rudbeckia are new species for the Postharvest Evaluation of Cut Dahlia, cut flower industry. ‘Karma Thalia’ Linaria, Lupine, Poppy, Rudbeckia, dahlia, ‘Jemmy Royal Purple’ trache- lium, and ‘Sun Gold’ and ‘Benary’s Trachelium, and Zinnia Giant Scarlet’ zinnias are established species in the cut flower industry, 1,4 2 3 but the cultivars are new. The lack of John M. Dole , Zenaida Viloria , Frankie L. Fanelli , information about postharvest han- and William Fonteno1 dling of the above-listed species and cultivars makes it necessary to de- velop efficient and practical techniques ADDITIONAL INDEX WORDS. hydrator, preservative, cold storage, ethylene sensitivity, for flower producers, wholesalers, 1-MCP, silver thiosulfate, sucrose and retailers to enhance quality and SUMMARY. Vase life of ‘Karma Thalia’ dahlia (Dahlia ·hybrida), ‘Lace Violet’ linaria longevity. (Linaria maroccana), ‘Sunrise’ lupine (Lupinus hartwegii ssp. cruickshankii), The available literature describ- ‘Temptress’ poppy (Papaver nudicaule), ‘Indian Summer’ rudbeckia (Rudbeckia ing how vase water quality affects cut ·hybrida), ‘Jemmy Royal Purple’ trachelium (Trachelium caeruleum), and ‘Benary’s flower quality is variable, and recom- Giant Scarlet’ and ‘Sun Gold’ zinnias (Zinnia elegans) was determined after being mendations differ regarding the use subjected to postharvest handling procedures. Cut dahlia, lupine, poppy, rud- of tap or deionized (DI) water (Nowak beckia, trachelium, and ‘Sun Gold’ and ‘Benary’s Giant Scarlet’ zinnia flowers could and Rudnicki, 1990; Sacalis, 1993). be held in unamended tap or deionized (DI) water with no effect on vase life. Vase In some studies, tap water produced life of linaria was longest when placed in DI water with 8-hydroxyquinoline citrate the shortest vase life (Kamataka, and a solution pH of 3.5. A vase solution of 2% sucrose without foam extended consumer vase lives for linaria, trachelium, and ‘Benary’s Giant Scarlet’ zinnia. 2003), but in others, it resulted in a Floral foam or 2% or 4% sucrose had no effect on the consumer vase life of dahlia, longer vase life than DI water (van lupine, rudbeckia, and poppy. Trachelium and rudbeckia did not tolerate a 20% Meeteren et al., 2000). sucrose treatment for 24 h, whereas linaria and ‘Benary’s Giant Scarlet’ zinnia had a Adding sucrose, typically through longer vase life with a 10% sucrose pulse than a water-only pulse. For trachelium, the the use of commercial premixed longest (17.5 days) consumer vase life occurred when the Chrysal Professional 2 products, to the vase solution en- Processing solution (CP2) was used after pretreatment with DI water. Either of two hanced postharvest performance and commercial holding solutions, CP2 or Floralife Professional (FLP), similarly flower quality of many species (Cho extended the vase life of linaria. The use of FLP or CP2 improved consumer vase life et al., 2001; Jones et al., 1993; Sacalis, of dahlia, lupine, and poppy compared with DI water. Dahlia, trachelium, and 1993). Incorporating biocides in the zinnia flowers could not be cold stored at 2 C. Lupine and poppy could be stored at 2 C wet or dry for 2 weeks. Linaria and rudbeckia could be cold stored for 3 weeks. vase solutions decreases microbial Lupine and trachelium were susceptible to 1 mLÁL–1 exogenous ethylene, which growth and therefore maintains induced floret abscission in lupine and stopped floret opening in trachelium. 1- healthier vascular tissue. Results may Methylcyclopropene and silver thiosulfate similarly suppressed the ethylene effect. be cultivar specific as vase life of Cut linaria, zinnia, dahlia, rudbeckia, and poppy flowers were unaffected by ‘Florex Gold’ calla lily (Zantedeschia exogenous ethylene. elliottiana) was extended after a 2-h pulse in 8-hydroxyquinoline citrate pecialty cut flowers comprise a that the customers—wholesalers, re- (8-HQC), while the same treatment large number of species, includ- tailers, and the final consumer—will reduced longevity and quality in Sing trees, shrubs, and herbaceous be satisfied and return to purchase ‘Black Magic’ calla lily (Janowska annuals and perennials. Two key as- more flowers. and Jerzy, 2004). A 24-h pulse in pects of the specialty cut flower indus- Of the many cut flowers intro- 8-HQC increased the longevity of try are introducing new species and duced to commercial markets each sunflower (Helianthus annuus) and marketing flowers with a long post- year, several show potential. ‘Lace Vio- weigela (Weigela spp.) but reduced harvest life. Interesting new cut flower let’ linaria, ‘Sunrise’ lupine, ‘Tempt- the vase life of yarrow (Achillea) species excite buyers and increase sales, ress’ poppy, and ‘Indian Summer’ (Redman et al., 2002). and a long postharvest life ensures
Department of Horticultural Science, North Carolina State University, Raleigh, NC 27695-7609 Units To convert U.S. to SI, To convert SI to U.S., We gratefully acknowledge support from the Ameri- can Floral Endowment, Association of Specialty Cut multiply by U.S. unit SI unit multiply by Flower Growers Research Foundation, and numerous 29.5735 fl oz mL 0.0338 suppliers. 0.3048 ft m 3.2808 We would like to thank Ingram McCall for producing 3.7854 gal L 0.2642 the cut flowers and assisting with the postharvest 2.54 inch(es) cm 0.3937 studies, and Beth Harden and Diane Mays for assisting 1 mmho/cm dSÁm-1 1 with the postharvest studies. 28,350 oz mg 3.5274 · 10-5 1Professor. 1 ppb nLÁL-1 1 -1 2Postdoctoral Research Assistant. 1 ppm mgÁL 1 0.001 ppm mLÁL-1 1000 3 Graduate Research Technician. 1 ppm mLÁL-1 1 4Corresponding author. E-mail: [email protected]. ( F – 32) O 1.8 F C(1.8· C) + 32
