considering production of floral crops in high tunnels, the emphasis is on flowering plants grown for cut flowers, rather than other categories of floriculture products such as bedding plants, potted flowering plants, and foliage plants that are normally grown
H. Chris Wien
Millie S. Williams, Terri W. Starman, and James E. Faust
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.
Tammy L. Everett and Paul V. Nelson
Five common sources of perlite used in the North American horticultural industry were tested for their release of fluoride during five successive teachings with pH 5.2 sodium phosphate buffer (1 cc perlite/ml buffer). Soluble fluoride in the first leachate ranged from 0.05 to 0.8 mg/l and in the fifth leachate from 0.01 to 0.18 mg/l. Lilium Asiatic hybrids `Pixie Grange' and `Sunray', Chlorophytum comosum (Thumb.) Jacques `Variegatum', and Gibasis pellucida (Martens & Gal.) D. Hunt `Bridal Veil' were. grown in sphagnum peat moss plus perlite substrates ranging up to 50% perlite and at substrate pH levels from 4.6 to 7.0. No fluoride toxicity occurred in these crops in any treatments. The precaution against the use of perlite in substrates used for growing fluoride sensitive crops needs to be reconsidered.
Don C. Wilkerson and Tony M. Garza
A survey of five different waste water treatment plants was conducted to identify potential variability in water quality factors. Salinity, pH, and alkalinity varied widely between sites. Mineral content did not differ significantly between sites. Syngonium spp. were subirrigated with four different combinations of treated waste water (TWW) and reverse osmosis (RO) water. Weekly measurements of EC and pH were taken and final height, width, and quality ratings were recorded. Based on these results, a 1 TWW: 1 RO water combination was then used to evaluate four different soluble fertility regimes. Salinity was the most limiting factor in the use of TWW on Syngonium spp. Growth and quality decreased as the percentage of treated waste water increased in each treatment combination. Salable plants were produced using a 1 TWW: 1 RO water combination and 100 ppm (N) fertilizer.
Inga A. Zasada, Clyde L. Elmore, Lani E. Yakabe, and James D. MacDonald
The cut flower and bulb industry in California is an important part of the state's agricultural economy and it has relied heavily upon the use of methyl bromide as a treatment to control soil-borne pests. With the phase out of methyl bromide, it is important to develop alternatives that will maintain crop productivity. This report describes research testing the efficacy of propargyl bromide against selected nematode, fungal, and weed species. Three sites were selected in California to represent different soil types and environments. Propargyl bromide was applied to soil in large, buried containers at rates ranging from 28 to 168 kg·ha−1 and compared with standard soil fumigants. The citrus nematode (Tylenchulus semipenetrans Cobb) and an isolate of Fusarium oxysporum Schlechtend:Fr were both controlled at the lowest rate of propargyl bromide tested: 28 kg·ha−1. Weed species varied greatly in their sensitivity to propargyl bromide. A 100% reduction in common purslane (Portulaca oleracea L.) and pigweed (Amaranthus retroflexus L.) germination occurred at 112 kg·ha−1 propargyl bromide, regardless of geographical location. Results for annual bluegrass (Poa annua L.) control were more variable across locations and years, but more than 90% control was consistently achieved with 168 kg·ha−1 propargyl bromide. Cheeseweed (Malva parviflora L.) and field bindweed (Convolvulus arvensis L.) were never consistently controlled by propargyl bromide. When compared with the soil fumigants methyl bromide, iodomethane, and metam sodium, propargyl bromide provided comparable control of all soil-borne pests, but at much lower rates. Although higher rates of propargyl bromide, more than 112 kg·ha−1, were needed to control weeds, these rates still were almost half that required of the other standard fumigants.
J. Ray Frank and Daniel L. Kunkel
Since the IR-4 Project for Ornamental Uses was initiated in 1977, over 13,500 research trials have been conducted. This effort has lead to over 3100 label-registrations for fungicides, herbicides, insecticides, nematicides and growth regulators.
This cooperative program is conducted by Federal and State workers in conjunction with growers of nursery, floral crop and landscape plant materials.
Christy T. Carter and Catharine M. Grieve
; Greenway and Munns, 1980 ). In most cases, exposure to salt stress results in injury or death resulting from salinity-induced nutritional disorders ( Grattan and Grieve, 1999 ). Yet many floral crops, including statice, cockscomb, stock, and sunflower, have
Shannon Rauter, Youping Sun, and Melanie Stock
crops for saline soils or water reuse systems ( Carter and Grieve, 2008 ). In floral crops specifically, salinity can advance or delay time to harvest, reduce stem length, impact bloom quality, and reduce yield ( Carter and Grieve, 2008 ; Grieve, 2011
D.K. Harris, A.D. Owings, and S.E. Newman
Poinsettias and other floral crops when treated with the growth retardant uniconazole, Sumagic™, are more compact in growth habit. They have also been shown to have reduced stem strength. Calcium applied as a drench has been demonstrated to increase plant height and plant dry weight of poinsettias. Unicomazole reduced plant height without affecting dry weight. Bract color was more intense when calcium was applied as a weekly spray. Poinsettia plants had greater levels of foliar calcium when applied as a drench. Poinsettia plants sprayed and drenched with calcium and treated with uniconazole had greater levels of foliar calcium, however, this was not significantly greater than the control plants treated with uniconazole alone. The lowest level of foliar calcium was observed in uniconazole treated plants where calcium was applied as a spray. Uniconazole applications weakened the stein structure of poinsettias as with other floral crop species.
D. Scott NeSmith and John R. Duval
Transplants for both vegetable and floral crops are produced in a number of various sized containers or cells. Varying container size alters the rooting volume of the plants, which can greatly affect plant growth. Container size is important to transplant producers as they seek to optimize production space. Transplant consumers are interested in container size as it relates to optimum post-transplant performance. The following is a comprehensive review of literature on container size, root restriction, and plant growth, along with suggestions for future research and concern.