The production of young plants from seed (plugs) for the annual bedding plant market commonly occurs during winter and early spring ( Styer, 2003 ). However, in northern latitudes, the natural photosynthetic daily light integral (DLI) is not
Joshua K. Craver, Jennifer K. Boldt, and Roberto G. Lopez
Richard O. Kelly and Brent K. Harbaugh
Annual bedding plants comprised 50% of the $4.6 billion wholesale value of United States floricultural crops in 2000. Florida is one of the top wholesale producers of bedding plants in this industry, and in 2000 was number one in the production of potted marigolds. Evaluation of marigold cultivars is vital for continued growth of the industry. We evaluated 84 cultivars of african marigold (Tagetes erecta) and french marigold (T. patula) in replicated class tests at the University of Florida's Gulf Coast Research and Education Center at Bradenton, Fla. (lat. 27°4' N, long. 82°5' W; AHS Heat Zone 10; USDA Cold Hardiness Zone 9b) in Fall 1999. In this report, we provide objective plant measurements of vegetative and floral characteristics as well as six weekly subjective ratings. Subjective ratings were on a 1 to 7 scale with the highest rating of 7 for excellent. In general, cultivars with vegetative and floral ratings ≥5 were considered outstanding, 4 to 4.9 as good performers, and ≤3.9 as fair to poor. These ratings permit readers to evaluate foliage and floral characteristics at different times during the season, and to evaluate performance over time. Cultivars were grouped into classes based on species, plant height, flower type, and flower color. Outstanding cultivars (those cultivars with an overall rating ≥5) and their class were: `Inca Gold' and `Royal Gold' [african marigold (African)—gold class]; `Mesa Orange' and `Royal Orange' (African— orange class); `Inca Yellow', `Mesa Yellow', and `Perfection Yellow' (African—yellow class); `Disco Granada' [french marigold (French) dwarf—single gold/red class], `Disco Flame' (French dwarf—single red/gold class); `Golden Boy' and `Hero Gold' (French dwarf—double gold class); `Bonanza Orange', `Orange Boy', `Girl Orange', `Jacket Orange' (French dwarf—double orange class); `Yellow Boy', `Girl Primrose', and `Jacket Yellow' (French dwarf—double yellow class); `Harmony Boy' (French dwarf— double orange/red class); `Hero Flame' (French dwarf—double red/orange class); `Bonanza Flame Improved' (French dwarf—double red/yellow class); `Legend Gold' (French double— gold class); `Legend Orange Improved' (French—double orange class); `Spry Boy' (French double—yellow/red class); `Durango Bee', `Durango Red', and `Hyper Red/Yellow' (French— double red/yellow class). We believe these cultivars would perform well in the southern U.S. or areas of the world with similar heat and cold hardiness zones.
James E. Barrett and Terril A. Nell
Bedding plant seedlings were obtained as plugs from commercial sources, transplanted into 10-cm pots, and grown using standard commercial procedures. When plants reached a marketable stage, they were treated with Hydretain, moved to a heavy shaded bench in the greenhouse, and time to first wilt was determined. At wilt, plants were given 180 ml of water, and time to second wilt was observed. Hydretain was applied directly to the media in a volume of 90 ml per pot. Hydretain dilutions in water were 1:4, 1:9, 1:14, 1:19, and 0:1 (controls). Time to first wilt in 'Red Elite' geraniums was 11, 10, 9, 10, and 5 days, respectively. For 'Little Bright Eyes' vinca, first wilt was in 7, 8, 5, 5, and 4 days; and time from treatment to second wilt was 18, 14, 11, 10, and 8 days, respectively. For 'Super Elfin Red' impatiens, first wilt was in 5, 4, 4, 3, and 3 days; and the water absorbed was 121, 167, 172, 132, and 148 ml, respectively. Second wilt was in 7, 7, 8, 5, and 5 days, respectively.
Roger T. Koide, Lena L. Landherr, Ylva L. Besmer, Jamie M. Detweiler, and E. Jay Holcomb
We inoculated six common annual bedding plant species with the vesicular-arbuscular mycorrhizal fungus Glomus intraradices Schenck & Smith using two fertilizer P concentrations (3 or 15 μg·mL-1) and three inoculation timings (inoculation at sowing, at transplanting, or at both times). The plant species used were: Salvia splendens F. Sellow ex Roem. & Schult. cv. Firecracker Rose; Impatiens walleriana Hook. f. cv. Sun and Shade Royal Red; Tagetes patula L. cv. Girls Golden; Petunia ×hybrida Hort. Vilm.-Andr. cv. Freedom Blue; Coleus ×hybridus Voss. cv. Jazz Salmon; and Viola ×wittrockiana Gams. cv. Majestic Giant White. In general, Coleus, Petunia, and Viola were colonized more than were Impatiens, Tagetes, and Salvia. Inoculation at sowing required less inoculum than either of the other methods. Moreover, it was generally as effective in promoting colonization as double inoculation, and was often more effective than inoculation at transplanting. Mycorrhizal colonization was significantly reduced by the higher P concentration. The use of Myconate®, a water-soluble form of the flavonoid formononetin, significantly stimulated colonization in Salvia.
