Pyrethrum produces a daisy-like flower that is used to make a natural insecticide. It grows best at high-altitude locations in the equatorial tropics, including in Papua New Guinea (PNG) and East Africa, and in some temperate-climate locations, such as Tasmania, Australia.
The active ingredient, pyrethrin, is extracted from dried pyrethrum flowers and used to make insecticides for household, agriculture, public health and food industry uses. These include aerosols, sprays, pet shampoo and mosquito coils. Pyrethrum is valued because it is highly effective at repelling or killing a broad range of insects, but is not toxic to mammals, including humans, and breaks down quickly in sunlight, leaving no residues.
Pyrethrum thrives at very high altitudes in the PNG highlands and flower production rises steeply with increasing altitude. Production of pyrethrum is weakly seasonal, being slightly higher in September–March and lower in April–August.
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Adoption and history
Pyrethrum plants were first introduced into PNG in 1938. A number of other introductions were made in the 1950s, with plants from Kenya in 1957 forming the basis for selection of planting material in PNG. Agronomic research commenced at Aiyura in Eastern Highlands Province in 1961, but it was quickly found that the station (1600 m altitude) was too low for pyrethrum production. A new research station was established in 1966 at Tambul in Western Highlands Province (2300 m) and the pyrethrum selection program was moved there. The current germplasm collection is maintained at the Taluma Research Station on the Sirunki Plateau in Enga Province.
A processing facility was established in 1964 by Stafford Allen Ltd (PNG) at Kagamuga near Mount Hagen in Western Highlands Province. The enterprise was not profitable and the Australian Administration purchased the facility in 1973 through the company Kagamuga Natural Products Pty Ltd. The factory operated for another 20 years, but closed in 1994. The plant has a capacity to process 420 tonnes of dried flower per year.
Distribution of production and planting
All crop production was done by villagers and pyrethrum was usually interplanted among sweet potato and other crops. The Department of Agriculture, Stock and Fisheries purchased dried flowers from growers. In the late 1960s production was encouraged in many places throughout the highlands, including the Lagaip, Kandep, Wabag and Wapenamanda areas of Enga Province; the Tambul area of Western Highlands Province; the
Nipa, Margarima, Ialibu and upper Mendi areas of Southern Highlands Province; the Kerowagi, Gumine and Gembogl areas of Simbu Province; and the Okapa, Henganofi and Lufa areas of Eastern Highlands Province.
Pyrethrum was initially grown by villagers at altitudes as low as 1800 m, but within a few years the producing areas shrank to a limited number of very high altitude locations where the crop was most productive. By the early 1970s much of the production was concentrated in the Laiagam area (Enga Province), with significant amounts also grown in the Tambul and Gembogl areas. In 1974 an estimated 22 300 villagers grew pyrethrum. By the late 1970s production was confined to a narrow very high altitude band, mostly in Enga Province (96–99%), and the high-altitude upper Nebilyer Valley in Western Highlands Province.
Levels of production
During the period 1965 to 1993, between 200 tonnes and 400 tonnes of dried flowers were purchased per year, with a peak of just under 600 tonnes in 1967. The volume of pyrethrum extract exported followed the pattern of flower purchases. The pyrethrum processing factory closed in 1994 and no flowers were purchased between 1995 and 1999.
In 1995, the Enga provincial government, concerned about the lack of cash-earning opportunities for villagers in high-altitude parts of the province, formed the Enga Pyrethrum Company to revive the industry. The company initially operated erratically but was revived in 1999 when the company took possession of the Kagamuga processing plant near Mount Hagen. Because pyrethrum was no longer being grown by villagers, it was necessary to multiply and distribute planting material again. This commenced in 1999 and dried flowers were purchased from 2000 onwards. In 2003–2006 the Enga Pyrethrum Company produced pyrethrum extract which it exported to the United States. The volume of exports has been small compared with volumes in the mid 1960s to early 1990s.
Processing, exporters and markets
One of the most important issues for regeneration of the PNG pyrethrum industry is to ensure that production takes place only at high altitudes (2400–2800 m) so that growers achieve the highest possible yields and the best returns on their labour.
Botanical Resources Australia Pty Ltd, a company based in Hobart, Australia, has signed an agreement with the Enga Government to import PNG’s pyrethrum extract from 2006 to 2008 with an option to extend this arrangement beyond 2008. This company is one of the largest pyrethrum producers in the world and has supplied about 40% of global natural pyrethrum products in recent years.
Enga Pyrethrum Company paid K1.50/kg for dried flowers in 2006 (K2/kg delivered to the Kagamuga factory). This was a much lower price in real terms than was paid in the past. For example, in 1989–1993, the price received by growers was K1.50/kg. However, the kina now has much less purchasing power than in the 1980s and early 1990s because of depreciation of the currency and inflation. At current prices, growers are receiving a gross payment of about K2 per day’s labour input. With such a low return to labour, production may not return to the levels experienced from the mid 1960s to the early 1990s. The PNG pyrethrum industry may become viable again but this will depend on improved productivity by the growers and the factory producing a reliable supply of good quality product for the export market.