List Of Topics:

Funding for research and development

IRRDB Research Strategy for Natural Rubber

Limiting factors to increasing productivity

Consumer demands and variability of properties

End user requirements

Widening the uses for natural rubber

Funding for research and development

Short-term goals

The last decades of the twentieth century have been characterized by an increasing concentration on short-term goals. Ever more rapid returns are sought on investment. Neither the natural nor the synthetic rubber industries are capable of thriving in such an environment. Glancing through the pages of the rubber trade press the reader is frequently assaulted with headlines which state that the current shortage of a particular polymer will be alleviated once plants being constructed come on stream in two or three years time. Viewed from the sidelines one might be tempted to consider that the purveyors of synthetic polymers are extremely tardy in implementing their investment plans, but one also knows that in the recent past there have been persistent low prices, excess capacities, and in some markets cheap imports.

It may appear perverse to begin with the problems of synthetic rubber supply and demand, but the key players in natural rubber consumption, that is senior executives in the major tyre companies, probably have a far greater appreciation of the problems experienced with the production of synthetic elastomers than they do those of the natural rubber industry. The reasons are partly the high degree of vertical integration between synthetic rubber production and tyre manufacture and partly geography. The latter is in general characterized by the sentiments that it is grown somewhere else, and if there are problems relating to long term investment then these are someone else’s problems, or those of the World Bank, to which such corporations contribute, albeit indirectly.

Finance for research

This global quest for short term remedies has had a serious influence on both the financial assistance available for development projects and for most scientific research which by its nature requires both a long time span and implies a high degree of risk. The finance available for development has decreased rapidly over the last twenty years: USAID fell from $1.2bn in 1986 to about $240m by 1997. Most of the limited funds available have had to be applied to the problems following wars, civil disturbances and natural disasters. The residue is being applied to the very worst cases of poverty in an attempt to provide some form of permanent alleviation. The funds which had been applied to earlier IRRDB projects via UNIDO and the Common Fund for Commodities are either no longer available, or have been diverted towards other, more immediate, problems.

A further inherent problem is that rubber, like cocoa, sugar and cotton, is an industrial crop. Most international aid is directed towards improving the performance of food crops. Industrial crops are supposed to be able to generate sufficient income to support their own research programmes, but tenaciously low natural rubber prices have eroded this ability. Furthermore, the major consumers have freely admitted that they have enjoyed a period of considerable prosperity because of these persistently low raw material prices, especially those for natural rubber.

The Economist Intelligence Unit’s publication, Rubber Trends, published an interview with M. Eric Bourdais de Charbonnière, Michelin's chief financial officer whose response to a question about raw material prices was: "Very kind. They [the raw material prices] are still very much in our favour. I think when you see raw material prices going up it will be both bad news and good news. It will be bad news for the cost of raw materials, but good news for world trade. So I am not very worried right now. I fear more cuts in raw material prices than an increase." Similar sentiments have been expressed by several other senior executives within the tyre industry.

New sources of funding

In its report to the International Rubber Study Group, and in a press release shortly after the IRRDB Annual Meeting, the Board clearly indicated that it is seeking new directions for funding. The Secretariat will be approaching several major consumers and it is hoped that either singly or collectively they may contribute towards financing some of the research and development work which is required to ensure a sustainable future for supplies of one of the tyre industry’s basic raw materials. An initial response to some informal approaches was that of mild surprise, but it seems that some senior executives within the major consumers are unaware of the basic problems which beset an industry based upon sylviculture.

The long delay between planting and harvesting possibly exceeds that required to commission new synthetic rubber capacity. Furthermore, in the case of new, or improved natural rubber capacity a great number of people are involved, whereas fresh synthetic rubber capacity "only" needs money. Until recent developments in the production of tree crops for energy generation, Hevea produced extremely rapid returns in relation to forestry in general. Nevertheless, within an environment where financial returns are sought within very limited time scales the idea of making plans for ten to fifteen years hence may appear completely alien to natural rubber’s major customers, although they must surely plan for the tyre industry to remain in existence over a similar time span.

Genetic modification of Hevea

The funds available for research in most industries have also been curtailed, although there are some notable exceptions: pharmaceuticals, electronics and genetic engineering certainly do not conform to this trend. Given the overall interest in genetic engineering, it is disappointing that Hevea appears to be receiving relatively little attention. In some respects this is very surprising. Firstly, unlike genetically-modified food, consumer response is far less likely to be unfavourable.

With the possible exception of chewing gum, natural rubber is not eaten, although it does come into close proximity with the human body in medical products and there has already been some highly ill-informed comments on the Internet concerning Hevea clones, although these are not true genetic clones. Secondly, the monoculture of rubber appears to have been achieved with few risks apart from the still-to-be-resolved problem of South American leaf blight. Moreover, rubber cultivation takes place within a far more controlled environment than most agriculture. In general, rubber seeds are not used by cultivators for propagation. In general, planting materials are obtained from a limited number of approved sources.

