Search Results
You are looking at 1 - 10 of 18 items for
- Author or Editor: Thomas M. Blessington x
Rooted cuttings of Euphorbia pulcherrima Willd. ex Klotzsch cv. Gutbier V-14 Glory were planted in 2-liter containers with growth media having 0% to 75% composted cotton burrs (CCB) in combination with sphagnum peat and/or composted pine bark. Leachates from media with 50% or more CCB had higher initial electrical conductance (EC) (3.7 to 4.0 dS·m-l) than that from media with 25% or no CCB (2.8 to 3.0 dS·m-l) 2 weeks after planting. The differences in leachate EC declined after an additional 9 weeks. Media containing CCB produced slightly shorter and narrower plants with 10% smaller inflorescences and less dry weight than plants grown in a medium consisting of equal volumes of peatmoss and bark. Number of branches and bracts, days to bloom, and plant grade after 30 days under 15 μmol·s-l· m-2 photosynthetic photon flux were unaffected by media.
Uniconazole and paclobutrazol were tested for their effects on greenhouse production of four foliage species. Soil drenches of uniconazole retarded shoot and petiole elongation of Brassaia actinophylla Endl. Paclobutrazol reduced shoot elongation, but required higher doses than uniconazole and did not reduce petiole growth. Foliar sprays with either retardant at 12.5 mg·liter-1 resulted in short stems on lateral shoots of Codiaeum variegatum (L.) Blume `Karen' after pinching, but soil drenches at low rates were less effective. Soil drenches of uniconazole or paclobutrazol were equally effective in reducing stem growth of Syngonium podophyllum Schott `White Butterfly' and increasing leaf width, but had no effect on the rate of leaf production or blade length. Both retardants induced short petioles in this species. Severe growth reduction occured on Plectranthus australis R. Br. even at the lowest rates of uniconazole and paclobutrazol (0.025 and 0.20 mg/pot, respectively) as soil drenches. Production of lateral shoots was inhibited for P. australis by both retardants. Chemical names used: (E)-1-(p-chlorophenyl)-4,4-dimethy1-2-(1,2,4-triazol-1-yl)-1-penten-3-ol (uniconazole); (2RS,3RS)-1-(4-chlorophenyl)-2-(1,1-dimethylethyl)-(H-1,2,4-triazol-l-Yl-)Dentan-3-ol (paclobutrazol).
Abstract
Ficus benjamina L. and Ficus lyrata Warb. were held at 4.4°, 21°, or 37°C during simulated transit (ST) for 3, 6, or 9 days. Both species were adversely affected during ST by 4.4° or 37°, with leaf loss increasing with exposure. Foliar damage was severe for all plants exposed to 37° for 6 or 9 days. Plant grade was lowest for both species when exposed to 37°. Plants held at 21° for 3, 6, or 9 days showed no foliar damage and only a slight loss of plant quality. After 8 weeks in a simulated interior environment (SIE), no plants had recovered from being held at 4.4° or 37° during ST, but showed even greater leaf loss and more severe foliar damage. Both species were lowest in dry weight and plant grade when held at 37° for 6 or 9 days. Chlorophyll content decreased as temperature increased from 4.4° to 21°.
Abstract
Schefflera arboricola Hayata ex. Kanehira was grown under light levels of 240, 480, and 720 μΕ m-2s-1. Plant grade and width were greatest when plants were produced under low light level but plant height and stem caliper were least. Leaf chlorophyll content was significantly lower under the high production light level than at medium or low levels. After subjecting plants to 0, 3, 6, 9, or 12 days of dark storage and a subsequent 12-week period indoors, growth index, fresh weight, and chlorophyll content generally were less as dark-storage duration increased. Leaf drop was greater and plant grade was lower as the duration of dark storage increased regardless of production light levels. After 12 weeks indoors, plants produced under 240 μΕ m-2s-1 and held for a period up to 6 days of dark maintained better plant quality than plants produced under the higher light levels.
Abstract
Ficus elastica ‘Decora’ Roxb. ex Hornern, Peperomia obtusifolia (L.) A. Deitr, and Hedera helix ‘Hahn’s Self-branching’ L. were produced under 15 and 30 klx light levels and treated with 4 concentrations of ancymidol (alpha-cyclopropyl-alpha-(p-methoxyphenyl)-5-pyrimi-dinemethanol) and several weeks later were placed in an interior holding environment for 6 weeks. Ficus was taller and heavier when produced under 15 klx light; different ancymidol concentrations caused no significant growth effects. Peperomia was taller with increasing light and decreased in growth with ancymidol treatments. After 6 weeks in the interior holding environment, plant grade increased with increasing production light for Peperomia and remained the same for Ficus. Both Ficus and Peperomia maintained similar responses to production treatment after 6 weeks indoors. Hedera was not influenced by production light or ancymidol treatments.
