Contents - Previous - Next

This is the old United Nations University website. Visit the new site at

Staple foods in Papua New Guinea: their relative supply in urban areas, 1971 to 1981

Tim Spencer and Peter Heywood
Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea


Food production in Papua New Guinea is predominantly based upon subsistence agricultural systems carried out in either humid tropical or highland tropical environments. The five main traditional staples are sweet potato (Ipomaea batatas), taro (Colocasia esculenta), yams (Dioscorea spp.), bananas (Muse spp.), and sago (Metroxylon spp.). Chinese taro (Xanthosoma sagittifolium), probably introduced within the last 100 years, is an increasingly important subsistence crop in many lowland and intermediate altitude areas. Cassava (Manihot esculenta) is grown as a minor crop, and may attain the status of a co-staple in some areas (1). Coconuts are also a staple energy food in some parts of the country. Commonly, only one or two of the starchy staple crops will dominate food production in any area.

At the start of the colonial era in 1884, cultivation was the predominant means of acquiring food for most of the population who lived in localized, essentially self-sufficient groups. In the ensuing 100 years many people have become dependent, to a greater or lesser extent, on imported foods. Initially, this was because of the introduction of commercial plantation agriculture and the attendant problem of feeding a growing labour force that was alienated from the traditional means of subsistence production. Subsequently, as urban areas were created by the colonizers, people began to migrate from the rural areas to towns for employment, and another group, who were also alienated from the traditional means of subsistence production, was created. Rice was imported into the country to feed these groups and for the first time, a section of the population became dependent upon imported foods.

This dependence has increased to the point where, in 1976, it was estimated by the National Planning Office (2) that, of all food consumed in Papua New Guinea, 53 per cent was supplied by subsistence production, 24 per cent from marketed domestic production, and 23 per cent was imported. The volume of imports for selected foods in 197576 is shown in table 1.

The single most important food import is rice and the quantities imported annually between 1963-64 and 1981-82 are shown in table 2. The volume of imports has more than trebled in this period and has risen by 61.8 per cent since 1975-76.

The rapid rate of growth in the urban population in the last two decades has been an important factor in this increasing dependence upon imported foods.

TABLE 1. Imports of Selected Foods and Food Preparations for 197-76

Item Quantity (tons) Value (in Kina).*
Rice, total 54,847 13,249
Flour, total 25,695 3,968
Potatoes, fresh 2,741 352
Sugar, total 19,402 6,691
Coffee, instant 151 1,039
Peanut butter 127 208
Beef, fresh 2,353 2,046
Beef, canned 1,896 3,241
Pork, fresh 499 807
Chicken, fresh 3,440 3,260
Meat, canned total 4,517 4,283
Fish canned 21,592 7,552
Total 137,260 46,696

Source: Reference 4. * one Kina = US S1.45 in 1981.

TABLE 2. Papua New Guinea Imports of Rice 1963-64 to 1981-82

Year Imported Rice (tons) Year Imported Rice(tons)
1963-64 24,021 1973-74 41,659
1964-65 28,119 1974-75 54,906
1965-66 33,781 1975-76 54,847
1966-67 32,816 1976-77 66,630
1967-68 38,678 1977-78 76,186
1968-69 38,260 1978-79 81,339
1969-70 45,188 1979-80 83,457
1970-71 47,069 1980-81 88,702
1971-72 48,552 1981-82 88,748
1972-73 61,648    

Source: Figures for 1963-64 to 1975-76 from Hale (7), and from 1976-77 to 1981-82 from P.N.G. Rice Industries Pty. Ltd.

Three national censuses have been conducted-in 1966, 1971, and 1980 (3). Table 3 shows the population of the eight largest urban centres enumerated in these censuses, and the annual growth rates for 1966 to 1971 and 1971 to 1980. During the first period the growth rates in all centres except Rabaul were high, and while in the second period the rates were less, they still represent considerable numbers of people who had become alienated from their traditional means of subsistence production.

TABLE 3. Population and Growth Rates of Eight Major Urban Centres

  Population Growth rate
(% p. a.)
1966 1971 1980 1966-71 1971 -80
Port Moresby 41,848 69,698 123,988 10.8 5.9
Lae 16,890 35,286 61,682 15.9 6.7
Madang 9,662 15,865 21,332 10.4 3.4
Kieta-Arawa-Panguna 755 13,449 20,838 78.4 4.6
Wewak 10,207 13,542 19,554 5.8 4.2
Goroka 6,916 7.719 18,797 9.8 4.4
Rabaul 10,561 12,201 14,973 2.9 2.5
Mount Hagen 3,315 9.635 13,642 12.1 7.3

Source: Reference 3.