What might the application of techniques from genetic engineering achieve? Firstly, it may be possible to reduce the period of immaturity from seven years, or more in marginal areas, to four to five years. Secondly, it may be possible to engineer the tree to be capable of being tapped at far greater intervals without the application of stimulants, but with an increase in yield per tapping: this is analogous to the more rapid ripening of fruit. Thirdly, it may be possible to reduce the variability of the output, whether via the latex and/or the timber: this is analogous to the potatoes which have been engineered to produce less fatty chips (French fries).

Fourthly, it should be possible to incorporate disease resistance within the trees: this is being achieved with cereal crops. It may be possible to engineer Hevea to be less dependent upon temperature and water: that is to thrive at higher or lower temperatures and to survive periods of drought. It may be possible to reduce the protein levels in the output from selected trees, or otherwise engineer the latex to act as a source of specific chemicals available on tap. Finally, it should be possible to enhance existing breeding techniques. In most cases such operations are already being performed on a wide variety of other crops and there has already been some work on the use of Hevea to produce starting materials for pharmaceuticals.

The application of techniques from genetic engineering to rubber cultivation would clearly involve a long term programme and a considerable financial investment as trees are vastly more complex genetically that most of the perenial crops which are currently receiving so much attention. Nevertheless, the potential returns should be of interest to the tyre industry and other major consumers of natural rubber. Some further consideration is given to the potential for genetic engineering in the Research Strategy section of this Report.

Latex protein allergy

The unhappy combination of "someone else’s problems" with the current obsession with short-term goals is manifested forcefully in some of the consumer response to the latex allergy problem. There is clearly an American body of opinion which would seek to "cure" a relatively minor medical condition found in a group, the size of which is probably inflated by the avaricious legal and medical industries, by banning the use of latex gloves. This is despite their proven ability to act as a highly effective barrier against medical and other pathogens including AIDS. Such a policy has already led to banning latex gloves from some food handling operations: presumably salmonella poisoning is less dangerous than latex allergy!

Furthermore, little attention appears to being paid to the risks associated with replacement materials, some of which contain residual carcinogens (approximating to the residual proteins in latex products), or cause the emissions of lethal toxic materials, such as dioxin, during disposal. Moreover, with the exception of the recent allergy problem there is much evidence to suggest that natural rubber latex used in close proximity with human organs has not been the cause of harm, and such use has extended to over a century. It should be noted that most of the problems which have been encountered, both in surgery and in allergy, stem from the cornstarch dusting agent which is added to the bulk of gloves to assist donning and to prevent agglomeration in storage. Within North America the dusting agents with some attached protein fragments tend to become airborne in the low humidity conditions experienced under air-conditioning in hospitals and other health facilities. Many of the replacement materials do not enjoy the long record and as is well-known some "inert materials", such as silicone implants, have subsequently been found to be the cause of serious health problems.

Those who may be tempted to consider that these comments are is in someway "anti-American" should contrast the response to latex protein allergy with that of peanut allergy, which is a significant cause of infant mortality. On the basis of banning natural rubber latex one should prohibit the cultivation of peanuts and their incorporation in any food products. Similarly on this basis, the medical profession would test for an allergic response before administering penicillin, but the profession estimates that the few fatalities due to an allergic response are more than justified by the overall curing power of the material.

www.irrdb.com

Work has continued on improving the IRRDB web site on the Internet. The amount of information and the number of illustrations has been greatly increased and some attempt has been made to enhance the appearance of the pages, but no attempt has been made to use some of the latest techniques available as these are unlikely to be available to all searchers on the Internet and tend to require considerable amounts of time to use creatively. Thus, frames and some other "advanced features" have not been exploited.

The primary aim has been to make information about the IRRDB as widely available as possible. The second aim has been to make as much information about natural rubber as possible within the limitations imposed by time and copyright. In general this second aim has been broadly polemical. Thus it is hoped that the general "surfer" on the Internet will be made aware of many of the strengths of natural rubber as a material and of the relative poverty of those who produce the material, and that the low cost of natural rubber is contributing to a long period of relative prosperity in many of the major natural rubber consuming countries.

Clearly, like most web sites it is hoped that it improves access to related organizations, such as the International Rubber Study Group, and to Member Institutes who have constructed web sites, most notably those of the Malaysian Rubber Board (which is accessible from several points including latex protein allergy) and the Indonesian Rubber Research Institute. Some access is also provided to appropriate commercial sites, such as that of Rubber World.

IRRDB business meetings

The IRRDB Meetings in 1998 were limited to those of the Committee of Directors and Chief Executives and the Board and were hosted by the Malaysian Rubber Board in Kuala Lumpur. The Board Meeting was the first to be held under the rules of the New Constitution. The Committee of Directors and Chief Executives discussed IRRDB Research Strategy at considerable length and a consequence of this is that the latest version of this document is incorporated as part of this Annual Report.

