Figure 29. A) Maté (Ilex paraguariensis); A1) inflorescence; A2) flower; A3) fruit; A4) gourd and tube for consuming the infusion
The author of this chapter is G.C. Giberti (Centre of Pharmacological and Botanical Studies, Buenos Aires, Argentina).
Family: Aquifoliaceae
Common names. English: maté, Brazilian tea, Paraguay tea: Guarani: ka'a; Kaingangue: kongóñ: Spanish: yerba maté, té de los jesuitas: Portuguese: congonha, erva maté
Maté, with a very restricted distribution outside America, is a tree that produces a raw material for industrialization and consumption as a stimulating infusion. So far, this has been the main use of this somewhat overlooked crop.
Although no archaeological remains have been found that show that it was used in pre-Columbian times. it is assumed that it was the Guarani Indians who taught the Spanish how to use it. However, what seems to be an indirect consequence of the discovery is the fact that the first people to have cultivated this species were the Jesuit missionaries who, around 1670, already had artificial maté plantations. In time, the settlements of Guarani Indians converted to Christianity were to become economically dependent on maté production.
The expulsion of the Jesuits from the Spanish dominions (1767) was a step backwards in the history of maté. There was a return to the forest exploitation method which utilized the natural maté plantations exclusively and inadequately. It may be said that this type of laborious and uneconomical forest management extended up to the first decades of the twentieth century, in spite of maté planting having been renewed in Nueva Germania, Paraguay and in Santa Ana, Argentina, in 1897.
Although very much reduced, maté production did not disappear with the Jesuit plantations. During the remainder of the colonial period, the use of this herb, which had spread extensively, persisted even in the region of the Viceroyalty of Peru, where there was another methyl xanthine stimulant of the same genus: Ilex guayusa Loes. emend. Shemluck, also marketed by the Jesuits from that region in Quito.
It has been established that trade in maté was not interrupted and that it was commonly used in what is now Peru and Ecuador. However, following the independence of the Spanish colonies and the adoption of free trade, English tea began to be introduced into those countries and so maté gradually lost the markets of those Andean countries.
The decline and complete disappearance of the maté plantations in the settlements of Christianized Indians (which ended around 1820 after a series of wars waged in the region between the Spanish and Portuguese Crowns, followed by the struggles for independence) and the policy of isolation and control of international trade maintained by the first governor of independent Paraguay meant that, in the 1820s, Brazil began commercial exploitation of its natural maté plantations.
The most accessible plantations were situated in the vicinity of Curitiba, Paraná, and as they were slowly exhausted they were gradually replaced by the others located towards the west. The Brazilian product, which then began to spread on the markets as "Paranagua maté", was considered to be of inferior quality to that from Paraguay. However, in the course of time it replaced the Paraguayan product, a development which became more marked after the war of the Triple Alliance ( 1870).
At the end of the nineteenth century, the limitations of the exhaustive exploitation of this forestry resource stimulated efforts to produce large plantations of I. paraguariensis once again. Eventually. these efforts were successful, especially in Argentina.
At the same time as the increase in Argentinian maté production, the extraordinary expansion of the agricultural frontiers in traditional maté-growing states of southern Brazil (Paraná, Santa Catarina. Rio Grande do Sul, Mato Grosso do Sul) took place. Regrettably, the disappearance of enormous areas of natural forests in those states jeopardized the conservation of maté's genetic richness.
The complicated economic history of this crop (barely sketched out here) which is characterized by periods of scarcity alternating with periods of excessive demand, the sporadic but real existence of periods during which it was adulterated with other plants and the most common method of preparation—maté sucked through a small tube—considered by many to be unhygienic, had a bearing on the limited spread of maté outside southern South America.
Its main use is in infusions prepared as tea with leaves and dried stems which have been industrially shredded. Generally speaking, it is drunk by tilling small gourds (maté gourds or cuias) with maté. to which boiling water is gradually added, the liquid being sucked up through a metal tube (the bombilla). Infusions of cimarrón, or bitter maté, are usually modified with sugar (sweet maté), milk or aromatic herbs. Other methods of consumption are boiled maté, tereré (maté prepared with cold water, common in Paraguay and northeastern Argentina), liqueurs prepared with maté, ice-creams, desserts, etc. The industry also produces compound maté (which contains aromatic and/or medicinal herbs), soluble maté and maté teabags.
The aqueous infusion of maté owes its stimulant properties to the caffeine content (between 1 and 2 percent) so that, 60 minutes after consuming maté, an average of 80 to 120 mg of this pseudoalkaloid is consumed. Its nutritional qualities are due to its content of vitamins A, C and B complex and the existence of minerals (P, Ca and Fe).
Argentina, the main producer and consumer, grows around 130000 ha of maté in the northeast of the country (Misiones and Corrientes), which produce about 140000 tonnes per year. Brazil is the world's second producer, followed by Paraguay. For the Argentinan province of Misiones, maté cultivation represents an important part of the country's GDP.
