Postharvest performance of cut marigold, Rose, and sunflower stems as influenced by homemade and commercial floral preservatives

Abstract

Effects of homemade or commercial floral preservatives, applied as 48-h grower treatments or continuous retailer/consumer applications, were studied on cut Double Eagle marigold, Red Bentley rose, and Sunbright sunflower. Cut stems of marigold placed in preservative solutions, irrespective of the duration, had a longer vase life than stems in tap water. Continuous use of soda (7 Up) or citric-Kathon and short-term use of citric-Al resulted in the longest extension of vase life. Cut stems of rose had the longest vase life when pulsed with citric-Kathon for 48 h or continuously placed in citric-Al until termination. For sunflower, use of citric-Kathon or citric-Greenshield both as a pulse and as a vase solution extended the vase life similar to commercial preservatives such as Floralife or Chrysal; it was 1.8 days longer than the vase life of stems in tap water. Continuous use of lemon juice plus sugar or citric acid plus sugar reduced the vase life of rose and sunflower stems. The pH of tap water solutions became more acidic when used after 48 h of pulsing with preservative solutions, while greater changes in electrical conductivity were recorded when the preservative solutions containing soda, lemon juice plus sugar, or citric-Al were used until termination. Stems of all species tested kept continuously in soda had the highest dry weight, while citric-Kathon had higher fresh weight at termination, compared to initial fresh weight at harvest, and higher solution uptake. In summary, continuous vase application of citric-Kathon, soda, or citric-Greenshield resulted in the best postharvest performance of marigold and sunflower, and continuous treatment with citric-Al or pulsing with citric-Kathon resulted in the best postharvest performance of cut roses; all of the aforementioned treatments resulted in a vase life similar to those of commercial preservatives. However, mixtures containing lemon juice or citric acid plus sugar had detrimental effects and should not be used for longer periods to handle cut stems of rose or sunflower.