Helianthus tuberosus L.
Jerusalem artichoke, Girasol, Gerasole
Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.
- Folk Medicine
- Yields and Economics
- Biotic Factors
Jerusalem artichoke is grown primarily for tubers which can be eaten fresh or
raw, cooked in appetizing ways similar to Irish potatoes, or pickled. Tubers
are used to fatten cattle, sheep and hogs. Stems and leaves are rich in fats,
protein and pectin, and make good forage and silage. The alcohol fermented
from the tubers is said to be of better quality than that from sugar beets. It
is good weed eradicator, as it makes so dense shade that few other plants can
compete. It is good in ridding fields of quackgrass.
Reported to be aperient, aphrodisiac, cholagogue, diuretic, spermatogenic,
stomachic, and tonic, Jerusalem artichoke is a folk remedy for diabetes and
rheumatism (Duke and Wain, 1981).
Since the food reserves are stored in the form of inulin, the tubers serve as
substitutes for potatoes and starches in diabetic diets. They are a potential
source of levulose for use in sweetening by diabetics. One report notes that
Jerusalem artichokes contain about 80% water, the remainder made up of about
15% protein, 1% fat, 75% nitrogen-free extract with 60% inulin, 4% fiber and 5%
ash. A different report cites 80% water, the remainder being 10% protein, 76%
starch, 1% oil, 6% fiber, 5% ash. Phosphorus is about 0.099%; calcium, 0.023%,
iron 3.4 mg/100 g with traces of aluminum, chlorine, iodine, magnesium,
potassium, solium, sulphur, and zinc. Small amounts of Vitamins B, and C;
purine bases arginine, histidine, betaine, choline, and hemagglutinin are
Perennial herb often cultivated as an annual, with tubers produced on the ends
and branches of underground stems or rootstocks as well as midway on the
rootstocks, tubers knobby, white, red or purple skinned, ranging in size from
7.510 cm long, 35 cm thick; stems erect 1.53 m tall, hirsute; leaves
opposite or the upper ones alternate, ovate to ovate-oblong, serrate-dentate,
rough above, with winged petiole; heads 57.5 cm across, few to many, terminal
on the branches; rays 12 to 20, light yellow, conspicuous, disk yellow, seeds
pubescent. Fl. JulyAug.
Thousands of forms, stocks and strains but no well-defined cvs. 'Jerusalem
White', Veitch's Improved Long White', 'Sutton's New White', 'Mammoth French
White' and 'French White Improved' are a few selected types propagated
vegetatively. In USDA experiments where 1300 seedlings from selected plants
were grown, 1300 varieties resulted, and each plant grown to maturity was
recognizably different. Only high yielding strains of acceptable color and
shape should be cultivated. From the North American Center of Diversity,
Jerusalem artichoke is reported to tolerate bacteria, frost, high pH, laterite,
low pH, photoperiod, sand, shade, slope, virus, waterlogging, and weeds
(2n = 102) (Duke, 1978).
Native to North America, and long used by the American Indian for food. Has
been introduced and become naturalized in all temperate regions in the Northern
and Southern Hemispheres.
Jerusalem artichoke is a suitable crop in any soil and climate where corn will
grow. It survives in poor soil and in areas as cold as Alaska. It tolerates
hot to sub-zero temperatures. The first frost kills the stems and leaves, but
tubers withstand freezing for months. It grows best in a loose circumneutral
loam, and in full sun, but can tolerate some shade. Plants do not flower in
northern Europe. Plants are sensitive to day-length, requiring longer periods
from seedling to maturation of plant, and shorter periods for tuber formation.
They do not grow where day-lengths vary little. Ranging from Cool Temperate
Steppe to Wet through Tropical Dry to Moist Forest Life Zones, Jerusalem
artichoke is reported to tolerate annual precipitation of 3.1 to 28.2 dm (mean
of 40 cases = 10.1), annual temperature of 6.3 to 26.6°C (mean of 40 cases =
13.3), and pH of 4.5 to 8.2 (mean of 37 cases = 64) (Duke, 1978, 1979).
Jerusalem artichoke is propagated by tubers, which should be planted as early
as possible in the spring when the soil can be satisfactorily worked. Late
planting usually reduces tuber yields and size seriously. Whole tubers or
pieces about 50 g (2 oz.) should be planted like potatoes and covered to a
depth of 10 cm. Pieces larger than 50 g do not increase the yield, though
those smaller will decrease it. Deeper planting may delay emergence, weaken
the sprouts, and cause the tubers to develop deeper, making harvest more
difficult. Seed pieces should be planted 60 cm apart in rows which are 90110
cm apart. Average yields per hill may be much greater at wider spacings, up to
120 cm apart, in rows to 6 m apart. Cultivation should be shallow, not more
than 3.55 cm deep, to avoid damaging the stolons and tubers. Tubers begin to
form in August. The crop should be cultivated or hoed only sufficiently to
control the weeds thoroughly. Little cultivation is required after stolon
formation is well under way, since by that time the plants have met in the
rows, and shade out weeds. Fertilizer helps produce a better crop, 500 to 750
kg/ha of a complete fertilizer (4-8-4 or 4-12-4) generally recommended.