The maté is a dioecious evergreen tree which grows up to 18 m in height. The leaves are alternate, coriaceous and obovate with a serrate margin and obtuse apex. The inflorescences are in corymboid fascicles, the male ones in a dichasium with three to 11 flowers, the female ones with one or three flowers. The flowers are small, and simple, number four or five and have a whitish corolla. The fruit is in a nucule; there are four or five single seed pyrenes (propagules).
Maté flowers in the spring (from October to November), has entomophilous pollination (diptera, hymenoptera) and fruits from March to June; dissemination is endozoic (birds). There is a rudimentary embryo in many externally ripe seeds which causes a long period of germination From the time of sowing.
Figure 29. A) Maté (Ilex paraguariensis); A1) inflorescence; A2) flower; A3) fruit; A4) gourd and tube for consuming the infusion
Prominent among the ecological requirements of this subtropical species are climatic conditions, especially mean annual precipitation and an even distribution of rainfall throughout the year. This must not be less than 1200 mm annually and, during the driest quarter—which in the region is winter—the minimum must be 250 mm. I. paraguariensis' wild distribution area is always unaffected by water shortages. The mean annual temperature of the area is approximately 21 to 22°C. The absolute minimum temperature that this species is able to tolerate is -6°C, even though winter snows are frequent on the plateaus and mountain regions to the south of Brazil and east of Misiones.
It requires lateritic, acid (pH between 5.8 and 6.8) soils that are of medium to fine texture.
Figure 30 shows the natural distribution of I. paraguariensis. The area of economic cultivation of maté coincides approximately with the main dispersion area of the var. paraguariensis.
Figure 30. Distribution area of Ilex paraguariensis var. paraguariensis and var. vestita
There is still no exhaustive modern picture that explains in biological terms the infraspecific variability of this species, which is widely dispersed geographically in South America. Up to the present, taking as a basis the morphological characteristics alone, at least two varieties are recognized: I. paraguariensis A. St-Hill var. paraguariensis (cultivated maté, almost completely glabrous) and I. paraguariensis var. vestita (Reisseck) Loes. (not acceptable for industrialization, of dense pubescence). Both varieties coexist in limited areas of Brazil.
The wild species closest to I. paraguariensis belong to the subgenus euilex Loes., subsection repandae Loes. Only I. cognata Reisseck lives in the distribution area of maté. I. cognata is very little known; its vernacular name is chá do mato and it is used to adulterate maté.
A number of wild species of Ilex are sympatric with genuine maté and have been, or are, used to manufacture the product although, up to the present and according to the legislation in force, they are to be considered adulterations. Of those most frequently referred to, the following deserve mention: Ilex affinis Gardner (the ca' a chirí or congonha of Goyaz, a species abundant in central Brazil and northeastern Paraguay); I. dumosa Reisseck var. guaranina Loes. (yerba señorita, aperea ka'a, cauna, caá chiri), native to Paraguay, Argentina and Brazil, the producer of a bitter-tasting maté and supposedly cultivated in Misiones by the Jesuits to produce their famous "caá miní" maté; I. theezans, C. Martius ex Reisseck (cauna de folhas largas, ca'a na, congonha), a good substitute for I. paraguariensis, found in Paraguay, Argentina and Brazil. I. brevicuspis Reisseck, known as cauna or voadeira, like the previous species, is a faithful companion of I. paraguariensis in plant communities characteristic of the region—where Araucaria is also prominent—but the product obtained from its experimental industrialization is of low quality.
Outside the natural area of distribution and production of maté, in northwestern Argentina and southeastern Bolivia, Ilex argentina Lillo, a related species that is known not to accumulate caffeine but theobromine, has been used to prepare maté. It is a tree characteristic of the area of transition between the forests of Myrtaceae and alder (Alnus spp.) of the phytogeographical province of the yungas.
Known cultivars of I. paraguariensis. The infraspecific classification of I. paraguariensis is still under study. Consequently, the correspondence between the biological varieties and the horticultural varieties of genuine maté is not clear. Following is a list of some of the varieties recognized as such by growers in the three countries: Erva de talo roxo, Erva de talo branco, Erva piriquita (Brazil); Caá verá, Caá manduví, Caá panambi, Caá cuatí, Caá ñú, Caá eté, Caá mi, Caá chacra, Caá-je-he-ni (Paraguay); Yerba colorada, Yerba señorita, Caá miní (Argentina).
INTA in Argentina recently began to distribute seeds of clones and selected clonal progeny which, following comparative trials, demonstrated their superiority.
In wild South American Ilex species and in the maté-growing region, the risks of genetic erosion are high because the natural forest is gradually giving way to agroforestry and livestock production, a process accentuated by the relatively low germinating capacity of many species (especially that of maté). As no suitable method has yet been discovered for maintaining the germinating capacity of I. paraguariensis for prolonged periods, there are no seed banks of the species. Nevertheless, at the Cerro Azul de Misiones experimental agricultural station in Argentina, a maté clonal garden began to be developed in 1976, complemented by the nursery started in 1986 with I. paraguariensis of various origins and with other species of Ilex.
