|By pinoyfarmer | August 4, 2007|
1 Introduction and Summary
The drawings on this page are by Kay Mirocha. Source: Jojoba: Guide to the Literature, Office of Arid Lands Studies, University of Arizona, Tucson. (c)Arizona Board of Regents, 1982.
A decade ago few could pronounce it, and today it still causes confusion, but jojoba (pronounced ho-ho-ba) is a name that is becoming increasingly common. At present, growers are attempting to produce this obscure desert shrub on about 40,000 acres (16,000 hectares) of semiarid land in the southwestern United States and in many other areas, including Mexico, parts of Latin America, Israel, South Africa, several other African nations, and Australia. Plantings in the United States alone increased 60 percent between 1982 and 1984 and represent about 32-48 million shrubs – an investment of perhaps $200 million.
For a slow-growing, perennial crop that was unknown to commercial agriculture as recently as 10 years ago, operations and investments of this magnitude are unusual and possibly unwise, but jojoba’s seeds contain an oil, unique in the vegetable kingdom, that seems to have exceptional commercial promise.
Jojoba oil, which makes up about half the weight of the seeds, differs so fundamentally from common vegetable oils and animal fats that it has its own distinct characteristics. Its chemical structure is that of a long straight-chain ester, whereas the others are triglycerides – branched esters based on the molecule glycerol. Chemists call it a liquid wax.
If jojoba seed is mature and dry and the processing is done appropriately the extracted oil is remarkably clean. It has few impurities, a precise and narrow range of carbon chain lengths, and a uniform number of double bonds (one in each end of its molecule). It has a slightly yellowish color but is easily made water-white by heating or by a simple filtration through fuller’s earth.
Jojoba oil’s purity, lack of odor, and resistance to rancidity make it a natural base for creams and ointments, and its initial market has been in cosmetics. But it also shows promise as a new basic feedstock for the chemical industry. Researchers in more than a dozen laboratories are acetylating, alkoxylating, epoxidizing, halogenating, hydrogenating, hydrolyzing, isomerizing, ozonizing, sulfonating, sulfurizing, sulfur-halogenating, and sulfur-phosphonating it. These transformations, collectively, yield many new chemicals with broad industrial potential.
Properly formulated with additives, the oil (or its sulfurized or sulfurhalogenated derivatives) has excellent lubricity and a long performance life. Moreover, derivatives of jojoba oil are thought to have possible use in the preparation of antifoaming agents, detergents, disinfectants, driers, emulsifiers, fibers, plasticizers, protective coatings, resins, and surfactants.
The process of hydrogenation converts most vegetable oils into semi-solids (for example, shortening and margarine), but it transforms jojoba oil into a white, crystalline wax. This hard solid has potential as a candle wax; a polishing wax for cars, floors, furniture, and shoes; a coating for fruits and pills; an insulation for batteries and wires; and an ingredient in chalks, crayons, and soaps. In addition, if the hydrogenation process is taken only part way it leads to a range of soft amorphous waxes that melt at different-and predictable-temperatures.
The oil’s double bonds are all in the cis-conformation. They can, however, be chemically isomerized into the more stable trans-form, thereby creating another range of soft waxes that seem to have considerable commercial potential of their own.
Only in the 1970s did jojoba’s broad industrial and agronomic possibilities gain public attention. Before then, a handful of researchers had undertaken basic research on the crop, but it was in 1971 that the first significant harvests were reaped in the United States. At that time
Indians began collecting and processing seed and producing oil from their reservations in Arizona and California. The resulting evaluations stimulated many researchers and entrepreneurs to begin the arduous task of converting the plant from a wild shrub to a commercial crop. For instance, various universities, corporations, and private research laboratories in Australia, Israel, Mexico, the United States, and other countries began substantial research efforts aimed at determining jojoba’s basic agronomic requirements. In a remarkably short time much was learned about the plant and its management. By 1978, several landowners were confident enough to attempt to cultivate the crop.
Today, it can be said that the plant’s fundamental qualities and cultivation requirements are well on the way to being understood, and that jojoba can be successfully grown in plantations. Indeed, perhaps a hundred plantations are already beginning to yield on a commercial scale. Harvesting equipment designed for use on grapes, blueberries, and raspberries has been modified for use on the crop, and custom-designed harvesters are being developed. In addition, several small companies are commercially extracting and selling jojoba oil.
In the near future, the oil’s availability is expected to increase significantly. Moreover, the costs of production will decrease as existing plantation mature , as extraction facilities become more efficient because of scale and as advances in agronomy (especially the selection of high-yielding cultivators) improve yields .
This is an important and far-reaching development. Deep-rooted, long-lived perennial plants such as jojoba offer promise for agriculture in harsh, arid environments where many conventional crops cannot survive. Such woody plants with their massive root systems can extract moisture from a large volume of desert soil and can thrive where herbaceous plants shrivel to dust.
Around the world are huge tracts of semiarid land where, in principle, jojoba might become an important cash crop. It is robust, drought tolerant, and withstands desert heat without requiring much water or shade. Moreover, its water requirements are timed to meet the availability of rainfall in many deserts. For instance, it needs little water during the dry months, when water is most scarce. (Cotton, sorghum, and other crops grown in arid regions usually require irrigation during the hot, dry summer to protect them from desiccation.) Further, some types are also adapted to salinity, which is often a problem in semiarid lands.
Jojoba cultivation around the world. In the last 10 years there has been a blossoming of interest in cultivating the crop, or at least in establishing a few plants as a trial.
For these reasons, jojoba cultivation and processing, the manufacture of jojoba products, and the use of by-products might help peoples in arid lands to become more self-supporting. For resource-deprived peoples – North American Indians, farmers in the Sahel zone of Africa, Bushmen in southern Africa, aborigines in Australia, peasants throughout the Middle East, Pakistan, and India, and inhabitants of arid areas in Central and South America – jojoba could become a valuable resource. It promises to be a high-value crop, and neither the seeds nor the oil are highly perishable, so that distance from the market should not seriously limit the plantation site.