An additional factor adding to the national demand for rice, particularly in the last decade, has been the growth in rural disposable incomes, most notably in the highlands, as a result of the boom in coffee prices between 1975 and 1979. Thus, while the consumption of rice has mostly been in an urban context, and necessary to fill the gap in food supplies in urban areas, Carrad et al. (4) have estimated that in 1979 at least 50 per cent of total rice consumption occurred in rural areas. In highlands areas, where there has been rapid economic development in the last 25 years, the changes in food patterns have been marked. Harvey and Heywood (5) have documented the changes in food consumption that have occurred in one village in Simbu Province between 1956 and 1981. In 1956 there were essentially no purchased foods in the diet, whereas in 1980 foods bought in trade stores contributed 26 per cent of total energy intake. Consumption in many other rural areas is less, but because a taste for rice has been acquired, the potential demand is great.

Papua New Guinea gained its independence in 1975, by which time the trend towards increasing food dependence was well established and evident. The need for national self-reliance in the face of rising imports, particularly of rice, was recognized, and a National Food and Nutrition Policy (NFNP) that acknowledged Papua New Guinea's food problems was drawn up in 1978. The NFNP recognized that, despite the large contribution made bY domestic production to total food consumption (77 per cent in 1976), ".... rural and urban population increases and other economic activities that compete with food production for resources could very well result in production not keeping pace with increasing demand. This would in turn give rise to increasing food imports. This must be avoided." A major aim of the NFNP was to increase the proportion of total food supplies by domestic production. To achieve this a number of recommendations were made to improve the production, processing, and marketing of domestically grown crops.

Despite the bold aims of the NFNP, the upward trend in food imports has continued. This is partly because there has not been a coherent programme on food production to accompany the NFNP. Agricultural policies under both preand post-independence administrations have consistently emphasized the production of export crops. The commercial production of food crops has often been neglected, with extension efforts largely confined to the distribution of new crops. For a recent history of agriculture in Papua New Guinea, see Denoon and Snowden (6).

The increase in domestic production of staples that is required to reduce food imports must come from either the production of non-traditional staples (such as rice) or from an increase in the production of traditional staples. Past attempts to produce rice in Papua New Guinea have not been successful. Smallholder production has failed to contribute significantly to the nation's rice requirements (7). Large-scale, mechanized production is now being attempted in Papua New Guinea; however, it is expensive in terms of the energy and capital required and faces many environmental constraints. An increase in the marketed production of traditional staples has been a relatively neglected option, yet it has been recognized that Papua New Guinea already has the technology for the commercial production of some of these crops (4).

The dangers of food dependency have recently been re emphasized by the unstable and, in some cases, falling prices of Papua New Guinea's main export commodities -coffee, copra, cocoa, copper, and gold-and this has led to renewed consideration of the problems of increasing domestic marketed production.

The discussion of food policy in Papua New Guinea is hampered by lack of data on the quantity of traditional fruit and vegetables produced or the quantity sold in urban markets. Surveys of the volume of food sold in markets have rarely been conducted on a regular and systematic basis. Those that have been conducted, for example by Belshaw (8), Epstein (9), McCullough (10), and von Fleckenstein (11), are too few to indicate reliably the long-term trends in the quantity of food supplied.

In addition to the lack of data on the quantity of food produced and marketed, there has also been little consideration of the relative price of nutrients as derived from different foods- in the case of staple foods, the price of energy.

While there are no data available on the volume of fruits and vegetables sold in markets, there is information on their prices in the markets of five main towns. The data are recorded by the Department of Primary Industry for the Consumer Price Index. MacEwan (12) analyzed these data for the years 1971 and 1976 and derived conclusions about the changing balance between demand and supply in each of the five towns, in four of which prices had generally increased, indicating a decline in relative supply.

The survey includes three important staple crops: sweet potato, Colocasia taro, and cooking bananas. (The absence of data on yams and Xanthosoma taro is unfortunate, as these are increasingly important foods in Papua New Guinea). A minor staple, cassava, is also included. This paper looks at the changes in price, and hence relative supply, of these traditional staples using the 11 years of data now available. Two sets of comparisons are then made. First, the price of the traditional staples is compared with the price of rice in each of the five towns. Second, the price of food energy from each of these staples is compared with the price of energy obtained from rice.