The Board Meeting was chaired by Datuk Haron Siraj, who had skilfully steered the New Constitution into existence at the Annual Meeting in Vietnam in 1997. This was the final meeting to be attended by Datuk Haron, as well as by General Ismail and by Dr Sanit Samosorn of Thailand. General Ismail was frequently able to target many of the strategic issues and express them with a direct clarity: this skill will be greatly missed, as will his generous good humour. Dr Sanit was another major contributor to the affairs of the IRRDB over many years. M. J Campaignolle, the former Chairman of the Finance Committee, retired after the meeting of the Committee: a presentation had been made to hime in Vietnam during the previous year.

Datuk Dr Aziz, Director General of the Malaysian Rubber Board, was appointed Chairman under the terms of the new Constitution and will serve for two years. Dr Asril Darussamin, Director of the Indonesian Rubber Research Institute and M Omont of CIRAD-CP, were appointed as Vice Chairmen, each for a period of three years.

The Board approved the continuing employment of the Secretary, but consideration will be given to the location of the Secretariat, the cost of which might be lower in an appropriate Member "country", and the recruitment of an eventual successor. Mr M Cronin, the Assistant Secretary, retired at the end of the year, and was not scheduled for replacement in 1999, although provision was made for the ad hoc employment of Mr Cronin to provide cover if the Secretary is unavailable. Mr Cronin had made a major contribution through his editing of the proceedings of IRRDB seminars and workshops and through his friendly communications with many staff in Member Institutes. On retirement he was presented with a Malaysian pewter tankard.

M Omont was elected as Chairman of the Finance Committee: the other Members of which are: Mr Chakraband Chandanasiri from the Royal Thai Embassy in London, a representative from the Indonesian Embassy in London, Dr C S L Baker (Director of the Tun Abdul Razak Research Centre – TARRC) and Dr Wan Rahaman (Vice-Chairman of TARRC). It had been agreed that there is a need for continuity within the composition of the Finance Committee, although this is not clearly stated in the new Constitution. The Finance Committee had considered the introduction of interest charges on outstanding Membership Contributions, but had considered that this would be difficult to administer.

There was considerable discussion on the funding for the two IRRDB Germplasm Centres in the Côte d’Ivoire and Malaysia which had been created as a part of the IRRDB Germplasm Collection Programme in the 1980s. It was agreed that the Plant Breeding Group should report on the status of the IRRDB Germplasm Collections at the next Board Meeting in 1999. Amongst questions which need to be considered are whether it is necessary to maintain two collections and whether it is possible to depend upon a core collection of reduced size.

It was agreed that the sum in excess of £200,000 in the Research and Development Fund could be regarded as a reserve fund, but with the primary function of it being used to fund training and research.

Training

The Secretary was requested to re-circulate the criteria for Study Fellowships. Proposals for training were required to fall within those areas identified, which in the previous year had been identified as being priorities, namely:

• To extend Hevea cultivation into marginal areas (including agro-forestry and rubberwood production)

• To enhance smallholder income and quality of life; to include studies on the social status of tappers.

• To increase productivity

• To evaluate competitive land use

• To apply techniques from molecular biology to breeding

• Latex protein allergy

• Environmental protection, such as effluent treatment.

Some of these priority areas are socio-economic in character rather than scientific: greater emphasis needs to be placed upon such activities.

Directors of Member Institutes were requested to ensure that where training is to be performed within another Member Institute that the Director of that Institute is willing and able to perform the training before an application is submitted to the Secretariat. Similarly, where external training is envisaged, that the institution specified would in principle be willing to accept the candidate.

Due to the general shortage of funds applicants were requested to minimize costs (air travel can be very cheap and subsistence costs may also be low). Preference would be given to proposals which are of realistic length (two to three months is the normal length of study anticipated). Consideration could be given to applications which are beyond the normal limits set by the IRRDB (£3,000 for internal and £5,000 for external training) provided that the Member Institute making the application is able to provide the remaining funding.

All successful applicants will be expected to provide a comprehensive Report which will be circulated to all Member Institutes through the IRRDB Information Quarterly and probably via the Internet. Failure to provide such reportage may lead to the Member Institute making the application being penalized when submitting further applications. In appropriate cases the successful candidates may also be eligible for an IRRDB Travel Fellowship to inform members at a Workshop or Seminar held during an IRRDB Annual Meeting. Member Institutes would be expected to bear some of the costs involved.

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IRRDB Research Strategy for Natural Rubber

A major industrial raw material

Natural rubber is a major industrial raw material. Currently nearly 6.7 million tonnes are produced per annum. The worth of this has declined sharply in recent times, but was still worth approximately $6 billion (US) in 1998.

Production by small farmers

Natural rubber cultivation is a major source of income to many small farmers. The number of families involved in rubber cultivation globally is in excess of 20 million. Most are low income smallholders with plots of less than 2 ha. The major producing countries are shown in Table 1. A significant and increasing part of the productive area is situated in Least Developed Countries: Côte d’Ivoire and Vietnam, for instance.

