Reproductive phenology and influence of abiotic variables for two mangrove species in northeastern Brazil

Information on plant phenological patterns aids in understanding the structure and functioning of ecosystems and support restoration projects in degraded areas. The aim of this study was to characterize the reproductive phenology of Avicennia germinans and Laguncularia racemosa in a mangrove forest in the Mamanguape River estuary in northeastern Brazil. The characterization was performed monthly from July 2016 to June 2017. We applied circular statistics to detect seasonal trends, calculated intra-specific synchrony, and performed regressions between the reproductive phenophases and the abiotic variables. Avicennia germinans exhibits seasonal responses to floral buds, flowers at anthesis, and fruit, with one reproductive episode per year (annual pattern). Laguncularia racemosa has no seasonal response, with one reproductive episode per year for floral buds (annual pattern) and two episodes for flowers at anthesis and fruits (subannual pattern). Reproductive phenophases of A. germinans exhibited higher intra-specific synchrony than L. racemosa. We provide evidence that temperature, solar radiation and rainfall are important drivers of the flowering rhythm in both species. In conclusion, the results of this study showed that the species exhibited different phenological responses, even though they were subjected to the same abiotic conditions.

Features of growth and development of species of the genus Echinacea Moench under the conditions of the Southern Coast of the Crimea

The results of an introduction study of five species of the genus Echinacea Moench ( Echinacea angustifolia DC., E. pallida (Nutt.) Nutt., E. paradoxa (Nort.) Britt., E. tennesseensis (Breadle) Small and E. purpurea (L.). Moench) are presented in the collection of aromatic and medicinal plants of the Nikitsky Botanical Gardens. The features of the passage of phenophases, heat supply, economically important features (productivity, raw material structure) were studied. It has been established that under the conditions of introduction, the studied species go through all phases of development and form complete seeds. The sums of active temperatures (≥10˚С) necessary for the species to pass through the phenophases are revealed and it is shown that the minimum limit values are characteristic for different species at different stages of growth and development. The minimum heat threshold for entering the flowering phase is set for E. tennesseensis , and in the phase of fruiting and seed maturation for E. pallida . The required sum of active temperatures for the mass budding phase of E. purpurea is 1021 ˚С, and mass flowering is 1749 ˚С. The longest flowering period under the conditions of the Southern Coast is characterized by E. tennesseensis - 65 days, the shortest E. pallida - 38 days. According to the flowering rhythm, the studied species are subdivided into late spring-early summer ( E. pallida , E. tennesseensis , E. angustifolia ) and mid-late summer ( E. paradoxa and E. purpurea ). The most full-bodied seeds are formed by E. paradoxa (1000 seeds weight 5.48 ± 0.05 g). The most promising species for productivity of aerial mass is E. purpurea (2.06 kg / m²). E. tennesseensis , occupying the second place in productivity, has the most valuable structural composition of medicinal raw materials, in which stems account for only 65% of the permissible norm (55.0%).

Floral Initiation and Flowering of Coffea arabica L. in Kenya

SUMMARYIn Kenya, coffee growing east of the Great Rift Valley has its main flowering either in February–March or in October–November. These flowerings are mainly initiated from approximately August to December and June to September, respectively. Changes from an early to a late flowering rhythm and vice versa can be caused by (a) pruning, (b) the condition of the tree, and (c) the weather pattern, but more information is needed for a complete understanding of this problem.