The author of this chapter is J. Mora-Urpi (School of Biology, UCR. San Jose, Costa Rica).
Family: Palmae = Arecaceae
Common names. English: peach-palm (Trinidad and Tobago), peyibay(e), pejivalle; Spanish: pejibaye (Costa Rica, Nicaragua), chantaduro (Colombia, Ecuador), pijuayo (Peru), pijiguao (Venezuela), tembé (Bolivia), pibá (Panama), cachipay (Colombia); Portuguese: pupunha (Brazil)
Bactris gasipaes was undoubtedly the most important palm of pre-Columbian America and constituted the main crop of the Amerindians of an extensive territory of the humid tropics and even some areas of the dry tropics.
Because organic material easily decomposes in the archaeological sites of the humid tropics, there are few references to findings of peach-palm material which enable its past to be reconstructed. The oldest come from seeds found in various localities on the two coasts of Costa Rica and date from 2300 to 1700 BC, when it is assumed that it was already cultivated. When contact with Europeans took place, accounts indicate that it was the main crop and sustenance of the indigenous population of the humid tropics of Costa Rica. The importance of the peach-palm also extended to numerous tribes of lower Central America and the humid tropics of South America, scattered across the basins of the Cauca, Magdalena, San Juan, Orinoco and Amazon Rivers and their tributaries as well as certain other areas. This dependence is still seen nowadays in some communities, such as the Sanema-Yanoama of Venezuela, the Shuars or Jivaros of Ecuador and the Yuracarés of Bolivia. During the years of the settlement and basically during this century, the crop has decreased in importance for various reasons.
Of these, we may mention the reduction in the indigenous population; the loss of traditions through European influence alien to these cultures and to this crop; the establishment of urban centres outside the areas of the humid tropics, where it was not traditional to grow or eat the peach-palm; the perishable nature of the fruit and the palmetto of this palm which, in the absence of processing industries, did not allow it to be traded with the new urban centres; the introduction of new short-cycle food crops; the aggressive expansion of stock farming which brought with it the extensive use of fire for land clearance and the establishment of pasture land; and, finally, soil compaction as a result of trampling by livestock. Fire, competition and soil compaction are not tolerated by this palm.
The use of B. gasipaes pre-Columbian times was complete. The fruit, its most important product, was used in two ways: cooked (boiled in water) and as a slightly fermented cool drink. In both forms, it constituted the basic food during the harvesting period in the indigenous communities which grew it. For consumption out of season. it was preserved mainly in ensiled form and prepared in a very similar way to today. with storage in trench silos made in the ground. One month after being covered over, it was ready for consumption or could be stored until the next harvest. This fermented material was consumed mixed with water as a cool drink. It could also be carried wrapped in leaves during journeys and merely had to be diluted in water for consumption. Another important form of preservation was drying the fruit, exposing it to heat and smoke and then placing it on mats suspended above a fire. To be eaten, it just had to be boiled in water. It was also eaten in the form of tortillas made from its dough, as with maize, or as farinha. The oil. which separates out when the fruit is boiled. was occasionally used for cooking other foods. Prolonged fermentationlasting one weekenabled the alcoholic drink, chicha, to be made for celebrating festive occasions. Thus, the fruit of each palm constituted a basic source of energy. replacing the functions and uses of grain in other cultures. It was especially significant as a substitute for maize, which it surpasses in nutritional value.
The wood of the trunk has great strength and elasticity which enabled it to be used to make weaponsbows, arrows and spearsas well as in construction. The apical section of the trunk, together with its embryonic fronds, is soft and has a delicate flavour; from this the palmetto or heart of the palm is extracted. The sap from this part of the trunk. either unfermented or fermented in various degrees, was used to prepare nutritional and intoxicating drinks.
The young inflorescences were also eaten roasted "the herdsman's way", without opening the protective spathe. Infusions of the roots were used in medicine as a vermicide.
Today, the Indians use the same basic products obtained from the peach-palm, which now produce a greater diversity of by-products, many of which are still being developed. Thus the wood is used to manufacture building materials such as parquet, panels, luxury furniture and handicraft items, taking advantage of its beauty and great strength. The long fibres on the inside of the trunk show promise for use in fibre cement products. Exploitation of the palmetto is a prosperous industry: having originated in Costa Rica in the 1970s, it is gradually gaining importance among the countries of the American humid tropics as a profitable crop and on account of its sound characteristics for ecological management, in accordance with new agronomic trends.
