| African oil palm | |
|---|---|
 | |
| African oil palm (Elaeis guineensis) | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Monocots |
| Clade: | Commelinids |
| Order: | Arecales |
| Family: | Arecaceae |
| Genus: | Elaeis |
| Species: | E. guineensis |
| Binomial name | |
| Elaeis guineensis | |
| Synonyms[2] | |
Elaeis guineensis is a species ofpalm commonly just calledoil palm but also sometimesAfrican oil palm ormacaw-fat.[3] The firstWestern person to describe it and bring back seeds was the French naturalistMichel Adanson.[4]
It is native towest andsouthwest Africa, specifically the area betweenAngola andThe Gambia; the species name,guineensis, refers to the name for thearea called Guinea, and not themodern country Guinea now bearing that name. The species is also now naturalised inMadagascar,Sri Lanka,Malaysia,Indonesia,Central America,Cambodia, theWest Indies, and several islands in theIndian andPacific Oceans. The closely related American oil palmE. oleifera and a more distantly related palm,Attalea maripa, are also used to produce palm oil.
E. guineensis was domesticated inWest Africa along the south-facing Atlantic coast. There is insufficient documentation and as of 2019[update][5] insufficient research to make any guesses as to when this occurred.[6] Human use of oil palms may date as far back as 5,000 years in Egypt; in the late 1800s, archaeologists discovered palm oil in a tomb atAbydos, Egypt, dating back to 3000 BCE[7] (but this information needs further investigation, due to recent reviews.[8][9] The oil found in Abydos may be just date oil or even animal fats).
It is the principal source ofpalm oil. Oil palms can produce much more oil per unit of land area than most other oil-producing plants (about nine times more thansoy and 4.5 times more thanrapeseed).[10]
E. guineensis is monocotyledonous.[11] Mature palms are single-stemmed and grow to 20 meters (66 ft) tall. Theleaves arepinnate and reach 3–5 m (10–16+1⁄2 ft) long. A young palm produces about 30 leaves a year. Established palms over 10 years produce about 20 leaves a year. Theflowers are produced in dense clusters; each individual flower is small, with three sepals and three petals.
The palm fruit takes 5–6 months to develop from pollination to maturity. It is reddish, about the size of a large plum, and grows in large bunches. Each fruit is made up of an oily, fleshy outer layer (the pericarp), with a singleseed (thepalm kernel), also rich in oil. When ripe, each bunch of fruit weighs between 5 and 30 kg (11 and 66 lb) depending on the age of the palm tree.
For eachhectare of oil palm, which is harvested year-round, the annual production averages 20 tonnes[citation needed] of fruit yielding4,000 kg of palm oil and750 kg[citation needed] ofseed kernels yielding500 kg of high-quality palm kernel oil, as well as600 kg of kernel meal. Kernel meal is processed for use aslivestock feed.[12]
All modern, commercial planting material consists oftenera palms or DxP hybrids, which are obtained by crossing thickshelleddura with shell-lesspisifera. Although common commercial germinated seed is as thick-shelled as thedura mother palm, the resulting palm will produce thin-shelledtenera fruit. An alternative to germinated seed, once constraints to mass production are overcome, are tissue-cultured or "clonal" palms, which provide true copies of high-yieldingDxP palms.[citation needed]
Size: 1,800megabase. First sequence available in 2013.[11]
Diploid, with a diploid number of2n = 32.[11]
The Asianeffective population size is very limited. Thecultivars comprising cultivation in Asia descend from only four trees, which are themselves probably the result of aselfing of one parent.[13]
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Unlike other relatives, oil palms do not produceoffshoots; propagation is by sowing theseeds.
Severalvarieties andforms ofE. guineensis have been selected that have different characteristics. These include:[14]
Before the Second World War, selection work had started in theDeli dura population in Malaya. Pollen was imported from Africa, and DxT and DxP crosses were made. Segregation of fruit forms in crosses made in the 1950s was often incorrect. In the absence of a good marker gene, there was no way of knowing whether control of pollination was adequate.
