Species of Paullinia with economic potential
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Guarana (Paullinia cupana)
Guarana (Paullinia cupana)
Botanical name: Paullinia cupana H.B.K.
Common name: guarana
Guarana is undoubtedly among the stimulants that are attracting most attention from the developed countries nowadays. All kinds of qualities are being attributed to it, from that of being a simple stimulant to an aphrodisiac, and it is now a must in the herbalist's shop. It was already cultivated at the time of the discovery and, from the seventeenth century, its seed occupied a prominent place among the products used for local consumption and export in the region of Manaus in Amazonia. According to one missionary, certain Indian tribes valued it in the same way as "the whites valued their gold". The use of guarana in Europe was documented in 1775, but information on its production up to the beginning of this century is very uncertain. The only information available for last century relates to the export of 262 arrobas (1 arroba = 11.5 kg) to Europe in 1852.
In 1923, the harvest was 3 873 kg. After a harvest of 124 000 kg in 1935, since no exports took place and domestic consumption had gone down, there was a surplus of guarana which led the government of the state of Amazonas and the producers to form the Emporio de Guarana, which was granted the marketing monopoly of the product. As from 1966, with the winding up of the Emporio, which served more as a stagnating than development factor, an industrial system for the product began to be established. The aggressive internal and external publicizing policy for guarana, adopted by the government and begun at the end of the 1940s, led to the present situation where demand is several times greater than supply.
Both official records and socio-economic studies indicate that there were two main production phases: the extraction or collecting phase, which extended up to the 1970s, and the cultivation phase from that time on.
Guarana is used mainly to produce a soft drink. For a long time, it was used empirically in medicine; it is attributed antipyretic, antineuralgic and antidiarrhoeal properties and is reputed to be a powerful stimulant, an analgesic comparable to aspirin and an anti-influenza agent. The seeds contain 2.7 to 3.5 percent caffeine as well as theophylline and theobromine. The traditional method of using guarana (the only one until the 1950s and one that is still widespread nowadays) is as follows: when the fruit has been harvested, the seeds are separated and stored until fermentation of the aril, which is then removed. They are then roasted and their seed coat is removed; this is marketed as "guarana en rama", i.e. raw guarana. The remaining seeds are immersed in water to form a paste. From this are made sticks which, after being dried over a slow fire and smoked for one month, are marketed. The traditional way of preparing the drink consists of grating part of the stick in water to produce an infusion. The guarana carbonated drinks industry began in 1907 and the product became Brazil's national drink during the 1940s. In 1973, the Law on Juices laid down regulations for the use of guarana, deeming the maximum and minimum concentrations for carbonated drinks, syrups and other products. In 1981, EMBRAPA's Agricultural Research Centre of the Semi-Humid Tropics (CPATU) developed soluble guarana. Nowadays, guarana is marketed as sticks and soluble or insoluble powder and is used industrially for the production of carbonated drinks, syrups and herbalists' products.
Guarana is a scandent shrub or woody liana. Its leaves are alternate with five folioles and, when tendrils exist, they are axillary. The inflorescences are on axillar racemes or originate on the tendrils. The flowers are male and female, zygomorphous and have five petals and sepals, eight stamens and a trilocular ovary with a glandular semi-disc at the base. The fruit occurs in a septicidal capsule. it is orangey-red and partially open when ripe, revealing one to three black or greenish seeds which are covered at the base with a white aril. The var. cupana differs from the var. sorbilis in that it has no tendrils, its folioles are more strongly lobed and its flowers and fruit are bigger.
Guarana is a monoecious, allogamous species. It is fertilized by bees of the genera Melipona and Apis. It is probably dispersed naturally by birds, although the distances to which it can be disseminated are not known. Its seeds are recalcitrant and lose their viability in 72 hours under normal conditions. Germination can take more than 100 days.
Ecology and phytogeography
The genus Paullina is predominantly neotropical, extending from Mexico and the southern United States to Argentina. A single species, P. pinnata, is found in both America and Africa.
The soils in which it is found in the native state are generally gley soils or dystrophic lateritic soils. The climate of the region of origin is Am in Köppen's classification, with an annual precipitation of approximately 2 200 to 2 500 mm. The temperature is isothermal, with an annual mean of 28 to 29°C.