The fruit, which in the past was only important in its areas of production because it is very perishable, is now seen as having great potential through processing to form flours and other derived products such as oil, beta-carotene and starch. Tests are even being carried out to see if the trypsin inhibitor contained in the fruit of some cultivars can be used as an insecticide. Flours made from peach-palm have an important future in human nutrition, being consumed in confectionery, bread-making and other preparations. It also has a great future in animal feeding, as a substitute or supplement for grain, in the manufacture of concentrates and fermented as ensilage. Fermentation of the fruit is being investigated with a view to its exploitation in the manufacture of various organic compounds. Its possible medicinal use, as practiced by the Indians, has yet to be explored.
B. gasipaes is a caespitose palm with an extensive but fairly superficial root system. The trunk has internodes covered with spines, alternating with nodes without spines, formed by leaf scars. These measure between 10 and 25 cm, with a lamina that is generally more than 2 m in length and with over 200 folioles. The inflorescence is covered with two bracts, the outer short and thick, the inner surrounding the inflorescence until it matures; the rachis is branched with thousands of male flowers intermixed with a few hundred female flowers, which are slightly bigger than the males. The fruit occurs in a drupe of variable size400 to 300 gwith a slender, red or yellow exocarp; a farinaceous mesocarp which is variably orange; and a dark and hard endocarp. The size of the seeds depends on the ecotype: in the cultivated plants they weigh about 4 g, are recalcitrant and take between 45 and 90 days to germinate. Its chromosome number is 2n = 28.
Pollination. The peach-palm is a monoecious plant with male and female flowers mixed on the rachillae. It is also protogynous, since the female flowers are fertile as from the opening of the spathe and continue to be receptive for 24 hours. Anthesis of the male flowers occurs on the second day of the cycle, i.e. 24 hours after the females. In both cases this occurs at the end of the afternoon, between 5 and 6 p.m.
The pollination cycle takes place over three days and consists of three complementary methods. The first is entomophilous and is the most important. It is effected by curculionids: in Central America by Audranthobius palmarum; and in the Amazon basin by several species of Phyllotrox. Occasionally, other insects also play a part but the Amazonian Cyclocephala has been erroneously cited as a pollinator.
The second pollination method is by gravity. When the pollen is released during the second day. it completely covers the inflorescence and, in doing so, covers its female flowers. This method is not very effective, as there is a system of genetic self-incompatibility which interferes with fertilization and possibly produces fertile seeds only occasionally.
The third method is anemophilous, occurring between adjacent plants during the morning of the second receptive day of the female flowers. In this case, the pollen deposited on the rachillae during male anthesis is scattered by the wind on the following morningthe third dayand if there are inflorescences on nearby plants, they may be pollinated in this way on the second day.
The controlled pollination technique consists of protecting the inflorescence from the sight of curculionids, using well-fitting bags of kraft paper and applying the pollen on the day following the opening of the spathe. It is not necessary to emasculate the male flowers.
Figure 24. A) Peach-palm (Bactris gasipaes) A1) racemes with fruit in a drupe; A2) cross-sections and profile of the fruit; A3) spine-covered internodes on the stem.
The peach-palm grows wild in well-drained soils with various physical and chemical conditions, including acid and poor soils, since it is assisted by its association with mycorrhizas. It is grown in climates with precipitations between 2000 mm and 5000 mm and annual mean temperatures exceeding 22°C. The recommended altitude for commercial cultivation ranges from 0 to 900 m.
Its natural distribution extends from Darién in Panama to the province of Santa Cruz in Bolivia, the state of Rondônia and possibly the Mato Grosso in Brazil. Its presumed natural origin, further to the north in Central America, has not been confirmed, although it has been cultivated for several thousand years as far as northeastern Honduras. Spontaneous dispersion occurs through the seeds being carried over short distances by birds, rodents and other mammals, and over greater distances possibly by water.
