Oil palm cropping
Oil palm is the world’s leading vegetable oil crop. Palm oil has many food and industrial uses. As a foodstuff, it is believed to have several important benefits, particularly in lowering the risk of heart disease. As a very high yielding crop it has become a major feedstock for biodieselDefinition Mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats for use in diesel engines. It refers to pure fuel before blending with conventional diesel fuel. Blends are denoted as, "BXX" with "XX" representing the percentage of biodiesel contained in the blend (ie: B20 is 20% biodiesel, 80% petroleum diesel). Authoritative On-line References and Resources http://www.eere.energy.gov/afdc/fuels/biodiesel.html The US Department of Energy's Office of Energy Efficiency and Renewable Energy has an Alternative Fuels and Advanced Vehicles Data Center containing key information on all biofuels. production.
Some say that the rise of oil palm has come at a price. They claim that expanding areas of production are bound to result in the further destruction of tropical rainforests, removing an invaluable carbon sink, destroying habitats, so reducing biodiversityDescription The variety of life in all its forms, levels and combinations. Includes ecosystem diversity, species diversity, and genetic diversity (IUCN, UNEP and WWF, 1991). Authoritative On-line References and Resources http://earthtrends.wri.org/ EarthTrends is a comprehensive online database, maintained by the World Resources Institute, that focuses on environmental, social, and economic trends. Statistics on biodiversity indicators are available., and causing severe soil erosionDescription Displacement of solids (soil, mud, rock and other particles) usually by the agents of currents such as, wind, water, or ice by downward or down-slope movement. Authoritative On-line References and Resources http://soilerosion.net/ This site brings together reliable information on soil erosion from a wide range of disciplines and sources. It aims to be the definitive internet source for those wishing to find out more about soil loss and soil conservation. on sloping terrain. However, The Roundtable on Sustainable Palm Oil has been established to ensure that these fears are unfounded. Protecting oil palm from weeds, pests and diseases, which flourish if unchecked in tropical climates, is key to productivity. Integrated pest management (IPM) approaches are widely used and encouraged to ensure that crops are protected in a sustainable way.
Paraquat is an essential tool in oil palm plantations
“In trials, we found that paraquat still gave an amazing performance even when it rained soon after spraying. It works especially well when mixed with sulfonylureas to give longer control of ferns. There is no danger to aquatic organisms or any water pollution because it can not leachDescription The natural process by which water soluble substances are carried downward through the soil into groundwater. from soil.”
Professor Edison Purba PhD, Senior Weed Scientist (Plantations), Indonesian Weed Science Society.
Weed management is central to IPM systems and paraquat has a key role. All green parts of plants may be damaged by paraquat because it works by interfering with photosynthesis and it is termed a ‘non-selectiveDescription A chemical product used for eliminating all types of weeds (annual and perennial grasses and broadleaved weeds). Authoritative On-line References and Resources http://www.weeds.iastate.edu/ An invaluable source of contemporary information about herbicides and weeds from Iowa State University.’ herbicide. However, paraquat is safe to spray around crops such as oil palm, even young seedlings, for two reasons. Firstly, paraquat is strongly adsorbed and deactivated on contact with the soil. It can not move to roots and be taken up into plants and it can not leach.
You can read more about paraquat’s unique soil properties here.
Secondly, mature bark is a very effective barrier to paraquat and even if small amounts land on leaves there is little or no crop damage because paraquat does not move through plants systemically like the alternative non-selective herbicide glyphosate.
Paraquat has a very robust environmental profile. Details of paraquat’s safety to the environment, spray operators and consumers can be found by referring to the Paraquat Fact Sheet.
Paraquat is very fast acting and rainfast. Weeds sprayed in the morning will often show symptoms by the afternoon, making it easy for spray operators and plantation managers to see which areas have already been sprayed. This holds even if rain falls within 15-30 minutes, making it possible to spray for longer before rain is expected.
A video showing paraquat’s unsurpassed speed of action can be viewed here.
In perennial crops such as oil palm, emphasis is on the management of weeds rather than their permanent removal. This is because maintaining a particular balance of weeds in the plantation flora is important for sustainability and minimising soil erosion though the anchoring effect of plant roots.
