Emergência de plântulas de tucumã (Astrocaryum aculeatum) em função do pré-tratamento das sementes e da condição de semeadura

Abstract

RESUMO -O objetivo desta pesquisa foi avaliar os efeitos de diferentes condições de embebição das sementes, associadas a diferentes substratos e ambientes de semeadura, sobre a emergência de plântulas de tucumã (Astrocaryum aculeatum). O delineamento experimental foi o inteiramente ao acaso, em esquema fatorial 2 (condições de embebição da semente: à sombra e a pleno sol) x 3 (substratos de semeadura: areia, serragem de madeira e areia + serragem) x 3 (sombreamentos do viveiro: 30%, 50% e 70%), com três repetições de 25 sementes. A semeadura foi feita em caixas de plástico, contendo os diferentes substratos, cobertas com filme de polietileno transparente, formando um estufim. A emergência e o índice de velocidade de emergência (IVE) apresentaram efeito de interação entre os fatores "condição de embebição" e "substrato de semeadura". A semeadura em serragem de sementes embebidas à sombra (26-27 ºC) proporcionou emergência de 73% e IVE de 0,710, sendo esses valores significativamente superiores aos obtidos em sementes embebidas a pleno sol (26-42 ºC), que alcançaram 58% e 0,578, respectivamente. Os sombreamentos de 30% e 50% proporcionaram o mesmo percentual de emergência (68%), que foi superior aos 44% de emergência alcançada sob 70% de sombreamento. Os ambientes de semeadura com maiores amplitudes térmicas (13-14 °C) e que atingiram maiores temperaturas médias (38-39 °C), favoreceram o processo germinativo de sementes de tucumã. Desse modo, o melhor desempenho de emergência de plântulas foi alcançado com pré-embebição das sementes à sombra e semeadura em serragem de madeira, sob estufim mantido em viveiro com sombreamento de 30% e 50%. Termos para indexação: Arecaceae, embebição, substrato, temperatura, estufim. EMERGENCE OF TUCUMÃ (Astrocaryum aculeatum) SEEDLINGS ACCORDING TO SEED PRE-TREATMENT AND SOWING CONDITIONABSTRACT -This research evaluates the effects of different conditions of seed soaking, associated with different substrates and shade levels on the emergence of tucumã (Astrocaryum aculeatum) seedlings. The experimental design was entirely randomized with three replicates and 25 seeds. The treatments form a factorial of 2 conditions of seed soaking (shade and full sun) x 3 sowing substrates (sand, sawdust and sand + sawdust) x 3 levels of shade (30%, 50% and 70%), The seeds were sown in plastic boxes containing the substrate and covered with transparent polyethylene film, forming mini greenhouses. The emergence and emergence velocity index (EVI) showed interaction between the factors "soaking condition" and "sowing substrate". Seeds soaked in the shade (26-27 ºC) and sown in sawdust showed 73% emergence and an EVI of 0.710, values significantly higher than those (58% and 0.578) obtained for seeds soaked in full sun (26-42 ºC). The 30% and 50% shade levels gave the same percentage of emergence (68%) which was higher than the 44% emergency obtained with 70% shade. Environments with a higher temperature range (13-14 °C) and higher average temperatures (38-39 °C) promoted the process of seed germination....

Seed germination at different stratification temperatures and development of Phytelephas macrocarpa Ruiz & Pavón seedlings

“…Alternating temperatures are generally less favorable than the constant ones for the germination of seeds from lots of palm trees; the difference between high and low temperatures must be equal or higher than 10 ºC (Baskin and Baskin, 2014a). In Astrocaryum aculeatum G. Mey, Ferreira et al (2010) verified that planting in growing houses with wider heat amplitudes (13-14 °C) and higher average maximum temperatures (38-39 °C), helped the germination process. Anyway, high temperatures seem to have a regulatory role in the process of overcoming dormancy, confirming what was said by Orozco-Segovia et al (2003) and Schlindwein et al (2013).…”

“…Each box was covered with agricultural film (150 Journal of Seed Science, v.39, n.1, p.020-026, 2017 micron thickness), in order to create a growing house, similar to the one adopted by Ferreira et al (2010), in the germination Astrocaryum aculeatum G. Mey. The boxes were kept in a natural environment, under a canvas vivarium (3º5'29.66"S; 59º59'34.65"W) with 50% shadowing, for 345 days.…”

“…Phytelephas macrocarpa Ruiz & Pavón (Arecaceae), known as ivory palm, is a species occurring in understories of the dry land rainforest, in plains from old floods or inundated plains of rivers in the Southeastern Amazon, in a region reaching territories from Peru, Brazil and Bolivia (Henderson et al, 1995). It is a palm tree with different uses, particularly the leaves, used to cover constructions, create baskets (utilities and handicrafts) and ropes (fibers), and the seeds, whose liquid or jelly endosperm is appreciated as human and animal food; when solidified, it is used as a substitute raw material for animal ivory, in the creation of jewelry and handicrafts (Costa et al, 2008).…”

Efeito da Astrocaryum aculeatum (Tucumã) na toxicidade da Doxorrubicina: modelo experimental in vivo

“…(1,2) This is an exceptionally tolerant species to acidic and nutrient poor soils, which is characteristic of the Amazonian region. (3) The fruit has an ovoid shape, whose fibrous mesocarp provides a high nutritional content. The pulp is well appreciated, and consumed in natura by the population, or as a filling in sandwiches, tapiocas, custard, ice cream, and flour.…”

Efeito da reidratação na germinação de sementes de açaí (Euterpe oleraceae Mart.)

“…O tratamento T4 (9 dias de embebição em água) apresentou o maior IVE (%), diferindo estatisticamente dos demais tratamentos (Tabela 1). Em sementes de Astrocaryum aculeatum, após nove dias de embebição em água, o percentual de germinação foi maior (FERREIRA & GENTIL 2006, FERREIRA et al 2010.…”