TABLE 4. Yearly Growth in the Real Price of Sweet Potato, Taro, Cooking Bananas, and Cassava, 1971-1981

  Sweet potato Taro Cooking bananas Cassava
Port Moresby + 5% + 7% + 5% No significant change
(p<0.01) (p<0.01) (p<0.01)
Lae + 6% + 12% No significant change No significant change
(p <0.01) (p <0.01)
Rabaul + 6% + 8% + 5% No significant change
(p<0.01) (p<0.01) (p<0.01)
Madang No significant change No significant change -3% No significant change
(p <0.05)
Goroka +6% + 14% +6% +4%
(p <0.05) (p <0.01) (p <0.01) (p <0.05)


The survey is being conducted by the Department of Primary Industry in the main urban markets of Port Moresby, Lae, Rabaul, Madang, and Goroka. The five towns are the indicator urban areas used in the Consumer Price Index, and represent different zones of the country. Port Moresby, the capital, is located in Papua.

Lae and Madang are the two main urban areas on the north coast of New Guinea. Rabaul represents the New Guinea islands, while Goroka is the indicator town for the highlands. The price of six bundles/units of each com modify are collected every Friday or Saturday (depending on the town). The data are made available through the National Statistical Office. The analysis in this paper concentrates on the change in price of the staple foods included in the survey.

Many of the crops exhibit a seasonal pattern in production and price. To remove this effect from the data, the year's average price was calculated for each product in each town by taking the mean of the quarterly prices.

All prices were expressed in real terms. Recorded prices were adjusted by the mean Consumer Price Index in each town for each year, to hold the value of money constant at the 1981 level. An exponential curve was fitted to the adjusted prices, and the yearly growth in price estimated for each product in each town.

The change in the real price of energy derived from each of the traditional staples-sweet potato, taro and cooking bananas-was compared with the change in the real price of energy derived from the imported substitute, rice. The analysis used "as purchased" energy content of each staple is given in the Food Composition Table for Use in East Asia (13).


Table 4 shows the yearly growth in the real price of sweet potato, taro, cooking bananas, and cassava in the five indicator towns between 1971 and 1981. Sweet potato and taro showed significant price increases in Port Moresby, Lae, Rabaul, and Goroka. The price of cooking bananas rose in Port Moresby, Rabaul, and Goroka. The minor staple, cassava, increased in price in Goroka. Taro exhibited by far the greatest increase in price. In Port Moresby, Lae, Rabaul, and Goroka prices, in general, increased. Only in Madang was there any indication of falling prices.

The real price of rice was slightly less in 1981 than in 1971. However, in all five towns the price rose to a peak in 1974, and from 1974 to 1981 a decrease of between 4 per cent and 5 per cent per annum in real price occurred.

Figure 1 presents the comparison between the price of food energy derived from the three traditional staples (cooking bananas, sweet potato, and taro) with the price of energy obtained from rice. In all five towns in 1981 it cost the urban consumer less to obtain energy by buying rice than by buying domestically produced sweet potato, taro, or cooking bananas. Moreover, in all towns except Madang the real cost of energy from these traditional staples has increased significantly between 1971 and 1981, while there has been no change in the real cost of energy from rice.

Of the three staple foods, taro is the most costly source of energy. This situation is most marked in Port Moresby and Goroka. In 1981 it cost the consumer in Port Moresby eight times as much to obtain an equivalent amount of energy by purchasing taro in preference to rice, while in Goroka it was over six times as expensive to obtain energy by purchasing tarot Even in Madang the cost of obtaining energy from taro was over twice the cost of obtaining it from rice. In 1971 in the markets of Lae and Rabaul, taro was highly competitive with rice as a source of energy. By 1981, however, this competitiveness had deteriorated markedly.

In 1981 food energy from cooking bananas was more expensive than that from either sweet potato or tarot Sweet potato, although more competitive with rice than taro or bananas, was still a more expensive energy food than rice in all five towns in 1981. Again, a trend of increasing cost of energy is evident in all towns except Madang. Between 1971 and 1976 in Lae, Rabaul, and Goroka sweet potato was the cheapest source of energy. By 1977, however, increases in the real price of sweet potato (and the decline in the real price of rice from its peak in 1974) caused the cost of energy from sweet potato to rise above that of rice.


