@article{kalinowski_ahmad_dole_2023, title={Chemical Promotion of Branching and Stem Elongation of Poinsettia}, volume={33}, ISSN={["1943-7714"]}, DOI={10.21273/HORTTECH05186-23}, abstractNote={Growers have traditionally used mechanical pinching and other cultural practices to control height and encourage branching for full and uniform poinsettia (Euphorbia pulcherrima) plants. A total of six experiments were conducted over 5 years to evaluate the impact of chemically treating poinsettia on final height, branching, first color, visible bud formation, and anthesis. The first four experiments evaluated the potential of benzyladenine (BA) and gibberellins [GA(4+7)] to increase height of treated poinsettia. Timing of the application was assessed during Expt. 1 using a combined concentration of 3 ppm BA and 3 ppm GA(4+7) applied at 5, 7, 9, or 11 weeks after pinching; some cultivars exhibited significantly more elongated inflorescences when treatment occurred 7 or 9 weeks after pinching. The application method and frequency was assessed during Expt. 2, and treatments were applied one or three times with either drench application at a concentration of 2 ppm or foliar application at a concentration of 5 ppm or untreated controls. All plants treated with three drench applications produced taller plants on average than when only applied once or when treated with a foliar application. Expt. 3 further assessed height gain and effects on flowering during late-season production with foliar applications of BA+GA(4 + 7) applied 2 weeks after first color at a concentration of 2 ppm compared with untreated control plants. One cultivar, Mars Red, was observed to have a significant decrease in days to anthesis when treated (9 days) compared with untreated plants, but no cultivars exhibited a significant change in height resulting from treatment. Expt. 4 assessed both the application method (foliar and drench) and change in final environment when plants were either maintained in a greenhouse or relocated to a postharvest room before anthesis. Most cultivars experienced a significant height increase when treated with foliar application of BA+GA(4 + 7) regardless of the final environment, but a significant delay in days to first color, visible bud, and anthesis was prevalent, and only one cultivar exhibited a treatment benefit from drench application with no significant delay in flowering or differences caused by changing environment. Expts. 5 and 6 were conducted over 2 growing years to evaluate the benefits of chemically pinching poinsettia using dikegulac sodium at a concentration of 800 ppm applied either once or twice (1 week apart) or 1600 ppm applied once to promote branching. The tallest plants were those treated one time at a concentration of 800 ppm showing lack of dominance in the apical meristem. The greatest number of shoots occurred when plants were treated with 800 ppm twice, whereas one application of 800 or 1600 ppm often, but not always, resulted in more shoots compared with mechanically pinched plants. Interestingly, the increased number of shoots from treated plants was often more than double the number compared with mechanical pinching, but those additional shoots failed to develop, which resulted in only one or two additional inflorescences. Production time was found to be a tradeoff because most dikegulac sodium-treated plants experienced an increased number of days to first color, visible bud, and/or anthesis. These results demonstrate that height control, whether to encourage stem elongation or halt apical dominance, is cultivar-specific, and that although both the method and concentration may be determined uniformly on some cultivars, the timing of application is crucial because of potential delays in floral development.}, number={3}, journal={HORTTECHNOLOGY}, author={Kalinowski, Jennifer and Ahmad, Iftikhar and Dole, John M.}, year={2023}, month={Jun}, pages={286–295} }
 @article{fatima_ahmad_dole_ahmad_asif_ziaf_badar_fatima_2022, title={Folk floral preservatives extend postharvest longevity of Eustoma grandiflorum L.}, volume={301}, ISSN={["1879-1018"]}, DOI={10.1016/j.scienta.2022.111132}, abstractNote={Lisianthus (Eustoma grandiflorum L.) is one of the most popular cut flowers worldwide due to its multi-flowered stems having single, semi-double and double rose-like flowers in a variety of colors. However, its postharvest life can be short if not handled properly. A study was conducted to evaluate the effectiveness of various homemade folk floral preservative solutions applied as pulses or vase solutions on cut lisianthus stems. Both experiments were laid out individually in completely randomized design, with five replications of two stems each and evaluated in a vase life evaluation room set at 20±2 °C temperature and 50±10% of relative humidity along with 12 h of light from white fluorescent tubes. Results revealed significant differences among different pulsing treatments as 2% sucrose + 150 mg L−1 citric acid had longest vase life (10.3 days), whereas, 2% sucrose + 3 mL L−1 lime juice, 2% sucrose + 5% aloe vera gel, 2% sucrose + 30 mL L−1 moringa leaf extract (MLE) and 2% sucrose + 15 mL L−1 bleach had best flower quality (8.3) and were statistically similar. Moreover, (50:50) lemon/lime soda and water had highest water uptake (98 mL) and ion leakage (326.8%), whereas, 2% sucrose had highest (735 µs cm−1) change in electric conductivity. Among vase treatments when compared to commercial solutions, Floralife Clear Professional Flower Food, Chrysal Clear Universal Flower Food and 2% sucrose + 4 mL L−1 lime juice had longest vase life (16.6, 15.9 and 15.7 days, respectively) and were statistically similar, whereas, highest microbial colonies (6.14 CFU mL−1) were observed in solution having 5% sucrose only and the lowest with the commercial solutions. In summary, lisianthus stems placed in vase treatments had longest vase life, while those pulsed ones had better visible quality and use of sugar with lemon/lime juice as a vase solution produced a similar vase life as commercial preservatives.}, journal={SCIENTIA HORTICULTURAE}, author={Fatima, Kainat and Ahmad, Iftikhar and Dole, John M. and Ahmad, Naveed and Asif, Muhammad and Ziaf, Khurram and Badar, Muhammad Adnan and Fatima, Kaneez}, year={2022}, month={Jul} }