In recent years, intensive use of glyphosate has caused new weed problems as less well controlled species have ‘shifted’ to become more dominant and some species have evolved biotypes which are resistant to glyphosate. Using paraquat as an alternative non-selective herbicide with a different mode of action in integrated weed managementDescription A decision support system for crop protection which focuses on long-term prevention or suppression of pest problems with minimum impact on human health, the environment, and non-target organisms. IPM takes into consideration all available pest control techniques and tactics (cultural, mechanical, biological, chemical). IPM emphasizes the growth of healthy crops for better productivity with the least possible disruption to agroecosystems. Authoritative On-line References and Resources http://www.ipmcenters.org "The USDA's National Site for the Regional IPM Centers' Information System provides information about US commodities, pests and pest management practices, people and issues." systems is helping to avoid problems of weed shiftsDescription A change in the weed community within a field i.e. relative abundance or type of weeds. This can be the result of a management practice like herbicide use or any other phenomenon that brings about a change in weed species composition. Species or biotypes adapted to current weed management practices increase, whereas weeds susceptible to those practices decrease. Authoritative On-line References and Resources http://www.weeds.iastate.edu/mgmt/qtr00-1/popdyn.htm A classic article on weed population dynamics on the Iowa State University Weed Science website. and resistanceDescription The inherited ability of a plant/weed to survive a dose of a herbicide normally lethal to that species. Authoritative On-line References and Resources http://www.weedscience.org/in.asp The International Survey of Herbicide Resistant Weeds monitors the evolution of resistant species and assesses their impact. All confirmed instances of new cases are listed..
The importance of paraquat in fighting weed resistance to glyphosate and maintaining farmers’ options to use conservation tillageDescription Any tillage and planting system that covers 30 percent or more of the soil surface with crop residue after planting to reduce soil erosion by water. Authoritative On-line References and Resources Purdue University-based Conservation Technology Information Centre. systems is discussed here.
You can read more about the benefits of using paraquat here.
Global Production of oil palm
Oil palm (Elaeis guineensis Jacq.) is a tropical crop originating in West Africa often growing 20 m tall. Oil palm fruit are clustered in large bunches, continuously harvested as they ripen. Individual fruit comprise the outer fleshy pulp (mesocarp) around a nut, inside which is a kernel. Palm oil is extracted from the pulp of the fruit and palm kernel oil from the kernel.
Oil palm now covers nearly 15 million ha. Three countries account for about 80% of the cropped area: Malaysia, Indonesia and Nigeria, but yields are 7-8 times greater in S.E. Asia than Africa. Oil palm is both economically and socially important to these countries.
Only a few decades ago, oil palm was a minor crop, but in 2004, production surpassed that of soybean oil as the major world vegetable oil crop. Oil yields from oil palm are more than five times that of other vegetable oil crops. This is because unlike soybeans, rape (canola), sunflower and olives, which are harvested once a year, oil palms are harvested throughout the year and benefit from the strong equatorial sunlight and ample soil moisture.
Food and industrial uses of palm oil
Oil palm is a versatile crop with many uses besides those of its two oils. These include wood for furniture and biomassDescription Mass of organic matter of non-fossil biological origin which can be exploited for energy purposes. Authoritative On-line References and Resources http://www1.eere.energy.gov/biomass The US Department of Energy's Office of Energy Efficiency and Renewable Energy has a Biomass Program working with industry, academia and US National Laboratories on research into biomass feedstocks and conversion technologies. The goal is cost competitive, high performance biofuels, bioproducts, and biopower. for energy generation from the trunk; fiber for boards and paper, and animal feed and fertilizer from the remnants of the bunches after oil extraction. However, the oils themselves are the most valuable commodities.
Palm oil contains much more saturated fat (around 40% palmitic acid) than other vegetable oils. Unlike other vegetable oils, it is a solid at room temperature and less susceptible to turning rancid. These properties make palm oil an increasingly valuable edible oil for use in cooking and food processing. Both palm oil and palm kernel oil are sources of basic chemicals such as olefins (alkenes) and have uses in manufacturing lubricants and detergents.
