From the Handbook
of Energy Crops, unpublished
by James A. Duke
Beta
vulgaris L.
Chenopodiaceae
Garden
beets, Chard, Sugar beets, Mangel, Spinach beet
Uses
Folk Medicine
Chemistry
Toxicity
Description
Germplasm
Distribution
Ecology
Cultivation
Harvesting
Yields and Economics
Energy
Biotic Factors
References
Uses
All the above crops are included in the subsp. vulgaris. Chard and
spinach beet are grown for the leaves which are used as a potherb.
Garden beets are grown for the roots which are eaten cooked, as a
vegetable, in salads or pickled. Mangels, developed from chard, are an
important cattle food in Europe. From the mangel the sugar beet was
developed. By selection, the sugar content has been raised from 5 to
more than 20%. About one-third of the world's production of sugar is
from sugar beets, the second most important source of sugar.
Folk Medicine
The decoction prepared from the seed is a folk remedy for tumors of the
intestines. Seed, boiled in water, is said to cure genital tumors. The
juice or other parts of the plant is said to help tumors, leukemia and
other forms of cancer, e.g. cancer of the breast, esophagus, glands,
head, intestines, leg, lip, lung, prostate, rectum, spleen, stomach,
and uterus.
Some figure that betacyanin and anthocyanin are important
in the exchange of substances of cancer cells; others note two main
components of the amines, choline and its oxidation product betaine,
whose absence produces tumors in mice (List and Horhammer, 1969–1979).
A decoction is used as a purgative by those who suffer from hemorrhoids
in South Africa. The juice has been applied to ulcers. Leaves and roots
used as an emmenagogue. Plant effective in feline ascariasis. In the
old days, beet juice was recommended for anemia and yellow jaundice,
and, put into the nostrils to purge the head, clear ringing ears, and
alleviate toothache. Beet juice in vinegar was said to rid the scalp of
dandruff as scurf, and was recommended to prevent falling hair. Juice
of the white beet was said to clear obstructions of the liver and
spleen. Culpepper (1653) recommended it for headache and vertigo as
well as all "affections of the brain."
Chemistry
Per 100 g, the leaf is reported to contain 45 calories, 86.4 g H2O, 3.2
g protein, 0.4 g fat, 8.1 g total carbohydrate, 3.8 g fiber, 1.9 g ash,
114 mg Ca, 34 mg P, 3.1 mg Fe, 3152 mg b-carotene quivalent, 0.07 mg
thiamine, 0.22 mg riboflavin, 0.6 mg niacin, and 50 mg ascorbic acid.
English root analyses showed 76.6% water, 1.1% protein, 0.1% oil, 20.4
soluble carbohydrates, 1.1% fiber, and 0.7% ash. On a zero-moisture
basis the roots contain 339–336 calories, 12.6–14.3% protein, 0.8–1.6%
fat, 77.9–79.4% total carbohydrate, 6.3–9.0% fiber, 6.0–8.7% ash,
115–182 mg Ca, 259–323 mg P, 5.5–8.7 mg Fe, 286–472 mg Na, 2619– 2638
mg K, 0.0–94.5 mg b-carotene equivalent, 0.08–0.24 mg thiamine,
0.32–0.39 mg riboflavin, 1.64–3.15 mg niacin, and 23–79 mg ascorbic
acid (Duke and Atchley, 1984). The pulp, after sugar extraction,
contains ca 30% galacturonic acid in the form of pectic substances.
This acid is a good starting base for vitamin C synthesis. Allantoin,
saponins, copper, and betaine are also reported. Hager's Handbook
mentions two betaxanthines, vulgaxanthine I and vulgaxanthine II,
kaempferol glycoside, chlorogenic and caffeic acid. Roots contain
leucine, tryptophane, valine, alanine, phenylalanine, tyrosine,
glutamine, glutamic acid, ornithine, five other amino acide, 0.01%
essential oil with farnesol. Leaves contain quercitin glucoside, a
vitexin combination with glucose, xylose, and 3-hydroxytyramine,
b-sitosterol, and a suite of organic acids, oxalic-, tricarballyl-,
aconitic-, ferulic-. Roots, herbage, and seeds contain raphanol, and
coniferin (C16H22O8), Vit. A, B, and C, and betaine. Roots contain a
crude oil with palmitic-, oleic-, erucic-, and gamma-aminobutyric
acids, free and bound invertase and pectolytic enzymes.
Toxicity
Feeding sugar beet to sheep has caused renal calculi, composed of uric
and phosphoric acids with lime. Fresh leaf may also cause poisoning due
to the 1% oxalic acid therein. Leaf may also contain dangerous levels
of HCN and/or nitrates and nitrites. Betaine acts as a mild diuretic.