Erin James and Marc van Iersel
The negative effects of nutrient runoff on the environment has come more to the forefront of greenhouse issues in the past few years. Alternative irrigation systems that reduce or eliminate runoff that are widely used in Europe have not yet gained much popularity in the southeastern United States, in part due to a lack of available information on their use. One such system is ebb-and-fl ow, which is a completely closed recirculating system, having no runoff whatsoever. In order to learn more about optimum growing practices using the ebb-and-fl ow system for bedding plants, marigolds and sunflowers were grown under a variety of conditions. After a 6-week period, pH of growing media of both marigolds and sunflowers decreased by 1, while EC increased by ≈1 dS/m. There were also significant differences in EC due to the different media types. The soilless medium with the highest percentage of vermiculite and lowest percentage of pine bark had the highest EC. Different types of fertilizer and fertilizer rates will be discussed, as well as interactions between fertilizer and media.
Wesley C. Randall and Roberto G. Lopez
compared with those under HPS lamps; and stem diameter of geranium, marigold, and snapdragon was 8% to 16% greater under 85:15 red:blue LEDs compared with seedlings grown under HPS lamps. To our knowledge, no studies have compared annual bedding plant
Jeff S. Kuehny, Matt Taylor, and Michael R. Evans
Bedding plants are one of the primary products of the floriculture industry. In the United States, the wholesale value for bedding and garden plants in 2007 was ≈$6.5 billion, which was 58% of total gross sales for floriculture crops [ U
J.E. Barrett, R.K. Schoellhorn, C.A. Bartuska, D.G. Clark, and T.A. Nell
Uniconazole was applied as a spray to the surface of container media prior to planting bedding plant plugs. This medium spray was compared to a standard whole-plant spray applied 2 weeks after planting. For petunia (Petunia ×hybrida Vilm.) and coleus (Solenostemon scutellarioides L.) the efficacy of the medium spray was similar to the whole-plant spray. However, for impatiens (Impatiens wallerana Hook. f.) and vinca [Catharanthus roseus (L.) G. Don.] the medium spray had greater efficacy than the whole-plant spray. Increased concentrations of uniconazole in the medium spray decreased plant height; however, the effect of higher concentrations was greater in a medium with out pine bark compared to a medium with pine bark as a component. In the above experiments, uniconazole was applied in a volume of 200 mL·m-2. In a test where spray volume varied, there was a negative linear relationship between plant height and spray volume. Chemical name used: (E)-(+)-(S)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-pent-1-ane-3-ol (uniconazole).
Jeff S. Kuehny, Aaron Painter, and Patricia C. Branch
Plug production has increased the finished quality and uniformity of bedding plants, making them one of the most important greenhouse crops grown. The wide range of cultural practices used by different growers to produce plugs, may influence the efficacy of plant growth regulators applied to the same crop in postplug production. Ten bedding plant species were grown from plugs obtained from two sources using different cultural practices. The plugs were transplanted to jumbo six packs and sprayed with either chlormequat/daminozide tank mix, ancymidol, or paclobutrazol at three concentrations at three times of year. The effect of each plant growth regulator varied by plant species and time of year applied. Source of plug material did have a significant effect on height and time of flowering of finished bedding plants and the use of plant growth regulators did not minimize the differences in height between sources in most cases.
David R. Hershey and Richard H. Merritt
Seedlings of Begonia × semperflorens-cultorum Hort. ‘Scarletta’ were grown in a greenhouse at a plant density of 193 plants/m2. Crop productivity (grams of dry matter produced per day per square meter of crop) and crop productivity efficiency (percentage of the photosynthetic photon flux incident on the crop that is stored in the form of crop dry matter as energy of combustion) did not increase when the photoperiod was extended from 9 to 13 hr with incandescent lights. However, stem and petiole length did increase under 13- compared to 9-hr photoperiods. Crop productivity of begonia was less than maximum values reported for some other bedding plants. However, when crop growth was expressed in terms of fresh weight rather than dry weight, begonia crop growth exceeded that reported for other bedding plants. This increased growth seemed to be due to the low dry weight to fresh weight ratio in wax begonia of 0.03.