• July–September 2009 19(3) 593 RESEARCH REPORTS
The ability for new cuts to per- bedding plant flats (35 mL volume ‘Karma Thalia’ dahlia, ‘Indian form well in floral foam is important, per cell) and were germinated at 16 ± Summer’ rudbeckia, and ‘Sun Gold’ especially to florists. Generally, when 1 C. Linaria seedlings were trans- and ‘Benary’s Giant Scarlet’ zinnia flowers are placed in floral foam, the planted on 17 Dec. 2002 into 4-inch- plants were field grown at 30 · 30 vase life is decreased (Sacalis, 1993), diameter (325 mL) pots spaced at 4 · cm spacing in a 4-ft-wide bed. Rooted but cut big bend bluebonnet (Lupi- 4 inches. Trachelium seeds were sown dahlia cuttings were received from a nus havardii) stems performed as well into open flats on 7 Jan. 2004 and commercial propagator and were in floral foam as in water (Davis et al., were transplanted on 4 March into planted in the field on 29 Apr. 1995). 806 bedding plant flats, which were 2003. Rudbeckia and zinnia seeds Cold storage is used to delay cut then transplanted on 3 May to stand- were directly sown on 28 Jan. and flower development and provide a ard bulb crates (52 · 38 cm, 11 cm 30 Mar. 2003, respectively, into 806 long vase life (Cevallos and Reid, deep) in a 4 · 5 arrangement (7.5 · bedding plant flats (35 mL volume 2001; Faragher et al., 1984; Redman 9.5 cm apart). Lupine seeds were per cell) using a peat-based commer- et al., 2002). In addition, antiethylene- directly sown on 25 Feb. 2004 into cial root substrate (Fafard 4P). Seeds binding products have been success- 6-inch-diameter (1160 mL) pots were germinated at 16 ± 1 Cin fully used on ethylene-sensitive species spaced at 6 · 6 inches. Poppy seedlings a polyethylene-covered greenhouse. (Geertsen, 1990; Ichimura et al., were received from a commercial Seedlings were transplanted into the 1998; Newman et al., 1998; Reid, grower and were transplanted on field on 20 March (rudbeckia) and 27 2004), but they have no effect on 7 Jan. 2003 into 6-inch- diameter Apr. (zinnia). Plants were irrigated extending vase life of nonsensitive (1160 mL) pots spaced at 12 · 12 inches. as needed with 100 mgÁL–1 N from species (Elgar et al., 1999; Kenza Linaria and poppy seedlings 20N–4.4P–16.6K fertilizer (Peter’s et al., 2000). were grown at 10 ± 1.1 C night Professional 20–10–20). Dahlia stems The objective of this study was temperatures, with day temperatures were harvested from 12 Aug. to 12 to evaluate water type, concentrated averaging 24 ± 1.6 C. Lupine seed- Sept. 2003, rudbeckia stems from 1 sucrose vase solutions, floral foam, lings were grown at 15 ± 1.2 C night July to 26 July 2003, and zinnia stems commercial hydrators and holding temperatures, with day temperatures from 17 June to 12 July 2004. solutions, cold storage, and ethylene averaging 24 ± 1.5 C. Trachelium Stems were harvested according sensitivity as components of the post- seedlings were grown at 15 ± 1.7 C to criteria set for each species (Table harvest handling of seven specialty cut night temperatures, with day temper- 1); placed into buckets of tap water flowers. atures averaging 27 ± 1.6 C. (pH 6.3–7.1; EC 0.18–0.23 dSÁm–1); Plants were irrigated as needed sorted into similar groups based on Materials and methods with 150 mgÁL–1 N from 20N–4.4P– stem length and diameter, flower bud CUT STEM PRODUCTION. ‘Lace 16.6K fertilizer (Peter’s Professional number and flower size, as appropri- Violet’ linaria, ‘Sunrise’ lupine, ‘Tempt- 20–10–20; Scott’s, Marysville, OH) ate for the species; re-cut; and sub- ress’ poppy, and ‘Jemmy Royal Pur- during the week and with unamended jected to appropriate experimental ple’ trachelium plants were grown in a tap water on the weekends. Linaria treatments. Stem length after recut- polyethylene-covered greenhouse us- stems were harvested from 8 March to ting was 30 cm for most species ing a peat-based commercial root sub- 2 Apr. 2003, lupine from 7 Apr. to 7 except linaria (45 cm) and zinnia (30 strate (Fafard 4P; Conrad Fafard, May 2004, poppy from 27 March to or 36 cm). Agawam, MA). Linaria were directly 17 Apr. 2003, and trachelium from CONTROL SOLUTIONS. Cut stems sown on 18 Nov. 2002 into 806 17 June to 19 July 2004. were held in DI water (pH 3.1–4.2;
Table 1. Harvest and vase life termination criteria for cut dahlia, linaria, lupine, poppy, rudbeckia, trachelium, and zinnia stems. Vase life termination criteria Species Harvest stage Retail vase life Consumer vase life Dahlia Two to several outer rows Not recorded. Browning on the petals was noticeable of petals fully expanded. when looking directly at the flower head. Linaria Two to four open florets. Immature florets opened Stem collapsed or more than 75% of florets pale or more than 50% of were discolored or shriveled. the spike opened. Lupine One to four fully open florets. Not recorded. Stem collapsed or more than 50% of florets were discolored, shriveled or dropped. Poppy Calyx cracked and petals visible. Petals opened enough that Petals shattered or become crinkled, discolored, the flowers no longer had a or brown, or the stem collapsed. cup shape. Rudbeckia Outer petals were fully open. Not recorded. Stem collapsed or the petals began to turn brown. Trachelium 25% open florets in a head. Florets were no longer uniform Florets turned brown or the florets in appearance. closed and/or did not continue to open. Zinnia Two to several rows of Not recorded. Petals were curling or browning or stem collapsed. petals are expanded.