Beet pollen can cause hay fever. Sugar appears to have caused
dermatitis in two-thirds of the workers in one crystallizing department.
Description
Annual or biennial herb; leaves glabrous, ovate to cordate, dark green
or reddish, frequently forming a rosette from the underground
stem;roots conspicuously swollen at junction with stem; flowering stalk
1.2–1.8 m tall, produced the second year from the top of the tuber;
flowers small, numerous in a tall open panicle; fruit an aggregate of 2
or more fruits forming an irregular dry body; in garden beets, roots
are usually a deep red color and may be globular or cylindrical; in
chard and spinach beet, leaves have thickened midribs; in sugar beet,
taproot is white and deep-penetrating. Fl. June–Sept. x = 9; 2n = 18.
Germplasm
Many varieties available, some having developed resistance to major
diseases; monogerm varieties of excellent quality also available. All
forms seem to be interfertile and are wind-pollinated, but are
self-incompatible. In 1964 a pollen-sterile inbreed was released,
suitable for F1 hybrid table beets. Best varieties are: 'Early Wonder',
'Detroit Dark Red', 'Ruby Queen', and 'Crosby'. Reported from the
Eurosiberian, Central Asia, and Mediterranean Centers of Diversity,
beet or cvs thereof is reported to tolerate aluminum, disease, frost,
fungus, hydrogen floride, high pH, manganese, salt, nematode, phage,
poor soil, slope, smog, SO2 and virus. 2n = (18, 27, 36).
Distribution
The ancestor of Beta
vulgaris subsp. vulgaris
is subsp. maritima,
growing wild on the seashores of southern Britain, through Europe and
Asia to the East Indies. Beets and their relatives are grown throughout
the world for human and stock food.
Ecology
Beets and their relatives require a cool climate, and are able to
withstand mild frost. In the southern part of their range they are a
fall–spring crop, while in the northern part they are a summer–fall
crop. Table beets develop light-colored bands if the weather is too
hot. In the sugar beet, the sugar content is highest in cool
temperatures with good sunlight. Beets grow well in a variety of soils,
growing best in a deep, friable well-drained soil abundant with organic
matter, but poorly on clay. Optimum pH is 6.0–6.8, but neutral and
alkaline soils are tolerated in some areas. Some salinity may be
tolerated after the seedling stage. Beets are notable for their
tolerance to manganese toxicity. Ranging from Boreal Moist to Rain
through Tropical Very Dry Forest Life Zones, beet is reported to
tolerate annual precipitation of 23 to 31.5 dm (mean of 110 cases =
8.8), annual temperature of 5.0 to 26.6°C (mean of 110 cases = 12.0°C),
and pH of 4.2 to 8.2 (mean of 99 cases = 6.3).
Cultivation
Beet crops are propagated from seed, sown in early spring when the
ground is suitable for tilling. In home gardens successive plantings
may be made every 10–14 days until 3–4 plantings are in, to insure a
continuing supply of fresh tender beets. The main crop, grown for
processing or for fall and winter marketing, especially in the North,
should be planted in May or June. Seed is drilled at intervals of 1.5–2
cm in rows 30–45 cm apart, at the rate of 4–6 kg/ha, and covered about
1.3 cm deep. The beet ball (seed) varies in size and the seeds
germinate irregularly, so that a uniform crop is difficult to attain.
Screening the seeds enhances the chance of getting a more uniform crop.
When the beets are large enough to eat as beet greens with the small
beets attached, rows should be thinned so that the remaining plants
stand about 7.5–10 cm apart. Shallow cultivation should be given to
control the weeds. Most cultivation is done by hand weeding, hand
cultivators or small tractor cultivators, as the lateral roots are very
shallow and are easily damaged. Beet seed retain their viability for
5–6 years under average storage conditions. They should be treated to
prevent damp-off and seed rot. Germination is best at 18–24°C. Seed
stalks are likely to be produced after temperatures of 5–10°C for 15
days or longer. After a soil test, commercial fertilizers containing
nitrogen, phosphorus and potash may be added. Fertilizer may also be
added as green manures, crop residues, animal manure and compost.
Monoculture, and beet crops should not be rotated with cole (Brassica)
crops, which are hosts for sugar beet nematodes; otherwise, plant beets
in rotation.