After the work of Beirnaert and Vanderweyen (1941), it became feasible to monitor the efficacy of controlled pollination. From 1963 until the introduction of the palm-pollinating weevilElaeidobius kamerunicus in 1982, contamination in Malaysia's commercial plantings was generally low. Thrips, the main pollinating agent at that time, apparently rarely gained access to bagged female inflorescences. However,E. kamerunicus is much more persistent, and after it was introduced,Deli dura contamination[clarification needed] became a significant problem.[citation needed] This problem apparently persisted for much of the 1980s, but in a 1991 comparison of seed sources, contamination had been reduced to below 2%, indicating control had been restored.[citation needed]
A 1992 study at a trial plot inBanting, Selangor, revealed the "yield of Deli dura oil palms after four generations of selection was 60% greater than that of the unselected base population. Crossing the dura and pisifera to give the thin-shelled tenera fruit type improved partitioning of dry matter within the fruit, giving a 30% increase in oil yield at the expense of shell, without changing total dry matter production."[15]
Croset al., 2014 findgenomic selection is very effective in this crop.[16]
In 2013, the gene responsible for controlling shell thickness was discovered, making it possible to verify tenera (DxP) status while palms are still in the nursery.[17]
TheDEFICIENS gene regulatesfloral architecture. One of itsepialleles,Bad Karma, reduces yield.[18]
E. guineensis is almost entirely pollinated by insects and not by wind.[CT 1]Elaeidobius kamerunicus is the most specially adapted pollination partner in Africa.[19][CT 1] It has been deliberately introduced[19] into southeast Asia in 1981 and the results have been dramatic[CT 1] – Cik Mohd Rizuan et al., 2013 find good results inFelda Sahabat [my] inSabah.[19] Contrary to earlier speculation, the introduced population was not tooinbred, andinbreeding depression was not the cause of some incidences of lessenedfruit set in SEA. Other causes have been proposed.[CT 1]E. kamerunicus and the pollination it provides can be negatively affected bynematodes.[CT 1]
Worldwide the two most impactful diseases areGanoderma orbiforme (syn.Ganoderma boninense, basal stem rot, BSR, reviewed by Chonget al., 2017[20]) andPhytophthora palmivora (bud rot, reviewed by Torres et al. 2016[21]).[22] The earliest stages of data gathering and investigation have been performed fordisease resistance breeding howeverpropagation material is not available and fullbreeding programs are not ongoing as of 2015[update].[CT 2]
Basal stem rot[23] is the most serious disease of oil palm in Malaysia and Indonesia. Previously, research on basal stem rot was hampered by the failure to artificially infect oil palms with the fungus. AlthoughGanoderma had been associated with BSR, proof of its pathogenicity to satisfy Koch's postulate was only achieved in the early 1990s by inoculating oil palm seedling roots or by using rubber wood blocks. A reliable and quick technique was developed for testing the pathogenicity of the fungus by inoculating oil palm germinated seeds.[24]
This fatal disease can lead to losses as much as 80% after repeated planting cycles.Ganoderma produces enzymes that degrade the infected xylem, thus causing serious problems to the distribution of water and other nutrients to the top of the palm.[25]Ganoderma infection is well defined by its lesion in the stem. The cross-section of infected palm stem shows that the lesion appears as a light brown area of rotting tissue with a distinctive, irregularly shaped, darker band at the borders of this area.[26] The infected tissue become as an ashen-grey powdery and if the palm remains standing, the infected trunk rapidly becomes hollow.[27]
In a 2007 study in Portugal, scientists suggested control of the fungus on oil palms would benefit from further consideration of the process as one of white rot.Ganoderma is an extraordinary organism capable exclusively of degradinglignin tocarbon dioxide and water; celluloses are then available as nutrients for the fungus. It is necessary to consider this mode of attack as a white rot involving lignin biodegradation, for integrated control. The existing literature does not report this area and appears to be concerned particularly with the mode of spread and molecular biology ofGanoderma. The white rot perception opens up new fields in breeding/selecting for resistant cultivars of oil palms with highlignin content, ensuring the conditions for lignin decomposition are reduced, and simply sealing damaged oil palms to stop decay. The spread likely is by spores rather than roots. The knowledge gained can be employed in the rapid degradation of oil palm waste on the plantation floor by inoculating suitable fungi, and/or treating the waste more appropriately (e.g. chipping and spreading over the floor rather than windrowing).[28]
Markomet al., 2009 developed and successfully used anelectronic nose system for detection.[29]
