The effect of increasing temperatures on the duration of postharvest flower development was determined for three specialty crop species: marguerite (Argyranthemum frutescens Webb ex Schultz-Bip.) `Butterfly' and `Sugar Baby'; swan river daisy (Brachycome hybrid Cass.) `Ultra'; and bacopa (Sutera cordata Roth.) `Snowflake'. Plants were grown in a greenhouse at 18 °C (65 °F) until flowering, and then transferred into a phytotron to determine heat tolerance. Plants were stored for 8 weeks at constant temperatures of 18, 23, 28, and 33 °C (65, 73, 82, and 91 °F) for 2-week intervals. Flower bud and flower number were recorded weekly. Sutera cordata `Snowflake' and B. hybrid `Ultra' had the greatest flower number at the 23 °C temperature, decreasing in the 28 °C environment. Argyranthemum frutescens `Butterfly' and `Sugar Baby' had greatest flower number at 28 °C, but flowers were of lower quality thanat 23 °C. Flower development of all cultivars ceased at 33 °C, at the end of 8 weeks at increasing temperatures, but when plants were returned to the 18 °C production greenhouse, flower development resumed. High temperatures (28 °C) reduce the postharvest performance of S. cordata, B. hybrid, and A. frutescens plants grown in hanging baskets; therefore, these species should be marketed as spring-flowering products since summer performance may be unsatisfactory in warm climates.
Millie S. Williams, Terri W. Starman, and James E. Faust
Neil S. Mattson and W. Roland Leatherwood
Cherry Spark’ to 2606 mg·kg −1 for argyranthemum [ Argyranthemum frutescens (L.) Sch. Bip. ‘Sunlight’] ( Fig. 1 ). Seven cultivars in the control treatment had leaf Si concentrations greater than 1000 mg·kg −1 (i.e., 0.1% of DW); these were
Christopher J. Currey, Veronica A. Hutchinson, and Roberto G. Lopez
bedding plant species. Materials and Methods Plant material and culture. Stock plants of Angelonia angustifolia ‘AngelMist White Cloud’, Argyranthemum frutescens ‘Madeira Cherry Red’, Diascia barberae ‘Wink Coral’, Lantana camara ‘Lucky Gold
Diane M. Camberato, James J. Camberato, and Roberto G. Lopez
evaluation of CRF under more ideal conditions. Materials and Methods On 9 Mar. 2011, 54 rooted cuttings each of Argyranthemum frutescens ‘Madeira Cherry Red’, Calibrachoa ‘Cabaret Pink Hot’, Diascia barberae ‘Wink Coral’, and Sutera cordata ‘Abunda
Shannon E. Beach* and Terri W. Starman
Vegetative annuals are increasing in popularity among greenhouse growers and consumers but little is known about their postharvest shelf life. Twenty-two cultivars from ten species of vegetative annuals were grown to marketability with optimum greenhouse culture. Plants were then subjected to one of three shipping durations (0, 1, or 2 days) in simulated shipping i.e., a growth chamber at 26.7 ± 0.3 °C, 0 μmol·m-2·s-1, and 50% relative humidity. The plants were then moved to simulated postharvest environment i.e., growth room at 21.1 ± 1.3 °C and 6 μmol·m-2·s-1 to evaluate shelf life. Flower number and plant quality rating were measured weekly in addition to observations of plant appearances. Some of the postharvest disorders noted on several species and cultivars were stem die back, leaf chlorosis, stem elongation, bud abortion, flower drop, and flower fading. The majority of the cultivars maintained their quality one-week postharvest although flower drop was common. After the first week of shelf life, decline in vegetative and reproductive tissues were noted in most plants. Cultivars from nine species: Argyranthemum frutescens (L.) Sch. Bip, Bracteantha bracteata (Vent.) Anderb. & Haegi, Calibrachoa hybrid Lave Lex, Diascia ×hybrida, Lantana camara L., Nemesia ×hybrida, Petunia ×hybrida, Sutera hybrida, and Sutera cordata showed decreased flower number and/or quality rating due to shipping duration, with increased shipping duration causing accelerated postharvest disorders. The only species unaffected by shipping duration was Angelonia angustifolia Benth.
James E. Faust and Larry W. Grimes
Stock plants of four vegetatively propagated annual species (Argyranthemum frutescens `Comet Pink', Nemesia fruticans `Plum Sachet' Venten., Osteospermum fruticosum `Zulu' L., and Verbena ×hybrida `Lanai Bright Pink' L.) were grown with one (P), two (PP), or three (PPP) pinches during the scaffold development phase. The number of pinches applied to all four species affected the yield and distribution of cuttings produced over time. P began to produce cuttings first; however, the rate (number of cuttings per week) of cutting production was relatively low resulting in the fewest total cuttings produced by the end of the experiment. Cutting harvest from PPP started 3 to 6 weeks after cuttings were initially harvested from P. However, the rate of increase in cutting production was greater in PPP than P for all species, except Osteospermum, so the total cutting yield of PPP equaled P after 3 to 5 weeks of cutting production. The final cutting yield for PPP was 38%, 38%, 20%, and 8% higher than P for Argyranthemum, Nemesia, Osteospermum, and Verbena, respectively. PP produced 24%, 17%, and 21% more total cuttings than P for Argyranthemum, Nemesia, and Osteospermum, respectively, while Verbena displayed no significant difference. At the termination of the experiment, the weekly rate of cutting production increased 66.3%, 84.0%, and 30.5% as pinch number increased from P to PPP for Argyranthemum, Nemesia, and Verbena, respectively. This study demonstrates that the number of pinches performed on stock plants during scaffold development can have a significant impact on the timing, the weekly production rate, and cumulative yield of cuttings harvested.
