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Forestry Engineering

Wood out of rubber

Study shows feasibility of using the trunk of the Pará rubber tree to manufacture furniture

ILLUSTRATION BY NANA LAHOZ WITH PHOTOGRAPH BY EDUARDO CESARRubber from the Pará rubber tree is still the best. It is used as a component for car  and truck tires in a proportion ranging from 16% to 40% and up to 100% for aircraft tires. In addition, the rubber is used to produce other products, such as surgical gloves and condoms. Natural rubber is softer, more flexible and resistant, and has higher impermeability and electric isolation capacity than synthetic rubber. The natural wealth provided by latex – the raw material extracted by means of incisions in and tapping of the bark of the Hevea brasiliensis tree trunk – is expected to increase by using this tree to make furniture. A study conducted by professor Francisco José do Nascimento Kronka, from the Forestry Institute, linked to the São Paulo State Bureau of the Environment, proved the technical and commercial feasibility of using the bark of the rubber tree when the production of latex diminishes – which occurs approximately 35 years after the tree is planted. “The bark of the rubber tree has already been successfully used in countries such as Thailand, Malaysia, Indonesia and Vietnam, in Southeast Asia,” says Kronka. “In 2008, when I was in Vietnam, exports of furniture produced from the rubber tree amounted to US$4 billion.”

“Brazil lacks a market for wood produced from rubber trees and most of this wood is burned in furnaces and boilers or used in isolated experiments, such as in the State of Mato Grosso, to manufacture clogs,” says Heiko Rossmann, secretary-director of Apabor, the rubber industry’s state trade association. This association was one of the five partnering institutions involved in Kronka’s study . The project lasted for five years and was funded by FAPESP under its Public Policies Research Program. The other partnering entities were Abimovel (the Furniture Industry Trade Association), Cati (the São Paulo State Bureau of Agriculture and Food Technical Service Coordinating Office), Sebrae (the Small Enterprise Support Service) and Cemad (the Votuporanga Technological Center for the Professional Training for Wood and Furniture Work) of Senai, the National Industrial Training Service. The Luiz de Queiroz College of Agriculture at the University of São Paulo (Esalq-USP) was the partner from the academic community.

Although the field of energy requires increasing amounts of biomass, the burning of wood from the rubber tree whitish in color, though it can be treated to acquire other colors is a considerable loss because this hardwood lends itself to the manufacturing of tables, chairs, beds and shelves, as well as to the production of laminated wood boards and plywood. “Carpenters to whom we showed the rubber tree wood were willing to pay 20 to 30 percent more than for pinewood (Pinus sp. or pine, from the trees commonly used for reforestation in Brazil) because the quality is better,” says Kronka, who has already visited several companies. He also showed wood from the rubber tree to pencil manufacturer Faber Castell. Rubber tree logs were sent to the company’s sawmill in the municipal region of Prata, State of Minas Gerais, for processing. This wood was then taken to the company’s plant in the city of São Carlos, State of São Paulo. “Company personnel analyzed the wood and it was successfully accepted for the manufacturing of pencils,” says Kronka. The result of another study conducted by Kronka is published on page 50 of this issue of Revista FAPESP.

According to the researcher’s study, the pine used in the pencil and furniture industries is expected to be in short supply in forthcoming years, thanks to a growing demand, which is higher than the current supply of planted trees. The demand for eucalyptus, another widely used tree for reforestation, should also be higher than supply in the next decade. Another important factor driving the need for furniture wood is the drop in wood extracted from native forests, because of the restrictions dictated by production quotas, environmental pressure, and distance from major consumption centers. “It’s a shame that this wood from rubber trees is burned,” says Kronka. He had heard that a sugarcane mill in the State of São Paulo, which produces sugarcane and electric power by burning bagasse and other agricultural residues, had purchased such wood for R$45 per ton. Meanwhile, according to the industry association, in March of this year, one cubic meter (m3) of Indonesian wood from rubber trees sold for US$66, a lower than average price because of the economic crisis of 2009. In November 2008, the average price of Indonesian wood from rubber trees had reached US$230 per cubic meter.