Table 1: Natural rubber production (IRSG: 1998)

Importance of natural rubber to the tyre industry

Nearly 40 per cent of all rubber (natural plus synthetic) used is natural rubber. Between 60 and 70 per cent of natural rubber is consumed by the tyre industry where its excellent properties are sought both during manufacture and in the end product. Natural rubber provides excellent cohesive strength to brass-plated steel cord during manufacture. In service, natural rubber contributes several significant properties. Low internal heat generation is very important in tyres operating under high severity: this includes the tyres for earthmovers, aircraft, long-haul trucks and metro systems. The low rolling resistance afforded by natural rubber treads enables vehicles to use less fuel and is of considerable environmental significance. Natural rubber is highly resistant to cutting and tearing, and this is important in tyres used off-the-road, especially in mineral extraction. The excellent traction on snow and ice is highly appreciated in northern latitudes. The presence of natural rubber in tyres ensures safety and endurance in the final product.

National consumption patterns

Uptake varies greatly between countries – in some individual countries (notably France) the tyre industry consumes around 90 per cent of all natural rubber imported. Heavy duty truck tyres form the largest single market segment (in excess of 2 million tonnes) for natural rubber. Tyres for aircraft and earthmoving equipment are key outlets: both are highly demanding applications and reflect natural rubber’s excellent properties. Lesser quantities are used in passenger car tyres, but overall uptake in this sector remains highly significant.

Strong demand for natural rubber in tyres

Demand for tyres, especially for truck tyres, has been increasing for many years and there is no indication that this trend will alter. For instance, between 1991 and 1997 truck tyre production grew from 33 million to nearly 48 million units in the USA; and between the former year and 1998 German production grew from nearly 6 million to over 7 million units, and in India production grew from 6 million to 8 million units. On the other hand, natural rubber production can only grow at a modest rate due to the constraints imposed by tree crops. It takes from five to ten years to bring new, or replacement, plantings into production. Output is declining in one of the major producers (Malaysia) due to competition for land, labour for manufacturing industry and the higher returns available from other crops. To an extent these pressures are also liable to be experienced in parts of Thailand within the near future unless there are radical developments in cultivation and harvesting to improve the availability of natural rubber. Otherwise, faced with these pressures, major consumers may be tempted to switch to other far less environmentally-friendly materials, such as synthetic polyisoprene. Thus there is an urgent need for natural rubber producers to increase and improve their output whilst reducing their costs.

Diversity of end uses

Other end uses are extremely diverse. Disposable medical gloves provide a vital barrier against the spread of infection and disease, especially hepatitis and AIDS. Such gloves are mainly manufactured in natural rubber producing countries and have enabled a considerable overall increase in national earnings from natural rubber to be achieved within Malaysia, Thailand, Sri Lanka and elsewhere. Extruded thread, catheters and condoms are further latex products which are predominantly manufactured in latex producing areas.

Natural rubber finds markets in hose, belting and footwear as well as in many engineering components. This last group includes engine mounts for automobiles, bridge bearings, fenders, and bearings to protect buildings from external and internal sources of vibration, and as an extension of this, from earthquakes. The market size of this sector is difficult to quantify, but is believed to be at least 250,000 tonnes. Engineering components form an especially valuable market as the products, which are typically rubber-to-metal laminates, are of high value. Furthermore, they tend to consume high grade rubber which should be capable of commanding premium prices.

There is a growing tendency for natural rubber to be consumed within the producing countries (notably Malaysia), but large quantities are still consumed by the major industrial countries (Table 2).

Table 2: Natural rubber consumption (IRSG: 1998)

In some major producer/consumer countries, India for example, many components are still manufactured from natural rubber which are made from synthetic rubber elsewhere. The extremely low natural rubber consumption in Russia (only 6,000 tonnes in 1998) should be noted: this is due to its displacement by synthetic polyisoprene. It had been widely assumed that once the former Soviet economy became more open then natural rubber uptake would increase, but this has not happened.

Environmental significance

Natural rubber is an inherently environmentally-friendly, sustainable material as it not only uses minimal amounts of non-renewable materials in its production (Tables 3 and 4), but the rubber trees act as a sink for carbon dioxide and provide timber as a valuable co-product. As a carbon dioxide sink, it is only marginally inferior in this respect to the natural tropical forest which has been displaced. In terms of soil protection Hevea is comparable with natural forest cover, and provided that the best agricultural practice is adopted replanting and new planting should not lead to erosion. It is virtually the only raw material, other than rayon (in tyre cords), used by the automotive industry which falls into this desirable category. Thus, in environmental terms it is of considerable significance that the industry should continue to flourish.

Table 3: Energy inputs for natural rubber production (Giga Joule/tonne)

Table 4: Energy content (Giga Joule/tonne) of some synthetic rubbers

It should be noted that the natural rubber industry has not ignored the genetic potential available within the species. It is well-known that the main industry in both Asia and Africa was based upon a limited seed gathering expedition performed during the mid-nineteenth century. The industry was aware of its limited genetic base and in 1983 the IRRDB organized a major germplasm collecting expedition to the Amazon Basin in Brazil. This was financed from internal resources as was the establishment of two living germplasm collections, one in Malaysia, and the other in the Côte d’Ivoire.