In the wide and varied economic production area of maté, the practices for the cultivation or exploitation of natural maté vary considerably in their technical aspects, resulting in different yields per hectare.
Three methods of production can be distinguished which are arranged here in increasing order of importance reflecting the use of techniques and their yields:
Extractive exploitation of the natural forest. Here the richness of natural maté plantations is utilized. Harvesting is not mechanized and the pruning system is generally incorrect. This form of production is diffused mainly in Brazil.
Mixed system or system for the enrichment of the natural forest. This consists of increasing the number of natural plantations and reconstituting those that have been lost. In Brazil, where this method is most commonly practiced, it is called densifying the maté plantation. Since, generally speaking, this technique is accompanied by others that increase the yield, such as cultivation care and improved pruning methods, the higher production cost is compensated for.
Cultivated maté plantations. This is undoubtedly the best system, and came into general use in Argentina around 1915. In spite of higher costs, the yield per hectare greatly increases. Complemented by measures such as improvement in the layout of plantations (which have evolved from trees planted in quincunxes, with spaced out plants used by Jesuits, to cultivation following contour lines, with a high density per hectare and use of the corte mesa pruning and plant management system), with well-timed pruning, cultivation work and harvesting, this system enabled Argentinian production to exceed that of Brazil, in spite of the former being carried out in a very reduced area and even outside the environments most suited for maté. For example, rising from a density of 1000 to 1500 plants per hectare (still fairly widespread) to a density of 2500 or 4000 plants per hectare, production can increase from around 1000 to 1800 kg to 2100 to 3300 kg per hectare.
The corte mesa system not only increases the yield but is also better suited to mechanical harvesting.
Yields are improved by: planting following contours; the use of natural or introduced cover (rape, legumes, etc.); fertilization (NPK); weed control (mechanical and/or using herbicides); suitable phytosanitary treatments; and rational harvesting. The relevant experiments have been going on for some years but, regrettably, their results have not become generalized. The introduction into cultivation of improved cultivars is much less widespread.
Conventional propagation techniques. Sexual propagation ("seeds" = pyrenes). This is the most common reproduction technique. In the case of maté, the advantage of sexual propagation lies in the fact that the variability in descendants may give rise to individuals better suited to different environments (which on other occasions may not be desired).
The seeds are harvested in the region (from February to April). They must be stratified or sown immediately, otherwise they quickly lose their viability.
Stored at 5°C, they maintain a very reduced germinating capacity (1.7 to 6.6 percent) for a further 11 months. The relatively short period of viability together with the low germination rate (immature embryos, phytosanitary problems) have undoubtedly been the cause of the difficulties in its cultivation spreading to other continents in the past.
Agamic reproduction. Grafting, propagation by cuttings and layering are not very widespread. It is relatively difficult to obtain rooted cuttings and this is generally achieved by using young branches from the stools, irrespective of whether plant hormone treatment is used. Additional experiments are necessary if the intention is to increase the rooting percentage.
In vitro cultivation of I. paraguariensis is being tried out in Brazil and Argentina by various research groups, with varying results which still do not clearly indicate which are the economically viable techniques for the clonal reproduction of selected individuals.
According to the Under-Secretariat for Agriculture and Livestock, in Argentina in 1988, the average yield of semi-processed maté was 1220 kg per hectare.
The limitations of cultivation are due to the fact that there is no demand for the product on a macroeconomic scale. The recurrent cycles of surplus supply, low prices, disinvestment in plantations, scarcity of raw materials, high prices—very often linked with international trading terms between producer countries, which result in a greater distortion—have historically acted against a stable supply of the product in terms of quality and quantity. Even worse, they have discouraged the continuation of basic and/or applied research, which cultivation and processing require. The partial or total absence of knowledge concerning maté biology, plant chemistry, dietetics, agronomics and industrialization have made it difficult to adopt international standards which would lay down norms for the quality of the product and improve and guarantee it over time, depending on its distribution to the major international markets for the production of methyl xanthine infusions.
Potential areas for the introduction of this crop are subtropical regions with acid soils and a water supply similar to those of the species' natural area of dispersal.
It has recently been suggested that Ilex verticillata, a North American species, could be a source of biodegradable detergents because of its high saponin content. Since research regarding similar subjects is being continued on I. paraguariensis and, furthermore, since other related species are studied even less than maté from the chemical point of view, it would be advantageous to go into these aspects more deeply.
Ilex argentina is also a possible caffeine-free maté and is, moreover, remarkable for its richness in liver-protecting phenolics similar to those in artichokes (Cynara scolymus).
There are also reports of a range of non-traditional uses for I. paraguariensis, for instance as a source of edible oils, furfural and cosmetics.
Finally, the importance of the wild Ilex species in genetic improvement of the crop should be mentioned.