9 Research Needs

Basic research, the underpinning for the crop's future development, deserves greater support. Government agencies, foundations, corporations, and individuals who fund agricultural research should support jojoba studies. Some particular needs are listed below.

Agronomic Research

Agricultural Practices

Jojoba has demonstrated a favorable response to many of the practices and techniques currently used in agriculture, but research is needed to understand its unique properties that can be manipulated to coax the crop to reach its fullest potential. Among agronomic questions that cannot be readily answered with assurance are:

· What plant spacing is best?
· What ratio of females to males is best?
· When is the best time to irrigate, and how much should be applied?
· What is the best method to control weeds?
· What are jojoba's fertilization requirements?
· When is the best time to prune? How little, how much, and what part of the plant to prune?
· What criterion should be the basis for selecting superior plants?
· What is the best way to harvest: By hand? By machine? And what type of harvester: Over-the-row? Vacuum?
· What is the relationship between a superior plant at a young age and long-term performance?

All these questions point to valuable areas for research and testing.

Plant Selection

It is vital to find and replicate quality jojoba specimens. They will produce plantations that yield faster and several times higher than has

been possible heretofore. In making selections among different jojoba plants, the most significant yield components to consider are:

· Seed production at every node;
· Large seed size;
· High oil content in the seed;
· Late flowering (to escape frost damage);
· Precocity (for instance, starting seed production before the third year);
· Consistent production from year to year; and
· Upright growth habit (for easy harvesting).

To combine all these features in one superior variety will require years of persistent selection and testing. The recent availability of vegetative propagation, however, makes possible its more rapid accomplishment. It is desirable to measure the average annual yield of oil over as many years as possible before massively propagating any clone.

Some particular points of plant selection follow.

Reducing Plant Size. At present, the optimal biomass for maximum seed production is unknown. However, vegetative growth should be reduced as much as possible without severely reducing seed production. Dwarf varieties have less nutritional demand, they allow more plants to be grown per acre, and they can make harvesting easier.

Synchronizing Flowering. Many generations of breeding have gone into making conventional crops flower uniformly. All wheat plants, for example, flower within a few days of each other in many environments. Because most jojoba plantations have been established using heterogeneous seed, flowering is not synchronized. To get seeds maturing at the same time would be an important benefit to a grower. Research should focus on genetic traits as well as on management techniques. The goal should be to develop high-yielding clones that ripen uniformly and can be harvested in one pass.

Selecting Superior Males. So far, there has been little selection of male plants. Current types are variable: some have short flowering seasons, others long. To select male plants that produce an abundance of flowers, shed pollen over a long period, and result in superior seeds (with high oil content, for example) is a particular research need. In selecting superior males, some criteria to look for are: large clusters of flowers; tallness (so that the pollen disseminates well), plants whose pollen has long viability, and plants that produce pollen at the time when females are receptive.

Increasing Oil Content. It is important to select plants with a high percentage of oil in the seeds. The average oil content is 50 percent - a substantial figure - but seeds with 63 percent oil have been discovered. A diligent improvement project (which would be facilitated by a simple method for testing oil content) could almost certainly boost the oil content of the plantation seeds by 20 percent. This is important because the target for all growers, after all, should be not the seed yield per acre, but the oil yield per acre.

Harvesting

The question of how to harvest jojoba mechanically is a pressing one. This is not strictly an engineering challenge: the harvest's outcome depends on the plant and machine fitting together. A clone that may yield exceptionally may be prohibitively expensive to harvest. For example, some have short internodes and are tight bushes, and a mechanized picker requires a somewhat open bush that its "fingers" can comb through. (The density of the bush is less important if the seed is to be swept or sucked off the ground.)