Cultivated peach-palm may be considered a synthetic species, the result of the independent domestication of several wild populations.
The latter, which are very extensive in their geographical distribution, were known to several primitive societies which began to grow them independently. The degree of domestication reached at the time of contact with Europeans differed depending on the region. This is still reflected in characteristics such as fruit size. Thus, the cultivar developed in Bolivia from Bactris insignia represents an incipient stage of domestication because of its small fruit size and high fibre content, while the cultivar of the Vaupés River in Colombia reflects an advanced domestication process through its large fruit size and high starch content. The variety or species which gave rise to this cultivar has still not been determined. Between these two extremesnorth and southof the Amazon/Orinoco basin, other cultivated varieties and at least two wild species are found. One of them, Bactris ciliata (= B. microcarpa, B. dahlgreniana) possibly gave rise to more than one of the cultivars which are recognized today, for example Pampa Hermosa and Pastaza, which show an intermediate degree of domestication between the first two mentioned. In some cases, the presence of the wild species near the plantings had a negative effect on the improvement process as a result of spontaneous backcrossing.
Table 7. Species linked with the origin of the peach-palm
|Bactris ciliata||Peru: Ucayali, Huallaga, Madre de Dios Rivers|
|Bactris insignis||Bolivia: Santa Cruz, Chapare, Alto Beni|
|Bactris sp.||Brazil: Acre, Rondônia1|
|Bactris sp.||Colombia: Alto Putumayo, Caqueta|
|Bactris macana||Venezuela: Maracaibo; Colombia: Santa Marta|
|Bactris caribea||Venezuela: Maracaibo; Colombia: Santa Marta|
|Bactris chantaduro (?)||Colombia Cauca River valley|
|Bactris sp.||Ecuador: Central and northern Pactfic slope|
|Bactris sp.||Panama: Darién; Colombia: Chocó (possibly)|
The subsequent spread of the different genotypes through neighbouring regions contributed in some cases to the creation of greater local diversity. Geological and climatic history also contributed to the geographical isolation of populations, which was necessary for the process which gave rise to this complex. The gene flow between distant regions over generations has been limited in the peach-palm, since there are absolute barriers to the pollinating curculionids and to natural seed migration.
The first division between cultivars and species is based on the geographical distribution of two major groups: the eastern or Amazonian, situated to the east of the Andes; and the western, situated on the opposite slope. The former generally have a smoother trunk, with less wood, a lower spine density, fewer tufts and less soil anchorage when young. The other characteristic is fruit size, with the varieties being classified into microcarps, mesocarps and macrocarps.
The exchange of germplasm, especially in recent decades, has resulted in a considerable number of local varieties being contaminated with foreign germplasm, thereby obscuring the characteristics that were specific to them. In general, this phenomenon occurs with greater frequency in localities associated with urban centres. but occasionally it affects more extensive regions.
Table 8. Cultivated varieties of peach-palm
(weight less than 20 g)
|Tembé||Bolivia: eastern part|
|Pará||Brazil: state of Para|
|Juruá||Brazil: Jurua River|
|Rama||Nicaragua: Rama, Bluefields|
|Chontilla||Ecuador: western part|
(weight 21 to 70 g)
|Inírida||Colombia: Inírida and Guaviare Rivers|
|Sollimões||Brazil: middle course of the Amazon|
|Pastaza||Ecuador: foothills of the Andes|
|Pampa Hermosa||Peru: Hermosa pampa|
|Utilis||Costa Rica, Panama and perhaps the coasts of Colombia|
|Guatuso||Costa Rica: San Carlos|
|Cauca||Colombia: Cauca and Magdalena (?) valleys|
(weight exceeding 70 g)1
|Vaupés||Colombia: Vaupés River|
|Putumayo||Colombia, Ecuador, Peru, Brazil: Putumayo, Caquetá, Napo, Alto Solimões, Huallagas Rivers|
Genetic erosion and conservation. The reasons for the decline in importance of this crop are also responsible for the accelerated genetic erosion being sustained by its germplasm. To these should be added the expansion of some towns in whose surroundings interesting peach-palms are to be found, such as Yurimagua, with its spineless variety, and Iquitos in Peru; and also the deterioration in the social organization of small communities which is threatening their very existence, as is the case of the Yuvineto settlements of the Sequoya tribesituated on a small tributary of the Putumayo river in Peru who have bred a local variety which is exceptional for its vigour, total absence of spines, large fruit and racemes and excellent table quality; and of the Guatuso in Costa Rica, a community of the Maleko tribe, which also developed a good-quality. spineless cultivar. These situations are not exclusive to the examples mentioned, but are fairly widespread in all the countries contained within B. gasipaes' distribution area. In Costa Rica, for example, it is possible to predict the extinction of the peach-palm within a few decades unless there is a resurgence of interest in its cultivation.