Abstract
Soil drenches of alpha-cyclopropyl-alpha-(p-methoxyphenyl)-5-pyrimidinemethanol (ancymidol) were applied 2 weeks after planting to Brassaia actinophylla Endl., X Fatshedera lizei (Cochet) Guillaum, Philodendron scandens Subsp. oxycardium (Schott) Bunt., and Tradescantia fluminensis Vell, at concentrations of 0. 0.25, 0.5, and 1.0 mg/15 cm pot to retard their growth and elongation while growing in a greenhouse under specific acclimatization procedures. Several months later the plants were placed in a controlled environment room under variable artificial light intensities (270, 540, 1080 lux) and after a 6-week period were evaluated as decorative materials. All plants treated with ancymidol, except Brassaia, showed decreased internodal length, were more compact in growth habit and displayed more intense color than those untreated. Ancymidol treatments maintained the decrease in internodal length at all light intensities for Tradescantia, Philodendron and Fatshedera with the greatest decrease evident at the highest (1.0 mg/pot) concentration. Only Brassaia exhibited leaf drop and no phytotoxicity was noted on any ancymidol treated plants.
Abstract
Rhododendron obtusum (Lindl.) Planch. ‘Hinodegiri’ responded to the different fertilizer sources and application methods similarly regardless of growing media. Plants top-dressed with Osmocote 18N-3P-10K had a significantly higher growth index, larger stem caliper and increased fresh weight than plants top-dressed with Pro-Grow 24N-3P-10K. Incorporation of either fertilizer source resulted in reduced plant growth and quality. The best fertilization method was a surface application regardless of fertilizer source or media.
Abstract
A 2 × 4 × 4 factorial experiment was conducted to test the effect of combinations of soluble fertilizer (20N–8.8P–16.6K) and controlled-release fertilizer (14N–6.2P–11.6K, Osmocote) on flowering, growth, and quality of Hibiscus rosa-sinensis L. grown under two light levels, 840 μmol·s-1·m-2 (full sun) and 420 μmol·s-1·m-2 (50% shade). Plants grown in full sun flowered earlier and had a larger number of buds and flowers than those in partial shade; how ever, flower diameter was greater with 50% shade. Plants grown in 50% shade were larger and had a darker green color and higher plant quality than those grown in full sun. Light level determined the effect of soluble fertilizer on number of buds, flowers, plant size, leaf area, fresh weight, foliar color, and plant quality. The effect of controlled-release fertilizer (CRF) on flower diameter, leaf area, and foliar color was influenced by light level. Soluble fertilizer and CRF interacted on total buds, flowers, plant size, foliar color, and plant quality. The optimum conditions for growth of high-quality hibiscus plants was found to be 50% shade and a fertilizer combination of 200 ppm N/12 g CRF per 18-cm pot.
Abstract
Three experiments were conducted with double-flowering Persian violet (Exacum affine Balf.) to evaluate the effet of gibberellic acid (GA) applied at different flower bud sizes, developmental stages (ages) of the plant, and application frequencies. In Expt. 1, the greatest number of flowers was produced in plants with 8-mm bud size, with the largest flower diameter obtained with 4-mm bud size. Treatment with GA increased the number of flowers. Flower diameter was greatest with a GA concentration of 125 ppm. Plant quality of GA-treated plants was best when sprayed at 8-mm bud size with a concentration of 125 ppm. In Expt. 2, plants treated at 12 weeks after transplanting had the most flowers. Flower diameter decreased for all treated plants and all age groups in comparison with non treated plants. GA at 125 ppm produced the largest increase in number of flowers and maintained a large flower diameter. Plants treated 8 weeks after transplanting with 125 ppm GA had the most desirable plant size and flowering characteristics. In Expt. 3, a single application of 125 ppm GA was the most effective in contrast to multiple applications for flower induction, number of flowers, and flower diameter.
Abstract
After 4 weeks indoors, ‘Annette Hegg Dark Red’ (‘AHDR’) and ‘Gutbier V-14 Glory’ (‘GV14’) had higher leaf abscission than ‘Mikkel Improved Roch-ford’ (‘MIR’). ‘AHDR’ abscised more bracts than ‘MIR’ or ‘GV14’. Plant grade was highest for ‘GV14’. Fritted Trace Elements-treated (FTE) and Micromax-treated (MICROMAX) plants lost fewer leaves and bracts and had a higher plant grade than Perk-treated (PERK) or Soluble Trace Element Mix-treated (STEM) plants. Plants held in dark storage for 3 or 6 days had greater leaf abscission than plants not subjected to storage. Bract drop was highest for 6 days storage. Dark storage of 0 or 3 days had higher plant grade than 6 days dark storage.