Invironmental protection

As noted previously, natural rubber is an inherently environmentally-friendly raw material and is certainly the only industrial polymer available in substantial quantities which does not have an overwhelming burden of fossil fuel associated with its production (Tables 3 and 4). Having established a worthwhile set of environmental credentials it is essential that the natural rubber producing industry is environmentally sensitive and does not cause pollution either to the atmosphere or to water-courses. Most of the atmospheric pollution is associated with the odours involved either in primary or secondary processing: the majority is associated with the proteins which exist within the material. Such odours may be unpleasant, but are not believed to be harmful.

A considerable amount of water is associated with the production of latex concentrate and baled natural rubber and there is a substantial effluent problem unless measures are taken to ensure that such water is treated prior to its return to rivers and other water courses. Many techniques have been developed to reduce the effluent problem, but uptake has varied greatly from country to country. Thus, there is a need to disseminate existing "good practice" more widely. The IRRDB has established a limited number of Environmental Protection Fellowships to enable the technology available at the Rubber Research Institute of Sri Lanka to be transferred to other countries.

There is a continuing need to develop newer, more cost-effective methods especially for handling effluents from downstream activities, such as the manufacture of latex gloves where the operations are more difficult due to the presence of zinc and lack of space (manufacturing tends to take place in urban areas).

Some waste products are being converted into useful materials: methane can be generated as a source of fuel and some solid material can be used as fertilizer.

Global research strategy

A global research strategy for natural rubber must focus on activities which will increase productivity, especially when it is grown in marginal and non-traditional areas. The period of immaturity before trees can be exploited is a major problem for small-scale cultivators: this problem is exacerbated in "marginal" areas. There is an urgent need to enhance smallholder income (and the social status of tappers). In some areas a more integrated approach, known as agro-forestry, is needed: in this Hevea plantings are combined with the cultivation of other trees, food crops and animal husbandry.

One major change has occurred during the past two decades. In areas enjoying an appropriate infrastructure rubberwood has become a major by-product and in some areas, notably Malaysia, Hevea is now perceived as a major source of timber with the latex being tapped as a by-product. The timber finds both domestic and export markets (especially in Europe) and is used in furniture, as a light construction material and hardboard. In remote areas the timber is used as fuel both for domestic purposes and for drying rubber. Obviously, the timber is a further environmental credit where it displaces non-sustainable materials, such as some forms of timber and, more notably, thermoplastics. There is a need to ensure that trees are bred to optimize or maximize the output of rubber and timber to meet the needs of local conditions.

Further major issues include: the development of trees with greater tolerance to disease and climatic conditions; improved agricultural techniques to combat disease and other hazards; improving the consistency of natural rubber as an industrial raw material, improving effluent treatment from rubber processing plants, overcoming the latex protein allergy problem, and the application of biotechnology to the breeding of improved planting materials where the industry appears to be "falling behind" other tree cultivation.

Natural rubber productivity

Most of the traditional natural rubber producing countries are experiencing, or expect to experience in the near future, a severe shortage of labour to cultivate rubber. One obvious manifestation of this problem is the very high number of untapped trees in some countries, notably Malaysia, and the switch from Hevea cultivation to crops which are cheaper and more profitable to harvest, such as oil palm and fruits.

The time which trees take to reach maturity (five to ten years) is the cause of considerable difficulty to the industry and particularly to small farmers, the typical cultivators in the majority of natural rubber producing countries. Hence, there is an urgent need to reduce the period of immaturity before trees can be tapped. Table 5 shows what has been achieved so far. The data are old, but they are intended to demonstrate the advantage of reducing the period of immaturity.

Table 5

The breeding of improved varieties of Hevea to date has been a major agricultural success, especially in terms of increasing yield.

There has been limited success in breeding trees which are resistant to specific diseases and other conditions. Where such success has apparently been attained there is mounting evidence that in many cases present breeding techniques merely provide a transient protection as the pests or diseases adapt to overcome the "resistance". This is an area where newer and more radical techniques need to be introduced from the sphere of molecular biology to ensure more rapid development and more lasting achievements.

In some regions, especially where there is a shortage of land or labour, there is a need to cultivate Hevea under less than optimal conditions and this further reduces productivity and incomes. For instance, unfavourable soils and/or climates reduce tree growth and extend the length of time before which newly planted material can produce a financial return: in "marginal areas" it may take ten years before rubber can be harvested, as against a typical seven years in favourable areas. Techniques for enhancing productivity need to be developed within farming systems which are appropriate to small-scale family groupings.

Ways of enhancing productivity include:

1. ensuring that existing farmers use the best techniques currently available,
2. developing improved agricultural techniques, especially those appropriate to small farmers,
3. developing new planting materials, especially ones appropriate for marginal areas,
4. removing impediments to productivity, such as disease and the time for trees to reach maturity.