Populations of wild peach-palm are also threatened with extinction: B. insignis in Bolivia; B. ciliata in Peru; Bactris sp. (chontilla) in western Ecuador; Bactris sp. in Darién, Panama; B. macana in Venezuela; and B. chantaduro (?) (chinamato) in Colombia.
The collection and inclusion of germplasm in ex situ banks is one of the most important immediate measures to be taken and significant et: forts have been made in this connection, especially in Costa Rica, Brazil, Colombia, Peru and Ecuador through self-funding and funds provided by international agencies.
Table 9. Peach-palm gene banks
|Country||Locality||Institution responsible||Approximate number of accessions|
|Colombia||Buenaventura||Departamento de Agricultura y Fomento del Valle||400|
|Araracuara||Corporación de Araracuara||100|
|San José, Guaviare||Corporación de Araracuara||100|
|Costa Rica||Guápiles||UCR, CORBANA, MAG||950|
Several products are obtained from the peach-palm, with the result that specific agronomic technologies have emerged for their exploitation. In fact, they are different crops. We shall deal here with the general aspects of two of these crops exploited on a commercial scale: palmetto and fruit.
Palmetto production. The seed beds are set up using soil beds or closed polyethylene bags. In the latter case, the seed's moisture content must be approximately 40 percent. A germination rate of 75 percent is achieved in soil beds and 90 to 100 percent in plastic bags. At ambient temperature (24 to 25°C) its germination begins in 1.5 months and may be regarded as being over at three months. Two asexual methods of propagation are currently being developed: tissue culture and culture from shoots; with both of these, however. there are difficulties which have still not been overcome. The newly germinated seedlings are taken from the seed bed to the nursery and at three to six months are planted out in the field. Transplanting can be done with soil or with bare roots. Planting density is 2 x 1 m or 1.5 x 1.5 m, and the number of shoots with which the rootstock is used is four to six. Depending on the size of the seedlings at transplanting and on soil fertility, the stems are ready for harvesting when they measure approximately 9 cm in diameter, which they attain 12 to 18 months after transplanting.
The first harvest is one stem per rootstock but from then onwards, if the plot is well managed, there may be an average of three or more stems per rootstock per year. The annual industrial yield. which is guided by current quality standards for canned palmetto, is approximately 1 tonne per hectare.
Because of the heterogeneity in the ages of the shoots. the population is composed of stems at all stages of development, which means harvesting must be done by hand. This consists of cutting the apical sector of the stem, removing the foliage and some of the sheathes covering it, and leaving two of them to protect it during transportation to the industrial plant. Harvesting produces a great amount of organic residue and, as it is done throughout the year, it contributes to the maintenance of an organic cover on the soil.
One hectare of palmetto produces 19.5 tonnes per year of dry matter, of which the extracted crude palmetto represents only 1.76 tonnes, i.e. 9 percent of the biomass produced.
The most important routine operations are the establishment of a drainage system before sowing and. subsequently, weed control, fertilization and pruning excess shoots. Regarding the latter, there are cultivars that frequently do not produce sufficient shoots or do not produce any at all, and this is a serious drawback. Putumayo is characterized by such behaviour.
No pests or diseases of any economic importance have yet occurred in plantations of peach-palm palmetto. Those that do appear occasionally are due to poor handling conditions. However, as in any crop, these will appear as the cultivation area grows. Peach-palm palmetto is a perennial crop which is constantly renewed through the shoots. The oldest plantation is 18 years old and continues to produce efficiently.