The var. cupana, on the basis of which the species was described from material collected by Humboldt in San Fernando de Atabapo, Venezuela, is known only in the area between the south of the Atures and Maipures torrents of the Orinoco River and in the region of the upper Negro River and tributaries on the frontiers between Brazil, Colombia and Venezuela, where it seems to be relatively common. It is used by the natives of the Mapiripan region on the Guaviare River in Colombia. The var. sorbilis or true guarana, seems to have been domesticated in the southern strip of the Amazon River between the gorges of the Purús and Madeira Rivers. From the middle of the last century, it was cultivated in what are now the municipalities of Borba, Maués, Parintins, Manaus and Itacoatiara, and these continue to be the most important centres for the cultivation and distribution of material for other localities. The geographical disjunction between the two varieties has been attributed to anthropic factors: according to this hypothesis, the species was domesticated in the Maués region from a woody liana which reaches the forest canopy. Both the plant and the way of eating it were introduced to the upper Negro River area by the Barrés (or Bares), who gradually migrated north. Domestication of the species must have been very old to enable the formation of a new variety. According to this hypothesis, the var. cupana is a subspontaneous form derived from domesticated guarana. Regarding the existence of guarana in the native state, some information available suggests that, even today, the Maués Indians are introducing wild material into their crops in spite of the fact that it has been stated that guarana is known only in cultivation. Its presence outside the areas mentioned is poorly documented. A specimen collected at the Curuquetê River, on the border between the states of Amazonas and Acre (Brazil), seems to be P. cupana, and there are also reports that it grows spontaneously around Santarém in Para. The same thing is happening in the case of guarana as has happened with other cultivated species: botanists are ignoring them because they are not taxonomically new.
FIGURE 25 A) Guarana (Paullinia cupana);A1) inflorescences on the raceme; A2) fruit in the capsule; A3) trilocular ovary
Paullinia yoco, the other species used as a stimulant, is only known in the wild state and is distributed in a relatively small region along the Putumayo River on the frontier between Colombia and Peru.
There are two varieties of Paullinia cupana.. There is no information on the genetic variability of the var. cupana which is little known and little studied.
P cupana var. sorbilis shows a high degree of variability. It grows mainly in the planted fields of small producers in the municipalities of Maues, Parintins and Borba in the state of Amazonas. EMBRAPA has a valuable collection located in the experimental field of Maués and a gene bank with more than 200 accessions in Belém (CPATU). There is also a working collection at the CPAA/EMBRAPA in Manaus, with over 700 accessions. There appears to be no risk of genetic erosion. since both the agricultural research system and the producers are aware of the value of the material in their possession. The closest wild species belong to the Pleurotechus section of the genus. There are nine species of it in Brazilian Amazonia, all with certain morphological resemblances to P. cupana. The closest taxon is P. cuneata, which may belong to the same species (P. cupana). This, together with P. yoco, merits special attention for possible improvement programmes. The areas of greatest interest for prospecting are the basin of the Putumayo River (P. yoco) and the frontier area between Brazil, Peru and Bolivia (the Madre de Dios river basin), where P. cuneata and a species which may be a wild form of P. cupana are found. Also of great importance is the upper Negro River, including considerable portions of the Amazonia and Orinoco regions of Colombia and Venezuela. Nowadays, the var. cupana is considered to be of possible fundamental importance for the improvement of guarana.
Traditional cultivation of guarana is carried out with full exposure to sun on soils with a low fertility (exchange capacity of 20 to 40 ppm), a low acidity (pH between 3.5 and 4.5) and with high concentrations of aluminium. Fertilizers are not used. Spacing of the plants is approximately 4 x 5 m, which gives 500 plants per hectare. Alter the second year, pruning is carried out to remove old and diseased branches and those which flowered the previous year. Since 1980, a new type of management has been adopted, using the same layout but with fertilizations and pruning to direct the branches along supports. According to technical recommendations, guarana must be grown in areas with a climate similar to its region of origin, with a mean annual temperature between 22 and 20°C. The minimum temperature tolerated is 12°C. Annual precipitation must exceed 1 400 mm, with rain well distributed during the year. Soils must be deep, medium or heavy in texture, well drained and with a high organic matter content. Traditional planting is by sowing: the oldest plantations are very heterogeneous both from the genetic and the phenotypical points of view. Prominent among the more modern techniques is propagation from cuttings, for which misting chambers, grafts and tissue culture propagation need to be used.
