Propagation of Brazil nut (Humb. y Bonpl) seedlings using seeds in mini-greenhouses

Resumen

The species Bertholletia excelsa H.B.K., the Brazil nut, is an Amazonian species belonging to the family Lecythidaceae. It has great economic value. One of the principle means of B. excelsa propagation is via sexual reproduction (seeds), but the presence of dormancy makes it difficult to produce seedlings, mainly due to the long germination period, and uncertainties regarding timing. The purpose of the current study was to describe a technology that allows the development, in mini-greenhouses, of all processes involved in Brazil nut seedling propagation. The study evaluated response of B. excelsa seedlings to different substrates in mini- greenhouses at the scarification, germination and growth stages. Germination counts were first was performed five days after sowing, and ended at 40 days, when no further germination was observed. Subsequently, germination percentages of normal and abnormal seedlings, dormant and dead seeds were calculated. Sawdust and forest soil substrates provided a shorter husk removal time, while forest soil substrate had the highest percentage of healthy seeds. Germination rates for B. excelsa seed in mini-greenhouses were not affected by substrate type. The substrates sand and sand+sawdust showed highest B. excelsa seedling development.