Heliotropism and water availability effects on flowering dynamics and seed production in Macroptilium lathyroides

The experiment was carried out in pots in a glasshouse, with one plant per pot and nine repetitions per treatment. The treatments consisted of free or restricted leaves, submited to 90-100% or 60-70% soil field capacity (FC). Only independent effects of water availability or leaf movement were observed on yield components. Plants under well-watered conditions and with freely orienting leaves were taller, and had a larger number of ramifications. The greater development favored the setting of a higher number of inflorescences per plant in these treatments. This behavior resulted in a high number of flowers, green and mature legumes per plant, thus resulting in high seed production which was the most evident response to water availability. Although individual seed weight was higher in the water stress treatment, total seed production was higher for well- watered plants, with no statistically significant effect of leaf movements. RESUMO - O experimento foi conduzido em casa de vegetacao, em vasos, com uma planta por vaso e nove repeticoes por tratamento. Os tratamentos constituiram: plantas com folhas livremente orientadas ou restritas, submetidas as condicoes hidricas de 90-100% e 60-70% da capacidade de campo. Foram observados efeitos independentes da disponibilidade hidrica e da movimentacao foliar para os componentes do rendimento de sementes ao longo do periodo experimental. Plantas submetidas a alta disponibilidade hidrica e com folhas livremente orientadas apresentaram maior numero de ramificacoes por planta. Este melhor desenvolvimento favoreceu a emissao de maior numero de inflorescencias por planta, proporcionando maior numero de flores, legumes verdes e legumes maduros por planta que, por sua vez, gerou maior producao diaria de sementes. Esta resposta foi evidenciada ao se avaliar o efeito da disponibilidade hidrica. Apesar da massa individual da semente ter apresentado valores superiores para o tratamento com restricao hidrica, a producao total de sementes foi superior no tratamento com alta disponibilidade hidrica, nao se observando efeito significativo para a movimentacao foliar.

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