Germination of tucumã (Astrocaryum aculeatum G. Mey.) as a function of thermal pretreatment and stratification temperature

Abstract

Germination of tucumã (Astrocaryum aculeatum G. Mey.) seeds is slow and although the removal of the endocarp favors the speed of the process, the time is still considered long. Thus, this study aimed to investigate the effects of different pretreatment and stratification temperatures on the germination of tucumã seeds. Two experiments were set up. The first experiment was conducted using a completely randomized design in a factorial scheme and seedling emergence was evaluated as a function of the pretreatment of diaspores at different temperatures (27, 30, 35, and 40 °C) during different periods (20, 40, and 60 days). The second experiment was also conducted in a completely randomized design and seed germination was evaluated as a function of seed stratification at constant (25, 30, 35, and 40 °C) and alternating temperatures (26 - 30, 26 - 35, and 26 - 40 °C). Germination decreased progressively in all tested periods as the pretreatment temperature increased. Seed stratification at different constant and alternating temperatures showed different results. The pretreatment of diaspores at different temperatures for different periods was not effective in overcoming the dormancy of tucumã seeds. Seed stratification at alternating temperatures, with the highest thermal amplitude (26 - 40 °C), favored the overcoming of dormancy and the germination of tucumã seeds.

GERMINATION AND POST-SEMINAL DEVELOPMENT OF Astrocaryum murumuru MART. PROGENIES

“…In Astrocaryum acaule Mart., germinative bud formation occurs, on average, at 113 days, with minimum and maximum time of 14 and 250 days, respectively (Corrêa et al, 2019). The removal of the endocarp, followed by imbibition and stratifi cation at alternating temperature (26-40 ºC), favors the germination of A. aculeatum seeds (Ferreira et al, 2021). Baskin and Baskin (2014) observed that the seeds of most palm trees have morphophysiological type dormancy or are morphologically dormant, something that needs to be proven for Amazonian species.…”