Eduardo CesarDeck chair: one of the furniture options made out of wood from rubber treesEduardo Cesar

In view of such a difference relative to the global market, it is very important to train the farmers involved with planting rubber trees on how to use the wood more productively. “We need clones (varieties) that adapt to cutting and constant thinning to straighten the trunks.” The measures studied by Kronka include the treatment of the wood after the tree is felled. “The wood must be cut into rafters and boards as quickly as possible and soaked for five-minute immersion in fungicide to avoid the fungi that attack recently-felled trees.” Then the wood must be soaked in insecticide and mineral solvent to avoid attacks by tree borer when the wood dries.

“This wood is incredibly valuable,” says researcher Paulo de Souza Gonçalves, from Empresa Brasileira de Pesquisa Agropecuária (Embrapa), the crop and livestock research enterprise, who has been involved research at IAC, the Campinas Agronomy Institute, since 1987. “The sale of wood could offset the investment in planting new groves, which cost about R$10 thousand per hectare,” adds Gonçalves. In his opinion, Kronka’s work should encourage better use of the rubber tree trunk and the adoption of more productive varieties, and increase the area of plantation, especially in the State of São Paulo, which accounts for 55% of Brazil’s production. The state’s output in 2008 came to 67.1 thousand tons of rubber. In Kronka’s opinion, there is an additional advantage to using the rubber tree wood “the furniture industry complex in the municipal regions of São José do Rio Preto, Votuporanga and Tupã is close to the state’s main rubber tree plantations.”

Brazil produced 123.1 thousand tons in 2008, or 1.2% of the world’s output, which is led by Thailand, accounting for 30.8% of the total output. Thailand, Malaysia, Indonesia and Vietnam account for 75,5% of the world’s rubber supply, followed by India, with 8.8%, and China, with 5.6%. In terms of consumption, Brazil’s needs in 2008 totaled 366 thousand tons of rubber, 3.5% of the world’s total. China is the biggest consumer, accounting for 29%. Brazil’s deficit is covered by imports totaling US$666.4 million, according to data provided by researcher Paulo Gonçalves. “The State of São Paulo alone has 14 million hectares that could be used for planting rubber trees,” he says. This region starts in the center of the state and extends northward. It includes the states of Mato Grosso, Bahia, Espírito Santo, Minas Gerais. The region also comprises millions of hectares in the north of the State of Paraná. Incentives for production are multiplying. In 2005, Apabor launched a planting campaign, the goal of which was to plant 250 thousand new hectares in 15 years. “The campaign resulted in private sector investments and 60 thousand hectares were planted up to 2008,” says Rossmann, from Apabor. “Nowadays, rubber plantations in the state amount to approximately 90 thousand hectares,” he adds. “The government should foster this culture by means of incentives and interest-free funding from the time the trees are planted until the seventh year, when latex collection begins,” says Marcelo Tournillon Ramos, president of the Sector Chamber of the Rubber Production Chain at the Ministry of Agriculture and director of Iteb, the Rubber Technological Institute in the city of Rio de Janeiro.

FRANCISCO KRONKA/IFHevea brasiliensis plantation in São Paulo: sale of wood offsets investment in the planting of new rubber treesFRANCISCO KRONKA/IF

The attempt to increase domestic production is ironical historically, because the commercial exploitation of rubber first started in Brazil, when latex was extracted from the rubber trees found in the Amazon Jungle. At the end of the nineteenth century, rubber accounted for approximately 40 percent of Brazilian exports. The industry’s fall began as a result of the widely-known stealing of approximately 70 thousand seeds taken to England by Henry Wickham in 1876. The idea was to implement plantations in Great Britain’s colonies in Southeast Asia. Initially, the seeds were taken to London’s Kew Gardens. Because of the loss of the seeds’ germinating power, only 4 percent of these seeds germinated. Approximately 1,900 seedlings survived, however, and were taken to the Botanical Gardens in Ceylon, currently named Sri Lanka, a British colony at the time. Some of the seedlings were then taken to Malaysia. Plantations were developed in Southeast Asian countries and the industrial production of rubber grew. Brazil, where rubber was still being extracted as before, was unable to keep up with growing global demand. The attempts to plant rubber trees in the Amazon Region, as exemplified by the experience of Fordlândia (see Pesquisa FAPESP issue 158), were unsuccessful because of a foliage disease caused by the Microcylus ulei fungus.

