Leaf Yellowing Control and Physiological Responses of Alstroemeria Under Postharvest Solutions with Growth Regulators and Silver Thiosulfate

One of the challenges in the postharvest phase of Alstroemeria is the rapid yellowing of leaves before the senescence of flowers. It is hypothesized that using preservative solutions prepared with growth regulators preceded by pulsing could mitigate this issue. The objective of this study was to evaluate the occurrence of yellowing and the extension of postharvest longevity of Alstroemeria hybrida cv. Akemi floral stems using preservative solutions. After harvest, the stems were standardized, and half were subjected to pulsing with silver thiosulfate (STS) for 1 h. Subsequently, all floral stems were kept in different preservative solutions prepared with 6-benzyladenine, gibberellin, Floralife Crystal Clear®, silver thiosulfate, and the same treatments supplemented with 1.0 mg L⁻¹ of chlorine, in addition to the control treatment with stems kept in distilled water or distilled water with 1.0 mg L⁻¹ of chlorine. The stems were placed in a room with continuous lighting, a temperature of 16 ± 2 ºC, and relative humidity of 67% ± 3%, until senescence, totaling a period of 30 days. Quality and physiological analyses were conducted, revealing that pulsing with STS enhanced postharvest longevity, regardless of the preservative solution used. Among the tested solutions, gibberellin was particularly effective, extending longevity and delaying the onset of leaf yellowing.