Features that fit a plant to harvesting by picker are:

· Upright growth with a clear base for access;
· Maximal density for high yields, but not too dense for efficient picking;
· Uniform timing of female flower receptivity;
· Annually consistent female receptivity;
· Uniform maturity of seeds on each selected plant;
· Optimal fruit removal (requires assessment of natural dehiscence and the force needed to
shake seeds off);
· Flexible limbs that are not easily damaged by harvesters; and
· Minimal root and stem suckering (to keep open access to the base of the plants).

Combating Desertification

Claims have been made that jojoba has potential for overcoming "desert creep." This possibility deserves to be explored. In its favor, jojoba has a hardy, drought-tolerant nature. More importantly, it produces a high-value product in drylands, thus giving inhabitants an incentive to stay "on the farm" and protect their land from the advancing desert creep by growing other species that may halt the threatening sand dunes.

Product Research

Jojoba offers many areas for chemists and industrial researchers to explore. As noted previously, the oil has been transformed into at least 50 derivatives that seem to have commercial utility. This wealth of new compounds deserves careful evaluation and development. (Indeed, the whole topic of wax esters, whether they be from jojoba, from fish oils, or from synthesized materials, deserves much greater recognition from chemists. Useful first steps would be a comprehensive review paper, a symposium, or a book devoted to wax esters)

A few broad research subjects are highlighted here.

Lubricants

Qualification Testing. Jojoba oil has performed exceedingly well in small-scale diagnostic lubricant tests. It has not yet, however, been assessed in documented, full-scale trials conducted in actual operating equipment and compared against controls. This is a vital need.

Full qualification trials will take several years because the steps include formulating blends for different purposes, putting them into operating engines, and measuring performance features such as engine output, heat build-up, oil stability, and performance life (A paper identifying the requirements for completely evaluating jojoba Oil as a lubricant is available from R. M. Estefan, Southwest Research Institute, 6220 Culebra Road, San Antonio, Texas 78284, USA).

The cost for such an evaluation would be high: perhaps $250,000 for formulating and bench-testing blends, and perhaps $500,000 for in-service testing. But until this is done, uncertainty over jojoba oil's potential in the lubrication industry will remain. And without published evaluations that are accepted by the automotive industry, the oil cannot penetrate broad markets (For example, in most cases the vehicle manufacturer's approve, will be required if the vehicle's warranty is not to be voided).

Overcoming the High Pour Point. The fact that jojoba oil tends to solidify in cool weather is a particular problem if it is to be used as a base stock in the automotive industry in temperate-zone countries. Therefore, a particular research need is to find uses in which this is not a concern, or to lower the point at which the oil thickens. This latter might be tackled from the plant end - there are indications, for example, that growing jojoba in hot regions produces oil of lower molecular weight. It might also be tackled from the chemical end - jojoba oil can be trans-esterified with different acids and alcohols to produce many shorter chain esters with widely different freezing points and viscosities.

The high pour point is a problem mainly if the oil is to be used as a base stock. If used as an additive, it is unlikely to be a serious concern.

Derivatives as Lubricants. The straight oil has excellent metal-wetting properties and gives metal a slippery surface. The sulfurized oil is valuable at high temperatures and pressures, which create metal-sulfur links that chemically bond the jojoba molecule to the metal surface. But other derivatives with good lubricating qualities are also likely to be found. Adding dimercaptothiadiazole to the jojoba molecule, for instance, reduces the (already extremely good) coefficient of friction by 20 percent, and the product protects copper against corrosion at the same time (Information from P. Landis).

Cutting Oils. Jojoba oil might find a particular niche in cutting fluids that are used to cool, lubricate, prevent rust, and flush away chips in metal-working machines. Because these emulsions are aqueous and are continuously recycled, they grow bacteria and fungi, and because they get on workers' hands, even slightly toxic preservatives cannot be added. Jojoba, because it is largely resistant to microbial attack, may be of particular benefit in this application.

Jet Engine Lubricants. Its high-temperature stability and excellent viscosity index suggest the possibility of jojoba oil's use as an additive in jet engine lubricants. To assess this is an important research need. Its thermal and oxidative stability, as well as its decomposition products, would have to be analyzed.

