Mobility and ionic form of silver as related to longevity of cut carnations

Abstract

The mobility of different ionic forms of silver (^110mAg) has been studied using semiconductor radiation detectors. Silver, applied as silvernitrate (2mM), moves upward in the stems of cut carnations (Dianthus caryophyllus L.) at about 3 cm day^-1. This transport has the characteristics of a chromatographic exchange transport, but is not promoted by the addition of other cations (K⁺ or Ca²⁺). The silverthiosulphate anionic complex is transported at the same speed as [³²P]phosphate (about 2 m h^-1); orders of magnitude faster than Ag⁺. The antiethylene action of silver is preserved in this complex, as shown by a significant improvement of the longevity of carnation flowers in the presence or absence of ethephon, even after a short treatment with the silverthiosulphate complex. Analysis of the silver content of different flower parts after a silverthiosulphate treatment shows a distinct accumulation in the receptacle, possibly associated with the antiethylene action.