When the trees grow too close one to the other, the Microcyclus ulei fungus is devastating, especially in the region where the rubber tree comes from. “The disease spreads in hot regions with relatively high humidity,” says Gonçalves. In the natural habitat of the forests, rubber trees are only a few meters apart, and are separated by other trees that keep the disease from spreading. In São Paulo, the fungus that attacks the new leaves and prevents growth was detected in the region of Ubatuba, in 1961, on a plantation run by IAC. However, the north of the state is less humid; lower humidity acts as a barrier against the fungus. This adaptability was seen in the state’s earliest plantations, in 1917, on the Santa Sofia plantation, in the region of Gavião Peixoto. The farm was owned by Colonel José Procópio de Araújo Ferraz, a friend of Marshall Cândido Rondon, a military officer and explorer who had led the integration of the Amazon Region to the rest of the country by implementing telegraph services. Rondon had given thousands of rubber tree seeds to the owner of the farm. Twenty seven seeds germinated and in 1942 the IAC acquired seeds from these trees to plant them in experimental centers in the cities of Campinas, Ribeirão Preto and Pindorama.

Further studies were conducted in 1951, when Brazil started importing rubber from Malaysia; this rubber came from the trees that were the offspring of the seeds taken from the Amazon Region. The institute brought rubber tree seeds from Liberia, in Africa, and then it imported clones from Malaysia. Paulo Gonçalves and Francisco Kronka agree that this import-related dependence on a native tree is not a problem that will last forever. Soybeans, which are native to China, have powerful enemies in that country, as does the sunflower in the United States (Russia is the world’s biggest sunflower producer) and coffee in Ethiopia, where coffee trees are not planted. “We have examples such as sugarcane and soybeans, both of which came from Asia and did very well in Brazil,” he says.

FRANCISCO KRONKA/IFIdentification of genes of economic interest to help improve plantationsFRANCISCO KRONKA/IF

Hevea genetics
A better genetic understanding of the Hevea brasiliensis is expected to be part of a new phase for the rubber tree in Brazil, resulting in the possible increase of rubber tree plantations and the potential creation of a market for the wood in the furniture industry. The genetic characteristics of this tree were first unveiled at the State University of Campinas (Unicamp), under the coordination of professor Anete Pereira de Souza, from the Molecular Biology and Genetic Engineering Center. “FAPESP has funded several research projects and scholarship grants that will result in the functional genome of the rubber tree,” says Anete. “This study will locate genes of interest to identify the most productive and resistant rubber tree clones, especially those with the strongest resistance to the Microcyclus ulei fungus, the crop’s worst enemy. We intend to obtain a map with 200 functional markers associated with the genes responsible for economic characteristics,” says Anete. One of the objectives is to find the micro-satellites, the small DNA sequences that are repeated throughout an organism’s genome, or to find timely variations of this DNA (also referred to as Single Nucleotide Polymorphism/SNP), responsible, for instance, for tolerating cold temperatures. The control of this possible group of genes could extend the planting of rubber trees to states in the south of Brazil and to cooler countries.

The study is to be conducted on two recombinants, comprised of three types of clones (genetic variations) planted in Brazil. These plant populations for genetic mapping are being prepared by researcher Paulo de Souza Gonçalves, from IAC, who has studied rubber tree clones for 39 years. He and his colleagues from the institute have already registered 22 varieties, or cultivars, 17 of which were registered in 2009 alone; many of these were the result of projects funded by FAPESP. Most of the rubber tree plantations in the southeast of Brazil are the offspring of a clone from Malaysia, introduced into Brazil in 1952. This is the RRIM 60 clone, RRIM being the acronym for the Rubber Research Institute of Malaysia. This variety is planted in 80% of the rubber tree plantations in the State of São Paulo. Gonçalves, who does not use this collection in the recombinant populations, believes that the situation will lead to monoclonal planting, “which might lead to disastrous consequences, such as widespread epidemics of pests and diseases common to monocultures because of the absence of broad genetic variability in rubber tree plantations. Although this is not imminent, it is up to us, who are experts in this field, to warn rubber tree plantation owners of the possible risk of damages.