Magnetic Memory Media Lubricants. The stable ester structure of jojoba oil might make it suitable as a lubricant for reducing frictional wear in floppy discs, digital tape, audio tape, magnetizable film, and other magnetic memory media.

Sperm oil is (or has been) widely used as an internal lubricant in audio and video recording tapes to reduce wear on the tape itself and on the recording/playback heads. With the demise of sperm oil, this is another use for which jojoba should be tested.

High-Temperature Oils

Jojoba oil's viscosity index is almost twice that of most petroleum oils. Although there is some disagreement over the actual number, it is in the range of 190 to 230, whereas the mineral oils are in the range of 90 to 100. Viscosity index is a measure of a liquid's change in viscosity with changing temperature. As they get hot, liquids with lower indexes get thinner than those with higher indexes. Normally an increase in viscosity index of just two or three points means a big improvement in the lubricating quality of an oil as it heats up. Jojoba oil with a viscosity index 100 points higher than average could boost low-grade oils even in small amounts. This possibility should excite the interest of all industries that want an oil to maintain its viscosity as it is heated.

Fermentations

Scores of widely used fermentations suffer from excessive foaming. Sperm oil was once commonly used to overcome this problem, but in its absence silicone oil or vegetable oils are used. Jojoba oil deserves investigation because it seems to have particular advantages over these. Unlike silicone oil it is biodegradable and should not build up a gummy layer inside the fermentation vessels and pipes. On the other hand, it is less biodegradable than conventional vegetable oils and is probably largely inert to most of the fermentation organisms. Thus it could be more effective than the triglyceride oils. Fermentations producing antibiotics, steroids, alcohol, and citric acid are some in which jojoba oil deserves testing as an antifoam.

Medicinal Effects

Possible Anti-Inflammatory Effects. Preliminary indications suggest that jojoba oil has beneficial effects on acute and chronic inflammation of the skin. The possibility that jojoba oil could be beneficial in the treatment of sunburn and perhaps more serious burns should be investigated.

The oil is absorbed into skin through secondary structures such as hair follicles (see picture page 51). Further research is needed into this percutaneous absorption, and particularly its effects on the inflammatory response. The research could involve in-vitro assays to look at the effects on neutrophils and the blastic response, as well as invivo assays on animals and humans.

Possible Antimicrobial Effects. Jojoba oil has shown antimicrobial effects in-vitro, and research to investigate its ability to counteract acute and chronic skin and other infections is warranted.

A particularly interesting research area is to test jojoba oil's effects on tuberculosis, leprosy, and brucellosis. The bacteria causing these diseases shelter inside "cocoons" of wax and are difficult to reach with antibiotics. (The current treatment for TB, for instance, requires that patients take medication each day for a year or more). The waxes are made up of esters whose chemical structure is like that of jojoba oil, although their chain lengths are much longer. Because of the chemical similarity, it seems possible that the liquid jojoba oil could help dissolve the solid wax coatings around the bacilli. An antibiotic used with jojoba as a "penetrating oil" might be a particularly effective combination. This suggestion is highly speculative, but in view of the widespread nature of these diseases, and their relative resistance to attack, the possibility deserves at least preliminary assessment.

Food

The idea of using jojoba oil as a low-calorie oil for human consumption is tantalizing. Potentially, it is the largest market of all for jojoba. Both the oil and the roasted seeds have long been eaten by Indians in the Sonoran Desert region, but extensive trials are necessary before jojoba can be approved for use as a modern foodstuff for sale to the general public.

So far, experiments in rats have shown no fundamental barriers to the concept of using jojoba oil as a foodstuff, but much more basic research is needed before the Food and Drug Administration or its equivalent overseas will authorize its use. This research should be carried out, but to complete it will take at least two-and-a-half years of concentrated research and an expenditure of an estimated $2.5 million, and there is no guarantee that some health hazard won't be uncovered.