Postharvest quality of Aster ericoides after treatment with silver thiosulphate and sucrose

Aster (Aster ericoides L.) is a flower crop of North American origin, which belongs to the family Asteraceae. This plant presents capitulum-type inflorescences, widely used as cut flowers. In Brazil, it has been grown only recently, but still has a high expansion potential. In floriculture, pulsing and conditioning solutions are often used to extend the vase life of cut flowers. The present study aimed to evaluate the influence of silver thiosulphate (STS) pulsing and sucrose solutions on the postharvest life of A. ericoides stems. The experiment was carried out under a complete randomized design with treatments arranged in a 2x5 factorial scheme. Treatments consisted of flower stems treated with STS pulsing for 30 minutes, combined with four sucrose concentrations (5, 10, 15, and 20%) for six hours, plus a control (without treatment). Each plot contained four replicates of 10 stems, totalizing 400 stems. The following variables were daily: vase life, fresh mass, and relative water content (RWC). For pulsing data, means were compared by the Tukey’s test (p≥5%). Yet for sucrose concentrations, means were submitted to a polynomial regression to verify the behavior of variables as a function of concentrations increases. Likewise, each treatment was evaluated for fresh mass and RWC variations over time by a polynomial regression. Results indicated no effect of STS pulsing (2mM) on the vase-life length of aster stems. In contrast, the sucrose solution at 10% extended the vase life of stems by two days, decreased fresh mass loss, and helped maintain water balance in stems. RESUMO: O áster (Aster ericoides L.) é originário da América do Norte, pertence à família Asteraceae, possui inflorescências do tipo capítulo e é muito usada como flor de corte. No Brasil, sua produção é recente e apresenta grande potencial de expansão. O uso de soluções de “pulsing” e de acondicionamento, em flores de corte, é bastante empregado na floricultura para prolongar o tempo de prateleira. O objetivo do presente estudo foi avaliar a influência do “pulsing” de STS (tiossulfato de prata) e do condicionamento em soluções de sacarose na vida pós-colheita de hastes de A. ericoides. O delineamento experimental foi inteiramente casualizado e os tratamentos foram arranjados em esquema fatorial 2x5, ou seja, com e sem aplicação de “pulsing” com tiossulfato de prata (STS) 2mM por 30 minutos, combinados com quatro concentrações de sacarose: 5, 10, 15 e 20% por 6 horas e tratamento controle; for