Germination and initial growth of Machaerium brasiliense Vogel (Fabaceae) in a greenhouse

Machaerium brasiliense Vogel is an arboreal species, popularly known as “pau-sangue”, “jacarandá-bico-de-pato” and “sapuva” (State of Paraná, Brazil). Aiming to analyze the germination, M. brasiliense seeds were kept at 20°, 25° and 30° C in a growth chamber with a 12h photoperiod or continuous darkness. For initial growth, plants were analyzed for height, length of root, shoot and root dry mass, total dry mass and the number of  leaves at 90, 180, 270 and 360 days after transplanting (DAT).The presence or absence of light showed no effect on the performance of seeds, with a higher germination percentage (PG) found for seeds at 20 and 25 °C, as verified for the germination speed index (IVG). The shortest average germination time (TMG) was observed at 30 °C. Regarding the growth parameters, the highest values were obtained at 270 and 360 DAT, with no statistical difference between these two evaluation periods. The presence of root nodules was verified from 180 DAT.Machaerium brasiliense Vogel é uma espécie arbórea, conhecida popularmente como pau-sangue, jacarandá-bico-de-pato e sapuva. Com o objetivo de verificar a germinação, sementes de M. brasiliense foram mantidas sob temperatura de 20°, 25° e 30 °C, em câmara de germinação com fotoperíodo de 12h ou escuro contínuo. Para análise do crescimento inicial, avaliaram-se, aos 90, 180, 270 e 360 dias após o transplante (DAT), a altura, o comprimento da raiz, a massa seca da parte aérea, da raiz e total e o número de folhas de plantas mantidas em casa de vegetação. A presença ou ausência de luz não influenciou o desempenho das sementes, observando-se maior porcentagem de germinação (PG) para as sementes submetidas a 20 e 25 °C, o mesmo sendo verificado para o parâmetro índice de velocidade de germinação (IVG). O menor tempo médio de germinação (TMG) foi observado a 30 °C. Em relação aos parâmetros de crescimento, os maiores valores foram obtidos aos 270 e 360 DAT, não ocorrendo diferença estatística entre esses dois períodos de avaliação. A presença de nódulos radiculares foi observada a partir dos 180 DAT

Lonchocarpus cultratus (Vell.) A.V.G. Azevedo & H.C. Lima (Fabaceae) growth under different shade and water availability conditions

ABSTRACT Light and water availability are among the environmental factors that most influence plant growth and development. The ability to acclimate to shade and tolerate drought can be assessed by growth characteristics. Thus, the objective of this study was to analyze the effect of water availability and shading on the initial growth of Lonchocarpus cultratus, a tree species, common name ‘embira-de-sapo’, abundant in several areas of South and Southeastern Brazil. The experiment was arranged in a 3x2 factorial completely randomized design. The plants were kept under 0%, 50%, and 80% shading and two conditions of water availability (daily irrigation - ID and twice a week - NDI). The variables height, root length, dry biomass of leaves, stem, and root were evaluated at 30, 60 and 90 days after emergence (DAE). Total, a, and b chlorophyll, mycorrhizal colonization, and nodulation were determined. Death of young plants maintained at 0% NDI occurred at the beginning of growth. At 90 DAE, plants kept under 80% shading and ID showed the highest height and etiolated plants due to the reduction of light intensity in this treatment. Over the experimental period, 0% and 50% shaded plants irrigated daily had the highest percentage of mycorrhizal colonization, and nodulation was observed in all plants regardless of the treatment