2. A time to live...
Jumping for joy
Sierra Leone is a country on the west coast of Africa with a population of
some 3,600,000. It takes its name ("Lion mountain") from that given by
the Portuguese explorer Pedro da Sintra around 1460 to the peninsula
which is the site of Freetown, the country's capital. In 1787 a settlement
for freed slaves was established on land where Freetown now stands. In
1961 Sierra Leone achieved independence, and ten years later became a
republic. Some 65 per cent of the work force is occupied in agriculture,
with rice as the main food crop. Sierra Leone is the world's sixth largest
producer of diamonds. Above, body bent back and almost obscuring the
ball, a boy throws himself into a game of soccer in a Freetown street.
52 Sierra Leone
6. Drawing shows in highly simplified form
one of the techniques used in modem
biotechnology for experimentation under
controlled conditions with plant cells, tis¬
sues and organs and for vegetative (i.e.
non-sexual) propagation of plants in ster¬
ile laboratory conditions. The sterilized
plant material which is cultured in the nut¬
rient medium may be a meristem (see
drawing at bottom of page), or some other
piece of plant tissue (see photo story
pages 8-9), or a protoplast, a plant cell
whose outer walls have been removed
plant culture of colony of regeneration mini- greenhouse (see page 10). From this organ, tissue, or
meristem or cells of plantlets
cells
protoplast, a proliferating clump of dis¬
multiplication
organized tissue called a callus can be
in sterile
obtained. From this it is possible to re¬
conditions
generate whole intact plants, and to pro¬
duce many genetically identical copies,
known as clones, in a relatively short time.
A one-cubic-centimetre culture may con¬
In addition to improving yield, the main culture of the meristem or other plant tain one million cells each carrying the
purpose of selection is to obtain new vari¬ tissues. Meristem is the name given to a potential of becoming an entire new plant.
eties which are resistant to parasites and to grouping of embryonic cells situated at the By selecting cells with certain properties,
the process of breeding new varieties of
bacterial and viral diseases. In recent years tip of the plant stem (see drawing below).
disease-resistant, stress-tolerant crops,
a number of new techniques have made Cultivated in aseptic conditions on a solid,
trees or flowers can be greatly
their appearance, some of which are nutritive culture medium, these cells accelerated.
already in use while others are still at the proliferate producing a callus which can be
laboratory stage. One of their main aims is divided and reproduced many times.
to reduce considerably the time needed for Treated with plant hormones (auxins,
a new variety to be put on the market and cytokins and gibberelins), the calluses diffe¬ months, 2,000 million identical tubers,
brought into large-scale cultivation. Using rentiate into plantlets having all the prop¬ spread over an area of 40 hectares, were
classic methods the lead time required to erties of the original plant. obtained from a single potato tuber derived
achieve this is of the order of ten years, By this means, in a period of eight from a meristem, that is a rate of propaga¬
whereas, given the capacity for adaptation tion 100,000 times greater than that of sex¬
of the phytopathogenic agents (the bacte¬ ual reproduction. A further advantage is
ria, viruses, etc., that cause plant disease), that plants obtained from meristems are
the useful life of a new variety is estimated The apical meristem is a tiny mass of cells
free of pathogenic contaminants, in particu¬
where growth takes place at the tip of a
to be a mere five years. lar of viruses, which means that it is possible
plant stem. It plays a particularly important
Another advantage of certain recently role in plant propagation because it re¬ to regenerate stock threatened with extinc¬
evolved techniques is that they make it pos¬ mains healthy even when the rest of the tion due to diseases that cannot be treated
sible to cross-breed species that are too far plant is infected with a virus. In vitro cul¬ in any other way.
apart for normal sexual reproduction, thus ture of the meristem of a diseased speci¬ Tropical agriculture has much to gain
men makes it possible to generate a new,
opening the way for the creation of entirely from micro-propagation. For example, a
healthy plant, and allows the rapid produc¬
new plant varieties. single oil palm regenerated from a fragment
tion of virus-free planting materials. Be¬
The first major successes were achieved low, sectional drawing of a plant bud of leaf tissue could, within a year, supply
by means of vegetative hybridization of shows the apical meristem at centre, pro¬ 500,000 identical, filariosis-resistant plants
cereal seedlings. This method, which con¬ tected by enfolding leaf shoots. Meristem producing up to 6 tonnes of oil per hectare
sists of cross-breeding between plants by culture calls for particular care in the per year, that is six to thirty times more than
choice of culture conditions and nutritive
the elimination of self-fertilization, is com¬ the principal oil-producing plants (sun¬
media.
