Although patauá has been widely recommended as an interesting and potentially valuable crop, with potential to become an extractivist-industrial species, there is surprisingly little information available about yields. Sirotti & Malagutti (1950) estimated yields from a natural population of patauá in Venezuela. These authors analyzed an oligarchic population, called a sejal in Venezuela, and reported between 400 and 500 potentially fruit-bearing plants/ha. Balick (1988) considers this to be too high to obtain maximum yields, since it is equivalent to a monoculture spacing of 5 × 5 m (= 400 plants/ha) to 4.5 × 4.5 m (= 494 plants/ha). A mature patauá tree would probably require a monoculture spacing of 7 × 7 m square (= 204 plants/ha) or triangular (= 216 plants/ha).
Sirotti & Malagutti found that 72% of the mature plants bore fruit during the season, of which 30% bore only one bunch, 42% bore two and 38% bore three bunches (mean bunch number = 2.28). Average bunch weight was 14.5 kg, of which 10.4 kg was fruit (fruit/bunch ratio = 72%). Although Sirotti & Malagutti did not estimate yields, their numbers suggest a yield between 9.5 and 11.8 MT/ha, which is much higher than improved oil palm and extremely unlikely to occur in the wild or in cultivation.
Balick (1988) estimated the yield of 100 fruiting plants at 155 bunches containing 1.6 metric tons of fruit. Peters et al. (1989) estimated a yield of 3.5 MT in their study of 104 plants/ha, slightly more than double Balick's (1988) estimated yield for 100 plants, due either to larger bunches (probable) or more bunches/tree (less probable) or a combination of both (most probable).
Thus, from a hectare of natural oligarchic palm forest, yields vary from 1.6 to 1.5 MT of fresh fruit. This is equivalent to 112-260 kg of patauá oil/ha or 1.1-2.6 kg/plant. If 204 plants/ha is an appropriate density for a plantation, yields of 3.27 MT of fresh fruit could be expected with no further agronomic practices. This is equivalent to 240-525 kg of patauá oil.
In the early decades of this century, the African oil palm (Elaeis guineensis) yielded only 1.9-4.5 kg of oil/plant (@ 205 plants/ha, oil yields were 400-900 kg/ha). Today this species yields 4-5 MT of oil/ha, due principally to improved agronomic practices and better germplasm (Hartley 1977). An-equivalent period (about 50 years) of genetic and agronomic improvement could raise patauá yields to the 2-3 MT/ha range with little difficulty (Balick 1988). In fact, modern improvement techniques, combined with an extensive germplasm prospecting, could allow equivalent progress to be made in one-half the time. This range is 2-3 times the yield of the olive tree, suggesting that patauá has the yield potential to take a share of that market through lower prices due to more efficient production.
If the patauá fruit bunch is not cut from the tree when ripe, fruit will fall over a period of a week or more. Unfortunately, much of the exploitation of the natural populations to supply patauá oil during World War II was done by cutting the tree, rather than the bunch (Balick 1986). There are, however, numerous easy ways of climbing a patauá palm to collect the bunch. It is also possible to harvest it from the ground, as is done with pejibaye (Bactris gasipaes).
Traditionally Amerindians extracted oil by heating the mashed mesocarp and pressing it in a tipitipi, a long woven tube that shrinks in diameter as it is-stretched in length. This method is described in detail by Balick (1986, 1988) but is only about 35% efficient (Blaak 1988).
G. Blaak, of the Royal Tropical Institute, Amsterdam, and now at FAO Plant Production and Protection Division, developed the pilot project for a small-scale, village-level processing plant for patauá located at Las Gaviotas, Colombia, in the Llanos region. Blaak (1988) details this experimental project, which is not presently operating, despite the fact that Blaak's analysis was very positive. Undercapitalization of the project and a small supply of mature patauá stands in the immediate vicinity contributed to the decision to halt the project at Las Gaviotas.
Oil extraction efficiency of this pilot plant was on the order of 85-89%. The equipment and buildings cost US$ 29,000 in 1980. This could handle 1 MT of fruit per day, which, during one harvest season is the equivalent of 4500-5000 plants, a 45-50 ha oligarchic population. This plant would need a working capital of US$ 25,000 a year to turn a profit of US$ 7,000/yr (29% on investment). Las Gaviotas sold clarified patauá oil at the processing plant gate for US$ 3.75/kg, approximately equal to the whole sale price of olive oil on the US market in the same period.