But these are merely speculations. Past production around the world has been too small for any large-scale marketing of consumer goods containing jojoba oil. Until the last year or two, the supply has been limited to that available from hand-harvesting scattered native bushes in the Sonoran Desert of northwestern Mexico and the southwestern United States. Production in recent years, therefore, has only been 100-300 tons per year, and because of the vagaries of the desert rainfall it has fluctuated widely from year to year. Most jojoba has been sold at relatively high prices (between $3,000 and $20,000 per ton) to research institutions, specialty lubricant manufacturers, and cosmetic companies in Europe, Japan, and the United States.
Nevertheless, in spite of the small and erratic availability of seed from wild plants and the consequent fluctuating prices of the oil, the jojoba industry has experienced increasing success. The oil, now available in barrel amounts, soon will be pouring out of plantations in tanker quantities. In the 1986 season, for example, North American jojoba oil production (from the plantations that will then be four years old or more) could be as much as one million pounds (450,000 kg). And, theoretically, production will double in 1987 and possibly double again two to three years later as the plants mature and as acreage comes into production. It is estimated that the amount of jojoba oil annually coming from those plantations that are now established will increase to 42 million pounds (21,000 tons) in the next eight years or so.
The small cosmetic companies that initially bought jojoba oil often added it to their products for its “fashionable” value more than anything else. However, with the development of commercial plantations and the availability of experienced oilseed processors, the larger cosmetic manufacturers are beginning to add jojoba oil to their products based on its functional value. Companies such as Alberto-Culver, Faberge, Plough-Coppertone, L’Oreal, Shiseido (Japan), and Crabtree and Evelyn are already using jojoba oil in sun-, skin-, and lip-care products, often without advertising the fact.
In research laboratories around the world, jojoba oil is being investigated for use as a treatment for burns, acne, and psoriasis. Some research is also being conducted to test its use in processed foods. Because of its unusual molecular structure, the oil is a possible low-calorie substitute for conventional food oils, as well as a possible cholesterol-reducing agent. These dermatological and food applications are interesting but highly conjectural possibilities that require much additional study (as well as eventual approval by the U.S. Food and Drug Administration and similar agencies) before they can safely be applied.
The oil’s use in lubricants and other industrial products, however, is much more certain. These applications have in the past been severely limited by the small quantity of oil available as well as by uncertainties in price. Nevertheless, two small California specialty-lubricant manufacturers, Wynn Oil and Key Oil, already use jojoba oil as lubricant additives. Among large corporations, Tenneco West has evaluated and formulated jojoba-based lubricants, and some well-known companies in the chemical, oil, and lubricants industries have tested the oil and have expressed an interest in incorporating it into various products when supplies increase and prices decrease.
Although there are economic risks involved in farming any crop, they increase considerably when it has not been cultivated before. Jojoba, therefore, is not for amateurs or disinterested investors. To pioneer the production of such an untested plant takes dedication, commitment, hard work, and financial reserves. There have already been some financial failures. However, no crop is immune from that, and analysis shows that the failures were caused by inept management, undercapitalization, or poor choice of site, not by any major problem inherent in the plant itself.
Nonetheless, jojoba is a crop for which time-tested advice cannot be given. To manage it in plantations does not require new agricultural techniques or specialized equipment, but it is expensive, and on many sites some irrigation is required to make it profitable. So far, no significant diseases or pests have seriously affected the plant, but growers find themselves constantly battling weeds, and it seems probable that other pests and diseases will soon appear. Also, although the main factors affecting plant production are fairly well established, many subtle factors result in economic uncertainties. For instance, the genetic improvement is in its early stages and there are essentially no named varieties or cultivars of jojoba. Thus the performance of any plant cannot be predicted or relied upon. Today’s specimens (notably those established from seed) vary enormously in size, shape, precocity, yield, and oil content.
Further, jojoba is too new a crop for reliable yield predictions. Because there are no mature commercial plantations, all yield estimates are based on small experimental plots or, more recently, on young commercial plantations in Arizona, California, Israel, and Mexico. Such projections can be wildly inappropriate for other sites and they change yearly as more is learned about the crop and its requirements.
Productivity obviously depends on plant selection, suitability to local conditions, planting densities, and management practices. And these features are only just now being clarified. Different researchers and growers have differing opinions.
From present experience, it appears that on suitable sites jojoba plants grown from seedlings will produce a scattering of seed when three years old, a modest harvest worth picking at four years, and true on-line production from five years onward. This is a long delay for any investor to endure without a financial return. However, it is thought that in the eighth to tenth year the plants will reach essentially full maturity and maximum production, and from then on they should bear fruitfully with minimal attention for decades. Significant laboratory research on the basic chemistry of jojoba oil and its derivatives has been completed. However, more product formulation and testing are required before large amounts of jojoba oil can be absorbed by industry. The crop is so new and the production so small that, as of 1985, its profitability and the eventual size and identity of its markets can only be surmised. Supplies of jojoba oil will still be limited for the next few years, which will cause continued uncertainty over the size and value of markets. Industrial users need stable supplies and prices before they will even consider reformulating products.
The jojoba industry is fast moving into the production stage, and it will have to resolve these uncertainties soon. In a year or two, yields will surpass the needs of the present cosmetics markets, and jojoba producers will have to move from providing a high-priced speciality product to providing a lower-priced industrial commodity.
