Postharvest performance of cut marigold, rose, and sunfower stems as infuenced by homemade and commercial foral preservatives

Abstract

Efects of homemade or commercial foral preservatives, applied as 48-h grower treatments or continuous retailer/consumerapplications, were studied on cut Double Eagle marigold, Red Bentley rose, and Sunbright sunfower. Cut stems of marigold placed inpreservative solutions, irrespective of the duration, had a longer vase life than stems in tap water. Continuous use of soda (7 Up) orcitric-Kathon and short-term use of citric-Al resulted in the longest extension of vase life. Cut stems of rose had the longest vase lifewhen pulsed with citric-Kathon for 48 h or continuously placed in citric-Al until termination. For sunfower, use of citric-Kathon orcitric-Greenshield both as a pulse and as a vase solution extended the vase life similar to commercial preservatives such as Floralifeor 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 plussugar reduced the vase life of rose and sunfower stems. Te pH of tap water solutions became more acidic when used afer 48 h ofpulsing with preservative solutions, while greater changes in electrical conductivity were recorded when the preservative solutionscontaining soda, lemon juice plus sugar, or citric-Al were used until termination. Stems of all species tested kept continuously in sodahad 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 bestpostharvest performance of marigold and sunfower, and continuous treatment with citric-Al or pulsing with citric-Kathon resulted inthe best postharvest performance of cut roses; all of the aforementioned treatments resulted in a vase life similar to those of commercialpreservatives. However, mixtures containing lemon juice or citric acid plus sugar had detrimental efects and should not be used forlonger periods to handle cut stems of rose or sunfower.