 @article{abdullah_ahmad_dole_2020, title={Optimal sowing time and planting density for selected field grown cut Antirrhinum and Matthiola}, volume={261}, ISSN={["1879-1018"]}, DOI={10.1016/j.scienta.2019.108909}, abstractNote={A field study was conducted on selected cultivars of Antirrhinum majus L. and Matthiola incana L. at University of Agriculture, Faisalabad, Pakistan, to determine the best planting time and density to develop optimal planting protocols to grow these species as cut flowers in the sub-tropics. Antirrhinum and Matthiola seeds were sown five times at 15 or 16 d intervals on 15 Sept., 01 Oct., 15 Oct., 01 Nov. or 15 Nov. In a separate study, the optimum planting density was determined by transplanting seedlings at 15 × 15, 15 × 22.5, 22.5 × 22.5, 22.5 × 30 or 30 × 30 cm apart. For planting time, both species demonstrated shorter crop time with delayed sowings, but delayed sowing reduced stem quality. Cultivars of both species sown on 15 Sept. had the tallest plant height, 104.2 and 58.6 cm for Antirrhinum and Matthiola, respectively, along with the greatest number of leaves (176.7 and 28.9), leaf area (13.7 and 35.0 cm2), number of florets (32.8 and 14.8), floret diameter (41.3 and 47.3 mm), raceme length (27.2 and 14.6 cm) and stem diameter 14.8 and 9.9 mm for Antirrhinum and Matthiola, respectively, compared to those sown on 15 Nov. Moreover, vase life of stems of both species decreased (4.0 d for Antirrhinum and 5.5 d for Matthiola) with delayed sowing time. Among all tested cultivars of Antirrhinum, ‘Admiral White’ flowered the earliest, ‘Potomac Orange’ and ‘Potomac Yellow’ flowered mid season, and ‘Potomac Rose’ and ‘Potomac White’ took longest to produce flowers, while all Matthiola cultivars produced flowers at similar times for each sowing date. Antirrhinum and Matthiola planted at 30 × 30 cm spacing had greatest number of leaves (198.1 and 31.4 for Antirrhinum and Matthiola, respectively), leaf area (14.3 and 40.1 cm2), number of florets (32.4 and 15.4), floret diameter (36.1 and 47.7 mm), raceme length (26.2 cm of Antirrhinum only) and stem diameter (14.1 and 14.7 mm for Antirrhinum and Matthiola, respectively) compared to those planted at 15 cm × 15 cm. In summary, for extending harvest season, Antirrhinum cultivars may be sown at same time, but Matthiola cultivars should be grown using staggered sowing times. Antirrhinum and Matthiola cultivars may be sown on 15th September to 1st October and transplanted at 22.5 × 22.5 cm spacing for best cut stem quality.}, journal={SCIENTIA HORTICULTURAE}, author={Abdullah, Bilal and Ahmad, Iftikhar and Dole, John M.}, year={2020}, month={Feb} }
 @article{bergmann_ahmad_dole_2019, title={Benzyladenine and gibberellic acid pulses improve flower quality and extend vase life of cut dahlias}, volume={99}, ISSN={["1918-1833"]}, DOI={10.1139/cjps-2018-0126}, abstractNote={Abstract: A 24-h pulse of cut dahlias in a solution containing both benzyladenine and gibberellic acid at 10–20 mg L-1 improved flower quality after 4 d in the vase and prolonged vase life regardless of handling method (dry packed or held in water from harvest through delivery).}, number={1}, journal={CANADIAN JOURNAL OF PLANT SCIENCE}, author={Bergmann, Ben A. and Ahmad, Iftikhar and Dole, John M.}, year={2019}, month={Feb}, pages={97–101} }
 @article{ahmad_tanveer_liaqat_dole_2019, title={Comparison of corm soaks with preharvest foliar application of moringa leaf extract for improving growth and yield of cut Freesia hybrida}, volume={254}, ISSN={["1879-1018"]}, DOI={10.1016/j.scienta.2019.04.074}, abstractNote={Moringa leaf extract (MLE) is an organic bio-stimulant that can enhance crop growth and alleviate various stresses. The use of MLE might address a number of production issues on freesia, which is a popular bulbous cut flower grown and shipped worldwide. A field study was conducted to compare the effects of corm soaking with preharvest foliar applications of MLE on various morphological, physiological and yield attributes of freesia (Freesia hybrida L.). Two experiments were conducted; in experiment I, corms were soaked in 1%, 2%, 5% or 10% MLE solution for 24 h followed by air drying before planting, while in experiment II, untreated corms were planted and MLE at 1%, 2%, 3% or 5% was sprayed until runoff at 30 and 60 days after planting. Corms soaked in 5% MLE exhibited rapid 50% sprouting (3.2 d earlier compared to control), produced tallest plants (58.6 cm) with shortest production time (9 d earlier than control), highest number of leaves per plant (21.6), leaf area (109.2 cm2), leaf total chlorophyll contents (64.1 SPAD), stem diameter (4.3 mm), number of flowers per stem (6.6), number of marketable stems (3.1) and longest vase life (9 d), while flower diameter was highest (36.7 mm) when corms were treated with 2% MLE. In experiment II, foliar application of 3% MLE at 30 and 60 d after planting produced the tallest plants (16.3 cm taller than control) with shortest production time (9 d earlier than control), greatest leaf area (88.6 cm2), leaf total chlorophyll contents (57.02 SPAD), flower diameter (34.9 mm), number of leaves per plant (21.9), stem length (53.3 cm), stem diameter (3.9 mm), number of flowers per stem (6.5), and number of marketable stems (2.8) with longest vase life (3.3 d longer than control). Results demonstrated that MLE application significantly improved growth, quality and yield of Freesia hybrida by providing growth substances and minerals required for optimal growth and may be used by the growers as corm soak or foliar application for high quality cut freesia production. Among application methods, corm soaks were better than foliar applications.}, journal={SCIENTIA HORTICULTURAE}, author={Ahmad, Iftikhar and Tanveer, Muhammad U. and Liaqat, Madiha and Dole, John M.}, year={2019}, month={Aug}, pages={21–25} }
 @article{ahmad_abdullah_dole_shahid_ziaf_2019, title={Evaluation of the air pollution tolerance index of ornamentals growing in an industrial area compared to a less polluted area}, volume={60}, ISSN={["2211-3460"]}, DOI={10.1007/s13580-019-00141-9}, number={4}, journal={HORTICULTURE ENVIRONMENT AND BIOTECHNOLOGY}, author={Ahmad, Iftikhar and Abdullah, Bilal and Dole, John Martin and Shahid, Muhammad and Ziaf, Khurram}, year={2019}, month={Aug}, pages={595–601} }