paratively easy in the case of allogamous flower, soya, peanut). This same technique
cereals, such as maize, in which the male is now being applied to the propagation of
leaf shoots
organs are separated from the female new varieties of coconut palms.
organs and can thus be manually eliminated Another technique which holds great
before fertilization has taken place. It is promise for the future is the in vitro produc¬
more difficult with autogamous plants, such tion of haploid plants (plants whose cells
as wheat, tomatoes, soya and lupin, in contain a single set of chromosomes). Tra¬
which the male and the female organs are ditional methods of selection are made
contained in close proximity within the more time-consuming and complicated
flower. Today, this difficulty has been over¬ because of the diploid nature of vegetative
come by the discovery of chemical com¬ plants, that is to say, because the cells of
pounds which render the pollen sterile. which they consist contain a double set of
Many varieties of hybrid cereals and chromosomes, one coming from each pa¬
other plants are now on the market. Gener¬ rent. As a result, some so-called "recessive"
ally speaking, fields should be sown with characteristics carried by a chromosome
first generation hybrid seed. Hybrid seed may be masked by a dominant homologous
usually tends to degenerate and must be chromosome and its presence may only
renewed annually. At all events, the world be revealed, through the operation of
market for hybrid seed is growing rapidly Mendelian segregation, after several
and, according to a recent estimate, will generations.
attain a value of $20,000 million by the year This, of course, slows down the work of
2000.
the person undertaking the selection. The
Other techniques now being developed recent emergence of a technique somewhat
are more distant in prospect yet just as similar to micro-propagation has made it
promising. One of these is in vitro vegetative possible to overcome this difficulty. This
propagation, or micro-propagation, by the technique enables a complete plant to be
7. obtained either from the male gametes, or in regenerating somatic hybrid cells of sev¬ Nitrogen fixation
reproductive cells (androgenesis), or from eral plants of agricultural interest such as
the female gametes (gynogenesis). Like the rapeseed, chicory and potato. On the other Through its World Network of Micro¬
gametes from which they are derived, these hand, attempts to do the same with sun¬ biological Resources Centres (MIRCENs),
plants are haploid. Since they have only one flower, cereals and legumes have so far one of whose priority programmes is
set of chromosomes, their genetic charac¬ failed. Nevertheless, there is hope that devoted to the question of nitrogen fixa¬
teristics, whether recessive or dominant, present difficulties will soon be overcome, tion, Unesco is contributing actively to
are immediately evident to the person mak¬ at least in obtaining hybrids of varieties of another field of biotechnology that is rich in
ing the selection. Haploid plants are usually the same species. promise (see article page 27).
infertile, but by treating them with col¬ The great advantage of somatic hybrid¬ The nif genes, which are coded for the
chicine, which induces a doubling of the ization is that it makes it possible to transfer fixation of nitrogen, have now been identi¬
chromosomes, a fertile plant is obtained not only the genetic characteristics borne by fied and their structure is on the point of
with two sets of identical chromosomes and the chromosomes of the nucleus, but also being fully mapped out. Furthermore, these
with phenotypically stable characteristics. those of the specialized parts of the cell genes have been transmitted to non-
Another technique used in gynogenesis is to contained in the cytoplasm (the "liquid" nitrogen-fixing organisms such as Proteus
fertilize the ovule with irradiated pollen. portion of a cell surrounding the nucleus) vulgaris, Agrobacterium tumefaciens and
In China, new varieties of rice obtained such as mitochondria and chloroplasts. Escherichia coli. In principle there is no
by androgenesis are being cultivated on sev¬ These latter are the key to processes and reason why they should not also be trans¬
eral millions of hectares of land. Laboratory properties of great importance such as ferred to higher plants and important
experiments in gynogenesis are also now photosynthesis, the assimilation of carbon results in this direction can be expected
being undertaken on barley, rice, wheat, dioxide, male sterility and resistance to soon. However, the creation of nitrogen-
maize, sugar-beet and other species. herbicides, diseases and drought. fixing cereals is a distant prospect still in the
Somatic hybridization has paved the way realm of science fiction.
