Substrate and temperature on germination and performance of "Albizia niopoides" Benth. Seedlings

EnglishThis study aimed to determine the most appropriate conditions of temperature and substrate for germination and performance of A. niopoides seedlings. The design was completely randomized in 10x7 factorial arrangement (eight constant temperatures of 5, 10, 15, 20, 25, 30, 35, and 40°C and two alternating temperatures of 20-30 and 25-35°C, and seven substrates, that are paper towel, vermiculite, sand, blotting paper, coir dust, sugarcane bagasse, and tropstrato®) with four replicates of 25 seeds. The following variables were analyzed: (1) germination percentage; (2) germination speed index; (3) shoot length and primary root; and (4) dry weight of shoot and of root system. There was a significant interaction among the tested factors for all variables. The A. niopoides seeds germinate under a wide temperature range, with minimum and maximum limit at 10 and 40°C temperatures, respectively. Alternating temperatures of 20-30 and 25-35°C with sand substrate are ideal conditions for germination and performance of A. niopoides seedlings. Key words: forest seeds; seed analysis; vigor portuguesObjetivou-se com a realizacao deste estudo determinar as condicoes mais adequadas de temperatura e substrato para germinacao e desempenho de plântulas de Albizia niopoides. O delineamento utilizado foi o inteiramente casualizado em arranjo fatorial 10x7 (oito temperaturas constantes de 5, 10, 15, 20, 25, 30, 35 e 40°C e duas alternadas 20-30 e 25-35°C e sete substratos: papel tolha, vermiculita, areia, papel mata borrao, po de coco, bagaco de cana e tropstrato®), com quatro repeticoes de 25 sementes. Foram analisadas as seguintes variaveis: percentagem de germinacao, indice de velocidade de germinacao, comprimento de parte aerea e raiz primaria e massa seca da parte aerea e do sistema radicular. Houve interacao significativa dos fatores testados para as todas as variaveis analisadas. As sementes de A. niopoides germinam em uma ampla faixa de temperatura, com limite minimo e maximo nas temperaturas de 10 e 40°C, respectivamente. As temperaturas alternadas de 20-30°C e 25-35 °C com o substrato areia sao condicoes ideais para germinacao e desempenho de plântulas de A. niopoides. Palavras-chave: sementes florestais; analise de sementes; vigor