594 • July–September 2009 19(3) EC 0 dSÁm–1), DI water supple- lupine, poppy, and rudbeckia, hydra- indicated, DI water at 22 C was used mented with 200 mgÁL–1 8-HQC tor or commercial preservative treat- in all experiments as a vase solution. (pH 2.8–3.1; EC 0.12–0.15 dSÁm–1), ments were evaluated separately, not Retail vase life termination was eval- tap water (pH 6.3–7.1; EC 0.18–0.23 in combinations. Unamended DI water uated for linaria, poppy, and trache- dSÁm–1), or tap water with 8-HQC was used as a control solution for lium and was defined as the first day a (pH 3.5–4.5; EC 0.26–0.34 dSÁm–1). hydrator and preservative treatments. visible change in the flower or inflor- In addition, the pH of DI solutions COLD STORAGE. For dry storage, escence develops that would make the was adjusted to 3.5 using citric acid cut stems were placed in cardboard stems unmarketable by retailers. Con- and compared with non-pH-adjusted floral boxes lined with newspaper. sumer vase life was evaluated in all solutions. Buckets filled with DI water were experiments. Vase life termination char- SUCROSE AND VASE SUBSTRATE. used for wet storage. All stems were acteristics for each species are de- Cut stems were placed into vases stored in a cooler at 2 C and 80% to scribed in Table 1. containing sucrose at 0%, 2%, or 4% 90% relative humidity in the dark. STATISTICAL ANALYSIS. All ex- dissolved in DI water, with or without Fifteen stems were randomly selected periments were arranged in a com- floral foam (Oasis Floral Foam, from dry and wet storage treatments pletely randomized design, with 12 to Smithers-Oasis, Kent, OH). Before after 1, 2, or 3 weeks to evaluate the 15 replications of a single stem per insertion of the stems, foam was vase life. Unstored stems were as- floral vase. Each experiment was re- soaked in the appropriate sucrose sessed for vase life as a control treat- peated once. Analysis of variance was solution for 4 h. ment. All stems were recut under performed for all experiments, and SUCROSE PULSE. Cut stems were water after storage and placed into factorial design and mixed models pulsed in DI water amended with floral vases. were applied when two factors at sucrose at 0%, 10%, or 20% for 24 h ETHYLENE SENSITIVITY. Cut various levels were studied. Means at 20 ± 1 C in the dark. Thereafter, stems were pulsed with 0.2 mM silver separation was accomplished by least stems were transferred to floral vases thiosulfate (STS) [1 mLÁL–1 Chrysal significant difference using SAS (ver- containing DI water. AVB (Pokan & Chrysal, Miami, FL)], sion 9.1; SAS Institute, Cary, NC). COMMERCIAL HYDRATOR AND 1-methylcyclopropene (MCP) [400 TM PRESERVATIVE TREATMENTS. Cut lina- mg Ethylbloc (Agrofresh, Spring Results ria, trachelium, and ‘Benary’s Giant House, Philadelphia) dissolved in 50 CONTROL SOLUTIONS. DI supple- Scarlet’ and ‘Sun Gold’ zinnia stems mL of DI water at 30 C for a final mented with 8-HQC extended linaria were initially pulsed in a commercial concentration in a 210-L gas-tight retail and consumer vase life, espe- hydrator solution [Chrysal Profes- chamber of 700 nLÁL–1 (ppb)], or cially if adjusted to pH 3.5 (Table 2). sional 1 (CP1) Hydrating Solution DI water for 4 h. Subsequently, cut Consumer vase life of rudbeckia, tra- (Bendien, Naarden, The Nether- stems were transferred to vases filled chelium, and ‘Sun Gold’ zinnia was lands) or Floralife Hydraflor 100 with DI water, placed in a 210-L gas- longer when stems were held in un- (FL100) (FloralifeÒ, Walterboro, tight chambers, and immediately amended DI or tap water. Solutions SC)] at 2 and 5 mLÁL–1, respectively, treated with exogenous ethylene at had no effect on the consumer vase or DI water for 4 h at 5 C in the dark. 0or1mLÁL–1 for 16 h. life of cut lupine, dahlia, poppy, and Thereafter, stems were placed into GENERAL PROCEDURES. During ‘Benary’s Giant Scarlet’ zinnia or the floral vases containing a commercial vase life evaluation, stems were held retail vase life for poppy and trache- holding solution [Chrysal Professio- at 40% to 60% relative humidity, 20 ± lium stems (data not presented). nal 2 Processing solution (CP2) or 2 C, and a 12-h photoperiod at 20 SUCROSE AND VASE SUBSTRATE. Floralife Professional (FLP)] at 10 to 40 mmolÁm–2.s–1 from cool white The addition of 2% or 4% sucrose to mLÁL–1 each or DI water. For dahlia, fluorescent lamps. Unless otherwise vase water extended consumer vase