The "best available techniques" may not always be appropriate to specific locations and conditions. In some areas, notably parts of Indonesia, Papua New Guinea and Vietnam, rubber cultivation is being extended into areas where the native populations have been used to shifting cultivation. Hevea needs to be introduced alongside improved agricultural techniques to ensure that such populations enjoy the benefits of a stable, social environment. By their nature such communities have a rich and diverse heritage: Hevea cultivation techniques need to be developed to accommodate this.

A proposed Agroforestry project seeks to implement a specific type of agricultural practice in certain parts of Indonesia. In many cases it is necessary to improve overall agricultural practice to ensure that earnings are maximised. For instance, it is essential to ensure that smallholders have access to the most appropriate planting materials: these need to be suited to the specific environments and agricultural practices. As rubber trees are relatively slow to reach maturity it is vital that smallholders are able to exploit other crops on their plots whilst the rubber trees are in the immature phase.

There is a need to optimize harvesting methods to ensure that labour inputs are minimized and rubber output is maximized. The use of stimulation, with ethylene-
releasing chemicals, or ethylene as such, enables a marked reduction in tapping frequencies and is an important means of increasing productivity. Traditional tapping methods require trees to be tapped every second day (d/2). The figure demonstrates how the use of stimulants permits less frequent tapping: every third day (d/3); every fourth day (d/4), etc, with stimulation. Even if all the mechanisms of yield stimulation are not yet fully understood, a considerable amount of work has been developed on the subject in research institutes and by planters to enhance the benefits and to be aware of the dangers of detrimental effects upon the trees.

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Limiting factors to increasing productivity

There are several diseases and other conditions which seriously limit rubber cultivation: the three most serious are discussed below. There are other serious diseases, but it is believed that these three require urgent priority action.

South American Leaf Blight

The most severe disease is South American Leaf Blight (SALB). This disease is endemic throughout the rubber growing areas in the Americas and greatly inhibits output there. It also poses a major global threat. It is caused by a fungus, Microcyclus ulei, which defoliates rubber trees and frequently leads to their total loss.

Although Hevea is indigenous to Brazil the yield from cultivars in that country seldom reach those which are attained in Asia or Africa. SALB is capable of devastating rubber plantations and moderately disease resistant clones involve the exploitation of low yielding materials. In Brazil it is not possible to cultivate high yielding materials in the most favoured climatic regions although it is possible to cultivate Hevea in areas which are cooler or drier and far less prone to fungal attack.

Clearly, there is a need to develop planting materials which are capable of high yields in SALB-prone areas. At present SALB is restricted to the Americas, but there is an urgent need to improve phytosanitary techniques to ensure that the disease is not inadvertently introduced into Africa or Asia. Furthermore, there is an additional need to develop methods which would contain and eliminate SALB should it enter an existing disease-free region.

Corynespora leaf fall disease

The leaf fall disease caused by Corynespora cassiicola is in many ways similar to SALB, in that it is also caused by fungal attack and may lead to the total loss of plantings. It differs in that it is prevalent in much of Africa and Asia, as well as the Americas. It is capable of causing very serious losses and formerly "resistant" clones have now become prone to attack. The disease is especially severe in Indonesia and Sri Lanka, but there are few areas which are not affected to some extent.

At present the normal prophylactic action is to eliminate disease prone material and to replant with "resistant" trees. Clearly, there is a danger of loss in confidence if farmers discover that "resistant" material becomes prone to attack. Research must be directed towards controlling the pathogen, improving the methods of introducing resistance (possibly through the introduction of genetic engineering), and by new techniques in husbandry. Integrated pest management offers one promising approach.

Fatigue due to high yield

Tapping panel dryness (TPD) is a group of conditions which clearly have more than one cause and may, or may not, be reversible. The phenomena are associated with a major decline in the yield of latex from TPD affected-trees and is commonly found in high yielding clones. TPD is particularly common where Hevea is grown under less than optimal conditions, such as areas with poor soils, droughts, high winds, low temperatures and excessive heat, or excessive surface water. This form of TPD is linked to stress and may be reversible and, within limits, can be manageable. TPD has been the subject of an IRRDB cooperative research project using the limited resources of the IRRDB and the Member Institutes in China, India and Malaysia, but far greater effort is required to combat this major productivity-inhibiting factor.

Advanced techniques from biotechnology

Considerable advances are being made in bio-engineering which already promise very considerable gains in productivity and disease and pest resistance in a wide variety of crops. The techniques include genetic modification and tissue culture. Many of the techniques are essentially generic (that is they can be applied to many plants) and could, given sufficient financial backing, be applied to Hevea. Nevertheless, if the techniques are to be fully exploited there will be a key need to identify the DNA structure of the relevant organs within Hevea which relate to rubber production and timber quality.

As is well-known, many of the techniques are subject to stringent patent protection and there are major commercial dimensions to the application of such technology. Furthermore, it is probable that for some applications there would be an adverse consumer response to genetically modified materials, despite the wide acceptance of "tailor-synthesized" polymers from petrochemicals. Nevertheless, it is difficult to imagine that the natural rubber industry in the long term will prosper without the application of these advanced techniques, especially as these are already being applied to other tropical tree crops.