The substantial increase in the price of taro suggests that supply has declined rapidly in relation to demand. Taro is a very old food in Papua New Guinea. It is, or was, grown extensively in lowland and intermediate altitude parts of the country as a staple or co-staple crop. In highland areas it is frequently an important supplementary staple. Around Lae, Rabaul, and Madang, taro has traditionally been a major crop, while around Goroka it is an important supplementary crop to sweet potato.

It is well documented that taro production is declining relatively rapidly in many parts of Papua New Guinea, and is being replaced by Xanthosoma taro, sweet potato, and cassava. Over the decade 1971 to 1981, taro declined greatly in significance on New Irelend, on the Gazelle Peninsula of New Britain (the source of taro for the Rabaul market), in the coastal areas south-east of Lae, around Collingwood Bay in Oro Province, and in Kanabea area of Gulf Province. Taro has virtually disappeared as a staple on Manus Island, where it has been displaced by cassava (14). Throughout the highlands, where taro has been a significant supplementary crop to sweet potato, it is being replaced by sweet potato (R. M. Bourke, personal communication).

Bourke (1) suggests a number of reasons for the rapid decline in taro production in Papua New Guinea, viz unavailability of land of adequate soil fertility, high labour inputs relative to yield returns, virus diseases, taro beetle (Papuana spp), taro blight (Phytophthora colocasiae), unavailability of planting materials, decline of spiritual values associated with the crop, and the availability of alternative, easier-to-grow staples.

In many areas sweet potato has replaced taro, yet this staple also showed a significant yearly growth in price of between 5 per cent and 6 per cent in all towns except Madang.

The high rates of growth in the real price of cooking bananas in Port Moresby and Rabaul and of cassava in Goroka is disturbing. In the hinterland of Port Moresby and Rabaul, cooking bananas are a particularly important staple food. Cassava is a co-staple in the Korofeigu area near Goroka.

While the increases in the price of taro may be explained by changing patterns in the production of the traditional staple crops, the increase in the price of sweet potato and cooking bananas is more disturbing from the point of view of Papua New Guinea's national food policy generally, and rice imports in particular. Sweet potato and cooking bananas are two of the major traditional staples of Papua New Guinea, and the price increases probably reflect an overall decline in the relative supply of domestically produced staples for urban areas. Moreover, this decline in relative supply has occurred during a decade in which the real price of imported rice, after rising to a peak, has declined by between 4 per cent and 5 per cent a year, and imports of rice have risen from just under 50,000 tonnes per annum to almost 90,000.

FIG. 1. Differences in the Real Cost of Food Energy

These trends are at the heart of the paradox that lies behind food policy in Papua New Guinea. On the one hand there is a rhetoric of self-reliance very clearly stated in the National Food and Nutrition Policy. On the other hand, there is the reality of a growing dependency on rice imported from Australia, a very efficient producer whose rice industry is highly motivated to maintain and expand the market in Papua New Guinea.

With respect to implementation of its National Food and Nutrition Policy, Papua New Guinea has been long on rhetoric and short on action. While the aim of food independence was warmly embraced, very little was done to limit food imports or increase domestic food production. Consequently, rice, whose supply is essentially elastic in this situation, is at a marked advantage. It is produced at relatively low cost in a country that spends a considerable amount of money on research and development of the industry, and rice is supplied under long term agreements that, in effect, mean that the price of rice is controlled. This advantage is considerably increased by the hard currency policies of the Papua New Guinea Government.

In contrast, domestically produced staples are in a very different situation. Their supply is not necessarily elastic in the short run, very little money is spent on the research and development necessary if domestically produced root crops are to compete with imported cereals, and the current structure of production, which is essentially one of subsistence surplus, is inappropriate. Moreover, because there is a lack of information on the elasticity of demand with respect to both price and income, the specific implications of the data presented here for food policy are unclear. And underlying these questions is the biological one of formulation of an adequate diet based on root crops.

If Papua New Guinea is to decrease its dependence on imported staples it can produce its own rice and/or increase production of traditional staples. Past attempts to produce rice on a smallholder basis have failed. Schemes to produce it on a large-scale, mechanized, capital-intensive basis have been proposed for some years, but, on the basis of experience in other countries of the South Pacific, there appear to be few grounds for optimism. It may, in the end, be more realistic to try smallholder production of rain-fed rice again in areas where other cash crop possibilities are limited.