Because of this transition, any recently quoted prices for jojoba oil ($40-$55 per gallon in mid-1985, the equivalent of $10-$14 per liter) are misleading for the long term. In coming years the price will fall substantially, and many early investors, whose financial projections were based on the high prices, may have difficulty surviving. Eventually, to penetrate large markets such as that for lubricants, the oil’s price will have to be comparable to that of competing high-quality synthetic or petroleum-based products. The Future Jojoba is graduating from the wild to the domestic, and its agronomic future looks more and more promising as experience is accumulated with each passing year. For example, plants with superior characteristics in plantations are being identified. This will allow future plantations to be established with specimens selected for high performance and cloned by rooted cuttings or tissue-cultured plantlets. Such vegetative propagation results in substantial gains in yields and harvestable production in three to four years, a year or two earlier than today. With success in the plantations, the uncertainty of jojoba development has moved forward into the world of industrial chemistry and of product formulation and marketing. In many ways’ the crop’s future rests on the creativity of the chemical industry – on its ability to devise out of this unique natural product, never before available, new products and materials that will benefit both the crop, the chemical industry, and the consumer. Jojoba has a good chance of being very profitable in the long run. It produces a premium oil. It grows in soils of marginal fertility, needs less water than most crops, withstands salinity, and apparently has a low fertilizer requirement. It has been unaffected by catastrophic diseases or insect pests – at least so far. It requires no specialized cultivation equipment and its oil can be extracted inexpensively with conventional machinery used for vegetable oils. Jojoba growing is a challenging activity that carries risk, but it also carries the promise of excitement and personal satisfaction for the pioneers who are successful. Investment, therefore, should be made with extreme caution, but the indications are that this crop’s longterm future could indeed be bright. It is not the miracle plant some have claimed, but neither is it a mirage. Many challenges are ahead, but none seems insurmountable, and success will provide the world with a new, renewable, natural resource that can fill many industry needs. 2 The Plant
Jojoba is native to a triangle of the Sonoran Desert whose corners are roughly Los Angeles (California), Phoenix (Arizona), and the southern tip of Baja California (Mexico). This area encompasses some of the earth’s most inhospitable land: in some places rainfall is as sparse as 3 inches (8 cm) a year, and temperatures soar as high as 130°F (54°C). Few crops could survive this blistering environment, but among the rocks, gravel, and sand, jojoba endures.
The severity of its native habitat endows the plant with a rugged, robust nature. Some of the most northerly jojoba plants get snowed on in winter. Some westerly ones grow in sand dunes, often exposed to ocean spray, which few other species can survive. The easterly ones are in dry deserts where some years rain refuses to come at all.
Distribution of native jojoba in the southwestern United States and northwestern Mexico. The plant occurs naturally over a range of latitudes and altitudes. It extends from the coast to inland deserts. The germplasm through much of this area still remains to be collected and evaluated. (Office of Arid Lands Studies, University of Arizona, based on an original map by R. Turner)
Although frequently stunted to a height of 2-3 feet (60-90 cm) by the harshness of its environment or by heavy browsing by wildlife, jojoba can grow to more than 15 feet (5 m) in well-watered sites and in plantations. An evergreen, it has thick gray-green leaves and brown seed. Its natural lifespan appears to be at least 40 years. (Jojoba bushes with more than 200 rings are in fact known in the wild, although it is not known whether these represent annual rings or just growth spurts after heavy rains.)
The leaves are endowed with a dense covering of wax plates – a cuticular barrier that reduces moisture loss and protects against fungi, insects, and pollutants.
Most native jojoba plants grow among palo verde, mesquite, ocotillo, and saguaro in the desert foothills and washes. Their leaves, like soft leather ovals, stand out stiffly in pairs, creating a shield held up by a network of sturdy grey branches. Often finding little soil, they nestle together as compact spheres. On better sites, however, they resemble olive trees in their shape and color.
Early in the nineteenth century, at the botanic garden of Berlin, a package of plants collected in Baja California was confused with another collected in China. When the American plants were described they were assumed to be Chinese. One, described by the garden director Johann H. F. Link in 1822, was jojoba. He named it Buxus chinensis.
In 1844, American botanist Thomas Nuttall described jojoba collected from San Diego. He put it in a new genus, Simmondsia, named to honor the English naturalist, F. W. Simmonds, a colleague who had died while studying the plants of Trinidad 18 years earlier. Nuttall’s full designation was Simmondsia californica.
Other names and descriptions for jojoba appeared at about the same time, as well as later that century, and in 1912 the multiplicity of names was clarified by the Austrian botanist Camillo Karl Schneider. He retained Nuttall’s generic name Simmondsia and Link’s specific name chinensis, resulting in the full botanic epithet: Simmondsia chinensis (Link) C. K. Schneider. Despite the geographical inconsistency, this is currently jojoba’s formal name.
These early botanists placed the plant in the boxwood family, Buxaceae. However, in 1898 the Belgian botanist van Tieghem suggested (on the basis of the dioecious breeding system, floral morphology, and wood anatomy) that jojoba be put into a family of its own, Simmondsiaceae. In recent times this view has been championed by several taxonomists and is beginning to gain acceptance among botanists (Information from R.F. Thorne).
Jojoba bushes are either male or female. The males produce pollen and have flowers containing only stamens. The females produce the fruit and seeds and have flowers containing one ovary with three ovules. Tendencies toward hermaphroditism are noted in a few male bushes. These produce all grades of perfect flowers: from those with an undeveloped pistil to those with a complete ovary that can even yield fertile seed.
The sex of a young jojoba plant cannot be judged until the first flower buds appear. In precocious individuals this may be in the summer of the first year, whereas in slow plants it may take until the fourth year.
Typically, flowering occurs at alternate nodes along the branches, although some plants produce flowers at each node and others produce them at every third node.
Male flowers occur in clusters; female flowers are commonly solitary. However, in certain populations many of the female bushes have clustered flowers. As many as 50 female flowers in a single cluster have been recorded.
Female flowers have no petals or odors to attract insects, and the plant depends almost entirely on wind for pollination. Although honey bees and a variety of other insects are often seen foraging for pollen on the male and on the hermaphroditic flowers, they rarely visit female flowers.
