that are gray, white or tan in color.
Cause
Bacterium
Comments
Bacteria survive in soil; disease emergence favors dry conditions.
Management
Do not plant in soil know to be infected; avoid crop rotation with potato.

Bacterial blight
Pseudomonas syringae pv. aptata

Symptoms
The infected leaves show irregular to circular shaped spots with tan to dark brown centers and dark black borders. In some instance symptoms also appear on the edges of the leaves which initially may appear water-soaked and later turn yellow and then necrotic. These spots may join together between the veins an the dried area falls off, which gives a ragged appearance.
Cause
Bacterium
Comments
The bacteria spreads mainly by splashing rainfall, mechanical and insect injuries. The pathogen also infects other crops like bean, eggplant, lettuce, and pepper.
Management
Use healthy and disease free seeds.

Damping off
Rhizoctonia solani
Phoma betae
Pythium ultimum
Aphanomyces cochlioides

Symptoms
Seedlings collapsing; blackened roots; constriction of plant crown.
Cause
Fungi
Comments
Warm, wet weather favors disease emergence; beet very susceptible.
Management
Treat seeds with fungicide prior to planting; plant in well draining soil; do not plant until soil is sufficiently warm.

Cercospora leaf spot
Cercospora beticola

Symptoms
Brown to gray flecks or spots surrounded by red-purple halos on leaves; yellow or brown necrotic leaves.
Cause
Fungus
Comments
Fungal spores spread by wind and rain; high temperatures and humidity promote infection; fungus overwinters on crop residue or in seed.
Management
Rotate crops every 2-3 years; apply a fungicide at first sign of disease; plow crop debris into soil immediately after harvest.

Downy mildew
Peronospora farinosa

Symptoms
Plant leaves appear lighter green; small, puckered, thickened leaves; fuzzy gray growth on both leaf surfaces.
Cause
Fungus
Comments
Fungus survives in crop residues over winter to infect new crop.
Management
Grow available resistant varieties. Remove and destroy the infected crop debris.

Powdery mildew
Erysiphe betae

Symptoms
Initially the symptom appears on older leaves as small, scattered, circular, white mycelium mats on lower surface. Later all the leaves of the plant infected and appear dusty white on both surfaces. If the disease is severe the leaves become yellow and then turn purplish-brown.
Cause
Fungus
Comments
The spores are transmitted by air. If the weather conditions are good, one can see, particularly on the upper surface of the older leaves dark brown to black, globular, sexual reproductive structures (chasmothecia = cleistothecia).
Management
Grow available resistant varieties. If the disease is severe, spray suitable fungicide.

Fusarium yellows and root rot
Fusarium oxysporum f. sp. spinaciae
Fusarium oxysporum f. sp. betae

Symptoms
The infected leaves exhibit yellowing between the larger veins. Later entire leaves become dry, brittle and remain clustered around the crown. Typically only one side of the leaves is affected and appear scorched. The vascular tissues of infected plants become discolored. Plant appear wilted during day time and recover at night. The tip of taproot becomes black due to rotting.
Cause
Fungus
Comments
The pathogen survive on weeds like pigweed, Kochia, and lambs quarters during off season.
Management
Plant resistant varieties. Crop rotation with non host crop. Keep field free from weeds.

Leafminers
Lyriomyza spp.

Symptoms
Thin, white, winding trails on leaves; heavy mining can result in white blotches on leaves and leaves dropping from the plant prematurely; early infestation can cause fruit yield to be reduced; adult leafminer is a small black and yellow fly which lays its eggs in the leaf; larave hatch and feed on leaf interior.
Cause
Insect
Comments
Mature larvae drop from leaves into soil to pupate; entire lifecycle can take as little as 2 weeks in warm weather; insect may go through 7 to 10 generations per year.
Management
Check transplants for signs of leafminer damage prior to planting; remove plants from soil immediately after harvest; only use insecticides when leafminer damage has been identified as unnecessary spraying will also reduce populations of their natural enemies.

Darkling beetle (Rove beetle)
Blapstinus spp.
Staphylinid spp

Symptoms
Feeding damage on stems; death of seedlings; seeds dug up; insect is a dull blue-black or brown beetle about 0.6 cm (0.52 in) long; tips of antennae are often enlarged, resembling a club.
Cause
Insect
Comments
Beetles are generally active at night; during the day beetles hide in organic debris.
Management
Ditches filled with water can prevent spread of beetle to/from adjacent fields; remove all weeds from garden borders; if beetle is problematic then appropriate insecticides can provide control; insecticides are usually in the form of baits.

Root knot nematode
Meloidogyne spp.

Symptoms
Galls on roots which can be up to 3.3 cm (1 in) in diameter but are usually smaller; reduction in plant vigor; yellowing plants which wilt in hot weather.
Cause
Nematode
Comments
Galls can appear as quickly as a month prior to planting; nematodes prefer sandy soils and damage in areas of field or garden with this type of soil is most likely.
Management
Plant resistant varieties if nematodes are known to be present in the soil; check roots of plants mid-season or sooner if symptoms indicate nematodes; solarizing soil can reduce nematode populations in the soil and levels of inoculum of many other pathogens.

Beet cyst nematode
Heterodera schachtii

Symptoms
The symptoms may vary depend on the stage of the crop infected by the nematode. The infected seedling exhibit stunting and reduced leaf growth. Also the older leaves of seedlings will become yellow and wilted during the hot period of the day. Below ground, the roots appear stunted with lots of secondary roots. Also the infected roots show yellow-brown cysts. If the nematodes infect the older plants the symptoms are not much noticeable.
Cause
Nematode
Comments
Nematodes are mainly transmitted by irrigation water, equipment, weed plants etc.
Management
Keep the field free from weeds. Follow crop rotation. Deep summer plowing helps in exposing cyst in the soil to sunlight. Grow available resistant varieties.

Beet curly top disease
Beet curly top virus (BCTV)
Beet severe curly top virus (BSCTV)
Beet mild curly top virus (BMCTV)

Symptoms
The infected leaves become a dwarf, crinkle and rolled upward and inward. The veins become irregularly swollen on the lower surface. The diseased beet shows discoloration of the vascular tissue. The young roots become dwarfed and rootlets are twisted and distorted. The death of rootlets leads to growth of new rootlets which gives the hairy root appearance.
Cause
Virus
Comments
The beet curly top virus is transmitted by beet leafhopper, Circulifer tenellus. The virus infect many weed plants and act as a source of inoculum for the next cropping season.
Management
Grow available resistant varieties. Keep the field free from overwintered weeds. Spray suitable insecticide to control leafhoppers.

Beet western yellows virus
Beet Western Yellows Virus (BWYV)

Symptoms
The symptoms first start on older leaves as yellowing between the veins with possible small reddish brown spots which gives a distinct bronze cast on infected leaves. Later the leaves become thick, leathery, and brittle.
Cause
Virus
Comments
The virus is transmitted by aphids (green peach aphids and black bean aphids). It has an extensive host range.
Management
Grow available resistant varieties. Keep the fields free from the previous season crop in the off season. Control aphids.