Palm oil is rich in anti-oxidants, eg carotenoids (vitamin A), giving it a reddish color, and tocopherols and tocotrienols (forms of vitamin E). It also has what is now generally considered a very valuable blend of saturated, monounsaturated and polyunsaturated fatty acids, which give it an important dietary role. As a solid, palm oil can be used in many processed foods, unlike many other vegetable oils which first need to be hydrogenated. This process results in trans-fats which are now known to be harmful to health.
Palm oil is a very good source of biodiesel because of its very high yields. Biodiesel is produced by the trans-esterification of vegetable oils. This results in biodiesel (methylated fatty acids) and glycerol as a by-product. Compared to regular diesel, biodiesel gives much lower emissions of carbon monoxide, carbon dioxide, aromatic (benzene-like) hydrocarbons, particulates and emits no sulfur. Oxides of nitrogen are similar if engines are fitted with catalytic converters. An oil palm plantation can produce more than 6000 liters/ha of biodiesel compared to only about 500 liters/ha from soybean and 1000-1500 liters/ha from other arable oilseeds.
Sustainable palm oil production
The rapid expansion of the area under oil palm plantations in South East Asia has raised concerns amongst environmental groups that the problems this causes outweigh the benefits of palm oil. A combined response from the Malaysian Palm Oil Association, Malaysian Palm Oil Board and Malaysian Palm Oil Promotion Council points out a number of facts to allay these fears, including that:
- Large areas of oil palm claimed to have recently replaced tropical rainforest are actually not new incursions and have replaced other crops such as rubber and cocoa.
- Oil palm is not a monoculture comparable to temperate arable crops and maintains a diverse range of habitats and species in its under-storey. In addition, it is highly efficient in terms of the overall cost and environmental footprint of inputs relative to its very high yields.
- The oil palm industry in Malaysia has a long history of working with groups such as WWF and the Roundtable on Sustainable Palm Oil has been set-up
The Roundtable on Sustainable Palm Oil
The Roundtable on Sustainable Palm Oil (RSPO) is a multi-stakeholder not-for-profit association designed to promote the growth and use of sustainable palm oil through cooperation and open dialogue. Members come from organizations throughout the supply chain including growers, processors, food and consumer goods manufacturers, retailers and environmental and social NGOs. RSPO has published a set of Principles and Criteria for Sustainable Palm Oil Production.
Growing oil palm
Oil palm trees are grown in plantations, typically in a triangular arrangement with trees 9 metres apart. Seedlings are raised in a nursery for 16-18 months before being transplanted out in the plantation at beginning of rainy season. In areas where there is no distinct dry season, as in Malaysia, seedlings may be planted out all year round, but this is usually done during months with the highest rainfall. Legume cover cropsDescription Cover crops are primarily planted not to be harvested for food but to reduce soil erosion, control weeds and improve soil quality. They are usually plowed or tilled under before the next food crop is planted, in which cases the "cover crop" is used as a soil amendment and is synonymous with "green manure crop." Authoritative On-line References and Resources http://attra.ncat.org/attra-pub/covercrop.html ATTRA is the US National Centre for Appropriate Technology's Sustainable Agriculture Information Centre. (LCC) are usually planted to provide a mulch to control weeds and as a source of nitrogen fertilizer. A mixture of the creeping broad-leaved species Calopogonium mucunoides, Centrosema pubescens, Desmodium ovalifolium and Pueraria phaseoloides is very common in South East Asia. In many areas oil palms are intercropped with food plants, such as maize, yams, bananas, cassava or taro.
A first harvest is taken after 2-3 years. Bunches ripen 5-6 months after the flowers are pollinated. Bunches must be harvested at correct degree of ripeness. Under-ripe fruits have a low oil concentration and over-ripe fruits have high free fatty acid content. Harvesting is usually done every 7-10 days, by cutting down whole bunches of fruit. Palm oil comprises about 25% of the total bunch weight. This is extracted from the fleshy mesocarp of the fruit; palm kernel oil comes from the kernel within the fruit and yields oil to about 2.5% of total bunch weight.