High hopes are also being placed in soma¬
tic hybridization, a technique which consists for the newly emerging discipline of plant With regard to plants other than the
of fusing two cells whose cell walls have genetic engineering which is concerned with legumes, attention is now concentrated on
previously been removed by enzymatic the implantation of specific genes", whether nitrogen fixation by bacteria and fungi
treatment. Using this technique scientists of vegetal or other origin, into the genetic which invade their roots either on the root
have succeeded in fusing plant cells not only make-up of a plant (see article page 13). surface or by entering their tissue where
with other plant cells but also with animal Using these new techniques the nutritional they form nitrogen-fixing nodules. These
and even human cells. In most cases, value of the haricot bean, for example, has studies have not yet reached the molecular
however, the chromosomes of one of the been improved by the transfer of a gene biology or the genetic engineering stage,
fused cells are quickly eliminated and it has from the Brazil nut. but they hold out much promise for tropical
only been possible to obtain complete, In Europe, Japan and the United States forestry, sand dune stabilization and the
stable hybrid cells from the fusion of cells of America, a number of large multina¬ fight against desertification.
from very closely related species. Further¬ tional companies are showing keen interest Finally, mention should be made of stud¬
more, even when stable stock has been in these new techniques of plant improve¬ ies being made in the Philippines and Sene¬
obtained, it has proved difficult to regener¬ ment with a view to competing for the world gal on the use of the water fern Azolla pin-
ate a complete plant from such fused cells. market. Nevertheless, this branch of bio¬ nata as a biological fertilizer in rice fields
The first success achieved was the regenera¬ technology also offers great opportunities (seethe Unesco Courier, December 1984).
tion of the pomato, a cross between a potato for the developing countries. These new In symbiotic association with the blue-green
and a tomato. However, the plant is sterile techniques, which they have already algaAnabaena this water fern has the ability
and remains no more than a laboratory acquired or can rapidly master, will enable to fix atmospheric nitrogen. Ploughed into
curiosity. them to adapt their agricultural production the soil between harvests, this "green fertil¬
More recently scientists have succeeded to meet local conditions and requirements. izer" can increase the crop by over 50 per
r The Green Revolution
RESEARCH into the selection of new even better adapted and which gave a better end of the 1970s. In the Punjab, farm re¬
high-yield cereal varieties began after yield. In addition to wheat and rice, this venues doubled in 1972, six years after the
the Second World War. Wheat and research also concerned millet and sorghum, introduction of new cereal varieties.
rice varieties were selected In Mexico and the triticale, maize and several leguminous plant In some regions of Asia where water
Philippines respectively, then during the species. resources permitted, the shortening of the
1960s the new strains were used in other In just over a decade, more than half the growing period of new rice varieties allowed
parts of the world, and it was later established surface of corn-growing land and one-third of two or three crops to be harvested per year.
that they had contributed to a significant that of rlceland in developing countries had The prime beneficiaries of the "Green
increase in agricultural yields. been sown with high-yield cereal varieties. Revolution" were the wealthier farmers of
In the mid-1960s, following the introduction When the latter are irrigated, and receive ade¬ some developing countries. The countries of
of these high-yield varieties Into several coun¬ quate supplies of fertilizer and weed-killer, the Africa south of the Sahara were scarcely
tries of Asia and Latin America, the expres¬ yield is two or three times higher than that of affected; only Kenya and Zimbabwe in¬
sion "Green Revolution" was coined to traditional varieties. creased the area of land on which new vari¬
describe the various efforts made to increase The new varieties of wheat were introduced eties of maize were grown. The wheat and rice
agricultural production in the developing to India in 1966 and Indian wheat production varieties were not introduced at the same
countries by means of these new varieties, had doubled by 1970-1971, when it reached pace as in Asia where the development of
especially wheat and rice. The cultivation of 23.4 million tonnes. As a result of local efforts irrigation, adequate fertilizer supplies, and the
these crops required the use of pesticides and to improve varieties and a more widespread marketing system of farm produce played an
Irrigation in addition to fertilization and sound use of selected seeds, output reached 33 mil¬ important role in the success of the "Green
agricultural practices. Cross-breeding be¬ lion tonnes in 1978-1980. From being the Revolution."
tween these varieties and hardy local breeds world's second largest cereal importer in Source: Oue//es biotechnologies pour les pays en développe¬
made it possible to obtain cultivars that were 1966, India had become self-sufficient by the ment? by A. Sasson, Biofutur/Unesco, Paris. 1986
10. Powerful protoplasts
Techniques for the cloning of plants are
now so refined that a single cell removed
from the body of a plant can be cultured in
the laboratory and then induced to re¬
generate a complete individual plant.