Floral buds appear on the current season’s growth, mainly in the summer and the fall. They usually open in the following spring. This flowering is triggered by the stress of cold or drought or both. Unseasonal weather – for example, a cool fall followed by a warm, wet winter period – can trigger early flowering, which often leads to loss of the crop if the weather turns harsh.
The fruits, which are about the size of acorns, are greenish at first but turn brown as they mature, sometime during the early summer. They contain one seed, occasionally two or three. Eventually, the flesh and outer husks dry out, shrink, split, and peel back to expose the soft-skinned brown seed or seeds inside.
To help survive drought, the plants have an exceptionally deep root system that taps into the underground moisture. Bushes a mere 1-2 years old have been found with roots 12-16 feet (4-5 m) deep. Some mature shrubs have been found with roots penetrating as far as 40 feet (13 m) into the soil.
Seedlings devote most of their energy to producing a taproot – a natural survival mechanism in deserts where surface soil dries out rapidly. A seedling’s taproot may grow as much as an inch (2.5 cm) a day. Often young plants have roots 10 times longer than the height of the plant above ground. Seedlings normally take about 21 days to break through the soil, by which time they can have roots 18 inches (46 cm) deep.
A strong taproot may be essential to jojoba’s survival in many desert areas, but the plant uses water from deep soil layers only as a reservoir to resist and recover from drought stress. Some 80 percent of its feeding roots are in the top 2.5 feet (80 cm) of soil.
A symbiotic fungus, tentatively identified as Glomus deserticola, has been found on jojoba roots in its native state. On citrus trees, a closely related mycorrhizal fungi, Glomus fasciculatus, is known to stimulate the uptake of phosphorus, zinc, copper, and many other elements. The jojoba mycorrhiza probably does the same; in laboratory experiments, plants inoculated with it have experienced increased growth rates, reduced transplant shock, and heightened disease resistance.
Natural populations occur between 23° and 35°N latitude. However, jojoba flowers and sets seed well near Fortaleza, Brazil (latitude 4°S); Mombasa, Kenya (4°S); San Jose, Costa Rica (10°N); and Erkowit, Sudan (18°N). It would appear, therefore, that differences in latitude and daylength are not important limitations to jojoba cultivation.
Jojoba tolerates extremely high temperatures: during the summer, daily shade readings of 95°-120°F (35°-48°C) are common in its natural habitat. Often the ambient air temperature is 120°F (48°C) and soil temperature 150°F (65°C). However, temperatures above 100°F (38°C) appear to be of no advantage to the crop, and may actually decrease its productivity because they cause the stomata to close, thereby stopping vegetative growth.
When selecting a site, it is important to consider low-temperature hazards. Aberrations in weather can cause freezes in most desert areas – on occasion. Ideally, the land should be frost free. Jojoba can grow where occasional light frosts occur, but in such areas the plants should be grown on slopes (preferably facing the sun) or where there is good air drainage. Valley bottoms where cold air collects must be avoided. Sites where temperatures frequently fall bellow 23°F (-5°C) for prolonged periods should never planted to jojoba.
Hardened plants can endure 16°F (-9°C) without sustaining longterm damage, but flower buds and any newly set seed can be damaged at 28°F ( – 2°C) and killed at 22°F (-6°C).
A desert native, jojoba thrives under soil and moisture conditions unsuited to many agricultural crops. Most natural stands grow in areas receiving 8-18 inches (200-460 mm) of annual precipitation. However, although it has been called “the plant that doesn’t get thirsty,” it does require moderate amounts of water for quick plantation establishment and for best yields. In addition, soil moisture is critical from spring to early summer, the period in which flowering and fruit development occur.
For economic reasons, 18-24 inches (460-610 mm) of annual moisture appears to be most suitable for establishing plantations, and, in most areas, is probably needed to ensure commercial success. However, where drainage is good, extra water may not be detrimental: jojoba has been observed growing satisfactorily in sand where rainfall is 50 inches (1,270 mm) annually.
Wherever the plant is grown, good drainage is vital; jojoba cannot survive waterlogging. Flooding twice destroyed test plots near Yuma, Arizona, and most plants were killed when a test plot in Western Australia was flooded for less than two days. Losing an established plantation would be a financial catastrophe, so the possibility of a “freak” or “100-year” flood should be considered when choosing a plantation site.
Jojoba’s native habitat covers areas where the main rainy seasons are in winter and/or summer. There seems to be no difficulty growing the crop in other regions that display either pattern. For example, jojoba is developing well in both the eastern (summer rainfall) and western (winter rainfall) parts of Australia. Mombasa, Kenya, gets two monsoons a year, and four-year-old plants there flower twice a year, each time following the rains.
In the Sonoran Desert, the biggest and most vigorous jojoba plants are on sloping, well-drained soils with silt and clay in the lower horizon. In cultivated stands, some plants are successful on sandy soils, others on silt-loam. Heavy clays may be suitable in some areas, but only if internal drainage is high. The plant cannot withstand soils with poor porosity. For instance, heavy bottomland soils prone to flooding are not suited to it.
Extensive measurements made in wild jojoba populations in Mexico and the United States have shown the plant thriving in soils ranging from pH 5 to 8, indicating that, within reason, soil acidity or alkalinity is probably not a limiting factor.
The buildup of salt – because of excessive irrigation and high surface temperatures – is a common problem of arid lands. Jojoba tolerates water of low quality, provided its application is wisely managed and the soil drainage is adequate. In California, plants are growing satisfactorily with water containing 2,000 parts per million of salts. In one large planting by the Salton Sea, young seedlings are growing without obvious sign of stress, in spite of a brackish water table just 6 feet (1.8 m) below the surface. When tested in the laboratory, one variety of jojoba showed no reduced growth of flower production at a soilwater salinity of about 7,000 ppm.(Information from D. M. Yermanos) Jojoba’s tolerance of saline water has also been demonstrated in Israel, for example, at the commercial and experimental plantings at Kalia, near the Dead Sea.