 @article{ahmad_jabeen_ziaf_dole_khan_bakhtavar_2017, title={Macronutrient application affects morphological, physiological, and seed yield attributes of Calendula officinalis L.}, volume={97}, ISSN={["1918-1833"]}, DOI={10.1139/cjps-2016-0301}, abstractNote={Abstract: Effects of N, P, and K applications alone or in various combinations and ratios were studied on the morphological, physiological, and seed yield attributes and on seed production of calendula. Treatment combinations were control (no N–P–K application), 150 kg ha-1 N, 80 kg ha-1 P, 150 kg ha-1 K, N–P, N–K, P–K, and N–P–K, while in a second experiment, different ratios of N–P–K were compared to determine the best combination and ratio of tested nutrients for optimal growth, quality, yield, and seed production. Plants supplied with N–P–K had vigorous growth, had higher total leaf chlorophyll content, and flowered earlier with greater flower fresh and dry weights, along with improved photosynthetic performance. Plant biomass and seed yield along with leaf N and K were also higher in plants fertilized with N–P–K. In the second experiment, the application of 200–100–100 kg ha-1 N–P–K resulted in maximum growth, flowering, and seed yield, along with higher photosynthetic activity. Increased leaf area and improved leaf nutrient status were observed at 150–150–150 kg ha-1 N–P–K, while 200–200–200 kg ha-1 N–P–K increased stomatal conductance, photosynthetic rate, leaf P, and flower weights. Results demonstrated that a higher level of N along with lower level of P and K are vital for quality calendula flower and seed production.}, number={5}, journal={CANADIAN JOURNAL OF PLANT SCIENCE}, author={Ahmad, I. and Jabeen, N. and Ziaf, K. and Dole, J. M. and Khan, M. A. S. and Bakhtavar, M. A.}, year={2017}, month={Oct}, pages={906–916} }
 @article{ahmad_saleem_dole_matthysse_2016, title={BIO-CONTROL ACTIVITY OF BACTERIAL STRAINS ON POSTHARVEST PERFORMANCE OF Gladiolus L. HYBRIDS 'MAMMOTH'}, volume={53}, ISSN={["2076-0906"]}, DOI={10.21162/pakjas/16.3769}, abstractNote={Gladiolus (Gladiolus L. hybrids), one of the most popular bulbous cut flowers of the world, has the problem of shorter vase life due to vascular occlusion by bacteria. Stem blockage in cut flowers is generally caused by bacterial proliferation along with their decay products (Teixeira-da-Silva, 2003). Bio-control through bacteria represent a potential alternative management approach (Jetiyanon and Kloepper, 2002) and may help in developing an organic method for effectively controlling detrimental microbes in the vase solutions (Carlson et al., 2015). The bio-control agents are used for biological management of pests to control a specific microbe (Shanmugam et al., 2011; Sajjad et al., 2014). Among bacterial antagonists, Pseudomonas fluorescens is most effective against a wide range of plant pathogens infecting different plants such as carnation, bean, radish, cucumber, tomato, and tobacco (van Loon et al., 1998), while P. fulva has extended vase life of cut zinnia stems (Carlson et al., 2015). Moreover, Burkholderia cepacia and Bacillus spp. (spore forming Gram-positive bacteria) have effectively been used to control plant diseases (Kloepper et al., 2004). Use of compatible and multiple bio-control agents in various groups also helps to control plant diseases, such as combinations of bacteria (Raupach and Kloepper, 1998; Shanmugam et al., 2002), fungi (Paulitz et al., 1990), bacteria and fungi (Duffy et al., 1996), yeasts (Janisiewicz, 1996), and bacteria and yeast (Janisiewicz and Bors, 1995). An experiment was conducted to compare different beneficial bacterial strains for their efficacy to control detrimental bacteria in vase solutions with gladiolus stems. There is dire need to develop organic preservatives for keeping flower organic grown without chemicals until end of vase life. However, there are currently no effective organic preservatives available in the market and those available are not effective (Ahmad et al., 2014). Organic carbohydrate source and acidifier are available but organic biocides are not available. Therefore, this study was conducted to elucidate the effect of bio-control bacterial strains, some of which have been proved effective for various agronomic crops, in controlling detrimental bacteria in vase solutions and effect on the postharvest water relations and quality characteristics of cut gladiolus. Moreover, the findings of the study would help develop an organic floral preservative to be used for handling organically grown cut flowers. Pak. J. Agri. Sci., Vol. 53(3), 593-598; 2016 ISSN (Print) 0552-9034, ISSN (Online) 2076-0906 DOI:10.21162/PAKJAS/16.3769 http://www.pakjas.com.pk}, number={3}, journal={PAKISTAN JOURNAL OF AGRICULTURAL SCIENCES}, author={Ahmad, Iftikhar and Saleem, Muhammad and Dole, John M. and Matthysse, Ann G.}, year={2016}, month={Sep}, pages={593–598} }
 @article{ahmad_saleem_dole_2016, title={Postharvest performance of cut 'White Prosperity' gladiolus spikes in response to nano- and other silver sources}, volume={96}, ISSN={["1918-1833"]}, DOI={10.1139/cjps-2015-0281}, abstractNote={Abstract: A study was conducted to compare the efficacy of nano-silver (NS), silver thiosulfate (STS), and silver nitrate as novel postharvest treatments, and evaluate the potential of nano-silver pulse (higher concentration) or vase (lower concentration) applications on postharvest performance of cut gladiolus (Gladiolus hybrids ‘White Prosperity’) spikes. Among silver compounds, spikes kept in silver nitrate had longest vase life. Spikes placed in STS at 10 or 20 mg L-1 had longer vase life than stems placed in NS, but similar to the stems placed in water. For NS pulse applications, spikes pulsed with 50 mg L-1 NS for 1 h at 20 ± 2 °C had 2.2 d longer vase life compared to the spikes in water. Pulsing of spikes for 1 h extended the vase life of cut gladiolus compared with 4 or 8 h pulsing durations. Spikes kept continuously in NS until end of vase life resulted in 4.2 d longer vase life at a lower concentration of 0.01 mg L-1. With increasing NS concentration to 10 mg L-1, vase life decreased to similar vase life as with tap water. The results demonstrated that NS at a 50 mg L-1 pulse for 1 h or 0.01 mg L-1 vase application can be used for extending vase life of cut gladiolus spikes.}, number={3}, journal={CANADIAN JOURNAL OF PLANT SCIENCE}, author={Ahmad, Iftikhar and Saleem, Muhammad and Dole, John M.}, year={2016}, month={Jun}, pages={511–516} }
