About 150 plant species are grown in Papua New Guinea (PNG) that have an edible part which can be classed as a vegetable. These include leafy greens, plants with other edible parts such as beans, stems or flowers, spices and flavourings. Leafy green vegetables are eaten with most main meals in both urban and rural areas. Green vegetables were recorded as being eaten in 75% of households in the PNG Household Survey in 1996.
Table of Contents
Pumpkin is grown very widely. More than 70% of the population in the highlands and lowlands eat the cooked tips of the youngest leaves and vines. Pumpkin fruit is grown by 17% of the rural population and is an important food in some highlands locations, for example on the Nembi Plateau in Southern Highlands Province. Pumpkin grows in a wide range of environments and is tolerant of reduced soil fertility. The most commonly grown species (Cucurbita moschata) bears both leaves and fruit from sea level to 2350 m, although other minor species bear higher. Production of tips is non-seasonal. Fruit production in the intermediate and highlands altitudes is seasonal, with the best supply between September and April. Pumpkin was first introduced in 1847 to Woodlark Island in Milne Bay Province and again in 1871 on the Rai Coast of Madang Province (see History of Agriculture in Papua New Guinea). It was subsequently introduced to other locations and widely adopted.
Aibika is grown by more than 60% of the rural population. The leaves and stems are eaten cooked. Aibika grows from sea level to 1900 m, although it is more common in the lowlands and intermediate altitude classes than in the highlands. Production is mildly seasonal in the highlands and lowlands, with the best supply between January and March. Aibika was probably introduced to PNG thousands of years ago, but may have been domesticated in the New Guinea area. Consumption was estimated as 40 000 tonnes per year in the 1996 PNG Household Survey. No data are available on production trends, but it is likely that production has not expanded as rapidly as population growth has over the past 50 years.
Amaranthus is grown by 60% of the rural population. The leaves are eaten cooked. Three species, all of South-East Asian origin, are common in the lowlands through to the highlands: Amaranthus tricolor (0–1950 m), A. dubius (0–1800 m) and A. blitum (0–2050 m). Two other species, both of which were domesticated in Central or South America, are grown at high altitudes: A. cruentus (1350–2300 m) and A. caudatus (1600–2400 m). Amaranthus tricolor and A. cruentus are probably the two most widely grown species in PNG. All species grow best where soil fertility is high and are tolerant of a wide range in rainfall. Production is markedly seasonal in the highlands. Amaranthus tricolor was probably introduced to PNG thousands of years ago. Amaranthus blitum, A. caudatus and A. cruentus are post-1870 introductions. The antiquity of A. dubius is not known, but it is probably also a post-1870 introduction. Production of A. cruentus has increased rapidly from a small base over the past 60 years, while that of A. tricolor has probably not increased as rapidly as population growth.
Highland pitpit is grown by over half the rural population. The stem is consumed after cooking. It is important in the highlands, but is also commonly grown in the Momase and Southern regions. Despite its English common name, highland pitpit grows from sea level to 2700 m, although it is more prevalent above 500 m. It can be grown in a wide range of environments, including in low fertility soils. Production is usually non-seasonal, but it is somewhat seasonal in some highland locations. Highland pitpit was domesticated in the New Guinea area a long time ago.
Lowland pitpit is grown by over half the rural population. The edible portion of lowland pitpit is the inflorescence (flower), which is eaten cooked. Lowland pitpit is widely grown in most environments in lowland and intermediate altitude locations. It is occasionally grown in highland valleys up to 1800 m. Production tends to be seasonal, with crops maturing sometime between November and May, particularly in January to March. It was domesticated in the New Guinea area a long time ago.
Common bean is grown by almost half the rural population, mostly in the highlands. The edible part is the bean, which is commonly harvested and cooked when reasonably mature. It grows from sea level to 2350 m, but it is rarely grown below 400 m altitude and is less common between 400 m and 1200 m. Beans are available throughout the year in most highlands locations, but production is seasonal with the best supply between September and April. Common bean was first introduced into PNG in the 1800s, with the first recorded introduction in 1847. Production has increased in the highlands over the past 50 years.
Cucumber is grown by more than 40% of the rural population in all environments up to 1950 m altitude. The edible portion is the fruit, which is eaten uncooked, often as a snack food. Cucumber is a seasonal crop. Seasonality of production is greater in the highlands than in the lowlands. It is typically planted during the drier months in May–July in the highlands, presumably to avoid fungal damage in the wetter part of the year. The period of best supply varies between locations, but is generally between November and March. Cucumber is a pre-European crop, but because new types have been introduced since 1870 it is sometimes assumed to be a post-European introduction. It was probably introduced from South-East Asia thousands of years ago.
Rungia is grown by more than 40% of the rural population, mainly in the highlands. The young leaves are edible and are usually cooked, but can be eaten raw. Rungia grows in all highland environments over an altitudinal range of 950–2700 m, although it is more common between about 1400 m and 2300 m. Production is nonseasonal. Rungia is an ancient crop in PNG and was probably domesticated in New Guinea.
