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Naqvi, H.H. and I.P. Ting. 1990. Jojoba: A unique liquid wax producer from the American desert. p. 247-251. In: J. Janick and J.E. Simon (eds.), Advances in new crops. Timber Press, Portland, OR.

Jojoba: A Unique Liquid Wax Producer from the American Desert

Himayat H. Naqvi and Irwin P. Ting

  1. INTRODUCTION
  2. DISTRIBUTION AND ECOLOGY
  3. DOMESTICATION
  4. MAJOR AGRONOMIC PROBLEMS
    1. Low Yields
    2. Frost Damage
    3. Insect Pest Damage and Diseases
    4. Lack of Crop Management Protocols
  5. RESEARCH ACTIVITIES AT UC RIVERSIDE
    1. Yield Improvement
    2. Crop Ecophysiology
    3. Frost Tolerance and Field Management
  6. DISCUSSION AND CONCLUSIONS
  7. REFERENCES
  8. Fig. 1

INTRODUCTION

Jojoba, [Simmondsia chinensis (Link) Schneider] is a new oil-producing industrial crop that has attracted much attention in recent years (National Academy of Science 1985). Jojoba oil, which is commonly known as liquid wax, is colorless and odorless with unique physical and chemical properties. Unlike most other vegetable seed oils, which are triglycerides, jojoba oil is made of long-chain fatty acids and fatty alcohols with no side branching. This unique chemical configuration accords jojoba special characteristics unparalleled in the plant kingdom. It is similar to sperm whale oil and can be substituted for it in many applications (National Academy of Science 1985, Wisniak 1987). The most important uses are in the cosmetic industry, as a high-temperature high-pressure lubricant, and as a potential low-calorie edible oil. Other possible uses are as an anti-foaming agent in the fermentation industry and as a magnetic memory media lubricant. Jojoba oil can easily be hydrogenated into a soft wax and can be used in candle wax, various kinds of polishes, coating material for fruits and pills, and insulation for batteries and electrical wires.

Presently, most of the jojoba seed produced in the United States is used in the high-priced cosmetic industry, and many other potential markets have not been fully developed. It is probable that as production increases and the seed prices decrease, jojoba could penetrate into these much larger markets. There are, however, agronomic obstacles which must first be overcome to increase productivity. The most important among them include a shortage of high-yielding planting material and serious damage due to frost. Our jojoba research program at UC Riverside is designed to assist in these and other agronomic problems as well as to understand basic physiology and genetics of the species.

DISTRIBUTION AND ECOLOGY

Jojoba is a native to the Sonoran Desert. Most natural populations exist only inside a quadrangle with Riverside (California), Globe (Arizona), Guaymas (Sonora, Mexico), and Cabo San Lucas (Baja California, Mexico) as its four corners, and comprise about 100,000 square miles between latitudes 25° and 34° North. These disjunct jojoba populations occur from sea level to about 1,500 m altitude on coarse, sandy or gravelly soils with good water drainage. The rainfall in the area ranges from 75 mm to about 400 mm, and the plant communities are exposed to temperatures between -9°C and 50°C (Yermanos 1982).

Jojoba is a perennial, dioecious, evergreen shrub or small tree that lives under diverse environmental conditions. It has an extensive and deep root system and requires little care if maximum seed production is not desired. Jojoba is valuable as a soil conservation and landscape plant for highway shoulders, city parks, and other places that cannot afford much care.

DOMESTICATION

Jojoba has been well known by indigenous Amerinds living in what is now Sonora and Baja California who used jojoba seed and oil for cooking, hair care, and many medical treatments. The first taxonomic description appeared in 1822, when Johann Link of The Berlin Botanical Garden named it as Buxus chinensis. It was later changed to Simmondsia californica by Thomas Nuttall in 1844. Finally, in 1912, the Austrian botanist, Camillo Karl Schneider, renamed it as Simmondsia chinensis. Although earlier botanists placed jojoba in the family Buxaceae, many other botanists believe that it should be placed in its own family due to its morphological and anatomical distinctiveness.

The first experimental jojoba planting was established at The Boyce Thompson Southwestern Arboretum, in Superior, Arizona, in 1925. Later, jojoba seed from these and the wild stands in the area were sent to the University of Arizona at Tucson, for chemical analyses. A major breakthrough came in 1935, when the University of Arizona chemists declared the uniqueness of the jojoba seed compared to other conventional oil-seed crops. It was also established that jojoba oil was very similar to sperm whale oil which was commonly used as an important high-temperature and high-pressure lubricant. Many laboratories started working on the chemical nature of jojoba oil, and many patents were filed on its various applications. However, since sperm whale oil was readily available at that time, jojoba domestication and agronomic development lagged behind. Many plant explorers and botanists continued research into various aspects of jojoba distribution and natural history, which appeared in scientific publications during the following few years.