Oil yields of up to 10 t/ha have been recorded and a theoretical potential of 18.5 t/ha has been calculated (Corley, 1996). However, average oil yields in even the more advanced oil palm growing countries are currently only about a quarter of this figure. Constraints on higher yields have been identified as:
- Deficiencies in agronomy
- Lack of labor and/or mechanisation
- Soil erosion
Erosion on sloping ground is especially serious with losses of up to 14 t/ha/year. Topsoil can only be replaced by natural processes on extremely long timescales. Plantations affected cannot be re-planted and new land must be found. Paraquat has a valuable role in preventing soil erosion (see Integrated Pest Management).
Weeds, pests and diseases
Tropical climates with ample sunshine, heat and moisture mean that weeds thrive and may compete with crops for space, water and nutrients, and shade crop plants, especially when they are young. A large number of weeds, both annualsDefinition Weeds that complete their life cycle within one growing season, or year. From seed to flowering to seed before the year ends. Authoritative On-line References and Resources The International Weed Science Society represents individual associations around the world. and perennialsDescription Weeds that return year after year. Some die back in the winter but their roots remain alive and shoots reappear in spring; some don't die back and grow in size and stature the next season. Authoritative On-line References and Resources The International Weed Science Society represents individual associations around the world., infest oil palm plantations. However, if effectively managed, with ‘noxious’ species being removed, many weeds have longer term benefits.
A number of insects are potentially damaging to oil palm in various parts of the world including: palm weevils (Rhynchophorus spp.), rhinoceros beetles (Oryctes spp.), weevils (Strategus aloeus, Temnoschoita quadripustulata), leaf-miners (Coelaenomenodera elaeidis, Hispolepis elaeidis, Alurunus humeralis), slug caterpillar (Parasa viridissima), nettle caterpillar (Setora nitens) and bagworms (Cremastophysche pendula, Mahasena corbetti, Metisa plana).
Oil palm diseases include: blasts (Pythium splendens, Rhizoctonia lamellifera), freckle (Cercospora elaeidis), anthracnose (Botryodiplodia palmarum, Melanconium elaeidis, Glomerella cingulata), seedling blight (Curvularia eragrostidis), yellow patch and vascular wilt (Fusarium oxysporum), basal trunk rot (Ceratocystis paradoxa, Ganoderma spp., Armillaria mellea); crown disease and fruit rot (Marasmius palmivorus). Spear (bud) rot is caused by the bacterium Erwinia spp., which has been devastating in Central Africa.
Other pests include soil nematodes (eg Aphelenchus avenae, Helicotylenchus spp., Meloidogyne spp.) which damage roots; and rodents which can eat seedlings and fruit.
Integrated pest management
There are many examples of how IPM has given benefits in oil palm. For example:
- Elaeidobius kamerunicus, a weevil introduced into South East Asia in the 1970’s eliminated the need for costly and inefficient hand pollinating, resulting in a sharp increase in oil yields
- Owls are encouraged for rodent control
- Leaving less competitive species of weeds provides a habitat for predators of insect pests and helps to prevent soil erosion.
“Paraquat has always given good value, with fast and effective weed control, especially of difficult weeds like ferns, woody shrubs and volunteer oil palm seedlings, even in the rainy season. These days, it is important to use paraquat in Conservation Agriculture to prevent weed succession problems caused by glyphosate.”
Professor Gembira Sinuraya, a weed scientist at North Sumatra University who also owns and manages an oil palm and rubber plantation and is involved with the Indonesian Weed Science Society.
Weed management plays a central role in IPM. Initially, plantation floors are cleared of vegetation, but are usually sown with legume cover crops. Circles around newly planted oil palms are kept weed-free to ensure the successful establishment of the crop. Paths are sprayed-out for access and as the oil palm canopy develops, the cover crop becomes shaded out. This allows a wide range of weed species to invade and broad spectrum non-selective herbicidesDescription A chemical product used for eliminating certain types of weeds only (ie either grasses or broadleaved weeds) and not affecting specified crops. Authoritative On-line References and Resources http://www.weeds.iastate.edu/ An invaluable source of contemporary information about herbicides and weeds from Iowa State University. are used to control these.