The average production of the harvesting phase (1938 to 1970) was 175 tonnes per year, with many fluctuations. In the last five years for which cultivation data are available (1983 to 1987), the average was a little over 1 200 tonnes per year, with about a sevenfold increase over the former statistics. Although an extension of the cultivated area influenced this increase, the rise in productivity per hectare also made a substantial contribution, its average almost doubling between the first five years of the 1970s and the last five years recorded, with averages of 71.5 and 137.8 kg of seed per hectare, respectively. This increase in production can easily be attributed to the new type of management, since in field experiments production data were obtained for the traditional system (79 kg per hectare) and improved system (130 kg per hectare) which were very similar to the averages referred to.
As may be seen, Brazil's production is increasing considerably. Until the mid-1970s, the state of Amazonas was the only producer; in the last ten years, other states have begun to produce guarana, notably Bahia and Mato Grosso. In 1987, Bahia's production exceeded that of the state of Amazonas for the first time.
Outside Brazil, other countries are beginning to produce guarana. However, there is little information available. In the great majority of eases, cultivation is beginning with a very limited genetic base, since Brazil does not authorize the export of seeds for vegetative material.
Prospects for improvement
Undoubtedly the biggest limitation today is low productivity, since an average yield per individual ranges between 250 g (traditional cultivation) and 520 g (improved management) of dry kernel and therefore still leaves much to be desired. In part, this problem is strictly agronomic and will be resolved once plantings are carried out under more favourable conditions.
The selection of more productive early material that is resistant to disease and stress - a process begun in Manaus as early as 1980 - will be bound to lead to an increase in productivity, since individuals have been identified in experimental and commercial plantings with yields of between 4 and 6 kg of dry seed per hectare per year. The production of hybrids, either through traditional methods or using genetic engineering techniques, will also be of great importance, especially in conjunction with the production of clonal material which allows more uniform treatment and management to be achieved. The genetic basis for these improvement programmes already exists, not only within the available genetic stock of guarana but also of cupana, and possibly in other species of Paullinia such as P. yoco and P. cuneata. The potential market for 1983 was estimated to be around 16 000 tonnes and has increased since that year. The shortfall of guarana is around 10 to 15 times the current production volume, which still allows a considerable expansion of cultivation.
Aguilera, F.J.P. 1983. Ensaio de polinização entomófila com abelhas sem ferro (Apidae meliponini) em plantios de guaraná. In Anais do I Simósio Brasileiro do Guaraná. UEPAE/Manaus- EMBRAPA .
Carvalho, J.E.U., Kato, A.K. & Figueirêdo, F.J.C. 1983. Efeito do estado de maturaçao do fruto sobre a qualidade da semente do guaranazeiro. In Anais do I Simpósio Brasilero do Guaraná UEPAE/Manaus/EMBRAPA.
Corrêa, M.P.F., Fonseca, C.E.L. & Alvim, P.T.1983. Sistemas de cultivo do guaranazeiro. In Anais do I Simpósio Brasileiro do Guaraná, p. 317-324. UEPAE Manaus-EMBRAPA.
Corrêa, M.P.F., Kato, A.K., Escobar, J.E. & Canto, A.C. 1984. O estado atual de conhecimentos sobre a culture do guaraná. In Anales / Simpósio del Trópico Humedo (Cultivos perennes), 4: 265-280. Belém. Brazil, EMBRAPA/CPATU.
Costa, F.G. 1983. Palestra: a indústria do guaraná no Amazonas. In Anais do I Simpósio Brasileiro, do Guaraná p. 93-103. UEPAE/ Manaus-EMBRAPA.
Ducke, A. 1937. Diversidade do guaraná. Rodrigues: 155- 156.
Escobar, J.R., Corrêa, M.P.F. & Motta, A.S. 1984. Seleção de clones de guaraná (Paullinia cupana var. sorbilis (Mart.) Ducke) baseada em vigor e adaptação ao campo. In Analas Simpósio del Trópico Humedo (Cultivos perennes). 4: 295-304. Belém, Brazil, EMBRAPA/CPATU.