 @article{ahmad_whipker_dole_2015, title={Paclobutrazol or Ancymidol Effects on Postharvest Performance of Potted Ornamental Plants and Plugs}, volume={50}, ISSN={["2327-9834"]}, DOI={10.21273/hortsci.50.9.1370}, abstractNote={. Effects of paclobutrazol and ancymidol on postharvest performance and growth control of potted sunflower ( Helianthus annuus L.), zinnia ( Zinnia elegans Jacq.) and marigold ( Tagetes erecta L.), petunia ( Petunia 3 hybrida Vilm.) plugs, respectively, were studied. Paclobutrazol was applied as a drench at 0, 1.0, 2.0, or 4.0 mg of a.i. per 15.2-cm pot for sunflower and 0, 0.5, 1.0, or 2.0 mg per 12.5-cm pot for zinnia, while ancymidol was applied at 0, 40, 80, and 160 mg · L L 1 with a volume of 0.21 L · m L 2 as a foliar spray for marigolds or petunia plug crops. With an increase in paclobutrazol dose or ancymidol concentration, plant growth (plant height and diameter, shoot fresh or dry weight) was controlled for all species tested. Use of 1.0–2.0 mg paclobutrazol per pot produced 21% to 28% shorter plants with 12% to 15% smaller plant diameter, 13% to 19% less shoot fresh weight, 15% to 21%}, number={9}, journal={HORTSCIENCE}, author={Ahmad, Iftikhar and Whipker, Brian E. and Dole, John M.}, year={2015}, month={Sep}, pages={1370–1374} }
 @article{ahmad_dole_whipker_2015, title={Paclobutrazol or uniconazole effects on ethylene sensitivity of potted ornamental plants and plugs}, volume={192}, ISSN={["1879-1018"]}, DOI={10.1016/j.scienta.2015.04.032}, abstractNote={Effects of paclobutrazol on postharvest ethylene sensitivity of potted cuphea (Cuphea hyssopifolia Kunth) and petunia (Petunia × hybrida Vilm.) plants, and uniconazole on portulaca (Portulaca oleracea L.) plugs were evaluated. Paclobutrazol was applied as a drench at 0, 1, 2, or 4 mg L−1 per 12.5 cm pot for cuphea, or 0, 2, 4, or 8 mg L−1 per 15.2 cm pot for petunia, while uniconazole was applied at 0, 2.0, 4.0, or 8.0 mg L−1 with a volume of 0.21 L m−2 as a foliar spray for portulaca plugs. With an increase in paclobutrazol dose or uniconazole concentration, plant growth [plant height and diameter (potted plants only), shoot fresh weight, or dry weight] was controlled for all species tested. While use of paclobutrazol or uniconazole controlled excessive plant growth of all three species, the plant growth retardants had no effect on postharvest ethylene sensitivity as most flowers abscised from all plants exposed to exogenous ethylene. However, both paclobutrazol and uniconazole reduced postharvest flower abscission of plants not treated with exogenous ethylene. During simulated shipping and marketing, paclobutrazol and uniconazole maintained darker foliage and controlled height. Drench applications of 2–4 mg L−1 paclobutrazol for cuphea and 4–8 mg L−1 for petunia potted plants and spray applications of 4–8 mg L−1 uniconazole for portulaca plugs produced compact, high quality plants while also extending postharvest longevity and quality.}, journal={SCIENTIA HORTICULTURAE}, author={Ahmad, Iftikhar and Dole, John M. and Whipker, Brian E.}, year={2015}, month={Aug}, pages={350–356} }
 @inproceedings{ahmad_dole_clark_funnell_2015, title={Pre- and postharvest studies on Sandersonia x gloriosa 'Firelight' (SG84)}, volume={1104}, booktitle={Xxix international horticultural congress on horticulture: sustaining lives, livelihoods and landscapes (ihc2014): international symposium on ornamental horticulture in the global greenhouse}, author={Ahmad, I. and Dole, J. M. and Clark, G. E. and Funnell, K. A.}, year={2015}, pages={295–301} }
 @article{ahmad_dole_blazich_2014, title={Effects of Daily Harvest Time on Postharvest Longevity, Water Relations, and Carbohydrate Status of Selected Specialty Cut Flowers}, volume={49}, ISSN={["2327-9834"]}, DOI={10.21273/hortsci.49.3.297}, abstractNote={Effects of harvest time (morning, noon, or afternoon) on water uptake, fresh weight changes, termination symptoms, leaf relative water content (LRWC), carbohydrate status, and vase life of cut ‘ABC Purple’ lisianthus (Eustoma grandiflorum Salisb.), ‘Double Eagle’ African Gold Coin Series marigold (Tagetes erecta L.), and ‘Deep Red’ Benary’s Giant Series zinnia (Zinnia elegans Jacq.) were studied. For stems of lisianthus harvested and then stored in the dark with the basal ends in water for 2 weeks at 3 ± 1 8C, those harvested at noon (1200 HR to 1300 HR) or in the afternoon (1700 HR to 1800 HR) had longer vase life compared with stems harvested in the morning (0700 HR to 0800 HR). However, stems of lisianthus evaluated without storage had no differences in vase life. Stems of marigold harvested in the afternoon had longer vase life than morningor noonharvested stems. Time of harvest had no effect on cut flower longevity of zinnia. However, vase life was considerably shorter for stems of all species when tested after 2 weeks storage compared with freshly harvested stems. Stems of zinnia harvested at noon had lower LRWC than morningor afternoon-harvested stems. Marigold stems harvested in the afternoon and evaluated without storage had lowest LRWC on Day 7 of vase life. Harvest time or storage did not influence LRWC of lisianthus. Stems of marigold and lisianthus harvested at noon or in the afternoon had higher levels of carbohydrates compared with morning-harvested stems, whereas freshly harvested stems had higher concentrations of glucose and sucrose, which decreased during storage or the vase period. Sucrose concentrations varied more significantly among various tissues than other sugars presumably as a result of translocation during vase life. In summary, carbohydrate status of stems harvested at different times of the day varied greatly and affected postharvest longevity of cut marigold and lisianthus, but not zinnia. Many post-production factors affect vase life of cut flowers including developmental stage at harvest, temperature during the vase period, water loss, and various aspects of the vase solution such as sucrose levels, microbial populations, pH, electrical conductivity (EC), and overall water quality (Sacalis, 1993). To maintain flower quality, studies have focused on storage (Ahmad et al., 2012; Cxelikel and Reid, 2002; Jones et al., 2004), floral preservatives (Doi and Reid, 1995; Elhindi, 2012; Gast, 1997), or use of ethylene inhibitors, e.g., silver thiosulfate and 1methylcyclopropene (Blankenship and Dole, 2003; Chamani et al., 2005), nano-silver (Kim et al., 2005; Liu et al., 2012), and other commercial antiethylene agents (Staby et al., 1993). However, postharvest longevity of cut flowers is also affected by a variety of both preharvest (e.g., harvest season, solar radiation, temperature, relative humidity, water, and mineral nutrient stress) (Halevy and Mayak, 1979; Reid and Jiang, 2012; Slootweg, 2005) and postharvest (e.g., harvest stage, harvest procedures, ethylene, vase water quality, preservatives, storage method and duration, etc.) factors (Halevy and Mayak, 1981; Marissen and Benninga, 2001; van Doorn, 2012). In addition to the aforementioned factors, the time of the day when stems are harvested may be a potentially important consideration (Clarkson et al., 2005; Hasperué et al., 2011; Rapaka et al., 2007). Generally, stems are harvested by growers in the morning allowing more time for processing and marketing and to avoid field heat, which preserves quality and minimizes transpiration and thereby desiccation. However, for many species, morning harvest may not be the proper time because many plant physiological processes change diurnally and can affect postharvest longevity of cut stems. For instance, diurnal variations in ascorbic acid levels of spinach (Spinacea oleracea L.) (Kiyota et al., 2006) and chlorophyll precursors in bean (Phaseolus vulgaris L.) (ArgyroudiAkoyunoglou and Prombona, 1996) have been reported. However, the most pronounced effect of diurnal fluctuations has been observed on carbohydrate metabolism in plants (Hasperué et al., 2011). Changes in solar radiation greatly affect endogenous carbohydrate reserves, which accumulate during the day and are remobilized by the end of the dark period (Sicher et al., 1984). Harvesting later in the day compared with morning harvesting increased shelf life considerably for leaves of basil (Ocimum basilicum L.) (Lange and Cameron, 1994), baby salad [Eruca vesicaria (L.) ssp. Sativa (Mill.)] Thell. (Clarkson et al., 2005), and unrooted shoot-tip cuttings of lantana (Lantana comara L.) (Rapaka et al., 2007). These variations in shelf life were attributed to varying carbohydrate levels and diurnal changes in plant metabolic processes. Genotype and environmental conditions can also impact postharvest longevity. Cultivars of lettuce (Lactuca sativa L.) harvested at different times during the day have varying postharvest quality (Moccia et al., 1998). Butterhead lettuce had the best quality when harvested later in the day, whereas Latin-type lettuce had the best quality when harvested in early morning. Moreover, fluctuations in carbohydrate levels of field-grown crisphead lettuce have been observed between morning and afternoon harvests (Forney and Austin, 1988). Crisphead lettuce harvested in the afternoon had higher sucrose than morning harvests, whereas glucose and fructose were greater in morning harvests. Soluble sugars like sucrose act as signaling molecules for plants under stress and move between cells causing fluctuations in sugar concentrations during senescence (Chuang and Chang, 2013). Moreover, sucrose application reduced ethylene responsiveness in florets of broccoli (Brassica oleracea L.) and carnation (Dianthus caryophyllus L.) flowers (Nishikawa et al., 2005; Verlinden and Garcia, 2004). These diurnal plant carbohydrate changes can greatly affect postharvest longevity of cut flowers. However, limited information is available on the effects of time of harvest on extending postharvest performance (vase life) of particular ornamental crops. Therefore, Received for publication 13 Nov. 2013. Accepted for publication 27 Dec. 2013. This research was funded in part by the North Carolina Agricultural Research Service (NCARS), Raleigh, NC. Use of trade names in this publication does not imply endorsement by the NCARS of products named nor criticism of similar ones not mentioned. We thank John D. Williamson for critically reviewing the manuscript and Weiwen Guo for technical assistance with carbohydrate analysis. We are also grateful to the Endowment Fund Secretariat, University of Agriculture, Faisalabad, Pakistan, for financial support of the senior author. Postdoc Scholar. Professor and Head. Alumni Distinguished Graduate Professor Emeritus. To whom reprint requests should be addressed; e-mail iftikharahmadhashmi@gmail.com, iahmad3@ ncsu.edu. HORTSCIENCE VOL. 49(3) MARCH 2014 297 | POSTHARVEST BIOLOGY AND TECHNOLOGY}, number={3}, journal={HORTSCIENCE}, author={Ahmad, Iftikhar and Dole, John M. and Blazich, Frank A.}, year={2014}, month={Mar}, pages={297–305} }
 @article{ahmad_dole_clark_blazich_2014, title={Floral foam and/or conventional or organic preservatives affect the vase-life and quality of cut rose (Rosa X hybrida L.) stems}, volume={89}, ISSN={["1462-0316"]}, DOI={10.1080/14620316.2014.11513046}, abstractNote={Summary We studied the effects of floral foam (Oasis®), with or without conventional or organic preservatives, to determine the optimum treatment to extend the vase-life of the cut rose (Rosa × hybrida L.) cultivars ‘Freedom’ and ‘Charlotte’. In general, floral foam resulted in similar or reduced vase-lives in cut ‘Freedom’ and ‘Charlotte’ rose, and had no influence on the symptoms of senescence in either cultivar. ‘Freedom’ showed more petal browning and rot, as well as reduced flower bud opening, compared to ‘Charlotte’. Vase solutions containing either of two conventional preservatives resulted in longer vase-lives in the stems of both cultivars than stems in deionised (DI) water. Floral foam saturated with DI water resulted in greater changes in the pH of the vase solution in both cultivars. Among the preservatives tested, conventional products such as Floralife Premium Rose Food or Chrysal Rose Vase (each at 10 ml l–1) extended the vase-life by 5.5 d or 3.9 d, respectively; whereas organic products such as Vita Flora or Vita One Step (each at 0.53 ml l–1) resulted in statistically similar vase-lives (9.3 d or 8.3 d, respectively) as stems in DI water (7.5 d), irrespective of the use of floral foam. These findings suggest that floral foam should not be used during the post-harvest handling of cut rose stems. Moreover, conventional preservatives were more effective than the organic products.}, number={1}, journal={JOURNAL OF HORTICULTURAL SCIENCE & BIOTECHNOLOGY}, author={Ahmad, Iftikhar and Dole, John M. and Clark, Erin M. R. and Blazich, Frank A.}, year={2014}, month={Jan}, pages={41–46} }