Harvesting
For fresh market, beets are harvested when 4–5 cm in diameter, and
bunches 4–6; those 5–10 cm in diameter are sold as topped beets. Topped
beets in transparent film bags have a longer shelf life than bunched
beets with the tops attached. Most home and local beets are hand
pulled, washed to remove adhering soil and variously marketed. Beets
grown commercially for canning and frozen foods are harvested by a
mechanical beet harvester, which lifts the beets, cuts off the tops,
and conveys the topped beets to a truck alongside the harvester. The
beets are then delivered to canneries, storage warehouses or to market.
Beets more than 7.5 cm in diameter are in low demand, and they can only
be used for diced beets or baby food products. Beets may be stored in
cold, moist, root cellars for 3–5 months, at temperatures near the
freezing point, but they should not be allowed to freeze. Humidity
should be about 90%.
Yields and Economics
For seed, mangels yield 1,100 kg/ha; for garden beet seed, 600–1,200
kg/ha; for sugar-beets, open-pollinated varieties, 1,500–2,000 kg/ha,
hybrids, 2,500–3,000 kg/ha. Sugar-beets yield 5 tons sugar/ha. The
1969–1970 world production of sugar beets: Europe 105,146,000 MT; North
America 26,140,000 MT; Latin America 1,471,000 MT; Near East 7,395,000
MT; Far East 2,253,000 MT;Africa 1,007,000 MT. Beet sugar 1969
wholesale prices in US cents/kg: Denmark 24.5; France 20.9; Fed. Rep.
Germany 24.4; Italy 34.9; Netherlands 31.9; Spain 21.0. The world
production of beets of all varieties approximates 300,000,000 MT.
World-wide production of sugar-beets in 1967 was 7.4 million ha.
Energy
Sugar beet wastes are estimated as 1.22 times sugar production, since
the total dry matter of processing wastes and field wastes exceed the
weight of sugar in the ratio of 55:45. Some or all of this may be used
for fodder. In Britain, following cereal harvest, Palz and Chartier
(1980) estimate an additional 3 MT/ha dry biomass could be obtained by
planting fodder beet. Taking the average sugar beet yield of ca 6 MT
sugar per hectare, about 13.5 MT DM will usually be obtained; the cost
is likely to be close to $73.9/MT or $4.2 per GJ. At this figure,
assuming 70% of the beet solids is sucrose, 62% of the total dry weight
is root and 90% of theoretical conversion of beet sucrose to recovered
alcohol, the feedstock costs alone to a sugar beet alcohol plant will
be some $303/MT of alcohol produced and onto this the cost of transport
to the plant and the processing costs (which, with present technology,
involve heavy energy expenditure), must be added. These costs may be
reduced if all residues are returned to the land (with or without prior
passage through farm animals) but the effect upon such heavy costs will
be marginal. Moreover, the above costs take no account of farmer's
interest charges and profit; at present, sugar beet gives the farmer
his best gross margin, estimated at $1,334/ha; therefore, the cost of
beet to a purchaser is around $50/MT or $225/MT, $15.0/GJ gross thermal
content. Due to lower insolation and crop growth, and more expensive
and scarcer land, the prospects are for European alcohol to remain more
expensive than that produced in the tropics. It may be of interest,
however, to consider what area of good quality arable land would be
needed to supply a certain quantity of energy, say 5% of estimated 1985
consumption in the Community, which is an amount calculated to make a
major impact upon the overall supply of fuel for transportation
purposes. This would amount to some 2,600 x 106 GJ/y. With sugar beet
yielding approximately 240 GJ/ha/y, 45% of it convertible to alcohol,
108 GJ/ha/y will be obtainable in the form of liquid fuel. Hence, about
24 x 106 ha would be required, about thirteen times the area at present
planted with sugar beet and 54% of the total arable area of the
Community. Even then, all the required process energy, cultivation and
fertilizer energy would have to be provided from other sources. To
obtain these energy inputs from the sugar beet crop itself would demand
a substantially greater area, depending upon the efficiency of
cultivation and processing. The need might well encompass the entire
arable area of the Community. In practice, therefore, it is difficult
to visualise a situation in which more than 1% of the total Community
energy demand could be met by sugar beet alcohol, since this would
entail re-allocation of over 4.5 million hectares of good arable land
even if there were very substantial inputs of other forms of fuel. In
short, it seems apparent that, compared with the situation in Brazil,
where fuel alcohol production from biomass is increasing rapidly, the
prospects in the Community are far less attractive (Palz and Chartier,
1980). For alcohol production, chicory and Jerusalem artichoke, which
both have a high content of easily hydrolysed inuli, may have a
technical advantage over cellulose feedstocks that could be derived
from perennial energy plantations. However, as cellulose hydrolysis
methods improve, alcohol from cellulosic feedstocks may become
comparable in cost to that from grains and sugary, inuliferous, or
starchy feedstocks.