It is exactly this type of processing plant that would allow the wider use of the numerous oligarchic patauá populations found throughout Amazônia. A village-level processing plant, similar to that at Las Gaviotas, combined with market contacts, could be a viable component of a forest community or extractivist reserve in Amazônia.
The fresh seed should have the pulp removed and be soaked in warm water (» 50°C) for 30-60 minutes. Alternatively, seeds used to make vinho de patauá (if they have not been boiled) can be sown, as they will have received approximately the same treatment. When pre-treated this way, 90-98% of fresh seed will germinate within 50-60 days (Balick 1988). Seed viability is lost rapidly, with significant reductions occurring in 4-6 weeks. Germination should be carried out in partial shade.
Although no research on preparation of patauá seedlings for planting has been published, a few general comments can be made from empirical observations on patauá As soon after germination as possible, the seedling should be transplanted to a black plastic nursery bag containing a substrate with 1 part sandy loam, 2 parts clay loam and 1 part organic matter, preferably well-rotted animal manure. Seedlings should be maintained in partial shade (» 50%) during the initial nursery growth period.
St. John (1988) has shown that patauá seedlings inoculated with mycorrhiza produce more leaves and a greater leaf biomass than those not inoculated. If the nursery substrate is obtained from forest soils, as would be the case if Amazonian farmers prepared the seedlings, sufficient mycorrhizal inoculum should be present. If artificial substrates or treated soils are used, the substrate should be inoculated.
If the seedlings will be used for enrichment plantings, either in partially forested or second growth areas, they can be planted directly from the nursery to the field. If they are to go into full sun, as in a monoculture plantation, they should be hardened-off first. When transplanted, they should be semi-shaded with a cut leaf of an adult palm folded over.
Kahn's (1988) work suggests, however, that juvenile material like this may have problems adapting to full sun at an early age, not unexpected in a species adapted to the forest environment. This may partially explain why several patauá seedlings planted in full sun at INPA, Manaus, did not grow satisfactorily. Research should be carried out to determine at what age plants can be transplanted to full sun, since, theoretically, they should grow more vigorously in this environment than in forest enrichment plantings.
Since the patauá is a large palm, it can not be planted at extremely high population densities without reducing yields. Blaak (1988) suggests a 7 × 7 m spacing, used in yield calculation above. This suggestion is based on empirical evidence and would be worth testing. Different genotypes might accept higher or demand lower densities.
Some authors have reported that patauá takes 10-15 years to fruit (Balick 1988). As with most palms, however, this time may be reduced by modifications in the agroecosystem, especially by reducing competition and enriching the nutrient content of the soil. Blaak (1988) comments that 1.5 kg of fertilizer/plant should double yields. Balick (1986) observed a plant in Ecuador that fruited very precociously, at less than two meters from the ground. The patauá germplasm bank being organized at the Centro de Pesquisas Agropecuárias do Trópico Umido, in Belém, Pará, will provide information on the precocity of different genotypes in plantations. This trait generally has a moderate to high heritability and can be selected for in an improvement program.
Many economically important palms are frequently spared in forest clearing and become part of diversified agroforestry systems in the region. patauá is no exception, as patauá fruit are very popular. There are no reports of patauá being planted into Amazonian agroforestry systems, but this practice is to be expected, even though there is a long juvenile stage before fruiting. Balick et al. (1988) note that palms in agroforestry systems studied in Colombia have larger bunches (fruit: flower ratio) than those studied in primary forest. This suggests that lessened competition and increased availability of light, nutrients and pollinators could result in immediate yield increases.
Dr. Michael J. Balick, Director Institute of Economic Botany; The New York Botanical Garden; Bronx, NY 10458, USA.
Ing. G. Blaak, Senior Officer Industrial Crops; Plant Production and Protection Division; FAO; via delle Terme di Caracalla; 00100 Rome, Italy.
Dr. Lidio Coradin; Centro Nacional de Recursos Genéticos CENARGEN/EMBRAPA; Cx. Postal 10.2372; 70.770 Brasilia, DF, Brazil.
Dr. Rodrigo Bernal; Instituto de Ciencias Naturales; Universidad Nacional de Colombia; Aptdo. 7495; Bogotá, DE, Colombia.