SUCROSESUCROSE AND CITRIC ACID IN PRESERVATIVE SOLUTIONS WITH NANO SILVER PARTICLES IN THE VASE LIFE OF ROSA

Abstract

The silver nanoparticles (Ag NPs) in the vase solutions are antimicrobial agents and ethylene inhibitors in some species for cut flowers, but the combined effect of sucrosesucrose and citric acid remains uninvestigated. The biosynthesis of Ag NPs with plant extracts is an efficient and ecologically friendly method. The objective of the present study was to evaluate the effect of sucrosesucrose and citric acid in combination with 1 ppm NPs of Ag in the vase life of Rosa hybrida cv. Freedom. The NPs were synthesized with Camelia sinensis extract and characterized them with UV-Vis spectrometry and Transmission Electron Microscopy. The design was completely randomized and the treatments were: 1) 1 ppm Ag NPs; 2) 1 ppm Ag NPs + 2% sucrosesucrose (pH 6); 3) 1 ppm Ag NPs + citric acid (pH 3), d) 1 ppm Ag NPs + citric acid + 2% sucrosesucrose; 4) control (distilled water, pH 6). The experimental unit was a floral stem with 15 replicates per treatment. The treatment 1 ppm NPs + citric acid generated the longest vase life (7.3 d), the highest water consumption (147.08 mL) and the highest relative fresh weight (89.50 %). The treatments with AgNPs alone and AgNPs + citric acid delayed the maximum floral opening (5.33 d and 6.80 d) with respect to the control (3.13 d); variable related to the longevity of the flower. The presence of AgNPs in the solution inhibited bacterial growth but the citric acid increased the water consumption and the fresh weight of the floral stem. The presence of sucrosesucrose in the solution reduced the vase life, the consumption of water and increased the bacterial count but the acidification of the medium with citric acid partially reversed the negative effect of sucrosesucrose.