Table 2. Retail and consumer vase life of cut linaria, rudbeckia, trachelium, and zinnia stems held in deionized (DI) water, with or without 200 mgÁL–1 (ppm) 8-hydroxyquinoline citrate (8-HQC), and non-or -adjusted pH or tap water or tap water with 8-HQC and adjusted pH postharvest room conditions: 40% to 60% relative humidity, 20 ± 2 C (68.0 ± 3.6 F), and 12-h photoperiod at 20 to 40 mmolÁm–2Ás–1. Means are an average of 15 stems. ‘Indian Summer’ ‘Jemmy Royal ‘Lace Violet’ linaria rudbeckia Purple’ trachelium ‘Sun Gold’ zinnia Retail Consumer Consumer Consumer Consumer Solutions Vase life (d) DI water 2.8 bz 5.3 c 33.1 a 9.5 a 14.9 a DI water pH 3.5 2.9 b 5.5 c —y —— DI water + 8-HQC 6.7 a 8.4 b 20.7 b 8.6 ab 9.9 b DI water + 8-HQC pH 3.5 7.9 a 11.3 a — — — Tap water 4.4 b 7.3 bc 32.9 a 9.4 a 13.9 ab Tap water + 8-HQC pH 3.5 — — — 8.5 b 11.3 ab Significance *** *** ** ** * zWithin columns, means followed by the same letter are not significantly different according to least significant difference test at P £ 0.05. yTreatment not conducted. *, **, ***Significant at P £ 0.05, 0.01, or 0.001, respectively.
• July–September 2009 19(3) 595 RESEARCH REPORTS life of linaria with or without floral and consumer vase life decreased rudbeckia (32.4 d) and ‘Benary’s foam (Table 3). The consumer vase when pulsed with 20% sucrose. Con- Giant Scarlet’ (19.2 d) and ‘Sun life of trachelium increased signifi- sumer vase life of ‘Benary’s Giant Gold’ (18.8 d) zinnias were unaf- cantly (P < 0.05) in a holding solution Scarlet’ zinnia was significantly ex- fected by the commercial preserva- containing 2% sucrose with or with- tended by a 10% sucrose pulse com- tives (data not presented). For dahlia, out floral foam. In zinnias, the longest pared with the control. Sucrose pulse lupine, and poppy, FLP commercial consumer vase life was recorded when had no effect on retail and consumer holding preservative, without previ- cut stems were held in 2% sucrose vase lives for poppy or consumer vase ous hydrator treatment, significantly without foam for ‘Benary’s Giant life of dahlia, lupine, and ‘Sun Gold’ improved (P < 0.05) the consumer Scarlet’. ‘Sun Gold’ zinnia lasted lon- zinnia (data not presented). vase life (Table 6). gest with just DI water or with COMMERCIAL PRESERVATIVES. COLD STORAGE. Cold storage for sucrose at 4% and no foam. Floral Cut linaria stems showed the longest 1 week significantly decreased the foam or sucrose had no effect on the retail and consumer vase lives when a vase life of cut dahlia stems, and stem consumer vase life of dahlia, lupine, commercial holding solution (FLP or rehydration was not possible after 2 rudbeckia, and poppy or on the retail CP2) was used (Table 5). The hydra- weeks (Table 7). Retail vase life of vase life of linaria and trachelium tor solution itself did not improve the nonstored cut linaria stems was sim- (data not presented). vase life. For trachelium, consumer ilar to that of stems stored for 2 or 3 SUCROSE PULSE. Linaria retail vase life was longest when cut stems weeks, and no differences were ob- and consumer vase lives were ex- were held in the DI/CP2 hydrator/ served between wet or dry storage. tended by pulsing in 10% or 20% holding solution combination; the Wet storage for 1 or 2 weeks main- sugar concentration, but no differ- vase life of the FL100/DI and DI/ tained the consumer longevity of cut ences were observed between concen- DI treatments was shorter than the lupine stems compared with unstored trations (Table 4). Sucrose pulse at DI/CP2 treatment but longer than stems. Consumer vase life of poppy any concentration significantly re- the remaining treatment combina- was similar to unstored controls after duced (P < 0.05) the consumer vase tions. Retail vase life of trachelium 1 week in wet or dry storage. For life of rudbeckia. Trachelium retail (9.0 d) and consumer vase life of trachelium, the retail and consumer
Table 3. Consumer vase life of cut linaria, trachelium, and zinnia stems held in sucrose solutions with or without floral foam substrate. Postharvest room conditions: 40% to 60% relative humidity, 20 ± 2 C (68.0 ± 3.6 F), and 12-h photoperiod at 20 to 40 mmolÁm–2Ás–1. Means are an average of 15 stems. ‘Jemmy Royal’ ‘Benary’s Giant ‘Lace Violet’ linaria Purple’ trachelium Scarlet’ zinnia ‘Sun Gold’ zinnia Treatments Consumer Consumer Consumer Consumer Substrate Sucrose (%) Vase life (d) None 0 9.1 cz 13.2 cd 11.3 bc 15.3 a 2 17.5 a 17.7 ab 16.1 a 10.5 b 4 13.7 b 15.3 bc 10.1 c 14.9 a Floral foam 0 9.2 c 10.1 d 9.3 c 10.5 b 2 18.4 a 20.6 a 12.9 b 9.3 b 4 19.2 a 15.9 bc 11.5 bc 7.9 b Significance Substrate (Sb) * NS * *** Sucrose (Sc) ** ** *** ** Sb · Sc ** * ** ** zWithin columns, means followed by the same letter are not significantly different according to least significant difference test at P £ 0.05. NS, *, **, ***Not significant or significant at P £ 0.05, 0.01, or 0.001, respectively.