Drawings at left and below are a schematic
representation of the cloning process
used by Prof. James F. Shepard and his
colleagues at Kansas State University to
regenerate a complete potato plant from
protoplasts (living cells stripped of their
outer wall) prepared from leaf cells. Small
terminal leaves are first removed from a
young potato plant (1). The leaves are
placed in a solution containing a combina¬
tion of enzymes capable of dissolving the
cell wall to produce protoplasts (2). The
solution also causes the protoplasts to
withdraw from the cell wall and to become
spherical, thereby protecting the proto¬
plasm during the disintegration of the
walls (3). The protoplasts are next grown
in a culture medium (4) where they divide
and begin to synthesize new cell walls (5).
After 2 weeks of culture in these con¬
ditions, each protoplast gives rise to a
clump of undifferentiated cells or micro-
calluses (6). These microcalluses develop
into full-size calluses in another culture
medium (7) and their cells begin to dif¬
ferentiate, forming a primordial shoot (8).
The shoot develops into a small plant with
roots in a third culture medium and is then tonnes of straw, to which can be added
planted in soil (9). Under appropriate con¬ some 127 million tonnes of bagasse from
ditions protoplasts from 2 different plants
sugar-cane and pulp from sugar-beet. At
can be fused to form a cell possessing
present, the main obstacle to their use for
genes of plants which cannot be crossed
using classic methods. The fused proto¬ the production of proteins is the lack of
plasts of some species can be grown into sufficiently active microbial strains for this
plants in a process known as somatic specific purpose. Recently achieved labora¬
hybridization.
tory results suggest that this problem will
soon be overcome.
Cuba is, at present, the only developing
country producing single-cell edible protein
from agricultural raw material. Eighty
thousand tonnes of forage yeasts for use as
animal feed are produced annually from
sugar-cane molasses. The Cuban example
will probably soon be followed in other
countries, such as India, where molasses is
also available at a low price.
10
13. by Bernard Dixon
The gene
revolution
GIVEN the mixture of benefits and which they are part. The astronomically
problems spawned by the first long DNA molecule can be subdivided into
Green Revolution two decades regions genes which determine particu¬
lar characteristics. Recombinant DNA is
ago (see box page 7) , it is not surprising that
both optimism and apprehension surround the name given to the product when a piece
the application of genetic engineering now of DNA from one organism is combined
to agriculture tomorrow. Mixed reactions artificially with that from another.
are appropriate, because those develop¬ Genetic manipulation of this sort is the
ments focused upon so-called recombi¬ basis for the boom that has occurred during
nant DNA are destined to have even the past decade in biotechnology. Such
more far-reaching effects than the tech¬ activities were, of course, possible pre¬
niques deployed in the first revolution. viously. Some, like the art of fermenting
Photo above shows the distinctive knot¬ sugar to make alcoholic drinks, are almost
Today's new wizardry could undoubtedly
like growths or nodules which form on the as ancient as Man himself. Others, includ¬
transform agriculture throughout the
roots ol legumes (plants of the pea family)
world. At the same time, its precision in ing the first mass production of antibiotics,
when they are infected by certain bacteria.
These bacteria, known as rhizobia, take modifying living cells offers a stern chal¬ were developed earlier this century. But all
nitrogen from the air and change it into lenge to our prudence and wisdom. of these processes were based on organisms
forms the plants can use. One important At the centre of the stage is deoxy¬ as they occur in nature albeit with other,
aim of research in biotechnology is to ex¬ equally natural, methods being used to
ribonucleic acid (DNA), the material which
tend this process of nitrogen fixation to
carries in coded form the hereditary instruc¬ select high-yielding strains.
