Brazil Nut Plantations
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Title
Brazil Nut Plantations
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Authors
Scott Alan Mori
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Description
The methodology for growing Brazil nuts in large plantations has been developed by Müller and his associates of CPATU, Belém, Brazil. An English summary of their work is provided by Mori and Prance (1990b). As mentioned previously, most Brazil nut production is still gathered from wild trees. However, plantations are being developed in various parts of the amazon. In January 1990, I visited Fazenda Aruanã, a Brazil nut plantation located at kilometer 215 on the Manaus/Itacoatiara Road in Amazonas State, Brazil. This is a 12,000 hectare former cattle ranch partially converted to Brazil nut plantation in 1980. At the time of my visit, 318,660 Brazil nut trees were planted on 3,341 hectares. In addition, there were an unknown number of individuals growing in nearby forests belonging to Fazenda Aruanã. The original intent at Fazenda Aruanà was to plant Brazil nut trees in 20 by 20 meter grids and allow cattle grazing between the trees. At first the cattle did not eat the leaves of the trees, but later they did. As a result, the spacing was reduced to 10 by 10 meter rids and the number of cattle was reduced to 300 head. The trees in the Aruanã plantation are the result of grafting high yielding clones from the region of Abufari Amazonas where Brazil nuts are known for their large fruits and seeds. An important consideration in the establishment of this and other plantations is the provenance of the seed. Moritz (1984) has shown that fruit production as the result of fertilization between trees of the same clone is low. Based on this concept, Müller (1981) recommends that buds for grafting should be obtained from at least five different trees. A danger in using so few clones for grafting is that selecting for high fruit yield may also reduce the plantation's ability to resist future attacks of disease and insects. Root stock is grown in Fazenda Aruanã from seed. The seeds are germinated by softening them in moist sand and subsequently removing the embryo by opening the seed coat along its edges. The embryos, which are treated with a fungicide, germinate in approximately 20 days and the seedlings are grown in plastic bags or cups. When the seedlings are transplanted to the field, about 200 grams of phosphorous is added to the hole in which they are planted. Root stock is ready for grafting at about 1.5 to 2 years when the young trees have become well established in the field. Better scions are obtained if the leaves are removed from the branches 8 to 10 days before the scion is removed. This promotes the formation of vigorous buds that take better to grafting. Thirty days after the graft has been made, the root stock is ringed distally to the graft. This allows the scion to gradually outgrow the branches of the root stock. After six years, the trees begin to produce fruit. However, at the time of my visit all fruit produced until then had been used to grow more root stock or to produce seedlings for sale to others. The plantation does not appear to have problems resulting from the lack of pollinators.
had been planted to provide pollen as a food source for pollinators. Moreover there is extensive natural forest surrounding the plantation and windrows with natural vegetation transect the plantation. The windrows harbor numerous plants known to be food sources for the pollinators of Brazil nut trees. Although the trees were nearly 10 years old at the time, there was no evidence or history of disease. The owners of Fazenda Aruanã have great expectations for this plantation. At the end of 12 years, they expect yields of 4.8 kilograms per tree and $480 per hectare. At the end of 18 years, they predict 8.5 kilograms per tree and $850 per hectare.