Hope K. Onken and Terri W. Starman
Argyranthemum frutescens `Sugar Baby', Calibrachoa hybrid `Million Bells Cherry Pink', and Orthosiphon stamineus `Lavender' are three vegetatively propagated specialty annuals that are recent introductions into the floriculture industry. It is important to understand how the growth and development of these new crops is best controlled. Rooted cuttings of these three species where transplanted into 10-cm pots on 7 Oct. and the plant growth regulator treatments were applied on 19 Oct. 1999. Foliar spray treatments included ancymidol at 66 and 132, daminozide at 2500 and 5000, paclobutrazol at 20 and 40, ethephon at 500 and 1000, and uniconazole at 10 and 20 mg/L. Uniconazole medium drench treatment was applied at 1 and 2 mg/L. Control was a water foliar spray. At harvest, plant height, plant width, number of flowers, pedicle length, stem length, stem node number and internode length, and fresh and dry weights were measured. Uniconazole spray at 20 mg/L reduced plant height and width without affecting the fresh and dry weights of Argyranthemum. Flower number was increased and pedicel length was reduced. The overall plant height and width of Calibrachoa were not reduced with 20 mg /L uniconazole foliar spray, but plant form was improved by decreased internode elongation. Uniconazole foliar spray at 20 mg/L reduced Orthosiphon stem and internode length. Ethephon reduced plant height, plant width, and flower number of all species. Branching and days to flower were increased in Orthosiphon. In all species, daminozide and paclobutrazol were found to be ineffective, while ancymidol spray and uniconazole drench stunted and distorted growth.
Shannon E. Beach, Terri W. Starman, Kristen L. Eixmann, H. Brent Pemberton, and Kevin M. Heinz
Twenty-one cultivars of vegetative annuals were treated with 0%, 50%, or 100% of the production fertilization rate of 300 mg·L−1 N starting 2 weeks before and continuing until harvest. At harvest, plant width, flower number, and quality rating were measured. The plants were then placed in a simulated interior environment where flower number was counted and quality rating was assigned to each plant weekly for 3 weeks. Overall, 14% of the cultivars maintained a marketable quality (i.e., quality rating of ≥3.0 of 5) for 3 weeks, 43% for 2 weeks, 38% for 1 week, and one cultivar did not maintain quality during the postharvest evaluation. Reduced end-of-production fertilization rate (EPFR) resulted in higher quality ratings for at least one additional week of simulated shelf life for three cultivars, including ‘Dreamtime Copper’ bracteantha (Bracteantha bracteata), ‘Vanilla Sachet’ nemesia (Nemesia ×hybrida), and ‘Bridal Showers’ sutera (Sutera hybrida). ‘Comet White’ and ‘Sunlight’ argyranthemum (Argyranthemum frutescens) retained flowers an additional 2 weeks and ‘Caritas Lavender’ angelonia (Angelonia angustifolia), ‘Dreamtime Copper’ bracteantha, ‘Liricashowers Deep Blue Imp.’ and ‘Starlette Trailing Purple’ calibrachoa (Calibrachoa hybrid), ‘Vanilla Sachet’ nemesia, ‘Cascadias Pink’ petunia (Petunia ×hybrida), and ‘Bridal Showers’ sutera retained flowers an additional 1 week when treated with 0% compared with 50% or 100% EPFR. Four cultivars had decreased plant width at harvest with 0% EPFR. These results indicate that reducing fertilization 2 weeks before harvest can prolong shelf life of some vegetative annuals. Differences in the length of shelf life and responses to reduced EPFR occurred among cultivars of all the affected species. Reduced EPFR did not increase the shelf life of two species, including diascia (Diascia ×hybrida) and lantana (Lantana camara).
marguerite daisy ( Argyranthemum frutescens ) varieties `Butterfly' and `Sugar Baby' flowered best when the average daily temperature was below 82 °F. Bacopa ( Sutera cordata ) `Snowflake' and swan river daisy ( Brachycome hybrid ) `Ultra' flowered best when
Michelle A. Grabowski and Dean K. Malvick
Calceolaria integrifolia in Italy Plant Dis. 92 1133 Garibaldi, A. Pensa, P. Gullino, M.L. 2008b First report of Sclerotinia sclerotiorum on Argyranthemum frutescens in Italy Plant Dis. 92 1250 Garibaldi, A. Pensa, P. Minuto, A. Gullino, M.L. 2008c First