However, it is clear that Papua New Guinea can produce root crop staples. Nevertheless, it is also clear that the relative supply of traditional staples to urban markets has declined in the last decade. If this trend is to be reversed and Papua New Guinea's reliance on imported food decreased, a major and coordinated food production effort is needed. Because the production techniques of subsistence agriculture cannot produce a surplus sufficient to meet urban demand, this food production effort will involve changes in the structure of production, improvements in transport, marketing and processing, and an erosion of the price advantages currently enjoyed by imported rice.

Some of the characteristics of root crops, particularly the demand for frequent harvesting, and their high water content, mean that processing may be most efficiently carried out as close as possible to the place at which the crop is grown. This, in addition to the large distances and difficulty of road transport between major urban centres, may mean that the most efficient approach is specific projects that aim to feed particular urban areas.

Although this approach has been tried for Port Moresby, the largest urban area, it has not been particularly successful, largely because of the inhospitable environment in the immediately surrounding area. However, the environments surrounding other major urban centres are much more suited to production of a range of foods. Much of the production technology is available. Other technology, particularly with respect to food processing and transport, needs further development. These require further and substantial government investment.

If these steps are not taken soon, rice will continue to gain ground at the expense of locally produced staples and Papua New Guinea will quickly, if it is not already, be irrevocably committed to food dependency.


The authors would like to acknowledge the National Statistical Office who made available the data presented in this paper.


1. R. M. Bourke, "Root Crops in Papua New Guinea," in: Proceedings of the Second Papua New Guinea Food Crops Conference, R.M. Bourke and V. Kesavan (Eds.) (Department of Primary Industry, Port Moresby, in press).

2. National Planning Office, Food Policy, N.P.O. Background Paper (no date).

3. J. Harding, Urban Growth, 1980 National Population Census, Research Monograph No. 1 (National Statistical Office, Port Moresby, 1981).

4. B. Carrad, R.M. Bourke, and P.F. Heywood, "Papua New Guinea's Food Problems," in: Proceedings of the Second Papua New Guinea Food Crops Conference, R.M. Bourke and K. Kesavan (Eds.) (Department of Primary Industry, Port Moresby, in press).

5. P.W. Harvey and P.F. Heywood, "Twenty-five Years of Dietary Change in Simbu Province, Papua New Guinea." Ecol. Food Nutr., 13: 27 (1983).

6. D. Denoon and C. Snowden, A Time to Plant and a Time to Uproot, A History of Agriculture in Papua Now Guinea (Institute of Papua New Guinea Studies, Port Moresby, 1981),

7. P. R. Hale, "Rice," in: Agriculture in the Economy, D. R. J. Densley (Ed.) (Department of Primary Industry, Port Moresby, 1978).

8. C. S. Belshaw, "Port Moresby Canoe Traders," Oceania, 23: 26 (1952).

9. S. Epstein, "Buyers and Prices at Indigenous Produce Markets in T.P.N.G." Industrial Rev., 7: 18 (1969).

10. A. R. McCullough, "Koki Market in Port Moresby." Papua Now Guinea Agric. J., 22: 134 (1971).

11. F. von Fleckenstein, "Sweet Potato in the Goroka Market, a Melanesian Market?" in: Proceedings of the First Papua New Guinea Food Crops Conference, K. Wilson and R. M. Bourke (Eds.) (Department of Primary Industry, Port Moresby, 1975).

12. J. MacEwan, "Long Term Trends in Vegetable Prices and Supply." (Mimeographed Document, Department of Primary Industry, Port Moresby, 1977).

13. U.S. Department of Health, Education, and Welfare, National Institutes of Health; Nutrition Program, Center for Disease Control; and Food and Agriculture Organization of the United Nations, Food Policy and Nutrition Division, Food Composition Table for Use in East Asia, DREW Publication No. (NIH) 73465, Bethesda, Maryland, 1972.

14. W. J. Rooney, "Changing Food Supply Systems in Eastern Island Manus," in: Proceedings of the Second Papua New Guinea Food Crops Conference, R. M. Bourke and V. Kesavan (Eds.) (Department of Primary Industry, Port Moresby, in press).


Contents - Previous - Next