However, some jojoba lines apparently do not survive salt stress well because leaf damage and retarded growth have been noted in some areas. The type of salt appears to be more significant than the amount: high sodium adsorption ratios (SAR) should be avoided or need to be carefully managed. Further, long-term tolerance to salinity in plantations has not been demonstrated. Salinity buildup in the root zone could be a future problem for plantations with restricted drainage that use saline water.
Plantations are often established in raw desert or abandoned agricultural land. To prepare the site, a source of water is first assured and the land then cleared of vegetation. The soil is ripped, plowed, disked, or land-planed prior to planting. In the United States it is often leveled (with surveying assisted by laser) or furrowed, as needed, for irrigation. Access roads may also have to be constructed, ditches dug, and fencing erected. In areas subject to flash flooding, dikes may have to be built to deflect runoff.
Plantations are created using seeds, seedlings, rooted cuttings, or plantlets produced from tissue culture.
Direct Seeding. Most direct-seeded commercial jojoba fields are grown in raised beds. The seedbed is prepared (often using commercially available planters) as if for planting cotton or corn. In Arizona, experience has shown that with two planters mounted on a tool bar, one tractor operator can plant 60 acres (24 hectares) a day.
Jojoba seed varies greatly in size. One pound (450 g) of large seeds may number 300; one pound of small ones may contain 1,000 or more. Normally, large seed is preferred for planting because it produces more-vigorous seedlings during the first 2-3 months of growth. Most seeds, if properly handled, are 90-95 percent fertile. In cool, dry storage they remain viable enough for planting for 5 years or more.
Plantings are best done during the warmth of late spring or early fall. When soil temperatures are between 70°F (21°C) and 95°F (35°C), germination occurs within a week and the plants emerge above ground in about 20 days. Low temperatures delay germination, sometimes as much as several months, and may cause complete failure if the seed rots before germination can occur. Also, planting should be avoided during the hottest months.
During the first 2-3 months, irrigation must be applied constantly to maintain moisture near the soil surface, thereby ensuring good root establishment. Later, irrigation may be employed at monthly intervals to supply the field with a total of about 1.5 acre-feet (45 hectare-cm) of water. Overwatering can be disastrous.
About half the seeds produce male plants. Once these can be identified, farmers usually cut most of them out, leaving a scattering of a few strong, healthy ones for pollination. This makes room for the female bushes to grow bigger.
Seedling Transplants. To produce a seedling that is suitable for transplanting takes from 2 to 4 months in the nursery. Containers are at least 8 inches (20 cm) deep. The media is well drained and sterile to avoid fungal root diseases. Air-pruning of the vigorous taproots helps avoid the problem of the roots curling around and around in the container and refusing to grow downwards when planted out.
Where winters are cool, transplanting to the field is best done in spring or early summer. In warmer areas the early fall may be the best. The key is to get the seedlings well established before the heat of summer or the cold of winter.
Cuttings. In the United States, most jojoba plantings are currently done with cuttings. These are taken from superior bearing plants in cultivation or in the wild. Cuttings from some jojoba shrubs have demonstrated rooting rates of up to 95 percent, although this is unusual. However, many are genetically indisposed to vegetative propagation; cuttings taken from them either root poorly or fail to root at all.
Cuttings are most successfully rooted with misting techniques, using bottom heat to accelerate the process. In mist-propagation chambers kept at about 72°F (22°C), stem- and apical-wood cuttings (treated with fungicide and rooting hormone) produce roots within 3-8 weeks, depending on the season. The propagating medium is usually a mix of perlite and vermiculite. After roots have been established, the plantlets are transferred to biodegradable containers and gradually hardened off, so that planting them in the fields causes them minimum shock.
Machinery designed for planting tomato seedlings works well for planting jojoba cuttings. One grower in Arizona plants female cuttings in September or March/April and gets better than a 90-percent survival rate. He then puts cuttings of male plants into the spaces left by the females that failed to survive. Other growers plant male cuttings in a prescribed pattern from the start.
Creating a plantation by using cuttings is more expensive than by using seed. But it saves the effort and expense of roguing out and replacing unwanted plants; it gives the grower uniform plants of known sex, placement, and parentage; and it produces bushes that bear seed one or two years earlier than those from seedlings. When cuttings are cloned from superior cultivars, the yield per acre is expected to be 300-500 percent higher than that of a seed-planted field, with all its inherent genetic variability.
Cuttings are also useful for upgrading plantations that were created from seed. Replacing badly performing bushes with cuttings selected from those that perform best can more than double the overall yields.
Tissue Culture. Tissue culture techniques for propagating jojoba are available for commercial use. The economics of this procedure are uncertain, but the plantlets provide the same benefits as cuttings. Indeed, in the critical first years tissue cultured plants reportedly are the fastest growing of all planting materials.
The optimum density for a plantation depends on the size and shape of the bushes and the management practices to be used. Time-tested prescriptions cannot be given at present. With more experience, a variety of densities undoubtedly will be found for different site types and cultivation practices.
An acre of tall, tree-like jojobas might contain fewer than 600 plants; an acre of small bushlike ones could hold perhaps 2,000 plants. (In metric units these represent 1,500 large jojobas or 5,000 small jojobas per hectare.) University of Arizona researchers aim at a density of about 900 plants per acre (4 feet x 12 feet spacing, or 1.2 m x 3.7 m), but are testing densities up to 1,450 per acre (3,600 per hectare). At this time most commercial growers are working toward a density of 1,000 plants per acre (10 feet x 4 feet spacing, or 3 m x 1.2 m).
