The germination of bush mint (Hyptis marrubioides EPL.) seeds as a function of harvest stage, light, temperature and duration of storage

Abstract

ABSTRACT. This study evaluated the effect of light, temperature, physiologic stage at harvest and length of time on the germination of Hyptis marrubioides seeds. Two trials were conducted. The first experiment was performed immediately after the seed harvest and consisted of a 2 x 3 x 3 factorial design with 2 environmental conditions (light and dark), 3 temperatures (20, 30 and 20/30ºC) and 3 seed harvest times (green colored seeds, light brown seeds and dark brown seeds). The second experiment was conducted in the presence of light at a temperature of 30ºC and consisted of a 4 x 3 factorial design, with 4 storage times (0, 6, 12 and 18 months) and the 3 three harvest physiologic stages used in the previous experiment. Both of the experiments were conducted in randomized blocks, with 4 replications of 100 seeds. Light did not affect germination. By contrast, a temperature of 20ºC retarded the germination process, although the percentage of germinating seeds was not affected. Seed storage and the different harvest physiologic stages affected the Speed of germination index (SGI) and the germination percentage. Seeds that were harvested at the more mature stage (dark brown color) could be stored for up to 18 months. RESUMO. Germinação de sementes de hortelã-do-campo (Hyptis marrubioides EPL.) em função da época de colheita, da luz, temperatura e armazenamento. O presente trabalho teve como objetivos avaliar a influência da luz, da temperatura, do estádio fisiológico na colheita e do armazenamento na germinação das sementes de Hyptis marrubioides. Foram realizados dois experimentos, sendo o primeiro implantado logo após a colheita das sementes, constituído por um fatorial 2 x 3 x 3, com 2 ambientes (luz e escuro) x 3 temperaturas (20, 30 e 20/30ºC) x 3 épocas de colheita das sementes (sementes com coloração verde, coloração marrom claro e coloração marrom escuro). O segundo experimento, em presença de luz e à temperatura de 30ºC, foi constituído por um esquema fatorial 4 x 3, sendo 4 tempos de armazenamento (0, 6, 12 e 18 meses) e 3 três estádios fisiológicos de coleta mencionados no experimento anterior. Ambos os experimentos foram implantados no delineamento em blocos ao acaso, com quatro repetições de 100 sementes. Foi verificado que o fator luz não influenciou a germinação. Por outro lado, a temperatura de 20ºC retardou a germinação, apesar de não influenciar a sua porcentagem. O armazenamento e os diferentes estádios fisiológicos de colheita das sementes influenciaram o IVG e a porcentagem de germinação. Sementes coletadas no estádio mais maduro (coloração marron escuro) demonstraram ser apropriadas para o armazenamento por até 18 meses.Palavras-chave: planta medicinal, viabilidade, Lamiaceae.

Influence of light, temperature and humidity on substrate and osmoconditioning during the germination of Mimosa bimucronata (DC) O. Kuntze.

“…The requirement for seeds germination of different species at alternate temperatures was also verified by some authors such as Sales et al (2011) who stated that germination increased at constant temperatures of 30 °C and alternated at 20-30 °C in all light regimes and for seeds of Crataeva tapia. Galindo et al (2012), found only the alternating temperature of 20-30 ºC under the regimes of white and red light.…”

Quality of soybean seeds treated with fungicides and insecticides before and after storage

“…Regardless of the product used for the treatment and of cultivars, seed germination was reduced in the treated and stored and the smallest seedlings were obtained when the seeds quality after storage were assessed. This reduction in germination of seeds is due to many circumstances such as the environmental conditions during the production of seeds, insect attack, lipid and water content in seeds, presence of mechanical damage arising from transport and processing, storage conditions, and especially, in the case of seed with high quality, of the chemicals used in seed treatment (Sales et al, 2011). In this study, when the seeds were stored there was phytotoxic effect treated by the contact time of the products with the seeds.…”

Importance of the Natural Incidence of the Fusarium Genus in Food Crops Established in Northern México

“…Reductions in seed germination levels were related to the production environment and storage conditions and duration. Other negative factors were mechanical damages caused during the harvest-threshing and seed cleaning processes, as well as the seed fungi load and chemicals used for the seed treatment [29,30]. Seedlings wilting was also observed during the germination test due to soil infestation and seed contamination by fungi.…”