Present status and future prospects of cut rose (Rosa ×hybrida) flower production and postharvest management in Punjab, Pakistan, were investigated. Cut roses were the leading flower crop in the area under study, but production systems and practices were outdated and primitive, resulting in cut stems that were not acceptable in international markets. The majority of growers (65%) had only basic education (grade 10 or less) and 57% had small landholdings (<1 ha); therefore, they did not have modern production techniques and resources for high-quality cut rose production. Moreover, lack of production and postharvest facilities, ignorance of both public and private resources, and poor production and postharvest practices were prevalent. Growers' training regarding production and postharvest management would be required to lift the quality standards of this industry up to the international level. However, a positive trend was observed in cut rose businesses as more than half of growers (52%) entered into the business during last 5 years. In addition, 30% of growers were in business over 10 years, indicating that cut rose production can provide a sustained income for producers. This analysis of the cut rose industry in Punjab can serve as a model for other countries whose cut flowers industries are at a similar stage of development.
Iftikhar Ahmad, John M. Dole, M. Aslam Khan, M. Qasim, Tanveer Ahmad, and A.S. Khan
John M. Dole, Frankie L. Fanelli, William C. Fonteno, Beth Harden, and Sylvia M. Blankenship
Optimum postharvest handling procedures were determined for Linaria maroccana `Lace Violet', Trachelium`Jemmy Royal Purple', and Zinnia elegans `Benary's Giant Scarlet' and `Sungold.' A 24-hour 10% or 20% sucrose pulse increased the vase life of Linaria by 2–4 days, resulting in a vase life of 9 days as compared to 5 days for control flowers held in deionized (DI) water. Use of floral foam and cold storage at 1 °C for 1 week decreased vase life. Treatment with either 0.1 or 1.0 ppm ethylene had no effect. The use of a commercial holding solution (Floralife Professional or Chrysal Professional 2 Processing Solution) or 2% or 3% sucrose increased vase life 4–10 days. For cut Trachelium, ethylene caused florets to close entirely or stop opening; 1-MCP and STS prevented these ethylene effects. Stems tolerated 4 days of 1 °C storage, but 1 week or more of storage reduced the 14-day vase life of unstored flowers to 9 days. Stems in 2% or 4% sucrose had a longer vase life compared to DI water. While the use of floral foam was not detrimental when used with sucrose solutions, it reduced vase life when sucrose was not used. Zinnia stems could not be cold stored for 1 week at 1 °C due to loss of turgidity and cold damage. Stems stored dry at 5 °C regained turgidity and averaged a vase life of 14 days; however, petals remained slightly twisted and curled after being in the vase for several days. Treatment with ethylene had no effect. Floral foam reduced vase life to 9–10 days.
John M. Dole, Frankie L. Fanelli, William C. Fonteno, Beth Harden, and Sylvia M. Blankenship
Optimum postharvest handling procedures were determined for Dahlia `Karma Thalia', Lupinusmutabilis ssp. cruickshankii`Sunrise', Papaver nudicaule `Temptress', and Rudbeckia`Indian Summer.' Dahlia harvested fully open had a vase life of 7–10 days in deionized (DI) water that was increased by 1.5–2 days using commercial holding solutions (Chrysal Professional 2 Processing Solution or Floralife Professional). Neither floral foam nor 0.1–1.0 ppm ethylene had any effect on vase life. One week of cold storage at 1 °C reduced vase life up to 2 days. The longest vase life, 12–13 days, was obtained when floral buds, showing a minimum of 50% color, were harvested at the breaking stage (one petal open) and placed in 2% or 4% sucrose or a commercial holding solution. Lupinus flowers held in DI water lasted 8–12 days; 1 week cold storage at 1 °C reduced vase life by 3 days. Florets and buds abscised or failed to open when exposed to ethylene; STS pretreatment prevented the effects of ethylene. Commercial holding solutions increased Papaver vase life to 7–8 days from 5.5 days for stems held in DI water. While stems could be cold stored for 1 week at 1 °C with no decrease in vase life, 2 weeks of cold storage reduced vase life. Flowers were not affected by foam or ethylene. Rudbeckia had a vase life of 27–37 days and no treatments extended vase life. Stems could be stored at 2 °C for up to 2 weeks and were not ethylene sensitive. Floral foam reduced the vase life over 50%, but still resulted in a 13-day vase life.