Table 4. Retail and consumer vase life of cut linaria, trachelium, rudbeckia, and zinnia stems pulsed in 0%, 10%, or 20% sucrose solutions for 24 h. Postharvest room conditions: 40% to 60% relative humidity, 20 ± 2 C (68.0 ± 3.6 F), and 12-h photoperiod at 20 to 40 mmolÁm–2Ás–1. Means are an average of 15 stems. ‘Jemmy Royal Purple’ ‘Indian Summer’ ‘Benary’s Giant ‘Lace Violet’ linaria trachelium rudbeckia Scarlet’ zinnia Retail Consumer Retail Consumer Consumer Consumer Sucrose (%) Vase life (d) 0 4.0 bz 5.1 b 11.3 a 19.0 a 37.1 a 8.9 b 10 6.1 a 8.9 a 12.7 a 18.6 a 8.7 b 13.7 a 20 6.9 a 9.2 a 6.9 b 2.1 b 6.9 b 10.1 ab Significance *** *** ** *** *** ** zWithin columns, means followed by the same letter are not significantly different according to least significant difference test at P £ 0.05. **, ***Significant at P £ 0.01 or 0.001, respectively.
596 • July–September 2009 19(3) Table 5. Retail and consumer vase life of cut linaria and trachelium stems pulsed solution is often debated (van Meete- in Chrysal Professional 1 Hydrating Solutionz (CP1), Floralife Hydraflor 100y ren et al., 2000). Most of the specialty (FL100), or deionized water (DI) and held in Chrysal Professional 2 Processing cut flowers tested in this study can be z y solution (CP2), Floralife Professional (FLP), or deionized water (DI) as held in tap or DI water without holding solutions. Postharvest room conditions: 40% to 60% relative humidity, altering their vase lives (Table 2). An 20 ± 2 C (68.0 ± 3.6 F), and 12-h photoperiod at 20 to 40 mmolÁm–2Ás–1. Means are an average of 11 to 15 stems. exception was cut linaria stems in which DI supplemented with 8- ‘Jemmy Royal HQC with adjusted or nonadjusted ‘Lace Violet’ linaria Purple’ trachelium pH produced the longest retail vase Treatments Retail Consumer Consumer life. It was also necessary to adjust pH Hydrator Holding Vase life (d) and add 8-HQC to the holding water DI CP2 8.3 ax 9.8 a 17.5 a to significantly extend the consumer FLP 9.0 a 11.8 a 11.2 c vase life of linaria. DI or tap water DI 5.3 b 5.6 b 15.1 b similarly reduced the retail and con- CP1 CP2 9.1 a 10.5 a 11.0 c sumer lives of linaria. Thus, the addi- DI 5.2 b 5.2 b 10.9 c tion of the germicide 8-HQC was FL100 FLP 9.5 a 12.9 a 10.9 c crucial to increase the vase life in DI 5.4 b 5.4 b 15.1 b linaria. With cut roses (Rosa hybrida), Significance *** *** *** 8-HQC and low pH avoided vascular zBendien, Naarden, The Netherlands. blockage in stems due to the reduc- yFloralifeÒ, Walterboro, SC. tion of bacterial population (van xWithin columns, means followed by the same letter are not significantly different according to least significant Doorn and Perik, 1990). Further- difference test at P £ 0.05. ***Significant at P £ 0.001. more, fresh weight was improved in carnation (Dianthus caryophyllus) and alstroemeria (Alstroemeria hybrids) (Knee, 2000) after the incorporation Table 6. Consumer vase life of cut dahlia, lupine, and poppy stems after holding of 8-HQC in the vase solution. In z y in Chrysal Professional 2 Processing (CP2), Floralife Professional (FLP), or general, germicides enhance fresh deionized water (DI) solutions. Postharvest room conditions: 40% to 60% weight by improving solution uptake relative humidity, 20 ± 2 C (68.0 ± 3.6 F), and 12-h photoperiod at 20 to (Jones and Hill, 1993). 