 @article{ahmad_dole_2014, title={Homemade Floral Preservatives Affect Postharvest Performance of Selected Specialty Cut Flowers}, volume={24}, ISSN={["1943-7714"]}, DOI={10.21273/horttech.24.3.384}, abstractNote={Effects of homemade or commercial floral preservatives, applied as 48-hour grower treatment or continuous retailer/consumer application, were studied on cut ‘ABC Blue’ lisianthus (Eustoma grandiflorum), ‘Maryland Plumblossom’ snapdragon (Antirrhinum majus), ‘Mid Cheerful Yellow’ stock (Matthiola incana), and ‘Deep Red’ Benary’s zinnia (Zinnia violacea). Cut stems were placed in solutions containing 500 mL L lemon/lime soda (soda); 6 mL L lemon juice plus 20 g L sugar (lemon juice); 100 mg L citric acid plus 20 g L sugar plus 200 mg L aluminum sulfate (C-AS); 400 mg L citric acid plus 20 g L sugar alone (citric acid), or combined with either 0.5 mL L quaternary ammonium chloride (C-QA), or 0.007 mL L isothiazolinone (C-IS); 10 mL L Floralife Clear Professional Flower Food (Floralife); or 10 mL L Chrysal Clear Professional 2 (Chrysal), dissolved in tap water, which was also used as control without any added compound. Cut stems of lisianthus and stock had longest vase lives (22.1 and 12.7 days, respectively) when placed in C-IS continuously, while snapdragon and zinnia stems had longest vase lives (22.3 and 16.3 days, respectively) when placed in C-QA solution continuously. Continuous use of soda extended vase life of cut lisianthus, snapdragon, and stock stems, but not zinnia, compared with tap water. Citric acid extended the vase life of lisianthus and stock when used continuously and of zinnia when used for 48 hours. Use of C-AS or lemon juice either had no effect or reduced vase life of the tested species, except lemon juice increased zinnia vase life when used as a 48-hour treatment. Stems of lisianthus, stock, and zinnia placed continuously in C-IS, C-QA, or citric acid had high solution uptake. No significant differences were observed for vase life of all tested species with short duration (48 hours) application of solutions, except 48hour use of citric acid or lemon juice increased zinnia vase life compared with tap water. Overall, continuous vase application of the homemade preservatives resulted in longer vase life extension than 48-hour treatment. Among tested preservative recipes, C-IS, C-QA, soda, or citric acid demonstrated best postharvest performance of tested species. However, recipes containing C-AS or lemon juice had detrimental effects and should not be used for handling cut stems of tested species.}, number={3}, journal={HORTTECHNOLOGY}, author={Ahmad, Iftikhar and Dole, John M.}, year={2014}, month={Jun}, pages={384–393} }
 @article{ahmad_dole_2014, title={Optimal postharvest handling protocols for Celosia argentea var. cristata L. 'Fire Chief' and Antirrhinum majus L. 'Chantilly Yellow'}, volume={172}, ISSN={["1879-1018"]}, DOI={10.1016/j.scienta.2014.04.026}, abstractNote={Celosia (Celosia argentea var. cristata L.) and snapdragon (Antirrhinum majus L.) are commercially important specialty cut flowers, but postharvest handling protocols for extending vase life need to be optimized. Stems of ‘Fire Chief’ celosia harvested when the flower heads were <2 cm in diameter had 14.0 days longer vase life than stems harvested with flower heads >5 cm at harvest, while ‘Chantilly Yellow’ snapdragon stems harvested when the lowermost florets started expanding had 3.4 days more vase life than stems harvested with three to five florets opened at harvest. However, visual quality of later-harvested stems of both species was higher than early harvested stems due to showier, larger flower celosia heads and a greater number of total florets of snapdragon spikes opened during the vase period. Harvest procedures, exogenous ethylene, anti-ethylene agents, and commercial hydrators had no effect on longevity of both species except silver thiosulfate, an anti-ethylene agent, increased vase life of snapdragon 3.2 or 3.7 days more than deionized (DI) water or 1-methylcyclopropene, respectively. Stems of celosia did not tolerate storage at 3 ± 1 °C, irrespective of the storage method, and if necessary, should only be stored for ≤1 week in water. On the other hand, snapdragon stems could be dry-stored for 2 weeks with no decrease in vase life and had a longer vase life than stems stored in water. Pulsing with 5 or 10% sucrose supplemented with the antimicrobial agent, isothiazolinone at 0.007 mL L−1, for 24 h, and use of hydrator for 4 hours and/or holding preservatives for 44 h reduced vase life of celosia stems compared to DI water. Whereas, use of both hydrator for 4 h and holding preservatives for 44 h did not result in significant differences in vase life, but pulsing with 5 or 10% sucrose supplemented with the antimicrobial agent, isothiazolinone at 0.007 mL L−1, for 24 h doubled vase life of snapdragon stems and increased flower bud opening and fresh weight of stems during the vase period. Celosia stems kept continuously in Floralife Clear Professional Flower Food with or without floral foam had longer vase life compared with Chrysal Clear Universal Flower Food or foam saturated with DI water, while snapdragon stems kept continuously in commercial preservatives had 2-fold longer vase life compared with DI water. Floral foam reduced vase life of snapdragon when saturated with preservatives, or had no effect when saturated with DI water. Vase life and quality of both ‘Fire Chief’ celosia and ‘Chantilly Yellow’ snapdragon stems can be extended by following appropriate postharvest handling procedures.}, journal={SCIENTIA HORTICULTURAE}, author={Ahmad, Iftikhar and Dole, John M.}, year={2014}, month={Jun}, pages={308–316} }
 @article{ahmad_dole_schiappacasse_saleem_manzano_2014, title={Optimal postharvest handling protocols for cut 'Line Dance' and 'Tap Dance' Eremurus inflorescences}, volume={179}, ISSN={["1879-1018"]}, DOI={10.1016/j.scienta.2014.09.031}, abstractNote={Eremurus, commonly known as Foxtail lily, is a novel, commercially important specialty cut flower, but postharvest handling procedures need to be optimized for longest vase life. Cut inflorescences of ‘Line Dance’ and ‘Tap Dance’ eremurus were evaluated for optimal harvest stage, harvest procedures, effects of anti-ethylene agents, and storage methods and duration. Also, the effects of commercial hydrators, hydrators along with holding preservatives, or continuous use of floral foam saturated with or without commercial preservatives were investigated. Inflorescences of both cultivars harvested with 0 florets open had longer vase life than stems harvested with 3–5 rows of florets opened. Handling of ‘Line Dance’ stems in water after harvest extended the vase life, but reduced the vase life of ‘Tap Dance’ compared to inflorescences handled dry. Application of anti-ethylene agents had no significant effect on eremurus longevity. Inflorescences of both cultivars stored for 1 week had similar vase life as of unstored stems irrespective of dry or wet storage. Storage longer than 1 week greatly reduced the vase life of both cultivars. Use of either or both hydrator and holding preservatives did not result in significant differences in vase life for both cultivars, while pulsing with 10% sucrose supplemented with an antimicrobial agent, isothiazolinone at 0.007 mL L−1, for 24 h extended vase life by 2.2 or 1.9 d for ‘Line Dance’ and ‘Tap Dance’ inflorescences, respectively, compared with tap water. Inflorescences of ‘Line Dance’ kept continuously in commercial preservatives had longest vase life compared with tap water and use of floral foam reduced vase life. However, inflorescences of ‘Tap Dance’ kept continuously in floral foam saturated with tap water, or just Floralife Clear Professional Flower food had longest vase life.}, journal={SCIENTIA HORTICULTURAE}, author={Ahmad, Iftikhar and Dole, John M. and Schiappacasse, Flavia and Saleem, Muhammad and Manzano, Elizabeth}, year={2014}, month={Nov}, pages={212–220} }