Intensive use of glyphosate, has led to changes in plantation weed flora (‘weed succession’) as more tolerant species become dominant. ‘Soft’ weeds which are easily controlled, and can have some benefits such as helping to minimise soil erosion, are replaced by re-invasion of cleared land by more aggressive ‘noxious’ weeds which reduce crop yields. Apart from having a virtually unique mode of action (shared only by its sister, the desiccant diquat), paraquat only removes the top growth of well established weeds, allowing them to re-grow after 1-2 months. In this way, soft weeds can be controlled but not eliminated.
Examples of soft weeds are the prostrate grassesDescription The leaves are "narrow" as opposed to the "broad" leaves of broadleaved weeds. Also called 'monocots' having one seed leaf opposed to 'dicots' having two seed leaves. Authoritative On-line References and Resources The International Weed Science Society represents individual associations around the world. Axonopus spp., Digitaria spp., Ottochloa spp. and Paspalum spp. A controlled presence of soft weeds maintains the balance of the weed flora and prevents weed succession by noxious species simply because bare ground for them to colonise is less available.
Noxious weeds include the perennial grass Imperata cylindrica, and the creeping broad-leaved weed Mikania micrantha which aggressively compete with the crop for nutrients and moisture. Other noxious weeds affect spray operations, fertilizer application and harvesting because of the presence of thorns (Mimosa spp.) or dense coverage (Asystasia spp., Ischaemum spp., Pennisetum spp. and Stenochlaena spp.). The ferns Dicranopteris linearis, Lygodium flexuosum and Stenochloena palastris are found in mature shaded areas obstructing harvest. Paraquat is specifically recommended for managing ferns.
Extensive field trials and practical experience have shown the advantages of using an integrated approach to weed management by, for example, using two spray rounds of paraquat products followed by one of glyphosate (Lam et al, 1993, Lim et al, 1996, Quah et al, 1997). This program keeps a controlled presence of soft weeds and removes noxious weeds.
CASE STUDY: Paraquat is important to Malaysian smallholders
A survey of paraquat use by smallholders was jointly commissioned by the Malaysian Palm Oil Association, the National Association of Smallholders of Malaysia and the Malaysian Estate Owners Association.
200,000 smallholders grow oil palm in Malaysia, each having on average 7ha. Seventy-five percent of them use paraquat which is critical to providing effective weed control and preventing soil erosion.
Without paraquat, more expensive herbicides such as glufosinate would have to be used. These are not as effective and re-spraying would be necessary after rain. In addition, hand weeding would be needed to complete the control of weeds. Labor is scarce and increasingly costly to smallholders. More glyphosate could not be used because it is not safe to the young oil palm crop. Erosion has consequences for loss in yield as well as environmental problems such as the silting-up of water courses. Without the benefits of paraquat and with the extra costs incurred, if smallholders could not use paraquat, they would lose 7% of their annual income, the survey concluded.
References & Resources
Palm oil associations, etc
Production and trade in palm oil
Corley, R.H.V. (1996) What is the upper limit to oil extraction ratio? In: Proceedings of the International conference on oil and kernel production in oil palm - A global perspective (eds Rajanaidu, N., Henson, I.E. and Jalani, B.S.), pp. 256-269. PORIM and Ministry of Primary Industries, Malaysia, Kuala Lumpur, Malaysia, 27-28 September 1996.
Integrated weed management
Lim JL, Quah KB & Badrulisam J, (1996). Integrating paraquat and sulfosate in weed management programs to overcome weed succession problems, in First MAPPS/ISP Seminar ‘A New Era in Weed Management’, Genting Highlands, Malaysia.
Quah KB, Lim JL & Badrulisam J, (1997). Alternating herbicides to minimise weed succession in the plantation, in Extended Abstract Proceedings of 2nd International Pesticides Conference - ‘Crop Protection Towards 2000’, MACA, Kuala Lumpur, pp 110–113.
Lam CH, Lim JK & Badrulisam J, (1993). Comparative studies of paraquat mixtures and glyphosate and/or its mixtures on weed succession in plantation crops. The Planter (Kuala Lumpur) 69:525–535.
Lim, K.H. (1990) Soil erosion control under mature oil palms on slopes. In: Proceedings of the 1989 PORIM International Palm Oil Development Conference. Module II Agriculture, Palm Oil Research Institute of Malaysia, Kuala Lumpur.