40 mmolÁm–2Ás–1. Means are an average of 12 to 15 stems. However, consumer vase life in ‘Karma Thalia’ rudbeckia and ‘Sun Gold’ zinnia Commercial holding dahlia ‘Sunrise’ lupine ‘Temptress’ poppy decreased significantly when 8-HQC preservative Consumer vase life (d) was added to the vase water. The DI 8.6 b x 8.6 b 5.5 b addition of 8-HQC to the holding CP2 10.1 ab 9.9 ab 7.9 a water caused phytotoxicity in ‘Fanta- FLP 10.8 a 12.2 a 7.6 a sia’ statice (Limonium hybrids) (Doi Significance ** *** *** and Reid, 1995). Germicide effect zBendien, Naarden, The Netherlands. can vary considerably among species yFloralifeÒ, Walterboro, SC. and cultivars (Jones and Hill, 1993). xWithin columns, means followed by the same letter are not significantly different according to least significant For example, Stimart et al. (1983) difference test at P £ 0.05. **, ***Significant at P £ 0.01 or 0.001, respectively. noted that 8-HQC increased zinnia fresh weight. Floral foam was designed to vase lives decreased significantly as the after ethylene application, and could absorb water evenly and to hold stems storage was prolonged, regardless of be increased with the application of in place for floral designs, but water the storage condition. In addition, MCP or STS (Table 8). Retail and release depends on the density of rehydration did not occur in lupine, consumer vase lives of trachelium foam. Floral foam might restrict water poppy, and trachelium after dry or were dramatically reduced by ethyl- uptake, as reported for cut poinsettia wet storage for 3 weeks. Cut zinnia ene application, which caused florets (Euphorbia pulcherrima) stems (Dole stems did not rehydrate after any to close entirely or stop opening. et al., 2004), therefore shortening length of cold storage (data not pre- Ethylene effect on retail and con- vase life. In this study, while the use sented); vase life of nonstored stems sumer vase life was overcome when of floral foam reduced vase life of both averaged 16.4 d for ‘Benary’s Giant cut trachelium stems were initially zinnia cultivars at 0% or 2% sucrose, it Scarlet’ and 11.4 d for ‘Sun Gold’. treated with MCP or STS. Cut linaria, did not affect the vase lives of most Up to 3 weeks of cold storage did not zinnia, dahlia, rudbeckia, and poppy cut flowers compared with treatments affect consumer vase life of linaria (4.6 stems were unaffected by exogenous without foam (Table 3). Big bend d) and rudbeckia (34.3 d) or the retail ethylene or antiethylene treatments bluebonnet inflorescences showed vase life of poppy (3.7 d) (data not (data not presented). similar vase life (10 d) when set in presented). water or floral foam (Davis et al., ETHYLENE SENSITIVITY. Con- Discussion 1995). Sucrose supplementation of sumer vase life of cut lupine stems In vase life experiments, the use 2% was sufficient to improve vase life was decreased due to floret abscission of tap or DI water as a control in linaria, trachelium, and ‘Benary’s
• July–September 2009 19(3) 597 RESEARCH REPORTS
Table 7. Retail and consumer vase life of dahlia, linaria, lupine, poppy and trachelium stems after dry or wet storage for 1, 2, or 3 weeks at 2 C (35.6 F). Postharvest room conditions: 40% to 60% relative humidity, 20 ± 2 C (68.0 ± 3.6 F), and 12-h photoperiod at 20 to 40 mmolÁm–2Ás–1. Means are an average of 12 to 15 stems. ‘Karma Thalia’ ‘Lace Violet’ ‘Sunrise’ ‘Temptress’ ‘Jemmy Royal dahlia linaria lupine poppy Purple’ trachelium Consumer Retail Consumer Consumer Retail Consumer Treatments Vase life (d) 0 0 8.5 az 4.2 a 11.5 a 6.6 a 12.3 a 14.3 a 1 Wet 6.7 b 2.6 b 8.5 ab 6.6 a 7.7 b 9.0 b Dry 6.6 b 2.5 b 7.2 b 6.0 a 6.8 b 9.1 b 2 Wet —y 3.7 ab 8.8 ab 4.9 ab 4.4 c 5.0 c Dry — 3.8 ab 5.8 b 3.6 b 4.9 c 6.7 c 3 Wet — 3.1 ab — — — — Dry 4.2 a — — — — Significance Week (W) — ** NS ** ** * Condition (C) NS NS * NS NS NS W · C—NS NS NS NS NS zWithin columns, means followed by the same letter are not significantly different according to least significant difference test at P £ 0.05. yFlowers did not rehydrate after storage. NS, *, **Not siginificant or significant at P £ 0.05 or 0.01, respectively.