 @article{ahmad_whipker_dole_mccall_2014, title={Paclobutrazol and ancymidol lower water use of potted ornamental plants and plugs}, volume={79}, number={6}, journal={European Journal of Horticultural Science}, author={Ahmad, I. and Whipker, B. E. and Dole, J. M. and McCall, I.}, year={2014}, pages={318–326} }
 @article{ahmad_yasin_khan_2014, title={Planting time, cultivar and preservative effects on the growth, yield, postharvest longevity and water relations of Gladiolus}, volume={97}, number={1}, journal={Philippine Agricultural Scientist}, author={Ahmad, I. and Yasin, M. A. and Khan, A. S.}, year={2014}, pages={28–35} }
 @article{ahmad_dole_viloria_blazich_2014, title={Postharvest performance of cut carnation, chrysanthemum and rose as influenced by conventional and organic floral preservatives}, volume={30}, ISSN={["2165-0616"]}, DOI={10.1080/01448765.2013.878880}, abstractNote={Selected commercial preservatives were tested to determine the optimum conventional and organic hydrator and holding solutions for vase life extension and suppression of microbial populations in vase solutions of cut carnation (Dianthus caryophyllus L.) Select Red, chrysanthemum [Dendranthemum grandiflora (Ramat.) Kitam.] Anastasia, and rose (Rosa × hybrida L.) Freedom. Hydrators extended vase life of carnation but had no effect on chrysanthemum or rose. Chrysal Professional 2 (conventional holding solution), after hydration with deionized (DI) water, extended vase life of cut carnation to 36.0 days compared with DI water or Vita One Step (organic preservative solution), resulting in vase lives of 21.0 or 20.9 days, respectively. For chrysanthemum, all preservative solutions had statistically similar vase life. Holding solutions increased vase life of cut roses and carnation, but were ineffective for chrysanthemum. The greatest vase life extension occurred with Floralife Premium Rose Food (conventional holding solution), 7.9 and 7.3 days longer, than with DI water in cut Freedom roses after treatment with Floralife Hydraflor 100 (conventional hydrator solution) and DI water, respectively. However, Vita One Step (organic hydrator and holding solution) reduced vase life by 2.4 days and had higher bent neck incidence (93%) than DI water. Floralife Premium Rose Food and Chrysal Rose Vase (conventional holding solution) effectively controlled bent neck. DI water with organic Vita products had higher bacterial populations than conventional products for all species tested. Among the preservatives investigated, conventional products increased vase life more than organic products, indicating the need for organic preservatives with effective antimicrobial activity.}, number={2}, journal={BIOLOGICAL AGRICULTURE & HORTICULTURE}, author={Ahmad, Iftikhar and Dole, John M. and Viloria, Zenaida and Blazich, Frank A.}, year={2014}, month={Apr}, pages={109–118} }
 @article{ahmad_dole_2014, title={Postharvest performance of cut marigold, rose, and sunflower stems as influenced by homemade and commercial floral preservatives}, volume={38}, ISSN={["1303-6173"]}, DOI={10.3906/tar-1402-31}, abstractNote={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.}, number={6}, journal={TURKISH JOURNAL OF AGRICULTURE AND FORESTRY}, author={Ahmad, Iftikhar and Dole, John Martin}, year={2014}, pages={916–925} }
 @article{ahmad_dole_favero_2014, title={Pulsing With Low Concentration Gibberellin Plus Benzyladenine or Commercial Floral Preservatives Affect Postharvest Longevity, Quality, and Leaf Chlorosis of Cut Lilies and Gladioli}, volume={24}, ISSN={["1943-7714"]}, DOI={10.21273/horttech.24.5.560}, abstractNote={Effects of pulsing with different concentrations of gibberellin plus benzyladenine (GA4D7 D BA), a proprietary mixture of GA4D7 plus BA in a commercial floral preservative (GA4D7 D BA D preservative), or a propriety mixture of sugar plus acidifier developed for bulbous flowers (floral bulb preservative) were studied on postharvest performance and quality of cut lily (Lilium hybrids) and gladiolus (Gladiolus hybrids) flowers. Pulsing of cut stems of lily with GA4D7 D BA at 5 or 2 mL L GA4D7 D BA D preservative for 20 hours at 3 ± 1 C extended the vase life and controlled leaf chlorosis of ‘Cobra’ oriental lily and ‘Cappuccino’ and ‘Dot Com’ asiatic lily. Cut ‘Orange Art’ asiatic lily performed best when pulsed with GA4D7 D BA at 10 mg L. For cut gladiolus, pulsing with GA4D7 D BA at 10 mg L extended the vase life of ‘Alice’, ‘Mammoth’, and ‘Passion’, while ‘Scarlet’ had the longest vase life when pulsed with 5 mg L GA4D7 D BA. GA4D7 D BA D preservative also extended the vase life and controlled leaf chlorosis, but the floral bulb preservative had no effect on vase life extension or preventing leaf chlorosis of lilies. Gladiolus cultivars had no or minor leaf chlorosis during vase period. Overall, overnight pulsing with GA4D7 D BA or GA4D7 D BA D preservative extended the vase life and prevented leaf chlorosis and can be used by growers and wholesalers for maintaining quality of cut stems.}, number={5}, journal={HORTTECHNOLOGY}, author={Ahmad, Iftikhar and Dole, John M. and Favero, Bruno T.}, year={2014}, month={Oct}, pages={560–564} }
 @article{saleem_khan_ahmad_ahmad_2014, title={Vase water effects on postharvest longevity and water relations of Gladiolus grandiflorus 'White Prosperity'}, volume={51}, number={1}, journal={Pakistan Journal of Agricultural Sciences}, author={Saleem, M. and Khan, M. A. and Ahmad, I. and Ahmad, R.}, year={2014}, pages={137–141} }