Douglas C. Sanders, Dennis J. Osborne, Mary M. Peet, John M. Dole, and Julia L. Kornegay
Many potential students, because of distance from the university campus and/or job requirements, cannot take traditional courses on-campus. This group of learners is “place-bound”—a group of learners who may be employed full-time, most likely married with job responsibilities and/or other situations demanding most of their attention. The Horticultural Science Department and Graduate School at N.C. State University are addressing place-bound limitations in several ways, including the creation and offering of a Graduate Certificate Program in Horticultural Science via distance education (DE). By using DE, high demand, low-seat-available classes can offer additional enrollment for credit. Second, courses can be offered asynchronously or with alternative delivery methods. Also, courses offered collaboratively among institutions can generate a level of interest and enthusiasm that may not exist for “home-grown” courses. Such efforts as these promise to help meet continuing education demands of “non-traditional” students. These include Cooperative Extension's more than 120 Horticultural Crops Extension Agents (“field faculty”) and over 300 other field faculty whose interests include horticultural topics.
Erin M.R. Clark, John M. Dole, and Jennifer Kalinowski
Six experiments were conducted using three cultivars to investigate the impact of water electrical conductivity (EC) and the addition of nutrients to vase solutions on postharvest quality of cut rose (Rosa hybrids) stems. Postharvest quality of cut ‘Freedom’ rose stems was evaluated using solutions containing either distilled water with sodium chloride (DW+NaCl) or DW+NaCl with the addition of a commercial floral preservative (holding solution containing carbohydrates and biocide) to generate a range of EC values (Expts. 1 and 2). The third experiment compared the effect of different EC levels from the salts NaCl, sodium sulfate (Na2SO4), and calcium chloride (CaCl2). The fourth experiment investigated EC’s impact on rose stems with the addition of two rose cultivars (Charlotte and Classy). When ‘Freedom’ stems were subjected to DW+NaCl, the longest vase life was achieved with 0.5 dS·m–1. The addition of holding solution not only extended vase life but also counteracted the negative effects of high EC with maximum vase life occurring at 1.0 dS·m–1. Furthermore, stems in the holding solution experienced significantly less bent neck and the flowers opened more fully than those in DW. Stems placed in DW with a holding solution also experienced more petal bluing, pigment loss, necrotic edges, and wilting than those held in DW alone. This effect was likely due to increased vase life. Salt solutions containing Na2SO4 and CaCl2 resulted in extended vase life at 1.0 dS·m–1, but increasing salt levels decreased overall vase life. As EC increased, regardless of salt type, water uptake also increased up to a maximum at 0.5 or 1.0 dS·m–1 and then continually declined. Maximum vase life was observed at 1.5 dS·m–1 for cut ‘Charlotte’ stems, and at 1.0 dS·m–1 for ‘Classy’ with the addition of a holding solution. Physiological effects were different based on cultivar, as observed with Charlotte and Freedom flowers that opened further and had less petal browning than Classy flowers. ‘Freedom’ had the greatest pigment loss, but this effect decreased with increasing EC. Further correlational analysis showed that in water-only solutions, initial and final EC accounted for 44% and 41% of the variation in vase life data, respectively, whereas initial pH accounted for 24% of variation. However, the presence of carbohydrates and biocides from the holding solution was found to have a greater effect on overall vase life compared with water pH or EC. Finally, in Expts. 5 and 6, cut ‘Freedom’ stems were subjected to DW solutions containing 0.1, 1, 10, or 100 mg·L–1 boron, copper, iron, potassium, magnesium, manganese, or zinc. None of these solutions increased vase life. Conversely, 10 or 100 mg·L–1 boron and 100 mg·L–1 copper solutions reduced vase life. Finally, the addition of NaCl to a maximum of 0.83 dS·m–1 increased the vase life in all solutions. These analyses highlight the importance of water quality and its elemental constituents on the vase life of cut rose stems and that the use of a holding solution can overcome the negative effects of high EC water.