In Europe, sugarbeet is likely to be preferred
among non-cellulosic crops for alcohol production because the
carbohydrate is in an immediately fermentable form, whereas the starchy
crops like potato and Jerusalem artichoke do not offer better yields,
yet require hydrolysis as an extra step (Palz and Chartier, 1980).
Australians are getting 2,500 gallons (ca 10,000 liters) of alcohol per
hectare from a newly developed fodder beet, which is, however,
susceptible to curly-top virus and hence unsuitable for the western US.
John Galian from the University of Idaho is evaluating 65 lines of
fodder beets for alcohol potential and seeking high-yielding hybrids
between sugarbeets and fodder beets. Energy beets do not need to be low
in N, Na and K, which interfere with sugar extraction. Nor does the
presence of sugars other than sucrose interfere with fermentation and
distillation (McGill, 1981). Sugarbeet in New Zealand showed an average
biomass yield of 9.6 MT/ha. But under intensive cultivation, beet, over
240 days in California, had a mean growth rate of 14 g/m2/day for
production of 33.8 MT/ha; in Netherlands, the same growth rate over 160
days yielded production of 22 MT/ha (Boardman, 1980). In UK, prices for
sugarbeet on a GJ basis are not much more than twice those for coal "we
may be nearer than we think to shovelling sugar into our domestic and
power station boilers if coal prices continue to rise!" (Swift-Hook,
1980). For Australia, irrigated sugarbeet yields were estimated at 50
MT/ha (8 MT sugar), rainfed at 35 MT (5.6 MT sugar). Conversion rates
were estimated at 130 MT commercial sugar, 45 MT molasses, and 63 MT
dried beet pulp from 1000 MT beet. In two unirrigated trials, fodder
beets averaged 20.8 and 17.3 MT ha DM root with 2.9 and 3.7 MT tops
(DM). The estimated cost of fodder beet delivered to the factory in New
Zealand was $40 MT (DM) and the estimatedcost of production of ethanol
in plant of 0.68 PJ yearly capacity using current technology was $0.15
per liter of which $0.09 covered the cost of feedstock and $0.06
covered conversion costs (when petrol in Australia was $0.15 to $0.19
per liter). The beet pulp can be anaerobically fermented to produce
methane as a source of energy for the distillery. Ca 75% of the energy
in the pulp can be converted to methane under mesophilic conditions
with solids retention time of ca 8 days (Stewart et al., 1979). In
California, Hills et al. (1983) reported ca 5000–6650 liter alcohol/ha
for sugarbeets, ca 5700–7600 liter for fodderbeets, compared to 3300 to
4400 for corn, and 4000 to 5400 for sweet sorghum. The fodderbeet
yields approached 50 barrels per hectare at a cost of less than $50.00
per barrel. For maximum alcohol yield, fodderbeet required ca 100 kg
N/ha, sugarbeet ca 50, compared to 200 for corn and 0 for sorghum
(Hills et al., 1983). Best experimental yields with fodderbeet were 48
bbls/ha at $47/bbl.
Biotic Factors
Diseases in commercial crops are relatively few in number. The most
serious is Beet leaf spot, which causes numerous dead spots on the
leaves, the spots having a white center with a purple border. Leaves of
infected plants may curl, dry up and die. Spraying with Bordeaux
(4–5–50) when the spots first appear and then again in about 10 days
usually controls the disease. Crop rotation will also help the
situation. Many other fungi attack Beta
vulgaris: Actinomyces
scabies,
Alternaria
tenuis, A.
brassicicola, Aphanomyces
cochlioides, Cercospora
beticola (most common disease of beets), Clasterosporium putrefaciens,
Cylindoocarpon radicicola, Fusarium spp. (root-infecting
and storage
rot), Gloeosporium
betae, Helicobasidium purpureum, Heterosporium
betae, Macrophomina phaseoli, Itycosphaerella tabifica, Pellicularia
filimentosa, Peronospora schachtii, P. farinosa, Phoma betae,
Phymatotrichum omnivorum, Physalospora rhodina, Phytophthora
drechsleri, P. cactorum, Puccinis aristidae, Ramularia beticola, R.