Table 8. Retail and consumer vase life of cut lupine and trachelium after occurred in kangaroo paw (Anigo- treatment with 700 nLÁL–1 (ppb) 1-methylcyclopropene (MCP) or 0.2 mM silver zanthos hybrids) (Teagle et al., thiosulfate (STS) before application of exogenous ethylene at 0 or 1 mLÁL–1 for 1991) after pulsing in 20% sucrose. 16 h. Postharvest room conditions: 40% to 60% relative humidity, 20 ± 2 C The fact that commercial hy- (68.0 ± 3.6 F), and 12-h photoperiod at 20 to 40 mmolÁm–2Ás–1. Means are an drators did not enhance retail or average of 7 to 15 stems. consumer vase life of any species test- ‘Jemmy Royal ed confirms that cut stems need Treatments ‘Sunrise’ lupine Purple’ trachelium treatments other than hydration to Antiethylene Consumer Retail Consumer maintain quality and to enhance post- treatment Ethylene(mLÁL–1) Vase life (d) harvest life (Tables 5 and 6). Com- mercial holding agents not only None 0 8.0 abz 7.7 ab 8.1 a provided ingredients to hydrate cut 1 2.0 c 2.5 c 2.5 b stems, but also carbohydrates to MCP 0 9.9 a 8.3 ab 9.1 a extend postharvest quality and lon- 1 8.3 ab 7.5 ab 8.5 a gevity. In many species, commercial STS 0 10.1 a 8.0 ab 8.8 a holding solutions increase vase life 1 6.3 b 7.2 b 8.6 a (Sacalis, 1993). For example, vase life, Significance flower size, and number of open Anti-ethylene (A) *** *** *** flowers increased in brazilian snapdra- Ethylene (E) *** *** *** gon (Otacanthus coeruleus) with the A · E *** *** *** addition of Chrysal Universal to the zWithin columns, means followed by the same letter are not significantly different according to least significant difference test at P £ 0.05. vase solution (Geertsen, 1990). ***Significant at P £ 0.001. The inconsistent effectiveness of the preservatives observed among the species of this study has been reported Giant Scarlet’ zinnia. The addition of (20%) sucrose pretreatment increased within cultivars of the same species 0% or 4% sucrose induced the longest water uptake of cut gladioli after the (Heuser and Evensen, 1986; Maclean vase life of ‘Sun Gold’ zinnia. Sucrose stems were transferred into water and Rasmussen, 1980). Consequently, is very useful in extending vase life (Mayak et al., 1973). Also, sucrose additional preservative sources, doses, by helping water balance and turgid- treatments delayed the onset of ethyl- and developmental stages of cut stems ity and by providing a carbohydrate ene production and responsiveness in must be also studied. source (Nair et al., 2003). ‘White Sim’ carnation petals (Verlinden In this study, dry or wet storage Only linaria and ‘Benary’s Giant and Vicente Garcia, 2004). In con- at a low temperature had a similar Scarlet’ zinnia showed a positive trast, a 20% sucrose pulse decreased effect on vase life of all cut flowers, response to sucrose pulses at 10% or the consumer and retail vase lives of except for lupine, where wet storage 20% (Table 4). Similarly, high sucrose trachelium, and a 10% and 20% was slightly more beneficial than dry in pulsing or holding solution en- sucrose pulse reduced the vase life of storage (Table 7). Similarly, dry or hanced sugar concentration in cut rudbeckia. Premature drying and yel- wet storage for species-specific dura- lisianthus (Eustoma grandiflorum) lowing were observed in lisianthus tions at temperature between 0 and stems (Cho et al., 2001). High (Cho et al., 2001), and leaf browning 10 C did not affect vase life of
598 • July–September 2009 19(3) carnation, daffodil (Narcissus pseudo- Arnosky, 2003; E. Hitt, personal 6.6 d for unstored, untreated stems. narcissus), iris (Iris hollandica), killian communication). However, the use of commercial hold- daisy (Chrysanthemum maximum), Ethylene application only short- ing solutions increased vase life to at paperwhite narcissus (Narcissus taz- ened the vase life of lupine and tra- least 9 d, which would allow it to be etta), rose, or tulip (Tulipa gesneri- chelium; hence, the incorporation of used commercially. ana) (Cevallos and Reid, 2001). antiethylene-binding chemicals ex- The commercial potential of Linaria and rudbeckia could be tended their vase lives (Table 8). ‘Lace Violet’ linaria may be restricted stored for 3 weeks without significant MCP and STS were similarly effective due to a vase life of less than 7 d in loss of vase life. Longevity of cut in extending cut flower vase life of some experiments and due to a wide dahlia and trachelium stems de- lupine and trachelium. In big bend variation in vase life from a low of 4.6 creased significantly with the first bluebonnet, MCP also extended the d to a high of 9.1 d in the nonstored week of storage. Cut poppy and vase life longevity by about 2 d DI water treatments. Such variability lupine stems tolerated cold storage (Valenzuela-Vasquez et al., 2007). would reduce confidence in the spe- for a maximum of 2 weeks. In a In summary, most of the species, cies by retailers, limiting use of the previous report, STS-preconditioned ‘Karma Thalia’ dahlia, ‘Indian Sum- linaria to events where only a 5 d or cut big bend bluebonnet inflorescen- mer’ rudbeckia, ‘Sunrise’ lupine, shorter vase life is necessary. Trache- ces, stored wet at 5 C for 3 d, had a ‘Jemmy Royal Purple’ trachelium, lium and ‘Benary’s Giant Scarlet’ zin- vase life similar to nonstored stems (9 and zinnia cultivars ‘Benary’s Giant nia similarly exhibited a wide variation d) without quality loss (Davis et al., Scarlet’ and ‘Sun Gold’, have excel- in vase life; however, the