Condições de luminosidade e temperatura na germinação de chia e calêndula

Abstract

Chia (Salvia hispanica L.) and Calendula (Calendula officinalis L.) are present in society in various ways, with chia primarily as food and calendula used in medicinal forms, mainly ointments, and also its flowers consumed. Chia, part of the Lamiaceae family, and calendula, of the Asteraceae family, have limited studies on their germination under varying temperature conditions. Therefore, the aim of this study was to analyze the effects of different temperature and light conditions. Tests were conducted in a laboratory where 25 seeds were placed in germination boxes, in 4 repetitions, in a factorial manner to avoid direct light exposure to the seeds. The germination boxes were placed in a BOD incubator at 5 different temperatures: 8, 16, 24, 32, and 40°C, consistently maintained until all seeds germinated or remained stable for three days. The study assessed germination, Germination Speed Index (GSI), and seedling length. It was observed that light did not affect germination for both species but did influence seedling length, particularly for chia. The effect of temperature on the crops was similar, with optimal temperatures for chia ranging from 24 to 32°C, while for calendula, depending on the analyzed factor, temperatures ranged from 16 to 32°C. Temperature significantly affected the GSI of both species, showing better performance when seeds were exposed to optimal temperatures.