Phytophthora palmivora[21] has caused a loss of 5,000 hectares (12,355 acres) ofE. guineensis nearSan Lorenzo inEcuador. Theprotozoa cause bud rot (Spanish:pudrición del cogollo). In reaction, growers there replanted using a hybrid ofE. guineensis andE. oleifera, the South American oil palm.[30]
Endophytic bacteria are organisms inhabiting plant organs that at some time in their life cycles can colonize the internal plant tissues without causing apparent harm to the host.[31] Introducing endophytic bacteria to the roots to control plant disease is to manipulate the indigenous bacterial communities of the roots in a manner, which leads to enhanced suppression of soil-borne pathogens. The use of endophytic bacteria should thus be preferred to other biological control agents, as they are internal colonizers, with better ability to compete within the vascular systems, limitingGanoderma for both nutrients and space during its proliferation. Two bacterial isolates,Burkholderia cepacia (B3) andPseudomonas aeruginosa (P3) were selected for evaluation in the glasshouse for their efficacy in enhancing growth and subsequent suppression of the spread of BSR in oil palm seedlings.[32]
Little leaf syndrome has not been fully explained, but has often been confused with boron deficiency. The growing point is damaged, sometimes byOryctes beetles. Small, distorted leaves resembling those due to a boron deficiency emerge. This is often followed by secondary pathogenic infections in the spear that can lead to spear rot and palm death.[33]
Cadang-cadang disease is a viral disease that also infectscoconuts.[34]
Red ring disease is caused byBursaphelenchus cocophilus,[35] see§Nematode pests below.
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Besides direct damage to plant material, insects are alsovectors of oil palm diseases.[CT 3]
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M. plana is aLepidopteranmoth and a major pest ofoil palms in Malaysia.[36]M. plana outbreaks inMalaysia are highlycorrelated withrelative humidity.[37] Relative humidity estimates based onsatelliteremote sensing data were fed into bothregression models andneural networks.[37] Thepredictions of both were found to be closely correlated with actualM. plana appearance on plantations, with the NN producing the best results.[37]
As of 2012[update]R. indica was invading theYucatan[W 1] placing 11states of Mexico underphytosanitary vigilance.[W 2]
R. ferrugineus has placed 13 states of Mexico under phytosanitary vigilance.[W 2]
Other arthropods include:Bagworm moths (the Psychidae family), the coconut rhinoceros beetle (Oryctes rhinoceros),[38]Rhynchophorus palmarum (the South American palm weevil),Tirathaba mundella (the oil palm bunch moth), andTirathaba rufivena (the coconut spike moth).
Besides direct damage to plant material, rats also predate onElaeidobius kamerunicus, the African palm pollinatingweevil.[CT 4]
Chimpanzees (Pan troglodytes) are known to use stones to crack open the nuts ofE. guineensis, a rare example oftool use by animals.[39]
Grey parrots (Psittacus erithacus) are known to prefer oil palm fruit in the wild.[40] One of their chief predators, thepalm-nut vulture (Gypohierax angolensis),[41] also heavily depends on oil palm fruit for its diet, making up over 60% of the adult bird's diet and over 90% of the juvenile bird's diet (along withRaffia palm).[42]
| This sectionneeds expansion. You can help byadding to it.(November 2020) |
Bursaphelenchus cocophilus is a nematode pest which is better known for infectingcoconut palms.[43][35] (It also afflicts a few other of theArecaceae.)[35] It causes "red ring disease", so named because it produces a red colored layer within the trunk of the tree, which looks like a red ring in a cross section cut.[43]B. cocophilus is obligately transmitted as the third juvenile stage byvectors, specifically several species of weevil.[35] Unlike congenerB. xylophilus there arenot thought to be any non plant hosts to serve asreservoir hosts for infection ofE. guineensis.[35] Besides direct infestation of the palm, other nematodes infest the pollinating weevilElaeidobius kamerunicus, reducing pollination and yield.[CT 1]
Because each tree is relatively big and has an individual value, information about its pest and disease status is valuable. Although visual inspection is the oldest method, others are under development or occasional use.[44]
Volatiles andmicrofocus X-rayfluorescence are two methods can be used to non-invasively detect pre-emergenceGanoderma orbiforme disease as a lab test.Sonic tomography is already in use with good results, at 96% accuracy. On the other handsatellite imagery andcomputer vision has low classification accuracy as to severity.[44]
Oil palms were introduced toJava by the Dutch in 1848,[45] and toMalaysia (then the British colony ofMalaya) in 1910 by Scotsman William Sime and English banker Henry Darby. The species of palm treeElaeis guineensis was taken to Malaysia from Eastern Nigeria in 1961. As noted it originally grew in West Africa. The southern coast of Nigeria was originally called the Palm oil coast by the first Europeans who arrived there and traded in the commodity. This area was later renamed the Bight of Biafra.