minimum 1995). lent commercial potential, as they had vase life was greater than 7 d. Varia- Zinnias should not be cold a consumer vase life that exceeded 7 d tion in vase life needs to be docu- stored at 2 C because both cultivars when stems were not treated or mented for new cut flower species to lost petal and foliar turgidity, did not stored. A summary table showing ensure that growers and retailers are rehydrate, and exhibited cold damage the responses of each species and cul- aware of the problem. regardless of being stored dry or wet. tivar to the treatments is included In this study, the variation in vase Cold storing ‘Sun Gold’ flowers (Table 9). Of note, rudbeckia was life for a specific species from experi- resulted in flower petal browning the longest-lived species, lasting at ment to experiment may have been and stem collapse, while ‘Benary’s least 20 d. The focus on nonstored due to preharvest factors of light level, Giant Scarlet’ showed yellow patches treatments is important because production temperature, water avail- on the red petals and stem collapse. many specialty cut flower growers ability, and humidity (Adachi et al., The yellow patches on the petals of direct-retail their flowers, and spe- 1999; de Barrera and Arenas, 1999; ‘Benary’s Giant Scarlet’ were ob- cialty cut flower growers are an van Gorsel, 1993). For example, van served 1 to 2 d after cold storage. increasingly important segment of Gorsel (1993) noted that the vase life Zinnia producers have also noted that the cut flower industry in the United of bouvardia (Bouvardia hybrid) var- 1 to 3 d of cold storage below 5 C States. ied from 9 d during the early spring to reduced vase life and sometimes pro- In contrast, the vase life of 18 d during the fall and that season duced petal browning (Arnosky and ‘Temptress’ poppy was only 5.5 to had a more pronounced effect on vase
Table 9. Postharvest performance of cut dahlia, linaria, lupine, poppy, rudbeckia, trachelium, and zinnia stems subjected to different treatments, which increased vase life (+), reduced vase life (–), or had no effect (NE) compared with the control treatments. Sucrose and floral foam = stems pulsed in 0%, 10%, or 20% sucrose solutions for 24 h (Pulse) or subjected to 0%, 2%, or 4% in the vase solution (Vase water) with or without floral foam substrate. Commercial preservatives = stems pulsed in hydrating solution (Chrysal Professional 1 Hydrating Solutionz, Floralife Hydraflor 100y, or deionized water) and held in a holding solution (Chrysal Professional 2 Processing solutionz, Floralife Professionaly, or deionized water) until termination. Cold storage = stems stored dry or wet for 1, 2, or 3 weeks at 2 C (35.6 F). Ethylene sensitivity = stems treated with either 700 nLÁL–1 (ppb) 1-methylcyclopropene (MCP) or 0.2 mM silver thiosulfate (STS) before application of exogenous ethylene (Exog.) at 0 or 1 mLÁL–1 (ppm) for 16 h. Postharvest room conditions were 40% to 60% relative humidity, 20 ± 2 C (68.0 ± 3.6 F), and 12-h photoperiod at 20 to 40 mmolÁm–2Ás–1. Sucrose Commercial Vase Floral preservatives Cold storage Ethylene sensitivity Cut flowers Pulse waterfoam Hydrator Holding Dry Wet Weekx Exog. STS MCP ‘Karma Thalia’ dahlia NE NE NE NE + NE NE 0 NE NE NE ‘Lace Violet’ linaria + + NE NE + NE NE 3 NE NE NE ‘Sunrise’ lupine NE NE NE NE + NE NE 1 – + + ‘Temptress’ poppy NE NE NE NE + NE NE 1 NE NE NE ‘Indian Summer’ rudbeckia – NE NE NE NE NE NE 3 NE NE NE ‘Jemmy Royal Purple’ trachelium – + NE NE + NE NE 0 – + + ‘Benary’s Giant Scarlet’ zinnia + + – NE NE NE NE 0 NE NE NE ‘Sun Gold’ zinnia NE + – NE NE NE NE 0 NE NE NE zBendien, Naarden, The Netherlands. yFloralifeÒ, Walterboro, SC. xMaximum number of weeks stems could be stored without reducing vase life.
• July–September 2009 19(3) 599 RESEARCH REPORTS life than production temperature. Faragher, J.D., S. Mayak, T. Tirosh, and philla paniculata L. HortTechnology Studies have linked vase life to com- A.H. Havely. 1984. Cold storage of rose 8:58–63. flowers: Effect of cold storage and water mercial greenhouse production con- Nowak, J. and R.M. Rudnicki. 1990. ditions and noted that high light and loss on opening and vase life of ‘Mercedes’ roses. Scientia Hort. 24:369–378. Postharvest handling and storage of cut low relative humidity were correlated flowers, florist greens, and potted plants. with increased vase life (Marissen, Geertsen, V. 1990. The keeping quality of Timber Press, Portland, OR. 2005; Slootweg, 2005). In our stud- Otacanthus coeruleus: A potential new cut flower. Scientia Hort. 43:145–153. Redman, P.B., J.M. Dole, N.O. Maness, ies, all experiments for each species and J.A. Anderson. 2002. Postharvest were completed within 1 month, but Heuser, C.W. and K.B. Evensen. 1986. handling of nine specialty cut flower spe- there may have been sufficient varia- Cut flower longevity of peony. J. Amer. cies. Scientia Hort. 92:293–303. tion in growing conditions during Soc. Hort. Sci. 111:896–899. that time to influence vase life. Sloot- Reid, M.S. 2004. Cut flowers and greens. weg (2005) noted that conditions in Ichimura, K., M. Shimamura, and T. In: K. Gross (ed.). The commercial stor- Hisamatsu. 1998. Role of ethylene in age of fruits, vegetables, and florist and the last 2 weeks before harvest may be senescence of cut Eustoma flowers. Post- nursery stocks. U.S. Dept. Agr. Hdbk. 66. most critical. harvest Biol. Technol. 14:193–198. 15 Feb. 2009.
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