Winged bean is grown by 40% of the rural population. The green bean is eaten in the lowlands and the green bean, young leaves and tubers are eaten in the highlands. All edible parts of the plant are eaten cooked. The crop grows from sea level to 1900 m, with tuber production over the range 1200–1900 m. It is most common in locations that have a seasonally drier climate in Eastern Highlands, Western Highlands, East Sepik and Simbu provinces. Production of tubers, green beans and leaves is seasonal in all environments. In parts of the highlands, tubers are produced from plantings made in the drier months of the year on welldrained sites. The seasonal pattern varies between locations. In the Kainantu area of Eastern Highlands Province, gardens intended to produce tubers are planted in May–August and tubers are harvested in January–March. Plantings intended for bean production (in mixed vegetable gardens) are made in September–December, with young leaves available in January–March and green beans in March–April. Winged bean was introduced from South-East Asia some hundreds to thousands of years ago. Plantings for tuber production in the highlands appear not to be expanding with population growth and production may have decreased in recent decades.
Tulip is a significant vegetable for more than a third of the rural population. The young leaves of this tree are an important vegetable, particularly in sago-growing locations where only limited areas of food gardens are planted. The leaves are eaten cooked; young flowers (cooked) and fruit (raw or cooked) are also eaten. Tulip is widely grown in the lowlands. It bears leaves, flowers and fruit from sea level to 1100 m altitude. The best supply of young leaves occurs about November–December and the best supply of fruit in December–February. Tulip was probably introduced from South-East Asia a long time ago.
Snake bean is grown by more than a third of the rural population in a wide range of lowland environments. It is most common in New Ireland, Oro, East New Britain, Milne Bay, Central and East Sepik provinces. It bears from sea level to 1600 m, but is uncommon above about 1000 m. The semi-mature or immature bean is cooked and eaten. The production pattern is not known, but seems to be non-seasonal. Snake bean was introduced to PNG after 1870.
Kumu musong leaves
Kumu musong (means ‘hairy vegetable’ in Tok Pisin, named because of raised bristles on the leaves and stems.) leaves are grown by about a third of the rural population. Young leaves (cooked) and raw fruit of a number of fig-bearing trees are eaten, with kumu musong being the most commonly eaten. The cooked leaves are eaten more often than the fruit. The species grows from sea level to 2200 m, but it is less common above about 1200 m altitude. It is found in secondary forest in lowland locations and self-sows in newly cleared gardens, where it is protected from burning. It is most common in Bougainville, West New Britain, East New Britain, Manus, Sandaun, Milne Bay and Oro provinces. In the highlands the young leaves are most abundant in September–November. In Milne Bay Province, leaves are most abundant in January–March and fruit in January–February. This species was probably taken into cultivation in the New Guinea area, although it could have been introduced from Indonesia a long time ago. Consumption of both leaves and fruit has probably declined with the availability of various introduced vegetables and fruit.
Peanut is grown by about a third of the rural population. The edible part is the kernel (nut), which is eaten raw or roasted. Peanut is grown in both the lowlands and highlands, up to the crop’s altitudinal limit of 1850 m. The greatest volume is grown in the Markham and Ramu valleys of Morobe and Madang provinces. Production there is partly mechanised, with tractors used to till large plots. A significant proportion of the crop is sold in local markets. The Markham and Ramu valleys crop is mainly sold to middlemen who retail peanut throughout the highlands. Peanut has replaced winged bean in sweet potato–legume rotations in parts of the highlands where sweet potato is grown for long periods on the same land.
The environments where peanut is most common have a seasonally dry climate; mean annual rainfall in the range 1500–2500 mm; flat or gently sloping land; and reasonably fertile and friable soil. Production is mildly seasonal in most lowland locations, with the best supply typically in January–February, but the pattern varies between locations and between years. Production is more seasonal in Eastern Highlands Province, with the best supply in January–March. Peanut was introduced into PNG after 1870. It was grown as an export cash crop in the Markham Valley in the 1950s and 1960s and on a smaller scale in the Goroka area in the 1960s and early 1970s. It was promoted for village production in the Markham Valley as raw material for a peanut butter factory from the early 1970s to the mid 1980s. Peanut was heavily promoted in the highlands in the 1960s to improve the protein intake of villagers. Production was estimated as 21 000 tonnes per year in the 1996 PNG Household Survey. The quantity grown has increased over the past 30 years, particularly in the Markham Valley.
Oenanthe is grown by about a third of the rural population, mainly in the highlands and highlands fringe. The leaves are generally eaten cooked, but occasionally people eat them raw as a snack. It is grown in a wide range of environments, but grows best in moist sites. It was grown over an altitudinal range of 1050–2700 m until about 40 years ago, but highland migrants now grow it in coastal locations. Production is non-seasonal. Oenanthe is an ancient crop that was probably domesticated in New Guinea. There are no data on production trends, but it is likely that production has declined or not kept up with population growth as other vegetables have been adopted in the highlands.
Cabbage is grown by a quarter of the rural population, with most production in the highlands provinces and in the mountains of Morobe Province. The head (leaves) is the edible part and is generally eaten cooked. In the highlands, cabbage grows over a wide environmental range. It is grown between 700 m and 2700 m altitude, although it is more common above 1700 m. Crops are planted in some lowland locations and sold at nearby urban food markets. These plantings use modern varieties and are grown from seed, in contrast to the highlands where propagation is by the stems of old plants. Production seems to be weakly seasonal in parts of the highlands. For example, in the Kainantu area cabbage is more abundant in September–December. Cabbage was introduced into PNG after 1870. It was promoted as a cash crop for local markets in the highlands from the 1950s onwards. Production has increased rapidly over the past 50 years, particularly at high-altitude locations.