According to Israeli researchers, jojoba plants seem capable of withstanding considerable crowding without displaying depressed growth or reduced production. This is probably because jojoba has few spreading roots to compete with those of neighboring bushes. However, crowded plants may compete for deep soil moisture as they mature and the long-term effects of crowding are unknown.
Experience suggests that one male plant can provide adequate pollination for at least five female plants. Males should be spaced throughout the plantation with consideration given to average wind speed and direction. Recently, a computer program has been developed to help calculate the best location and spacing of males for a given site.(Information from C. Niklas)
For satisfactory growth and production, jojoba seems to need only a third (or less) of the moisture that crops such as citrus or cotton require. Nevertheless, in most places where annual rainfall is less than 25 inches (640 mm), supplementary irrigation is needed to ensure profitable production, unless the roots can reach permanent soil moisture. Supplemental irrigation can maximize production by:
· Allowing more dense plantings; · Ensuring that the crop establishes well; · Shortening the time that a young plantation takes to reach maturity; · Doubling the number of roots; · Increasing the bud formation in early spring; and · Increasing the time of photosynthesis.*
For these reasons, the often-quoted statement that jojoba needs little or no irrigation can be misleading. The plants do indeed need little for survival, but economic consideration may dictate that irrigation is essential. For a healthy, profitable crop in many dry areas, extra water will be necessary.
Different methods, ranging from furrow irrigation to elaborate and expensive sprinkler systems, as well as drip or underground biwall tubes, are being used. The choice depends on the availability and cost of water, the land form, and the soil type. Normally, growers install drip and sprinkler irrigation systems on sandy soils and furrow irrigation systems on heavier soils.
The average annual irrigation applied in the United States is 2-3 acre-feet of water (50-90 cm per hectare) for established plantations and 2,000-4,000 liters per plant under drip irrigation.
Desert soils, particularly those used for planting jojoba, are notoriously lacking in some elements. Like all crops, jojoba needs proper nutrition, but its optimum requirements are unknown at present. However, there are indications that the plant responds to nitrogen and zinc, especially on sandy soils. (Information from W. Feldman.) In general, though, most jojoba plantations have not been fertilized, and, so far at least, this has not obviously limited their productivity.
To provide income during the first few years while the plants are getting established, some growers plant another crop between the rows of jojoba. Asparagus, wheat, melon, barley, sesame, safflower, sorghum, and alfalfa have all been tried. In such cases the jojoba rows may be separated by as much as 15-24 feet (5-7 m). This reduces the amount of jojoba eventually produced, but intercropping suppresses weeds and helps protect the crop from desert winds that can literally sandblast the leaves off small tender bushes, or that can scarify leaf tissues, leaving them vulnerable to fungi and other disease organisms.
Intercropping, however, is not easy. The second crop can draw pests to, and water away from, the jojoba. So far, there have been many failures and few successes with intercropping jojoba in the United States.
Pests and Diseases
More than 100 species of insects have been identified on jojoba plants, but few cause any known economic damage. Thick hedgerows (normally an attractive habitat for insects and fungi) of jojoba have been growing for more than 14 years near Riverside, California, without requiring pesticides. On the other hand, spider mites, grasshoppers, and salt-marsh caterpillars have attacked some plants in Mesa, Arizona, and leafcutter ants have caused damage in parts of Latin America. And in 1985 a serious infestation of thrips and spider mites occurred in jojoba fields at Desert Center, California. These are ubiquitous pests, and similar attacks can be expected elsewhere.
On poorly drained, heavy soils, jojoba, like other crops, contracts waterborne fungal diseases – verticillium wilt, fusarium, pythium, and phytophthora, for example. In regions where soils drain well, this does not seem to be a problem. Fungal root diseases also can be a problem in nurseries. Alternaria species have been associated with jojoba, defoliating not only seedlings but also cuttings propagated under mist in greenhouses.
Wild vertebrates that may graze on jojoba foilage or fruit include birds, game animals, rabbits, and rodents. Livestock such as goats and cattle have also been known to feed on jojoba. Burrowing rodents, such as gophers, will often eat the roots. These problems can usually be reduced by fencing the fields or by setting traps.
Weeds are the single most serious pest problem. During a plantation’s early years of growth, they can be difficult to control. In the United States, Bermudagrass is one of the worst. Some growers recommend irrigating newly prepared fields to encourage the weeds to grow and then spraying herbicide before planting the jojoba crop.
The weed problem usually disappears after two years. By then, the weeds become shaded and suppressed by the growing jojoba plants.
It is the between-plant weeds that are the most troublesome; weeds between the rows are easily removed by cultivation.
Timing of herbicide application is important. Care must be taken to avoid causing the flowers (both male and female) to abort.
Jojoba seeds are harvested when they are fully mature. Earlier harvesting reduces the quantity of wax that can be extracted and diminishes the vigor of seedlings they produce. Jojoba is nonshattering, there is enough delay between the time the seeds mature and the time they drop to allow for harvesting the crop.
In many countries, mechanical harvesting is probably essential for commercial jojoba production. In Israel and the United States, large, over-the-row jojoba pickers – modified from grape, raspberry, and blueberry pickers – have worked reasonably well. The machines use layers of plastic fingers to flip seeds off the plants and onto belts that deliver them to containers on the harvester.
These pickers have received the most attention, but machines that suck up fallen seeds from the ground are also being tested. Vacuuming can best be done if the soil lends itself to crusting. If not, a form of net may be used to catch the seed. The system has the disadvantage that the suction may pick up dirt and rocks, but it has the advantage that the seed is mature, dry, and already dehulled when it falls off ring, and by selecting cultivars that ripen at the same time.
Because of their low-branching habit, jojoba bushes will require pruning before mechanical harvesters can be used. Removing basal branches can get the plant “up in the air,” making it amenable to mechanical harvest, but it is not yet known whether this will reduce yields. Some farmers suggest that pruning may reduce production by 20-30 percent.