Fruit production. Seed germination and shoot production is the same as described for palmetto production. However, in this case it is more important to plant shoots in polyethylene bags or another type of container that allows the young plant to grow for nine months so that it can then be taken to the field when it is larger.
In cultivation for fruit production, the plants must attain their full development. The root system is therefore bigger and, because of this, greater drainage depth is required. The sowing densities chiefly adopted are 5 x 5 m and 4 x 4 x 8 m, with one or two stems being left on the rootstock.
An important aspect is the management of shoots with the aim of renewing old stocks. These must be handled in such a way that they are never absent, i.e. they must be cut before the bare stem appears because at that stage the axillary buds of the rhizome, which constitute the basic source of shoots, will have died. Shoot production is induced by eliminating apical dominance.
Harvesting the fruit is the most difficult operation of all crop management practices because of the height reached by the stems. For this reason, the stipes must be renewed when, they reach heights which make the collection of racemes too difficult, i.e. at ten to 12 years of age. To prepare for its renewal, a shoot is allowed to grow for one year or 18 months before the removal of the stem in question, which is done after harvesting. The shoot will begin to produce in the following harvesting period.
Exploitation of the peach-palm for fruit production brings with it pests and diseases of greater economic importance than in the case of palmetto. The most serious disease is Monilia sp., which attacks the fruit and is at its worst during the more humid years, especially if drainage is deficient or planting very dense. The most destructive pests are parrots, which attack the fruit. These birds, which like the fruit when it is still green. appear in huge flocks and cause considerable damage.
Production per hectare is variable, depending on the cultivar, ecological conditions and management. Under good management, plantings with cultivars of the varieties Utilis, Putumayo and Sollimões produce approximately 25 tonnes per hectare in a year of normal climatic conditions. As soon as the selections obtained can be reproduced by cloning, the yield per hectare will increase considerably.
Except in Brazil, where current domestic consumption is much greater than in the rest of the world. the palmetto is an export product, although its international market is still small (approximately 20000 tonnes per year). In this area it has to compete with the Euterpe palmetto, extracted from the forests, and which, at present, meets approximately 85 percent of international demand (Brazil's domestic consumption of palmetto from this other palm exceeds 100000 tonnes per year). However, because of its greater productivity and because of world conflict over related ecological issues, it is envisaged that the cultivated peach-palm will gradually replace the Euterpe palmetto. The following may be mentioned as factors limiting the peach-palm's development:
In genetic improvement, for the production of high-yielding varieties, the gene banks contain plants that have a very high fruit yield, and others that show great vigour and earliness for palmetto production.
Using normal plant improvement methods, this limitation can be overcome. Several gene banks have already evaluatedat least partiallythe accessions and have selected highly productive and good-quality plants for certain uses. As far as their evaluation under different ecological conditions and their subsequent distribution to farmers is concerned. the difficulty is the absence of an asexual reproduction method enabling clonal populations to be obtained.
The same process and difficulty are involved in the second stage of the use of hybridization to bring desired characteristics together and exploit the possible expression of heterosis.
The scant research which has been carried out in the industrial sphere is also a limitation. In the case of palmetto, work has only been done concerning canning problems, without concentrating on other possible uses such as dried or liquid soups, packs for fresh palmetto, toasted palmetto (crisps), etc., which offer potential for broadening the market. Palmetto is a suitable product for modern diets, as it is rich in fibre, tasty and, when dry, a nutritional product. Industrialization of the fruit has demonstrated its nutritional value (as a source of energy, beta-carotene, oil and other nutrients) for human consumption and as animal feed. The range of products that can be prepared with the fruit is similar to that prepared with various grains. Industrialization has barely begun, but it does not seem to pose any major technical problems. Its limited development is the main difficulty that normally faces a new product on its introduction to the market, a process which requires costly promotion and generally long-term investment.
The geographical regions suited to this crop are very extensive in all the countries of the American tropics and outside the continent. Even in small countries such as those in Central America. hundreds of thousands of hectares are suitable: for example, in Costa Rica these have been estimated as totaling 700000 ha. The cropping technology is adaptable to any scale.
The most pressing research requirements to raise peach-palm cultivation to a competitive level on international and local markets are as follows: