Search Results

You are looking at 1 - 10 of 18 items for

  • Author or Editor: Thomas M. Blessington x
Clear All Modify Search

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).

Free access

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.

Free access

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.

Open Access

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.

Open Access

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°.

Open Access

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.

Open Access

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.

Open Access

Abstract

Plant growth and quality were determined for 2 species of schefflera grown under 3 production light levels and 2 fertilizer treatments. High production light (828 μE m−2s−1) resulted in better growth of Brassaia actinophylla Endl. but generally had no effect on the growth parameters of Schefflera arboricola Hayata ex. Kanehira. Increasing fertilizer levels decreased plant growth and quality for S. arboricola in the production phase but caused no difference for B. actinophylla. However, after 3 months in an interior environment, B. actinophylla produced under the highest light level and S. arboricola produced under the lowest light level (276 μE m−2s−1) maintained better growth and plant quality. Both species receiving the lowest fertilizer treatment (200 mg N/pot·week) were better in growth and quality after 3 months indoors in contrast to the highest fertilizer treatment (400 mg N/pot·week).

Open Access

Abstract

Brassaia actinophylla Endl. was larger in growth and better in quality when produced under 828 and 414 μE m−2s−1. Schefflera arboricola Hayata ex Kanehira increased in growth and quality when produced under 414 and 276 μE m−2s−1. Both species increased in growth and generally maintained good quality after a post holding period in an interior environment. Plants produced under the lower production light levels maintained good growth after 3 months indoors under interior light levels of 24, 16 and 8 μE m−2s−1. S. arboricola maintained better quality than B. actinophylla when hdd under the lowest interior light level.

Open Access

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.

Open Access