The greatest impetus to jojoba domestication came in 1969 when the Endangered Species Conservation Act was passed and sperm whales were put on the protected species list. In 1971, the United States banned the import of sperm whale oil, and the industry was forced to search for a substitute. Jojoba entered a new era of interest and industrial acceptability

Although small-scale experimental plantations of jojoba were already in existence at the University of California, Riverside, and other places by the end of the 1960s, a major jojoba commercialization activity centered around the San Carlos Apache Indian Reservation (Office of Arid Lands Studies and Midwest Research Institute, 1980). The U.S. Office of Economic Opportunity (OEC), in 1972, funded the first experimental harvest of jojoba seed at San Carlos Reservation. The overall goals of the harvest were to collect significant amounts of seed for extraction and distribution to research laboratories for evaluation, and to also provide a source of income for participating native Americans. Over 23 tons of dry jojoba seed were harvested during the first 3 years of the project; most of that was sent to process developers in the industry This project was turned into a big enterprise during the next few years. They continued to harvest approximately an average of 13 tons of seed per year during the 1975-1977 period, and it reached a record high yield of 30 tons in 1978. Realizing the importance of agronomic development of the plant, the San Carlos Apache Tribal Council, with the help of public funds, established a 9 ha jojoba plantation near the Dripping Springs cattle pens on the Reservation. Unfortunately, a record low temperature in the area killed about 85% of the plants. The following year, the Reservation also began operating its first jojoba seed processing facility, and San Carlos became a center of jojoba seed and processed oil. The San Carlos tribal enterprise entered into a contract with the University of Arizona for technical assistance in replanting the damaged pilot plantation on the reservation. The following winter was again very severe and the resulting freeze again resulted in a major failure on the Reservation. Some activities did continue for a time, but ultimately the project collapsed completely

The strong demand for jojoba oil in the late 1970s initiated a new era in the history of jojoba development in the United States. The popular press labeled it as the "golden wax," which lured many entrepreneurs and non-agricultural venture capitalists to jump on the band wagon. They rushed to buy large areas of land in the lower desert of California and Arizona, which was mostly under irrigated cotton crop previously. These lands were planted with wild-picked jojoba seed because of the unavailability of high-yielding varieties and the inexperience of the producers who rushed to get into the business.

According to Harington (1987), and McKay (1987), plantation establishments were initiated in 1978. By 1982, it reached about 8,000 ha, hit a peak of about 16,000 ha in 1985 and leveled off. The first harvest from these commercial plantations were made in 1982. Seed harvests continued as approximately 50 tons in 1823,200 tons in 1984,120 tons in 1985,470 tons in 1986, 500 tons in 1987, and over 1,000 tons harvested in 1988. Jojoba seed prices have also been fluctuating during the past few years (Watson, 1987). Seed were sold for about $3.00 per kg in 1976, continuously rose to over $10.00 per kg in 1981, and gradually declined to about $3.50 per kg in 1987. It is selling at a slightly higher price this year. There are two points that need mentioning here. The first is that most of the yields are based on only 20-25% of the total plantations that have been continuously harvested since 1982. The condition of the rest of the plantations is so poor that it did not justify harvesting them. According to estimates, about two-thirds of all the jojoba plantings have either been already abandoned, or will do so in the near future. The second point is that the yield increases during the last few years can be attributed to improvements made in some crop management practices, and the establishment of clonally propagated fields by some growers. Some public and private organizations played an important role in these accomplishments, but a lot more needs to be done in order to make jojoba a viable major industrial crop.

MAJOR AGRONOMIC PROBLEMS

Low Yields

According to a Jojoba Growers Association Report (1987), the average harvested yield for 1987 was about 130 kg/ha from vegetatively-propagated fields, and 92 kg/ha from seed-planted fields. Most of the vegetatively propagated fields had not reached their maximum potential at that time. Some individual growers reported up to 800 kg/ha from their small-scale upgraded seeded fields, and up to 2,000 kg/ha from their vegetatively propagated experimental plots. These were exceptions, rather than the rule. All the plantations in these yield surveys were irrigated, fertilized, and supposedly better managed. The significant yield increases in the vegetatively propagated fields indicates great potential for yield improvement through the development of high-yielding female clones.

Frost Damage

Frost damage is the major agronomic problem limiting successful cultivation of jojoba in the southwestern United States. Major damage has occurred in each of the last 5 years, mostly in Arizona. In jojoba, the process of flower initiation and development takes about 14 months. The timing of frost is very critical. Frost at anthesis may kill flowers, resulting in complete loss of seed production the following summer. Flower anthesis has coincided with frost episodes in many plantations in Arizona, causing significant losses.

