Since 1971 there has been a revival of interest in the possibilities for cultivation of the true sago palm Metroxylon spp. Agronomic and economic research shows that the palm can become an important starch producing crop. Many queries concerning the agronomy of the crop have been solved. The palm is especially suited to humid tropical lowlands. It is fairly salinity tolerant, but less tolerant to swampy conditions than generally thought. Research programmes to solve the remaining problems have been started in Sarawak on peat soils and will be started in Indonesia on mineral soils, both regarding the cultivated crop and exploitation of natural stands. Yields of 5 tons of dry starch per hectare and year in the first year, increasing to 15 tons in the tenth, are to be expected in good quality natural stands under cultivation and on mineral soils. In new plantings there will be no yield in the first eight years; after that yields will increase rapidly to 25 tons per hectare a year, tapering off slowly to 15 tons. Yields on peat soils under cultivation are expected to remain 25% lower. In both natural stands and plantings an extensive drainage system is to be provided, which also allows the trunks, the raw material, to be floated out to the factory. Both systems of cultivation are expected to be economically viable with an internal rate of return estimated at 10%.
The palm Leopoldinia piassaba, which grows in the upper Rio Negro and Orinoco drainages of Venezuela, Brazil, and Colombia, is used for handicrafts, house construction and harvested for fruit.
Babassu palms Orbignya ssp. cover nearly 200,000 km2 in Brazil, providing cash income, fuel, fibre, edible oil and food to a large number of tenant farm households. Babassu is closely integrated within pastoral and shifting cultivation systems of mid-north Brazil. In pastures, babassu provides shade for cattle, aids soil moisture retention, produces organic matter, generates supplementary farm income at little cost, and offers year-round employment. On the other hand, the persistence of juvenile palms reduces pasture grass productivity due to plant competition, and therefore there is a trend to eradicate babassu through clearcutting and understorey suppression. At moderate densities of less than 100 individuals per ha, mature babassu palms in cropland do not appear to harm crop productivity. In such cases, palms are thinned and leaves of the remaining ones are cut back, supplying fuel for the burn and nutrients to the soil. However, reduced fallow cycles due to pasture conversion threaten babassu as well as crop productivity.
Nipa palm Nypa fruticans is a useful, versatile, and fairly common component of mangrove forests of Asia and Oceania. Because of its usefulness, it has been introduced into West Africa. In addition to a host of local subsistence uses ranging from medicines to hats and raincoats, some important commercial uses have led to management efforts and are initiating a new interest in its potential. Sap production from nipa produces an intoxicating beverage, sugar, vinegar, and alcohol that may be used as fuel. The tapping of nipa for sap involves a rather unusual kicking or beating process called 'gonchanging'. Further research in nipa sap production, together with development of more efficient collection and handling methods, might greatly enhance the usefulness of this palm.
Aguaje Mauritia flexuosa is a naturally occurring palm in Peru and features in the economy of Iquitos. Mauritia fruits are collected and sold in large quantity and are locally processed into a number of products. Trade in the fruits and related products provides employment and income for a large number of area residents, most of them women. Compared with commerce in other regional products, aguaje appears to offer an exceptional opportunity for economic advancement to women. Destructive harvesting practices are threatening continued supply of the fruit.