Intraditional African medicine different parts of the plant are used aslaxative anddiuretic, as a poison antidote, as a cure forgonorrhea,menorrhagia, andbronchitis, to treat headaches andrheumatism, to promote healing of fresh wounds and treat skin infections.[46]
InYoruba religion, it is associated with its creation myth as the first tree thatỌbatala finds descending to earth; it is also believed asỌrunmila'saxis mundi connecting heaven and earth. Thus, oil palm fronds often mark areas of sacred religious important or incorporated in traditionalorisha garment; its kernels are also prepared to use as a tool of receiving Ọrunmila's words to thebabalawo.[47]
In Cambodia, this palm was introduced as a decorative plant in public gardens, itsKhmer name isdôô:ng préing (doong=palm, preing=oil).[48]
In Malaysia, the first plantations were mostly established and operated by British plantation owners, such asSime Darby andBoustead, and remainedlisted inLondon until the Malaysian government engineered their "Malaysianisation" throughout the 1960s and 1970s.[49]
Federal Land Development Authority (Felda) is the world's biggest oil palm planter, with planted area close to 900,000 hectares in Malaysia and Indonesia. Felda was formed on July 1, 1956, when the Land Development Act came into force with the main aim of eradicating poverty. Settlers were each allocated 10acres of land (about 4hectares) planted either with oil palm or rubber, and given 20 years to pay off the debt for the land.[50]
After Malaysia achieved independence in 1957, the government focused on value-added of rubber planting, boosting exports, and alleviating poverty through land schemes. In the 1960s and 1970s, the government encouraged planting of other crops, to cushion the economy when world prices of tin and rubber plunged. Rubber estates gave way to oil palm plantations. In 1961, Felda's first oil palm settlement opened, with 3.75 km2 of land. As of 2000, 6855.2 km2 (approximately 76%) of the land under Felda's programmes were devoted to oil palms.[51] By 2008, Felda's resettlement broadened to 112,635 families, who work on 8533.13 km2 of agriculture land throughout Malaysia. Oil palm planting took up 84% of Felda's plantation landbank.[52]
Felda's success led to the establishment of other development schemes to support the establishment of small-farmer oil palm cultivation. The Federal Land Consolidation and Rehabilitation Authority (FELCRA) was established in 1966[53] and the Sarawak Land Consolidation and Rehabilitation Authority (SALCRA) was formed in 1976.[54] The primary objective of these organizations is to assist in the development of rural communities and reduce poverty through the cultivation of high yielding crops such as palm oil.[53][54]
As of November 2011[update], SALCRA had developed 18 estates totalling approximately 51,000 hectares. That year the organization shared dividends with 16,374 landowners participating in the program.[55]
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Oil is extracted from both the pulp of the fruit (palm oil, an edible oil) and the kernel (palm kernel oil, used in foods and forsoap manufacture). For every 100 kg of fruit bunches, typically 22 kg of palm oil and 1.6 kg of palm kernel oil can be extracted.
The high oil yield of oil palms (as high as 7,250 liters per hectare per year) has made it a common cooking ingredient inSoutheast Asia and the tropical belt of Africa. Its increasing use in the commercial food industry in other parts of the world is buoyed by its cheaper pricing,[56] the high oxidative stability of the refined product,[57][58] and high levels of natural antioxidants.[59]
The oil palm originated inWest Africa, but has since been planted successfully in tropical regions within 20 degrees of the equator. In theRepublic of the Congo, or Congo Brazzaville, precisely in the Northern part, not far fromOuesso, local people produce this oil by hand. They harvest the fruit, boil it to let the water evaporate, then press what is left to collect the reddish-orange-colored oil.