Gonçalves says that Brazil needs to set up a germplasm bank of rubber tree plants with the varieties of the plants found in a natural habitat. Such a bank almost materialized a few years ago. In the late 1970s, rubber producers from Malaysia and other production centers realized that there was a shortage of rubber tree varieties and entered into agreement through the International Rubber Research and Development Board/ IRRDB for the exchange of clones and the collection of new specimens from the plant’s original site, to result in new cultivars.

Bank in Malaysia
The expedition to collect the specimens was restricted to Brazil, because of IRRDB’s financial constraints, as reported by researcher and historian Warren Dean, from New York University, in his book Brazil and the struggle for rubber. The Brazilian government agreed to this measure, provided that it would benefit the country in the form of samples of all the specimens that would be collected. Brazilian researchers took part in the expedition, which began in 1981. Paulo Gonçalves, one of the expedition members, collected plants and seeds in the state of Rondônia. “Other colleagues went to the states of Acre and Mato Grosso.”

The researchers collected 64,723 seeds and 1,160 seedlings, according to Dean. Part of this material went to Malaysia and another part remained in Manaus. As a result, two in vivo plant germplasm banks were created (there are seed germplasm banks stored in cold chambers for future use), where the researchers could evaluate the agronomic and productive qualities of each specimen for the purpose of producing new varieties. Brazil has germplasm banks for sugar cane, coffee (considered exotic plants because they are not native to Brazil) and for manioc, which is native to the country. However, the Brazilian rubber tree collection was unsuccessful, because it was devastated by the Microcyclus fungus. “The plants might have survived had they been planted in the São Paulo state area that is the center of the rubber tree plantations,” says Gonçalves. He and Kronka, from the Forestry Institute, went to Malaysia recently and saw that the rubber tree collection there is well looked after. Several colleagues and experts in this field have already suggested to Gonçalves that Brazil should enter into an agreement with Malaysia to bring a clone from that country’s germplasm bank to plant in Brazil. Gonçalves, however, refuses to do so: “I’m terribly ashamed that we have to repatriate our own plants!” he says. Gonçalves has set up a germoplasm bank at IAC. It is still small, basically comprising cultivars planted in Brazil. The bank includes clones produced abroad and has no specimen from any plant originally collected in the Amazon Region. The collection has proven to be useful for the creation of new cultivars and for the populations that will be used in the genome-related work conducted by Anete.

The projects
1. Construction of a genetic-molecular map with micro-satellites and site mapping linked to tolerance of cold temperatures and other economically important characteristics of the rubber tree (nº 07/50562-4); Type Regular Aid for Research Project; Coordinator Anete Pereira de Souza – Unicamp; Investment R$ 186,230.32 and US$ 28,525.32 (FAPESP)
2. Obtaining a recombinant population for the mapping of economically important characteristics of the rubber tree [Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell.-Arg.] (nº 07/52922-8); Type Regular Aid for Research Project; Coordinator Paulo de Souza Gonçalves – IAC; Investment R$ 109,040.88 and US$ 8,654.00 (FAPESP)
3. Genetic improvement of the rubber tree (Hevea spp.) for the State of São Paulo (nº 96/01268-0); Type Thematic Project; Coordinator Paulo de Souza Gonçalves – IAC; Investment R$ 423,372.60 (FAPESP)
4. Availability of rubber tree (Hevea brasiliensis) wood as raw material for the manufacturing of furniture in the State of São Paulo (nº 03/06440-0); Type Public Policies Program; Coordinator Francisco José do Nascimento Kronka – Instituto Florestal; Investment R$ 225,499.30 (FAPESP)