Paul B. Hedman, John M. Dole, Niels O. Maness, and Jeffrey A. Anderson
The postharvest biosynthesis of ethylene and CO2 was measured at 0, 12, 24, and 48 h after harvest and the effects of exogenous applications of 0.0, 0.2, or 1.0 μl·liter–1 ethylene for 20 h was observed on eight speciality cut flower species. Helianthus maximilliani (Maximillian's sunflower), Penstemon digitalis (penstemon), Achillea fillipendulina [`Coronation Gold' (yarrow)], Celosia plumosa [`Forest Fire' (celosia)], Cosmos bipinnatus [`Sensation' (cosmos)], Buddleia davidii (butterfly bush), and Weigela sp. (weigela) exhibited a climacteric-like pattern of ethylene production followed by a steady rise in CO2 production. Echinacea purpurea (coneflower) ethylene biosynthesis was not significant during the 48-h period after harvest. Vase life of coneflower, yarrow, celosia, cosmos, and butterfly bush was not affected by exogenous ethylene. Exogenous ethylene applications to Maximillian's sunflower, penstemon, and weigela resulted in flower abscission and decreased vase life, indicating that they are probably ethylene-sensitive cut flower species.
Vijaya Kumar Rapaka, James E. Faust, John M. Dole, and Erik S. Runkle
This study investigated the preharvest carbohydrate status and postharvest ethylene action of unrooted shoot-tip cuttings of lantana ‘Dallas Red’ harvested at three times during the day (0800, 1200, and 1600 hr) in relation to subsequent leaf abscission, shoot apices blackening, and adventitious root formation. The cuttings harvested at various times during the day were stored in darkness at 20 ± 1 °C for 4 days in sealed polyethylene bags. The cuttings harvested at 0800 hr had lowest total nonstructural carbohydrate concentrations; however, the amount of ethylene production during postharvest storage was similar among harvest times and increased during the storage period. After 4 days of storage, 69% of the leaves of cuttings harvested at 0800 hr abscised, but only 22% and 8% of the leaves abscised in cuttings harvested at 1200 and 1600 hr, respectively. Application of 1-methylcyclopropene (1-MCP) increased ethylene production and suppressed leaf abscission regardless of the harvest time, but cuttings harvested at 0800 hr developed blackened shoot apices. Leaf abscission was negatively correlated with total nonstructural carbohydrate concentration in the leaves, but no relationship was found with ethylene production. These results indicate that a high endogenous carbohydrate status decreases the postharvest ethylene sensitivity in unrooted shoot-tip cuttings of lantana. Time of harvest influenced subsequent rooting response; however, 1-MCP application did not inhibit rooting. Among various storage treatments, the best rooting response was observed in cuttings harvested at 1600 hr and treated with 1-MCP. Therefore, significant improvement of postharvest storage quality in vegetative lantana cuttings could be achieved by harvesting cuttings late in the day and treating with 1-MCP.