Lleras, E. 1983. Consideraçães sobre a distribuição geográfica e taxonomia do guaraná (Paullinia cupana var. sorbilis) e taxa afins na Amazônia. In Anais do I Simpósio Brasileiro do Guaraná, p. 281-292. UEPAE/Manaus-EMBRAPA.
Machado, O. 1946. Contribuição ao estudo das plantas medicinais do Brasil. O guaraná. Rodriguesia, 10(2): 89-110.
Maravalhas, N.1965. Estudos sobre o guaraná e outras plantas produtoras de cafeina. INPA. Publ. Avul. Quimica 10: 1-16.
Patiño, V.M. 1967. Plantas cultivadas y animales domésticos en América equinoccial, Vol. 3. Fibras. Medicina, Miscelanea. Cali, Colombia, Imprenta Departamental.
Santos, A.V.P. & Sacramento, C.K. 1983. Aplicação da culture de tecidos na propagação clonal do guaranazeiro. In Anais do I Simpósio Brasileiro do Guaraná. p. 237-239. UEPAE/Manaus-EMBRAPA.
Teixeira, S.M. 1983. Estudo do mercado do guaraná. In Anais do I Simpósio Brasileiro do Guaruná, p. 157-177. UEPAE/Manaus-EMBRAPA.
Jaboticaba (Myrciaria spp.)
Jaboticaba (Myrciaria spp.)
Botanical names: Myrciaria
cauliflora Berg., M. jaboticaba Berg., M. trunciflora Berg.
Common names. English jaboticaba; Spanish jaboticaba; Portuguese: jaboticatuba sabará, jaboticaba murta, jaboti-catuba, jaboticatuba grande jaboticaba olho-de-boi, jaboticaba-de-cabinho (Brazil)
Among the Myrtaceae, various species of the genera Psidium, Eugenia Feijoa, Myrciaria, Campomanesia and Paivaea stand out which are native plants of neotropical flora and produce fruit of commercial value. Jaboticaba, which has been cultivated in Brazil since pre-Columbian times and is much in demand in the centre and south of the country, is a promising fruit of this family. It is grown in small commercial gardens of 500 to 1000 trees and in domestic gardens.
Jaboticaba is eaten fresh and is known on account of its outstanding qualities. having an abundance of juice and a particularly sweet flavour. It is used industrially for jellies and to prepare domestic liqueurs and wines. It must be consumed immediately after harvesting, since it does not keep well at ambient temperature and lasts no more than three days.
The jaboticaba is a tree of medium habit, not exceeding 12 m in height. with a voluminous and symmetrical crown' one or more trunks and many branches. The leaves are ovate or lanceolate, 5 x 2.5 cm. smooth and shiny. The flowers occur in short racemes which emerge from the trunk, from the ground and on the main branches; there are tour white petals and numerous long stamens.
The fruit is a spherical berry, 2 cm in diameter in the Sabará variety and 3 cm in the Jaboticatuba. It is grouped in racemes of three to seven, is red initially and shiny black when ripe. Sabará is the best variety; it produces polyembryonic seeds and the majority of the embryos are apomictic, while Jaboticatuba is monoembryonic with zygotic embryos. During flowering in spring, particularly in areas with dry winters, the tree flowers abundantly with the first rainfall giving the Impression that the trunk is covered with snow.
Ecology and phytogeography
As a subtropical, deciduous species, jaboticaba is frost-tolerant. In tropical conditions it does not flower as abundantly as in the areas where the winter is cold and dry. Flowering can be brought forward with irrigation, but the flower buds must already be developed. From ten to 20 days elapse between flowering and fruiting. Fruiting is very short and harvesting does not exceed two weeks.
The species is distributed from lat. 21 °S in the state of Minas Gerais to Rio Grande do Sul. at lat. 30°S, always at altitudes higher than 500 m. It grows best in groups, on deep, acid and fertile soils. However, there are wild populations which have withstood the felling of forests in Minas Gerais, São Paulo and Rio Grande do Sul.
