Period of time taken by Brachiaria humidicola (Rendle) Scheweick seed to complete germination

Abstract

The period of 21 days suggested by the Brazilian Rules for Seed Testing for the germination test of B. humidicola seeds seems too long for seed producing companies and laboratories since they depend on the results for decisions concerning the storage or the commercialization of the seed lots. So, the objective of this work was to evaluate the possibility of getting germination results of B. humidicola seeds in a shorter period. The procedures consisted in submitting the seeds to a dormancy breaking treatment and to alternating temperatures during the germination test. Seed samples of nineteen S1 and S2 seed lots were submitted to the following treatments: moistening the germination substratum with 1) deionized water (check treatment), 2) a KNO 3 (0.2%) solution, and 3) scarifying the seeds with sulfuric acid for 10 minutes. The germination test was conducted under the conditions of 1) alternating temperatures of 20 and 35 °C and 2) alternating temperatures of 15 and 35 °C both with 8 hours of light. Normal seedlings were evaluated in daily countings. The results showed that the germination test of B. humidicola seeds may be carried out under alternating temperatures of 15 and 35 °C without breaking seed dormancy with a final evaluation of the germination 10 days after the sowing of the seeds. Key words: Dormancy. Forage grass. Pasture. Temperature. ResumoO período de 21 dias recomendado pelas Regras para Análise de Sementes para o teste de germinação de sementes de B. humidicola é considerado excessivo por produtores, comerciantes e laboratórios de análise de sementes, que dependem dos resultados do teste para o controle de qualidade e a comercialização. Desta forma, o objetivo do trabalho foi avaliar a possibilidade de reduzir o período necessário para a condução do teste de germinação de sementes de B. humidicola, estabelecendo o método para superação da dormência e a temperatura ideal. Dezenove lotes de sementes comerciais S1 e S2 recém-recebidos na unidade de beneficiamento foram avaliados quanto à germinação, em quatro subamostras de 100 sementes por tratamento, constituído de: substrato umedecido com água deionizada (testemunha), substrato umedecido com KNO 3 (0,2%) e escarificação com ácido sulfúrico por 10 minutos. Para o teste de germinação, foram avaliadas duas condições de temperaturas alternadas (20-

An integrative insight on dormancy alleviation in diaspores of Urochloa humidicola (Rendle) Morrone & Zuloaga, a tropical grass with great economic and ecological impact

“…Martins & Silva ; Tomaz et al . ). However, there are no reports documenting if these factors are synergic in dormancy alleviation.…”

Origin and temperature on the germination of beggartick seeds

“…Considering the data of germination speed index and germination test evaluated together (Tables 3 and 6), it was possible to identify the optimal temperature for beggartick germination, since the optimal temperature can be considered as the one that leads to maximum germination in the shortest time interval (Carvalho & Nakagawa, 2012;Tomaz et al, 2015Tomaz et al, , 2016.…”

Germination test of Eucalyptus phaeotricha seeds

“…First count: Conducted along with the germination test, by computing normal seedlings when the count reached 50% of the final germination (Tomaz et al, 2016).…”

“…propagation by seeds is viable and adopted by small nursery owners to produce seedlings (Cetnarski Filho & Carvalho, 2009). Seed germination is used to calculate sowing rate, evaluate the physiological quality of a lot, and establish criteria for commercialization (Martins et al, 2008;Tomaz et al, 2016).…”