Some of the areas in which bio-engineering should be exploited include, at the present time:

1. Inducing disease resistance

2. Assist in increasing tolerance to drought and extreme temperatures

3. Reducing the period of immaturity

4. Increasing latex output and reducing tapping frequency

5. Reducing the variability of raw latex

6. Optimizing rubberwood production

7. Production of novel materials

8. Improving traditional breeding techniques

9. Using molecular markers

The last two listed above are currently being exploited to a limited extent. There have been several experimental applications of tissue culture and molecular markers are being exploited in connection with clonal identification; germplasm characterization, and genome mapping.

The pressure to protect developments in this area may create problems which are similar to those currently experienced in downstream projects where competitive commercial pressures restrict the free exchange of knowledge.



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Consumer demands and variability of properties

Natural rubber, as an industrial raw material, has to compete with a range of synthetic elastomers which enjoy a number of inherent advantages:

1. within limits they can be "tailor-made" to meet specific requirements,

2. in general, they are less variable in quality than natural rubber,

3. a wide range of materials is available from a limited number of sources,

4. important properties (resistance to oils, for instance) can be achieved.

Obviously, natural rubber enjoys a considerable competitive edge in certain critical properties: if it did not do so it would not have survived as an industrial material. Nevertheless, natural rubber is perceived by its major consumers as being variable in quality in comparison with its synthetic competitors. Furthermore, modern manufacturing technology is tending to place ever-increasing demands upon the suppliers of all raw materials. "Zero tolerance" is one concept which is difficult to balance with a natural material. In part it may be suspected that this variability is a consequence of the consumers demanding a low priced commodity, but there is also some truth in consumer assertions that natural rubber is more variable than it need be.

The variability can be partially diminished by greater control of natural rubber production - and this is one of the key aims of the CFC-funded African Natural Rubber Association (ANRA) Project where greater control of the production process should ensure a higher quality and more consistent material. There is certainly a need to apply similar techniques to other producers of "inferior quality" rubber in areas other than Africa.

A considerable amount of work has been performed by some of the major producers to reduce variability, although a certain amount can still be attributed to the variability inherent in a natural product. The techniques which can be employed to reduce this variability include:

1. the introduction of "best practice" on smallholdings and small estates to ensure that the rubber is not adulterated and that its inherent excellent properties are not lost through unskilled handling;

2. identifying the causes of variation within clones and between clones in terms of variability;

3. the establishment of modern processing facilities to ensure that the material produced for export, or local consumption, is in a form acceptable to major consumers;

4. the imposition of standards, controls and testing to monitor the quality of the rubber being produced.

There has been a considerable amount of effort, both at national and international levels, to introduce quality assurance schemes. Much rubber is produced in conformity with ISO 9000, and work is well under way to produce material in conformity with ISO 14000 - good environmental practice.

Certain countries and areas are far more advanced in the implementation of the above techniques than others. Malaysia introduced the Standard Malaysian Rubber scheme in 1965 which sought to ensure that Malaysian rubber would enjoy a competitive edge by being produced to a technical specification with a guaranteed level of quality. Measures were put in place to ensure that the specified quality was achieved, and the

Malaysian Government enabled smallholders to share in the benefits of the scheme by establishing processing factories to handle smallholder rubber (the MARDEC factories). Subsequently, MARDEC was to become involved in assisting in the development of rubber factories to further assist in the development of smallholder incomes. RISDA sought to introduce "best practice" onto smallholdings through training and by the establishment of small-scale (appropriate technology) group processing centres which aimed to improve the quality of the output and enhance incomes for a low capital investment. Many of the improvements could be achieved solely via the use of manual labour.

Many of these methods have been adopted elsewhere. There are now few countries which do not offer some system similar to the Malaysian SMR scheme: SIR in Indonesia; STR in Thailand, etc, but some countries still lag far behind. The ANRA project being funded by the Common Fund for Commodities is an example of an internationally-funded project which seeks to enhance the quality of rubber through the second and third aspects: improved factory processing and standardization/control.

It is probable that further scientific work to diminish this basic variability may produce some return. The proposed CFC-funded research into a processability measuring device may be of assistance in reducing some of the variability. However, there are other measuring techniques and it is not clear whether the fundamental priority is for further techniques rather than a project to bring about the application of existing good practice on a more general basis.
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End user requirements

Most rubber products are consumed within the rich nations of North America, Europe and Japan. In these countries there is strong consumer demand for health and safety and (to a much lesser extent) for environmentally-friendly products. Health and safety is a complex issue and is frequently driven by a lack of coherent, rational motives. Furthermore, it is relatively simple for unscrupulous competitors to exploit health and safety issues to another material's detriment.

