Floricultural crops without the benefits of extensive breeding or selection often pose problems for commercial cutting and finished plant producers. The objective of this work was to determine the effects, if any, of daylength control on the growth and flowering of the following genera; Barleria cristata, Angelonia angustifolia `Pandiana', Stachytarpheta mutabilis var. violacea, Streptosolen jamesonii, Mandevilla sanderi, Dichorisandra thyrsiflora, and Pseuderanthemum laxiflorum. Daylength of 8, 10, 12, or 14 h was imposed for 20 weeks, with cuttings harvested from plants every 4 weeks. At 20 weeks, plants were evaluated for degree of flowering and plant size. Photoperiod had a significant interaction with genera grown. Compared to plants grown under 14-h daylength; flowering and growth were reduced in Stachytarpheta and Angelonia at 8- and 10-h daylength. Flowering was increased, but overall growth reduced in Pseuderanthemum, Mandevilla, Barleria, and Dichorisandra as daylength decreased. Flowering of Streptosolen was not evident under any photoperiod. Vegetative growth was greatest with 14 h daylength for all genera tested, but only increased flower number of Stachytarpheta. Production temperatures of 20 °C night and 30 °C day were maintained throughout the study, the experiment was conducted in the summer production seasons of 1997 and 1998.
Richard K. Schoellhorn and A.J. Compton
Sandra B. Wilson and Peter J. Stoffella
Peat is used extensively in the nursery industry as a primary component in commercial “soilless” potting media. The increased use of peat as an organic amendment with superior water-holding capacity is challenged by economic and environmental pressures. Developing inexpensive and nutrient-rich organic media alternatives can potentially reduce fertilization rates, irrigation rates, and ultimately, nursery costs. In addition, controversy over the effects of peat mining has inspired a national search for peat substitutes. With our burgeoning population, it is logical to screen waste products as potential alternatives to peat. Growth of Pachystachys lutea Nees. (Golden Shrimp Plant) transplants was evaluated in media containing 0%, 25%, 50%, 75%, or 100% compost derived from biosolids and yard trimmings. Compost was amended with a commercial peat- or coir-based media. As compost composition in the peat or coir-based media increased from 0% to 100%, carbon/nitrogen (C/N) ratios decreased, and media stability, N mobilization, pH, and electrical conductivity (EC) increased. Bulk density, particle density, air-filled porosity, container capacity, and total porosity increased as more compost was added to either peat- or coir-based media. Plants grown in media with high volumes of compost (75 or 100%) had reduced leaf area and reduced shoot and root DW than the controls (no compost). Regardless of percentage of compost composition in either peat or coir-based media, all plants were considered marketable after 8 weeks.
S.B. Wilson, P.J. Stoffella, and D.A. Graetz
Growth of golden shrimp plant (Pachystachys lutea Nees.) transplants was evaluated in media containing 0%, 25%, 50%, 75%, or 100% compost derived from biosolids and yard trimmings. A commercial coir- or peat-based media was amended with compost. As compost composition in the peat or coir-based media increased from 0% to 100%, carbon/nitrogen ratios decreased; and media stability, nitrogen mobilization, pH, and electrical conductivity increased. Bulk density, particle density, air-filled porosity, container capacity, and total porosity increased as more compost was added to either peat- or coir-based media. Plants grown in media with high volumes of compost (75% or 100%) had less leaf area and lower shoot and root dry weight compared to the controls (no compost). Regardless of percentage of compost composition in either peat or coir-based media, all plants were considered marketable after 8 weeks.
Mauricio J. Sarmiento and Jeff S. Kuehny
Curcuma alismatifolia `Chiang Mai Pink' is a tropical perennial from the Zingiberaceae family with attractive flowers that make it useful as potted plant. Curcuma alismatifolia produces a tall inflorescence resulting in an unmarketable plant due to excessive height. Rhizomes of C. alismatifolia were soaked for 10 minutes in GA at concentrations of 0, 100, 200 or 500 ppm. The same plants were drenched with paclobutrazol at 0, 2, 3 or 4 mg a.i./container when shoots were 10 cm. GA significantly delayed rhizome emergence and flowering and reduced flower height. Paclobutrazol significantly reduced height; however, greater concentrations must be applied to obtain a marketable plant height. Number of flowering stems, postproduction life, and postproduction stretching were not affected by GA or paclobutrazol. Curcuma alismatifolia had an excellent postproduction life (4.64 ± 0.28 weeks) with little postproduction stretching (2.27 ± 0.38 cm).
Mauricio José Sarmiento and Jeff S. Kuehny
Gingers are tropical perennials from the Zingiberaceae family with attractive long-lived flowers that can be grown as potted plants in subtropical and temperate zones under protected conditions. Development of production practices for this new flowering pot crop is essential for optimum plant growth. The effect of photoperiod on growth and flowering was evaluated on Curcuma gracillima, C. cordata, C. alismatifolia, C. petiolata `Emperor', Curcuma `Chang Mai dwarf', Siphonichilus decora, and S. kirkii. Plants were grown under daylengths of 8, 12, 16, and 20 h. Plant height, number of new leaves, number of shoots, and leaf area were larger for plants growing under an extended daylength (16- and 20-h photo-period) than for plants under 8 and 12 h. Plants grown under an 8-h daylength approached dormancy sooner than those growing under 12, 16, or 20 h of light, and no flowering occurred.
Wayne F. Whitehead and Bharat P. Singh
Parwal [Trichosanthus dioica (Roxb.)] is a tropical perennial vine producing small fleshy fruits used as a vegetable. It bears male and female flowers on separate plants. During the summer of 1996, a field study was conducted to determine if male and female plants differed in their gas exchange behavior. Three leaves per plant replicated six times for each sex were tagged randomly at initiation of gas exchange measurements. Transpiration (E), stomatal conductance (gs), CO2 exchange rate (CER), and internal leaf CO2 concentration (Ci) were measured when the leaves were 6, 18, 36, 47, 71, and 81 days old. In general, the gas exchange values for both sexes were similar. The leaves of male plants attained highest E, gs, and CER at 18 days of age. In female plants, CER peaked at an early leaf age of 6 days, while the peaks for E and gs were reached 30 days later. The highest Ci for both sexes were observed in 47-day-old leaves. Eighty-four-day-old leaves were no longer actively exchanging gases.
Robert H. Stamps
foliage crops Acta Hort. 770 169 176 Wilson, S.B. Rajapakse, N.C. 2001a Growth control of Lisianthus by photoselective plastic films HortTechnology 11 581 584 Wilson, S.B. Rajapakse, N.C. 2001b Growth regulation of sub-tropical perennials by
Aidan D. Farrell, Sarah Evelyn, Adrian M. Lennon, and Pathmanathan Umaharan
Anthurium ( Anthurium andraeanum Hort.) is a herbaceous tropical perennial highly sought after on the world market as a cut flower. The bloom is composed of a modified bract (spathe) and a stalk-like inflorescence (spadix) supported on a peduncle
Neil O. Anderson and Richard T. Olsen
continued to the present day. Burbank contributed to canna development at the tail end of the first wave of interest in these tropical perennials. Coincidentally, Burbank unknowingly crossed a canna ‘Crozy’-hybrid selection with Canna flaccida , a North