2022 Volume 21 Issue 4 Pages 501-506
Silver thiosulfate complex (STS) treatment of Delphiniums (Delphinium elatum) with strong ethylene sensitivity is fundamental for growers before shipping cut flowers. However, early flower drop owing to inadequate STS treatment is often reported by markets to growers. Since high humidity owing to rainfall before and after harvest possibly causes inadequate STS treatment, the effects of relative humidity (RH) before harvest, and temperature and relative humidity during STS treatment on the absorption of STS solution and silver content of cut flowers were investigated. Potted D. elatum plants were held for 6 days before harvest in a phytotron under different RH conditions. STS solution absorption by flowers cut from plants under high-RH conditions was higher than that of flowers harvested under low-RH conditions. The stoma size of the sepals of flowers harvested under high-RH conditions was significantly larger than that of flowers harvested under low-RH conditions. STS treatments were performed at 23°C-70%, 23°C-80%, 30°C-70%, and 30°C-80%. At a given temperature, STS solution absorption at low-RH was greater than that at high-RH. The effects of RH conditions before harvest and during pulse treatment on STS solution absorption were then compared. When treated with STS under high-RH, RH encountered before harvest did not affect STS solution absorption. When treated with STS under low-RH, cut flowers harvested from plants under high-RH absorbed more STS solution than cut flowers harvested under low-RH.
