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  • Author or Editor: B. K. Harbaugh x
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Seedlings of commercial lisianthus cultivars form rosettes when grown at 25 to 28°C. Rosetted plants have a basal cluster of leaves, very short internodes typical of biennials, and do not bolt or flower for months without being exposed to 3 to 4 weeks at <15 to 18°C to reverse heat-induced rosetting. Semirosetted plants develop when seedlings are grown at a constant 22 to 25°C or at <22°C night with >28°C day. Semirosetted plants have one or more side shoots which may elongate and flower, but plants flower unpredictably and are of poor quality as cut flowers or potted plants. `Maurine Blue' and Florida Blue' were released from the Univ. of Florida in 1995. To our knowledge, they are the first heat-tolerant lisianthus cultivars. Seedlings and plants can be grown at 28 to 31°C without rosetting. `Maurine Blue' ranged in height from 38 cm (summer) to 67 cm (spring) during 1994 and 1995 production trials in Florida. `Maurine Blue' has potential for use as a tall bedding plant if sold as green transplants, a flowering potted plant if grown with three plants per 15-cm-diameter pot with a growth retardant, or as a bouquet-type cut flower. `Florida Blue' plants (38 cm) grown in an 11.5-cm square pot (0.65-L) with capillary mat irrigation were similar in height to `Blue Lisa' (32 cm) and taller than `Little Belle Blue' (22 cm) and `Mermaid Blue' (24 cm). `Florida Blue' was designated as a semi-dwarf cultivar with an intended use as a bedding plant. Growth retardants would be useful for production in pots <10 to 12 cm in diameter. Complete descriptive information, photographs and pedigrees will be presented.

Free access

Abstract

A simulated marketing system was designed to test the effect of light intensity and duration of packaging (conditions similar to those of warehousing, transportation, and retail marketing) on packaged and unpackaged potted ornamental plants. No significant differences were recorded in quality between plants held at 525 and 1600 lux when stored in packages for 14 or 28 days. Six days of darkness did not reduce the time plants could be kept in packages. Packaging duration and plant species were the chief factors affecting the marketability of the plants; the various simulated market conditions had only minor effects. Packaged Pilea cadierei Gagnep. & Guillaum, Philodendron cordatum (Veil.) Kunth, Fittonia verschaffeltii (Lem.) Coem. var. argyroneura (Coem.) Nichols, and Plectranthus australis R. Br. were marketable for 60 days, Gynura aurantiaca (Blume) DC. for 30 days, and Catharanthus roseus L. for 18 days. Plants in sealed packages did not require watering.

Open Access

Abstract

Plant size, and number of flowers of chrysanthemums (Chrysanthemum ×morifolium Ramat. cvs. Yellow Mandalay and Royal Trophy) were reduced when grown in a soil containing granular α-cyclopropyl-α-(4-methoxyphenyl)-5 pyrimidine (ancymidol) or provided ancymidol drench or butanedioic acid mono-(2,2-dimethylhydrazide) (daminozide) spray but not when sprayed with ancymidol (0.5 mg). Granular ancymidol at 0.5 mg/pot reduced plant height 9% on ‘Yellow Mandalay’ and 30% on ‘Royal Trophy’ compared to controls. Foliar applications of daminozide reduced height 27% on ‘Yellow Mandalay’ and 47% on ‘Royal Trophy’.

Open Access

Abstract

Costs for growing 10 cm and 15 cm potted chrysanthemums (Chrysanthemum morifolium Ramet.) under shade cloth on capillary mats in Florida were estimated to be $0.42 and $1.52 per plant, respectively. If 10 cm and 15 cm potted chrysanthemums wholesale at $0.60 and $2.00 per plant, respectively, annual return above growing costs from a 2 ha structure would be $37, 514 and $13, 667 for 10 cm and 15 cm plants, respectively. Growers would need to wholesale 15 cm pot chrysanthemums at about $2.25 to equal annual return from 10 cm plants.

Open Access

Abstract

A granular formulation of ancymidol [α-cyclopropyl-α-(4-methoxyphenyl)-5pyrimidine] was compared to ancymidol and chlormequat [(2-chloroethyl) trimethylammonium chloride] drenches for height control of multi-branched poinsettias (Euphorbia pulcherrima Wild.) grown in 10 cm diameter pots. Granular ancymidol at 0.125 mg ai/pot retarded plant growth with no retardation in bract diameter. Granular ancymidol at 0.25 mg ai/pot was as effective as 0.5 mg ancymidol applied as a drench and produced the ideally proportioned plants. All ancymidol treatments were more effective in height retardation than chlormequat applied at 240 mg ai/pot. Bract diameter was reduced in all ancymidol treatments and 0.5 mg ai/pot.

Open Access

Abstract

Leaf water potential (LWP) data for cut-flower chrysanthemums (Crysanthemum morifolium Ramat.) collected from 5 different irrigation rate treatments throughout the growing season were compared to the final plant characteristics and yield in order to evaluate the usefulness of LWP for estimating water stress effects on ultimate yield. Significant treatment differences for LWP response measured during high evaporative demand periods were similar to treatment differences for yields and final plant characteristics. Treatment differences for LWP response measured during low evaporative demand periods were not significant and did not reflect the significant treatment differences for yields and final plant characteristics. Results indicate that LWP measurements vary with changes in atmospheric conditions, such as cloud cover, and are difficult to interpret relative to water stress effects on final plant characteristics. Plant growth parameters, such as height or growth rate, when monitored during the season, were found to be more adequate indicators of stress effects on final yield.

Open Access

Abstract

The numbers of twospotted spider mites (Tetranychus urticae Koch) per unit of leaf area on ‘Manatee Yellow Iceberg’ chrysanthemum (Chrysanthemum X morifolium Ramat.) grown with 13.6, 20.3, 27.1, 33.9, or 40.7 cm of water during the crop cycle were inversely related to amounts of water provided on both of 2 sampling dates. The numbers of mites per leaf were inversely related to amounts of water provided on the first of the 2 sampling dates. There was no significant response of leafmine densities with various amounts of water provided.

Open Access

Abstract

The minimum water requirement to produce the greatest number of marketa- bie cut flowers of Chrysanthemum × morifolium Ramat. ‘Manatee Yellow Iceberg’ was 35 cm with trickle irrigation, a 91% reduction in water uses as compared to overhead irrigation systems. Linear responses for fresh weight, dry weight, leaf area, leaf number, and flower number between 13.6 and 40.7 cm of water supplied during production indicated that an additional 6 cm of water would improve marketable stem's quality.

Open Access

Abstract

Damage by leafminer [Liriomyza trifolii (Burgess)], increased linearly as leaf nitrogen increased from 2.2% to 4.0% in spring and fall plantings of Chrysanthemum x morifolium Ramat. ‘Manatee Yellow Iceberg’. The number of marketable stems was related quadratically to leaf nitrogen with maximum yields estimated to occur at 3.6% at harvest.

Open Access

Abstract

Interactive effects of trickle irrigation rates, cultivars and culture (single or pinched stem), on Chrysanthemum × morifolium Ramat. cut flower yield and quality were evaluated. The minimum amount of water required to produce the greatest number of marketable stems of high quality was estimated to be from 0.96 to 1.07 cm/day. Responses to irrigation rate were similar regardless of culture or cultivar variables. Seasonal water use, however, would vary due to differences in cropping time influenced by the production method and choice of cultivars.

Open Access