 @article{ahmad_saquib_qasim_saleem_khan_yaseen_2013, title={Humic acid and cultivar effects on growth, yield, vase life, and corm characteristics of gladiolus}, volume={73}, number={4}, journal={Chilean journal of Agricultural Research}, author={Ahmad, I. and Saquib, R. U. and Qasim, M. and Saleem, M. and Khan, A. S. and Yaseen, M.}, year={2013}, pages={339–344} }
 @article{ahmad_dole_saleem_khan_akram_khan_2013, title={Preservatives and packaging material have an impact on the post-harvest longevity of cut Rosa hybrida L. 'Kardinal' flowers}, volume={88}, ISSN={["2380-4084"]}, DOI={10.1080/14620316.2013.11512963}, abstractNote={Summary We studied the effects of various preservatives (sucrose, ascorbic acid, salicylic acid, and acetylsalicylic acid) alone, or in various combinations, on the post-harvest performance of cut Rosa hybrida L. ‘Kardinal’ flowers. The effects of packaging material, including boxes (used boxes without vents), newspaper, butter paper (a waxy paper used to avoid moisture loss), craft paper (a thin, less-waxy paper used for wrapping floral bunches), cellophane paper, single cardboard boxes with or without a cellophane lining, and standard double cardboard boxes with or without a cellophane lining, were also studied. Among the preservatives, 4% (w/v) sucrose alone, or combined with 100 mg l–1 acetylsalicylic acid, 200 mg l–1 salicylic acid, or 600 mg l–1 ascorbic acid resulted in longer vase-lives (7.1, 5.6, 5.5, or 5.3 d, respectively). Individual or combined applications of ascorbic acid and/or salicylic acid had no effect on vase-life. Stems in deionised (DI) water or 4% (w/v) sucrose alone had larger petal areas and flower diameters compared to all other preservatives. Pulsing with 0.5 mM silver thiosulphate (STS) for 2 h at room temperature further extended the vase-life, maintained flower diameter, increased petal area, and increased the uptake of vase solution during the first 2 d of the vase period. Stems packed in double-cardboard floral boxes lined with cellophane, or cellophane alone, gave a longer vase-life than newspaper, butter paper, or the spent boxes used by growers in the study area. Packaging in single or double cardboard floral boxes, with or without a cellophane lining, maintained flower quality, increased flower diameter, and increased ion leakage from petals (possibly due to the longer vase-life) more than spent boxes, craft paper, butter paper, or newspaper. By increasing the duration of storage from 2 d to 8 d, vase-life and ion leakage decreased from 4.2 d to 2.6 d, and from 102% to 85%, respectively, while subsequent flower diameter increased to 0.61 cm from a decrease of 0.16 cm.}, number={3}, journal={JOURNAL OF HORTICULTURAL SCIENCE & BIOTECHNOLOGY}, author={Ahmad, Iftikhar and Dole, John M. and Saleem, Muhammad and Khan, Muhammad A. and Akram, Ahsan and Khan, Ahmad S.}, year={2013}, month={May}, pages={251–256} }
 @article{ahmad_dole_carlson_blazich_2013, title={Water quality effects on postharvest performance of cut calla, hydrangea, and snapdragon}, volume={153}, ISSN={["1879-1018"]}, DOI={10.1016/j.scienta.2013.01.015}, abstractNote={Effects of water quality on water uptake, change in fresh weight, vase solution pH and electrical conductivity (EC) change, termination symptoms, and longevity of cut ‘Nicole Yellow’ calla (Zantedeschia L.), ‘White Extra’ hydrangea [Hydrangea macrophylla (Thunb.) Ser.], and ‘Admiral Pink’ snapdragon (Antirrhinum majus L.) were studied. Calla was tolerant of high water pH (8.1); vase life varied only from 9.2 d for acidic solutions (pH 3.2) to 10.1 d for solutions with intermediate pH (6.3). Calla had the longest vase life at an EC of 0.75 dS m−1, whereas addition of floral preservative (Floralife Professional, Floralife, Walterboro, SC at 10 ml L−1) was ineffective. Low solution pH (2.9–3.3), increasing EC (up to 2.5 dS m−1), and use of floral preservative increased vase life of hydrangea. Increasing EC increased vase life of hydrangea from a low of 7.3 d to a high of 15.4 d at 2.5 dS m−1, when floral preservative was used and from a low of 3.5 d to a high of 5.7 d at 4.0 dS m−1 in distilled water. Vase solution pH of snapdragon had no significant effect on vase life or water uptake. Increasing EC increased vase life to a maximum of 14.8 d at 2.0 dS m−1 with preservative and to 9.7 d at 3.0 dS m−1 without preservative. Each species had differing responses to varying pH and EC levels; however, solution pH should be low, as high pH solutions either had no effect or reduced vase life, such as with hydrangea. EC of vase water for hydrangea and snapdragon should be approximately 2.0–2.5 dS m−1, when preservatives are used and 3.0–4.0 dS m−1 without, which is higher than most recommendations. Addition of preservative to vase solutions extended vase life of hydrangea and snapdragon, but did not affect calla.}, journal={SCIENTIA HORTICULTURAE}, author={Ahmad, Iftikhar and Dole, John M. and Carlson, Alicain S. and Blazich, Frank A.}, year={2013}, month={Apr}, pages={26–33} }
 @article{ahmad_dole_amjad_ahmad_2012, title={Dry Storage Effects on Postharvest Performance of Selected Cut Flowers}, volume={22}, ISSN={["1943-7714"]}, DOI={10.21273/horttech.22.4.463}, abstractNote={Effects of wet and dry storage methods were compared to improve postharvest performance of specialty cut flower species. While increasing duration of storage reduced vase life, vase life declined less with dry storage for marigold (Tagetes erecta) and rose (Rosa hybrida), but not for zinnia (Zinnia elegans) or lisianthus (Eustoma grandiflorum) over wet storage. Marigold stems had 1.9, 4.6, and 1.5 days longer vase life after 1, 2, or 3 weeks in dry storage, respectively, as compared with storage in water. Zinnia stems did not tolerate either wet or dry storage, while lisianthus stems had a longer vase life when stored in water as compared with dry storage. For rose, dry storage for 2 weeks increased vase life compared with wet storage. Dry stored marigold and lisianthus stems had higher water uptake after being placed in the vase as compared with the stems stored in water, while zinnia and rose had less uptake. Storage method had no effect on leaf relative water content (LRWC) in lisianthus, marigold, and zinnia; however, LRWC decreased with increased storage duration. This necessitates evaluation of storage method and duration effects for each species and cultivar to ensure extended storage life and improve postharvest quality.}, number={4}, journal={HORTTECHNOLOGY}, author={Ahmad, Iftikhar and Dole, John M. and Amjad, Atyab and Ahmad, Sagheer}, year={2012}, month={Aug}, pages={463–469} }