In 1995, Malaysia was the world's largest producer, with a 51% of world share, but since 2007,Indonesia has been the world's largest producer, supplying approximately 50% of world palm oil volume.
Worldwide palm oil production for season 2011/2012 was 50.3 million metric tons (55.4 million short tons), increasing to 52.3 million metric tons (57.7 million short tons) for 2012/13.[60]In 2010/2011, total production of palm kernels was 12.6 million metric tons (13.9 million short tons).[61]In 2019 total production was 75.7 million metric tons (83.4 million short tons)[62]E. guineensis is among the few tropical tree crops (along with bananas and citrus) with high productivity in actual growing conditions, i.e. outside of test plots.[13]
TheUrhobo people of Nigeria use the extract to makeamiedi soup.
The social and environmental impact of oil palm cultivation is a highly controversial topic.[63][64] Oil palm is a valuable economic crop and provides a major source of employment. It allows many small landholders to participate in the cash economy and often results in the upgrade of the infrastructure (schools, roads, telecommunications) within that area.[citation needed] According to theIBGE oil palm is a common crop inagroforestry practices in theAmazon.[65][66] However, there are cases where native customary lands have been appropriated by oil palm plantations without any form of consultation or compensation,[67] leading to social conflict between the plantations and local residents.[68] In some cases, oil palm plantations are dependent on imported labour or illegal immigrants, with some concerns about the employment conditions and social impacts of these practices.[69]
Biodiversity loss (including the potential extinction ofcharismatic species) is one of the most serious negative effects of oil palm cultivation. On the other hand, it also helps to pushinvasive species further, e.g.Anoplolepis gracilipes insoutheast Asia.[70] Large areas of already threatened tropical rainforest are often cleared to make way for palm oil plantations, especially in Southeast Asia, where enforcement of forest protection laws is lacking. In some states where oil palm is established, lax enforcement of environmental legislation leads to encroachment of plantations into protected areas,[71] encroachment into riparian strips,[72] open burning of plantation wastes,[citation needed] and release of palm mill pollutants such as palm oil mill effluent (POME) in the environment.[72] Some of these states have recognised the need for increased environmental protection, resulting in more environment-friendly practices.[73][74] Among those approaches is anaerobic treatment of POME, which can be a good source for biogas (methane) production and electricity generation. Anaerobic treatment of POME has been practiced in Malaysia and Indonesia. Like most wastewater sludge, anaerobic treatment of POME results in dominance ofMethanosaeta concilii. It plays an important role in methane production from acetate, and the optimum condition for its growth should be considered to harvest biogas as renewable fuel.[75]
Demand for palm oil has increased in recent years due to its use as abiofuel,[76] but recognition that this increases the environmental impact of cultivation, as well as causing afood vs fuel issue, has forced some developed nations to reconsider their policies on biofuel to improve standards and ensure sustainability.[77] However, critics point out that even companies signed up to the Roundtable on Sustainable Palm Oil continue to engage in environmentally damaging practices[78] and that using palm oil as biofuel is perverse because it encourages the conversion of natural habitats such as forests and peatlands, releasing large quantities of greenhouse gases.[79]
Oil palm production has been documented as a cause of substantial and often irreversible damage to the natural environment.[80] Its impacts includedeforestation, habitat loss ofcritically endangered species,[81][82][83] and a significant increase ingreenhouse gas emissions.[84]
The pollution is exacerbated because many rainforests in Indonesia and Malaysia lie atoppeat bogs that store great quantities of carbon, which are released when the forests are cut down and the bogs are drained to make way for the plantations.