The most widespread species, Myrciaria cauliflora, produces apomictic embryos and, for this reason, shows very little genetic variability, while the zygotic species, Jaboticatuba, shows much variation but is a much rarer plant. Other Myrciaria species are little known.
Propagation and cultivation techniques
The preferred method of propagating jaboticaba is from the seeds, which are recalcitrant and not resistant to desiccation. They are sown 10 cm apart in a fertile seed bed, with 30 cm between the rows, where they remain for one year. When they are 10 to 15 cm high, they are transplanted to the nursery with a rootball and spaced 1 m apart with 2 m between rows. They stay in the nursery from three to five years and. when they reach 1.5 m in height, are planted out in the garden with the rootball measuring 60 cm in diameter. The plant's growth is slow. It is planted out at 6 x 6 m or 6x4 m' end it does not matter if the crowns are close together.
Various vegetative propagation techniques are used to obtain earlier plants, mainly through root cuttings, layering and grafts. However. the tree's development is always slow. In this species it is advantageous to have the greatest area of trunk and branches from which the fruit emerges. Since early production delays the plant's development, the only advantage of vegetative reproduction would be the possibility of planting at a greater density, such as 4 x 2 m.
Prospects for improvement
There is no advantage in the genetic improvement of jaboticaba. However, crossing Jaboticatuba, which produces large fruit and zygotic embryos, with the cultivar Sabará, which is of better quality but produces smaller fruit could be recommended. As 1 00 percent of hybrids would be obtained, it would eventually be possible to obtain selections of jaboticaba bearing large fruit of better quality.
Arazá (Eugenia stipitata)
Botanical name: Eugenia stipitata McVaugh
Common names. English: arazá; Spanish: arazá (Peru); Portuguese: araçá-boi (Brazil)
Eugenia stipitata includes two subspecies: stipitata, from the state of Acre in Brazil, and sororia, which is more widely distributed from the basin of the Ucayali River in Peru. The latter seems to have been semi-domesticated in western Amazonia, although it may have originated in the southeastern portion of Amazonia. The arazá must have undergone a long process of selection by the Amerindian communities, as can be deduced from the large size of the fruit which, within the cultivated material, can be as large as 12 cm in diameter and 740 g in weight, compared with the wild populations which do not exceed 7 cm in diameter and 30 g in weight.
The species is still in the full process of domestication. The two institutions which have worked most on this fruit are INIAP's experimental station of San Roque in Iquitos, Peru, and INPA in Manaus. Brazil.
Today, the arazá is cultivated on small properties throughout the basin of the Solimões (Alto Amazonas), not as a commercial crop but as part of the complex mosaic of crops characteristic of the traditional agriculture of the region. It is relatively common on the town markets of Tefé, which is midway between Manaus and Iquitos.
FIGURE 26 A) Jaboticaba (Myrciaria spp.); A1) cross-section of the fruit; B) arazá (Eugenia stipitata)
Uses and nutritional value
Arazá is used to make juices, soft drinks, icecream, preserves and desserts. The fruit is rarely eaten raw because of its acidity (pH 2.4 in the case of the juice). Unlike camucamu (Myrciaria dubia) more than 20 percent of whose fresh weight is represented by 2 percent of ascorbic acid, arazá's potential is due to its intrinsic characteristics as a fruit: pleasant flavour, colour, texture and smell.
The nutritional value of arazá is very similar to that of oranges, with the exception of the vitamin C content which is more than double in arazá.
The arazá is a shrub or small tree which grows up to 2.5 m, with a fair degree of branching from the base. The leaves are simple, opposite, elliptical to slightly oval and measure 6 to 1 8 x 3.5 to 9.5 cm. The apex is acuminate, the base rounded to subcordate and the primary and secondary nervations are fairly evident. The inflorescences are in axillary racemes, usually with two to five Powers which are 1 cm wide and pedicillate, have four rounded sepals and five white, ova] petals. There are numerous stamens and an ovary with three or four locules. The fruit is a subspherical berry, reaching 12 cm in diameter and weighing 750 g when ripe; the flesh is yellow and thin; the skin is shiny, velvety and yellow, with few seeds which are oblong and measure up to 2.5 cm.
The subspecies stipitata has fewer stamens and an arboreal habit, whereas the subspecies sororia has a shrub habit and has more stamens.