Kenneth E. Conway, John M. Dole, Theresa L. Bosma, and Niels O. Maness
Field seedling emergence of four african marigold (Tagetes erecta) breeding lines, A-975, E-1236, I-822, and `Orange Lady', was examined using three or four spring sowing dates and either osmotic or solid matrix priming. Delayed sowing decreased emergence time. Sowing from middle to late April [average soil temperatures 77.0 to 84.2 °F (25 to 29 °C)] resulted in the highest total emergence percentages. Greater fl ower quantities [4.9 to 5.1 million/acre (12.11 to 12.60 million/ha)] and estimated yield [7.5 to 10.8 tons/acre (16.81 to 24.20 t·ha-1)] indicate mid to late April is the optimum time period for direct sowing unprimed seed in the southern Great Plains. Differences between lines were evident in emergence parameters and fl ower harvest data for each year examined, but results were inconsistent from year to year. However, A-975 and E-1236 produced harvestable fl owers most quickly, about 15 d before I-822, which could result in an additional harvest during a season. Osmotic priming of E-1236 and I-822 seed shortened emergence time, increased emergence uniformity, and increased total emergence percentage at early sowing dates as compared to both solid matrix primed and unprimed seed.
Brian A. Krug, Brian E. Whipker, Ingram McCall, and John M. Dole
Preplant bulb soaks of flurprimidol, paclobutrazol, and uniconazole; foliar sprays of ethephon and flurprimidol; and substrate drenches of flurprimidol were compared for height control of `Anna Marie' hyacinths (Hyacinthus orientalis). Preplant bulb soak concentrations of flurprimidol and paclobutrazol were from 25 to 400 mg·L-1, and uniconazole from 5 to 80 mg·L-1. Height control was evaluated at anthesis and 11 days later under postharvest conditions. Ethephon (250 to 2000 mg·L-1) and flurprimidol (5 to 80 mg·L-1) foliar sprays were ineffective. Flurprimidol (0.25 to 4 mg/pot) drenches had no effect during forcing, but controlled postharvest height at concentrations ≥0.25 mg/pot a.i. with at least 4% shorter plants than the untreated control. Preplant bulb soaks resulted in height control with flurprimidol ≥25 mg·L-1, paclobutrazol ≥100 mg·L-1, and uniconazole ≥40 mg·L-1; having at least 9%, 6%, and 19%, respectively, shorter plants than the untreated control. Based on our results, flurprimidol preplant bulb soaks have a greater efficacy than either uniconazole or paclobutrazol. Preplant PGR soaks are a cost-effective method of controlling plant height of hyacinths because of the limited amount of chemical required to treat a large quantity of bulbs.
Brian A. Krug, Brian E. Whipker, Ingram McCall, and John M. Dole
Three experiments were conducted to determine the effectiveness of plant growth regulators (PGRs) on `Tete a Tete', `Dutch Master', and `Sweetness' narcissus (Narcissus pseudonarcissus). Ethephon foliar sprays (500 to 2500 mg·L-1) and substrate drenches of flurprimidol and paclobutrazol (0.25 to 4 mg/pot a.i.) did not control height during greenhouse forcing of `Tete a Tete' at any concentration trialed. Stem stretch was controlled during postharvest evaluation with ethephon foliar sprays ≥1000 mg·L-1, flurprimidol substrate drenches ≥0.5 mg/pot a.i., and paclobutrazol substrate drenches of 4 mg/pot a.i. A second experiment investigated preplant bulb soaks of flurprimidol (10 to 40 mg·L-1) applied to `Dutch Master' and `Tete a Tete' narcissus bulbs. Flurprimidol preplant bulb soaks controlled postharvest stretch on `Tete a Tete' and `Dutch Master' at concentrations ≥15 and ≥10 mg·L-1, respectively. A third experiment was conducted with paclobutrazol (75 to 375 mg·L-1) on `Tete a Tete' and `Dutch Master' and three concentrations of flurprimidol on `Sweetness' to determine optimal soak recommendations. Paclobutrazol preplant bulb soaks ≥75 mg·L-1 controlled postharvest stretch of `Tete a Tete' and `Dutch Master', while 37.5 mg·L-1 of flurprimidol controlled postharvest stretch of `Sweetness'. Based on the results of these experiments, growers can now select a PGR to help control excessive plant growth.