Environmental groups, such asGreenpeace, claim the deforestation caused by making way for oil palm plantations is far more damaging for the climate than the benefits gained by switching to biofuel.[85] Fresh land clearances, especially inBorneo, are contentious for their environmental impact.[86][87]Despite thousands of square kilometres of land standing unplanted in Indonesia, tropical hardwood forests are being cleared for palm oil plantations. Furthermore, as the remaining unprotected lowland forest dwindles, developers are looking to plantpeat swamp land, using drainage that begins anoxidation process of the peat which can release 5,000 to 10,000 years worth of stored carbon. Drained peat is also at very high risk of forest fire. There is a clear record of fire being used to clear vegetation for oil palm development inIndonesia, where in recent years drought and man-made clearances have led tomassive uncontrolled forest fires, covering parts ofSoutheast Asia in haze and leading to an internationalcrisis with Malaysia. These fires have been blamed on a government with little ability to enforce its own laws, while impoverished small farmers and large plantation owners illegally burn and clear forests and peat lands to develop the land rather than reap the environmental benefits it could offer.[88][89]
Many of the major companies in thevegetable oil economy participate in theRoundtable on Sustainable Palm Oil, which is trying to address this problem. For example, in 2008, Unilever, a member of the group, committed to use only oil palm oil which is certified as sustainable, by ensuring the large companies and smallholders that supply it convert to sustainable production by 2015.[90]
Meanwhile, much of the recent investment in new palm plantations for biofuel has been funded throughcarbon credit projects through theClean Development Mechanism; however, the reputational risk associated with the unsustainable palm plantations in Indonesia has now made many funds wary of such investment.[91]
Some scientists and companies are going beyond using just the oil, and are proposing to convert fronds, empty fruit bunches and palm kernel shells harvested from oil palm plantations into renewable electricity,[92]cellulosic ethanol,[93]biogas,[94]biohydrogen[95] andbioplastic.[96] Thus, by using both the biomass from the plantation as well as the processing residues from palm oil production (fibers, kernel shells, palm oil mill effluent), bioenergy from palm plantations can have an effect on reducing greenhouse gas emissions. Examples of these production techniques have been registered as projects under theKyoto Protocol'sClean Development Mechanism.
By using palm biomass to generate renewable energy, fuels andbiodegradable products, both theenergy balance and the greenhouse gas emissions balance for palm biodiesel is improved. For every tonne of palm oil produced from fresh fruit bunches, a farmer harvests around 6 tonnes of waste palm fronds, 1 tonne of palm trunks, 5 tonnes of empty fruit bunches, 1 tonne of press fiber (from the mesocarp of the fruit), half a tonne ofpalm kernel endocarp, 250 kg of palm kernel press cake, and 100 tonnes of palm oil mill effluent.[citation needed] Some oil palm plantations incinerate biomass to generate power for palm oil mills. Some other oil palm plantations yield large amount of biomass that can be recycled into medium density fibreboards and light furniture.[97] In efforts to reduce greenhouse gas emissions, scientists treat palm oil mill effluent to extract biogas. After purification, biogas can substitute for natural gas for use at factories. Anaerobic treatment of palm oil mill effluent, practiced in Malaysia and Indonesia, results in domination ofMethanosaeta concilii. It plays an important role in methane production from acetate and the optimum condition for its growth should be considered to harvest biogas as renewable fuel.[75][98]
Unfortunately, the production of palm oil has detrimental effects on the environment and is not considered to be a sustainable biofuel. The deforestation occurring throughout Malaysia and Indonesia as a result of the growing demand for this plant has made scarce natural habitats fororangutans and other rainforest dwellers. More carbon is released during the life cycle of a palm oil plant to its use as a biofuel than is emitted by the same volume of fossil fuels.[99]
In July 2024,Hong Wai Onn from theResearch Institute for Sustainable Excellence and Leadership asserted that the European Union's classification of palm oil as a highindirect land use change (ILUC) risk biofuel is flawed. He called for a reevaluation of ILUC factors to ensure more accuratecarbon intensity measurements. He argued that ignoring this issue unfairly limits palm oil's potential as a low ILUC-risk biofuel and its role in supporting global climate efforts.[100]
{{cite journal}}: CS1 maint: DOI inactive as of July 2025 (link)As well as causing direct damage, some insects play an important role as vectors of disease (Gitauet al., 2009).
The main predators on the weevil in the Far East are undoubtedly rats. These consume large numbers of larvae, destroying the old male inflorescences in the process, and Liau (1985) showed that rats grew more rapidly on a diet supplemented with weevil larvae. Basri Wahid and Halim Hassan (1985) considered that rat populations, and the amount of damage done, had increased since the introduction of the weevil. Chiuet al. (1985) estimated that up to 80% of weevil larvae might be eaten by rats, but noted that the weevil population remained high enough to ensure good fruit set.
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