Ecology and phytogeography
The arazá is a species of semi-open or open areas. Most of the wild populations are found on old, non-floodable terraces in tropical, white, highly leached podzolic soils, which are distributed specifically within the area between the Marañón and Ucayali Rivers and where the Amazon begins and as far as Iquitos (ssp. sororia). The camucamu and arazá have sclerophyllous leaves, which makes them very efficient in absorbing nutrients and utilizing water.
It is not surprising that the arazá can produce between 20 and 30 tonnes of fruit per hectare annually without any great selection or improvement effort and that, under cultivation on Amazonian terraces, it is more productive than the camucamu.
Although there are no detailed studies on its reproductive system, on the basis of its floral morphology, the species must be allogamous with optional autogamy, since rates of autogamy of around 2 percent are recorded. This would enable it both to maintain a high evolutionary potential and have some degree of adaptation to its environment.
The species is harvested several times a year. If a comparison is made of the production curves of. flowers and fruit with precipitation during the same period, it will be seen that they coincide fairly well with an out-of-phase period of approximately one month, which suggests that the water conditions serve to promote the phenological processes.
No data are available on the genetic variability of the arazá. The tact that it shows optional allogamy suggests that it has a high degree of heterozygosity which corresponds to what is expected of the majority of the species of the region.
Dispersal over a long distance is probably effected by birds and possibly fruit-bats, with very variable dispersal distances, thus allowing an exchange of genes between distant populations. There is likely to be a bigger difference within one and the same population than between populations. However, the fact that two subspecies exist in relatively restricted areas suggests that dispersal over a long distance is not very effective and that there are barriers to its distribution which are difficult to explain from the ecological point of view. Genetic variability does not seem to be in danger. However, there are only two collections of germplasm: that of San Roque. with 50 accessions, and that of INPA, with five accessions.
Seed beds. The seeds are recalcitrant and, after 40 days in cold storage, they lose more than 70 percent of their viability. Consequently, seed beds must be established in the first five days after the seeds have been harvested.
The seed beds are kept completely in the shade; the seeds are planted 2 cm apart and only lightly covered, as greater coverings inhibit germination. As a seed bed, partly decomposed softwood is recommended while the use of earth is not advised. Germination is not uniform and may take up to 80 days; in the conditions described, the germination rate may reach around 100 percent.
Nurseries. The seedlings are kept in the seed bed until they reach a height of 7 to 10 cm. They are then transplanted into 6 to 8 kg polyethylene bags filled with a mixture of earth and 10 percent manure. The plants stay in the bags for up to one year; six months in the shade and 6 months in partial shade.
Planting out. After one year, the plants are planted out on their final site. In San Roque, distances of 3 x 3 m have been adopted, with holes measuring 50 cm deep and 30 to 50 cm in diameter. The soil is mixed with 0.50 kg of manure. It is recommended that weeds be eliminated from the planted area each month and organic material added to the soil. Experimental results on fertilization suggest that organic fertilizer with manure is preferable to chemical fertilizers.
In Amazonia. it is recommended that chemical fertilizers not be used since their possible effect on the environment is unknown. In addition, the cost of these applications may make the crop economically unviable. In fertilization trials, chemical fertilizers had no influence on fruit formation (between 20 and 40 percent, average 25 percent) or on the total yield, which justifies not recommending its use in the region.
Prospects for improvement
It is difficult to predict the upper limits of arazá production, as it is still in an early phase of domestication. The genetic base is not known and knowledge about management practices is so limited that it is impossible to make realistic projections. Undoubtedly, under suitable cultivation conditions. its productivity may be somewhat higher than at present while its cultivation in other regions may amply justify chemical fertilization.
There do not appear to be any serious plant health problems. The species suffers heavy attack from the fruit fly, which reduces the normal density of plantings if sophisticated biological control measures are not adopted.
The success of arazá as a widespread crop will depend above all on technological developments that facilitate its acceptance on markets outside the region. Any improvement or selection programme will have to involve parameters such as appearance, colour, smell, palatability and resistance of the fruit to transportation and storage.
Feijoa (Feijoa sellowiana)
Botanical names: Feijoa sellowiana O.