betae, Rhizoctonia aderholdii, R. solani, R. violacea, Sclerotinia
sclerotiorum, Sclerotium rolfsii, Septoria betae, Stemphylium
botryosum, Streptomyces scabies, Uromyces betae, Verticillium
albo-atrum, V. lateritium, Volutella oxyspora. Several viruses also
attack beets, the most serious being Curly top virus. Other viruses
isolated from beets are: Argentine sunflower, Barley stripe mosaic,
Brazilian tobacco streak, Cabbage black ringspot, Carnation mottle,
Celery yellow vein, Cucumber mosaic and necrosis, Hydrangea ringspot,
Lucern mosaic, Pelargonium leaf curl, Potato boquet, Potato mop-top (X
and Y), Raspberry ringspot, Raspberry yellow dwarf, Red ringspot, Spoon
leaf of red currant, Tobacco mosaic, necrosis, ringspot and severe
etch, Tomato aspermy, black ring and spotted wilt, Yellow net, Yellows.
The following bacteria are known to infect beets: Bacterial soft rot,
affects leaves and root, especially as a market disease of bunched
beets: Bacillus
lacerans, B. mensentericus bulgatus, B. mycoides,
Bacterium busser, B. carotovora, B. scabiegenum, B. tumefaciens,
Cornyebacterium betae, Erwinia betivora, E. carotovora, Pectobacterium
carotovorum, Pseudomonas aptata, Xanthosomas beticola.
Physiological
diseases are caused by: Heart rot or dry rot, boron deficiency;
Bronzing, potassium deficiency; Black heart, phosphorus deficiency;
Chlorosis, mineral deficiency and soil alkalinity. Among the insects
the Beet flea-bettle attacks the plants as soon as they are above
ground. Larvae infesting chickweed and pigweed and spreads from these
weeds to beets. Eliminating these weeds and spraying the beets with
arsenate of lead as soon as the insect appears and by repeated
sprayings helps control it. Also the Beet leafhopper (Circulifer
tenellus), Army cutworm (Euxoa auxiliaris),
Beet webworm (Loxostege
sticticalis), aphids, and leaf-miners attack garden beets.
Sugar beets
are affected by the Sugarbeet wireworm (Limonius californicus),
Beet
webworm, and Sugarbeet root maggot (Tetanops
myopaeformis). Being a
root crop, beets and sugarbeets are attacked by many nematodes:
Aphelenchoides
avenae, A. bicaudatus, A. parietinus, Belonolaimus
gracilis, Diplogaster iheritieri, Ditylenchus destructor, D. dipsaci,
Eucephalobus elongatus, Helicotylenchus dihysteria, H. microlobus,
HeuLicycliophora conida, H. obtusa, H. similis, H. typica, Heterodera
chachtii, H. trifolii, Hexatylus viviparus, Longidorus elogatus, L.
menthasolanus, L. maximus, Meloidogyne arenaria, M. hapla, M.
incognita, M. incognita acrita, M. javanica, M. naasi, M. thamesii,
Nacobbus aberrans, Paratylenchus projectus, Pratylenchus neglectus, P.
penetrans, P. pratensis, P. scribneri, P. thornei, Rotylenclius
robustus, Trichodorus christiei, T. primitivus, T. teres, and
Tropliurusminnesotensis (Golden, p.c. 1984).
References
Boardman, N.K. 1980. Energy from the biological conversion of solar
energy. Phil. Trans. R. Soc. London A 295:477–489.
Culpepper, N. 1653. Culpepper's complete herbal. W. Foulsham &
Co., Ltd., London.
Duke,
J.A. and Atchley, A.A. 1984. Proximate analysis. In: Christie, B.R.
(ed.), The handbook of plant science in agriculture. CRC Press, Inc.,
Boca Raton, FL.
Hills, F.J., Johnson, S.S. , Geng, S., Abshahi, A.,
and Peterson, G.R. 1983. Comparison of four crops for alcohol yield.
Calif. Agr. 37(3/4):17–19.
List, P.H. and Horhammer, L. 1969–1979. Hager's handbuch der
pharmazeutischen praxis. vols 2–6. Springer-Verlag, Berlin.
McGill, S. 1981. Breeding better biomass crops. Furrow 86(5):38.
Palz, W. and Chartier, P. (eds.). 1980. Energy from biomass in Europe.
Applied Science Publishers Ltd., London.
Stewart,
G.A., Gartside, G., Gifford, R.M., Nix, H.A., Rawlins, W.H.M., and
Siemon, J.R. 1979. The potential for liquid fuels from agriculture and
forestry in Australia. CSIRO. Alexander Bros., Mentone, Victoria,
Australia.
Swift-Hook, D.T. 1980. Discussion. Phil. Trans. R. Soc. London A 295.
p. 489.
Last update December 30, 1997
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