other crops by incorporating nitrogen-fix¬
tions responsible for the behaviour of cells The arrival of recombinant DNA, how¬
ing genes into their genetic heritage. The
goal is proving difficult to attain. and the plants, animals or microbes of ever, has altered the rules profoundly. It
13
14. has already greatly enhanced our specificity pieces of DNA in this way, genetic engi¬ teria and gives the plants the capacity to
and power in tailoring living organisms for neers are beginning to create pedigree produce a toxin that is lethal to insects. The
beneficial purposes. In future, it will extend microbes for a wide range of new purposes inbuilt insecticide makes the plants resistant
our range of options much further. in agriculture, medicine and industry. to insect attack and does not, of course,
The breakthroughs which have led to this Although genetic manipulation is taking have to be applied repeatedly. Some plants
historic watershed in the fabrication of longer to perfect in plants, several tech¬ can mobilize defences against virus infec¬
novel plants and microbes happened during niques are now emerging. The most useful tion through a process analogous to immu¬
the early 1970s. The key discoveries were so far is based on Agrobacterium tumefa- nization in animals, and this suggests
made by molecular biologists who learned ciens, a bacterium that causes crown galls another route for genetic alteration. Incor¬
how to splice into bacteria genes which they on many flowering plants. It contains a poration of one virus gene into tobacco has
had taken from other bacteria, and even tumour-inducing (Ti) plasmid which is helped to protect this plant against subse¬
from totally unrelated animal or plant cells. responsible for triggering the disorderly quent inoculation with the entire virus.
They first found out how to locate the par¬ growth that appears as ugly galls. Genetic Another development concerns
ticular gene they wanted among the count¬ engineers have learned how to delete the Ti weeds a major limitation on crop hus¬
less numbers on the DNA of one organism. plasmid's tumour-inducing genes and use it bandry in most countries. Although weeds
Then they used natural catalysts called as a vector with which to carry new genes can be combatted using selective her¬
enzymes to cut out that gene and "stitch" it into plants. bicides, these often impair the growth of the
into a vector. This is usually a virus or a A serious drawback so far is that while A. crop too. It is now possible, however, to
plasmid (a piece of DNA that replicates tumefaciens infects potatoes, tomatoes, and introduce resistance genes into tobacco and
independently from the nucleus, the main many forest trees, it does not normally petunia. One such manipulation results in
repository of DNA). The vector became a attack the monocotyledons such as cereals, the synthesis of enzymes in the plant that
vehicle for ferrying the selected DNA frag¬ which are prime targets for genetic im¬ are no longer sensitive to the inhibitory
ment into the recipient. Once inside its new provement. Progress is being made, action of the herbicide glyphosate. Com¬
host, the foreign gene divided as the cell however, and recent research indicates that mercial companies now plan to market a
divided leading to a clone of cells, each rice in particular can be manipulated using package containing both herbicide and
containing exact copies of that gene. the Ti plasmid. Alternative vectors and resistance seed.
Because the enzymes used for genetic other methods of transferring genes are also Some 70 per cent of the world's intake of
engineering are highly specific, genes can being developed. One exciting possibility is dietary protein consists of cereal grains and
be excised from one organism and placed in to use an electric current to promote the seeds of legumes. On their own, neither
another with extraordinary precision. Such incorporation of foreign DNA. This works cereals nor legumes can provide a balanced
manipulations contrast sharply with the with maize cells, though scientists still have diet for human consumption, because the
much less predictable gene transfers that to persuade the cells to develop into whole "storage proteins" they each contain are
occur in nature. They also make it possible plants. deficient in one or more amino acids. Now,
to splice genes that would be unlikely to One gene that has been transferred into added to analyses of the proteins in both
come together naturally. By mobilizing tobacco by A. tumefaciens comes from bac cereals and legumes, we have precise infor-
How to recombine DNA Drawing shows how a micro-organism (in this case a bacterium) is manipulated
to make it synthesize a desired substance. (1) A bacterium contains a plasmid,
which is a circular piece of DNA. This plasmid is isolated (2) and, with the help of
a restriction enzyme, opened in a precise spot (3). Meanwhile, with the help of
other restriction enzymes, the gene for synthesis of the desired substance is
isolated from the DNA of another organism (4). Still using enzymes, this gene is
grafted onto the previously opened plasmid (5). The plasmid is re-introduced
into a bacterium (6). The manipulated bacteria are put into a culture, where they
synthesize the desired substance. (7)
o
ó
14
15. mation about the DNA sequences coding
for them. This knowledge may well lead to
methods of altering those sequences or
introducing new genes that code for a more
balanced spectrum of amino acids.
The world's energy and food supplies rest
upon the ability of green plants to convert
atmospheric carbon dioxide into carbo¬
hydrates, fats and proteins, using light from
the sun. Unfortunately, the mechanism by
which they consume carbon dioxide is inef¬
ficient in those plants, such as wheat, barley
and potatoes, that are cultivated in tem¬
perate climes. Oxygen in the atmosphere
interferes with the first enzyme involved in
the assimilation of carbon dioxide. Consid¬
erable efforts are now being made to alter
the DNA sequence of the gene coding for
this enzyme, to prevent the deleterious
action of oxygen. Other researchers are try¬
ing to introduce into temperate zone
plants certain genes taken from maize,
which has a more efficient mechanism of
carbon dioxide uptake. In nature this
mechanism appears to operate only at
higher temperatures, but there are hopes of
"switching it on" in cooler areas.
Another atmospheric gas is the subject of
parallel efforts to make plants more effi¬
cient. Nitrogen constitutes 80 per cent of
the air, yet plants cannot use the gas
directly. Hence the heavy dependence of
modern intensive agriculture on fertil¬
izers nitrate, ammonia or urea syn¬
thesized by the chemical industry. Natural
nitrogen fixation depends in part on
rhizobia, bacteria that live symbiotically
with legumes such as peas, beans and
clover. The bacteria grow on sugars
provided by the plant, and are maintained
in characteristic nodules on the plant. There
they convert nitrogen directly into
ammonia, leading in turn to the synthesis of
plant proteins.
Molecular biologists have now isolated
and characterized several of the genes
required for nitrogen fixation. They have
found, however, that many more bacterial
and plant genes are involved than they first fixation. Drought resistance which depends A key area in biotechnology research is
imagined. This makes the manipulation of on a reduced area of leaf surface, for exam¬ concerned with the development of tech¬
those genes correspondingly more difficult. ple, may be caused by the interaction of niques for isolating genes of one plant and
So it will be some years before we can enjoy multiple genes. introducing them into another as a means
of endowing the host plant with new char¬
the cost and energy savings that should Microbes that contribute to healthy plant
acteristics such as higher protein content
accrue by providing crops such as wheat and growth are also on the drawing board for
or resistance to pests. One promising
maize with the ability to fix their own genetic engineering. One possibility being technique for transferring genes uses
nitrogen. examined is the production and deliberate Plasmids (small pieces of genetic material)
Drought and high temperatures are release of rhizobia that fix nitrogen more from a bacterium which causes tumour
unwelcome to all plants, despite being bet¬ efficiently than natural strains. Other bacte¬ growths when it infects certain plants,
above. It is possible to delete the plasmid's
ter tolerated by varieties that have evolved ria capable of forming nitrogen-fixing part¬
tumour-inducing genes and use the plas¬
in such environments. Desiccated soils also nerships with wheat and maize are also mid to ferry new "useful" genes into
often contain high levels of salts and metal¬ being considered. A third type of prospect plants. Genes of a bean protein have been
lic elements, which are toxic to plant follows the discovery by researchers at the transferred to the sunflower using this
method.
growth. Genetic engineers would dearly University of California, Berkeley, that
like to fabricate plants resistant to such frost damage to strawberries is triggered by
stresses, but success is unlikely in the near bacteria which act as nucleii for the forma¬
future. Before being able to identify the tion of ice crystals on leaves. The cause is a
relevant DNA sequences for transfer particular bacterial protein, the gene for
between plants, they require a far better which the California biologists have learned
understanding of the many ways in which to delete. They believe they can prevent the
plants respond to their environment. An extremely costly frost damage by spraying
additional problem may be the involvement crops with this "ice minus" strain , which will
of several different genes, as with nitrogen outgrow the natural flora.
15
17. Tomatomation
Japan's high-tech food factories
by Koichibara Hiroshi
THE harnessing of high technology to Light, temperature and humidity are com¬ '85 (see the Unesco Courier, March 1985).
vegetable farming may be about to puter controlled in this vegetable factory This was a major success for a hydroponic
in a Tokyo suburb. High electricity con¬ culture system developed after many years
trigger a new agricultural revolu¬
sumption is a drawback.
tion in Japan, where some large manufac¬ of research by a Japanese agronomist,
turers are already offering fully automatic Nozawa Shigeo. The growth of the plant
"factories" in which vegetables are grown in was accelerated in a nutritive solution which
a computer-controlled artificial environ¬ replaced soil and in an artificially controlled
ment. In their use of automation and high development is hydroponics, the cultivation environment. As a result the plant pro¬
technology these facilities resemble auto¬ of plants in nutritive solutions. Factory duced more than 13,000 tomatoes during
mobile or electronics plants, but instead of farms are air-conditioned, and high-pres¬ the six months of the Expo.
automobiles or video tape recorders their sure sodium lamps provide twenty-four- Daiei, Japan's biggest supermarket
mass production lines produce fresh vegeta¬ hour-a-day illumination. The density of car¬ chain , has installed a factory farm next to its
bles, regardless of season or climate. bon dioxide, oxygen, temperature and store in the Tokyo suburb of Fanabashi.
Strictly speaking, today's factory farming humidity are controlled by a computer to This experimental facility, constructed in
technology is based not on biotechnology maintain an optimum growing environ¬ co-operation with Hitachi Ltd. to grow let¬
but on applying industrial production man¬ ment. tuce for sale in the adjoining supermarket,
agement techniques to conventional agri¬ The hardware used in this process is not may be the world's first commercial factory
cultural engineering. The aim is to use new. It is readily available from manufac¬ farm using full automatic hydroponic cul¬
artificially controlled environments to grow turers of electrical consumer goods, and this ture technology. The system produces some
plants rapidly and efficiently rather than may be the reason why Japanese electrical 130 heads of lettuce and other green vegeta¬
improve the adaptation of plants to natural conglomerates are active in this field. Com¬ bles per day (some 47,000 per year) on a
conditions. Such ideas have already been panies in Denmark, the United States and floor space of no more than 66 square
applied to poultry farming, egg production Austria are also experimenting with vegeta¬ metres. Grown from seed, the lettuce is big
systems, and even the production of foie ble factories but for the moment the Jap¬ enough for harvesting in only five weeks,
gras. Factory farms may thus make a big anese seem to be leading the field. 3.5 times faster than plants cultivated using
In 1985, a "supertomato" plant was dis¬ conventional methods.
impact on conventional agriculture since
they provide planned cultivation regardless played in the Japanese government- In this futuristic factory, the sun is
of weather, season, climate or soil. sponsored pavilion at an international replaced by artificial twenty-four-hour
The essential element in this new exhibition held in Japan, Tsukuba Expo. lighting, soil with nutritive solution and
17
18. farmers with a micro-computer. The crop is metres and a construction cost of $60,000.
tasty and free from pesticides and her¬ Since May, each factory has been producing
bicides, and is in great demand, regardless 120 heads of lettuce a day. Experiments are
of the price tag, which is double that of being carried out on the cultivation of other
conventionally grown lettuce. vegetables such as tomatoes, cabbage,
In Mitsubishi Electric's Amagasaki labo¬ asparagus, melon and green peppers. In the
Trays of growing lettuce were rotated up ratory, a prototype food factory assembly case of JNR, electric power supplied by its
and down on chain conveyors in this line succeeded in growing lettuce seedlings own power plants can be efficiently used at
vegetable factory installation shown in the from 2 grams to 130 grams in 15 days 6 night when demand is low, and open spaces
Japanese Government pavilion at Expo
times faster than the natural growth rate. beneath the overhead railway or aban¬
'85, an international exhibition held at Tsu-
kuba (Japan) in 1985. The lettuce were With specially developed fluorescent doned tunnels can be utilized as sites.
grown in liquid nutrients, using the tech¬ lamps, the photosynthetic ratio is said to be Artificial lighting and computers are not
nique known as hydroponics. The 24- better than that of the sun. Sprouts cloned essential elements in factory farming.
hour-a-day lighting, carbon-dioxide-rich from the tissues of mature plants start at one Hydroponic food factories can be installed
atmosphere and constant temperature
end of a conveyor and move along at the in developing countries where food facto¬
helped the lettuce to reach maturity in 20
rate of 20 centimetres a day. ries may be most needed. Matsushita Elec¬
days, 4 to 5 times faster than normal. The
moving conveyor belts ensured that every In March 1986 Japanese National Rail¬ tric has, for example, installed a vegetable
plant was exposed to the same amount of ways (JNR) built two experimental vegeta¬ factory with minimal automation in the
heat and light. ble factories, each with a size of 50 square Maldives. The system, which has a plastic
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