Berg, F. sellowiana var. rugosa Mattos
Common names: feijoa (throughout the world); English: feijoa (throughout the world), pineapple guava (United States); Spanish: guayabo grande, guayabo chico (Uruguay); Portuguese: goiaba serrana, goiaba verde, goiaba abacaxi (Brazil)
The feijoa is a subtropical fruit, known in southern Brazil. northeastern Argentina, Uruguay and eastern Paraguay since pre-Hispanic times. It has been known on the French Cote d'Azur since 1890, when it was introduced through seeds from Argentina by Professor Edouard André of the Versailles School of Horticulture. In 1990, it was introduced into California, where its cultivation has spread. In Uruguay, it has been grown commercially for 50 years. It is grown and greatly valued in New Zealand. In Brazil, studies and the selection of varieties have been carried out but it has never attained any commercial importance.
The fresh fruit is widely consumed because of its characteristic flavour and aroma, which are similar to pineapple. The fleshy petals of its beautiful flowers are also appreciated. In addition, there is a wide variety of industrialized products on the market in the form of paste, jam. crystallized fruits. preserves in syrup and liqueur. The flesh can be used in the soft drinks and ice-cream industries.
The feijoa plant is a shrub or small tree, 3 to 5 m in height and very branching. It has cylindrical trunks which are a reddish ash-grey in colour, with small pieces peeling off from the bark. The leaves are opposite, short petiolate, with lamina that are 2 to 5 cm long by 1 to 3 cm wide, coriaceous and oblong, with a shiny dark-green upper surface and whitish lower surface. It has axillary uniflorous peduncles. The flowers have four fleshy, oval petals which are white on the outside and purple on the inside, with four persistent sepals. There are numerous erect purple stamens. The fruit is oblong or spheroid, 5 to cm long and 3 to 7 cm in diameter. There are smooth or rough varieties of fruit which are green and yellow in colour. The feijoa flowers in spring and the fruit ripens in autumn from March to May in the Southern Hemisphere and from October to December in the Northern Hemisphere. The early varieties ripen in March, while the late varieties do so from April onwards in the Southern Hemisphere.
Ecology and phytogeography
The species is widely distributed in the southern part of South America, from lat. 26°S in southern Paraná in Brazil, to lat. 35°S in Uruguay, including northeastern Argentina and southern-central Paraguay. In Brazil there are still wild populations in forests (gallery) and deforested areas on sites at altitudes over 500 m, for which reason it is known as goiaba serrana or "mountain guava". It frequently occurs in the states of Santa Catarina and Rio Grande do Sul, in the cima da serra, upper northeastern coast and southwestern serra regions and in Santana do Livramento. At these sites, the summer is hot and rainy and the winter reaches temperatures of 0 to 8°C, sometimes dropping to -4°C.
It is a cross-pollinated plant and self-sterility is frequent. However, there are self-fertile selections. When it has been propagated from seed, it displays great genetic variability, both in the wild and in gardens. Variability is shown in the form and habit of the plant and in the characteristics of the fruit. In Uruguay, 11 cultivars are known, prominent among these are: Botali, because of its size - the fruit measures 6.5 x 3.8 cm - its pronounced flavour and late ripening: and M-4, which is round, a beautiful reddish yellow colour and extraordinarily sweet. In Brazil Santa Elisa and Campineira have been bred; the first is of average size, 4.5 x 3.5 cm, smooth, sweet and flavoursome while the second is ridged and also oblong. In California, Coolidge, Superb, Choiseana, Triumph and Hehre are cultivated. In France, André and Besson are of excellent quality.
FIGURE 27 Feijoa (Feijoa sellowiana),shapes and cross-sections of the fruit
Feijoas are propagated from seed, layering, cutting and grafting. Propagation from seed produces very heterogeneous plants. Consequently, this method is used only in the production of rootstock and in small domestic gardens. The seeds are recalcitrant and are therefore sown as soon as they are collected, either in seed beds, using the conventional technique, or directly into 30 x 20 cm polyethylene bags. They are transplanted into the nursery at a distance of 1 x 0.40 m until they reach a height of 60 to 80 cm, or are grafted with selected varieties. Layering is a tedious method, used for the production of a small number of plants.