Insect Pest Damage and Diseases

During the 1987 and 1988 harvest season, many growers in Arizona suffered serious losses due to pest damage. Some of the most common pests included thrips, citrus cutworm, stinkbug, grasshoppers, and loopers (Whittaker 1988) resulting in losses of up to one million dollars per year. Registration for pesticides for these insects is currently being sought by the jojoba Growers Association. Verticillium wilt, Texas root rot, dry root rot, and other diseases have been reported but serious crop damage has not occurred.

Lack of Crop Management Protocols

Management protocols are fairly straight-forward for those who grow conventional crops and buy improved seed and obtain management advice from their county or university extension services. Unfortunately, none of these facilities is available to the jojoba growers who must develop their own planting material and learn management on an ad hoc basis. Only a few of the scientifically oriented and financially stable growers have established working relationships with the university researchers and obtained helpful advice along with superior plant material. Help is practically non-existent for most jojoba and other new crop growers due to the changing research priorities in public institutions in the United States.

RESEARCH ACTIVITIES AT UC RIVERSIDE

The main objectives of the jojoba research program at UCR are to develop high-yielding and frost-tolerant jojoba cultivars and to understand the crop physiology of the plant in order to develop appropriate management practices (Naqvi et al. 1988a, 1988b).

Yield Improvement

Jojoba is a dioecious, cross-pollinated species although plants with hermaphroditic flowers can be found. Genetic variability is high. For example, seed yield from the progeny of a single plant varied from 210 g to 1,195 g per plant. One crop improvement strategy is to follow a recurrent selection program to increase the frequency of high-yielding plants in each generation. Some progress has been made (Naqvi and Ting, 1989) but for a perennial shrub like jojoba, this is a long-term approach. Short-term gain can be obtained by clonal multiplication of selected pistillate plants. Semi-green shoots root easily and permit rapid multiplication of a superior clone. Once the existing variability is exhausted, more desired traits in the population will have to be developed through recombination and perhaps biotechnological procedures. A systematic screening of our plants during the past two years suggests that jojoba germplasm at UCR has the potential to develop clones capable of producing over 4,000 g of seed per pistillate plant (Naqvi et al., 1988a). With approximately 2,000 pistillate plants per hectare, this could be a significant breakthrough (Fig. 1).

Crop Ecophysiology

A clear understanding of the ecology and physiology of a species is essential for developing proper cultural and management practices. Since jojoba is being developed as an arid land crop, water stress and low temperature are the important aspects of our investigations. Jojoba plants growing under 3 irrigation regimes at UCR, and also in a typical Baja California jojoba community near Boojum National Park, were monitored for leaf water potential and gas exchange parameters. Preliminary results suggest that jojoba is a drought-resistant plant that can survive under low leaf water potential. Moreover, it can adjust its photosynthetic apparatus to a high level of water-stress without becoming dormant. The orientation of the leaves, and stomatal adjustments help the plant favorably survive under these conditions. It is possible, under these circumstances, to obtain a reasonable yield without much irrigation. The next important question is to find out how much irrigation will be required to harvest a profitable yield.

Frost Tolerance and Field Management

Our research indicates that jojoba has the capacity to "supercool" to many degrees below the freezing point (Goldstein et al. 1989). The objective of the experiment was to determine if the water-balance of the plant affects its susceptibility to frost. Young leaves and buds of the jojoba plants grown under normal irrigation and water stress conditions were subjected to slow cooling in a refrigerated water bath programmed to go to -25°C. The appearance of isotherms on the recorder indicated the freezing of the tissue being monitored. The tissues collected from the water-stressed plants froze at -17°C, i.e., 5°C below the tissues collected from the well-irrigated plants. This indicates that a mild water stress to the plant before the onset of frost may help reduce frost damage.

DISCUSSION AND CONCLUSIONS

Jojoba is one of our first native plants to be grown as an oil-producing cash crop in the United States. It produces a product that is unique in the plant kingdom. Jojoba is very drought-resistant and can be grown on marginal lands in the southwest without replacing any existing crops. For optimum production, the crop needs irrigation, care, and a good cultivar.

Jojoba became partially commercialized before any standard cultivars were developed. Many aspects of crop management, including irrigation scheduling, frost protection, and pest and pathogen management, were also unknown. As a result, many of the early growers have vanished, and those that survived are facing serious problems. It is estimated that most of the existing plantations will have to be removed and re-established. There is a serious need for research into the areas of crop production and improvement.

At UCR, we have the largest collection of diverse jojoba germplasm that has been assembled during the past quarter of a century (Yermanos 1979, 1982). In our crop improvement programs, many potential clones capable of increasing existing yield have been identified and some have already been released to industry.

REFERENCES

Fig. 1. An improved jojoba selection at UCR Agricultural Experiment Station.
Last update August 27, 1997 by aw