Either a crop of forage or a crop of tubers can be harvested from a planting,
but not both. The maximum yield of green tops for forage is available at or
just before flowering. Then the yields of green tops and dry matter decline
rapidly, due to movement of food materials from tops to tubers. At this stage
of maximum top yield, the tuber yield would be about 40%60% of the normal
yield of tubers. Tops left undisturbed until frost to obtain the maximum yield
of tubers are of little or no value for forage. The first freeze blackens the
leaves, which soon dry out and fall. The large woody tops must be removed
first from the plants. The conventional potato-harvesting machinery is
inadequate and no efficient harvesting on a commercial scale at low cost has
been devised yet. Turning out the tubers with a plow leaves many in the soil.
Hand-digging with forks yields the largest percentage of the tubers in the soil
but is laborious and expensive. Tubers are small, and picking proceeds slowly.
Tubers are difficult to store because of the thin skin which permits shrinkage
and injury that leads to decay. They keep perfectly if left in the soil until
needed, freezing does no damage. Although they cannot be harvested from frozen
soil, tubers for spring planting are best left in place until spring. They
should then be harvested and handled promptly before they sprout appreciably.
Tubers should not be left in poorly drained soil. Good, sound, diseasefree
tubers can be successfully kept several months in cold storage at a high
humidity and a temperature of 0°C. After harvesting in the spring,
volunteer growth should be discouraged by deep plowing in late spring, and the
crop followed with a late-sown, quick-growing hay crop or a cultivated crop, or
rotated as in France with oats, clover and wheat, but corn, rye, potatoes, or
turnips may also be used.
Average tuber yields of 16,00020,000 kg/ha may be expected from crops grown
under ordinary farm conditions. Production costs, except for harvesting,
should not be greatly different from those for potatoes. In France, alcohol
yields are placed at 60100 liters/MT of tubers. Yields of tops for forage
average 18,00028,000 kg/ha green weight. "Fuseau", a garden vegetable in
France, is grown and recommended as producing a very heavy yield of forage.
Pigs foraging in artichoke have produced 800 kg meat per hectare.
For alcohol production, chicory and Jerusalem artichoke, which both have a high
content of easily hydrolysed inulin, 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 well become comparable in cost to that from grains and sugary,
inuliferous, or starchy feedstocks. In Europe, sugarbeet is likely to be
preferred among noncellulosic 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). Recently (acc. to press
release March 25, 1983), a Minnesota firm sold more than $19 million in the US,
partly by a sales pitch indicating that growers could make as much as $90,000
per ha growing artichokes. In Montpelier, France, fresh stem biomass was
highest in September (51.4 MT/ha), gradually decreasing as the reserves were
transferred to the tubers. In October, total DM yields were ca 9.5 MT/ha, but
in November, tuber DM was at 11 MT, stem DM at 8 (4654 around Montpelier,
France). Tuber yields can reach 90 MT/ha and their polyfructosan (inulin - ca
80% of DM) can be used as a fermentation substrate. During the last two world
wars, the tubers were used for ethanol production applying a water extraction
technique followed by a hot acid hydrolysis step and fermentation with
distiller's yeast. The energy-intensive hydrolysis step can be bypassed using
yeast strains with good alcohol-producing and inulinase activity.
Kluyveromyces marxianus can produce 12% alcohol from extracts containing
200 g sugar/liter. In a continuous production system with non-sterile medium
at pH 3.5 (Chabbert et al, 1983).
Jerusalem artichoke is attacked by many fungi including: Acrochyta
helianthi, Cercospora bidentis, C. helianthi, Coleosporum helianthi, Corticium
rolfsii, C. solani, Erysiphe cichoracearum, Fusarium sp., Macrophomina
phaseoli, Myrothecium roridum, Oidium helianthi, Phymatotrichum omnivorum,
Plasmopora halstedii, Puccinia helianthi, Rhizopus nodosus, Rh. stolonifer,
Sclerotinia fuckeliana, S. libertiana, S. rolfsii, Septoria helianthi,
Sphaerophoma brenchklei, Sphaerotheca fuligines, Uromyces junci, Verticillium
dahliae. It is also attacked by: Agrobacterium tumefaciens, Pseudomonas
helianthi, Tobacco mosaic virus and the following nematodes: Caconema
radicicola, Ditylenchus dipsaci (stem nematode), Aphelenchoides
ritzemabosi (leaf nematode), Heterodera marioni, Het. schachtii,
and Meloidogyne sp. (root-knot nematode). Puccinia helianthi
is the most serious pest; burning the tops and a change of locality is
Complete list of references for Duke, Handbook of Energy Crops
- Chabbert, N., Braun, P., Guiraud, J.P., Arnoux, M., and Galzy, P. 1983.
Productivity and fermentability of Jerusulam artichoke according to harvesting
date. Biomass 3:209224.
- Duke, J.A. 1978. The quest for tolerant germplasm. p. 161. In: ASA Special
Symposium 32, Crop tolerance to suboptimal land conditions. Am. Soc. Agron.
- Duke, J.A. 1979. Ecosystematic data on economic plants. Quart. J. Crude Drug
- Duke, J.A. and Wain, K.K. 1981. Medicinal plants of the world. Computer index
with more than 85,000 entries. 3 vols.
- Palz, W. and Chartier, P. (eds.). 1980. Energy from biomass in Europe. Applied
Science Publishers Ltd., London.
Last update Wednesday, January 7, 1998 by aw