Propagation from semi-ligneous, leaf-bearing, terminal shoots is very much to be recommended. They must be 10 to 15 cm long, treated with rooting hormones and placed in glass or plastic frames saturated with moisture. They put out roots in 15 to 20 days. The rooted cuttings are transferred into 30 x 20 cm polyethylene bags in which they remain for one year until they reach a height of 60 to 80 cm, at which stage they are planted in gardens.
Grafting is by a side grain on rootstock existing in the nursery or in polyethylene bags. The technique is known as Veneer" grafting. When the young plants from a grafted cutting reach 60 to 80 cm in height, they are transplanted into the garden at a distance of 6 x 3 m or 6 x 2 m, which will give 550 to 850 saplings per hectare. With an average production of 1 000 fruits per adult tree and fruits weighing 30 to 60 g, these densities produce yields ranging from 16 to 50 tonnes per hectare.
Feijoa fruit is attractive to fruit flies, mainly Anastrepha sp., particularly in places with high temperatures in South America, and Ceratitis c capitata in the Mediterranean and in high areas in South America.
The fruit is fairly resistant to transportation. However, for the fresh fruit market it requires special care from harvesting, packaging and cold storage to transportation. In industry it does not require such care, and even fruit that has fallen to the ground can be collected if it is unblemished.
Prospects for improvement
The green colour of the fruit of most of the known varieties is considered a drawback from the marketing point of view because it is not very attractive. For this reason, yellow and red cultivars are sought. Partial or total self-sterility is another problem that affects production. There is a need for sell:fertile selections and studies on pollinating compatibility between varieties.
Feijoa cultivation can be expanded through the subtropical regions which do not have harsh winters, but this species needs to be better known, particularly its characteristics and cultivation conditions. The availability of germplasm may contribute to the expansion of this valuable fruit of neotropical flora.
Anderson, O. & Anderson, V.U. 1988. As frutas silvestres brasileiras. Publicações O Globo Rural.
Berg, O.C. 1857-59. Myrtaceae. In Flora brasiliensis. Martius. C.F.P.
Cavalcante, P.B. 1988. Frutas comestíveis da Amazônia. Museu Paraense Emilio Goeldi, 4th ed. Souza Cruz, Belém, Brazil.
Chavez, W.B. & Clement, C.R. 1984. Considerações sobre o araçá-boi (Eugenia stipitata McVaugh, Myrtaceae) na Amazônia brasileira. Anais Congr. Bras. Fruticultura 7: 167-177
Clement, C.R. 1991. Frutas de la Amazonia: descuidadas y amenazadas pero todavía recursos potencialmente ricos. Diversity 7: 62-64.
Falco, M.A., Chavez, W.B., Ferreira, S.A.N., Clement, C.R., Barros, M.J.B., Brito, J.M.C. & Santos, T.C.T. 1988. Aspectos fenológicos e ecológicos do araçá-boi (Eugenia stipitata McVaugh) na Amazônia central. I. Plantas juvenis. Acta Amazónica 13: 27- 38.
Hoene, F.C.1946. Frutus indígenas. Instituto de Botânica, Sc. Agric. Ind. e Com.
Legrand, C.D. & Klein, R.M.1977. Mirtáceas. In Flora ilustrada de Sunta Catarina. Mirtáceas. Itajaí. Brazil, Reitz, R.
Legrand, C.D. & Klein, R.M.1978. Mirtáceas. In Flora ilustrada catarinense p. 733-777. Itajaí, Brazil, Reitz, R.
Mattos, J.R.1986. A goiabeira serrana. Instituto de Pesquisa de Recursos Naturais Renováveis. Sec. Agricultural R.G. Sul. Publicações IPRNR, 1984.
Pinedo, M., Ramírez, F. & Blasco, M. 1981. Notas preliminares sobre el arazá (Eugenia stipitata), frutal nativo de la Amazonia peruana Publicación Miscelánea No. 229. Lima, IICA.
Popenoe, W.1934. Manual of tropical and subtropical fruits. New York, Macmillan.
Roosmalen, M.G.M. 1984. Fruits of the Guianan flora. The Netherlands, Institute of Systematic Botany, Utrecht University.
Tamaro, D. 1964. Tratado de fruticultura 4th ed. Barcelona, Spain, Gustavo Gil.
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