4 Jojoba Oil
In 1935, research chemists at the University of Arizona found that the oil in jojoba seeds was totally unlike that secreted by any other plant. Conventional oilseed crops, such as soybean, corn, olive, and peanut, produce glyceride oils, in which fatty acids are connected to a glycerol molecule. Jojoba oil, on the other hand, contains no glycerides or glycerol. It is composed of fatty acids connected directly to fatty alcohols.
No other plant is known to produce liquids of this type (In recent years, loose claims that meadowfoam produces this kind of oil have been reported. However, it produces a glyceride oil much like rapeseed oil; to convert it into a jojobalike oil takes a series of chemical transformations). Jojoba apparently evolved unique enzymes and biosynthetic pathways to produce and metabolize (during seed germination) its unusual lipid. The chemical structure of the oil does not vary appreciably with plant type, growing location, soil type, rainfall, or altitude. For instance, plants throughout California and Arizona produce oil of virtually the same composition.
Most seeds contain between 45 and 55 percent oil, and average about 50 percent – more than twice the amount found in soybeans and somewhat more than in most oilseed crops. Extracting the oil is a straightforward process done with standard mechanical presses used for separating oil from peanuts, cottonseeds, soybeans, and other oilseeds. The presses extract about 76 percent of the oil in the first run and an additional 6-10 percent in a second pressing. Although all the remaining oil can be removed by solvent extraction, this is commercially impractical at present because too little seed is available to warrant its use. Experiments have shown that jojoba can also be extracted using carbon dioxide in the “supercritical process.”
A light-gold fluid, raw jojoba oil has few impurities, and for most purposes requires little or no refining. It contains no resins, tars, or alkaloids – and only traces of saturated wax, steroids, tocopherols, and hydrocarbons. Neutralizing is usually unnecessary because the oil is normally low in free fatty acids. Bleaching is also usually unnecessary, but simple commercial techniques (for instance, filtration through fuller’s earth) can be used to remove yellow pigments and produce a colorless product. For cosmetic and pharmaceutical use, the oil is frequently pasteurized to kill microorganisms.
Jojoba oil’s chemical structure is similar to that of sperm oil, but it is radically different from that of other vegetable oils. Of some 15000 plant oils tested at the U.S. . Department of agriculture, only jojoba had the liquid fatty acid/fatty alcohol ester structure. The straight chain alcohols and straight chain acids that form the esters chain acids that form the esters each have one double bond
The oil content in jojoba seeds varies from less than 30 percent to more than 60 percent. Selecting plants that yield seeds with a high oil content is a target for jojoba breeders. It is not easy to accomplish because both the female bush and the pollinating plant have an effect on inducing the high-oil trait in the seeds. For this histogram, oil contents were measured by wideline nuclear magnetic resonance. This is a nondestructive technique, allowing individual high-oil seeds to be selected and then planted out. (Information from L. Anderson, R. D. Benson, and W. O’Brien)
Jojoba oil is easy to work with. It is nontoxic and biodegradable. It dissolves readily in common organic solvents such as benzene, petroleum ether, chloroform, carbon tetrachloride, and carbon disulfide, but it is immiscible with methanol and acetone.
For many industrial needs, the oil has promising physical properties: high viscosity index, high flash and fire points, high dielectric constant, and high stability. It has low volatility and its composition is little affected by repeated heating to remarkably high temperatures – up to 570°F (300°C), for instance.
TABLE I Properties of Jojoba Oil (a)
|Freezing point||10.6-7.0°C||iodine value||82|
|Melting point||6.8-7.0°C||Saponification value||92|
|Boiling point at 757 mm under N2||398°C||Acid value||2|
|Smoke point (AOCS Cc 9a-48) (b)||195°C||Acetyl value||2|
|Flash point (AOCS Cc 9a-48) (b)||295°C||Unsaponifiable matter||51%|
|Fire point (COC)||338°C||Total acids||52%|
|Heat of fusion by differential|
|scanning calorimetry||21 cal/g||Iodine value of alcohols||77|
|Refractive index at 25°C||1.4650||Iodine value of acids||76|
|Specific gravity, 25/25°C||0.863||Average molecular weight of wax esters||606|
|MV-1 rotor in MV cup||35 cp|
|Plate and cone with Pk-1||33 cp|
|Brookfield, spindle #1, 25°C||37 cp|
|Cannon-Fenske, 25°C||50 cp|
|Cannon-Fenske, 100°C||27 centistokes|
|Saybolt, 100°F||127 SUS (c)|
|Saybolt 210 deg C||48 SUS (b)|
a) Oil from expeller-pressed jojoba seeds starts to freeze at 10.6°C (51°F). It solidifies into a thick paste at 7°C. Frozen oil, allowed to warm up, melts at 7°C (45°F). b) Smoke and flash points determined according to the official method, Cc 9a-48, of the American Oil Chemists’ Society. c) Saybolt Universal seconds. SOURCE: T. K. Miwa.
Jojoba oil also has good keeping qualities and an exceptional shelf life. This is apparently due to the presence of natural antioxidants (alpha-, gamma-, and delta-tocopherols), which occur in concentrations of about 50 ppm. In practical terms, these antioxidants keep the oil from becoming rancid, and companies processing raw jojoba oil are reporting very low acid values (0.2-0.3), even without neutralization.
In one experiment, seeds analyzed 25 years after harvest showed no change in composition. It appears, therefore, that the dry seeds can be stored without deterioration or chemical changes.
For a raw natural extract, the oil is remarkable for its molecular uniformity: it is 97 percent linear wax esters. (The remainder comprises free fatty alcohols and acids, and tocopherols.) It also has an amazing internal homogeneity – more than 87 percent of the esters present are combinations of acids and alcohols with chain lengths of 20 or 22 carbon atoms. By contrast, common vegetable oils have fatty acids whose carbon chain lengths are mostly 16 and 18.
