Germination and vigor of Caesalpinia pulcherrima (L.) Sw. seeds under different light and temperature conditions

Abstract

Caesalpinia pulcherrima is a Fabaceae family species from Central America, which has a small size and is widely used as a living fence in the urban afforestation for streets, parks, and gardens. Based on this importance, the aim of this research was to study the influence of light and temperature on the germination of C. pulcherrima seeds. The study was carried out at the Laboratory of Seed Analysis of the Center of Agricultural Sciences of the Universidade Federal da Paraíba, Areia, PB, Brazil. The experimental design was completely randomized, comprising a 3x5 (three temperatures and five light regimes) factorial scheme with four replicates containing 25 seeds each. Germination and vigor of seeds were evaluated under temperatures of 25°C and 30ºC constant and 20-30ºC alternated in different light regimes: white, green, red-distant, red, and absence of light. Variables analyzed were: germination, first germination count, germination speed index, root length, shoot length, and the ratio of dry mass of root/shoot of the seedlings. Seeds of C. pulcherrima germinate in the presence and absence of light, being a neutral photoblastic. Recommendation to test the vigor of these seeds is the temperature of 30°C in the white light regime.

Influence of “El Niño Southern Oscillation” periods on plant density of Hoffmannseggia aphylla (Fabaceae) an endangered species

“…However, the increase in water availability must necessarily be accompanied by an increase in humidity during the summer in the same study site for this germination phenomenon to take place, in which values above 50% seem to break the physiological dormancy of this species. Previous investigations, carried out at the laboratory level, agree that water availability, temperature and increased environmental humidity are limiting factors for breaking dormancy in species of this genus (Alves et al, 2018;Moreno et al, 2018). There has been some controversy regarding the effects of environmental variables on germination.…”

Superação De Dormência Em Sementes De Parkia Pendula (Willd.) Benth. Ex Walp. (Fabaceae) / Overcoming Dormancy in Seeds of Parkia Pendula (Willd.) Benth. Ex Walp. (Fabaceae)

“…Trabalhos já foram realizados e a literatura já reconhece uma série de temperaturas e métodos de superação adequados e inadequados para espécies nativas. (ALVES et al, 2018;SILVA et al, 2017;NASCIMENTO et al, 2009;GARCIA DE SANTANA et al, 2015), contudo ainda há controvérsias em relação aos métodos mais eficientes e ambientalmente seguros para a superação de dormência das sementes do gênero Parkia, bem como qual a temperatura mais adequada.…”