The rubber industry is, like many industries, beset with health and safety problems, some of which have reasonable scientific foundations, such as the former association of occupational cancer with certain previously employed rubber chemicals. Others are much more difficult to justify in a world which "tolerates" lung cancer from cigarette smoking and an unacceptable level of road accidents. Examples of these include the presence of nitrosamines in a wide variety of rubber goods (both natural and synthetic) and the problem of latex protein allergy. These are significant phenomena which need to be more thoroughly understood so that appropriate measures can be taken to minimize their impact.

Latex protein allergy

Latex protein allergy has emerged as a serious threat, especially in the USA. A small number of individuals are sensitized to some of the proteins in latex. These are mainly health care workers who have been exposed to latex over a long period by their use of medical gloves. There can be no question that the main solution lies in the general adoption of existing good practice to lessen the spread of the allergy.

Techniques are known for producing low protein rubbers, but commercial uptake may not be sufficiently large to justify the cost of producing such modified materials, although it should be noted that the United States Government is providing limited financial support to fund research on guayule latex in which the protein content appears to be low. There is a continuing need to monitor the health of workers in the rubber processing sector who are exposed to high levels of natural rubber proteins, but do not appear to suffer health problems. This last appears to conflict with American allegations of a high incidence of "latex allergy" amongst workers in the US rubber industry.

Latex protein allergy, whatever its genuine status, would appear to pose a significant threat not only to latex but also to other products containing natural rubber. Thus, there is a danger to the industry of "appearing to be doing nothing". In the United States there is considerable pressure to ban the use of latex gloves in environments where there is no risk of exposure to pathogens. Thus, there are quasi-official documents which argue that latex gloves should not be used for food handling and in housekeeping tasks in hospitals and elsewhere. This represents a significant potential market loss and the risks require to be assessed through reputable independent research. Such research might also assess the true nature, and risk, of "airborne latex particles" (corn starch powders used in glove manufacture which allegedly convey latex protein allergens into the air conditioning systems of hospitals in the USA) and the already largely discredited "allergenic" tyre dust particles.

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Widening the uses for natural rubber

In the past, one of the primary aims of natural rubber research has been to establish new end uses for natural rubber, and to modify natural rubber for it to adapt to a wider variety of applications. Competitive commercial pressures have made research in this area more complex. Nevertheless, some innovations have failed to reach their full market potential. Furthermore, there is a great disparity in the uptake of natural rubber, both in tyres and in other products, between different geographical regions. Uptake is extremely low in Russia, but has greatly increased in Central Europe since the decline in influence of Russian polymer technology and the enhancement in the quality of manufactured products, such as tyres, from Central Europe. With what appears to be a slight excess of capacity in natural rubber production effort should be directed towards stimulating uptake.

Modified forms of natural rubber

There have been many research programmes which have sought to modify rubber to enable it to extend its range of end uses. The IRRDB has been associated with several of these: to produce liquid, powdered and thermoplastic forms of natural rubber. Work to produce a modified form with greater oil resistance and improved damping properties (epoxidized natural rubber) has also achieved some commercial success, but to date less than was originally expected. Unless there is a radical economic shift in the relative cost of natural rubber and petrochemicals, or in the perceptions of fossil fuel uptake, it is improbable that further work in this area will produce a significant opportunity for such products.

Blends with speciality synthetics

The most recent IRRDB project, and one of its most successful, sought to enhance the technology which would enable natural rubber to be blended with speciality synthetic rubbers, thus enabling natural rubber to capture, or recapture, some of the market share from synthetic rubbers, especially in those countries where synthetic rubbers have to be imported. This recent project produced techniques which enable natural rubber to be blended with nitrile rubber and EPDM - both of which are produced in large quantities, and in the case of the latter have rapidly expanding markets. Further work is needed to encourage more widespread adoption of this technology and to cover areas which remain to be explored. The technique is especially appropriate for countries like India which produce substantial quantities of natural rubber for domestic consumption, but lack major facilities for synthetic rubber production.

Earthquake protection of buildings

Probably, the most significant of these new uses is the application of natural rubber bearings to protect buildings from earthquakes. This technique was originally envisaged over fifteen years ago. There are now a substantial number of buildings mounted on rubber bearings in seismically-active areas. Furthermore, it is known that such buildings are able to cope with the forces involved in earthquakes to protect both the structures and the contents of such structures. Nevertheless, uptake is far less than might have been expected, especially as earthquakes remain one of the most serious threats to life and property in many parts of the world. Action is required to promote the technique to enable it to be employed on a scale comparable with the threat to life and social stability in earthquake-prone regions of the world.

Rubberized bitumen for roads

The addition of relatively small quantities of natural rubber, either in the form of latex or crumb, greatly enhances the properties of bitumen for road surface dressings and other applications. These improvements relate especially to wear and skid resistance: rubberized bitumen lasts longer in service and contributes to road safety. Like many seemingly excellent ideas market uptake has never matched its potential and further work seems to be justified to ensure that the technique is more widely known, especially in natural rubber producing countries where off-grade material should be able to find a ready outlet (one of the problems of this market is that high grade material is too expensive in comparison with the very low cost of bitumen - a by-product from the petrochemical industry).

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