The esters are composed almost entirely of straight-chain acids and alcohols. The acids are a mixture of eicosanoic (C20) and docosanoic (C22), with small quantities of palmitoleic (C18) and oleic (C16). The alcohols are a mixture of eicosanol and docosanol, with smaller quantities of hexacosanol and alcohols of lower molecular weight.
Jojoba oil esters are made up of fatty alcohols and fatty acids that are predominantly 20 or 22 carbon atoms long. Compared with most vegetable oils, the carbon chain lengths are remarkably uniform. (Information from T.K. Miwa)
The acids and alcohols that make up jojoba oil each have a single double bond. Moreover, all double bonds are in the W9 position (i.e., between carbon 9 and carbon 10, counting from the methyl end). This is a remarkable molecular purity, and the double bond position is different from that usually found in vegetable oils.
The nature of the oil can be grossly changed by reactions at the double bonds and ester functions, and many new products can result. One research laboratory in Israel, for example, has produced more than 40 different jojoba-based chemicals that appear to have commercial industrial applications.(Information from A. Shani and J. Wisniak)
Jojoba oil can be transformed into a remarkable array of products. Research chemists have already produced more than 40 different compounds of potential commercial significance. Many of these conversions are simple, cheap, and can be readily made on an industrial scale. Once jojoba oil becomes available in quantity, it promises to be a new raw feedstock for the chemical industry. (Based on information from P. Landis, A. Shani, and J. Wisniak)
TABLE 2: Alcohol / Acid Structures of Jojoba Oil Determined by Gas Chromatography and Mass Spectrometry
As in other natural oils, the double bonds in fresh jojoba oil are all in the cis configuration. However, they can be easily isomerized (twisted around in space), using as catalysts traces of selenium, nitrogen oxides, or active earth. This produces an equilibrium mixture with 20 percent cis and 80 percent trans double bonds. This simple process dramatically transforms the liquid into a soft, opaque cream resembling face cream. It can be stopped at various intermediate degrees of isomerization, resulting in a family of pastelike waxes with melting points of 50°-140°F (10°-60°C). This process can, for example, provide soft solids that melt on contact with human skin. These soft solids, therefore, could be attractive to the pharmaceutical and cosmetics industries. Their other properties also differ from those of cis-jojoba oil and they offer a promising field for experimentation.
Hydrogenation (commercially called “hardening”) is one of the most well-known transformations of fats and oils. Hardened vegetable oils are ingredients in shortening and margarine. Hardening jojoba oil through hydrogenation produces a crystalline wax.(To chemists, liquid jojoba oil is also a wax and they call the hard solid “hydrogenated jojoba oil.” In this report, we use the words jojoba oil and jojoba wax to distinguish the liquid from the hydrogenated solid) This lustrous, pearly white, crystalline solid has properties like those of beeswax, candelilla, carnauba, and spermaceti – all of which waxes are commercially in demand and subject to steeply rising costs and uncertainties of supply.
The hydrogenation process can be carried out with standard equipment used in the fats industry. It can be stopped part way to produce a range of soft-to-hard waxes, as desired.
Composed essentially of pure wax esters with no double bonds, jojoba wax is made up of saturated C20 and C22 fatty acids and alcohols. X-ray diffraction has shown that the ester molecules are lined up in hexagonal arrays, but the samples are not completely crystalline, probably because the slightly differing lengths of the carbon chains prohibit perfect ordering.
Jojoba wax is now available in quantities adequate for industrial purposes, and it appears to have considerable commercial promise. Hard waxes are in demand, but most are from wild species whose supplies are intermittent, haphazard, or declining. Carnauba wax, which is laboriously scraped from fronds of a palm that grows in Brazil, is in erratic and dwindling supply, and its price (fueled by greatly increased labor and transportation costs) is rising. Candelilla, another cuticular wax, is obtained by boiling the stems of a wild shrub found in Mexican deserts. Its supply, too, is uncertain, and for the same reasons. Spermaceti (the saturated form of sperm oil) was once an important hard wax, but its use in the United States and most other countries has been banned since the 1970s because of the sperm whale’s endangered status.
TABLE 3 Properties of Industrial-Grade Jojoba Oils
|Gardner color||Maximum – 9|
|Acid value||Less than 1.00|
|Total plate count||Less than 50/gram|
|Flash point||295 deg C|
SOURCE: T. K. Miwa.
Hardness is one of jojoba wax’s most outstanding characteristics. It is harder than beeswax but is slightly softer than carnauba. In fact, the hardness (which industrial chemists register-by melting point) of fully hydrogenated wax approaches that of the “king of waxes,” carnauba. Its melting point is about 158°F (70°C). Although this is slightly lower than that of carnauba, it is higher than that of most other waxes. Moreover, jojoba wax is sparkling, white, and crystalline, and in many applications may be superior to the yellow amorphous waxes such as carnauba.
Because it is produced from liquid, unsaturated oil, which is more readily and cheaply purified than a solid such as carnauba, hydrogenated jojoba wax can be made exceptionally pure. Where crystallinity is a disadvantage, jojoba wax can easily be made amorphous by adulterating it with small amounts of other waxes.
Jojoba oil’s double bonds offer chemical functionality that can be put to advantage to produce partially hydrogenated oils. This change produces a range of soft plastic waxes melting at temperatures up to 140°F (60°C). This offers alluring possibilities for industry because an array of soft white waxes and creams with a range of melting points can be produced to a given melting-point specification.
Jojoba wax has the capability to form a “gel” with many other chemicals. It has been found to improve the physical structure of many cosmetic products through special coupling mechanisms that allow two previously incompatible materials to be used together in the same formula. (Information from J. H. Brown)
Source: Jojoba: New Crop for Arid Lands, New raw Material for Industry Wikipedia.org [photo]